src/neighbors.cc

   1 /*
   2  * DEBUG: section 15    Neighbor Routines
   3  * AUTHOR: Harvest Derived
   4  *
   5  * SQUID Web Proxy Cache          http://www.squid-cache.org/
   6  * ----------------------------------------------------------
   7  *
   8  *  Squid is the result of efforts by numerous individuals from
   9  *  the Internet community; see the CONTRIBUTORS file for full
  10  *  details.   Many organizations have provided support for Squid's
  11  *  development; see the SPONSORS file for full details.  Squid is
  12  *  Copyrighted (C) 2001 by the Regents of the University of
  13  *  California; see the COPYRIGHT file for full details.  Squid
  14  *  incorporates software developed and/or copyrighted by other
  15  *  sources; see the CREDITS file for full details.
  16  *
  17  *  This program is free software; you can redistribute it and/or modify
  18  *  it under the terms of the GNU General Public License as published by
  19  *  the Free Software Foundation; either version 2 of the License, or
  20  *  (at your option) any later version.
  21  *
  22  *  This program is distributed in the hope that it will be useful,
  23  *  but WITHOUT ANY WARRANTY; without even the implied warranty of
  24  *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  25  *  GNU General Public License for more details.
  26  *
  27  *  You should have received a copy of the GNU General Public License
  28  *  along with this program; if not, write to the Free Software
  29  *  Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111, USA.
  30  *
  31  */
  32
  33 #include "squid.h"
  34 #include "acl/FilledChecklist.h"
  35 #include "anyp/PortCfg.h"
  36 #include "CacheDigest.h"
  37 #include "comm/Connection.h"
  38 #include "comm/ConnOpener.h"
  39 #include "event.h"
  40 #include "forward.h"
  41 #include "globals.h"
  42 #include "htcp.h"
  43 #include "HttpRequest.h"
  44 #include "icmp/net_db.h"
  45 #include "ICP.h"
  46 #include "int.h"
  47 #include "ip/Address.h"
  48 #include "ip/tools.h"
  49 #include "ipcache.h"
  50 #include "MemObject.h"
  51 #include "mgr/Registration.h"
  52 #include "multicast.h"
  53 #include "neighbors.h"
  54 #include "PeerDigest.h"
  55 #include "PeerSelectState.h"
  56 #include "SquidMath.h"
  57 #include "SquidTime.h"
  58 #include "stat.h"
  59 #include "Store.h"
  60 #include "store_key_md5.h"
  61 #include "tools.h"
  62 #include "URL.h"
  63
  64 /* count mcast group peers every 15 minutes */
  65 #define MCAST_COUNT_RATE 900
  66
  67 bool peerAllowedToUse(const peer *, HttpRequest *);
  68 static int peerWouldBePinged(const peer *, HttpRequest *);
  69 static void neighborRemove(peer *);
  70 static void neighborAlive(peer *, const MemObject *, const icp_common_t *);
  71 #if USE_HTCP
  72 static void neighborAliveHtcp(peer *, const MemObject *, const htcpReplyData *);
  73 #endif
  74 static void neighborCountIgnored(peer *);
  75 static void peerRefreshDNS(void *);
  76 static IPH peerDNSConfigure;
  77 static bool peerProbeConnect(peer *);
  78 static CNCB peerProbeConnectDone;
  79 static void peerCountMcastPeersDone(void *data);
  80 static void peerCountMcastPeersStart(void *data);
  81 static void peerCountMcastPeersSchedule(peer * p, time_t when);
  82 static IRCB peerCountHandleIcpReply;
  83
  84 static void neighborIgnoreNonPeer(const Ip::Address &, icp_opcode);
  85 static OBJH neighborDumpPeers;
  86 static OBJH neighborDumpNonPeers;
  87 static void dump_peers(StoreEntry * sentry, peer * peers);
  88
  89 static unsigned short echo_port;
  90
  91 static int NLateReplies = 0;
  92 static peer *first_ping = NULL;
  93
  94 const char *
  95 neighborTypeStr(const peer * p)
  96 {
  97     if (p->type == PEER_NONE)
  98         return "Non-Peer";
  99
 100     if (p->type == PEER_SIBLING)
 101         return "Sibling";
 102
 103     if (p->type == PEER_MULTICAST)
 104         return "Multicast Group";
 105
 106     return "Parent";
 107 }
 108
 109 peer *
 110 whichPeer(const Ip::Address &from)
 111 {
 112     int j;
 113
 114     peer *p = NULL;
 115     debugs(15, 3, "whichPeer: from " << from);
 116
 117     for (p = Config.peers; p; p = p->next) {
 118         for (j = 0; j < p->n_addresses; ++j) {
 119             if (from == p->addresses[j] && from.GetPort() == p->icp.port) {
 120                 return p;
 121             }
 122         }
 123     }
 124
 125     return NULL;
 126 }
 127
 128 peer_t
 129 neighborType(const peer * p, const HttpRequest * request)
 130 {
 131
 132     const struct _domain_type *d = NULL;
 133
 134     for (d = p->typelist; d; d = d->next) {
 135         if (0 == matchDomainName(request->GetHost(), d->domain))
 136             if (d->type != PEER_NONE)
 137                 return d->type;
 138     }
 139 #if PEER_MULTICAST_SIBLINGS
 140     if (p->type == PEER_MULTICAST)
 141         if (p->options.mcast_siblings)
 142             return PEER_SIBLING;
 143 #endif
 144
 145     return p->type;
 146 }
 147
 148 /**
 149  * \return Whether it is appropriate to fetch REQUEST from PEER.
 150  */
 151 bool
 152 peerAllowedToUse(const peer * p, HttpRequest * request)
 153 {
 154
 155     const struct _domain_ping *d = NULL;
 156     assert(request != NULL);
 157
 158     if (neighborType(p, request) == PEER_SIBLING) {
 159 #if PEER_MULTICAST_SIBLINGS
 160         if (p->type == PEER_MULTICAST && p->options.mcast_siblings &&
 161                 (request->flags.nocache || request->flags.refresh || request->flags.loopdetect || request->flags.need_validation))
 162             debugs(15, 2, "peerAllowedToUse(" << p->name << ", " << request->GetHost() << ") : multicast-siblings optimization match");
 163 #endif
 164         if (request->flags.nocache)
 165             return false;
 166
 167         if (request->flags.refresh)
 168             return false;
 169
 170         if (request->flags.loopdetect)
 171             return false;
 172
 173         if (request->flags.need_validation)
 174             return false;
 175     }
 176
 177     // CONNECT requests are proxy requests. Not to be forwarded to origin servers.
 178     // Unless the destination port matches, in which case we MAY perform a 'DIRECT' to this peer.
