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 */
rxrpc_set_conn_aborted(struct rxrpc_connection * conn,struct sk_buff * skb,s32 abort_code,int err,enum rxrpc_call_completion compl)22 static 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 */
rxrpc_abort_conn(struct rxrpc_connection * conn,struct sk_buff * skb,s32 abort_code,int err,enum rxrpc_abort_reason why)49 int 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 */
rxrpc_input_conn_abort(struct rxrpc_connection * conn,struct sk_buff * skb)66 static void rxrpc_input_conn_abort(struct rxrpc_connection *conn,
67 struct sk_buff *skb)
68 {
69 trace_rxrpc_rx_conn_abort(conn, skb);
70 rxrpc_set_conn_aborted(conn, skb, skb->priority, -ECONNABORTED,
71 RXRPC_CALL_REMOTELY_ABORTED);
72 }
73
74 /*
75 * Retransmit terminal ACK or ABORT of the previous call.
76 */
rxrpc_conn_retransmit_call(struct rxrpc_connection * conn,struct sk_buff * skb,unsigned int channel)77 void rxrpc_conn_retransmit_call(struct rxrpc_connection *conn,
78 struct sk_buff *skb,
79 unsigned int channel)
80 {
81 struct rxrpc_skb_priv *sp = skb ? rxrpc_skb(skb) : NULL;
82 struct rxrpc_channel *chan;
83 struct msghdr msg;
84 struct kvec iov[3];
85 struct {
86 struct rxrpc_wire_header whdr;
87 union {
88 __be32 abort_code;
89 struct rxrpc_ackpacket ack;
90 };
91 } __attribute__((packed)) pkt;
92 struct rxrpc_acktrailer trailer;
93 size_t len;
94 int ret, ioc;
95 u32 serial, mtu, call_id, padding;
96
97 _enter("%d", conn->debug_id);
98
99 if (sp && sp->hdr.type == RXRPC_PACKET_TYPE_ACK) {
100 if (skb_copy_bits(skb, sizeof(struct rxrpc_wire_header),
101 &pkt.ack, sizeof(pkt.ack)) < 0)
102 return;
103 if (pkt.ack.reason == RXRPC_ACK_PING_RESPONSE)
104 return;
105 }
106
107 chan = &conn->channels[channel];
108
109 /* If the last call got moved on whilst we were waiting to run, just
110 * ignore this packet.
111 */
112 call_id = chan->last_call;
113 if (skb && call_id != sp->hdr.callNumber)
114 return;
115
116 msg.msg_name = &conn->peer->srx.transport;
117 msg.msg_namelen = conn->peer->srx.transport_len;
118 msg.msg_control = NULL;
119 msg.msg_controllen = 0;
120 msg.msg_flags = 0;
121
122 iov[0].iov_base = &pkt;
123 iov[0].iov_len = sizeof(pkt.whdr);
124 iov[1].iov_base = &padding;
125 iov[1].iov_len = 3;
126 iov[2].iov_base = &trailer;
127 iov[2].iov_len = sizeof(trailer);
128
129 serial = rxrpc_get_next_serial(conn);
130
131 pkt.whdr.epoch = htonl(conn->proto.epoch);
132 pkt.whdr.cid = htonl(conn->proto.cid | channel);
133 pkt.whdr.callNumber = htonl(call_id);
134 pkt.whdr.serial = htonl(serial);
135 pkt.whdr.seq = 0;
