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 38 #include "rds.h" 39 #include "tcp.h" 40 41 int rds_tcp_keepalive(struct socket *sock) 42 { 43 /* values below based on xs_udp_default_timeout */ 44 int keepidle = 5; /* send a probe 'keepidle' secs after last data */ 45 int keepcnt = 5; /* number of unack'ed probes before declaring dead */ 46 int keepalive = 1; 47 int ret = 0; 48 49 ret = kernel_setsockopt(sock, SOL_SOCKET, SO_KEEPALIVE, 50 (char *)&keepalive, sizeof(keepalive)); 51 if (ret < 0) 52 goto bail; 53 54 ret = kernel_setsockopt(sock, IPPROTO_TCP, TCP_KEEPCNT, 55 (char *)&keepcnt, sizeof(keepcnt)); 56 if (ret < 0) 57 goto bail; 58 59 ret = kernel_setsockopt(sock, IPPROTO_TCP, TCP_KEEPIDLE, 60 (char *)&keepidle, sizeof(keepidle)); 61 if (ret < 0) 62 goto bail; 63 64 /* KEEPINTVL is the interval between successive probes. We follow 65 * the model in xs_tcp_finish_connecting() and re-use keepidle. 66 */ 67 ret = kernel_setsockopt(sock, IPPROTO_TCP, TCP_KEEPINTVL, 68 (char *)&keepidle, sizeof(keepidle)); 69 bail: 70 return ret; 71 } 72 73 /* rds_tcp_accept_one_path(): if accepting on cp_index > 0, make sure the 74 * client's ipaddr < server's ipaddr. Otherwise, close the accepted 75 * socket and force a reconneect from smaller -> larger ip addr. The reason 76 * we special case cp_index 0 is to allow the rds probe ping itself to itself 77 * get through efficiently. 78 * Since reconnects are only initiated from the node with the numerically 79 * smaller ip address, we recycle conns in RDS_CONN_ERROR on the passive side 80 * by moving them to CONNECTING in this function. 81 */ 82 static 83 struct rds_tcp_connection *rds_tcp_accept_one_path(struct rds_connection *conn) 84 { 85 int i; 86 int npaths = max_t(int, 1, conn->c_npaths); 87 88 /* for mprds, all paths MUST be initiated by the peer 89 * with the smaller address. 90 */ 91 if (rds_addr_cmp(&conn->c_faddr, &conn->c_laddr) >= 0) { 92 /* Make sure we initiate at least one path if this 93 * has not already been done; rds_start_mprds() will 94 * take care of additional paths, if necessary. 95 */ 96 if (npaths == 1) 97 rds_conn_path_connect_if_down(&conn->c_path[0]); 98 return NULL; 99 } 100 101 for (i = 0; i < npaths; i++) { 102 struct rds_conn_path *cp = &conn->c_path[i]; 103 104 if (rds_conn_path_transition(cp, RDS_CONN_DOWN, 105 RDS_CONN_CONNECTING) || 106 rds_conn_path_transition(cp, RDS_CONN_ERROR, 107 RDS_CONN_CONNECTING)) { 108 return cp->cp_transport_data; 109 } 110 } 111 return NULL; 112 } 113 114 void rds_tcp_set_linger(struct socket *sock) 115 { 116 struct linger no_linger = { 117 .l_onoff = 1, 118 .l_linger = 0, 119 }; 120 121 kernel_setsockopt(sock, SOL_SOCKET, SO_LINGER, 122 (char *)&no_linger, sizeof(no_linger)); 123 } 124 125 int rds_tcp_accept_one(struct socket *sock) 126 { 127 struct socket *new_sock = NULL; 128 struct rds_connection *conn; 129 int ret; 130 struct inet_sock *inet; 131 struct rds_tcp_connection *rs_tcp = NULL; 132 int conn_state; 133 struct rds_conn_path *cp; 134 struct in6_addr *my_addr, *peer_addr; 135 #if !IS_ENABLED(CONFIG_IPV6) 136 struct in6_addr saddr, daddr; 137 #endif 138 int dev_if = 0; 139 140 if (!sock) /* module unload or netns delete in progress */ 141 return -ENETUNREACH; 142 143 ret = sock_create_lite(sock->sk->sk_family, 144 