net/rxrpc/transport.c

   1 /* transport.c: Rx Transport routines
   2  *
   3  * Copyright (C) 2002 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 #include <linux/sched.h>
  13 #include <linux/slab.h>
  14 #include <linux/module.h>
  15 #include <rxrpc/transport.h>
  16 #include <rxrpc/peer.h>
  17 #include <rxrpc/connection.h>
  18 #include <rxrpc/call.h>
  19 #include <rxrpc/message.h>
  20 #include <rxrpc/krxiod.h>
  21 #include <rxrpc/krxsecd.h>
  22 #include <linux/udp.h>
  23 #include <linux/in.h>
  24 #include <linux/in6.h>
  25 #include <linux/icmp.h>
  26 #include <linux/skbuff.h>
  27 #include <net/sock.h>
  28 #include <net/ip.h>
  29 #if defined(CONFIG_IPV6) || defined (CONFIG_IPV6_MODULE)
  30 #include <linux/ipv6.h> /* this should _really_ be in errqueue.h.. */
  31 #endif
  32 #include <linux/errqueue.h>
  33 #include <asm/uaccess.h>
  34 #include <asm/checksum.h>
  35 #include "internal.h"
  36
  37 struct errormsg {
  38         struct cmsghdr                  cmsg;           /* control message header */
  39         struct sock_extended_err        ee;             /* extended error information */
  40         struct sockaddr_in              icmp_src;       /* ICMP packet source address */
  41 };
  42
  43 static DEFINE_SPINLOCK(rxrpc_transports_lock);
  44 static struct list_head rxrpc_transports = LIST_HEAD_INIT(rxrpc_transports);
  45
  46 __RXACCT_DECL(atomic_t rxrpc_transport_count);
  47 LIST_HEAD(rxrpc_proc_transports);
  48 DECLARE_RWSEM(rxrpc_proc_transports_sem);
  49
  50 static void rxrpc_data_ready(struct sock *sk, int count);
  51 static void rxrpc_error_report(struct sock *sk);
  52 static int rxrpc_trans_receive_new_call(struct rxrpc_transport *trans,
  53                                         struct list_head *msgq);
  54 static void rxrpc_trans_receive_error_report(struct rxrpc_transport *trans);
  55
  56 /*****************************************************************************/
  57 /*
  58  * create a new transport endpoint using the specified UDP port
  59  */
  60 int rxrpc_create_transport(unsigned short port,
  61                            struct rxrpc_transport **_trans)
  62 {
  63         struct rxrpc_transport *trans;
  64         struct sockaddr_in sin;
  65         mm_segment_t oldfs;
  66         struct sock *sock;
  67         int ret, opt;
  68
  69         _enter("%hu", port);
  70
  71         trans = kzalloc(sizeof(struct rxrpc_transport), GFP_KERNEL);
  72         if (!trans)
  73                 return -ENOMEM;
  74
  75         atomic_set(&trans->usage, 1);
  76         INIT_LIST_HEAD(&trans->services);
  77         INIT_LIST_HEAD(&trans->link);
  78         INIT_LIST_HEAD(&trans->krxiodq_link);
  79         spin_lock_init(&trans->lock);
  80         INIT_LIST_HEAD(&trans->peer_active);
  81         INIT_LIST_HEAD(&trans->peer_graveyard);
  82         spin_lock_init(&trans->peer_gylock);
  83         init_waitqueue_head(&trans->peer_gy_waitq);
  84         rwlock_init(&trans->peer_lock);
  85         atomic_set(&trans->peer_count, 0);
  86         trans->port = port;
  87
  88         /* create a UDP socket to be my actual transport endpoint */
  89         ret = sock_create_kern(PF_INET, SOCK_DGRAM, IPPROTO_UDP, &trans->socket);
  90         if (ret < 0)
  91                 goto error;
  92
  93         /* use the specified port */
  94         if (port) {
  95                 memset(&sin, 0, sizeof(sin));
  96                 sin.sin_family = AF_INET;
  97                 sin.sin_port = htons(port);
  98                 ret = trans->socket->ops->bind(trans->socket,
  99                                                (struct sockaddr *) &sin,
 100                                                sizeof(sin));
 101                 if (ret < 0)
 102                         goto error;
 103         }
 104
 105         opt = 1;
 106         oldfs = get_fs();
 107         set_fs(KERNEL_DS);
 108         ret = trans->socket->ops->setsockopt(trans->socket, SOL_IP, IP_RECVERR,
 109                                              (char *) &opt, sizeof(opt));
 110         set_fs(oldfs);
 111
 112         spin_lock(&rxrpc_transports_lock);
 113         list_add(&trans->link, &rxrpc_transports);
