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);
83 INIT_LIST_HEAD(&local->link);
84 INIT_WORK(&local->processor, rxrpc_local_processor);
85 init_rwsem(&local->defrag_sem);
86 skb_queue_head_init(&local->reject_queue);
87 skb_queue_head_init(&local->event_queue);
88 local->client_conns = RB_ROOT;
89 spin_lock_init(&local->client_conns_lock);
90 spin_lock_init(&local->lock);
91 rwlock_init(&local->services_lock);
92 local->debug_id = atomic_inc_return(&rxrpc_debug_id);
93 memcpy(&local->srx, srx, sizeof(*srx));
94 local->srx.srx_service = 0;
95 trace_rxrpc_local(local, rxrpc_local_new, 1, NULL);
98 _leave(" = %p", local);
103 * create the local socket
104 * - must be called with rxrpc_local_mutex locked
106 static int rxrpc_open_socket(struct rxrpc_local *local, struct net *net)
112 local, local->srx.transport_type, local->srx.transport.family);
114 /* create a socket to represent the local endpoint */
115 ret = sock_create_kern(net, local->srx.transport.family,
116 local->srx.transport_type, 0, &local->socket);
118 _leave(" = %d [socket]", ret);
122 /* set the socket up */
123 usk = local->socket->sk;
124 inet_sk(usk)->mc_loop = 0;
126 /* Enable CHECKSUM_UNNECESSARY to CHECKSUM_COMPLETE conversion */
127 inet_inc_convert_csum(usk);
129 rcu_assign_sk_user_data(usk, local);
131 udp_sk(usk)->encap_type = UDP_ENCAP_RXRPC;
132 udp_sk(usk)->encap_rcv = rxrpc_input_packet;
133 udp_sk(usk)->encap_destroy = NULL;
134 udp_sk(usk)->gro_receive = NULL;
135 udp_sk(usk)->gro_complete = NULL;
138 #if IS_ENABLED(CONFIG_AF_RXRPC_IPV6)
139 if (local->srx.transport.family == AF_INET6)
140 udpv6_encap_enable();
142 usk->sk_error_report = rxrpc_error_report;
144 /* if a local address was supplied then bind it */
145 if (local->srx.transport_len > sizeof(sa_family_t)) {
147 ret = kernel_bind(local->socket,
148 (struct sockaddr *)&local->srx.transport,
149 local->srx.transport_len);
151 _debug("bind failed %d", ret);
156 switch (local->srx.transport.family) {
158 /* we want to receive ICMPv6 errors */
160 ret = kernel_setsockopt(local->socket, SOL_IPV6, IPV6_RECVERR,
161 (char *) &opt, sizeof(opt));
163 _debug("setsockopt failed");
167 /* we want to set the don't fragment bit */
168 opt = IPV6_PMTUDISC_DO;
169 ret = kernel_setsockopt(local->socket, SOL_IPV6, IPV6_MTU_DISCOVER,
170 (char *) &opt, sizeof(opt));
172 _debug("setsockopt failed");
176 /* Fall through and set IPv4 options too otherwise we don't get
177 * errors from IPv4 packets sent through the IPv6 socket.
181 /* we want to receive ICMP errors */
183 ret = kernel_setsockopt(local->socket, SOL_IP, IP_RECVERR,
184 (char *) &opt, sizeof(opt));
186 _debug("setsockopt failed");
190 /* we want to set the don't fragment bit */
191 opt = IP_PMTUDISC_DO;
192 ret = kernel_setsockopt(local->socket, SOL_IP, IP_MTU_DISCOVER,
193 (char *) &opt, sizeof(opt));
195 _debug("setsockopt failed");
199 /* We want receive timestamps. */
201 ret = kernel_setsockopt(local->socket, SOL_SOCKET, SO_TIMESTAMPNS_OLD,
202 (char *)&opt, sizeof(opt));
204 _debug("setsockopt failed");
217 kernel_sock_shutdown(local->socket, SHUT_RDWR);
218 local->socket->sk->sk_user_data = NULL;
219 sock_release(local->socket);
220 local->socket = NULL;
222 _leave(" = %d", ret);
227 * Look up or create a new local endpoint using the specified local address.
229 struct rxrpc_local *rxrpc_lookup_local(struct net *net,
230 const struct sockaddr_rxrpc *srx)
232 struct rxrpc_local *local;
233 struct rxrpc_net *rxnet = rxrpc_net(net);
234 struct list_head *cursor;
239 _enter("{%d,%d,%pISp}",
240 srx->transport_type, srx->transport.family, &srx->transport);
242 mutex_lock(&rxnet->local_mutex);
244 for (cursor = rxnet->local_endpoints.next;
245 cursor != &rxnet->local_endpoints;
246 cursor = cursor->next) {
247 local = list_entry(cursor, struct rxrpc_local, link);
249 diff = rxrpc_local_cmp_key(local, srx);
255 /* Services aren't allowed to share transport sockets, so
256 * reject that here. It is possible that the object is dying -
257 * but it may also still have the local transport address that
260 if (srx->srx_service) {
265 /* Found a match. We replace a dying object. Attempting to
266 * bind the transport socket may still fail if we're attempting
267 * to use a local address that the dying object is still using.
