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 "comm/Connection.h"
  37 #include "comm/ConnOpener.h"
  38 #include "event.h"
  39 #include "globals.h"
  40 #include "htcp.h"
  41 #include "HttpRequest.h"
  42 #include "icmp/net_db.h"
  43 #include "ICP.h"
  44 #include "ip/Address.h"
  45 #include "ip/tools.h"
  46 #include "ipcache.h"
  47 #include "MemObject.h"
  48 #include "mgr/Registration.h"
  49 #include "PeerDigest.h"
  50 #include "PeerSelectState.h"
  51 #include "protos.h"
  52 #include "SquidMath.h"
  53 #include "SquidTime.h"
  54 #include "Store.h"
  55
  56 /* count mcast group peers every 15 minutes */
  57 #define MCAST_COUNT_RATE 900
  58
  59 bool peerAllowedToUse(const peer *, HttpRequest *);
  60 static int peerWouldBePinged(const peer *, HttpRequest *);
  61 static void neighborRemove(peer *);
  62 static void neighborAlive(peer *, const MemObject *, const icp_common_t *);
  63 #if USE_HTCP
  64 static void neighborAliveHtcp(peer *, const MemObject *, const htcpReplyData *);
  65 #endif
  66 static void neighborCountIgnored(peer *);
  67 static void peerRefreshDNS(void *);
  68 static IPH peerDNSConfigure;
  69 static bool peerProbeConnect(peer *);
  70 static CNCB peerProbeConnectDone;
  71 static void peerCountMcastPeersDone(void *data);
  72 static void peerCountMcastPeersStart(void *data);
  73 static void peerCountMcastPeersSchedule(peer * p, time_t when);
  74 static IRCB peerCountHandleIcpReply;
  75
  76 static void neighborIgnoreNonPeer(const Ip::Address &, icp_opcode);
  77 static OBJH neighborDumpPeers;
  78 static OBJH neighborDumpNonPeers;
  79 static void dump_peers(StoreEntry * sentry, peer * peers);
  80
  81 static unsigned short echo_port;
  82
  83 static int NLateReplies = 0;
  84 static peer *first_ping = NULL;
  85
  86 const char *
  87 neighborTypeStr(const peer * p)
  88 {
  89     if (p->type == PEER_NONE)
  90         return "Non-Peer";
  91
  92     if (p->type == PEER_SIBLING)
  93         return "Sibling";
  94
  95     if (p->type == PEER_MULTICAST)
  96         return "Multicast Group";
  97
  98     return "Parent";
  99 }
 100
 101
 102 peer *
 103 whichPeer(const Ip::Address &from)
 104 {
 105     int j;
 106
 107     peer *p = NULL;
 108     debugs(15, 3, "whichPeer: from " << from);
 109
 110     for (p = Config.peers; p; p = p->next) {
 111         for (j = 0; j < p->n_addresses; ++j) {
 112             if (from == p->addresses[j] && from.GetPort() == p->icp.port) {
 113                 return p;
 114             }
 115         }
 116     }
 117
 118     return NULL;
 119 }
 120
 121 peer_t
 122 neighborType(const peer * p, const HttpRequest * request)
 123 {
 124
 125     const struct _domain_type *d = NULL;
 126
 127     for (d = p->typelist; d; d = d->next) {
 128         if (0 == matchDomainName(request->GetHost(), d->domain))
 129             if (d->type != PEER_NONE)
 130                 return d->type;
 131     }
 132 #if PEER_MULTICAST_SIBLINGS
 133     if (p->type == PEER_MULTICAST)
 134         if (p->options.mcast_siblings)
 135             return PEER_SIBLING;
 136 #endif
 137
 138     return p->type;
 139 }
 140
 141 /**
 142  * \return Whether it is appropriate to fetch REQUEST from PEER.
 143  */
 144 bool
 145 peerAllowedToUse(const peer * p, HttpRequest * request)
 146 {
 147
 148     const struct _domain_ping *d = NULL;
 149     assert(request != NULL);
 150
 151     if (neighborType(p, request) == PEER_SIBLING) {
 152 #if PEER_MULTICAST_SIBLINGS
 153         if (p->type == PEER_MULTICAST && p->options.mcast_siblings &&
 154                 (request->flags.nocache || request->flags.refresh || request->flags.loopdetect || request->flags.need_validation))
 155             debugs(15, 2, "peerAllowedToUse(" << p->name << ", " << request->GetHost() << ") : multicast-siblings optimization match");
 156 #endif
 157         if (request->flags.nocache)
 158             return false;
 159
 160         if (request->flags.refresh)
 161             return false;
 162
 163         if (request->flags.loopdetect)
 164             return false;
 165
 166         if (request->flags.need_validation)
 167             return false;
 168     }
 169
 170     // CONNECT requests are proxy requests. Not to be forwarded to origin servers.
