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         if (sp && sp->hdr.type == RXRPC_PACKET_TYPE_ACK) {
  45                 if (skb_copy_bits(skb, sizeof(struct rxrpc_wire_header),
  46                                   &pkt.ack, sizeof(pkt.ack)) < 0)
  47                         return;
  48                 if (pkt.ack.reason == RXRPC_ACK_PING_RESPONSE)
  49                         return;
  50         }
  51
  52         chan = &conn->channels[channel];
  53
  54         /* If the last call got moved on whilst we were waiting to run, just
  55          * ignore this packet.
  56          */
  57         call_id = READ_ONCE(chan->last_call);
  58         /* Sync with __rxrpc_disconnect_call() */
  59         smp_rmb();
  60         if (skb && call_id != sp->hdr.callNumber)
  61                 return;
  62
  63         msg.msg_name    = &conn->params.peer->srx.transport;
  64         msg.msg_namelen = conn->params.peer->srx.transport_len;
  65         msg.msg_control = NULL;
  66         msg.msg_controllen = 0;
  67         msg.msg_flags   = 0;
  68
  69         iov[0].iov_base = &pkt;
  70         iov[0].iov_len  = sizeof(pkt.whdr);
  71         iov[1].iov_base = &padding;
  72         iov[1].iov_len  = 3;
  73         iov[2].iov_base = &ack_info;
  74         iov[2].iov_len  = sizeof(ack_info);
  75
  76         pkt.whdr.epoch          = htonl(conn->proto.epoch);
  77         pkt.whdr.cid            = htonl(conn->proto.cid | channel);
  78         pkt.whdr.callNumber     = htonl(call_id);
  79         pkt.whdr.seq            = 0;
  80         pkt.whdr.type           = chan->last_type;
  81         pkt.whdr.flags          = conn->out_clientflag;
  82         pkt.whdr.userStatus     = 0;
  83         pkt.whdr.securityIndex  = conn->security_ix;
  84         pkt.whdr._rsvd          = 0;
  85         pkt.whdr.serviceId      = htons(conn->service_id);
  86
  87         len = sizeof(pkt.whdr);
  88         switch (chan->last_type) {
  89         case RXRPC_PACKET_TYPE_ABORT:
  90                 pkt.abort_code  = htonl(chan->last_abort);
  91                 iov[0].iov_len += sizeof(pkt.abort_code);
  92                 len += sizeof(pkt.abort_code);
  93                 ioc = 1;
  94                 break;
  95
  96         case RXRPC_PACKET_TYPE_ACK:
  97                 mtu = conn->params.peer->if_mtu;
  98                 mtu -= conn->params.peer->hdrsize;
  99                 pkt.ack.bufferSpace     = 0;
 100                 pkt.ack.maxSkew         = htons(skb ? skb->priority : 0);
 101                 pkt.ack.firstPacket     = htonl(chan->last_seq + 1);
 102                 pkt.ack.previousPacket  = htonl(chan->last_seq);
 103                 pkt.ack.serial          = htonl(skb ? sp->hdr.serial : 0);
 104                 pkt.ack.reason          = skb ? RXRPC_ACK_DUPLICATE : RXRPC_ACK_IDLE;
 105                 pkt.ack.nAcks           = 0;
 106                 ack_info.rxMTU          = htonl(rxrpc_rx_mtu);
 107                 ack_info.maxMTU         = htonl(mtu);
 108                 ack_info.rwind          = htonl(rxrpc_rx_window_size);
 109                 ack_info.jumbo_max      = htonl(rxrpc_rx_jumbo_max);
 110                 pkt.whdr.flags          |= RXRPC_SLOW_START_OK;
 111                 padding                 = 0;
 112                 iov[0].iov_len += sizeof(pkt.ack);
 113                 len += sizeof(pkt.ack) + 3 + sizeof(ack_info);
 114                 ioc = 3;
 115                 break;
 116
 117         default:
 118                 return;
 119         }
 120
 121         /* Resync with __rxrpc_disconnect_call() and check that the last call
 122          * didn't get advanced whilst we were filling out the packets.
