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 "acl/FilledChecklist.h"
  35 #include "anyp/PortCfg.h"
  36 #include "CacheDigest.h"
  37 #include "CachePeer.h"
  38 #include "CachePeerDomainList.h"
  39 #include "comm/Connection.h"
  40 #include "comm/ConnOpener.h"
  41 #include "event.h"
  42 #include "FwdState.h"
  43 #include "globals.h"
  44 #include "htcp.h"
  45 #include "HttpRequest.h"
  46 #include "icmp/net_db.h"
  47 #include "ICP.h"
  48 #include "int.h"
  49 #include "ip/Address.h"
  50 #include "ip/tools.h"
  51 #include "ipcache.h"
  52 #include "MemObject.h"
  53 #include "mgr/Registration.h"
  54 #include "multicast.h"
  55 #include "neighbors.h"
  56 #include "NeighborTypeDomainList.h"
  57 #include "pconn.h"
  58 #include "PeerDigest.h"
  59 #include "PeerPoolMgr.h"
  60 #include "PeerSelectState.h"
  61 #include "RequestFlags.h"
  62 #include "SquidConfig.h"
  63 #include "SquidMath.h"
  64 #include "SquidTime.h"
  65 #include "stat.h"
  66 #include "Store.h"
  67 #include "store_key_md5.h"
  68 #include "tools.h"
  69 #include "URL.h"
  70
  71 /* count mcast group peers every 15 minutes */
  72 #define MCAST_COUNT_RATE 900
  73
  74 bool peerAllowedToUse(const CachePeer *, HttpRequest *);
  75 static int peerWouldBePinged(const CachePeer *, HttpRequest *);
  76 static void neighborRemove(CachePeer *);
  77 static void neighborAlive(CachePeer *, const MemObject *, const icp_common_t *);
  78 #if USE_HTCP
  79 static void neighborAliveHtcp(CachePeer *, const MemObject *, const HtcpReplyData *);
  80 #endif
  81 static void neighborCountIgnored(CachePeer *);
  82 static void peerRefreshDNS(void *);
  83 static IPH peerDNSConfigure;
  84 static bool peerProbeConnect(CachePeer *);
  85 static CNCB peerProbeConnectDone;
  86 static void peerCountMcastPeersDone(void *data);
  87 static void peerCountMcastPeersStart(void *data);
  88 static void peerCountMcastPeersSchedule(CachePeer * p, time_t when);
  89 static IRCB peerCountHandleIcpReply;
  90
  91 static void neighborIgnoreNonPeer(const Ip::Address &, icp_opcode);
  92 static OBJH neighborDumpPeers;
  93 static OBJH neighborDumpNonPeers;
  94 static void dump_peers(StoreEntry * sentry, CachePeer * peers);
  95
  96 static unsigned short echo_port;
  97
  98 static int NLateReplies = 0;
  99 static CachePeer *first_ping = NULL;
 100
 101 const char *
 102 neighborTypeStr(const CachePeer * p)
 103 {
 104     if (p->type == PEER_NONE)
 105         return "Non-Peer";
 106
 107     if (p->type == PEER_SIBLING)
 108         return "Sibling";
 109
 110     if (p->type == PEER_MULTICAST)
 111         return "Multicast Group";
 112
 113     return "Parent";
 114 }
 115
 116 CachePeer *
 117 whichPeer(const Ip::Address &from)
 118 {
 119     int j;
 120
 121     CachePeer *p = NULL;
 122     debugs(15, 3, "whichPeer: from " << from);
 123
 124     for (p = Config.peers; p; p = p->next) {
 125         for (j = 0; j < p->n_addresses; ++j) {
 126             if (from == p->addresses[j] && from.port() == p->icp.port) {
 127                 return p;
 128             }
 129         }
 130     }
 131
 132     return NULL;
 133 }
 134
 135 peer_t
 136 neighborType(const CachePeer * p, const HttpRequest * request)
 137 {
 138
 139     const NeighborTypeDomainList *d = NULL;
 140
 141     for (d = p->typelist; d; d = d->next) {
 142         if (0 == matchDomainName(request->GetHost(), d->domain))
 143             if (d->type != PEER_NONE)
 144                 return d->type;
 145     }
 146 #if PEER_MULTICAST_SIBLINGS
 147     if (p->type == PEER_MULTICAST)
 148         if (p->options.mcast_siblings)
 149             return PEER_SIBLING;
 150 #endif
 151
 152     return p->type;
 153 }
 154
 155 /**
 156  * \return Whether it is appropriate to fetch REQUEST from PEER.
 157  */
 158 bool
 159 peerAllowedToUse(const CachePeer * p, HttpRequest * request)
 160 {
 161
 162     const CachePeerDomainList *d = NULL;
 163     assert(request != NULL);
 164
 165     if (neighborType(p, request) == PEER_SIBLING) {
 166 #if PEER_MULTICAST_SIBLINGS
 167         if (p->type == PEER_MULTICAST && p->options.mcast_siblings &&
 168                 (request->flags.noCache || request->flags.refresh || request->flags.loopDetected || request->flags.needValidation))
 169             debugs(15, 2, "peerAllowedToUse(" << p->name << ", " << request->GetHost() << ") : multicast-siblings optimization match");
 170 #endif
 171         if (request->flags.noCache)
 172             return false;
 173
 174         if (request->flags.refresh)
 175             return false;
 176
 177         if (request->flags.loopDetected)
 178             return false;
 179
 180         if (request->flags.needValidation)
 181             return false;
 182     }
 183
 184     // CONNECT requests are proxy requests. Not to be forwarded to origin servers.
 185     // Unless the destination port matches, in which case we MAY perform a 'DIRECT' to this CachePeer.
 186     if (p->options.originserver && request->method == Http::METHOD_CONNECT && request->port != p->in_addr.port())
 187         return false;
 188
 189     if (p->peer_domain == NULL && p->access == NULL)
 190         return true;
 191
 192     bool do_ping = false;
 193     for (d = p->peer_domain; d; d = d->next) {
 194         if (0 == matchDomainName(request->GetHost(), d->domain)) {
 195             do_ping = d->do_ping;
 196             break;
 197         }
 198
 199         do_ping = !d->do_ping;
 200     }
 201
 202     if (p->peer_domain && !do_ping)
 203         return false;
 204
 205     if (p->access == NULL)
 206         return do_ping;
 207
 208     ACLFilledChecklist checklist(p->access, request, NULL);
 209
 210     return (checklist.fastCheck() == ACCESS_ALLOWED);
 211 }
 212
 213 /* Return TRUE if it is okay to send an ICP request to this CachePeer.   */
 214 static int
 215 peerWouldBePinged(const CachePeer * p, HttpRequest * request)
 216 {
 217     if (p->icp.port == 0)
 218         return 0;
 219
 220     if (p->options.no_query)
 221         return 0;
 222
 223     if (p->options.mcast_responder)
 224         return 0;
 225
 226     if (p->n_addresses == 0)
 227         return 0;
 228
 229     if (p->options.background_ping && (squid_curtime - p->stats.last_query < Config.backgroundPingRate))
 230         return 0;
 231
 232     /* the case below seems strange, but can happen if the
 233      * URL host is on the other side of a firewall */
 234     if (p->type == PEER_SIBLING)
 235         if (!request->flags.hierarchical)
 236             return 0;
 237
 238     if (!peerAllowedToUse(p, request))
 239         return 0;
 240
 241     /* Ping dead peers every timeout interval */
 242     if (squid_curtime - p->stats.last_query > Config.Timeout.deadPeer)
 243         return 1;
 244
 245     if (!neighborUp(p))
 246         return 0;
 247
 248     return 1;
 249 }
 250
 251 bool
 252 peerCanOpenMore(const CachePeer *p)
 253 {
 254     const int effectiveLimit = p->max_conn <= 0 ? Squid_MaxFD : p->max_conn;
 255     const int remaining = effectiveLimit - p->stats.conn_open;
 256     debugs(15, 7, remaining << '=' << effectiveLimit << '-' << p->stats.conn_open);
 257     return remaining > 0;
 258 }
 259
 260 bool
 261 peerHasConnAvailable(const CachePeer *p)
 262 {
 263     // Standby connections can be used without opening new connections.
 264     const int standbys = p->standby.pool ? p->standby.pool->count() : 0;
 265
 266     // XXX: Some idle pconns can be used without opening new connections.
