blob: a9a9be5519b9abfbc6d627279b4e64a35e4b05bd [file] [log] [blame]
David Howells17926a72007-04-26 15:48:28 -07001/* incoming call handling
2 *
3 * Copyright (C) 2007 Red Hat, Inc. All Rights Reserved.
4 * Written by David Howells (dhowells@redhat.com)
5 *
6 * This program is free software; you can redistribute it and/or
7 * modify it under the terms of the GNU General Public License
8 * as published by the Free Software Foundation; either version
9 * 2 of the License, or (at your option) any later version.
10 */
11
Joe Perches9b6d5392016-06-02 12:08:52 -070012#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
13
David Howells17926a72007-04-26 15:48:28 -070014#include <linux/module.h>
15#include <linux/net.h>
16#include <linux/skbuff.h>
17#include <linux/errqueue.h>
18#include <linux/udp.h>
19#include <linux/in.h>
20#include <linux/in6.h>
21#include <linux/icmp.h>
Tejun Heo5a0e3ad2010-03-24 17:04:11 +090022#include <linux/gfp.h>
David Howells00e90712016-09-08 11:10:12 +010023#include <linux/circ_buf.h>
David Howells17926a72007-04-26 15:48:28 -070024#include <net/sock.h>
25#include <net/af_rxrpc.h>
26#include <net/ip.h>
27#include "ar-internal.h"
28
29/*
David Howells00e90712016-09-08 11:10:12 +010030 * Preallocate a single service call, connection and peer and, if possible,
31 * give them a user ID and attach the user's side of the ID to them.
32 */
33static int rxrpc_service_prealloc_one(struct rxrpc_sock *rx,
34 struct rxrpc_backlog *b,
35 rxrpc_notify_rx_t notify_rx,
36 rxrpc_user_attach_call_t user_attach_call,
David Howellsa25e21f2018-03-27 23:03:00 +010037 unsigned long user_call_ID, gfp_t gfp,
38 unsigned int debug_id)
David Howells00e90712016-09-08 11:10:12 +010039{
40 const void *here = __builtin_return_address(0);
41 struct rxrpc_call *call;
David Howells2baec2c2017-05-24 17:02:32 +010042 struct rxrpc_net *rxnet = rxrpc_net(sock_net(&rx->sk));
David Howells00e90712016-09-08 11:10:12 +010043 int max, tmp;
44 unsigned int size = RXRPC_BACKLOG_MAX;
45 unsigned int head, tail, call_head, call_tail;
46
47 max = rx->sk.sk_max_ack_backlog;
48 tmp = rx->sk.sk_ack_backlog;
49 if (tmp >= max) {
50 _leave(" = -ENOBUFS [full %u]", max);
51 return -ENOBUFS;
52 }
53 max -= tmp;
54
55 /* We don't need more conns and peers than we have calls, but on the
56 * other hand, we shouldn't ever use more peers than conns or conns
57 * than calls.
58 */
59 call_head = b->call_backlog_head;
60 call_tail = READ_ONCE(b->call_backlog_tail);
61 tmp = CIRC_CNT(call_head, call_tail, size);
62 if (tmp >= max) {
63 _leave(" = -ENOBUFS [enough %u]", tmp);
64 return -ENOBUFS;
65 }
66 max = tmp + 1;
67
68 head = b->peer_backlog_head;
69 tail = READ_ONCE(b->peer_backlog_tail);
70 if (CIRC_CNT(head, tail, size) < max) {
71 struct rxrpc_peer *peer = rxrpc_alloc_peer(rx->local, gfp);
72 if (!peer)
73 return -ENOMEM;
74 b->peer_backlog[head] = peer;
75 smp_store_release(&b->peer_backlog_head,
76 (head + 1) & (size - 1));
77 }
78
79 head = b->conn_backlog_head;
80 tail = READ_ONCE(b->conn_backlog_tail);
81 if (CIRC_CNT(head, tail, size) < max) {
82 struct rxrpc_connection *conn;
83
David Howells2baec2c2017-05-24 17:02:32 +010084 conn = rxrpc_prealloc_service_connection(rxnet, gfp);
David Howells00e90712016-09-08 11:10:12 +010085 if (!conn)
86 return -ENOMEM;
87 b->conn_backlog[head] = conn;
88 smp_store_release(&b->conn_backlog_head,
89 (head + 1) & (size - 1));
David Howells363deea2016-09-17 10:49:14 +010090
91 trace_rxrpc_conn(conn, rxrpc_conn_new_service,
92 atomic_read(&conn->usage), here);
David Howells00e90712016-09-08 11:10:12 +010093 }
94
95 /* Now it gets complicated, because calls get registered with the
96 * socket here, particularly if a user ID is preassigned by the user.
