1 // SPDX-License-Identifier: GPL-2.0-or-later
2 /* Local endpoint object management
4 * Copyright (C) 2016 Red Hat, Inc. All Rights Reserved.
5 * Written by David Howells (dhowells@redhat.com)
8 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
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>
16 #include <linux/hashtable.h>
19 #include <net/af_rxrpc.h>
20 #include "ar-internal.h"
22 static void rxrpc_local_processor(struct work_struct *);
23 static void rxrpc_local_rcu(struct rcu_head *);
26 * Compare a local to an address. Return -ve, 0 or +ve to indicate less than,
27 * same or greater than.
29 * We explicitly don't compare the RxRPC service ID as we want to reject
30 * conflicting uses by differing services. Further, we don't want to share
31 * addresses with different options (IPv6), so we don't compare those bits
34 static long rxrpc_local_cmp_key(const struct rxrpc_local *local,
35 const struct sockaddr_rxrpc *srx)
39 diff = ((local->srx.transport_type - srx->transport_type) ?:
40 (local->srx.transport_len - srx->transport_len) ?:
41 (local->srx.transport.family - srx->transport.family));
45 switch (srx->transport.family) {
47 /* If the choice of UDP port is left up to the transport, then
48 * the endpoint record doesn't match.
50 return ((u16 __force)local->srx.transport.sin.sin_port -
51 (u16 __force)srx->transport.sin.sin_port) ?:
52 memcmp(&local->srx.transport.sin.sin_addr,
53 &srx->transport.sin.sin_addr,
54 sizeof(struct in_addr));
55 #ifdef CONFIG_AF_RXRPC_IPV6
57 /* If the choice of UDP6 port is left up to the transport, then
58 * the endpoint record doesn't match.
60 return ((u16 __force)local->srx.transport.sin6.sin6_port -
61 (u16 __force)srx->transport.sin6.sin6_port) ?:
62 memcmp(&local->srx.transport.sin6.sin6_addr,
63 &srx->transport.sin6.sin6_addr,
64 sizeof(struct in6_addr));
72 * Allocate a new local endpoint.
74 static struct rxrpc_local *rxrpc_alloc_local(struct rxrpc_net *rxnet,
75 const struct sockaddr_rxrpc *srx)
77 struct rxrpc_local *local;
79 local = kzalloc(sizeof(struct rxrpc_local), GFP_KERNEL);
81 atomic_set(&local->usage, 1);
82 atomic_set(&local->active_users, 1);
84 INIT_LIST_HEAD(&local->link);
85 INIT_WORK(&local->processor, rxrpc_local_processor);
86 init_rwsem(&local->defrag_sem);
87 skb_queue_head_init(&local->reject_queue);
88 skb_queue_head_init(&local->event_queue);
89 local->client_conns = RB_ROOT;
90 spin_lock_init(&local->client_conns_lock);
91 spin_lock_init(&local->lock);
92 rwlock_init(&local->services_lock);
93 local->debug_id = atomic_inc_return(&rxrpc_debug_id);
94 memcpy(&local->srx, srx, sizeof(*srx));
95 local->srx.srx_service = 0;
96 trace_rxrpc_local(local->debug_id, rxrpc_local_new, 1, NULL);
99 _leave(" = %p", local);
104 * create the local socket
105 * - must be called with rxrpc_local_mutex locked
107 static int rxrpc_open_socket(struct rxrpc_local *local, struct net *net)
113 local, local->srx.transport_type, local->srx.transport.family);
115 /* create a socket to represent the local endpoint */
116 ret = sock_create_kern(net, local->srx.transport.family,
117 local->srx.transport_type, 0, &local->socket);
119 _leave(" = %d [socket]", ret);
123 /* set the socket up */
124 usk = local->socket->sk;
125 inet_sk(usk)->mc_loop = 0;
127 /* Enable CHECKSUM_UNNECESSARY to CHECKSUM_COMPLETE conversion */
128 inet_inc_convert_csum(usk);
130 rcu_assign_sk_user_data(usk, local);
132 udp_sk(usk)->encap_type = UDP_ENCAP_RXRPC;
133 udp_sk(usk)->encap_rcv = rxrpc_input_packet;
134 udp_sk(usk)->encap_destroy = NULL;
135 udp_sk(usk)->gro_receive = NULL;
136 udp_sk(usk)->gro_complete = NULL;
139 #if IS_ENABLED(CONFIG_AF_RXRPC_IPV6)
140 if (local->srx.transport.family == AF_INET6)
141 udpv6_encap_enable();
143 usk->sk_error_report = rxrpc_error_report;
145 /* if a local address was supplied then bind it */
146 if (local->srx.transport_len > sizeof(sa_family_t)) {
148 ret = kernel_bind(local->socket,
149 (struct sockaddr *)&local->srx.transport,
150 local->srx.transport_len);
152 _debug("bind failed %d", ret);
157 switch (local->srx.transport.family) {
159 /* we want to receive ICMPv6 errors */
161 ret = kernel_setsockopt(local->socket, SOL_IPV6, IPV6_RECVERR,
162 (char *) &opt, sizeof(opt));
164 _debug("setsockopt failed");
168 /* Fall through and set IPv4 options too otherwise we don't get
169 * errors from IPv4 packets sent through the IPv6 socket.
