1// SPDX-License-Identifier: GPL-2.0
2/* Copyright (c) 2020, Tessares SA. */
3/* Copyright (c) 2022, SUSE. */
4
5#include <linux/bpf.h>
6#include <bpf/bpf_helpers.h>
7#include "bpf_tcp_helpers.h"
8
9char _license[] SEC("license") = "GPL";
10__u32 token = 0;
11
12struct mptcp_storage {
13	__u32 invoked;
14	__u32 is_mptcp;
15	struct sock *sk;
16	__u32 token;
17	struct sock *first;
18	char ca_name[TCP_CA_NAME_MAX];
19};
20
21struct {
22	__uint(type, BPF_MAP_TYPE_SK_STORAGE);
23	__uint(map_flags, BPF_F_NO_PREALLOC);
24	__type(key, int);
25	__type(value, struct mptcp_storage);
26} socket_storage_map SEC(".maps");
27
28SEC("sockops")
29int _sockops(struct bpf_sock_ops *ctx)
30{
31	struct mptcp_storage *storage;
32	struct mptcp_sock *msk;
33	int op = (int)ctx->op;
34	struct tcp_sock *tsk;
35	struct bpf_sock *sk;
36	bool is_mptcp;
37
38	if (op != BPF_SOCK_OPS_TCP_CONNECT_CB)
39		return 1;
40
41	sk = ctx->sk;
42	if (!sk)
43		return 1;
44
45	tsk = bpf_skc_to_tcp_sock(sk);
46	if (!tsk)
47		return 1;
48
49	is_mptcp = bpf_core_field_exists(tsk->is_mptcp) ? tsk->is_mptcp : 0;
50	if (!is_mptcp) {
51		storage = bpf_sk_storage_get(&socket_storage_map, sk, 0,
52					     BPF_SK_STORAGE_GET_F_CREATE);
53		if (!storage)
54			return 1;
55
56		storage->token = 0;
57		__builtin_memset(storage->ca_name, 0, TCP_CA_NAME_MAX);
58		storage->first = NULL;
59	} else {
60		msk = bpf_skc_to_mptcp_sock(sk);
61		if (!msk)
62			return 1;
63
64		storage = bpf_sk_storage_get(&socket_storage_map, msk, 0,
65					     BPF_SK_STORAGE_GET_F_CREATE);
66		if (!storage)
67			return 1;
68
69		storage->token = msk->token;
70		__builtin_memcpy(storage->ca_name, msk->ca_name, TCP_CA_NAME_MAX);
71		storage->first = msk->first;
72	}
73	storage->invoked++;
74	storage->is_mptcp = is_mptcp;
75	storage->sk = (struct sock *)sk;
76
77	return 1;
78}
79
80SEC("fentry/mptcp_pm_new_connection")
81int BPF_PROG(trace_mptcp_pm_new_connection, struct mptcp_sock *msk,
82	     const struct sock *ssk, int server_side)
83{
84	if (!server_side)
85		token = msk->token;
86
87	return 0;
88}
89