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 refcount_set(&local->ref, 1);
82 atomic_set(&local->active_users, 1);
84 INIT_HLIST_NODE(&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_bundles = RB_ROOT;
90 spin_lock_init(&local->client_bundles_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 */
160 ip6_sock_set_recverr(local->socket->sk);
162 /* Fall through and set IPv4 options too otherwise we don't get
163 * errors from IPv4 packets sent through the IPv6 socket.
167 /* we want to receive ICMP errors */
168 ip_sock_set_recverr(local->socket->sk);
170 /* we want to set the don't fragment bit */
171 ip_sock_set_mtu_discover(local->socket->sk, IP_PMTUDISC_DO);
173 /* We want receive timestamps. */
174 sock_enable_timestamps(local->socket->sk);
185 kernel_sock_shutdown(local->socket, SHUT_RDWR);
186 local->socket->sk->sk_user_data = NULL;
187 sock_release(local->socket);
188 local->socket = NULL;
190 _leave(" = %d", ret);
195 * Look up or create a new local endpoint using the specified local address.
197 struct rxrpc_local *rxrpc_lookup_local(struct net *net,
198 const struct sockaddr_rxrpc *srx)
200 struct rxrpc_local *local;
201 struct rxrpc_net *rxnet = rxrpc_net(net);
202 struct hlist_node *cursor;
207 _enter("{%d,%d,%pISp}",
208 srx->transport_type, srx->transport.family, &srx->transport);
210 mutex_lock(&rxnet->local_mutex);
212 hlist_for_each(cursor, &rxnet->local_endpoints) {
213 local = hlist_entry(cursor, struct rxrpc_local, link);
215 diff = rxrpc_local_cmp_key(local, srx);
219 /* Services aren't allowed to share transport sockets, so
220 * reject that here. It is possible that the object is dying -
221 * but it may also still have the local transport address that
224 if (srx->srx_service) {
229 /* Found a match. We want to replace a dying object.
230 * Attempting to bind the transport socket may still fail if
231 * we're attempting to use a local address that the dying
232 * object is still using.
234 if (!rxrpc_use_local(local))
241 local = rxrpc_alloc_local(rxnet, srx);
245 ret = rxrpc_open_socket(local, net);
250 hlist_replace_rcu(cursor, &local->link);
251 cursor->pprev = NULL;
253 hlist_add_head_rcu(&local->link, &rxnet->local_endpoints);
258 mutex_unlock(&rxnet->local_mutex);
260 _net("LOCAL %s %d {%pISp}",
261 age, local->debug_id, &local->srx.transport);
263 _leave(" = %p", local);
269 mutex_unlock(&rxnet->local_mutex);
271 call_rcu(&local->rcu, rxrpc_local_rcu);
272 _leave(" = %d", ret);
276 mutex_unlock(&rxnet->local_mutex);
277 _leave(" = -EADDRINUSE");
278 return ERR_PTR(-EADDRINUSE);
282 * Get a ref on a local endpoint.
284 struct rxrpc_local *rxrpc_get_local(struct rxrpc_local *local)
286 const void *here = __builtin_return_address(0);
289 __refcount_inc(&local->ref, &r);
290 trace_rxrpc_local(local->debug_id, rxrpc_local_got, r + 1, here);
295 * Get a ref on a local endpoint unless its usage has already reached 0.
297 struct rxrpc_local *rxrpc_get_local_maybe(struct rxrpc_local *local)
299 const void *here = __builtin_return_address(0);
303 if (__refcount_inc_not_zero(&local->ref, &r))
304 trace_rxrpc_local(local->debug_id, rxrpc_local_got,
313 * Queue a local endpoint and pass the caller's reference to the work item.
315 void rxrpc_queue_local(struct rxrpc_local *local)
317 const void *here = __builtin_return_address(0);
318 unsigned int debug_id = local->debug_id;
319 int r = refcount_read(&local->ref);
321 if (rxrpc_queue_work(&local->processor))
322 trace_rxrpc_local(debug_id, rxrpc_local_queued, r + 1, here);
324 rxrpc_put_local(local);
328 * Drop a ref on a local endpoint.