136 pkt.whdr.type = chan->last_type;
137 pkt.whdr.flags = conn->out_clientflag;
138 pkt.whdr.userStatus = 0;
139 pkt.whdr.securityIndex = conn->security_ix;
140 pkt.whdr._rsvd = 0;
141 pkt.whdr.serviceId = htons(conn->service_id);
142
143 len = sizeof(pkt.whdr);
144 switch (chan->last_type) {
145 case RXRPC_PACKET_TYPE_ABORT:
146 pkt.abort_code = htonl(chan->last_abort);
147 iov[0].iov_len += sizeof(pkt.abort_code);
148 len += sizeof(pkt.abort_code);
149 ioc = 1;
150 break;
151
152 case RXRPC_PACKET_TYPE_ACK:
153 mtu = conn->peer->if_mtu;
154 mtu -= conn->peer->hdrsize;
155 pkt.ack.bufferSpace = 0;
156 pkt.ack.maxSkew = htons(skb ? skb->priority : 0);
157 pkt.ack.firstPacket = htonl(chan->last_seq + 1);
158 pkt.ack.previousPacket = htonl(chan->last_seq);
159 pkt.ack.serial = htonl(skb ? sp->hdr.serial : 0);
160 pkt.ack.reason = skb ? RXRPC_ACK_DUPLICATE : RXRPC_ACK_IDLE;
161 pkt.ack.nAcks = 0;
162 trailer.maxMTU = htonl(rxrpc_rx_mtu);
163 trailer.ifMTU = htonl(mtu);
164 trailer.rwind = htonl(rxrpc_rx_window_size);
165 trailer.jumbo_max = htonl(rxrpc_rx_jumbo_max);
166 pkt.whdr.flags |= RXRPC_SLOW_START_OK;
167 padding = 0;
168 iov[0].iov_len += sizeof(pkt.ack);
169 len += sizeof(pkt.ack) + 3 + sizeof(trailer);
170 ioc = 3;
171
172 trace_rxrpc_tx_ack(chan->call_debug_id, serial,
173 ntohl(pkt.ack.firstPacket),
174 ntohl(pkt.ack.serial),
175 pkt.ack.reason, 0, rxrpc_rx_window_size);
176 break;
177
178 default:
179 return;
180 }
181
182 ret = kernel_sendmsg(conn->local->socket, &msg, iov, ioc, len);
183 conn->peer->last_tx_at = ktime_get_seconds();
184 if (ret < 0)
185 trace_rxrpc_tx_fail(chan->call_debug_id, serial, ret,
186 rxrpc_tx_point_call_final_resend);
187 else
188 trace_rxrpc_tx_packet(chan->call_debug_id, &pkt.whdr,
189 rxrpc_tx_point_call_final_resend);
190
191 _leave("");
192 }
193
194 /*
195 * pass a connection-level abort onto all calls on that connection
196 */
rxrpc_abort_calls(struct rxrpc_connection * conn)197 static void rxrpc_abort_calls(struct rxrpc_connection *conn)
198 {
199 struct rxrpc_call *call;
200 int i;
201
202 _enter("{%d},%x", conn->debug_id, conn->abort_code);
203
204 for (i = 0; i < RXRPC_MAXCALLS; i++) {
205 call = conn->channels[i].call;
206 if (call) {
207 rxrpc_see_call(call, rxrpc_call_see_conn_abort);
208 rxrpc_set_call_completion(call,
209 conn->completion,
210 conn->abort_code,
211 conn->error);
212 rxrpc_poke_call(call, rxrpc_call_poke_conn_abort);
213 }
214 }
215
216 _leave("");
217 }
218
219 /*
220 * mark a call as being on a now-secured channel
221 * - must be called with BH's disabled.
