name : bpf_helper_defs.h /* This is auto-generated file. See bpf_doc.py for details. */ /* Forward declarations of BPF structs */ struct bpf_fib_lookup; struct bpf_sk_lookup; struct bpf_perf_event_data; struct bpf_perf_event_value; struct bpf_pidns_info; struct bpf_redir_neigh; struct bpf_sock; struct bpf_sock_addr; struct bpf_sock_ops; struct bpf_sock_tuple; struct bpf_spin_lock; struct bpf_sysctl; struct bpf_tcp_sock; struct bpf_tunnel_key; struct bpf_xfrm_state; struct linux_binprm; struct pt_regs; struct sk_reuseport_md; struct sockaddr; struct tcphdr; struct seq_file; struct tcp6_sock; struct tcp_sock; struct tcp_timewait_sock; struct tcp_request_sock; struct udp6_sock; struct unix_sock; struct task_struct; struct cgroup; struct __sk_buff; struct sk_msg_md; struct xdp_md; struct path; struct btf_ptr; struct inode; struct socket; struct file; struct bpf_timer; struct mptcp_sock; struct bpf_dynptr; struct iphdr; struct ipv6hdr; /* * bpf_map_lookup_elem * * Perform a lookup in *map* for an entry associated to *key*. * * Returns * Map value associated to *key*, or **NULL** if no entry was * found. */ static void *(*bpf_map_lookup_elem)(void *map, const void *key) = (void *) 1; /* * bpf_map_update_elem * * Add or update the value of the entry associated to *key* in * *map* with *value*. *flags* is one of: * * **BPF_NOEXIST** * The entry for *key* must not exist in the map. * **BPF_EXIST** * The entry for *key* must already exist in the map. * **BPF_ANY** * No condition on the existence of the entry for *key*. * * Flag value **BPF_NOEXIST** cannot be used for maps of types * **BPF_MAP_TYPE_ARRAY** or **BPF_MAP_TYPE_PERCPU_ARRAY** (all * elements always exist), the helper would return an error. * * Returns * 0 on success, or a negative error in case of failure. */ static long (*bpf_map_update_elem)(void *map, const void *key, const void *value, __u64 flags) = (void *) 2; /* * bpf_map_delete_elem * * Delete entry with *key* from *map*. * * Returns * 0 on success, or a negative error in case of failure. */ static long (*bpf_map_delete_elem)(void *map, const void *key) = (void *) 3; /* * bpf_probe_read * * For tracing programs, safely attempt to read *size* bytes from * kernel space address *unsafe_ptr* and store the data in *dst*. * * Generally, use **bpf_probe_read_user**\ () or * **bpf_probe_read_kernel**\ () instead. * * Returns * 0 on success, or a negative error in case of failure. */ static long (*bpf_probe_read)(void *dst, __u32 size, const void *unsafe_ptr) = (void *) 4; /* * bpf_ktime_get_ns * * Return the time elapsed since system boot, in nanoseconds. * Does not include time the system was suspended. * See: **clock_gettime**\ (**CLOCK_MONOTONIC**) * * Returns * Current *ktime*. */ static __u64 (*bpf_ktime_get_ns)(void) = (void *) 5; /* * bpf_trace_printk * * This helper is a "printk()-like" facility for debugging. It * prints a message defined by format *fmt* (of size *fmt_size*) * to file *\/sys/kernel/tracing/trace* from TraceFS, if * available. It can take up to three additional **u64** * arguments (as an eBPF helpers, the total number of arguments is * limited to five). * * Each time the helper is called, it appends a line to the trace. * Lines are discarded while *\/sys/kernel/tracing/trace* is * open, use *\/sys/kernel/tracing/trace_pipe* to avoid this. * The format of the trace is customizable, and the exact output * one will get depends on the options set in * *\/sys/kernel/tracing/trace_options* (see also the * *README* file under the same directory). However, it usually * defaults to something like: * * :: * * telnet-470 [001] .N.. 419421.045894: 0x00000001: <formatted msg> * * In the above: * * * ``telnet`` is the name of the current task. * * ``470`` is the PID of the current task. * * ``001`` is the CPU number on which the task is * running. * * In ``.N..``, each character refers to a set of * options (whether irqs are enabled, scheduling * options, whether hard/softirqs are running, level of * preempt_disabled respectively). **N** means that * **TIF_NEED_RESCHED** and **PREEMPT_NEED_RESCHED** * are set. * * ``419421.045894`` is a timestamp. * * ``0x00000001`` is a fake value used by BPF for the * instruction pointer register. * * ``<formatted msg>`` is the message formatted with * *fmt*. * * The conversion specifiers supported by *fmt* are similar, but * more limited than for printk(). They are **%d**, **%i**, * **%u**, **%x**, **%ld**, **%li**, **%lu**, **%lx**, **%lld**, * **%lli**, **%llu**, **%llx**, **%p**, **%s**. No modifier (size * of field, padding with zeroes, etc.) is available, and the * helper will return **-EINVAL** (but print nothing) if it * encounters an unknown specifier. * * Also, note that **bpf_trace_printk**\ () is slow, and should * only be used for debugging purposes. For this reason, a notice * block (spanning several lines) is printed to kernel logs and * states that the helper should not be used "for production use" * the first time this helper is used (or more precisely, when * **trace_printk**\ () buffers are allocated). For passing values * to user space, perf events should be preferred. * * Returns * The number of bytes written to the buffer, or a negative error * in case of failure. */ static long (*bpf_trace_printk)(const char *fmt, __u32 fmt_size, ...) = (void *) 6; /* * bpf_get_prandom_u32 * * Get a pseudo-random number. * * From a security point of view, this helper uses its own * pseudo-random internal state, and cannot be used to infer the * seed of other random functions in the kernel. However, it is * essential to note that the generator used by the helper is not * cryptographically secure. * * Returns * A random 32-bit unsigned value. */ static __u32 (*bpf_get_prandom_u32)(void) = (void *) 7; /* * bpf_get_smp_processor_id * * Get the SMP (symmetric multiprocessing) processor id. Note that * all programs run with migration disabled, which means that the * SMP processor id is stable during all the execution of the * program. * * Returns * The SMP id of the processor running the program. */ static __u32 (*bpf_get_smp_processor_id)(void) = (void *) 8; /* * bpf_skb_store_bytes * * Store *len* bytes from address *from* into the packet * associated to *skb*, at *offset*. *flags* are a combination of * **BPF_F_RECOMPUTE_CSUM** (automatically recompute the * checksum for the packet after storing the bytes) and * **BPF_F_INVALIDATE_HASH** (set *skb*\ **->hash**, *skb*\ * **->swhash** and *skb*\ **->l4hash** to 0). * * A call to this helper is susceptible to change the underlying * packet buffer. Therefore, at load time, all checks on pointers * previously done by the verifier are invalidated and must be * performed again, if the helper is used in combination with * direct packet access. * * Returns * 0 on success, or a negative error in case of failure. */ static long (*bpf_skb_store_bytes)(struct __sk_buff *skb, __u32 offset, const void *from, __u32 len, __u64 flags) = (void *) 9; /* * bpf_l3_csum_replace * * Recompute the layer 3 (e.g. IP) checksum for the packet * associated to *skb*. Computation is incremental, so the helper * must know the former value of the header field that was * modified (*from*), the new value of this field (*to*), and the * number of bytes (2 or 4) for this field, stored in *size*. * Alternatively, it is possible to store the difference between * the previous and the new values of the header field in *to*, by * setting *from* and *size* to 0. For both methods, *offset* * indicates the location of the IP checksum within the packet. * * This helper works in combination with **bpf_csum_diff**\ (), * which does not update the checksum in-place, but offers more * flexibility and can handle sizes larger than 2 or 4 for the * checksum to update. * * A call to this helper is susceptible to change the underlying * packet buffer. Therefore, at load time, all checks on pointers * previously done by the verifier are invalidated and must be * performed again, if the helper is used in combination with * direct packet access. * * Returns * 0 on success, or a negative error in case of failure. */ static long (*bpf_l3_csum_replace)(struct __sk_buff *skb, __u32 offset, __u64 from, __u64 to, __u64 size) = (void *) 10; /* * bpf_l4_csum_replace * * Recompute the layer 4 (e.g. TCP, UDP or ICMP) checksum for the * packet associated to *skb*. Computation is incremental, so the * helper must know the former value of the header field that was * modified (*from*), the new value of this field (*to*), and the * number of bytes (2 or 4) for this field, stored on the lowest * four bits of *flags*. Alternatively, it is possible to store * the difference between the previous and the new values of the * header field in *to*, by setting *from* and the four lowest * bits of *flags* to 0. For both methods, *offset* indicates the * location of the IP checksum within the packet. In addition to * the size of the field, *flags* can be added (bitwise OR) actual * flags. With **BPF_F_MARK_MANGLED_0**, a null checksum is left * untouched (unless **BPF_F_MARK_ENFORCE** is added as well), and * for updates resulting in a null checksum the value is set to * **CSUM_MANGLED_0** instead. Flag **BPF_F_PSEUDO_HDR** indicates * the checksum is to be computed against a pseudo-header. * * This helper works in combination with **bpf_csum_diff**\ (), * which does not update the checksum in-place, but offers more * flexibility and can handle sizes larger than 2 or 4 for the * checksum to update. * * A call to this helper is susceptible to change the underlying * packet buffer. Therefore, at load time, all checks on pointers * previously done by the verifier are invalidated and must be * performed again, if the helper is used in combination with * direct packet access. * * Returns * 0 on success, or a negative error in case of failure. */ static long (*bpf_l4_csum_replace)(struct __sk_buff *skb, __u32 offset, __u64 from, __u64 to, __u64 flags) = (void *) 11; /* * bpf_tail_call * * This special helper is used to trigger a "tail call", or in * other words, to jump into another eBPF program. The same stack * frame is used (but values on stack and in registers for the * caller are not accessible to the callee). This mechanism allows * for program chaining, either for raising the maximum number of * available eBPF instructions, or to execute given programs in * conditional blocks. For security reasons, there is an upper * limit to the number of successive tail calls that can be * performed. * * Upon call of this helper, the program attempts to jump into a * program referenced at index *index* in *prog_array_map*, a * special map of type **BPF_MAP_TYPE_PROG_ARRAY**, and passes * *ctx*, a pointer to the context. * * If the call succeeds, the kernel immediately runs the first * instruction of the new program. This is not a function call, * and it never returns to the previous program. If the call * fails, then the helper has no effect, and the caller continues * to run its subsequent instructions. A call can fail if the * destination program for the jump does not exist (i.e. *index* * is superior to the number of entries in *prog_array_map*), or * if the maximum number of tail calls has been reached for this * chain of programs. This limit is defined in the kernel by the * macro **MAX_TAIL_CALL_CNT** (not accessible to user space), * which is currently set to 33. * * Returns * 0 on success, or a negative error in case of failure. */ static long (*bpf_tail_call)(void *ctx, void *prog_array_map, __u32 index) = (void *) 12; /* * bpf_clone_redirect * * Clone and redirect the packet associated to *skb* to another * net device of index *ifindex*. Both ingress and egress * interfaces can be used for redirection. The **BPF_F_INGRESS** * value in *flags* is used to make the distinction (ingress path * is selected if the flag is present, egress path otherwise). * This is the only flag supported for now. * * In comparison with **bpf_redirect**\ () helper, * **bpf_clone_redirect**\ () has the associated cost of * duplicating the packet buffer, but this can be executed out of * the eBPF program. Conversely, **bpf_redirect**\ () is more * efficient, but it is handled through an action code where the * redirection happens only after the eBPF program has returned. * * A call to this helper is susceptible to change the underlying * packet buffer. Therefore, at load time, all checks on pointers * previously done by the verifier are invalidated and must be * performed again, if the helper is used in combination with * direct packet access. * * Returns * 0 on success, or a negative error in case of failure. Positive * error indicates a potential drop or congestion in the target * device. The particular positive error codes are not defined. */ static long (*bpf_clone_redirect)(struct __sk_buff *skb, __u32 ifindex, __u64 flags) = (void *) 13; /* * bpf_get_current_pid_tgid * * Get the current pid and tgid. * * Returns * A 64-bit integer containing the current tgid and pid, and * created as such: * *current_task*\ **->tgid << 32 \|** * *current_task*\ **->pid**. */ static __u64 (*bpf_get_current_pid_tgid)(void) = (void *) 14; /* * bpf_get_current_uid_gid * * Get the current uid and gid. * * Returns * A 64-bit integer containing the current GID and UID, and * created as such: *current_gid* **<< 32 \|** *current_uid*. */ static __u64 (*bpf_get_current_uid_gid)(void) = (void *) 15; /* * bpf_get_current_comm * * Copy the **comm** attribute of the current task into *buf* of * *size_of_buf*. The **comm** attribute contains the name of * the executable (excluding the path) for the current task. The * *size_of_buf* must be strictly positive. On success, the * helper makes sure that the *buf* is NUL-terminated. On failure, * it is filled with zeroes. * * Returns * 0 on success, or a negative error in case of failure. */ static long (*bpf_get_current_comm)(void *buf, __u32 size_of_buf) = (void *) 16; /* * bpf_get_cgroup_classid * * Retrieve the classid for the current task, i.e. for the net_cls * cgroup to which *skb* belongs. * * This helper can be used on TC egress path, but not on ingress. * * The net_cls cgroup provides an interface to tag network packets * based on a user-provided identifier for all traffic coming from * the tasks belonging to the related cgroup. See also the related * kernel documentation, available from the Linux sources in file * *Documentation/admin-guide/cgroup-v1/net_cls.rst*. * * The Linux kernel has two versions for cgroups: there are * cgroups v1 and cgroups v2. Both are available to users, who can * use a mixture of them, but note that the net_cls cgroup is for * cgroup v1 only. This makes it incompatible with BPF programs * run on cgroups, which is a cgroup-v2-only feature (a socket can * only hold data for one version of cgroups at a time). * * This helper is only available is the kernel was compiled with * the **CONFIG_CGROUP_NET_CLASSID** configuration option set to * "**y**" or to "**m**". * * Returns * The classid, or 0 for the default unconfigured classid. */ static __u32 (*bpf_get_cgroup_classid)(struct __sk_buff *skb) = (void *) 17; /* * bpf_skb_vlan_push * * Push a *vlan_tci* (VLAN tag control information) of protocol * *vlan_proto* to the packet associated to *skb*, then update * the checksum. Note that if *vlan_proto* is different from * **ETH_P_8021Q** and **ETH_P_8021AD**, it is considered to * be **ETH_P_8021Q**. * * A call to this helper is susceptible to change the underlying * packet buffer. Therefore, at load time, all checks on pointers * previously done by the verifier are invalidated and must be * performed again, if the helper is used in combination with * direct packet access. * * Returns * 0 on success, or a negative error in case of failure. */ static long (*bpf_skb_vlan_push)(struct __sk_buff *skb, __be16 vlan_proto, __u16 vlan_tci) = (void *) 18; /* * bpf_skb_vlan_pop * * Pop a VLAN header from the packet associated to *skb*. * * A call to this helper is susceptible to change the underlying * packet buffer. Therefore, at load time, all checks on pointers * previously done by the verifier are invalidated and must be * performed again, if the helper is used in combination with * direct packet access. * * Returns * 0 on success, or a negative error in case of failure. */ static long (*bpf_skb_vlan_pop)(struct __sk_buff *skb) = (void *) 19; /* * bpf_skb_get_tunnel_key * * Get tunnel metadata. This helper takes a pointer *key* to an * empty **struct bpf_tunnel_key** of **size**, that will be * filled with tunnel metadata for the packet associated to *skb*. * The *flags* can be set to **BPF_F_TUNINFO_IPV6**, which * indicates that the tunnel is based on IPv6 protocol instead of * IPv4. * * The **struct bpf_tunnel_key** is an object that generalizes the * principal parameters used by various tunneling protocols into a * single struct. This way, it can be used to easily make a * decision based on the contents of the encapsulation header, * "summarized" in this struct. In particular, it holds the IP * address of the remote end (IPv4 or IPv6, depending on the case) * in *key*\ **->remote_ipv4** or *key*\ **->remote_ipv6**. Also, * this struct exposes the *key*\ **->tunnel_id**, which is * generally mapped to a VNI (Virtual Network Identifier), making * it programmable together with the **bpf_skb_set_tunnel_key**\ * () helper. * * Let's imagine that the following code is part of a program * attached to the TC ingress interface, on one end of a GRE * tunnel, and is supposed to filter out all messages coming from * remote ends with IPv4 address other than 10.0.0.1: * * :: * * int ret; * struct bpf_tunnel_key key = {}; * * ret = bpf_skb_get_tunnel_key(skb, &key, sizeof(key), 0); * if (ret < 0) * return TC_ACT_SHOT; // drop packet * * if (key.remote_ipv4 != 0x0a000001) * return TC_ACT_SHOT; // drop packet * * return TC_ACT_OK; // accept packet * * This interface can also be used with all encapsulation devices * that can operate in "collect metadata" mode: instead of having * one network device per specific configuration, the "collect * metadata" mode only requires a single device where the * configuration can be extracted from this helper. * * This can be used together with various tunnels such as VXLan, * Geneve, GRE or IP in IP (IPIP). * * Returns * 0 on success, or a negative error in case of failure. */ static long (*bpf_skb_get_tunnel_key)(struct __sk_buff *skb, struct bpf_tunnel_key *key, __u32 size, __u64 flags) = (void *) 20; /* * bpf_skb_set_tunnel_key * * Populate tunnel metadata for packet associated to *skb.