net/mptcp/diag.c

   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(struct sock *sk, struct sk_buff *skb)
  17 {
  18         struct mptcp_subflow_context *sf;
  19         struct nlattr *start;
  20         u32 flags = 0;
  21         bool slow;
  22         int err;
  23
  24         if (inet_sk_state_load(sk) == TCP_LISTEN)
  25                 return 0;
  26
  27         start = nla_nest_start_noflag(skb, INET_ULP_INFO_MPTCP);
  28         if (!start)
  29                 return -EMSGSIZE;
  30
  31         slow = lock_sock_fast(sk);
  32         rcu_read_lock();
  33         sf = rcu_dereference(inet_csk(sk)->icsk_ulp_data);
  34         if (!sf) {
  35                 err = 0;
  36                 goto nla_failure;
  37         }
  38
  39         if (sf->mp_capable)
  40                 flags |= MPTCP_SUBFLOW_FLAG_MCAP_REM;
  41         if (sf->request_mptcp)
  42                 flags |= MPTCP_SUBFLOW_FLAG_MCAP_LOC;
  43         if (sf->mp_join)
  44                 flags |= MPTCP_SUBFLOW_FLAG_JOIN_REM;
  45         if (sf->request_join)
  46                 flags |= MPTCP_SUBFLOW_FLAG_JOIN_LOC;
  47         if (sf->backup)
  48                 flags |= MPTCP_SUBFLOW_FLAG_BKUP_REM;
  49         if (sf->request_bkup)
  50                 flags |= MPTCP_SUBFLOW_FLAG_BKUP_LOC;
  51         if (sf->fully_established)
  52                 flags |= MPTCP_SUBFLOW_FLAG_FULLY_ESTABLISHED;
  53         if (sf->conn_finished)
  54                 flags |= MPTCP_SUBFLOW_FLAG_CONNECTED;
  55         if (sf->map_valid)
  56                 flags |= MPTCP_SUBFLOW_FLAG_MAPVALID;
  57
  58         if (nla_put_u32(skb, MPTCP_SUBFLOW_ATTR_TOKEN_REM, sf->remote_token) ||
  59             nla_put_u32(skb, MPTCP_SUBFLOW_ATTR_TOKEN_LOC, sf->token) ||
  60             nla_put_u32(skb, MPTCP_SUBFLOW_ATTR_RELWRITE_SEQ,
  61                         sf->rel_write_seq) ||
  62             nla_put_u64_64bit(skb, MPTCP_SUBFLOW_ATTR_MAP_SEQ, sf->map_seq,
  63                               MPTCP_SUBFLOW_ATTR_PAD) ||
  64             nla_put_u32(skb, MPTCP_SUBFLOW_ATTR_MAP_SFSEQ,
  65                         sf->map_subflow_seq) ||
  66             nla_put_u32(skb, MPTCP_SUBFLOW_ATTR_SSN_OFFSET, sf->ssn_offset) ||
  67             nla_put_u16(skb, MPTCP_SUBFLOW_ATTR_MAP_DATALEN,
  68                         sf->map_data_len) ||
  69             nla_put_u32(skb, MPTCP_SUBFLOW_ATTR_FLAGS, flags) ||
  70             nla_put_u8(skb, MPTCP_SUBFLOW_ATTR_ID_REM, sf->remote_id) ||
  71             nla_put_u8(skb, MPTCP_SUBFLOW_ATTR_ID_LOC, subflow_get_local_id(sf))) {
  72                 err = -EMSGSIZE;
  73                 goto nla_failure;
  74         }
  75
  76         rcu_read_unlock();
  77         unlock_sock_fast(sk, slow);
  78         nla_nest_end(skb, start);
  79         return 0;
  80
  81 nla_failure:
  82         rcu_read_unlock();
  83         unlock_sock_fast(sk, slow);
  84         nla_nest_cancel(skb, start);
  85         return err;
  86 }
  87
  88 static size_t subflow_get_info_size(const struct sock *sk)
  89 {
  90         size_t size = 0;
  91
  92         size += nla_total_size(0) +     /* INET_ULP_INFO_MPTCP */
  93                 nla_total_size(4) +     /* MPTCP_SUBFLOW_ATTR_TOKEN_REM */
  94                 nla_total_size(4) +     /* MPTCP_SUBFLOW_ATTR_TOKEN_LOC */
  95                 nla_total_size(4) +     /* MPTCP_SUBFLOW_ATTR_RELWRITE_SEQ */
  96                 nla_total_size_64bit(8) +       /* MPTCP_SUBFLOW_ATTR_MAP_SEQ */
  97                 nla_total_size(4) +     /* MPTCP_SUBFLOW_ATTR_MAP_SFSEQ */
  98                 nla_total_size(2) +     /* MPTCP_SUBFLOW_ATTR_SSN_OFFSET */
  99                 nla_total_size(2) +     /* MPTCP_SUBFLOW_ATTR_MAP_DATALEN */
 100                 nla_total_size(4) +     /* MPTCP_SUBFLOW_ATTR_FLAGS */
 101                 nla_total_size(1) +     /* MPTCP_SUBFLOW_ATTR_ID_REM */
 102                 nla_total_size(1) +     /* MPTCP_SUBFLOW_ATTR_ID_LOC */
 103                 0;
 104         return size;
 105 }
 106
 107 void mptcp_diag_subflow_init(struct tcp_ulp_ops *ops)
 108 {
 109         ops->get_info = subflow_get_info;
 110         ops->get_info_size = subflow_get_info_size;
 111 }