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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/af_rxrpc.h>
20#include "ar-internal.h"
21
22static void rxrpc_local_processor(struct work_struct *);
23static void rxrpc_local_rcu(struct rcu_head *);
24
25/*
26 * Compare a local to an address. Return -ve, 0 or +ve to indicate less than,
27 * same or greater than.
28 *
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
32 * either.
33 */
34static long rxrpc_local_cmp_key(const struct rxrpc_local *local,
35 const struct sockaddr_rxrpc *srx)
36{
37 long diff;
38
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));
42 if (diff != 0)
43 return diff;
44
45 switch (srx->transport.family) {
46 case AF_INET:
47 /* If the choice of UDP port is left up to the transport, then
48 * the endpoint record doesn't match.
49 */
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
56 case AF_INET6:
57 /* If the choice of UDP6 port is left up to the transport, then
58 * the endpoint record doesn't match.
59 */
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));
65#endif
66 default:
67 BUG();
68 }
69}
70
71/*
72 * Allocate a new local endpoint.
73 */
74static struct rxrpc_local *rxrpc_alloc_local(struct rxrpc_net *rxnet,
75 const struct sockaddr_rxrpc *srx)
76{
77 struct rxrpc_local *local;
78
79 local = kzalloc(sizeof(struct rxrpc_local), GFP_KERNEL);
80 if (local) {
81 atomic_set(&local->usage, 1);
82 atomic_set(&local->active_users, 1);
83 local->rxnet = rxnet;
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);
97 }
98
99 _leave(" = %p", local);
100 return local;
101}
102
103/*
104 * create the local socket
105 * - must be called with rxrpc_local_mutex locked
106 */
107static int rxrpc_open_socket(struct rxrpc_local *local, struct net *net)
108{
109 struct sock *usk;
110 int ret, opt;
111
112 _enter("%p{%d,%d}",
113 local, local->srx.transport_type, local->srx.transport.family);
114
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);
118 if (ret < 0) {
119 _leave(" = %d [socket]", ret);
120 return ret;
121 }
122
123 /* set the socket up */
124 usk = local->socket->sk;
125 inet_sk(usk)->mc_loop = 0;
126
127 /* Enable CHECKSUM_UNNECESSARY to CHECKSUM_COMPLETE conversion */
128 inet_inc_convert_csum(usk);
129
130 rcu_assign_sk_user_data(usk, local);
131
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;
137
138 udp_encap_enable();
139#if IS_ENABLED(CONFIG_AF_RXRPC_IPV6)
140 if (local->srx.transport.family == AF_INET6)
141 udpv6_encap_enable();
142#endif
143 usk->sk_error_report = rxrpc_error_report;
144
145 /* if a local address was supplied then bind it */
146 if (local->srx.transport_len > sizeof(sa_family_t)) {
147 _debug("bind");
148 ret = kernel_bind(local->socket,
149 (struct sockaddr *)&local->srx.transport,
150 local->srx.transport_len);
151 if (ret < 0) {
152 _debug("bind failed %d", ret);
153 goto error;
154 }
155 }
156
157 switch (local->srx.transport.family) {
158 case AF_INET6:
159 /* we want to receive ICMPv6 errors */
160 opt = 1;
161 ret = kernel_setsockopt(local->socket, SOL_IPV6, IPV6_RECVERR,
162 (char *) &opt, sizeof(opt));
163 if (ret < 0) {
164 _debug("setsockopt failed");
165 goto error;
166 }
167
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));
172 if (ret < 0) {
173 _debug("setsockopt failed");
174 goto error;
175 }
176
177 /* Fall through and set IPv4 options too otherwise we don't get
178 * errors from IPv4 packets sent through the IPv6 socket.
179 */
180 /* Fall through */
181 case AF_INET:
182 /* we want to receive ICMP errors */
183 opt = 1;
184 ret = kernel_setsockopt(local->socket, SOL_IP, IP_RECVERR,
185 (char *) &opt, sizeof(opt));
186 if (ret < 0) {
187 _debug("setsockopt failed");
188 goto error;
189 }
190
191 /* we want to set the don't fragment bit */
192 opt = IP_PMTUDISC_DO;
193 ret = kernel_setsockopt(local->socket, SOL_IP, IP_MTU_DISCOVER,
194 (char *) &opt, sizeof(opt));
195 if (ret < 0) {
196 _debug("setsockopt failed");
197 goto error;
198 }
199
200 /* We want receive timestamps. */
201 opt = 1;
202 ret = kernel_setsockopt(local->socket, SOL_SOCKET, SO_TIMESTAMPNS_OLD,
203 (char *)&opt, sizeof(opt));
204 if (ret < 0) {
205 _debug("setsockopt failed");
206 goto error;
207 }
208 break;
209
210 default:
211 BUG();
212 }
213
214 _leave(" = 0");
215 return 0;
216
217error:
218 kernel_sock_shutdown(local->socket, SHUT_RDWR);
219 local->socket->sk->sk_user_data = NULL;
220 sock_release(local->socket);
221 local->socket = NULL;
222
223 _leave(" = %d", ret);
224 return ret;
225}
226
227/*
228 * Look up or create a new local endpoint using the specified local address.
