1 /* 2 * Copyright (c) 2006, 2018 Oracle and/or its affiliates. All rights reserved. 3 * 4 * This software is available to you under a choice of one of two 5 * licenses. You may choose to be licensed under the terms of the GNU 6 * General Public License (GPL) Version 2, available from the file 7 * COPYING in the main directory of this source tree, or the 8 * OpenIB.org BSD license below: 9 * 10 * Redistribution and use in source and binary forms, with or 11 * without modification, are permitted provided that the following 12 * conditions are met: 13 * 14 * - Redistributions of source code must retain the above 15 * copyright notice, this list of conditions and the following 16 * disclaimer. 17 * 18 * - Redistributions in binary form must reproduce the above 19 * copyright notice, this list of conditions and the following 20 * disclaimer in the documentation and/or other materials 21 * provided with the distribution. 22 * 23 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, 24 * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF 25 * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND 26 * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS 27 * BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN 28 * ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN 29 * CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE 30 * SOFTWARE. 31 * 32 */ 33 #include <linux/kernel.h> 34 #include <linux/gfp.h> 35 #include <linux/in.h> 36 #include <net/tcp.h> 37 #include <trace/events/sock.h> 38 39 #include "rds.h" 40 #include "tcp.h" 41 42 void rds_tcp_keepalive(struct socket *sock) 43 { 44 /* values below based on xs_udp_default_timeout */ 45 int keepidle = 5; /* send a probe 'keepidle' secs after last data */ 46 int keepcnt = 5; /* number of unack'ed probes before declaring dead */ 47 48 sock_set_keepalive(sock->sk); 49 tcp_sock_set_keepcnt(sock->sk, keepcnt); 50 tcp_sock_set_keepidle(sock->sk, keepidle); 51 /* KEEPINTVL is the interval between successive probes. We follow 52 * the model in xs_tcp_finish_connecting() and re-use keepidle. 53 */ 54 tcp_sock_set_keepintvl(sock->sk, keepidle); 55 } 56 57 /* rds_tcp_accept_one_path(): if accepting on cp_index > 0, make sure the 58 * client's ipaddr < server's ipaddr. Otherwise, close the accepted 59 * socket and force a reconneect from smaller -> larger ip addr. The reason 60 * we special case cp_index 0 is to allow the rds probe ping itself to itself 61 * get through efficiently. 62 * Since reconnects are only initiated from the node with the numerically 63 * smaller ip address, we recycle conns in RDS_CONN_ERROR on the passive side 64 * by moving them to CONNECTING in this function. 65 */ 66 static 67 struct rds_tcp_connection *rds_tcp_accept_one_path(struct rds_connection *conn) 68 { 69 int i; 70 int npaths = max_t(int, 1, conn->c_npaths); 71 72 /* for mprds, all paths MUST be initiated by the peer 73 * with the smaller address. 74 */ 75 if (rds_addr_cmp(&conn->c_faddr, &conn->c_laddr) >= 0) { 76 /* Make sure we initiate at least one path if this 77 * has not already been done; rds_start_mprds() will 78 * take care of additional paths, if necessary. 