1 // SPDX-License-Identifier: GPL-2.0-or-later 2 /* Local endpoint object management 3 * 4 * Copyright (C) 2016 Red Hat, Inc. All Rights Reserved. 5 * Written by David Howells (dhowells@redhat.com) 6 */ 7 8 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt 9 10 #include <linux/module.h> 11 #include <linux/net.h> 12 #include <linux/skbuff.h> 13 #include <linux/slab.h> 14 #include <linux/udp.h> 15 #include <linux/ip.h> 16 #include <linux/hashtable.h> 17 #include <net/sock.h> 18 #include <net/udp.h> 19 #include <net/udp_tunnel.h> 20 #include <net/af_rxrpc.h> 21 #include "ar-internal.h" 22 23 static void rxrpc_local_rcu(struct rcu_head *); 24 25 /* 26 * Handle an ICMP/ICMP6 error turning up at the tunnel. Push it through the 27 * usual mechanism so that it gets parsed and presented through the UDP 28 * socket's error_report(). 29 */ 30 static void rxrpc_encap_err_rcv(struct sock *sk, struct sk_buff *skb, int err, 31 __be16 port, u32 info, u8 *payload) 32 { 33 if (ip_hdr(skb)->version == IPVERSION) 34 return ip_icmp_error(sk, skb, err, port, info, payload); 35 if (IS_ENABLED(CONFIG_AF_RXRPC_IPV6)) 36 return ipv6_icmp_error(sk, skb, err, port, info, payload); 37 } 38 39 /* 40 * Set or clear the Don't Fragment flag on a socket. 41 */ 42 void rxrpc_local_dont_fragment(const struct rxrpc_local *local, bool set) 43 { 44 if (set) 45 ip_sock_set_mtu_discover(local->socket->sk, IP_PMTUDISC_DO); 46 else 47 ip_sock_set_mtu_discover(local->socket->sk, IP_PMTUDISC_DONT); 48 } 49 50 /* 51 * Compare a local to an address. Return -ve, 0 or +ve to indicate less than, 52 * same or greater than. 53 * 54 * We explicitly don't compare the RxRPC service ID as we want to reject 55 * conflicting uses by differing services. Further, we don't want to share 56 * addresses with different options (IPv6), so we don't compare those bits 57 * either. 58 */ 59 static long rxrpc_local_cmp_key(const struct rxrpc_local *local, 60 const struct sockaddr_rxrpc *srx) 61 { 62 long diff; 63 64 diff = ((local->srx.transport_type - srx->transport_type) ?: 65 (local->srx.transport_len - srx->transport_len) ?: 66 (local->srx.transport.family - srx->transport.family)); 67 if (diff != 0) 68 return diff; 69 70 switch (srx->transport.family) { 71 case AF_INET: 72 /* If the choice of UDP port is left up to the transport, then 73 * the endpoint record doesn't match. 74 */ 75 return ((u16 __force)local->srx.transport.sin.sin_port - 76 (u16 __force)srx->transport.sin.sin_port) ?: 77 memcmp(&local->srx.transport.sin.sin_addr, 78 &srx->transport.sin.sin_addr, 79 sizeof(struct in_addr)); 80 #ifdef CONFIG_AF_RXRPC_IPV6 81 case AF_INET6: 82 /* If the choice of UDP6 port is left up to the transport, then 83 * the endpoint record doesn't match. 84 */ 85 return ((u16 __force)local->srx.transport.sin6.sin6_port - 86 (u16 __force)srx->transport.sin6.sin6_port) ?: 87 memcmp(&local->srx.transport.sin6.sin6_addr, 88 &srx->transport.sin6.sin6_addr, 89 sizeof(struct in6_addr)); 90 #endif 91 default: 92 BUG(); 93 } 94 } 95 96 static void rxrpc_client_conn_reap_timeout(struct timer_list *timer) 97 { 98 struct rxrpc_local *local = 99 container_of(timer, struct rxrpc_local, client_conn_reap_timer); 100 101 if (!local->kill_all_client_conns && 102 test_and_set_bit(RXRPC_CLIENT_CONN_REAP_TIMER, &local->client_conn_flags)) 103 rxrpc_wake_up_io_thread(local); 104 } 105 106 /* 107 * Allocate a new local endpoint. 