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