xref: /kernel/linux/linux-5.10/net/mptcp/diag.c (revision 8c2ecf20)
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
16static 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
75nla_failure:
76	rcu_read_unlock();
77	nla_nest_cancel(skb, start);
78	return err;
79}
80
81static 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
100void 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