 179     if (p->options.originserver && request->method == METHOD_CONNECT && request->port != p->in_addr.GetPort())
 180         return false;
 181
 182     if (p->peer_domain == NULL && p->access == NULL)
 183         return true;
 184
 185     bool do_ping = false;
 186     for (d = p->peer_domain; d; d = d->next) {
 187         if (0 == matchDomainName(request->GetHost(), d->domain)) {
 188             do_ping = d->do_ping;
 189             break;
 190         }
 191
 192         do_ping = !d->do_ping;
 193     }
 194
 195     if (p->peer_domain && !do_ping)
 196         return false;
 197
 198     if (p->access == NULL)
 199         return do_ping;
 200
 201     ACLFilledChecklist checklist(p->access, request, NULL);
 202     checklist.src_addr = request->client_addr;
 203     checklist.my_addr = request->my_addr;
 204
 205     return (checklist.fastCheck() == ACCESS_ALLOWED);
 206 }
 207
 208 /* Return TRUE if it is okay to send an ICP request to this peer.   */
 209 static int
 210 peerWouldBePinged(const peer * p, HttpRequest * request)
 211 {
 212     if (p->icp.port == 0)
 213         return 0;
 214
 215     if (p->options.no_query)
 216         return 0;
 217
 218     if (p->options.mcast_responder)
 219         return 0;
 220
 221     if (p->n_addresses == 0)
 222         return 0;
 223
 224     if (p->options.background_ping && (squid_curtime - p->stats.last_query < Config.backgroundPingRate))
 225         return 0;
 226
 227     /* the case below seems strange, but can happen if the
 228      * URL host is on the other side of a firewall */
 229     if (p->type == PEER_SIBLING)
 230         if (!request->flags.hierarchical)
 231             return 0;
 232
 233     if (!peerAllowedToUse(p, request))
 234         return 0;
 235
 236     /* Ping dead peers every timeout interval */
 237     if (squid_curtime - p->stats.last_query > Config.Timeout.deadPeer)
 238         return 1;
 239
 240     if (!neighborUp(p))
 241         return 0;
 242
 243     return 1;
 244 }
 245
 246 /* Return TRUE if it is okay to send an HTTP request to this peer. */
 247 int
 248 peerHTTPOkay(const peer * p, HttpRequest * request)
 249 {
 250     if (p->max_conn)
 251         if (p->stats.conn_open >= p->max_conn)
 252             return 0;
 253
 254     if (!peerAllowedToUse(p, request))
 255         return 0;
 256
 257     if (!neighborUp(p))
 258         return 0;
 259
 260     return 1;
 261 }
 262
 263 int
 264 neighborsCount(HttpRequest * request)
 265 {
 266     peer *p = NULL;
 267     int count = 0;
 268
 269     for (p = Config.peers; p; p = p->next)
 270         if (peerWouldBePinged(p, request))
 271             ++count;
 272
 273     debugs(15, 3, "neighborsCount: " << count);
 274
 275     return count;
 276 }
 277
 278 peer *
 279 getFirstUpParent(HttpRequest * request)
 280 {
 281     peer *p = NULL;
 282
 283     for (p = Config.peers; p; p = p->next) {
 284         if (!neighborUp(p))
 285             continue;
 286
 287         if (neighborType(p, request) != PEER_PARENT)
 288             continue;
 289
 290         if (!peerHTTPOkay(p, request))
 291             continue;
 292
 293         break;
 294     }
 295
 296     debugs(15, 3, "getFirstUpParent: returning " << (p ? p->host : "NULL"));
 297     return p;
 298 }
 299
 300 peer *
 301 getRoundRobinParent(HttpRequest * request)
 302 {
 303     peer *p;
 304     peer *q = NULL;
 305
 306     for (p = Config.peers; p; p = p->next) {
 307         if (!p->options.roundrobin)
 308             continue;
 309
 310         if (neighborType(p, request) != PEER_PARENT)
 311             continue;
 312
 313         if (!peerHTTPOkay(p, request))
 314             continue;
 315
 316         if (p->weight == 0)
 317             continue;
 318
 319         if (q) {
 320             if (p->weight == q->weight) {
 321                 if (q->rr_count < p->rr_count)
 322                     continue;
 323             } else if ( ((double) q->rr_count / q->weight) < ((double) p->rr_count / p->weight)) {
 324                 continue;
 325             }
 326         }
 327
 328         q = p;
 329     }
 330
 331     if (q)
 332         ++ q->rr_count;
 333
 334     debugs(15, 3, HERE << "returning " << (q ? q->host : "NULL"));
 335
 336     return q;
 337 }
 338
 339 peer *
 340 getWeightedRoundRobinParent(HttpRequest * request)
 341 {
 342     peer *p;
 343     peer *q = NULL;
 344     int weighted_rtt;
 345
 346     for (p = Config.peers; p; p = p->next) {
 347         if (!p->options.weighted_roundrobin)
 348             continue;
 349
 350         if (neighborType(p, request) != PEER_PARENT)
 351             continue;
 352
 353         if (!peerHTTPOkay(p, request))
 354             continue;
 355
 356         if (q && q->rr_count < p->rr_count)
 357             continue;
 358
 359         q = p;
 360     }
 361
 362     if (q && q->rr_count > 1000000)
 363         for (p = Config.peers; p; p = p->next) {
 364             if (!p->options.weighted_roundrobin)
 365                 continue;
 366
 367             if (neighborType(p, request) != PEER_PARENT)
 368                 continue;
 369
 370             p->rr_count = 0;
 371         }
 372
 373     if (q) {
 374         weighted_rtt = (q->stats.rtt - q->basetime) / q->weight;
 375
 376         if (weighted_rtt < 1)
 377             weighted_rtt = 1;
 378
 379         q->rr_count += weighted_rtt;
 380
 381         debugs(15, 3, "getWeightedRoundRobinParent: weighted_rtt " << weighted_rtt);
 382     }
 383
 384     debugs(15, 3, "getWeightedRoundRobinParent: returning " << (q ? q->host : "NULL"));
 385     return q;
 386 }
 387
 388 /**
 389  * This gets called every 5 minutes to clear the round-robin counter.
 390  * The exact timing is an arbitrary default, set on estimate timing of a
 391  * large number of requests in a high-performance environment during the
 392  * period. The larger the number of requests between cycled resets the
 393  * more balanced the operations.
 394  *
 395  \param data    unused.
 396  \todo Make the reset timing a selectable parameter in squid.conf
 397  */
 398 static void
 399 peerClearRRLoop(void *data)
 400 {
 401     peerClearRR();
 402     eventAdd("peerClearRR", peerClearRRLoop, data, 5 * 60.0, 0);
 403 }
 404
 405 /**
 406  * This gets called on startup and restart to kick off the peer round-robin
 407  * maintenance event. It ensures that no matter how many times its called
 408  * no more than one event is scheduled.
 409  */
 410 void
 411 peerClearRRStart(void)
 412 {
 413     static bool event_added = false;
 414     if (!event_added) {
 415         peerClearRRLoop(NULL);
 416         event_added=true;
 417     }
 418 }
 419
 420 /**
 421  * Called whenever the round-robin counters need to be reset to a sane state.
 422  * So far those times are:
 423  *  - On startup and reconfigure - to set the counters to sane initial settings.
 424  *  -  When a peer has revived from dead, to prevent the revived peer being
 425  *     flooded with requests which it has 'missed' during the down period.
 426  */
 427 void
 428 peerClearRR()
 429 {
 430     peer *p = NULL;
 431     for (p = Config.peers; p; p = p->next) {
 432         p->rr_count = 0;
 433     }
 434 }
 435
 436 /**
 437  * Perform all actions when a peer is detected revived.