 171     // Unless the destination port matches, in which case we MAY perform a 'DIRECT' to this peer.
 172     if (p->options.originserver && request->method == METHOD_CONNECT && request->port != p->in_addr.GetPort())
 173         return false;
 174
 175     if (p->peer_domain == NULL && p->access == NULL)
 176         return true;
 177
 178     bool do_ping = false;
 179     for (d = p->peer_domain; d; d = d->next) {
 180         if (0 == matchDomainName(request->GetHost(), d->domain)) {
 181             do_ping = d->do_ping;
 182             break;
 183         }
 184
 185         do_ping = !d->do_ping;
 186     }
 187
 188     if (p->peer_domain && !do_ping)
 189         return false;
 190
 191     if (p->access == NULL)
 192         return do_ping;
 193
 194     ACLFilledChecklist checklist(p->access, request, NULL);
 195     checklist.src_addr = request->client_addr;
 196     checklist.my_addr = request->my_addr;
 197
 198 #if 0 && USE_IDENT
 199     /*
 200      * this is currently broken because 'request->user_ident' has been
 201      * moved to conn->rfc931 and we don't have access to the parent
 202      * ConnStateData here.
 203      */
 204     if (request->user_ident[0])
 205         xstrncpy(checklist.rfc931, request->user_ident, USER_IDENT_SZ);
 206
 207 #endif
 208
 209     return (checklist.fastCheck() == ACCESS_ALLOWED);
 210 }
 211
 212 /* Return TRUE if it is okay to send an ICP request to this peer.   */
 213 static int
 214 peerWouldBePinged(const peer * p, HttpRequest * request)
 215 {
 216     if (p->icp.port == 0)
 217         return 0;
 218
 219     if (p->options.no_query)
 220         return 0;
 221
 222     if (p->options.mcast_responder)
 223         return 0;
 224
 225     if (p->n_addresses == 0)
 226         return 0;
 227
 228     if (p->options.background_ping && (squid_curtime - p->stats.last_query < Config.backgroundPingRate))
 229         return 0;
 230
 231     /* the case below seems strange, but can happen if the
 232      * URL host is on the other side of a firewall */
 233     if (p->type == PEER_SIBLING)
 234         if (!request->flags.hierarchical)
 235             return 0;
 236
 237     if (!peerAllowedToUse(p, request))
 238         return 0;
 239
 240     /* Ping dead peers every timeout interval */
 241     if (squid_curtime - p->stats.last_query > Config.Timeout.deadPeer)
 242         return 1;
 243
 244     if (!neighborUp(p))
 245         return 0;
 246
 247     return 1;
 248 }
 249
 250 /* Return TRUE if it is okay to send an HTTP request to this peer. */
 251 int
 252 peerHTTPOkay(const peer * p, HttpRequest * request)
 253 {
 254     if (p->max_conn)
 255         if (p->stats.conn_open >= p->max_conn)
 256             return 0;
 257
 258     if (!peerAllowedToUse(p, request))
 259         return 0;
 260
 261     if (!neighborUp(p))
 262         return 0;
 263
 264     return 1;
 265 }
 266
 267 int
 268 neighborsCount(HttpRequest * request)
 269 {
 270     peer *p = NULL;
 271     int count = 0;
 272
 273     for (p = Config.peers; p; p = p->next)
 274         if (peerWouldBePinged(p, request))
 275             ++count;
 276
 277     debugs(15, 3, "neighborsCount: " << count);
 278
 279     return count;
 280 }
 281
 282 peer *
 283 getFirstUpParent(HttpRequest * request)
 284 {
 285     peer *p = NULL;
 286
 287     for (p = Config.peers; p; p = p->next) {
 288         if (!neighborUp(p))
 289             continue;
 290
 291         if (neighborType(p, request) != PEER_PARENT)
 292             continue;
 293
 294         if (!peerHTTPOkay(p, request))
 295             continue;
 296
 297         break;
 298     }
 299
 300     debugs(15, 3, "getFirstUpParent: returning " << (p ? p->host : "NULL"));
