name : xdp_redirect_cpu.py #!/usr/bin/python # # xdp_redirect_cpu.py Redirect the incoming packet to the specific CPU # # Copyright (c) 2018 Gary Lin # Licensed under the Apache License, Version 2.0 (the "License") from bcc import BPF import time import sys from multiprocessing import cpu_count import ctypes as ct flags = 0 def usage(): print("Usage: {0} <in ifdev> <CPU id>".format(sys.argv[0])) print("e.g.: {0} eth0 2\n".format(sys.argv[0])) exit(1) if len(sys.argv) != 3: usage() in_if = sys.argv[1] cpu_id = int(sys.argv[2]) max_cpu = cpu_count() if (cpu_id > max_cpu): print("Invalid CPU id") exit(1) # load BPF program b = BPF(text = """ #include <uapi/linux/bpf.h> #include <linux/in.h> #include <linux/if_ether.h> BPF_CPUMAP(cpumap, __MAX_CPU__); BPF_ARRAY(dest, uint32_t, 1); BPF_PERCPU_ARRAY(rxcnt, long, 1); int xdp_redirect_cpu(struct xdp_md *ctx) { void* data_end = (void*)(long)ctx->data_end; void* data = (void*)(long)ctx->data; struct ethhdr *eth = data; uint32_t key = 0; long *value; uint32_t *cpu; uint64_t nh_off; nh_off = sizeof(*eth); if (data + nh_off > data_end) return XDP_DROP; cpu = dest.lookup(&key); if (!cpu) return XDP_PASS; value = rxcnt.lookup(&key); if (value) *value += 1; return cpumap.redirect_map(*cpu, 0); } """, cflags=["-w", "-D__MAX_CPU__=%u" % max_cpu], debug=0) dest = b.get_table("dest") dest[0] = ct.c_uint32(cpu_id) cpumap = b.get_table("cpumap") cpumap[cpu_id] = ct.c_uint32(192) in_fn = b.load_func("xdp_redirect_cpu", BPF.XDP) b.attach_xdp(in_if, in_fn, flags) rxcnt = b.get_table("rxcnt") prev = 0 print("Printing redirected packets, hit CTRL+C to stop") while 1: try: val = rxcnt.sum(0).value if val: delta = val - prev prev = val print("{} pkt/s to CPU {}".format(delta, cpu_id)) time.sleep(1) except KeyboardInterrupt: print("Removing filter from device") break b.remove_xdp(in_if, flags)