 438  */
 439 void
 440 peerAlive(peer *p)
 441 {
 442     if (p->stats.logged_state == PEER_DEAD && p->tcp_up) {
 443         debugs(15, DBG_IMPORTANT, "Detected REVIVED " << neighborTypeStr(p) << ": " << p->name);
 444         p->stats.logged_state = PEER_ALIVE;
 445         peerClearRR();
 446     }
 447
 448     p->stats.last_reply = squid_curtime;
 449     p->stats.probe_start = 0;
 450 }
 451
 452 peer *
 453 getDefaultParent(HttpRequest * request)
 454 {
 455     peer *p = NULL;
 456
 457     for (p = Config.peers; p; p = p->next) {
 458         if (neighborType(p, request) != PEER_PARENT)
 459             continue;
 460
 461         if (!p->options.default_parent)
 462             continue;
 463
 464         if (!peerHTTPOkay(p, request))
 465             continue;
 466
 467         debugs(15, 3, "getDefaultParent: returning " << p->host);
 468
 469         return p;
 470     }
 471
 472     debugs(15, 3, "getDefaultParent: returning NULL");
 473     return NULL;
 474 }
 475
 476 peer *
 477 getNextPeer(peer * p)
 478 {
 479     return p->next;
 480 }
 481
 482 peer *
 483 getFirstPeer(void)
 484 {
 485     return Config.peers;
 486 }
 487
 488 static void
 489 neighborRemove(peer * target)
 490 {
 491     peer *p = NULL;
 492     peer **P = NULL;
 493     p = Config.peers;
 494     P = &Config.peers;
 495
 496     while (p) {
 497         if (target == p)
 498             break;
 499
 500         P = &p->next;
 501
 502         p = p->next;
 503     }
 504
 505     if (p) {
 506         *P = p->next;
 507         cbdataFree(p);
 508         --Config.npeers;
 509     }
 510
 511     first_ping = Config.peers;
 512 }
 513
 514 static void
 515 neighborsRegisterWithCacheManager()
 516 {
 517     Mgr::RegisterAction("server_list",
 518                         "Peer Cache Statistics",
 519                         neighborDumpPeers, 0, 1);
 520
 521     if (Comm::IsConnOpen(icpIncomingConn)) {
 522         Mgr::RegisterAction("non_peers",
 523                             "List of Unknown sites sending ICP messages",
 524                             neighborDumpNonPeers, 0, 1);
 525     }
 526 }
 527
 528 void
 529 neighbors_init(void)
 530 {
 531     struct servent *sep = NULL;
 532     const char *me = getMyHostname();
 533     peer *thisPeer = NULL;
 534     peer *next = NULL;
 535
 536     neighborsRegisterWithCacheManager();
 537
 538     if (Comm::IsConnOpen(icpIncomingConn)) {
 539
 540         for (thisPeer = Config.peers; thisPeer; thisPeer = next) {
 541             next = thisPeer->next;
 542
 543             if (0 != strcmp(thisPeer->host, me))
 544                 continue;
 545
 546             for (AnyP::PortCfg *s = Config.Sockaddr.http; s; s = s->next) {
 547                 if (thisPeer->http_port != s->s.GetPort())
 548                     continue;
 549
 550                 debugs(15, DBG_IMPORTANT, "WARNING: Peer looks like this host");
 551
 552                 debugs(15, DBG_IMPORTANT, "         Ignoring " <<
 553                        neighborTypeStr(thisPeer) << " " << thisPeer->host <<
 554                        "/" << thisPeer->http_port << "/" <<
 555                        thisPeer->icp.port);
 556
 557                 neighborRemove(thisPeer);
 558             }
 559         }
 560     }
 561
 562     peerRefreshDNS((void *) 1);
 563
 564     sep = getservbyname("echo", "udp");
 565     echo_port = sep ? ntohs((unsigned short) sep->s_port) : 7;
 566
 567     first_ping = Config.peers;
 568 }
 569
 570 int
 571 neighborsUdpPing(HttpRequest * request,
 572                  StoreEntry * entry,
 573                  IRCB * callback,
 574                  void *callback_data,
 575                  int *exprep,
 576                  int *timeout)
 577 {
 578     const char *url = entry->url();
 579     MemObject *mem = entry->mem_obj;
 580     peer *p = NULL;
 581     int i;
 582     int reqnum = 0;
 583     int flags;
 584     icp_common_t *query;
 585     int queries_sent = 0;
 586     int peers_pinged = 0;
 587     int parent_timeout = 0, parent_exprep = 0;
 588     int sibling_timeout = 0, sibling_exprep = 0;
 589     int mcast_timeout = 0, mcast_exprep = 0;
 590
 591     if (Config.peers == NULL)
 592         return 0;
 593
 594     assert(entry->swap_status == SWAPOUT_NONE);
 595
 596     mem->start_ping = current_time;
 597
 598     mem->ping_reply_callback = callback;
 599
 600     mem->ircb_data = callback_data;
 601
 602     reqnum = icpSetCacheKey((const cache_key *)entry->key);
 603
 604     for (i = 0, p = first_ping; i++ < Config.npeers; p = p->next) {
 605         if (p == NULL)
 606             p = Config.peers;
 607
 608         debugs(15, 5, "neighborsUdpPing: Peer " << p->host);
 609
 610         if (!peerWouldBePinged(p, request))
 611             continue;           /* next peer */
 612
 613         ++peers_pinged;
 614
 615         debugs(15, 4, "neighborsUdpPing: pinging peer " << p->host << " for '" << url << "'");
 616
 617         debugs(15, 3, "neighborsUdpPing: key = '" << entry->getMD5Text() << "'");
 618
 619         debugs(15, 3, "neighborsUdpPing: reqnum = " << reqnum);
 620
 621 #if USE_HTCP
 622         if (p->options.htcp && !p->options.htcp_only_clr) {
 623             if (Config.Port.htcp <= 0) {
 624                 debugs(15, DBG_CRITICAL, "HTCP is disabled! Cannot send HTCP request to peer.");
 625                 continue;
 626             }
 627
 628             debugs(15, 3, "neighborsUdpPing: sending HTCP query");
 629             if (htcpQuery(entry, request, p) <= 0)
 630                 continue; // unable to send.
 631         } else
 632 #endif
 633         {
 634             if (Config.Port.icp <= 0 || !Comm::IsConnOpen(icpOutgoingConn)) {
 635                 debugs(15, DBG_CRITICAL, "ICP is disabled! Cannot send ICP request to peer.");
 636                 continue;
 637             } else {
 638
 639                 if (p->type == PEER_MULTICAST)
 640                     mcastSetTtl(icpOutgoingConn->fd, p->mcast.ttl);
 641
 642                 if (p->icp.port == echo_port) {
 643                     debugs(15, 4, "neighborsUdpPing: Looks like a dumb cache, send DECHO ping");
 644                     query = _icp_common_t::createMessage(ICP_DECHO, 0, url, reqnum, 0);
 645                     icpUdpSend(icpOutgoingConn->fd, p->in_addr, query, LOG_ICP_QUERY, 0);
 646                 } else {
 647                     flags = 0;
 648
 649                     if (Config.onoff.query_icmp)
 650                         if (p->icp.version == ICP_VERSION_2)
 651                             flags |= ICP_FLAG_SRC_RTT;
 652
 653                     query = _icp_common_t::createMessage(ICP_QUERY, flags, url, reqnum, 0);
 654
 655                     icpUdpSend(icpOutgoingConn->fd, p->in_addr, query, LOG_ICP_QUERY, 0);
 656                 }
 657             }
 658         }
 659
 660         ++queries_sent;
 661
 662         ++ p->stats.pings_sent;
 663
 664         if (p->type == PEER_MULTICAST) {
 665             mcast_exprep += p->mcast.n_replies_expected;
 666             mcast_timeout += (p->stats.rtt * p->mcast.n_replies_expected);
 667         } else if (neighborUp(p)) {
 668             /* its alive, expect a reply from it */
 669
 670             if (neighborType(p, request) == PEER_PARENT) {
 671                 ++parent_exprep;
 672                 parent_timeout += p->stats.rtt;
 673             } else {
 674                 ++sibling_exprep;
 675                 sibling_timeout += p->stats.rtt;
 676             }
 677         } else {
 678             /* Neighbor is dead; ping it anyway, but don't expect a reply */
 679             /* log it once at the threshold */
 680
 681             if (p->stats.logged_state == PEER_ALIVE) {
 682                 debugs(15, DBG_IMPORTANT, "Detected DEAD " << neighborTypeStr(p) << ": " << p->name);
 683                 p->stats.logged_state = PEER_DEAD;
 684             }
 685         }
 686
 687         p->stats.last_query = squid_curtime;
 688
 689         /*
 690          * keep probe_start == 0 for a multicast peer,
 691          * so neighborUp() never says this peer is dead.
 692          */
 693
 694         if ((p->type != PEER_MULTICAST) && (p->stats.probe_start == 0))
 695             p->stats.probe_start = squid_curtime;
 696     }
 697
 698     if ((first_ping = first_ping->next) == NULL)
 699         first_ping = Config.peers;
 700
 701     /*
 702      * How many replies to expect?