 301     return p;
 302 }
 303
 304 peer *
 305 getRoundRobinParent(HttpRequest * request)
 306 {
 307     peer *p;
 308     peer *q = NULL;
 309
 310     for (p = Config.peers; p; p = p->next) {
 311         if (!p->options.roundrobin)
 312             continue;
 313
 314         if (neighborType(p, request) != PEER_PARENT)
 315             continue;
 316
 317         if (!peerHTTPOkay(p, request))
 318             continue;
 319
 320         if (p->weight == 0)
 321             continue;
 322
 323         if (q) {
 324             if (p->weight == q->weight) {
 325                 if (q->rr_count < p->rr_count)
 326                     continue;
 327             } else if ( ((double) q->rr_count / q->weight) < ((double) p->rr_count / p->weight)) {
 328                 continue;
 329             }
 330         }
 331
 332         q = p;
 333     }
 334
 335     if (q)
 336         ++ q->rr_count;
 337
 338     debugs(15, 3, HERE << "returning " << (q ? q->host : "NULL"));
 339
 340     return q;
 341 }
 342
 343 peer *
 344 getWeightedRoundRobinParent(HttpRequest * request)
 345 {
 346     peer *p;
 347     peer *q = NULL;
 348     int weighted_rtt;
 349
 350     for (p = Config.peers; p; p = p->next) {
 351         if (!p->options.weighted_roundrobin)
 352             continue;
 353
 354         if (neighborType(p, request) != PEER_PARENT)
 355             continue;
 356
 357         if (!peerHTTPOkay(p, request))
 358             continue;
 359
 360         if (q && q->rr_count < p->rr_count)
 361             continue;
 362
 363         q = p;
 364     }
 365
 366     if (q && q->rr_count > 1000000)
 367         for (p = Config.peers; p; p = p->next) {
 368             if (!p->options.weighted_roundrobin)
 369                 continue;
 370
 371             if (neighborType(p, request) != PEER_PARENT)
 372                 continue;
 373
 374             p->rr_count = 0;
 375         }
 376
 377     if (q) {
 378         weighted_rtt = (q->stats.rtt - q->basetime) / q->weight;
 379
 380         if (weighted_rtt < 1)
 381             weighted_rtt = 1;
 382
 383         q->rr_count += weighted_rtt;
 384
 385         debugs(15, 3, "getWeightedRoundRobinParent: weighted_rtt " << weighted_rtt);
 386     }
 387
 388     debugs(15, 3, "getWeightedRoundRobinParent: returning " << (q ? q->host : "NULL"));
 389     return q;
 390 }
 391
 392 /**
 393  * This gets called every 5 minutes to clear the round-robin counter.
 394  * The exact timing is an arbitrary default, set on estimate timing of a
 395  * large number of requests in a high-performance environment during the
 396  * period. The larger the number of requests between cycled resets the
 397  * more balanced the operations.
 398  *
 399  \param data    unused.
 400  \todo Make the reset timing a selectable parameter in squid.conf
 401  */
 402 static void
 403 peerClearRRLoop(void *data)
 404 {
 405     peerClearRR();
 406     eventAdd("peerClearRR", peerClearRRLoop, data, 5 * 60.0, 0);
 407 }
 408
 409 /**
 410  * This gets called on startup and restart to kick off the peer round-robin
 411  * maintenance event. It ensures that no matter how many times its called
 412  * no more than one event is scheduled.
 413  */
 414 void
 415 peerClearRRStart(void)
 416 {
 417     static int event_added = 0;
 418     if (!event_added) {
 419         peerClearRRLoop(NULL);
 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 peer has revived from dead, to prevent the revived peer being
 428  *     flooded with requests which it has 'missed' during the down period.
 429  */
 430 void
 431 peerClearRR()
 432 {
 433     peer *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 peer is detected revived.
