src/neighbors.cc

   1 /*
   2  * DEBUG: section 15    Neighbor Routines
   3  * AUTHOR: Harvest Derived
   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 #include "squid.h"
  34 #include "ProtoPort.h"
  35 #include "acl/FilledChecklist.h"
  36 #include "event.h"
  37 #include "htcp.h"
  38 #include "HttpRequest.h"
  39 #include "ICP.h"
  40 #include "ip/tools.h"
  41 #include "MemObject.h"
  42 #include "PeerDigest.h"
  43 #include "PeerSelectState.h"
  44 #include "SquidMath.h"
  45 #include "SquidTime.h"
  46 #include "Store.h"
  47 #include "icmp/net_db.h"
  48 #include "ip/Address.h"
  49 #include "ip/tools.h"
  50 #include "mgr/Registration.h"
  51
  52 /* count mcast group peers every 15 minutes */
  53 #define MCAST_COUNT_RATE 900
  54
  55 int peerAllowedToUse(const peer *, HttpRequest *);
  56 static int peerWouldBePinged(const peer *, HttpRequest *);
  57 static void neighborRemove(peer *);
  58 static void neighborAlive(peer *, const MemObject *, const icp_common_t *);
  59 #if USE_HTCP
  60 static void neighborAliveHtcp(peer *, const MemObject *, const htcpReplyData *);
  61 #endif
  62 static void neighborCountIgnored(peer *);
  63 static void peerRefreshDNS(void *);
  64 static IPH peerDNSConfigure;
  65 static int peerProbeConnect(peer *);
  66 static CNCB peerProbeConnectDone;
  67 static void peerCountMcastPeersDone(void *data);
  68 static void peerCountMcastPeersStart(void *data);
  69 static void peerCountMcastPeersSchedule(peer * p, time_t when);
  70 static IRCB peerCountHandleIcpReply;
  71
  72 static void neighborIgnoreNonPeer(const Ip::Address &, icp_opcode);
  73 static OBJH neighborDumpPeers;
  74 static OBJH neighborDumpNonPeers;
  75 static void dump_peers(StoreEntry * sentry, peer * peers);
  76
  77 static icp_common_t echo_hdr;
  78 static u_short echo_port;
  79
  80 static int NLateReplies = 0;
  81 static peer *first_ping = NULL;
  82
  83 const char *
  84 neighborTypeStr(const peer * p)
  85 {
  86     if (p->type == PEER_NONE)
  87         return "Non-Peer";
  88
  89     if (p->type == PEER_SIBLING)
  90         return "Sibling";
  91
  92     if (p->type == PEER_MULTICAST)
  93         return "Multicast Group";
  94
  95     return "Parent";
  96 }
  97
  98
  99 peer *
 100 whichPeer(const Ip::Address &from)
 101 {
 102     int j;
 103
 104     peer *p = NULL;
 105     debugs(15, 3, "whichPeer: from " << from);
 106
 107     for (p = Config.peers; p; p = p->next) {
 108         for (j = 0; j < p->n_addresses; j++) {
 109             if (from == p->addresses[j] && from.GetPort() == p->icp.port) {
 110                 return p;
 111             }
 112         }
 113     }
 114
 115     return NULL;
 116 }
 117
 118 peer_t
 119 neighborType(const peer * p, const HttpRequest * request)
 120 {
 121
 122     const struct _domain_type *d = NULL;
 123
 124     for (d = p->typelist; d; d = d->next) {
 125         if (0 == matchDomainName(request->GetHost(), d->domain))
 126             if (d->type != PEER_NONE)
 127                 return d->type;
 128     }
 129 #if PEER_MULTICAST_SIBLINGS
 130     if (p->type == PEER_MULTICAST)
 131         if (p->options.mcast_siblings)
 132             return PEER_SIBLING;
 133 #endif
 134
 135     return p->type;
 136 }
 137
 138 /*
 139  * peerAllowedToUse
 140  *
 141  * this function figures out if it is appropriate to fetch REQUEST
 142  * from PEER.
 143  */
 144 int
 145 peerAllowedToUse(const peer * p, HttpRequest * request)
 146 {
 147
 148     const struct _domain_ping *d = NULL;
 149     int do_ping = 1;
 150     assert(request != NULL);
 151
 152     if (neighborType(p, request) == PEER_SIBLING) {
 153 #if PEER_MULTICAST_SIBLINGS
 154         if (p->type == PEER_MULTICAST && p->options.mcast_siblings &&
 155                 (request->flags.nocache || request->flags.refresh || request->flags.loopdetect || request->flags.need_validation))
 156             debugs(15, 2, "peerAllowedToUse(" << p->name << ", " << request->GetHost() << ") : multicast-siblings optimization match");
 157 #endif
 158         if (request->flags.nocache)
 159             return 0;
 160
 161         if (request->flags.refresh)
 162             return 0;
 163
 164         if (request->flags.loopdetect)
 165             return 0;
 166
 167         if (request->flags.need_validation)
 168             return 0;
 169     }
 170
 171     // CONNECT requests are proxy requests. Not to be forwarded to origin servers.
 172     // Unless the destination port matches, in which case we MAY perform a 'DIRECT' to this peer.
 173     if (p->options.originserver && request->method == METHOD_CONNECT && request->port != p->in_addr.GetPort())
 174         return 0;
 175
 176     if (p->peer_domain == NULL && p->access == NULL)
 177         return do_ping;
 178
 179     do_ping = 0;
 180
 181     for (d = p->peer_domain; d; d = d->next) {
 182         if (0 == matchDomainName(request->GetHost(), d->domain)) {
 183             do_ping = d->do_ping;
 184             break;
 185         }
 186
 187         do_ping = !d->do_ping;
 188     }
 189
 190     if (p->peer_domain && 0 == do_ping)
 191         return do_ping;
 192
 193     if (p->access == NULL)
 194         return do_ping;
 195
 196     ACLFilledChecklist checklist(p->access, request, NULL);
 197     checklist.src_addr = request->client_addr;
 198     checklist.my_addr = request->my_addr;
 199
 200 #if 0 && USE_IDENT
 201     /*
 202      * this is currently broken because 'request->user_ident' has been
 203      * moved to conn->rfc931 and we don't have access to the parent
 204      * ConnStateData here.
