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