1/* RxRPC packet reception
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
12#include <linux/module.h>
13#include <linux/net.h>
14#include <linux/skbuff.h>
15#include <linux/errqueue.h>
16#include <linux/udp.h>
17#include <linux/in.h>
18#include <linux/in6.h>
19#include <linux/icmp.h>
20#include <linux/gfp.h>
21#include <net/sock.h>
22#include <net/af_rxrpc.h>
23#include <net/ip.h>
24#include <net/udp.h>
25#include <net/net_namespace.h>
26#include "ar-internal.h"
27
28const char *rxrpc_pkts[] = {
29	"?00",
30	"DATA", "ACK", "BUSY", "ABORT", "ACKALL", "CHALL", "RESP", "DEBUG",
31	"?09", "?10", "?11", "?12", "?13", "?14", "?15"
32};
33
34/*
35 * queue a packet for recvmsg to pass to userspace
36 * - the caller must hold a lock on call->lock
37 * - must not be called with interrupts disabled (sk_filter() disables BH's)
38 * - eats the packet whether successful or not
39 * - there must be just one reference to the packet, which the caller passes to
40 *   this function
41 */
42int rxrpc_queue_rcv_skb(struct rxrpc_call *call, struct sk_buff *skb,
43			bool force, bool terminal)
44{
45	struct rxrpc_skb_priv *sp;
46	struct rxrpc_sock *rx = call->socket;
47	struct sock *sk;
48	int ret;
49
50	_enter(",,%d,%d", force, terminal);
51
52	ASSERT(!irqs_disabled());
53
54	sp = rxrpc_skb(skb);
55	ASSERTCMP(sp->call, ==, call);
56
57	/* if we've already posted the terminal message for a call, then we
58	 * don't post any more */
59	if (test_bit(RXRPC_CALL_TERMINAL_MSG, &call->flags)) {
60		_debug("already terminated");
61		ASSERTCMP(call->state, >=, RXRPC_CALL_COMPLETE);
62		skb->destructor = NULL;
63		sp->call = NULL;
64		rxrpc_put_call(call);
65		rxrpc_free_skb(skb);
66		return 0;
67	}
68
69	sk = &rx->sk;
70
71	if (!force) {
72		/* cast skb->rcvbuf to unsigned...  It's pointless, but
73		 * reduces number of warnings when compiling with -W
74		 * --ANK */
75//		ret = -ENOBUFS;
76//		if (atomic_read(&sk->sk_rmem_alloc) + skb->truesize >=
77//		    (unsigned int) sk->sk_rcvbuf)
78//			goto out;
79
80		ret = sk_filter(sk, skb);
81		if (ret < 0)
82			goto out;
83	}
84
85	spin_lock_bh(&sk->sk_receive_queue.lock);
86	if (!test_bit(RXRPC_CALL_TERMINAL_MSG, &call->flags) &&
87	    !test_bit(RXRPC_CALL_RELEASED, &call->flags) &&
88	    call->socket->sk.sk_state != RXRPC_CLOSE) {
89		skb->destructor = rxrpc_packet_destructor;
90		skb->dev = NULL;
91		skb->sk = sk;
92		atomic_add(skb->truesize, &sk->sk_rmem_alloc);
93
94		if (terminal) {
95			_debug("<<<< TERMINAL MESSAGE >>>>");
96			set_bit(RXRPC_CALL_TERMINAL_MSG, &call->flags);
97		}
98
99		/* allow interception by a kernel service */
100		if (rx->interceptor) {
101			rx->interceptor(sk, call->user_call_ID, skb);
102			spin_unlock_bh(&sk->sk_receive_queue.lock);
103		} else {
104			_net("post skb %p", skb);
105			__skb_queue_tail(&sk->sk_receive_queue, skb);
106			spin_unlock_bh(&sk->sk_receive_queue.lock);
107
108			if (!sock_flag(sk, SOCK_DEAD))
109				sk->sk_data_ready(sk);
110		}
111		skb = NULL;
112	} else {
113		spin_unlock_bh(&sk->sk_receive_queue.lock);