 205      */
 206     if (request->user_ident[0])
 207         xstrncpy(checklist.rfc931, request->user_ident, USER_IDENT_SZ);
 208
 209 #endif
 210
 211     return checklist.fastCheck();
 212 }
 213
 214 /* Return TRUE if it is okay to send an ICP request to this peer.   */
 215 static int
 216 peerWouldBePinged(const peer * p, HttpRequest * request)
 217 {
 218     if (!peerAllowedToUse(p, request))
 219         return 0;
 220
 221     if (p->options.no_query)
 222         return 0;
 223
 224     if (p->options.background_ping && (squid_curtime - p->stats.last_query < Config.backgroundPingRate))
 225         return 0;
 226
 227     if (p->options.mcast_responder)
 228         return 0;
 229
 230     if (p->n_addresses == 0)
 231         return 0;
 232
 233     if (p->icp.port == 0)
 234         return 0;
 235
 236     /* the case below seems strange, but can happen if the
 237      * URL host is on the other side of a firewall */
 238     if (p->type == PEER_SIBLING)
 239         if (!request->flags.hierarchical)
 240             return 0;
 241
 242     /* Ping dead peers every timeout interval */
 243     if (squid_curtime - p->stats.last_query > Config.Timeout.deadPeer)
 244         return 1;
 245
 246     if (!neighborUp(p))
 247         return 0;
 248
 249     return 1;
 250 }
 251
 252 /* Return TRUE if it is okay to send an HTTP request to this peer. */
 253 int
 254 peerHTTPOkay(const peer * p, HttpRequest * request)
 255 {
 256     if (!peerAllowedToUse(p, request))
 257         return 0;
 258
 259     if (!neighborUp(p))
 260         return 0;
 261
 262     if (p->max_conn)
 263         if (p->stats.conn_open >= p->max_conn)
 264             return 0;
 265
 266     return 1;
 267 }
 268
 269 int
 270 neighborsCount(HttpRequest * request)
 271 {
 272     peer *p = NULL;
 273     int count = 0;
 274
 275     for (p = Config.peers; p; p = p->next)
 276         if (peerWouldBePinged(p, request))
 277             count++;
 278
 279     debugs(15, 3, "neighborsCount: " << count);
 280
 281     return count;
 282 }
 283
 284 peer *
 285 getFirstUpParent(HttpRequest * request)
 286 {
 287     peer *p = NULL;
 288
 289     for (p = Config.peers; p; p = p->next) {
 290         if (!neighborUp(p))
 291             continue;
 292
 293         if (neighborType(p, request) != PEER_PARENT)
 294             continue;
 295
 296         if (!peerHTTPOkay(p, request))
 297             continue;
 298
 299         break;
 300     }
 301
 302     debugs(15, 3, "getFirstUpParent: returning " << (p ? p->host : "NULL"));
 303     return p;
 304 }
 305
 306 peer *
 307 getRoundRobinParent(HttpRequest * request)
 308 {
 309     peer *p;
 310     peer *q = NULL;
 311
 312     for (p = Config.peers; p; p = p->next) {
 313         if (!p->options.roundrobin)
 314             continue;
 315
 316         if (neighborType(p, request) != PEER_PARENT)
 317             continue;
 318
 319         if (!peerHTTPOkay(p, request))
 320             continue;
 321
 322         if (p->weight == 0)
 323             continue;
 324
 325         if (q) {
 326             if (p->weight == q->weight) {
 327                 if (q->rr_count < p->rr_count)
 328                     continue;
 329             } else if ( ((double) q->rr_count / q->weight) < ((double) p->rr_count / p->weight)) {
 330                 continue;
 331             }
 332         }
 333
 334         q = p;
 335     }
 336
 337     if (q)
 338         q->rr_count++;
 339
 340     debugs(15, 3, HERE << "returning " << (q ? q->host : "NULL"));
 341
 342     return q;
 343 }
 344
 345 peer *
 346 getWeightedRoundRobinParent(HttpRequest * request)
 347 {
 348     peer *p;
 349     peer *q = NULL;
 350     int weighted_rtt;
 351
 352     for (p = Config.peers; p; p = p->next) {
 353         if (!p->options.weighted_roundrobin)
 354             continue;
 355
 356         if (neighborType(p, request) != PEER_PARENT)
 357             continue;
 358
 359         if (!peerHTTPOkay(p, request))
 360             continue;
 361
 362         if (q && q->rr_count < p->rr_count)
 363             continue;
 364
 365         q = p;
 366     }
 367
 368     if (q && q->rr_count > 1000000)
 369         for (p = Config.peers; p; p = p->next) {
 370             if (!p->options.weighted_roundrobin)
 371                 continue;
 372
 373             if (neighborType(p, request) != PEER_PARENT)
 374                 continue;
 375
 376             p->rr_count = 0;
 377         }
 378
 379     if (q) {
 380         weighted_rtt = (q->stats.rtt - q->basetime) / q->weight;
 381
 382         if (weighted_rtt < 1)
 383             weighted_rtt = 1;
 384
 385         q->rr_count += weighted_rtt;
 386
 387         debugs(15, 3, "getWeightedRoundRobinParent: weighted_rtt " << weighted_rtt);
 388     }
 389
 390     debugs(15, 3, "getWeightedRoundRobinParent: returning " << (q ? q->host : "NULL"));
 391     return q;
 392 }
 393
 394 /**
 395  * This gets called every 5 minutes to clear the round-robin counter.
 396  * The exact timing is an arbitrary default, set on estimate timing of a
 397  * large number of requests in a high-performance environment during the
 398  * period. The larger the number of requests between cycled resets the
 399  * more balanced the operations.
 400  *
 401  \param data    unused.
 402  \todo Make the reset timing a selectable parameter in squid.conf
 403  */
 404 static void
 405 peerClearRRLoop(void *data)
 406 {
 407     peerClearRR();
 408     eventAdd("peerClearRR", peerClearRRLoop, data, 5 * 60.0, 0);
 409 }
 410
 411 /**
 412  * This gets called on startup and restart to kick off the peer round-robin
 413  * maintenance event. It ensures that no matter how many times its called
 414  * no more than one event is scheduled.
 415  */
 416 void
 417 peerClearRRStart(void)
 418 {
 419     static int event_added = 0;
 420     if (!event_added) {
 421         peerClearRRLoop(NULL);
 422     }
 423 }
 424
 425 /**
 426  * Called whenever the round-robin counters need to be reset to a sane state.
 427  * So far those times are:
 428  *  - On startup and reconfigure - to set the counters to sane initial settings.
 429  *  -  When a peer has revived from dead, to prevent the revived peer being
 430  *     flooded with requests which it has 'missed' during the down period.
 431  */
 432 void
 433 peerClearRR()
 434 {
 435     peer *p = NULL;
 436     for (p = Config.peers; p; p = p->next) {
 437         p->rr_count = 0;
 438     }
 439 }
 440
 441 /**
 442  * Perform all actions when a peer is detected revived.
 443  */
 444 void
 445 peerAlive(peer *p)
 446 {
 447     if (p->stats.logged_state == PEER_DEAD && p->tcp_up) {
 448         debugs(15, 1, "Detected REVIVED " << neighborTypeStr(p) << ": " << p->name);
 449         p->stats.logged_state = PEER_ALIVE;
 450         peerClearRR();
 451     }
 452
 453     p->stats.last_reply = squid_curtime;
 454     p->stats.probe_start = 0;
 455 }
 456
 457 peer *
 458 getDefaultParent(HttpRequest * request)
 459 {
 460     peer *p = NULL;
 461
 462     for (p = Config.peers; p; p = p->next) {
 463         if (neighborType(p, request) != PEER_PARENT)
 464             continue;
 465
 466         if (!p->options.default_parent)
 467             continue;
 468
 469         if (!peerHTTPOkay(p, request))
 470             continue;
 471
 472         debugs(15, 3, "getDefaultParent: returning " << p->host);
 473
 474         return p;
 475     }
 476
 477     debugs(15, 3, "getDefaultParent: returning NULL");
 478     return NULL;
 479 }
 480
 481 /*
 482  * XXX DW thinks this function is equivalent to/redundant with
 483  * getFirstUpParent().  peerHTTPOkay() only returns true if the
 484  * peer is UP anyway, so this function would not return a
 485  * DOWN parent.