 123          */
 124         smp_rmb();
 125         if (READ_ONCE(chan->last_call) != call_id)
 126                 return;
 127
 128         serial = atomic_inc_return(&conn->serial);
 129         pkt.whdr.serial = htonl(serial);
 130
 131         switch (chan->last_type) {
 132         case RXRPC_PACKET_TYPE_ABORT:
 133                 _proto("Tx ABORT %%%u { %d } [re]", serial, conn->abort_code);
 134                 break;
 135         case RXRPC_PACKET_TYPE_ACK:
 136                 trace_rxrpc_tx_ack(chan->call_debug_id, serial,
 137                                    ntohl(pkt.ack.firstPacket),
 138                                    ntohl(pkt.ack.serial),
 139                                    pkt.ack.reason, 0);
 140                 _proto("Tx ACK %%%u [re]", serial);
 141                 break;
 142         }
 143
 144         ret = kernel_sendmsg(conn->params.local->socket, &msg, iov, ioc, len);
 145         conn->params.peer->last_tx_at = ktime_get_seconds();
 146         if (ret < 0)
 147                 trace_rxrpc_tx_fail(chan->call_debug_id, serial, ret,
 148                                     rxrpc_tx_point_call_final_resend);
 149         else
 150                 trace_rxrpc_tx_packet(chan->call_debug_id, &pkt.whdr,
 151                                       rxrpc_tx_point_call_final_resend);
 152
 153         _leave("");
 154 }
 155
 156 /*
 157  * pass a connection-level abort onto all calls on that connection
 158  */
 159 static void rxrpc_abort_calls(struct rxrpc_connection *conn,
 160                               enum rxrpc_call_completion compl,
 161                               rxrpc_serial_t serial)
 162 {
 163         struct rxrpc_call *call;
 164         int i;
 165
 166         _enter("{%d},%x", conn->debug_id, conn->abort_code);
 167
 168         spin_lock(&conn->bundle->channel_lock);
 169
 170         for (i = 0; i < RXRPC_MAXCALLS; i++) {
 171                 call = rcu_dereference_protected(
 172                         conn->channels[i].call,
 173                         lockdep_is_held(&conn->bundle->channel_lock));
 174                 if (call) {
 175                         if (compl == RXRPC_CALL_LOCALLY_ABORTED)
 176                                 trace_rxrpc_abort(call->debug_id,
 177                                                   "CON", call->cid,
 178                                                   call->call_id, 0,
 179                                                   conn->abort_code,
 180                                                   conn->error);
 181                         else
 182                                 trace_rxrpc_rx_abort(call, serial,
 183                                                      conn->abort_code);
 184                         rxrpc_set_call_completion(call, compl,
 185                                                   conn->abort_code,
 186                                                   conn->error);
 187                 }
 188         }
 189
 190         spin_unlock(&conn->bundle->channel_lock);
 191         _leave("");
 192 }
 193
 194 /*
 195  * generate a connection-level abort
 196  */
 197 static int rxrpc_abort_connection(struct rxrpc_connection *conn,
 198                                   int error, u32 abort_code)
 199 {
 200         struct rxrpc_wire_header whdr;
 201         struct msghdr msg;
 202         struct kvec iov[2];
 203         __be32 word;
 204         size_t len;
 205         u32 serial;
 206         int ret;
 207
 208         _enter("%d,,%u,%u", conn->debug_id, error, abort_code);
 209
 210         /* generate a connection-level abort */
 211         spin_lock_bh(&conn->state_lock);
 212         if (conn->state >= RXRPC_CONN_REMOTELY_ABORTED) {
 213                 spin_unlock_bh(&conn->state_lock);
