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 ([email protected])
   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->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->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->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         spin_unlock_bh(&conn->state_lock);
 214
 215         msg.msg_name    = &conn->params.peer->srx.transport;
 216         msg.msg_namelen = conn->params.peer->srx.transport_len;
 217         msg.msg_control = NULL;
 218         msg.msg_controllen = 0;
 219         msg.msg_flags   = 0;
 220
 221         whdr.epoch      = htonl(conn->proto.epoch);
 222         whdr.cid        = htonl(conn->proto.cid);
 223         whdr.callNumber = 0;
 224         whdr.seq        = 0;
 225         whdr.type       = RXRPC_PACKET_TYPE_ABORT;
 226         whdr.flags      = conn->out_clientflag;
 227         whdr.userStatus = 0;
 228         whdr.securityIndex = conn->security_ix;
 229         whdr._rsvd      = 0;
 230         whdr.serviceId  = htons(conn->service_id);
 231
 232         word            = htonl(conn->abort_code);
 233
 234         iov[0].iov_base = &whdr;
 235         iov[0].iov_len  = sizeof(whdr);
 236         iov[1].iov_base = &word;
 237         iov[1].iov_len  = sizeof(word);
 238
 239         len = iov[0].iov_len + iov[1].iov_len;
 240
 241         serial = atomic_inc_return(&conn->serial);
 242         rxrpc_abort_calls(conn, RXRPC_CALL_LOCALLY_ABORTED, serial);
 243         whdr.serial = htonl(serial);
 244         _proto("Tx CONN ABORT %%%u { %d }", serial, conn->abort_code);
 245
 246         ret = kernel_sendmsg(conn->params.local->socket, &msg, iov, 2, len);
 247         if (ret < 0) {
 248                 trace_rxrpc_tx_fail(conn->debug_id, serial, ret,
 249                                     rxrpc_tx_point_conn_abort);
 250                 _debug("sendmsg failed: %d", ret);
 251                 return -EAGAIN;
 252         }
 253
 254         trace_rxrpc_tx_packet(conn->debug_id, &whdr, rxrpc_tx_point_conn_abort);
 255
 256         conn->params.peer->last_tx_at = ktime_get_seconds();
 257
 258         _leave(" = 0");
 259         return 0;
 260 }
 261
 262 /*
 263  * mark a call as being on a now-secured channel
 264  * - must be called with BH's disabled.
 265  */
 266 static void rxrpc_call_is_secure(struct rxrpc_call *call)
 267 {
 268         _enter("%p", call);
 269         if (call) {
 270                 write_lock_bh(&call->state_lock);
 271                 if (call->state == RXRPC_CALL_SERVER_SECURING) {
 272                         call->state = RXRPC_CALL_SERVER_ACCEPTING;
 273                         rxrpc_notify_socket(call);
 274                 }
 275                 write_unlock_bh(&call->state_lock);
 276         }
 277 }
 278
 279 /*
 280  * connection-level Rx packet processor
 281  */
 282 static int rxrpc_process_event(struct rxrpc_connection *conn,
 283                                struct sk_buff *skb,
 284                                u32 *_abort_code)
 285 {
 286         struct rxrpc_skb_priv *sp = rxrpc_skb(skb);
 287         __be32 wtmp;
 288         u32 abort_code;
 289         int loop, ret;
 290
 291         if (conn->state >= RXRPC_CONN_REMOTELY_ABORTED) {
 292                 _leave(" = -ECONNABORTED [%u]", conn->state);
 293                 return -ECONNABORTED;
 294         }
 295
 296         _enter("{%d},{%u,%%%u},", conn->debug_id, sp->hdr.type, sp->hdr.serial);
 297
 298         switch (sp->hdr.type) {
 299         case RXRPC_PACKET_TYPE_DATA:
 300         case RXRPC_PACKET_TYPE_ACK:
 301                 rxrpc_conn_retransmit_call(conn, skb,
 302                                            sp->hdr.cid & RXRPC_CHANNELMASK);