 486  */
 487 peer *
 488 getAnyParent(HttpRequest * request)
 489 {
 490     peer *p = NULL;
 491
 492     for (p = Config.peers; p; p = p->next) {
 493         if (neighborType(p, request) != PEER_PARENT)
 494             continue;
 495
 496         if (!peerHTTPOkay(p, request))
 497             continue;
 498
 499         debugs(15, 3, "getAnyParent: returning " << p->host);
 500
 501         return p;
 502     }
 503
 504     debugs(15, 3, "getAnyParent: returning NULL");
 505     return NULL;
 506 }
 507
 508 peer *
 509 getNextPeer(peer * p)
 510 {
 511     return p->next;
 512 }
 513
 514 peer *
 515 getFirstPeer(void)
 516 {
 517     return Config.peers;
 518 }
 519
 520 static void
 521 neighborRemove(peer * target)
 522 {
 523     peer *p = NULL;
 524     peer **P = NULL;
 525     p = Config.peers;
 526     P = &Config.peers;
 527
 528     while (p) {
 529         if (target == p)
 530             break;
 531
 532         P = &p->next;
 533
 534         p = p->next;
 535     }
 536
 537     if (p) {
 538         *P = p->next;
 539         cbdataFree(p);
 540         Config.npeers--;
 541     }
 542
 543     first_ping = Config.peers;
 544 }
 545
 546 static void
 547 neighborsRegisterWithCacheManager()
 548 {
 549     Mgr::RegisterAction("server_list",
 550                         "Peer Cache Statistics",
 551                         neighborDumpPeers, 0, 1);
 552
 553     if (theInIcpConnection >= 0) {
 554         Mgr::RegisterAction("non_peers",
 555                             "List of Unknown sites sending ICP messages",
 556                             neighborDumpNonPeers, 0, 1);
 557     }
 558 }
 559
 560 void
 561 neighbors_init(void)
 562 {
 563     Ip::Address nul;
 564     struct addrinfo *AI = NULL;
 565     struct servent *sep = NULL;
 566     const char *me = getMyHostname();
 567     peer *thisPeer = NULL;
 568     peer *next = NULL;
 569     int fd = theInIcpConnection;
 570
 571     neighborsRegisterWithCacheManager();
 572
 573     /* setup addrinfo for use */
 574     nul.InitAddrInfo(AI);
 575
 576     if (fd >= 0) {
 577
 578         if (getsockname(fd, AI->ai_addr, &AI->ai_addrlen) < 0)
 579             debugs(15, 1, "getsockname(" << fd << "," << AI->ai_addr << "," << &AI->ai_addrlen << ") failed.");
 580
 581         for (thisPeer = Config.peers; thisPeer; thisPeer = next) {
 582             http_port_list *s = NULL;
 583             next = thisPeer->next;
 584
 585             if (0 != strcmp(thisPeer->host, me))
 586                 continue;
 587
 588             for (s = Config.Sockaddr.http; s; s = s->next) {
 589                 if (thisPeer->http_port != s->s.GetPort())
 590                     continue;
 591
 592                 debugs(15, DBG_IMPORTANT, "WARNING: Peer looks like this host");
 593
 594                 debugs(15, DBG_IMPORTANT, "         Ignoring " <<
 595                        neighborTypeStr(thisPeer) << " " << thisPeer->host <<
 596                        "/" << thisPeer->http_port << "/" <<
 597                        thisPeer->icp.port);
 598
 599                 neighborRemove(thisPeer);
 600             }
 601         }
 602     }
 603
 604     peerRefreshDNS((void *) 1);
 605
 606     if (echo_hdr.opcode == ICP_INVALID) {
 607         echo_hdr.opcode = ICP_SECHO;
 608         echo_hdr.version = ICP_VERSION_CURRENT;
 609         echo_hdr.length = 0;
 610         echo_hdr.reqnum = 0;
 611         echo_hdr.flags = 0;
 612         echo_hdr.pad = 0;
 613         nul = *AI;
 614         nul.GetInAddr( *((struct in_addr*)&echo_hdr.shostid) );
 615         sep = getservbyname("echo", "udp");
 616         echo_port = sep ? ntohs((u_short) sep->s_port) : 7;
 617     }
 618
 619     first_ping = Config.peers;
 620     nul.FreeAddrInfo(AI);
 621 }
 622
 623 int
 624 neighborsUdpPing(HttpRequest * request,
 625                  StoreEntry * entry,
 626                  IRCB * callback,
 627                  void *callback_data,
 628                  int *exprep,
 629                  int *timeout)
 630 {
 631     const char *url = entry->url();
 632     MemObject *mem = entry->mem_obj;
 633     peer *p = NULL;
 634     int i;
 635     int reqnum = 0;
 636     int flags;
 637     icp_common_t *query;
 638     int queries_sent = 0;
 639     int peers_pinged = 0;
 640     int parent_timeout = 0, parent_exprep = 0;
 641     int sibling_timeout = 0, sibling_exprep = 0;
 642     int mcast_timeout = 0, mcast_exprep = 0;
 643
 644     if (Config.peers == NULL)
 645         return 0;
 646
 647     assert(entry->swap_status == SWAPOUT_NONE);
 648
 649     mem->start_ping = current_time;
 650
 651     mem->ping_reply_callback = callback;
 652
 653     mem->ircb_data = callback_data;
 654
 655     reqnum = icpSetCacheKey((const cache_key *)entry->key);
 656
 657     for (i = 0, p = first_ping; i++ < Config.npeers; p = p->next) {
 658         if (p == NULL)
 659             p = Config.peers;
 660
 661         debugs(15, 5, "neighborsUdpPing: Peer " << p->host);
 662
 663         if (!peerWouldBePinged(p, request))
 664             continue;           /* next peer */
 665
 666         peers_pinged++;
 667
 668         debugs(15, 4, "neighborsUdpPing: pinging peer " << p->host << " for '" << url << "'");
 669
 670         debugs(15, 3, "neighborsUdpPing: key = '" << entry->getMD5Text() << "'");
 671
 672         debugs(15, 3, "neighborsUdpPing: reqnum = " << reqnum);
 673
 674 #if USE_HTCP
 675         if (p->options.htcp && !p->options.htcp_only_clr) {
 676             if (Config.Port.htcp <= 0) {
 677                 debugs(15, DBG_CRITICAL, "HTCP is disabled! Cannot send HTCP request to peer.");
 678                 continue;
 679             }
 680
 681             debugs(15, 3, "neighborsUdpPing: sending HTCP query");
 682             if (htcpQuery(entry, request, p) <= 0) continue; // unable to send.
 683         } else
 684 #endif
 685         {
 686             if (Config.Port.icp <= 0 || theOutIcpConnection <= 0) {
 687                 debugs(15, DBG_CRITICAL, "ICP is disabled! Cannot send ICP request to peer.");
 688                 continue;
 689             } else {
 690
 691                 if (p->type == PEER_MULTICAST)
 692                     mcastSetTtl(theOutIcpConnection, p->mcast.ttl);
 693
 694                 if (p->icp.port == echo_port) {
 695                     debugs(15, 4, "neighborsUdpPing: Looks like a dumb cache, send DECHO ping");
 696                     echo_hdr.reqnum = reqnum;
 697                     query = _icp_common_t::createMessage(ICP_DECHO, 0, url, reqnum, 0);
 698                     icpUdpSend(theOutIcpConnection,p->in_addr,query,LOG_ICP_QUERY,0);
 699                 } else {
 700                     flags = 0;
 701
 702                     if (Config.onoff.query_icmp)
 703                         if (p->icp.version == ICP_VERSION_2)
 704                             flags |= ICP_FLAG_SRC_RTT;
 705
 706                     query = _icp_common_t::createMessage(ICP_QUERY, flags, url, reqnum, 0);
 707
 708                     icpUdpSend(theOutIcpConnection, p->in_addr, query, LOG_ICP_QUERY, 0);
 709                 }
 710             }
 711         }
 712
 713         queries_sent++;
 714
 715         p->stats.pings_sent++;
 716
 717         if (p->type == PEER_MULTICAST) {
 718             mcast_exprep += p->mcast.n_replies_expected;
 719             mcast_timeout += (p->stats.rtt * p->mcast.n_replies_expected);
 720         } else if (neighborUp(p)) {
 721             /* its alive, expect a reply from it */
 722
 723             if (neighborType(p, request) == PEER_PARENT) {
 724                 parent_exprep++;
 725                 parent_timeout += p->stats.rtt;
 726             } else {
 727                 sibling_exprep++;
 728                 sibling_timeout += p->stats.rtt;
 729             }
 730         } else {
 731             /* Neighbor is dead; ping it anyway, but don't expect a reply */
 732             /* log it once at the threshold */
 733
 734             if (p->stats.logged_state == PEER_ALIVE) {
 735                 debugs(15, 1, "Detected DEAD " << neighborTypeStr(p) << ": " << p->name);
 736                 p->stats.logged_state = PEER_DEAD;
 737             }
 738         }
 739
 740         p->stats.last_query = squid_curtime;
 741
 742         /*
 743          * keep probe_start == 0 for a multicast peer,
 744          * so neighborUp() never says this peer is dead.
 745          */
 746
 747         if ((p->type != PEER_MULTICAST) && (p->stats.probe_start == 0))
 748             p->stats.probe_start = squid_curtime;
 749     }
 750
 751     if ((first_ping = first_ping->next) == NULL)
 752         first_ping = Config.peers;
 753
 754     /*
 755      * How many replies to expect?
