1 // SPDX-License-Identifier: GPL-2.0-or-later 2 /* 3 * tcp_diag.c Module for monitoring TCP transport protocols sockets. 4 * 5 * Authors: Alexey Kuznetsov, <kuznet@ms2.inr.ac.ru> 6 */ 7 8 #include <linux/module.h> 9 #include <linux/net.h> 10 #include <linux/sock_diag.h> 11 #include <linux/inet_diag.h> 12 13 #include <linux/tcp.h> 14 15 #include <net/netlink.h> 16 #include <net/tcp.h> 17 18 static void tcp_diag_get_info(struct sock *sk, struct inet_diag_msg *r, 19 void *_info) 20 { 21 struct tcp_info *info = _info; 22 23 if (inet_sk_state_load(sk) == TCP_LISTEN) { 24 r->idiag_rqueue = sk->sk_ack_backlog; 25 r->idiag_wqueue = sk->sk_max_ack_backlog; 26 } else if (sk->sk_type == SOCK_STREAM) { 27 const struct tcp_sock *tp = tcp_sk(sk); 28 29 r->idiag_rqueue = max_t(int, tp->rcv_nxt - tp->copied_seq, 0); 30 r->idiag_wqueue = tp->write_seq - tp->snd_una; 31 } 32 if (info) 33 tcp_get_info(sk, info); 34 } 35 36 #ifdef CONFIG_TCP_MD5SIG 37 static void tcp_diag_md5sig_fill(struct tcp_diag_md5sig *info, 38 const struct tcp_md5sig_key *key) 39 { 40 info->tcpm_family = key->family; 41 info->tcpm_prefixlen = key->prefixlen; 42 info->tcpm_keylen = key->keylen; 43 memcpy(info->tcpm_key, key->key, key->keylen); 44 45 if (key->family == AF_INET) 46 info->tcpm_addr[0] = key->addr.a4.s_addr; 47 #if IS_ENABLED(CONFIG_IPV6) 48 else if (key->family == AF_INET6) 49 memcpy(&info->tcpm_addr, &key->addr.a6, 50 sizeof(info->tcpm_addr)); 51 #endif 52 } 53 54 static int tcp_diag_put_md5sig(struct sk_buff *skb, 55 const struct tcp_md5sig_info *md5sig) 56 { 57 const struct tcp_md5sig_key *key; 58 struct tcp_diag_md5sig *info; 59 struct nlattr *attr; 60 int md5sig_count = 0; 61 62 hlist_for_each_entry_rcu(key, &md5sig->head, node) 63 md5sig_count++; 64 if (md5sig_count == 0) 65 return 0; 66 67 attr = nla_reserve(skb, INET_DIAG_MD5SIG, 68 md5sig_count * sizeof(struct tcp_diag_md5sig)); 69 if (!attr) 70 return -EMSGSIZE; 71 72 info = nla_data(attr); 73 memset(info, 0, md5sig_count * sizeof(struct tcp_diag_md5sig)); 74 hlist_for_each_entry_rcu(key, &md5sig->head, node) { 75 tcp_diag_md5sig_fill(info++, key); 76 if (--md5sig_count == 0) 77 break; 78 } 79 80 return 0; 81 } 82 #endif 83 84 static int tcp_diag_get_aux(struct sock *sk, bool net_admin, 85 struct sk_buff *skb) 86 { 87 #ifdef CONFIG_TCP_MD5SIG 88 if (net_admin) { 89 struct tcp_md5sig_info *md5sig; 90 int err = 0; 91 92 rcu_read_lock(); 93 md5sig = rcu_dereference(tcp_sk(sk)->md5sig_info); 94 if (md5sig) 95 err = tcp_diag_put_md5sig(skb, md5sig); 96 rcu_read_unlock(); 97 if (err < 0) 98 return err; 99 } 100 #endif 101 102 return 0; 103 } 104 105 static size_t tcp_diag_get_aux_size(struct sock *sk, bool net_admin) 106 { 107 size_t size = 0; 108 109 #ifdef CONFIG_TCP_MD5SIG 110 if (net_admin && sk_fullsock(sk)) { 111 const struct tcp_md5sig_info *md5sig; 112 const struct tcp_md5sig_key *key; 113 size_t md5sig_count = 0; 114 115 rcu_read_lock(); 116 md5sig = rcu_dereference(tcp_sk(sk)->md5sig_info); 117 if (md5sig) { 118 hlist_for_each_entry_rcu(key, &md5sig->head, node) 119 md5sig_count++; 120 } 121 rcu_read_unlock(); 122 size += nla_total_size(md5sig_count * 123 sizeof(struct tcp_diag_md5sig)); 124 } 125 #endif 126 127 return size; 128 } 129 130 static void tcp_diag_dump(struct sk_buff *skb, struct netlink_callback *cb, 131 const struct inet_diag_req_v2 *r, struct nlattr *bc) 132 { 133 inet_diag_dump_icsk(&tcp_hashinfo, skb, cb, r, bc); 134 } 135 136 static int tcp_diag_dump_one(struct sk_buff *in_skb, const struct nlmsghdr *nlh, 137 const struct inet_diag_req_v2 *req) 138 { 139 return inet_diag_dump_one_icsk(&tcp_hashinfo, in_skb, nlh, req); 140 } 141 142 #ifdef CONFIG_INET_DIAG_DESTROY 143 static int tcp_diag_destroy(struct sk_buff *in_skb, 144 const struct inet_diag_req_v2 *req) 145 { 146 struct net *net = sock_net(in_skb->sk); 147 struct sock *sk = inet_diag_find_one_icsk(net, &tcp_hashinfo, req); 148 int err; 149 150 if (IS_ERR(sk)) 151 return PTR_ERR(sk); 152 153 err = sock_diag_destroy(sk, ECONNABORTED); 154 155 sock_gen_put(sk); 156 157 return err; 158 } 159 #endif 160 161 static const struct inet_diag_handler tcp_diag_handler = { 162 .dump = tcp_diag_dump, 163 .dump_one = tcp_diag_dump_one, 164 .idiag_get_info = tcp_diag_get_info, 165 .idiag_get_aux = tcp_diag_get_aux, 166 .idiag_get_aux_size = tcp_diag_get_aux_size, 167 .idiag_type = IPPROTO_TCP, 168 .idiag_info_size = sizeof(struct tcp_info), 169 #ifdef CONFIG_INET_DIAG_DESTROY 170 .destroy = tcp_diag_destroy, 171 #endif 172 }; 173 174 static int __init tcp_diag_init(void) 175 { 176 return inet_diag_register(&tcp_diag_handler); 177 } 178 179 static void __exit tcp_diag_exit(void) 180 { 181 inet_diag_unregister(&tcp_diag_handler); 182 } 183 184 module_init(tcp_diag_init); 185 module_exit(tcp_diag_exit); 186 MODULE_LICENSE("GPL"); 187 MODULE_ALIAS_NET_PF_PROTO_TYPE(PF_NETLINK, NETLINK_SOCK_DIAG, 2-6 /* AF_INET - IPPROTO_TCP */); 188