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 <net/sock.h>
  27 #include <net/ip.h>
  28 #if defined(CONFIG_IPV6) || defined (CONFIG_IPV6_MODULE)
  29 #include <linux/ipv6.h> /* this should _really_ be in errqueue.h.. */
  30 #endif
  31 #include <linux/errqueue.h>
  32 #include <asm/uaccess.h>
  33 #include <asm/checksum.h>
  34 #include "internal.h"
  35
  36 struct errormsg {
  37         struct cmsghdr                  cmsg;           /* control message header */
  38         struct sock_extended_err        ee;             /* extended error information */
  39         struct sockaddr_in              icmp_src;       /* ICMP packet source address */
  40 };
  41
  42 static DEFINE_SPINLOCK(rxrpc_transports_lock);
  43 static struct list_head rxrpc_transports = LIST_HEAD_INIT(rxrpc_transports);
  44
  45 __RXACCT_DECL(atomic_t rxrpc_transport_count);
  46 LIST_HEAD(rxrpc_proc_transports);
  47 DECLARE_RWSEM(rxrpc_proc_transports_sem);
  48
  49 static void rxrpc_data_ready(struct sock *sk, int count);
  50 static void rxrpc_error_report(struct sock *sk);
  51 static int rxrpc_trans_receive_new_call(struct rxrpc_transport *trans,
  52                                         struct list_head *msgq);
  53 static void rxrpc_trans_receive_error_report(struct rxrpc_transport *trans);
  54
  55 /*****************************************************************************/
  56 /*
  57  * create a new transport endpoint using the specified UDP port
  58  */
  59 int rxrpc_create_transport(unsigned short port,
  60                            struct rxrpc_transport **_trans)
  61 {
  62         struct rxrpc_transport *trans;
  63         struct sockaddr_in sin;
  64         mm_segment_t oldfs;
  65         struct sock *sock;
  66         int ret, opt;
  67
  68         _enter("%hu", port);
  69
  70         trans = kmalloc(sizeof(struct rxrpc_transport), GFP_KERNEL);
  71         if (!trans)
  72                 return -ENOMEM;
  73
  74         memset(trans, 0, sizeof(struct rxrpc_transport));
  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 = kmalloc(sizeof(struct rxrpc_message), GFP_KERNEL);
 315         if (!msg) {
 316                 _leave(" = -ENOMEM");
 317                 return -ENOMEM;
 318         }
 319
 320         memset(msg, 0, sizeof(*msg));
 321         atomic_set(&msg->usage, 1);
 322         list_add_tail(&msg->link,msgq);
 323
 324         /* dig out the Rx routing parameters */
 325         if (skb_copy_bits(pkt, sizeof(struct udphdr),
 326                           &msg->hdr, sizeof(msg->hdr)) < 0) {
 327                 ret = -EBADMSG;
 328                 goto error;
 329         }
 330
 331         msg->trans = trans;
 332         msg->state = RXRPC_MSG_RECEIVED;
 333         msg->stamp = pkt->stamp;
 334         if (msg->stamp.tv_sec == 0) {
 335                 do_gettimeofday(&msg->stamp);
 336                 if (pkt->sk)
 337                         sock_enable_timestamp(pkt->sk);
 338         }
 339         msg->seq = ntohl(msg->hdr.seq);
 340
 341         /* attach the packet */
 342         skb_get(pkt);
 343         msg->pkt = pkt;
 344
 345         msg->offset = sizeof(struct udphdr) + sizeof(struct rxrpc_header);
 346         msg->dsize = msg->pkt->len - msg->offset;
 347
 348         _net("Rx Received packet from %s (%08x;%08x,%1x,%d,%s,%02x,%d,%d)",
 349              msg->hdr.flags & RXRPC_CLIENT_INITIATED ? "client" : "server",
 350              ntohl(msg->hdr.epoch),
 351              (ntohl(msg->hdr.cid) & RXRPC_CIDMASK) >> RXRPC_CIDSHIFT,
 352              ntohl(msg->hdr.cid) & RXRPC_CHANNELMASK,
 353              ntohl(msg->hdr.callNumber),
 354              rxrpc_pkts[msg->hdr.type],
 355              msg->hdr.flags,
 356              ntohs(msg->hdr.serviceId),
 357              msg->hdr.securityIndex);
 358
 359         __RXACCT(atomic_inc(&rxrpc_message_count));
 360
 361         /* split off jumbo packets */
 362         while (msg->hdr.type == RXRPC_PACKET_TYPE_DATA &&
 363                msg->hdr.flags & RXRPC_JUMBO_PACKET
 364                ) {
 365                 struct rxrpc_jumbo_header jumbo;
 366                 struct rxrpc_message *jumbomsg = msg;