 214                 _leave(" = 0 [already dead]");
 215                 return 0;
 216         }
 217
 218         conn->error = error;
 219         conn->abort_code = abort_code;
 220         conn->state = RXRPC_CONN_LOCALLY_ABORTED;
 221         set_bit(RXRPC_CONN_DONT_REUSE, &conn->flags);
 222         spin_unlock_bh(&conn->state_lock);
 223
 224         msg.msg_name    = &conn->params.peer->srx.transport;
 225         msg.msg_namelen = conn->params.peer->srx.transport_len;
 226         msg.msg_control = NULL;
 227         msg.msg_controllen = 0;
 228         msg.msg_flags   = 0;
 229
 230         whdr.epoch      = htonl(conn->proto.epoch);
 231         whdr.cid        = htonl(conn->proto.cid);
 232         whdr.callNumber = 0;
 233         whdr.seq        = 0;
 234         whdr.type       = RXRPC_PACKET_TYPE_ABORT;
 235         whdr.flags      = conn->out_clientflag;
 236         whdr.userStatus = 0;
 237         whdr.securityIndex = conn->security_ix;
 238         whdr._rsvd      = 0;
 239         whdr.serviceId  = htons(conn->service_id);
 240
 241         word            = htonl(conn->abort_code);
 242
 243         iov[0].iov_base = &whdr;
 244         iov[0].iov_len  = sizeof(whdr);
 245         iov[1].iov_base = &word;
 246         iov[1].iov_len  = sizeof(word);
 247
 248         len = iov[0].iov_len + iov[1].iov_len;
 249
 250         serial = atomic_inc_return(&conn->serial);
 251         rxrpc_abort_calls(conn, RXRPC_CALL_LOCALLY_ABORTED, serial);
 252         whdr.serial = htonl(serial);
 253         _proto("Tx CONN ABORT %%%u { %d }", serial, conn->abort_code);
 254
 255         ret = kernel_sendmsg(conn->params.local->socket, &msg, iov, 2, len);
 256         if (ret < 0) {
 257                 trace_rxrpc_tx_fail(conn->debug_id, serial, ret,
 258                                     rxrpc_tx_point_conn_abort);
 259                 _debug("sendmsg failed: %d", ret);
 260                 return -EAGAIN;
 261         }
 262
 263         trace_rxrpc_tx_packet(conn->debug_id, &whdr, rxrpc_tx_point_conn_abort);
 264
 265         conn->params.peer->last_tx_at = ktime_get_seconds();
 266
 267         _leave(" = 0");
 268         return 0;
 269 }
 270
 271 /*
 272  * mark a call as being on a now-secured channel
 273  * - must be called with BH's disabled.
 274  */
 275 static void rxrpc_call_is_secure(struct rxrpc_call *call)
 276 {
 277         _enter("%p", call);
 278         if (call) {
 279                 write_lock_bh(&call->state_lock);
 280                 if (call->state == RXRPC_CALL_SERVER_SECURING) {
 281                         call->state = RXRPC_CALL_SERVER_RECV_REQUEST;
 282                         rxrpc_notify_socket(call);
 283                 }
 284                 write_unlock_bh(&call->state_lock);
 285         }
 286 }
 287
 288 /*
 289  * connection-level Rx packet processor
 290  */
 291 static int rxrpc_process_event(struct rxrpc_connection *conn,
 292                                struct sk_buff *skb,
 293                                u32 *_abort_code)
 294 {
 295         struct rxrpc_skb_priv *sp = rxrpc_skb(skb);
 296         __be32 wtmp;
 297         u32 abort_code;
 298         int loop, ret;
 299
 300         if (conn->state >= RXRPC_CONN_REMOTELY_ABORTED) {
 301                 _leave(" = -ECONNABORTED [%u]", conn->state);
 302                 return -ECONNABORTED;
 303         }
 304
 305         _enter("{%d},{%u,%%%u},", conn->debug_id, sp->hdr.type, sp->hdr.serial);
 306
 307         switch (sp->hdr.type) {
 308         case RXRPC_PACKET_TYPE_DATA:
 309         case RXRPC_PACKET_TYPE_ACK:
 310                 rxrpc_conn_retransmit_call(conn, skb,
 311                                            sp->hdr.cid & RXRPC_CHANNELMASK);
 312                 return 0;
 313
