net/rxrpc/conn_event.c

   1 /* connection-level event handling
   2  *
   3  * Copyright (C) 2007 Red Hat, Inc. All Rights Reserved.
   4  * Written by David Howells (dhowells@redhat.com)
   5  *
   6  * This program is free software; you can redistribute it and/or
   7  * modify it under the terms of the GNU General Public License
   8  * as published by the Free Software Foundation; either version
   9  * 2 of the License, or (at your option) any later version.
  10  */
  11
  12 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
  13
  14 #include <linux/module.h>
  15 #include <linux/net.h>
  16 #include <linux/skbuff.h>
  17 #include <linux/errqueue.h>
  18 #include <net/sock.h>
  19 #include <net/af_rxrpc.h>
  20 #include <net/ip.h>
  21 #include "ar-internal.h"
  22
  23 /*
  24  * Retransmit terminal ACK or ABORT of the previous call.
  25  */
  26 static void rxrpc_conn_retransmit_call(struct rxrpc_connection *conn,
  27                                        struct sk_buff *skb,
  28                                        unsigned int channel)
  29 {
  30         struct rxrpc_skb_priv *sp = skb ? rxrpc_skb(skb) : NULL;
  31         struct rxrpc_channel *chan;
  32         struct msghdr msg;
  33         struct kvec iov[3];
  34         struct {
  35                 struct rxrpc_wire_header whdr;
  36                 union {
  37                         __be32 abort_code;
  38                         struct rxrpc_ackpacket ack;
  39                 };
  40         } __attribute__((packed)) pkt;
  41         struct rxrpc_ackinfo ack_info;
  42         size_t len;
  43         int ret, ioc;
  44         u32 serial, mtu, call_id, padding;
  45
  46         _enter("%d", conn->debug_id);
  47
  48         if (sp && sp->hdr.type == RXRPC_PACKET_TYPE_ACK) {
  49                 if (skb_copy_bits(skb, sizeof(struct rxrpc_wire_header),
  50                                   &pkt.ack, sizeof(pkt.ack)) < 0)
  51                         return;
  52                 if (pkt.ack.reason == RXRPC_ACK_PING_RESPONSE)
  53                         return;
  54         }
  55
  56         chan = &conn->channels[channel];
  57
  58         /* If the last call got moved on whilst we were waiting to run, just
  59          * ignore this packet.
  60          */
  61         call_id = READ_ONCE(chan->last_call);
  62         /* Sync with __rxrpc_disconnect_call() */
  63         smp_rmb();
  64         if (skb && call_id != sp->hdr.callNumber)
  65                 return;
  66
  67         msg.msg_name    = &conn->params.peer->srx.transport;
  68         msg.msg_namelen = conn->params.peer->srx.transport_len;
  69         msg.msg_control = NULL;
  70         msg.msg_controllen = 0;
  71         msg.msg_flags   = 0;
  72
  73         iov[0].iov_base = &pkt;
  74         iov[0].iov_len  = sizeof(pkt.whdr);
  75         iov[1].iov_base = &padding;
  76         iov[1].iov_len  = 3;
  77         iov[2].iov_base = &ack_info;
  78         iov[2].iov_len  = sizeof(ack_info);
  79
  80         pkt.whdr.epoch          = htonl(conn->proto.epoch);
  81         pkt.whdr.cid            = htonl(conn->proto.cid | channel);
  82         pkt.whdr.callNumber     = htonl(call_id);
  83         pkt.whdr.seq            = 0;
  84         pkt.whdr.type           = chan->last_type;
  85         pkt.whdr.flags          = conn->out_clientflag;
  86         pkt.whdr.userStatus     = 0;
  87         pkt.whdr.securityIndex  = conn->security_ix;
  88         pkt.whdr._rsvd          = 0;
  89         pkt.whdr.serviceId      = htons(conn->service_id);
  90
  91         len = sizeof(pkt.whdr);
  92         switch (chan->last_type) {
  93         case RXRPC_PACKET_TYPE_ABORT:
  94                 pkt.abort_code  = htonl(chan->last_abort);