 441  */
 442 void
 443 peerAlive(peer *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 peer *
 456 getDefaultParent(HttpRequest * request)
 457 {
 458     peer *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 peer *
 480 getNextPeer(peer * p)
 481 {
 482     return p->next;
 483 }
 484
 485 peer *
 486 getFirstPeer(void)
 487 {
 488     return Config.peers;
 489 }
 490
 491 static void
 492 neighborRemove(peer * target)
 493 {
 494     peer *p = NULL;
 495     peer **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     peer *thisPeer = NULL;
 537     peer *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.GetPort())
 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     peer *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 peer */
 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 peer,
 694          * so neighborUp() never says this peer 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 peer */
 737 lookup_t
 738 peerDigestLookup(peer * 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 peer based on cache digests */
 779 peer *
 780 neighborsDigestSelect(HttpRequest * request)
 781 {
 782     peer *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     peer *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 peer 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, peer * 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));
 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(peer * 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(peer * 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(peer * 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(peer * p)
 906 {
 907     if (p == NULL)
 908         return;
 909
 910     ++ p->stats.ignored_replies;
 911
 912     ++NLateReplies;
 913 }
 914
 915 static peer *non_peers = NULL;
 916
 917 static void
 918 neighborIgnoreNonPeer(const Ip::Address &from, icp_opcode opcode)
 919 {
 920     peer *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.GetPort() != from.GetPort())
 927             continue;
 928
 929         break;
 930     }
 931
 932     if (np == NULL) {
 933         np = (peer *)xcalloc(1, sizeof(peer));
 934         np->in_addr = from;
 935         np->icp.port = from.GetPort();
 936         np->type = PEER_NONE;
 937         np->host = new char[MAX_IPSTRLEN];
 938         from.NtoA(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 peer
 953  * * from being used
 954  */
 955 static int
 956 ignoreMulticastReply(peer * 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     peer *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 peer *
1093 peerFindByName(const char *name)
1094 {
1095     peer *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 peer *
1106 peerFindByNameAndPort(const char *name, unsigned short port)
1107 {
1108     peer *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 peer * p)
1125 {
1126     if (!p->tcp_up) {
1127         if (!peerProbeConnect((peer *) p)) {
1128             debugs(15, 8, "neighborUp: DOWN (probed): " << p->host << " (" << p->in_addr << ")");
1129             return 0;
1130         }
1131     }
1132
1133     /*
1134      * The peer 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     peer *p = (peer *)data;
1161
1162     if (p == NULL)
1163         return;
1164
1165     struct _domain_ping *nl = NULL;
1166
1167     for (struct _domain_ping *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(peer * 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     peer *p = (peer *)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.SetPort(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     peer *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(peer * 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(peer *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(peer * 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(peer * 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 peer. 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.SetPort(p->http_port);
1319         getOutgoingAddress(NULL, conn);
1320
1321         ++ p->testing_now;
1322
1323         AsyncCall::Pointer call = commCbCall(15,3, "peerProbeConnectDone", CommConnectCbPtrFun(peerProbeConnectDone, p));
1324         Comm::ConnOpener *cs = new Comm::ConnOpener(conn, call, ctimeout);
1325         cs->setHost(p->host);
1326         AsyncJob::Start(cs);
1327     }
1328
1329     p->stats.last_connect_probe = squid_curtime;
1330
1331     return ret;
1332 }
1333
1334 static void
1335 peerProbeConnectDone(const Comm::ConnectionPointer &conn, comm_err_t status, int xerrno, void *data)
1336 {
1337     peer *p = (peer*)data;
1338
1339     if (status == COMM_OK) {
1340         peerConnectSucceded(p);
1341     } else {
1342         peerConnectFailedSilent(p);
1343     }
1344
1345     -- p->testing_now;
1346     conn->close();
1347     // TODO: log this traffic.
