summaryrefslogtreecommitdiffstats
path: root/net/rxrpc/conn_event.c
blob: 9e9a8db1bc9cd0f1afd3efd7e9e26c4d2890a7d3 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
/* connection-level event handling
 *
 * Copyright (C) 2007 Red Hat, Inc. All Rights Reserved.
 * Written by David Howells (dhowells@redhat.com)
 *
 * This program is free software; you can redistribute it and/or
 * modify it under the terms of the GNU General Public License
 * as published by the Free Software Foundation; either version
 * 2 of the License, or (at your option) any later version.
 */

#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt

#include <linux/module.h>
#include <linux/net.h>
#include <linux/skbuff.h>
#include <linux/errqueue.h>
#include <net/sock.h>
#include <net/af_rxrpc.h>
#include <net/ip.h>
#include "ar-internal.h"

/*
 * Retransmit terminal ACK or ABORT of the previous call.
 */
static void rxrpc_conn_retransmit_call(struct rxrpc_connection *conn,
				       struct sk_buff *skb,
				       unsigned int channel)
{
	struct rxrpc_skb_priv *sp = skb ? rxrpc_skb(skb) : NULL;
	struct rxrpc_channel *chan;
	struct msghdr msg;
	struct kvec iov;
	struct {
		struct rxrpc_wire_header whdr;
		union {
			struct {
				__be32 code;
			} abort;
			struct {
				struct rxrpc_ackpacket ack;
				u8 padding[3];
				struct rxrpc_ackinfo info;
			};
		};
	} __attribute__((packed)) pkt;
	size_t len;
	u32 serial, mtu, call_id;

	_enter("%d", conn->debug_id);

	chan = &conn->channels[channel];

	/* If the last call got moved on whilst we were waiting to run, just
	 * ignore this packet.
	 */
	call_id = READ_ONCE(chan->last_call);
	/* Sync with __rxrpc_disconnect_call() */
	smp_rmb();
	if (skb && call_id != sp->hdr.callNumber)
		return;

	msg.msg_name	= &conn->params.peer->srx.transport;
	msg.msg_namelen	= conn->params.peer->srx.transport_len;
	msg.msg_control	= NULL;
	msg.msg_controllen = 0;
	msg.msg_flags	= 0;

	pkt.whdr.epoch		= htonl(conn->proto.epoch);
	pkt.whdr.cid		= htonl(conn->proto.cid);
	pkt.whdr.callNumber	= htonl(call_id);
	pkt.whdr.seq		= 0;
	pkt.whdr.type		= chan->last_type;
	pkt.whdr.flags		= conn->out_clientflag;
	pkt.whdr.userStatus	= 0;
	pkt.whdr.securityIndex	= conn->security_ix;
	pkt.whdr._rsvd		= 0;
	pkt.whdr.serviceId	= htons(conn->service_id);

	len = sizeof(pkt.whdr);
	switch (chan->last_type) {
	case RXRPC_PACKET_TYPE_ABORT:
		pkt.abort.code	= htonl(chan->last_abort);
		len += sizeof(pkt.abort);
		break;

	case RXRPC_PACKET_TYPE_ACK:
		mtu = conn->params.peer->if_mtu;
		mtu -= conn->params.peer->hdrsize;
		pkt.ack.bufferSpace	= 0;
		pkt.ack.maxSkew		= htons(skb ? skb->priority : 0);
		pkt.ack.firstPacket	= htonl(chan->last_seq + 1);
		pkt.ack.previousPacket	= htonl(chan->last_seq);
		pkt.ack.serial		= htonl(skb ? sp->hdr.serial : 0);
		pkt.ack.reason		= skb ? RXRPC_ACK_DUPLICATE : RXRPC_ACK_IDLE;
		pkt.ack.nAcks		= 0;
		pkt.info.rxMTU		= htonl(rxrpc_rx_mtu);
		pkt.info.maxMTU		= htonl(mtu);
		pkt.info.rwind		= htonl(rxrpc_rx_window_size);
		pkt.info.jumbo_max	= htonl(rxrpc_rx_jumbo_max);
		pkt.whdr.flags		|= RXRPC_SLOW_START_OK;
		len += sizeof(pkt.ack) + sizeof(pkt.info);
		break;
	}

