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v6.2
  1// SPDX-License-Identifier: GPL-2.0-or-later
  2/* RxRPC packet reception
  3 *
  4 * Copyright (C) 2007, 2016, 2022 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 "ar-internal.h"
 11
 12static int rxrpc_input_packet_on_conn(struct rxrpc_connection *conn,
 13				      struct sockaddr_rxrpc *peer_srx,
 14				      struct sk_buff *skb);
 15
 16/*
 17 * handle data received on the local endpoint
 18 * - may be called in interrupt context
 19 *
 20 * [!] Note that as this is called from the encap_rcv hook, the socket is not
 21 * held locked by the caller and nothing prevents sk_user_data on the UDP from
 22 * being cleared in the middle of processing this function.
 23 *
 24 * Called with the RCU read lock held from the IP layer via UDP.
 25 */
 26int rxrpc_encap_rcv(struct sock *udp_sk, struct sk_buff *skb)
 27{
 
 28	struct rxrpc_local *local = rcu_dereference_sk_user_data(udp_sk);
 29
 30	if (unlikely(!local)) {
 31		kfree_skb(skb);
 32		return 0;
 33	}
 34	if (skb->tstamp == 0)
 35		skb->tstamp = ktime_get_real();
 36
 37	skb->mark = RXRPC_SKB_MARK_PACKET;
 38	rxrpc_new_skb(skb, rxrpc_skb_new_encap_rcv);
 39	skb_queue_tail(&local->rx_queue, skb);
 
 
 
 
 
 
 
 
 
 40	rxrpc_wake_up_io_thread(local);
 41	return 0;
 42}
 43
 44/*
 45 * Handle an error received on the local endpoint.
 46 */
 47void rxrpc_error_report(struct sock *sk)
 48{
 49	struct rxrpc_local *local;
 50	struct sk_buff *skb;
 51
 52	rcu_read_lock();
 53	local = rcu_dereference_sk_user_data(sk);
 54	if (unlikely(!local)) {
 55		rcu_read_unlock();
 56		return;
 57	}
 58
 59	while ((skb = skb_dequeue(&sk->sk_error_queue))) {
 60		skb->mark = RXRPC_SKB_MARK_ERROR;
 61		rxrpc_new_skb(skb, rxrpc_skb_new_error_report);
 62		skb_queue_tail(&local->rx_queue, skb);
 63	}
 64
 65	rxrpc_wake_up_io_thread(local);
 66	rcu_read_unlock();
 67}
 68
 69/*
 70 * Directly produce an abort from a packet.
 71 */
 72bool rxrpc_direct_abort(struct sk_buff *skb, enum rxrpc_abort_reason why,
 73			s32 abort_code, int err)
 74{
 75	struct rxrpc_skb_priv *sp = rxrpc_skb(skb);
 76
 77	trace_rxrpc_abort(0, why, sp->hdr.cid, sp->hdr.callNumber, sp->hdr.seq,
 78			  abort_code, err);
 79	skb->mark = RXRPC_SKB_MARK_REJECT_ABORT;
 80	skb->priority = abort_code;
 81	return false;
 82}
 83
 84static bool rxrpc_bad_message(struct sk_buff *skb, enum rxrpc_abort_reason why)
 85{
 86	return rxrpc_direct_abort(skb, why, RX_PROTOCOL_ERROR, -EBADMSG);
 87}
 88
 89#define just_discard true
 90
 91/*
 92 * Process event packets targeted at a local endpoint.
 93 */
 94static bool rxrpc_input_version(struct rxrpc_local *local, struct sk_buff *skb)
 95{
 96	struct rxrpc_skb_priv *sp = rxrpc_skb(skb);
 97	char v;
 98
 99	_enter("");
100
101	rxrpc_see_skb(skb, rxrpc_skb_see_version);
102	if (skb_copy_bits(skb, sizeof(struct rxrpc_wire_header), &v, 1) >= 0) {
103		if (v == 0)
104			rxrpc_send_version_request(local, &sp->hdr, skb);
105	}
106
107	return true;
108}
109
110/*
111 * Extract the wire header from a packet and translate the byte order.
112 */
113static bool rxrpc_extract_header(struct rxrpc_skb_priv *sp,
114				 struct sk_buff *skb)
115{
116	struct rxrpc_wire_header whdr;
117
118	/* dig out the RxRPC connection details */
119	if (skb_copy_bits(skb, 0, &whdr, sizeof(whdr)) < 0)
120		return rxrpc_bad_message(skb, rxrpc_badmsg_short_hdr);
121
122	memset(sp, 0, sizeof(*sp));
123	sp->hdr.epoch		= ntohl(whdr.epoch);
124	sp->hdr.cid		= ntohl(whdr.cid);
125	sp->hdr.callNumber	= ntohl(whdr.callNumber);
126	sp->hdr.seq		= ntohl(whdr.seq);
127	sp->hdr.serial		= ntohl(whdr.serial);
128	sp->hdr.flags		= whdr.flags;
129	sp->hdr.type		= whdr.type;
130	sp->hdr.userStatus	= whdr.userStatus;
131	sp->hdr.securityIndex	= whdr.securityIndex;
132	sp->hdr._rsvd		= ntohs(whdr._rsvd);
133	sp->hdr.serviceId	= ntohs(whdr.serviceId);
134	return true;
135}
136
137/*
138 * Extract the abort code from an ABORT packet and stash it in skb->priority.