97 */
David Howellsa25e21f2018-03-27 23:03:00 +010098 call = rxrpc_alloc_call(rx, gfp, debug_id);
David Howells00e90712016-09-08 11:10:12 +010099 if (!call)
100 return -ENOMEM;
101 call->flags |= (1 << RXRPC_CALL_IS_SERVICE);
102 call->state = RXRPC_CALL_SERVER_PREALLOC;
103
104 trace_rxrpc_call(call, rxrpc_call_new_service,
105 atomic_read(&call->usage),
106 here, (const void *)user_call_ID);
107
108 write_lock(&rx->call_lock);
109 if (user_attach_call) {
110 struct rxrpc_call *xcall;
111 struct rb_node *parent, **pp;
112
113 /* Check the user ID isn't already in use */
114 pp = &rx->calls.rb_node;
115 parent = NULL;
116 while (*pp) {
117 parent = *pp;
118 xcall = rb_entry(parent, struct rxrpc_call, sock_node);
119 if (user_call_ID < call->user_call_ID)
120 pp = &(*pp)->rb_left;
121 else if (user_call_ID > call->user_call_ID)
122 pp = &(*pp)->rb_right;
123 else
124 goto id_in_use;
125 }
126
127 call->user_call_ID = user_call_ID;
128 call->notify_rx = notify_rx;
David Howellscbd00892016-09-13 09:12:34 +0100129 rxrpc_get_call(call, rxrpc_call_got_kernel);
David Howells00e90712016-09-08 11:10:12 +0100130 user_attach_call(call, user_call_ID);
131 rxrpc_get_call(call, rxrpc_call_got_userid);
132 rb_link_node(&call->sock_node, parent, pp);
133 rb_insert_color(&call->sock_node, &rx->calls);
134 set_bit(RXRPC_CALL_HAS_USERID, &call->flags);
135 }
136
David Howells248f2192016-09-08 11:10:12 +0100137 list_add(&call->sock_link, &rx->sock_calls);
138
David Howells00e90712016-09-08 11:10:12 +0100139 write_unlock(&rx->call_lock);
140
David Howellsd3be4d22018-03-30 21:05:23 +0100141 rxnet = call->rxnet;
David Howells2baec2c2017-05-24 17:02:32 +0100142 write_lock(&rxnet->call_lock);
143 list_add_tail(&call->link, &rxnet->calls);
144 write_unlock(&rxnet->call_lock);
David Howells00e90712016-09-08 11:10:12 +0100145
146 b->call_backlog[call_head] = call;
147 smp_store_release(&b->call_backlog_head, (call_head + 1) & (size - 1));
148 _leave(" = 0 [%d -> %lx]", call->debug_id, user_call_ID);
149 return 0;
150
151id_in_use:
152 write_unlock(&rx->call_lock);
153 rxrpc_cleanup_call(call);
154 _leave(" = -EBADSLT");
155 return -EBADSLT;
156}
157
158/*
159 * Preallocate sufficient service connections, calls and peers to cover the
160 * entire backlog of a socket. When a new call comes in, if we don't have
161 * sufficient of each available, the call gets rejected as busy or ignored.
162 *
163 * The backlog is replenished when a connection is accepted or rejected.
164 */
165int rxrpc_service_prealloc(struct rxrpc_sock *rx, gfp_t gfp)
166{
167 struct rxrpc_backlog *b = rx->backlog;
168
169 if (!b) {
170 b = kzalloc(sizeof(struct rxrpc_backlog), gfp);
171 if (!b)
172 return -ENOMEM;
173 rx->backlog = b;
174 }
175
176 if (rx->discard_new_call)
177 return 0;
178
David Howellsa25e21f2018-03-27 23:03:00 +0100179 while (rxrpc_service_prealloc_one(rx, b, NULL, NULL, 0, gfp,
180 atomic_inc_return(&rxrpc_debug_id)) == 0)
David Howells00e90712016-09-08 11:10:12 +0100181 ;
182
183 return 0;
184}
185
186/*
187 * Discard the preallocation on a service.
188 */
189void rxrpc_discard_prealloc(struct rxrpc_sock *rx)
190{
191 struct rxrpc_backlog *b = rx->backlog;
David Howells2baec2c2017-05-24 17:02:32 +0100192 struct rxrpc_net *rxnet = rxrpc_net(sock_net(&rx->sk));
David Howells00e90712016-09-08 11:10:12 +0100193 unsigned int size = RXRPC_BACKLOG_MAX, head, tail;
194
195 if (!b)
196 return;
197 rx->backlog = NULL;
198
David Howells248f2192016-09-08 11:10:12 +0100199 /* Make sure that there aren't any incoming calls in progress before we
200 * clear the preallocation buffers.