79 */ 80 if (npaths == 1) 81 rds_conn_path_connect_if_down(&conn->c_path[0]); 82 return NULL; 83 } 84 85 for (i = 0; i < npaths; i++) { 86 struct rds_conn_path *cp = &conn->c_path[i]; 87 88 if (rds_conn_path_transition(cp, RDS_CONN_DOWN, 89 RDS_CONN_CONNECTING) || 90 rds_conn_path_transition(cp, RDS_CONN_ERROR, 91 RDS_CONN_CONNECTING)) { 92 return cp->cp_transport_data; 93 } 94 } 95 return NULL; 96 } 97 98 int rds_tcp_accept_one(struct socket *sock) 99 { 100 struct socket *new_sock = NULL; 101 struct rds_connection *conn; 102 int ret; 103 struct inet_sock *inet; 104 struct rds_tcp_connection *rs_tcp = NULL; 105 int conn_state; 106 struct rds_conn_path *cp; 107 struct in6_addr *my_addr, *peer_addr; 108 #if !IS_ENABLED(CONFIG_IPV6) 109 struct in6_addr saddr, daddr; 110 #endif 111 int dev_if = 0; 112 113 if (!sock) /* module unload or netns delete in progress */ 114 return -ENETUNREACH; 115 116 ret = sock_create_lite(sock->sk->sk_family, 117 sock->sk->sk_type, sock->sk->sk_protocol, 118 &new_sock); 119 if (ret) 120 goto out; 121 122 ret = sock->ops->accept(sock, new_sock, O_NONBLOCK, true); 123 if (ret < 0) 124 goto out; 125 126 /* sock_create_lite() does not get a hold on the owner module so we 127 * need to do it here. Note that sock_release() uses sock->ops to 128 * determine if it needs to decrement the reference count. So set 129 * sock->ops after calling accept() in case that fails. And there's 130 * no need to do try_module_get() as the listener should have a hold 131 * already. 132 */ 133 new_sock->ops = sock->ops; 134 __module_get(new_sock->ops->owner); 135 136 rds_tcp_keepalive(new_sock); 137 if (!rds_tcp_tune(new_sock)) { 138 ret = -EINVAL; 139 goto out; 140 } 141 142 inet = inet_sk(new_sock->sk); 143 144 #if IS_ENABLED(CONFIG_IPV6) 145 my_addr = &new_sock->sk->sk_v6_rcv_saddr; 146 peer_addr = &new_sock->sk->sk_v6_daddr; 147 #else 148 ipv6_addr_set_v4mapped(inet->inet_saddr, &saddr); 149 ipv6_addr_set_v4mapped(inet->inet_daddr, &daddr); 150 my_addr = &saddr; 151 peer_addr = &daddr; 152 #endif 153 rdsdebug("accepted family %d tcp %pI6c:%u -> %pI6c:%u\n", 154 sock->sk->sk_family, 155 my_addr, ntohs(inet->inet_sport), 156 peer_addr, ntohs(inet->inet_dport)); 157 158 #if IS_ENABLED(CONFIG_IPV6) 159 /* sk_bound_dev_if is not set if the peer address is not link local 160 * address. In this case, it happens that mcast_oif is set. So 161 * just use it. 162 */ 163 if ((ipv6_addr_type(my_addr) & IPV6_ADDR_LINKLOCAL) && 164 !(ipv6_addr_type(peer_addr) & IPV6_ADDR_LINKLOCAL)) { 165 struct ipv6_pinfo *inet6; 166 167 inet6 = inet6_sk(new_sock->sk); 168 dev_if = inet6->mcast_oif; 169 } else { 170 dev_if = new_sock->sk->sk_bound_dev_if; 171 } 172 #endif 173 174 if (!rds_tcp_laddr_check(sock_net(sock->sk), peer_addr, dev_if)) { 175 /* local address connection is only allowed via loopback */ 176 ret = -EOPNOTSUPP; 177 goto out; 178 } 179 180 conn = rds_conn_create(sock_net(sock->sk), 181 my_addr, peer_addr, 182 &rds_tcp_transport, 0, GFP_KERNEL, dev_if); 183 184 if (IS_ERR(conn)) { 185 ret = PTR_ERR(conn); 186 goto out; 187 } 188 /* An incoming SYN request came in, and TCP just accepted it. 189 * 190 * If the client reboots, this conn will need to be cleaned up. 191 * rds_tcp_state_change() will do that cleanup 192 */ 193 rs_tcp = rds_tcp_accept_one_path(conn); 194 if (!rs_tcp) 195 goto rst_nsk; 196 mutex_lock(&rs_tcp->t_conn_path_lock); 197 cp = rs_tcp->t_cpath; 198 conn_state = rds_conn_path_state(cp); 199 WARN_ON(conn_state == RDS_CONN_UP); 200 if (conn_state != RDS_CONN_CONNECTING && conn_state != RDS_CONN_ERROR) 201 goto rst_nsk; 202 if (rs_tcp->t_sock) { 203 /* Duelling SYN has been handled in rds_tcp_accept_one() */ 204 rds_tcp_reset_callbacks(new_sock, cp); 205 /* rds_connect_path_complete() marks RDS_CONN_UP */ 206 rds_connect_path_complete(cp, RDS_CONN_RESETTING); 207 } else { 208 rds_tcp_set_callbacks(new_sock, cp); 209 rds_connect_path_complete(cp, RDS_CONN_CONNECTING); 210 } 211 new_sock = NULL; 212 ret = 0; 213 if (conn->c_npaths == 0) 214 rds_send_ping(cp->cp_conn, cp->cp_index); 215 goto out; 216 rst_nsk: 217 /* reset the newly returned accept sock and