139 */
140static bool rxrpc_extract_abort(struct sk_buff *skb)
141{
142	__be32 wtmp;
143
144	if (skb_copy_bits(skb, sizeof(struct rxrpc_wire_header),
145			  &wtmp, sizeof(wtmp)) < 0)
146		return false;
147	skb->priority = ntohl(wtmp);
148	return true;
149}
150
151/*
152 * Process packets received on the local endpoint
153 */
154static bool rxrpc_input_packet(struct rxrpc_local *local, struct sk_buff **_skb)
155{
156	struct rxrpc_connection *conn;
157	struct sockaddr_rxrpc peer_srx;
158	struct rxrpc_skb_priv *sp;
159	struct rxrpc_peer *peer = NULL;
160	struct sk_buff *skb = *_skb;
161	bool ret = false;
162
163	skb_pull(skb, sizeof(struct udphdr));
164
165	sp = rxrpc_skb(skb);
166
167	/* dig out the RxRPC connection details */
168	if (!rxrpc_extract_header(sp, skb))
169		return just_discard;
170
171	if (IS_ENABLED(CONFIG_AF_RXRPC_INJECT_LOSS)) {
172		static int lose;
173		if ((lose++ & 7) == 7) {
174			trace_rxrpc_rx_lose(sp);
175			return just_discard;
176		}
177	}
178
179	trace_rxrpc_rx_packet(sp);
180
181	switch (sp->hdr.type) {
182	case RXRPC_PACKET_TYPE_VERSION:
183		if (rxrpc_to_client(sp))
184			return just_discard;
185		return rxrpc_input_version(local, skb);
186
187	case RXRPC_PACKET_TYPE_BUSY:
188		if (rxrpc_to_server(sp))
189			return just_discard;
190		fallthrough;
191	case RXRPC_PACKET_TYPE_ACK:
192	case RXRPC_PACKET_TYPE_ACKALL:
193		if (sp->hdr.callNumber == 0)
194			return rxrpc_bad_message(skb, rxrpc_badmsg_zero_call);
195		break;
196	case RXRPC_PACKET_TYPE_ABORT:
197		if (!rxrpc_extract_abort(skb))
198			return just_discard; /* Just discard if malformed */
199		break;
200
201	case RXRPC_PACKET_TYPE_DATA:
202		if (sp->hdr.callNumber == 0)
203			return rxrpc_bad_message(skb, rxrpc_badmsg_zero_call);
204		if (sp->hdr.seq == 0)
205			return rxrpc_bad_message(skb, rxrpc_badmsg_zero_seq);
206
207		/* Unshare the packet so that it can be modified for in-place
208		 * decryption.
209		 */
210		if (sp->hdr.securityIndex != 0) {
211			skb = skb_unshare(skb, GFP_ATOMIC);
212			if (!skb) {
213				rxrpc_eaten_skb(*_skb, rxrpc_skb_eaten_by_unshare_nomem);
214				*_skb = NULL;
215				return just_discard;
216			}
217
218			if (skb != *_skb) {
219				rxrpc_eaten_skb(*_skb, rxrpc_skb_eaten_by_unshare);
220				*_skb = skb;
221				rxrpc_new_skb(skb, rxrpc_skb_new_unshared);
222				sp = rxrpc_skb(skb);
223			}
224		}
225		break;
226
227	case RXRPC_PACKET_TYPE_CHALLENGE:
228		if (rxrpc_to_server(sp))
229			return just_discard;
230		break;
231	case RXRPC_PACKET_TYPE_RESPONSE:
232		if (rxrpc_to_client(sp))
233			return just_discard;
234		break;
235
236		/* Packet types 9-11 should just be ignored. */
237	case RXRPC_PACKET_TYPE_PARAMS:
238	case RXRPC_PACKET_TYPE_10:
239	case RXRPC_PACKET_TYPE_11:
240		return just_discard;
241
242	default:
243		return rxrpc_bad_message(skb, rxrpc_badmsg_unsupported_packet);
244	}
245
246	if (sp->hdr.serviceId == 0)
247		return rxrpc_bad_message(skb, rxrpc_badmsg_zero_service);
248
249	if (WARN_ON_ONCE(rxrpc_extract_addr_from_skb(&peer_srx, skb) < 0))
250		return just_discard; /* Unsupported address type. */
251
252	if (peer_srx.transport.family != local->srx.transport.family &&
253	    (peer_srx.transport.family == AF_INET &&
254	     local->srx.transport.family != AF_INET6)) {
255		pr_warn_ratelimited("AF_RXRPC: Protocol mismatch %u not %u\n",
256				    peer_srx.transport.family,
257				    local->srx.transport.family);
258		return just_discard; /* Wrong address type. */
259	}
260
261	if (rxrpc_to_client(sp)) {
262		rcu_read_lock();
263		conn = rxrpc_find_client_connection_rcu(local, &peer_srx, skb);
264		conn = rxrpc_get_connection_maybe(conn, rxrpc_conn_get_call_input);
265		rcu_read_unlock();
266		if (!conn)
267			return rxrpc_protocol_error(skb, rxrpc_eproto_no_client_conn);
268
269		ret = rxrpc_input_packet_on_conn(conn, &peer_srx, skb);
270		rxrpc_put_connection(conn, rxrpc_conn_put_call_input);
271		return ret;
272	}
273
274	/* We need to look up service connections by the full protocol
275	 * parameter set.  We look up the peer first as an intermediate step
276	 * and then the connection from the peer's tree.