201 */
202 spin_lock_bh(&rx->incoming_lock);
203 spin_unlock_bh(&rx->incoming_lock);
204
David Howells00e90712016-09-08 11:10:12 +0100205 head = b->peer_backlog_head;
206 tail = b->peer_backlog_tail;
207 while (CIRC_CNT(head, tail, size) > 0) {
208 struct rxrpc_peer *peer = b->peer_backlog[tail];
209 kfree(peer);
210 tail = (tail + 1) & (size - 1);
211 }
212
213 head = b->conn_backlog_head;
214 tail = b->conn_backlog_tail;
215 while (CIRC_CNT(head, tail, size) > 0) {
216 struct rxrpc_connection *conn = b->conn_backlog[tail];
David Howells2baec2c2017-05-24 17:02:32 +0100217 write_lock(&rxnet->conn_lock);
David Howells00e90712016-09-08 11:10:12 +0100218 list_del(&conn->link);
219 list_del(&conn->proc_link);
David Howells2baec2c2017-05-24 17:02:32 +0100220 write_unlock(&rxnet->conn_lock);
David Howells00e90712016-09-08 11:10:12 +0100221 kfree(conn);
David Howells31f5f9a162018-03-30 21:05:33 +0100222 if (atomic_dec_and_test(&rxnet->nr_conns))
Linus Torvalds5bb053b2018-04-03 14:04:18 -0700223 wake_up_var(&rxnet->nr_conns);
David Howells00e90712016-09-08 11:10:12 +0100224 tail = (tail + 1) & (size - 1);
225 }
226
227 head = b->call_backlog_head;
228 tail = b->call_backlog_tail;
229 while (CIRC_CNT(head, tail, size) > 0) {
230 struct rxrpc_call *call = b->call_backlog[tail];
David Howells88f2a8252018-03-30 21:05:17 +0100231 rcu_assign_pointer(call->socket, rx);
David Howells00e90712016-09-08 11:10:12 +0100232 if (rx->discard_new_call) {
233 _debug("discard %lx", call->user_call_ID);
234 rx->discard_new_call(call, call->user_call_ID);
David Howells3432a752016-09-13 09:05:14 +0100235 rxrpc_put_call(call, rxrpc_call_put_kernel);
David Howells00e90712016-09-08 11:10:12 +0100236 }
237 rxrpc_call_completed(call);
238 rxrpc_release_call(rx, call);
239 rxrpc_put_call(call, rxrpc_call_put);
240 tail = (tail + 1) & (size - 1);
241 }
242
243 kfree(b);
244}
245
246/*
David Howells248f2192016-09-08 11:10:12 +0100247 * Allocate a new incoming call from the prealloc pool, along with a connection
248 * and a peer as necessary.
David Howells17926a72007-04-26 15:48:28 -0700249 */
David Howells248f2192016-09-08 11:10:12 +0100250static struct rxrpc_call *rxrpc_alloc_incoming_call(struct rxrpc_sock *rx,
251 struct rxrpc_local *local,
252 struct rxrpc_connection *conn,
253 struct sk_buff *skb)
David Howells17926a72007-04-26 15:48:28 -0700254{
David Howells248f2192016-09-08 11:10:12 +0100255 struct rxrpc_backlog *b = rx->backlog;
256 struct rxrpc_peer *peer, *xpeer;
257 struct rxrpc_call *call;
258 unsigned short call_head, conn_head, peer_head;
259 unsigned short call_tail, conn_tail, peer_tail;
260 unsigned short call_count, conn_count;
David Howells17926a72007-04-26 15:48:28 -0700261
David Howells248f2192016-09-08 11:10:12 +0100262 /* #calls >= #conns >= #peers must hold true. */
263 call_head = smp_load_acquire(&b->call_backlog_head);
264 call_tail = b->call_backlog_tail;
265 call_count = CIRC_CNT(call_head, call_tail, RXRPC_BACKLOG_MAX);
266 conn_head = smp_load_acquire(&b->conn_backlog_head);
267 conn_tail = b->conn_backlog_tail;
268 conn_count = CIRC_CNT(conn_head, conn_tail, RXRPC_BACKLOG_MAX);
269 ASSERTCMP(conn_count, >=, call_count);
270 peer_head = smp_load_acquire(&b->peer_backlog_head);
271 peer_tail = b->peer_backlog_tail;
272 ASSERTCMP(CIRC_CNT(peer_head, peer_tail, RXRPC_BACKLOG_MAX), >=,
273 conn_count);
David Howells17926a72007-04-26 15:48:28 -0700274
David Howells248f2192016-09-08 11:10:12 +0100275 if (call_count == 0)
276 return NULL;
David Howells0d12f8a2016-03-04 15:53:46 +0000277
David Howells248f2192016-09-08 11:10:12 +0100278 if (!conn) {
279 /* No connection. We're going to need a peer to start off
280 * with. If one doesn't yet exist, use a spare from the
281 * preallocation set. We dump the address into the spare in
282 * anticipation - and to save on stack space.
