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_irq(&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_irq(&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, max_mtu, if_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 if_mtu = conn->peer->if_mtu - conn->peer->hdrsize;
154 if (conn->peer->ackr_adv_pmtud) {
155 max_mtu = umax(conn->peer->max_data, rxrpc_rx_mtu);
156 } else {
157 if_mtu = umin(1444, if_mtu);
158 max_mtu = if_mtu;
159 }
160 pkt.ack.bufferSpace = 0;
161 pkt.ack.maxSkew = htons(skb ? skb->priority : 0);
162 pkt.ack.firstPacket = htonl(chan->last_seq + 1);
163 pkt.ack.previousPacket = htonl(chan->last_seq);
164 pkt.ack.serial = htonl(skb ? sp->hdr.serial : 0);
165 pkt.ack.reason = skb ? RXRPC_ACK_DUPLICATE : RXRPC_ACK_IDLE;
166 pkt.ack.nAcks = 0;
167 trailer.maxMTU = htonl(max_mtu);
168 trailer.ifMTU = htonl(if_mtu);
169 trailer.rwind = htonl(rxrpc_rx_window_size);
170 trailer.jumbo_max = 0;
171 pkt.whdr.flags |= RXRPC_SLOW_START_OK;
172 padding = 0;
173 iov[0].iov_len += sizeof(pkt.ack);
174 len += sizeof(pkt.ack) + 3 + sizeof(trailer);
175 ioc = 3;
176
177 trace_rxrpc_tx_ack(chan->call_debug_id, serial,
178 ntohl(pkt.ack.firstPacket),
179 ntohl(pkt.ack.serial),
180 pkt.ack.reason, 0, rxrpc_rx_window_size,
181 rxrpc_propose_ack_retransmit);
182 break;
183
184 default:
185 return;
186 }
187
188 ret = kernel_sendmsg(conn->local->socket, &msg, iov, ioc, len);
189 conn->peer->last_tx_at = ktime_get_seconds();
190 if (ret < 0)
191 trace_rxrpc_tx_fail(chan->call_debug_id, serial, ret,
192 rxrpc_tx_point_call_final_resend);
193 else
194 trace_rxrpc_tx_packet(chan->call_debug_id, &pkt.whdr,
195 rxrpc_tx_point_call_final_resend);
196
197 _leave("");
198 }
199
200 /*
201 * pass a connection-level abort onto all calls on that connection
202 */
rxrpc_abort_calls(struct rxrpc_connection * conn)203 static void rxrpc_abort_calls(struct rxrpc_connection *conn)
204 {
205 struct rxrpc_call *call;
206 int i;
207
208 _enter("{%d},%x", conn->debug_id, conn->abort_code);
209
210 for (i = 0; i < RXRPC_MAXCALLS; i++) {
211 call = conn->channels[i].call;
212 if (call) {
213 rxrpc_see_call(call, rxrpc_call_see_conn_abort);
214 rxrpc_set_call_completion(call,
215 conn->completion,
216 conn->abort_code,
217 conn->error);
218 rxrpc_poke_call(call, rxrpc_call_poke_conn_abort);
219 }
220 }
221
222 _leave("");
223 }
224
225 /*
226 * mark a call as being on a now-secured channel
227 * - must be called with BH's disabled.