1348 }
1349
1350 static void
1351 peerCountMcastPeersSchedule(peer * p, time_t when)
1352 {
1353     if (p->mcast.flags.count_event_pending)
1354         return;
1355
1356     eventAdd("peerCountMcastPeersStart",
1357              peerCountMcastPeersStart,
1358              p,
1359              (double) when, 1);
1360
1361     p->mcast.flags.count_event_pending = 1;
1362 }
1363
1364 static void
1365 peerCountMcastPeersStart(void *data)
1366 {
1367     peer *p = (peer *)data;
1368     ps_state *psstate;
1369     StoreEntry *fake;
1370     MemObject *mem;
1371     icp_common_t *query;
1372     int reqnum;
1373     LOCAL_ARRAY(char, url, MAX_URL);
1374     assert(p->type == PEER_MULTICAST);
1375     p->mcast.flags.count_event_pending = 0;
1376     snprintf(url, MAX_URL, "http://");
1377     p->in_addr.ToURL(url+7, MAX_URL -8 );
1378     strcat(url, "/");
1379     fake = storeCreateEntry(url, url, request_flags(), METHOD_GET);
1380     HttpRequest *req = HttpRequest::CreateFromUrl(url);
1381     psstate = new ps_state;
1382     psstate->request = HTTPMSGLOCK(req);
1383     psstate->entry = fake;
1384     psstate->callback = NULL;
1385     psstate->callback_data = cbdataReference(p);
1386     psstate->ping.start = current_time;
1387     mem = fake->mem_obj;
1388     mem->request = HTTPMSGLOCK(psstate->request);
1389     mem->start_ping = current_time;
1390     mem->ping_reply_callback = peerCountHandleIcpReply;
1391     mem->ircb_data = psstate;
1392     mcastSetTtl(icpOutgoingConn->fd, p->mcast.ttl);
1393     p->mcast.id = mem->id;
1394     reqnum = icpSetCacheKey((const cache_key *)fake->key);
1395     query = _icp_common_t::createMessage(ICP_QUERY, 0, url, reqnum, 0);
1396     icpUdpSend(icpOutgoingConn->fd, p->in_addr, query, LOG_ICP_QUERY, 0);
1397     fake->ping_status = PING_WAITING;
1398     eventAdd("peerCountMcastPeersDone",
1399              peerCountMcastPeersDone,
1400              psstate,
1401              Config.Timeout.mcast_icp_query / 1000.0, 1);
1402     p->mcast.flags.counting = 1;
1403     peerCountMcastPeersSchedule(p, MCAST_COUNT_RATE);
1404 }
1405
1406 static void
1407 peerCountMcastPeersDone(void *data)
1408 {
1409     ps_state *psstate = (ps_state *)data;
1410     StoreEntry *fake = psstate->entry;
1411
1412     if (cbdataReferenceValid(psstate->callback_data)) {
1413         peer *p = (peer *)psstate->callback_data;
1414         p->mcast.flags.counting = 0;
1415         p->mcast.avg_n_members = Math::doubleAverage(p->mcast.avg_n_members, (double) psstate->ping.n_recv, ++p->mcast.n_times_counted, 10);
1416         debugs(15, DBG_IMPORTANT, "Group " << p->host  << ": " << psstate->ping.n_recv  <<
1417                " replies, "<< std::setw(4)<< std::setprecision(2) <<
1418                p->mcast.avg_n_members <<" average, RTT " << p->stats.rtt);
1419         p->mcast.n_replies_expected = (int) p->mcast.avg_n_members;
1420     }
1421
1422     cbdataReferenceDone(psstate->callback_data);
1423
1424     fake->abort(); // sets ENTRY_ABORTED and initiates releated cleanup
1425     HTTPMSGUNLOCK(fake->mem_obj->request);
1426     fake->unlock();
1427     HTTPMSGUNLOCK(psstate->request);
1428     cbdataFree(psstate);
1429 }
1430
1431 static void
1432 peerCountHandleIcpReply(peer * p, peer_t type, AnyP::ProtocolType proto, void *hdrnotused, void *data)
1433 {
1434     int rtt_av_factor;
1435
1436     ps_state *psstate = (ps_state *)data;
1437     StoreEntry *fake = psstate->entry;
1438     MemObject *mem = fake->mem_obj;
1439     int rtt = tvSubMsec(mem->start_ping, current_time);
1440     assert(proto == AnyP::PROTO_ICP);
1441     assert(fake);
1442     assert(mem);
1443     ++ psstate->ping.n_recv;
1444     rtt_av_factor = RTT_AV_FACTOR;
1445
1446     if (p->options.weighted_roundrobin)
1447         rtt_av_factor = RTT_BACKGROUND_AV_FACTOR;
1448
1449     p->stats.rtt = Math::intAverage(p->stats.rtt, rtt, psstate->ping.n_recv, rtt_av_factor);
1450 }
1451
1452 static void
