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(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                               u32 abort_code, int error)
 158 {
 159         struct rxrpc_call *call;
 160         int i;
 161
 162         _enter("{%d},%x", conn->debug_id, abort_code);
 163
 164         spin_lock(&conn->channel_lock);
 165
 166         for (i = 0; i < RXRPC_MAXCALLS; i++) {
 167                 call = rcu_dereference_protected(
 168                         conn->channels[i].call,
 169                         lockdep_is_held(&conn->channel_lock));
 170                 if (call) {
 171                         if (compl == RXRPC_CALL_LOCALLY_ABORTED)
 172                                 trace_rxrpc_abort(call->debug_id,
 173                                                   "CON", call->cid,
 174                                                   call->call_id, 0,
 175                                                   abort_code, error);
 176                         if (rxrpc_set_call_completion(call, compl,
 177                                                       abort_code, error))
 178                                 rxrpc_notify_socket(call);
 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->state = RXRPC_CONN_LOCALLY_ABORTED;
 211         spin_unlock_bh(&conn->state_lock);
 212
 213         rxrpc_abort_calls(conn, RXRPC_CALL_LOCALLY_ABORTED, abort_code, error);
 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->local_abort);
 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         whdr.serial = htonl(serial);
 243         _proto("Tx CONN ABORT %%%u { %d }", serial, conn->local_abort);
 244
 245         ret = kernel_sendmsg(conn->params.local->socket, &msg, iov, 2, len);
 246         if (ret < 0) {
 247                 trace_rxrpc_tx_fail(conn->debug_id, serial, ret,
 248                                     rxrpc_tx_point_conn_abort);
 249                 _debug("sendmsg failed: %d", ret);
 250                 return -EAGAIN;
 251         }
 252
 253         trace_rxrpc_tx_packet(conn->debug_id, &whdr, rxrpc_tx_point_conn_abort);
 254
 255         conn->params.peer->last_tx_at = ktime_get_seconds();
 256
 257         _leave(" = 0");
 258         return 0;
 259 }
 260
 261 /*
 262  * mark a call as being on a now-secured channel
 263  * - must be called with BH's disabled.
 264  */
 265 static void rxrpc_call_is_secure(struct rxrpc_call *call)
 266 {
 267         _enter("%p", call);
 268         if (call) {
 269                 write_lock_bh(&call->state_lock);
 270                 if (call->state == RXRPC_CALL_SERVER_SECURING) {
 271                         call->state = RXRPC_CALL_SERVER_ACCEPTING;
 272                         rxrpc_notify_socket(call);
 273                 }
 274                 write_unlock_bh(&call->state_lock);
 275         }
 276 }
 277
 278 /*
 279  * connection-level Rx packet processor
 280  */
 281 static int rxrpc_process_event(struct rxrpc_connection *conn,
 282                                struct sk_buff *skb,
 283                                u32 *_abort_code)
 284 {
 285         struct rxrpc_skb_priv *sp = rxrpc_skb(skb);
 286         __be32 wtmp;
 287         u32 abort_code;
 288         int loop, ret;
 289
 290         if (conn->state >= RXRPC_CONN_REMOTELY_ABORTED) {
 291                 _leave(" = -ECONNABORTED [%u]", conn->state);
 292                 return -ECONNABORTED;
 293         }
 294
 295         _enter("{%d},{%u,%%%u},", conn->debug_id, sp->hdr.type, sp->hdr.serial);
 296
 297         switch (sp->hdr.type) {
 298         case RXRPC_PACKET_TYPE_DATA:
 299         case RXRPC_PACKET_TYPE_ACK:
 300                 rxrpc_conn_retransmit_call(conn, skb,
 301                                            sp->hdr.cid & RXRPC_CHANNELMASK);
 302                 return 0;
 303
 304         case RXRPC_PACKET_TYPE_BUSY:
 305                 /* Just ignore BUSY packets for now. */
 306                 return 0;
 307
 308         case RXRPC_PACKET_TYPE_ABORT:
 309                 if (skb_copy_bits(skb, sizeof(struct rxrpc_wire_header),
 310                                   &wtmp, sizeof(wtmp)) < 0) {
 311                         trace_rxrpc_rx_eproto(NULL, sp->hdr.serial,
 312                                               tracepoint_string("bad_abort"));
 313                         return -EPROTO;
 314                 }
 315                 abort_code = ntohl(wtmp);
 316                 _proto("Rx ABORT %%%u { ac=%d }", sp->hdr.serial, abort_code);
 317
 318                 conn->state = RXRPC_CONN_REMOTELY_ABORTED;
 319                 rxrpc_abort_calls(conn, RXRPC_CALL_REMOTELY_ABORTED,
 320                                   abort_code, -ECONNABORTED);
 321                 return -ECONNABORTED;
 322
 323         case RXRPC_PACKET_TYPE_CHALLENGE:
 324                 return conn->security->respond_to_challenge(conn, skb,
 325                                                             _abort_code);
 326
 327         case RXRPC_PACKET_TYPE_RESPONSE:
 328                 ret = conn->security->verify_response(conn, skb, _abort_code);
 329                 if (ret < 0)
 330                         return ret;
 331
 332                 ret = conn->security->init_connection_security(conn);
 333                 if (ret < 0)
 334                         return ret;
 335
 336                 ret = conn->security->prime_packet_security(conn);
 337                 if (ret < 0)
 338                         return ret;
 339
 340                 spin_lock(&conn->channel_lock);
 341                 spin_lock(&conn->state_lock);
 342
 343                 if (conn->state == RXRPC_CONN_SERVICE_CHALLENGING) {
 344                         conn->state = RXRPC_CONN_SERVICE;
