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