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