1453 neighborDumpPeers(StoreEntry * sentry)
1454 {
1455     dump_peers(sentry, Config.peers);
1456 }
1457
1458 static void
1459 neighborDumpNonPeers(StoreEntry * sentry)
1460 {
1461     dump_peers(sentry, non_peers);
1462 }
1463
1464 void
1465 dump_peer_options(StoreEntry * sentry, peer * p)
1466 {
1467     if (p->options.proxy_only)
1468         storeAppendPrintf(sentry, " proxy-only");
1469
1470     if (p->options.no_query)
1471         storeAppendPrintf(sentry, " no-query");
1472
1473     if (p->options.background_ping)
1474         storeAppendPrintf(sentry, " background-ping");
1475
1476     if (p->options.no_digest)
1477         storeAppendPrintf(sentry, " no-digest");
1478
1479     if (p->options.default_parent)
1480         storeAppendPrintf(sentry, " default");
1481
1482     if (p->options.roundrobin)
1483         storeAppendPrintf(sentry, " round-robin");
1484
1485     if (p->options.carp)
1486         storeAppendPrintf(sentry, " carp");
1487
1488 #if USE_AUTH
1489     if (p->options.userhash)
1490         storeAppendPrintf(sentry, " userhash");
1491 #endif
1492
1493     if (p->options.sourcehash)
1494         storeAppendPrintf(sentry, " sourcehash");
1495
1496     if (p->options.weighted_roundrobin)
1497         storeAppendPrintf(sentry, " weighted-round-robin");
1498
1499     if (p->options.mcast_responder)
1500         storeAppendPrintf(sentry, " multicast-responder");
1501
1502 #if PEER_MULTICAST_SIBLINGS
1503     if (p->options.mcast_siblings)
1504         storeAppendPrintf(sentry, " multicast-siblings");
1505 #endif
1506
1507     if (p->weight != 1)
1508         storeAppendPrintf(sentry, " weight=%d", p->weight);
1509
1510     if (p->options.closest_only)
1511         storeAppendPrintf(sentry, " closest-only");
1512
1513 #if USE_HTCP
1514     if (p->options.htcp) {
1515         storeAppendPrintf(sentry, " htcp");
1516         if (p->options.htcp_oldsquid || p->options.htcp_no_clr || p->options.htcp_no_purge_clr || p->options.htcp_only_clr) {
1517             int doneopts=0;
1518             if (p->options.htcp_oldsquid)
1519                 storeAppendPrintf(sentry, "%soldsquid",(doneopts++>0?",":"="));
1520             if (p->options.htcp_no_clr)
1521                 storeAppendPrintf(sentry, "%sno-clr",(doneopts++>0?",":"="));
1522             if (p->options.htcp_no_purge_clr)
1523                 storeAppendPrintf(sentry, "%sno-purge-clr",(doneopts++>0?",":"="));
1524             if (p->options.htcp_only_clr)
1525                 storeAppendPrintf(sentry, "%sonly-clr",(doneopts++>0?",":"="));
1526         }
1527     }
1528 #endif
1529
1530     if (p->options.no_netdb_exchange)
1531         storeAppendPrintf(sentry, " no-netdb-exchange");
1532
1533 #if USE_DELAY_POOLS
1534     if (p->options.no_delay)
1535         storeAppendPrintf(sentry, " no-delay");
1536 #endif
1537
1538     if (p->login)
1539         storeAppendPrintf(sentry, " login=%s", p->login);
1540
1541     if (p->mcast.ttl > 0)
1542         storeAppendPrintf(sentry, " ttl=%d", p->mcast.ttl);
1543
1544     if (p->connect_timeout > 0)
1545         storeAppendPrintf(sentry, " connect-timeout=%d", (int) p->connect_timeout);
1546
1547     if (p->connect_fail_limit != PEER_TCP_MAGIC_COUNT)
1548         storeAppendPrintf(sentry, " connect-fail-limit=%d", p->connect_fail_limit);
1549
1550 #if USE_CACHE_DIGESTS
1551
1552     if (p->digest_url)
1553         storeAppendPrintf(sentry, " digest-url=%s", p->digest_url);
1554
1555 #endif
1556
1557     if (p->options.allow_miss)
1558         storeAppendPrintf(sentry, " allow-miss");
1559
1560     if (p->options.no_tproxy)
1561         storeAppendPrintf(sentry, " no-tproxy");
1562
1563     if (p->max_conn > 0)
1564         storeAppendPrintf(sentry, " max-conn=%d", p->max_conn);
1565
1566     if (p->options.originserver)
1567         storeAppendPrintf(sentry, " originserver");
1568
1569     if (p->domain)
1570         storeAppendPrintf(sentry, " forceddomain=%s", p->domain);
