tools/testing/selftests/bpf/progs/sockopt_multi.c

   1 // SPDX-License-Identifier: GPL-2.0
   2 #include <netinet/in.h>
   3 #include <linux/bpf.h>
   4 #include <bpf/bpf_helpers.h>
   5
   6 char _license[] SEC("license") = "GPL";
   7 __u32 _version SEC("version") = 1;
   8
   9 SEC("cgroup/getsockopt/child")
  10 int _getsockopt_child(struct bpf_sockopt *ctx)
  11 {
  12         __u8 *optval_end = ctx->optval_end;
  13         __u8 *optval = ctx->optval;
  14
  15         if (ctx->level != SOL_IP || ctx->optname != IP_TOS)
  16                 return 1;
  17
  18         if (optval + 1 > optval_end)
  19                 return 0; /* EPERM, bounds check */
  20
  21         if (optval[0] != 0x80)
  22                 return 0; /* EPERM, unexpected optval from the kernel */
  23
  24         ctx->retval = 0; /* Reset system call return value to zero */
  25
  26         optval[0] = 0x90;
  27         ctx->optlen = 1;
  28
  29         return 1;
  30 }
  31
  32 SEC("cgroup/getsockopt/parent")
  33 int _getsockopt_parent(struct bpf_sockopt *ctx)
  34 {
  35         __u8 *optval_end = ctx->optval_end;
  36         __u8 *optval = ctx->optval;
  37
  38         if (ctx->level != SOL_IP || ctx->optname != IP_TOS)
  39                 return 1;
  40
  41         if (optval + 1 > optval_end)
  42                 return 0; /* EPERM, bounds check */
  43
  44         if (optval[0] != 0x90)
  45                 return 0; /* EPERM, unexpected optval from the kernel */
  46
  47         ctx->retval = 0; /* Reset system call return value to zero */
  48
  49         optval[0] = 0xA0;
  50         ctx->optlen = 1;
  51
  52         return 1;
  53 }
  54
  55 SEC("cgroup/setsockopt")
  56 int _setsockopt(struct bpf_sockopt *ctx)
  57 {
  58         __u8 *optval_end = ctx->optval_end;
  59         __u8 *optval = ctx->optval;
  60
  61         if (ctx->level != SOL_IP || ctx->optname != IP_TOS)
  62                 return 1;
  63
  64         if (optval + 1 > optval_end)
  65                 return 0; /* EPERM, bounds check */
  66
  67         optval[0] += 0x10;
  68         ctx->optlen = 1;
  69
  70         return 1;
  71 }