 367
 368                 _debug("split jumbo packet");
 369
 370                 /* quick sanity check */
 371                 ret = -EBADMSG;
 372                 if (msg->dsize <
 373                     RXRPC_JUMBO_DATALEN + sizeof(struct rxrpc_jumbo_header))
 374                         goto error;
 375                 if (msg->hdr.flags & RXRPC_LAST_PACKET)
 376                         goto error;
 377
 378                 /* dig out the secondary header */
 379                 if (skb_copy_bits(pkt, msg->offset + RXRPC_JUMBO_DATALEN,
 380                                   &jumbo, sizeof(jumbo)) < 0)
 381                         goto error;
 382
 383                 /* allocate a new message record */
 384                 ret = -ENOMEM;
 385                 msg = kmalloc(sizeof(struct rxrpc_message), GFP_KERNEL);
 386                 if (!msg)
 387                         goto error;
 388
 389                 memcpy(msg, jumbomsg, sizeof(*msg));
 390                 list_add_tail(&msg->link, msgq);
 391
 392                 /* adjust the jumbo packet */
 393                 jumbomsg->dsize = RXRPC_JUMBO_DATALEN;
 394
 395                 /* attach the packet here too */
 396                 skb_get(pkt);
 397
 398                 /* adjust the parameters */
 399                 msg->seq++;
 400                 msg->hdr.seq = htonl(msg->seq);
 401                 msg->hdr.serial = htonl(ntohl(msg->hdr.serial) + 1);
 402                 msg->offset += RXRPC_JUMBO_DATALEN +
 403                         sizeof(struct rxrpc_jumbo_header);
 404                 msg->dsize -= RXRPC_JUMBO_DATALEN +
 405                         sizeof(struct rxrpc_jumbo_header);
 406                 msg->hdr.flags = jumbo.flags;
 407                 msg->hdr._rsvd = jumbo._rsvd;
 408
 409                 _net("Rx Split jumbo packet from %s"
 410                      " (%08x;%08x,%1x,%d,%s,%02x,%d,%d)",
 411                      msg->hdr.flags & RXRPC_CLIENT_INITIATED ? "client" : "server",
 412                      ntohl(msg->hdr.epoch),
 413                      (ntohl(msg->hdr.cid) & RXRPC_CIDMASK) >> RXRPC_CIDSHIFT,
 414                      ntohl(msg->hdr.cid) & RXRPC_CHANNELMASK,
 415                      ntohl(msg->hdr.callNumber),
 416                      rxrpc_pkts[msg->hdr.type],
 417                      msg->hdr.flags,
 418                      ntohs(msg->hdr.serviceId),
 419                      msg->hdr.securityIndex);
 420
 421                 __RXACCT(atomic_inc(&rxrpc_message_count));
 422         }
 423
 424         _leave(" = 0 #%d", atomic_read(&rxrpc_message_count));
 425         return 0;
 426
 427  error:
 428         while (!list_empty(msgq)) {
 429                 msg = list_entry(msgq->next, struct rxrpc_message, link);
 430                 list_del_init(&msg->link);
 431
 432                 rxrpc_put_message(msg);
 433         }
 434
 435         _leave(" = %d", ret);
 436         return ret;
 437 } /* end rxrpc_incoming_msg() */
 438
 439 /*****************************************************************************/
 440 /*
 441  * accept a new call
 442  * - called from krxiod in process context
 443  */
 444 void rxrpc_trans_receive_packet(struct rxrpc_transport *trans)
 445 {
 446         struct rxrpc_message *msg;
 447         struct rxrpc_peer *peer;
 448         struct sk_buff *pkt;
 449         int ret;
 450         __be32 addr;
 451         __be16 port;
 452
 453         LIST_HEAD(msgq);
 454
 455         _enter("%p{%d}", trans, trans->port);
 456
 457         for (;;) {
 458                 /* deal with outstanting errors first */
 459                 if (trans->error_rcvd)
 460                         rxrpc_trans_receive_error_report(trans);
 461
 462                 /* attempt to receive a packet */
 463                 pkt = skb_recv_datagram(trans->socket->sk, 0, 1, &ret);
 464                 if (!pkt) {
 465                         if (ret == -EAGAIN) {
 466                                 _leave(" EAGAIN");
 467                                 return;
 468                         }
 469
 470                         /* an icmp error may have occurred */
 471                         rxrpc_krxiod_queue_transport(trans);