 703      */
 704     *exprep = parent_exprep + sibling_exprep + mcast_exprep;
 705
 706     /*
 707      * If there is a configured timeout, use it
 708      */
 709     if (Config.Timeout.icp_query)
 710         *timeout = Config.Timeout.icp_query;
 711     else {
 712         if (*exprep > 0) {
 713             if (parent_exprep)
 714                 *timeout = 2 * parent_timeout / parent_exprep;
 715             else if (mcast_exprep)
 716                 *timeout = 2 * mcast_timeout / mcast_exprep;
 717             else
 718                 *timeout = 2 * sibling_timeout / sibling_exprep;
 719         } else
 720             *timeout = 2000;    /* 2 seconds */
 721
 722         if (Config.Timeout.icp_query_max)
 723             if (*timeout > Config.Timeout.icp_query_max)
 724                 *timeout = Config.Timeout.icp_query_max;
 725
 726         if (*timeout < Config.Timeout.icp_query_min)
 727             *timeout = Config.Timeout.icp_query_min;
 728     }
 729
 730     return peers_pinged;
 731 }
 732
 733 /* lookup the digest of a given peer */
 734 lookup_t
 735 peerDigestLookup(peer * p, HttpRequest * request)
 736 {
 737 #if USE_CACHE_DIGESTS
 738     const cache_key *key = request ? storeKeyPublicByRequest(request) : NULL;
 739     assert(p);
 740     assert(request);
 741     debugs(15, 5, "peerDigestLookup: peer " << p->host);
 742     /* does the peeer have a valid digest? */
 743
 744     if (!p->digest) {
 745         debugs(15, 5, "peerDigestLookup: gone!");
 746         return LOOKUP_NONE;
 747     } else if (!peerHTTPOkay(p, request)) {
 748         debugs(15, 5, "peerDigestLookup: !peerHTTPOkay");
 749         return LOOKUP_NONE;
 750     } else if (!p->digest->flags.needed) {
 751         debugs(15, 5, "peerDigestLookup: note need");
 752         peerDigestNeeded(p->digest);
 753         return LOOKUP_NONE;
 754     } else if (!p->digest->flags.usable) {
 755         debugs(15, 5, "peerDigestLookup: !ready && " << (p->digest->flags.requested ? "" : "!") << "requested");
 756         return LOOKUP_NONE;
 757     }
 758
 759     debugs(15, 5, "peerDigestLookup: OK to lookup peer " << p->host);
 760     assert(p->digest->cd);
 761     /* does digest predict a hit? */
 762
 763     if (!cacheDigestTest(p->digest->cd, key))
 764         return LOOKUP_MISS;
 765
 766     debugs(15, 5, "peerDigestLookup: peer " << p->host << " says HIT!");
 767
 768     return LOOKUP_HIT;
 769
 770 #endif
 771
 772     return LOOKUP_NONE;
 773 }
 774
 775 /* select best peer based on cache digests */
 776 peer *
 777 neighborsDigestSelect(HttpRequest * request)
 778 {
 779     peer *best_p = NULL;
 780 #if USE_CACHE_DIGESTS
 781
 782     int best_rtt = 0;
 783     int choice_count = 0;
 784     int ichoice_count = 0;
 785     peer *p;
 786     int p_rtt;
 787     int i;
 788
 789     if (!request->flags.hierarchical)
 790         return NULL;
 791
 792     storeKeyPublicByRequest(request);
 793
 794     for (i = 0, p = first_ping; i++ < Config.npeers; p = p->next) {
 795         lookup_t lookup;
 796
 797         if (!p)
 798             p = Config.peers;
 799
 800         if (i == 1)
 801             first_ping = p;
 802
 803         lookup = peerDigestLookup(p, request);
 804
 805         if (lookup == LOOKUP_NONE)
 806             continue;
 807
 808         ++choice_count;
 809
 810         if (lookup == LOOKUP_MISS)
 811             continue;
 812
 813         p_rtt = netdbHostRtt(p->host);
 814
 815         debugs(15, 5, "neighborsDigestSelect: peer " << p->host << " rtt: " << p_rtt);
 816
 817         /* is this peer better than others in terms of rtt ? */
 818         if (!best_p || (p_rtt && p_rtt < best_rtt)) {
 819             best_p = p;
 820             best_rtt = p_rtt;
 821
 822             if (p_rtt)          /* informative choice (aka educated guess) */
 823                 ++ichoice_count;
 824
 825             debugs(15, 4, "neighborsDigestSelect: peer " << p->host << " leads with rtt " << best_rtt);
 826         }
 827     }
 828
 829     debugs(15, 4, "neighborsDigestSelect: choices: " << choice_count << " (" << ichoice_count << ")");
 830     peerNoteDigestLookup(request, best_p,
 831                          best_p ? LOOKUP_HIT : (choice_count ? LOOKUP_MISS : LOOKUP_NONE));
 832     request->hier.n_choices = choice_count;
 833     request->hier.n_ichoices = ichoice_count;
 834 #endif
 835
 836     return best_p;
 837 }
 838
 839 void
 840 peerNoteDigestLookup(HttpRequest * request, peer * p, lookup_t lookup)
 841 {
 842 #if USE_CACHE_DIGESTS
 843     if (p)
 844         strncpy(request->hier.cd_host, p->host, sizeof(request->hier.cd_host));
 845     else
 846         *request->hier.cd_host = '\0';
 847
 848     request->hier.cd_lookup = lookup;
 849     debugs(15, 4, "peerNoteDigestLookup: peer " << (p? p->host : "<none>") << ", lookup: " << lookup_t_str[lookup]  );
 850 #endif
 851 }
 852
 853 static void
 854 neighborAlive(peer * p, const MemObject * mem, const icp_common_t * header)
 855 {
 856     peerAlive(p);
 857     ++ p->stats.pings_acked;
 858
 859     if ((icp_opcode) header->opcode <= ICP_END)
 860         ++ p->icp.counts[header->opcode];
 861
 862     p->icp.version = (int) header->version;
 863 }
 864
 865 static void
 866 neighborUpdateRtt(peer * p, MemObject * mem)
 867 {
 868     int rtt, rtt_av_factor;
 869
 870     if (!mem)
 871         return;
 872
 873     if (!mem->start_ping.tv_sec)
 874         return;
 875
 876     rtt = tvSubMsec(mem->start_ping, current_time);
 877
 878     if (rtt < 1 || rtt > 10000)
 879         return;
 880
 881     rtt_av_factor = RTT_AV_FACTOR;
 882
 883     if (p->options.weighted_roundrobin)
 884         rtt_av_factor = RTT_BACKGROUND_AV_FACTOR;
 885
 886     p->stats.rtt = Math::intAverage(p->stats.rtt, rtt, p->stats.pings_acked, rtt_av_factor);
 887 }
 888
 889 #if USE_HTCP
 890 static void
 891 neighborAliveHtcp(peer * p, const MemObject * mem, const htcpReplyData * htcp)
 892 {
 893     peerAlive(p);
 894     ++ p->stats.pings_acked;
 895     ++ p->htcp.counts[htcp->hit ? 1 : 0];
 896     p->htcp.version = htcp->version;
 897 }
 898
 899 #endif
 900
 901 static void
 902 neighborCountIgnored(peer * p)
 903 {
 904     if (p == NULL)
 905         return;
 906
 907     ++ p->stats.ignored_replies;
 908
 909     ++NLateReplies;
 910 }
 911
 912 static peer *non_peers = NULL;
 913
 914 static void
 915 neighborIgnoreNonPeer(const Ip::Address &from, icp_opcode opcode)
 916 {
 917     peer *np;
 918
 919     for (np = non_peers; np; np = np->next) {
 920         if (np->in_addr != from)
 921             continue;
 922
 923         if (np->in_addr.GetPort() != from.GetPort())
 924             continue;
 925
 926         break;
 927     }
 928
 929     if (np == NULL) {
 930         np = (peer *)xcalloc(1, sizeof(peer));
 931         np->in_addr = from;
 932         np->icp.port = from.GetPort();
 933         np->type = PEER_NONE;
 934         np->host = new char[MAX_IPSTRLEN];
 935         from.NtoA(np->host,MAX_IPSTRLEN);
 936         np->next = non_peers;
 937         non_peers = np;
 938     }
 939
 940     ++ np->icp.counts[opcode];
 941
 942     if (isPowTen(++np->stats.ignored_replies))
 943         debugs(15, DBG_IMPORTANT, "WARNING: Ignored " << np->stats.ignored_replies << " replies from non-peer " << np->host);
 944 }
 945
 946 /* ignoreMulticastReply
 947  *
 948  * * We want to ignore replies from multicast peers if the
 949  * * cache_host_domain rules would normally prevent the peer
 950  * * from being used
 951  */
 952 static int
 953 ignoreMulticastReply(peer * p, MemObject * mem)
 954 {
 955     if (p == NULL)
 956         return 0;
 957
 958     if (!p->options.mcast_responder)
 959         return 0;
 960
 961     if (peerHTTPOkay(p, mem->request))
 962         return 0;
 963
 964     return 1;
 965 }
 966
 967 /**
 968  * I should attach these records to the entry.  We take the first
 969  * hit we get our wait until everyone misses.  The timeout handler
 970  * call needs to nip this shopping list or call one of the misses.
