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(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 }