283 */
284 xpeer = b->peer_backlog[peer_tail];
David Howells7b674e32017-08-29 10:18:37 +0100285 if (rxrpc_extract_addr_from_skb(local, &xpeer->srx, skb) < 0)
David Howells248f2192016-09-08 11:10:12 +0100286 return NULL;
David Howells17926a72007-04-26 15:48:28 -0700287
David Howells248f2192016-09-08 11:10:12 +0100288 peer = rxrpc_lookup_incoming_peer(local, xpeer);
289 if (peer == xpeer) {
290 b->peer_backlog[peer_tail] = NULL;
291 smp_store_release(&b->peer_backlog_tail,
292 (peer_tail + 1) &
293 (RXRPC_BACKLOG_MAX - 1));
294 }
David Howells17926a72007-04-26 15:48:28 -0700295
David Howells248f2192016-09-08 11:10:12 +0100296 /* Now allocate and set up the connection */
297 conn = b->conn_backlog[conn_tail];
298 b->conn_backlog[conn_tail] = NULL;
299 smp_store_release(&b->conn_backlog_tail,
300 (conn_tail + 1) & (RXRPC_BACKLOG_MAX - 1));
David Howells09d2bf52018-03-30 21:05:28 +0100301 conn->params.local = rxrpc_get_local(local);
David Howells248f2192016-09-08 11:10:12 +0100302 conn->params.peer = peer;
David Howells363deea2016-09-17 10:49:14 +0100303 rxrpc_see_connection(conn);
David Howells47229742017-06-05 14:30:49 +0100304 rxrpc_new_incoming_connection(rx, conn, skb);
David Howells248f2192016-09-08 11:10:12 +0100305 } else {
306 rxrpc_get_connection(conn);
David Howells17926a72007-04-26 15:48:28 -0700307 }
308
David Howells248f2192016-09-08 11:10:12 +0100309 /* And now we can allocate and set up a new call */
310 call = b->call_backlog[call_tail];
311 b->call_backlog[call_tail] = NULL;
312 smp_store_release(&b->call_backlog_tail,
313 (call_tail + 1) & (RXRPC_BACKLOG_MAX - 1));
314
David Howellscbd00892016-09-13 09:12:34 +0100315 rxrpc_see_call(call);
David Howells248f2192016-09-08 11:10:12 +0100316 call->conn = conn;
317 call->peer = rxrpc_get_peer(conn->params.peer);
David Howellsf7aec122017-06-14 17:56:50 +0100318 call->cong_cwnd = call->peer->cong_cwnd;
David Howells248f2192016-09-08 11:10:12 +0100319 return call;
David Howells17926a72007-04-26 15:48:28 -0700320}
321
322/*
David Howells248f2192016-09-08 11:10:12 +0100323 * Set up a new incoming call. Called in BH context with the RCU read lock
324 * held.
325 *
326 * If this is for a kernel service, when we allocate the call, it will have
327 * three refs on it: (1) the kernel service, (2) the user_call_ID tree, (3) the
328 * retainer ref obtained from the backlog buffer. Prealloc calls for userspace
329 * services only have the ref from the backlog buffer. We want to pass this
330 * ref to non-BH context to dispose of.
331 *
332 * If we want to report an error, we mark the skb with the packet type and
333 * abort code and return NULL.
David Howells540b1c42017-02-27 15:43:06 +0000334 *
335 * The call is returned with the user access mutex held.