 971  *
 972  * If a hit process is already started, then sobeit
 973  */
 974 void
 975 neighborsUdpAck(const cache_key * key, icp_common_t * header, const Ip::Address &from)
 976 {
 977     peer *p = NULL;
 978     StoreEntry *entry;
 979     MemObject *mem = NULL;
 980     peer_t ntype = PEER_NONE;
 981     icp_opcode opcode = (icp_opcode) header->opcode;
 982
 983     debugs(15, 6, "neighborsUdpAck: opcode " << opcode << " '" << storeKeyText(key) << "'");
 984
 985     if (NULL != (entry = Store::Root().get(key)))
 986         mem = entry->mem_obj;
 987
 988     if ((p = whichPeer(from)))
 989         neighborAlive(p, mem, header);
 990
 991     if (opcode > ICP_END)
 992         return;
 993
 994     const char *opcode_d = icp_opcode_str[opcode];
 995
 996     if (p)
 997         neighborUpdateRtt(p, mem);
 998
 999     /* Does the entry exist? */
1000     if (NULL == entry) {
1001         debugs(12, 3, "neighborsUdpAck: Cache key '" << storeKeyText(key) << "' not found");
1002         neighborCountIgnored(p);
1003         return;
1004     }
1005
1006     /* check if someone is already fetching it */
1007     if (EBIT_TEST(entry->flags, ENTRY_DISPATCHED)) {
1008         debugs(15, 3, "neighborsUdpAck: '" << storeKeyText(key) << "' already being fetched.");
1009         neighborCountIgnored(p);
1010         return;
1011     }
1012
1013     if (mem == NULL) {
1014         debugs(15, 2, "Ignoring " << opcode_d << " for missing mem_obj: " << storeKeyText(key));
1015         neighborCountIgnored(p);
1016         return;
1017     }
1018
1019     if (entry->ping_status != PING_WAITING) {
1020         debugs(15, 2, "neighborsUdpAck: Late " << opcode_d << " for " << storeKeyText(key));
1021         neighborCountIgnored(p);
1022         return;
1023     }
1024
1025     if (entry->lock_count == 0) {
1026         // TODO: many entries are unlocked; why is this reported at level 1?
1027         debugs(12, DBG_IMPORTANT, "neighborsUdpAck: '" << storeKeyText(key) << "' has no locks");
1028         neighborCountIgnored(p);
1029         return;
1030     }
1031
1032     debugs(15, 3, "neighborsUdpAck: " << opcode_d << " for '" << storeKeyText(key) << "' from " << (p ? p->host : "source") << " ");
1033
1034     if (p) {
1035         ntype = neighborType(p, mem->request);
1036     }
1037
1038     if (ignoreMulticastReply(p, mem)) {
1039         neighborCountIgnored(p);
1040     } else if (opcode == ICP_MISS) {
1041         if (p == NULL) {
1042             neighborIgnoreNonPeer(from, opcode);
1043         } else {
1044             mem->ping_reply_callback(p, ntype, AnyP::PROTO_ICP, header, mem->ircb_data);
1045         }
1046     } else if (opcode == ICP_HIT) {
1047         if (p == NULL) {
1048             neighborIgnoreNonPeer(from, opcode);
1049         } else {
1050             header->opcode = ICP_HIT;
1051             mem->ping_reply_callback(p, ntype, AnyP::PROTO_ICP, header, mem->ircb_data);
1052         }
1053     } else if (opcode == ICP_DECHO) {
1054         if (p == NULL) {
1055             neighborIgnoreNonPeer(from, opcode);
1056         } else if (ntype == PEER_SIBLING) {
1057             debug_trap("neighborsUdpAck: Found non-ICP cache as SIBLING\n");
1058             debug_trap("neighborsUdpAck: non-ICP neighbors must be a PARENT\n");
1059         } else {
1060             mem->ping_reply_callback(p, ntype, AnyP::PROTO_ICP, header, mem->ircb_data);
1061         }
1062     } else if (opcode == ICP_SECHO) {
1063         if (p) {
1064             debugs(15, DBG_IMPORTANT, "Ignoring SECHO from neighbor " << p->host);
1065             neighborCountIgnored(p);
1066         } else {
1067             debugs(15, DBG_IMPORTANT, "Unsolicited SECHO from " << from);
1068         }
1069     } else if (opcode == ICP_DENIED) {
1070         if (p == NULL) {
1071             neighborIgnoreNonPeer(from, opcode);
1072         } else if (p->stats.pings_acked > 100) {
1073             if (100 * p->icp.counts[ICP_DENIED] / p->stats.pings_acked > 95) {
1074                 debugs(15, DBG_CRITICAL, "95%% of replies from '" << p->host << "' are UDP_DENIED");
1075                 debugs(15, DBG_CRITICAL, "Disabling '" << p->host << "', please check your configuration.");
1076                 neighborRemove(p);
1077                 p = NULL;
1078             } else {
1079                 neighborCountIgnored(p);
1080             }
1081         }
1082     } else if (opcode == ICP_MISS_NOFETCH) {
1083         mem->ping_reply_callback(p, ntype, AnyP::PROTO_ICP, header, mem->ircb_data);
1084     } else {
1085         debugs(15, DBG_CRITICAL, "neighborsUdpAck: Unexpected ICP reply: " << opcode_d);
1086     }
1087 }
1088
1089 peer *
1090 peerFindByName(const char *name)
1091 {
1092     peer *p = NULL;
1093
1094     for (p = Config.peers; p; p = p->next) {
1095         if (!strcasecmp(name, p->name))
1096             break;
1097     }
1098
1099     return p;
1100 }
1101
1102 peer *
1103 peerFindByNameAndPort(const char *name, unsigned short port)
1104 {
1105     peer *p = NULL;
1106
1107     for (p = Config.peers; p; p = p->next) {
1108         if (strcasecmp(name, p->name))
1109             continue;
1110
1111         if (port != p->http_port)
1112             continue;
1113
1114         break;
1115     }
1116
1117     return p;
1118 }
1119
1120 int
1121 neighborUp(const peer * p)
1122 {
1123     if (!p->tcp_up) {
1124         if (!peerProbeConnect((peer *) p)) {
1125             debugs(15, 8, "neighborUp: DOWN (probed): " << p->host << " (" << p->in_addr << ")");
1126             return 0;
1127         }
1128     }
1129
1130     /*
1131      * The peer can not be UP if we don't have any IP addresses
1132      * for it.