 756      */
 757     *exprep = parent_exprep + sibling_exprep + mcast_exprep;
 758
 759     /*
 760      * If there is a configured timeout, use it
 761      */
 762     if (Config.Timeout.icp_query)
 763         *timeout = Config.Timeout.icp_query;
 764     else {
 765         if (*exprep > 0) {
 766             if (parent_exprep)
 767                 *timeout = 2 * parent_timeout / parent_exprep;
 768             else if (mcast_exprep)
 769                 *timeout = 2 * mcast_timeout / mcast_exprep;
 770             else
 771                 *timeout = 2 * sibling_timeout / sibling_exprep;
 772         } else
 773             *timeout = 2000;    /* 2 seconds */
 774
 775         if (Config.Timeout.icp_query_max)
 776             if (*timeout > Config.Timeout.icp_query_max)
 777                 *timeout = Config.Timeout.icp_query_max;
 778
 779         if (*timeout < Config.Timeout.icp_query_min)
 780             *timeout = Config.Timeout.icp_query_min;
 781     }
 782
 783     return peers_pinged;
 784 }
 785
 786 /* lookup the digest of a given peer */
 787 lookup_t
 788 peerDigestLookup(peer * p, HttpRequest * request)
 789 {
 790 #if USE_CACHE_DIGESTS
 791     const cache_key *key = request ? storeKeyPublicByRequest(request) : NULL;
 792     assert(p);
 793     assert(request);
 794     debugs(15, 5, "peerDigestLookup: peer " << p->host);
 795     /* does the peeer have a valid digest? */
 796
 797     if (!p->digest) {
 798         debugs(15, 5, "peerDigestLookup: gone!");
 799         return LOOKUP_NONE;
 800     } else if (!peerHTTPOkay(p, request)) {
 801         debugs(15, 5, "peerDigestLookup: !peerHTTPOkay");
 802         return LOOKUP_NONE;
 803     } else if (!p->digest->flags.needed) {
 804         debugs(15, 5, "peerDigestLookup: note need");
 805         peerDigestNeeded(p->digest);
 806         return LOOKUP_NONE;
 807     } else if (!p->digest->flags.usable) {
 808         debugs(15, 5, "peerDigestLookup: !ready && " << (p->digest->flags.requested ? "" : "!") << "requested");
 809         return LOOKUP_NONE;
 810     }
 811
 812     debugs(15, 5, "peerDigestLookup: OK to lookup peer " << p->host);
 813     assert(p->digest->cd);
 814     /* does digest predict a hit? */
 815
 816     if (!cacheDigestTest(p->digest->cd, key))
 817         return LOOKUP_MISS;
 818
 819     debugs(15, 5, "peerDigestLookup: peer " << p->host << " says HIT!");
 820
 821     return LOOKUP_HIT;
 822
 823 #endif
 824
 825     return LOOKUP_NONE;
 826 }
 827
 828 /* select best peer based on cache digests */
 829 peer *
 830 neighborsDigestSelect(HttpRequest * request)
 831 {
 832     peer *best_p = NULL;
 833 #if USE_CACHE_DIGESTS
 834
 835     int best_rtt = 0;
 836     int choice_count = 0;
 837     int ichoice_count = 0;
 838     peer *p;
 839     int p_rtt;
 840     int i;
 841
 842     if (!request->flags.hierarchical)
 843         return NULL;
 844
 845     storeKeyPublicByRequest(request);
 846
 847     for (i = 0, p = first_ping; i++ < Config.npeers; p = p->next) {
 848         lookup_t lookup;
 849
 850         if (!p)
 851             p = Config.peers;
 852
 853         if (i == 1)
 854             first_ping = p;
 855
 856         lookup = peerDigestLookup(p, request);
 857
 858         if (lookup == LOOKUP_NONE)
 859             continue;
 860
 861         choice_count++;
 862
 863         if (lookup == LOOKUP_MISS)
 864             continue;
 865
 866         p_rtt = netdbHostRtt(p->host);
 867
 868         debugs(15, 5, "neighborsDigestSelect: peer " << p->host << " rtt: " << p_rtt);
 869
 870         /* is this peer better than others in terms of rtt ? */
 871         if (!best_p || (p_rtt && p_rtt < best_rtt)) {
 872             best_p = p;
 873             best_rtt = p_rtt;
 874
 875             if (p_rtt)          /* informative choice (aka educated guess) */
 876                 ichoice_count++;
 877
 878             debugs(15, 4, "neighborsDigestSelect: peer " << p->host << " leads with rtt " << best_rtt);
 879         }
 880     }
 881
 882     debugs(15, 4, "neighborsDigestSelect: choices: " << choice_count << " (" << ichoice_count << ")");
 883     peerNoteDigestLookup(request, best_p,
 884                          best_p ? LOOKUP_HIT : (choice_count ? LOOKUP_MISS : LOOKUP_NONE));
 885     request->hier.n_choices = choice_count;
 886     request->hier.n_ichoices = ichoice_count;
 887 #endif
 888
 889     return best_p;
 890 }
 891
 892 void
 893 peerNoteDigestLookup(HttpRequest * request, peer * p, lookup_t lookup)
 894 {
 895 #if USE_CACHE_DIGESTS
 896     if (p)
 897         strncpy(request->hier.cd_host, p->host, sizeof(request->hier.cd_host));
 898     else
 899         *request->hier.cd_host = '\0';
 900
 901     request->hier.cd_lookup = lookup;
 902     debugs(15, 4, "peerNoteDigestLookup: peer " << (p? p->host : "<none>") << ", lookup: " << lookup_t_str[lookup]  );
 903 #endif
 904 }
 905
 906 static void
 907 neighborAlive(peer * p, const MemObject * mem, const icp_common_t * header)
 908 {
 909     peerAlive(p);
 910     p->stats.pings_acked++;
 911
 912     if ((icp_opcode) header->opcode <= ICP_END)
 913         p->icp.counts[header->opcode]++;
 914
 915     p->icp.version = (int) header->version;
 916 }
 917
 918 static void
 919 neighborUpdateRtt(peer * p, MemObject * mem)
 920 {
 921     int rtt, rtt_av_factor;
 922
 923     if (!mem)
 924         return;
 925
 926     if (!mem->start_ping.tv_sec)
 927         return;
 928
 929     rtt = tvSubMsec(mem->start_ping, current_time);
 930
 931     if (rtt < 1 || rtt > 10000)
 932         return;
 933
 934     rtt_av_factor = RTT_AV_FACTOR;
 935
 936     if (p->options.weighted_roundrobin)
 937         rtt_av_factor = RTT_BACKGROUND_AV_FACTOR;
 938
 939     p->stats.rtt = Math::intAverage(p->stats.rtt, rtt, p->stats.pings_acked, rtt_av_factor);
 940 }
 941
 942 #if USE_HTCP
 943 static void
 944 neighborAliveHtcp(peer * p, const MemObject * mem, const htcpReplyData * htcp)
 945 {
 946     peerAlive(p);
 947     p->stats.pings_acked++;
 948     p->htcp.counts[htcp->hit ? 1 : 0]++;
 949     p->htcp.version = htcp->version;
 950 }
 951
 952 #endif
 953
 954 static void
 955 neighborCountIgnored(peer * p)
 956 {
 957     if (p == NULL)
 958         return;
 959
 960     p->stats.ignored_replies++;
 961
 962     NLateReplies++;
 963 }
 964
 965 static peer *non_peers = NULL;
 966
 967 static void
 968 neighborIgnoreNonPeer(const Ip::Address &from, icp_opcode opcode)
 969 {
 970     peer *np;
 971
 972     for (np = non_peers; np; np = np->next) {
 973         if (np->in_addr != from)
 974             continue;
 975
 976         if (np->in_addr.GetPort() != from.GetPort())
 977             continue;
 978
 979         break;
 980     }
 981
 982     if (np == NULL) {
 983         np = (peer *)xcalloc(1, sizeof(peer));
 984         np->in_addr = from;
 985         np->icp.port = from.GetPort();
 986         np->type = PEER_NONE;
 987         np->host = new char[MAX_IPSTRLEN];
 988         from.NtoA(np->host,MAX_IPSTRLEN);
 989         np->next = non_peers;
 990         non_peers = np;
 991     }
 992
 993     np->icp.counts[opcode]++;
 994
 995     if (isPowTen(++np->stats.ignored_replies))
 996         debugs(15, 1, "WARNING: Ignored " << np->stats.ignored_replies << " replies from non-peer " << np->host);
 997 }
 998
 999 /* ignoreMulticastReply
1000  *
1001  * * We want to ignore replies from multicast peers if the
1002  * * cache_host_domain rules would normally prevent the peer
1003  * * from being used
1004  */
1005 static int
1006 ignoreMulticastReply(peer * p, MemObject * mem)
1007 {
1008     if (p == NULL)
1009         return 0;
1010
1011     if (!p->options.mcast_responder)
1012         return 0;
1013
1014     if (peerHTTPOkay(p, mem->request))
1015         return 0;
1016
1017     return 1;
1018 }
1019
1020 /**
1021  * I should attach these records to the entry.  We take the first
1022  * hit we get our wait until everyone misses.  The timeout handler
1023  * call needs to nip this shopping list or call one of the misses.