 114         spin_unlock(&rxrpc_transports_lock);
 115
 116         /* set the socket up */
 117         sock = trans->socket->sk;
 118         sock->sk_user_data      = trans;
 119         sock->sk_data_ready     = rxrpc_data_ready;
 120         sock->sk_error_report   = rxrpc_error_report;
 121
 122         down_write(&rxrpc_proc_transports_sem);
 123         list_add_tail(&trans->proc_link, &rxrpc_proc_transports);
 124         up_write(&rxrpc_proc_transports_sem);
 125
 126         __RXACCT(atomic_inc(&rxrpc_transport_count));
 127
 128         *_trans = trans;
 129         _leave(" = 0 (%p)", trans);
 130         return 0;
 131
 132  error:
 133         /* finish cleaning up the transport (not really needed here, but...) */
 134         if (trans->socket)
 135                 trans->socket->ops->shutdown(trans->socket, 2);
 136
 137         /* close the socket */
 138         if (trans->socket) {
 139                 trans->socket->sk->sk_user_data = NULL;
 140                 sock_release(trans->socket);
 141                 trans->socket = NULL;
 142         }
 143
 144         kfree(trans);
 145
 146
 147         _leave(" = %d", ret);
 148         return ret;
 149 } /* end rxrpc_create_transport() */
 150
 151 /*****************************************************************************/
 152 /*
 153  * destroy a transport endpoint
 154  */
 155 void rxrpc_put_transport(struct rxrpc_transport *trans)
 156 {
 157         _enter("%p{u=%d p=%hu}",
 158                trans, atomic_read(&trans->usage), trans->port);
 159
 160         BUG_ON(atomic_read(&trans->usage) <= 0);
 161
 162         /* to prevent a race, the decrement and the dequeue must be
 163          * effectively atomic */
 164         spin_lock(&rxrpc_transports_lock);
 165         if (likely(!atomic_dec_and_test(&trans->usage))) {
 166                 spin_unlock(&rxrpc_transports_lock);
 167                 _leave("");
 168                 return;
 169         }
 170
 171         list_del(&trans->link);
 172         spin_unlock(&rxrpc_transports_lock);
 173
 174         /* finish cleaning up the transport */
 175         if (trans->socket)
 176                 trans->socket->ops->shutdown(trans->socket, 2);
 177
 178         rxrpc_krxsecd_clear_transport(trans);
 179         rxrpc_krxiod_dequeue_transport(trans);
 180
 181         /* discard all peer information */
 182         rxrpc_peer_clearall(trans);
 183
 184         down_write(&rxrpc_proc_transports_sem);
 185         list_del(&trans->proc_link);
 186         up_write(&rxrpc_proc_transports_sem);
 187         __RXACCT(atomic_dec(&rxrpc_transport_count));
 188
 189         /* close the socket */
 190         if (trans->socket) {
 191                 trans->socket->sk->sk_user_data = NULL;
 192                 sock_release(trans->socket);
 193                 trans->socket = NULL;
 194         }
 195
 196         kfree(trans);
 197
 198         _leave("");
 199 } /* end rxrpc_put_transport() */
 200
 201 /*****************************************************************************/
 202 /*
 203  * add a service to a transport to be listened upon
 204  */
 205 int rxrpc_add_service(struct rxrpc_transport *trans,
 206                       struct rxrpc_service *newsrv)
 207 {
 208         struct rxrpc_service *srv;
 209         struct list_head *_p;
 210         int ret = -EEXIST;
 211
 212         _enter("%p{%hu},%p{%hu}",
 213                trans, trans->port, newsrv, newsrv->service_id);
 214
 215         /* verify that the service ID is not already present */
 216         spin_lock(&trans->lock);
 217
 218         list_for_each(_p, &trans->services) {
 219                 srv = list_entry(_p, struct rxrpc_service, link);
 220                 if (srv->service_id == newsrv->service_id)
 221                         goto out;
 222         }
 223
 224         /* okay - add the transport to the list */
 225         list_add_tail(&newsrv->link, &trans->services);
 226         rxrpc_get_transport(trans);
 227         ret = 0;
 228
 229  out:
 230         spin_unlock(&trans->lock);
 231
 232         _leave("= %d", ret);
 233         return ret;
 234 } /* end rxrpc_add_service() */
 235
 236 /*****************************************************************************/