* The * tunnel metadata is set to the contents of *key*, of *size*. The * *flags* can be set to a combination of the following values: * * **BPF_F_TUNINFO_IPV6** * Indicate that the tunnel is based on IPv6 protocol * instead of IPv4. * **BPF_F_ZERO_CSUM_TX** * For IPv4 packets, add a flag to tunnel metadata * indicating that checksum computation should be skipped * and checksum set to zeroes. * **BPF_F_DONT_FRAGMENT** * Add a flag to tunnel metadata indicating that the * packet should not be fragmented. * **BPF_F_SEQ_NUMBER** * Add a flag to tunnel metadata indicating that a * sequence number should be added to tunnel header before * sending the packet. This flag was added for GRE * encapsulation, but might be used with other protocols * as well in the future. * **BPF_F_NO_TUNNEL_KEY** * Add a flag to tunnel metadata indicating that no tunnel * key should be set in the resulting tunnel header. * * Here is a typical usage on the transmit path: * * :: * * struct bpf_tunnel_key key; * populate key ... * bpf_skb_set_tunnel_key(skb, &key, sizeof(key), 0); * bpf_clone_redirect(skb, vxlan_dev_ifindex, 0); * * See also the description of the **bpf_skb_get_tunnel_key**\ () * helper for additional information. * * Returns * 0 on success, or a negative error in case of failure. */ static long (*bpf_skb_set_tunnel_key)(struct __sk_buff *skb, struct bpf_tunnel_key *key, __u32 size, __u64 flags) = (void *) 21; /* * bpf_perf_event_read * * Read the value of a perf event counter. This helper relies on a * *map* of type **BPF_MAP_TYPE_PERF_EVENT_ARRAY**. The nature of * the perf event counter is selected when *map* is updated with * perf event file descriptors. The *map* is an array whose size * is the number of available CPUs, and each cell contains a value * relative to one CPU. The value to retrieve is indicated by * *flags*, that contains the index of the CPU to look up, masked * with **BPF_F_INDEX_MASK**. Alternatively, *flags* can be set to * **BPF_F_CURRENT_CPU** to indicate that the value for the * current CPU should be retrieved. * * Note that before Linux 4.13, only hardware perf event can be * retrieved. * * Also, be aware that the newer helper * **bpf_perf_event_read_value**\ () is recommended over * **bpf_perf_event_read**\ () in general. The latter has some ABI * quirks where error and counter value are used as a return code * (which is wrong to do since ranges may overlap). This issue is * fixed with **bpf_perf_event_read_value**\ (), which at the same * time provides more features over the **bpf_perf_event_read**\ * () interface. Please refer to the description of * **bpf_perf_event_read_value**\ () for details. * * Returns * The value of the perf event counter read from the map, or a * negative error code in case of failure. */ static __u64 (*bpf_perf_event_read)(void *map, __u64 flags) = (void *) 22; /* * bpf_redirect * * Redirect the packet to another net device of index *ifindex*. * This helper is somewhat similar to **bpf_clone_redirect**\ * (), except that the packet is not cloned, which provides * increased performance. * * Except for XDP, both ingress and egress interfaces can be used * for redirection. The **BPF_F_INGRESS** value in *flags* is used * to make the distinction (ingress path is selected if the flag * is present, egress path otherwise). Currently, XDP only * supports redirection to the egress interface, and accepts no * flag at all. * * The same effect can also be attained with the more generic * **bpf_redirect_map**\ (), which uses a BPF map to store the * redirect target instead of providing it directly to the helper. * * Returns * For XDP, the helper returns **XDP_REDIRECT** on success or * **XDP_ABORTED** on error. For other program types, the values * are **TC_ACT_REDIRECT** on success or **TC_ACT_SHOT** on * error. */ static long (*bpf_redirect)(__u32 ifindex, __u64 flags) = (void *) 23; /* * bpf_get_route_realm * * Retrieve the realm or the route, that is to say the * **tclassid** field of the destination for the *skb*. The * identifier retrieved is a user-provided tag, similar to the * one used with the net_cls cgroup (see description for * **bpf_get_cgroup_classid**\ () helper), but here this tag is * held by a route (a destination entry), not by a task. * * Retrieving this identifier works with the clsact TC egress hook * (see also **tc-bpf(8)**), or alternatively on conventional * classful egress qdiscs, but not on TC ingress path. In case of * clsact TC egress hook, this has the advantage that, internally, * the destination entry has not been dropped yet in the transmit * path. Therefore, the destination entry does not need to be * artificially held via **netif_keep_dst**\ () for a classful * qdisc until the *skb* is freed. * * This helper is available only if the kernel was compiled with * **CONFIG_IP_ROUTE_CLASSID** configuration option. * * Returns * The realm of the route for the packet associated to *skb*, or 0 * if none was found. */ static __u32 (*bpf_get_route_realm)(struct __sk_buff *skb) = (void *) 24; /* * bpf_perf_event_output * * Write raw *data* blob into a special BPF perf event held by * *map* of type **BPF_MAP_TYPE_PERF_EVENT_ARRAY**. This perf * event must have the following attributes: **PERF_SAMPLE_RAW** * as **sample_type**, **PERF_TYPE_SOFTWARE** as **type**, and * **PERF_COUNT_SW_BPF_OUTPUT** as **config**. * * The *flags* are used to indicate the index in *map* for which * the value must be put, masked with **BPF_F_INDEX_MASK**. * Alternatively, *flags* can be set to **BPF_F_CURRENT_CPU** * to indicate that the index of the current CPU core should be * used. * * The value to write, of *size*, is passed through eBPF stack and * pointed by *data*. * * The context of the program *ctx* needs also be passed to the * helper. * * On user space, a program willing to read the values needs to * call **perf_event_open**\ () on the perf event (either for * one or for all CPUs) and to store the file descriptor into the * *map*. This must be done before the eBPF program can send data * into it. An example is available in file * *samples/bpf/trace_output_user.c* in the Linux kernel source * tree (the eBPF program counterpart is in * *samples/bpf/trace_output_kern.c*). * * **bpf_perf_event_output**\ () achieves better performance * than **bpf_trace_printk**\ () for sharing data with user * space, and is much better suitable for streaming data from eBPF * programs. * * Note that this helper is not restricted to tracing use cases * and can be used with programs attached to TC or XDP as well, * where it allows for passing data to user space listeners. Data * can be: * * * Only custom structs, * * Only the packet payload, or * * A combination of both. * * Returns * 0 on success, or a negative error in case of failure. */ static long (*bpf_perf_event_output)(void *ctx, void *map, __u64 flags, void *data, __u64 size) = (void *) 25; /* * bpf_skb_load_bytes * * This helper was provided as an easy way to load data from a * packet. It can be used to load *len* bytes from *offset* from * the packet associated to *skb*, into the buffer pointed by * *to*. * * Since Linux 4.7, usage of this helper has mostly been replaced * by "direct packet access", enabling packet data to be * manipulated with *skb*\ **->data** and *skb*\ **->data_end** * pointing respectively to the first byte of packet data and to * the byte after the last byte of packet data. However, it * remains useful if one wishes to read large quantities of data * at once from a packet into the eBPF stack. * * Returns * 0 on success, or a negative error in case of failure. */ static long (*bpf_skb_load_bytes)(const void *skb, __u32 offset, void *to, __u32 len) = (void *) 26; /* * bpf_get_stackid * * Walk a user or a kernel stack and return its id. To achieve * this, the helper needs *ctx*, which is a pointer to the context * on which the tracing program is executed, and a pointer to a * *map* of type **BPF_MAP_TYPE_STACK_TRACE**. * * The last argument, *flags*, holds the number of stack frames to * skip (from 0 to 255), masked with * **BPF_F_SKIP_FIELD_MASK**. The next bits can be used to set * a combination of the following flags: * * **BPF_F_USER_STACK** * Collect a user space stack instead of a kernel stack. * **BPF_F_FAST_STACK_CMP** * Compare stacks by hash only. * **BPF_F_REUSE_STACKID** * If two different stacks hash into the same *stackid*, * discard the old one. * * The stack id retrieved is a 32 bit long integer handle which * can be further combined with other data (including other stack * ids) and used as a key into maps. This can be useful for * generating a variety of graphs (such as flame graphs or off-cpu * graphs). * * For walking a stack, this helper is an improvement over * **bpf_probe_read**\ (), which can be used with unrolled loops * but is not efficient and consumes a lot of eBPF instructions. * Instead, **bpf_get_stackid**\ () can collect up to * **PERF_MAX_STACK_DEPTH** both kernel and user frames. Note that * this limit can be controlled with the **sysctl** program, and * that it should be manually increased in order to profile long * user stacks (such as stacks for Java programs). To do so, use: * * :: * * # sysctl kernel.perf_event_max_stack=<new value> * * Returns * The positive or null stack id on success, or a negative error * in case of failure. */ static long (*bpf_get_stackid)(void *ctx, void *map, __u64 flags) = (void *) 27; /* * bpf_csum_diff * * Compute a checksum difference, from the raw buffer pointed by * *from*, of length *from_size* (that must be a multiple of 4), * towards the raw buffer pointed by *to*, of size *to_size* * (same remark). An optional *seed* can be added to the value * (this can be cascaded, the seed may come from a previous call * to the helper). * * This is flexible enough to be used in several ways: * * * With *from_size* == 0, *to_size* > 0 and *seed* set to * checksum, it can be used when pushing new data. * * With *from_size* > 0, *to_size* == 0 and *seed* set to * checksum, it can be used when removing data from a packet. * * With *from_size* > 0, *to_size* > 0 and *seed* set to 0, it * can be used to compute a diff. Note that *from_size* and * *to_size* do not need to be equal. * * This helper can be used in combination with * **bpf_l3_csum_replace**\ () and **bpf_l4_csum_replace**\ (), to * which one can feed in the difference computed with * **bpf_csum_diff**\ (). * * Returns * The checksum result, or a negative error code in case of * failure. */ static __s64 (*bpf_csum_diff)(__be32 *from, __u32 from_size, __be32 *to, __u32 to_size, __wsum seed) = (void *) 28; /* * bpf_skb_get_tunnel_opt * * Retrieve tunnel options metadata for the packet associated to * *skb*, and store the raw tunnel option data to the buffer *opt* * of *size*. * * This helper can be used with encapsulation devices that can * operate in "collect metadata" mode (please refer to the related * note in the description of **bpf_skb_get_tunnel_key**\ () for * more details). A particular example where this can be used is * in combination with the Geneve encapsulation protocol, where it * allows for pushing (with **bpf_skb_get_tunnel_opt**\ () helper) * and retrieving arbitrary TLVs (Type-Length-Value headers) from * the eBPF program. This allows for full customization of these * headers. * * Returns * The size of the option data retrieved. */ static long (*bpf_skb_get_tunnel_opt)(struct __sk_buff *skb, void *opt, __u32 size) = (void *) 29; /* * bpf_skb_set_tunnel_opt * * Set tunnel options metadata for the packet associated to *skb* * to the option data contained in the raw buffer *opt* of *size*. * * See also the description of the **bpf_skb_get_tunnel_opt**\ () * helper for additional information. * * Returns * 0 on success, or a negative error in case of failure. */ static long (*bpf_skb_set_tunnel_opt)(struct __sk_buff *skb, void *opt, __u32 size) = (void *) 30; /* * bpf_skb_change_proto * * Change the protocol of the *skb* to *proto*. Currently * supported are transition from IPv4 to IPv6, and from IPv6 to * IPv4. The helper takes care of the groundwork for the * transition, including resizing the socket buffer. The eBPF * program is expected to fill the new headers, if any, via * **skb_store_bytes**\ () and to recompute the checksums with * **bpf_l3_csum_replace**\ () and **bpf_l4_csum_replace**\ * (). The main case for this helper is to perform NAT64 * operations out of an eBPF program. * * Internally, the GSO type is marked as dodgy so that headers are * checked and segments are recalculated by the GSO/GRO engine. * The size for GSO target is adapted as well. * * All values for *flags* are reserved for future usage, and must * be left at zero. * * A call to this helper is susceptible to change the underlying * packet buffer. Therefore, at load time, all checks on pointers * previously done by the verifier are invalidated and must be * performed again, if the helper is used in combination with * direct packet access. * * Returns * 0 on success, or a negative error in case of failure. */ static long (*bpf_skb_change_proto)(struct __sk_buff *skb, __be16 proto, __u64 flags) = (void *) 31; /* * bpf_skb_change_type * * Change the packet type for the packet associated to *skb*. This * comes down to setting *skb*\ **->pkt_type** to *type*, except * the eBPF program does not have a write access to *skb*\ * **->pkt_type** beside this helper. Using a helper here allows * for graceful handling of errors. * * The major use case is to change incoming *skb*s to * **PACKET_HOST** in a programmatic way instead of having to * recirculate via **redirect**\ (..., **BPF_F_INGRESS**), for * example. * * Note that *type* only allows certain values. At this time, they * are: * * **PACKET_HOST** * Packet is for us. * **PACKET_BROADCAST** * Send packet to all. * **PACKET_MULTICAST** * Send packet to group. * **PACKET_OTHERHOST** * Send packet to someone else. * * Returns * 0 on success, or a negative error in case of failure. */ static long (*bpf_skb_change_type)(struct __sk_buff *skb, __u32 type) = (void *) 32; /* * bpf_skb_under_cgroup * * Check whether *skb* is a descendant of the cgroup2 held by * *map* of type **BPF_MAP_TYPE_CGROUP_ARRAY**, at *index*. * * Returns * The return value depends on the result of the test, and can be: * * * 0, if the *skb* failed the cgroup2 descendant test. * * 1, if the *skb* succeeded the cgroup2 descendant test. * * A negative error code, if an error occurred. */ static long (*bpf_skb_under_cgroup)(struct __sk_buff *skb, void *map, __u32 index) = (void *) 33; /* * bpf_get_hash_recalc * * Retrieve the hash of the packet, *skb*\ **->hash**. If it is * not set, in particular if the hash was cleared due to mangling, * recompute this hash. Later accesses to the hash can be done * directly with *skb*\ **->hash**. * * Calling **bpf_set_hash_invalid**\ (), changing a packet * prototype with **bpf_skb_change_proto**\ (), or calling * **bpf_skb_store_bytes**\ () with the * **BPF_F_INVALIDATE_HASH** are actions susceptible to clear * the hash and to trigger a new computation for the next call to * **bpf_get_hash_recalc**\ (). * * Returns * The 32-bit hash. */ static __u32 (*bpf_get_hash_recalc)(struct __sk_buff *skb) = (void *) 34; /* * bpf_get_current_task * * Get the current task. * * Returns * A pointer to the current task struct. */ static __u64 (*bpf_get_current_task)(void) = (void *) 35; /* * bpf_probe_write_user * * Attempt in a safe way to write *len* bytes from the buffer * *src* to *dst* in memory. It only works for threads that are in * user context, and *dst* must be a valid user space address. * * This helper should not be used to implement any kind of * security mechanism because of TOC-TOU attacks, but rather to * debug, divert, and manipulate execution of semi-cooperative * processes. * * Keep in mind that this feature is meant for experiments, and it * has a risk of crashing the system and running programs. * Therefore, when an eBPF program using this helper is attached, * a warning including PID and process name is printed to kernel * logs. * * Returns * 0 on success, or a negative error in case of failure. */ static long (*bpf_probe_write_user)(void *dst, const void *src, __u32 len) = (void *) 36; /* * bpf_current_task_under_cgroup * * Check whether the probe is being run is the context of a given * subset of the cgroup2 hierarchy. The cgroup2 to test is held by * *map* of type **BPF_MAP_TYPE_CGROUP_ARRAY**, at *index*. * * Returns * The return value depends on the result of the test, and can be: * * * 1, if current task belongs to the cgroup2. * * 0, if current task does not belong to the cgroup2. * * A negative error code, if an error occurred. */ static long (*bpf_current_task_under_cgroup)(void *map, __u32 index) = (void *) 37; /* * bpf_skb_change_tail * * Resize (trim or grow) the packet associated to *skb* to the * new *len*. The *flags* are reserved for future usage, and must * be left at zero. * * The basic idea is that the helper performs the needed work to * change the size of the packet, then the eBPF program rewrites * the rest via helpers like **bpf_skb_store_bytes**\ (), * **bpf_l3_csum_replace**\ (), **bpf_l3_csum_replace**\ () * and others. This helper is a slow path utility intended for * replies with control messages. And because it is targeted for * slow path, the helper itself can afford to be slow: it * implicitly linearizes, unclones and drops offloads from the * *skb*. * * A call to this helper is susceptible to change the underlying * packet buffer. Therefore, at load time, all checks on pointers * previously done by the verifier are invalidated and must be * performed again, if the helper is used in combination with * direct packet access. * * Returns * 0 on success, or a negative error in case of failure. */ static long (*bpf_skb_change_tail)(struct __sk_buff *skb, __u32 len, __u64 flags) = (void *) 38; /* * bpf_skb_pull_data * * Pull in non-linear data in case the *skb* is non-linear and not * all of *len* are part of the linear section. Make *len* bytes * from *skb* readable and writable. If a zero value is passed for * *len*, then all bytes in the linear part of *skb* will be made * readable and writable. * * This helper is only needed for reading and writing with direct * packet access. * * For direct packet access, testing that offsets to access * are within packet boundaries (test on *skb*\ **->data_end**) is * susceptible to fail if offsets are invalid, or if the requested * data is in non-linear parts of the *skb*. On failure the * program can just bail out, or in the case of a non-linear * buffer, use a helper to make the data available. The * **bpf_skb_load_bytes**\ () helper is a first solution to access * the data. Another one consists in using **bpf_skb_pull_data** * to pull in once the non-linear parts, then retesting and * eventually access the data. * * At the same time, this also makes sure the *skb* is uncloned, * which is a necessary condition for direct write. As this needs * to be an invariant for the write part only, the verifier * detects writes and adds a prologue that is calling * **bpf_skb_pull_data()** to effectively unclone the *skb* from * the very beginning in case it is indeed cloned. * * A call to this helper is susceptible to change the underlying * packet buffer. Therefore, at load time, all checks on pointers * previously done by the verifier are invalidated and must be * performed again, if the helper is used in combination with * direct packet access. * * Returns * 0 on success, or a negative error in case of failure. */ static long (*bpf_skb_pull_data)(struct __sk_buff *skb, __u32 len) = (void *) 39; /* * bpf_csum_update * * Add the checksum *csum* into *skb*\ **->csum** in case the * driver has supplied a checksum for the entire packet into that * field. Return an error otherwise. This helper is intended to be * used in combination with **bpf_csum_diff**\ (), in particular * when the checksum needs to be updated after data has been * written into the packet through direct packet access. * * Returns * The checksum on success, or a negative error code in case of * failure. */ static __s64 (*bpf_csum_update)(struct __sk_buff *skb, __wsum csum) = (void *) 40; /* * bpf_set_hash_invalid * * Invalidate the current *skb*\ **->hash**. It can be used after * mangling on headers through direct packet access, in order to * indicate that the hash is outdated and to trigger a * recalculation the next time the kernel tries to access this * hash or when the **bpf_get_hash_recalc**\ () helper is called. * * Returns * void. */ static void (*bpf_set_hash_invalid)(struct __sk_buff *skb) = (void *) 41; /* * bpf_get_numa_node_id * * Return the id of the current NUMA node. The primary use case * for this helper is the selection of sockets for the local NUMA * node, when the program is attached to sockets using the * **SO_ATTACH_REUSEPORT_EBPF** option (see also **socket(7)**), * but the helper is also available to other eBPF program types, * similarly to **bpf_get_smp_processor_id**\ (). * * Returns * The id of current NUMA node. */ static long (*bpf_get_numa_node_id)(void) = (void *) 42; /* * bpf_skb_change_head * * Grows headroom of packet associated to *skb* and adjusts the * offset of the MAC header accordingly, adding *len* bytes of * space. It automatically extends and reallocates memory as * required. * * This helper can be used on a layer 3 *skb* to push a MAC header * for redirection into a layer 2 device. * * All values for *flags* are reserved for future usage, and must * be left at zero. * * A call to this helper is susceptible to change the underlying * packet buffer. Therefore, at load time, all checks on pointers * previously done by the verifier are invalidated and must be * performed again, if the helper is used in combination with * direct packet access. * * Returns * 0 on success, or a negative error in case of failure. */ static long (*bpf_skb_change_head)(struct __sk_buff *skb, __u32 len, __u64 flags) = (void *) 43; /* * bpf_xdp_adjust_head * * Adjust (move) *xdp_md*\ **->data** by *delta* bytes. Note that * it is possible to use a negative value for *delta*. This helper * can be used to prepare the packet for pushing or popping * headers. * * A call to this helper is susceptible to change the underlying * packet buffer. Therefore, at load time, all checks on pointers * previously done by the verifier are invalidated and must be * performed again, if the helper is used in combination with * direct packet access. * * Returns * 0 on success, or a negative error in case of failure. */ static long (*bpf_xdp_adjust_head)(struct xdp_md *xdp_md, int delta) = (void *) 44; /* * bpf_probe_read_str * * Copy a NUL terminated string from an unsafe kernel address * *unsafe_ptr* to *dst*. See **bpf_probe_read_kernel_str**\ () for * more details. * * Generally, use **bpf_probe_read_user_str**\ () or * **bpf_probe_read_kernel_str**\ () instead. * * Returns * On success, the strictly positive length of the string, * including