src/icp_v2.cc

   1 /*
   2  * DEBUG: section 12    Internet Cache Protocol (ICP)
   3  * AUTHOR: Duane Wessels
   4  *
   5  * SQUID Web Proxy Cache          http://www.squid-cache.org/
   6  * ----------------------------------------------------------
   7  *
   8  *  Squid is the result of efforts by numerous individuals from
   9  *  the Internet community; see the CONTRIBUTORS file for full
  10  *  details.   Many organizations have provided support for Squid's
  11  *  development; see the SPONSORS file for full details.  Squid is
  12  *  Copyrighted (C) 2001 by the Regents of the University of
  13  *  California; see the COPYRIGHT file for full details.  Squid
  14  *  incorporates software developed and/or copyrighted by other
  15  *  sources; see the CREDITS file for full details.
  16  *
  17  *  This program is free software; you can redistribute it and/or modify
  18  *  it under the terms of the GNU General Public License as published by
  19  *  the Free Software Foundation; either version 2 of the License, or
  20  *  (at your option) any later version.
  21  *
  22  *  This program is distributed in the hope that it will be useful,
  23  *  but WITHOUT ANY WARRANTY; without even the implied warranty of
  24  *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  25  *  GNU General Public License for more details.
  26  *
  27  *  You should have received a copy of the GNU General Public License
  28  *  along with this program; if not, write to the Free Software
  29  *  Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111, USA.
  30  *
  31  */
  32
  33 /**
  34  \defgroup ServerProtocolICPInternal2 ICPv2 Internals
  35  \ingroup ServerProtocolICPAPI
  36  */
  37
  38 #include "squid.h"
  39 #include "Store.h"
  40 #include "comm.h"
  41 #include "ICP.h"
  42 #include "HttpRequest.h"
  43 #include "acl/FilledChecklist.h"
  44 #include "acl/Acl.h"
  45 #include "AccessLogEntry.h"
  46 #include "wordlist.h"
  47 #include "SquidTime.h"
  48 #include "SwapDir.h"
  49 #include "icmp/net_db.h"
  50 #include "ip/Address.h"
  51 #include "ip/tools.h"
  52 #include "ipc/StartListening.h"
  53 #include "rfc1738.h"
  54
  55 /// dials icpIncomingConnectionOpened call
  56 class IcpListeningStartedDialer: public CallDialer,
  57         public Ipc::StartListeningCb
  58 {
  59 public:
  60     typedef void (*Handler)(int fd, int errNo, Ip::Address& addr);
  61     IcpListeningStartedDialer(Handler aHandler, Ip::Address& anAddr):
  62             handler(aHandler), addr(anAddr) {}
  63
  64     virtual void print(std::ostream &os) const {
  65         startPrint(os) <<
  66         ", address=" << addr << ')';
  67     }
  68
  69     virtual bool canDial(AsyncCall &) const { return true; }
  70     virtual void dial(AsyncCall &) { (handler)(fd, errNo, addr); }
  71
  72 public:
  73     Handler handler;
  74     Ip::Address addr;
  75 };
  76
  77 static void icpIncomingConnectionOpened(int fd, int errNo, Ip::Address& addr);
  78
  79 /// \ingroup ServerProtocolICPInternal2
  80 static void icpLogIcp(const Ip::Address &, log_type, int, const char *, int);
  81
  82 /// \ingroup ServerProtocolICPInternal2
  83 static void icpHandleIcpV2(int, Ip::Address &, char *, int);
  84
  85 /// \ingroup ServerProtocolICPInternal2
  86 static void icpCount(void *, int, size_t, int);
  87
  88 /**
  89  \ingroup ServerProtocolICPInternal2
  90  * IcpQueueHead is global so comm_incoming() knows whether or not
  91  * to call icpUdpSendQueue.