330 void rxrpc_put_local(struct rxrpc_local *local)
332 const void *here = __builtin_return_address(0);
333 unsigned int debug_id;
338 debug_id = local->debug_id;
340 dead = __refcount_dec_and_test(&local->ref, &r);
341 trace_rxrpc_local(debug_id, rxrpc_local_put, r, here);
344 call_rcu(&local->rcu, rxrpc_local_rcu);
349 * Start using a local endpoint.
351 struct rxrpc_local *rxrpc_use_local(struct rxrpc_local *local)
353 local = rxrpc_get_local_maybe(local);
357 if (!__rxrpc_use_local(local)) {
358 rxrpc_put_local(local);
366 * Cease using a local endpoint. Once the number of active users reaches 0, we
367 * start the closure of the transport in the work processor.
369 void rxrpc_unuse_local(struct rxrpc_local *local)
372 if (__rxrpc_unuse_local(local)) {
373 rxrpc_get_local(local);
374 rxrpc_queue_local(local);
380 * Destroy a local endpoint's socket and then hand the record to RCU to dispose
383 * Closing the socket cannot be done from bottom half context or RCU callback
384 * context because it might sleep.
386 static void rxrpc_local_destroyer(struct rxrpc_local *local)
388 struct socket *socket = local->socket;
389 struct rxrpc_net *rxnet = local->rxnet;
391 _enter("%d", local->debug_id);
395 mutex_lock(&rxnet->local_mutex);
396 hlist_del_init_rcu(&local->link);
397 mutex_unlock(&rxnet->local_mutex);
399 rxrpc_clean_up_local_conns(local);
400 rxrpc_service_connection_reaper(&rxnet->service_conn_reaper);
401 ASSERT(!local->service);
404 local->socket = NULL;
405 kernel_sock_shutdown(socket, SHUT_RDWR);
406 socket->sk->sk_user_data = NULL;
407 sock_release(socket);
410 /* At this point, there should be no more packets coming in to the
413 rxrpc_purge_queue(&local->reject_queue);
414 rxrpc_purge_queue(&local->event_queue);
418 * Process events on an endpoint. The work item carries a ref which
421 static void rxrpc_local_processor(struct work_struct *work)
423 struct rxrpc_local *local =
424 container_of(work, struct rxrpc_local, processor);
430 trace_rxrpc_local(local->debug_id, rxrpc_local_processing,
431 refcount_read(&local->ref), NULL);
435 if (!__rxrpc_use_local(local)) {
436 rxrpc_local_destroyer(local);
440 if (!skb_queue_empty(&local->reject_queue)) {
441 rxrpc_reject_packets(local);
445 if (!skb_queue_empty(&local->event_queue)) {
446 rxrpc_process_local_events(local);
450 __rxrpc_unuse_local(local);
453 rxrpc_put_local(local);
457 * Destroy a local endpoint after the RCU grace period expires.
459 static void rxrpc_local_rcu(struct rcu_head *rcu)
461 struct rxrpc_local *local = container_of(rcu, struct rxrpc_local, rcu);
463 _enter("%d", local->debug_id);
465 ASSERT(!work_pending(&local->processor));
467 _net("DESTROY LOCAL %d", local->debug_id);
473 * Verify the local endpoint list is empty by this point.
475 void rxrpc_destroy_all_locals(struct rxrpc_net *rxnet)
477 struct rxrpc_local *local;
481 flush_workqueue(rxrpc_workqueue);
483 if (!hlist_empty(&rxnet->local_endpoints)) {
484 mutex_lock(&rxnet->local_mutex);
485 hlist_for_each_entry(local, &rxnet->local_endpoints, link) {
486 pr_err("AF_RXRPC: Leaked local %p {%d}\n",
487 local, refcount_read(&local->ref));
489 mutex_unlock(&rxnet->local_mutex);