229 */
230struct rxrpc_local *rxrpc_lookup_local(struct net *net,
231 const struct sockaddr_rxrpc *srx)
232{
233 struct rxrpc_local *local;
234 struct rxrpc_net *rxnet = rxrpc_net(net);
235 struct list_head *cursor;
236 const char *age;
237 long diff;
238 int ret;
239
240 _enter("{%d,%d,%pISp}",
241 srx->transport_type, srx->transport.family, &srx->transport);
242
243 mutex_lock(&rxnet->local_mutex);
244
245 for (cursor = rxnet->local_endpoints.next;
246 cursor != &rxnet->local_endpoints;
247 cursor = cursor->next) {
248 local = list_entry(cursor, struct rxrpc_local, link);
249
250 diff = rxrpc_local_cmp_key(local, srx);
251 if (diff < 0)
252 continue;
253 if (diff > 0)
254 break;
255
256 /* Services aren't allowed to share transport sockets, so
257 * reject that here. It is possible that the object is dying -
258 * but it may also still have the local transport address that
259 * we want bound.
260 */
261 if (srx->srx_service) {
262 local = NULL;
263 goto addr_in_use;
264 }
265
266 /* Found a match. We replace a dying object. Attempting to
267 * bind the transport socket may still fail if we're attempting
268 * to use a local address that the dying object is still using.
269 */
270 if (!rxrpc_use_local(local))
271 break;
272
273 age = "old";
274 goto found;
275 }
276
277 local = rxrpc_alloc_local(rxnet, srx);
278 if (!local)
279 goto nomem;
280
281 ret = rxrpc_open_socket(local, net);
282 if (ret < 0)
283 goto sock_error;
284
285 if (cursor != &rxnet->local_endpoints)
286 list_replace_init(cursor, &local->link);
287 else
288 list_add_tail(&local->link, cursor);
289 age = "new";
290
291found:
292 mutex_unlock(&rxnet->local_mutex);
293
294 _net("LOCAL %s %d {%pISp}",
295 age, local->debug_id, &local->srx.transport);
296
297 _leave(" = %p", local);
298 return local;
299
300nomem:
301 ret = -ENOMEM;
302sock_error:
303 mutex_unlock(&rxnet->local_mutex);
304 if (local)
305 call_rcu(&local->rcu, rxrpc_local_rcu);
306 _leave(" = %d", ret);
307 return ERR_PTR(ret);
308
309addr_in_use:
310 mutex_unlock(&rxnet->local_mutex);
311 _leave(" = -EADDRINUSE");
312 return ERR_PTR(-EADDRINUSE);
313}
314
315/*
316 * Get a ref on a local endpoint.
317 */
318struct rxrpc_local *rxrpc_get_local(struct rxrpc_local *local)
319{
320 const void *here = __builtin_return_address(0);
321 int n;
322
323 n = atomic_inc_return(&local->usage);
324 trace_rxrpc_local(local->debug_id, rxrpc_local_got, n, here);
325 return local;
326}
327
328/*
329 * Get a ref on a local endpoint unless its usage has already reached 0.
330 */
331struct rxrpc_local *rxrpc_get_local_maybe(struct rxrpc_local *local)
332{
333 const void *here = __builtin_return_address(0);
334
335 if (local) {
336 int n = atomic_fetch_add_unless(&local->usage, 1, 0);
337 if (n > 0)
338 trace_rxrpc_local(local->debug_id, rxrpc_local_got,
339 n + 1, here);
340 else
341 local = NULL;
342 }
343 return local;
344}
345
346/*
347 * Queue a local endpoint and pass the caller's reference to the work item.
348 */
349void rxrpc_queue_local(struct rxrpc_local *local)
350{
351 const void *here = __builtin_return_address(0);
352 unsigned int debug_id = local->debug_id;
353 int n = atomic_read(&local->usage);
354
355 if (rxrpc_queue_work(&local->processor))
356 trace_rxrpc_local(debug_id, rxrpc_local_queued, n, here);
357 else
358 rxrpc_put_local(local);
359}
360
361/*
362 * Drop a ref on a local endpoint.
363 */
364void rxrpc_put_local(struct rxrpc_local *local)
365{
366 const void *here = __builtin_return_address(0);
367 int n;
368
369 if (local) {
370 n = atomic_dec_return(&local->usage);
371 trace_rxrpc_local(local->debug_id, rxrpc_local_put, n, here);
372
373 if (n == 0)
374 call_rcu(&local->rcu, rxrpc_local_rcu);
375 }
376}
377
378/*
379 * Start using a local endpoint.
