Merge tag 'mmc-v6.3' of git://git.kernel.org/pub/scm/linux/kernel/git/ulfh/mmc
[platform/kernel/linux-rpi.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  * Set the completion state on an aborted connection.
21  */
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  */
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  */
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  */
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_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, rxrpc_rx_window_size);
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  */
188 static 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  */
211 static 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  */
222 static 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  */
273 static 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  */
283 void 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
289 again:
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  */
323 static 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
349 void 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  */
367 static 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  */
380 bool 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  */
415 void 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 }