the trailing NUL character. On error, a negative * value. */ static long (*bpf_probe_read_str)(void *dst, __u32 size, const void *unsafe_ptr) = (void *) 45; /* * bpf_get_socket_cookie * * If the **struct sk_buff** pointed by *skb* has a known socket, * retrieve the cookie (generated by the kernel) of this socket. * If no cookie has been set yet, generate a new cookie. Once * generated, the socket cookie remains stable for the life of the * socket. This helper can be useful for monitoring per socket * networking traffic statistics as it provides a global socket * identifier that can be assumed unique. * * Returns * A 8-byte long unique number on success, or 0 if the socket * field is missing inside *skb*. */ static __u64 (*bpf_get_socket_cookie)(void *ctx) = (void *) 46; /* * bpf_get_socket_uid * * Get the owner UID of the socked associated to *skb*. * * Returns * The owner UID of the socket associated to *skb*. If the socket * is **NULL**, or if it is not a full socket (i.e. if it is a * time-wait or a request socket instead), **overflowuid** value * is returned (note that **overflowuid** might also be the actual * UID value for the socket). */ static __u32 (*bpf_get_socket_uid)(struct __sk_buff *skb) = (void *) 47; /* * bpf_set_hash * * Set the full hash for *skb* (set the field *skb*\ **->hash**) * to value *hash*. * * Returns * 0 */ static long (*bpf_set_hash)(struct __sk_buff *skb, __u32 hash) = (void *) 48; /* * bpf_setsockopt * * Emulate a call to **setsockopt()** on the socket associated to * *bpf_socket*, which must be a full socket. The *level* at * which the option resides and the name *optname* of the option * must be specified, see **setsockopt(2)** for more information. * The option value of length *optlen* is pointed by *optval*. * * *bpf_socket* should be one of the following: * * * **struct bpf_sock_ops** for **BPF_PROG_TYPE_SOCK_OPS**. * * **struct bpf_sock_addr** for **BPF_CGROUP_INET4_CONNECT**, * **BPF_CGROUP_INET6_CONNECT** and **BPF_CGROUP_UNIX_CONNECT**. * * This helper actually implements a subset of **setsockopt()**. * It supports the following *level*\ s: * * * **SOL_SOCKET**, which supports the following *optname*\ s: * **SO_RCVBUF**, **SO_SNDBUF**, **SO_MAX_PACING_RATE**, * **SO_PRIORITY**, **SO_RCVLOWAT**, **SO_MARK**, * **SO_BINDTODEVICE**, **SO_KEEPALIVE**, **SO_REUSEADDR**, * **SO_REUSEPORT**, **SO_BINDTOIFINDEX**, **SO_TXREHASH**. * * **IPPROTO_TCP**, which supports the following *optname*\ s: * **TCP_CONGESTION**, **TCP_BPF_IW**, * **TCP_BPF_SNDCWND_CLAMP**, **TCP_SAVE_SYN**, * **TCP_KEEPIDLE**, **TCP_KEEPINTVL**, **TCP_KEEPCNT**, * **TCP_SYNCNT**, **TCP_USER_TIMEOUT**, **TCP_NOTSENT_LOWAT**, * **TCP_NODELAY**, **TCP_MAXSEG**, **TCP_WINDOW_CLAMP**, * **TCP_THIN_LINEAR_TIMEOUTS**, **TCP_BPF_DELACK_MAX**, * **TCP_BPF_RTO_MIN**. * * **IPPROTO_IP**, which supports *optname* **IP_TOS**. * * **IPPROTO_IPV6**, which supports the following *optname*\ s: * **IPV6_TCLASS**, **IPV6_AUTOFLOWLABEL**. * * Returns * 0 on success, or a negative error in case of failure. */ static long (*bpf_setsockopt)(void *bpf_socket, int level, int optname, void *optval, int optlen) = (void *) 49; /* * bpf_skb_adjust_room * * Grow or shrink the room for data in the packet associated to * *skb* by *len_diff*, and according to the selected *mode*. * * By default, the helper will reset any offloaded checksum * indicator of the skb to CHECKSUM_NONE. This can be avoided * by the following flag: * * * **BPF_F_ADJ_ROOM_NO_CSUM_RESET**: Do not reset offloaded * checksum data of the skb to CHECKSUM_NONE. * * There are two supported modes at this time: * * * **BPF_ADJ_ROOM_MAC**: Adjust room at the mac layer * (room space is added or removed between the layer 2 and * layer 3 headers). * * * **BPF_ADJ_ROOM_NET**: Adjust room at the network layer * (room space is added or removed between the layer 3 and * layer 4 headers). * * The following flags are supported at this time: * * * **BPF_F_ADJ_ROOM_FIXED_GSO**: Do not adjust gso_size. * Adjusting mss in this way is not allowed for datagrams. * * * **BPF_F_ADJ_ROOM_ENCAP_L3_IPV4**, * **BPF_F_ADJ_ROOM_ENCAP_L3_IPV6**: * Any new space is reserved to hold a tunnel header. * Configure skb offsets and other fields accordingly. * * * **BPF_F_ADJ_ROOM_ENCAP_L4_GRE**, * **BPF_F_ADJ_ROOM_ENCAP_L4_UDP**: * Use with ENCAP_L3 flags to further specify the tunnel type. * * * **BPF_F_ADJ_ROOM_ENCAP_L2**\ (*len*): * Use with ENCAP_L3/L4 flags to further specify the tunnel * type; *len* is the length of the inner MAC header. * * * **BPF_F_ADJ_ROOM_ENCAP_L2_ETH**: * Use with BPF_F_ADJ_ROOM_ENCAP_L2 flag to further specify the * L2 type as Ethernet. * * * **BPF_F_ADJ_ROOM_DECAP_L3_IPV4**, * **BPF_F_ADJ_ROOM_DECAP_L3_IPV6**: * Indicate the new IP header version after decapsulating the outer * IP header. Used when the inner and outer IP versions are different. * * A call to this helper is susceptible to change the underlying * packet buffer. Therefore, at load time, all checks on pointers * previously done by the verifier are invalidated and must be * performed again, if the helper is used in combination with * direct packet access. * * Returns * 0 on success, or a negative error in case of failure. */ static long (*bpf_skb_adjust_room)(struct __sk_buff *skb, __s32 len_diff, __u32 mode, __u64 flags) = (void *) 50; /* * bpf_redirect_map * * Redirect the packet to the endpoint referenced by *map* at * index *key*. Depending on its type, this *map* can contain * references to net devices (for forwarding packets through other * ports), or to CPUs (for redirecting XDP frames to another CPU; * but this is only implemented for native XDP (with driver * support) as of this writing). * * The lower two bits of *flags* are used as the return code if * the map lookup fails. This is so that the return value can be * one of the XDP program return codes up to **XDP_TX**, as chosen * by the caller. The higher bits of *flags* can be set to * BPF_F_BROADCAST or BPF_F_EXCLUDE_INGRESS as defined below. * * With BPF_F_BROADCAST the packet will be broadcasted to all the * interfaces in the map, with BPF_F_EXCLUDE_INGRESS the ingress * interface will be excluded when do broadcasting. * * See also **bpf_redirect**\ (), which only supports redirecting * to an ifindex, but doesn't require a map to do so. * * Returns * **XDP_REDIRECT** on success, or the value of the two lower bits * of the *flags* argument on error. */ static long (*bpf_redirect_map)(void *map, __u64 key, __u64 flags) = (void *) 51; /* * bpf_sk_redirect_map * * Redirect the packet to the socket referenced by *map* (of type * **BPF_MAP_TYPE_SOCKMAP**) at index *key*. Both ingress and * egress interfaces can be used for redirection. The * **BPF_F_INGRESS** value in *flags* is used to make the * distinction (ingress path is selected if the flag is present, * egress path otherwise). This is the only flag supported for now. * * Returns * **SK_PASS** on success, or **SK_DROP** on error. */ static long (*bpf_sk_redirect_map)(struct __sk_buff *skb, void *map, __u32 key, __u64 flags) = (void *) 52; /* * bpf_sock_map_update * * Add an entry to, or update a *map* referencing sockets. The * *skops* is used as a new value for the entry associated to * *key*. *flags* is one of: * * **BPF_NOEXIST** * The entry for *key* must not exist in the map. * **BPF_EXIST** * The entry for *key* must already exist in the map. * **BPF_ANY** * No condition on the existence of the entry for *key*. * * If the *map* has eBPF programs (parser and verdict), those will * be inherited by the socket being added. If the socket is * already attached to eBPF programs, this results in an error. * * Returns * 0 on success, or a negative error in case of failure. */ static long (*bpf_sock_map_update)(struct bpf_sock_ops *skops, void *map, void *key, __u64 flags) = (void *) 53; /* * bpf_xdp_adjust_meta * * Adjust the address pointed by *xdp_md*\ **->data_meta** by * *delta* (which can be positive or negative). Note that this * operation modifies the address stored in *xdp_md*\ **->data**, * so the latter must be loaded only after the helper has been * called. * * The use of *xdp_md*\ **->data_meta** is optional and programs * are not required to use it. The rationale is that when the * packet is processed with XDP (e.g. as DoS filter), it is * possible to push further meta data along with it before passing * to the stack, and to give the guarantee that an ingress eBPF * program attached as a TC classifier on the same device can pick * this up for further post-processing. Since TC works with socket * buffers, it remains possible to set from XDP the **mark** or * **priority** pointers, or other pointers for the socket buffer. * Having this scratch space generic and programmable allows for * more flexibility as the user is free to store whatever meta * data they need. * * A call to this helper is susceptible to change the underlying * packet buffer. Therefore, at load time, all checks on pointers * previously done by the verifier are invalidated and must be * performed again, if the helper is used in combination with * direct packet access. * * Returns * 0 on success, or a negative error in case of failure. */ static long (*bpf_xdp_adjust_meta)(struct xdp_md *xdp_md, int delta) = (void *) 54; /* * bpf_perf_event_read_value * * Read the value of a perf event counter, and store it into *buf* * of size *buf_size*. This helper relies on a *map* of type * **BPF_MAP_TYPE_PERF_EVENT_ARRAY**. The nature of the perf event * counter is selected when *map* is updated with perf event file * descriptors. The *map* is an array whose size is the number of * available CPUs, and each cell contains a value relative to one * CPU. The value to retrieve is indicated by *flags*, that * contains the index of the CPU to look up, masked with * **BPF_F_INDEX_MASK**. Alternatively, *flags* can be set to * **BPF_F_CURRENT_CPU** to indicate that the value for the * current CPU should be retrieved. * * This helper behaves in a way close to * **bpf_perf_event_read**\ () helper, save that instead of * just returning the value observed, it fills the *buf* * structure. This allows for additional data to be retrieved: in * particular, the enabled and running times (in *buf*\ * **->enabled** and *buf*\ **->running**, respectively) are * copied. In general, **bpf_perf_event_read_value**\ () is * recommended over **bpf_perf_event_read**\ (), which has some * ABI issues and provides fewer functionalities. * * These values are interesting, because hardware PMU (Performance * Monitoring Unit) counters are limited resources. When there are * more PMU based perf events opened than available counters, * kernel will multiplex these events so each event gets certain * percentage (but not all) of the PMU time. In case that * multiplexing happens, the number of samples or counter value * will not reflect the case compared to when no multiplexing * occurs. This makes comparison between different runs difficult. * Typically, the counter value should be normalized before * comparing to other experiments. The usual normalization is done * as follows. * * :: * * normalized_counter = counter * t_enabled / t_running * * Where t_enabled is the time enabled for event and t_running is * the time running for event since last normalization. The * enabled and running times are accumulated since the perf event * open. To achieve scaling factor between two invocations of an * eBPF program, users can use CPU id as the key (which is * typical for perf array usage model) to remember the previous * value and do the calculation inside the eBPF program. * * Returns * 0 on success, or a negative error in case of failure. */ static long (*bpf_perf_event_read_value)(void *map, __u64 flags, struct bpf_perf_event_value *buf, __u32 buf_size) = (void *) 55; /* * bpf_perf_prog_read_value * * For an eBPF program attached to a perf event, retrieve the * value of the event counter associated to *ctx* and store it in * the structure pointed by *buf* and of size *buf_size*. Enabled * and running times are also stored in the structure (see * description of helper **bpf_perf_event_read_value**\ () for * more details). * * Returns * 0 on success, or a negative error in case of failure. */ static long (*bpf_perf_prog_read_value)(struct bpf_perf_event_data *ctx, struct bpf_perf_event_value *buf, __u32 buf_size) = (void *) 56; /* * bpf_getsockopt * * Emulate a call to **getsockopt()** on the socket associated to * *bpf_socket*, which must be a full socket. The *level* at * which the option resides and the name *optname* of the option * must be specified, see **getsockopt(2)** for more information. * The retrieved value is stored in the structure pointed by * *opval* and of length *optlen*. * * *bpf_socket* should be one of the following: * * * **struct bpf_sock_ops** for **BPF_PROG_TYPE_SOCK_OPS**. * * **struct bpf_sock_addr** for **BPF_CGROUP_INET4_CONNECT**, * **BPF_CGROUP_INET6_CONNECT** and **BPF_CGROUP_UNIX_CONNECT**. * * This helper actually implements a subset of **getsockopt()**. * It supports the same set of *optname*\ s that is supported by * the **bpf_setsockopt**\ () helper. The exceptions are * **TCP_BPF_*** is **bpf_setsockopt**\ () only and * **TCP_SAVED_SYN** is **bpf_getsockopt**\ () only. * * Returns * 0 on success, or a negative error in case of failure. */ static long (*bpf_getsockopt)(void *bpf_socket, int level, int optname, void *optval, int optlen) = (void *) 57; /* * bpf_override_return * * Used for error injection, this helper uses kprobes to override * the return value of the probed function, and to set it to *rc*. * The first argument is the context *regs* on which the kprobe * works. * * This helper works by setting the PC (program counter) * to an override function which is run in place of the original * probed function. This means the probed function is not run at * all. The replacement function just returns with the required * value. * * This helper has security implications, and thus is subject to * restrictions. It is only available if the kernel was compiled * with the **CONFIG_BPF_KPROBE_OVERRIDE** configuration * option, and in this case it only works on functions tagged with * **ALLOW_ERROR_INJECTION** in the kernel code. * * Also, the helper is only available for the architectures having * the CONFIG_FUNCTION_ERROR_INJECTION option. As of this writing, * x86 architecture is the only one to support this feature. * * Returns * 0 */ static long (*bpf_override_return)(struct pt_regs *regs, __u64 rc) = (void *) 58; /* * bpf_sock_ops_cb_flags_set * * Attempt to set the value of the **bpf_sock_ops_cb_flags** field * for the full TCP socket associated to *bpf_sock_ops* to * *argval*. * * The primary use of this field is to determine if there should * be calls to eBPF programs of type * **BPF_PROG_TYPE_SOCK_OPS** at various points in the TCP * code. A program of the same type can change its value, per * connection and as necessary, when the connection is * established. This field is directly accessible for reading, but * this helper must be used for updates in order to return an * error if an eBPF program tries to set a callback that is not * supported in the current kernel. * * *argval* is a flag array which can combine these flags: * * * **BPF_SOCK_OPS_RTO_CB_FLAG** (retransmission time out) * * **BPF_SOCK_OPS_RETRANS_CB_FLAG** (retransmission) * * **BPF_SOCK_OPS_STATE_CB_FLAG** (TCP state change) * * **BPF_SOCK_OPS_RTT_CB_FLAG** (every RTT) * * Therefore, this function can be used to clear a callback flag by * setting the appropriate bit to zero. e.g. to disable the RTO * callback: * * **bpf_sock_ops_cb_flags_set(bpf_sock,** * **bpf_sock->bpf_sock_ops_cb_flags & ~BPF_SOCK_OPS_RTO_CB_FLAG)** * * Here are some examples of where one could call such eBPF * program: * * * When RTO fires. * * When a packet is retransmitted. * * When the connection terminates. * * When a packet is sent. * * When a packet is received. * * Returns * Code **-EINVAL** if the socket is not a full TCP socket; * otherwise, a positive number containing the bits that could not * be set is returned (which comes down to 0 if all bits were set * as required). */ static long (*bpf_sock_ops_cb_flags_set)(struct bpf_sock_ops *bpf_sock, int argval) = (void *) 59; /* * bpf_msg_redirect_map * * This helper is used in programs implementing policies at the * socket level. If the message *msg* is allowed to pass (i.e. if * the verdict eBPF program returns **SK_PASS**), redirect it to * the socket referenced by *map* (of type * **BPF_MAP_TYPE_SOCKMAP**) at index *key*. Both ingress and * egress interfaces can be used for redirection. The * **BPF_F_INGRESS** value in *flags* is used to make the * distinction (ingress path is selected if the flag is present, * egress path otherwise). This is the only flag supported for now. * * Returns * **SK_PASS** on success, or **SK_DROP** on error. */ static long (*bpf_msg_redirect_map)(struct sk_msg_md *msg, void *map, __u32 key, __u64 flags) = (void *) 60; /* * bpf_msg_apply_bytes * * For socket policies, apply the verdict of the eBPF program to * the next *bytes* (number of bytes) of message *msg*. * * For example, this helper can be used in the following cases: * * * A single **sendmsg**\ () or **sendfile**\ () system call * contains multiple logical messages that the eBPF program is * supposed to read and for which it should apply a verdict. * * An eBPF program only cares to read the first *bytes* of a * *msg*. If the message has a large payload, then setting up * and calling the eBPF program repeatedly for all bytes, even * though the verdict is already known, would create unnecessary * overhead. * * When called from within an eBPF program, the helper sets a * counter internal to the BPF infrastructure, that is used to * apply the last verdict to the next *bytes*. If *bytes* is * smaller than the current data being processed from a * **sendmsg**\ () or **sendfile**\ () system call, the first * *bytes* will be sent and the eBPF program will be re-run with * the pointer for start of data pointing to byte number *bytes* * **+ 1**. If *bytes* is larger than the current data being * processed, then the eBPF verdict will be applied to multiple * **sendmsg**\ () or **sendfile**\ () calls until *bytes* are * consumed. * * Note that if a socket closes with the internal counter holding * a non-zero value, this is not a problem because data is not * being buffered for *bytes* and is sent as it is received. * * Returns * 0 */ static long (*bpf_msg_apply_bytes)(struct sk_msg_md *msg, __u32 bytes) = (void *) 61; /* * bpf_msg_cork_bytes * * For socket policies, prevent the execution of the verdict eBPF * program for message *msg* until *bytes* (byte number) have been * accumulated. * * This can be used when one needs a specific number of bytes * before a verdict can be assigned, even if the data spans * multiple **sendmsg**\ () or **sendfile**\ () calls. The extreme * case would be a user calling **sendmsg**\ () repeatedly with * 1-byte long message segments. Obviously, this is bad for * performance, but it is still valid. If the eBPF program needs * *bytes* bytes to validate a header, this helper can be used to * prevent the eBPF program to be called again until *bytes* have * been accumulated. * * Returns * 0 */ static long (*bpf_msg_cork_bytes)(struct sk_msg_md *msg, __u32 bytes) = (void *) 62; /* * bpf_msg_pull_data * * For socket policies, pull in non-linear data from user space * for *msg* and set pointers *msg*\ **->data** and *msg*\ * **->data_end** to *start* and *end* bytes offsets into *msg*, * respectively. * * If a program of type **BPF_PROG_TYPE_SK_MSG** is run on a * *msg* it can only parse data that the (**data**, **data_end**) * pointers have already consumed. For **sendmsg**\ () hooks this * is likely the first scatterlist element. But for calls relying * on the **sendpage** handler (e.g. **sendfile**\ ()) this will * be the range (**0**, **0**) because the data is shared with * user space and by default the objective is to avoid allowing * user space to modify data while (or after) eBPF verdict is * being decided. This helper can be used to pull in data and to * set the start and end pointer to given values. Data will be * copied if necessary (i.e. if data was not linear and if start * and end pointers do not point to the same chunk). * * A call to this helper is susceptible to change the underlying * packet buffer. Therefore, at load time, all checks on pointers * previously done by the verifier are invalidated and must be * performed again, if the helper is used in combination with * direct packet access. * * All values for *flags* are reserved for future usage, and must * be left at zero. * * Returns * 0 on success, or a negative error in case of failure. */ static long (*bpf_msg_pull_data)(struct sk_msg_md *msg, __u32 start, __u32 end, __u64 flags) = (void *) 63; /* * bpf_bind * * Bind the socket associated to *ctx* to the address pointed by * *addr*, of length *addr_len*. This allows for making outgoing * connection from the desired IP address, which can be useful for * example when all processes inside a cgroup should use one * single IP address on a host that has multiple IP configured. * * This helper works for IPv4 and IPv6, TCP and UDP sockets. The * domain (*addr*\ **->sa_family**) must be **AF_INET** (or * **AF_INET6**). It's advised to pass zero port (**sin_port** * or **sin6_port**) which triggers IP_BIND_ADDRESS_NO_PORT-like * behavior and lets the kernel efficiently pick up an unused * port as long as 4-tuple is unique. Passing non-zero port might * lead to degraded performance. * * Returns * 0 on success, or a negative error in case of failure. */ static long (*bpf_bind)(struct bpf_sock_addr *ctx, struct sockaddr *addr, int addr_len) = (void *) 64; /* * bpf_xdp_adjust_tail * * Adjust (move) *xdp_md*\ **->data_end** by *delta* bytes. It is * possible to both shrink and grow the packet tail. * Shrink done via *delta* being a negative integer. * * A call to this helper is susceptible to change the underlying * packet buffer. Therefore, at load time, all checks on pointers * previously done by the verifier are invalidated and must be * performed again, if the helper is used in combination with * direct packet access. * * Returns * 0 on success, or a negative error in case of failure. */ static long (*bpf_xdp_adjust_tail)(struct xdp_md *xdp_md, int delta) = (void *) 65; /* * bpf_skb_get_xfrm_state * * Retrieve the XFRM state (IP transform framework, see also * **ip-xfrm(8)**) at *index* in XFRM "security path" for *skb*. * * The retrieved value is stored in the **struct bpf_xfrm_state** * pointed by *xfrm_state* and of length *size*. * * All values for *flags* are reserved for future usage, and must * be left at zero. * * This helper is available only if the kernel was compiled with * **CONFIG_XFRM** configuration option. * * Returns * 0 on success, or a negative error in case of failure. */ static long (*bpf_skb_get_xfrm_state)(struct __sk_buff *skb, __u32 index, struct bpf_xfrm_state *xfrm_state, __u32 size, __u64 flags) = (void *) 66; /* * bpf_get_stack * * Return a user or a kernel stack in bpf program provided buffer. * To achieve this, the helper needs *ctx*, which is a pointer * to the context on which the tracing program is executed. * To store the stacktrace, the bpf program provides *buf* with * a nonnegative *size*. * * The last argument, *flags*, holds the number of stack frames to * skip (from 0 to 255), masked with * **BPF_F_SKIP_FIELD_MASK**. The next bits can be used to set * the following flags: * * **BPF_F_USER_STACK** * Collect a user space stack instead of a kernel stack. * **BPF_F_USER_BUILD_ID** * Collect (build_id, file_offset) instead of ips for user * stack, only valid if **BPF_F_USER_STACK** is also * specified. * * *file_offset* is an offset relative to the beginning * of the executable or shared object file backing the vma * which the *ip* falls in. It is *not* an offset relative * to that object's base address. Accordingly, it must be * adjusted by adding (sh_addr - sh_offset), where * sh_{addr,offset} correspond to the executable section * containing *file_offset* in the object, for comparisons * to symbols' st_value to be valid. * * **bpf_get_stack**\ () can collect up to * **PERF_MAX_STACK_DEPTH** both kernel and user frames, subject * to sufficient large buffer size. Note that * this limit can be controlled with the **sysctl** program, and * that it should be manually increased in order to profile long * user stacks (such as stacks for Java programs). To do so, use: * * :: * * # sysctl kernel.perf_event_max_stack=<new value> * * Returns * The non-negative copied *buf* length equal to or less than * *size* on success, or a negative error in case of failure. */ static long (*bpf_get_stack)(void *ctx, void *buf, __u32 size, __u64 flags) = (void *) 67; /* * bpf_skb_load_bytes_relative * * This helper is similar to **bpf_skb_load_bytes**\ () in that * it provides an easy way to load *len* bytes from *offset* * from the packet associated to *skb*, into the buffer pointed * by *to*. The difference to **bpf_skb_load_bytes**\ () is that * a fifth argument *start_header* exists in order to select a * base offset to start from. *start_header* can be one of: * * **BPF_HDR_START_MAC** * Base offset to load data from is *skb*'s mac header. * **BPF_HDR_START_NET** * Base offset to load data from is *skb*'s network header. * * In general, "direct packet access" is the preferred method to * access packet data, however, this helper is in particular useful * in socket filters where *skb*\ **->data** does not always point * to the start of the mac header and where "direct packet access" * is not available. * * Returns * 0 on success, or a negative error in case of failure. */ static long (*bpf_skb_load_bytes_relative)(const void *skb, __u32 offset, void *to, __u32 len, __u32 start_header) = (void *) 68; /* * bpf_fib_lookup * * Do FIB lookup in kernel tables using parameters in *params*. * If lookup is successful and result shows packet is to be * forwarded, the neighbor tables are searched for the nexthop. * If successful (ie., FIB lookup shows forwarding and nexthop * is resolved), the nexthop address is returned in ipv4_dst * or ipv6_dst based on family, smac is set to mac address of * egress device, dmac is set to nexthop mac address, rt_metric * is set to metric from route (IPv4/IPv6 only), and ifindex * is set to the device index of the nexthop from the FIB lookup. * * *plen* argument is the size of the passed in struct. * *flags* argument can be a combination of one or more of the * following values: * * **BPF_FIB_LOOKUP_DIRECT** * Do a direct table lookup vs full lookup using FIB * rules. * **BPF_FIB_LOOKUP_TBID** * Used with BPF_FIB_LOOKUP_DIRECT. * Use the routing table ID present in *params*->tbid * for the fib lookup. * **BPF_FIB_LOOKUP_OUTPUT** * Perform lookup from an egress perspective (default is * ingress). * **BPF_FIB_LOOKUP_SKIP_NEIGH** * Skip the neighbour table lookup. *params*->dmac * and *params*->smac will not be set as output. A common * use case is to call **bpf_redirect_neigh**\ () after * doing **bpf_fib_lookup**\ (). * **BPF_FIB_LOOKUP_SRC** * Derive and set source IP addr in *params*->ipv{4,6}_src * for the nexthop. If the src addr cannot be derived, * **BPF_FIB_LKUP_RET_NO_SRC_ADDR** is returned. In this * case, *params*->dmac and *params*->smac are not set either. * * *ctx* is either **struct xdp_md** for XDP programs or * **struct sk_buff** tc cls_act programs. * * Returns * * < 0 if any input argument is invalid * * 0 on success (packet is forwarded, nexthop neighbor exists) * * > 0 one of **BPF_FIB_LKUP_RET_** codes explaining why the * packet is not forwarded or needs assist from full stack * * If lookup fails with BPF_FIB_LKUP_RET_FRAG_NEEDED, then the MTU * was exceeded and output params->mtu_result contains the MTU. */ static long (*bpf_fib_lookup)(void *ctx, struct bpf_fib_lookup *params, int plen, __u32 flags) = (void *) 69; /* * bpf_sock_hash_update * * Add an entry to, or update a sockhash *map* referencing sockets. * The *skops* is used as a new value for the entry associated to * *key*. *flags* is one of: * * **BPF_NOEXIST** * The entry for *key* must not exist in the map. * **BPF_EXIST** * The entry for *key* must already exist in the map. * **BPF_ANY** * No condition on the existence of the entry for *key*. * * If the *map* has eBPF programs (parser and verdict), those will * be inherited by the socket being added. If the socket is * already attached to eBPF programs, this results in an error. * * Returns * 0 on success, or a negative error in case of failure. */ static long (*bpf_sock_hash_update)(struct bpf_sock_ops *skops, void *map, void *key, __u64 flags) = (void *) 70; /* * bpf_msg_redirect_hash * * This helper is used in programs implementing policies at the * socket level. If the message *msg* is allowed to pass (i.e. if * the verdict eBPF program returns **SK_PASS**), redirect it to * the socket referenced by *map* (of type * **BPF_MAP_TYPE_SOCKHASH**) using hash *key*. Both ingress and * egress interfaces can be used for redirection. The * **BPF_F_INGRESS** value in *flags* is used to make the * distinction (ingress path is selected if the flag is present, * egress path otherwise). This is the only flag supported for now. * * Returns * **SK_PASS** on success, or **SK_DROP** on error. */ static long (*bpf_msg_redirect_hash)(struct sk_msg_md *msg, void *map, void *key, __u64 flags) = (void *) 71; /* * bpf_sk_redirect_hash * * This helper is used in programs implementing policies at the * skb socket level. If the sk_buff *skb* is allowed to pass (i.e. * if the verdict eBPF program returns **SK_PASS**), redirect it * to the socket referenced by *map* (of type * **BPF_MAP_TYPE_SOCKHASH**) using hash *key*. Both ingress and * egress interfaces can be used for redirection. The * **BPF_F_INGRESS** value in *flags* is used to make the * distinction (ingress path is selected if the flag is present, * egress otherwise). This is the only flag supported for now. * * Returns * **SK_PASS** on success, or **SK_DROP** on error. */ static long (*bpf_sk_redirect_hash)(struct __sk_buff *skb, void *map, void *key, __u64 flags) = (void *) 72; /* * bpf_lwt_push_encap * * Encapsulate the packet associated to *skb* within a Layer 3 * protocol header. This header is provided in the buffer at * address *hdr*, with *len* its size in bytes. *type* indicates * the protocol of the header and can be one of: * * **BPF_LWT_ENCAP_SEG6** * IPv6 encapsulation with Segment Routing Header * (**struct ipv6_sr_hdr**). *hdr* only contains the SRH, * the IPv6 header is computed by the kernel. * **BPF_LWT_ENCAP_SEG6_INLINE** * Only works if *skb* contains an IPv6 packet. Insert a * Segment Routing Header (**struct ipv6_sr_hdr**) inside * the IPv6 header. * **BPF_LWT_ENCAP_IP** * IP encapsulation (GRE/GUE/IPIP/etc). The outer header * must be IPv4 or IPv6, followed by zero or more * additional headers, up to **LWT_BPF_MAX_HEADROOM** * total bytes in all prepended headers. Please note that * if **skb_is_gso**\ (*skb*) is true, no more than two * headers can be prepended, and the inner header, if * present, should be either GRE or UDP/GUE. * * **BPF_LWT_ENCAP_SEG6**\ \* types can be called by BPF programs * of type **BPF_PROG_TYPE_LWT_IN**; **BPF_LWT_ENCAP_IP** type can * be called by bpf programs of types **BPF_PROG_TYPE_LWT_IN** and * **BPF_PROG_TYPE_LWT_XMIT**. * * A call to this helper is susceptible to change the underlying * packet buffer. Therefore, at load time, all checks on pointers * previously done by the verifier are invalidated and must be * performed again, if the helper is used in combination with * direct packet access. * * Returns * 0 on success, or a negative error in case of failure. */ static long (*bpf_lwt_push_encap)(struct __sk_buff *skb, __u32 type, void *hdr, __u32 len) = (void *) 73; /* * bpf_lwt_seg6_store_bytes * * Store *len* bytes from address *from* into the packet * associated to *skb*, at *offset*. Only the flags, tag and TLVs * inside the outermost IPv6 Segment Routing Header can be * modified through this helper. * * A call to this helper is susceptible to change the underlying * packet buffer. Therefore, at load time, all checks on pointers * previously done by the verifier are invalidated and must be * performed again, if the helper is used in combination with * direct packet access. * * Returns * 0 on success, or a negative error in case of failure. */ static long (*bpf_lwt_seg6_store_bytes)(struct __sk_buff *skb, __u32 offset, const void *from, __u32 len) = (void *) 74; /* * bpf_lwt_seg6_adjust_srh * * Adjust the size allocated to TLVs in the outermost IPv6 * Segment Routing Header contained in the packet associated to * *skb*, at position *offset* by *delta* bytes. Only offsets * after the segments are accepted. *delta* can be as well * positive (growing) as negative (shrinking). * * A call to this helper is susceptible to change the underlying * packet buffer. Therefore, at load time, all checks on pointers * previously done by the verifier are invalidated and must be * performed again, if the helper is used in combination with * direct packet access. * * Returns * 0 on success, or a negative error in case of failure. */ static long (*bpf_lwt_seg6_adjust_srh)(struct __sk_buff *skb, __u32 offset, __s32 delta) = (void *) 75; /* * bpf_lwt_seg6_action * * Apply an IPv6 Segment Routing action of type *action* to the * packet associated to *skb*. Each action takes a parameter * contained at address *param*, and of length *param_len* bytes. * *action* can be one of: * * **SEG6_LOCAL_ACTION_END_X** * End.X action: Endpoint with Layer-3 cross-connect. * Type of *param*: **struct in6_addr**. * **SEG6_LOCAL_ACTION_END_T** * End.T action: Endpoint with specific IPv6 table lookup. * Type of *param*: **int**. * **SEG6_LOCAL_ACTION_END_B6** * End.B6 action: Endpoint bound to an SRv6 policy. * Type of *param*: **struct ipv6_sr_hdr**. * **SEG6_LOCAL_ACTION_END_B6_ENCAP** * End.B6.Encap action: Endpoint bound to an SRv6 * encapsulation policy. * Type of *param*: **struct ipv6_sr_hdr**. * * A call to this helper is susceptible to change the underlying * packet buffer. Therefore, at load time, all checks on pointers * previously done by the verifier are invalidated and must be * performed again, if the helper is used in combination with * direct packet access. * * Returns * 0 on success, or a negative error in case of failure. */ static long (*bpf_lwt_seg6_action)(struct __sk_buff *skb, __u32 action, void *param, __u32 param_len) = (void *) 76; /* * bpf_rc_repeat * * This helper is used in programs implementing IR decoding, to * report a successfully decoded repeat key message. This delays * the generation of a key up event for previously generated * key down event. * * Some IR protocols like NEC have a special IR message for * repeating last button, for when a button is held down. * * The *ctx* should point to the lirc sample as passed into * the program. * * This helper is only available is the kernel was compiled with * the **CONFIG_BPF_LIRC_MODE2** configuration option set to * "**y**". * * Returns * 0 */ static long (*bpf_rc_repeat)(void *ctx) = (void *) 77; /* * bpf_rc_keydown * * This helper is used in programs implementing IR decoding, to * report a successfully decoded key press with *scancode*, * *toggle* value in the given *protocol*. The scancode will be * translated to a keycode using the rc keymap, and reported as * an input key down event. After a period a key up event is * generated. This period can be extended by calling either * **bpf_rc_keydown**\ () again with the same values, or calling * **bpf_rc_repeat**\ (). * * Some protocols include a toggle bit, in case the button was * released and pressed again between consecutive scancodes. * * The *ctx* should point to the lirc sample as passed into * the program. * * The *protocol* is the decoded protocol number (see * **enum rc_proto** for some predefined values). * * This helper is only available is the kernel was compiled with * the **CONFIG_BPF_LIRC_MODE2** configuration option set to * "**y**". * * Returns * 0 */ static long (*bpf_rc_keydown)(void *ctx, __u32 protocol, __u64 scancode, __u32 toggle) = (void *) 78; /* * bpf_skb_cgroup_id * * Return the cgroup v2 id of the socket associated with the *skb*. * This is roughly similar to the **bpf_get_cgroup_classid**\ () * helper for cgroup v1 by providing a tag resp. identifier that * can be matched on or used for map lookups e.g. to implement * policy. The cgroup v2 id of a given path in the hierarchy is * exposed in user space through the f_handle API in order to get * to the same 64-bit id. * * This helper can be used on TC egress path, but not on ingress, * and is available only if the kernel was compiled with the * **CONFIG_SOCK_CGROUP_DATA** configuration option. * * Returns * The id is returned or 0 in case the id could not be retrieved. */ static __u64 (*bpf_skb_cgroup_id)(struct __sk_buff *skb) = (void *) 79; /* * bpf_get_current_cgroup_id * * Get the current cgroup id based on the cgroup within which * the current task is running. * * Returns * A 64-bit integer containing the current cgroup id based * on the cgroup within which the current task is running. */ static __u64 (*bpf_get_current_cgroup_id)(void) = (void *) 80; /* * bpf_get_local_storage * * Get the pointer to the local storage area. * The type and the size of the local storage is defined * by the *map* argument. * The *flags* meaning is specific for each map type, * and has to be 0 for cgroup local storage. * * Depending on the BPF program type, a local storage area * can be shared between multiple instances of the BPF program, * running simultaneously. * * A user should care about the synchronization by himself. * For example, by using the **BPF_ATOMIC** instructions to alter * the shared data. * * Returns * A pointer to the local storage area. */ static void *(*bpf_get_local_storage)(void *map, __u64 flags) = (void *) 81; /* * bpf_sk_select_reuseport * * Select a **SO_REUSEPORT** socket from a * **BPF_MAP_TYPE_REUSEPORT_SOCKARRAY** *map*. * It checks the selected socket is matching the incoming * request in the socket buffer. * * Returns * 0 on success, or a negative error in case of failure. */ static long (*bpf_sk_select_reuseport)(struct sk_reuseport_md *reuse, void *map, void *key, __u64 flags) = (void *) 82; /* * bpf_skb_ancestor_cgroup_id * * Return id of cgroup v2 that is ancestor of cgroup associated * with the *skb* at the *ancestor_level*. The root cgroup is at * *ancestor_level* zero and each step down the hierarchy * increments the level. If *ancestor_level* == level of cgroup * associated with *skb*, then return value will be same as that * of **bpf_skb_cgroup_id**\ (). * * The helper is useful to implement policies based on cgroups * that are upper in hierarchy than immediate cgroup associated * with *skb*. * * The format of returned id and helper limitations are same as in * **bpf_skb_cgroup_id**\ (). * * Returns * The id is returned or 0 in case the id could not be retrieved. */ static __u64 (*bpf_skb_ancestor_cgroup_id)(struct __sk_buff *skb, int ancestor_level) = (void *) 83; /* * bpf_sk_lookup_tcp * * Look for TCP socket matching *tuple*, optionally in a child * network namespace *netns*. The return value must be checked, * and if non-**NULL**, released via **bpf_sk_release**\ (). * * The *ctx* should point to the context of the program, such as * the skb or socket (depending on the hook in use). This is used * to determine the base network namespace for the lookup. * * *tuple_size* must be one of: * * **sizeof**\ (*tuple*\ **->ipv4**) * Look for an IPv4 socket. * **sizeof**\ (*tuple*\ **->ipv6**) * Look for an IPv6 socket. * * If the *netns* is a negative signed 32-bit integer, then the * socket lookup table in the netns associated with the *ctx* * will be used. For the TC hooks, this is the netns of the device * in the skb. For socket hooks, this is the netns of the socket. * If *netns* is any other signed 32-bit value greater than or * equal to zero then it specifies the ID of the netns relative to * the netns associated with the *ctx*. *netns* values beyond the * range of 32-bit integers are reserved for future use. * * All values for *flags* are reserved for future usage, and must * be left at zero. * * This helper is available only if the kernel was compiled with * **CONFIG_NET** configuration option. * * Returns * Pointer to **struct bpf_sock**, or **NULL** in case of failure. * For sockets with reuseport option, the **struct bpf_sock** * result is from *reuse*\ **->socks**\ [] using the hash of the * tuple. */ static struct bpf_sock *(*bpf_sk_lookup_tcp)(void *ctx, struct bpf_sock_tuple *tuple, __u32 tuple_size, __u64 netns, __u64 flags) = (void *) 84; /* * bpf_sk_lookup_udp * * Look for UDP socket matching *tuple*, optionally in a child * network namespace *netns*. The return value must be checked, * and if non-**NULL**, released via **bpf_sk_release**\ (). * * The *ctx* should point to the context of the program, such as * the skb or socket (depending on the hook in use). This is used * to determine the base network namespace for the lookup. * * *tuple_size* must be one of: * * **sizeof**\ (*tuple*\ **->ipv4**) * Look for an IPv4 socket. * **sizeof**\ (*tuple*\ **->ipv6**) * Look for an IPv6 socket. * * If the *netns* is a negative signed 32-bit integer, then the * socket lookup table in the netns associated with