  92  */
  93 static icpUdpData *IcpQueueHead = NULL;
  94 /// \ingroup ServerProtocolICPInternal2
  95 static icpUdpData *IcpQueueTail = NULL;
  96
  97 /// \ingroup ServerProtocolICPInternal2
  98 Ip::Address theOutICPAddr;
  99
 100 /* icp_common_t */
 101 _icp_common_t::_icp_common_t() : opcode(ICP_INVALID), version(0), length(0), reqnum(0), flags(0), pad(0), shostid(0)
 102 {}
 103
 104 _icp_common_t::_icp_common_t(char *buf, unsigned int len)
 105 {
 106     if (len < sizeof(_icp_common_t)) {
 107         /* mark as invalid */
 108         length = len + 1;
 109         return;
 110     }
 111
 112     xmemcpy(this, buf, sizeof(icp_common_t));
 113     /*
 114      * Convert network order sensitive fields
 115      */
 116     length = ntohs(length);
 117     reqnum = ntohl(reqnum);
 118     flags = ntohl(flags);
 119     pad = ntohl(pad);
 120 }
 121
 122 icp_opcode
 123 _icp_common_t::getOpCode() const
 124 {
 125     if (opcode > (char)ICP_END)
 126         return ICP_INVALID;
 127
 128     return (icp_opcode)opcode;
 129 }
 130
 131 /* ICPState */
 132
 133 ICPState::ICPState(icp_common_t &aHeader, HttpRequest *aRequest):
 134         header(aHeader),
 135         request(HTTPMSGLOCK(aRequest)),
 136         fd(-1),
 137         url(NULL)
 138 {}
 139
 140 ICPState::~ICPState()
 141 {
 142     safe_free(url);
 143     HTTPMSGUNLOCK(request);
 144 }
 145
 146
 147 /* End ICPState */
 148
 149 /* ICP2State */
 150
 151 /// \ingroup ServerProtocolICPInternal2
 152 class ICP2State : public ICPState, public StoreClient
 153 {
 154
 155 public:
 156     ICP2State(icp_common_t & aHeader, HttpRequest *aRequest):
 157             ICPState(aHeader, aRequest),rtt(0),src_rtt(0),flags(0) {}
 158
 159     ~ICP2State();
 160     void created(StoreEntry * newEntry);
 161
 162     int rtt;
 163     int src_rtt;
 164     uint32_t flags;
 165 };
 166
 167 ICP2State::~ICP2State()
 168 {}
 169
 170 void
 171 ICP2State::created(StoreEntry *newEntry)
 172 {
 173     StoreEntry *entry = newEntry->isNull () ? NULL : newEntry;
 174     debugs(12, 5, "icpHandleIcpV2: OPCODE " << icp_opcode_str[header.opcode]);
 175     icp_opcode codeToSend;
 176
 177     if (icpCheckUdpHit(entry, request)) {
 178         codeToSend = ICP_HIT;
 179     } else {
 180 #if USE_ICMP
 181         if (Config.onoff.test_reachability && rtt == 0) {
 182             if ((rtt = netdbHostRtt(request->GetHost())) == 0)
 183                 netdbPingSite(request->GetHost());
 184         }
 185 #endif /* USE_ICMP */
 186
 187         if (icpGetCommonOpcode() != ICP_ERR)
 188             codeToSend = icpGetCommonOpcode();
 189         else if (Config.onoff.test_reachability && rtt == 0)
 190             codeToSend = ICP_MISS_NOFETCH;
 191         else
 192             codeToSend = ICP_MISS;
 193     }
 194
 195     icpCreateAndSend(codeToSend, flags, url, header.reqnum, src_rtt, fd, from);
 196     delete this;
 197 }
 198
 199 /* End ICP2State */
 200
 201 /// \ingroup ServerProtocolICPInternal2
 202 static void
 203 icpLogIcp(const Ip::Address &caddr, log_type logcode, int len, const char *url, int delay)
 204 {
 205     AccessLogEntry al;
 206
 207     if (LOG_TAG_NONE == logcode)
 208         return;
 209
 210     if (LOG_ICP_QUERY == logcode)
 211         return;
 212
 213     clientdbUpdate(caddr, logcode, PROTO_ICP, len);
 214
 215     if (!Config.onoff.log_udp)
 216         return;
 217
 218     al.icp.opcode = ICP_QUERY;
 219
 220     al.url = url;
 221
 222     al.cache.caddr = caddr;
 223
 224     al.cache.replySize = len;
 225
 226     al.cache.code = logcode;
 227
 228     al.cache.msec = delay;
 229
 230     accessLogLog(&al, NULL);
 231 }
 232
 233 /// \ingroup ServerProtocolICPInternal2
 234 void
