ACPI: SBS: Simplify the code using module_acpi_driver()
[linux-2.6-microblaze.git] / net / rxrpc / conn_event.c
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  * Retransmit terminal ACK or ABORT of the previous call.
21  */
22 static void rxrpc_conn_retransmit_call(struct rxrpc_connection *conn,
23                                        struct sk_buff *skb,
24                                        unsigned int channel)
25 {
26         struct rxrpc_skb_priv *sp = skb ? rxrpc_skb(skb) : NULL;
27         struct rxrpc_channel *chan;
28         struct msghdr msg;
29         struct kvec iov[3];
30         struct {
31                 struct rxrpc_wire_header whdr;
32                 union {
33                         __be32 abort_code;
34                         struct rxrpc_ackpacket ack;
35                 };
36         } __attribute__((packed)) pkt;
37         struct rxrpc_ackinfo ack_info;
38         size_t len;
39         int ret, ioc;
40         u32 serial, mtu, call_id, padding;
41
42         _enter("%d", conn->debug_id);
43
44         chan = &conn->channels[channel];
45
46         /* If the last call got moved on whilst we were waiting to run, just
47          * ignore this packet.
48          */
49         call_id = READ_ONCE(chan->last_call);
50         /* Sync with __rxrpc_disconnect_call() */
51         smp_rmb();
52         if (skb && call_id != sp->hdr.callNumber)
53                 return;
54
55         msg.msg_name    = &conn->params.peer->srx.transport;
56         msg.msg_namelen = conn->params.peer->srx.transport_len;
57         msg.msg_control = NULL;
58         msg.msg_controllen = 0;
59         msg.msg_flags   = 0;
60
61         iov[0].iov_base = &pkt;
62         iov[0].iov_len  = sizeof(pkt.whdr);
63         iov[1].iov_base = &padding;
64         iov[1].iov_len  = 3;
65         iov[2].iov_base = &ack_info;
66         iov[2].iov_len  = sizeof(ack_info);
67
68         pkt.whdr.epoch          = htonl(conn->proto.epoch);
69         pkt.whdr.cid            = htonl(conn->proto.cid | channel);
70         pkt.whdr.callNumber     = htonl(call_id);
71         pkt.whdr.seq            = 0;
72         pkt.whdr.type           = chan->last_type;
73         pkt.whdr.flags          = conn->out_clientflag;
74         pkt.whdr.userStatus     = 0;
75         pkt.whdr.securityIndex  = conn->security_ix;
76         pkt.whdr._rsvd          = 0;
77         pkt.whdr.serviceId      = htons(conn->service_id);
78
79         len = sizeof(pkt.whdr);
80         switch (chan->last_type) {
81         case RXRPC_PACKET_TYPE_ABORT:
82                 pkt.abort_code  = htonl(chan->last_abort);
83                 iov[0].iov_len += sizeof(pkt.abort_code);
84                 len += sizeof(pkt.abort_code);
85                 ioc = 1;
86                 break;
87
88         case RXRPC_PACKET_TYPE_ACK:
89                 mtu = conn->params.peer->if_mtu;
90                 mtu -= conn->params.peer->hdrsize;
91                 pkt.ack.bufferSpace     = 0;
92                 pkt.ack.maxSkew         = htons(skb ? skb->priority : 0);
93                 pkt.ack.firstPacket     = htonl(chan->last_seq + 1);
94                 pkt.ack.previousPacket  = htonl(chan->last_seq);
95                 pkt.ack.serial          = htonl(skb ? sp->hdr.serial : 0);
96                 pkt.ack.reason          = skb ? RXRPC_ACK_DUPLICATE : RXRPC_ACK_IDLE;
97                 pkt.ack.nAcks           = 0;
98                 ack_info.rxMTU          = htonl(rxrpc_rx_mtu);
99                 ack_info.maxMTU         = htonl(mtu);
100                 ack_info.rwind          = htonl(rxrpc_rx_window_size);
101                 ack_info.jumbo_max      = htonl(rxrpc_rx_jumbo_max);
102                 pkt.whdr.flags          |= RXRPC_SLOW_START_OK;
103                 padding                 = 0;
104                 iov[0].iov_len += sizeof(pkt.ack);
105                 len += sizeof(pkt.ack) + 3 + sizeof(ack_info);
106                 ioc = 3;
107                 break;
108
109         default:
110                 return;
111         }
112
113         /* Resync with __rxrpc_disconnect_call() and check that the last call
114          * didn't get advanced whilst we were filling out the packets.