 472                         _leave(" error %d\n", ret);
 473                         return;
 474                 }
 475
 476                 /* we'll probably need to checksum it (didn't call
 477                  * sock_recvmsg) */
 478                 if (pkt->ip_summed != CHECKSUM_UNNECESSARY) {
 479                         if ((unsigned short)
 480                             csum_fold(skb_checksum(pkt, 0, pkt->len,
 481                                                    pkt->csum))) {
 482                                 kfree_skb(pkt);
 483                                 rxrpc_krxiod_queue_transport(trans);
 484                                 _leave(" CSUM failed");
 485                                 return;
 486                         }
 487                 }
 488
 489                 addr = pkt->nh.iph->saddr;
 490                 port = pkt->h.uh->source;
 491
 492                 _net("Rx Received UDP packet from %08x:%04hu",
 493                      ntohl(addr), ntohs(port));
 494
 495                 /* unmarshall the Rx parameters and split jumbo packets */
 496                 ret = rxrpc_incoming_msg(trans, pkt, &msgq);
 497                 if (ret < 0) {
 498                         kfree_skb(pkt);
 499                         rxrpc_krxiod_queue_transport(trans);
 500                         _leave(" bad packet");
 501                         return;
 502                 }
 503
 504                 BUG_ON(list_empty(&msgq));
 505
 506                 msg = list_entry(msgq.next, struct rxrpc_message, link);
 507
 508                 /* locate the record for the peer from which it
 509                  * originated */
 510                 ret = rxrpc_peer_lookup(trans, addr, &peer);
 511                 if (ret < 0) {
 512                         kdebug("Rx No connections from that peer");
 513                         rxrpc_trans_immediate_abort(trans, msg, -EINVAL);
 514                         goto finished_msg;
 515                 }
 516
 517                 /* try and find a matching connection */
 518                 ret = rxrpc_connection_lookup(peer, msg, &msg->conn);
 519                 if (ret < 0) {
 520                         kdebug("Rx Unknown Connection");
 521                         rxrpc_trans_immediate_abort(trans, msg, -EINVAL);
 522                         rxrpc_put_peer(peer);
 523                         goto finished_msg;
 524                 }
 525                 rxrpc_put_peer(peer);
 526
 527                 /* deal with the first packet of a new call */
 528                 if (msg->hdr.flags & RXRPC_CLIENT_INITIATED &&
 529                     msg->hdr.type == RXRPC_PACKET_TYPE_DATA &&
 530                     ntohl(msg->hdr.seq) == 1
 531                     ) {
 532                         _debug("Rx New server call");
 533                         rxrpc_trans_receive_new_call(trans, &msgq);
 534                         goto finished_msg;
 535                 }
 536
 537                 /* deal with subsequent packet(s) of call */
 538                 _debug("Rx Call packet");
 539                 while (!list_empty(&msgq)) {
 540                         msg = list_entry(msgq.next, struct rxrpc_message, link);
 541                         list_del_init(&msg->link);
 542
 543                         ret = rxrpc_conn_receive_call_packet(msg->conn, NULL, msg);
 544                         if (ret < 0) {
 545                                 rxrpc_trans_immediate_abort(trans, msg, ret);
 546                                 rxrpc_put_message(msg);
 547                                 goto finished_msg;
 548                         }
 549
 550                         rxrpc_put_message(msg);
 551                 }
 552
 553                 goto finished_msg;
 554
 555                 /* dispose of the packets */
 556         finished_msg:
 557                 while (!list_empty(&msgq)) {
 558                         msg = list_entry(msgq.next, struct rxrpc_message, link);
 559                         list_del_init(&msg->link);
 560
 561                         rxrpc_put_message(msg);
 562                 }
 563                 kfree_skb(pkt);