 237 /*
 238  * remove a service from a transport
 239  */
 240 void rxrpc_del_service(struct rxrpc_transport *trans, struct rxrpc_service *srv)
 241 {
 242         _enter("%p{%hu},%p{%hu}", trans, trans->port, srv, srv->service_id);
 243
 244         spin_lock(&trans->lock);
 245         list_del(&srv->link);
 246         spin_unlock(&trans->lock);
 247
 248         rxrpc_put_transport(trans);
 249
 250         _leave("");
 251 } /* end rxrpc_del_service() */
 252
 253 /*****************************************************************************/
 254 /*
 255  * INET callback when data has been received on the socket.
 256  */
 257 static void rxrpc_data_ready(struct sock *sk, int count)
 258 {
 259         struct rxrpc_transport *trans;
 260
 261         _enter("%p{t=%p},%d", sk, sk->sk_user_data, count);
 262
 263         /* queue the transport for attention by krxiod */
 264         trans = (struct rxrpc_transport *) sk->sk_user_data;
 265         if (trans)
 266                 rxrpc_krxiod_queue_transport(trans);
 267
 268         /* wake up anyone waiting on the socket */
 269         if (sk->sk_sleep && waitqueue_active(sk->sk_sleep))
 270                 wake_up_interruptible(sk->sk_sleep);
 271
 272         _leave("");
 273 } /* end rxrpc_data_ready() */
 274
 275 /*****************************************************************************/
 276 /*
 277  * INET callback when an ICMP error packet is received
 278  * - sk->err is error (EHOSTUNREACH, EPROTO or EMSGSIZE)
 279  */
 280 static void rxrpc_error_report(struct sock *sk)
 281 {
 282         struct rxrpc_transport *trans;
 283
 284         _enter("%p{t=%p}", sk, sk->sk_user_data);
 285
 286         /* queue the transport for attention by krxiod */
 287         trans = (struct rxrpc_transport *) sk->sk_user_data;
 288         if (trans) {
 289                 trans->error_rcvd = 1;
 290                 rxrpc_krxiod_queue_transport(trans);
 291         }
 292
 293         /* wake up anyone waiting on the socket */
 294         if (sk->sk_sleep && waitqueue_active(sk->sk_sleep))
 295                 wake_up_interruptible(sk->sk_sleep);
 296
 297         _leave("");
 298 } /* end rxrpc_error_report() */
 299
 300 /*****************************************************************************/
 301 /*
 302  * split a message up, allocating message records and filling them in
 303  * from the contents of a socket buffer
 304  */
 305 static int rxrpc_incoming_msg(struct rxrpc_transport *trans,
 306                               struct sk_buff *pkt,
 307                               struct list_head *msgq)
 308 {
 309         struct rxrpc_message *msg;
 310         int ret;
 311
 312         _enter("");
 313
 314         msg = kzalloc(sizeof(struct rxrpc_message), GFP_KERNEL);
 315         if (!msg) {
 316                 _leave(" = -ENOMEM");
 317                 return -ENOMEM;
 318         }
 319
 320         atomic_set(&msg->usage, 1);
 321         list_add_tail(&msg->link,msgq);
 322
 323         /* dig out the Rx routing parameters */
 324         if (skb_copy_bits(pkt, sizeof(struct udphdr),
 325                           &msg->hdr, sizeof(msg->hdr)) < 0) {
 326                 ret = -EBADMSG;
 327                 goto error;
 328         }
 329
 330         msg->trans = trans;
 331         msg->state = RXRPC_MSG_RECEIVED;
 332         skb_get_timestamp(pkt, &msg->stamp);
 333         if (msg->stamp.tv_sec == 0) {
 334                 do_gettimeofday(&msg->stamp);
 335                 if (pkt->sk)
 336                         sock_enable_timestamp(pkt->sk);
 337         }
 338         msg->seq = ntohl(msg->hdr.seq);
 339
 340         /* attach the packet */
 341         skb_get(pkt);
 342         msg->pkt = pkt;
 343
 344         msg->offset = sizeof(struct udphdr) + sizeof(struct rxrpc_header);
 345         msg->dsize = msg->pkt->len - msg->offset;
 346
 347         _net("Rx Received packet from %s (%08x;%08x,%1x,%d,%s,%02x,%d,%d)",
 348              msg->hdr.flags & RXRPC_CLIENT_INITIATED ? "client" : "server",
 349              ntohl(msg->hdr.epoch),
 350              (ntohl(msg->hdr.cid) & RXRPC_CIDMASK) >> RXRPC_CIDSHIFT,
 351              ntohl(msg->hdr.cid) & RXRPC_CHANNELMASK,
