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->abort_code);
 130                 break;
 131         case RXRPC_PACKET_TYPE_ACK:
 132                 trace_rxrpc_tx_ack(chan->call_debug_id, serial,
 133                                    ntohl(pkt.ack.firstPacket),
 134                                    ntohl(pkt.ack.serial),
 135                                    pkt.ack.reason, 0);
 136                 _proto("Tx ACK %%%u [re]", serial);
 137                 break;
 138         }
 139
 140         ret = kernel_sendmsg(conn->params.local->socket, &msg, iov, ioc, len);
 141         conn->params.peer->last_tx_at = ktime_get_seconds();
 142         if (ret < 0)
 143                 trace_rxrpc_tx_fail(chan->call_debug_id, serial, ret,
 144                                     rxrpc_tx_point_call_final_resend);
 145         else
 146                 trace_rxrpc_tx_packet(chan->call_debug_id, &pkt.whdr,
 147                                       rxrpc_tx_point_call_final_resend);
 148
 149         _leave("");
 150 }
 151
 152 /*
 153  * pass a connection-level abort onto all calls on that connection
 154  */
 155 static void rxrpc_abort_calls(struct rxrpc_connection *conn,
 156                               enum rxrpc_call_completion compl)
 157 {
 158         struct rxrpc_call *call;
 159         int i;
 160
 161         _enter("{%d},%x", conn->debug_id, conn->abort_code);
 162
 163         spin_lock(&conn->channel_lock);
 164
 165         for (i = 0; i < RXRPC_MAXCALLS; i++) {
 166                 call = rcu_dereference_protected(
 167                         conn->channels[i].call,
 168                         lockdep_is_held(&conn->channel_lock));
 169                 if (call) {
 170                         if (compl == RXRPC_CALL_LOCALLY_ABORTED)
 171                                 trace_rxrpc_abort(call->debug_id,
 172                                                   "CON", call->cid,
 173                                                   call->call_id, 0,
 174                                                   conn->abort_code,
 175                                                   conn->error);
 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         rxrpc_abort_calls(conn, RXRPC_CALL_LOCALLY_ABORTED);
 217
 218         msg.msg_name    = &conn->params.peer->srx.transport;
 219         msg.msg_namelen = conn->params.peer->srx.transport_len;
 220         msg.msg_control = NULL;
 221         msg.msg_controllen = 0;
 222         msg.msg_flags   = 0;
 223
 224         whdr.epoch      = htonl(conn->proto.epoch);
 225         whdr.cid        = htonl(conn->proto.cid);
 226         whdr.callNumber = 0;
 227         whdr.seq        = 0;
 228         whdr.type       = RXRPC_PACKET_TYPE_ABORT;
 229         whdr.flags      = conn->out_clientflag;
 230         whdr.userStatus = 0;
 231         whdr.securityIndex = conn->security_ix;
 232         whdr._rsvd      = 0;
 233         whdr.serviceId  = htons(conn->service_id);
 234
 235         word            = htonl(conn->abort_code);
 236
 237         iov[0].iov_base = &whdr;
 238         iov[0].iov_len  = sizeof(whdr);
 239         iov[1].iov_base = &word;
 240         iov[1].iov_len  = sizeof(word);
 241
 242         len = iov[0].iov_len + iov[1].iov_len;
 243
 244         serial = atomic_inc_return(&conn->serial);
 245         whdr.serial = htonl(serial);
 246         _proto("Tx CONN ABORT %%%u { %d }", serial, conn->abort_code);
 247
 248         ret = kernel_sendmsg(conn->params.local->socket, &msg, iov, 2, len);
 249         if (ret < 0) {
 250                 trace_rxrpc_tx_fail(conn->debug_id, serial, ret,
 251                                     rxrpc_tx_point_conn_abort);
 252                 _debug("sendmsg failed: %d", ret);
 253                 return -EAGAIN;
 254         }
 255
 256         trace_rxrpc_tx_packet(conn->debug_id, &whdr, rxrpc_tx_point_conn_abort);
 257
 258         conn->params.peer->last_tx_at = ktime_get_seconds();
 259
 260         _leave(" = 0");
 261         return 0;
 262 }
 263
 264 /*
 265  * mark a call as being on a now-secured channel
 266  * - must be called with BH's disabled.