277	 */
278	rcu_read_lock();
279
280	peer = rxrpc_lookup_peer_rcu(local, &peer_srx);
281	if (!peer) {
282		rcu_read_unlock();
283		return rxrpc_new_incoming_call(local, NULL, NULL, &peer_srx, skb);
284	}
285
286	conn = rxrpc_find_service_conn_rcu(peer, skb);
287	conn = rxrpc_get_connection_maybe(conn, rxrpc_conn_get_call_input);
288	if (conn) {
289		rcu_read_unlock();
290		ret = rxrpc_input_packet_on_conn(conn, &peer_srx, skb);
291		rxrpc_put_connection(conn, rxrpc_conn_put_call_input);
292		return ret;
293	}
294
295	peer = rxrpc_get_peer_maybe(peer, rxrpc_peer_get_input);
296	rcu_read_unlock();
297
298	ret = rxrpc_new_incoming_call(local, peer, NULL, &peer_srx, skb);
299	rxrpc_put_peer(peer, rxrpc_peer_put_input);
300	return ret;
301}
302
303/*
304 * Deal with a packet that's associated with an extant connection.
305 */
306static int rxrpc_input_packet_on_conn(struct rxrpc_connection *conn,
307				      struct sockaddr_rxrpc *peer_srx,
308				      struct sk_buff *skb)
309{
310	struct rxrpc_skb_priv *sp = rxrpc_skb(skb);
311	struct rxrpc_channel *chan;
312	struct rxrpc_call *call = NULL;
313	unsigned int channel;
314	bool ret;
315
316	if (sp->hdr.securityIndex != conn->security_ix)
317		return rxrpc_direct_abort(skb, rxrpc_eproto_wrong_security,
318					  RXKADINCONSISTENCY, -EBADMSG);
319
320	if (sp->hdr.serviceId != conn->service_id) {
321		int old_id;
322
323		if (!test_bit(RXRPC_CONN_PROBING_FOR_UPGRADE, &conn->flags))
324			return rxrpc_protocol_error(skb, rxrpc_eproto_reupgrade);
325
326		old_id = cmpxchg(&conn->service_id, conn->orig_service_id,
327				 sp->hdr.serviceId);
328		if (old_id != conn->orig_service_id &&
329		    old_id != sp->hdr.serviceId)
330			return rxrpc_protocol_error(skb, rxrpc_eproto_bad_upgrade);
331	}
332
333	if (after(sp->hdr.serial, conn->hi_serial))
334		conn->hi_serial = sp->hdr.serial;
335
336	/* It's a connection-level packet if the call number is 0. */
337	if (sp->hdr.callNumber == 0)
338		return rxrpc_input_conn_packet(conn, skb);
339
340	/* Call-bound packets are routed by connection channel. */
341	channel = sp->hdr.cid & RXRPC_CHANNELMASK;
342	chan = &conn->channels[channel];
343
344	/* Ignore really old calls */
345	if (sp->hdr.callNumber < chan->last_call)
346		return just_discard;
347
348	if (sp->hdr.callNumber == chan->last_call) {
349		if (chan->call ||
350		    sp->hdr.type == RXRPC_PACKET_TYPE_ABORT)
351			return just_discard;
352
353		/* For the previous service call, if completed successfully, we
354		 * discard all further packets.
355		 */
356		if (rxrpc_conn_is_service(conn) &&
357		    chan->last_type == RXRPC_PACKET_TYPE_ACK)
358			return just_discard;
359
360		/* But otherwise we need to retransmit the final packet from
361		 * data cached in the connection record.
362		 */
363		if (sp->hdr.type == RXRPC_PACKET_TYPE_DATA)
364			trace_rxrpc_rx_data(chan->call_debug_id,
365					    sp->hdr.seq,
366					    sp->hdr.serial,
367					    sp->hdr.flags);
368		rxrpc_conn_retransmit_call(conn, skb, channel);
369		return just_discard;
370	}
371
372	call = rxrpc_try_get_call(chan->call, rxrpc_call_get_input);
373
374	if (sp->hdr.callNumber > chan->call_id) {
375		if (rxrpc_to_client(sp)) {
376			rxrpc_put_call(call, rxrpc_call_put_input);
377			return rxrpc_protocol_error(skb,
378						    rxrpc_eproto_unexpected_implicit_end);
379		}
380
381		if (call) {
382			rxrpc_implicit_end_call(call, skb);
383			rxrpc_put_call(call, rxrpc_call_put_input);
384			call = NULL;
385		}
386	}
387
388	if (!call) {
389		if (rxrpc_to_client(sp))
390			return rxrpc_protocol_error(skb, rxrpc_eproto_no_client_call);
391		return rxrpc_new_incoming_call(conn->local, conn->peer, conn,
392					       peer_srx, skb);
393	}
394
395	ret = rxrpc_input_call_event(call, skb);
396	rxrpc_put_call(call, rxrpc_call_put_input);
397	return ret;
398}
399
400/*
401 * I/O and event handling thread.