	/* Resync with __rxrpc_disconnect_call() and check that the last call
	 * didn't get advanced whilst we were filling out the packets.
	 */
	smp_rmb();
	if (READ_ONCE(chan->last_call) != call_id)
		return;

	iov.iov_base	= &pkt;
	iov.iov_len	= len;

	serial = atomic_inc_return(&conn->serial);
	pkt.whdr.serial = htonl(serial);

	switch (chan->last_type) {
	case RXRPC_PACKET_TYPE_ABORT:
		_proto("Tx ABORT %%%u { %d } [re]", serial, conn->local_abort);
		break;
	case RXRPC_PACKET_TYPE_ACK:
		trace_rxrpc_tx_ack(NULL, serial, chan->last_seq, 0,
				   RXRPC_ACK_DUPLICATE, 0);
		_proto("Tx ACK %%%u [re]", serial);
		break;
	}

	kernel_sendmsg(conn->params.local->socket, &msg, &iov, 1, len);
	_leave("");
	return;
}

/*
 * pass a connection-level abort onto all calls on that connection
 */
static void rxrpc_abort_calls(struct rxrpc_connection *conn,
			      enum rxrpc_call_completion compl,
			      u32 abort_code, int error)
{
	struct rxrpc_call *call;
	int i;

	_enter("{%d},%x", conn->debug_id, abort_code);

	spin_lock(&conn->channel_lock);

	for (i = 0; i < RXRPC_MAXCALLS; i++) {
		call = rcu_dereference_protected(
			conn->channels[i].call,
			lockdep_is_held(&conn->channel_lock));
		if (call) {
			if (compl == RXRPC_CALL_LOCALLY_ABORTED)
				trace_rxrpc_abort("CON", call->cid,
						  call->call_id, 0,
						  abort_code, error);
			if (rxrpc_set_call_completion(call, compl,
						      abort_code, error))
				rxrpc_notify_socket(call);
		}
	}

	spin_unlock(&conn->channel_lock);
	_leave("");
}

/*
 * generate a connection-level abort
 */
static int rxrpc_abort_connection(struct rxrpc_connection *conn,
				  int error, u32 abort_code)
{
	struct rxrpc_wire_header whdr;
	struct msghdr msg;
	struct kvec iov[2];
	__be32 word;
	size_t len;
	u32 serial;
	int ret;

	_enter("%d,,%u,%u", conn->debug_id, error, abort_code);

	/* generate a connection-level abort */
	spin_lock_bh(&conn->state_lock);
	if (conn->state >= RXRPC_CONN_REMOTELY_ABORTED) {
		spin_unlock_bh(&conn->state_lock);
		_leave(" = 0 [already dead]");
		return 0;
	}

	conn->state = RXRPC_CONN_LOCALLY_ABORTED;
	spin_unlock_bh(&conn->state_lock);

	rxrpc_abort_calls(conn, RXRPC_CALL_LOCALLY_ABORTED, abort_code, error);

	msg.msg_name	= &conn->params.peer->srx.transport;
	msg.msg_namelen	= conn->params.peer->srx.transport_len;
	msg.msg_control	= NULL;
	msg.msg_controllen = 0;
	msg.msg_flags	= 0;

	whdr.epoch	= htonl(conn->proto.epoch);
	whdr.cid	= htonl(conn->proto.cid);
	whdr.callNumber	= 0;
	whdr.seq	= 0;
	whdr.type	= RXRPC_PACKET_TYPE_ABORT;
	whdr.flags	= conn->out_clientflag;
	whdr.userStatus	= 0;
	whdr.securityIndex = conn->security_ix;
	whdr._rsvd	= 0;
	whdr.serviceId	= htons(conn->service_id);

	word		= htonl(conn->local_abort);

	iov[0].iov_base	= &whdr;
	iov[0].iov_len	= sizeof(whdr);
	iov[1].iov_base	= &word;
	iov[1].iov_len	= sizeof(word);

	len = iov[0].iov_len + iov[1].iov_len;

	serial = atomic_inc_return(&conn->serial);
	whdr.serial = htonl(serial);
	_proto("Tx CONN ABORT %%%u { %d }", serial, conn->local_abort);

	ret = kernel_sendmsg(conn->params.local->socket, &msg, iov, 2, len);
	if (ret < 0) {
		_debug("sendmsg failed: %d", ret);
		return -EAGAIN;
	}