222 */
rxrpc_call_is_secure(struct rxrpc_call * call)223 static void rxrpc_call_is_secure(struct rxrpc_call *call)
224 {
225 if (call && __rxrpc_call_state(call) == RXRPC_CALL_SERVER_SECURING) {
226 rxrpc_set_call_state(call, RXRPC_CALL_SERVER_RECV_REQUEST);
227 rxrpc_notify_socket(call);
228 }
229 }
230
231 /*
232 * connection-level Rx packet processor
233 */
rxrpc_process_event(struct rxrpc_connection * conn,struct sk_buff * skb)234 static int rxrpc_process_event(struct rxrpc_connection *conn,
235 struct sk_buff *skb)
236 {
237 struct rxrpc_skb_priv *sp = rxrpc_skb(skb);
238 int ret;
239
240 if (conn->state == RXRPC_CONN_ABORTED)
241 return -ECONNABORTED;
242
243 _enter("{%d},{%u,%%%u},", conn->debug_id, sp->hdr.type, sp->hdr.serial);
244
245 switch (sp->hdr.type) {
246 case RXRPC_PACKET_TYPE_CHALLENGE:
247 return conn->security->respond_to_challenge(conn, skb);
248
249 case RXRPC_PACKET_TYPE_RESPONSE:
250 ret = conn->security->verify_response(conn, skb);
251 if (ret < 0)
252 return ret;
253
254 ret = conn->security->init_connection_security(
255 conn, conn->key->payload.data[0]);
256 if (ret < 0)
257 return ret;
258
259 spin_lock(&conn->state_lock);
260 if (conn->state == RXRPC_CONN_SERVICE_CHALLENGING)
261 conn->state = RXRPC_CONN_SERVICE;
262 spin_unlock(&conn->state_lock);
263
264 if (conn->state == RXRPC_CONN_SERVICE) {
265 /* Offload call state flipping to the I/O thread. As
266 * we've already received the packet, put it on the
267 * front of the queue.
268 */
269 skb->mark = RXRPC_SKB_MARK_SERVICE_CONN_SECURED;
270 rxrpc_get_skb(skb, rxrpc_skb_get_conn_secured);
271 skb_queue_head(&conn->local->rx_queue, skb);
272 rxrpc_wake_up_io_thread(conn->local);
273 }
274 return 0;
275
276 default:
277 WARN_ON_ONCE(1);
278 return -EPROTO;
279 }
280 }
281
282 /*
283 * set up security and issue a challenge
284 */
rxrpc_secure_connection(struct rxrpc_connection * conn)285 static void rxrpc_secure_connection(struct rxrpc_connection *conn)
286 {
287 if (conn->security->issue_challenge(conn) < 0)
288 rxrpc_abort_conn(conn, NULL, RX_CALL_DEAD, -ENOMEM,
289 rxrpc_abort_nomem);
290 }
291
292 /*
293 * Process delayed final ACKs that we haven't subsumed into a subsequent call.
294 */
rxrpc_process_delayed_final_acks(struct rxrpc_connection * conn,bool force)295 void rxrpc_process_delayed_final_acks(struct rxrpc_connection *conn, bool force)
296 {
297 unsigned long j = jiffies, next_j;
298 unsigned int channel;
299 bool set;
300
301 again:
302 next_j = j + LONG_MAX;
303 set = false;
304 for (channel = 0; channel < RXRPC_MAXCALLS; channel++) {
305 struct rxrpc_channel *chan = &conn->channels[channel];
306 unsigned long ack_at;
307
308 if (!test_bit(RXRPC_CONN_FINAL_ACK_0 + channel, &conn->flags))
309 continue;
310
311 ack_at = chan->final_ack_at;
312 if (time_before(j, ack_at) && !force) {
313 if (time_before(ack_at, next_j)) {
314 next_j = ack_at;
315 set = true;
316 }
317 continue;
318 }
319
320 if (test_and_clear_bit(RXRPC_CONN_FINAL_ACK_0 + channel,
321 &conn->flags))
322 rxrpc_conn_retransmit_call(conn, NULL, channel);
323 }
324
325 j = jiffies;
326 if (time_before_eq(next_j, j))
327 goto again;
328 if (set)
329 rxrpc_reduce_conn_timer(conn, next_j);
330 }
331
332 /*
333 * connection-level event processor
334 */
rxrpc_do_process_connection(struct rxrpc_connection * conn)335 static void rxrpc_do_process_connection(struct rxrpc_connection *conn)
336 {
337 struct sk_buff *skb;
338 int ret;
339
340 if (test_and_clear_bit(RXRPC_CONN_EV_CHALLENGE, &conn->events))
341 rxrpc_secure_connection(conn);
342
343 /* go through the conn-level event packets, releasing the ref on this
344 * connection that each one has when we've finished with it */
345 while ((skb = skb_dequeue(&conn->rx_queue))) {
346 rxrpc_see_skb(skb, rxrpc_skb_see_conn_work);
347 ret = rxrpc_process_event(conn, skb);
348 switch (ret) {
349 case -ENOMEM:
350 case -EAGAIN:
351 skb_queue_head(&conn->rx_queue, skb);
352 rxrpc_queue_conn(conn, rxrpc_conn_queue_retry_work);
353 break;
354 default:
355 rxrpc_free_skb(skb, rxrpc_skb_put_conn_work);
356 break;
357 }
358 }
359 }
360
rxrpc_process_connection(struct work_struct * work)361 void rxrpc_process_connection(struct work_struct *work)
362 {
363 struct rxrpc_connection *conn =
364 container_of(work, struct rxrpc_connection, processor);
365
366 rxrpc_see_connection(conn, rxrpc_conn_see_work);
367
368 if (__rxrpc_use_local(conn->local, rxrpc_local_use_conn_work)) {
369 rxrpc_do_process_connection(conn);
370 rxrpc_unuse_local(conn->local, rxrpc_local_unuse_conn_work);
371 }
372 }
373
374 /*
375 * post connection-level events to the connection
376 * - this includes challenges, responses, some aborts and call terminal packet
377 * retransmission.