 303                 return 0;
 304
 305         case RXRPC_PACKET_TYPE_BUSY:
 306                 /* Just ignore BUSY packets for now. */
 307                 return 0;
 308
 309         case RXRPC_PACKET_TYPE_ABORT:
 310                 if (skb_copy_bits(skb, sizeof(struct rxrpc_wire_header),
 311                                   &wtmp, sizeof(wtmp)) < 0) {
 312                         trace_rxrpc_rx_eproto(NULL, sp->hdr.serial,
 313                                               tracepoint_string("bad_abort"));
 314                         return -EPROTO;
 315                 }
 316                 abort_code = ntohl(wtmp);
 317                 _proto("Rx ABORT %%%u { ac=%d }", sp->hdr.serial, abort_code);
 318
 319                 conn->error = -ECONNABORTED;
 320                 conn->abort_code = abort_code;
 321                 conn->state = RXRPC_CONN_REMOTELY_ABORTED;
 322                 rxrpc_abort_calls(conn, RXRPC_CALL_REMOTELY_ABORTED, sp->hdr.serial);
 323                 return -ECONNABORTED;
 324
 325         case RXRPC_PACKET_TYPE_CHALLENGE:
 326                 return conn->security->respond_to_challenge(conn, skb,
 327                                                             _abort_code);
 328
 329         case RXRPC_PACKET_TYPE_RESPONSE:
 330                 ret = conn->security->verify_response(conn, skb, _abort_code);
 331                 if (ret < 0)
 332                         return ret;
 333
 334                 ret = conn->security->init_connection_security(conn);
 335                 if (ret < 0)
 336                         return ret;
 337
 338                 ret = conn->security->prime_packet_security(conn);
 339                 if (ret < 0)
 340                         return ret;
 341
 342                 spin_lock(&conn->channel_lock);
 343                 spin_lock(&conn->state_lock);
 344
 345                 if (conn->state == RXRPC_CONN_SERVICE_CHALLENGING) {
 346                         conn->state = RXRPC_CONN_SERVICE;
 347                         spin_unlock(&conn->state_lock);
 348                         for (loop = 0; loop < RXRPC_MAXCALLS; loop++)
 349                                 rxrpc_call_is_secure(
 350                                         rcu_dereference_protected(
 351                                                 conn->channels[loop].call,
 352                                                 lockdep_is_held(&conn->channel_lock)));
 353                 } else {
 354                         spin_unlock(&conn->state_lock);
 355                 }
 356
 357                 spin_unlock(&conn->channel_lock);
 358                 return 0;
 359
 360         default:
 361                 trace_rxrpc_rx_eproto(NULL, sp->hdr.serial,
 362                                       tracepoint_string("bad_conn_pkt"));
 363                 return -EPROTO;
 364         }
 365 }
 366
 367 /*
 368  * set up security and issue a challenge
 369  */
 370 static void rxrpc_secure_connection(struct rxrpc_connection *conn)
 371 {
 372         u32 abort_code;
 373         int ret;
 374
 375         _enter("{%d}", conn->debug_id);
 376
 377         ASSERT(conn->security_ix != 0);
 378         ASSERT(conn->server_key);
 379
 380         if (conn->security->issue_challenge(conn) < 0) {
 381                 abort_code = RX_CALL_DEAD;
 382                 ret = -ENOMEM;
 383                 goto abort;
 384         }
 385
 386         _leave("");
 387         return;
 388
 389 abort:
 390         _debug("abort %d, %d", ret, abort_code);
 391         rxrpc_abort_connection(conn, ret, abort_code);
 392         _leave(" [aborted]");
 393 }
 394
 395 /*
 396  * Process delayed final ACKs that we haven't subsumed into a subsequent call.