114	}
115	ret = 0;
116
117out:
118	/* release the socket buffer */
119	if (skb) {
120		skb->destructor = NULL;
121		sp->call = NULL;
122		rxrpc_put_call(call);
123		rxrpc_free_skb(skb);
124	}
125
126	_leave(" = %d", ret);
127	return ret;
128}
129
130/*
131 * process a DATA packet, posting the packet to the appropriate queue
132 * - eats the packet if successful
133 */
134static int rxrpc_fast_process_data(struct rxrpc_call *call,
135				   struct sk_buff *skb, u32 seq)
136{
137	struct rxrpc_skb_priv *sp;
138	bool terminal;
139	int ret, ackbit, ack;
140
141	_enter("{%u,%u},,{%u}", call->rx_data_post, call->rx_first_oos, seq);
142
143	sp = rxrpc_skb(skb);
144	ASSERTCMP(sp->call, ==, NULL);
145
146	spin_lock(&call->lock);
147
148	if (call->state > RXRPC_CALL_COMPLETE)
149		goto discard;
150
151	ASSERTCMP(call->rx_data_expect, >=, call->rx_data_post);
152	ASSERTCMP(call->rx_data_post, >=, call->rx_data_recv);
153	ASSERTCMP(call->rx_data_recv, >=, call->rx_data_eaten);
154
155	if (seq < call->rx_data_post) {
156		_debug("dup #%u [-%u]", seq, call->rx_data_post);
157		ack = RXRPC_ACK_DUPLICATE;
158		ret = -ENOBUFS;
159		goto discard_and_ack;
160	}
161
162	/* we may already have the packet in the out of sequence queue */
163	ackbit = seq - (call->rx_data_eaten + 1);
164	ASSERTCMP(ackbit, >=, 0);
165	if (__test_and_set_bit(ackbit, call->ackr_window)) {
166		_debug("dup oos #%u [%u,%u]",
167		       seq, call->rx_data_eaten, call->rx_data_post);
168		ack = RXRPC_ACK_DUPLICATE;
169		goto discard_and_ack;
170	}
171
172	if (seq >= call->ackr_win_top) {
173		_debug("exceed #%u [%u]", seq, call->ackr_win_top);
174		__clear_bit(ackbit, call->ackr_window);
175		ack = RXRPC_ACK_EXCEEDS_WINDOW;
176		goto discard_and_ack;
177	}
178
179	if (seq == call->rx_data_expect) {
180		clear_bit(RXRPC_CALL_EXPECT_OOS, &call->flags);
181		call->rx_data_expect++;
182	} else if (seq > call->rx_data_expect) {
183		_debug("oos #%u [%u]", seq, call->rx_data_expect);
184		call->rx_data_expect = seq + 1;
185		if (test_and_set_bit(RXRPC_CALL_EXPECT_OOS, &call->flags)) {
186			ack = RXRPC_ACK_OUT_OF_SEQUENCE;
187			goto enqueue_and_ack;
188		}
189		goto enqueue_packet;
190	}
191
192	if (seq != call->rx_data_post) {
193		_debug("ahead #%u [%u]", seq, call->rx_data_post);
194		goto enqueue_packet;
195	}
196
197	if (test_bit(RXRPC_CALL_RCVD_LAST, &call->flags))
198		goto protocol_error;
199
200	/* if the packet need security things doing to it, then it goes down
201	 * the slow path */
202	if (call->conn->security)
203		goto enqueue_packet;
204
205	sp->call = call;
206	rxrpc_get_call(call);
207	terminal = ((sp->hdr.flags & RXRPC_LAST_PACKET) &&
208		    !(sp->hdr.flags & RXRPC_CLIENT_INITIATED));
209	ret = rxrpc_queue_rcv_skb(call, skb, false, terminal);
210	if (ret < 0) {
211		if (ret == -ENOMEM || ret == -ENOBUFS) {
212			__clear_bit(ackbit, call->ackr_window);
213			ack = RXRPC_ACK_NOSPACE;
214			goto discard_and_ack;
215		}
216		goto out;
217	}
218
219	skb = NULL;
220
221	_debug("post #%u", seq);
222	ASSERTCMP(call->rx_data_post, ==, seq);