269 if (!rxrpc_get_local_maybe(local)) {
270 cursor = cursor->next;
271 list_del_init(&local->link);
279 local = rxrpc_alloc_local(rxnet, srx);
283 ret = rxrpc_open_socket(local, net);
287 list_add_tail(&local->link, cursor);
291 mutex_unlock(&rxnet->local_mutex);
293 _net("LOCAL %s %d {%pISp}",
294 age, local->debug_id, &local->srx.transport);
296 _leave(" = %p", local);
302 mutex_unlock(&rxnet->local_mutex);
304 call_rcu(&local->rcu, rxrpc_local_rcu);
305 _leave(" = %d", ret);
309 mutex_unlock(&rxnet->local_mutex);
310 _leave(" = -EADDRINUSE");
311 return ERR_PTR(-EADDRINUSE);
315 * Get a ref on a local endpoint.
317 struct rxrpc_local *rxrpc_get_local(struct rxrpc_local *local)
319 const void *here = __builtin_return_address(0);
322 n = atomic_inc_return(&local->usage);
323 trace_rxrpc_local(local, rxrpc_local_got, n, here);
328 * Get a ref on a local endpoint unless its usage has already reached 0.
330 struct rxrpc_local *rxrpc_get_local_maybe(struct rxrpc_local *local)
332 const void *here = __builtin_return_address(0);
335 int n = atomic_fetch_add_unless(&local->usage, 1, 0);
337 trace_rxrpc_local(local, rxrpc_local_got, n + 1, here);
345 * Queue a local endpoint.
347 void rxrpc_queue_local(struct rxrpc_local *local)
349 const void *here = __builtin_return_address(0);
351 if (rxrpc_queue_work(&local->processor))
352 trace_rxrpc_local(local, rxrpc_local_queued,
353 atomic_read(&local->usage), here);
357 * A local endpoint reached its end of life.
359 static void __rxrpc_put_local(struct rxrpc_local *local)
361 _enter("%d", local->debug_id);
362 rxrpc_queue_work(&local->processor);
366 * Drop a ref on a local endpoint.
368 void rxrpc_put_local(struct rxrpc_local *local)
370 const void *here = __builtin_return_address(0);
374 n = atomic_dec_return(&local->usage);
375 trace_rxrpc_local(local, rxrpc_local_put, n, here);
378 __rxrpc_put_local(local);
383 * Destroy a local endpoint's socket and then hand the record to RCU to dispose
386 * Closing the socket cannot be done from bottom half context or RCU callback
387 * context because it might sleep.
389 static void rxrpc_local_destroyer(struct rxrpc_local *local)
391 struct socket *socket = local->socket;
392 struct rxrpc_net *rxnet = local->rxnet;
394 _enter("%d", local->debug_id);
396 /* We can get a race between an incoming call packet queueing the
397 * processor again and the work processor starting the destruction
398 * process which will shut down the UDP socket.
401 _leave(" [already dead]");
406 mutex_lock(&rxnet->local_mutex);
407 list_del_init(&local->link);
408 mutex_unlock(&rxnet->local_mutex);
410 ASSERT(RB_EMPTY_ROOT(&local->client_conns));
411 ASSERT(!local->service);
414 local->socket = NULL;
415 kernel_sock_shutdown(socket, SHUT_RDWR);
416 socket->sk->sk_user_data = NULL;
417 sock_release(socket);
420 /* At this point, there should be no more packets coming in to the
423 rxrpc_purge_queue(&local->reject_queue);
424 rxrpc_purge_queue(&local->event_queue);
426 _debug("rcu local %d", local->debug_id);
427 call_rcu(&local->rcu, rxrpc_local_rcu);
431 * Process events on an endpoint
433 static void rxrpc_local_processor(struct work_struct *work)
435 struct rxrpc_local *local =
436 container_of(work, struct rxrpc_local, processor);
439 trace_rxrpc_local(local, rxrpc_local_processing,
440 atomic_read(&local->usage), NULL);
444 if (atomic_read(&local->usage) == 0)
445 return rxrpc_local_destroyer(local);
447 if (!skb_queue_empty(&local->reject_queue)) {
448 rxrpc_reject_packets(local);
452 if (!skb_queue_empty(&local->event_queue)) {
453 rxrpc_process_local_events(local);
460 * Destroy a local endpoint after the RCU grace period expires.
462 static void rxrpc_local_rcu(struct rcu_head *rcu)
464 struct rxrpc_local *local = container_of(rcu, struct rxrpc_local, rcu);
466 _enter("%d", local->debug_id);
468 ASSERT(!work_pending(&local->processor));
470 _net("DESTROY LOCAL %d", local->debug_id);
476 * Verify the local endpoint list is empty by this point.
478 void rxrpc_destroy_all_locals(struct rxrpc_net *rxnet)
480 struct rxrpc_local *local;
484 flush_workqueue(rxrpc_workqueue);
486 if (!list_empty(&rxnet->local_endpoints)) {
487 mutex_lock(&rxnet->local_mutex);
488 list_for_each_entry(local, &rxnet->local_endpoints, link) {
489 pr_err("AF_RXRPC: Leaked local %p {%d}\n",
490 local, atomic_read(&local->usage));
492 mutex_unlock(&rxnet->local_mutex);