bail. 218 * It is safe to set linger on new_sock because the RDS connection 219 * has not been brought up on new_sock, so no RDS-level data could 220 * be pending on it. By setting linger, we achieve the side-effect 221 * of avoiding TIME_WAIT state on new_sock. 222 */ 223 sock_no_linger(new_sock->sk); 224 kernel_sock_shutdown(new_sock, SHUT_RDWR); 225 ret = 0; 226 out: 227 if (rs_tcp) 228 mutex_unlock(&rs_tcp->t_conn_path_lock); 229 if (new_sock) 230 sock_release(new_sock); 231 return ret; 232 } 233 234 void rds_tcp_listen_data_ready(struct sock *sk) 235 { 236 void (*ready)(struct sock *sk); 237 238 trace_sk_data_ready(sk); 239 rdsdebug("listen data ready sk %p\n", sk); 240 241 read_lock_bh(&sk->sk_callback_lock); 242 ready = sk->sk_user_data; 243 if (!ready) { /* check for teardown race */ 244 ready = sk->sk_data_ready; 245 goto out; 246 } 247 248 /* 249 * ->sk_data_ready is also called for a newly established child socket 250 * before it has been accepted and the accepter has set up their 251 * data_ready.. we only want to queue listen work for our listening 252 * socket 253 * 254 * (*ready)() may be null if we are racing with netns delete, and 255 * the listen socket is being torn down. 256 */ 257 if (sk->sk_state == TCP_LISTEN) 258 rds_tcp_accept_work(sk); 259 else 260 ready = rds_tcp_listen_sock_def_readable(sock_net(sk)); 261 262 out: 263 read_unlock_bh(&sk->sk_callback_lock); 264 if (ready) 265 ready(sk); 266 } 267 268 struct socket *rds_tcp_listen_init(struct net *net, bool isv6) 269 { 270 struct socket *sock = NULL; 271 struct sockaddr_storage ss; 272 struct sockaddr_in6 *sin6; 273 struct sockaddr_in *sin; 274 int addr_len; 275 int ret; 276 277 ret = sock_create_kern(net, isv6 ? PF_INET6 : PF_INET, SOCK_STREAM, 278 IPPROTO_TCP, &sock); 279 if (ret < 0) { 280 rdsdebug("could not create %s listener socket: %d\n", 281 isv6 ? "IPv6" : "IPv4", ret); 282 goto out; 283 } 284 285 sock->sk->sk_reuse = SK_CAN_REUSE; 286 tcp_sock_set_nodelay(sock->sk); 287 288 write_lock_bh(&sock->sk->sk_callback_lock); 289 sock->sk->sk_user_data = sock->sk->sk_data_ready; 290 sock->sk->sk_data_ready = rds_tcp_listen_data_ready; 291 write_unlock_bh(&sock->sk->sk_callback_lock); 292 293 if (isv6) { 294 sin6 = (struct sockaddr_in6 *)&ss; 295 sin6->sin6_family = PF_INET6; 296 sin6->sin6_addr = in6addr_any; 297 sin6->sin6_port = (__force u16)htons(RDS_TCP_PORT); 298 sin6->sin6_scope_id = 0; 299 sin6->sin6_flowinfo = 0; 300 addr_len = sizeof(*sin6); 301 } else { 302 sin = (struct sockaddr_in *)&ss; 303 sin->sin_family = PF_INET; 304 sin->sin_addr.s_addr = INADDR_ANY; 305 sin->sin_port = (__force u16)htons(RDS_TCP_PORT); 306 addr_len = sizeof(*sin); 307 } 308 309 ret = sock->ops->bind(sock, (struct sockaddr *)&ss, addr_len); 310 if (ret < 0) { 311 rdsdebug("could not bind %s listener socket: %d\n", 312 isv6 ? "IPv6" : "IPv4", ret); 313 goto out; 314 } 315 316 ret = sock->ops->listen(sock, 64); 317 if (ret < 0) 318 goto out; 319 320 return sock; 321 out: 322 if (sock) 323 sock_release(sock); 324 return NULL; 325 } 326 327 void rds_tcp_listen_stop(struct socket *sock, struct work_struct *acceptor) 328 { 329 struct sock *sk; 330 331 if (!sock) 332 return; 333 334 sk = sock->sk; 335 336 /* serialize with and prevent further callbacks */ 337 lock_sock(sk); 338 write_lock_bh(&sk->sk_callback_lock); 339 if (sk->sk_user_data) { 340 sk->sk_data_ready = sk->sk_user_data; 341 sk->sk_user_data = NULL; 342 } 343 write_unlock_bh(&sk->sk_callback_lock); 344 release_sock(sk); 345 346 /* wait for accepts to stop and close the socket */ 347 flush_workqueue(rds_wq); 348 flush_work(acceptor); 349 sock_release(sock); 350 } 351