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 "ProtoPort.h"
  35 #include "acl/FilledChecklist.h"
  36 #include "event.h"
  37 #include "htcp.h"
  38 #include "HttpRequest.h"
  39 #include "ICP.h"
  40 #include "ip/tools.h"
  41 #include "MemObject.h"
  42 #include "PeerDigest.h"
  43 #include "PeerSelectState.h"
  44 #include "SquidMath.h"
  45 #include "SquidTime.h"
  46 #include "Store.h"
  47 #include "icmp/net_db.h"
  48 #include "ip/Address.h"
  49 #include "ip/tools.h"
  50 #include "mgr/Registration.h"
  51
  52 /* count mcast group peers every 15 minutes */
  53 #define MCAST_COUNT_RATE 900
  54
  55 int peerAllowedToUse(const peer *, HttpRequest *);
  56 static int peerWouldBePinged(const peer *, HttpRequest *);
  57 static void neighborRemove(peer *);
  58 static void neighborAlive(peer *, const MemObject *, const icp_common_t *);
  59 #if USE_HTCP
  60 static void neighborAliveHtcp(peer *, const MemObject *, const htcpReplyData *);
  61 #endif
  62 static void neighborCountIgnored(peer *);
  63 static void peerRefreshDNS(void *);
  64 static IPH peerDNSConfigure;
  65 static int peerProbeConnect(peer *);
  66 static CNCB peerProbeConnectDone;
  67 static void peerCountMcastPeersDone(void *data);
  68 static void peerCountMcastPeersStart(void *data);
  69 static void peerCountMcastPeersSchedule(peer * p, time_t when);
  70 static IRCB peerCountHandleIcpReply;
  71
  72 static void neighborIgnoreNonPeer(const Ip::Address &, icp_opcode);
  73 static OBJH neighborDumpPeers;
  74 static OBJH neighborDumpNonPeers;
  75 static void dump_peers(StoreEntry * sentry, peer * peers);
  76
  77 static icp_common_t echo_hdr;
  78 static u_short echo_port;
  79
  80 static int NLateReplies = 0;
  81 static peer *first_ping = NULL;
  82
  83 const char *
  84 neighborTypeStr(const peer * p)
  85 {
  86     if (p->type == PEER_NONE)
  87         return "Non-Peer";
  88
  89     if (p->type == PEER_SIBLING)
  90         return "Sibling";
  91
  92     if (p->type == PEER_MULTICAST)
  93         return "Multicast Group";
  94
  95     return "Parent";
  96 }
  97
  98
  99 peer *
 100 whichPeer(const Ip::Address &from)
 101 {
 102     int j;
 103
 104     peer *p = NULL;
 105     debugs(15, 3, "whichPeer: from " << from);
 106
 107     for (p = Config.peers; p; p = p->next) {
 108         for (j = 0; j < p->n_addresses; j++) {
 109             if (from == p->addresses[j] && from.GetPort() == p->icp.port) {
 110                 return p;
 111             }
 112         }
 113     }
 114
 115     return NULL;
 116 }
 117
 118 peer_t
 119 neighborType(const peer * p, const HttpRequest * request)
 120 {
 121
 122     const struct _domain_type *d = NULL;
 123
 124     for (d = p->typelist; d; d = d->next) {
 125         if (0 == matchDomainName(request->GetHost(), d->domain))
 126             if (d->type != PEER_NONE)
 127                 return d->type;
 128     }
 129 #if PEER_MULTICAST_SIBLINGS
 130     if (p->type == PEER_MULTICAST)
 131         if (p->options.mcast_siblings)
 132             return PEER_SIBLING;
 133 #endif
 134
 135     return p->type;
 136 }
 137
 138 /*
 139  * peerAllowedToUse
 140  *
 141  * this function figures out if it is appropriate to fetch REQUEST
 142  * from PEER.
 143  */
 144 int
 145 peerAllowedToUse(const peer * p, HttpRequest * request)
 146 {
 147
 148     const struct _domain_ping *d = NULL;
 149     int do_ping = 1;
 150     assert(request != NULL);
 151
 152     if (neighborType(p, request) == PEER_SIBLING) {
 153 #if PEER_MULTICAST_SIBLINGS
 154         if (p->type == PEER_MULTICAST && p->options.mcast_siblings &&
 155                 (request->flags.nocache || request->flags.refresh || request->flags.loopdetect || request->flags.need_validation))
 156             debugs(15, 2, "peerAllowedToUse(" << p->name << ", " << request->GetHost() << ") : multicast-siblings optimization match");
 157 #endif
 158         if (request->flags.nocache)
 159             return 0;
 160
 161         if (request->flags.refresh)
 162             return 0;
 163
 164         if (request->flags.loopdetect)
 165             return 0;
 166
 167         if (request->flags.need_validation)
 168             return 0;
 169     }
 170
 171     // CONNECT requests are proxy requests. Not to be forwarded to origin servers.