 267     // Complication: Idle pconns cannot be reused for some requests.
 268     const int usableIdles = 0;
 269
 270     const int available = standbys + usableIdles;
 271     debugs(15, 7, available << '=' << standbys << '+' << usableIdles);
 272     return available > 0;
 273 }
 274
 275 void
 276 peerConnClosed(CachePeer *p)
 277 {
 278     --p->stats.conn_open;
 279     if (p->standby.waitingForClose && peerCanOpenMore(p)) {
 280         p->standby.waitingForClose = false;
 281         PeerPoolMgr::Checkpoint(p->standby.mgr, "conn closed");
 282     }
 283 }
 284
 285 /* Return TRUE if it is okay to send an HTTP request to this CachePeer. */
 286 int
 287 peerHTTPOkay(const CachePeer * p, HttpRequest * request)
 288 {
 289     if (!peerCanOpenMore(p) && !peerHasConnAvailable(p))
 290         return 0;
 291
 292     if (!peerAllowedToUse(p, request))
 293         return 0;
 294
 295     if (!neighborUp(p))
 296         return 0;
 297
 298     return 1;
 299 }
 300
 301 int
 302 neighborsCount(HttpRequest * request)
 303 {
 304     CachePeer *p = NULL;
 305     int count = 0;
 306
 307     for (p = Config.peers; p; p = p->next)
 308         if (peerWouldBePinged(p, request))
 309             ++count;
 310
 311     debugs(15, 3, "neighborsCount: " << count);
 312
 313     return count;
 314 }
 315
 316 CachePeer *
 317 getFirstUpParent(HttpRequest * request)
 318 {
 319     CachePeer *p = NULL;
 320
 321     for (p = Config.peers; p; p = p->next) {
 322         if (!neighborUp(p))
 323             continue;
 324
 325         if (neighborType(p, request) != PEER_PARENT)
 326             continue;
 327
 328         if (!peerHTTPOkay(p, request))
 329             continue;
 330
 331         break;
 332     }
 333
 334     debugs(15, 3, "getFirstUpParent: returning " << (p ? p->host : "NULL"));
 335     return p;
 336 }
 337
 338 CachePeer *
 339 getRoundRobinParent(HttpRequest * request)
 340 {
 341     CachePeer *p;
 342     CachePeer *q = NULL;
 343
 344     for (p = Config.peers; p; p = p->next) {
 345         if (!p->options.roundrobin)
 346             continue;
 347
 348         if (neighborType(p, request) != PEER_PARENT)
 349             continue;
 350
 351         if (!peerHTTPOkay(p, request))
 352             continue;
 353
 354         if (p->weight == 0)
 355             continue;
 356
 357         if (q) {
 358             if (p->weight == q->weight) {
 359                 if (q->rr_count < p->rr_count)
 360                     continue;
 361             } else if ( ((double) q->rr_count / q->weight) < ((double) p->rr_count / p->weight)) {
 362                 continue;
 363             }
 364         }
 365
 366         q = p;
 367     }
 368
 369     if (q)
 370         ++ q->rr_count;
 371
 372     debugs(15, 3, HERE << "returning " << (q ? q->host : "NULL"));
 373
 374     return q;
 375 }
 376
 377 CachePeer *
 378 getWeightedRoundRobinParent(HttpRequest * request)
 379 {
 380     CachePeer *p;
 381     CachePeer *q = NULL;
 382     int weighted_rtt;
 383
 384     for (p = Config.peers; p; p = p->next) {
 385         if (!p->options.weighted_roundrobin)
 386             continue;
 387
 388         if (neighborType(p, request) != PEER_PARENT)
 389             continue;
 390
 391         if (!peerHTTPOkay(p, request))
 392             continue;
 393
 394         if (q && q->rr_count < p->rr_count)
 395             continue;
 396
 397         q = p;
 398     }
 399
 400     if (q && q->rr_count > 1000000)
 401         for (p = Config.peers; p; p = p->next) {
 402             if (!p->options.weighted_roundrobin)
 403                 continue;
 404
 405             if (neighborType(p, request) != PEER_PARENT)
 406                 continue;
 407
 408             p->rr_count = 0;
 409         }
 410
 411     if (q) {
 412         weighted_rtt = (q->stats.rtt - q->basetime) / q->weight;
 413
 414         if (weighted_rtt < 1)
 415             weighted_rtt = 1;
 416
 417         q->rr_count += weighted_rtt;
 418
 419         debugs(15, 3, "getWeightedRoundRobinParent: weighted_rtt " << weighted_rtt);
 420     }
 421
 422     debugs(15, 3, "getWeightedRoundRobinParent: returning " << (q ? q->host : "NULL"));
 423     return q;
 424 }
 425
 426 /**
 427  * This gets called every 5 minutes to clear the round-robin counter.
 428  * The exact timing is an arbitrary default, set on estimate timing of a
 429  * large number of requests in a high-performance environment during the
 430  * period. The larger the number of requests between cycled resets the
 431  * more balanced the operations.
 432  *
 433  \param data    unused.
 434  \todo Make the reset timing a selectable parameter in squid.conf
 435  */
 436 static void
 437 peerClearRRLoop(void *data)
 438 {
 439     peerClearRR();
 440     eventAdd("peerClearRR", peerClearRRLoop, data, 5 * 60.0, 0);
 441 }
 442
 443 /**
 444  * This gets called on startup and restart to kick off the CachePeer round-robin
 445  * maintenance event. It ensures that no matter how many times its called
 446  * no more than one event is scheduled.
 447  */
 448 void
 449 peerClearRRStart(void)
 450 {
 451     static bool event_added = false;
 452     if (!event_added) {
 453         peerClearRRLoop(NULL);
 454         event_added=true;
 455     }
 456 }
 457
 458 /**
 459  * Called whenever the round-robin counters need to be reset to a sane state.
 460  * So far those times are:
 461  *  - On startup and reconfigure - to set the counters to sane initial settings.
 462  *  -  When a CachePeer has revived from dead, to prevent the revived CachePeer being
 463  *     flooded with requests which it has 'missed' during the down period.
 464  */
 465 void
 466 peerClearRR()
 467 {
 468     CachePeer *p = NULL;
 469     for (p = Config.peers; p; p = p->next) {
 470         p->rr_count = 1;
 471     }
 472 }
 473
 474 /**
 475  * Perform all actions when a CachePeer is detected revived.