 235 icpUdpSendQueue(int fd, void *unused)
 236 {
 237     icpUdpData *q;
 238
 239     while ((q = IcpQueueHead) != NULL) {
 240         int delay = tvSubUsec(q->queue_time, current_time);
 241         /* increment delay to prevent looping */
 242         const int x = icpUdpSend(fd, q->address, (icp_common_t *) q->msg, q->logcode, ++delay);
 243         IcpQueueHead = q->next;
 244         xfree(q);
 245
 246         if (x < 0)
 247             break;
 248     }
 249 }
 250
 251 _icp_common_t *
 252 _icp_common_t::createMessage(
 253     icp_opcode opcode,
 254     int flags,
 255     const char *url,
 256     int reqnum,
 257     int pad)
 258 {
 259     char *buf = NULL;
 260     icp_common_t *headerp = NULL;
 261     char *urloffset = NULL;
 262     int buf_len;
 263     buf_len = sizeof(icp_common_t) + strlen(url) + 1;
 264
 265     if (opcode == ICP_QUERY)
 266         buf_len += sizeof(uint32_t);
 267
 268     buf = (char *) xcalloc(buf_len, 1);
 269
 270     headerp = (icp_common_t *) (void *) buf;
 271
 272     headerp->opcode = (char) opcode;
 273
 274     headerp->version = ICP_VERSION_CURRENT;
 275
 276     headerp->length = (uint16_t) htons(buf_len);
 277
 278     headerp->reqnum = htonl(reqnum);
 279
 280     headerp->flags = htonl(flags);
 281
 282     headerp->pad = htonl(pad);
 283
 284     theOutICPAddr.GetInAddr( *((struct in_addr*)&headerp->shostid) );
 285
 286     urloffset = buf + sizeof(icp_common_t);
 287
 288     if (opcode == ICP_QUERY)
 289         urloffset += sizeof(uint32_t);
 290
 291     xmemcpy(urloffset, url, strlen(url));
 292
 293     return (icp_common_t *)buf;
 294 }
 295
 296 int
 297 icpUdpSend(int fd,
 298            const Ip::Address &to,
 299            icp_common_t * msg,
 300            log_type logcode,
 301            int delay)
 302 {
 303     icpUdpData *queue;
 304     int x;
 305     int len;
 306     len = (int) ntohs(msg->length);
 307     debugs(12, 5, "icpUdpSend: FD " << fd << " sending " <<
 308            icp_opcode_str[msg->opcode] << ", " << len << " bytes to " << to);
 309
 310     x = comm_udp_sendto(fd, to, msg, len);
 311
 312     if (x >= 0) {
 313         /* successfully written */
 314         icpLogIcp(to, logcode, len, (char *) (msg + 1), delay);
 315         icpCount(msg, SENT, (size_t) len, delay);
 316         safe_free(msg);
 317     } else if (0 == delay) {
 318         /* send failed, but queue it */
 319         queue = (icpUdpData *) xcalloc(1, sizeof(icpUdpData));
 320         queue->address = to;
 321         queue->msg = msg;
 322         queue->len = (int) ntohs(msg->length);
 323         queue->queue_time = current_time;
 324         queue->logcode = logcode;
 325
 326         if (IcpQueueHead == NULL) {
 327             IcpQueueHead = queue;
 328             IcpQueueTail = queue;
 329         } else if (IcpQueueTail == IcpQueueHead) {
 330             IcpQueueTail = queue;
 331             IcpQueueHead->next = queue;
 332         } else {
 333             IcpQueueTail->next = queue;
 334             IcpQueueTail = queue;
 335         }
 336
 337         commSetSelect(fd, COMM_SELECT_WRITE, icpUdpSendQueue, NULL, 0);
 338         statCounter.icp.replies_queued++;
 339     } else {
 340         /* don't queue it */
 341         statCounter.icp.replies_dropped++;
 342     }
 343
 344     return x;
 345 }
 346
 347 int
 348 icpCheckUdpHit(StoreEntry * e, HttpRequest * request)
 349 {
 350     if (e == NULL)
 351         return 0;
 352
 353     if (!e->validToSend())
 354         return 0;
 355
 356     if (Config.onoff.icp_hit_stale)
 357         return 1;
 358
 359     if (refreshCheckICP(e, request))
 360         return 0;
 361
 362     return 1;
 363 }
 364
 365 /**
 366  * This routine selects an ICP opcode for ICP misses.