402 */
403int rxrpc_io_thread(void *data)
404{
405	struct rxrpc_connection *conn;
406	struct sk_buff_head rx_queue;
407	struct rxrpc_local *local = data;
408	struct rxrpc_call *call;
409	struct sk_buff *skb;
 
 
 
410	bool should_stop;
411
412	complete(&local->io_thread_ready);
413
414	skb_queue_head_init(&rx_queue);
415
416	set_user_nice(current, MIN_NICE);
417
418	for (;;) {
419		rxrpc_inc_stat(local->rxnet, stat_io_loop);
420
421		/* Deal with connections that want immediate attention. */
422		conn = list_first_entry_or_null(&local->conn_attend_q,
423						struct rxrpc_connection,
424						attend_link);
425		if (conn) {
426			spin_lock_bh(&local->lock);
427			list_del_init(&conn->attend_link);
428			spin_unlock_bh(&local->lock);
429
430			rxrpc_input_conn_event(conn, NULL);
431			rxrpc_put_connection(conn, rxrpc_conn_put_poke);
432			continue;
433		}
434
435		if (test_and_clear_bit(RXRPC_CLIENT_CONN_REAP_TIMER,
436				       &local->client_conn_flags))
437			rxrpc_discard_expired_client_conns(local);
438
439		/* Deal with calls that want immediate attention. */
440		if ((call = list_first_entry_or_null(&local->call_attend_q,
441						     struct rxrpc_call,
442						     attend_link))) {
443			spin_lock_bh(&local->lock);
444			list_del_init(&call->attend_link);
445			spin_unlock_bh(&local->lock);
446
447			trace_rxrpc_call_poked(call);
448			rxrpc_input_call_event(call, NULL);
449			rxrpc_put_call(call, rxrpc_call_put_poke);
450			continue;
451		}
452
453		if (!list_empty(&local->new_client_calls))
454			rxrpc_connect_client_calls(local);
455
456		/* Process received packets and errors. */
457		if ((skb = __skb_dequeue(&rx_queue))) {
458			struct rxrpc_skb_priv *sp = rxrpc_skb(skb);
459			switch (skb->mark) {
460			case RXRPC_SKB_MARK_PACKET:
461				skb->priority = 0;
462				if (!rxrpc_input_packet(local, &skb))
463					rxrpc_reject_packet(local, skb);
464				trace_rxrpc_rx_done(skb->mark, skb->priority);
465				rxrpc_free_skb(skb, rxrpc_skb_put_input);
466				break;
467			case RXRPC_SKB_MARK_ERROR:
468				rxrpc_input_error(local, skb);
469				rxrpc_free_skb(skb, rxrpc_skb_put_error_report);
470				break;
471			case RXRPC_SKB_MARK_SERVICE_CONN_SECURED:
472				rxrpc_input_conn_event(sp->conn, skb);
473				rxrpc_put_connection(sp->conn, rxrpc_conn_put_poke);
474				rxrpc_free_skb(skb, rxrpc_skb_put_conn_secured);
475				break;
476			default:
477				WARN_ON_ONCE(1);
478				rxrpc_free_skb(skb, rxrpc_skb_put_unknown);
479				break;
480			}
481			continue;
482		}
483
 
 
 
 
 
 
 
 
 
 
 
484		if (!skb_queue_empty(&local->rx_queue)) {
485			spin_lock_irq(&local->rx_queue.lock);
486			skb_queue_splice_tail_init(&local->rx_queue, &rx_queue);
487			spin_unlock_irq(&local->rx_queue.lock);
488			continue;
489		}
490
491		set_current_state(TASK_INTERRUPTIBLE);
492		should_stop = kthread_should_stop();
493		if (!skb_queue_empty(&local->rx_queue) ||
494		    !list_empty(&local->call_attend_q) ||
495		    !list_empty(&local->conn_attend_q) ||
496		    !list_empty(&local->new_client_calls) ||
497		    test_bit(RXRPC_CLIENT_CONN_REAP_TIMER,
498			     &local->client_conn_flags)) {
499			__set_current_state(TASK_RUNNING);
500			continue;
501		}
502
503		if (should_stop)
504			break;
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
505		schedule();
506	}
507
508	__set_current_state(TASK_RUNNING);
509	rxrpc_see_local(local, rxrpc_local_stop);
510	rxrpc_destroy_local(local);
511	local->io_thread = NULL;
512	rxrpc_see_local(local, rxrpc_local_stopped);
513	return 0;
514}
v6.8
  1// SPDX-License-Identifier: GPL-2.0-or-later
  2/* RxRPC packet reception
  3 *
  4 * Copyright (C) 2007, 2016, 2022 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 "ar-internal.h"
 11
 12static int rxrpc_input_packet_on_conn(struct rxrpc_connection *conn,
 13				      struct sockaddr_rxrpc *peer_srx,
 14				      struct sk_buff *skb);
 15
 16/*
 17 * handle data received on the local endpoint
 18 * - may be called in interrupt context
 19 *
 20 * [!] Note that as this is called from the encap_rcv hook, the socket is not
 21 * held locked by the caller and nothing prevents sk_user_data on the UDP from
 22 * being cleared in the middle of processing this function.
 23 *
 24 * Called with the RCU read lock held from the IP layer via UDP.
