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