223	call->rx_data_post++;
224
225	if (sp->hdr.flags & RXRPC_LAST_PACKET)
226		set_bit(RXRPC_CALL_RCVD_LAST, &call->flags);
227
228	/* if we've reached an out of sequence packet then we need to drain
229	 * that queue into the socket Rx queue now */
230	if (call->rx_data_post == call->rx_first_oos) {
231		_debug("drain rx oos now");
232		read_lock(&call->state_lock);
233		if (call->state < RXRPC_CALL_COMPLETE &&
234		    !test_and_set_bit(RXRPC_CALL_DRAIN_RX_OOS, &call->events))
235			rxrpc_queue_call(call);
236		read_unlock(&call->state_lock);
237	}
238
239	spin_unlock(&call->lock);
240	atomic_inc(&call->ackr_not_idle);
241	rxrpc_propose_ACK(call, RXRPC_ACK_DELAY, sp->hdr.serial, false);
242	_leave(" = 0 [posted]");
243	return 0;
244
245protocol_error:
246	ret = -EBADMSG;
247out:
248	spin_unlock(&call->lock);
249	_leave(" = %d", ret);
250	return ret;
251
252discard_and_ack:
253	_debug("discard and ACK packet %p", skb);
254	__rxrpc_propose_ACK(call, ack, sp->hdr.serial, true);
255discard:
256	spin_unlock(&call->lock);
257	rxrpc_free_skb(skb);
258	_leave(" = 0 [discarded]");
259	return 0;
260
261enqueue_and_ack:
262	__rxrpc_propose_ACK(call, ack, sp->hdr.serial, true);
263enqueue_packet:
264	_net("defer skb %p", skb);
265	spin_unlock(&call->lock);
266	skb_queue_tail(&call->rx_queue, skb);
267	atomic_inc(&call->ackr_not_idle);
268	read_lock(&call->state_lock);
269	if (call->state < RXRPC_CALL_DEAD)
270		rxrpc_queue_call(call);
271	read_unlock(&call->state_lock);
272	_leave(" = 0 [queued]");
273	return 0;
274}
275
276/*
277 * assume an implicit ACKALL of the transmission phase of a client socket upon
278 * reception of the first reply packet
279 */
280static void rxrpc_assume_implicit_ackall(struct rxrpc_call *call, u32 serial)
281{
282	write_lock_bh(&call->state_lock);
283
284	switch (call->state) {
285	case RXRPC_CALL_CLIENT_AWAIT_REPLY:
286		call->state = RXRPC_CALL_CLIENT_RECV_REPLY;
287		call->acks_latest = serial;
288
289		_debug("implicit ACKALL %%%u", call->acks_latest);
290		set_bit(RXRPC_CALL_RCVD_ACKALL, &call->events);
291		write_unlock_bh(&call->state_lock);
292
293		if (try_to_del_timer_sync(&call->resend_timer) >= 0) {
294			clear_bit(RXRPC_CALL_RESEND_TIMER, &call->events);
295			clear_bit(RXRPC_CALL_RESEND, &call->events);
296			clear_bit(RXRPC_CALL_RUN_RTIMER, &call->flags);
297		}
298		break;
299
300	default:
301		write_unlock_bh(&call->state_lock);
302		break;
303	}
304}
305
306/*
307 * post an incoming packet to the nominated call to deal with
308 * - must get rid of the sk_buff, either by freeing it or by queuing it
309 */
310void rxrpc_fast_process_packet(struct rxrpc_call *call, struct sk_buff *skb)
311{
312	struct rxrpc_skb_priv *sp = rxrpc_skb(skb);
313	__be32 _abort_code;
314	u32 serial, hi_serial, seq, abort_code;
315
316	_enter("%p,%p", call, skb);
317
318	ASSERT(!irqs_disabled());
319
320#if 0 // INJECT RX ERROR
321	if (sp->hdr.type == RXRPC_PACKET_TYPE_DATA) {
322		static int skip = 0;
323		if (++skip == 3) {
324			printk("DROPPED 3RD PACKET!!!!!!!!!!!!!\n");
