1 // SPDX-License-Identifier: GPL-2.0
2 /* MPTCP socket monitoring support
3 *
4 * Copyright (c) 2019 Red Hat
5 *
6 * Author: Davide Caratti <dcaratti@redhat.com>
7 */
8
9 #include <linux/kernel.h>
10 #include <linux/net.h>
11 #include <linux/inet_diag.h>
12 #include <net/netlink.h>
13 #include <uapi/linux/mptcp.h>
14 #include "protocol.h"
15
subflow_get_info(struct sock * sk,struct sk_buff * skb)16 static int subflow_get_info(struct sock *sk, struct sk_buff *skb)
17 {
18 struct mptcp_subflow_context *sf;
19 struct nlattr *start;
20 u32 flags = 0;
21 bool slow;
22 int err;
23
24 if (inet_sk_state_load(sk) == TCP_LISTEN)
25 return 0;
26
27 start = nla_nest_start_noflag(skb, INET_ULP_INFO_MPTCP);
28 if (!start)
29 return -EMSGSIZE;
30
31 slow = lock_sock_fast(sk);
32 rcu_read_lock();
33 sf = rcu_dereference(inet_csk(sk)->icsk_ulp_data);
34 if (!sf) {
35 err = 0;
36 goto nla_failure;
37 }
38
39 if (sf->mp_capable)
40 flags |= MPTCP_SUBFLOW_FLAG_MCAP_REM;
41 if (sf->request_mptcp)
42 flags |= MPTCP_SUBFLOW_FLAG_MCAP_LOC;
43 if (sf->mp_join)
44 flags |= MPTCP_SUBFLOW_FLAG_JOIN_REM;
45 if (sf->request_join)
46 flags |= MPTCP_SUBFLOW_FLAG_JOIN_LOC;
47 if (sf->backup)
48 flags |= MPTCP_SUBFLOW_FLAG_BKUP_REM;
49 if (sf->request_bkup)
50 flags |= MPTCP_SUBFLOW_FLAG_BKUP_LOC;
51 if (sf->fully_established)
52 flags |= MPTCP_SUBFLOW_FLAG_FULLY_ESTABLISHED;
53 if (sf->conn_finished)
54 flags |= MPTCP_SUBFLOW_FLAG_CONNECTED;
55 if (sf->map_valid)
56 flags |= MPTCP_SUBFLOW_FLAG_MAPVALID;
57
58 if (nla_put_u32(skb, MPTCP_SUBFLOW_ATTR_TOKEN_REM, sf->remote_token) ||
59 nla_put_u32(skb, MPTCP_SUBFLOW_ATTR_TOKEN_LOC, sf->token) ||
60 nla_put_u32(skb, MPTCP_SUBFLOW_ATTR_RELWRITE_SEQ,
61 sf->rel_write_seq) ||
62 nla_put_u64_64bit(skb, MPTCP_SUBFLOW_ATTR_MAP_SEQ, sf->map_seq,
63 MPTCP_SUBFLOW_ATTR_PAD) ||
64 nla_put_u32(skb, MPTCP_SUBFLOW_ATTR_MAP_SFSEQ,
65 sf->map_subflow_seq) ||
66 nla_put_u32(skb, MPTCP_SUBFLOW_ATTR_SSN_OFFSET, sf->ssn_offset) ||
67 nla_put_u16(skb, MPTCP_SUBFLOW_ATTR_MAP_DATALEN,
68 sf->map_data_len) ||
69 nla_put_u32(skb, MPTCP_SUBFLOW_ATTR_FLAGS, flags) ||
70 nla_put_u8(skb, MPTCP_SUBFLOW_ATTR_ID_REM, sf->remote_id) ||
71 nla_put_u8(skb, MPTCP_SUBFLOW_ATTR_ID_LOC, subflow_get_local_id(sf))) {
72 err = -EMSGSIZE;
73 goto nla_failure;
74 }
75
76 rcu_read_unlock();
77 unlock_sock_fast(sk, slow);
78 nla_nest_end(skb, start);
79 return 0;
80
81 nla_failure:
82 rcu_read_unlock();
83 unlock_sock_fast(sk, slow);
84 nla_nest_cancel(skb, start);
85 return err;
86 }
87
subflow_get_info_size(const struct sock * sk)88 static size_t subflow_get_info_size(const struct sock *sk)
89 {
90 size_t size = 0;
91
92 size += nla_total_size(0) + /* INET_ULP_INFO_MPTCP */
93 nla_total_size(4) + /* MPTCP_SUBFLOW_ATTR_TOKEN_REM */
94 nla_total_size(4) + /* MPTCP_SUBFLOW_ATTR_TOKEN_LOC */
95 nla_total_size(4) + /* MPTCP_SUBFLOW_ATTR_RELWRITE_SEQ */
96 nla_total_size_64bit(8) + /* MPTCP_SUBFLOW_ATTR_MAP_SEQ */
97 nla_total_size(4) + /* MPTCP_SUBFLOW_ATTR_MAP_SFSEQ */
98 nla_total_size(4) + /* MPTCP_SUBFLOW_ATTR_SSN_OFFSET */
99 nla_total_size(2) + /* MPTCP_SUBFLOW_ATTR_MAP_DATALEN */
100 nla_total_size(4) + /* MPTCP_SUBFLOW_ATTR_FLAGS */
101 nla_total_size(1) + /* MPTCP_SUBFLOW_ATTR_ID_REM */
102 nla_total_size(1) + /* MPTCP_SUBFLOW_ATTR_ID_LOC */
103 0;
104 return size;
105 }
106
mptcp_diag_subflow_init(struct tcp_ulp_ops * ops)107 void mptcp_diag_subflow_init(struct tcp_ulp_ops *ops)
108 {
109 ops->get_info = subflow_get_info;
110 ops->get_info_size = subflow_get_info_size;
111 }
112