 172     // Unless the destination port matches, in which case we MAY perform a 'DIRECT' to this peer.
 173     if (p->options.originserver && request->method == METHOD_CONNECT && request->port != p->in_addr.GetPort())
 174         return 0;
 175
 176     if (p->peer_domain == NULL && p->access == NULL)
 177         return do_ping;
 178
 179     do_ping = 0;
 180
 181     for (d = p->peer_domain; d; d = d->next) {
 182         if (0 == matchDomainName(request->GetHost(), d->domain)) {
 183             do_ping = d->do_ping;
 184             break;
 185         }
 186
 187         do_ping = !d->do_ping;
 188     }
 189
 190     if (p->peer_domain && 0 == do_ping)
 191         return do_ping;
 192
 193     if (p->access == NULL)
 194         return do_ping;
 195
 196     ACLFilledChecklist checklist(p->access, request, NULL);
 197     checklist.src_addr = request->client_addr;
 198     checklist.my_addr = request->my_addr;
 199
 200 #if 0 && USE_IDENT
 201     /*
 202      * this is currently broken because 'request->user_ident' has been
 203      * moved to conn->rfc931 and we don't have access to the parent
 204      * ConnStateData here.
 205      */
 206     if (request->user_ident[0])
 207         xstrncpy(checklist.rfc931, request->user_ident, USER_IDENT_SZ);
 208
 209 #endif
 210
 211     return checklist.fastCheck();
 212 }
 213
 214 /* Return TRUE if it is okay to send an ICP request to this peer.   */
 215 static int
 216 peerWouldBePinged(const peer * p, HttpRequest * request)
 217 {
 218     if (!peerAllowedToUse(p, request))
 219         return 0;
 220
 221     if (p->options.no_query)
 222         return 0;
 223
 224     if (p->options.background_ping && (squid_curtime - p->stats.last_query < Config.backgroundPingRate))
 225         return 0;
 226
 227     if (p->options.mcast_responder)
 228         return 0;
 229
 230     if (p->n_addresses == 0)
 231         return 0;
 232
 233     if (p->icp.port == 0)
 234         return 0;
 235
 236     /* the case below seems strange, but can happen if the
 237      * URL host is on the other side of a firewall */
 238     if (p->type == PEER_SIBLING)
 239         if (!request->flags.hierarchical)
 240             return 0;
 241
 242     /* Ping dead peers every timeout interval */
 243     if (squid_curtime - p->stats.last_query > Config.Timeout.deadPeer)
 244         return 1;
 245
 246     if (!neighborUp(p))
 247         return 0;
 248
 249     return 1;
 250 }
 251
 252 /* Return TRUE if it is okay to send an HTTP request to this peer. */
 253 int
 254 peerHTTPOkay(const peer * p, HttpRequest * request)
 255 {
 256     if (!peerAllowedToUse(p, request))
 257         return 0;
 258
 259     if (!neighborUp(p))
 260         return 0;
 261
 262     if (p->max_conn)
 263         if (p->stats.conn_open >= p->max_conn)
 264             return 0;
 265
 266     return 1;
 267 }
 268
 269 int
 270 neighborsCount(HttpRequest * request)
 271 {
 272     peer *p = NULL;
 273     int count = 0;
 274
 275     for (p = Config.peers; p; p = p->next)
 276         if (peerWouldBePinged(p, request))
 277             count++;
 278
 279     debugs(15, 3, "neighborsCount: " << count);
 280
 281     return count;
 282 }
 283
 284 peer *
 285 getFirstUpParent(HttpRequest * request)
 286 {
 287     peer *p = NULL;
 288
 289     for (p = Config.peers; p; p = p->next) {
 290         if (!neighborUp(p))
 291             continue;
 292
 293         if (neighborType(p, request) != PEER_PARENT)
 294             continue;
 295
 296         if (!peerHTTPOkay(p, request))
 297             continue;
 298
 299         break;
 300     }
 301
 302     debugs(15, 3, "getFirstUpParent: returning " << (p ? p->host : "NULL"));
 303     return p;
 304 }
 305
 306 peer *
 307 getRoundRobinParent(HttpRequest * request)
 308 {
 309     peer *p;
 310     peer *q = NULL;
 311
 312     for (p = Config.peers; p; p = p->next) {
 313         if (!p->options.roundrobin)
 314             continue;
 315
 316         if (neighborType(p, request) != PEER_PARENT)
 317             continue;
 318
 319         if (!peerHTTPOkay(p, request))
 320             continue;
 321
 322         if (p->weight == 0)
 323             continue;
 324
 325         if (q) {
 326             if (p->weight == q->weight) {
 327                 if (q->rr_count < p->rr_count)
 328                     continue;
 329             } else if ( ((double) q->rr_count / q->weight) < ((double) p->rr_count / p->weight)) {
