1 /* Local endpoint object management
3 * Copyright (C) 2016 Red Hat, Inc. All Rights Reserved.
4 * Written by David Howells (dhowells@redhat.com)
6 * This program is free software; you can redistribute it and/or
7 * modify it under the terms of the GNU General Public Licence
8 * as published by the Free Software Foundation; either version
9 * 2 of the Licence, or (at your option) any later version.
12 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
14 #include <linux/module.h>
15 #include <linux/net.h>
16 #include <linux/skbuff.h>
17 #include <linux/slab.h>
18 #include <linux/udp.h>
20 #include <linux/hashtable.h>
22 #include <net/af_rxrpc.h>
23 #include "ar-internal.h"
25 static void rxrpc_local_processor(struct work_struct *);
26 static void rxrpc_local_rcu(struct rcu_head *);
29 * Compare a local to an address. Return -ve, 0 or +ve to indicate less than,
30 * same or greater than.
32 * We explicitly don't compare the RxRPC service ID as we want to reject
33 * conflicting uses by differing services. Further, we don't want to share
34 * addresses with different options (IPv6), so we don't compare those bits
37 static long rxrpc_local_cmp_key(const struct rxrpc_local *local,
38 const struct sockaddr_rxrpc *srx)
42 diff = ((local->srx.transport_type - srx->transport_type) ?:
43 (local->srx.transport_len - srx->transport_len) ?:
44 (local->srx.transport.family - srx->transport.family));
48 switch (srx->transport.family) {
50 /* If the choice of UDP port is left up to the transport, then
51 * the endpoint record doesn't match.
53 return ((u16 __force)local->srx.transport.sin.sin_port -
54 (u16 __force)srx->transport.sin.sin_port) ?:
55 memcmp(&local->srx.transport.sin.sin_addr,
56 &srx->transport.sin.sin_addr,
57 sizeof(struct in_addr));
58 #ifdef CONFIG_AF_RXRPC_IPV6
60 /* If the choice of UDP6 port is left up to the transport, then
61 * the endpoint record doesn't match.
63 return ((u16 __force)local->srx.transport.sin6.sin6_port -
64 (u16 __force)srx->transport.sin6.sin6_port) ?:
65 memcmp(&local->srx.transport.sin6.sin6_addr,
66 &srx->transport.sin6.sin6_addr,
67 sizeof(struct in6_addr));
75 * Allocate a new local endpoint.
77 static struct rxrpc_local *rxrpc_alloc_local(struct rxrpc_net *rxnet,
78 const struct sockaddr_rxrpc *srx)
80 struct rxrpc_local *local;
82 local = kzalloc(sizeof(struct rxrpc_local), GFP_KERNEL);
84 atomic_set(&local->usage, 1);
86 INIT_LIST_HEAD(&local->link);
87 INIT_WORK(&local->processor, rxrpc_local_processor);
88 init_rwsem(&local->defrag_sem);
89 skb_queue_head_init(&local->reject_queue);
90 skb_queue_head_init(&local->event_queue);
91 local->client_conns = RB_ROOT;
92 spin_lock_init(&local->client_conns_lock);
93 spin_lock_init(&local->lock);
94 rwlock_init(&local->services_lock);
95 local->debug_id = atomic_inc_return(&rxrpc_debug_id);
96 memcpy(&local->srx, srx, sizeof(*srx));
97 local->srx.srx_service = 0;
98 trace_rxrpc_local(local, rxrpc_local_new, 1, NULL);
101 _leave(" = %p", local);
106 * create the local socket
107 * - must be called with rxrpc_local_mutex locked
109 static int rxrpc_open_socket(struct rxrpc_local *local, struct net *net)
115 local, local->srx.transport_type, local->srx.transport.family);
117 /* create a socket to represent the local endpoint */
118 ret = sock_create_kern(net, local->srx.transport.family,
119 local->srx.transport_type, 0, &local->socket);