 352              ntohl(msg->hdr.callNumber),
 353              rxrpc_pkts[msg->hdr.type],
 354              msg->hdr.flags,
 355              ntohs(msg->hdr.serviceId),
 356              msg->hdr.securityIndex);
 357
 358         __RXACCT(atomic_inc(&rxrpc_message_count));
 359
 360         /* split off jumbo packets */
 361         while (msg->hdr.type == RXRPC_PACKET_TYPE_DATA &&
 362                msg->hdr.flags & RXRPC_JUMBO_PACKET
 363                ) {
 364                 struct rxrpc_jumbo_header jumbo;
 365                 struct rxrpc_message *jumbomsg = msg;
 366
 367                 _debug("split jumbo packet");
 368
 369                 /* quick sanity check */
 370                 ret = -EBADMSG;
 371                 if (msg->dsize <
 372                     RXRPC_JUMBO_DATALEN + sizeof(struct rxrpc_jumbo_header))
 373                         goto error;
 374                 if (msg->hdr.flags & RXRPC_LAST_PACKET)
 375                         goto error;
 376
 377                 /* dig out the secondary header */
 378                 if (skb_copy_bits(pkt, msg->offset + RXRPC_JUMBO_DATALEN,
 379                                   &jumbo, sizeof(jumbo)) < 0)
 380                         goto error;
 381
 382                 /* allocate a new message record */
 383                 ret = -ENOMEM;
 384                 msg = kmalloc(sizeof(struct rxrpc_message), GFP_KERNEL);
 385                 if (!msg)
 386                         goto error;
 387
 388                 memcpy(msg, jumbomsg, sizeof(*msg));
 389                 list_add_tail(&msg->link, msgq);
 390
 391                 /* adjust the jumbo packet */
 392                 jumbomsg->dsize = RXRPC_JUMBO_DATALEN;
 393
 394                 /* attach the packet here too */
 395                 skb_get(pkt);
 396
 397                 /* adjust the parameters */
 398                 msg->seq++;
 399                 msg->hdr.seq = htonl(msg->seq);
 400                 msg->hdr.serial = htonl(ntohl(msg->hdr.serial) + 1);
 401                 msg->offset += RXRPC_JUMBO_DATALEN +
 402                         sizeof(struct rxrpc_jumbo_header);
 403                 msg->dsize -= RXRPC_JUMBO_DATALEN +
 404                         sizeof(struct rxrpc_jumbo_header);
 405                 msg->hdr.flags = jumbo.flags;
 406                 msg->hdr._rsvd = jumbo._rsvd;
 407
 408                 _net("Rx Split jumbo packet from %s"
 409                      " (%08x;%08x,%1x,%d,%s,%02x,%d,%d)",
 410                      msg->hdr.flags & RXRPC_CLIENT_INITIATED ? "client" : "server",
 411                      ntohl(msg->hdr.epoch),
 412                      (ntohl(msg->hdr.cid) & RXRPC_CIDMASK) >> RXRPC_CIDSHIFT,
 413                      ntohl(msg->hdr.cid) & RXRPC_CHANNELMASK,
 414                      ntohl(msg->hdr.callNumber),
 415                      rxrpc_pkts[msg->hdr.type],
 416                      msg->hdr.flags,
 417                      ntohs(msg->hdr.serviceId),
 418                      msg->hdr.securityIndex);
 419
 420                 __RXACCT(atomic_inc(&rxrpc_message_count));
 421         }
 422
 423         _leave(" = 0 #%d", atomic_read(&rxrpc_message_count));
 424         return 0;
 425
 426  error:
 427         while (!list_empty(msgq)) {
 428                 msg = list_entry(msgq->next, struct rxrpc_message, link);
 429                 list_del_init(&msg->link);
 430
 431                 rxrpc_put_message(msg);
 432         }
 433
 434         _leave(" = %d", ret);
 435         return ret;
 436 } /* end rxrpc_incoming_msg() */
 437
 438 /*****************************************************************************/
 439 /*
 440  * accept a new call
 441  * - called from krxiod in process context
 442  */
 443 void rxrpc_trans_receive_packet(struct rxrpc_transport *trans)
 444 {
 445         struct rxrpc_message *msg;
 446         struct rxrpc_peer *peer;
 447         struct sk_buff *pkt;
 448         int ret;
 449         __be32 addr;
 450         __be16 port;
 451
 452         LIST_HEAD(msgq);
 453
 454         _enter("%p{%d}", trans, trans->port);
 455
 456         for (;;) {
 457                 /* deal with outstanting errors first */
 458                 if (trans->error_rcvd)
