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  1// SPDX-License-Identifier: GPL-2.0-or-later
  2/* connection-level event handling
  3 *
  4 * Copyright (C) 2007 Red Hat, Inc. All Rights Reserved.
  5 * Written by David Howells (dhowells@redhat.com)
  6 */
  7
  8#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
  9
 10#include <linux/module.h>
 11#include <linux/net.h>
 12#include <linux/skbuff.h>
 13#include <linux/errqueue.h>
 14#include <net/sock.h>
 15#include <net/af_rxrpc.h>
 16#include <net/ip.h>
 17#include "ar-internal.h"
 18
 19/*
 20 * Set the completion state on an aborted connection.
 21 */
 22static bool rxrpc_set_conn_aborted(struct rxrpc_connection *conn, struct sk_buff *skb,
 23				   s32 abort_code, int err,
 24				   enum rxrpc_call_completion compl)
 25{
 26	bool aborted = false;
 27
 28	if (conn->state != RXRPC_CONN_ABORTED) {
 29		spin_lock(&conn->state_lock);
 30		if (conn->state != RXRPC_CONN_ABORTED) {
 31			conn->abort_code = abort_code;
 32			conn->error	 = err;
 33			conn->completion = compl;
 34			/* Order the abort info before the state change. */
 35			smp_store_release(&conn->state, RXRPC_CONN_ABORTED);
 36			set_bit(RXRPC_CONN_DONT_REUSE, &conn->flags);
 37			set_bit(RXRPC_CONN_EV_ABORT_CALLS, &conn->events);
 38			aborted = true;
 39		}
 40		spin_unlock(&conn->state_lock);
 41	}
 42
 43	return aborted;
 44}
 45
 46/*
 47 * Mark a socket buffer to indicate that the connection it's on should be aborted.
 48 */
 49int rxrpc_abort_conn(struct rxrpc_connection *conn, struct sk_buff *skb,
 50		     s32 abort_code, int err, enum rxrpc_abort_reason why)
 51{
 52	struct rxrpc_skb_priv *sp = rxrpc_skb(skb);
 53
 54	if (rxrpc_set_conn_aborted(conn, skb, abort_code, err,
 55				   RXRPC_CALL_LOCALLY_ABORTED)) {
 56		trace_rxrpc_abort(0, why, sp->hdr.cid, sp->hdr.callNumber,
 57				  sp->hdr.seq, abort_code, err);
 58		rxrpc_poke_conn(conn, rxrpc_conn_get_poke_abort);
 59	}
 60	return -EPROTO;
 61}
 62
 63/*
 64 * Mark a connection as being remotely aborted.
 65 */
 66static bool rxrpc_input_conn_abort(struct rxrpc_connection *conn,
 67				   struct sk_buff *skb)
 68{
 69	return rxrpc_set_conn_aborted(conn, skb, skb->priority, -ECONNABORTED,
 70				      RXRPC_CALL_REMOTELY_ABORTED);
 71}
 72
 73/*
 74 * Retransmit terminal ACK or ABORT of the previous call.
 75 */
 76void rxrpc_conn_retransmit_call(struct rxrpc_connection *conn,
 77				struct sk_buff *skb,
 78				unsigned int channel)
 79{
 80	struct rxrpc_skb_priv *sp = skb ? rxrpc_skb(skb) : NULL;
 81	struct rxrpc_channel *chan;
 82	struct msghdr msg;
 83	struct kvec iov[3];
 84	struct {
 85		struct rxrpc_wire_header whdr;
 86		union {
 87			__be32 abort_code;
 88			struct rxrpc_ackpacket ack;
 89		};
 90	} __attribute__((packed)) pkt;
 91	struct rxrpc_ackinfo ack_info;
 92	size_t len;
 93	int ret, ioc;
 94	u32 serial, mtu, call_id, padding;
 95
 96	_enter("%d", conn->debug_id);
 97
 98	chan = &conn->channels[channel];
 99
100	/* If the last call got moved on whilst we were waiting to run, just
101	 * ignore this packet.