1571
1572     if (p->connection_auth == 0)
1573         storeAppendPrintf(sentry, " connection-auth=off");
1574     else if (p->connection_auth == 1)
1575         storeAppendPrintf(sentry, " connection-auth=on");
1576     else if (p->connection_auth == 2)
1577         storeAppendPrintf(sentry, " connection-auth=auto");
1578
1579     storeAppendPrintf(sentry, "\n");
1580 }
1581
1582 static void
1583 dump_peers(StoreEntry * sentry, peer * peers)
1584 {
1585     peer *e = NULL;
1586     char ntoabuf[MAX_IPSTRLEN];
1587     struct _domain_ping *d = NULL;
1588     icp_opcode op;
1589     int i;
1590
1591     if (peers == NULL)
1592         storeAppendPrintf(sentry, "There are no neighbors installed.\n");
1593
1594     for (e = peers; e; e = e->next) {
1595         assert(e->host != NULL);
1596         storeAppendPrintf(sentry, "\n%-11.11s: %s\n",
1597                           neighborTypeStr(e),
1598                           e->name);
1599         storeAppendPrintf(sentry, "Host       : %s/%d/%d\n",
1600                           e->host,
1601                           e->http_port,
1602                           e->icp.port);
1603         storeAppendPrintf(sentry, "Flags      :");
1604         dump_peer_options(sentry, e);
1605
1606         for (i = 0; i < e->n_addresses; ++i) {
1607             storeAppendPrintf(sentry, "Address[%d] : %s\n", i,
1608                               e->addresses[i].NtoA(ntoabuf,MAX_IPSTRLEN) );
1609         }
1610
1611         storeAppendPrintf(sentry, "Status     : %s\n",
1612                           neighborUp(e) ? "Up" : "Down");
1613         storeAppendPrintf(sentry, "FETCHES    : %d\n", e->stats.fetches);
1614         storeAppendPrintf(sentry, "OPEN CONNS : %d\n", e->stats.conn_open);
1615         storeAppendPrintf(sentry, "AVG RTT    : %d msec\n", e->stats.rtt);
1616
1617         if (!e->options.no_query) {
1618             storeAppendPrintf(sentry, "LAST QUERY : %8d seconds ago\n",
1619                               (int) (squid_curtime - e->stats.last_query));
1620
1621             if (e->stats.last_reply > 0)
1622                 storeAppendPrintf(sentry, "LAST REPLY : %8d seconds ago\n",
1623                                   (int) (squid_curtime - e->stats.last_reply));
1624             else
1625                 storeAppendPrintf(sentry, "LAST REPLY : none received\n");
1626
1627             storeAppendPrintf(sentry, "PINGS SENT : %8d\n", e->stats.pings_sent);
1628
1629             storeAppendPrintf(sentry, "PINGS ACKED: %8d %3d%%\n",
1630                               e->stats.pings_acked,
1631                               Math::intPercent(e->stats.pings_acked, e->stats.pings_sent));
1632         }
1633
1634         storeAppendPrintf(sentry, "IGNORED    : %8d %3d%%\n", e->stats.ignored_replies, Math::intPercent(e->stats.ignored_replies, e->stats.pings_acked));
1635
1636         if (!e->options.no_query) {
1637             storeAppendPrintf(sentry, "Histogram of PINGS ACKED:\n");
1638 #if USE_HTCP
1639
1640             if (e->options.htcp) {
1641                 storeAppendPrintf(sentry, "\tMisses\t%8d %3d%%\n",
1642                                   e->htcp.counts[0],
1643                                   Math::intPercent(e->htcp.counts[0], e->stats.pings_acked));
1644                 storeAppendPrintf(sentry, "\tHits\t%8d %3d%%\n",
1645                                   e->htcp.counts[1],
1646                                   Math::intPercent(e->htcp.counts[1], e->stats.pings_acked));
1647             } else {
1648 #endif
1649
1650                 for (op = ICP_INVALID; op < ICP_END; ++op) {
1651                     if (e->icp.counts[op] == 0)
1652                         continue;
1653
1654                     storeAppendPrintf(sentry, "    %12.12s : %8d %3d%%\n",
1655                                       icp_opcode_str[op],
1656                                       e->icp.counts[op],
1657                                       Math::intPercent(e->icp.counts[op], e->stats.pings_acked));