 459                         rxrpc_trans_receive_error_report(trans);
 460
 461                 /* attempt to receive a packet */
 462                 pkt = skb_recv_datagram(trans->socket->sk, 0, 1, &ret);
 463                 if (!pkt) {
 464                         if (ret == -EAGAIN) {
 465                                 _leave(" EAGAIN");
 466                                 return;
 467                         }
 468
 469                         /* an icmp error may have occurred */
 470                         rxrpc_krxiod_queue_transport(trans);
 471                         _leave(" error %d\n", ret);
 472                         return;
 473                 }
 474
 475                 /* we'll probably need to checksum it (didn't call
 476                  * sock_recvmsg) */
 477                 if (skb_checksum_complete(pkt)) {
 478                         kfree_skb(pkt);
 479                         rxrpc_krxiod_queue_transport(trans);
 480                         _leave(" CSUM failed");
 481                         return;
 482                 }
 483
 484                 addr = pkt->nh.iph->saddr;
 485                 port = pkt->h.uh->source;
 486
 487                 _net("Rx Received UDP packet from %08x:%04hu",
 488                      ntohl(addr), ntohs(port));
 489
 490                 /* unmarshall the Rx parameters and split jumbo packets */
 491                 ret = rxrpc_incoming_msg(trans, pkt, &msgq);
 492                 if (ret < 0) {
 493                         kfree_skb(pkt);
 494                         rxrpc_krxiod_queue_transport(trans);
 495                         _leave(" bad packet");
 496                         return;
 497                 }
 498
 499                 BUG_ON(list_empty(&msgq));
 500
 501                 msg = list_entry(msgq.next, struct rxrpc_message, link);
 502
 503                 /* locate the record for the peer from which it
 504                  * originated */
 505                 ret = rxrpc_peer_lookup(trans, addr, &peer);
 506                 if (ret < 0) {
 507                         kdebug("Rx No connections from that peer");
 508                         rxrpc_trans_immediate_abort(trans, msg, -EINVAL);
 509                         goto finished_msg;
 510                 }
 511
 512                 /* try and find a matching connection */
 513                 ret = rxrpc_connection_lookup(peer, msg, &msg->conn);
 514                 if (ret < 0) {
 515                         kdebug("Rx Unknown Connection");
 516                         rxrpc_trans_immediate_abort(trans, msg, -EINVAL);
 517                         rxrpc_put_peer(peer);
 518                         goto finished_msg;
 519                 }
 520                 rxrpc_put_peer(peer);
 521
 522                 /* deal with the first packet of a new call */
 523                 if (msg->hdr.flags & RXRPC_CLIENT_INITIATED &&
 524                     msg->hdr.type == RXRPC_PACKET_TYPE_DATA &&
 525                     ntohl(msg->hdr.seq) == 1
 526                     ) {
 527                         _debug("Rx New server call");
 528                         rxrpc_trans_receive_new_call(trans, &msgq);
 529                         goto finished_msg;
 530                 }
 531
 532                 /* deal with subsequent packet(s) of call */
 533                 _debug("Rx Call packet");
 534                 while (!list_empty(&msgq)) {
 535                         msg = list_entry(msgq.next, struct rxrpc_message, link);
 536                         list_del_init(&msg->link);
 537
 538                         ret = rxrpc_conn_receive_call_packet(msg->conn, NULL, msg);
 539                         if (ret < 0) {
 540                                 rxrpc_trans_immediate_abort(trans, msg, ret);
 541                                 rxrpc_put_message(msg);
 542                                 goto finished_msg;
 543                         }
 544
 545                         rxrpc_put_message(msg);
 546                 }
 547
 548                 goto finished_msg;
 549
 550                 /* dispose of the packets */
 551         finished_msg:
 552                 while (!list_empty(&msgq)) {
 553                         msg = list_entry(msgq.next, struct rxrpc_message, link);
