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}