102	 */
103	call_id = chan->last_call;
104	if (skb && call_id != sp->hdr.callNumber)
105		return;
106
107	msg.msg_name	= &conn->peer->srx.transport;
108	msg.msg_namelen	= conn->peer->srx.transport_len;
109	msg.msg_control	= NULL;
110	msg.msg_controllen = 0;
111	msg.msg_flags	= 0;
112
113	iov[0].iov_base	= &pkt;
114	iov[0].iov_len	= sizeof(pkt.whdr);
115	iov[1].iov_base	= &padding;
116	iov[1].iov_len	= 3;
117	iov[2].iov_base	= &ack_info;
118	iov[2].iov_len	= sizeof(ack_info);
119
120	serial = atomic_inc_return(&conn->serial);
121
122	pkt.whdr.epoch		= htonl(conn->proto.epoch);
123	pkt.whdr.cid		= htonl(conn->proto.cid | channel);
124	pkt.whdr.callNumber	= htonl(call_id);
125	pkt.whdr.serial		= htonl(serial);
126	pkt.whdr.seq		= 0;
127	pkt.whdr.type		= chan->last_type;
128	pkt.whdr.flags		= conn->out_clientflag;
129	pkt.whdr.userStatus	= 0;
130	pkt.whdr.securityIndex	= conn->security_ix;
131	pkt.whdr._rsvd		= 0;
132	pkt.whdr.serviceId	= htons(conn->service_id);
133
134	len = sizeof(pkt.whdr);
135	switch (chan->last_type) {
136	case RXRPC_PACKET_TYPE_ABORT:
137		pkt.abort_code	= htonl(chan->last_abort);
138		iov[0].iov_len += sizeof(pkt.abort_code);
139		len += sizeof(pkt.abort_code);
140		ioc = 1;
141		break;
142
143	case RXRPC_PACKET_TYPE_ACK:
144		mtu = conn->peer->if_mtu;
145		mtu -= conn->peer->hdrsize;
146		pkt.ack.bufferSpace	= 0;
147		pkt.ack.maxSkew		= htons(skb ? skb->priority : 0);
148		pkt.ack.firstPacket	= htonl(chan->last_seq + 1);
149		pkt.ack.previousPacket	= htonl(chan->last_seq);
150		pkt.ack.serial		= htonl(skb ? sp->hdr.serial : 0);
151		pkt.ack.reason		= skb ? RXRPC_ACK_DUPLICATE : RXRPC_ACK_IDLE;
152		pkt.ack.nAcks		= 0;
153		ack_info.rxMTU		= htonl(rxrpc_rx_mtu);
154		ack_info.maxMTU		= htonl(mtu);
155		ack_info.rwind		= htonl(rxrpc_rx_window_size);
156		ack_info.jumbo_max	= htonl(rxrpc_rx_jumbo_max);
157		pkt.whdr.flags		|= RXRPC_SLOW_START_OK;
158		padding			= 0;
159		iov[0].iov_len += sizeof(pkt.ack);
160		len += sizeof(pkt.ack) + 3 + sizeof(ack_info);
161		ioc = 3;
162
163		trace_rxrpc_tx_ack(chan->call_debug_id, serial,
164				   ntohl(pkt.ack.firstPacket),
165				   ntohl(pkt.ack.serial),
166				   pkt.ack.reason, 0);
167		break;
168
169	default:
170		return;
171	}
172
173	ret = kernel_sendmsg(conn->local->socket, &msg, iov, ioc, len);
174	conn->peer->last_tx_at = ktime_get_seconds();
175	if (ret < 0)
176		trace_rxrpc_tx_fail(chan->call_debug_id, serial, ret,
177				    rxrpc_tx_point_call_final_resend);
178	else
179		trace_rxrpc_tx_packet(chan->call_debug_id, &pkt.whdr,
180				      rxrpc_tx_point_call_final_resend);
181
182	_leave("");
183}
184
185/*
186 * pass a connection-level abort onto all calls on that connection
187 */
188static void rxrpc_abort_calls(struct rxrpc_connection *conn)
189{
190	struct rxrpc_call *call;
191	int i;
192
193	_enter("{%d},%x", conn->debug_id, conn->abort_code);
194
195	for (i = 0; i < RXRPC_MAXCALLS; i++) {
196		call = conn->channels[i].call;
197		if (call)
198			rxrpc_set_call_completion(call,
199						  conn->completion,
200						  conn->abort_code,
201						  conn->error);
202	}
203
204	_leave("");
205}
206
207/*
208 * mark a call as being on a now-secured channel
209 * - must be called with BH's disabled.