David Howells17926a72007-04-26 15:48:28 -0700336 */
David Howells248f2192016-09-08 11:10:12 +0100337struct rxrpc_call *rxrpc_new_incoming_call(struct rxrpc_local *local,
338 struct rxrpc_connection *conn,
339 struct sk_buff *skb)
David Howells17926a72007-04-26 15:48:28 -0700340{
David Howells248f2192016-09-08 11:10:12 +0100341 struct rxrpc_skb_priv *sp = rxrpc_skb(skb);
342 struct rxrpc_sock *rx;
David Howells17926a72007-04-26 15:48:28 -0700343 struct rxrpc_call *call;
David Howells1e9e5c92016-09-29 22:37:15 +0100344 u16 service_id = sp->hdr.serviceId;
David Howells17926a72007-04-26 15:48:28 -0700345
346 _enter("");
347
David Howells248f2192016-09-08 11:10:12 +0100348 /* Get the socket providing the service */
David Howells1e9e5c92016-09-29 22:37:15 +0100349 rx = rcu_dereference(local->service);
David Howells28036f42017-06-05 14:30:49 +0100350 if (rx && (service_id == rx->srx.srx_service ||
351 service_id == rx->second_service))
David Howells1e9e5c92016-09-29 22:37:15 +0100352 goto found_service;
David Howells248f2192016-09-08 11:10:12 +0100353
David Howellsa25e21f2018-03-27 23:03:00 +0100354 trace_rxrpc_abort(0, "INV", sp->hdr.cid, sp->hdr.callNumber, sp->hdr.seq,
David Howells248f2192016-09-08 11:10:12 +0100355 RX_INVALID_OPERATION, EOPNOTSUPP);
356 skb->mark = RXRPC_SKB_MARK_LOCAL_ABORT;
357 skb->priority = RX_INVALID_OPERATION;
358 _leave(" = NULL [service]");
359 return NULL;
David Howells17926a72007-04-26 15:48:28 -0700360
361found_service:
David Howells248f2192016-09-08 11:10:12 +0100362 spin_lock(&rx->incoming_lock);
David Howells210f0352017-01-05 10:38:36 +0000363 if (rx->sk.sk_state == RXRPC_SERVER_LISTEN_DISABLED ||
364 rx->sk.sk_state == RXRPC_CLOSE) {
David Howellsa25e21f2018-03-27 23:03:00 +0100365 trace_rxrpc_abort(0, "CLS", sp->hdr.cid, sp->hdr.callNumber,
David Howells248f2192016-09-08 11:10:12 +0100366 sp->hdr.seq, RX_INVALID_OPERATION, ESHUTDOWN);
367 skb->mark = RXRPC_SKB_MARK_LOCAL_ABORT;
368 skb->priority = RX_INVALID_OPERATION;
369 _leave(" = NULL [close]");
370 call = NULL;
371 goto out;
372 }
David Howells17926a72007-04-26 15:48:28 -0700373
David Howells248f2192016-09-08 11:10:12 +0100374 call = rxrpc_alloc_incoming_call(rx, local, conn, skb);
375 if (!call) {
376 skb->mark = RXRPC_SKB_MARK_BUSY;
377 _leave(" = NULL [busy]");
378 call = NULL;
379 goto out;
380 }
381
David Howells58dc63c2016-09-17 10:49:13 +0100382 trace_rxrpc_receive(call, rxrpc_receive_incoming,
383 sp->hdr.serial, sp->hdr.seq);
384
David Howells540b1c42017-02-27 15:43:06 +0000385 /* Lock the call to prevent rxrpc_kernel_send/recv_data() and
386 * sendmsg()/recvmsg() inconveniently stealing the mutex once the
387 * notification is generated.
388 *
389 * The BUG should never happen because the kernel should be well
390 * behaved enough not to access the call before the first notification
391 * event and userspace is prevented from doing so until the state is
392 * appropriate.
393 */
394 if (!mutex_trylock(&call->user_mutex))
395 BUG();
396
David Howells248f2192016-09-08 11:10:12 +0100397 /* Make the call live. */
398 rxrpc_incoming_call(rx, call, skb);
399 conn = call->conn;
400
401 if (rx->notify_new_call)
402 rx->notify_new_call(&rx->sk, call, call->user_call_ID);
David Howellse6f3afb2016-09-17 10:49:11 +0100403 else
404 sk_acceptq_added(&rx->sk);
David Howells248f2192016-09-08 11:10:12 +0100405
406 spin_lock(&conn->state_lock);
407 switch (conn->state) {
408 case RXRPC_CONN_SERVICE_UNSECURED:
409 conn->state = RXRPC_CONN_SERVICE_CHALLENGING;
410 set_bit(RXRPC_CONN_EV_CHALLENGE, &call->conn->events);
411 rxrpc_queue_conn(call->conn);
412 break;
413
414 case RXRPC_CONN_SERVICE:
415 write_lock(&call->state_lock);
416 if (rx->discard_new_call)
417 call->state = RXRPC_CALL_SERVER_RECV_REQUEST;
418 else
419 call->state = RXRPC_CALL_SERVER_ACCEPTING;
420 write_unlock(&call->state_lock);
421 break;
422
423 case RXRPC_CONN_REMOTELY_ABORTED:
424 rxrpc_set_call_completion(call, RXRPC_CALL_REMOTELY_ABORTED,
David Howells3a927892017-04-06 10:11:56 +0100425 conn->remote_abort, -ECONNABORTED);
David Howells248f2192016-09-08 11:10:12 +0100426 break;
427 case RXRPC_CONN_LOCALLY_ABORTED:
428 rxrpc_abort_call("CON", call, sp->hdr.seq,
David Howells3a927892017-04-06 10:11:56 +0100429 conn->local_abort, -ECONNABORTED);
David Howells248f2192016-09-08 11:10:12 +0100430 break;
David Howells17926a72007-04-26 15:48:28 -0700431 default:
432 BUG();
433 }
David Howells248f2192016-09-08 11:10:12 +0100434 spin_unlock(&conn->state_lock);
David Howells17926a72007-04-26 15:48:28 -0700435
David Howells248f2192016-09-08 11:10:12 +0100436 if (call->state == RXRPC_CALL_SERVER_ACCEPTING)
437 rxrpc_notify_socket(call);
David Howells17926a72007-04-26 15:48:28 -0700438
David Howells3432a752016-09-13 09:05:14 +0100439 /* We have to discard the prealloc queue's ref here and rely on a
440 * combination of the RCU read lock and refs held either by the socket
441 * (recvmsg queue, to-be-accepted queue or user ID tree) or the kernel
442 * service to prevent the call from being deallocated too early.
