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->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                         if (rxrpc_set_call_completion(call, compl,
 177                                                       conn->abort_code,
 178                                                       conn->error))
 179                                 rxrpc_notify_socket(call);
 180                 }
 181         }
 182
 183         spin_unlock(&conn->channel_lock);
 184         _leave("");
 185 }
 186
 187 /*
 188  * generate a connection-level abort
 189  */
 190 static int rxrpc_abort_connection(struct rxrpc_connection *conn,
 191                                   int error, u32 abort_code)
 192 {
 193         struct rxrpc_wire_header whdr;
 194         struct msghdr msg;
 195         struct kvec iov[2];
 196         __be32 word;
 197         size_t len;
 198         u32 serial;
 199         int ret;
 200
 201         _enter("%d,,%u,%u", conn->debug_id, error, abort_code);
 202
 203         /* generate a connection-level abort */
 204         spin_lock_bh(&conn->state_lock);
 205         if (conn->state >= RXRPC_CONN_REMOTELY_ABORTED) {
 206                 spin_unlock_bh(&conn->state_lock);
 207                 _leave(" = 0 [already dead]");
 208                 return 0;
 209         }
 210
 211         conn->error = error;
 212         conn->abort_code = abort_code;
 213         conn->state = RXRPC_CONN_LOCALLY_ABORTED;
 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_ACCEPTING;
 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                 rxrpc_abort_calls(conn, RXRPC_CALL_REMOTELY_ABORTED, sp->hdr.serial);
 324                 return -ECONNABORTED;
 325
 326         case RXRPC_PACKET_TYPE_CHALLENGE:
 327                 return conn->security->respond_to_challenge(conn, skb,
 328                                                             _abort_code);
 329
 330         case RXRPC_PACKET_TYPE_RESPONSE:
 331                 ret = conn->security->verify_response(conn, skb, _abort_code);
 332                 if (ret < 0)
 333                         return ret;
 334
 335                 ret = conn->security->init_connection_security(conn);
 336                 if (ret < 0)
 337                         return ret;
 338
 339                 ret = conn->security->prime_packet_security(conn);
 340                 if (ret < 0)
 341                         return ret;
 342
 343                 spin_lock(&conn->channel_lock);
 344                 spin_lock(&conn->state_lock);
 345
 346                 if (conn->state == RXRPC_CONN_SERVICE_CHALLENGING) {
 347                         conn->state = RXRPC_CONN_SERVICE;
 348                         spin_unlock(&conn->state_lock);
 349                         for (loop = 0; loop < RXRPC_MAXCALLS; loop++)
 350                                 rxrpc_call_is_secure(
 351                                         rcu_dereference_protected(
 352                                                 conn->channels[loop].call,
 353                                                 lockdep_is_held(&conn->channel_lock)));
 354                 } else {
 355                         spin_unlock(&conn->state_lock);
 356                 }
 357
 358                 spin_unlock(&conn->channel_lock);
 359                 return 0;
 360
 361         default:
 362                 trace_rxrpc_rx_eproto(NULL, sp->hdr.serial,
 363                                       tracepoint_string("bad_conn_pkt"));
 364                 return -EPROTO;
 365         }
 366 }
 367
 368 /*
 369  * set up security and issue a challenge
 370  */
 371 static void rxrpc_secure_connection(struct rxrpc_connection *conn)
 372 {
 373         u32 abort_code;
 374         int ret;
 375
 376         _enter("{%d}", conn->debug_id);
 377
 378         ASSERT(conn->security_ix != 0);
 379         ASSERT(conn->server_key);
 380
 381         if (conn->security->issue_challenge(conn) < 0) {
 382                 abort_code = RX_CALL_DEAD;
 383                 ret = -ENOMEM;
 384                 goto abort;
 385         }
 386
 387         _leave("");
 388         return;
 389
 390 abort:
 391         _debug("abort %d, %d", ret, abort_code);
 392         rxrpc_abort_connection(conn, ret, abort_code);
 393         _leave(" [aborted]");
 394 }
 395
 396 /*
 397  * Process delayed final ACKs that we haven't subsumed into a subsequent call.