 367  *
 368  \retval ICP_ERR            no opcode selected here
 369  \retval ICP_MISS_NOFETCH   store is rebuilding, no fetch is possible yet
 370  */
 371 icp_opcode
 372 icpGetCommonOpcode()
 373 {
 374     /* if store is rebuilding, return a UDP_MISS_NOFETCH */
 375
 376     if ((StoreController::store_dirs_rebuilding && opt_reload_hit_only) ||
 377             hit_only_mode_until > squid_curtime) {
 378         return ICP_MISS_NOFETCH;
 379     }
 380
 381     return ICP_ERR;
 382 }
 383
 384 log_type
 385 icpLogFromICPCode(icp_opcode opcode)
 386 {
 387     if (opcode == ICP_ERR)
 388         return LOG_UDP_INVALID;
 389
 390     if (opcode == ICP_DENIED)
 391         return LOG_UDP_DENIED;
 392
 393     if (opcode == ICP_HIT)
 394         return LOG_UDP_HIT;
 395
 396     if (opcode == ICP_MISS)
 397         return LOG_UDP_MISS;
 398
 399     if (opcode == ICP_MISS_NOFETCH)
 400         return LOG_UDP_MISS_NOFETCH;
 401
 402     fatal("expected ICP opcode\n");
 403
 404     return LOG_UDP_INVALID;
 405 }
 406
 407 void
 408 icpCreateAndSend(icp_opcode opcode, int flags, char const *url, int reqnum, int pad, int fd, const Ip::Address &from)
 409 {
 410     icp_common_t *reply = _icp_common_t::createMessage(opcode, flags, url, reqnum, pad);
 411     icpUdpSend(fd, from, reply, icpLogFromICPCode(opcode), 0);
 412 }
 413
 414 void
 415 icpDenyAccess(Ip::Address &from, char *url, int reqnum, int fd)
 416 {
 417     debugs(12, 2, "icpDenyAccess: Access Denied for " << from << " by " << AclMatchedName << ".");
 418
 419     if (clientdbCutoffDenied(from)) {
 420         /*
 421          * count this DENIED query in the clientdb, even though
 422          * we're not sending an ICP reply...
 423          */
 424         clientdbUpdate(from, LOG_UDP_DENIED, PROTO_ICP, 0);
 425     } else {
 426         icpCreateAndSend(ICP_DENIED, 0, url, reqnum, 0, fd, from);
 427     }
 428 }
 429
 430 int
 431 icpAccessAllowed(Ip::Address &from, HttpRequest * icp_request)
 432 {
 433     /* absent an explicit allow, we deny all */
 434     if (!Config.accessList.icp)
 435         return 0;
 436
 437     ACLFilledChecklist checklist(Config.accessList.icp, icp_request, NULL);
 438     checklist.src_addr = from;
 439     checklist.my_addr.SetNoAddr();
 440     int result = checklist.fastCheck();
 441     return result;
 442 }
 443
 444 char const *
 445 icpGetUrlToSend(char *url)
 446 {
 447     if (strpbrk(url, w_space))
 448         return rfc1738_escape(url);
 449     else
 450         return url;
 451 }
 452
 453 HttpRequest *
 454 icpGetRequest(char *url, int reqnum, int fd, Ip::Address &from)
 455 {
 456     if (strpbrk(url, w_space)) {
 457         url = rfc1738_escape(url);
 458         icpCreateAndSend(ICP_ERR, 0, rfc1738_escape(url), reqnum, 0, fd, from);
 459         return NULL;
 460     }
 461
 462     HttpRequest *result;
 463
 464     if ((result = HttpRequest::CreateFromUrl(url)) == NULL)
 465         icpCreateAndSend(ICP_ERR, 0, url, reqnum, 0, fd, from);
 466
 467     return result;
 468
 469 }
 470
 471 static void
 472 doV2Query(int fd, Ip::Address &from, char *buf, icp_common_t header)
 473 {
 474     int rtt = 0;
 475     int src_rtt = 0;
 476     uint32_t flags = 0;
 477     /* We have a valid packet */
 478     char *url = buf + sizeof(icp_common_t) + sizeof(uint32_t);
 479     HttpRequest *icp_request = icpGetRequest(url, header.reqnum, fd, from);
 480
 481     if (!icp_request)
 482         return;
 483
 484     HTTPMSGLOCK(icp_request);
 485