1133      */
1134     if (0 == p->n_addresses) {
1135         debugs(15, 8, "neighborUp: DOWN (no-ip): " << p->host << " (" << p->in_addr << ")");
1136         return 0;
1137     }
1138
1139     if (p->options.no_query) {
1140         debugs(15, 8, "neighborUp: UP (no-query): " << p->host << " (" << p->in_addr << ")");
1141         return 1;
1142     }
1143
1144     if (p->stats.probe_start != 0 &&
1145             squid_curtime - p->stats.probe_start > Config.Timeout.deadPeer) {
1146         debugs(15, 8, "neighborUp: DOWN (dead): " << p->host << " (" << p->in_addr << ")");
1147         return 0;
1148     }
1149
1150     debugs(15, 8, "neighborUp: UP: " << p->host << " (" << p->in_addr << ")");
1151     return 1;
1152 }
1153
1154 void
1155 peerDestroy(void *data)
1156 {
1157     peer *p = (peer *)data;
1158
1159     if (p == NULL)
1160         return;
1161
1162     struct _domain_ping *nl = NULL;
1163
1164     for (struct _domain_ping *l = p->peer_domain; l; l = nl) {
1165         nl = l->next;
1166         safe_free(l->domain);
1167         xfree(l);
1168     }
1169
1170     safe_free(p->host);
1171     safe_free(p->name);
1172     safe_free(p->domain);
1173 #if USE_CACHE_DIGESTS
1174
1175     cbdataReferenceDone(p->digest);
1176 #endif
1177 }
1178
1179 void
1180 peerNoteDigestGone(peer * p)
1181 {
1182 #if USE_CACHE_DIGESTS
1183     cbdataReferenceDone(p->digest);
1184 #endif
1185 }
1186
1187 static void
1188 peerDNSConfigure(const ipcache_addrs *ia, const DnsLookupDetails &, void *data)
1189 {
1190     peer *p = (peer *)data;
1191
1192     int j;
1193
1194     if (p->n_addresses == 0) {
1195         debugs(15, DBG_IMPORTANT, "Configuring " << neighborTypeStr(p) << " " << p->host << "/" << p->http_port << "/" << p->icp.port);
1196
1197         if (p->type == PEER_MULTICAST)
1198             debugs(15, DBG_IMPORTANT, "    Multicast TTL = " << p->mcast.ttl);
1199     }
1200
1201     p->n_addresses = 0;
1202
1203     if (ia == NULL) {
1204         debugs(0, DBG_CRITICAL, "WARNING: DNS lookup for '" << p->host << "' failed!");
1205         return;
1206     }
1207
1208     if ((int) ia->count < 1) {
1209         debugs(0, DBG_CRITICAL, "WARNING: No IP address found for '" << p->host << "'!");
1210         return;
1211     }
1212
1213     p->tcp_up = p->connect_fail_limit;
1214
1215     for (j = 0; j < (int) ia->count && j < PEER_MAX_ADDRESSES; ++j) {
1216         p->addresses[j] = ia->in_addrs[j];
1217         debugs(15, 2, "--> IP address #" << j << ": " << p->addresses[j]);
1218         ++ p->n_addresses;
1219     }
1220
1221     p->in_addr.SetEmpty();
1222     p->in_addr = p->addresses[0];
1223     p->in_addr.SetPort(p->icp.port);
1224
1225     if (p->type == PEER_MULTICAST)
1226         peerCountMcastPeersSchedule(p, 10);
1227
1228 #if USE_ICMP
1229     if (p->type != PEER_MULTICAST)
1230         if (!p->options.no_netdb_exchange)
1231             eventAddIsh("netdbExchangeStart", netdbExchangeStart, p, 30.0, 1);
1232 #endif
1233
1234 }
1235
1236 static void
1237 peerRefreshDNS(void *data)
1238 {
1239     peer *p = NULL;
1240
1241     if (eventFind(peerRefreshDNS, NULL))
1242         eventDelete(peerRefreshDNS, NULL);
1243
1244     if (!data && 0 == stat5minClientRequests()) {
1245         /* no recent client traffic, wait a bit */
1246         eventAddIsh("peerRefreshDNS", peerRefreshDNS, NULL, 180.0, 1);
1247         return;
1248     }
1249
1250     for (p = Config.peers; p; p = p->next)
1251         ipcache_nbgethostbyname(p->host, peerDNSConfigure, p);
1252
1253     /* Reconfigure the peers every hour */
1254     eventAddIsh("peerRefreshDNS", peerRefreshDNS, NULL, 3600.0, 1);
1255 }
1256
1257 static void
1258 peerConnectFailedSilent(peer * p)
1259 {
1260     p->stats.last_connect_failure = squid_curtime;
1261
1262     if (!p->tcp_up) {
1263         debugs(15, 2, "TCP connection to " << p->host << "/" << p->http_port <<
1264                " dead");
1265         return;
1266     }
1267
1268     -- p->tcp_up;
1269
1270     if (!p->tcp_up) {
1271         debugs(15, DBG_IMPORTANT, "Detected DEAD " << neighborTypeStr(p) << ": " << p->name);
1272         p->stats.logged_state = PEER_DEAD;
1273     }
1274 }
1275
1276 void
1277 peerConnectFailed(peer *p)
1278 {
1279     debugs(15, DBG_IMPORTANT, "TCP connection to " << p->host << "/" << p->http_port << " failed");
1280     peerConnectFailedSilent(p);
1281 }
1282
1283 void
1284 peerConnectSucceded(peer * p)
1285 {
1286     if (!p->tcp_up) {
1287         debugs(15, 2, "TCP connection to " << p->host << "/" << p->http_port << " succeded");
1288         p->tcp_up = p->connect_fail_limit; // NP: so peerAlive(p) works properly.
1289         peerAlive(p);
1290         if (!p->n_addresses)
1291             ipcache_nbgethostbyname(p->host, peerDNSConfigure, p);
1292     } else
1293         p->tcp_up = p->connect_fail_limit;
1294 }
1295
1296 /*
1297 * peerProbeConnect will be called on dead peers by neighborUp
1298 */
1299 static bool
1300 peerProbeConnect(peer * p)
1301 {
1302     time_t ctimeout = p->connect_timeout > 0 ? p->connect_timeout : Config.Timeout.peer_connect;
1303     bool ret = (squid_curtime - p->stats.last_connect_failure) > (ctimeout * 10);
1304
1305     if (p->testing_now > 0)
1306         return ret;/* probe already running */
1307
1308     if (squid_curtime - p->stats.last_connect_probe == 0)
1309         return ret;/* don't probe to often */
1310
1311     /* for each IP address of this peer. find one that we can connect to and probe it. */
1312     for (int i = 0; i < p->n_addresses; ++i) {
1313         Comm::ConnectionPointer conn = new Comm::Connection;
1314         conn->remote = p->addresses[i];
1315         conn->remote.SetPort(p->http_port);
1316         getOutgoingAddress(NULL, conn);
1317
1318         ++ p->testing_now;
1319
1320         AsyncCall::Pointer call = commCbCall(15,3, "peerProbeConnectDone", CommConnectCbPtrFun(peerProbeConnectDone, p));
1321         Comm::ConnOpener *cs = new Comm::ConnOpener(conn, call, ctimeout);
1322         cs->setHost(p->host);
1323         AsyncJob::Start(cs);
1324     }
1325
1326     p->stats.last_connect_probe = squid_curtime;
1327
1328     return ret;
1329 }
1330
1331 static void
1332 peerProbeConnectDone(const Comm::ConnectionPointer &conn, comm_err_t status, int xerrno, void *data)
1333 {
1334     peer *p = (peer*)data;
1335
1336     if (status == COMM_OK) {
1337         peerConnectSucceded(p);
1338     } else {
1339         peerConnectFailedSilent(p);
1340     }
1341
1342     -- p->testing_now;
1343     conn->close();
1344     // TODO: log this traffic.
