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