 486     if (!icpAccessAllowed(from, icp_request)) {
 487         icpDenyAccess(from, url, header.reqnum, fd);
 488         HTTPMSGUNLOCK(icp_request);
 489         return;
 490     }
 491 #if USE_ICMP
 492     if (header.flags & ICP_FLAG_SRC_RTT) {
 493         rtt = netdbHostRtt(icp_request->GetHost());
 494         int hops = netdbHostHops(icp_request->GetHost());
 495         src_rtt = ((hops & 0xFFFF) << 16) | (rtt & 0xFFFF);
 496
 497         if (rtt)
 498             flags |= ICP_FLAG_SRC_RTT;
 499     }
 500 #endif /* USE_ICMP */
 501
 502     /* The peer is allowed to use this cache */
 503     ICP2State *state = new ICP2State (header, icp_request);
 504
 505     state->fd = fd;
 506
 507     state->from = from;
 508
 509     state->url = xstrdup (url);
 510
 511     state->flags = flags;
 512
 513     state->rtt = rtt;
 514
 515     state->src_rtt = src_rtt;
 516
 517     StoreEntry::getPublic (state, url, METHOD_GET);
 518
 519     HTTPMSGUNLOCK(icp_request);
 520 }
 521
 522 void
 523 _icp_common_t::handleReply(char *buf, Ip::Address &from)
 524 {
 525     if (neighbors_do_private_keys && reqnum == 0) {
 526         debugs(12, 0, "icpHandleIcpV2: Neighbor " << from << " returned reqnum = 0");
 527         debugs(12, 0, "icpHandleIcpV2: Disabling use of private keys");
 528         neighbors_do_private_keys = 0;
 529     }
 530
 531     char *url = buf + sizeof(icp_common_t);
 532     debugs(12, 3, "icpHandleIcpV2: " << icp_opcode_str[opcode] << " from " << from << " for '" << url << "'");
 533
 534     const cache_key *key = icpGetCacheKey(url, (int) reqnum);
 535     /* call neighborsUdpAck even if ping_status != PING_WAITING */
 536     neighborsUdpAck(key, this, from);
 537 }
 538
 539 static void
 540 icpHandleIcpV2(int fd, Ip::Address &from, char *buf, int len)
 541 {
 542     if (len <= 0) {
 543         debugs(12, 3, "icpHandleIcpV2: ICP message is too small");
 544         return;
 545     }
 546
 547     icp_common_t header(buf, len);
 548     /*
 549      * Length field should match the number of bytes read
 550      */
 551
 552     if (len != header.length) {
 553         debugs(12, 3, "icpHandleIcpV2: ICP message is too small");
 554         return;
 555     }
 556
 557     switch (header.opcode) {
 558
 559     case ICP_QUERY:
 560         /* We have a valid packet */
 561         doV2Query(fd, from, buf, header);
 562         break;
 563
 564     case ICP_HIT:
 565
 566     case ICP_DECHO:
 567
 568     case ICP_MISS:
 569
 570     case ICP_DENIED:
 571
 572     case ICP_MISS_NOFETCH:
 573         header.handleReply(buf, from);
 574         break;
 575
 576     case ICP_INVALID:
 577
 578     case ICP_ERR:
 579         break;
 580
 581     default:
 582         debugs(12, 0, "icpHandleIcpV2: UNKNOWN OPCODE: " << header.opcode << " from " << from);
 583
 584         break;
 585     }
 586 }
 587
 588 #ifdef ICP_PKT_DUMP
 589 static void
 590 icpPktDump(icp_common_t * pkt)
 591 {
 592     Ip::Address a;
 593
 594     debugs(12, 9, "opcode:     " << std::setw(3) << pkt->opcode  << " " << icp_opcode_str[pkt->opcode]);
 595     debugs(12, 9, "version: "<< std::left << std::setw(8) << pkt->version);
 596     debugs(12, 9, "length:  "<< std::left << std::setw(8) << ntohs(pkt->length));
 597     debugs(12, 9, "reqnum:  "<< std::left << std::setw(8) << ntohl(pkt->reqnum));
 598     debugs(12, 9, "flags:   "<< std::left << std::hex << std::setw(8) << ntohl(pkt->flags));
 599     a = (struct in_addr)pkt->shostid;
 600     debugs(12, 9, "shostid: " << a );
