1 /* 2 * tcp_diag.c Module for monitoring TCP transport protocols sockets. 3 * 4 * Authors: Alexey Kuznetsov, <kuznet@ms2.inr.ac.ru> 5 * 6 * This program is free software; you can redistribute it and/or 7 * modify it under the terms of the GNU General Public License 8 * as published by the Free Software Foundation; either version 9 * 2 of the License, or (at your option) any later version. 10 */ 11 12 #include <linux/module.h> 13 #include <linux/net.h> 14 #include <linux/sock_diag.h> 15 #include <linux/inet_diag.h> 16 17 #include <linux/tcp.h> 18 19 #include <net/netlink.h> 20 #include <net/tcp.h> 21 22 static void tcp_diag_get_info(struct sock *sk, struct inet_diag_msg *r, 23 void *_info) 24 { 25 struct tcp_info *info = _info; 26 27 if (inet_sk_state_load(sk) == TCP_LISTEN) { 28 r->idiag_rqueue = sk->sk_ack_backlog; 29 r->idiag_wqueue = sk->sk_max_ack_backlog; 30 } else if (sk->sk_type == SOCK_STREAM) { 31 const struct tcp_sock *tp = tcp_sk(sk); 32 33 r->idiag_rqueue = max_t(int, tp->rcv_nxt - tp->copied_seq, 0); 34 r->idiag_wqueue = tp->write_seq - tp->snd_una; 35 } 36 if (info) 37 tcp_get_info(sk, info); 38 } 39 40 #ifdef CONFIG_TCP_MD5SIG 41 static void tcp_diag_md5sig_fill(struct tcp_diag_md5sig *info, 42 const struct tcp_md5sig_key *key) 43 { 44 info->tcpm_family = key->family; 45 info->tcpm_prefixlen = key->prefixlen; 46 info->tcpm_keylen = key->keylen; 47 memcpy(info->tcpm_key, key->key, key->keylen); 48 49 if (key->family == AF_INET) 50 info->tcpm_addr[0] = key->addr.a4.s_addr; 51 #if IS_ENABLED(CONFIG_IPV6) 52 else if (key->family == AF_INET6) 53 memcpy(&info->tcpm_addr, &key->addr.a6, 54 sizeof(info->tcpm_addr)); 55 #endif 56 } 57 58 static int tcp_diag_put_md5sig(struct sk_buff *skb, 59 const struct tcp_md5sig_info *md5sig) 60 { 61 const struct tcp_md5sig_key *key; 62 struct tcp_diag_md5sig *info; 63 struct nlattr *attr; 64 int md5sig_count = 0; 65 66 hlist_for_each_entry_rcu(key, &md5sig->head, node) 67 md5sig_count++; 68 if (md5sig_count == 0) 69 return 0; 70 71 attr = nla_reserve(skb, INET_DIAG_MD5SIG, 72 md5sig_count * sizeof(struct tcp_diag_md5sig)); 73 if (!attr) 74 return -EMSGSIZE; 75 76 info = nla_data(attr); 77 memset(info, 0, md5sig_count * sizeof(struct tcp_diag_md5sig)); 78 hlist_for_each_entry_rcu(key, &md5sig->head, node) { 79 tcp_diag_md5sig_fill(info++, key); 80 if (--md5sig_count == 0) 81 break; 82 } 83 84 return 0; 85 } 86 #endif 87 88 static int tcp_diag_get_aux(struct sock *sk, bool net_admin, 89 struct sk_buff *skb) 90 { 91 #ifdef CONFIG_TCP_MD5SIG 92 if (net_admin) { 93 struct tcp_md5sig_info *md5sig; 94 int err = 0; 95 96 rcu_read_lock(); 97 md5sig = rcu_dereference(tcp_sk(sk)->md5sig_info); 98 if (md5sig) 99 err = tcp_diag_put_md5sig(skb, md5sig); 100 rcu_read_unlock(); 101 if (err < 0) 102 return err; 103 } 104 #endif 105 106 return 0; 107 } 108 109 static size_t tcp_diag_get_aux_size(struct sock *sk, bool net_admin) 110 { 111 size_t size = 0; 112 113 #ifdef CONFIG_TCP_MD5SIG 114 if (net_admin && sk_fullsock(sk)) { 115 const struct tcp_md5sig_info *md5sig; 116 const struct tcp_md5sig_key *key; 117 size_t md5sig_count = 0; 118 119 rcu_read_lock(); 120 md5sig = rcu_dereference(tcp_sk(sk)->md5sig_info); 121 if (md5sig) { 122 hlist_for_each_entry_rcu(key, &md5sig->head, node) 123 md5sig_count++; 124 } 125 rcu_read_unlock(); 126 size += nla_total_size(md5sig_count * 127 sizeof(struct tcp_diag_md5sig)); 128 } 129 #endif 130 131 return size; 132 } 133 134 static void tcp_diag_dump(struct sk_buff *skb, struct netlink_callback *cb, 135 const struct inet_diag_req_v2 *r, struct nlattr *bc) 136 { 137 inet_diag_dump_icsk(&tcp_hashinfo, skb, cb, r, bc); 138 } 139 140 static int tcp_diag_dump_one(struct sk_buff *in_skb, const struct nlmsghdr *nlh, 141 const struct inet_diag_req_v2 *req) 142 { 143 return inet_diag_dump_one_icsk(&tcp_hashinfo, in_skb, nlh, req); 144 } 145 146 #ifdef CONFIG_INET_DIAG_DESTROY 147 static int tcp_diag_destroy(struct sk_buff *in_skb, 148 const struct inet_diag_req_v2 *req) 149 { 150 struct net *net = sock_net(in_skb->sk); 151 struct sock *sk = inet_diag_find_one_icsk(net, &tcp_hashinfo, req); 152 int err; 153 154 if (IS_ERR(sk)) 155 return PTR_ERR(sk); 156 157 err = sock_diag_destroy(sk, ECONNABORTED); 158 159 sock_gen_put(sk); 160 161 return err; 162 } 163 #endif 164 165 static const struct inet_diag_handler tcp_diag_handler = { 166 .dump = tcp_diag_dump, 167 .dump_one = tcp_diag_dump_one, 168 .idiag_get_info = tcp_diag_get_info, 169 .idiag_get_aux = tcp_diag_get_aux, 170 .idiag_get_aux_size = tcp_diag_get_aux_size, 171 .idiag_type = IPPROTO_TCP, 172 .idiag_info_size = sizeof(struct tcp_info), 173 #ifdef CONFIG_INET_DIAG_DESTROY 174 .destroy = tcp_diag_destroy, 175 #endif 176 }; 177 178 static int __init tcp_diag_init(void) 179 { 180 return inet_diag_register(&tcp_diag_handler); 181 } 182 183 static void __exit tcp_diag_exit(void) 184 { 185 inet_diag_unregister(&tcp_diag_handler); 186 } 187 188 module_init(tcp_diag_init); 189 module_exit(tcp_diag_exit); 190 MODULE_LICENSE("GPL"); 191 MODULE_ALIAS_NET_PF_PROTO_TYPE(PF_NETLINK, NETLINK_SOCK_DIAG, 2-6 /* AF_INET - IPPROTO_TCP */); 192