 330                 continue;
 331             }
 332         }
 333
 334         q = p;
 335     }
 336
 337     if (q)
 338         q->rr_count++;
 339
 340     debugs(15, 3, HERE << "returning " << (q ? q->host : "NULL"));
 341
 342     return q;
 343 }
 344
 345 peer *
 346 getWeightedRoundRobinParent(HttpRequest * request)
 347 {
 348     peer *p;
 349     peer *q = NULL;
 350     int weighted_rtt;
 351
 352     for (p = Config.peers; p; p = p->next) {
 353         if (!p->options.weighted_roundrobin)
 354             continue;
 355
 356         if (neighborType(p, request) != PEER_PARENT)
 357             continue;
 358
 359         if (!peerHTTPOkay(p, request))
 360             continue;
 361
 362         if (q && q->rr_count < p->rr_count)
 363             continue;
 364
 365         q = p;
 366     }
 367
 368     if (q && q->rr_count > 1000000)
 369         for (p = Config.peers; p; p = p->next) {
 370             if (!p->options.weighted_roundrobin)
 371                 continue;
 372
 373             if (neighborType(p, request) != PEER_PARENT)
 374                 continue;
 375
 376             p->rr_count = 0;
 377         }
 378
 379     if (q) {
 380         weighted_rtt = (q->stats.rtt - q->basetime) / q->weight;
 381
 382         if (weighted_rtt < 1)
 383             weighted_rtt = 1;
 384
 385         q->rr_count += weighted_rtt;
 386
 387         debugs(15, 3, "getWeightedRoundRobinParent: weighted_rtt " << weighted_rtt);
 388     }
 389
 390     debugs(15, 3, "getWeightedRoundRobinParent: returning " << (q ? q->host : "NULL"));
 391     return q;
 392 }
 393
 394 /**
 395  * This gets called every 5 minutes to clear the round-robin counter.
 396  * The exact timing is an arbitrary default, set on estimate timing of a
 397  * large number of requests in a high-performance environment during the
 398  * period. The larger the number of requests between cycled resets the
 399  * more balanced the operations.
 400  *
 401  \param data    unused.
 402  \todo Make the reset timing a selectable parameter in squid.conf
 403  */
 404 static void
 405 peerClearRRLoop(void *data)
 406 {
 407     peerClearRR();
 408     eventAdd("peerClearRR", peerClearRRLoop, data, 5 * 60.0, 0);
 409 }
 410
 411 /**
 412  * This gets called on startup and restart to kick off the peer round-robin
 413  * maintenance event. It ensures that no matter how many times its called
 414  * no more than one event is scheduled.
 415  */
 416 void
 417 peerClearRRStart(void)
 418 {
 419     static int event_added = 0;
 420     if (!event_added) {
 421         peerClearRRLoop(NULL);
 422     }
 423 }
 424
 425 /**
 426  * Called whenever the round-robin counters need to be reset to a sane state.
 427  * So far those times are:
 428  *  - On startup and reconfigure - to set the counters to sane initial settings.
 429  *  -  When a peer has revived from dead, to prevent the revived peer being
 430  *     flooded with requests which it has 'missed' during the down period.
 431  */
 432 void
 433 peerClearRR()
 434 {
 435     peer *p = NULL;
 436     for (p = Config.peers; p; p = p->next) {
 437         p->rr_count = 0;
 438     }
 439 }
 440
 441 /**
 442  * Perform all actions when a peer is detected revived.
 443  */
 444 void
 445 peerAlive(peer *p)
 446 {
 447     if (p->stats.logged_state == PEER_DEAD && p->tcp_up) {
 448         debugs(15, 1, "Detected REVIVED " << neighborTypeStr(p) << ": " << p->name);
 449         p->stats.logged_state = PEER_ALIVE;
 450         peerClearRR();
 451     }
 452
 453     p->stats.last_reply = squid_curtime;
 454     p->stats.probe_start = 0;
 455 }
 456
 457 peer *
 458 getDefaultParent(HttpRequest * request)
 459 {
 460     peer *p = NULL;
 461
 462     for (p = Config.peers; p; p = p->next) {
 463         if (neighborType(p, request) != PEER_PARENT)
 464             continue;
 465
 466         if (!p->options.default_parent)
 467             continue;
 468
 469         if (!peerHTTPOkay(p, request))
 470             continue;
 471
 472         debugs(15, 3, "getDefaultParent: returning " << p->host);
 473
 474         return p;
 475     }
 476
 477     debugs(15, 3, "getDefaultParent: returning NULL");
 478     return NULL;
 479 }
 480
 481 /*
 482  * XXX DW thinks this function is equivalent to/redundant with
 483  * getFirstUpParent().  peerHTTPOkay() only returns true if the
 484  * peer is UP anyway, so this function would not return a
 485  * DOWN parent.
