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 "protocol.h" 14 15 static int subflow_get_info(struct sock *sk, struct sk_buff *skb) 16 { 17 struct mptcp_subflow_context *sf; 18 struct nlattr *start; 19 u32 flags = 0; 20 bool slow; 21 int err; 22 23 if (inet_sk_state_load(sk) == TCP_LISTEN) 24 return 0; 25 26 start = nla_nest_start_noflag(skb, INET_ULP_INFO_MPTCP); 27 if (!start) 28 return -EMSGSIZE; 29 30 slow = lock_sock_fast(sk); 31 rcu_read_lock(); 32 sf = rcu_dereference(inet_csk(sk)->icsk_ulp_data); 33 if (!sf) { 34 err = 0; 35 goto nla_failure; 36 } 37 38 if (sf->mp_capable) 39 flags |= MPTCP_SUBFLOW_FLAG_MCAP_REM; 40 if (sf->request_mptcp) 41 flags |= MPTCP_SUBFLOW_FLAG_MCAP_LOC; 42 if (sf->mp_join) 43 flags |= MPTCP_SUBFLOW_FLAG_JOIN_REM; 44 if (sf->request_join) 45 flags |= MPTCP_SUBFLOW_FLAG_JOIN_LOC; 46 if (sf->backup) 47 flags |= MPTCP_SUBFLOW_FLAG_BKUP_REM; 48 if (sf->request_bkup) 49 flags |= MPTCP_SUBFLOW_FLAG_BKUP_LOC; 50 if (sf->fully_established) 51 flags |= MPTCP_SUBFLOW_FLAG_FULLY_ESTABLISHED; 52 if (sf->conn_finished) 53 flags |= MPTCP_SUBFLOW_FLAG_CONNECTED; 54 if (sf->map_valid) 55 flags |= MPTCP_SUBFLOW_FLAG_MAPVALID; 56 57 if (nla_put_u32(skb, MPTCP_SUBFLOW_ATTR_TOKEN_REM, sf->remote_token) || 58 nla_put_u32(skb, MPTCP_SUBFLOW_ATTR_TOKEN_LOC, sf->token) || 59 nla_put_u32(skb, MPTCP_SUBFLOW_ATTR_RELWRITE_SEQ, 60 sf->rel_write_seq) || 61 nla_put_u64_64bit(skb, MPTCP_SUBFLOW_ATTR_MAP_SEQ, sf->map_seq, 62 MPTCP_SUBFLOW_ATTR_PAD) || 63 nla_put_u32(skb, MPTCP_SUBFLOW_ATTR_MAP_SFSEQ, 64 sf->map_subflow_seq) || 65 nla_put_u32(skb, MPTCP_SUBFLOW_ATTR_SSN_OFFSET, sf->ssn_offset) || 66 nla_put_u16(skb, MPTCP_SUBFLOW_ATTR_MAP_DATALEN, 67 sf->map_data_len) || 68 nla_put_u32(skb, MPTCP_SUBFLOW_ATTR_FLAGS, flags) || 69 nla_put_u8(skb, MPTCP_SUBFLOW_ATTR_ID_REM, sf->remote_id) || 70 nla_put_u8(skb, MPTCP_SUBFLOW_ATTR_ID_LOC, subflow_get_local_id(sf))) { 71 err = -EMSGSIZE; 72 goto nla_failure; 73 } 74 75 rcu_read_unlock(); 76 unlock_sock_fast(sk, slow); 77 nla_nest_end(skb, start); 78 return 0; 79 80 nla_failure: 81 rcu_read_unlock(); 82 unlock_sock_fast(sk, slow); 83 nla_nest_cancel(skb, start); 84 return err; 85 } 86 87 static size_t subflow_get_info_size(const struct sock *sk) 88 { 89 size_t size = 0; 90 91 size += nla_total_size(0) + /* INET_ULP_INFO_MPTCP */ 92 nla_total_size(4) + /* MPTCP_SUBFLOW_ATTR_TOKEN_REM */ 93 nla_total_size(4) + /* MPTCP_SUBFLOW_ATTR_TOKEN_LOC */ 94 nla_total_size(4) + /* MPTCP_SUBFLOW_ATTR_RELWRITE_SEQ */ 95 nla_total_size_64bit(8) + /* MPTCP_SUBFLOW_ATTR_MAP_SEQ */ 96 nla_total_size(4) + /* MPTCP_SUBFLOW_ATTR_MAP_SFSEQ */ 97 nla_total_size(2) + /* MPTCP_SUBFLOW_ATTR_SSN_OFFSET */ 98 nla_total_size(2) + /* MPTCP_SUBFLOW_ATTR_MAP_DATALEN */ 99 nla_total_size(4) + /* MPTCP_SUBFLOW_ATTR_FLAGS */ 100 nla_total_size(1) + /* MPTCP_SUBFLOW_ATTR_ID_REM */ 101 nla_total_size(1) + /* MPTCP_SUBFLOW_ATTR_ID_LOC */ 102 0; 103 return size; 104 } 105 106 void mptcp_diag_subflow_init(struct tcp_ulp_ops *ops) 107 { 108 ops->get_info = subflow_get_info; 109 ops->get_info_size = subflow_get_info_size; 110 } 111