 476  */
 477 void
 478 peerAlive(CachePeer *p)
 479 {
 480     if (p->stats.logged_state == PEER_DEAD && p->tcp_up) {
 481         debugs(15, DBG_IMPORTANT, "Detected REVIVED " << neighborTypeStr(p) << ": " << p->name);
 482         p->stats.logged_state = PEER_ALIVE;
 483         peerClearRR();
 484         if (p->standby.mgr.valid())
 485             PeerPoolMgr::Checkpoint(p->standby.mgr, "revived peer");
 486     }
 487
 488     p->stats.last_reply = squid_curtime;
 489     p->stats.probe_start = 0;
 490 }
 491
 492 CachePeer *
 493 getDefaultParent(HttpRequest * request)
 494 {
 495     CachePeer *p = NULL;
 496
 497     for (p = Config.peers; p; p = p->next) {
 498         if (neighborType(p, request) != PEER_PARENT)
 499             continue;
 500
 501         if (!p->options.default_parent)
 502             continue;
 503
 504         if (!peerHTTPOkay(p, request))
 505             continue;
 506
 507         debugs(15, 3, "getDefaultParent: returning " << p->host);
 508
 509         return p;
 510     }
 511
 512     debugs(15, 3, "getDefaultParent: returning NULL");
 513     return NULL;
 514 }
 515
 516 CachePeer *
 517 getNextPeer(CachePeer * p)
 518 {
 519     return p->next;
 520 }
 521
 522 CachePeer *
 523 getFirstPeer(void)
 524 {
 525     return Config.peers;
 526 }
 527
 528 static void
 529 neighborRemove(CachePeer * target)
 530 {
 531     CachePeer *p = NULL;
 532     CachePeer **P = NULL;
 533     p = Config.peers;
 534     P = &Config.peers;
 535
 536     while (p) {
 537         if (target == p)
 538             break;
 539
 540         P = &p->next;
 541
 542         p = p->next;
 543     }
 544
 545     if (p) {
 546         *P = p->next;
 547         cbdataFree(p);
 548         --Config.npeers;
 549     }
 550
 551     first_ping = Config.peers;
 552 }
 553
 554 static void
 555 neighborsRegisterWithCacheManager()
 556 {
 557     Mgr::RegisterAction("server_list",
 558                         "Peer Cache Statistics",
 559                         neighborDumpPeers, 0, 1);
 560
 561     if (Comm::IsConnOpen(icpIncomingConn)) {
 562         Mgr::RegisterAction("non_peers",
 563                             "List of Unknown sites sending ICP messages",
 564                             neighborDumpNonPeers, 0, 1);
 565     }
 566 }
 567
 568 void
 569 neighbors_init(void)
 570 {
 571     struct servent *sep = NULL;
 572     const char *me = getMyHostname();
 573     CachePeer *thisPeer = NULL;
 574     CachePeer *next = NULL;
 575
 576     neighborsRegisterWithCacheManager();
 577
 578     if (Comm::IsConnOpen(icpIncomingConn)) {
 579
 580         for (thisPeer = Config.peers; thisPeer; thisPeer = next) {
 581             next = thisPeer->next;
 582
 583             if (0 != strcmp(thisPeer->host, me))
 584                 continue;
 585
 586             for (AnyP::PortCfg *s = Config.Sockaddr.http; s; s = s->next) {
 587                 if (thisPeer->http_port != s->s.port())
 588                     continue;
 589
 590                 debugs(15, DBG_IMPORTANT, "WARNING: Peer looks like this host");
 591
 592                 debugs(15, DBG_IMPORTANT, "         Ignoring " <<
 593                        neighborTypeStr(thisPeer) << " " << thisPeer->host <<
 594                        "/" << thisPeer->http_port << "/" <<
 595                        thisPeer->icp.port);
 596
 597                 neighborRemove(thisPeer);
 598             }
 599         }
 600     }
 601
 602     peerRefreshDNS((void *) 1);
 603
 604     sep = getservbyname("echo", "udp");
 605     echo_port = sep ? ntohs((unsigned short) sep->s_port) : 7;
 606
 607     first_ping = Config.peers;
 608 }
 609
 610 int
 611 neighborsUdpPing(HttpRequest * request,
 612                  StoreEntry * entry,
 613                  IRCB * callback,
 614                  void *callback_data,
 615                  int *exprep,
 616                  int *timeout)
 617 {
 618     const char *url = entry->url();
 619     MemObject *mem = entry->mem_obj;
 620     CachePeer *p = NULL;
 621     int i;
 622     int reqnum = 0;
 623     int flags;
 624     icp_common_t *query;
 625     int queries_sent = 0;
 626     int peers_pinged = 0;
 627     int parent_timeout = 0, parent_exprep = 0;
 628     int sibling_timeout = 0, sibling_exprep = 0;
 629     int mcast_timeout = 0, mcast_exprep = 0;
 630
 631     if (Config.peers == NULL)
 632         return 0;
 633
 634     assert(entry->swap_status == SWAPOUT_NONE);
 635
 636     mem->start_ping = current_time;
 637
 638     mem->ping_reply_callback = callback;
 639
 640     mem->ircb_data = callback_data;
 641
 642     reqnum = icpSetCacheKey((const cache_key *)entry->key);
 643
 644     for (i = 0, p = first_ping; i++ < Config.npeers; p = p->next) {
 645         if (p == NULL)
 646             p = Config.peers;
 647
 648         debugs(15, 5, "neighborsUdpPing: Peer " << p->host);
 649
 650         if (!peerWouldBePinged(p, request))
 651             continue;           /* next CachePeer */
 652
 653         ++peers_pinged;
 654
 655         debugs(15, 4, "neighborsUdpPing: pinging peer " << p->host << " for '" << url << "'");
 656
 657         debugs(15, 3, "neighborsUdpPing: key = '" << entry->getMD5Text() << "'");
 658
 659         debugs(15, 3, "neighborsUdpPing: reqnum = " << reqnum);
 660
 661 #if USE_HTCP
 662         if (p->options.htcp && !p->options.htcp_only_clr) {
 663             if (Config.Port.htcp <= 0) {
 664                 debugs(15, DBG_CRITICAL, "HTCP is disabled! Cannot send HTCP request to peer.");
 665                 continue;
 666             }
 667
 668             debugs(15, 3, "neighborsUdpPing: sending HTCP query");
 669             if (htcpQuery(entry, request, p) <= 0)
 670                 continue; // unable to send.
 671         } else
 672 #endif
 673         {
 674             if (Config.Port.icp <= 0 || !Comm::IsConnOpen(icpOutgoingConn)) {
 675                 debugs(15, DBG_CRITICAL, "ICP is disabled! Cannot send ICP request to peer.");
 676                 continue;
 677             } else {
 678
 679                 if (p->type == PEER_MULTICAST)
 680                     mcastSetTtl(icpOutgoingConn->fd, p->mcast.ttl);
 681
 682                 if (p->icp.port == echo_port) {
 683                     debugs(15, 4, "neighborsUdpPing: Looks like a dumb cache, send DECHO ping");
 684                     query = _icp_common_t::createMessage(ICP_DECHO, 0, url, reqnum, 0);
 685                     icpUdpSend(icpOutgoingConn->fd, p->in_addr, query, LOG_ICP_QUERY, 0);
 686                 } else {
 687                     flags = 0;
 688
 689                     if (Config.onoff.query_icmp)
 690                         if (p->icp.version == ICP_VERSION_2)
 691                             flags |= ICP_FLAG_SRC_RTT;
 692
 693                     query = _icp_common_t::createMessage(ICP_QUERY, flags, url, reqnum, 0);
 694
 695                     icpUdpSend(icpOutgoingConn->fd, p->in_addr, query, LOG_ICP_QUERY, 0);
 696                 }
 697             }
 698         }
 699
 700         ++queries_sent;
 701
 702         ++ p->stats.pings_sent;
 703
 704         if (p->type == PEER_MULTICAST) {
 705             mcast_exprep += p->mcast.n_replies_expected;
 706             mcast_timeout += (p->stats.rtt * p->mcast.n_replies_expected);
 707         } else if (neighborUp(p)) {
 708             /* its alive, expect a reply from it */
 709
 710             if (neighborType(p, request) == PEER_PARENT) {
 711                 ++parent_exprep;
 712                 parent_timeout += p->stats.rtt;
 713             } else {
 714                 ++sibling_exprep;
 715                 sibling_timeout += p->stats.rtt;
 716             }
 717         } else {
 718             /* Neighbor is dead; ping it anyway, but don't expect a reply */
 719             /* log it once at the threshold */
 720
 721             if (p->stats.logged_state == PEER_ALIVE) {
 722                 debugs(15, DBG_IMPORTANT, "Detected DEAD " << neighborTypeStr(p) << ": " << p->name);
 723                 p->stats.logged_state = PEER_DEAD;
 724             }
 725         }
 726
 727         p->stats.last_query = squid_curtime;
 728
 729         /*
 730          * keep probe_start == 0 for a multicast CachePeer,
 731          * so neighborUp() never says this CachePeer is dead.
 732          */
 733
 734         if ((p->type != PEER_MULTICAST) && (p->stats.probe_start == 0))
 735             p->stats.probe_start = squid_curtime;
 736     }
 737
 738     if ((first_ping = first_ping->next) == NULL)
 739         first_ping = Config.peers;
 740
 741     /*
 742      * How many replies to expect?