173 /* we want to receive ICMP errors */
175 ret = kernel_setsockopt(local->socket, SOL_IP, IP_RECVERR,
176 (char *) &opt, sizeof(opt));
178 _debug("setsockopt failed");
182 /* we want to set the don't fragment bit */
183 opt = IP_PMTUDISC_DO;
184 ret = kernel_setsockopt(local->socket, SOL_IP, IP_MTU_DISCOVER,
185 (char *) &opt, sizeof(opt));
187 _debug("setsockopt failed");
191 /* We want receive timestamps. */
193 ret = kernel_setsockopt(local->socket, SOL_SOCKET, SO_TIMESTAMPNS_OLD,
194 (char *)&opt, sizeof(opt));
196 _debug("setsockopt failed");
209 kernel_sock_shutdown(local->socket, SHUT_RDWR);
210 local->socket->sk->sk_user_data = NULL;
211 sock_release(local->socket);
212 local->socket = NULL;
214 _leave(" = %d", ret);
219 * Look up or create a new local endpoint using the specified local address.
221 struct rxrpc_local *rxrpc_lookup_local(struct net *net,
222 const struct sockaddr_rxrpc *srx)
224 struct rxrpc_local *local;
225 struct rxrpc_net *rxnet = rxrpc_net(net);
226 struct list_head *cursor;
231 _enter("{%d,%d,%pISp}",
232 srx->transport_type, srx->transport.family, &srx->transport);
234 mutex_lock(&rxnet->local_mutex);
236 for (cursor = rxnet->local_endpoints.next;
237 cursor != &rxnet->local_endpoints;
238 cursor = cursor->next) {
239 local = list_entry(cursor, struct rxrpc_local, link);
241 diff = rxrpc_local_cmp_key(local, srx);
247 /* Services aren't allowed to share transport sockets, so
248 * reject that here. It is possible that the object is dying -
249 * but it may also still have the local transport address that
252 if (srx->srx_service) {
257 /* Found a match. We replace a dying object. Attempting to
258 * bind the transport socket may still fail if we're attempting
259 * to use a local address that the dying object is still using.
261 if (!rxrpc_use_local(local))
268 local = rxrpc_alloc_local(rxnet, srx);
272 ret = rxrpc_open_socket(local, net);
276 if (cursor != &rxnet->local_endpoints)
277 list_replace_init(cursor, &local->link);
279 list_add_tail(&local->link, cursor);
283 mutex_unlock(&rxnet->local_mutex);
285 _net("LOCAL %s %d {%pISp}",
286 age, local->debug_id, &local->srx.transport);
288 _leave(" = %p", local);
294 mutex_unlock(&rxnet->local_mutex);
296 call_rcu(&local->rcu, rxrpc_local_rcu);
297 _leave(" = %d", ret);
301 mutex_unlock(&rxnet->local_mutex);
302 _leave(" = -EADDRINUSE");
303 return ERR_PTR(-EADDRINUSE);
307 * Get a ref on a local endpoint.
309 struct rxrpc_local *rxrpc_get_local(struct rxrpc_local *local)
311 const void *here = __builtin_return_address(0);
314 n = atomic_inc_return(&local->usage);
315 trace_rxrpc_local(local->debug_id, rxrpc_local_got, n, here);
320 * Get a ref on a local endpoint unless its usage has already reached 0.