378 */
rxrpc_post_packet_to_conn(struct rxrpc_connection * conn,struct sk_buff * skb)379 static void rxrpc_post_packet_to_conn(struct rxrpc_connection *conn,
380 struct sk_buff *skb)
381 {
382 _enter("%p,%p", conn, skb);
383
384 rxrpc_get_skb(skb, rxrpc_skb_get_conn_work);
385 skb_queue_tail(&conn->rx_queue, skb);
386 rxrpc_queue_conn(conn, rxrpc_conn_queue_rx_work);
387 }
388
389 /*
390 * Input a connection-level packet.
391 */
rxrpc_input_conn_packet(struct rxrpc_connection * conn,struct sk_buff * skb)392 bool rxrpc_input_conn_packet(struct rxrpc_connection *conn, struct sk_buff *skb)
393 {
394 struct rxrpc_skb_priv *sp = rxrpc_skb(skb);
395
396 switch (sp->hdr.type) {
397 case RXRPC_PACKET_TYPE_BUSY:
398 /* Just ignore BUSY packets for now. */
399 return true;
400
401 case RXRPC_PACKET_TYPE_ABORT:
402 if (rxrpc_is_conn_aborted(conn))
403 return true;
404 rxrpc_input_conn_abort(conn, skb);
405 rxrpc_abort_calls(conn);
406 return true;
407
408 case RXRPC_PACKET_TYPE_CHALLENGE:
409 case RXRPC_PACKET_TYPE_RESPONSE:
410 if (rxrpc_is_conn_aborted(conn)) {
411 if (conn->completion == RXRPC_CALL_LOCALLY_ABORTED)
412 rxrpc_send_conn_abort(conn);
413 return true;
414 }
415 rxrpc_post_packet_to_conn(conn, skb);
416 return true;
417
418 default:
419 WARN_ON_ONCE(1);
420 return true;
421 }
422 }
423
424 /*
425 * Input a connection event.
426 */
rxrpc_input_conn_event(struct rxrpc_connection * conn,struct sk_buff * skb)427 void rxrpc_input_conn_event(struct rxrpc_connection *conn, struct sk_buff *skb)
428 {
429 unsigned int loop;
430
431 if (test_and_clear_bit(RXRPC_CONN_EV_ABORT_CALLS, &conn->events))
432 rxrpc_abort_calls(conn);
433
434 switch (skb->mark) {
435 case RXRPC_SKB_MARK_SERVICE_CONN_SECURED:
436 if (conn->state != RXRPC_CONN_SERVICE)
437 break;
438
439 for (loop = 0; loop < RXRPC_MAXCALLS; loop++)
440 rxrpc_call_is_secure(conn->channels[loop].call);
441 break;
442 }
443
444 /* Process delayed ACKs whose time has come. */
445 if (conn->flags & RXRPC_CONN_FINAL_ACK_MASK)
446 rxrpc_process_delayed_final_acks(conn, false);
447 }
448