 743      */
 744     *exprep = parent_exprep + sibling_exprep + mcast_exprep;
 745
 746     /*
 747      * If there is a configured timeout, use it
 748      */
 749     if (Config.Timeout.icp_query)
 750         *timeout = Config.Timeout.icp_query;
 751     else {
 752         if (*exprep > 0) {
 753             if (parent_exprep)
 754                 *timeout = 2 * parent_timeout / parent_exprep;
 755             else if (mcast_exprep)
 756                 *timeout = 2 * mcast_timeout / mcast_exprep;
 757             else
 758                 *timeout = 2 * sibling_timeout / sibling_exprep;
 759         } else
 760             *timeout = 2000;    /* 2 seconds */
 761
 762         if (Config.Timeout.icp_query_max)
 763             if (*timeout > Config.Timeout.icp_query_max)
 764                 *timeout = Config.Timeout.icp_query_max;
 765
 766         if (*timeout < Config.Timeout.icp_query_min)
 767             *timeout = Config.Timeout.icp_query_min;
 768     }
 769
 770     return peers_pinged;
 771 }
 772
 773 /* lookup the digest of a given CachePeer */
 774 lookup_t
 775 peerDigestLookup(CachePeer * p, HttpRequest * request)
 776 {
 777 #if USE_CACHE_DIGESTS
 778     const cache_key *key = request ? storeKeyPublicByRequest(request) : NULL;
 779     assert(p);
 780     assert(request);
 781     debugs(15, 5, "peerDigestLookup: peer " << p->host);
 782     /* does the peeer have a valid digest? */
 783
 784     if (!p->digest) {
 785         debugs(15, 5, "peerDigestLookup: gone!");
 786         return LOOKUP_NONE;
 787     } else if (!peerHTTPOkay(p, request)) {
 788         debugs(15, 5, "peerDigestLookup: !peerHTTPOkay");
 789         return LOOKUP_NONE;
 790     } else if (!p->digest->flags.needed) {
 791         debugs(15, 5, "peerDigestLookup: note need");
 792         peerDigestNeeded(p->digest);
 793         return LOOKUP_NONE;
 794     } else if (!p->digest->flags.usable) {
 795         debugs(15, 5, "peerDigestLookup: !ready && " << (p->digest->flags.requested ? "" : "!") << "requested");
 796         return LOOKUP_NONE;
 797     }
 798
 799     debugs(15, 5, "peerDigestLookup: OK to lookup peer " << p->host);
 800     assert(p->digest->cd);
 801     /* does digest predict a hit? */
 802
 803     if (!cacheDigestTest(p->digest->cd, key))
 804         return LOOKUP_MISS;
 805
 806     debugs(15, 5, "peerDigestLookup: peer " << p->host << " says HIT!");
 807
 808     return LOOKUP_HIT;
 809
 810 #endif
 811
 812     return LOOKUP_NONE;
 813 }
 814
 815 /* select best CachePeer based on cache digests */
 816 CachePeer *
 817 neighborsDigestSelect(HttpRequest * request)
 818 {
 819     CachePeer *best_p = NULL;
 820 #if USE_CACHE_DIGESTS
 821
 822     int best_rtt = 0;
 823     int choice_count = 0;
 824     int ichoice_count = 0;
 825     CachePeer *p;
 826     int p_rtt;
 827     int i;
 828
 829     if (!request->flags.hierarchical)
 830         return NULL;
 831
 832     storeKeyPublicByRequest(request);
 833
 834     for (i = 0, p = first_ping; i++ < Config.npeers; p = p->next) {
 835         lookup_t lookup;
 836
 837         if (!p)
 838             p = Config.peers;
 839
 840         if (i == 1)
 841             first_ping = p;
 842
 843         lookup = peerDigestLookup(p, request);
 844
 845         if (lookup == LOOKUP_NONE)
 846             continue;
 847
 848         ++choice_count;
 849
 850         if (lookup == LOOKUP_MISS)
 851             continue;
 852
 853         p_rtt = netdbHostRtt(p->host);
 854
 855         debugs(15, 5, "neighborsDigestSelect: peer " << p->host << " rtt: " << p_rtt);
 856
 857         /* is this CachePeer better than others in terms of rtt ? */
 858         if (!best_p || (p_rtt && p_rtt < best_rtt)) {
 859             best_p = p;
 860             best_rtt = p_rtt;
 861
 862             if (p_rtt)          /* informative choice (aka educated guess) */
 863                 ++ichoice_count;
 864
 865             debugs(15, 4, "neighborsDigestSelect: peer " << p->host << " leads with rtt " << best_rtt);
 866         }
 867     }
 868
 869     debugs(15, 4, "neighborsDigestSelect: choices: " << choice_count << " (" << ichoice_count << ")");
 870     peerNoteDigestLookup(request, best_p,
 871                          best_p ? LOOKUP_HIT : (choice_count ? LOOKUP_MISS : LOOKUP_NONE));
 872     request->hier.n_choices = choice_count;
 873     request->hier.n_ichoices = ichoice_count;
 874 #endif
 875
 876     return best_p;
 877 }
 878
 879 void
 880 peerNoteDigestLookup(HttpRequest * request, CachePeer * p, lookup_t lookup)
 881 {
 882 #if USE_CACHE_DIGESTS
 883     if (p)
 884         strncpy(request->hier.cd_host, p->host, sizeof(request->hier.cd_host)-1);
 885     else
 886         *request->hier.cd_host = '\0';
 887
 888     request->hier.cd_lookup = lookup;
 889     debugs(15, 4, "peerNoteDigestLookup: peer " << (p? p->host : "<none>") << ", lookup: " << lookup_t_str[lookup]  );
 890 #endif
 891 }
 892
 893 static void
 894 neighborAlive(CachePeer * p, const MemObject * mem, const icp_common_t * header)
 895 {
 896     peerAlive(p);
 897     ++ p->stats.pings_acked;
 898
 899     if ((icp_opcode) header->opcode <= ICP_END)
 900         ++ p->icp.counts[header->opcode];
 901
 902     p->icp.version = (int) header->version;
 903 }
 904
 905 static void
 906 neighborUpdateRtt(CachePeer * p, MemObject * mem)
 907 {
 908     int rtt, rtt_av_factor;
 909
 910     if (!mem)
 911         return;
 912
 913     if (!mem->start_ping.tv_sec)
 914         return;
 915
 916     rtt = tvSubMsec(mem->start_ping, current_time);
 917
 918     if (rtt < 1 || rtt > 10000)
 919         return;
 920
 921     rtt_av_factor = RTT_AV_FACTOR;
 922
 923     if (p->options.weighted_roundrobin)
 924         rtt_av_factor = RTT_BACKGROUND_AV_FACTOR;
 925
 926     p->stats.rtt = Math::intAverage(p->stats.rtt, rtt, p->stats.pings_acked, rtt_av_factor);
 927 }
 928
 929 #if USE_HTCP
 930 static void
 931 neighborAliveHtcp(CachePeer * p, const MemObject * mem, const HtcpReplyData * htcp)
 932 {
 933     peerAlive(p);
 934     ++ p->stats.pings_acked;
 935     ++ p->htcp.counts[htcp->hit ? 1 : 0];
 936     p->htcp.version = htcp->version;
 937 }
 938
 939 #endif
 940
 941 static void
 942 neighborCountIgnored(CachePeer * p)
 943 {
 944     if (p == NULL)
 945         return;
 946
 947     ++ p->stats.ignored_replies;
 948
 949     ++NLateReplies;
 950 }
 951
 952 static CachePeer *non_peers = NULL;
 953
 954 static void
 955 neighborIgnoreNonPeer(const Ip::Address &from, icp_opcode opcode)
 956 {
 957     CachePeer *np;
 958
 959     for (np = non_peers; np; np = np->next) {
 960         if (np->in_addr != from)
 961             continue;
 962
 963         if (np->in_addr.port() != from.port())
 964             continue;
 965
 966         break;
 967     }
 968
 969     if (np == NULL) {
 970         np = (CachePeer *)xcalloc(1, sizeof(CachePeer));
 971         np->in_addr = from;
 972         np->icp.port = from.port();
 973         np->type = PEER_NONE;
 974         np->host = new char[MAX_IPSTRLEN];
 975         from.toStr(np->host,MAX_IPSTRLEN);
 976         np->next = non_peers;
 977         non_peers = np;
 978     }
 979
 980     ++ np->icp.counts[opcode];
 981
 982     if (isPowTen(++np->stats.ignored_replies))
 983         debugs(15, DBG_IMPORTANT, "WARNING: Ignored " << np->stats.ignored_replies << " replies from non-peer " << np->host);
 984 }
 985
 986 /* ignoreMulticastReply
 987  *
 988  * * We want to ignore replies from multicast peers if the
 989  * * cache_host_domain rules would normally prevent the CachePeer
 990  * * from being used
 991  */
 992 static int
 993 ignoreMulticastReply(CachePeer * p, MemObject * mem)
 994 {
 995     if (p == NULL)
 996         return 0;
 997
 998     if (!p->options.mcast_responder)
 999         return 0;
1000
1001     if (peerHTTPOkay(p, mem->request))
1002         return 0;
1003
1004     return 1;
1005 }
1006
1007 /**
1008  * I should attach these records to the entry.  We take the first
1009  * hit we get our wait until everyone misses.  The timeout handler
1010  * call needs to nip this shopping list or call one of the misses.