 601     debugs(12, 9, "payload: " << (char *) pkt + sizeof(icp_common_t));
 602 }
 603
 604 #endif
 605
 606 void
 607 icpHandleUdp(int sock, void *data)
 608 {
 609     int *N = &incoming_sockets_accepted;
 610
 611     Ip::Address from;
 612     LOCAL_ARRAY(char, buf, SQUID_UDP_SO_RCVBUF);
 613     int len;
 614     int icp_version;
 615     int max = INCOMING_ICP_MAX;
 616     commSetSelect(sock, COMM_SELECT_READ, icpHandleUdp, NULL, 0);
 617
 618     while (max--) {
 619         len = comm_udp_recvfrom(sock,
 620                                 buf,
 621                                 SQUID_UDP_SO_RCVBUF - 1,
 622                                 0,
 623                                 from);
 624
 625         if (len == 0)
 626             break;
 627
 628         if (len < 0) {
 629             if (ignoreErrno(errno))
 630                 break;
 631
 632 #ifdef _SQUID_LINUX_
 633             /* Some Linux systems seem to set the FD for reading and then
 634              * return ECONNREFUSED when sendto() fails and generates an ICMP
 635              * port unreachable message. */
 636             /* or maybe an EHOSTUNREACH "No route to host" message */
 637             if (errno != ECONNREFUSED && errno != EHOSTUNREACH)
 638 #endif
 639
 640                 debugs(50, 1, "icpHandleUdp: FD " << sock << " recvfrom: " << xstrerror());
 641
 642             break;
 643         }
 644
 645         (*N)++;
 646         icpCount(buf, RECV, (size_t) len, 0);
 647         buf[len] = '\0';
 648         debugs(12, 4, "icpHandleUdp: FD " << sock << ": received " <<
 649                (unsigned long int)len << " bytes from " << from);
 650
 651 #ifdef ICP_PACKET_DUMP
 652
 653         icpPktDump(buf);
 654 #endif
 655
 656         if ((size_t) len < sizeof(icp_common_t)) {
 657             debugs(12, 4, "icpHandleUdp: Ignoring too-small UDP packet");
 658             break;
 659         }
 660
 661         icp_version = (int) buf[1];     /* cheat! */
 662
 663         if (icp_version == ICP_VERSION_2)
 664             icpHandleIcpV2(sock, from, buf, len);
 665         else if (icp_version == ICP_VERSION_3)
 666             icpHandleIcpV3(sock, from, buf, len);
 667         else
 668             debugs(12, 1, "WARNING: Unused ICP version " << icp_version <<
 669                    " received from " << from);
 670     }
 671 }
 672
 673 void
 674 icpConnectionsOpen(void)
 675 {
 676     uint16_t port;
 677     Ip::Address addr;
 678
 679     if ((port = Config.Port.icp) <= 0)
 680         return;
 681
 682     addr = Config.Addrs.udp_incoming;
 683     addr.SetPort(port);
 684
 685     if (!Ip::EnableIpv6 && !addr.SetIPv4()) {
 686         debugs(12, DBG_CRITICAL, "ERROR: IPv6 is disabled. " << addr << " is not an IPv4 address.");
 687         fatal("ICP port cannot be opened.");
 688     }
 689     /* split-stack for now requires default IPv4-only ICP */
 690     if (Ip::EnableIpv6&IPV6_SPECIAL_SPLITSTACK && addr.IsAnyAddr()) {
 691         addr.SetIPv4();
 692     }
 693
 694     AsyncCall::Pointer call = asyncCall(12, 2,
 695                                         "icpIncomingConnectionOpened",
 696                                         IcpListeningStartedDialer(&icpIncomingConnectionOpened, addr));
 697
 698     Ipc::StartListening(SOCK_DGRAM,
 699                         IPPROTO_UDP,
 700                         addr,
 701                         COMM_NONBLOCKING,
 702                         Ipc::fdnInIcpSocket, call);
 703
 704     addr.SetEmpty(); // clear for next use.