121 _leave(" = %d [socket]", ret);
125 /* if a local address was supplied then bind it */
126 if (local->srx.transport_len > sizeof(sa_family_t)) {
128 ret = kernel_bind(local->socket,
129 (struct sockaddr *)&local->srx.transport,
130 local->srx.transport_len);
132 _debug("bind failed %d", ret);
137 switch (local->srx.transport.family) {
139 /* we want to receive ICMP errors */
141 ret = kernel_setsockopt(local->socket, SOL_IP, IP_RECVERR,
142 (char *) &opt, sizeof(opt));
144 _debug("setsockopt failed");
148 /* we want to set the don't fragment bit */
149 opt = IP_PMTUDISC_DO;
150 ret = kernel_setsockopt(local->socket, SOL_IP, IP_MTU_DISCOVER,
151 (char *) &opt, sizeof(opt));
153 _debug("setsockopt failed");
159 /* we want to receive ICMP errors */
161 ret = kernel_setsockopt(local->socket, SOL_IPV6, IPV6_RECVERR,
162 (char *) &opt, sizeof(opt));
164 _debug("setsockopt failed");
168 /* we want to set the don't fragment bit */
169 opt = IPV6_PMTUDISC_DO;
170 ret = kernel_setsockopt(local->socket, SOL_IPV6, IPV6_MTU_DISCOVER,
171 (char *) &opt, sizeof(opt));
173 _debug("setsockopt failed");
182 /* set the socket up */
183 sock = local->socket->sk;
184 sock->sk_user_data = local;
185 sock->sk_data_ready = rxrpc_data_ready;
186 sock->sk_error_report = rxrpc_error_report;
191 kernel_sock_shutdown(local->socket, SHUT_RDWR);
192 local->socket->sk->sk_user_data = NULL;
193 sock_release(local->socket);
194 local->socket = NULL;
196 _leave(" = %d", ret);
201 * Look up or create a new local endpoint using the specified local address.
203 struct rxrpc_local *rxrpc_lookup_local(struct net *net,
204 const struct sockaddr_rxrpc *srx)
206 struct rxrpc_local *local;
207 struct rxrpc_net *rxnet = rxrpc_net(net);
208 struct list_head *cursor;
213 _enter("{%d,%d,%pISp}",
214 srx->transport_type, srx->transport.family, &srx->transport);
216 mutex_lock(&rxnet->local_mutex);
218 for (cursor = rxnet->local_endpoints.next;
219 cursor != &rxnet->local_endpoints;
220 cursor = cursor->next) {
221 local = list_entry(cursor, struct rxrpc_local, link);
223 diff = rxrpc_local_cmp_key(local, srx);
229 /* Services aren't allowed to share transport sockets, so
230 * reject that here. It is possible that the object is dying -
231 * but it may also still have the local transport address that
234 if (srx->srx_service) {
239 /* Found a match. We replace a dying object. Attempting to
240 * bind the transport socket may still fail if we're attempting
241 * to use a local address that the dying object is still using.
243 if (!rxrpc_get_local_maybe(local)) {
244 cursor = cursor->next;
245 list_del_init(&local->link);
253 local = rxrpc_alloc_local(rxnet, srx);
257 ret = rxrpc_open_socket(local, net);
261 list_add_tail(&local->link, cursor);
265 mutex_unlock(&rxnet->local_mutex);
267 _net("LOCAL %s %d {%pISp}",
268 age, local->debug_id, &local->srx.transport);
270 _leave(" = %p", local);
276 mutex_unlock(&rxnet->local_mutex);
278 _leave(" = %d", ret);
282 mutex_unlock(&rxnet->local_mutex);
283 _leave(" = -EADDRINUSE");
284 return ERR_PTR(-EADDRINUSE);
288 * Get a ref on a local endpoint.
290 struct rxrpc_local *rxrpc_get_local(struct rxrpc_local *local)
292 const void *here = __builtin_return_address(0);
295 n = atomic_inc_return(&local->usage);
296 trace_rxrpc_local(local, rxrpc_local_got, n, here);
301 * Get a ref on a local endpoint unless its usage has already reached 0.