1011  *
1012  * If a hit process is already started, then sobeit
1013  */
1014 void
1015 neighborsUdpAck(const cache_key * key, icp_common_t * header, const Ip::Address &from)
1016 {
1017     CachePeer *p = NULL;
1018     StoreEntry *entry;
1019     MemObject *mem = NULL;
1020     peer_t ntype = PEER_NONE;
1021     icp_opcode opcode = (icp_opcode) header->opcode;
1022
1023     debugs(15, 6, "neighborsUdpAck: opcode " << opcode << " '" << storeKeyText(key) << "'");
1024
1025     if (NULL != (entry = Store::Root().get(key)))
1026         mem = entry->mem_obj;
1027
1028     if ((p = whichPeer(from)))
1029         neighborAlive(p, mem, header);
1030
1031     if (opcode > ICP_END)
1032         return;
1033
1034     const char *opcode_d = icp_opcode_str[opcode];
1035
1036     if (p)
1037         neighborUpdateRtt(p, mem);
1038
1039     /* Does the entry exist? */
1040     if (NULL == entry) {
1041         debugs(12, 3, "neighborsUdpAck: Cache key '" << storeKeyText(key) << "' not found");
1042         neighborCountIgnored(p);
1043         return;
1044     }
1045
1046     /* check if someone is already fetching it */
1047     if (EBIT_TEST(entry->flags, ENTRY_DISPATCHED)) {
1048         debugs(15, 3, "neighborsUdpAck: '" << storeKeyText(key) << "' already being fetched.");
1049         neighborCountIgnored(p);
1050         return;
1051     }
1052
1053     if (mem == NULL) {
1054         debugs(15, 2, "Ignoring " << opcode_d << " for missing mem_obj: " << storeKeyText(key));
1055         neighborCountIgnored(p);
1056         return;
1057     }
1058
1059     if (entry->ping_status != PING_WAITING) {
1060         debugs(15, 2, "neighborsUdpAck: Late " << opcode_d << " for " << storeKeyText(key));
1061         neighborCountIgnored(p);
1062         return;
1063     }
1064
1065     if (!entry->locked()) {
1066         // TODO: many entries are unlocked; why is this reported at level 1?
1067         debugs(12, DBG_IMPORTANT, "neighborsUdpAck: '" << storeKeyText(key) << "' has no locks");
1068         neighborCountIgnored(p);
1069         return;
1070     }
1071
1072     debugs(15, 3, "neighborsUdpAck: " << opcode_d << " for '" << storeKeyText(key) << "' from " << (p ? p->host : "source") << " ");
1073
1074     if (p) {
1075         ntype = neighborType(p, mem->request);
1076     }
1077
1078     if (ignoreMulticastReply(p, mem)) {
1079         neighborCountIgnored(p);
1080     } else if (opcode == ICP_MISS) {
1081         if (p == NULL) {
1082             neighborIgnoreNonPeer(from, opcode);
1083         } else {
1084             mem->ping_reply_callback(p, ntype, AnyP::PROTO_ICP, header, mem->ircb_data);
1085         }
1086     } else if (opcode == ICP_HIT) {
1087         if (p == NULL) {
1088             neighborIgnoreNonPeer(from, opcode);
1089         } else {
1090             header->opcode = ICP_HIT;
1091             mem->ping_reply_callback(p, ntype, AnyP::PROTO_ICP, header, mem->ircb_data);
1092         }
1093     } else if (opcode == ICP_DECHO) {
1094         if (p == NULL) {
1095             neighborIgnoreNonPeer(from, opcode);
1096         } else if (ntype == PEER_SIBLING) {
1097             debug_trap("neighborsUdpAck: Found non-ICP cache as SIBLING\n");
1098             debug_trap("neighborsUdpAck: non-ICP neighbors must be a PARENT\n");
1099         } else {
1100             mem->ping_reply_callback(p, ntype, AnyP::PROTO_ICP, header, mem->ircb_data);
1101         }
1102     } else if (opcode == ICP_SECHO) {
1103         if (p) {
1104             debugs(15, DBG_IMPORTANT, "Ignoring SECHO from neighbor " << p->host);
1105             neighborCountIgnored(p);
1106         } else {
1107             debugs(15, DBG_IMPORTANT, "Unsolicited SECHO from " << from);
1108         }
1109     } else if (opcode == ICP_DENIED) {
1110         if (p == NULL) {
1111             neighborIgnoreNonPeer(from, opcode);
1112         } else if (p->stats.pings_acked > 100) {
1113             if (100 * p->icp.counts[ICP_DENIED] / p->stats.pings_acked > 95) {
1114                 debugs(15, DBG_CRITICAL, "95%% of replies from '" << p->host << "' are UDP_DENIED");
1115                 debugs(15, DBG_CRITICAL, "Disabling '" << p->host << "', please check your configuration.");
1116                 neighborRemove(p);
1117                 p = NULL;
1118             } else {
1119                 neighborCountIgnored(p);
1120             }
1121         }
1122     } else if (opcode == ICP_MISS_NOFETCH) {
1123         mem->ping_reply_callback(p, ntype, AnyP::PROTO_ICP, header, mem->ircb_data);
1124     } else {
1125         debugs(15, DBG_CRITICAL, "neighborsUdpAck: Unexpected ICP reply: " << opcode_d);
1126     }
1127 }
1128
1129 CachePeer *
1130 peerFindByName(const char *name)
1131 {
1132     CachePeer *p = NULL;
1133
1134     for (p = Config.peers; p; p = p->next) {
1135         if (!strcasecmp(name, p->name))
1136             break;
1137     }
1138
1139     return p;
1140 }
1141
1142 CachePeer *
1143 peerFindByNameAndPort(const char *name, unsigned short port)
1144 {
1145     CachePeer *p = NULL;
1146
1147     for (p = Config.peers; p; p = p->next) {
1148         if (strcasecmp(name, p->name))
1149             continue;
1150
1151         if (port != p->http_port)
1152             continue;
1153
1154         break;
1155     }
1156
1157     return p;
1158 }
1159
1160 int
1161 neighborUp(const CachePeer * p)
1162 {
1163     if (!p->tcp_up) {
1164         if (!peerProbeConnect((CachePeer *) p)) {
1165             debugs(15, 8, "neighborUp: DOWN (probed): " << p->host << " (" << p->in_addr << ")");
1166             return 0;
1167         }
1168     }
1169
1170     /*
1171      * The CachePeer can not be UP if we don't have any IP addresses
1172      * for it.
1173      */
1174     if (0 == p->n_addresses) {
1175         debugs(15, 8, "neighborUp: DOWN (no-ip): " << p->host << " (" << p->in_addr << ")");
1176         return 0;
1177     }
1178
1179     if (p->options.no_query) {
1180         debugs(15, 8, "neighborUp: UP (no-query): " << p->host << " (" << p->in_addr << ")");
1181         return 1;
1182     }
1183
1184     if (p->stats.probe_start != 0 &&
1185             squid_curtime - p->stats.probe_start > Config.Timeout.deadPeer) {
1186         debugs(15, 8, "neighborUp: DOWN (dead): " << p->host << " (" << p->in_addr << ")");
1187         return 0;
1188     }
1189
1190     debugs(15, 8, "neighborUp: UP: " << p->host << " (" << p->in_addr << ")");
1191     return 1;
1192 }
1193
1194 void
1195 peerDestroy(void *data)
1196 {
1197     CachePeer *p = (CachePeer *)data;
1198
1199     if (p == NULL)
1200         return;
1201
1202     CachePeerDomainList *nl = NULL;
1203
1204     for (CachePeerDomainList *l = p->peer_domain; l; l = nl) {
1205         nl = l->next;
1206         safe_free(l->domain);
1207         xfree(l);
1208     }
1209
1210     safe_free(p->host);
1211     safe_free(p->name);
1212     safe_free(p->domain);
1213 #if USE_CACHE_DIGESTS
1214
1215     cbdataReferenceDone(p->digest);
1216 #endif
1217 }
1218
1219 void
1220 peerNoteDigestGone(CachePeer * p)
1221 {
1222 #if USE_CACHE_DIGESTS
1223     cbdataReferenceDone(p->digest);
1224 #endif
1225 }
1226
1227 static void
1228 peerDNSConfigure(const ipcache_addrs *ia, const DnsLookupDetails &, void *data)
1229 {
1230     // TODO: connections to no-longer valid IP addresses should be
1231     // closed when we can detect such IP addresses.