 398  */
 399 static void rxrpc_process_delayed_final_acks(struct rxrpc_connection *conn)
 400 {
 401         unsigned long j = jiffies, next_j;
 402         unsigned int channel;
 403         bool set;
 404
 405 again:
 406         next_j = j + LONG_MAX;
 407         set = false;
 408         for (channel = 0; channel < RXRPC_MAXCALLS; channel++) {
 409                 struct rxrpc_channel *chan = &conn->channels[channel];
 410                 unsigned long ack_at;
 411
 412                 if (!test_bit(RXRPC_CONN_FINAL_ACK_0 + channel, &conn->flags))
 413                         continue;
 414
 415                 smp_rmb(); /* vs rxrpc_disconnect_client_call */
 416                 ack_at = READ_ONCE(chan->final_ack_at);
 417
 418                 if (time_before(j, ack_at)) {
 419                         if (time_before(ack_at, next_j)) {
 420                                 next_j = ack_at;
 421                                 set = true;
 422                         }
 423                         continue;
 424                 }
 425
 426                 if (test_and_clear_bit(RXRPC_CONN_FINAL_ACK_0 + channel,
 427                                        &conn->flags))
 428                         rxrpc_conn_retransmit_call(conn, NULL, channel);
 429         }
 430
 431         j = jiffies;
 432         if (time_before_eq(next_j, j))
 433                 goto again;
 434         if (set)
 435                 rxrpc_reduce_conn_timer(conn, next_j);
 436 }
 437
 438 /*
 439  * connection-level event processor
 440  */
 441 static void rxrpc_do_process_connection(struct rxrpc_connection *conn)
 442 {
 443         struct sk_buff *skb;
 444         u32 abort_code = RX_PROTOCOL_ERROR;
 445         int ret;
 446
 447         if (test_and_clear_bit(RXRPC_CONN_EV_CHALLENGE, &conn->events))
 448                 rxrpc_secure_connection(conn);
 449
 450         /* Process delayed ACKs whose time has come. */
 451         if (conn->flags & RXRPC_CONN_FINAL_ACK_MASK)
 452                 rxrpc_process_delayed_final_acks(conn);
 453
 454         /* go through the conn-level event packets, releasing the ref on this
 455          * connection that each one has when we've finished with it */
 456         while ((skb = skb_dequeue(&conn->rx_queue))) {
 457                 rxrpc_see_skb(skb, rxrpc_skb_seen);
 458                 ret = rxrpc_process_event(conn, skb, &abort_code);
 459                 switch (ret) {
 460                 case -EPROTO:
 461                 case -EKEYEXPIRED:
 462                 case -EKEYREJECTED:
 463                         goto protocol_error;
 464                 case -ENOMEM:
 465                 case -EAGAIN:
 466                         goto requeue_and_leave;
 467                 case -ECONNABORTED:
 468                 default:
 469                         rxrpc_free_skb(skb, rxrpc_skb_freed);
 470                         break;
 471                 }
 472         }
 473
 474         return;
 475
 476 requeue_and_leave:
 477         skb_queue_head(&conn->rx_queue, skb);
 478         return;
 479
 480 protocol_error:
 481         if (rxrpc_abort_connection(conn, ret, abort_code) < 0)
 482                 goto requeue_and_leave;
 483         rxrpc_free_skb(skb, rxrpc_skb_freed);
 484         return;
 485 }
 486
 487 void rxrpc_process_connection(struct work_struct *work)
 488 {
 489         struct rxrpc_connection *conn =
 490                 container_of(work, struct rxrpc_connection, processor);
 491
 492         rxrpc_see_connection(conn);
 493
 494         if (__rxrpc_use_local(conn->params.local)) {
 495                 rxrpc_do_process_connection(conn);
 496                 rxrpc_unuse_local(conn->params.local);
 497         }
 498
 499         rxrpc_put_connection(conn);
 500         _leave("");
 501         return;
 502 }