the *ctx* * will be used. For the TC hooks, this is the netns of the device * in the skb. For socket hooks, this is the netns of the socket. * If *netns* is any other signed 32-bit value greater than or * equal to zero then it specifies the ID of the netns relative to * the netns associated with the *ctx*. *netns* values beyond the * range of 32-bit integers are reserved for future use. * * All values for *flags* are reserved for future usage, and must * be left at zero. * * This helper is available only if the kernel was compiled with * **CONFIG_NET** configuration option. * * Returns * Pointer to **struct bpf_sock**, or **NULL** in case of failure. * For sockets with reuseport option, the **struct bpf_sock** * result is from *reuse*\ **->socks**\ [] using the hash of the * tuple. */ static struct bpf_sock *(*bpf_sk_lookup_udp)(void *ctx, struct bpf_sock_tuple *tuple, __u32 tuple_size, __u64 netns, __u64 flags) = (void *) 85; /* * bpf_sk_release * * Release the reference held by *sock*. *sock* must be a * non-**NULL** pointer that was returned from * **bpf_sk_lookup_xxx**\ (). * * Returns * 0 on success, or a negative error in case of failure. */ static long (*bpf_sk_release)(void *sock) = (void *) 86; /* * bpf_map_push_elem * * Push an element *value* in *map*. *flags* is one of: * * **BPF_EXIST** * If the queue/stack is full, the oldest element is * removed to make room for this. * * Returns * 0 on success, or a negative error in case of failure. */ static long (*bpf_map_push_elem)(void *map, const void *value, __u64 flags) = (void *) 87; /* * bpf_map_pop_elem * * Pop an element from *map*. * * Returns * 0 on success, or a negative error in case of failure. */ static long (*bpf_map_pop_elem)(void *map, void *value) = (void *) 88; /* * bpf_map_peek_elem * * Get an element from *map* without removing it. * * Returns * 0 on success, or a negative error in case of failure. */ static long (*bpf_map_peek_elem)(void *map, void *value) = (void *) 89; /* * bpf_msg_push_data * * For socket policies, insert *len* bytes into *msg* at offset * *start*. * * If a program of type **BPF_PROG_TYPE_SK_MSG** is run on a * *msg* it may want to insert metadata or options into the *msg*. * This can later be read and used by any of the lower layer BPF * hooks. * * This helper may fail if under memory pressure (a malloc * fails) in these cases BPF programs will get an appropriate * error and BPF programs will need to handle them. * * Returns * 0 on success, or a negative error in case of failure. */ static long (*bpf_msg_push_data)(struct sk_msg_md *msg, __u32 start, __u32 len, __u64 flags) = (void *) 90; /* * bpf_msg_pop_data * * Will remove *len* bytes from a *msg* starting at byte *start*. * This may result in **ENOMEM** errors under certain situations if * an allocation and copy are required due to a full ring buffer. * However, the helper will try to avoid doing the allocation * if possible. Other errors can occur if input parameters are * invalid either due to *start* byte not being valid part of *msg* * payload and/or *pop* value being to large. * * Returns * 0 on success, or a negative error in case of failure. */ static long (*bpf_msg_pop_data)(struct sk_msg_md *msg, __u32 start, __u32 len, __u64 flags) = (void *) 91; /* * bpf_rc_pointer_rel * * This helper is used in programs implementing IR decoding, to * report a successfully decoded pointer movement. * * The *ctx* should point to the lirc sample as passed into * the program. * * This helper is only available is the kernel was compiled with * the **CONFIG_BPF_LIRC_MODE2** configuration option set to * "**y**". * * Returns * 0 */ static long (*bpf_rc_pointer_rel)(void *ctx, __s32 rel_x, __s32 rel_y) = (void *) 92; /* * bpf_spin_lock * * Acquire a spinlock represented by the pointer *lock*, which is * stored as part of a value of a map. Taking the lock allows to * safely update the rest of the fields in that value. The * spinlock can (and must) later be released with a call to * **bpf_spin_unlock**\ (\ *lock*\ ). * * Spinlocks in BPF programs come with a number of restrictions * and constraints: * * * **bpf_spin_lock** objects are only allowed inside maps of * types **BPF_MAP_TYPE_HASH** and **BPF_MAP_TYPE_ARRAY** (this * list could be extended in the future). * * BTF description of the map is mandatory. * * The BPF program can take ONE lock at a time, since taking two * or more could cause dead locks. * * Only one **struct bpf_spin_lock** is allowed per map element. * * When the lock is taken, calls (either BPF to BPF or helpers) * are not allowed. * * The **BPF_LD_ABS** and **BPF_LD_IND** instructions are not * allowed inside a spinlock-ed region. * * The BPF program MUST call **bpf_spin_unlock**\ () to release * the lock, on all execution paths, before it returns. * * The BPF program can access **struct bpf_spin_lock** only via * the **bpf_spin_lock**\ () and **bpf_spin_unlock**\ () * helpers. Loading or storing data into the **struct * bpf_spin_lock** *lock*\ **;** field of a map is not allowed. * * To use the **bpf_spin_lock**\ () helper, the BTF description * of the map value must be a struct and have **struct * bpf_spin_lock** *anyname*\ **;** field at the top level. * Nested lock inside another struct is not allowed. * * The **struct bpf_spin_lock** *lock* field in a map value must * be aligned on a multiple of 4 bytes in that value. * * Syscall with command **BPF_MAP_LOOKUP_ELEM** does not copy * the **bpf_spin_lock** field to user space. * * Syscall with command **BPF_MAP_UPDATE_ELEM**, or update from * a BPF program, do not update the **bpf_spin_lock** field. * * **bpf_spin_lock** cannot be on the stack or inside a * networking packet (it can only be inside of a map values). * * **bpf_spin_lock** is available to root only. * * Tracing programs and socket filter programs cannot use * **bpf_spin_lock**\ () due to insufficient preemption checks * (but this may change in the future). * * **bpf_spin_lock** is not allowed in inner maps of map-in-map. * * Returns * 0 */ static long (*bpf_spin_lock)(struct bpf_spin_lock *lock) = (void *) 93; /* * bpf_spin_unlock * * Release the *lock* previously locked by a call to * **bpf_spin_lock**\ (\ *lock*\ ). * * Returns * 0 */ static long (*bpf_spin_unlock)(struct bpf_spin_lock *lock) = (void *) 94; /* * bpf_sk_fullsock * * This helper gets a **struct bpf_sock** pointer such * that all the fields in this **bpf_sock** can be accessed. * * Returns * A **struct bpf_sock** pointer on success, or **NULL** in * case of failure. */ static struct bpf_sock *(*bpf_sk_fullsock)(struct bpf_sock *sk) = (void *) 95; /* * bpf_tcp_sock * * This helper gets a **struct bpf_tcp_sock** pointer from a * **struct bpf_sock** pointer. * * Returns * A **struct bpf_tcp_sock** pointer on success, or **NULL** in * case of failure. */ static struct bpf_tcp_sock *(*bpf_tcp_sock)(struct bpf_sock *sk) = (void *) 96; /* * bpf_skb_ecn_set_ce * * Set ECN (Explicit Congestion Notification) field of IP header * to **CE** (Congestion Encountered) if current value is **ECT** * (ECN Capable Transport). Otherwise, do nothing. Works with IPv6 * and IPv4. * * Returns * 1 if the **CE** flag is set (either by the current helper call * or because it was already present), 0 if it is not set. */ static long (*bpf_skb_ecn_set_ce)(struct __sk_buff *skb) = (void *) 97; /* * bpf_get_listener_sock * * Return a **struct bpf_sock** pointer in **TCP_LISTEN** state. * **bpf_sk_release**\ () is unnecessary and not allowed. * * Returns * A **struct bpf_sock** pointer on success, or **NULL** in * case of failure. */ static struct bpf_sock *(*bpf_get_listener_sock)(struct bpf_sock *sk) = (void *) 98; /* * bpf_skc_lookup_tcp * * Look for TCP socket matching *tuple*, optionally in a child * network namespace *netns*. The return value must be checked, * and if non-**NULL**, released via **bpf_sk_release**\ (). * * This function is identical to **bpf_sk_lookup_tcp**\ (), except * that it also returns timewait or request sockets. Use * **bpf_sk_fullsock**\ () or **bpf_tcp_sock**\ () to access the * full structure. * * This helper is available only if the kernel was compiled with * **CONFIG_NET** configuration option. * * Returns * Pointer to **struct bpf_sock**, or **NULL** in case of failure. * For sockets with reuseport option, the **struct bpf_sock** * result is from *reuse*\ **->socks**\ [] using the hash of the * tuple. */ static struct bpf_sock *(*bpf_skc_lookup_tcp)(void *ctx, struct bpf_sock_tuple *tuple, __u32 tuple_size, __u64 netns, __u64 flags) = (void *) 99; /* * bpf_tcp_check_syncookie * * Check whether *iph* and *th* contain a valid SYN cookie ACK for * the listening socket in *sk*. * * *iph* points to the start of the IPv4 or IPv6 header, while * *iph_len* contains **sizeof**\ (**struct iphdr**) or * **sizeof**\ (**struct ipv6hdr**). * * *th* points to the start of the TCP header, while *th_len* * contains the length of the TCP header (at least * **sizeof**\ (**struct tcphdr**)). * * Returns * 0 if *iph* and *th* are a valid SYN cookie ACK, or a negative * error otherwise. */ static long (*bpf_tcp_check_syncookie)(void *sk, void *iph, __u32 iph_len, struct tcphdr *th, __u32 th_len) = (void *) 100; /* * bpf_sysctl_get_name * * Get name of sysctl in /proc/sys/ and copy it into provided by * program buffer *buf* of size *buf_len*. * * The buffer is always NUL terminated, unless it's zero-sized. * * If *flags* is zero, full name (e.g. "net/ipv4/tcp_mem") is * copied. Use **BPF_F_SYSCTL_BASE_NAME** flag to copy base name * only (e.g. "tcp_mem"). * * Returns * Number of character copied (not including the trailing NUL). * * **-E2BIG** if the buffer wasn't big enough (*buf* will contain * truncated name in this case). */ static long (*bpf_sysctl_get_name)(struct bpf_sysctl *ctx, char *buf, unsigned long buf_len, __u64 flags) = (void *) 101; /* * bpf_sysctl_get_current_value * * Get current value of sysctl as it is presented in /proc/sys * (incl. newline, etc), and copy it as a string into provided * by program buffer *buf* of size *buf_len*. * * The whole value is copied, no matter what file position user * space issued e.g. sys_read at. * * The buffer is always NUL terminated, unless it's zero-sized. * * Returns * Number of character copied (not including the trailing NUL). * * **-E2BIG** if the buffer wasn't big enough (*buf* will contain * truncated name in this case). * * **-EINVAL** if current value was unavailable, e.g. because * sysctl is uninitialized and read returns -EIO for it. */ static long (*bpf_sysctl_get_current_value)(struct bpf_sysctl *ctx, char *buf, unsigned long buf_len) = (void *) 102; /* * bpf_sysctl_get_new_value * * Get new value being written by user space to sysctl (before * the actual write happens) and copy it as a string into * provided by program buffer *buf* of size *buf_len*. * * User space may write new value at file position > 0. * * The buffer is always NUL terminated, unless it's zero-sized. * * Returns * Number of character copied (not including the trailing NUL). * * **-E2BIG** if the buffer wasn't big enough (*buf* will contain * truncated name in this case). * * **-EINVAL** if sysctl is being read. */ static long (*bpf_sysctl_get_new_value)(struct bpf_sysctl *ctx, char *buf, unsigned long buf_len) = (void *) 103; /* * bpf_sysctl_set_new_value * * Override new value being written by user space to sysctl with * value provided by program in buffer *buf* of size *buf_len*. * * *buf* should contain a string in same form as provided by user * space on sysctl write. * * User space may write new value at file position > 0. To override * the whole sysctl value file position should be set to zero. * * Returns * 0 on success. * * **-E2BIG** if the *buf_len* is too big. * * **-EINVAL** if sysctl is being read. */ static long (*bpf_sysctl_set_new_value)(struct bpf_sysctl *ctx, const char *buf, unsigned long buf_len) = (void *) 104; /* * bpf_strtol * * Convert the initial part of the string from buffer *buf* of * size *buf_len* to a long integer according to the given base * and save the result in *res*. * * The string may begin with an arbitrary amount of white space * (as determined by **isspace**\ (3)) followed by a single * optional '**-**' sign. * * Five least significant bits of *flags* encode base, other bits * are currently unused. * * Base must be either 8, 10, 16 or 0 to detect it automatically * similar to user space **strtol**\ (3). * * Returns * Number of characters consumed on success. Must be positive but * no more than *buf_len*. * * **-EINVAL** if no valid digits were found or unsupported base * was provided. * * **-ERANGE** if resulting value was out of range. */ static long (*bpf_strtol)(const char *buf, unsigned long buf_len, __u64 flags, long *res) = (void *) 105; /* * bpf_strtoul * * Convert the initial part of the string from buffer *buf* of * size *buf_len* to an unsigned long integer according to the * given base and save the result in *res*. * * The string may begin with an arbitrary amount of white space * (as determined by **isspace**\ (3)). * * Five least significant bits of *flags* encode base, other bits * are currently unused. * * Base must be either 8, 10, 16 or 0 to detect it automatically * similar to user space **strtoul**\ (3). * * Returns * Number of characters consumed on success. Must be positive but * no more than *buf_len*. * * **-EINVAL** if no valid digits were found or unsupported base * was provided. * * **-ERANGE** if resulting value was out of range. */ static long (*bpf_strtoul)(const char *buf, unsigned long buf_len, __u64 flags, unsigned long *res) = (void *) 106; /* * bpf_sk_storage_get * * Get a bpf-local-storage from a *sk*. * * Logically, it could be thought of getting the value from * a *map* with *sk* as the **key**. From this * perspective, the usage is not much different from * **bpf_map_lookup_elem**\ (*map*, **&**\ *sk*) except this * helper enforces the key must be a full socket and the map must * be a **BPF_MAP_TYPE_SK_STORAGE** also. * * Underneath, the value is stored locally at *sk* instead of * the *map*. The *map* is used as the bpf-local-storage * "type". The bpf-local-storage "type" (i.e. the *map*) is * searched against all bpf-local-storages residing at *sk*. * * *sk* is a kernel **struct sock** pointer for LSM program. * *sk* is a **struct bpf_sock** pointer for other program types. * * An optional *flags* (**BPF_SK_STORAGE_GET_F_CREATE**) can be * used such that a new bpf-local-storage will be * created if one does not exist. *value* can be used * together with **BPF_SK_STORAGE_GET_F_CREATE** to specify * the initial value of a bpf-local-storage. If *value* is * **NULL**, the new bpf-local-storage will be zero initialized. * * Returns * A bpf-local-storage pointer is returned on success. * * **NULL** if not found or there was an error in adding * a new bpf-local-storage. */ static void *(*bpf_sk_storage_get)(void *map, void *sk, void *value, __u64 flags) = (void *) 107; /* * bpf_sk_storage_delete * * Delete a bpf-local-storage from a *sk*. * * Returns * 0 on success. * * **-ENOENT** if the bpf-local-storage cannot be found. * **-EINVAL** if sk is not a fullsock (e.g. a request_sock). */ static long (*bpf_sk_storage_delete)(void *map, void *sk) = (void *) 108; /* * bpf_send_signal * * Send signal *sig* to the process of the current task. * The signal may be delivered to any of this process's threads. * * Returns * 0 on success or successfully queued. * * **-EBUSY** if work queue under nmi is full. * * **-EINVAL** if *sig* is invalid. * * **-EPERM** if no permission to send the *sig*. * * **-EAGAIN** if bpf program can try again. */ static long (*bpf_send_signal)(__u32 sig) = (void *) 109; /* * bpf_tcp_gen_syncookie * * Try to issue a SYN cookie for the packet with corresponding * IP/TCP headers, *iph* and *th*, on the listening socket in *sk*. * * *iph* points to the start of the IPv4 or IPv6 header, while * *iph_len* contains **sizeof**\ (**struct iphdr**) or * **sizeof**\ (**struct ipv6hdr**). * * *th* points to the start of the TCP header, while *th_len* * contains the length of the TCP header with options (at least * **sizeof**\ (**struct tcphdr**)). * * Returns * On success, lower 32 bits hold the generated SYN cookie in * followed by 16 bits which hold the MSS value for that cookie, * and the top 16 bits are unused. * * On failure, the returned value is one of the following: * * **-EINVAL** SYN cookie cannot be issued due to error * * **-ENOENT** SYN cookie should not be issued (no SYN flood) * * **-EOPNOTSUPP** kernel configuration does not enable SYN cookies * * **-EPROTONOSUPPORT** IP packet version is not 4 or 6 */ static __s64 (*bpf_tcp_gen_syncookie)(void *sk, void *iph, __u32 iph_len, struct tcphdr *th, __u32 th_len) = (void *) 110; /* * bpf_skb_output * * Write raw *data* blob into a special BPF perf event held by * *map* of type **BPF_MAP_TYPE_PERF_EVENT_ARRAY**. This perf * event must have the following attributes: **PERF_SAMPLE_RAW** * as **sample_type**, **PERF_TYPE_SOFTWARE** as **type**, and * **PERF_COUNT_SW_BPF_OUTPUT** as **config**. * * The *flags* are used to indicate the index in *map* for which * the value must be put, masked with **BPF_F_INDEX_MASK**. * Alternatively, *flags* can be set to **BPF_F_CURRENT_CPU** * to indicate that the index of the current CPU core should be * used. * * The value to write, of *size*, is passed through eBPF stack and * pointed by *data*. * * *ctx* is a pointer to in-kernel struct sk_buff. * * This helper is similar to **bpf_perf_event_output**\ () but * restricted to raw_tracepoint bpf programs. * * Returns * 0 on success, or a negative error in case of failure. */ static long (*bpf_skb_output)(void *ctx, void *map, __u64 flags, void *data, __u64 size) = (void *) 111; /* * bpf_probe_read_user * * Safely attempt to read *size* bytes from user space address * *unsafe_ptr* and store the data in *dst*. * * Returns * 0 on success, or a negative error in case of failure. */ static long (*bpf_probe_read_user)(void *dst, __u32 size, const void *unsafe_ptr) = (void *) 112; /* * bpf_probe_read_kernel * * Safely attempt to read *size* bytes from kernel space address * *unsafe_ptr* and store the data in *dst*. * * Returns * 0 on success, or a negative error in case of failure. */ static long (*bpf_probe_read_kernel)(void *dst, __u32 size, const void *unsafe_ptr) = (void *) 113; /* * bpf_probe_read_user_str * * Copy a NUL terminated string from an unsafe user address * *unsafe_ptr* to *dst*. The *size* should include the * terminating NUL byte. In case the string length is smaller than * *size*, the target is not padded with further NUL bytes. If the * string length is larger than *size*, just *size*-1 bytes are * copied and the last byte is set to NUL. * * On success, returns the number of bytes that were written, * including the terminal NUL. This makes this helper useful in * tracing programs for reading strings, and more importantly to * get its length at runtime. See the following snippet: * * :: * * SEC("kprobe/sys_open") * void bpf_sys_open(struct pt_regs *ctx) * { * char buf[PATHLEN]; // PATHLEN is defined to 256 * int res = bpf_probe_read_user_str(buf, sizeof(buf), * ctx->di); * * // Consume buf, for example push it to * // userspace via bpf_perf_event_output(); we * // can use res (the string length) as event * // size, after checking its boundaries. * } * * In comparison, using **bpf_probe_read_user**\ () helper here * instead to read the string would require to estimate the length * at compile time, and would often result in copying more memory * than necessary. * * Another useful use case is when parsing individual process * arguments or individual environment variables navigating * *current*\ **->mm->arg_start** and *current*\ * **->mm->env_start**: using this helper and the return value, * one can quickly iterate at the right offset of the memory area. * * Returns * On success, the strictly positive length of the output string, * including the trailing NUL character. On error, a negative * value. */ static long (*bpf_probe_read_user_str)(void *dst, __u32 size, const void *unsafe_ptr) = (void *) 114; /* * bpf_probe_read_kernel_str * * Copy a NUL terminated string from an unsafe kernel address *unsafe_ptr* * to *dst*. Same semantics as with **bpf_probe_read_user_str**\ () apply. * * Returns * On success, the strictly positive length of the string, including * the trailing NUL character. On error, a negative value. */ static long (*bpf_probe_read_kernel_str)(void *dst, __u32 size, const void *unsafe_ptr) = (void *) 115; /* * bpf_tcp_send_ack * * Send out a tcp-ack. *tp* is the in-kernel struct **tcp_sock**. * *rcv_nxt* is the ack_seq to be sent out. * * Returns * 0 on success, or a negative error in case of failure. */ static long (*bpf_tcp_send_ack)(void *tp, __u32 rcv_nxt) = (void *) 116; /* * bpf_send_signal_thread * * Send signal *sig* to the thread corresponding to the current task. * * Returns * 0 on success or successfully queued. * * **-EBUSY** if work queue under nmi is full. * * **-EINVAL** if *sig* is invalid. * * **-EPERM** if no permission to send the *sig*. * * **-EAGAIN** if bpf program can try again. */ static long (*bpf_send_signal_thread)(__u32 sig) = (void *) 117; /* * bpf_jiffies64 * * Obtain the 64bit jiffies * * Returns * The 64 bit jiffies */ static __u64 (*bpf_jiffies64)(void) = (void *) 118; /* * bpf_read_branch_records * * For an eBPF program attached to a perf event, retrieve the * branch records (**struct perf_branch_entry**) associated to *ctx* * and store it in the buffer pointed by *buf* up to size * *size* bytes. * * Returns * On success, number of bytes written to *buf*. On error, a * negative value. * * The *flags* can be set to **BPF_F_GET_BRANCH_RECORDS_SIZE** to * instead return the number of bytes required to store all the * branch entries. If this flag is set, *buf* may be NULL. * * **-EINVAL** if arguments invalid or **size** not a multiple * of **sizeof**\ (**struct perf_branch_entry**\ ). * * **-ENOENT** if architecture does not support branch records. */ static long (*bpf_read_branch_records)(struct bpf_perf_event_data *ctx, void *buf, __u32 size, __u64 flags) = (void *) 119; /* * bpf_get_ns_current_pid_tgid * * Returns 0 on success, values for *pid* and *tgid* as seen from the current * *namespace* will be returned in *nsdata*. * * Returns * 0 on success, or one of the following in case of failure: * * **-EINVAL** if dev and inum supplied don't match dev_t and inode number * with nsfs of current task, or if dev conversion to dev_t lost high bits. * * **-ENOENT** if pidns does not exists for the current task. */ static long (*bpf_get_ns_current_pid_tgid)(__u64 dev, __u64 ino, struct bpf_pidns_info *nsdata, __u32 size) = (void *) 120; /* * bpf_xdp_output * * Write raw *data* blob into a special BPF perf event held by * *map* of type **BPF_MAP_TYPE_PERF_EVENT_ARRAY**. This perf * event must have the following attributes: **PERF_SAMPLE_RAW** * as **sample_type**, **PERF_TYPE_SOFTWARE** as **type**, and * **PERF_COUNT_SW_BPF_OUTPUT** as **config**. * * The *flags* are used to indicate the index in *map* for which * the value must be put, masked with **BPF_F_INDEX_MASK**. * Alternatively, *flags* can be set to **BPF_F_CURRENT_CPU** * to indicate that the index of the current CPU core should be * used. * * The value to write, of *size*, is passed through eBPF stack and * pointed by *data*. * * *ctx* is a pointer to in-kernel struct xdp_buff. * * This helper is similar to **bpf_perf_eventoutput**\ () but * restricted to raw_tracepoint bpf programs. * * Returns * 0 on success, or a negative error in case of failure. */ static long (*bpf_xdp_output)(void *ctx, void *map, __u64 flags, void *data, __u64 size) = (void *) 121; /* * bpf_get_netns_cookie * * Retrieve the cookie (generated by the kernel) of the network * namespace the input *ctx* is associated with. The network * namespace cookie remains stable for its lifetime and provides * a global identifier that can be assumed unique. If *ctx* is * NULL, then the helper returns the cookie for the initial * network namespace. The cookie itself is very similar to that * of **bpf_get_socket_cookie**\ () helper, but for network * namespaces instead of sockets. * * Returns * A 8-byte long opaque number. */ static __u64 (*bpf_get_netns_cookie)(void *ctx) = (void *) 122; /* * bpf_get_current_ancestor_cgroup_id * * Return id of cgroup v2 that is ancestor of the cgroup associated * with the current task at the *ancestor_level*. The root cgroup * is at *ancestor_level* zero and each step down the hierarchy * increments the level. If *ancestor_level* == level of cgroup * associated with the current task, then return value will be the * same as that of **bpf_get_current_cgroup_id**\ (). * * The helper is useful to implement policies based on cgroups * that are upper in hierarchy than immediate cgroup associated * with the current task. * * The format of returned id and helper limitations are same as in * **bpf_get_current_cgroup_id**\ (). * * Returns * The id is returned or 0 in case the id could not be retrieved. */ static __u64 (*bpf_get_current_ancestor_cgroup_id)(int ancestor_level) = (void *) 123; /* * bpf_sk_assign * * Helper is overloaded depending on BPF program type. This * description applies to **BPF_PROG_TYPE_SCHED_CLS** and * **BPF_PROG_TYPE_SCHED_ACT** programs. * * Assign the *sk* to the *skb*. When combined with appropriate * routing configuration to receive the packet towards the socket, * will cause *skb* to be delivered to the specified socket. * Subsequent redirection of *skb* via **bpf_redirect**\ (), * **bpf_clone_redirect**\ () or other methods outside of BPF may * interfere with successful delivery to the socket. * * This operation is only valid from TC ingress path. * * The *flags* argument must be zero. * * Returns * 0 on success, or a negative error in case of failure: * * **-EINVAL** if specified *flags* are not supported. * * **-ENOENT** if the socket is unavailable for assignment. * * **-ENETUNREACH** if the socket is unreachable (wrong netns). * * **-EOPNOTSUPP** if the operation is not supported, for example * a call from outside of TC ingress. */ static long (*bpf_sk_assign)(void *ctx, void *sk, __u64 flags) = (void *) 124; /* * bpf_ktime_get_boot_ns * * Return the time elapsed since system boot, in nanoseconds. * Does include the time the system was suspended. * See: **clock_gettime**\ (**CLOCK_BOOTTIME**) * * Returns * Current *ktime*. */ static __u64 (*bpf_ktime_get_boot_ns)(void) = (void *) 125; /* * bpf_seq_printf * * **bpf_seq_printf**\ () uses seq_file **seq_printf**\ () to print * out the format string. * The *m* represents the seq_file. The *fmt* and *fmt_size* are for * the format string itself. The *data* and *data_len* are format string * arguments. The *data* are a **u64** array and corresponding format string * values are stored in the array. For strings and pointers where pointees * are accessed, only the pointer values are stored in the *data* array. * The *data_len* is the size of *data* in bytes - must be a multiple of 8. * * Formats **%s**, **%p{i,I}{4,6}** requires to read kernel memory. * Reading kernel memory may fail due to either invalid address or * valid address but requiring a major memory fault. If reading kernel memory * fails, the string for **%s** will be an empty string, and the ip * address for **%p{i,I}{4,6}** will be 0. Not returning error to * bpf program is consistent with what **bpf_trace_printk**\ () does for now. * * Returns * 0 on success, or a negative error in case of failure: * * **-EBUSY** if per-CPU memory copy buffer is busy, can try again * by returning 1 from bpf program. * * **-EINVAL** if arguments are invalid, or if *fmt* is invalid/unsupported. * * **-E2BIG** if *fmt* contains too many format specifiers. * * **-EOVERFLOW** if an overflow happened: The same object will be tried again. */ static long (*bpf_seq_printf)(struct seq_file *m, const char *fmt, __u32 fmt_size, const void *data, __u32 data_len) = (void *) 126; /* * bpf_seq_write * * **bpf_seq_write**\ () uses seq_file **seq_write**\ () to write the data. * The *m* represents the seq_file. The *data* and *len* represent the * data to write in bytes. * * Returns * 0 on success, or a negative error in case of failure: * * **-EOVERFLOW** if an overflow happened: The same object will be tried again. */ static long (*bpf_seq_write)(struct seq_file *m, const void *data, __u32 len) = (void *) 127; /* * bpf_sk_cgroup_id * * Return the cgroup v2 id of the socket *sk*. * * *sk* must be a non-**NULL** pointer to a socket, e.g. one * returned from **bpf_sk_lookup_xxx**\ (), * **bpf_sk_fullsock**\ (), etc. The format of returned id is * same as in **bpf_skb_cgroup_id**\ (). * * This helper is available only if the kernel was compiled with * the **CONFIG_SOCK_CGROUP_DATA** configuration option. * * Returns * The id is returned or 0 in case the id could not be retrieved. */ static __u64 (*bpf_sk_cgroup_id)(void *sk) = (void *) 128; /* * bpf_sk_ancestor_cgroup_id * * Return id of cgroup v2 that is ancestor of cgroup associated * with the *sk* at the *ancestor_level*. The root cgroup is at * *ancestor_level* zero and each step down the hierarchy * increments the level. If *ancestor_level* == level of cgroup * associated with *sk*, then return value will be same as that * of **bpf_sk_cgroup_id**\ (). * * The helper is useful to implement policies based on cgroups * that are upper in hierarchy than immediate cgroup associated * with *sk*. * * The format of returned id and helper limitations are same as in * **bpf_sk_cgroup_id**\ (). * * Returns * The id is returned or 0 in case the id could not be retrieved. */ static __u64 (*bpf_sk_ancestor_cgroup_id)(void *sk, int ancestor_level) = (void *) 129; /* * bpf_ringbuf_output * * Copy *size* bytes from *data* into a ring buffer *ringbuf*. * If **BPF_RB_NO_WAKEUP** is specified in *flags*, no notification * of new data availability is sent. * If **BPF_RB_FORCE_WAKEUP** is specified in *flags*, notification * of new data availability is sent unconditionally. * If **0** is specified in *flags*, an adaptive notification * of new data availability is sent. * * An adaptive notification is a notification sent whenever the user-space * process has caught up and consumed all available payloads. In case the user-space * process is still processing a previous payload, then no notification is needed * as it will process the newly added payload automatically. * * Returns * 0 on success, or a negative error in case of failure. */ static long (*bpf_ringbuf_output)(void *ringbuf, void *data, __u64 size, __u64 flags) = (void *) 130; /* * bpf_ringbuf_reserve * * Reserve *size* bytes of payload in a ring buffer *ringbuf*. * *flags* must be 0. * * Returns * Valid pointer with *size* bytes of memory available; NULL, * otherwise. */ static void *(*bpf_ringbuf_reserve)(void *ringbuf, __u64 size, __u64 flags) = (void *) 131; /* * bpf_ringbuf_submit * * Submit reserved ring buffer sample, pointed to by *data*. * If **BPF_RB_NO_WAKEUP** is specified in *flags*, no notification * of new data availability is sent. * If **BPF_RB_FORCE_WAKEUP** is specified in *flags*, notification * of new data availability is sent unconditionally. * If **0** is specified in *flags*, an adaptive notification * of new data availability is sent. * * See 'bpf_ringbuf_output()' for the definition of adaptive notification. * * Returns * Nothing. Always succeeds. */ static void (*bpf_ringbuf_submit)(void *data, __u64 flags) = (void *) 132; /* * bpf_ringbuf_discard * * Discard reserved ring buffer sample, pointed to by *data*. * If **BPF_RB_NO_WAKEUP** is specified in *flags*, no notification * of new data availability is sent. * If **BPF_RB_FORCE_WAKEUP** is specified in *flags*, notification * of new data availability is sent unconditionally. * If **0** is specified in *flags*, an adaptive notification * of new data availability is sent. * * See 'bpf_ringbuf_output()' for the definition of adaptive notification. * * Returns * Nothing. Always succeeds. */ static void (*bpf_ringbuf_discard)(void *data, __u64 flags) = (void *) 133; /* * bpf_ringbuf_query * * Query various characteristics of provided ring buffer. What * exactly is queries is determined by *flags*: * * * **BPF_RB_AVAIL_DATA**: Amount of data not yet consumed. * * **BPF_RB_RING_SIZE**: The size of ring buffer. * * **BPF_RB_CONS_POS**: Consumer position (can wrap around). * * **BPF_RB_PROD_POS**: Producer(s) position (can wrap around). * * Data returned is just a momentary snapshot of actual values * and could be inaccurate, so this facility should be used to * power heuristics and for reporting, not to make 100% correct * calculation. * * Returns * Requested value, or 0, if *flags* are not recognized. */ static __u64 (*bpf_ringbuf_query)(void *ringbuf, __u64 flags) = (void *) 134; /* * bpf_csum_level * * Change the skbs checksum level by one layer up or down, or * reset it entirely to none in order to have the stack perform * checksum validation. The level is applicable to the following * protocols: TCP, UDP, GRE, SCTP, FCOE. For example, a decap of * | ETH | IP | UDP | GUE | IP | TCP | into | ETH | IP | TCP | * through **bpf_skb_adjust_room**\ () helper with passing in * **BPF_F_ADJ_ROOM_NO_CSUM_RESET** flag would require one call * to **bpf_csum_level**\ () with **BPF_CSUM_LEVEL_DEC** since * the UDP header is removed. Similarly, an encap of the latter * into the former could be accompanied by a helper call to * **bpf_csum_level**\ () with **BPF_CSUM_LEVEL_INC** if the * skb is still intended to be processed in higher layers of the * stack instead of just egressing at tc. * * There are three supported level settings at this time: * * * **BPF_CSUM_LEVEL_INC**: Increases skb->csum_level for skbs * with CHECKSUM_UNNECESSARY. * * **BPF_CSUM_LEVEL_DEC**: Decreases skb->csum_level for skbs * with CHECKSUM_UNNECESSARY. * * **BPF_CSUM_LEVEL_RESET**: Resets skb->csum_level to 0 and * sets CHECKSUM_NONE to force checksum validation by the stack. * * **BPF_CSUM_LEVEL_QUERY**: No-op, returns the current * skb->csum_level. * * Returns * 0 on success, or a negative error in case of failure. In the * case of **BPF_CSUM_LEVEL_QUERY**, the current skb->csum_level * is returned or the error code -EACCES in case the skb is not * subject to CHECKSUM_UNNECESSARY. */ static long (*bpf_csum_level)(struct __sk_buff *skb, __u64 level) = (void *) 135; /* * bpf_skc_to_tcp6_sock * * Dynamically cast a *sk* pointer to a *tcp6_sock* pointer. * * Returns * *sk* if casting is valid, or **NULL** otherwise. */ static struct tcp6_sock *(*bpf_skc_to_tcp6_sock)(void *sk) = (void *) 136; /* * bpf_skc_to_tcp_sock * * Dynamically cast a *sk* pointer to a *tcp_sock* pointer. * * Returns * *sk* if casting is valid, or **NULL** otherwise. */ static struct tcp_sock *(*bpf_skc_to_tcp_sock)(void *sk) = (void *) 137; /* * bpf_skc_to_tcp_timewait_sock * * Dynamically cast a *sk* pointer to a *tcp_timewait_sock* pointer. * * Returns * *sk* if casting is valid, or **NULL** otherwise. */ static struct tcp_timewait_sock *(*bpf_skc_to_tcp_timewait_sock)(void *sk) = (void *) 138; /* * bpf_skc_to_tcp_request_sock * * Dynamically cast a *sk* pointer to a *tcp_request_sock* pointer. * * Returns * *sk* if casting is valid, or **NULL** otherwise. */ static struct tcp_request_sock *(*bpf_skc_to_tcp_request_sock)(void *sk) = (void *) 139; /* * bpf_skc_to_udp6_sock * * Dynamically cast a *sk* pointer to a *udp6_sock* pointer. * * Returns * *sk* if casting is valid, or **NULL** otherwise. */ static struct udp6_sock *(*bpf_skc_to_udp6_sock)(void *sk) = (void *) 140; /* * bpf_get_task_stack * * Return a user or a kernel stack in bpf program provided buffer. * Note: the user stack will only be populated if the *task* is * the current task; all other tasks will return -EOPNOTSUPP. * To achieve this, the helper needs *task*, which is a valid * pointer to **struct task_struct**. To store the stacktrace, the * bpf program provides *buf* with a nonnegative *size*. * * The last argument, *flags*, holds the number of stack frames to * skip (from 0 to 255), masked with * **BPF_F_SKIP_FIELD_MASK**. The next bits can be used to set * the following flags: * * **BPF_F_USER_STACK** * Collect a user space stack instead of a kernel stack. * The *task* must be the current task. * **BPF_F_USER_BUILD_ID** * Collect buildid+offset instead of ips for user stack, * only valid if **BPF_F_USER_STACK** is also specified. * * **bpf_get_task_stack**\ () can collect up to * **PERF_MAX_STACK_DEPTH** both kernel and user frames, subject * to sufficient large buffer size. Note that * this limit can be controlled with the **sysctl** program, and * that it should be manually increased in order to profile long * user stacks (such as stacks for Java programs). To do so, use: * * :: * * # sysctl kernel.perf_event_max_stack=<new value> * * Returns * The non-negative copied *buf* length equal to or less than * *size* on success, or a negative error in case of failure. */ static long (*bpf_get_task_stack)(struct task_struct *task, void *buf, __u32 size, __u64 flags) = (void *) 141; /* * bpf_load_hdr_opt * * Load header option. Support reading a particular TCP header * option for bpf program (**BPF_PROG_TYPE_SOCK_OPS**). * * If *flags* is 0, it will search the option from the * *skops*\ **->skb_data**. The comment in **struct bpf_sock_ops** * has details on what skb_data contains under different * *skops*\ **->op**. * * The first byte of the *searchby_res* specifies the * kind that it wants to search. * * If the searching kind is an experimental kind * (i.e. 253 or 254 according to RFC6994). It also * needs to specify the "magic" which is either * 2 bytes or 4 bytes. It then also needs to * specify the size of the magic by using * the 2nd byte which is "kind-length" of a TCP * header option and the "kind-length" also * includes the first 2 bytes "kind" and "kind-length" * itself as a normal TCP header option also does. * * For example, to search experimental kind 254 with * 2 byte magic 0xeB9F, the searchby_res should be * [ 254, 4, 0xeB, 0x9F, 0, 0, .... 0 ]. * * To search for the standard window scale option (3), * the *searchby_res* should be [ 3, 0, 0, .... 0 ]. * Note, kind-length must be 0 for regular option. * * Searching for No-Op (0) and End-of-Option-List (1) are * not supported. * * *len* must be at least 2 bytes which is the minimal size * of a header option. * * Supported flags: * * * **BPF_LOAD_HDR_OPT_TCP_SYN** to search from the * saved_syn packet or the just-received syn packet. * * * Returns * > 0 when found, the header option is copied to *searchby_res*. * The return value is the total length copied. On failure, a * negative error code is returned: * * **-EINVAL** if a parameter is invalid. * * **-ENOMSG** if the option is not found. * * **-ENOENT** if no syn packet is available when * **BPF_LOAD_HDR_OPT_TCP_SYN** is used. * * **-ENOSPC** if there is not enough space. Only *len* number of * bytes are copied. * * **-EFAULT** on failure to parse the header options in the * packet. * * **-EPERM** if the helper cannot be used under the current * *skops*\ **->op**. */ static long (*bpf_load_hdr_opt)(struct bpf_sock_ops *skops, void *searchby_res, __u32 len, __u64 flags) = (void *) 142; /* * bpf_store_hdr_opt * * Store header option. The data will be copied * from buffer *from* with length *len* to the TCP header. * * The buffer *from* should have the whole option that * includes the kind, kind-length, and the actual * option data. The *len* must be at least kind-length * long. The kind-length does not have to be 4 byte * aligned. The kernel will take care of the padding * and setting the 4 bytes aligned value to th->doff. * * This helper will check for duplicated option * by searching the same option in the outgoing skb. * * This helper can only be called during * **BPF_SOCK_OPS_WRITE_HDR_OPT_CB**. * * * Returns * 0 on success, or negative error in case of failure: * * **-EINVAL** If param is invalid. * * **-ENOSPC** if there is not enough space in the header. * Nothing has been written * * **-EEXIST** if the option already exists. * * **-EFAULT** on failure to parse the existing header options. * * **-EPERM** if the helper cannot be used under the current * *skops*\ **->op**. */ static long (*bpf_store_hdr_opt)(struct bpf_sock_ops *skops, const void *from, __u32 len, __u64 flags) = (void *) 143; /* * bpf_reserve_hdr_opt * * Reserve *len* bytes for the bpf header option. The * space will be used by **bpf_store_hdr_opt**\ () later in * **BPF_SOCK_OPS_WRITE_HDR_OPT_CB**. * * If **bpf_reserve_hdr_opt**\ () is called multiple times, * the total number of bytes will be reserved. * * This helper can only be called during * **BPF_SOCK_OPS_HDR_OPT_LEN_CB**. * * * Returns * 0 on success, or negative error in case of failure: * * **-EINVAL** if a parameter is invalid. * * **-ENOSPC** if there is not enough space in the header. * * **-EPERM** if the helper cannot be used under the current * *skops*\ **->op**. */ static long (*bpf_reserve_hdr_opt)(struct bpf_sock_ops *skops, __u32 len, __u64 flags) = (void *) 144; /* * bpf_inode_storage_get * * Get a bpf_local_storage from an *inode*. * * Logically, it could be thought of as getting the value from * a *map* with *inode* as the **key**. From this * perspective, the usage is not much different from * **bpf_map_lookup_elem**\ (*map*, **&**\ *inode*) except this * helper enforces the key must be an inode and the map must also * be a **BPF_MAP_TYPE_INODE_STORAGE**. * * Underneath, the