228 */
rxrpc_call_is_secure(struct rxrpc_call * call)229 static void rxrpc_call_is_secure(struct rxrpc_call *call)
230 {
231 if (call && __test_and_clear_bit(RXRPC_CALL_CONN_CHALLENGING, &call->flags))
232 rxrpc_notify_socket(call);
233 }
234
235 /*
236 * connection-level Rx packet processor
237 */
rxrpc_process_event(struct rxrpc_connection * conn,struct sk_buff * skb)238 static int rxrpc_process_event(struct rxrpc_connection *conn,
239 struct sk_buff *skb)
240 {
241 struct rxrpc_skb_priv *sp = rxrpc_skb(skb);
242 int ret;
243
244 if (conn->state == RXRPC_CONN_ABORTED)
245 return -ECONNABORTED;
246
247 _enter("{%d},{%u,%%%u},", conn->debug_id, sp->hdr.type, sp->hdr.serial);
248
249 switch (sp->hdr.type) {
250 case RXRPC_PACKET_TYPE_CHALLENGE:
251 return conn->security->respond_to_challenge(conn, skb);
252
253 case RXRPC_PACKET_TYPE_RESPONSE:
254 ret = conn->security->verify_response(conn, skb);
255 if (ret < 0)
256 return ret;
257
258 ret = conn->security->init_connection_security(
259 conn, conn->key->payload.data[0]);
260 if (ret < 0)
261 return ret;
262
263 spin_lock_irq(&conn->state_lock);
264 if (conn->state == RXRPC_CONN_SERVICE_CHALLENGING)
265 conn->state = RXRPC_CONN_SERVICE;
266 spin_unlock_irq(&conn->state_lock);
267
268 if (conn->state == RXRPC_CONN_SERVICE) {
269 /* Offload call state flipping to the I/O thread. As
270 * we've already received the packet, put it on the
271 * front of the queue.
272 */
273 sp->conn = rxrpc_get_connection(conn, rxrpc_conn_get_poke_secured);
274 skb->mark = RXRPC_SKB_MARK_SERVICE_CONN_SECURED;
275 rxrpc_get_skb(skb, rxrpc_skb_get_conn_secured);
276 skb_queue_head(&conn->local->rx_queue, skb);
277 rxrpc_wake_up_io_thread(conn->local);
278 }
279 return 0;
280
281 default:
282 WARN_ON_ONCE(1);
283 return -EPROTO;
284 }
285 }
286
287 /*
288 * set up security and issue a challenge
289 */
rxrpc_secure_connection(struct rxrpc_connection * conn)290 static void rxrpc_secure_connection(struct rxrpc_connection *conn)
291 {
292 if (conn->security->issue_challenge(conn) < 0)
293 rxrpc_abort_conn(conn, NULL, RX_CALL_DEAD, -ENOMEM,
294 rxrpc_abort_nomem);
295 }
296
297 /*
298 * Process delayed final ACKs that we haven't subsumed into a subsequent call.
299 */
rxrpc_process_delayed_final_acks(struct rxrpc_connection * conn,bool force)300 void rxrpc_process_delayed_final_acks(struct rxrpc_connection *conn, bool force)
301 {
302 unsigned long j = jiffies, next_j;
303 unsigned int channel;
304 bool set;
305
306 again:
307 next_j = j + LONG_MAX;
308 set = false;
309 for (channel = 0; channel < RXRPC_MAXCALLS; channel++) {
310 struct rxrpc_channel *chan = &conn->channels[channel];
311 unsigned long ack_at;
312
313 if (!test_bit(RXRPC_CONN_FINAL_ACK_0 + channel, &conn->flags))
314 continue;
315
316 ack_at = chan->final_ack_at;
317 if (time_before(j, ack_at) && !force) {
318 if (time_before(ack_at, next_j)) {
319 next_j = ack_at;
320 set = true;
321 }
322 continue;
323 }
324
325 if (test_and_clear_bit(RXRPC_CONN_FINAL_ACK_0 + channel,
326 &conn->flags))
327 rxrpc_conn_retransmit_call(conn, NULL, channel);
328 }
329
330 j = jiffies;
331 if (time_before_eq(next_j, j))
332 goto again;
333 if (set)
334 rxrpc_reduce_conn_timer(conn, next_j);
335 }
336
337 /*
338 * connection-level event processor
339 */
rxrpc_do_process_connection(struct rxrpc_connection * conn)340 static void rxrpc_do_process_connection(struct rxrpc_connection *conn)
341 {
342 struct sk_buff *skb;
343 int ret;
344
345 if (test_and_clear_bit(RXRPC_CONN_EV_CHALLENGE, &conn->events))
346 rxrpc_secure_connection(conn);
347
348 /* go through the conn-level event packets, releasing the ref on this
349 * connection that each one has when we've finished with it */
350 while ((skb = skb_dequeue(&conn->rx_queue))) {
351 rxrpc_see_skb(skb, rxrpc_skb_see_conn_work);
352 ret = rxrpc_process_event(conn, skb);
353 switch (ret) {
354 case -ENOMEM:
355 case -EAGAIN:
356 skb_queue_head(&conn->rx_queue, skb);
357 rxrpc_queue_conn(conn, rxrpc_conn_queue_retry_work);
358 break;
359 default:
360 rxrpc_free_skb(skb, rxrpc_skb_put_conn_work);
361 break;
362 }
363 }
364 }
365
rxrpc_process_connection(struct work_struct * work)366 void rxrpc_process_connection(struct work_struct *work)
367 {
368 struct rxrpc_connection *conn =
369 container_of(work, struct rxrpc_connection, processor);
370
371 rxrpc_see_connection(conn, rxrpc_conn_see_work);
372
373 if (__rxrpc_use_local(conn->local, rxrpc_local_use_conn_work)) {
374 rxrpc_do_process_connection(conn);
375 rxrpc_unuse_local(conn->local, rxrpc_local_unuse_conn_work);
376 }
377 }
378
379 /*
380 * post connection-level events to the connection
381 * - this includes challenges, responses, some aborts and call terminal packet
382 * retransmission.