115          */
116         smp_rmb();
117         if (READ_ONCE(chan->last_call) != call_id)
118                 return;
119
120         serial = atomic_inc_return(&conn->serial);
121         pkt.whdr.serial = htonl(serial);
122
123         switch (chan->last_type) {
124         case RXRPC_PACKET_TYPE_ABORT:
125                 _proto("Tx ABORT %%%u { %d } [re]", serial, conn->abort_code);
126                 break;
127         case RXRPC_PACKET_TYPE_ACK:
128                 trace_rxrpc_tx_ack(chan->call_debug_id, serial,
129                                    ntohl(pkt.ack.firstPacket),
130                                    ntohl(pkt.ack.serial),
131                                    pkt.ack.reason, 0);
132                 _proto("Tx ACK %%%u [re]", serial);
133                 break;
134         }
135
136         ret = kernel_sendmsg(conn->params.local->socket, &msg, iov, ioc, len);
137         conn->params.peer->last_tx_at = ktime_get_seconds();
138         if (ret < 0)
139                 trace_rxrpc_tx_fail(chan->call_debug_id, serial, ret,
140                                     rxrpc_tx_point_call_final_resend);
141         else
142                 trace_rxrpc_tx_packet(chan->call_debug_id, &pkt.whdr,
143                                       rxrpc_tx_point_call_final_resend);
144
145         _leave("");
146 }
147
148 /*
149  * pass a connection-level abort onto all calls on that connection
150  */
151 static void rxrpc_abort_calls(struct rxrpc_connection *conn,
152                               enum rxrpc_call_completion compl,
153                               rxrpc_serial_t serial)
154 {
155         struct rxrpc_call *call;
156         int i;
157
158         _enter("{%d},%x", conn->debug_id, conn->abort_code);
159
160         spin_lock(&conn->bundle->channel_lock);
161
162         for (i = 0; i < RXRPC_MAXCALLS; i++) {
163                 call = rcu_dereference_protected(
164                         conn->channels[i].call,
165                         lockdep_is_held(&conn->bundle->channel_lock));
166                 if (call) {
167                         if (compl == RXRPC_CALL_LOCALLY_ABORTED)
168                                 trace_rxrpc_abort(call->debug_id,
169                                                   "CON", call->cid,
170                                                   call->call_id, 0,
171                                                   conn->abort_code,
172                                                   conn->error);
173                         else
174                                 trace_rxrpc_rx_abort(call, serial,
175                                                      conn->abort_code);
176                         rxrpc_set_call_completion(call, compl,
177                                                   conn->abort_code,
178                                                   conn->error);
179                 }
180         }
181
182         spin_unlock(&conn->bundle->channel_lock);
183         _leave("");
184 }
185
186 /*
187  * generate a connection-level abort
188  */
189 static int rxrpc_abort_connection(struct rxrpc_connection *conn,
190                                   int error, u32 abort_code)
191 {
192         struct rxrpc_wire_header whdr;
193         struct msghdr msg;
194         struct kvec iov[2];
195         __be32 word;
196         size_t len;
197         u32 serial;
198         int ret;
199
200         _enter("%d,,%u,%u", conn->debug_id, error, abort_code);
201
202         /* generate a connection-level abort */
203         spin_lock_bh(&conn->state_lock);
204         if (conn->state >= RXRPC_CONN_REMOTELY_ABORTED) {
205                 spin_unlock_bh(&conn->state_lock);
206                 _leave(" = 0 [already dead]");
207                 return 0;
208         }
209
210         conn->error = error;
211         conn->abort_code = abort_code;
212         conn->state = RXRPC_CONN_LOCALLY_ABORTED;
213         set_bit(RXRPC_CONN_DONT_REUSE, &conn->flags);
214         spin_unlock_bh(&conn->state_lock);
215
216         msg.msg_name    = &conn->params.peer->srx.transport;
217         msg.msg_namelen = conn->params.peer->srx.transport_len;
218         msg.msg_control = NULL;
219         msg.msg_controllen = 0;
220         msg.msg_flags   = 0;
221
222         whdr.epoch      = htonl(conn->proto.epoch);
223         whdr.cid        = htonl(conn->proto.cid);
224         whdr.callNumber = 0;
225         whdr.seq        = 0;
226         whdr.type       = RXRPC_PACKET_TYPE_ABORT;
227         whdr.flags      = conn->out_clientflag;
228         whdr.userStatus = 0;
229         whdr.securityIndex = conn->security_ix;
230         whdr._rsvd      = 0;
231         whdr.serviceId  = htons(conn->service_id);
232
233         word            = htonl(conn->abort_code);
234
235         iov[0].iov_base = &whdr;
236         iov[0].iov_len  = sizeof(whdr);
237         iov[1].iov_base = &word;
238         iov[1].iov_len  = sizeof(word);
239
240         len = iov[0].iov_len + iov[1].iov_len;
241
242         serial = atomic_inc_return(&conn->serial);
243         rxrpc_abort_calls(conn, RXRPC_CALL_LOCALLY_ABORTED, serial);
244         whdr.serial = htonl(serial);
245         _proto("Tx CONN ABORT %%%u { %d }", serial, conn->abort_code);
246
247         ret = kernel_sendmsg(conn->params.local->socket, &msg, iov, 2, len);
248         if (ret < 0) {
249                 trace_rxrpc_tx_fail(conn->debug_id, serial, ret,
250                                     rxrpc_tx_point_conn_abort);
251                 _debug("sendmsg failed: %d", ret);
252                 return -EAGAIN;
253         }
254
255         trace_rxrpc_tx_packet(conn->debug_id, &whdr, rxrpc_tx_point_conn_abort);
256
257         conn->params.peer->last_tx_at = ktime_get_seconds();
258
259         _leave(" = 0");
260         return 0;
261 }
262
263 /*
264  * mark a call as being on a now-secured channel
265  * - must be called with BH's disabled.