 705     addr = Config.Addrs.udp_outgoing;
 706     if ( !addr.IsNoAddr() ) {
 707         enter_suid();
 708         addr.SetPort(port);
 709
 710         if (!Ip::EnableIpv6 && !addr.SetIPv4()) {
 711             debugs(49, DBG_CRITICAL, "ERROR: IPv6 is disabled. " << addr << " is not an IPv4 address.");
 712             fatal("ICP port cannot be opened.");
 713         }
 714         /* split-stack for now requires default IPv4-only ICP */
 715         if (Ip::EnableIpv6&IPV6_SPECIAL_SPLITSTACK && addr.IsAnyAddr()) {
 716             addr.SetIPv4();
 717         }
 718
 719         theOutIcpConnection = comm_open_listener(SOCK_DGRAM,
 720                               IPPROTO_UDP,
 721                               addr,
 722                               COMM_NONBLOCKING,
 723                               "ICP Port");
 724         leave_suid();
 725
 726         if (theOutIcpConnection < 0)
 727             fatal("Cannot open Outgoing ICP Port");
 728
 729         commSetSelect(theOutIcpConnection,
 730                       COMM_SELECT_READ,
 731                       icpHandleUdp,
 732                       NULL,
 733                       0);
 734
 735         debugs(12, 1, "Outgoing ICP messages on port " << addr.GetPort() << ", FD " << theOutIcpConnection << ".");
 736
 737         fd_note(theOutIcpConnection, "Outgoing ICP socket");
 738         icpGetOutgoingIpAddress();
 739     }
 740 }
 741
 742 static void
 743 icpGetOutgoingIpAddress()
 744 {
 745     struct addrinfo *xai = NULL;
 746     theOutICPAddr.SetEmpty();
 747     theOutICPAddr.InitAddrInfo(xai);
 748
 749     if (getsockname(theOutIcpConnection, xai->ai_addr, &xai->ai_addrlen) < 0)
 750         debugs(50, 1, "theOutIcpConnection FD " << theOutIcpConnection << ": getsockname: " << xstrerror());
 751     else
 752         theOutICPAddr = *xai;
 753
 754     theOutICPAddr.FreeAddrInfo(xai);
 755 }
 756
 757 static void
 758 icpIncomingConnectionOpened(int fd, int errNo, Ip::Address& addr)
 759 {
 760     theInIcpConnection = fd;
 761
 762     if (theInIcpConnection < 0)
 763         fatal("Cannot open ICP Port");
 764
 765     commSetSelect(theInIcpConnection,
 766                   COMM_SELECT_READ,
 767                   icpHandleUdp,
 768                   NULL,
 769                   0);
 770
 771     for (const wordlist *s = Config.mcast_group_list; s; s = s->next)
 772         ipcache_nbgethostbyname(s->key, mcastJoinGroups, NULL);
 773
 774     debugs(12, 1, "Accepting ICP messages at " << addr << ", FD " << theInIcpConnection << ".");
 775
 776     fd_note(theInIcpConnection, "Incoming ICP socket");
 777
 778     if (Config.Addrs.udp_outgoing.IsNoAddr()) {
 779         theOutIcpConnection = theInIcpConnection;
 780         icpGetOutgoingIpAddress();
 781     }
 782 }
 783
 784 /**
 785  * icpConnectionShutdown only closes the 'in' socket if it is
 786  * different than the 'out' socket.