210 */
211static void rxrpc_call_is_secure(struct rxrpc_call *call)
212{
213	if (call && __rxrpc_call_state(call) == RXRPC_CALL_SERVER_SECURING) {
214		rxrpc_set_call_state(call, RXRPC_CALL_SERVER_RECV_REQUEST);
215		rxrpc_notify_socket(call);
216	}
217}
218
219/*
220 * connection-level Rx packet processor
221 */
222static int rxrpc_process_event(struct rxrpc_connection *conn,
223			       struct sk_buff *skb)
224{
225	struct rxrpc_skb_priv *sp = rxrpc_skb(skb);
226	int ret;
227
228	if (conn->state == RXRPC_CONN_ABORTED)
229		return -ECONNABORTED;
230
231	_enter("{%d},{%u,%%%u},", conn->debug_id, sp->hdr.type, sp->hdr.serial);
232
233	switch (sp->hdr.type) {
234	case RXRPC_PACKET_TYPE_CHALLENGE:
235		return conn->security->respond_to_challenge(conn, skb);
236
237	case RXRPC_PACKET_TYPE_RESPONSE:
238		ret = conn->security->verify_response(conn, skb);
239		if (ret < 0)
240			return ret;
241
242		ret = conn->security->init_connection_security(
243			conn, conn->key->payload.data[0]);
244		if (ret < 0)
245			return ret;
246
247		spin_lock(&conn->state_lock);
248		if (conn->state == RXRPC_CONN_SERVICE_CHALLENGING)
249			conn->state = RXRPC_CONN_SERVICE;
250		spin_unlock(&conn->state_lock);
251
252		if (conn->state == RXRPC_CONN_SERVICE) {
253			/* Offload call state flipping to the I/O thread.  As
254			 * we've already received the packet, put it on the
255			 * front of the queue.
256			 */
257			skb->mark = RXRPC_SKB_MARK_SERVICE_CONN_SECURED;
258			rxrpc_get_skb(skb, rxrpc_skb_get_conn_secured);
259			skb_queue_head(&conn->local->rx_queue, skb);
260			rxrpc_wake_up_io_thread(conn->local);
261		}
262		return 0;
263
264	default:
265		WARN_ON_ONCE(1);
266		return -EPROTO;
267	}
268}
269
270/*
271 * set up security and issue a challenge
272 */
273static void rxrpc_secure_connection(struct rxrpc_connection *conn)
274{
275	if (conn->security->issue_challenge(conn) < 0)
276		rxrpc_abort_conn(conn, NULL, RX_CALL_DEAD, -ENOMEM,
277				 rxrpc_abort_nomem);
278}
279
280/*
281 * Process delayed final ACKs that we haven't subsumed into a subsequent call.
282 */
283void rxrpc_process_delayed_final_acks(struct rxrpc_connection *conn, bool force)
284{
285	unsigned long j = jiffies, next_j;
286	unsigned int channel;
287	bool set;
288
289again:
290	next_j = j + LONG_MAX;
291	set = false;
292	for (channel = 0; channel < RXRPC_MAXCALLS; channel++) {
293		struct rxrpc_channel *chan = &conn->channels[channel];
294		unsigned long ack_at;
295
296		if (!test_bit(RXRPC_CONN_FINAL_ACK_0 + channel, &conn->flags))
297			continue;
298
299		ack_at = chan->final_ack_at;
300		if (time_before(j, ack_at) && !force) {
301			if (time_before(ack_at, next_j)) {
302				next_j = ack_at;
303				set = true;
304			}
305			continue;
306		}
307
308		if (test_and_clear_bit(RXRPC_CONN_FINAL_ACK_0 + channel,
309				       &conn->flags))
310			rxrpc_conn_retransmit_call(conn, NULL, channel);
311	}
312
313	j = jiffies;
314	if (time_before_eq(next_j, j))
315		goto again;
316	if (set)
317		rxrpc_reduce_conn_timer(conn, next_j);
318}
319
320/*
321 * connection-level event processor
322 */
323static void rxrpc_do_process_connection(struct rxrpc_connection *conn)