  95                 iov[0].iov_len += sizeof(pkt.abort_code);
  96                 len += sizeof(pkt.abort_code);
  97                 ioc = 1;
  98                 break;
  99
 100         case RXRPC_PACKET_TYPE_ACK:
 101                 mtu = conn->params.peer->if_mtu;
 102                 mtu -= conn->params.peer->hdrsize;
 103                 pkt.ack.bufferSpace     = 0;
 104                 pkt.ack.maxSkew         = htons(skb ? skb->priority : 0);
 105                 pkt.ack.firstPacket     = htonl(chan->last_seq + 1);
 106                 pkt.ack.previousPacket  = htonl(chan->last_seq);
 107                 pkt.ack.serial          = htonl(skb ? sp->hdr.serial : 0);
 108                 pkt.ack.reason          = skb ? RXRPC_ACK_DUPLICATE : RXRPC_ACK_IDLE;
 109                 pkt.ack.nAcks           = 0;
 110                 ack_info.rxMTU          = htonl(rxrpc_rx_mtu);
 111                 ack_info.maxMTU         = htonl(mtu);
 112                 ack_info.rwind          = htonl(rxrpc_rx_window_size);
 113                 ack_info.jumbo_max      = htonl(rxrpc_rx_jumbo_max);
 114                 pkt.whdr.flags          |= RXRPC_SLOW_START_OK;
 115                 padding                 = 0;
 116                 iov[0].iov_len += sizeof(pkt.ack);
 117                 len += sizeof(pkt.ack) + 3 + sizeof(ack_info);
 118                 ioc = 3;
 119                 break;
 120
 121         default:
 122                 return;
 123         }
 124
 125         /* Resync with __rxrpc_disconnect_call() and check that the last call
 126          * didn't get advanced whilst we were filling out the packets.
 127          */
 128         smp_rmb();
 129         if (READ_ONCE(chan->last_call) != call_id)
 130                 return;
 131
 132         serial = atomic_inc_return(&conn->serial);
 133         pkt.whdr.serial = htonl(serial);
 134
 135         switch (chan->last_type) {
 136         case RXRPC_PACKET_TYPE_ABORT:
 137                 _proto("Tx ABORT %%%u { %d } [re]", serial, conn->abort_code);
 138                 break;
 139         case RXRPC_PACKET_TYPE_ACK:
 140                 trace_rxrpc_tx_ack(chan->call_debug_id, serial,
 141                                    ntohl(pkt.ack.firstPacket),
 142                                    ntohl(pkt.ack.serial),
 143                                    pkt.ack.reason, 0);
 144                 _proto("Tx ACK %%%u [re]", serial);
 145                 break;
 146         }
 147
 148         ret = kernel_sendmsg(conn->params.local->socket, &msg, iov, ioc, len);
 149         conn->params.peer->last_tx_at = ktime_get_seconds();
 150         if (ret < 0)
 151                 trace_rxrpc_tx_fail(chan->call_debug_id, serial, ret,
 152                                     rxrpc_tx_point_call_final_resend);
 153         else
 154                 trace_rxrpc_tx_packet(chan->call_debug_id, &pkt.whdr,
 155                                       rxrpc_tx_point_call_final_resend);
 156
 157         _leave("");
 158 }
 159
 160 /*
 161  * pass a connection-level abort onto all calls on that connection
 162  */
 163 static void rxrpc_abort_calls(struct rxrpc_connection *conn,
 164                               enum rxrpc_call_completion compl)
 165 {
 166         struct rxrpc_call *call;
 167         int i;
 168
 169         _enter("{%d},%x", conn->debug_id, conn->abort_code);
 170
 171         spin_lock(&conn->channel_lock);
 172
 173         for (i = 0; i < RXRPC_MAXCALLS; i++) {
 174                 call = rcu_dereference_protected(
 175                         conn->channels[i].call,
 176                         lockdep_is_held(&conn->channel_lock));
 177                 if (call) {
 178                         if (compl == RXRPC_CALL_LOCALLY_ABORTED)