 486  */
 487 peer *
 488 getAnyParent(HttpRequest * request)
 489 {
 490     peer *p = NULL;
 491
 492     for (p = Config.peers; p; p = p->next) {
 493         if (neighborType(p, request) != PEER_PARENT)
 494             continue;
 495
 496         if (!peerHTTPOkay(p, request))
 497             continue;
 498
 499         debugs(15, 3, "getAnyParent: returning " << p->host);
 500
 501         return p;
 502     }
 503
 504     debugs(15, 3, "getAnyParent: returning NULL");
 505     return NULL;
 506 }
 507
 508 peer *
 509 getNextPeer(peer * p)
 510 {
 511     return p->next;
 512 }
 513
 514 peer *
 515 getFirstPeer(void)
 516 {
 517     return Config.peers;
 518 }
 519
 520 static void
 521 neighborRemove(peer * target)
 522 {
 523     peer *p = NULL;
 524     peer **P = NULL;
 525     p = Config.peers;
 526     P = &Config.peers;
 527
 528     while (p) {
 529         if (target == p)
 530             break;
 531
 532         P = &p->next;
 533
 534         p = p->next;
 535     }
 536
 537     if (p) {
 538         *P = p->next;
 539         cbdataFree(p);
 540         Config.npeers--;
 541     }
 542
 543     first_ping = Config.peers;
 544 }
 545
 546 static void
 547 neighborsRegisterWithCacheManager()
 548 {
 549     Mgr::RegisterAction("server_list",
 550                         "Peer Cache Statistics",
 551                         neighborDumpPeers, 0, 1);
 552
 553     if (theInIcpConnection >= 0) {
 554         Mgr::RegisterAction("non_peers",
 555                             "List of Unknown sites sending ICP messages",
 556                             neighborDumpNonPeers, 0, 1);
 557     }
 558 }
 559
 560 void
 561 neighbors_init(void)
 562 {
 563     Ip::Address nul;
 564     struct addrinfo *AI = NULL;
 565     struct servent *sep = NULL;
 566     const char *me = getMyHostname();
 567     peer *thisPeer = NULL;
 568     peer *next = NULL;
 569     int fd = theInIcpConnection;
 570
 571     neighborsRegisterWithCacheManager();
 572
 573     /* setup addrinfo for use */
 574     nul.InitAddrInfo(AI);
 575
 576     if (fd >= 0) {
 577
 578         if (getsockname(fd, AI->ai_addr, &AI->ai_addrlen) < 0)
 579             debugs(15, 1, "getsockname(" << fd << "," << AI->ai_addr << "," << &AI->ai_addrlen << ") failed.");
 580
 581         for (thisPeer = Config.peers; thisPeer; thisPeer = next) {
 582             http_port_list *s = NULL;
 583             next = thisPeer->next;
 584
 585             if (0 != strcmp(thisPeer->host, me))
 586                 continue;
 587
 588             for (s = Config.Sockaddr.http; s; s = s->next) {
 589                 if (thisPeer->http_port != s->s.GetPort())
 590                     continue;
 591
 592                 debugs(15, 1, "WARNING: Peer looks like this host");
 593
 594                 debugs(15, 1, "         Ignoring " <<
 595                        neighborTypeStr(thisPeer) << " " << thisPeer->host <<
 596                        "/" << thisPeer->http_port << "/" <<
 597                        thisPeer->icp.port);
 598
 599                 neighborRemove(thisPeer);
 600             }
 601         }
 602     }
 603
 604     peerRefreshDNS((void *) 1);
 605
 606     if (ICP_INVALID == echo_hdr.opcode) {
 607         echo_hdr.opcode = ICP_SECHO;
 608         echo_hdr.version = ICP_VERSION_CURRENT;
 609         echo_hdr.length = 0;
 610         echo_hdr.reqnum = 0;
 611         echo_hdr.flags = 0;
 612         echo_hdr.pad = 0;
 613         nul = *AI;
 614         nul.GetInAddr( *((struct in_addr*)&echo_hdr.shostid) );
 615         sep = getservbyname("echo", "udp");
 616         echo_port = sep ? ntohs((u_short) sep->s_port) : 7;
 617     }
 618
 619     first_ping = Config.peers;
 620     nul.FreeAddrInfo(AI);
 621 }
 622
 623 int
 624 neighborsUdpPing(HttpRequest * request,
 625                  StoreEntry * entry,
 626                  IRCB * callback,
 627                  void *callback_data,
 628                  int *exprep,
 629                  int *timeout)
 630 {
 631     const char *url = entry->url();
 632     MemObject *mem = entry->mem_obj;
 633     peer *p = NULL;
 634     int i;
 635     int reqnum = 0;
 636     int flags;
 637     icp_common_t *query;