	_leave(" = 0");
	return 0;
}

/*
 * mark a call as being on a now-secured channel
 * - must be called with BH's disabled.
 */
static void rxrpc_call_is_secure(struct rxrpc_call *call)
{
	_enter("%p", call);
	if (call) {
		write_lock_bh(&call->state_lock);
		if (call->state == RXRPC_CALL_SERVER_SECURING) {
			call->state = RXRPC_CALL_SERVER_ACCEPTING;
			rxrpc_notify_socket(call);
		}
		write_unlock_bh(&call->state_lock);
	}
}

/*
 * connection-level Rx packet processor
 */
static int rxrpc_process_event(struct rxrpc_connection *conn,
			       struct sk_buff *skb,
			       u32 *_abort_code)
{
	struct rxrpc_skb_priv *sp = rxrpc_skb(skb);
	__be32 wtmp;
	u32 abort_code;
	int loop, ret;

	if (conn->state >= RXRPC_CONN_REMOTELY_ABORTED) {
		_leave(" = -ECONNABORTED [%u]", conn->state);
		return -ECONNABORTED;
	}

	_enter("{%d},{%u,%%%u},", conn->debug_id, sp->hdr.type, sp->hdr.serial);

	switch (sp->hdr.type) {
	case RXRPC_PACKET_TYPE_DATA:
	case RXRPC_PACKET_TYPE_ACK:
		rxrpc_conn_retransmit_call(conn, skb,
					   sp->hdr.cid & RXRPC_CHANNELMASK);
		return 0;

	case RXRPC_PACKET_TYPE_BUSY:
		/* Just ignore BUSY packets for now. */
		return 0;

	case RXRPC_PACKET_TYPE_ABORT:
		if (skb_copy_bits(skb, sizeof(struct rxrpc_wire_header),
				  &wtmp, sizeof(wtmp)) < 0) {
			trace_rxrpc_rx_eproto(NULL, sp->hdr.serial,
					      tracepoint_string("bad_abort"));
			return -EPROTO;
		}
		abort_code = ntohl(wtmp);
		_proto("Rx ABORT %%%u { ac=%d }", sp->hdr.serial, abort_code);

		conn->state = RXRPC_CONN_REMOTELY_ABORTED;
		rxrpc_abort_calls(conn, RXRPC_CALL_REMOTELY_ABORTED,
				  abort_code, -ECONNABORTED);
		return -ECONNABORTED;

	case RXRPC_PACKET_TYPE_CHALLENGE:
		return conn->security->respond_to_challenge(conn, skb,
							    _abort_code);

	case RXRPC_PACKET_TYPE_RESPONSE:
		ret = conn->security->verify_response(conn, skb, _abort_code);
		if (ret < 0)
			return ret;

		ret = conn->security->init_connection_security(conn);
		if (ret < 0)
			return ret;

		ret = conn->security->prime_packet_security(conn);
		if (ret < 0)
			return ret;

		spin_lock(&conn->channel_lock);
		spin_lock(&conn->state_lock);

		if (conn->state == RXRPC_CONN_SERVICE_CHALLENGING) {
			conn->state = RXRPC_CONN_SERVICE;
			spin_unlock(&conn->state_lock);
			for (loop = 0; loop < RXRPC_MAXCALLS; loop++)
				rxrpc_call_is_secure(
					rcu_dereference_protected(
						conn->channels[loop].call,
						lockdep_is_held(&conn->channel_lock)));
		} else {
			spin_unlock(&conn->state_lock);
		}

		spin_unlock(&conn->channel_lock);
		return 0;

	default:
		trace_rxrpc_rx_eproto(NULL, sp->hdr.serial,
				      tracepoint_string("bad_conn_pkt"));
		return -EPROTO;
	}
}