1024  *
1025  * If a hit process is already started, then sobeit
1026  */
1027 void
1028 neighborsUdpAck(const cache_key * key, icp_common_t * header, const Ip::Address &from)
1029 {
1030     peer *p = NULL;
1031     StoreEntry *entry;
1032     MemObject *mem = NULL;
1033     peer_t ntype = PEER_NONE;
1034     icp_opcode opcode = (icp_opcode) header->opcode;
1035
1036     debugs(15, 6, "neighborsUdpAck: opcode " << opcode << " '" << storeKeyText(key) << "'");
1037
1038     if (NULL != (entry = Store::Root().get(key)))
1039         mem = entry->mem_obj;
1040
1041     if ((p = whichPeer(from)))
1042         neighborAlive(p, mem, header);
1043
1044     if (opcode > ICP_END)
1045         return;
1046
1047     const char *opcode_d = icp_opcode_str[opcode];
1048
1049     if (p)
1050         neighborUpdateRtt(p, mem);
1051
1052     /* Does the entry exist? */
1053     if (NULL == entry) {
1054         debugs(12, 3, "neighborsUdpAck: Cache key '" << storeKeyText(key) << "' not found");
1055         neighborCountIgnored(p);
1056         return;
1057     }
1058
1059     /* check if someone is already fetching it */
1060     if (EBIT_TEST(entry->flags, ENTRY_DISPATCHED)) {
1061         debugs(15, 3, "neighborsUdpAck: '" << storeKeyText(key) << "' already being fetched.");
1062         neighborCountIgnored(p);
1063         return;
1064     }
1065
1066     if (mem == NULL) {
1067         debugs(15, 2, "Ignoring " << opcode_d << " for missing mem_obj: " << storeKeyText(key));
1068         neighborCountIgnored(p);
1069         return;
1070     }
1071
1072     if (entry->ping_status != PING_WAITING) {
1073         debugs(15, 2, "neighborsUdpAck: Late " << opcode_d << " for " << storeKeyText(key));
1074         neighborCountIgnored(p);
1075         return;
1076     }
1077
1078     if (entry->lock_count == 0) {
1079         debugs(12, 1, "neighborsUdpAck: '" << storeKeyText(key) << "' has no locks");
1080         neighborCountIgnored(p);
1081         return;
1082     }
1083
1084     debugs(15, 3, "neighborsUdpAck: " << opcode_d << " for '" << storeKeyText(key) << "' from " << (p ? p->host : "source") << " ");
1085
1086     if (p) {
1087         ntype = neighborType(p, mem->request);
1088     }
1089
1090     if (ignoreMulticastReply(p, mem)) {
1091         neighborCountIgnored(p);
1092     } else if (opcode == ICP_MISS) {
1093         if (p == NULL) {
1094             neighborIgnoreNonPeer(from, opcode);
1095         } else {
1096             mem->ping_reply_callback(p, ntype, AnyP::PROTO_ICP, header, mem->ircb_data);
1097         }
1098     } else if (opcode == ICP_HIT) {
1099         if (p == NULL) {
1100             neighborIgnoreNonPeer(from, opcode);
1101         } else {
1102             header->opcode = ICP_HIT;
1103             mem->ping_reply_callback(p, ntype, AnyP::PROTO_ICP, header, mem->ircb_data);
1104         }
1105     } else if (opcode == ICP_DECHO) {
1106         if (p == NULL) {
1107             neighborIgnoreNonPeer(from, opcode);
1108         } else if (ntype == PEER_SIBLING) {
1109             debug_trap("neighborsUdpAck: Found non-ICP cache as SIBLING\n");
1110             debug_trap("neighborsUdpAck: non-ICP neighbors must be a PARENT\n");
1111         } else {
1112             mem->ping_reply_callback(p, ntype, AnyP::PROTO_ICP, header, mem->ircb_data);
1113         }
1114     } else if (opcode == ICP_SECHO) {
1115         if (p) {
1116             debugs(15, 1, "Ignoring SECHO from neighbor " << p->host);
1117             neighborCountIgnored(p);
1118         } else {
1119             debugs(15, 1, "Unsolicited SECHO from " << from);
1120         }
1121     } else if (opcode == ICP_DENIED) {
1122         if (p == NULL) {
1123             neighborIgnoreNonPeer(from, opcode);
1124         } else if (p->stats.pings_acked > 100) {
1125             if (100 * p->icp.counts[ICP_DENIED] / p->stats.pings_acked > 95) {
1126                 debugs(15, 0, "95%% of replies from '" << p->host << "' are UDP_DENIED");
1127                 debugs(15, 0, "Disabling '" << p->host << "', please check your configuration.");
1128                 neighborRemove(p);
1129                 p = NULL;
1130             } else {
1131                 neighborCountIgnored(p);
1132             }
1133         }
1134     } else if (opcode == ICP_MISS_NOFETCH) {
1135         mem->ping_reply_callback(p, ntype, AnyP::PROTO_ICP, header, mem->ircb_data);
1136     } else {
1137         debugs(15, 0, "neighborsUdpAck: Unexpected ICP reply: " << opcode_d);
1138     }
1139 }
1140
1141 peer *
1142 peerFindByName(const char *name)
1143 {
1144     peer *p = NULL;
1145
1146     for (p = Config.peers; p; p = p->next) {
1147         if (!strcasecmp(name, p->name))
1148             break;
1149     }
1150
1151     return p;
1152 }
1153
1154 peer *
1155 peerFindByNameAndPort(const char *name, unsigned short port)
1156 {
1157     peer *p = NULL;
1158
1159     for (p = Config.peers; p; p = p->next) {
1160         if (strcasecmp(name, p->name))
1161             continue;
1162
1163         if (port != p->http_port)
1164             continue;
1165
1166         break;
1167     }
1168
1169     return p;
1170 }
1171
1172 int
1173 neighborUp(const peer * p)
1174 {
1175     if (!p->tcp_up) {
1176         if (!peerProbeConnect((peer *) p)) {
1177             debugs(15, 8, "neighborUp: DOWN (probed): " << p->host << " (" << p->in_addr << ")");
1178             return 0;
1179         }
1180     }
1181
1182     /*
1183      * The peer can not be UP if we don't have any IP addresses
1184      * for it.