 638     int queries_sent = 0;
 639     int peers_pinged = 0;
 640     int parent_timeout = 0, parent_exprep = 0;
 641     int sibling_timeout = 0, sibling_exprep = 0;
 642     int mcast_timeout = 0, mcast_exprep = 0;
 643
 644     if (Config.peers == NULL)
 645         return 0;
 646
 647     assert(entry->swap_status == SWAPOUT_NONE);
 648
 649     mem->start_ping = current_time;
 650
 651     mem->ping_reply_callback = callback;
 652
 653     mem->ircb_data = callback_data;
 654
 655     reqnum = icpSetCacheKey((const cache_key *)entry->key);
 656
 657     for (i = 0, p = first_ping; i++ < Config.npeers; p = p->next) {
 658         if (p == NULL)
 659             p = Config.peers;
 660
 661         debugs(15, 5, "neighborsUdpPing: Peer " << p->host);
 662
 663         if (!peerWouldBePinged(p, request))
 664             continue;           /* next peer */
 665
 666         peers_pinged++;
 667
 668         debugs(15, 4, "neighborsUdpPing: pinging peer " << p->host << " for '" << url << "'");
 669
 670         debugs(15, 3, "neighborsUdpPing: key = '" << entry->getMD5Text() << "'");
 671
 672         debugs(15, 3, "neighborsUdpPing: reqnum = " << reqnum);
 673
 674 #if USE_HTCP
 675         if (p->options.htcp && !p->options.htcp_only_clr) {
 676             if (Config.Port.htcp <= 0) {
 677                 debugs(15, DBG_CRITICAL, "HTCP is disabled! Cannot send HTCP request to peer.");
 678                 continue;
 679             }
 680
 681             debugs(15, 3, "neighborsUdpPing: sending HTCP query");
 682             if (htcpQuery(entry, request, p) <= 0) continue; // unable to send.
 683         } else
 684 #endif
 685         {
 686             if (Config.Port.icp <= 0 || theOutIcpConnection <= 0) {
 687                 debugs(15, DBG_CRITICAL, "ICP is disabled! Cannot send ICP request to peer.");
 688                 continue;
 689             } else {
 690
 691                 if (p->type == PEER_MULTICAST)
 692                     mcastSetTtl(theOutIcpConnection, p->mcast.ttl);
 693
 694                 if (p->icp.port == echo_port) {
 695                     debugs(15, 4, "neighborsUdpPing: Looks like a dumb cache, send DECHO ping");
 696                     echo_hdr.reqnum = reqnum;
 697                     query = _icp_common_t::createMessage(ICP_DECHO, 0, url, reqnum, 0);
 698                     icpUdpSend(theOutIcpConnection,p->in_addr,query,LOG_ICP_QUERY,0);
 699                 } else {
 700                     flags = 0;
 701
 702                     if (Config.onoff.query_icmp)
 703                         if (p->icp.version == ICP_VERSION_2)
 704                             flags |= ICP_FLAG_SRC_RTT;
 705
 706                     query = _icp_common_t::createMessage(ICP_QUERY, flags, url, reqnum, 0);
 707
 708                     icpUdpSend(theOutIcpConnection, p->in_addr, query, LOG_ICP_QUERY, 0);
 709                 }
 710             }
 711         }
 712
 713         queries_sent++;
 714
 715         p->stats.pings_sent++;
 716
 717         if (p->type == PEER_MULTICAST) {
 718             mcast_exprep += p->mcast.n_replies_expected;
 719             mcast_timeout += (p->stats.rtt * p->mcast.n_replies_expected);
 720         } else if (neighborUp(p)) {
 721             /* its alive, expect a reply from it */
 722
 723             if (neighborType(p, request) == PEER_PARENT) {
 724                 parent_exprep++;
 725                 parent_timeout += p->stats.rtt;
 726             } else {
 727                 sibling_exprep++;
 728                 sibling_timeout += p->stats.rtt;
 729             }
 730         } else {
 731             /* Neighbor is dead; ping it anyway, but don't expect a reply */
 732             /* log it once at the threshold */
 733
 734             if (p->stats.logged_state == PEER_ALIVE) {
 735                 debugs(15, 1, "Detected DEAD " << neighborTypeStr(p) << ": " << p->name);
 736                 p->stats.logged_state = PEER_DEAD;
 737             }
 738         }
 739
 740         p->stats.last_query = squid_curtime;
 741
 742         /*
 743          * keep probe_start == 0 for a multicast peer,
 744          * so neighborUp() never says this peer is dead.