 179                                 trace_rxrpc_abort(call->debug_id,
 180                                                   "CON", call->cid,
 181                                                   call->call_id, 0,
 182                                                   conn->abort_code,
 183                                                   conn->error);
 184                         if (rxrpc_set_call_completion(call, compl,
 185                                                       conn->abort_code,
 186                                                       conn->error))
 187                                 rxrpc_notify_socket(call);
 188                 }
 189         }
 190
 191         spin_unlock(&conn->channel_lock);
 192         _leave("");
 193 }
 194
 195 /*
 196  * generate a connection-level abort
 197  */
 198 static int rxrpc_abort_connection(struct rxrpc_connection *conn,
 199                                   int error, u32 abort_code)
 200 {
 201         struct rxrpc_wire_header whdr;
 202         struct msghdr msg;
 203         struct kvec iov[2];
 204         __be32 word;
 205         size_t len;
 206         u32 serial;
 207         int ret;
 208
 209         _enter("%d,,%u,%u", conn->debug_id, error, abort_code);
 210
 211         /* generate a connection-level abort */
 212         spin_lock_bh(&conn->state_lock);
 213         if (conn->state >= RXRPC_CONN_REMOTELY_ABORTED) {
 214                 spin_unlock_bh(&conn->state_lock);
 215                 _leave(" = 0 [already dead]");
 216                 return 0;
 217         }
 218
 219         conn->error = error;
 220         conn->abort_code = abort_code;
 221         conn->state = RXRPC_CONN_LOCALLY_ABORTED;
 222         spin_unlock_bh(&conn->state_lock);
 223
 224         rxrpc_abort_calls(conn, RXRPC_CALL_LOCALLY_ABORTED);
 225
 226         msg.msg_name    = &conn->params.peer->srx.transport;
 227         msg.msg_namelen = conn->params.peer->srx.transport_len;
 228         msg.msg_control = NULL;
 229         msg.msg_controllen = 0;
 230         msg.msg_flags   = 0;
 231
 232         whdr.epoch      = htonl(conn->proto.epoch);
 233         whdr.cid        = htonl(conn->proto.cid);
 234         whdr.callNumber = 0;
 235         whdr.seq        = 0;
 236         whdr.type       = RXRPC_PACKET_TYPE_ABORT;
 237         whdr.flags      = conn->out_clientflag;
 238         whdr.userStatus = 0;
 239         whdr.securityIndex = conn->security_ix;
 240         whdr._rsvd      = 0;
 241         whdr.serviceId  = htons(conn->service_id);
 242
 243         word            = htonl(conn->abort_code);
 244
 245         iov[0].iov_base = &whdr;
 246         iov[0].iov_len  = sizeof(whdr);
 247         iov[1].iov_base = &word;
 248         iov[1].iov_len  = sizeof(word);
 249
 250         len = iov[0].iov_len + iov[1].iov_len;
 251
 252         serial = atomic_inc_return(&conn->serial);
 253         whdr.serial = htonl(serial);
 254         _proto("Tx CONN ABORT %%%u { %d }", serial, conn->abort_code);
 255
 256         ret = kernel_sendmsg(conn->params.local->socket, &msg, iov, 2, len);
 257         if (ret < 0) {
 258                 trace_rxrpc_tx_fail(conn->debug_id, serial, ret,
 259                                     rxrpc_tx_point_conn_abort);
 260                 _debug("sendmsg failed: %d", ret);
 261                 return -EAGAIN;
 262         }
 263
 264         trace_rxrpc_tx_packet(conn->debug_id, &whdr, rxrpc_tx_point_conn_abort);
 265
 266         conn->params.peer->last_tx_at = ktime_get_seconds();
 267
 268         _leave(" = 0");
 269         return 0;
 270 }
 271
 272 /*
 273  * mark a call as being on a now-secured channel
 274  * - must be called with BH's disabled.