266  */
267 static void rxrpc_call_is_secure(struct rxrpc_call *call)
268 {
269         _enter("%p", call);
270         if (call) {
271                 write_lock_bh(&call->state_lock);
272                 if (call->state == RXRPC_CALL_SERVER_SECURING) {
273                         call->state = RXRPC_CALL_SERVER_RECV_REQUEST;
274                         rxrpc_notify_socket(call);
275                 }
276                 write_unlock_bh(&call->state_lock);
277         }
278 }
279
280 /*
281  * connection-level Rx packet processor
282  */
283 static int rxrpc_process_event(struct rxrpc_connection *conn,
284                                struct sk_buff *skb,
285                                u32 *_abort_code)
286 {
287         struct rxrpc_skb_priv *sp = rxrpc_skb(skb);
288         __be32 wtmp;
289         u32 abort_code;
290         int loop, ret;
291
292         if (conn->state >= RXRPC_CONN_REMOTELY_ABORTED) {
293                 _leave(" = -ECONNABORTED [%u]", conn->state);
294                 return -ECONNABORTED;
295         }
296
297         _enter("{%d},{%u,%%%u},", conn->debug_id, sp->hdr.type, sp->hdr.serial);
298
299         switch (sp->hdr.type) {
300         case RXRPC_PACKET_TYPE_DATA:
301         case RXRPC_PACKET_TYPE_ACK:
302                 rxrpc_conn_retransmit_call(conn, skb,
303                                            sp->hdr.cid & RXRPC_CHANNELMASK);
304                 return 0;
305
306         case RXRPC_PACKET_TYPE_BUSY:
307                 /* Just ignore BUSY packets for now. */
308                 return 0;
309
310         case RXRPC_PACKET_TYPE_ABORT:
311                 if (skb_copy_bits(skb, sizeof(struct rxrpc_wire_header),
312                                   &wtmp, sizeof(wtmp)) < 0) {
313                         trace_rxrpc_rx_eproto(NULL, sp->hdr.serial,
314                                               tracepoint_string("bad_abort"));
315                         return -EPROTO;
316                 }
317                 abort_code = ntohl(wtmp);
318                 _proto("Rx ABORT %%%u { ac=%d }", sp->hdr.serial, abort_code);
319
320                 conn->error = -ECONNABORTED;
321                 conn->abort_code = abort_code;
322                 conn->state = RXRPC_CONN_REMOTELY_ABORTED;
323                 set_bit(RXRPC_CONN_DONT_REUSE, &conn->flags);
324                 rxrpc_abort_calls(conn, RXRPC_CALL_REMOTELY_ABORTED, sp->hdr.serial);
325                 return -ECONNABORTED;
326
327         case RXRPC_PACKET_TYPE_CHALLENGE:
328                 return conn->security->respond_to_challenge(conn, skb,
329                                                             _abort_code);
330
331         case RXRPC_PACKET_TYPE_RESPONSE:
332                 ret = conn->security->verify_response(conn, skb, _abort_code);
333                 if (ret < 0)
334                         return ret;
335
336                 ret = conn->security->init_connection_security(conn);
337                 if (ret < 0)
338                         return ret;
339
340                 ret = conn->security->prime_packet_security(conn);
341                 if (ret < 0)
342                         return ret;
343
344                 spin_lock(&conn->bundle->channel_lock);
345                 spin_lock_bh(&conn->state_lock);
346
347                 if (conn->state == RXRPC_CONN_SERVICE_CHALLENGING) {
348                         conn->state = RXRPC_CONN_SERVICE;
349                         spin_unlock_bh(&conn->state_lock);
350                         for (loop = 0; loop < RXRPC_MAXCALLS; loop++)
351                                 rxrpc_call_is_secure(
352                                         rcu_dereference_protected(
353                                                 conn->channels[loop].call,
354                                                 lockdep_is_held(&conn->bundle->channel_lock)));
355                 } else {
356                         spin_unlock_bh(&conn->state_lock);
357                 }
358
359                 spin_unlock(&conn->bundle->channel_lock);
360                 return 0;
361
362         default:
363                 trace_rxrpc_rx_eproto(NULL, sp->hdr.serial,
364                                       tracepoint_string("bad_conn_pkt"));
365                 return -EPROTO;
366         }
367 }
368
369 /*
370  * set up security and issue a challenge
371  */
372 static void rxrpc_secure_connection(struct rxrpc_connection *conn)
373 {
374         u32 abort_code;
375         int ret;
376
377         _enter("{%d}", conn->debug_id);
378
379         ASSERT(conn->security_ix != 0);
380         ASSERT(conn->server_key);
381
382         if (conn->security->issue_challenge(conn) < 0) {
383                 abort_code = RX_CALL_DEAD;
384                 ret = -ENOMEM;
385                 goto abort;
386         }
387
388         _leave("");
389         return;
390
391 abort:
392         _debug("abort %d, %d", ret, abort_code);
393         rxrpc_abort_connection(conn, ret, abort_code);
394         _leave(" [aborted]");
395 }
396
397 /*
398  * Process delayed final ACKs that we haven't subsumed into a subsequent call.