1185      */
1186     if (0 == p->n_addresses) {
1187         debugs(15, 8, "neighborUp: DOWN (no-ip): " << p->host << " (" << p->in_addr << ")");
1188         return 0;
1189     }
1190
1191     if (p->options.no_query) {
1192         debugs(15, 8, "neighborUp: UP (no-query): " << p->host << " (" << p->in_addr << ")");
1193         return 1;
1194     }
1195
1196     if (p->stats.probe_start != 0 &&
1197             squid_curtime - p->stats.probe_start > Config.Timeout.deadPeer) {
1198         debugs(15, 8, "neighborUp: DOWN (dead): " << p->host << " (" << p->in_addr << ")");
1199         return 0;
1200     }
1201
1202     debugs(15, 8, "neighborUp: UP: " << p->host << " (" << p->in_addr << ")");
1203     return 1;
1204 }
1205
1206 void
1207 peerDestroy(void *data)
1208 {
1209     peer *p = (peer *)data;
1210
1211     if (p == NULL)
1212         return;
1213
1214     struct _domain_ping *nl = NULL;
1215
1216     for (struct _domain_ping *l = p->peer_domain; l; l = nl) {
1217         nl = l->next;
1218         safe_free(l->domain);
1219         xfree(l);
1220     }
1221
1222     safe_free(p->host);
1223     safe_free(p->name);
1224     safe_free(p->domain);
1225 #if USE_CACHE_DIGESTS
1226
1227     cbdataReferenceDone(p->digest);
1228 #endif
1229 }
1230
1231 void
1232 peerNoteDigestGone(peer * p)
1233 {
1234 #if USE_CACHE_DIGESTS
1235     cbdataReferenceDone(p->digest);
1236 #endif
1237 }
1238
1239 static void
1240 peerDNSConfigure(const ipcache_addrs *ia, const DnsLookupDetails &, void *data)
1241 {
1242     peer *p = (peer *)data;
1243
1244     int j;
1245
1246     if (p->n_addresses == 0) {
1247         debugs(15, 1, "Configuring " << neighborTypeStr(p) << " " << p->host << "/" << p->http_port << "/" << p->icp.port);
1248
1249         if (p->type == PEER_MULTICAST)
1250             debugs(15, 1, "    Multicast TTL = " << p->mcast.ttl);
1251     }
1252
1253     p->n_addresses = 0;
1254
1255     if (ia == NULL) {
1256         debugs(0, 0, "WARNING: DNS lookup for '" << p->host << "' failed!");
1257         return;
1258     }
1259
1260     if ((int) ia->count < 1) {
1261         debugs(0, 0, "WARNING: No IP address found for '" << p->host << "'!");
1262         return;
1263     }
1264
1265     p->tcp_up = p->connect_fail_limit;
1266
1267     for (j = 0; j < (int) ia->count && j < PEER_MAX_ADDRESSES; j++) {
1268         p->addresses[j] = ia->in_addrs[j];
1269         debugs(15, 2, "--> IP address #" << j << ": " << p->addresses[j]);
1270         p->n_addresses++;
1271     }
1272
1273     p->in_addr.SetEmpty();
1274     p->in_addr = p->addresses[0];
1275     p->in_addr.SetPort(p->icp.port);
1276
1277     if (p->type == PEER_MULTICAST)
1278         peerCountMcastPeersSchedule(p, 10);
1279
1280 #if USE_ICMP
1281     if (p->type != PEER_MULTICAST)
1282         if (!p->options.no_netdb_exchange)
1283             eventAddIsh("netdbExchangeStart", netdbExchangeStart, p, 30.0, 1);
1284 #endif
1285
1286 }
1287
1288 static void
1289 peerRefreshDNS(void *data)
1290 {
1291     peer *p = NULL;
1292
1293     if (eventFind(peerRefreshDNS, NULL))
1294         eventDelete(peerRefreshDNS, NULL);
1295
1296     if (!data && 0 == stat5minClientRequests()) {
1297         /* no recent client traffic, wait a bit */
1298         eventAddIsh("peerRefreshDNS", peerRefreshDNS, NULL, 180.0, 1);
1299         return;
1300     }
1301
1302     for (p = Config.peers; p; p = p->next)
1303         ipcache_nbgethostbyname(p->host, peerDNSConfigure, p);
1304
1305     /* Reconfigure the peers every hour */
1306     eventAddIsh("peerRefreshDNS", peerRefreshDNS, NULL, 3600.0, 1);
1307 }
1308
1309 static void
1310 peerConnectFailedSilent(peer * p)
1311 {
1312     p->stats.last_connect_failure = squid_curtime;
1313
1314     if (!p->tcp_up) {
1315         debugs(15, 2, "TCP connection to " << p->host << "/" << p->http_port <<
1316                " dead");
1317         return;
1318     }
1319
1320     p->tcp_up--;
1321
1322     if (!p->tcp_up) {
1323         debugs(15, 1, "Detected DEAD " << neighborTypeStr(p) << ": " << p->name);
1324         p->stats.logged_state = PEER_DEAD;
1325     }
1326 }
1327
1328 void
1329 peerConnectFailed(peer *p)
1330 {
1331     debugs(15, 1, "TCP connection to " << p->host << "/" << p->http_port << " failed");
1332     peerConnectFailedSilent(p);
1333 }
1334
1335 void
1336 peerConnectSucceded(peer * p)
1337 {
1338     if (!p->tcp_up) {
1339         debugs(15, 2, "TCP connection to " << p->host << "/" << p->http_port << " succeded");
1340         p->tcp_up = p->connect_fail_limit; // NP: so peerAlive(p) works properly.
1341         peerAlive(p);
1342         if (!p->n_addresses)
1343             ipcache_nbgethostbyname(p->host, peerDNSConfigure, p);
1344     } else
1345         p->tcp_up = p->connect_fail_limit;
1346 }
1347
1348 /// called by Comm when test_fd is closed while connect is in progress
1349 static void
1350 peerProbeClosed(int fd, void *data)
1351 {
1352     peer *p = (peer*)data;
1353     p->test_fd = -1;
1354     // it is a failure because we failed to connect
1355     peerConnectFailedSilent(p);
1356 }
1357
1358 static void
1359 peerProbeConnectTimeout(int fd, void *data)
1360 {
1361     peer * p = (peer *)data;
1362     comm_remove_close_handler(fd, &peerProbeClosed, p);
1363     comm_close(fd);
1364     p->test_fd = -1;
1365     peerConnectFailedSilent(p);
1366 }
1367
1368 /*
1369 * peerProbeConnect will be called on dead peers by neighborUp
1370 */
1371 static int
1372 peerProbeConnect(peer * p)
1373 {
1374     int fd;
1375     time_t ctimeout = p->connect_timeout > 0 ? p->connect_timeout
1376                       : Config.Timeout.peer_connect;
1377     int ret = squid_curtime - p->stats.last_connect_failure > ctimeout * 10;
1378
1379     if (p->test_fd != -1)
1380         return ret;/* probe already running */
1381
1382     if (squid_curtime - p->stats.last_connect_probe == 0)
1383         return ret;/* don't probe to often */
1384
1385     Ip::Address temp(getOutgoingAddr(NULL,p));
1386
1387     // if IPv6 is disabled try to force IPv4-only outgoing.
1388     if (!Ip::EnableIpv6 && !temp.SetIPv4()) {
1389         debugs(50, DBG_IMPORTANT, "WARNING: IPv6 is disabled. Failed to use " << temp << " to probe " << p->host);
1390         return ret;
1391     }
1392
1393     // if IPv6 is split-stack, prefer IPv4
1394     if (Ip::EnableIpv6&IPV6_SPECIAL_SPLITSTACK) {
1395         // NP: This is not a great choice of default,
1396         // but with the current Internet being IPv4-majority has a higher success rate.
1397         // if setting to IPv4 fails we dont care, that just means to use IPv6 outgoing.
1398         temp.SetIPv4();
1399     }
1400
1401     fd = comm_open(SOCK_STREAM, IPPROTO_TCP, temp, COMM_NONBLOCKING, p->host);
1402
1403     if (fd < 0)
1404         return ret;
1405
1406     comm_add_close_handler(fd, &peerProbeClosed, p);
1407     commSetTimeout(fd, ctimeout, peerProbeConnectTimeout, p);
1408
1409     p->test_fd = fd;
1410
1411     p->stats.last_connect_probe = squid_curtime;
1412
1413     commConnectStart(p->test_fd,
1414                      p->host,
1415                      p->http_port,
1416                      peerProbeConnectDone,
1417                      p);
1418
1419     return ret;
1420 }
1421
1422 static void
1423 peerProbeConnectDone(int fd, const DnsLookupDetails &, comm_err_t status, int xerrno, void *data)
1424 {
1425     peer *p = (peer*)data;
1426
1427     if (status == COMM_OK) {
1428         peerConnectSucceded(p);
1429     } else {
1430         peerConnectFailedSilent(p);
1431     }
1432
1433     comm_remove_close_handler(fd, &peerProbeClosed, p);
1434     comm_close(fd);
1435     p->test_fd = -1;
1436     return;
1437 }
1438
1439 static void
1440 peerCountMcastPeersSchedule(peer * p, time_t when)
1441 {
1442     if (p->mcast.flags.count_event_pending)