 554                         list_del_init(&msg->link);
 555
 556                         rxrpc_put_message(msg);
 557                 }
 558                 kfree_skb(pkt);
 559         }
 560
 561         _leave("");
 562
 563 } /* end rxrpc_trans_receive_packet() */
 564
 565 /*****************************************************************************/
 566 /*
 567  * accept a new call from a client trying to connect to one of my services
 568  * - called in process context
 569  */
 570 static int rxrpc_trans_receive_new_call(struct rxrpc_transport *trans,
 571                                         struct list_head *msgq)
 572 {
 573         struct rxrpc_message *msg;
 574
 575         _enter("");
 576
 577         /* only bother with the first packet */
 578         msg = list_entry(msgq->next, struct rxrpc_message, link);
 579         list_del_init(&msg->link);
 580         rxrpc_krxsecd_queue_incoming_call(msg);
 581         rxrpc_put_message(msg);
 582
 583         _leave(" = 0");
 584
 585         return 0;
 586 } /* end rxrpc_trans_receive_new_call() */
 587
 588 /*****************************************************************************/
 589 /*
 590  * perform an immediate abort without connection or call structures
 591  */
 592 int rxrpc_trans_immediate_abort(struct rxrpc_transport *trans,
 593                                 struct rxrpc_message *msg,
 594                                 int error)
 595 {
 596         struct rxrpc_header ahdr;
 597         struct sockaddr_in sin;
 598         struct msghdr msghdr;
 599         struct kvec iov[2];
 600         __be32 _error;
 601         int len, ret;
 602
 603         _enter("%p,%p,%d", trans, msg, error);
 604
 605         /* don't abort an abort packet */
 606         if (msg->hdr.type == RXRPC_PACKET_TYPE_ABORT) {
 607                 _leave(" = 0");
 608                 return 0;
 609         }
 610
 611         _error = htonl(-error);
 612
 613         /* set up the message to be transmitted */
 614         memcpy(&ahdr, &msg->hdr, sizeof(ahdr));
 615         ahdr.epoch      = msg->hdr.epoch;
 616         ahdr.serial     = htonl(1);
 617         ahdr.seq        = 0;
 618         ahdr.type       = RXRPC_PACKET_TYPE_ABORT;
 619         ahdr.flags      = RXRPC_LAST_PACKET;
 620         ahdr.flags      |= ~msg->hdr.flags & RXRPC_CLIENT_INITIATED;
 621
 622         iov[0].iov_len  = sizeof(ahdr);
 623         iov[0].iov_base = &ahdr;
 624         iov[1].iov_len  = sizeof(_error);
 625         iov[1].iov_base = &_error;
 626
 627         len = sizeof(ahdr) + sizeof(_error);
 628
 629         memset(&sin,0,sizeof(sin));
 630         sin.sin_family          = AF_INET;
 631         sin.sin_port            = msg->pkt->h.uh->source;
 632         sin.sin_addr.s_addr     = msg->pkt->nh.iph->saddr;
 633
 634         msghdr.msg_name         = &sin;
 635         msghdr.msg_namelen      = sizeof(sin);
 636         msghdr.msg_control      = NULL;
 637         msghdr.msg_controllen   = 0;
 638         msghdr.msg_flags        = MSG_DONTWAIT;
 639
 640         _net("Sending message type %d of %d bytes to %08x:%d",
 641              ahdr.type,
 642              len,
 643              ntohl(sin.sin_addr.s_addr),
 644              ntohs(sin.sin_port));
 645
 646         /* send the message */
 647         ret = kernel_sendmsg(trans->socket, &msghdr, iov, 2, len);
 648
 649         _leave(" = %d", ret);
 650         return ret;
 651 } /* end rxrpc_trans_immediate_abort() */
 652
 653 /*****************************************************************************/
 654 /*
 655  * receive an ICMP error report and percolate it to all connections
 656  * heading to the affected host or port
 657  */
 658 static void rxrpc_trans_receive_error_report(struct rxrpc_transport *trans)
 659 {
 660         struct rxrpc_connection *conn;
 661         struct sockaddr_in sin;
 662         struct rxrpc_peer *peer;
 663         struct list_head connq, *_p;
 664         struct errormsg emsg;
 665         struct msghdr msg;
 666         __be16 port;
 667         int local, err;
 668
 669         _enter("%p", trans);
 670
 671         for (;;) {
 672                 trans->error_rcvd = 0;
 673
 674                 /* try and receive an error message */