 267  */
 268 static void rxrpc_call_is_secure(struct rxrpc_call *call)
 269 {
 270         _enter("%p", call);
 271         if (call) {
 272                 write_lock_bh(&call->state_lock);
 273                 if (call->state == RXRPC_CALL_SERVER_SECURING) {
 274                         call->state = RXRPC_CALL_SERVER_ACCEPTING;
 275                         rxrpc_notify_socket(call);
 276                 }
 277                 write_unlock_bh(&call->state_lock);
 278         }
 279 }
 280
 281 /*
 282  * connection-level Rx packet processor
 283  */
 284 static int rxrpc_process_event(struct rxrpc_connection *conn,
 285                                struct sk_buff *skb,
 286                                u32 *_abort_code)
 287 {
 288         struct rxrpc_skb_priv *sp = rxrpc_skb(skb);
 289         __be32 wtmp;
 290         u32 abort_code;
 291         int loop, ret;
 292
 293         if (conn->state >= RXRPC_CONN_REMOTELY_ABORTED) {
 294                 _leave(" = -ECONNABORTED [%u]", conn->state);
 295                 return -ECONNABORTED;
 296         }
 297
 298         _enter("{%d},{%u,%%%u},", conn->debug_id, sp->hdr.type, sp->hdr.serial);
 299
 300         switch (sp->hdr.type) {
 301         case RXRPC_PACKET_TYPE_DATA:
 302         case RXRPC_PACKET_TYPE_ACK:
 303                 rxrpc_conn_retransmit_call(conn, skb,
 304                                            sp->hdr.cid & RXRPC_CHANNELMASK);
 305                 return 0;
 306
 307         case RXRPC_PACKET_TYPE_BUSY:
 308                 /* Just ignore BUSY packets for now. */
 309                 return 0;
 310
 311         case RXRPC_PACKET_TYPE_ABORT:
 312                 if (skb_copy_bits(skb, sizeof(struct rxrpc_wire_header),
 313                                   &wtmp, sizeof(wtmp)) < 0) {
 314                         trace_rxrpc_rx_eproto(NULL, sp->hdr.serial,
 315                                               tracepoint_string("bad_abort"));
 316                         return -EPROTO;
 317                 }
 318                 abort_code = ntohl(wtmp);
 319                 _proto("Rx ABORT %%%u { ac=%d }", sp->hdr.serial, abort_code);
 320
 321                 conn->error = -ECONNABORTED;
 322                 conn->abort_code = abort_code;
 323                 conn->state = RXRPC_CONN_REMOTELY_ABORTED;
 324                 rxrpc_abort_calls(conn, RXRPC_CALL_REMOTELY_ABORTED);
 325                 return -ECONNABORTED;
 326
 327         case RXRPC_PACKET_TYPE_CHALLENGE:
 328                 return conn->security->respond_to_challenge(conn, skb,
 329                                                             _abort_code);
 330
 331         case RXRPC_PACKET_TYPE_RESPONSE:
 332                 ret = conn->security->verify_response(conn, skb, _abort_code);
 333                 if (ret < 0)
 334                         return ret;
 335
 336                 ret = conn->security->init_connection_security(conn);
 337                 if (ret < 0)
 338                         return ret;
 339
 340                 ret = conn->security->prime_packet_security(conn);
 341                 if (ret < 0)
 342                         return ret;
 343
 344                 spin_lock(&conn->channel_lock);
 345                 spin_lock(&conn->state_lock);
 346
 347                 if (conn->state == RXRPC_CONN_SERVICE_CHALLENGING) {
 348                         conn->state = RXRPC_CONN_SERVICE;
 349                         spin_unlock(&conn->state_lock);
 350                         for (loop = 0; loop < RXRPC_MAXCALLS; loop++)
 351                                 rxrpc_call_is_secure(
 352                                         rcu_dereference_protected(
 353                                                 conn->channels[loop].call,
 354                                                 lockdep_is_held(&conn->channel_lock)));
 355                 } else {
 356                         spin_unlock(&conn->state_lock);
 357                 }
 358
 359                 spin_unlock(&conn->channel_lock);
 360                 return 0;
 361
 362         default:
 363                 trace_rxrpc_rx_eproto(NULL, sp->hdr.serial,
 364                                       tracepoint_string("bad_conn_pkt"));
 365                 return -EPROTO;
 366         }
 367 }
 368
 369 /*
 370  * set up security and issue a challenge
 371  */
 372 static void rxrpc_secure_connection(struct rxrpc_connection *conn)
 373 {
 374         u32 abort_code;
 375         int ret;
 376
 377         _enter("{%d}", conn->debug_id);
 378
 379         ASSERT(conn->security_ix != 0);
 380
 381         if (!conn->params.key) {
 382                 _debug("set up security");
 383                 ret = rxrpc_init_server_conn_security(conn);
 384                 switch (ret) {
 385                 case 0:
 386                         break;
 387                 case -ENOENT:
 388                         abort_code = RX_CALL_DEAD;
 389                         goto abort;
 390                 default:
 391                         abort_code = RXKADNOAUTH;
 392                         goto abort;
 393                 }
 394         }
 395
 396         if (conn->security->issue_challenge(conn) < 0) {
 397                 abort_code = RX_CALL_DEAD;
 398                 ret = -ENOMEM;
 399                 goto abort;
 400         }
 401
 402         _leave("");
 403         return;
 404
 405 abort:
 406         _debug("abort %d, %d", ret, abort_code);
 407         rxrpc_abort_connection(conn, ret, abort_code);
 408         _leave(" [aborted]");
 409 }
 410
 411 /*
 412  * Process delayed final ACKs that we haven't subsumed into a subsequent call.