 397  */
 398 static void rxrpc_process_delayed_final_acks(struct rxrpc_connection *conn)
 399 {
 400         unsigned long j = jiffies, next_j;
 401         unsigned int channel;
 402         bool set;
 403
 404 again:
 405         next_j = j + LONG_MAX;
 406         set = false;
 407         for (channel = 0; channel < RXRPC_MAXCALLS; channel++) {
 408                 struct rxrpc_channel *chan = &conn->channels[channel];
 409                 unsigned long ack_at;
 410
 411                 if (!test_bit(RXRPC_CONN_FINAL_ACK_0 + channel, &conn->flags))
 412                         continue;
 413
 414                 smp_rmb(); /* vs rxrpc_disconnect_client_call */
 415                 ack_at = READ_ONCE(chan->final_ack_at);
 416
 417                 if (time_before(j, ack_at)) {
 418                         if (time_before(ack_at, next_j)) {
 419                                 next_j = ack_at;
 420                                 set = true;
 421                         }
 422                         continue;
 423                 }
 424
 425                 if (test_and_clear_bit(RXRPC_CONN_FINAL_ACK_0 + channel,
 426                                        &conn->flags))
 427                         rxrpc_conn_retransmit_call(conn, NULL, channel);
 428         }
 429
 430         j = jiffies;
 431         if (time_before_eq(next_j, j))
 432                 goto again;
 433         if (set)
 434                 rxrpc_reduce_conn_timer(conn, next_j);
 435 }
 436
 437 /*
 438  * connection-level event processor
 439  */
 440 static void rxrpc_do_process_connection(struct rxrpc_connection *conn)
 441 {
 442         struct sk_buff *skb;
 443         u32 abort_code = RX_PROTOCOL_ERROR;
 444         int ret;
 445
 446         if (test_and_clear_bit(RXRPC_CONN_EV_CHALLENGE, &conn->events))
 447                 rxrpc_secure_connection(conn);
 448
 449         /* Process delayed ACKs whose time has come. */
 450         if (conn->flags & RXRPC_CONN_FINAL_ACK_MASK)
 451                 rxrpc_process_delayed_final_acks(conn);
 452
 453         /* go through the conn-level event packets, releasing the ref on this
 454          * connection that each one has when we've finished with it */
 455         while ((skb = skb_dequeue(&conn->rx_queue))) {
 456                 rxrpc_see_skb(skb, rxrpc_skb_seen);
 457                 ret = rxrpc_process_event(conn, skb, &abort_code);
 458                 switch (ret) {
 459                 case -EPROTO:
 460                 case -EKEYEXPIRED:
 461                 case -EKEYREJECTED:
 462                         goto protocol_error;
 463                 case -ENOMEM:
 464                 case -EAGAIN:
 465                         goto requeue_and_leave;
 466                 case -ECONNABORTED:
 467                 default:
 468                         rxrpc_free_skb(skb, rxrpc_skb_freed);
 469                         break;
 470                 }
 471         }
 472
 473         return;
 474
 475 requeue_and_leave:
 476         skb_queue_head(&conn->rx_queue, skb);
 477         return;
 478
 479 protocol_error:
 480         if (rxrpc_abort_connection(conn, ret, abort_code) < 0)
 481                 goto requeue_and_leave;
 482         rxrpc_free_skb(skb, rxrpc_skb_freed);
 483         return;
 484 }
 485
 486 void rxrpc_process_connection(struct work_struct *work)
 487 {
 488         struct rxrpc_connection *conn =
 489                 container_of(work, struct rxrpc_connection, processor);
 490
 491         rxrpc_see_connection(conn);
 492
 493         if (__rxrpc_use_local(conn->params.local)) {
 494                 rxrpc_do_process_connection(conn);
 495                 rxrpc_unuse_local(conn->params.local);
 496         }
 497
 498         rxrpc_put_connection(conn);
 499         _leave("");
 500         return;
 501 }