108 */ 109 static struct rxrpc_local *rxrpc_alloc_local(struct net *net, 110 const struct sockaddr_rxrpc *srx) 111 { 112 struct rxrpc_local *local; 113 u32 tmp; 114 115 local = kzalloc(sizeof(struct rxrpc_local), GFP_KERNEL); 116 if (local) { 117 refcount_set(&local->ref, 1); 118 atomic_set(&local->active_users, 1); 119 local->net = net; 120 local->rxnet = rxrpc_net(net); 121 INIT_HLIST_NODE(&local->link); 122 init_completion(&local->io_thread_ready); 123 #ifdef CONFIG_AF_RXRPC_INJECT_RX_DELAY 124 skb_queue_head_init(&local->rx_delay_queue); 125 #endif 126 skb_queue_head_init(&local->rx_queue); 127 INIT_LIST_HEAD(&local->conn_attend_q); 128 INIT_LIST_HEAD(&local->call_attend_q); 129 130 local->client_bundles = RB_ROOT; 131 spin_lock_init(&local->client_bundles_lock); 132 local->kill_all_client_conns = false; 133 INIT_LIST_HEAD(&local->idle_client_conns); 134 timer_setup(&local->client_conn_reap_timer, 135 rxrpc_client_conn_reap_timeout, 0); 136 137 spin_lock_init(&local->lock); 138 rwlock_init(&local->services_lock); 139 local->debug_id = atomic_inc_return(&rxrpc_debug_id); 140 memcpy(&local->srx, srx, sizeof(*srx)); 141 local->srx.srx_service = 0; 142 idr_init(&local->conn_ids); 143 get_random_bytes(&tmp, sizeof(tmp)); 144 tmp &= 0x3fffffff; 145 if (tmp == 0) 146 tmp = 1; 147 idr_set_cursor(&local->conn_ids, tmp); 148 INIT_LIST_HEAD(&local->new_client_calls); 149 spin_lock_init(&local->client_call_lock); 150 151 trace_rxrpc_local(local->debug_id, rxrpc_local_new, 1, 1); 152 } 153 154 _leave(" = %p", local); 155 return local; 156 } 157 158 /* 159 * create the local socket 160 * - must be called with rxrpc_local_mutex locked 161 */ 162 static int rxrpc_open_socket(struct rxrpc_local *local, struct net *net) 163 { 164 struct udp_tunnel_sock_cfg tuncfg = {NULL}; 165 struct sockaddr_rxrpc *srx = &local->srx; 166 struct udp_port_cfg udp_conf = {0}; 167 struct task_struct *io_thread; 168 struct sock *usk; 169 int ret; 170 171 _enter("%p{%d,%d}", 172 local, srx->transport_type, srx->transport.family); 173 174 udp_conf.family = srx->transport.family; 175 udp_conf.use_udp_checksums = true; 176 if (udp_conf.family == AF_INET) { 177 udp_conf.local_ip = srx->transport.sin.sin_addr; 178 udp_conf.local_udp_port = srx->transport.sin.sin_port; 179 #if IS_ENABLED(CONFIG_AF_RXRPC_IPV6) 180 } else { 181 udp_conf.local_ip6 = srx->transport.sin6.sin6_addr; 182 udp_conf.local_udp_port = srx->transport.sin6.sin6_port; 183 udp_conf.use_udp6_tx_checksums = true; 184 udp_conf.use_udp6_rx_checksums = true; 185 #endif 186 } 187 ret = udp_sock_create(net, &udp_conf, &local->socket); 188 if (ret < 0) { 189 _leave(" = %d [socket]", ret); 190 return ret; 191 } 192 193 tuncfg.encap_type = UDP_ENCAP_RXRPC; 194 tuncfg.encap_rcv = rxrpc_encap_rcv; 195 tuncfg.encap_err_rcv = rxrpc_encap_err_rcv; 196 tuncfg.sk_user_data = local; 197 setup_udp_tunnel_sock(net, local->socket, &tuncfg); 198 199 /* set the socket up */ 200 usk = local->socket->sk; 201 usk->sk_error_report = rxrpc_error_report; 202 203 switch (srx->transport.family) { 204 case AF_INET6: 205 /* we want to receive ICMPv6 errors */ 206 ip6_sock_set_recverr(usk); 207 208 /* Fall through and set IPv4 options too otherwise we don't get 209 * errors from IPv4 packets sent through the IPv6 socket. 