 345                         spin_unlock(&conn->state_lock);
 346                         for (loop = 0; loop < RXRPC_MAXCALLS; loop++)
 347                                 rxrpc_call_is_secure(
 348                                         rcu_dereference_protected(
 349                                                 conn->channels[loop].call,
 350                                                 lockdep_is_held(&conn->channel_lock)));
 351                 } else {
 352                         spin_unlock(&conn->state_lock);
 353                 }
 354
 355                 spin_unlock(&conn->channel_lock);
 356                 return 0;
 357
 358         default:
 359                 trace_rxrpc_rx_eproto(NULL, sp->hdr.serial,
 360                                       tracepoint_string("bad_conn_pkt"));
 361                 return -EPROTO;
 362         }
 363 }
 364
 365 /*
 366  * set up security and issue a challenge
 367  */
 368 static void rxrpc_secure_connection(struct rxrpc_connection *conn)
 369 {
 370         u32 abort_code;
 371         int ret;
 372
 373         _enter("{%d}", conn->debug_id);
 374
 375         ASSERT(conn->security_ix != 0);
 376
 377         if (!conn->params.key) {
 378                 _debug("set up security");
 379                 ret = rxrpc_init_server_conn_security(conn);
 380                 switch (ret) {
 381                 case 0:
 382                         break;
 383                 case -ENOENT:
 384                         abort_code = RX_CALL_DEAD;
 385                         goto abort;
 386                 default:
 387                         abort_code = RXKADNOAUTH;
 388                         goto abort;
 389                 }
 390         }
 391
 392         if (conn->security->issue_challenge(conn) < 0) {
 393                 abort_code = RX_CALL_DEAD;
 394                 ret = -ENOMEM;
 395                 goto abort;
 396         }
 397
 398         _leave("");
 399         return;
 400
 401 abort:
 402         _debug("abort %d, %d", ret, abort_code);
 403         rxrpc_abort_connection(conn, ret, abort_code);
 404         _leave(" [aborted]");
 405 }
 406
 407 /*
 408  * Process delayed final ACKs that we haven't subsumed into a subsequent call.
 409  */
 410 static void rxrpc_process_delayed_final_acks(struct rxrpc_connection *conn)
 411 {
 412         unsigned long j = jiffies, next_j;
 413         unsigned int channel;
 414         bool set;
 415
 416 again:
 417         next_j = j + LONG_MAX;
 418         set = false;
 419         for (channel = 0; channel < RXRPC_MAXCALLS; channel++) {
 420                 struct rxrpc_channel *chan = &conn->channels[channel];
 421                 unsigned long ack_at;
 422
 423                 if (!test_bit(RXRPC_CONN_FINAL_ACK_0 + channel, &conn->flags))
 424                         continue;
 425
 426                 smp_rmb(); /* vs rxrpc_disconnect_client_call */
 427                 ack_at = READ_ONCE(chan->final_ack_at);
 428
 429                 if (time_before(j, ack_at)) {
 430                         if (time_before(ack_at, next_j)) {
 431                                 next_j = ack_at;
 432                                 set = true;
 433                         }
 434                         continue;
 435                 }
 436
 437                 if (test_and_clear_bit(RXRPC_CONN_FINAL_ACK_0 + channel,
 438                                        &conn->flags))
 439                         rxrpc_conn_retransmit_call(conn, NULL, channel);
 440         }
 441
 442         j = jiffies;
 443         if (time_before_eq(next_j, j))
 444                 goto again;
 445         if (set)
 446                 rxrpc_reduce_conn_timer(conn, next_j);
 447 }
 448
 449 /*
 450  * connection-level event processor
 451  */
 452 void rxrpc_process_connection(struct work_struct *work)
 453 {
 454         struct rxrpc_connection *conn =
 455                 container_of(work, struct rxrpc_connection, processor);
 456         struct sk_buff *skb;
 457         u32 abort_code = RX_PROTOCOL_ERROR;
 458         int ret;
 459
 460         rxrpc_see_connection(conn);
 461
 462         if (test_and_clear_bit(RXRPC_CONN_EV_CHALLENGE, &conn->events))
 463                 rxrpc_secure_connection(conn);
 464
 465         /* Process delayed ACKs whose time has come. */
 466         if (conn->flags & RXRPC_CONN_FINAL_ACK_MASK)
 467                 rxrpc_process_delayed_final_acks(conn);
 468
 469         /* go through the conn-level event packets, releasing the ref on this
 470          * connection that each one has when we've finished with it */
 471         while ((skb = skb_dequeue(&conn->rx_queue))) {
 472                 rxrpc_see_skb(skb, rxrpc_skb_rx_seen);
 473                 ret = rxrpc_process_event(conn, skb, &abort_code);
 474                 switch (ret) {
 475                 case -EPROTO:
 476                 case -EKEYEXPIRED:
 477                 case -EKEYREJECTED:
 478                         goto protocol_error;
 479                 case -ENOMEM:
 480                 case -EAGAIN:
 481                         goto requeue_and_leave;
 482                 case -ECONNABORTED:
 483                 default:
 484                         rxrpc_free_skb(skb, rxrpc_skb_rx_freed);
 485                         break;
 486                 }
 487         }
 488
 489 out:
 490         rxrpc_put_connection(conn);
 491         _leave("");
 492         return;
 493
 494 requeue_and_leave:
 495         skb_queue_head(&conn->rx_queue, skb);
 496         goto out;
 497
 498 protocol_error:
 499         if (rxrpc_abort_connection(conn, ret, abort_code) < 0)
 500                 goto requeue_and_leave;
 501         rxrpc_free_skb(skb, rxrpc_skb_rx_freed);
 502         goto out;
 503 }