1658                 }
1659
1660 #if USE_HTCP
1661
1662             }
1663
1664 #endif
1665
1666         }
1667
1668         if (e->stats.last_connect_failure) {
1669             storeAppendPrintf(sentry, "Last failed connect() at: %s\n",
1670                               Time::FormatHttpd(e->stats.last_connect_failure));
1671         }
1672
1673         if (e->peer_domain != NULL) {
1674             storeAppendPrintf(sentry, "DOMAIN LIST: ");
1675
1676             for (d = e->peer_domain; d; d = d->next) {
1677                 storeAppendPrintf(sentry, "%s%s ",
1678                                   d->do_ping ? null_string : "!", d->domain);
1679             }
1680
1681             storeAppendPrintf(sentry, "\n");
1682         }
1683
1684         storeAppendPrintf(sentry, "keep-alive ratio: %d%%\n", Math::intPercent(e->stats.n_keepalives_recv, e->stats.n_keepalives_sent));
1685     }
1686 }
1687
1688 #if USE_HTCP
1689 void
1690 neighborsHtcpReply(const cache_key * key, htcpReplyData * htcp, const Ip::Address &from)
1691 {
1692     StoreEntry *e = Store::Root().get(key);
1693     MemObject *mem = NULL;
1694     peer *p;
1695     peer_t ntype = PEER_NONE;
1696     debugs(15, 6, "neighborsHtcpReply: " <<
1697            (htcp->hit ? "HIT" : "MISS") << " " <<
1698            storeKeyText(key)  );
1699
1700     if (NULL != e)
1701         mem = e->mem_obj;
1702
1703     if ((p = whichPeer(from)))
1704         neighborAliveHtcp(p, mem, htcp);
1705
1706     /* Does the entry exist? */
1707     if (NULL == e) {
1708         debugs(12, 3, "neighyborsHtcpReply: Cache key '" << storeKeyText(key) << "' not found");
1709         neighborCountIgnored(p);
1710         return;
1711     }
1712
1713     /* check if someone is already fetching it */
1714     if (EBIT_TEST(e->flags, ENTRY_DISPATCHED)) {
1715         debugs(15, 3, "neighborsUdpAck: '" << storeKeyText(key) << "' already being fetched.");
1716         neighborCountIgnored(p);
1717         return;
1718     }
1719
1720     if (mem == NULL) {
1721         debugs(15, 2, "Ignoring reply for missing mem_obj: " << storeKeyText(key));
1722         neighborCountIgnored(p);
1723         return;
1724     }
1725
1726     if (e->ping_status != PING_WAITING) {
1727         debugs(15, 2, "neighborsUdpAck: Entry " << storeKeyText(key) << " is not PING_WAITING");
1728         neighborCountIgnored(p);
1729         return;
1730     }
1731
1732     if (e->lock_count == 0) {
1733         // TODO: many entries are unlocked; why is this reported at level 1?
1734         debugs(12, DBG_IMPORTANT, "neighborsUdpAck: '" << storeKeyText(key) << "' has no locks");
1735         neighborCountIgnored(p);
1736         return;
1737     }
1738
1739     if (p) {
1740         ntype = neighborType(p, mem->request);
1741         neighborUpdateRtt(p, mem);
1742     }
1743
1744     if (ignoreMulticastReply(p, mem)) {
1745         neighborCountIgnored(p);
1746         return;
1747     }
1748
1749     debugs(15, 3, "neighborsHtcpReply: e = " << e);
1750     mem->ping_reply_callback(p, ntype, AnyP::PROTO_HTCP, htcp, mem->ircb_data);
1751 }
1752
1753 /*
1754  * Send HTCP CLR messages to all peers configured to receive them.
1755  */
1756 void
1757 neighborsHtcpClear(StoreEntry * e, const char *uri, HttpRequest * req, const HttpRequestMethod &method, htcp_clr_reason reason)
1758 {
1759     peer *p;
1760     char buf[128];
1761
1762     for (p = Config.peers; p; p = p->next) {
1763         if (!p->options.htcp) {
1764             continue;
1765         }
1766         if (p->options.htcp_no_clr) {
1767             continue;
1768         }
1769         if (p->options.htcp_no_purge_clr && reason == HTCP_CLR_PURGE) {
1770             continue;
1771         }
1772         debugs(15, 3, "neighborsHtcpClear: sending CLR to " << p->in_addr.ToURL(buf, 128));
1773         htcpClear(e, uri, req, method, p, reason);
1774     }
1775 }
1776
1777 #endif