 25 */
 26int rxrpc_encap_rcv(struct sock *udp_sk, struct sk_buff *skb)
 27{
 28	struct sk_buff_head *rx_queue;
 29	struct rxrpc_local *local = rcu_dereference_sk_user_data(udp_sk);
 30
 31	if (unlikely(!local)) {
 32		kfree_skb(skb);
 33		return 0;
 34	}
 35	if (skb->tstamp == 0)
 36		skb->tstamp = ktime_get_real();
 37
 38	skb->mark = RXRPC_SKB_MARK_PACKET;
 39	rxrpc_new_skb(skb, rxrpc_skb_new_encap_rcv);
 40	rx_queue = &local->rx_queue;
 41#ifdef CONFIG_AF_RXRPC_INJECT_RX_DELAY
 42	if (rxrpc_inject_rx_delay ||
 43	    !skb_queue_empty(&local->rx_delay_queue)) {
 44		skb->tstamp = ktime_add_ms(skb->tstamp, rxrpc_inject_rx_delay);
 45		rx_queue = &local->rx_delay_queue;
 46	}
 47#endif
 48
 49	skb_queue_tail(rx_queue, skb);
 50	rxrpc_wake_up_io_thread(local);
 51	return 0;
 52}
 53
 54/*
 55 * Handle an error received on the local endpoint.
 56 */
 57void rxrpc_error_report(struct sock *sk)
 58{
 59	struct rxrpc_local *local;
 60	struct sk_buff *skb;
 61
 62	rcu_read_lock();
 63	local = rcu_dereference_sk_user_data(sk);
 64	if (unlikely(!local)) {
 65		rcu_read_unlock();
 66		return;
 67	}
 68
 69	while ((skb = skb_dequeue(&sk->sk_error_queue))) {
 70		skb->mark = RXRPC_SKB_MARK_ERROR;
 71		rxrpc_new_skb(skb, rxrpc_skb_new_error_report);
 72		skb_queue_tail(&local->rx_queue, skb);
 73	}
 74
 75	rxrpc_wake_up_io_thread(local);
 76	rcu_read_unlock();
 77}
 78
 79/*
 80 * Directly produce an abort from a packet.
 81 */
 82bool rxrpc_direct_abort(struct sk_buff *skb, enum rxrpc_abort_reason why,
 83			s32 abort_code, int err)
 84{
 85	struct rxrpc_skb_priv *sp = rxrpc_skb(skb);
 86
 87	trace_rxrpc_abort(0, why, sp->hdr.cid, sp->hdr.callNumber, sp->hdr.seq,
 88			  abort_code, err);
 89	skb->mark = RXRPC_SKB_MARK_REJECT_ABORT;
 90	skb->priority = abort_code;
 91	return false;
 92}
 93
 94static bool rxrpc_bad_message(struct sk_buff *skb, enum rxrpc_abort_reason why)
 95{
 96	return rxrpc_direct_abort(skb, why, RX_PROTOCOL_ERROR, -EBADMSG);
 97}
 98
 99#define just_discard true
100
101/*
102 * Process event packets targeted at a local endpoint.
103 */
104static bool rxrpc_input_version(struct rxrpc_local *local, struct sk_buff *skb)
105{
106	struct rxrpc_skb_priv *sp = rxrpc_skb(skb);
107	char v;
108
109	_enter("");
110
111	rxrpc_see_skb(skb, rxrpc_skb_see_version);
112	if (skb_copy_bits(skb, sizeof(struct rxrpc_wire_header), &v, 1) >= 0) {
113		if (v == 0)
114			rxrpc_send_version_request(local, &sp->hdr, skb);
115	}
116
117	return true;
118}
119
120/*
121 * Extract the wire header from a packet and translate the byte order.
122 */
123static bool rxrpc_extract_header(struct rxrpc_skb_priv *sp,
124				 struct sk_buff *skb)
125{
126	struct rxrpc_wire_header whdr;
127
128	/* dig out the RxRPC connection details */
129	if (skb_copy_bits(skb, 0, &whdr, sizeof(whdr)) < 0)
130		return rxrpc_bad_message(skb, rxrpc_badmsg_short_hdr);
131
132	memset(sp, 0, sizeof(*sp));
133	sp->hdr.epoch		= ntohl(whdr.epoch);
134	sp->hdr.cid		= ntohl(whdr.cid);
135	sp->hdr.callNumber	= ntohl(whdr.callNumber);
136	sp->hdr.seq		= ntohl(whdr.seq);
137	sp->hdr.serial		= ntohl(whdr.serial);
138	sp->hdr.flags		= whdr.flags;
139	sp->hdr.type		= whdr.type;
140	sp->hdr.userStatus	= whdr.userStatus;
141	sp->hdr.securityIndex	= whdr.securityIndex;
142	sp->hdr._rsvd		= ntohs(whdr._rsvd);
143	sp->hdr.serviceId	= ntohs(whdr.serviceId);
144	return true;
145}
146
147/*
148 * Extract the abort code from an ABORT packet and stash it in skb->priority.