443 */
444 rxrpc_put_call(call, rxrpc_call_put);
445
David Howells248f2192016-09-08 11:10:12 +0100446 _leave(" = %p{%d}", call, call->debug_id);
447out:
448 spin_unlock(&rx->incoming_lock);
449 return call;
David Howells17926a72007-04-26 15:48:28 -0700450}
451
452/*
453 * handle acceptance of a call by userspace
454 * - assign the user call ID to the call at the front of the queue
David Howells540b1c42017-02-27 15:43:06 +0000455 * - called with the socket locked.
David Howells17926a72007-04-26 15:48:28 -0700456 */
David Howells651350d2007-04-26 15:50:17 -0700457struct rxrpc_call *rxrpc_accept_call(struct rxrpc_sock *rx,
David Howellsd0016482016-08-30 20:42:14 +0100458 unsigned long user_call_ID,
459 rxrpc_notify_rx_t notify_rx)
David Howells540b1c42017-02-27 15:43:06 +0000460 __releases(&rx->sk.sk_lock.slock)
David Howells88f2a8252018-03-30 21:05:17 +0100461 __acquires(call->user_mutex)
David Howells17926a72007-04-26 15:48:28 -0700462{
463 struct rxrpc_call *call;
464 struct rb_node *parent, **pp;
465 int ret;
466
467 _enter(",%lx", user_call_ID);
468
469 ASSERT(!irqs_disabled());
470
471 write_lock(&rx->call_lock);
472
David Howellsb25de362016-09-13 22:36:22 +0100473 if (list_empty(&rx->to_be_accepted)) {
474 write_unlock(&rx->call_lock);
David Howells540b1c42017-02-27 15:43:06 +0000475 release_sock(&rx->sk);
David Howellsb25de362016-09-13 22:36:22 +0100476 kleave(" = -ENODATA [empty]");
477 return ERR_PTR(-ENODATA);
478 }
David Howells17926a72007-04-26 15:48:28 -0700479
480 /* check the user ID isn't already in use */
David Howells17926a72007-04-26 15:48:28 -0700481 pp = &rx->calls.rb_node;
482 parent = NULL;
483 while (*pp) {
484 parent = *pp;
485 call = rb_entry(parent, struct rxrpc_call, sock_node);
486
487 if (user_call_ID < call->user_call_ID)
488 pp = &(*pp)->rb_left;
489 else if (user_call_ID > call->user_call_ID)
490 pp = &(*pp)->rb_right;
491 else
David Howells248f2192016-09-08 11:10:12 +0100492 goto id_in_use;
David Howells17926a72007-04-26 15:48:28 -0700493 }
494
David Howells248f2192016-09-08 11:10:12 +0100495 /* Dequeue the first call and check it's still valid. We gain
496 * responsibility for the queue's reference.
497 */
498 call = list_entry(rx->to_be_accepted.next,
499 struct rxrpc_call, accept_link);
David Howells540b1c42017-02-27 15:43:06 +0000500 write_unlock(&rx->call_lock);
501
502 /* We need to gain the mutex from the interrupt handler without
503 * upsetting lockdep, so we have to release it there and take it here.
504 * We are, however, still holding the socket lock, so other accepts
505 * must wait for us and no one can add the user ID behind our backs.