 745          */
 746
 747         if ((p->type != PEER_MULTICAST) && (p->stats.probe_start == 0))
 748             p->stats.probe_start = squid_curtime;
 749     }
 750
 751     if ((first_ping = first_ping->next) == NULL)
 752         first_ping = Config.peers;
 753
 754     /*
 755      * How many replies to expect?
 756      */
 757     *exprep = parent_exprep + sibling_exprep + mcast_exprep;
 758
 759     /*
 760      * If there is a configured timeout, use it
 761      */
 762     if (Config.Timeout.icp_query)
 763         *timeout = Config.Timeout.icp_query;
 764     else {
 765         if (*exprep > 0) {
 766             if (parent_exprep)
 767                 *timeout = 2 * parent_timeout / parent_exprep;
 768             else if (mcast_exprep)
 769                 *timeout = 2 * mcast_timeout / mcast_exprep;
 770             else
 771                 *timeout = 2 * sibling_timeout / sibling_exprep;
 772         } else
 773             *timeout = 2000;    /* 2 seconds */
 774
 775         if (Config.Timeout.icp_query_max)
 776             if (*timeout > Config.Timeout.icp_query_max)
 777                 *timeout = Config.Timeout.icp_query_max;
 778
 779         if (*timeout < Config.Timeout.icp_query_min)
 780             *timeout = Config.Timeout.icp_query_min;
 781     }
 782
 783     return peers_pinged;
 784 }
 785
 786 /* lookup the digest of a given peer */
 787 lookup_t
 788 peerDigestLookup(peer * p, HttpRequest * request)
 789 {
 790 #if USE_CACHE_DIGESTS
 791     const cache_key *key = request ? storeKeyPublicByRequest(request) : NULL;
 792     assert(p);
 793     assert(request);
 794     debugs(15, 5, "peerDigestLookup: peer " << p->host);
 795     /* does the peeer have a valid digest? */
 796
 797     if (!p->digest) {
 798         debugs(15, 5, "peerDigestLookup: gone!");
 799         return LOOKUP_NONE;
 800     } else if (!peerHTTPOkay(p, request)) {
 801         debugs(15, 5, "peerDigestLookup: !peerHTTPOkay");
 802         return LOOKUP_NONE;
 803     } else if (!p->digest->flags.needed) {
 804         debugs(15, 5, "peerDigestLookup: note need");
 805         peerDigestNeeded(p->digest);
 806         return LOOKUP_NONE;
 807     } else if (!p->digest->flags.usable) {
 808         debugs(15, 5, "peerDigestLookup: !ready && " << (p->digest->flags.requested ? "" : "!") << "requested");
 809         return LOOKUP_NONE;
 810     }
 811
 812     debugs(15, 5, "peerDigestLookup: OK to lookup peer " << p->host);
 813     assert(p->digest->cd);
 814     /* does digest predict a hit? */
 815
 816     if (!cacheDigestTest(p->digest->cd, key))
 817         return LOOKUP_MISS;
 818
 819     debugs(15, 5, "peerDigestLookup: peer " << p->host << " says HIT!");
 820
 821     return LOOKUP_HIT;
 822
 823 #endif
 824
 825     return LOOKUP_NONE;
 826 }
 827
 828 /* select best peer based on cache digests */
 829 peer *
 830 neighborsDigestSelect(HttpRequest * request)
 831 {
 832     peer *best_p = NULL;
 833 #if USE_CACHE_DIGESTS
 834
 835     const cache_key *key;
 836     int best_rtt = 0;
 837     int choice_count = 0;
 838     int ichoice_count = 0;
 839     peer *p;
 840     int p_rtt;
 841     int i;
 842
 843     if (!request->flags.hierarchical)
 844         return NULL;
 845
 846     key = storeKeyPublicByRequest(request);
 847
 848     for (i = 0, p = first_ping; i++ < Config.npeers; p = p->next) {
 849         lookup_t lookup;
 850
 851         if (!p)
 852             p = Config.peers;
 853
 854         if (i == 1)
 855             first_ping = p;
 856
 857         lookup = peerDigestLookup(p, request);
 858
 859         if (lookup == LOOKUP_NONE)
 860             continue;
 861
 862         choice_count++;
 863
 864         if (lookup == LOOKUP_MISS)
 865             continue;
 866
 867         p_rtt = netdbHostRtt(p->host);
 868
 869         debugs(15, 5, "neighborsDigestSelect: peer " << p->host << " rtt: " << p_rtt);
 870
 871         /* is this peer better than others in terms of rtt ? */
 872         if (!best_p || (p_rtt && p_rtt < best_rtt)) {
 873             best_p = p;
 874             best_rtt = p_rtt;
 875
 876             if (p_rtt)          /* informative choice (aka educated guess) */