149 */
150static bool rxrpc_extract_abort(struct sk_buff *skb)
151{
152	__be32 wtmp;
153
154	if (skb_copy_bits(skb, sizeof(struct rxrpc_wire_header),
155			  &wtmp, sizeof(wtmp)) < 0)
156		return false;
157	skb->priority = ntohl(wtmp);
158	return true;
159}
160
161/*
162 * Process packets received on the local endpoint
163 */
164static bool rxrpc_input_packet(struct rxrpc_local *local, struct sk_buff **_skb)
165{
166	struct rxrpc_connection *conn;
167	struct sockaddr_rxrpc peer_srx;
168	struct rxrpc_skb_priv *sp;
169	struct rxrpc_peer *peer = NULL;
170	struct sk_buff *skb = *_skb;
171	bool ret = false;
172
173	skb_pull(skb, sizeof(struct udphdr));
174
175	sp = rxrpc_skb(skb);
176
177	/* dig out the RxRPC connection details */
178	if (!rxrpc_extract_header(sp, skb))
179		return just_discard;
180
181	if (IS_ENABLED(CONFIG_AF_RXRPC_INJECT_LOSS)) {
182		static int lose;
183		if ((lose++ & 7) == 7) {
184			trace_rxrpc_rx_lose(sp);
185			return just_discard;
186		}
187	}
188
189	trace_rxrpc_rx_packet(sp);
190
191	switch (sp->hdr.type) {
192	case RXRPC_PACKET_TYPE_VERSION:
193		if (rxrpc_to_client(sp))
194			return just_discard;
195		return rxrpc_input_version(local, skb);
196
197	case RXRPC_PACKET_TYPE_BUSY:
198		if (rxrpc_to_server(sp))
199			return just_discard;
200		fallthrough;
201	case RXRPC_PACKET_TYPE_ACK:
202	case RXRPC_PACKET_TYPE_ACKALL:
203		if (sp->hdr.callNumber == 0)
204			return rxrpc_bad_message(skb, rxrpc_badmsg_zero_call);
205		break;
206	case RXRPC_PACKET_TYPE_ABORT:
207		if (!rxrpc_extract_abort(skb))
208			return just_discard; /* Just discard if malformed */
209		break;
210
211	case RXRPC_PACKET_TYPE_DATA:
212		if (sp->hdr.callNumber == 0)
213			return rxrpc_bad_message(skb, rxrpc_badmsg_zero_call);
214		if (sp->hdr.seq == 0)
215			return rxrpc_bad_message(skb, rxrpc_badmsg_zero_seq);
216
217		/* Unshare the packet so that it can be modified for in-place
218		 * decryption.
219		 */
220		if (sp->hdr.securityIndex != 0) {
221			skb = skb_unshare(skb, GFP_ATOMIC);
222			if (!skb) {
223				rxrpc_eaten_skb(*_skb, rxrpc_skb_eaten_by_unshare_nomem);
224				*_skb = NULL;
225				return just_discard;
226			}
227
228			if (skb != *_skb) {
229				rxrpc_eaten_skb(*_skb, rxrpc_skb_eaten_by_unshare);
230				*_skb = skb;
231				rxrpc_new_skb(skb, rxrpc_skb_new_unshared);
232				sp = rxrpc_skb(skb);
233			}
234		}
235		break;
236
237	case RXRPC_PACKET_TYPE_CHALLENGE:
238		if (rxrpc_to_server(sp))
239			return just_discard;
240		break;
241	case RXRPC_PACKET_TYPE_RESPONSE:
242		if (rxrpc_to_client(sp))
243			return just_discard;
244		break;
245
246		/* Packet types 9-11 should just be ignored. */
247	case RXRPC_PACKET_TYPE_PARAMS:
248	case RXRPC_PACKET_TYPE_10:
249	case RXRPC_PACKET_TYPE_11:
250		return just_discard;
251
252	default:
253		return rxrpc_bad_message(skb, rxrpc_badmsg_unsupported_packet);
254	}
255
256	if (sp->hdr.serviceId == 0)
257		return rxrpc_bad_message(skb, rxrpc_badmsg_zero_service);
258
259	if (WARN_ON_ONCE(rxrpc_extract_addr_from_skb(&peer_srx, skb) < 0))
260		return just_discard; /* Unsupported address type. */
261
262	if (peer_srx.transport.family != local->srx.transport.family &&
263	    (peer_srx.transport.family == AF_INET &&
264	     local->srx.transport.family != AF_INET6)) {
265		pr_warn_ratelimited("AF_RXRPC: Protocol mismatch %u not %u\n",
266				    peer_srx.transport.family,
267				    local->srx.transport.family);
268		return just_discard; /* Wrong address type. */
269	}
270
271	if (rxrpc_to_client(sp)) {
272		rcu_read_lock();
273		conn = rxrpc_find_client_connection_rcu(local, &peer_srx, skb);
274		conn = rxrpc_get_connection_maybe(conn, rxrpc_conn_get_call_input);
275		rcu_read_unlock();
276		if (!conn)
277			return rxrpc_protocol_error(skb, rxrpc_eproto_no_client_conn);
278
279		ret = rxrpc_input_packet_on_conn(conn, &peer_srx, skb);
280		rxrpc_put_connection(conn, rxrpc_conn_put_call_input);
281		return ret;
282	}
283
284	/* We need to look up service connections by the full protocol
285	 * parameter set.  We look up the peer first as an intermediate step
286	 * and then the connection from the peer's tree.