380 */
381struct rxrpc_local *rxrpc_use_local(struct rxrpc_local *local)
382{
383 unsigned int au;
384
385 local = rxrpc_get_local_maybe(local);
386 if (!local)
387 return NULL;
388
389 au = atomic_fetch_add_unless(&local->active_users, 1, 0);
390 if (au == 0) {
391 rxrpc_put_local(local);
392 return NULL;
393 }
394
395 return local;
396}
397
398/*
399 * Cease using a local endpoint. Once the number of active users reaches 0, we
400 * start the closure of the transport in the work processor.
401 */
402void rxrpc_unuse_local(struct rxrpc_local *local)
403{
404 unsigned int au;
405
406 if (local) {
407 au = atomic_dec_return(&local->active_users);
408 if (au == 0)
409 rxrpc_queue_local(local);
410 else
411 rxrpc_put_local(local);
412 }
413}
414
415/*
416 * Destroy a local endpoint's socket and then hand the record to RCU to dispose
417 * of.
418 *
419 * Closing the socket cannot be done from bottom half context or RCU callback
420 * context because it might sleep.
421 */
422static void rxrpc_local_destroyer(struct rxrpc_local *local)
423{
424 struct socket *socket = local->socket;
425 struct rxrpc_net *rxnet = local->rxnet;
426
427 _enter("%d", local->debug_id);
428
429 local->dead = true;
430
431 mutex_lock(&rxnet->local_mutex);
432 list_del_init(&local->link);
433 mutex_unlock(&rxnet->local_mutex);
434
435 rxrpc_clean_up_local_conns(local);
436 rxrpc_service_connection_reaper(&rxnet->service_conn_reaper);
437 ASSERT(!local->service);
438
439 if (socket) {
440 local->socket = NULL;
441 kernel_sock_shutdown(socket, SHUT_RDWR);
442 socket->sk->sk_user_data = NULL;
443 sock_release(socket);
444 }
445
446 /* At this point, there should be no more packets coming in to the
447 * local endpoint.
448 */
449 rxrpc_purge_queue(&local->reject_queue);
450 rxrpc_purge_queue(&local->event_queue);
451}
452
453/*
454 * Process events on an endpoint. The work item carries a ref which
455 * we must release.
456 */
457static void rxrpc_local_processor(struct work_struct *work)
458{
459 struct rxrpc_local *local =
460 container_of(work, struct rxrpc_local, processor);
461 bool again;
462
463 trace_rxrpc_local(local->debug_id, rxrpc_local_processing,
464 atomic_read(&local->usage), NULL);
465
466 do {
467 again = false;
468 if (atomic_read(&local->active_users) == 0) {
469 rxrpc_local_destroyer(local);
470 break;
471 }
472
473 if (!skb_queue_empty(&local->reject_queue)) {
474 rxrpc_reject_packets(local);
475 again = true;
476 }
477
478 if (!skb_queue_empty(&local->event_queue)) {
479 rxrpc_process_local_events(local);
480 again = true;
481 }
482 } while (again);
483
484 rxrpc_put_local(local);
485}
486
487/*
488 * Destroy a local endpoint after the RCU grace period expires.
489 */
490static void rxrpc_local_rcu(struct rcu_head *rcu)
491{
492 struct rxrpc_local *local = container_of(rcu, struct rxrpc_local, rcu);
493
494 _enter("%d", local->debug_id);
495
496 ASSERT(!work_pending(&local->processor));
497
498 _net("DESTROY LOCAL %d", local->debug_id);
499 kfree(local);
500 _leave("");
501}
502
503/*
504 * Verify the local endpoint list is empty by this point.
505 */
506void rxrpc_destroy_all_locals(struct rxrpc_net *rxnet)
507{
508 struct rxrpc_local *local;
509
510 _enter("");
511
512 flush_workqueue(rxrpc_workqueue);
513
514 if (!list_empty(&rxnet->local_endpoints)) {
515 mutex_lock(&rxnet->local_mutex);
516 list_for_each_entry(local, &rxnet->local_endpoints, link) {
517 pr_err("AF_RXRPC: Leaked local %p {%d}\n",
518 local, atomic_read(&local->usage));
519 }
520 mutex_unlock(&rxnet->local_mutex);
521 BUG();
522 }
523}
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
23static 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 */
30static 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 */
42void 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 */
59static 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
96static 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 */
109static 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 */
162static 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
239error_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 */
250struct 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
307found:
308 mutex_unlock(&rxnet->local_mutex);
309 _leave(" = %p", local);
310 return local;
311
312nomem:
313 ret = -ENOMEM;
314sock_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
321addr_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 */
330struct 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 */
344struct 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 */
361void 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 */
382struct 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 */
401void 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 */
423void 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 */
460static 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 */
471void 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}