 275  */
 276 static void rxrpc_call_is_secure(struct rxrpc_call *call)
 277 {
 278         _enter("%p", call);
 279         if (call) {
 280                 write_lock_bh(&call->state_lock);
 281                 if (call->state == RXRPC_CALL_SERVER_SECURING) {
 282                         call->state = RXRPC_CALL_SERVER_ACCEPTING;
 283                         rxrpc_notify_socket(call);
 284                 }
 285                 write_unlock_bh(&call->state_lock);
 286         }
 287 }
 288
 289 /*
 290  * connection-level Rx packet processor
 291  */
 292 static int rxrpc_process_event(struct rxrpc_connection *conn,
 293                                struct sk_buff *skb,
 294                                u32 *_abort_code)
 295 {
 296         struct rxrpc_skb_priv *sp = rxrpc_skb(skb);
 297         __be32 wtmp;
 298         u32 abort_code;
 299         int loop, ret;
 300
 301         if (conn->state >= RXRPC_CONN_REMOTELY_ABORTED) {
 302                 _leave(" = -ECONNABORTED [%u]", conn->state);
 303                 return -ECONNABORTED;
 304         }
 305
 306         _enter("{%d},{%u,%%%u},", conn->debug_id, sp->hdr.type, sp->hdr.serial);
 307
 308         switch (sp->hdr.type) {
 309         case RXRPC_PACKET_TYPE_DATA:
 310         case RXRPC_PACKET_TYPE_ACK:
 311                 rxrpc_conn_retransmit_call(conn, skb,
 312                                            sp->hdr.cid & RXRPC_CHANNELMASK);
 313                 return 0;
 314
 315         case RXRPC_PACKET_TYPE_BUSY:
 316                 /* Just ignore BUSY packets for now. */
 317                 return 0;
 318
 319         case RXRPC_PACKET_TYPE_ABORT:
 320                 if (skb_copy_bits(skb, sizeof(struct rxrpc_wire_header),
 321                                   &wtmp, sizeof(wtmp)) < 0) {
 322                         trace_rxrpc_rx_eproto(NULL, sp->hdr.serial,
 323                                               tracepoint_string("bad_abort"));
 324                         return -EPROTO;
 325                 }
 326                 abort_code = ntohl(wtmp);
 327                 _proto("Rx ABORT %%%u { ac=%d }", sp->hdr.serial, abort_code);
 328
 329                 conn->error = -ECONNABORTED;
 330                 conn->abort_code = abort_code;
 331                 conn->state = RXRPC_CONN_REMOTELY_ABORTED;
 332                 rxrpc_abort_calls(conn, RXRPC_CALL_REMOTELY_ABORTED);
 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->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->channel_lock)));
 363                 } else {
 364                         spin_unlock_bh(&conn->state_lock);
 365                 }
 366
 367                 spin_unlock(&conn->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
 389         if (!conn->params.key) {
 390                 _debug("set up security");
 391                 ret = rxrpc_init_server_conn_security(conn);
 392                 switch (ret) {
 393                 case 0:
 394                         break;
 395                 case -ENOENT:
 396                         abort_code = RX_CALL_DEAD;
 397                         goto abort;
 398                 default:
 399                         abort_code = RXKADNOAUTH;
 400                         goto abort;
 401                 }
 402         }
 403
 404         if (conn->security->issue_challenge(conn) < 0) {
 405                 abort_code = RX_CALL_DEAD;
 406                 ret = -ENOMEM;
 407                 goto abort;
 408         }
 409
 410         _leave("");
 411         return;
 412
 413 abort:
 414         _debug("abort %d, %d", ret, abort_code);
 415         rxrpc_abort_connection(conn, ret, abort_code);
 416         _leave(" [aborted]");
 417 }
 418
 419 /*
 420  * Process delayed final ACKs that we haven't subsumed into a subsequent call.
