xref: /openbmc/linux/net/mptcp/diag.c (revision c4a54f70)
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  
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  
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  
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