 413  */
 414 static void rxrpc_process_delayed_final_acks(struct rxrpc_connection *conn)
 415 {
 416         unsigned long j = jiffies, next_j;
 417         unsigned int channel;
 418         bool set;
 419
 420 again:
 421         next_j = j + LONG_MAX;
 422         set = false;
 423         for (channel = 0; channel < RXRPC_MAXCALLS; channel++) {
 424                 struct rxrpc_channel *chan = &conn->channels[channel];
 425                 unsigned long ack_at;
 426
 427                 if (!test_bit(RXRPC_CONN_FINAL_ACK_0 + channel, &conn->flags))
 428                         continue;
 429
 430                 smp_rmb(); /* vs rxrpc_disconnect_client_call */
 431                 ack_at = READ_ONCE(chan->final_ack_at);
 432
 433                 if (time_before(j, ack_at)) {
 434                         if (time_before(ack_at, next_j)) {
 435                                 next_j = ack_at;
 436                                 set = true;
 437                         }
 438                         continue;
 439                 }
 440
 441                 if (test_and_clear_bit(RXRPC_CONN_FINAL_ACK_0 + channel,
 442                                        &conn->flags))
 443                         rxrpc_conn_retransmit_call(conn, NULL, channel);
 444         }
 445
 446         j = jiffies;
 447         if (time_before_eq(next_j, j))
 448                 goto again;
 449         if (set)
 450                 rxrpc_reduce_conn_timer(conn, next_j);
 451 }
 452
 453 /*
 454  * connection-level event processor
 455  */
 456 void rxrpc_process_connection(struct work_struct *work)
 457 {
 458         struct rxrpc_connection *conn =
 459                 container_of(work, struct rxrpc_connection, processor);
 460         struct sk_buff *skb;
 461         u32 abort_code = RX_PROTOCOL_ERROR;
 462         int ret;
 463
 464         rxrpc_see_connection(conn);
 465
 466         if (test_and_clear_bit(RXRPC_CONN_EV_CHALLENGE, &conn->events))
 467                 rxrpc_secure_connection(conn);
 468
 469         /* Process delayed ACKs whose time has come. */
 470         if (conn->flags & RXRPC_CONN_FINAL_ACK_MASK)
 471                 rxrpc_process_delayed_final_acks(conn);
 472
 473         /* go through the conn-level event packets, releasing the ref on this
 474          * connection that each one has when we've finished with it */
 475         while ((skb = skb_dequeue(&conn->rx_queue))) {
 476                 rxrpc_see_skb(skb, rxrpc_skb_rx_seen);
 477                 ret = rxrpc_process_event(conn, skb, &abort_code);
 478                 switch (ret) {
 479                 case -EPROTO:
 480                 case -EKEYEXPIRED:
 481                 case -EKEYREJECTED:
 482                         goto protocol_error;
 483                 case -ENOMEM:
 484                 case -EAGAIN:
 485                         goto requeue_and_leave;
 486                 case -ECONNABORTED:
 487                 default:
 488                         rxrpc_free_skb(skb, rxrpc_skb_rx_freed);
 489                         break;
 490                 }
 491         }
 492
 493 out:
 494         rxrpc_put_connection(conn);
 495         _leave("");
 496         return;
 497
 498 requeue_and_leave:
 499         skb_queue_head(&conn->rx_queue, skb);
 500         goto out;
 501
 502 protocol_error:
 503         if (rxrpc_abort_connection(conn, ret, abort_code) < 0)
 504                 goto requeue_and_leave;
 505         rxrpc_free_skb(skb, rxrpc_skb_rx_freed);
 506         goto out;
 507 }