1443         return;
1444
1445     eventAdd("peerCountMcastPeersStart",
1446              peerCountMcastPeersStart,
1447              p,
1448              (double) when, 1);
1449
1450     p->mcast.flags.count_event_pending = 1;
1451 }
1452
1453 static void
1454 peerCountMcastPeersStart(void *data)
1455 {
1456     peer *p = (peer *)data;
1457     ps_state *psstate;
1458     StoreEntry *fake;
1459     MemObject *mem;
1460     icp_common_t *query;
1461     int reqnum;
1462     LOCAL_ARRAY(char, url, MAX_URL);
1463     assert(p->type == PEER_MULTICAST);
1464     p->mcast.flags.count_event_pending = 0;
1465     snprintf(url, MAX_URL, "http://");
1466     p->in_addr.ToURL(url+7, MAX_URL -8 );
1467     strcat(url, "/");
1468     fake = storeCreateEntry(url, url, request_flags(), METHOD_GET);
1469     HttpRequest *req = HttpRequest::CreateFromUrl(url);
1470     psstate = new ps_state;
1471     psstate->request = HTTPMSGLOCK(req);
1472     psstate->entry = fake;
1473     psstate->callback = NULL;
1474     psstate->callback_data = cbdataReference(p);
1475     psstate->ping.start = current_time;
1476     mem = fake->mem_obj;
1477     mem->request = HTTPMSGLOCK(psstate->request);
1478     mem->start_ping = current_time;
1479     mem->ping_reply_callback = peerCountHandleIcpReply;
1480     mem->ircb_data = psstate;
1481     mcastSetTtl(theOutIcpConnection, p->mcast.ttl);
1482     p->mcast.id = mem->id;
1483     reqnum = icpSetCacheKey((const cache_key *)fake->key);
1484     query = _icp_common_t::createMessage(ICP_QUERY, 0, url, reqnum, 0);
1485     icpUdpSend(theOutIcpConnection,
1486                p->in_addr,
1487                query,
1488                LOG_ICP_QUERY,
1489                0);
1490     fake->ping_status = PING_WAITING;
1491     eventAdd("peerCountMcastPeersDone",
1492              peerCountMcastPeersDone,
1493              psstate,
1494              Config.Timeout.mcast_icp_query / 1000.0, 1);
1495     p->mcast.flags.counting = 1;
1496     peerCountMcastPeersSchedule(p, MCAST_COUNT_RATE);
1497 }
1498
1499 static void
1500 peerCountMcastPeersDone(void *data)
1501 {
1502     ps_state *psstate = (ps_state *)data;
1503     StoreEntry *fake = psstate->entry;
1504
1505     if (cbdataReferenceValid(psstate->callback_data)) {
1506         peer *p = (peer *)psstate->callback_data;
1507         p->mcast.flags.counting = 0;
1508         p->mcast.avg_n_members = Math::doubleAverage(p->mcast.avg_n_members, (double) psstate->ping.n_recv, ++p->mcast.n_times_counted, 10);
1509         debugs(15, 1, "Group " << p->host  << ": " << psstate->ping.n_recv  <<
1510                " replies, "<< std::setw(4)<< std::setprecision(2) <<
1511                p->mcast.avg_n_members <<" average, RTT " << p->stats.rtt);
1512         p->mcast.n_replies_expected = (int) p->mcast.avg_n_members;
1513     }
1514
1515     cbdataReferenceDone(psstate->callback_data);
1516
1517     EBIT_SET(fake->flags, ENTRY_ABORTED);
1518     HTTPMSGUNLOCK(fake->mem_obj->request);
1519     fake->releaseRequest();
1520     fake->unlock();
1521     HTTPMSGUNLOCK(psstate->request);
1522     cbdataFree(psstate);
1523 }
1524
1525 static void
1526 peerCountHandleIcpReply(peer * p, peer_t type, AnyP::ProtocolType proto, void *hdrnotused, void *data)
1527 {
1528     int rtt_av_factor;
1529
1530     ps_state *psstate = (ps_state *)data;
1531     StoreEntry *fake = psstate->entry;
1532     MemObject *mem = fake->mem_obj;
1533     int rtt = tvSubMsec(mem->start_ping, current_time);
1534     assert(proto == AnyP::PROTO_ICP);
1535     assert(fake);
1536     assert(mem);
1537     psstate->ping.n_recv++;
1538     rtt_av_factor = RTT_AV_FACTOR;
1539
1540     if (p->options.weighted_roundrobin)
1541         rtt_av_factor = RTT_BACKGROUND_AV_FACTOR;
1542
1543     p->stats.rtt = Math::intAverage(p->stats.rtt, rtt, psstate->ping.n_recv, rtt_av_factor);
1544 }
1545
1546 static void
1547 neighborDumpPeers(StoreEntry * sentry)
1548 {
1549     dump_peers(sentry, Config.peers);
1550 }
1551
1552 static void
1553 neighborDumpNonPeers(StoreEntry * sentry)
1554 {
1555     dump_peers(sentry, non_peers);
1556 }
1557
1558 void
1559 dump_peer_options(StoreEntry * sentry, peer * p)
1560 {
1561     if (p->options.proxy_only)
1562         storeAppendPrintf(sentry, " proxy-only");
1563
1564     if (p->options.no_query)
1565         storeAppendPrintf(sentry, " no-query");
1566
1567     if (p->options.background_ping)
1568         storeAppendPrintf(sentry, " background-ping");
1569
1570     if (p->options.no_digest)
1571         storeAppendPrintf(sentry, " no-digest");
1572
1573     if (p->options.default_parent)
1574         storeAppendPrintf(sentry, " default");
1575
1576     if (p->options.roundrobin)
1577         storeAppendPrintf(sentry, " round-robin");
1578
1579     if (p->options.carp)
1580         storeAppendPrintf(sentry, " carp");
1581
1582 #if USE_AUTH
1583     if (p->options.userhash)
1584         storeAppendPrintf(sentry, " userhash");
1585 #endif
1586
1587     if (p->options.sourcehash)
1588         storeAppendPrintf(sentry, " sourcehash");
1589
1590     if (p->options.weighted_roundrobin)
1591         storeAppendPrintf(sentry, " weighted-round-robin");
1592
1593     if (p->options.mcast_responder)
1594         storeAppendPrintf(sentry, " multicast-responder");
1595
1596 #if PEER_MULTICAST_SIBLINGS
1597     if (p->options.mcast_siblings)
1598         storeAppendPrintf(sentry, " multicast-siblings");
1599 #endif
1600
1601     if (p->weight != 1)
1602         storeAppendPrintf(sentry, " weight=%d", p->weight);
1603
1604     if (p->options.closest_only)
1605         storeAppendPrintf(sentry, " closest-only");
1606
1607 #if USE_HTCP
1608     if (p->options.htcp) {
1609         storeAppendPrintf(sentry, " htcp");
1610         if (p->options.htcp_oldsquid || p->options.htcp_no_clr || p->options.htcp_no_purge_clr || p->options.htcp_only_clr) {
1611             int doneopts=0;
1612             if (p->options.htcp_oldsquid)
1613                 storeAppendPrintf(sentry, "%soldsquid",(doneopts++>0?",":"="));
1614             if (p->options.htcp_no_clr)
1615                 storeAppendPrintf(sentry, "%sno-clr",(doneopts++>0?",":"="));
1616             if (p->options.htcp_no_purge_clr)
1617                 storeAppendPrintf(sentry, "%sno-purge-clr",(doneopts++>0?",":"="));
1618             if (p->options.htcp_only_clr)
1619                 storeAppendPrintf(sentry, "%sonly-clr",(doneopts++>0?",":"="));
1620         }
1621     }
1622 #endif
1623
1624     if (p->options.no_netdb_exchange)
1625         storeAppendPrintf(sentry, " no-netdb-exchange");
1626
1627 #if USE_DELAY_POOLS
1628     if (p->options.no_delay)
1629         storeAppendPrintf(sentry, " no-delay");
1630 #endif
1631
1632     if (p->login)
1633         storeAppendPrintf(sentry, " login=%s", p->login);
1634
1635     if (p->mcast.ttl > 0)
1636         storeAppendPrintf(sentry, " ttl=%d", p->mcast.ttl);
1637
1638     if (p->connect_timeout > 0)
1639         storeAppendPrintf(sentry, " connect-timeout=%d", (int) p->connect_timeout);
1640
1641     if (p->connect_fail_limit != PEER_TCP_MAGIC_COUNT)
1642         storeAppendPrintf(sentry, " connect-fail-limit=%d", p->connect_fail_limit);
1643
1644 #if USE_CACHE_DIGESTS
1645
1646     if (p->digest_url)
1647         storeAppendPrintf(sentry, " digest-url=%s", p->digest_url);
1648
1649 #endif
1650
1651     if (p->options.allow_miss)
1652         storeAppendPrintf(sentry, " allow-miss");
1653
1654     if (p->options.no_tproxy)
1655         storeAppendPrintf(sentry, " no-tproxy");
1656
1657     if (p->max_conn > 0)
1658         storeAppendPrintf(sentry, " max-conn=%d", p->max_conn);
1659
1660     if (p->options.originserver)
1661         storeAppendPrintf(sentry, " originserver");
1662
1663     if (p->domain)
1664         storeAppendPrintf(sentry, " forceddomain=%s", p->domain);