 314         case RXRPC_PACKET_TYPE_BUSY:
 315                 /* Just ignore BUSY packets for now. */
 316                 return 0;
 317
 318         case RXRPC_PACKET_TYPE_ABORT:
 319                 if (skb_copy_bits(skb, sizeof(struct rxrpc_wire_header),
 320                                   &wtmp, sizeof(wtmp)) < 0) {
 321                         trace_rxrpc_rx_eproto(NULL, sp->hdr.serial,
 322                                               tracepoint_string("bad_abort"));
 323                         return -EPROTO;
 324                 }
 325                 abort_code = ntohl(wtmp);
 326                 _proto("Rx ABORT %%%u { ac=%d }", sp->hdr.serial, abort_code);
 327
 328                 conn->error = -ECONNABORTED;
 329                 conn->abort_code = abort_code;
 330                 conn->state = RXRPC_CONN_REMOTELY_ABORTED;
 331                 set_bit(RXRPC_CONN_DONT_REUSE, &conn->flags);
 332                 rxrpc_abort_calls(conn, RXRPC_CALL_REMOTELY_ABORTED, sp->hdr.serial);
 333                 return -ECONNABORTED;
 334
 335         case RXRPC_PACKET_TYPE_CHALLENGE:
 336                 return conn->security->respond_to_challenge(conn, skb,
 337                                                             _abort_code);
 338
 339         case RXRPC_PACKET_TYPE_RESPONSE:
 340                 ret = conn->security->verify_response(conn, skb, _abort_code);
 341                 if (ret < 0)
 342                         return ret;
 343
 344                 ret = conn->security->init_connection_security(conn);
 345                 if (ret < 0)
 346                         return ret;
 347
 348                 ret = conn->security->prime_packet_security(conn);
 349                 if (ret < 0)
 350                         return ret;
 351
 352                 spin_lock(&conn->bundle->channel_lock);
 353                 spin_lock_bh(&conn->state_lock);
 354
 355                 if (conn->state == RXRPC_CONN_SERVICE_CHALLENGING) {
 356                         conn->state = RXRPC_CONN_SERVICE;
 357                         spin_unlock_bh(&conn->state_lock);
 358                         for (loop = 0; loop < RXRPC_MAXCALLS; loop++)
 359                                 rxrpc_call_is_secure(
 360                                         rcu_dereference_protected(
 361                                                 conn->channels[loop].call,
 362                                                 lockdep_is_held(&conn->bundle->channel_lock)));
 363                 } else {
 364                         spin_unlock_bh(&conn->state_lock);
 365                 }
 366
 367                 spin_unlock(&conn->bundle->channel_lock);
 368                 return 0;
 369
 370         default:
 371                 trace_rxrpc_rx_eproto(NULL, sp->hdr.serial,
 372                                       tracepoint_string("bad_conn_pkt"));
 373                 return -EPROTO;
 374         }
 375 }
 376
 377 /*
 378  * set up security and issue a challenge
 379  */
 380 static void rxrpc_secure_connection(struct rxrpc_connection *conn)
 381 {
 382         u32 abort_code;
 383         int ret;
 384
 385         _enter("{%d}", conn->debug_id);
 386
 387         ASSERT(conn->security_ix != 0);
 388         ASSERT(conn->server_key);
 389
 390         if (conn->security->issue_challenge(conn) < 0) {
 391                 abort_code = RX_CALL_DEAD;
 392                 ret = -ENOMEM;
 393                 goto abort;
 394         }
 395
 396         _leave("");
 397         return;
 398
 399 abort:
 400         _debug("abort %d, %d", ret, abort_code);
 401         rxrpc_abort_connection(conn, ret, abort_code);
 402         _leave(" [aborted]");
 403 }
 404
 405 /*
 406  * Process delayed final ACKs that we haven't subsumed into a subsequent call.