sock->sk->sk_type, sock->sk->sk_protocol, 145 &new_sock); 146 if (ret) 147 goto out; 148 149 ret = sock->ops->accept(sock, new_sock, O_NONBLOCK, true); 150 if (ret < 0) 151 goto out; 152 153 /* sock_create_lite() does not get a hold on the owner module so we 154 * need to do it here. Note that sock_release() uses sock->ops to 155 * determine if it needs to decrement the reference count. So set 156 * sock->ops after calling accept() in case that fails. And there's 157 * no need to do try_module_get() as the listener should have a hold 158 * already. 159 */ 160 new_sock->ops = sock->ops; 161 __module_get(new_sock->ops->owner); 162 163 ret = rds_tcp_keepalive(new_sock); 164 if (ret < 0) 165 goto out; 166 167 rds_tcp_tune(new_sock); 168 169 inet = inet_sk(new_sock->sk); 170 171 #if IS_ENABLED(CONFIG_IPV6) 172 my_addr = &new_sock->sk->sk_v6_rcv_saddr; 173 peer_addr = &new_sock->sk->sk_v6_daddr; 174 #else 175 ipv6_addr_set_v4mapped(inet->inet_saddr, &saddr); 176 ipv6_addr_set_v4mapped(inet->inet_daddr, &daddr); 177 my_addr = &saddr; 178 peer_addr = &daddr; 179 #endif 180 rdsdebug("accepted family %d tcp %pI6c:%u -> %pI6c:%u\n", 181 sock->sk->sk_family, 182 my_addr, ntohs(inet->inet_sport), 183 peer_addr, ntohs(inet->inet_dport)); 184 185 #if IS_ENABLED(CONFIG_IPV6) 186 /* sk_bound_dev_if is not set if the peer address is not link local 187 * address. In this case, it happens that mcast_oif is set. So 188 * just use it. 189 */ 190 if ((ipv6_addr_type(my_addr) & IPV6_ADDR_LINKLOCAL) && 191 !(ipv6_addr_type(peer_addr) & IPV6_ADDR_LINKLOCAL)) { 192 struct ipv6_pinfo *inet6; 193 194 inet6 = inet6_sk(new_sock->sk); 195 dev_if = inet6->mcast_oif; 196 } else { 197 dev_if = new_sock->sk->sk_bound_dev_if; 198 } 199 #endif 200 201 conn = rds_conn_create(sock_net(sock->sk), 202 my_addr, peer_addr, 203 &rds_tcp_transport, GFP_KERNEL, dev_if); 204 205 if (IS_ERR(conn)) { 206 ret = PTR_ERR(conn); 207 goto out; 208 } 209 /* An incoming SYN request came in, and TCP just accepted it. 210 * 211 * If the client reboots, this conn will need to be cleaned up. 212 * rds_tcp_state_change() will do that cleanup 213 */ 214 rs_tcp = rds_tcp_accept_one_path(conn); 215 if (!rs_tcp) 216 goto rst_nsk; 217 mutex_lock(&rs_tcp->t_conn_path_lock); 218 cp = rs_tcp->t_cpath; 219 conn_state = rds_conn_path_state(cp); 220 WARN_ON(conn_state == RDS_CONN_UP); 221 if (conn_state != RDS_CONN_CONNECTING && conn_state != RDS_CONN_ERROR) 222 goto rst_nsk; 223 if (rs_tcp->t_sock) { 224 /* Duelling SYN has been handled in rds_tcp_accept_one() */ 225 rds_tcp_reset_callbacks(new_sock, cp); 226 /* rds_connect_path_complete() marks RDS_CONN_UP */ 227 rds_connect_path_complete(cp, RDS_CONN_RESETTING); 228 } else { 229 rds_tcp_set_callbacks(new_sock, cp); 230 rds_connect_path_complete(cp, RDS_CONN_CONNECTING); 231 } 232 new_sock = NULL; 233 ret = 0; 234 if (conn->c_npaths == 0) 235 rds_send_ping(cp->cp_conn, cp->cp_index); 236 goto out; 237 rst_nsk: 238 /* reset the newly returned accept sock and bail. 239 * It is safe to set linger on new_sock because the RDS connection 240 * has not been brought up on new_sock, so no RDS-level data could 241 * be pending on it. By setting linger, we achieve the side-effect 242 * of avoiding TIME_WAIT state on new_sock. 243 */ 244 rds_tcp_set_linger(new_sock); 245 