/*
 * set up security and issue a challenge
 */
static void rxrpc_secure_connection(struct rxrpc_connection *conn)
{
	u32 abort_code;
	int ret;

	_enter("{%d}", conn->debug_id);

	ASSERT(conn->security_ix != 0);

	if (!conn->params.key) {
		_debug("set up security");
		ret = rxrpc_init_server_conn_security(conn);
		switch (ret) {
		case 0:
			break;
		case -ENOENT:
			abort_code = RX_CALL_DEAD;
			goto abort;
		default:
			abort_code = RXKADNOAUTH;
			goto abort;
		}
	}

	if (conn->security->issue_challenge(conn) < 0) {
		abort_code = RX_CALL_DEAD;
		ret = -ENOMEM;
		goto abort;
	}

	_leave("");
	return;

abort:
	_debug("abort %d, %d", ret, abort_code);
	rxrpc_abort_connection(conn, ret, abort_code);
	_leave(" [aborted]");
}

/*
 * Process delayed final ACKs that we haven't subsumed into a subsequent call.
 */
static void rxrpc_process_delayed_final_acks(struct rxrpc_connection *conn)
{
	unsigned long j = jiffies, next_j;
	unsigned int channel;
	bool set;

again:
	next_j = j + LONG_MAX;
	set = false;
	for (channel = 0; channel < RXRPC_MAXCALLS; channel++) {
		struct rxrpc_channel *chan = &conn->channels[channel];
		unsigned long ack_at;

		if (!test_bit(RXRPC_CONN_FINAL_ACK_0 + channel, &conn->flags))
			continue;

		smp_rmb(); /* vs rxrpc_disconnect_client_call */
		ack_at = READ_ONCE(chan->final_ack_at);

		if (time_before(j, ack_at)) {
			if (time_before(ack_at, next_j)) {
				next_j = ack_at;
				set = true;
			}
			continue;
		}

		if (test_and_clear_bit(RXRPC_CONN_FINAL_ACK_0 + channel,
				       &conn->flags))
			rxrpc_conn_retransmit_call(conn, NULL, channel);
	}

	j = jiffies;
	if (time_before_eq(next_j, j))
		goto again;
	if (set)
		rxrpc_reduce_conn_timer(conn, next_j);
}

/*
 * connection-level event processor
 */
void rxrpc_process_connection(struct work_struct *work)
{
	struct rxrpc_connection *conn =
		container_of(work, struct rxrpc_connection, processor);
	struct sk_buff *skb;
	u32 abort_code = RX_PROTOCOL_ERROR;
	int ret;

	rxrpc_see_connection(conn);

	if (test_and_clear_bit(RXRPC_CONN_EV_CHALLENGE, &conn->events))
		rxrpc_secure_connection(conn);

	/* Process delayed ACKs whose time has come. */
	if (conn->flags & RXRPC_CONN_FINAL_ACK_MASK)
		rxrpc_process_delayed_final_acks(conn);

	/* go through the conn-level event packets, releasing the ref on this
	 * connection that each one has when we've finished with it */
	while ((skb = skb_dequeue(&conn->rx_queue))) {
		rxrpc_see_skb(skb, rxrpc_skb_rx_seen);
		ret = rxrpc_process_event(conn, skb, &abort_code);
		switch (ret) {
		case -EPROTO:
		case -EKEYEXPIRED:
		case -EKEYREJECTED:
			goto protocol_error;
		case -EAGAIN:
			goto requeue_and_leave;
		case -ECONNABORTED:
		default:
			rxrpc_free_skb(skb, rxrpc_skb_rx_freed);
			break;
		}
	}

out:
	rxrpc_put_connection(conn);
	_leave("");
	return;

requeue_and_leave:
	skb_queue_head(&conn->rx_queue, skb);
	goto out;

protocol_error:
	if (rxrpc_abort_connection(conn, ret, abort_code) < 0)
		goto requeue_and_leave;
	rxrpc_free_skb(skb, rxrpc_skb_rx_freed);
	goto out;
}
OpenPOWER on IntegriCloud