 407  */
 408 void rxrpc_process_delayed_final_acks(struct rxrpc_connection *conn, bool force)
 409 {
 410         unsigned long j = jiffies, next_j;
 411         unsigned int channel;
 412         bool set;
 413
 414 again:
 415         next_j = j + LONG_MAX;
 416         set = false;
 417         for (channel = 0; channel < RXRPC_MAXCALLS; channel++) {
 418                 struct rxrpc_channel *chan = &conn->channels[channel];
 419                 unsigned long ack_at;
 420
 421                 if (!test_bit(RXRPC_CONN_FINAL_ACK_0 + channel, &conn->flags))
 422                         continue;
 423
 424                 smp_rmb(); /* vs rxrpc_disconnect_client_call */
 425                 ack_at = READ_ONCE(chan->final_ack_at);
 426
 427                 if (time_before(j, ack_at) && !force) {
 428                         if (time_before(ack_at, next_j)) {
 429                                 next_j = ack_at;
 430                                 set = true;
 431                         }
 432                         continue;
 433                 }
 434
 435                 if (test_and_clear_bit(RXRPC_CONN_FINAL_ACK_0 + channel,
 436                                        &conn->flags))
 437                         rxrpc_conn_retransmit_call(conn, NULL, channel);
 438         }
 439
 440         j = jiffies;
 441         if (time_before_eq(next_j, j))
 442                 goto again;
 443         if (set)
 444                 rxrpc_reduce_conn_timer(conn, next_j);
 445 }
 446
 447 /*
 448  * connection-level event processor
 449  */
 450 static void rxrpc_do_process_connection(struct rxrpc_connection *conn)
 451 {
 452         struct sk_buff *skb;
 453         u32 abort_code = RX_PROTOCOL_ERROR;
 454         int ret;
 455
 456         if (test_and_clear_bit(RXRPC_CONN_EV_CHALLENGE, &conn->events))
 457                 rxrpc_secure_connection(conn);
 458
 459         /* Process delayed ACKs whose time has come. */
 460         if (conn->flags & RXRPC_CONN_FINAL_ACK_MASK)
 461                 rxrpc_process_delayed_final_acks(conn, false);
 462
 463         /* go through the conn-level event packets, releasing the ref on this
 464          * connection that each one has when we've finished with it */
 465         while ((skb = skb_dequeue(&conn->rx_queue))) {
 466                 rxrpc_see_skb(skb, rxrpc_skb_seen);
 467                 ret = rxrpc_process_event(conn, skb, &abort_code);
 468                 switch (ret) {
 469                 case -EPROTO:
 470                 case -EKEYEXPIRED:
 471                 case -EKEYREJECTED:
 472                         goto protocol_error;
 473                 case -ENOMEM:
 474                 case -EAGAIN:
 475                         goto requeue_and_leave;
 476                 case -ECONNABORTED:
 477                 default:
 478                         rxrpc_free_skb(skb, rxrpc_skb_freed);
 479                         break;
 480                 }
 481         }
 482
 483         return;
 484
 485 requeue_and_leave:
 486         skb_queue_head(&conn->rx_queue, skb);
 487         return;
 488
 489 protocol_error:
 490         if (rxrpc_abort_connection(conn, ret, abort_code) < 0)
 491                 goto requeue_and_leave;
 492         rxrpc_free_skb(skb, rxrpc_skb_freed);
 493         return;
 494 }
 495
 496 void rxrpc_process_connection(struct work_struct *work)
 497 {
 498         struct rxrpc_connection *conn =
 499                 container_of(work, struct rxrpc_connection, processor);
 500
 501         rxrpc_see_connection(conn);
 502
 503         if (__rxrpc_use_local(conn->params.local)) {
 504                 rxrpc_do_process_connection(conn);
 505                 rxrpc_unuse_local(conn->params.local);
 506         }
 507
 508         rxrpc_put_connection(conn);
 509         _leave("");
 510         return;
 511 }