kernel_sock_shutdown(new_sock, SHUT_RDWR); 246 ret = 0; 247 out: 248 if (rs_tcp) 249 mutex_unlock(&rs_tcp->t_conn_path_lock); 250 if (new_sock) 251 sock_release(new_sock); 252 return ret; 253 } 254 255 void rds_tcp_listen_data_ready(struct sock *sk) 256 { 257 void (*ready)(struct sock *sk); 258 259 rdsdebug("listen data ready sk %p\n", sk); 260 261 read_lock_bh(&sk->sk_callback_lock); 262 ready = sk->sk_user_data; 263 if (!ready) { /* check for teardown race */ 264 ready = sk->sk_data_ready; 265 goto out; 266 } 267 268 /* 269 * ->sk_data_ready is also called for a newly established child socket 270 * before it has been accepted and the accepter has set up their 271 * data_ready.. we only want to queue listen work for our listening 272 * socket 273 * 274 * (*ready)() may be null if we are racing with netns delete, and 275 * the listen socket is being torn down. 276 */ 277 if (sk->sk_state == TCP_LISTEN) 278 rds_tcp_accept_work(sk); 279 else 280 ready = rds_tcp_listen_sock_def_readable(sock_net(sk)); 281 282 out: 283 read_unlock_bh(&sk->sk_callback_lock); 284 if (ready) 285 ready(sk); 286 } 287 288 struct socket *rds_tcp_listen_init(struct net *net, bool isv6) 289 { 290 struct socket *sock = NULL; 291 struct sockaddr_storage ss; 292 struct sockaddr_in6 *sin6; 293 struct sockaddr_in *sin; 294 int addr_len; 295 int ret; 296 297 ret = sock_create_kern(net, isv6 ? PF_INET6 : PF_INET, SOCK_STREAM, 298 IPPROTO_TCP, &sock); 299 if (ret < 0) { 300 rdsdebug("could not create %s listener socket: %d\n", 301 isv6 ? "IPv6" : "IPv4", ret); 302 goto out; 303 } 304 305 sock->sk->sk_reuse = SK_CAN_REUSE; 306 rds_tcp_nonagle(sock); 307 308 write_lock_bh(&sock->sk->sk_callback_lock); 309 sock->sk->sk_user_data = sock->sk->sk_data_ready; 310 sock->sk->sk_data_ready = rds_tcp_listen_data_ready; 311 write_unlock_bh(&sock->sk->sk_callback_lock); 312 313 if (isv6) { 314 sin6 = (struct sockaddr_in6 *)&ss; 315 sin6->sin6_family = PF_INET6; 316 sin6->sin6_addr = in6addr_any; 317 sin6->sin6_port = (__force u16)htons(RDS_TCP_PORT); 318 sin6->sin6_scope_id = 0; 319 sin6->sin6_flowinfo = 0; 320 addr_len = sizeof(*sin6); 321 } else { 322 sin = (struct sockaddr_in *)&ss; 323 sin->sin_family = PF_INET; 324 sin->sin_addr.s_addr = INADDR_ANY; 325 sin->sin_port = (__force u16)htons(RDS_TCP_PORT); 326 addr_len = sizeof(*sin); 327 } 328 329 ret = sock->ops->bind(sock, (struct sockaddr *)&ss, addr_len); 330 if (ret < 0) { 331 rdsdebug("could not bind %s listener socket: %d\n", 332 isv6 ? "IPv6" : "IPv4", ret); 333 goto out; 334 } 335 336 ret = sock->ops->listen(sock, 64); 337 if (ret < 0) 338 goto out; 339 340 return sock; 341 out: 342 if (sock) 343 sock_release(sock); 344 return NULL; 345 } 346 347 void rds_tcp_listen_stop(struct socket *sock, struct work_struct *acceptor) 348 { 349 struct sock *sk; 350 351 if (!sock) 352 return; 353 354 sk = sock->sk; 355 356 /* serialize with and prevent further callbacks */ 357 lock_sock(sk); 358 write_lock_bh(&sk->sk_callback_lock); 359 if (sk->sk_user_data) { 360 sk->sk_data_ready = sk->sk_user_data; 361 sk->sk_user_data = NULL; 362 } 363 write_unlock_bh(&sk->sk_callback_lock); 364 release_sock(sk); 365 366 /* wait for accepts to stop and close the socket */ 367 flush_workqueue(rds_wq); 368 flush_work(acceptor); 369 sock_release(sock); 370 } 371