LXR linux/tools/testing/selftests/bpf/progs/sockopt

   1// SPDX-License-Identifier: GPL-2.0
   2#include <linux/bpf.h>
   3#include <bpf/bpf_helpers.h>
   4
   5char _license[] SEC("license") = "GPL";
   6__u32 _version SEC("version") = 1;
   7
   8#define SOL_CUSTOM                      0xdeadbeef
   9#define CUSTOM_INHERIT1                 0
  10#define CUSTOM_INHERIT2                 1
  11#define CUSTOM_LISTENER                 2
  12
  13struct sockopt_inherit {
  14        __u8 val;
  15};
  16
  17struct {
  18        __uint(type, BPF_MAP_TYPE_SK_STORAGE);
  19        __uint(map_flags, BPF_F_NO_PREALLOC | BPF_F_CLONE);
  20        __type(key, int);
  21        __type(value, struct sockopt_inherit);
  22} cloned1_map SEC(".maps");
  23
  24struct {
  25        __uint(type, BPF_MAP_TYPE_SK_STORAGE);
  26        __uint(map_flags, BPF_F_NO_PREALLOC | BPF_F_CLONE);
  27        __type(key, int);
  28        __type(value, struct sockopt_inherit);
  29} cloned2_map SEC(".maps");
  30
  31struct {
  32        __uint(type, BPF_MAP_TYPE_SK_STORAGE);
  33        __uint(map_flags, BPF_F_NO_PREALLOC);
  34        __type(key, int);
  35        __type(value, struct sockopt_inherit);
  36} listener_only_map SEC(".maps");
  37
  38static __inline struct sockopt_inherit *get_storage(struct bpf_sockopt *ctx)
  39{
  40        if (ctx->optname == CUSTOM_INHERIT1)
  41                return bpf_sk_storage_get(&cloned1_map, ctx->sk, 0,
  42                                          BPF_SK_STORAGE_GET_F_CREATE);
  43        else if (ctx->optname == CUSTOM_INHERIT2)
  44                return bpf_sk_storage_get(&cloned2_map, ctx->sk, 0,
  45                                          BPF_SK_STORAGE_GET_F_CREATE);
  46        else
  47                return bpf_sk_storage_get(&listener_only_map, ctx->sk, 0,
  48                                          BPF_SK_STORAGE_GET_F_CREATE);
  49}
  50
  51SEC("cgroup/getsockopt")
  52int _getsockopt(struct bpf_sockopt *ctx)
  53{
  54        __u8 *optval_end = ctx->optval_end;
  55        struct sockopt_inherit *storage;
  56        __u8 *optval = ctx->optval;
  57
  58        if (ctx->level != SOL_CUSTOM)
  59                return 1; /* only interested in SOL_CUSTOM */
  60
  61        if (optval + 1 > optval_end)
  62                return 0; /* EPERM, bounds check */
  63
  64        storage = get_storage(ctx);
  65        if (!storage)
  66                return 0; /* EPERM, couldn't get sk storage */
  67
  68        ctx->retval = 0; /* Reset system call return value to zero */
  69
  70        optval[0] = storage->val;
  71        ctx->optlen = 1;
  72
  73        return 1;
  74}
  75
  76SEC("cgroup/setsockopt")
  77int _setsockopt(struct bpf_sockopt *ctx)
  78{
  79        __u8 *optval_end = ctx->optval_end;
  80        struct sockopt_inherit *storage;
  81        __u8 *optval = ctx->optval;
  82
  83        if (ctx->level != SOL_CUSTOM)
  84                return 1; /* only interested in SOL_CUSTOM */
  85
  86        if (optval + 1 > optval_end)
  87                return 0; /* EPERM, bounds check */
  88
  89        storage = get_storage(ctx);
  90        if (!storage)
  91                return 0; /* EPERM, couldn't get sk storage */
  92
  93        storage->val = optval[0];
  94        ctx->optlen = -1;
  95
  96        return 1;
  97}
  98