 564         }
 565
 566         _leave("");
 567
 568 } /* end rxrpc_trans_receive_packet() */
 569
 570 /*****************************************************************************/
 571 /*
 572  * accept a new call from a client trying to connect to one of my services
 573  * - called in process context
 574  */
 575 static int rxrpc_trans_receive_new_call(struct rxrpc_transport *trans,
 576                                         struct list_head *msgq)
 577 {
 578         struct rxrpc_message *msg;
 579
 580         _enter("");
 581
 582         /* only bother with the first packet */
 583         msg = list_entry(msgq->next, struct rxrpc_message, link);
 584         list_del_init(&msg->link);
 585         rxrpc_krxsecd_queue_incoming_call(msg);
 586         rxrpc_put_message(msg);
 587
 588         _leave(" = 0");
 589
 590         return 0;
 591 } /* end rxrpc_trans_receive_new_call() */
 592
 593 /*****************************************************************************/
 594 /*
 595  * perform an immediate abort without connection or call structures
 596  */
 597 int rxrpc_trans_immediate_abort(struct rxrpc_transport *trans,
 598                                 struct rxrpc_message *msg,
 599                                 int error)
 600 {
 601         struct rxrpc_header ahdr;
 602         struct sockaddr_in sin;
 603         struct msghdr msghdr;
 604         struct kvec iov[2];
 605         __be32 _error;
 606         int len, ret;
 607
 608         _enter("%p,%p,%d", trans, msg, error);
 609
 610         /* don't abort an abort packet */
 611         if (msg->hdr.type == RXRPC_PACKET_TYPE_ABORT) {
 612                 _leave(" = 0");
 613                 return 0;
 614         }
 615
 616         _error = htonl(-error);
 617
 618         /* set up the message to be transmitted */
 619         memcpy(&ahdr, &msg->hdr, sizeof(ahdr));
 620         ahdr.epoch      = msg->hdr.epoch;
 621         ahdr.serial     = htonl(1);
 622         ahdr.seq        = 0;
 623         ahdr.type       = RXRPC_PACKET_TYPE_ABORT;
 624         ahdr.flags      = RXRPC_LAST_PACKET;
 625         ahdr.flags      |= ~msg->hdr.flags & RXRPC_CLIENT_INITIATED;
 626
 627         iov[0].iov_len  = sizeof(ahdr);
 628         iov[0].iov_base = &ahdr;
 629         iov[1].iov_len  = sizeof(_error);
 630         iov[1].iov_base = &_error;
 631
 632         len = sizeof(ahdr) + sizeof(_error);
 633
 634         memset(&sin,0,sizeof(sin));
 635         sin.sin_family          = AF_INET;
 636         sin.sin_port            = msg->pkt->h.uh->source;
 637         sin.sin_addr.s_addr     = msg->pkt->nh.iph->saddr;
 638
 639         msghdr.msg_name         = &sin;
 640         msghdr.msg_namelen      = sizeof(sin);
 641         msghdr.msg_control      = NULL;
 642         msghdr.msg_controllen   = 0;
 643         msghdr.msg_flags        = MSG_DONTWAIT;
 644
 645         _net("Sending message type %d of %d bytes to %08x:%d",
 646              ahdr.type,
 647              len,
 648              ntohl(sin.sin_addr.s_addr),
 649              ntohs(sin.sin_port));
 650
 651         /* send the message */
 652         ret = kernel_sendmsg(trans->socket, &msghdr, iov, 2, len);
 653
 654         _leave(" = %d", ret);
 655         return ret;
 656 } /* end rxrpc_trans_immediate_abort() */
 657
 658 /*****************************************************************************/
 659 /*
 660  * receive an ICMP error report and percolate it to all connections
 661  * heading to the affected host or port
 662  */
 663 static void rxrpc_trans_receive_error_report(struct rxrpc_transport *trans)
 664 {
 665         struct rxrpc_connection *conn;
 666         struct sockaddr_in sin;
 667         struct rxrpc_peer *peer;
 668         struct list_head connq, *_p;
 669         struct errormsg emsg;
 670         struct msghdr msg;
 671         __be16 port;
 672         int local, err;
 673
 674         _enter("%p", trans);
 675
 676         for (;;) {
 677                 trans->error_rcvd = 0;
 678
 679                 /* try and receive an error message */
 680                 msg.msg_name    = &sin;
 681                 msg.msg_namelen = sizeof(sin);