325			skip = 0;
326			goto free_packet;
327		}
328	}
329#endif
330
331	/* track the latest serial number on this connection for ACK packet
332	 * information */
333	serial = ntohl(sp->hdr.serial);
334	hi_serial = atomic_read(&call->conn->hi_serial);
335	while (serial > hi_serial)
336		hi_serial = atomic_cmpxchg(&call->conn->hi_serial, hi_serial,
337					   serial);
338
339	/* request ACK generation for any ACK or DATA packet that requests
340	 * it */
341	if (sp->hdr.flags & RXRPC_REQUEST_ACK) {
342		_proto("ACK Requested on %%%u", serial);
343		rxrpc_propose_ACK(call, RXRPC_ACK_REQUESTED, sp->hdr.serial, false);
344	}
345
346	switch (sp->hdr.type) {
347	case RXRPC_PACKET_TYPE_ABORT:
348		_debug("abort");
349
350		if (skb_copy_bits(skb, 0, &_abort_code,
351				  sizeof(_abort_code)) < 0)
352			goto protocol_error;
353
354		abort_code = ntohl(_abort_code);
355		_proto("Rx ABORT %%%u { %x }", serial, abort_code);
356
357		write_lock_bh(&call->state_lock);
358		if (call->state < RXRPC_CALL_COMPLETE) {
359			call->state = RXRPC_CALL_REMOTELY_ABORTED;
360			call->abort_code = abort_code;
361			set_bit(RXRPC_CALL_RCVD_ABORT, &call->events);
362			rxrpc_queue_call(call);
363		}
364		goto free_packet_unlock;
365
366	case RXRPC_PACKET_TYPE_BUSY:
367		_proto("Rx BUSY %%%u", serial);
368
369		if (call->conn->out_clientflag)
370			goto protocol_error;
371
372		write_lock_bh(&call->state_lock);
373		switch (call->state) {
374		case RXRPC_CALL_CLIENT_SEND_REQUEST:
375			call->state = RXRPC_CALL_SERVER_BUSY;
376			set_bit(RXRPC_CALL_RCVD_BUSY, &call->events);
377			rxrpc_queue_call(call);
378		case RXRPC_CALL_SERVER_BUSY:
379			goto free_packet_unlock;
380		default:
381			goto protocol_error_locked;
382		}
383
384	default:
385		_proto("Rx %s %%%u", rxrpc_pkts[sp->hdr.type], serial);
386		goto protocol_error;
387
388	case RXRPC_PACKET_TYPE_DATA:
389		seq = ntohl(sp->hdr.seq);
390
391		_proto("Rx DATA %%%u { #%u }", serial, seq);
392
393		if (seq == 0)
394			goto protocol_error;
395
396		call->ackr_prev_seq = sp->hdr.seq;
397
398		/* received data implicitly ACKs all of the request packets we
399		 * sent when we're acting as a client */
400		if (call->state == RXRPC_CALL_CLIENT_AWAIT_REPLY)
401			rxrpc_assume_implicit_ackall(call, serial);
402
403		switch (rxrpc_fast_process_data(call, skb, seq)) {
404		case 0:
405			skb = NULL;
406			goto done;
407
408		default:
409			BUG();
410
411			/* data packet received beyond the last packet */
412		case -EBADMSG:
413			goto protocol_error;
414		}
415
416	case RXRPC_PACKET_TYPE_ACKALL:
417	case RXRPC_PACKET_TYPE_ACK:
418		/* ACK processing is done in process context */
419		read_lock_bh(&call->state_lock);
420		if (call->state < RXRPC_CALL_DEAD) {
421			skb_queue_tail(&call->rx_queue, skb);
422			rxrpc_queue_call(call);
423			skb = NULL;
424		}
425		read_unlock_bh(&call->state_lock);
426		goto free_packet;
427	}
428
429protocol_error:
430	_debug("protocol error");
431	write_lock_bh(&call->state_lock);
432protocol_error_locked:
433	if (call->state <= RXRPC_CALL_COMPLETE) {
434		call->state = RXRPC_CALL_LOCALLY_ABORTED;
435		call->abort_code = RX_PROTOCOL_ERROR;
436		set_bit(RXRPC_CALL_ABORT, &call->events);
437		rxrpc_queue_call(call);
438	}
439free_packet_unlock:
440	write_unlock_bh(&call->state_lock);
441free_packet:
442	rxrpc_free_skb(skb);
443done:
444	_leave("");
445}
446
447/*
448 * split up a jumbo data packet
449 */
450static void rxrpc_process_jumbo_packet(struct rxrpc_call *call,
451				       struct sk_buff *jumbo)
452{
453	struct rxrpc_jumbo_header jhdr;
454	struct rxrpc_skb_priv *sp;
455	struct sk_buff *part;
456
457	_enter(",{%u,%u}", jumbo->data_len, jumbo->len);
458
459	sp = rxrpc_skb(jumbo);
460
461	do {
462		sp->hdr.flags &= ~RXRPC_JUMBO_PACKET;
463
464		/* make a clone to represent the first subpacket in what's left
465		 * of the jumbo packet */
466		part = skb_clone(jumbo, GFP_ATOMIC);
467		if (!part) {
468			/* simply ditch the tail in the event of ENOMEM */
469			pskb_trim(jumbo, RXRPC_JUMBO_DATALEN);
470			break;
471		}
472		rxrpc_new_skb(part);
473
474		pskb_trim(part, RXRPC_JUMBO_DATALEN);
475
476		if (!pskb_pull(jumbo, RXRPC_JUMBO_DATALEN))
477			goto protocol_error;
478
479		if (skb_copy_bits(jumbo, 0, &jhdr, sizeof(jhdr)) < 0)
480			goto protocol_error;
481		if (!pskb_pull(jumbo, sizeof(jhdr)))
482			BUG();
483
484		sp->hdr.seq	= htonl(ntohl(sp->hdr.seq) + 1);
485		sp->hdr.serial	= htonl(ntohl(sp->hdr.serial) + 1);
486		sp->hdr.flags	= jhdr.flags;
487		sp->hdr._rsvd	= jhdr._rsvd;
488
489		_proto("Rx DATA Jumbo %%%u", ntohl(sp->hdr.serial) - 1);
490
491		rxrpc_fast_process_packet(call, part);
492		part = NULL;
493
494	} while (sp->hdr.flags & RXRPC_JUMBO_PACKET);
495
496	rxrpc_fast_process_packet(call, jumbo);
497	_leave("");
498	return;
499
500protocol_error:
501	_debug("protocol error");
502	rxrpc_free_skb(part);
503	rxrpc_free_skb(jumbo);
504	write_lock_bh(&call->state_lock);
505	if (call->state <= RXRPC_CALL_COMPLETE) {
506		call->state = RXRPC_CALL_LOCALLY_ABORTED;
507		call->abort_code = RX_PROTOCOL_ERROR;
508		set_bit(RXRPC_CALL_ABORT, &call->events);
509		rxrpc_queue_call(call);
510	}
511	write_unlock_bh(&call->state_lock);
512	_leave("");
513}
514
515/*
516 * post an incoming packet to the appropriate call/socket to deal with
517 * - must get rid of the sk_buff, either by freeing it or by queuing it
518 */
519static void rxrpc_post_packet_to_call(struct rxrpc_call *call,
520				      struct sk_buff *skb)
521{
522	struct rxrpc_skb_priv *sp;
523
524	_enter("%p,%p", call, skb);
525
526	sp = rxrpc_skb(skb);
527
528	_debug("extant call [%d]", call->state);
529
530	read_lock(&call->state_lock);
531	switch (call->state) {
532	case RXRPC_CALL_LOCALLY_ABORTED:
533		if (!test_and_set_bit(RXRPC_CALL_ABORT, &call->events)) {
534			rxrpc_queue_call(call);
535			goto free_unlock;
536		}
537	case RXRPC_CALL_REMOTELY_ABORTED:
538	case RXRPC_CALL_NETWORK_ERROR:
539	case RXRPC_CALL_DEAD:
540		goto dead_call;
541	case RXRPC_CALL_COMPLETE:
542	case RXRPC_CALL_CLIENT_FINAL_ACK:
543		/* complete server call */