383 */
rxrpc_post_packet_to_conn(struct rxrpc_connection * conn,struct sk_buff * skb)384 static void rxrpc_post_packet_to_conn(struct rxrpc_connection *conn,
385 struct sk_buff *skb)
386 {
387 _enter("%p,%p", conn, skb);
388
389 rxrpc_get_skb(skb, rxrpc_skb_get_conn_work);
390 skb_queue_tail(&conn->rx_queue, skb);
391 rxrpc_queue_conn(conn, rxrpc_conn_queue_rx_work);
392 }
393
394 /*
395 * Input a connection-level packet.
396 */
rxrpc_input_conn_packet(struct rxrpc_connection * conn,struct sk_buff * skb)397 bool rxrpc_input_conn_packet(struct rxrpc_connection *conn, struct sk_buff *skb)
398 {
399 struct rxrpc_skb_priv *sp = rxrpc_skb(skb);
400
401 switch (sp->hdr.type) {
402 case RXRPC_PACKET_TYPE_BUSY:
403 /* Just ignore BUSY packets for now. */
404 return true;
405
406 case RXRPC_PACKET_TYPE_ABORT:
407 if (rxrpc_is_conn_aborted(conn))
408 return true;
409 rxrpc_input_conn_abort(conn, skb);
410 rxrpc_abort_calls(conn);
411 return true;
412
413 case RXRPC_PACKET_TYPE_CHALLENGE:
414 case RXRPC_PACKET_TYPE_RESPONSE:
415 if (rxrpc_is_conn_aborted(conn)) {
416 if (conn->completion == RXRPC_CALL_LOCALLY_ABORTED)
417 rxrpc_send_conn_abort(conn);
418 return true;
419 }
420 rxrpc_post_packet_to_conn(conn, skb);
421 return true;
422
423 default:
424 WARN_ON_ONCE(1);
425 return true;
426 }
427 }
428
429 /*
430 * Input a connection event.
431 */
rxrpc_input_conn_event(struct rxrpc_connection * conn,struct sk_buff * skb)432 void rxrpc_input_conn_event(struct rxrpc_connection *conn, struct sk_buff *skb)
433 {
434 unsigned int loop;
435
436 if (test_and_clear_bit(RXRPC_CONN_EV_ABORT_CALLS, &conn->events))
437 rxrpc_abort_calls(conn);
438
439 if (skb) {
440 switch (skb->mark) {
441 case RXRPC_SKB_MARK_SERVICE_CONN_SECURED:
442 if (conn->state != RXRPC_CONN_SERVICE)
443 break;
444
445 for (loop = 0; loop < RXRPC_MAXCALLS; loop++)
446 rxrpc_call_is_secure(conn->channels[loop].call);
447 break;
448 }
449 }
450
451 /* Process delayed ACKs whose time has come. */
452 if (conn->flags & RXRPC_CONN_FINAL_ACK_MASK)
453 rxrpc_process_delayed_final_acks(conn, false);
454 }
455