322 struct rxrpc_local *rxrpc_get_local_maybe(struct rxrpc_local *local)
324 const void *here = __builtin_return_address(0);
327 int n = atomic_fetch_add_unless(&local->usage, 1, 0);
329 trace_rxrpc_local(local->debug_id, rxrpc_local_got,
338 * Queue a local endpoint and pass the caller's reference to the work item.
340 void rxrpc_queue_local(struct rxrpc_local *local)
342 const void *here = __builtin_return_address(0);
343 unsigned int debug_id = local->debug_id;
344 int n = atomic_read(&local->usage);
346 if (rxrpc_queue_work(&local->processor))
347 trace_rxrpc_local(debug_id, rxrpc_local_queued, n, here);
349 rxrpc_put_local(local);
353 * Drop a ref on a local endpoint.
355 void rxrpc_put_local(struct rxrpc_local *local)
357 const void *here = __builtin_return_address(0);
358 unsigned int debug_id;
362 debug_id = local->debug_id;
364 n = atomic_dec_return(&local->usage);
365 trace_rxrpc_local(debug_id, rxrpc_local_put, n, here);
368 call_rcu(&local->rcu, rxrpc_local_rcu);
373 * Start using a local endpoint.
375 struct rxrpc_local *rxrpc_use_local(struct rxrpc_local *local)
377 local = rxrpc_get_local_maybe(local);
381 if (!__rxrpc_use_local(local)) {
382 rxrpc_put_local(local);
390 * Cease using a local endpoint. Once the number of active users reaches 0, we
391 * start the closure of the transport in the work processor.
393 void rxrpc_unuse_local(struct rxrpc_local *local)
396 if (__rxrpc_unuse_local(local)) {
397 rxrpc_get_local(local);
398 rxrpc_queue_local(local);
404 * Destroy a local endpoint's socket and then hand the record to RCU to dispose
407 * Closing the socket cannot be done from bottom half context or RCU callback
408 * context because it might sleep.
410 static void rxrpc_local_destroyer(struct rxrpc_local *local)
412 struct socket *socket = local->socket;
413 struct rxrpc_net *rxnet = local->rxnet;
415 _enter("%d", local->debug_id);
419 mutex_lock(&rxnet->local_mutex);
420 list_del_init(&local->link);
421 mutex_unlock(&rxnet->local_mutex);
423 rxrpc_clean_up_local_conns(local);
424 rxrpc_service_connection_reaper(&rxnet->service_conn_reaper);
425 ASSERT(!local->service);
428 local->socket = NULL;
429 kernel_sock_shutdown(socket, SHUT_RDWR);
430 socket->sk->sk_user_data = NULL;
431 sock_release(socket);
434 /* At this point, there should be no more packets coming in to the
437 rxrpc_purge_queue(&local->reject_queue);
438 rxrpc_purge_queue(&local->event_queue);
442 * Process events on an endpoint. The work item carries a ref which
445 static void rxrpc_local_processor(struct work_struct *work)
447 struct rxrpc_local *local =
448 container_of(work, struct rxrpc_local, processor);
451 trace_rxrpc_local(local->debug_id, rxrpc_local_processing,
452 atomic_read(&local->usage), NULL);
456 if (!__rxrpc_use_local(local)) {
457 rxrpc_local_destroyer(local);
461 if (!skb_queue_empty(&local->reject_queue)) {
462 rxrpc_reject_packets(local);
466 if (!skb_queue_empty(&local->event_queue)) {
467 rxrpc_process_local_events(local);
471 __rxrpc_unuse_local(local);
474 rxrpc_put_local(local);
478 * Destroy a local endpoint after the RCU grace period expires.
480 static void rxrpc_local_rcu(struct rcu_head *rcu)
482 struct rxrpc_local *local = container_of(rcu, struct rxrpc_local, rcu);
484 _enter("%d", local->debug_id);
486 ASSERT(!work_pending(&local->processor));
488 _net("DESTROY LOCAL %d", local->debug_id);
494 * Verify the local endpoint list is empty by this point.
496 void rxrpc_destroy_all_locals(struct rxrpc_net *rxnet)
498 struct rxrpc_local *local;
502 flush_workqueue(rxrpc_workqueue);
504 if (!list_empty(&rxnet->local_endpoints)) {
505 mutex_lock(&rxnet->local_mutex);
506 list_for_each_entry(local, &rxnet->local_endpoints, link) {
507 pr_err("AF_RXRPC: Leaked local %p {%d}\n",
508 local, atomic_read(&local->usage));
510 mutex_unlock(&rxnet->local_mutex);