1345 }
1346
1347 static void
1348 peerCountMcastPeersSchedule(peer * p, time_t when)
1349 {
1350     if (p->mcast.flags.count_event_pending)
1351         return;
1352
1353     eventAdd("peerCountMcastPeersStart",
1354              peerCountMcastPeersStart,
1355              p,
1356              (double) when, 1);
1357
1358     p->mcast.flags.count_event_pending = 1;
1359 }
1360
1361 static void
1362 peerCountMcastPeersStart(void *data)
1363 {
1364     peer *p = (peer *)data;
1365     ps_state *psstate;
1366     StoreEntry *fake;
1367     MemObject *mem;
1368     icp_common_t *query;
1369     int reqnum;
1370     LOCAL_ARRAY(char, url, MAX_URL);
1371     assert(p->type == PEER_MULTICAST);
1372     p->mcast.flags.count_event_pending = 0;
1373     snprintf(url, MAX_URL, "http://");
1374     p->in_addr.ToURL(url+7, MAX_URL -8 );
1375     strcat(url, "/");
1376     fake = storeCreateEntry(url, url, request_flags(), METHOD_GET);
1377     HttpRequest *req = HttpRequest::CreateFromUrl(url);
1378     psstate = new ps_state;
1379     psstate->request = HTTPMSGLOCK(req);
1380     psstate->entry = fake;
1381     psstate->callback = NULL;
1382     psstate->callback_data = cbdataReference(p);
1383     psstate->ping.start = current_time;
1384     mem = fake->mem_obj;
1385     mem->request = HTTPMSGLOCK(psstate->request);
1386     mem->start_ping = current_time;
1387     mem->ping_reply_callback = peerCountHandleIcpReply;
1388     mem->ircb_data = psstate;
1389     mcastSetTtl(icpOutgoingConn->fd, p->mcast.ttl);
1390     p->mcast.id = mem->id;
1391     reqnum = icpSetCacheKey((const cache_key *)fake->key);
1392     query = _icp_common_t::createMessage(ICP_QUERY, 0, url, reqnum, 0);
1393     icpUdpSend(icpOutgoingConn->fd, p->in_addr, query, LOG_ICP_QUERY, 0);
1394     fake->ping_status = PING_WAITING;
1395     eventAdd("peerCountMcastPeersDone",
1396              peerCountMcastPeersDone,
1397              psstate,
1398              Config.Timeout.mcast_icp_query / 1000.0, 1);
1399     p->mcast.flags.counting = 1;
1400     peerCountMcastPeersSchedule(p, MCAST_COUNT_RATE);
1401 }
1402
1403 static void
1404 peerCountMcastPeersDone(void *data)
1405 {
1406     ps_state *psstate = (ps_state *)data;
1407     StoreEntry *fake = psstate->entry;
1408
1409     if (cbdataReferenceValid(psstate->callback_data)) {
1410         peer *p = (peer *)psstate->callback_data;
1411         p->mcast.flags.counting = 0;
1412         p->mcast.avg_n_members = Math::doubleAverage(p->mcast.avg_n_members, (double) psstate->ping.n_recv, ++p->mcast.n_times_counted, 10);
1413         debugs(15, DBG_IMPORTANT, "Group " << p->host  << ": " << psstate->ping.n_recv  <<
1414                " replies, "<< std::setw(4)<< std::setprecision(2) <<
1415                p->mcast.avg_n_members <<" average, RTT " << p->stats.rtt);
1416         p->mcast.n_replies_expected = (int) p->mcast.avg_n_members;
1417     }
1418
1419     cbdataReferenceDone(psstate->callback_data);
1420
1421     fake->abort(); // sets ENTRY_ABORTED and initiates releated cleanup
1422     HTTPMSGUNLOCK(fake->mem_obj->request);
1423     fake->unlock();
1424     HTTPMSGUNLOCK(psstate->request);
1425     cbdataFree(psstate);
1426 }
1427
1428 static void
1429 peerCountHandleIcpReply(peer * p, peer_t type, AnyP::ProtocolType proto, void *hdrnotused, void *data)
1430 {
1431     int rtt_av_factor;
1432
1433     ps_state *psstate = (ps_state *)data;
1434     StoreEntry *fake = psstate->entry;
1435     MemObject *mem = fake->mem_obj;
1436     int rtt = tvSubMsec(mem->start_ping, current_time);
1437     assert(proto == AnyP::PROTO_ICP);
1438     assert(fake);
1439     assert(mem);
1440     ++ psstate->ping.n_recv;
1441     rtt_av_factor = RTT_AV_FACTOR;
1442
1443     if (p->options.weighted_roundrobin)
1444         rtt_av_factor = RTT_BACKGROUND_AV_FACTOR;
1445
1446     p->stats.rtt = Math::intAverage(p->stats.rtt, rtt, psstate->ping.n_recv, rtt_av_factor);
1447 }
1448
1449 static void
1450 neighborDumpPeers(StoreEntry * sentry)
1451 {
1452     dump_peers(sentry, Config.peers);
1453 }
1454
1455 static void
1456 neighborDumpNonPeers(StoreEntry * sentry)
1457 {
1458     dump_peers(sentry, non_peers);
1459 }
1460
1461 void
1462 dump_peer_options(StoreEntry * sentry, peer * p)
1463 {
1464     if (p->options.proxy_only)
1465         storeAppendPrintf(sentry, " proxy-only");
1466
1467     if (p->options.no_query)
1468         storeAppendPrintf(sentry, " no-query");
1469
1470     if (p->options.background_ping)
1471         storeAppendPrintf(sentry, " background-ping");
1472
1473     if (p->options.no_digest)
1474         storeAppendPrintf(sentry, " no-digest");
1475
1476     if (p->options.default_parent)
1477         storeAppendPrintf(sentry, " default");
1478
1479     if (p->options.roundrobin)
1480         storeAppendPrintf(sentry, " round-robin");
1481
1482     if (p->options.carp)
1483         storeAppendPrintf(sentry, " carp");
1484
1485 #if USE_AUTH
1486     if (p->options.userhash)
1487         storeAppendPrintf(sentry, " userhash");
1488 #endif
1489
1490     if (p->options.sourcehash)
1491         storeAppendPrintf(sentry, " sourcehash");
1492
1493     if (p->options.weighted_roundrobin)
1494         storeAppendPrintf(sentry, " weighted-round-robin");
1495
1496     if (p->options.mcast_responder)
1497         storeAppendPrintf(sentry, " multicast-responder");
1498
1499 #if PEER_MULTICAST_SIBLINGS
1500     if (p->options.mcast_siblings)
1501         storeAppendPrintf(sentry, " multicast-siblings");
1502 #endif
1503
1504     if (p->weight != 1)
1505         storeAppendPrintf(sentry, " weight=%d", p->weight);
1506
1507     if (p->options.closest_only)
1508         storeAppendPrintf(sentry, " closest-only");
1509
1510 #if USE_HTCP
1511     if (p->options.htcp) {
1512         storeAppendPrintf(sentry, " htcp");
1513         if (p->options.htcp_oldsquid || p->options.htcp_no_clr || p->options.htcp_no_purge_clr || p->options.htcp_only_clr) {
1514             int doneopts=0;
1515             if (p->options.htcp_oldsquid)
1516                 storeAppendPrintf(sentry, "%soldsquid",(doneopts++>0?",":"="));
1517             if (p->options.htcp_no_clr)
1518                 storeAppendPrintf(sentry, "%sno-clr",(doneopts++>0?",":"="));
1519             if (p->options.htcp_no_purge_clr)
1520                 storeAppendPrintf(sentry, "%sno-purge-clr",(doneopts++>0?",":"="));
1521             if (p->options.htcp_only_clr)
1522                 storeAppendPrintf(sentry, "%sonly-clr",(doneopts++>0?",":"="));
1523         }
1524     }
1525 #endif
1526
1527     if (p->options.no_netdb_exchange)
1528         storeAppendPrintf(sentry, " no-netdb-exchange");
1529
1530 #if USE_DELAY_POOLS
1531     if (p->options.no_delay)
1532         storeAppendPrintf(sentry, " no-delay");
1533 #endif
1534
1535     if (p->login)
1536         storeAppendPrintf(sentry, " login=%s", p->login);
1537
1538     if (p->mcast.ttl > 0)
1539         storeAppendPrintf(sentry, " ttl=%d", p->mcast.ttl);
1540
1541     if (p->connect_timeout > 0)
1542         storeAppendPrintf(sentry, " connect-timeout=%d", (int) p->connect_timeout);
1543
1544     if (p->connect_fail_limit != PEER_TCP_MAGIC_COUNT)
1545         storeAppendPrintf(sentry, " connect-fail-limit=%d", p->connect_fail_limit);
1546
1547 #if USE_CACHE_DIGESTS
1548
1549     if (p->digest_url)
1550         storeAppendPrintf(sentry, " digest-url=%s", p->digest_url);
1551
1552 #endif
1553
1554     if (p->options.allow_miss)
1555         storeAppendPrintf(sentry, " allow-miss");
1556
1557     if (p->options.no_tproxy)
1558         storeAppendPrintf(sentry, " no-tproxy");
1559
1560     if (p->max_conn > 0)
1561         storeAppendPrintf(sentry, " max-conn=%d", p->max_conn);
1562
1563     if (p->options.originserver)
1564         storeAppendPrintf(sentry, " originserver");
1565
1566     if (p->domain)
1567         storeAppendPrintf(sentry, " forceddomain=%s", p->domain);