324{
325	struct sk_buff *skb;
326	int ret;
327
328	if (test_and_clear_bit(RXRPC_CONN_EV_CHALLENGE, &conn->events))
329		rxrpc_secure_connection(conn);
330
331	/* go through the conn-level event packets, releasing the ref on this
332	 * connection that each one has when we've finished with it */
333	while ((skb = skb_dequeue(&conn->rx_queue))) {
334		rxrpc_see_skb(skb, rxrpc_skb_see_conn_work);
335		ret = rxrpc_process_event(conn, skb);
336		switch (ret) {
337		case -ENOMEM:
338		case -EAGAIN:
339			skb_queue_head(&conn->rx_queue, skb);
340			rxrpc_queue_conn(conn, rxrpc_conn_queue_retry_work);
341			break;
342		default:
343			rxrpc_free_skb(skb, rxrpc_skb_put_conn_work);
344			break;
345		}
346	}
347}
348
349void rxrpc_process_connection(struct work_struct *work)
350{
351	struct rxrpc_connection *conn =
352		container_of(work, struct rxrpc_connection, processor);
353
354	rxrpc_see_connection(conn, rxrpc_conn_see_work);
355
356	if (__rxrpc_use_local(conn->local, rxrpc_local_use_conn_work)) {
357		rxrpc_do_process_connection(conn);
358		rxrpc_unuse_local(conn->local, rxrpc_local_unuse_conn_work);
359	}
360}
361
362/*
363 * post connection-level events to the connection
364 * - this includes challenges, responses, some aborts and call terminal packet
365 *   retransmission.
366 */
367static void rxrpc_post_packet_to_conn(struct rxrpc_connection *conn,
368				      struct sk_buff *skb)
369{
370	_enter("%p,%p", conn, skb);
371
372	rxrpc_get_skb(skb, rxrpc_skb_get_conn_work);
373	skb_queue_tail(&conn->rx_queue, skb);
374	rxrpc_queue_conn(conn, rxrpc_conn_queue_rx_work);
375}
376
377/*
378 * Input a connection-level packet.
379 */
380bool rxrpc_input_conn_packet(struct rxrpc_connection *conn, struct sk_buff *skb)
381{
382	struct rxrpc_skb_priv *sp = rxrpc_skb(skb);
383
384	switch (sp->hdr.type) {
385	case RXRPC_PACKET_TYPE_BUSY:
386		/* Just ignore BUSY packets for now. */
387		return true;
388
389	case RXRPC_PACKET_TYPE_ABORT:
390		if (rxrpc_is_conn_aborted(conn))
391			return true;
392		rxrpc_input_conn_abort(conn, skb);
393		rxrpc_abort_calls(conn);
394		return true;
395
396	case RXRPC_PACKET_TYPE_CHALLENGE:
397	case RXRPC_PACKET_TYPE_RESPONSE:
398		if (rxrpc_is_conn_aborted(conn)) {
399			if (conn->completion == RXRPC_CALL_LOCALLY_ABORTED)
400				rxrpc_send_conn_abort(conn);
401			return true;
402		}
403		rxrpc_post_packet_to_conn(conn, skb);
404		return true;
405
406	default:
407		WARN_ON_ONCE(1);
408		return true;
409	}
410}
411
412/*
413 * Input a connection event.
414 */
415void rxrpc_input_conn_event(struct rxrpc_connection *conn, struct sk_buff *skb)
416{
417	unsigned int loop;
418
419	if (test_and_clear_bit(RXRPC_CONN_EV_ABORT_CALLS, &conn->events))
420		rxrpc_abort_calls(conn);
421
422	switch (skb->mark) {
423	case RXRPC_SKB_MARK_SERVICE_CONN_SECURED:
424		if (conn->state != RXRPC_CONN_SERVICE)
425			break;
426
427		for (loop = 0; loop < RXRPC_MAXCALLS; loop++)
428			rxrpc_call_is_secure(conn->channels[loop].call);
429		break;
430	}
431
432	/* Process delayed ACKs whose time has come. */
433	if (conn->flags & RXRPC_CONN_FINAL_ACK_MASK)
434		rxrpc_process_delayed_final_acks(conn, false);
435}