210 */ 211 fallthrough; 212 case AF_INET: 213 /* we want to receive ICMP errors */ 214 ip_sock_set_recverr(usk); 215 216 /* we want to set the don't fragment bit */ 217 rxrpc_local_dont_fragment(local, true); 218 219 /* We want receive timestamps. */ 220 sock_enable_timestamps(usk); 221 break; 222 223 default: 224 BUG(); 225 } 226 227 io_thread = kthread_run(rxrpc_io_thread, local, 228 "krxrpcio/%u", ntohs(udp_conf.local_udp_port)); 229 if (IS_ERR(io_thread)) { 230 ret = PTR_ERR(io_thread); 231 goto error_sock; 232 } 233 234 wait_for_completion(&local->io_thread_ready); 235 local->io_thread = io_thread; 236 _leave(" = 0"); 237 return 0; 238 239 error_sock: 240 kernel_sock_shutdown(local->socket, SHUT_RDWR); 241 local->socket->sk->sk_user_data = NULL; 242 sock_release(local->socket); 243 local->socket = NULL; 244 return ret; 245 } 246 247 /* 248 * Look up or create a new local endpoint using the specified local address. 249 */ 250 struct rxrpc_local *rxrpc_lookup_local(struct net *net, 251 const struct sockaddr_rxrpc *srx) 252 { 253 struct rxrpc_local *local; 254 struct rxrpc_net *rxnet = rxrpc_net(net); 255 struct hlist_node *cursor; 256 long diff; 257 int ret; 258 259 _enter("{%d,%d,%pISp}", 260 srx->transport_type, srx->transport.family, &srx->transport); 261 262 mutex_lock(&rxnet->local_mutex); 263 264 hlist_for_each(cursor, &rxnet->local_endpoints) { 265 local = hlist_entry(cursor, struct rxrpc_local, link); 266 267 diff = rxrpc_local_cmp_key(local, srx); 268 if (diff != 0) 269 continue; 270 271 /* Services aren't allowed to share transport sockets, so 272 * reject that here. It is possible that the object is dying - 273 * but it may also still have the local transport address that 274 * we want bound. 275 */ 276 if (srx->srx_service) { 277 local = NULL; 278 goto addr_in_use; 279 } 280 281 /* Found a match. We want to replace a dying object. 282 * Attempting to bind the transport socket may still fail if 283 * we're attempting to use a local address that the dying 284 * object is still using. 285 */ 286 if (!rxrpc_use_local(local, rxrpc_local_use_lookup)) 287 break; 288 289 goto found; 290 } 291 292 local = rxrpc_alloc_local(net, srx); 293 if (!local) 294 goto nomem; 295 296 ret = rxrpc_open_socket(local, net); 297 if (ret < 0) 298 goto sock_error; 299 300 if (cursor) { 301 hlist_replace_rcu(cursor, &local->link); 302 cursor->pprev = NULL; 303 } else { 304 hlist_add_head_rcu(&local->link, &rxnet->local_endpoints); 305 } 306 307 found: 308 mutex_unlock(&rxnet->local_mutex); 309 _leave(" = %p", local); 310 return local; 311 312 nomem: 313 ret = -ENOMEM; 314 sock_error: 315 mutex_unlock(&rxnet->local_mutex); 316 if (local) 317 call_rcu(&local->rcu, rxrpc_local_rcu); 318 _leave(" = %d", ret); 319 return ERR_PTR(ret); 320 321 addr_in_use: 322 mutex_unlock(&rxnet->local_mutex); 323 _leave(" = -EADDRINUSE"); 324 return ERR_PTR(-EADDRINUSE); 325 } 326 327 /* 328 * Get a ref on a local endpoint. 329 */ 330 struct rxrpc_local *rxrpc_get_local(struct rxrpc_local *local, 331 enum rxrpc_local_trace why) 332 { 333 int r, u; 334 335 u = atomic_read(&local->active_users); 336 __refcount_inc(&local->ref, &r); 337 trace_rxrpc_local(local->debug_id, why, r + 1, u); 338 return local; 339 } 340 341 /* 342 * Get a ref on a local endpoint unless its usage has already reached 0. 343 */ 344 struct rxrpc_local *rxrpc_get_local_maybe(struct rxrpc_local *local, 345 enum rxrpc_local_trace why) 346 { 347 int r, u; 348 349 if (local && __refcount_inc_not_zero(&local->ref, &r)) { 350 u = atomic_read(&local->active_users); 351 trace_rxrpc_local(local->debug_id, why, r + 1, u); 352 return local; 353 } 354 355 return NULL; 356 } 357 358 /* 359 * Drop a ref on a local endpoint. 