506 */
507 if (mutex_lock_interruptible(&call->user_mutex) < 0) {
508 release_sock(&rx->sk);
509 kleave(" = -ERESTARTSYS");
510 return ERR_PTR(-ERESTARTSYS);
511 }
512
513 write_lock(&rx->call_lock);
David Howells17926a72007-04-26 15:48:28 -0700514 list_del_init(&call->accept_link);
515 sk_acceptq_removed(&rx->sk);
David Howellse34d4232016-08-30 09:49:29 +0100516 rxrpc_see_call(call);
David Howells17926a72007-04-26 15:48:28 -0700517
David Howells540b1c42017-02-27 15:43:06 +0000518 /* Find the user ID insertion point. */
519 pp = &rx->calls.rb_node;
520 parent = NULL;
521 while (*pp) {
522 parent = *pp;
523 call = rb_entry(parent, struct rxrpc_call, sock_node);
524
525 if (user_call_ID < call->user_call_ID)
526 pp = &(*pp)->rb_left;
527 else if (user_call_ID > call->user_call_ID)
528 pp = &(*pp)->rb_right;
529 else
530 BUG();
531 }
532
David Howells17926a72007-04-26 15:48:28 -0700533 write_lock_bh(&call->state_lock);
534 switch (call->state) {
535 case RXRPC_CALL_SERVER_ACCEPTING:
536 call->state = RXRPC_CALL_SERVER_RECV_REQUEST;
537 break;
David Howellsf5c17aa2016-08-30 09:49:28 +0100538 case RXRPC_CALL_COMPLETE:
539 ret = call->error;
David Howells17926a72007-04-26 15:48:28 -0700540 goto out_release;
David Howells17926a72007-04-26 15:48:28 -0700541 default:
542 BUG();
543 }
544
545 /* formalise the acceptance */
David Howellsd0016482016-08-30 20:42:14 +0100546 call->notify_rx = notify_rx;
David Howells17926a72007-04-26 15:48:28 -0700547 call->user_call_ID = user_call_ID;
David Howells248f2192016-09-08 11:10:12 +0100548 rxrpc_get_call(call, rxrpc_call_got_userid);
David Howells17926a72007-04-26 15:48:28 -0700549 rb_link_node(&call->sock_node, parent, pp);
550 rb_insert_color(&call->sock_node, &rx->calls);
551 if (test_and_set_bit(RXRPC_CALL_HAS_USERID, &call->flags))
552 BUG();
David Howells17926a72007-04-26 15:48:28 -0700553
554 write_unlock_bh(&call->state_lock);
555 write_unlock(&rx->call_lock);
David Howells248f2192016-09-08 11:10:12 +0100556 rxrpc_notify_socket(call);
557 rxrpc_service_prealloc(rx, GFP_KERNEL);
David Howells540b1c42017-02-27 15:43:06 +0000558 release_sock(&rx->sk);
David Howells651350d2007-04-26 15:50:17 -0700559 _leave(" = %p{%d}", call, call->debug_id);
560 return call;
David Howells17926a72007-04-26 15:48:28 -0700561
David Howells17926a72007-04-26 15:48:28 -0700562out_release:
David Howells248f2192016-09-08 11:10:12 +0100563 _debug("release %p", call);
David Howells651350d2007-04-26 15:50:17 -0700564 write_unlock_bh(&call->state_lock);
David Howells8d94aa32016-09-07 09:19:31 +0100565 write_unlock(&rx->call_lock);
David Howells8d94aa32016-09-07 09:19:31 +0100566 rxrpc_release_call(rx, call);
David Howells248f2192016-09-08 11:10:12 +0100567 rxrpc_put_call(call, rxrpc_call_put);
568 goto out;
569
570id_in_use:
571 ret = -EBADSLT;
David Howells651350d2007-04-26 15:50:17 -0700572 write_unlock(&rx->call_lock);
David Howells248f2192016-09-08 11:10:12 +0100573out:
574 rxrpc_service_prealloc(rx, GFP_KERNEL);
David Howells540b1c42017-02-27 15:43:06 +0000575 release_sock(&rx->sk);
David Howells651350d2007-04-26 15:50:17 -0700576 _leave(" = %d", ret);
577 return ERR_PTR(ret);
578}
579
580/*
David Howellsb4f13422016-03-04 15:56:19 +0000581 * Handle rejection of a call by userspace
David Howells651350d2007-04-26 15:50:17 -0700582 * - reject the call at the front of the queue
583 */
584int rxrpc_reject_call(struct rxrpc_sock *rx)
585{
586 struct rxrpc_call *call;
David Howells248f2192016-09-08 11:10:12 +0100587 bool abort = false;
David Howells651350d2007-04-26 15:50:17 -0700588 int ret;
589
590 _enter("");
591
592 ASSERT(!irqs_disabled());
593
594 write_lock(&rx->call_lock);
595
David Howells248f2192016-09-08 11:10:12 +0100596 if (list_empty(&rx->to_be_accepted)) {
David Howells8d94aa32016-09-07 09:19:31 +0100597 write_unlock(&rx->call_lock);
David Howells8d94aa32016-09-07 09:19:31 +0100598 return -ENODATA;
599 }
David Howells651350d2007-04-26 15:50:17 -0700600
David Howells248f2192016-09-08 11:10:12 +0100601 /* Dequeue the first call and check it's still valid. We gain
602 * responsibility for the queue's reference.