287	 */
288	rcu_read_lock();
289
290	peer = rxrpc_lookup_peer_rcu(local, &peer_srx);
291	if (!peer) {
292		rcu_read_unlock();
293		return rxrpc_new_incoming_call(local, NULL, NULL, &peer_srx, skb);
294	}
295
296	conn = rxrpc_find_service_conn_rcu(peer, skb);
297	conn = rxrpc_get_connection_maybe(conn, rxrpc_conn_get_call_input);
298	if (conn) {
299		rcu_read_unlock();
300		ret = rxrpc_input_packet_on_conn(conn, &peer_srx, skb);
301		rxrpc_put_connection(conn, rxrpc_conn_put_call_input);
302		return ret;
303	}
304
305	peer = rxrpc_get_peer_maybe(peer, rxrpc_peer_get_input);
306	rcu_read_unlock();
307
308	ret = rxrpc_new_incoming_call(local, peer, NULL, &peer_srx, skb);
309	rxrpc_put_peer(peer, rxrpc_peer_put_input);
310	return ret;
311}
312
313/*
314 * Deal with a packet that's associated with an extant connection.
315 */
316static int rxrpc_input_packet_on_conn(struct rxrpc_connection *conn,
317				      struct sockaddr_rxrpc *peer_srx,
318				      struct sk_buff *skb)
319{
320	struct rxrpc_skb_priv *sp = rxrpc_skb(skb);
321	struct rxrpc_channel *chan;
322	struct rxrpc_call *call = NULL;
323	unsigned int channel;
324	bool ret;
325
326	if (sp->hdr.securityIndex != conn->security_ix)
327		return rxrpc_direct_abort(skb, rxrpc_eproto_wrong_security,
328					  RXKADINCONSISTENCY, -EBADMSG);
329
330	if (sp->hdr.serviceId != conn->service_id) {
331		int old_id;
332
333		if (!test_bit(RXRPC_CONN_PROBING_FOR_UPGRADE, &conn->flags))
334			return rxrpc_protocol_error(skb, rxrpc_eproto_reupgrade);
335
336		old_id = cmpxchg(&conn->service_id, conn->orig_service_id,
337				 sp->hdr.serviceId);
338		if (old_id != conn->orig_service_id &&
339		    old_id != sp->hdr.serviceId)
340			return rxrpc_protocol_error(skb, rxrpc_eproto_bad_upgrade);
341	}
342
343	if (after(sp->hdr.serial, conn->hi_serial))
344		conn->hi_serial = sp->hdr.serial;
345
346	/* It's a connection-level packet if the call number is 0. */
347	if (sp->hdr.callNumber == 0)
348		return rxrpc_input_conn_packet(conn, skb);
349
350	/* Call-bound packets are routed by connection channel. */
351	channel = sp->hdr.cid & RXRPC_CHANNELMASK;
352	chan = &conn->channels[channel];
353
354	/* Ignore really old calls */
355	if (sp->hdr.callNumber < chan->last_call)
356		return just_discard;
357
358	if (sp->hdr.callNumber == chan->last_call) {
359		if (chan->call ||
360		    sp->hdr.type == RXRPC_PACKET_TYPE_ABORT)
361			return just_discard;
362
363		/* For the previous service call, if completed successfully, we
364		 * discard all further packets.
365		 */
366		if (rxrpc_conn_is_service(conn) &&
367		    chan->last_type == RXRPC_PACKET_TYPE_ACK)
368			return just_discard;
369
370		/* But otherwise we need to retransmit the final packet from
371		 * data cached in the connection record.
372		 */
373		if (sp->hdr.type == RXRPC_PACKET_TYPE_DATA)
374			trace_rxrpc_rx_data(chan->call_debug_id,
375					    sp->hdr.seq,
376					    sp->hdr.serial,
377					    sp->hdr.flags);
378		rxrpc_conn_retransmit_call(conn, skb, channel);
379		return just_discard;
380	}
381
382	call = rxrpc_try_get_call(chan->call, rxrpc_call_get_input);
383
384	if (sp->hdr.callNumber > chan->call_id) {
385		if (rxrpc_to_client(sp)) {
386			rxrpc_put_call(call, rxrpc_call_put_input);
387			return rxrpc_protocol_error(skb,
388						    rxrpc_eproto_unexpected_implicit_end);
389		}
390
391		if (call) {
392			rxrpc_implicit_end_call(call, skb);
393			rxrpc_put_call(call, rxrpc_call_put_input);
394			call = NULL;
395		}
396	}
397
398	if (!call) {
399		if (rxrpc_to_client(sp))
400			return rxrpc_protocol_error(skb, rxrpc_eproto_no_client_call);
401		return rxrpc_new_incoming_call(conn->local, conn->peer, conn,
402					       peer_srx, skb);
403	}
404
405	ret = rxrpc_input_call_event(call, skb);
406	rxrpc_put_call(call, rxrpc_call_put_input);
407	return ret;
408}
409
410/*
411 * I/O and event handling thread.