399  */
400 void rxrpc_process_delayed_final_acks(struct rxrpc_connection *conn, bool force)
401 {
402         unsigned long j = jiffies, next_j;
403         unsigned int channel;
404         bool set;
405
406 again:
407         next_j = j + LONG_MAX;
408         set = false;
409         for (channel = 0; channel < RXRPC_MAXCALLS; channel++) {
410                 struct rxrpc_channel *chan = &conn->channels[channel];
411                 unsigned long ack_at;
412
413                 if (!test_bit(RXRPC_CONN_FINAL_ACK_0 + channel, &conn->flags))
414                         continue;
415
416                 smp_rmb(); /* vs rxrpc_disconnect_client_call */
417                 ack_at = READ_ONCE(chan->final_ack_at);
418
419                 if (time_before(j, ack_at) && !force) {
420                         if (time_before(ack_at, next_j)) {
421                                 next_j = ack_at;
422                                 set = true;
423                         }
424                         continue;
425                 }
426
427                 if (test_and_clear_bit(RXRPC_CONN_FINAL_ACK_0 + channel,
428                                        &conn->flags))
429                         rxrpc_conn_retransmit_call(conn, NULL, channel);
430         }
431
432         j = jiffies;
433         if (time_before_eq(next_j, j))
434                 goto again;
435         if (set)
436                 rxrpc_reduce_conn_timer(conn, next_j);
437 }
438
439 /*
440  * connection-level event processor
441  */
442 static void rxrpc_do_process_connection(struct rxrpc_connection *conn)
443 {
444         struct sk_buff *skb;
445         u32 abort_code = RX_PROTOCOL_ERROR;
446         int ret;
447
448         if (test_and_clear_bit(RXRPC_CONN_EV_CHALLENGE, &conn->events))
449                 rxrpc_secure_connection(conn);
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         /* go through the conn-level event packets, releasing the ref on this
456          * connection that each one has when we've finished with it */
457         while ((skb = skb_dequeue(&conn->rx_queue))) {
458                 rxrpc_see_skb(skb, rxrpc_skb_seen);
459                 ret = rxrpc_process_event(conn, skb, &abort_code);
460                 switch (ret) {
461                 case -EPROTO:
462                 case -EKEYEXPIRED:
463                 case -EKEYREJECTED:
464                         goto protocol_error;
465                 case -ENOMEM:
466                 case -EAGAIN:
467                         goto requeue_and_leave;
468                 case -ECONNABORTED:
469                 default:
470                         rxrpc_free_skb(skb, rxrpc_skb_freed);
471                         break;
472                 }
473         }
474
475         return;
476
477 requeue_and_leave:
478         skb_queue_head(&conn->rx_queue, skb);
479         return;
480
481 protocol_error:
482         if (rxrpc_abort_connection(conn, ret, abort_code) < 0)
483                 goto requeue_and_leave;
484         rxrpc_free_skb(skb, rxrpc_skb_freed);
485         return;
486 }
487
488 void rxrpc_process_connection(struct work_struct *work)
489 {
490         struct rxrpc_connection *conn =
491                 container_of(work, struct rxrpc_connection, processor);
492
493         rxrpc_see_connection(conn);
494
495         if (__rxrpc_use_local(conn->params.local)) {
496                 rxrpc_do_process_connection(conn);
497                 rxrpc_unuse_local(conn->params.local);
498         }
499
500         rxrpc_put_connection(conn);
501         _leave("");
502         return;
503 }