603 */
604 call = list_entry(rx->to_be_accepted.next,
605 struct rxrpc_call, accept_link);
David Howells651350d2007-04-26 15:50:17 -0700606 list_del_init(&call->accept_link);
607 sk_acceptq_removed(&rx->sk);
David Howellse34d4232016-08-30 09:49:29 +0100608 rxrpc_see_call(call);
David Howells651350d2007-04-26 15:50:17 -0700609
610 write_lock_bh(&call->state_lock);
611 switch (call->state) {
612 case RXRPC_CALL_SERVER_ACCEPTING:
David Howells3a927892017-04-06 10:11:56 +0100613 __rxrpc_abort_call("REJ", call, 1, RX_USER_ABORT, -ECONNABORTED);
David Howells248f2192016-09-08 11:10:12 +0100614 abort = true;
615 /* fall through */
David Howellsf5c17aa2016-08-30 09:49:28 +0100616 case RXRPC_CALL_COMPLETE:
617 ret = call->error;
David Howells248f2192016-09-08 11:10:12 +0100618 goto out_discard;
David Howells651350d2007-04-26 15:50:17 -0700619 default:
620 BUG();
621 }
622
David Howells248f2192016-09-08 11:10:12 +0100623out_discard:
David Howells17926a72007-04-26 15:48:28 -0700624 write_unlock_bh(&call->state_lock);
David Howells17926a72007-04-26 15:48:28 -0700625 write_unlock(&rx->call_lock);
David Howells248f2192016-09-08 11:10:12 +0100626 if (abort) {
David Howells26cb02a2016-10-06 08:11:49 +0100627 rxrpc_send_abort_packet(call);
David Howells248f2192016-09-08 11:10:12 +0100628 rxrpc_release_call(rx, call);
629 rxrpc_put_call(call, rxrpc_call_put);
630 }
631 rxrpc_service_prealloc(rx, GFP_KERNEL);
David Howells17926a72007-04-26 15:48:28 -0700632 _leave(" = %d", ret);
633 return ret;
634}
David Howells651350d2007-04-26 15:50:17 -0700635
David Howells00e90712016-09-08 11:10:12 +0100636/*
637 * rxrpc_kernel_charge_accept - Charge up socket with preallocated calls
638 * @sock: The socket on which to preallocate
639 * @notify_rx: Event notification function for the call
640 * @user_attach_call: Func to attach call to user_call_ID
641 * @user_call_ID: The tag to attach to the preallocated call
642 * @gfp: The allocation conditions.
David Howellsa25e21f2018-03-27 23:03:00 +0100643 * @debug_id: The tracing debug ID.
David Howells00e90712016-09-08 11:10:12 +0100644 *
645 * Charge up the socket with preallocated calls, each with a user ID. A
646 * function should be provided to effect the attachment from the user's side.
647 * The user is given a ref to hold on the call.
648 *
649 * Note that the call may be come connected before this function returns.
650 */
651int rxrpc_kernel_charge_accept(struct socket *sock,
652 rxrpc_notify_rx_t notify_rx,
653 rxrpc_user_attach_call_t user_attach_call,
David Howellsa25e21f2018-03-27 23:03:00 +0100654 unsigned long user_call_ID, gfp_t gfp,
655 unsigned int debug_id)
David Howells00e90712016-09-08 11:10:12 +0100656{
657 struct rxrpc_sock *rx = rxrpc_sk(sock->sk);
658 struct rxrpc_backlog *b = rx->backlog;
659
660 if (sock->sk->sk_state == RXRPC_CLOSE)
661 return -ESHUTDOWN;
662
663 return rxrpc_service_prealloc_one(rx, b, notify_rx,
664 user_attach_call, user_call_ID,
David Howellsa25e21f2018-03-27 23:03:00 +0100665 gfp, debug_id);
David Howells00e90712016-09-08 11:10:12 +0100666}
667EXPORT_SYMBOL(rxrpc_kernel_charge_accept);