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