bpf/progs/netns_cookie_prog.c

0001 // SPDX-License-Identifier: GPL-2.0
0002
0003 #include "vmlinux.h"
0004
0005 #include <bpf/bpf_helpers.h>
0006
0007 #define AF_INET6 10
0008
0009 struct {
0010     __uint(type, BPF_MAP_TYPE_SK_STORAGE);
0011     __uint(map_flags, BPF_F_NO_PREALLOC);
0012     __type(key, int);
0013     __type(value, int);
0014 } sockops_netns_cookies SEC(".maps");
0015
0016 struct {
0017     __uint(type, BPF_MAP_TYPE_SK_STORAGE);
0018     __uint(map_flags, BPF_F_NO_PREALLOC);
0019     __type(key, int);
0020     __type(value, int);
0021 } sk_msg_netns_cookies SEC(".maps");
0022
0023 struct {
0024     __uint(type, BPF_MAP_TYPE_SOCKMAP);
0025     __uint(max_entries, 2);
0026     __type(key, __u32);
0027     __type(value, __u64);
0028 } sock_map SEC(".maps");
0029
0030 SEC("sockops")
0031 int get_netns_cookie_sockops(struct bpf_sock_ops *ctx)
0032 {
0033     struct bpf_sock *sk = ctx->sk;
0034     int *cookie;
0035     __u32 key = 0;
0036
0037     if (ctx->family != AF_INET6)
0038         return 1;
0039
0040     if (!sk)
0041         return 1;
0042
0043     switch (ctx->op) {
0044     case BPF_SOCK_OPS_TCP_CONNECT_CB:
0045         cookie = bpf_sk_storage_get(&sockops_netns_cookies, sk, 0,
0046                         BPF_SK_STORAGE_GET_F_CREATE);
0047         if (!cookie)
0048             return 1;
0049
0050         *cookie = bpf_get_netns_cookie(ctx);
0051         break;
0052     case BPF_SOCK_OPS_ACTIVE_ESTABLISHED_CB:
0053         bpf_sock_map_update(ctx, &sock_map, &key, BPF_NOEXIST);
0054         break;
0055     default:
0056         break;
0057     }
0058
0059     return 1;
0060 }
0061
0062 SEC("sk_msg")
0063 int get_netns_cookie_sk_msg(struct sk_msg_md *msg)
0064 {
0065     struct bpf_sock *sk = msg->sk;
0066     int *cookie;
0067
0068     if (msg->family != AF_INET6)
0069         return 1;
0070
0071     if (!sk)
0072         return 1;
0073
0074     cookie = bpf_sk_storage_get(&sk_msg_netns_cookies, sk, 0,
0075                     BPF_SK_STORAGE_GET_F_CREATE);
0076     if (!cookie)
0077         return 1;
0078
0079     *cookie = bpf_get_netns_cookie(msg);
0080
0081     return 1;
0082 }
0083
0084 char _license[] SEC("license") = "GPL";