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