544		if (call->conn->in_clientflag)
545			goto dead_call;
546		/* resend last packet of a completed call */
547		_debug("final ack again");
548		rxrpc_get_call(call);
549		set_bit(RXRPC_CALL_ACK_FINAL, &call->events);
550		rxrpc_queue_call(call);
551		goto free_unlock;
552	default:
553		break;
554	}
555
556	read_unlock(&call->state_lock);
557	rxrpc_get_call(call);
558
559	if (sp->hdr.type == RXRPC_PACKET_TYPE_DATA &&
560	    sp->hdr.flags & RXRPC_JUMBO_PACKET)
561		rxrpc_process_jumbo_packet(call, skb);
562	else
563		rxrpc_fast_process_packet(call, skb);
564
565	rxrpc_put_call(call);
566	goto done;
567
568dead_call:
569	if (sp->hdr.type != RXRPC_PACKET_TYPE_ABORT) {
570		skb->priority = RX_CALL_DEAD;
571		rxrpc_reject_packet(call->conn->trans->local, skb);
572		goto unlock;
573	}
574free_unlock:
575	rxrpc_free_skb(skb);
576unlock:
577	read_unlock(&call->state_lock);
578done:
579	_leave("");
580}
581
582/*
583 * post connection-level events to the connection
584 * - this includes challenges, responses and some aborts
585 */
586static void rxrpc_post_packet_to_conn(struct rxrpc_connection *conn,
587				      struct sk_buff *skb)
588{
589	_enter("%p,%p", conn, skb);
590
591	atomic_inc(&conn->usage);
592	skb_queue_tail(&conn->rx_queue, skb);
593	rxrpc_queue_conn(conn);
594}
595
596static struct rxrpc_connection *rxrpc_conn_from_local(struct rxrpc_local *local,
597					       struct sk_buff *skb,
598					       struct rxrpc_skb_priv *sp)
599{
600	struct rxrpc_peer *peer;
601	struct rxrpc_transport *trans;
602	struct rxrpc_connection *conn;
603
604	peer = rxrpc_find_peer(local, ip_hdr(skb)->saddr,
605				udp_hdr(skb)->source);
606	if (IS_ERR(peer))
607		goto cant_find_conn;
608
609	trans = rxrpc_find_transport(local, peer);
610	rxrpc_put_peer(peer);
611	if (!trans)
612		goto cant_find_conn;
613
614	conn = rxrpc_find_connection(trans, &sp->hdr);
615	rxrpc_put_transport(trans);
616	if (!conn)
617		goto cant_find_conn;
618
619	return conn;
620cant_find_conn:
621	return NULL;
622}
623
624/*
625 * handle data received on the local endpoint
626 * - may be called in interrupt context
627 */
628void rxrpc_data_ready(struct sock *sk)
629{
630	struct rxrpc_skb_priv *sp;
631	struct rxrpc_local *local;
632	struct sk_buff *skb;
633	int ret;
634
635	_enter("%p", sk);
636
637	ASSERT(!irqs_disabled());
638
639	read_lock_bh(&rxrpc_local_lock);
640	local = sk->sk_user_data;
641	if (local && atomic_read(&local->usage) > 0)
642		rxrpc_get_local(local);
643	else
644		local = NULL;
645	read_unlock_bh(&rxrpc_local_lock);
646	if (!local) {
647		_leave(" [local dead]");
648		return;
649	}
650
651	skb = skb_recv_datagram(sk, 0, 1, &ret);
652	if (!skb) {
653		rxrpc_put_local(local);
654		if (ret == -EAGAIN)
655			return;
656		_debug("UDP socket error %d", ret);
657		return;
658	}
659
660	rxrpc_new_skb(skb);
661
662	_net("recv skb %p", skb);
663
664	/* we'll probably need to checksum it (didn't call sock_recvmsg) */
665	if (skb_checksum_complete(skb)) {
666		rxrpc_free_skb(skb);
667		rxrpc_put_local(local);