 675                 msg.msg_name    = &sin;
 676                 msg.msg_namelen = sizeof(sin);
 677                 msg.msg_control = &emsg;
 678                 msg.msg_controllen = sizeof(emsg);
 679                 msg.msg_flags   = 0;
 680
 681                 err = kernel_recvmsg(trans->socket, &msg, NULL, 0, 0,
 682                                    MSG_ERRQUEUE | MSG_DONTWAIT | MSG_TRUNC);
 683
 684                 if (err == -EAGAIN) {
 685                         _leave("");
 686                         return;
 687                 }
 688
 689                 if (err < 0) {
 690                         printk("%s: unable to recv an error report: %d\n",
 691                                __FUNCTION__, err);
 692                         _leave("");
 693                         return;
 694                 }
 695
 696                 msg.msg_controllen = (char *) msg.msg_control - (char *) &emsg;
 697
 698                 if (msg.msg_controllen < sizeof(emsg.cmsg) ||
 699                     msg.msg_namelen < sizeof(sin)) {
 700                         printk("%s: short control message"
 701                                " (nlen=%u clen=%Zu fl=%x)\n",
 702                                __FUNCTION__,
 703                                msg.msg_namelen,
 704                                msg.msg_controllen,
 705                                msg.msg_flags);
 706                         continue;
 707                 }
 708
 709                 _net("Rx Received control message"
 710                      " { len=%Zu level=%u type=%u }",
 711                      emsg.cmsg.cmsg_len,
 712                      emsg.cmsg.cmsg_level,
 713                      emsg.cmsg.cmsg_type);
 714
 715                 if (sin.sin_family != AF_INET) {
 716                         printk("Rx Ignoring error report with non-INET address"
 717                                " (fam=%u)",
 718                                sin.sin_family);
 719                         continue;
 720                 }
 721
 722                 _net("Rx Received message pertaining to host addr=%x port=%hu",
 723                      ntohl(sin.sin_addr.s_addr), ntohs(sin.sin_port));
 724
 725                 if (emsg.cmsg.cmsg_level != SOL_IP ||
 726                     emsg.cmsg.cmsg_type != IP_RECVERR) {
 727                         printk("Rx Ignoring unknown error report"
 728                                " { level=%u type=%u }",
 729                                emsg.cmsg.cmsg_level,
 730                                emsg.cmsg.cmsg_type);
 731                         continue;
 732                 }
 733
 734                 if (msg.msg_controllen < sizeof(emsg.cmsg) + sizeof(emsg.ee)) {
 735                         printk("%s: short error message (%Zu)\n",
 736                                __FUNCTION__, msg.msg_controllen);
 737                         _leave("");
 738                         return;
 739                 }
 740
 741                 port = sin.sin_port;
 742
 743                 switch (emsg.ee.ee_origin) {
 744                 case SO_EE_ORIGIN_ICMP:
 745                         local = 0;
 746                         switch (emsg.ee.ee_type) {
 747                         case ICMP_DEST_UNREACH:
 748                                 switch (emsg.ee.ee_code) {
 749                                 case ICMP_NET_UNREACH:
 750                                         _net("Rx Received ICMP Network Unreachable");
 751                                         port = 0;
 752                                         err = -ENETUNREACH;
 753                                         break;
 754                                 case ICMP_HOST_UNREACH:
 755                                         _net("Rx Received ICMP Host Unreachable");
 756                                         port = 0;
 757                                         err = -EHOSTUNREACH;
 758                                         break;
 759                                 case ICMP_PORT_UNREACH:
 760                                         _net("Rx Received ICMP Port Unreachable");
 761                                         err = -ECONNREFUSED;
 762                                         break;