1232
1233     CachePeer *p = (CachePeer *)data;
1234
1235     int j;
1236
1237     if (p->n_addresses == 0) {
1238         debugs(15, DBG_IMPORTANT, "Configuring " << neighborTypeStr(p) << " " << p->host << "/" << p->http_port << "/" << p->icp.port);
1239
1240         if (p->type == PEER_MULTICAST)
1241             debugs(15, DBG_IMPORTANT, "    Multicast TTL = " << p->mcast.ttl);
1242     }
1243
1244     p->n_addresses = 0;
1245
1246     if (ia == NULL) {
1247         debugs(0, DBG_CRITICAL, "WARNING: DNS lookup for '" << p->host << "' failed!");
1248         return;
1249     }
1250
1251     if ((int) ia->count < 1) {
1252         debugs(0, DBG_CRITICAL, "WARNING: No IP address found for '" << p->host << "'!");
1253         return;
1254     }
1255
1256     p->tcp_up = p->connect_fail_limit;
1257
1258     for (j = 0; j < (int) ia->count && j < PEER_MAX_ADDRESSES; ++j) {
1259         p->addresses[j] = ia->in_addrs[j];
1260         debugs(15, 2, "--> IP address #" << j << ": " << p->addresses[j]);
1261         ++ p->n_addresses;
1262     }
1263
1264     p->in_addr.setEmpty();
1265     p->in_addr = p->addresses[0];
1266     p->in_addr.port(p->icp.port);
1267
1268     if (p->type == PEER_MULTICAST)
1269         peerCountMcastPeersSchedule(p, 10);
1270
1271 #if USE_ICMP
1272     if (p->type != PEER_MULTICAST && IamWorkerProcess())
1273         if (!p->options.no_netdb_exchange)
1274             eventAddIsh("netdbExchangeStart", netdbExchangeStart, p, 30.0, 1);
1275 #endif
1276
1277     if (p->standby.mgr.valid())
1278         PeerPoolMgr::Checkpoint(p->standby.mgr, "resolved peer");
1279 }
1280
1281 static void
1282 peerRefreshDNS(void *data)
1283 {
1284     CachePeer *p = NULL;
1285
1286     if (eventFind(peerRefreshDNS, NULL))
1287         eventDelete(peerRefreshDNS, NULL);
1288
1289     if (!data && 0 == stat5minClientRequests()) {
1290         /* no recent client traffic, wait a bit */
1291         eventAddIsh("peerRefreshDNS", peerRefreshDNS, NULL, 180.0, 1);
1292         return;
1293     }
1294
1295     for (p = Config.peers; p; p = p->next)
1296         ipcache_nbgethostbyname(p->host, peerDNSConfigure, p);
1297
1298     /* Reconfigure the peers every hour */
1299     eventAddIsh("peerRefreshDNS", peerRefreshDNS, NULL, 3600.0, 1);
1300 }
1301
1302 static void
1303 peerConnectFailedSilent(CachePeer * p)
1304 {
1305     p->stats.last_connect_failure = squid_curtime;
1306
1307     if (!p->tcp_up) {
1308         debugs(15, 2, "TCP connection to " << p->host << "/" << p->http_port <<
1309                " dead");
1310         return;
1311     }
1312
1313     -- p->tcp_up;
1314
1315     if (!p->tcp_up) {
1316         debugs(15, DBG_IMPORTANT, "Detected DEAD " << neighborTypeStr(p) << ": " << p->name);
1317         p->stats.logged_state = PEER_DEAD;
1318     }
1319 }
1320
1321 void
1322 peerConnectFailed(CachePeer *p)
1323 {
1324     debugs(15, DBG_IMPORTANT, "TCP connection to " << p->host << "/" << p->http_port << " failed");
1325     peerConnectFailedSilent(p);
1326 }
1327
1328 void
1329 peerConnectSucceded(CachePeer * p)
1330 {
1331     if (!p->tcp_up) {
1332         debugs(15, 2, "TCP connection to " << p->host << "/" << p->http_port << " succeded");
1333         p->tcp_up = p->connect_fail_limit; // NP: so peerAlive(p) works properly.
1334         peerAlive(p);
1335         if (!p->n_addresses)
1336             ipcache_nbgethostbyname(p->host, peerDNSConfigure, p);
1337     } else
1338         p->tcp_up = p->connect_fail_limit;
1339 }
1340
1341 /*
1342 * peerProbeConnect will be called on dead peers by neighborUp
1343 */
1344 static bool
1345 peerProbeConnect(CachePeer * p)
1346 {
1347     time_t ctimeout = p->connect_timeout > 0 ? p->connect_timeout : Config.Timeout.peer_connect;
1348     bool ret = (squid_curtime - p->stats.last_connect_failure) > (ctimeout * 10);
1349
1350     if (p->testing_now > 0)
1351         return ret;/* probe already running */
1352
1353     if (squid_curtime - p->stats.last_connect_probe == 0)
1354         return ret;/* don't probe to often */
1355
1356     /* for each IP address of this CachePeer. find one that we can connect to and probe it. */
1357     for (int i = 0; i < p->n_addresses; ++i) {
1358         Comm::ConnectionPointer conn = new Comm::Connection;
1359         conn->remote = p->addresses[i];
1360         conn->remote.port(p->http_port);
1361         conn->setPeer(p);
1362         getOutgoingAddress(NULL, conn);
1363
1364         ++ p->testing_now;
1365
1366         AsyncCall::Pointer call = commCbCall(15,3, "peerProbeConnectDone", CommConnectCbPtrFun(peerProbeConnectDone, p));
1367         Comm::ConnOpener *cs = new Comm::ConnOpener(conn, call, ctimeout);
1368         cs->setHost(p->host);
1369         AsyncJob::Start(cs);
1370     }
1371
1372     p->stats.last_connect_probe = squid_curtime;
1373
1374     return ret;
1375 }
1376
1377 static void
1378 peerProbeConnectDone(const Comm::ConnectionPointer &conn, Comm::Flag status, int xerrno, void *data)
1379 {
1380     CachePeer *p = (CachePeer*)data;
1381
1382     if (status == Comm::OK) {
1383         peerConnectSucceded(p);
1384     } else {
1385         peerConnectFailedSilent(p);
1386     }
1387
1388     -- p->testing_now;
1389     conn->close();
1390     // TODO: log this traffic.