668		UDP_INC_STATS_BH(&init_net, UDP_MIB_INERRORS, 0);
669		_leave(" [CSUM failed]");
670		return;
671	}
672
673	UDP_INC_STATS_BH(&init_net, UDP_MIB_INDATAGRAMS, 0);
674
675	/* the socket buffer we have is owned by UDP, with UDP's data all over
676	 * it, but we really want our own */
677	skb_orphan(skb);
678	sp = rxrpc_skb(skb);
679	memset(sp, 0, sizeof(*sp));
680
681	_net("Rx UDP packet from %08x:%04hu",
682	     ntohl(ip_hdr(skb)->saddr), ntohs(udp_hdr(skb)->source));
683
684	/* dig out the RxRPC connection details */
685	if (skb_copy_bits(skb, sizeof(struct udphdr), &sp->hdr,
686			  sizeof(sp->hdr)) < 0)
687		goto bad_message;
688	if (!pskb_pull(skb, sizeof(struct udphdr) + sizeof(sp->hdr)))
689		BUG();
690
691	_net("Rx RxRPC %s ep=%x call=%x:%x",
692	     sp->hdr.flags & RXRPC_CLIENT_INITIATED ? "ToServer" : "ToClient",
693	     ntohl(sp->hdr.epoch),
694	     ntohl(sp->hdr.cid),
695	     ntohl(sp->hdr.callNumber));
696
697	if (sp->hdr.type == 0 || sp->hdr.type >= RXRPC_N_PACKET_TYPES) {
698		_proto("Rx Bad Packet Type %u", sp->hdr.type);
699		goto bad_message;
700	}
701
702	if (sp->hdr.type == RXRPC_PACKET_TYPE_DATA &&
703	    (sp->hdr.callNumber == 0 || sp->hdr.seq == 0))
704		goto bad_message;
705
706	if (sp->hdr.callNumber == 0) {
707		/* This is a connection-level packet. These should be
708		 * fairly rare, so the extra overhead of looking them up the
709		 * old-fashioned way doesn't really hurt */
710		struct rxrpc_connection *conn;
711
712		conn = rxrpc_conn_from_local(local, skb, sp);
713		if (!conn)
714			goto cant_route_call;
715
716		_debug("CONN %p {%d}", conn, conn->debug_id);
717		rxrpc_post_packet_to_conn(conn, skb);
718		rxrpc_put_connection(conn);
719	} else {
720		struct rxrpc_call *call;
721		u8 in_clientflag = 0;
722
723		if (sp->hdr.flags & RXRPC_CLIENT_INITIATED)
724			in_clientflag = RXRPC_CLIENT_INITIATED;
725		call = rxrpc_find_call_hash(in_clientflag, sp->hdr.cid,
726					    sp->hdr.callNumber, sp->hdr.epoch,
727					    sp->hdr.serviceId, local, AF_INET,
728					    (u8 *)&ip_hdr(skb)->saddr);
729		if (call)
730			rxrpc_post_packet_to_call(call, skb);
731		else
732			goto cant_route_call;
733	}
734	rxrpc_put_local(local);
735	return;
736
737cant_route_call:
738	_debug("can't route call");
739	if (sp->hdr.flags & RXRPC_CLIENT_INITIATED &&
740	    sp->hdr.type == RXRPC_PACKET_TYPE_DATA) {
741		if (sp->hdr.seq == cpu_to_be32(1)) {
742			_debug("first packet");
743			skb_queue_tail(&local->accept_queue, skb);
744			rxrpc_queue_work(&local->acceptor);
745			rxrpc_put_local(local);
746			_leave(" [incoming]");
747			return;
748		}
749		skb->priority = RX_INVALID_OPERATION;
750	} else {
751		skb->priority = RX_CALL_DEAD;
752	}
753
754	if (sp->hdr.type != RXRPC_PACKET_TYPE_ABORT) {
755		_debug("reject type %d",sp->hdr.type);
756		rxrpc_reject_packet(local, skb);
757	}
758	rxrpc_put_local(local);
759	_leave(" [no call]");
760	return;
761
762bad_message:
763	skb->priority = RX_PROTOCOL_ERROR;
764	rxrpc_reject_packet(local, skb);
765	rxrpc_put_local(local);
766	_leave(" [badmsg]");
767}
768