 682                 msg.msg_control = &emsg;
 683                 msg.msg_controllen = sizeof(emsg);
 684                 msg.msg_flags   = 0;
 685
 686                 err = kernel_recvmsg(trans->socket, &msg, NULL, 0, 0,
 687                                    MSG_ERRQUEUE | MSG_DONTWAIT | MSG_TRUNC);
 688
 689                 if (err == -EAGAIN) {
 690                         _leave("");
 691                         return;
 692                 }
 693
 694                 if (err < 0) {
 695                         printk("%s: unable to recv an error report: %d\n",
 696                                __FUNCTION__, err);
 697                         _leave("");
 698                         return;
 699                 }
 700
 701                 msg.msg_controllen = (char *) msg.msg_control - (char *) &emsg;
 702
 703                 if (msg.msg_controllen < sizeof(emsg.cmsg) ||
 704                     msg.msg_namelen < sizeof(sin)) {
 705                         printk("%s: short control message"
 706                                " (nlen=%u clen=%Zu fl=%x)\n",
 707                                __FUNCTION__,
 708                                msg.msg_namelen,
 709                                msg.msg_controllen,
 710                                msg.msg_flags);
 711                         continue;
 712                 }
 713
 714                 _net("Rx Received control message"
 715                      " { len=%Zu level=%u type=%u }",
 716                      emsg.cmsg.cmsg_len,
 717                      emsg.cmsg.cmsg_level,
 718                      emsg.cmsg.cmsg_type);
 719
 720                 if (sin.sin_family != AF_INET) {
 721                         printk("Rx Ignoring error report with non-INET address"
 722                                " (fam=%u)",
 723                                sin.sin_family);
 724                         continue;
 725                 }
 726
 727                 _net("Rx Received message pertaining to host addr=%x port=%hu",
 728                      ntohl(sin.sin_addr.s_addr), ntohs(sin.sin_port));
 729
 730                 if (emsg.cmsg.cmsg_level != SOL_IP ||
 731                     emsg.cmsg.cmsg_type != IP_RECVERR) {
 732                         printk("Rx Ignoring unknown error report"
 733                                " { level=%u type=%u }",
 734                                emsg.cmsg.cmsg_level,
 735                                emsg.cmsg.cmsg_type);
 736                         continue;
 737                 }
 738
 739                 if (msg.msg_controllen < sizeof(emsg.cmsg) + sizeof(emsg.ee)) {
 740                         printk("%s: short error message (%Zu)\n",
 741                                __FUNCTION__, msg.msg_controllen);
 742                         _leave("");
 743                         return;
 744                 }
 745
 746                 port = sin.sin_port;
 747
 748                 switch (emsg.ee.ee_origin) {
 749                 case SO_EE_ORIGIN_ICMP:
 750                         local = 0;
 751                         switch (emsg.ee.ee_type) {
 752                         case ICMP_DEST_UNREACH:
 753                                 switch (emsg.ee.ee_code) {
 754                                 case ICMP_NET_UNREACH:
 755                                         _net("Rx Received ICMP Network Unreachable");
 756                                         port = 0;
 757                                         err = -ENETUNREACH;
 758                                         break;
 759                                 case ICMP_HOST_UNREACH:
 760                                         _net("Rx Received ICMP Host Unreachable");
 761                                         port = 0;
 762                                         err = -EHOSTUNREACH;
 763                                         break;
 764                                 case ICMP_PORT_UNREACH:
 765                                         _net("Rx Received ICMP Port Unreachable");
 766                                         err = -ECONNREFUSED;
 767                                         break;
 768                                 case ICMP_NET_UNKNOWN:
 769                                         _net("Rx Received ICMP Unknown Network");
 770                                         port = 0;
 771                                         err = -ENETUNREACH;
 772                                         break;
 773                                 case ICMP_HOST_UNKNOWN:
 774                                         _net("Rx Received ICMP Unknown Host");
 775                                         port = 0;
 776                                         err = -EHOSTUNREACH;
 777                                         break;
 778                                 default:
 779                                         _net("Rx Received ICMP DestUnreach { code=%u }",
 780                                              emsg.ee.ee_code);
 781                                         err = emsg.ee.ee_errno;
 782                                         break;
 783                                 }
 784                                 break;
 785
 786                         case ICMP_TIME_EXCEEDED:
 787                                 _net("Rx Received ICMP TTL Exceeded");
 788                                 err = emsg.ee.ee_errno;
 789                                 break;
 790
 791                         default:
 792                                 _proto("Rx Received ICMP error { type=%u code=%u }",
 793                                        emsg.ee.ee_type, emsg.ee.ee_code);
 794                                 err = emsg.ee.ee_errno;
 795                                 break;
 796                         }
 797                         break;
 798
 799                 case SO_EE_ORIGIN_LOCAL:
 800                         _proto("Rx Received local error { error=%d }",
 801                                emsg.ee.ee_errno);
 802                         local = 1;
 803                         err = emsg.ee.ee_errno;
 804                         break;
 805
 806                 case SO_EE_ORIGIN_NONE:
 807                 case SO_EE_ORIGIN_ICMP6:
 808                 default:
 809                         _proto("Rx Received error report { orig=%u }",
 810                                emsg.ee.ee_origin);
 811                         local = 0;
 812                         err = emsg.ee.ee_errno;
 813                         break;
 814                 }
 815
 816                 /* find all the connections between this transport and the
 817                  * affected destination */
 818                 INIT_LIST_HEAD(&connq);
 819
 820                 if (rxrpc_peer_lookup(trans, sin.sin_addr.s_addr,
 821                                       &peer) == 0) {
 822                         read_lock(&peer->conn_lock);
 823                         list_for_each(_p, &peer->conn_active) {
 824                                 conn = list_entry(_p, struct rxrpc_connection,
 825                                                   link);
 826                                 if (port && conn->addr.sin_port != port)
 827                                         continue;
 828                                 if (!list_empty(&conn->err_link))
 829                                         continue;
 830
 831                                 rxrpc_get_connection(conn);
 832                                 list_add_tail(&conn->err_link, &connq);
 833                         }
 834                         read_unlock(&peer->conn_lock);
 835
 836                         /* service all those connections */
 837                         while (!list_empty(&connq)) {
 838                                 conn = list_entry(connq.next,
 839                                                   struct rxrpc_connection,
 840                                                   err_link);
 841                                 list_del(&conn->err_link);
 842
 843                                 rxrpc_conn_handle_error(conn, local, err);
 844
 845                                 rxrpc_put_connection(conn);
 846                         }
 847
 848                         rxrpc_put_peer(peer);
 849                 }
 850         }
 851
 852         _leave("");
 853         return;
 854 } /* end rxrpc_trans_receive_error_report() */