 763                                 case ICMP_NET_UNKNOWN:
 764                                         _net("Rx Received ICMP Unknown Network");
 765                                         port = 0;
 766                                         err = -ENETUNREACH;
 767                                         break;
 768                                 case ICMP_HOST_UNKNOWN:
 769                                         _net("Rx Received ICMP Unknown Host");
 770                                         port = 0;
 771                                         err = -EHOSTUNREACH;
 772                                         break;
 773                                 default:
 774                                         _net("Rx Received ICMP DestUnreach { code=%u }",
 775                                              emsg.ee.ee_code);
 776                                         err = emsg.ee.ee_errno;
 777                                         break;
 778                                 }
 779                                 break;
 780
 781                         case ICMP_TIME_EXCEEDED:
 782                                 _net("Rx Received ICMP TTL Exceeded");
 783                                 err = emsg.ee.ee_errno;
 784                                 break;
 785
 786                         default:
 787                                 _proto("Rx Received ICMP error { type=%u code=%u }",
 788                                        emsg.ee.ee_type, emsg.ee.ee_code);
 789                                 err = emsg.ee.ee_errno;
 790                                 break;
 791                         }
 792                         break;
 793
 794                 case SO_EE_ORIGIN_LOCAL:
 795                         _proto("Rx Received local error { error=%d }",
 796                                emsg.ee.ee_errno);
 797                         local = 1;
 798                         err = emsg.ee.ee_errno;
 799                         break;
 800
 801                 case SO_EE_ORIGIN_NONE:
 802                 case SO_EE_ORIGIN_ICMP6:
 803                 default:
 804                         _proto("Rx Received error report { orig=%u }",
 805                                emsg.ee.ee_origin);
 806                         local = 0;
 807                         err = emsg.ee.ee_errno;
 808                         break;
 809                 }
 810
 811                 /* find all the connections between this transport and the
 812                  * affected destination */
 813                 INIT_LIST_HEAD(&connq);
 814
 815                 if (rxrpc_peer_lookup(trans, sin.sin_addr.s_addr,
 816                                       &peer) == 0) {
 817                         read_lock(&peer->conn_lock);
 818                         list_for_each(_p, &peer->conn_active) {
 819                                 conn = list_entry(_p, struct rxrpc_connection,
 820                                                   link);
 821                                 if (port && conn->addr.sin_port != port)
 822                                         continue;
 823                                 if (!list_empty(&conn->err_link))
 824                                         continue;
 825
 826                                 rxrpc_get_connection(conn);
 827                                 list_add_tail(&conn->err_link, &connq);
 828                         }
 829                         read_unlock(&peer->conn_lock);
 830
 831                         /* service all those connections */
 832                         while (!list_empty(&connq)) {
 833                                 conn = list_entry(connq.next,
 834                                                   struct rxrpc_connection,
 835                                                   err_link);
 836                                 list_del(&conn->err_link);
 837
 838                                 rxrpc_conn_handle_error(conn, local, err);
 839
 840                                 rxrpc_put_connection(conn);
 841                         }
 842
 843                         rxrpc_put_peer(peer);
 844                 }
 845         }
 846
 847         _leave("");
 848         return;
 849 } /* end rxrpc_trans_receive_error_report() */