1568
1569     if (p->connection_auth == 0)
1570         storeAppendPrintf(sentry, " connection-auth=off");
1571     else if (p->connection_auth == 1)
1572         storeAppendPrintf(sentry, " connection-auth=on");
1573     else if (p->connection_auth == 2)
1574         storeAppendPrintf(sentry, " connection-auth=auto");
1575
1576     storeAppendPrintf(sentry, "\n");
1577 }
1578
1579 static void
1580 dump_peers(StoreEntry * sentry, peer * peers)
1581 {
1582     peer *e = NULL;
1583     char ntoabuf[MAX_IPSTRLEN];
1584     struct _domain_ping *d = NULL;
1585     icp_opcode op;
1586     int i;
1587
1588     if (peers == NULL)
1589         storeAppendPrintf(sentry, "There are no neighbors installed.\n");
1590
1591     for (e = peers; e; e = e->next) {
1592         assert(e->host != NULL);
1593         storeAppendPrintf(sentry, "\n%-11.11s: %s\n",
1594                           neighborTypeStr(e),
1595                           e->name);
1596         storeAppendPrintf(sentry, "Host       : %s/%d/%d\n",
1597                           e->host,
1598                           e->http_port,
1599                           e->icp.port);
1600         storeAppendPrintf(sentry, "Flags      :");
1601         dump_peer_options(sentry, e);
1602
1603         for (i = 0; i < e->n_addresses; ++i) {
1604             storeAppendPrintf(sentry, "Address[%d] : %s\n", i,
1605                               e->addresses[i].NtoA(ntoabuf,MAX_IPSTRLEN) );
1606         }
1607
1608         storeAppendPrintf(sentry, "Status     : %s\n",
1609                           neighborUp(e) ? "Up" : "Down");
1610         storeAppendPrintf(sentry, "FETCHES    : %d\n", e->stats.fetches);
1611         storeAppendPrintf(sentry, "OPEN CONNS : %d\n", e->stats.conn_open);
1612         storeAppendPrintf(sentry, "AVG RTT    : %d msec\n", e->stats.rtt);
1613
1614         if (!e->options.no_query) {
1615             storeAppendPrintf(sentry, "LAST QUERY : %8d seconds ago\n",
1616                               (int) (squid_curtime - e->stats.last_query));
1617
1618             if (e->stats.last_reply > 0)
1619                 storeAppendPrintf(sentry, "LAST REPLY : %8d seconds ago\n",
1620                                   (int) (squid_curtime - e->stats.last_reply));
1621             else
1622                 storeAppendPrintf(sentry, "LAST REPLY : none received\n");
1623
1624             storeAppendPrintf(sentry, "PINGS SENT : %8d\n", e->stats.pings_sent);
1625
1626             storeAppendPrintf(sentry, "PINGS ACKED: %8d %3d%%\n",
1627                               e->stats.pings_acked,
1628                               Math::intPercent(e->stats.pings_acked, e->stats.pings_sent));
1629         }
1630
1631         storeAppendPrintf(sentry, "IGNORED    : %8d %3d%%\n", e->stats.ignored_replies, Math::intPercent(e->stats.ignored_replies, e->stats.pings_acked));
1632
1633         if (!e->options.no_query) {
1634             storeAppendPrintf(sentry, "Histogram of PINGS ACKED:\n");
1635 #if USE_HTCP
1636
1637             if (e->options.htcp) {
1638                 storeAppendPrintf(sentry, "\tMisses\t%8d %3d%%\n",
1639                                   e->htcp.counts[0],
1640                                   Math::intPercent(e->htcp.counts[0], e->stats.pings_acked));
1641                 storeAppendPrintf(sentry, "\tHits\t%8d %3d%%\n",
1642                                   e->htcp.counts[1],
1643                                   Math::intPercent(e->htcp.counts[1], e->stats.pings_acked));
1644             } else {
1645 #endif
1646
1647                 for (op = ICP_INVALID; op < ICP_END; ++op) {
1648                     if (e->icp.counts[op] == 0)
1649                         continue;
1650
1651                     storeAppendPrintf(sentry, "    %12.12s : %8d %3d%%\n",
1652                                       icp_opcode_str[op],
1653                                       e->icp.counts[op],
1654                                       Math::intPercent(e->icp.counts[op], e->stats.pings_acked));
1655                 }
1656
1657 #if USE_HTCP
1658
1659             }
1660
1661 #endif
1662
1663         }
1664
1665         if (e->stats.last_connect_failure) {
1666             storeAppendPrintf(sentry, "Last failed connect() at: %s\n",
1667                               Time::FormatHttpd(e->stats.last_connect_failure));
1668         }
1669
1670         if (e->peer_domain != NULL) {
1671             storeAppendPrintf(sentry, "DOMAIN LIST: ");
1672
1673             for (d = e->peer_domain; d; d = d->next) {
1674                 storeAppendPrintf(sentry, "%s%s ",
1675                                   d->do_ping ? null_string : "!", d->domain);
1676             }
1677
1678             storeAppendPrintf(sentry, "\n");
1679         }
1680
1681         storeAppendPrintf(sentry, "keep-alive ratio: %d%%\n", Math::intPercent(e->stats.n_keepalives_recv, e->stats.n_keepalives_sent));
1682     }
1683 }
1684
1685 #if USE_HTCP
1686 void
1687 neighborsHtcpReply(const cache_key * key, htcpReplyData * htcp, const Ip::Address &from)
1688 {
1689     StoreEntry *e = Store::Root().get(key);
1690     MemObject *mem = NULL;
1691     peer *p;
1692     peer_t ntype = PEER_NONE;
1693     debugs(15, 6, "neighborsHtcpReply: " <<
1694            (htcp->hit ? "HIT" : "MISS") << " " <<
1695            storeKeyText(key)  );
1696
1697     if (NULL != e)
1698         mem = e->mem_obj;
1699
1700     if ((p = whichPeer(from)))
1701         neighborAliveHtcp(p, mem, htcp);
1702
1703     /* Does the entry exist? */
1704     if (NULL == e) {
1705         debugs(12, 3, "neighyborsHtcpReply: Cache key '" << storeKeyText(key) << "' not found");
1706         neighborCountIgnored(p);
1707         return;
1708     }
1709
1710     /* check if someone is already fetching it */
1711     if (EBIT_TEST(e->flags, ENTRY_DISPATCHED)) {
1712         debugs(15, 3, "neighborsUdpAck: '" << storeKeyText(key) << "' already being fetched.");
1713         neighborCountIgnored(p);
1714         return;
1715     }
1716
1717     if (mem == NULL) {
1718         debugs(15, 2, "Ignoring reply for missing mem_obj: " << storeKeyText(key));
1719         neighborCountIgnored(p);
1720         return;
1721     }
1722
1723     if (e->ping_status != PING_WAITING) {
1724         debugs(15, 2, "neighborsUdpAck: Entry " << storeKeyText(key) << " is not PING_WAITING");
1725         neighborCountIgnored(p);
1726         return;
1727     }
1728
1729     if (e->lock_count == 0) {
1730         // TODO: many entries are unlocked; why is this reported at level 1?
1731         debugs(12, DBG_IMPORTANT, "neighborsUdpAck: '" << storeKeyText(key) << "' has no locks");
1732         neighborCountIgnored(p);
1733         return;
1734     }
1735
1736     if (p) {
1737         ntype = neighborType(p, mem->request);
1738         neighborUpdateRtt(p, mem);
1739     }
1740
1741     if (ignoreMulticastReply(p, mem)) {
1742         neighborCountIgnored(p);
1743         return;
1744     }
1745
1746     debugs(15, 3, "neighborsHtcpReply: e = " << e);
1747     mem->ping_reply_callback(p, ntype, AnyP::PROTO_HTCP, htcp, mem->ircb_data);
1748 }
1749
1750 /*
1751  * Send HTCP CLR messages to all peers configured to receive them.
1752  */
1753 void
1754 neighborsHtcpClear(StoreEntry * e, const char *uri, HttpRequest * req, const HttpRequestMethod &method, htcp_clr_reason reason)
1755 {
1756     peer *p;
1757     char buf[128];
1758
1759     for (p = Config.peers; p; p = p->next) {
1760         if (!p->options.htcp) {
1761             continue;
1762         }
1763         if (p->options.htcp_no_clr) {
1764             continue;
1765         }
1766         if (p->options.htcp_no_purge_clr && reason == HTCP_CLR_PURGE) {
1767             continue;
1768         }
1769         debugs(15, 3, "neighborsHtcpClear: sending CLR to " << p->in_addr.ToURL(buf, 128));
1770         htcpClear(e, uri, req, method, p, reason);
1771     }
1772 }
1773
1774 #endif