 787  */
 788 void
 789 icpConnectionShutdown(void)
 790 {
 791     if (theInIcpConnection < 0)
 792         return;
 793
 794     if (theInIcpConnection != theOutIcpConnection) {
 795         debugs(12, 1, "FD " << theInIcpConnection << " Closing ICP connection");
 796         comm_close(theInIcpConnection);
 797     }
 798
 799     /**
 800      * Here we set 'theInIcpConnection' to -1 even though the ICP 'in'
 801      * and 'out' sockets might be just one FD.  This prevents this
 802      * function from executing repeatedly.  When we are really ready to
 803      * exit or restart, main will comm_close the 'out' descriptor.
 804      */
 805     theInIcpConnection = -1;
 806
 807     /**
 808      * Normally we only write to the outgoing ICP socket, but
 809      * we also have a read handler there to catch messages sent
 810      * to that specific interface.  During shutdown, we must
 811      * disable reading on the outgoing socket.
 812      */
 813     assert(theOutIcpConnection > -1);
 814
 815     commSetSelect(theOutIcpConnection, COMM_SELECT_READ, NULL, NULL, 0);
 816 }
 817
 818 void
 819 icpConnectionClose(void)
 820 {
 821     icpConnectionShutdown();
 822
 823     if (theOutIcpConnection > -1) {
 824         debugs(12, 1, "FD " << theOutIcpConnection << " Closing ICP connection");
 825         comm_close(theOutIcpConnection);
 826         theOutIcpConnection = -1;
 827     }
 828 }
 829
 830 static void
 831 icpCount(void *buf, int which, size_t len, int delay)
 832 {
 833     icp_common_t *icp = (icp_common_t *) buf;
 834
 835     if (len < sizeof(*icp))
 836         return;
 837
 838     if (SENT == which) {
 839         statCounter.icp.pkts_sent++;
 840         kb_incr(&statCounter.icp.kbytes_sent, len);
 841
 842         if (ICP_QUERY == icp->opcode) {
 843             statCounter.icp.queries_sent++;
 844             kb_incr(&statCounter.icp.q_kbytes_sent, len);
 845         } else {
 846             statCounter.icp.replies_sent++;
 847             kb_incr(&statCounter.icp.r_kbytes_sent, len);
 848             /* this is the sent-reply service time */
 849             statHistCount(&statCounter.icp.reply_svc_time, delay);
 850         }
 851
 852         if (ICP_HIT == icp->opcode)
 853             statCounter.icp.hits_sent++;
 854     } else if (RECV == which) {
 855         statCounter.icp.pkts_recv++;
 856         kb_incr(&statCounter.icp.kbytes_recv, len);
 857
 858         if (ICP_QUERY == icp->opcode) {
 859             statCounter.icp.queries_recv++;
 860             kb_incr(&statCounter.icp.q_kbytes_recv, len);
 861         } else {
 862             statCounter.icp.replies_recv++;
 863             kb_incr(&statCounter.icp.r_kbytes_recv, len);
 864             /* statCounter.icp.query_svc_time set in clientUpdateCounters */
 865         }
 866
 867         if (ICP_HIT == icp->opcode)
 868             statCounter.icp.hits_recv++;
 869     }
 870 }
 871
 872 #define N_QUERIED_KEYS 8192
 873 #define N_QUERIED_KEYS_MASK 8191
 874 static cache_key queried_keys[N_QUERIED_KEYS][SQUID_MD5_DIGEST_LENGTH];
 875
 876 int
 877 icpSetCacheKey(const cache_key * key)
 878 {
 879     static int reqnum = 0;
 880
 881     if (++reqnum < 0)
 882         reqnum = 1;
 883
 884     storeKeyCopy(queried_keys[reqnum & N_QUERIED_KEYS_MASK], key);
 885
 886     return reqnum;
 887 }
 888
 889 const cache_key *
 890 icpGetCacheKey(const char *url, int reqnum)
 891 {
 892     if (neighbors_do_private_keys && reqnum)
 893         return queried_keys[reqnum & N_QUERIED_KEYS_MASK];
 894
 895     return storeKeyPublic(url, METHOD_GET);
 896 }