 877                 ichoice_count++;
 878
 879             debugs(15, 4, "neighborsDigestSelect: peer " << p->host << " leads with rtt " << best_rtt);
 880         }
 881     }
 882
 883     debugs(15, 4, "neighborsDigestSelect: choices: " << choice_count << " (" << ichoice_count << ")");
 884     peerNoteDigestLookup(request, best_p,
 885                          best_p ? LOOKUP_HIT : (choice_count ? LOOKUP_MISS : LOOKUP_NONE));
 886     request->hier.n_choices = choice_count;
 887     request->hier.n_ichoices = ichoice_count;
 888 #endif
 889
 890     return best_p;
 891 }
 892
 893 void
 894 peerNoteDigestLookup(HttpRequest * request, peer * p, lookup_t lookup)
 895 {
 896 #if USE_CACHE_DIGESTS
 897     if (p)
 898         strncpy(request->hier.cd_host, p->host, sizeof(request->hier.cd_host));
 899     else
 900         *request->hier.cd_host = '\0';
 901
 902     request->hier.cd_lookup = lookup;
 903     debugs(15, 4, "peerNoteDigestLookup: peer " << (p? p->host : "<none>") << ", lookup: " << lookup_t_str[lookup]  );
 904 #endif
 905 }
 906
 907 static void
 908 neighborAlive(peer * p, const MemObject * mem, const icp_common_t * header)
 909 {
 910     peerAlive(p);
 911     p->stats.pings_acked++;
 912
 913     if ((icp_opcode) header->opcode <= ICP_END)
 914         p->icp.counts[header->opcode]++;
 915
 916     p->icp.version = (int) header->version;
 917 }
 918
 919 static void
 920 neighborUpdateRtt(peer * p, MemObject * mem)
 921 {
 922     int rtt, rtt_av_factor;
 923
 924     if (!mem)
 925         return;
 926
 927     if (!mem->start_ping.tv_sec)
 928         return;
 929
 930     rtt = tvSubMsec(mem->start_ping, current_time);
 931
 932     if (rtt < 1 || rtt > 10000)
 933         return;
 934
 935     rtt_av_factor = RTT_AV_FACTOR;
 936
 937     if (p->options.weighted_roundrobin)
 938         rtt_av_factor = RTT_BACKGROUND_AV_FACTOR;
 939
 940     p->stats.rtt = Math::intAverage(p->stats.rtt, rtt, p->stats.pings_acked, rtt_av_factor);
 941 }
 942
 943 #if USE_HTCP
 944 static void
 945 neighborAliveHtcp(peer * p, const MemObject * mem, const htcpReplyData * htcp)
 946 {
 947     peerAlive(p);
 948     p->stats.pings_acked++;
 949     p->htcp.counts[htcp->hit ? 1 : 0]++;
 950     p->htcp.version = htcp->version;
 951 }
 952
 953 #endif
 954
 955 static void
 956 neighborCountIgnored(peer * p)
 957 {
 958     if (p == NULL)
 959         return;
 960
 961     p->stats.ignored_replies++;
 962
 963     NLateReplies++;
 964 }
 965
 966 static peer *non_peers = NULL;
 967
 968 static void
 969 neighborIgnoreNonPeer(const Ip::Address &from, icp_opcode opcode)
 970 {
 971     peer *np;
 972
 973     for (np = non_peers; np; np = np->next) {
 974         if (np->in_addr != from)
 975             continue;
 976
 977         if (np->in_addr.GetPort() != from.GetPort())
 978             continue;
 979
 980         break;
 981     }
 982
 983     if (np == NULL) {
 984         np = (peer *)xcalloc(1, sizeof(peer));
 985         np->in_addr = from;
 986         np->icp.port = from.GetPort();
 987         np->type = PEER_NONE;
 988         np->host = new char[MAX_IPSTRLEN];
 989         from.NtoA(np->host,MAX_IPSTRLEN);
 990         np->next = non_peers;
 991         non_peers = np;
 992     }
 993
 994     np->icp.counts[opcode]++;
 995
 996     if (isPowTen(++np->stats.ignored_replies))
 997         debugs(15, 1, "WARNING: Ignored " << np->stats.ignored_replies << " replies from non-peer " << np->host);
 998 }
 999
1000 /* ignoreMulticastReply
1001  *
1002  * * We want to ignore replies from multicast peers if the
1003  * * cache_host_domain rules would normally prevent the peer
1004  * * from being used
1005  */
1006 static int
1007 ignoreMulticastReply(peer * p, MemObject * mem)
1008 {
1009     if (p == NULL)
1010         return 0;
1011
1012     if (!p->options.mcast_responder)
1013         return 0;
1014
1015     if (peerHTTPOkay(p, mem->request))
1016         return 0;
1017
1018     return 1;
1019 }
1020
1021 /**
1022  * I should attach these records to the entry.  We take the first
1023  * hit we get our wait until everyone misses.  The timeout handler
1024  * call needs to nip this shopping list or call one of the misses.