412 */
413int rxrpc_io_thread(void *data)
414{
415	struct rxrpc_connection *conn;
416	struct sk_buff_head rx_queue;
417	struct rxrpc_local *local = data;
418	struct rxrpc_call *call;
419	struct sk_buff *skb;
420#ifdef CONFIG_AF_RXRPC_INJECT_RX_DELAY
421	ktime_t now;
422#endif
423	bool should_stop;
424
425	complete(&local->io_thread_ready);
426
427	skb_queue_head_init(&rx_queue);
428
429	set_user_nice(current, MIN_NICE);
430
431	for (;;) {
432		rxrpc_inc_stat(local->rxnet, stat_io_loop);
433
434		/* Deal with connections that want immediate attention. */
435		conn = list_first_entry_or_null(&local->conn_attend_q,
436						struct rxrpc_connection,
437						attend_link);
438		if (conn) {
439			spin_lock_bh(&local->lock);
440			list_del_init(&conn->attend_link);
441			spin_unlock_bh(&local->lock);
442
443			rxrpc_input_conn_event(conn, NULL);
444			rxrpc_put_connection(conn, rxrpc_conn_put_poke);
445			continue;
446		}
447
448		if (test_and_clear_bit(RXRPC_CLIENT_CONN_REAP_TIMER,
449				       &local->client_conn_flags))
450			rxrpc_discard_expired_client_conns(local);
451
452		/* Deal with calls that want immediate attention. */
453		if ((call = list_first_entry_or_null(&local->call_attend_q,
454						     struct rxrpc_call,
455						     attend_link))) {
456			spin_lock_bh(&local->lock);
457			list_del_init(&call->attend_link);
458			spin_unlock_bh(&local->lock);
459
460			trace_rxrpc_call_poked(call);
461			rxrpc_input_call_event(call, NULL);
462			rxrpc_put_call(call, rxrpc_call_put_poke);
463			continue;
464		}
465
466		if (!list_empty(&local->new_client_calls))
467			rxrpc_connect_client_calls(local);
468
469		/* Process received packets and errors. */
470		if ((skb = __skb_dequeue(&rx_queue))) {
471			struct rxrpc_skb_priv *sp = rxrpc_skb(skb);
472			switch (skb->mark) {
473			case RXRPC_SKB_MARK_PACKET:
474				skb->priority = 0;
475				if (!rxrpc_input_packet(local, &skb))
476					rxrpc_reject_packet(local, skb);
477				trace_rxrpc_rx_done(skb->mark, skb->priority);
478				rxrpc_free_skb(skb, rxrpc_skb_put_input);
479				break;
480			case RXRPC_SKB_MARK_ERROR:
481				rxrpc_input_error(local, skb);
482				rxrpc_free_skb(skb, rxrpc_skb_put_error_report);
483				break;
484			case RXRPC_SKB_MARK_SERVICE_CONN_SECURED:
485				rxrpc_input_conn_event(sp->conn, skb);
486				rxrpc_put_connection(sp->conn, rxrpc_conn_put_poke);
487				rxrpc_free_skb(skb, rxrpc_skb_put_conn_secured);
488				break;
489			default:
490				WARN_ON_ONCE(1);
491				rxrpc_free_skb(skb, rxrpc_skb_put_unknown);
492				break;
493			}
494			continue;
495		}
496
497		/* Inject a delay into packets if requested. */
498#ifdef CONFIG_AF_RXRPC_INJECT_RX_DELAY
499		now = ktime_get_real();
500		while ((skb = skb_peek(&local->rx_delay_queue))) {
501			if (ktime_before(now, skb->tstamp))
502				break;
503			skb = skb_dequeue(&local->rx_delay_queue);
504			skb_queue_tail(&local->rx_queue, skb);
505		}
506#endif
507
508		if (!skb_queue_empty(&local->rx_queue)) {
509			spin_lock_irq(&local->rx_queue.lock);
510			skb_queue_splice_tail_init(&local->rx_queue, &rx_queue);
511			spin_unlock_irq(&local->rx_queue.lock);
512			continue;
513		}
514
515		set_current_state(TASK_INTERRUPTIBLE);
516		should_stop = kthread_should_stop();
517		if (!skb_queue_empty(&local->rx_queue) ||
518		    !list_empty(&local->call_attend_q) ||
519		    !list_empty(&local->conn_attend_q) ||
520		    !list_empty(&local->new_client_calls) ||
521		    test_bit(RXRPC_CLIENT_CONN_REAP_TIMER,
522			     &local->client_conn_flags)) {
523			__set_current_state(TASK_RUNNING);
524			continue;
525		}
526
527		if (should_stop)
528			break;
529
530#ifdef CONFIG_AF_RXRPC_INJECT_RX_DELAY
531		skb = skb_peek(&local->rx_delay_queue);
532		if (skb) {
533			unsigned long timeout;
534			ktime_t tstamp = skb->tstamp;
535			ktime_t now = ktime_get_real();
536			s64 delay_ns = ktime_to_ns(ktime_sub(tstamp, now));
537
538			if (delay_ns <= 0) {
539				__set_current_state(TASK_RUNNING);
540				continue;
541			}
542
543			timeout = nsecs_to_jiffies(delay_ns);
544			timeout = max(timeout, 1UL);
545			schedule_timeout(timeout);
546			__set_current_state(TASK_RUNNING);
547			continue;
548		}
549#endif
550
551		schedule();
552	}
553
554	__set_current_state(TASK_RUNNING);
555	rxrpc_see_local(local, rxrpc_local_stop);
556	rxrpc_destroy_local(local);
557	local->io_thread = NULL;
558	rxrpc_see_local(local, rxrpc_local_stopped);
559	return 0;
560}