360 */ 361 void rxrpc_put_local(struct rxrpc_local *local, enum rxrpc_local_trace why) 362 { 363 unsigned int debug_id; 364 bool dead; 365 int r, u; 366 367 if (local) { 368 debug_id = local->debug_id; 369 370 u = atomic_read(&local->active_users); 371 dead = __refcount_dec_and_test(&local->ref, &r); 372 trace_rxrpc_local(debug_id, why, r, u); 373 374 if (dead) 375 call_rcu(&local->rcu, rxrpc_local_rcu); 376 } 377 } 378 379 /* 380 * Start using a local endpoint. 381 */ 382 struct rxrpc_local *rxrpc_use_local(struct rxrpc_local *local, 383 enum rxrpc_local_trace why) 384 { 385 local = rxrpc_get_local_maybe(local, rxrpc_local_get_for_use); 386 if (!local) 387 return NULL; 388 389 if (!__rxrpc_use_local(local, why)) { 390 rxrpc_put_local(local, rxrpc_local_put_for_use); 391 return NULL; 392 } 393 394 return local; 395 } 396 397 /* 398 * Cease using a local endpoint. Once the number of active users reaches 0, we 399 * start the closure of the transport in the I/O thread.. 400 */ 401 void rxrpc_unuse_local(struct rxrpc_local *local, enum rxrpc_local_trace why) 402 { 403 unsigned int debug_id; 404 int r, u; 405 406 if (local) { 407 debug_id = local->debug_id; 408 r = refcount_read(&local->ref); 409 u = atomic_dec_return(&local->active_users); 410 trace_rxrpc_local(debug_id, why, r, u); 411 if (u == 0) 412 kthread_stop(local->io_thread); 413 } 414 } 415 416 /* 417 * Destroy a local endpoint's socket and then hand the record to RCU to dispose 418 * of. 419 * 420 * Closing the socket cannot be done from bottom half context or RCU callback 421 * context because it might sleep. 422 */ 423 void rxrpc_destroy_local(struct rxrpc_local *local) 424 { 425 struct socket *socket = local->socket; 426 struct rxrpc_net *rxnet = local->rxnet; 427 428 _enter("%d", local->debug_id); 429 430 local->dead = true; 431 432 mutex_lock(&rxnet->local_mutex); 433 hlist_del_init_rcu(&local->link); 434 mutex_unlock(&rxnet->local_mutex); 435 436 rxrpc_clean_up_local_conns(local); 437 rxrpc_service_connection_reaper(&rxnet->service_conn_reaper); 438 ASSERT(!local->service); 439 440 if (socket) { 441 local->socket = NULL; 442 kernel_sock_shutdown(socket, SHUT_RDWR); 443 socket->sk->sk_user_data = NULL; 444 sock_release(socket); 445 } 446 447 /* At this point, there should be no more packets coming in to the 448 * local endpoint. 449 */ 450 #ifdef CONFIG_AF_RXRPC_INJECT_RX_DELAY 451 rxrpc_purge_queue(&local->rx_delay_queue); 452 #endif 453 rxrpc_purge_queue(&local->rx_queue); 454 rxrpc_purge_client_connections(local); 455 } 456 457 /* 458 * Destroy a local endpoint after the RCU grace period expires. 459 */ 460 static void rxrpc_local_rcu(struct rcu_head *rcu) 461 { 462 struct rxrpc_local *local = container_of(rcu, struct rxrpc_local, rcu); 463 464 rxrpc_see_local(local, rxrpc_local_free); 465 kfree(local); 466 } 467 468 /* 469 * Verify the local endpoint list is empty by this point. 470 */ 471 void rxrpc_destroy_all_locals(struct rxrpc_net *rxnet) 472 { 473 struct rxrpc_local *local; 474 475 _enter(""); 476 477 flush_workqueue(rxrpc_workqueue); 478 479 if (!hlist_empty(&rxnet->local_endpoints)) { 480 mutex_lock(&rxnet->local_mutex); 481 hlist_for_each_entry(local, &rxnet->local_endpoints, link) { 482 pr_err("AF_RXRPC: Leaked local %p {%d}\n", 483 local, refcount_read(&local->ref)); 484 } 485 mutex_unlock(&rxnet->local_mutex); 486 BUG(); 487 } 488 } 489