samples/bpf/libbpf.c

   1 /* eBPF mini library */
   2 #include <stdlib.h>
   3 #include <stdio.h>
   4 #include <linux/unistd.h>
   5 #include <unistd.h>
   6 #include <string.h>
   7 #include <errno.h>
   8 #include <net/ethernet.h>
   9 #include <net/if.h>
  10 #include <linux/if_packet.h>
  11 #include <arpa/inet.h>
  12 #include "libbpf.h"
  13
  14 int bpf_prog_attach(int prog_fd, int target_fd, enum bpf_attach_type type)
  15 {
  16         union bpf_attr attr = {
  17                 .target_fd = target_fd,
  18                 .attach_bpf_fd = prog_fd,
  19                 .attach_type = type,
  20         };
  21
  22         return syscall(__NR_bpf, BPF_PROG_ATTACH, &attr, sizeof(attr));
  23 }
  24
  25 int bpf_prog_detach(int target_fd, enum bpf_attach_type type)
  26 {
  27         union bpf_attr attr = {
  28                 .target_fd = target_fd,
  29                 .attach_type = type,
  30         };
  31
  32         return syscall(__NR_bpf, BPF_PROG_DETACH, &attr, sizeof(attr));
  33 }
  34
  35 int open_raw_sock(const char *name)
  36 {
  37         struct sockaddr_ll sll;
  38         int sock;
  39
  40         sock = socket(PF_PACKET, SOCK_RAW | SOCK_NONBLOCK | SOCK_CLOEXEC, htons(ETH_P_ALL));
  41         if (sock < 0) {
  42                 printf("cannot create raw socket\n");
  43                 return -1;
  44         }
  45
  46         memset(&sll, 0, sizeof(sll));
  47         sll.sll_family = AF_PACKET;
  48         sll.sll_ifindex = if_nametoindex(name);
  49         sll.sll_protocol = htons(ETH_P_ALL);
  50         if (bind(sock, (struct sockaddr *)&sll, sizeof(sll)) < 0) {
  51                 printf("bind to %s: %s\n", name, strerror(errno));
  52                 close(sock);
  53                 return -1;
  54         }
  55
  56         return sock;
  57 }
  58
  59 int perf_event_open(struct perf_event_attr *attr, int pid, int cpu,
  60                     int group_fd, unsigned long flags)
  61 {
  62         return syscall(__NR_perf_event_open, attr, pid, cpu,
  63                        group_fd, flags);
  64 }