1 // SPDX-License-Identifier: GPL-2.0
2 // Copyright (c) 2020 Isovalent, Inc.
3 #include "vmlinux.h"
4 #include <bpf/bpf_helpers.h>
5
6 struct {
7 __uint(type, BPF_MAP_TYPE_SOCKMAP);
8 __uint(max_entries, 2);
9 __type(key, __u32);
10 __type(value, __u64);
11 } sock_map SEC(".maps");
12
13 struct {
14 __uint(type, BPF_MAP_TYPE_SOCKHASH);
15 __uint(max_entries, 2);
16 __type(key, __u32);
17 __type(value, __u64);
18 } sock_hash SEC(".maps");
19
20 struct {
21 __uint(type, BPF_MAP_TYPE_SK_STORAGE);
22 __uint(map_flags, BPF_F_NO_PREALLOC);
23 __type(key, __u32);
24 __type(value, __u64);
25 } socket_storage SEC(".maps");
26
prog_msg_verdict_common(struct sk_msg_md * msg)27 static int prog_msg_verdict_common(struct sk_msg_md *msg)
28 {
29 struct task_struct *task = (struct task_struct *)bpf_get_current_task();
30 int verdict = SK_PASS;
31 __u32 pid, tpid;
32 __u64 *sk_stg;
33
34 pid = bpf_get_current_pid_tgid() >> 32;
35 sk_stg = bpf_sk_storage_get(&socket_storage, msg->sk, 0, BPF_SK_STORAGE_GET_F_CREATE);
36 if (!sk_stg)
37 return SK_DROP;
38 *sk_stg = pid;
39 bpf_probe_read_kernel(&tpid , sizeof(tpid), &task->tgid);
40 if (pid != tpid)
41 verdict = SK_DROP;
42 bpf_sk_storage_delete(&socket_storage, (void *)msg->sk);
43 return verdict;
44 }
45
46 SEC("sk_msg")
prog_msg_verdict(struct sk_msg_md * msg)47 int prog_msg_verdict(struct sk_msg_md *msg)
48 {
49 return prog_msg_verdict_common(msg);
50 }
51
52 SEC("sk_msg")
prog_msg_verdict_clone(struct sk_msg_md * msg)53 int prog_msg_verdict_clone(struct sk_msg_md *msg)
54 {
55 return prog_msg_verdict_common(msg);
56 }
57
58 SEC("sk_msg")
prog_msg_verdict_clone2(struct sk_msg_md * msg)59 int prog_msg_verdict_clone2(struct sk_msg_md *msg)
60 {
61 return prog_msg_verdict_common(msg);
62 }
63
64 SEC("sk_skb/stream_verdict")
prog_skb_verdict(struct __sk_buff * skb)65 int prog_skb_verdict(struct __sk_buff *skb)
66 {
67 return SK_PASS;
68 }
69
70 char _license[] SEC("license") = "GPL";
71