1391 }
1392
1393 static void
1394 peerCountMcastPeersSchedule(CachePeer * p, time_t when)
1395 {
1396     if (p->mcast.flags.count_event_pending)
1397         return;
1398
1399     eventAdd("peerCountMcastPeersStart",
1400              peerCountMcastPeersStart,
1401              p,
1402              (double) when, 1);
1403
1404     p->mcast.flags.count_event_pending = true;
1405 }
1406
1407 static void
1408 peerCountMcastPeersStart(void *data)
1409 {
1410     CachePeer *p = (CachePeer *)data;
1411     ps_state *psstate;
1412     StoreEntry *fake;
1413     MemObject *mem;
1414     icp_common_t *query;
1415     int reqnum;
1416     LOCAL_ARRAY(char, url, MAX_URL);
1417     assert(p->type == PEER_MULTICAST);
1418     p->mcast.flags.count_event_pending = false;
1419     snprintf(url, MAX_URL, "http://");
1420     p->in_addr.toUrl(url+7, MAX_URL -8 );
1421     strcat(url, "/");
1422     fake = storeCreateEntry(url, url, RequestFlags(), Http::METHOD_GET);
1423     HttpRequest *req = HttpRequest::CreateFromUrl(url);
1424     psstate = new ps_state;
1425     psstate->request = req;
1426     HTTPMSGLOCK(psstate->request);
1427     psstate->entry = fake;
1428     psstate->callback = NULL;
1429     psstate->callback_data = cbdataReference(p);
1430     psstate->ping.start = current_time;
1431     mem = fake->mem_obj;
1432     mem->request = psstate->request;
1433     HTTPMSGLOCK(mem->request);
1434     mem->start_ping = current_time;
1435     mem->ping_reply_callback = peerCountHandleIcpReply;
1436     mem->ircb_data = psstate;
1437     mcastSetTtl(icpOutgoingConn->fd, p->mcast.ttl);
1438     p->mcast.id = mem->id;
1439     reqnum = icpSetCacheKey((const cache_key *)fake->key);
1440     query = _icp_common_t::createMessage(ICP_QUERY, 0, url, reqnum, 0);
1441     icpUdpSend(icpOutgoingConn->fd, p->in_addr, query, LOG_ICP_QUERY, 0);
1442     fake->ping_status = PING_WAITING;
1443     eventAdd("peerCountMcastPeersDone",
1444              peerCountMcastPeersDone,
1445              psstate,
1446              Config.Timeout.mcast_icp_query / 1000.0, 1);
1447     p->mcast.flags.counting = true;
1448     peerCountMcastPeersSchedule(p, MCAST_COUNT_RATE);
1449 }
1450
1451 static void
1452 peerCountMcastPeersDone(void *data)
1453 {
1454     ps_state *psstate = (ps_state *)data;
1455     StoreEntry *fake = psstate->entry;
1456
1457     if (cbdataReferenceValid(psstate->callback_data)) {
1458         CachePeer *p = (CachePeer *)psstate->callback_data;
1459         p->mcast.flags.counting = false;
1460         p->mcast.avg_n_members = Math::doubleAverage(p->mcast.avg_n_members, (double) psstate->ping.n_recv, ++p->mcast.n_times_counted, 10);
1461         debugs(15, DBG_IMPORTANT, "Group " << p->host  << ": " << psstate->ping.n_recv  <<
1462                " replies, "<< std::setw(4)<< std::setprecision(2) <<
1463                p->mcast.avg_n_members <<" average, RTT " << p->stats.rtt);
1464         p->mcast.n_replies_expected = (int) p->mcast.avg_n_members;
1465     }
1466
1467     cbdataReferenceDone(psstate->callback_data);
1468
1469     fake->abort(); // sets ENTRY_ABORTED and initiates releated cleanup
1470     HTTPMSGUNLOCK(fake->mem_obj->request);
1471     fake->unlock("peerCountMcastPeersDone");
1472     HTTPMSGUNLOCK(psstate->request);
1473     cbdataFree(psstate);
1474 }
1475
1476 static void
1477 peerCountHandleIcpReply(CachePeer * p, peer_t type, AnyP::ProtocolType proto, void *hdrnotused, void *data)
1478 {
1479     int rtt_av_factor;
1480
1481     ps_state *psstate = (ps_state *)data;
1482     StoreEntry *fake = psstate->entry;
1483     MemObject *mem = fake->mem_obj;
1484     int rtt = tvSubMsec(mem->start_ping, current_time);
1485     assert(proto == AnyP::PROTO_ICP);
1486     assert(fake);
1487     assert(mem);
1488     ++ psstate->ping.n_recv;
1489     rtt_av_factor = RTT_AV_FACTOR;
1490
1491     if (p->options.weighted_roundrobin)
1492         rtt_av_factor = RTT_BACKGROUND_AV_FACTOR;
1493
1494     p->stats.rtt = Math::intAverage(p->stats.rtt, rtt, psstate->ping.n_recv, rtt_av_factor);
1495 }
1496
1497 static void
1498 neighborDumpPeers(StoreEntry * sentry)
1499 {
1500     dump_peers(sentry, Config.peers);
1501 }
1502
1503 static void
1504 neighborDumpNonPeers(StoreEntry * sentry)
1505 {
1506     dump_peers(sentry, non_peers);
1507 }
1508
1509 void
1510 dump_peer_options(StoreEntry * sentry, CachePeer * p)
1511 {
1512     if (p->options.proxy_only)
1513         storeAppendPrintf(sentry, " proxy-only");
1514
1515     if (p->options.no_query)
1516         storeAppendPrintf(sentry, " no-query");
1517
1518     if (p->options.background_ping)
1519         storeAppendPrintf(sentry, " background-ping");
1520
1521     if (p->options.no_digest)
1522         storeAppendPrintf(sentry, " no-digest");
1523
1524     if (p->options.default_parent)
1525         storeAppendPrintf(sentry, " default");
1526
1527     if (p->options.roundrobin)
1528         storeAppendPrintf(sentry, " round-robin");
1529
1530     if (p->options.carp)
1531         storeAppendPrintf(sentry, " carp");
1532
1533 #if USE_AUTH
1534     if (p->options.userhash)
1535         storeAppendPrintf(sentry, " userhash");
1536 #endif
1537
1538     if (p->options.sourcehash)
1539         storeAppendPrintf(sentry, " sourcehash");
1540
1541     if (p->options.weighted_roundrobin)
1542         storeAppendPrintf(sentry, " weighted-round-robin");
1543
1544     if (p->options.mcast_responder)
1545         storeAppendPrintf(sentry, " multicast-responder");
1546
1547 #if PEER_MULTICAST_SIBLINGS
1548     if (p->options.mcast_siblings)
1549         storeAppendPrintf(sentry, " multicast-siblings");
1550 #endif
1551
1552     if (p->weight != 1)
1553         storeAppendPrintf(sentry, " weight=%d", p->weight);
1554
1555     if (p->options.closest_only)
1556         storeAppendPrintf(sentry, " closest-only");
1557
1558 #if USE_HTCP
1559     if (p->options.htcp) {
1560         storeAppendPrintf(sentry, " htcp");
1561         if (p->options.htcp_oldsquid || p->options.htcp_no_clr || p->options.htcp_no_purge_clr || p->options.htcp_only_clr) {
1562             int doneopts=0;
1563             if (p->options.htcp_oldsquid)
1564                 storeAppendPrintf(sentry, "%soldsquid",(doneopts++>0?",":"="));
1565             if (p->options.htcp_no_clr)
1566                 storeAppendPrintf(sentry, "%sno-clr",(doneopts++>0?",":"="));
1567             if (p->options.htcp_no_purge_clr)
1568                 storeAppendPrintf(sentry, "%sno-purge-clr",(doneopts++>0?",":"="));
1569             if (p->options.htcp_only_clr)
1570                 storeAppendPrintf(sentry, "%sonly-clr",(doneopts++>0?",":"="));
1571         }
1572     }
1573 #endif
1574
1575     if (p->options.no_netdb_exchange)
1576         storeAppendPrintf(sentry, " no-netdb-exchange");
1577
1578 #if USE_DELAY_POOLS
1579     if (p->options.no_delay)
1580         storeAppendPrintf(sentry, " no-delay");
1581 #endif
1582
1583     if (p->login)
1584         storeAppendPrintf(sentry, " login=%s", p->login);
1585
1586     if (p->mcast.ttl > 0)
1587         storeAppendPrintf(sentry, " ttl=%d", p->mcast.ttl);
1588
1589     if (p->connect_timeout > 0)
1590         storeAppendPrintf(sentry, " connect-timeout=%d", (int) p->connect_timeout);
1591
1592     if (p->connect_fail_limit != PEER_TCP_MAGIC_COUNT)
1593         storeAppendPrintf(sentry, " connect-fail-limit=%d", p->connect_fail_limit);
1594
1595 #if USE_CACHE_DIGESTS
1596
1597     if (p->digest_url)
1598         storeAppendPrintf(sentry, " digest-url=%s", p->digest_url);
1599
1600 #endif
1601
1602     if (p->options.allow_miss)
1603         storeAppendPrintf(sentry, " allow-miss");
1604
1605     if (p->options.no_tproxy)
1606         storeAppendPrintf(sentry, " no-tproxy");
1607
1608     if (p->max_conn > 0)
1609         storeAppendPrintf(sentry, " max-conn=%d", p->max_conn);
1610     if (p->standby.limit > 0)
1611         storeAppendPrintf(sentry, " standby=%d", p->standby.limit);
1612
1613     if (p->options.originserver)
1614         storeAppendPrintf(sentry, " originserver");