1665
1666     if (p->connection_auth == 0)
1667         storeAppendPrintf(sentry, " connection-auth=off");
1668     else if (p->connection_auth == 1)
1669         storeAppendPrintf(sentry, " connection-auth=on");
1670     else if (p->connection_auth == 2)
1671         storeAppendPrintf(sentry, " connection-auth=auto");
1672
1673     storeAppendPrintf(sentry, "\n");
1674 }
1675
1676 static void
1677 dump_peers(StoreEntry * sentry, peer * peers)
1678 {
1679     peer *e = NULL;
1680     char ntoabuf[MAX_IPSTRLEN];
1681     struct _domain_ping *d = NULL;
1682     icp_opcode op;
1683     int i;
1684
1685     if (peers == NULL)
1686         storeAppendPrintf(sentry, "There are no neighbors installed.\n");
1687
1688     for (e = peers; e; e = e->next) {
1689         assert(e->host != NULL);
1690         storeAppendPrintf(sentry, "\n%-11.11s: %s\n",
1691                           neighborTypeStr(e),
1692                           e->name);
1693         storeAppendPrintf(sentry, "Host       : %s/%d/%d\n",
1694                           e->host,
1695                           e->http_port,
1696                           e->icp.port);
1697         storeAppendPrintf(sentry, "Flags      :");
1698         dump_peer_options(sentry, e);
1699
1700         for (i = 0; i < e->n_addresses; i++) {
1701             storeAppendPrintf(sentry, "Address[%d] : %s\n", i,
1702                               e->addresses[i].NtoA(ntoabuf,MAX_IPSTRLEN) );
1703         }
1704
1705         storeAppendPrintf(sentry, "Status     : %s\n",
1706                           neighborUp(e) ? "Up" : "Down");
1707         storeAppendPrintf(sentry, "FETCHES    : %d\n", e->stats.fetches);
1708         storeAppendPrintf(sentry, "OPEN CONNS : %d\n", e->stats.conn_open);
1709         storeAppendPrintf(sentry, "AVG RTT    : %d msec\n", e->stats.rtt);
1710
1711         if (!e->options.no_query) {
1712             storeAppendPrintf(sentry, "LAST QUERY : %8d seconds ago\n",
1713                               (int) (squid_curtime - e->stats.last_query));
1714
1715             if (e->stats.last_reply > 0)
1716                 storeAppendPrintf(sentry, "LAST REPLY : %8d seconds ago\n",
1717                                   (int) (squid_curtime - e->stats.last_reply));
1718             else
1719                 storeAppendPrintf(sentry, "LAST REPLY : none received\n");
1720
1721             storeAppendPrintf(sentry, "PINGS SENT : %8d\n", e->stats.pings_sent);
1722
1723             storeAppendPrintf(sentry, "PINGS ACKED: %8d %3d%%\n",
1724                               e->stats.pings_acked,
1725                               Math::intPercent(e->stats.pings_acked, e->stats.pings_sent));
1726         }
1727
1728         storeAppendPrintf(sentry, "IGNORED    : %8d %3d%%\n", e->stats.ignored_replies, Math::intPercent(e->stats.ignored_replies, e->stats.pings_acked));
1729
1730         if (!e->options.no_query) {
1731             storeAppendPrintf(sentry, "Histogram of PINGS ACKED:\n");
1732 #if USE_HTCP
1733
1734             if (e->options.htcp) {
1735                 storeAppendPrintf(sentry, "\tMisses\t%8d %3d%%\n",
1736                                   e->htcp.counts[0],
1737                                   Math::intPercent(e->htcp.counts[0], e->stats.pings_acked));
1738                 storeAppendPrintf(sentry, "\tHits\t%8d %3d%%\n",
1739                                   e->htcp.counts[1],
1740                                   Math::intPercent(e->htcp.counts[1], e->stats.pings_acked));
1741             } else {
1742 #endif
1743
1744                 for (op = ICP_INVALID; op < ICP_END; ++op) {
1745                     if (e->icp.counts[op] == 0)
1746                         continue;
1747
1748                     storeAppendPrintf(sentry, "    %12.12s : %8d %3d%%\n",
1749                                       icp_opcode_str[op],
1750                                       e->icp.counts[op],
1751                                       Math::intPercent(e->icp.counts[op], e->stats.pings_acked));
1752                 }
1753
1754 #if USE_HTCP
1755
1756             }
1757
1758 #endif
1759
1760         }
1761
1762         if (e->stats.last_connect_failure) {
1763             storeAppendPrintf(sentry, "Last failed connect() at: %s\n",
1764                               Time::FormatHttpd(e->stats.last_connect_failure));
1765         }
1766
1767         if (e->peer_domain != NULL) {
1768             storeAppendPrintf(sentry, "DOMAIN LIST: ");
1769
1770             for (d = e->peer_domain; d; d = d->next) {
1771                 storeAppendPrintf(sentry, "%s%s ",
1772                                   d->do_ping ? null_string : "!", d->domain);
1773             }
1774
1775             storeAppendPrintf(sentry, "\n");
1776         }
1777
1778         storeAppendPrintf(sentry, "keep-alive ratio: %d%%\n", Math::intPercent(e->stats.n_keepalives_recv, e->stats.n_keepalives_sent));
1779     }
1780 }
1781
1782 #if USE_HTCP
1783 void
1784 neighborsHtcpReply(const cache_key * key, htcpReplyData * htcp, const Ip::Address &from)
1785 {
1786     StoreEntry *e = Store::Root().get(key);
1787     MemObject *mem = NULL;
1788     peer *p;
1789     peer_t ntype = PEER_NONE;
1790     debugs(15, 6, "neighborsHtcpReply: " <<
1791            (htcp->hit ? "HIT" : "MISS") << " " <<
1792            storeKeyText(key)  );
1793
1794     if (NULL != e)
1795         mem = e->mem_obj;
1796
1797     if ((p = whichPeer(from)))
1798         neighborAliveHtcp(p, mem, htcp);
1799
1800     /* Does the entry exist? */
1801     if (NULL == e) {
1802         debugs(12, 3, "neighyborsHtcpReply: Cache key '" << storeKeyText(key) << "' not found");
1803         neighborCountIgnored(p);
1804         return;
1805     }
1806
1807     /* check if someone is already fetching it */
1808     if (EBIT_TEST(e->flags, ENTRY_DISPATCHED)) {
1809         debugs(15, 3, "neighborsUdpAck: '" << storeKeyText(key) << "' already being fetched.");
1810         neighborCountIgnored(p);
1811         return;
1812     }
1813
1814     if (mem == NULL) {
1815         debugs(15, 2, "Ignoring reply for missing mem_obj: " << storeKeyText(key));
1816         neighborCountIgnored(p);
1817         return;
1818     }
1819
1820     if (e->ping_status != PING_WAITING) {
1821         debugs(15, 2, "neighborsUdpAck: Entry " << storeKeyText(key) << " is not PING_WAITING");
1822         neighborCountIgnored(p);
1823         return;
1824     }
1825
1826     if (e->lock_count == 0) {
1827         debugs(12, 1, "neighborsUdpAck: '" << storeKeyText(key) << "' has no locks");
1828         neighborCountIgnored(p);
1829         return;
1830     }
1831
1832     if (p) {
1833         ntype = neighborType(p, mem->request);
1834         neighborUpdateRtt(p, mem);
1835     }
1836
1837     if (ignoreMulticastReply(p, mem)) {
1838         neighborCountIgnored(p);
1839         return;
1840     }
1841
1842     debugs(15, 3, "neighborsHtcpReply: e = " << e);
1843     mem->ping_reply_callback(p, ntype, AnyP::PROTO_HTCP, htcp, mem->ircb_data);
1844 }
1845
1846 /*
1847  * Send HTCP CLR messages to all peers configured to receive them.
1848  */
1849 void
1850 neighborsHtcpClear(StoreEntry * e, const char *uri, HttpRequest * req, const HttpRequestMethod &method, htcp_clr_reason reason)
1851 {
1852     peer *p;
1853     char buf[128];
1854
1855     for (p = Config.peers; p; p = p->next) {
1856         if (!p->options.htcp) {
1857             continue;
1858         }
1859         if (p->options.htcp_no_clr) {
1860             continue;
1861         }
1862         if (p->options.htcp_no_purge_clr && reason == HTCP_CLR_PURGE) {
1863             continue;
1864         }
1865         debugs(15, 3, "neighborsHtcpClear: sending CLR to " << p->in_addr.ToURL(buf, 128));
1866         htcpClear(e, uri, req, method, p, reason);
1867     }
1868 }
1869
1870 #endif