303 struct rxrpc_local *rxrpc_get_local_maybe(struct rxrpc_local *local)
305 const void *here = __builtin_return_address(0);
308 int n = atomic_fetch_add_unless(&local->usage, 1, 0);
310 trace_rxrpc_local(local, rxrpc_local_got, n + 1, here);
318 * Queue a local endpoint.
320 void rxrpc_queue_local(struct rxrpc_local *local)
322 const void *here = __builtin_return_address(0);
324 if (rxrpc_queue_work(&local->processor))
325 trace_rxrpc_local(local, rxrpc_local_queued,
326 atomic_read(&local->usage), here);
330 * A local endpoint reached its end of life.
332 static void __rxrpc_put_local(struct rxrpc_local *local)
334 _enter("%d", local->debug_id);
335 rxrpc_queue_work(&local->processor);
339 * Drop a ref on a local endpoint.
341 void rxrpc_put_local(struct rxrpc_local *local)
343 const void *here = __builtin_return_address(0);
347 n = atomic_dec_return(&local->usage);
348 trace_rxrpc_local(local, rxrpc_local_put, n, here);
351 __rxrpc_put_local(local);
356 * Destroy a local endpoint's socket and then hand the record to RCU to dispose
359 * Closing the socket cannot be done from bottom half context or RCU callback
360 * context because it might sleep.
362 static void rxrpc_local_destroyer(struct rxrpc_local *local)
364 struct socket *socket = local->socket;
365 struct rxrpc_net *rxnet = local->rxnet;
367 _enter("%d", local->debug_id);
369 /* We can get a race between an incoming call packet queueing the
370 * processor again and the work processor starting the destruction
371 * process which will shut down the UDP socket.
374 _leave(" [already dead]");
379 mutex_lock(&rxnet->local_mutex);
380 list_del_init(&local->link);
381 mutex_unlock(&rxnet->local_mutex);
383 ASSERT(RB_EMPTY_ROOT(&local->client_conns));
384 ASSERT(!local->service);
387 local->socket = NULL;
388 kernel_sock_shutdown(socket, SHUT_RDWR);
389 socket->sk->sk_user_data = NULL;
390 sock_release(socket);
393 /* At this point, there should be no more packets coming in to the
396 rxrpc_purge_queue(&local->reject_queue);
397 rxrpc_purge_queue(&local->event_queue);
399 _debug("rcu local %d", local->debug_id);
400 call_rcu(&local->rcu, rxrpc_local_rcu);
404 * Process events on an endpoint
406 static void rxrpc_local_processor(struct work_struct *work)
408 struct rxrpc_local *local =
409 container_of(work, struct rxrpc_local, processor);
412 trace_rxrpc_local(local, rxrpc_local_processing,
413 atomic_read(&local->usage), NULL);
417 if (atomic_read(&local->usage) == 0)
418 return rxrpc_local_destroyer(local);
420 if (!skb_queue_empty(&local->reject_queue)) {
421 rxrpc_reject_packets(local);
425 if (!skb_queue_empty(&local->event_queue)) {
426 rxrpc_process_local_events(local);
433 * Destroy a local endpoint after the RCU grace period expires.
435 static void rxrpc_local_rcu(struct rcu_head *rcu)
437 struct rxrpc_local *local = container_of(rcu, struct rxrpc_local, rcu);
439 _enter("%d", local->debug_id);
441 ASSERT(!work_pending(&local->processor));
443 _net("DESTROY LOCAL %d", local->debug_id);
449 * Verify the local endpoint list is empty by this point.
451 void rxrpc_destroy_all_locals(struct rxrpc_net *rxnet)
453 struct rxrpc_local *local;
457 flush_workqueue(rxrpc_workqueue);
459 if (!list_empty(&rxnet->local_endpoints)) {
460 mutex_lock(&rxnet->local_mutex);
461 list_for_each_entry(local, &rxnet->local_endpoints, link) {
462 pr_err("AF_RXRPC: Leaked local %p {%d}\n",
463 local, atomic_read(&local->usage));
465 mutex_unlock(&rxnet->local_mutex);