1615
1616     if (p->domain)
1617         storeAppendPrintf(sentry, " forceddomain=%s", p->domain);
1618
1619     if (p->connection_auth == 0)
1620         storeAppendPrintf(sentry, " connection-auth=off");
1621     else if (p->connection_auth == 1)
1622         storeAppendPrintf(sentry, " connection-auth=on");
1623     else if (p->connection_auth == 2)
1624         storeAppendPrintf(sentry, " connection-auth=auto");
1625
1626     storeAppendPrintf(sentry, "\n");
1627 }
1628
1629 static void
1630 dump_peers(StoreEntry * sentry, CachePeer * peers)
1631 {
1632     CachePeer *e = NULL;
1633     char ntoabuf[MAX_IPSTRLEN];
1634     CachePeerDomainList *d = NULL;
1635     icp_opcode op;
1636     int i;
1637
1638     if (peers == NULL)
1639         storeAppendPrintf(sentry, "There are no neighbors installed.\n");
1640
1641     for (e = peers; e; e = e->next) {
1642         assert(e->host != NULL);
1643         storeAppendPrintf(sentry, "\n%-11.11s: %s\n",
1644                           neighborTypeStr(e),
1645                           e->name);
1646         storeAppendPrintf(sentry, "Host       : %s/%d/%d\n",
1647                           e->host,
1648                           e->http_port,
1649                           e->icp.port);
1650         storeAppendPrintf(sentry, "Flags      :");
1651         dump_peer_options(sentry, e);
1652
1653         for (i = 0; i < e->n_addresses; ++i) {
1654             storeAppendPrintf(sentry, "Address[%d] : %s\n", i,
1655                               e->addresses[i].toStr(ntoabuf,MAX_IPSTRLEN) );
1656         }
1657
1658         storeAppendPrintf(sentry, "Status     : %s\n",
1659                           neighborUp(e) ? "Up" : "Down");
1660         storeAppendPrintf(sentry, "FETCHES    : %d\n", e->stats.fetches);
1661         storeAppendPrintf(sentry, "OPEN CONNS : %d\n", e->stats.conn_open);
1662         storeAppendPrintf(sentry, "AVG RTT    : %d msec\n", e->stats.rtt);
1663
1664         if (!e->options.no_query) {
1665             storeAppendPrintf(sentry, "LAST QUERY : %8d seconds ago\n",
1666                               (int) (squid_curtime - e->stats.last_query));
1667
1668             if (e->stats.last_reply > 0)
1669                 storeAppendPrintf(sentry, "LAST REPLY : %8d seconds ago\n",
1670                                   (int) (squid_curtime - e->stats.last_reply));
1671             else
1672                 storeAppendPrintf(sentry, "LAST REPLY : none received\n");
1673
1674             storeAppendPrintf(sentry, "PINGS SENT : %8d\n", e->stats.pings_sent);
1675
1676             storeAppendPrintf(sentry, "PINGS ACKED: %8d %3d%%\n",
1677                               e->stats.pings_acked,
1678                               Math::intPercent(e->stats.pings_acked, e->stats.pings_sent));
1679         }
1680
1681         storeAppendPrintf(sentry, "IGNORED    : %8d %3d%%\n", e->stats.ignored_replies, Math::intPercent(e->stats.ignored_replies, e->stats.pings_acked));
1682
1683         if (!e->options.no_query) {
1684             storeAppendPrintf(sentry, "Histogram of PINGS ACKED:\n");
1685 #if USE_HTCP
1686
1687             if (e->options.htcp) {
1688                 storeAppendPrintf(sentry, "\tMisses\t%8d %3d%%\n",
1689                                   e->htcp.counts[0],
1690                                   Math::intPercent(e->htcp.counts[0], e->stats.pings_acked));
1691                 storeAppendPrintf(sentry, "\tHits\t%8d %3d%%\n",
1692                                   e->htcp.counts[1],
1693                                   Math::intPercent(e->htcp.counts[1], e->stats.pings_acked));
1694             } else {
1695 #endif
1696
1697                 for (op = ICP_INVALID; op < ICP_END; ++op) {
1698                     if (e->icp.counts[op] == 0)
1699                         continue;
1700
1701                     storeAppendPrintf(sentry, "    %12.12s : %8d %3d%%\n",
1702                                       icp_opcode_str[op],
1703                                       e->icp.counts[op],
1704                                       Math::intPercent(e->icp.counts[op], e->stats.pings_acked));
1705                 }
1706
1707 #if USE_HTCP
1708
1709             }
1710
1711 #endif
1712
1713         }
1714
1715         if (e->stats.last_connect_failure) {
1716             storeAppendPrintf(sentry, "Last failed connect() at: %s\n",
1717                               Time::FormatHttpd(e->stats.last_connect_failure));
1718         }
1719
1720         if (e->peer_domain != NULL) {
1721             storeAppendPrintf(sentry, "DOMAIN LIST: ");
1722
1723             for (d = e->peer_domain; d; d = d->next) {
1724                 storeAppendPrintf(sentry, "%s%s ",
1725                                   d->do_ping ? null_string : "!", d->domain);
1726             }
1727
1728             storeAppendPrintf(sentry, "\n");
1729         }
1730
1731         storeAppendPrintf(sentry, "keep-alive ratio: %d%%\n", Math::intPercent(e->stats.n_keepalives_recv, e->stats.n_keepalives_sent));
1732     }
1733 }
1734
1735 #if USE_HTCP
1736 void
1737 neighborsHtcpReply(const cache_key * key, HtcpReplyData * htcp, const Ip::Address &from)
1738 {
1739     StoreEntry *e = Store::Root().get(key);
1740     MemObject *mem = NULL;
1741     CachePeer *p;
1742     peer_t ntype = PEER_NONE;
1743     debugs(15, 6, "neighborsHtcpReply: " <<
1744            (htcp->hit ? "HIT" : "MISS") << " " <<
1745            storeKeyText(key)  );
1746
1747     if (NULL != e)
1748         mem = e->mem_obj;
1749
1750     if ((p = whichPeer(from)))
1751         neighborAliveHtcp(p, mem, htcp);
1752
1753     /* Does the entry exist? */
1754     if (NULL == e) {
1755         debugs(12, 3, "neighyborsHtcpReply: Cache key '" << storeKeyText(key) << "' not found");
1756         neighborCountIgnored(p);
1757         return;
1758     }
1759
1760     /* check if someone is already fetching it */
1761     if (EBIT_TEST(e->flags, ENTRY_DISPATCHED)) {
1762         debugs(15, 3, "neighborsUdpAck: '" << storeKeyText(key) << "' already being fetched.");
1763         neighborCountIgnored(p);
1764         return;
1765     }
1766
1767     if (mem == NULL) {
1768         debugs(15, 2, "Ignoring reply for missing mem_obj: " << storeKeyText(key));
1769         neighborCountIgnored(p);
1770         return;
1771     }
1772
1773     if (e->ping_status != PING_WAITING) {
1774         debugs(15, 2, "neighborsUdpAck: Entry " << storeKeyText(key) << " is not PING_WAITING");
1775         neighborCountIgnored(p);
1776         return;
1777     }
1778
1779     if (!e->locked()) {
1780         // TODO: many entries are unlocked; why is this reported at level 1?
1781         debugs(12, DBG_IMPORTANT, "neighborsUdpAck: '" << storeKeyText(key) << "' has no locks");
1782         neighborCountIgnored(p);
1783         return;
1784     }
1785
1786     if (p) {
1787         ntype = neighborType(p, mem->request);
1788         neighborUpdateRtt(p, mem);
1789     }
1790
1791     if (ignoreMulticastReply(p, mem)) {
1792         neighborCountIgnored(p);
1793         return;
1794     }
1795
1796     debugs(15, 3, "neighborsHtcpReply: e = " << e);
1797     mem->ping_reply_callback(p, ntype, AnyP::PROTO_HTCP, htcp, mem->ircb_data);
1798 }
1799
1800 /*
1801  * Send HTCP CLR messages to all peers configured to receive them.
1802  */
1803 void
1804 neighborsHtcpClear(StoreEntry * e, const char *uri, HttpRequest * req, const HttpRequestMethod &method, htcp_clr_reason reason)
1805 {
1806     CachePeer *p;
1807     char buf[128];
1808
1809     for (p = Config.peers; p; p = p->next) {
1810         if (!p->options.htcp) {
1811             continue;
1812         }
1813         if (p->options.htcp_no_clr) {
1814             continue;
1815         }
1816         if (p->options.htcp_no_purge_clr && reason == HTCP_CLR_PURGE) {
1817             continue;
1818         }
1819         debugs(15, 3, "neighborsHtcpClear: sending CLR to " << p->in_addr.toUrl(buf, 128));
1820         htcpClear(e, uri, req, method, p, reason);
1821     }
1822 }
1823
1824 #endif