 421  */
 422 static void rxrpc_process_delayed_final_acks(struct rxrpc_connection *conn)
 423 {
 424         unsigned long j = jiffies, next_j;
 425         unsigned int channel;
 426         bool set;
 427
 428 again:
 429         next_j = j + LONG_MAX;
 430         set = false;
 431         for (channel = 0; channel < RXRPC_MAXCALLS; channel++) {
 432                 struct rxrpc_channel *chan = &conn->channels[channel];
 433                 unsigned long ack_at;
 434
 435                 if (!test_bit(RXRPC_CONN_FINAL_ACK_0 + channel, &conn->flags))
 436                         continue;
 437
 438                 smp_rmb(); /* vs rxrpc_disconnect_client_call */
 439                 ack_at = READ_ONCE(chan->final_ack_at);
 440
 441                 if (time_before(j, ack_at)) {
 442                         if (time_before(ack_at, next_j)) {
 443                                 next_j = ack_at;
 444                                 set = true;
 445                         }
 446                         continue;
 447                 }
 448
 449                 if (test_and_clear_bit(RXRPC_CONN_FINAL_ACK_0 + channel,
 450                                        &conn->flags))
 451                         rxrpc_conn_retransmit_call(conn, NULL, channel);
 452         }
 453
 454         j = jiffies;
 455         if (time_before_eq(next_j, j))
 456                 goto again;
 457         if (set)
 458                 rxrpc_reduce_conn_timer(conn, next_j);
 459 }
 460
 461 /*
 462  * connection-level event processor
 463  */
 464 static void rxrpc_do_process_connection(struct rxrpc_connection *conn)
 465 {
 466         struct sk_buff *skb;
 467         u32 abort_code = RX_PROTOCOL_ERROR;
 468         int ret;
 469
 470         if (test_and_clear_bit(RXRPC_CONN_EV_CHALLENGE, &conn->events))
 471                 rxrpc_secure_connection(conn);
 472
 473         /* Process delayed ACKs whose time has come. */
 474         if (conn->flags & RXRPC_CONN_FINAL_ACK_MASK)
 475                 rxrpc_process_delayed_final_acks(conn);
 476
 477         /* go through the conn-level event packets, releasing the ref on this
 478          * connection that each one has when we've finished with it */
 479         while ((skb = skb_dequeue(&conn->rx_queue))) {
 480                 rxrpc_see_skb(skb, rxrpc_skb_rx_seen);
 481                 ret = rxrpc_process_event(conn, skb, &abort_code);
 482                 switch (ret) {
 483                 case -EPROTO:
 484                 case -EKEYEXPIRED:
 485                 case -EKEYREJECTED:
 486                         goto protocol_error;
 487                 case -ENOMEM:
 488                 case -EAGAIN:
 489                         goto requeue_and_leave;
 490                 case -ECONNABORTED:
 491                 default:
 492                         rxrpc_free_skb(skb, rxrpc_skb_rx_freed);
 493                         break;
 494                 }
 495         }
 496
 497         return;
 498
 499 requeue_and_leave:
 500         skb_queue_head(&conn->rx_queue, skb);
 501         return;
 502
 503 protocol_error:
 504         if (rxrpc_abort_connection(conn, ret, abort_code) < 0)
 505                 goto requeue_and_leave;
 506         rxrpc_free_skb(skb, rxrpc_skb_rx_freed);
 507         return;
 508 }
 509
 510 void rxrpc_process_connection(struct work_struct *work)
 511 {
 512         struct rxrpc_connection *conn =
 513                 container_of(work, struct rxrpc_connection, processor);
 514
 515         rxrpc_see_connection(conn);
 516
 517         if (__rxrpc_use_local(conn->params.local)) {
 518                 rxrpc_do_process_connection(conn);
 519                 rxrpc_unuse_local(conn->params.local);
 520         }
 521
 522         rxrpc_put_connection(conn);
 523         _leave("");
 524         return;
 525 }
 526