value is stored locally at *inode* instead of * the *map*. The *map* is used as the bpf-local-storage * "type". The bpf-local-storage "type" (i.e. the *map*) is * searched against all bpf_local_storage residing at *inode*. * * An optional *flags* (**BPF_LOCAL_STORAGE_GET_F_CREATE**) can be * used such that a new bpf_local_storage will be * created if one does not exist. *value* can be used * together with **BPF_LOCAL_STORAGE_GET_F_CREATE** to specify * the initial value of a bpf_local_storage. If *value* is * **NULL**, the new bpf_local_storage will be zero initialized. * * Returns * A bpf_local_storage pointer is returned on success. * * **NULL** if not found or there was an error in adding * a new bpf_local_storage. */ static void *(*bpf_inode_storage_get)(void *map, void *inode, void *value, __u64 flags) = (void *) 145; /* * bpf_inode_storage_delete * * Delete a bpf_local_storage from an *inode*. * * Returns * 0 on success. * * **-ENOENT** if the bpf_local_storage cannot be found. */ static int (*bpf_inode_storage_delete)(void *map, void *inode) = (void *) 146; /* * bpf_d_path * * Return full path for given **struct path** object, which * needs to be the kernel BTF *path* object. The path is * returned in the provided buffer *buf* of size *sz* and * is zero terminated. * * * Returns * On success, the strictly positive length of the string, * including the trailing NUL character. On error, a negative * value. */ static long (*bpf_d_path)(struct path *path, char *buf, __u32 sz) = (void *) 147; /* * bpf_copy_from_user * * Read *size* bytes from user space address *user_ptr* and store * the data in *dst*. This is a wrapper of **copy_from_user**\ (). * * Returns * 0 on success, or a negative error in case of failure. */ static long (*bpf_copy_from_user)(void *dst, __u32 size, const void *user_ptr) = (void *) 148; /* * bpf_snprintf_btf * * Use BTF to store a string representation of *ptr*->ptr in *str*, * using *ptr*->type_id. This value should specify the type * that *ptr*->ptr points to. LLVM __builtin_btf_type_id(type, 1) * can be used to look up vmlinux BTF type ids. Traversing the * data structure using BTF, the type information and values are * stored in the first *str_size* - 1 bytes of *str*. Safe copy of * the pointer data is carried out to avoid kernel crashes during * operation. Smaller types can use string space on the stack; * larger programs can use map data to store the string * representation. * * The string can be subsequently shared with userspace via * bpf_perf_event_output() or ring buffer interfaces. * bpf_trace_printk() is to be avoided as it places too small * a limit on string size to be useful. * * *flags* is a combination of * * **BTF_F_COMPACT** * no formatting around type information * **BTF_F_NONAME** * no struct/union member names/types * **BTF_F_PTR_RAW** * show raw (unobfuscated) pointer values; * equivalent to printk specifier %px. * **BTF_F_ZERO** * show zero-valued struct/union members; they * are not displayed by default * * * Returns * The number of bytes that were written (or would have been * written if output had to be truncated due to string size), * or a negative error in cases of failure. */ static long (*bpf_snprintf_btf)(char *str, __u32 str_size, struct btf_ptr *ptr, __u32 btf_ptr_size, __u64 flags) = (void *) 149; /* * bpf_seq_printf_btf * * Use BTF to write to seq_write a string representation of * *ptr*->ptr, using *ptr*->type_id as per bpf_snprintf_btf(). * *flags* are identical to those used for bpf_snprintf_btf. * * Returns * 0 on success or a negative error in case of failure. */ static long (*bpf_seq_printf_btf)(struct seq_file *m, struct btf_ptr *ptr, __u32 ptr_size, __u64 flags) = (void *) 150; /* * bpf_skb_cgroup_classid * * See **bpf_get_cgroup_classid**\ () for the main description. * This helper differs from **bpf_get_cgroup_classid**\ () in that * the cgroup v1 net_cls class is retrieved only from the *skb*'s * associated socket instead of the current process. * * Returns * The id is returned or 0 in case the id could not be retrieved. */ static __u64 (*bpf_skb_cgroup_classid)(struct __sk_buff *skb) = (void *) 151; /* * bpf_redirect_neigh * * Redirect the packet to another net device of index *ifindex* * and fill in L2 addresses from neighboring subsystem. This helper * is somewhat similar to **bpf_redirect**\ (), except that it * populates L2 addresses as well, meaning, internally, the helper * relies on the neighbor lookup for the L2 address of the nexthop. * * The helper will perform a FIB lookup based on the skb's * networking header to get the address of the next hop, unless * this is supplied by the caller in the *params* argument. The * *plen* argument indicates the len of *params* and should be set * to 0 if *params* is NULL. * * The *flags* argument is reserved and must be 0. The helper is * currently only supported for tc BPF program types, and enabled * for IPv4 and IPv6 protocols. * * Returns * The helper returns **TC_ACT_REDIRECT** on success or * **TC_ACT_SHOT** on error. */ static long (*bpf_redirect_neigh)(__u32 ifindex, struct bpf_redir_neigh *params, int plen, __u64 flags) = (void *) 152; /* * bpf_per_cpu_ptr * * Take a pointer to a percpu ksym, *percpu_ptr*, and return a * pointer to the percpu kernel variable on *cpu*. A ksym is an * extern variable decorated with '__ksym'. For ksym, there is a * global var (either static or global) defined of the same name * in the kernel. The ksym is percpu if the global var is percpu. * The returned pointer points to the global percpu var on *cpu*. * * bpf_per_cpu_ptr() has the same semantic as per_cpu_ptr() in the * kernel, except that bpf_per_cpu_ptr() may return NULL. This * happens if *cpu* is larger than nr_cpu_ids. The caller of * bpf_per_cpu_ptr() must check the returned value. * * Returns * A pointer pointing to the kernel percpu variable on *cpu*, or * NULL, if *cpu* is invalid. */ static void *(*bpf_per_cpu_ptr)(const void *percpu_ptr, __u32 cpu) = (void *) 153; /* * bpf_this_cpu_ptr * * Take a pointer to a percpu ksym, *percpu_ptr*, and return a * pointer to the percpu kernel variable on this cpu. See the * description of 'ksym' in **bpf_per_cpu_ptr**\ (). * * bpf_this_cpu_ptr() has the same semantic as this_cpu_ptr() in * the kernel. Different from **bpf_per_cpu_ptr**\ (), it would * never return NULL. * * Returns * A pointer pointing to the kernel percpu variable on this cpu. */ static void *(*bpf_this_cpu_ptr)(const void *percpu_ptr) = (void *) 154; /* * bpf_redirect_peer * * Redirect the packet to another net device of index *ifindex*. * This helper is somewhat similar to **bpf_redirect**\ (), except * that the redirection happens to the *ifindex*' peer device and * the netns switch takes place from ingress to ingress without * going through the CPU's backlog queue. * * The *flags* argument is reserved and must be 0. The helper is * currently only supported for tc BPF program types at the ingress * hook and for veth device types. The peer device must reside in a * different network namespace. * * Returns * The helper returns **TC_ACT_REDIRECT** on success or * **TC_ACT_SHOT** on error. */ static long (*bpf_redirect_peer)(__u32 ifindex, __u64 flags) = (void *) 155; /* * bpf_task_storage_get * * Get a bpf_local_storage from the *task*. * * Logically, it could be thought of as getting the value from * a *map* with *task* as the **key**. From this * perspective, the usage is not much different from * **bpf_map_lookup_elem**\ (*map*, **&**\ *task*) except this * helper enforces the key must be a task_struct and the map must also * be a **BPF_MAP_TYPE_TASK_STORAGE**. * * Underneath, the value is stored locally at *task* instead of * the *map*. The *map* is used as the bpf-local-storage * "type". The bpf-local-storage "type" (i.e. the *map*) is * searched against all bpf_local_storage residing at *task*. * * An optional *flags* (**BPF_LOCAL_STORAGE_GET_F_CREATE**) can be * used such that a new bpf_local_storage will be * created if one does not exist. *value* can be used * together with **BPF_LOCAL_STORAGE_GET_F_CREATE** to specify * the initial value of a bpf_local_storage. If *value* is * **NULL**, the new bpf_local_storage will be zero initialized. * * Returns * A bpf_local_storage pointer is returned on success. * * **NULL** if not found or there was an error in adding * a new bpf_local_storage. */ static void *(*bpf_task_storage_get)(void *map, struct task_struct *task, void *value, __u64 flags) = (void *) 156; /* * bpf_task_storage_delete * * Delete a bpf_local_storage from a *task*. * * Returns * 0 on success. * * **-ENOENT** if the bpf_local_storage cannot be found. */ static long (*bpf_task_storage_delete)(void *map, struct task_struct *task) = (void *) 157; /* * bpf_get_current_task_btf * * Return a BTF pointer to the "current" task. * This pointer can also be used in helpers that accept an * *ARG_PTR_TO_BTF_ID* of type *task_struct*. * * Returns * Pointer to the current task. */ static struct task_struct *(*bpf_get_current_task_btf)(void) = (void *) 158; /* * bpf_bprm_opts_set * * Set or clear certain options on *bprm*: * * **BPF_F_BPRM_SECUREEXEC** Set the secureexec bit * which sets the **AT_SECURE** auxv for glibc. The bit * is cleared if the flag is not specified. * * Returns * **-EINVAL** if invalid *flags* are passed, zero otherwise. */ static long (*bpf_bprm_opts_set)(struct linux_binprm *bprm, __u64 flags) = (void *) 159; /* * bpf_ktime_get_coarse_ns * * Return a coarse-grained version of the time elapsed since * system boot, in nanoseconds. Does not include time the system * was suspended. * * See: **clock_gettime**\ (**CLOCK_MONOTONIC_COARSE**) * * Returns * Current *ktime*. */ static __u64 (*bpf_ktime_get_coarse_ns)(void) = (void *) 160; /* * bpf_ima_inode_hash * * Returns the stored IMA hash of the *inode* (if it's available). * If the hash is larger than *size*, then only *size* * bytes will be copied to *dst* * * Returns * The **hash_algo** is returned on success, * **-EOPNOTSUP** if IMA is disabled or **-EINVAL** if * invalid arguments are passed. */ static long (*bpf_ima_inode_hash)(struct inode *inode, void *dst, __u32 size) = (void *) 161; /* * bpf_sock_from_file * * If the given file represents a socket, returns the associated * socket. * * Returns * A pointer to a struct socket on success or NULL if the file is * not a socket. */ static struct socket *(*bpf_sock_from_file)(struct file *file) = (void *) 162; /* * bpf_check_mtu * * Check packet size against exceeding MTU of net device (based * on *ifindex*). This helper will likely be used in combination * with helpers that adjust/change the packet size. * * The argument *len_diff* can be used for querying with a planned * size change. This allows to check MTU prior to changing packet * ctx. Providing a *len_diff* adjustment that is larger than the * actual packet size (resulting in negative packet size) will in * principle not exceed the MTU, which is why it is not considered * a failure. Other BPF helpers are needed for performing the * planned size change; therefore the responsibility for catching * a negative packet size belongs in those helpers. * * Specifying *ifindex* zero means the MTU check is performed * against the current net device. This is practical if this isn't * used prior to redirect. * * On input *mtu_len* must be a valid pointer, else verifier will * reject BPF program. If the value *mtu_len* is initialized to * zero then the ctx packet size is use. When value *mtu_len* is * provided as input this specify the L3 length that the MTU check * is done against. Remember XDP and TC length operate at L2, but * this value is L3 as this correlate to MTU and IP-header tot_len * values which are L3 (similar behavior as bpf_fib_lookup). * * The Linux kernel route table can configure MTUs on a more * specific per route level, which is not provided by this helper. * For route level MTU checks use the **bpf_fib_lookup**\ () * helper. * * *ctx* is either **struct xdp_md** for XDP programs or * **struct sk_buff** for tc cls_act programs. * * The *flags* argument can be a combination of one or more of the * following values: * * **BPF_MTU_CHK_SEGS** * This flag will only works for *ctx* **struct sk_buff**. * If packet context contains extra packet segment buffers * (often knows as GSO skb), then MTU check is harder to * check at this point, because in transmit path it is * possible for the skb packet to get re-segmented * (depending on net device features). This could still be * a MTU violation, so this flag enables performing MTU * check against segments, with a different violation * return code to tell it apart. Check cannot use len_diff. * * On return *mtu_len* pointer contains the MTU value of the net * device. Remember the net device configured MTU is the L3 size, * which is returned here and XDP and TC length operate at L2. * Helper take this into account for you, but remember when using * MTU value in your BPF-code. * * * Returns * * 0 on success, and populate MTU value in *mtu_len* pointer. * * * < 0 if any input argument is invalid (*mtu_len* not updated) * * MTU violations return positive values, but also populate MTU * value in *mtu_len* pointer, as this can be needed for * implementing PMTU handing: * * * **BPF_MTU_CHK_RET_FRAG_NEEDED** * * **BPF_MTU_CHK_RET_SEGS_TOOBIG** */ static long (*bpf_check_mtu)(void *ctx, __u32 ifindex, __u32 *mtu_len, __s32 len_diff, __u64 flags) = (void *) 163; /* * bpf_for_each_map_elem * * For each element in **map**, call **callback_fn** function with * **map**, **callback_ctx** and other map-specific parameters. * The **callback_fn** should be a static function and * the **callback_ctx** should be a pointer to the stack. * The **flags** is used to control certain aspects of the helper. * Currently, the **flags** must be 0. * * The following are a list of supported map types and their * respective expected callback signatures: * * BPF_MAP_TYPE_HASH, BPF_MAP_TYPE_PERCPU_HASH, * BPF_MAP_TYPE_LRU_HASH, BPF_MAP_TYPE_LRU_PERCPU_HASH, * BPF_MAP_TYPE_ARRAY, BPF_MAP_TYPE_PERCPU_ARRAY * * long (\*callback_fn)(struct bpf_map \*map, const void \*key, void \*value, void \*ctx); * * For per_cpu maps, the map_value is the value on the cpu where the * bpf_prog is running. * * If **callback_fn** return 0, the helper will continue to the next * element. If return value is 1, the helper will skip the rest of * elements and return. Other return values are not used now. * * * Returns * The number of traversed map elements for success, **-EINVAL** for * invalid **flags**. */ static long (*bpf_for_each_map_elem)(void *map, void *callback_fn, void *callback_ctx, __u64 flags) = (void *) 164; /* * bpf_snprintf * * Outputs a string into the **str** buffer of size **str_size** * based on a format string stored in a read-only map pointed by * **fmt**. * * Each format specifier in **fmt** corresponds to one u64 element * in the **data** array. For strings and pointers where pointees * are accessed, only the pointer values are stored in the *data* * array. The *data_len* is the size of *data* in bytes - must be * a multiple of 8. * * Formats **%s** and **%p{i,I}{4,6}** require to read kernel * memory. Reading kernel memory may fail due to either invalid * address or valid address but requiring a major memory fault. If * reading kernel memory fails, the string for **%s** will be an * empty string, and the ip address for **%p{i,I}{4,6}** will be 0. * Not returning error to bpf program is consistent with what * **bpf_trace_printk**\ () does for now. * * * Returns * The strictly positive length of the formatted string, including * the trailing zero character. If the return value is greater than * **str_size**, **str** contains a truncated string, guaranteed to * be zero-terminated except when **str_size** is 0. * * Or **-EBUSY** if the per-CPU memory copy buffer is busy. */ static long (*bpf_snprintf)(char *str, __u32 str_size, const char *fmt, __u64 *data, __u32 data_len) = (void *) 165; /* * bpf_sys_bpf * * Execute bpf syscall with given arguments. * * Returns * A syscall result. */ static long (*bpf_sys_bpf)(__u32 cmd, void *attr, __u32 attr_size) = (void *) 166; /* * bpf_btf_find_by_name_kind * * Find BTF type with given name and kind in vmlinux BTF or in module's BTFs. * * Returns * Returns btf_id and btf_obj_fd in lower and upper 32 bits. */ static long (*bpf_btf_find_by_name_kind)(char *name, int name_sz, __u32 kind, int flags) = (void *) 167; /* * bpf_sys_close * * Execute close syscall for given FD. * * Returns * A syscall result. */ static long (*bpf_sys_close)(__u32 fd) = (void *) 168; /* * bpf_timer_init * * Initialize the timer. * First 4 bits of *flags* specify clockid. * Only CLOCK_MONOTONIC, CLOCK_REALTIME, CLOCK_BOOTTIME are allowed. * All other bits of *flags* are reserved. * The verifier will reject the program if *timer* is not from * the same *map*. * * Returns * 0 on success. * **-EBUSY** if *timer* is already initialized. * **-EINVAL** if invalid *flags* are passed. * **-EPERM** if *timer* is in a map that doesn't have any user references. * The user space should either hold a file descriptor to a map with timers * or pin such map in bpffs. When map is unpinned or file descriptor is * closed all timers in the map will be cancelled and freed. */ static long (*bpf_timer_init)(struct bpf_timer *timer, void *map, __u64 flags) = (void *) 169; /* * bpf_timer_set_callback * * Configure the timer to call *callback_fn* static function. * * Returns * 0 on success. * **-EINVAL** if *timer* was not initialized with bpf_timer_init() earlier. * **-EPERM** if *timer* is in a map that doesn't have any user references. * The user space should either hold a file descriptor to a map with timers * or pin such map in bpffs. When map is unpinned or file descriptor is * closed all timers in the map will be cancelled and freed. */ static long (*bpf_timer_set_callback)(struct bpf_timer *timer, void *callback_fn) = (void *) 170; /* * bpf_timer_start * * Set timer expiration N nanoseconds from the current time. The * configured callback will be invoked in soft irq context on some cpu * and will not repeat unless another bpf_timer_start() is made. * In such case the next invocation can migrate to a different cpu. * Since struct bpf_timer is a field inside map element the map * owns the timer. The bpf_timer_set_callback() will increment refcnt * of BPF program to make sure that callback_fn code stays valid. * When user space reference to a map reaches zero all timers * in a map are cancelled and corresponding program's refcnts are * decremented. This is done to make sure that Ctrl-C of a user * process doesn't leave any timers running. If map is pinned in * bpffs the callback_fn can re-arm itself indefinitely. * bpf_map_update/delete_elem() helpers and user space sys_bpf commands * cancel and free the timer in the given map element. * The map can contain timers that invoke callback_fn-s from different * programs. The same callback_fn can serve different timers from * different maps if key/value layout matches across maps. * Every bpf_timer_set_callback() can have different callback_fn. * * *flags* can be one of: * * **BPF_F_TIMER_ABS** * Start the timer in absolute expire value instead of the * default relative one. * **BPF_F_TIMER_CPU_PIN** * Timer will be pinned to the CPU of the caller. * * * Returns * 0 on success. * **-EINVAL** if *timer* was not initialized with bpf_timer_init() earlier * or invalid *flags* are passed. */ static long (*bpf_timer_start)(struct bpf_timer *timer, __u64 nsecs, __u64 flags) = (void *) 171; /* * bpf_timer_cancel * * Cancel the timer and wait for callback_fn to finish if it was running. * * Returns * 0 if the timer was not active. * 1 if the timer was active. * **-EINVAL** if *timer* was not initialized with bpf_timer_init() earlier. * **-EDEADLK** if callback_fn tried to call bpf_timer_cancel() on its * own timer which would have led to a deadlock otherwise. */ static long (*bpf_timer_cancel)(struct bpf_timer *timer) = (void *) 172; /* * bpf_get_func_ip * * Get address of the traced function (for tracing and kprobe programs). * * When called for kprobe program attached as uprobe it returns * probe address for both entry and return uprobe. * * * Returns * Address of the traced function for kprobe. * 0 for kprobes placed within the function (not at the entry). * Address of the probe for uprobe and return uprobe. */ static __u64 (*bpf_get_func_ip)(void *ctx) = (void *) 173; /* * bpf_get_attach_cookie * * Get bpf_cookie value provided (optionally) during the program * attachment. It might be different for each individual * attachment, even if BPF program itself is the same. * Expects BPF program context *ctx* as a first argument. * * Supported for the following program types: * - kprobe/uprobe; * - tracepoint; * - perf_event. * * Returns * Value specified by user at BPF link creation/attachment time * or 0, if it was not specified. */ static __u64 (*bpf_get_attach_cookie)(void *ctx) = (void *) 174; /* * bpf_task_pt_regs * * Get the struct pt_regs associated with **task**. * * Returns * A pointer to struct pt_regs. */ static long (*bpf_task_pt_regs)(struct task_struct *task) = (void *) 175; /* * bpf_get_branch_snapshot * * Get branch trace from hardware engines like Intel LBR. The * hardware engine is stopped shortly after the helper is * called. Therefore, the user need to filter branch entries * based on the actual use case. To capture branch trace * before the trigger point of the BPF program, the helper * should be called at the beginning of the BPF program. * * The data is stored as struct perf_branch_entry into output * buffer *entries*. *size* is the size of *entries* in bytes. * *flags* is reserved for now and must be zero. * * * Returns * On success, number of bytes written to *buf*. On error, a * negative value. * * **-EINVAL** if *flags* is not zero. * * **-ENOENT** if architecture does not support branch records. */ static long (*bpf_get_branch_snapshot)(void *entries, __u32 size, __u64 flags) = (void *) 176; /* * bpf_trace_vprintk * * Behaves like **bpf_trace_printk**\ () helper, but takes an array of u64 * to format and can handle more format args as a result. * * Arguments are to be used as in **bpf_seq_printf**\ () helper. * * Returns * The number of bytes written to the buffer, or a negative error * in case of failure. */ static long (*bpf_trace_vprintk)(const char *fmt, __u32 fmt_size, const void *data, __u32 data_len) = (void *) 177; /* * bpf_skc_to_unix_sock * * Dynamically cast a *sk* pointer to a *unix_sock* pointer. * * Returns * *sk* if casting is valid, or **NULL** otherwise. */ static struct unix_sock *(*bpf_skc_to_unix_sock)(void *sk) = (void *) 178; /* * bpf_kallsyms_lookup_name * * Get the address of a kernel symbol, returned in *res*. *res* is * set to 0 if the symbol is not found. * * Returns * On success, zero. On error, a negative value. * * **-EINVAL** if *flags* is not zero. * * **-EINVAL** if string *name* is not the same size as *name_sz*. * * **-ENOENT** if symbol is not found. * * **-EPERM** if caller does not have permission to obtain kernel address. */ static long (*bpf_kallsyms_lookup_name)(const char *name, int name_sz, int flags, __u64 *res) = (void *) 179; /* * bpf_find_vma * * Find vma of *task* that contains *addr*, call *callback_fn* * function with *task*, *vma*, and *callback_ctx*. * The *callback_fn* should be a static function and * the *callback_ctx* should be a pointer to the stack. * The *flags* is used to control certain aspects of the helper. * Currently, the *flags* must be 0. * * The expected callback signature is * * long (\*callback_fn)(struct task_struct \*task, struct vm_area_struct \*vma, void \*callback_ctx); * * * Returns * 0 on success. * **-ENOENT** if *task->mm* is NULL, or no vma contains *addr*. * **-EBUSY** if failed to try lock mmap_lock. * **-EINVAL** for invalid **flags**. */ static long (*bpf_find_vma)(struct task_struct *task, __u64 addr, void *callback_fn, void *callback_ctx, __u64 flags) = (void *) 180; /* * bpf_loop * * For **nr_loops**, call **callback_fn** function * with **callback_ctx** as the context parameter. * The **callback_fn** should be a static function and * the **callback_ctx** should be a pointer to the stack. * The **flags** is used to control certain aspects of the helper. * Currently, the **flags** must be 0. Currently, nr_loops is * limited to 1 << 23 (~8 million) loops. * * long (\*callback_fn)(u32 index, void \*ctx); * * where **index** is the current index in the loop. The index * is zero-indexed. * * If **callback_fn** returns 0, the helper will continue to the next * loop. If return value is 1, the helper will skip the rest of * the loops and return. Other return values are not used now, * and will be rejected by the verifier. * * * Returns * The number of loops performed, **-EINVAL** for invalid **flags**, * **-E2BIG** if **nr_loops** exceeds the maximum number of loops. */ static long (*bpf_loop)(__u32 nr_loops, void *callback_fn, void *callback_ctx, __u64 flags) = (void *) 181; /* * bpf_strncmp * * Do strncmp() between **s1** and **s2**. **s1** doesn't need * to be null-terminated and **s1_sz** is the maximum storage * size of **s1**. **s2** must be a read-only string. * * Returns * An integer less than, equal to, or greater than zero * if the first **s1_sz** bytes of **s1** is found to be * less than, to match, or be greater than **s2**. */ static long (*bpf_strncmp)(const char *s1, __u32 s1_sz, const char *s2) = (void *) 182; /* * bpf_get_func_arg * * Get **n**-th argument register (zero based) of the traced function (for tracing programs) * returned in **value**. * * * Returns * 0 on success. * **-EINVAL** if n >= argument register count of traced function. */ static long (*bpf_get_func_arg)(void *ctx, __u32 n, __u64 *value) = (void *) 183; /* * bpf_get_func_ret * * Get return value of the traced function (for tracing programs) * in **value**. * * * Returns * 0 on success. * **-EOPNOTSUPP** for tracing programs other than BPF_TRACE_FEXIT or BPF_MODIFY_RETURN. */ static long (*bpf_get_func_ret)(void *ctx, __u64 *value) = (void *) 184; /* * bpf_get_func_arg_cnt * * Get number of registers of the traced function (for tracing programs) where * function arguments are stored in these registers. * * * Returns * The number of argument registers of the traced function. */ static long (*bpf_get_func_arg_cnt)(void *ctx) = (void *) 185; /* * bpf_get_retval * * Get the BPF program's return value that will be returned to the upper layers. * * This helper is currently supported by cgroup programs and only by the hooks * where BPF program's return value is returned to the userspace via errno. * * Returns * The BPF program's return value. */ static int (*bpf_get_retval)(void) = (void *) 186; /* * bpf_set_retval * * Set the BPF program's return value that will be returned to the upper layers. * * This helper is currently supported by cgroup programs and only by the hooks * where BPF program's return value is returned to the userspace via errno. * * Note that there is the following corner case where the program exports an error * via bpf_set_retval but signals success via 'return 1': * * bpf_set_retval(-EPERM); * return 1; * * In this case, the BPF program's return value will use helper's -EPERM. This * still holds true for cgroup/bind{4,6} which supports extra 'return 3' success case. * * * Returns * 0 on success, or a negative error in case of failure. */ static int (*bpf_set_retval)(int retval) = (void *) 187; /* * bpf_xdp_get_buff_len * * Get the total size of a given xdp buff (linear and paged area) * * Returns * The total size of a given xdp buffer. */ static __u64 (*bpf_xdp_get_buff_len)(struct xdp_md *xdp_md) = (void *) 188; /* * bpf_xdp_load_bytes * * This helper is provided as an easy way to load data from a * xdp buffer. It can be used to load *len* bytes from *offset* from * the frame associated to *xdp_md*, into the buffer pointed by * *buf*. * * Returns * 0 on success, or a negative error in case of failure. */ static long (*bpf_xdp_load_bytes)(struct xdp_md *xdp_md, __u32 offset, void *buf, __u32 len) = (void *) 189; /* * bpf_xdp_store_bytes * * Store *len* bytes from buffer *buf* into the frame * associated to *xdp_md*, at *offset*. * * Returns * 0 on success, or a negative error in case of failure. */ static long (*bpf_xdp_store_bytes)(struct xdp_md *xdp_md, __u32 offset, void *buf, __u32 len) = (void *) 190; /* * bpf_copy_from_user_task * * Read *size* bytes from user space address *user_ptr* in *tsk*'s * address space, and stores the data in *dst*. *flags* is not * used yet and is provided for future extensibility. This helper * can only be used by sleepable programs. * * Returns * 0 on success, or a negative error in case of failure. On error * *dst* buffer is zeroed out. */ static long (*bpf_copy_from_user_task)(void *dst, __u32 size, const void *user_ptr, struct task_struct *tsk, __u64 flags) = (void *) 191; /* * bpf_skb_set_tstamp * * Change the __sk_buff->tstamp_type to *tstamp_type* * and set *tstamp* to the __sk_buff->tstamp together. * * If there is no need to change the __sk_buff->tstamp_type, * the tstamp value can be directly written to __sk_buff->tstamp * instead. * * BPF_SKB_TSTAMP_DELIVERY_MONO is the only tstamp that * will be kept during bpf_redirect_*(). A non zero * *tstamp* must be used with the BPF_SKB_TSTAMP_DELIVERY_MONO * *tstamp_type*. * * A BPF_SKB_TSTAMP_UNSPEC *tstamp_type* can only be used * with a zero *tstamp*. * * Only IPv4 and IPv6 skb->protocol are supported. * * This function is most useful when it needs to set a * mono delivery time to __sk_buff->tstamp and then * bpf_redirect_*() to the egress of an iface. For example, * changing the (rcv) timestamp in __sk_buff->tstamp at * ingress to a mono delivery time and then bpf_redirect_*() * to sch_fq@phy-dev. * * Returns * 0 on success. * **-EINVAL** for invalid input * **-EOPNOTSUPP** for unsupported protocol */ static long (*bpf_skb_set_tstamp)(struct __sk_buff *skb, __u64 tstamp, __u32 tstamp_type) = (void *) 192; /* * bpf_ima_file_hash * * Returns a calculated IMA hash of the *file*. * If the hash is larger than *size*, then only *size* * bytes will be copied to *dst* * * Returns * The **hash_algo** is returned on success, * **-EOPNOTSUP** if the hash calculation failed or **-EINVAL** if * invalid arguments are passed. */ static long (*bpf_ima_file_hash)(struct file *file, void *dst, __u32 size) = (void *) 193; /* * bpf_kptr_xchg * * Exchange kptr at pointer *map_value* with *ptr*, and return the * old value. *ptr* can be NULL, otherwise it must be a referenced * pointer which will be released when this helper is called. * * Returns * The old value of kptr (which can be NULL). The returned pointer * if not NULL, is a reference which must be released using its * corresponding release function, or moved into a BPF map before * program exit. */ static void *(*bpf_kptr_xchg)(void *map_value, void *ptr) = (void *) 194; /* * bpf_map_lookup_percpu_elem * * Perform a lookup in *percpu map* for an entry associated to * *key* on *cpu*. * * Returns * Map value associated to *key* on *cpu*, or **NULL** if no entry * was found or *cpu* is invalid. */ static void *(*bpf_map_lookup_percpu_elem)(void *map, const void *key, __u32 cpu) = (void *) 195; /* * bpf_skc_to_mptcp_sock * * Dynamically cast a *sk* pointer to a *mptcp_sock* pointer. * * Returns * *sk* if casting is valid, or **NULL** otherwise. */ static struct mptcp_sock *(*bpf_skc_to_mptcp_sock)(void *sk) = (void *) 196; /* * bpf_dynptr_from_mem * * Get a dynptr to local memory *data*. * * *data* must be a ptr to a map value. * The maximum *size* supported is DYNPTR_MAX_SIZE. * *flags* is currently unused. * * Returns * 0 on success, -E2BIG if the size exceeds DYNPTR_MAX_SIZE, * -EINVAL if flags is not 0. */ static long (*bpf_dynptr_from_mem)(void *data, __u32 size, __u64 flags, struct bpf_dynptr *ptr) = (void *) 197; /* * bpf_ringbuf_reserve_dynptr * * Reserve *size* bytes of payload in a ring buffer *ringbuf* * through the dynptr interface. *flags* must be 0. * * Please note that a corresponding bpf_ringbuf_submit_dynptr or * bpf_ringbuf_discard_dynptr must be called on *ptr*, even if the * reservation fails. This is enforced by the verifier. * * Returns * 0 on success, or a negative error in case of failure. */ static long (*bpf_ringbuf_reserve_dynptr)(void *ringbuf, __u32 size, __u64 flags, struct bpf_dynptr *ptr) = (void *) 198; /* * bpf_ringbuf_submit_dynptr * * Submit reserved ring buffer sample, pointed to by *data*, * through the dynptr interface. This is a no-op if the dynptr is * invalid/null. * * For more information on *flags*, please see * 'bpf_ringbuf_submit'. * * Returns * Nothing. Always succeeds. */ static void (*bpf_ringbuf_submit_dynptr)(struct bpf_dynptr *ptr, __u64 flags) = (void *) 199; /* * bpf_ringbuf_discard_dynptr * * Discard reserved ring buffer sample through the dynptr * interface. This is a no-op if the dynptr is invalid/null. * * For more information on *flags*, please see * 'bpf_ringbuf_discard'. * * Returns * Nothing. Always succeeds. */ static void (*bpf_ringbuf_discard_dynptr)(struct bpf_dynptr *ptr, __u64 flags) = (void *) 200; /* * bpf_dynptr_read * * Read *len* bytes from *src* into *dst*, starting from *offset* * into *src*. * *flags* is currently unused. * * Returns * 0 on success, -E2BIG if *offset* + *len* exceeds the length * of *src*'s data, -EINVAL if *src* is an invalid dynptr or if * *flags* is not 0. */ static long (*bpf_dynptr_read)(void *dst, __u32 len, const struct bpf_dynptr *src, __u32 offset, __u64 flags) = (void *) 201; /* * bpf_dynptr_write * * Write *len* bytes from *src* into *dst*, starting from *offset* * into *dst*. * * *flags* must be 0 except for skb-type dynptrs. * * For skb-type dynptrs: * * All data slices of the dynptr are automatically * invalidated after **bpf_dynptr_write**\ (). This is * because writing may pull the skb and change the * underlying packet buffer. * * * For *flags*, please see the flags accepted by * **bpf_skb_store_bytes**\ (). * * Returns * 0 on success, -E2BIG if *offset* + *len* exceeds the length * of *dst*'s data, -EINVAL if *dst* is an invalid dynptr or if *dst* * is a read-only dynptr or if *flags* is not correct. For skb-type dynptrs, * other errors correspond to errors returned by **bpf_skb_store_bytes**\ (). */ static long (*bpf_dynptr_write)(const struct bpf_dynptr *dst, __u32 offset, void *src, __u32 len, __u64 flags) = (void *) 202; /* * bpf_dynptr_data * * Get a pointer to the underlying dynptr data. * * *len* must be a statically known value. The returned data slice * is invalidated whenever the dynptr is invalidated. * * skb and xdp type dynptrs may not use bpf_dynptr_data. They should * instead use bpf_dynptr_slice and bpf_dynptr_slice_rdwr. * * Returns * Pointer to the underlying dynptr data, NULL if the dynptr is * read-only, if the dynptr is invalid, or if the offset and length * is out of bounds. */ static void *(*bpf_dynptr_data)(const struct bpf_dynptr *ptr, __u32 offset, __u32 len) = (void *) 203; /* * bpf_tcp_raw_gen_syncookie_ipv4 * * Try to issue a SYN cookie for the packet with corresponding * IPv4/TCP headers, *iph* and *th*, without depending on a * listening socket. * * *iph* points to the IPv4 header. * * *th* points to the start of the TCP header, while *th_len* * contains the length of the TCP header (at least * **sizeof**\ (**struct tcphdr**)). * * Returns * On success, lower 32 bits hold the generated SYN cookie in * followed by 16 bits which hold the MSS value for that cookie, * and the top 16 bits are unused. * * On failure, the returned value is one of the following: * * **-EINVAL** if *th_len* is invalid. */ static __s64 (*bpf_tcp_raw_gen_syncookie_ipv4)(struct iphdr *iph, struct tcphdr *th, __u32 th_len) = (void *) 204; /* * bpf_tcp_raw_gen_syncookie_ipv6 * * Try to issue a SYN cookie for the packet with corresponding * IPv6/TCP headers, *iph* and *th*, without depending on a * listening socket. * * *iph* points to the IPv6 header. * * *th* points to the start of the TCP header, while *th_len* * contains the length of the TCP header (at least * **sizeof**\ (**struct tcphdr**)). * * Returns * On success, lower 32 bits hold the generated SYN cookie in * followed by 16 bits which hold the MSS value for that cookie, * and the top 16 bits are unused. * * On failure, the returned value is one of the following: * * **-EINVAL** if *th_len* is invalid. * * **-EPROTONOSUPPORT** if CONFIG_IPV6 is not builtin. */ static __s64 (*bpf_tcp_raw_gen_syncookie_ipv6)(struct ipv6hdr *iph, struct tcphdr *th, __u32 th_len) = (void *) 205; /* * bpf_tcp_raw_check_syncookie_ipv4 * * Check whether *iph* and *th* contain a valid SYN cookie ACK * without depending on a listening socket. * * *iph* points to the IPv4 header. * * *th* points to the TCP header. * * Returns * 0 if *iph* and *th* are a valid SYN cookie ACK. * * On failure, the returned value is one of the following: * * **-EACCES** if the SYN cookie is not valid. */ static long (*bpf_tcp_raw_check_syncookie_ipv4)(struct iphdr *iph, struct tcphdr *th) = (void *) 206; /* * bpf_tcp_raw_check_syncookie_ipv6 * * Check whether *iph* and *th* contain a valid SYN cookie ACK * without depending on a listening socket. * * *iph* points to the IPv6 header. * * *th* points to the TCP header. * * Returns * 0 if *iph* and *th* are a valid SYN cookie ACK. * * On failure, the returned value is one of the following: * * **-EACCES** if the SYN cookie is not valid. * * **-EPROTONOSUPPORT** if CONFIG_IPV6 is not builtin. */ static long (*bpf_tcp_raw_check_syncookie_ipv6)(struct ipv6hdr *iph, struct tcphdr *th) = (void *) 207; /* * bpf_ktime_get_tai_ns * * A nonsettable system-wide clock derived from wall-clock time but * ignoring leap seconds. This clock does not experience * discontinuities and backwards jumps caused by NTP inserting leap * seconds as CLOCK_REALTIME does. * * See: **clock_gettime**\ (**CLOCK_TAI**) * * Returns * Current *ktime*. */ static __u64 (*bpf_ktime_get_tai_ns)(void) = (void *) 208; /* * bpf_user_ringbuf_drain * * Drain samples from the specified user ring buffer, and invoke * the provided callback for each such sample: * * long (\*callback_fn)(const struct bpf_dynptr \*dynptr, void \*ctx); * * If **callback_fn** returns 0, the helper will continue to try * and drain the next sample, up to a maximum of * BPF_MAX_USER_RINGBUF_SAMPLES samples. If the return value is 1, * the helper will skip the rest of the samples and return. Other * return values are not used now, and will be rejected by the * verifier. * * Returns * The number of drained samples if no error was encountered while * draining samples, or 0 if no samples were present in the ring * buffer. If a user-space producer was epoll-waiting on this map, * and at least one sample was drained, they will receive an event * notification notifying them of available space in the ring * buffer. If the BPF_RB_NO_WAKEUP flag is passed to this * function, no wakeup notification will be sent. If the * BPF_RB_FORCE_WAKEUP flag is passed, a wakeup notification will * be sent even if no sample was drained. * * On failure, the returned value is one of the following: * * **-EBUSY** if the ring buffer is contended, and another calling * context was concurrently draining the ring buffer. * * **-EINVAL** if user-space is not properly tracking the ring * buffer due to the producer position not being aligned to 8 * bytes, a sample not being aligned to 8 bytes, or the producer * position not matching the advertised length of a sample. * * **-E2BIG** if user-space has tried to publish a sample which is * larger than the size of the ring buffer, or which cannot fit * within a struct bpf_dynptr. */ static long (*bpf_user_ringbuf_drain)(void *map, void *callback_fn, void *ctx, __u64 flags) = (void *) 209; /* * bpf_cgrp_storage_get * * Get a bpf_local_storage from the *cgroup*. * * Logically, it could be thought of as getting the value from * a *map* with *cgroup* as the **key**. From this * perspective, the usage is not much different from * **bpf_map_lookup_elem**\ (*map*, **&**\ *cgroup*) except this * helper enforces the key must be a cgroup struct and the map must also * be a **BPF_MAP_TYPE_CGRP_STORAGE**. * * In reality, the local-storage value is embedded directly inside of the * *cgroup* object itself, rather than being located in the * **BPF_MAP_TYPE_CGRP_STORAGE** map. When the local-storage value is * queried for some *map* on a *cgroup* object, the kernel will perform an * O(n) iteration over all of the live local-storage values for that * *cgroup* object until the local-storage value for the *map* is found. * * An optional *flags* (**BPF_LOCAL_STORAGE_GET_F_CREATE**) can be * used such that a new bpf_local_storage will be * created if one does not exist. *value* can be used * together with **BPF_LOCAL_STORAGE_GET_F_CREATE** to specify * the initial value of a bpf_local_storage. If *value* is * **NULL**, the new bpf_local_storage will be zero initialized. * * Returns * A bpf_local_storage pointer is returned on success. * * **NULL** if not found or there was an error in adding * a new bpf_local_storage. */ static void *(*bpf_cgrp_storage_get)(void *map, struct cgroup *cgroup, void *value, __u64 flags) = (void *) 210; /* * bpf_cgrp_storage_delete * * Delete a bpf_local_storage from a *cgroup*. * * Returns * 0 on success. * * **-ENOENT** if the bpf_local_storage cannot be found. */ static long (*bpf_cgrp_storage_delete)(void *map, struct cgroup *cgroup) = (void *) 211;