1025  *
1026  * If a hit process is already started, then sobeit
1027  */
1028 void
1029 neighborsUdpAck(const cache_key * key, icp_common_t * header, const Ip::Address &from)
1030 {
1031     peer *p = NULL;
1032     StoreEntry *entry;
1033     MemObject *mem = NULL;
1034     peer_t ntype = PEER_NONE;
1035     icp_opcode opcode = (icp_opcode) header->opcode;
1036
1037     debugs(15, 6, "neighborsUdpAck: opcode " << opcode << " '" << storeKeyText(key) << "'");
1038
1039     if (NULL != (entry = Store::Root().get(key)))
1040         mem = entry->mem_obj;
1041
1042     if ((p = whichPeer(from)))
1043         neighborAlive(p, mem, header);
1044
1045     if (opcode > ICP_END)
1046         return;
1047
1048     const char *opcode_d = icp_opcode_str[opcode];
1049
1050     if (p)
1051         neighborUpdateRtt(p, mem);
1052
1053     /* Does the entry exist? */
1054     if (NULL == entry) {
1055         debugs(12, 3, "neighborsUdpAck: Cache key '" << storeKeyText(key) << "' not found");
1056         neighborCountIgnored(p);
1057         return;
1058     }
1059
1060     /* check if someone is already fetching it */
1061     if (EBIT_TEST(entry->flags, ENTRY_DISPATCHED)) {
1062         debugs(15, 3, "neighborsUdpAck: '" << storeKeyText(key) << "' already being fetched.");
1063         neighborCountIgnored(p);
1064         return;
1065     }
1066
1067     if (mem == NULL) {
1068         debugs(15, 2, "Ignoring " << opcode_d << " for missing mem_obj: " << storeKeyText(key));
1069         neighborCountIgnored(p);
1070         return;
1071     }
1072
1073     if (entry->ping_status != PING_WAITING) {
1074         debugs(15, 2, "neighborsUdpAck: Late " << opcode_d << " for " << storeKeyText(key));
1075         neighborCountIgnored(p);
1076         return;
1077     }
1078
1079     if (entry->lock_count == 0) {
1080         debugs(12, 1, "neighborsUdpAck: '" << storeKeyText(key) << "' has no locks");
1081         neighborCountIgnored(p);
1082         return;
1083     }
1084
1085     debugs(15, 3, "neighborsUdpAck: " << opcode_d << " for '" << storeKeyText(key) << "' from " << (p ? p->host : "source") << " ");
1086
1087     if (p) {
1088         ntype = neighborType(p, mem->request);
1089     }
1090
1091     if (ignoreMulticastReply(p, mem)) {
1092         neighborCountIgnored(p);
1093     } else if (opcode == ICP_MISS) {
1094         if (p == NULL) {
1095             neighborIgnoreNonPeer(from, opcode);
1096         } else {
1097             mem->ping_reply_callback(p, ntype, AnyP::PROTO_ICP, header, mem->ircb_data);
1098         }
1099     } else if (opcode == ICP_HIT) {
1100         if (p == NULL) {
1101             neighborIgnoreNonPeer(from, opcode);
1102         } else {
1103             header->opcode = ICP_HIT;
1104             mem->ping_reply_callback(p, ntype, AnyP::PROTO_ICP, header, mem->ircb_data);
1105         }
1106     } else if (opcode == ICP_DECHO) {
1107         if (p == NULL) {
1108             neighborIgnoreNonPeer(from, opcode);
1109         } else if (ntype == PEER_SIBLING) {
1110             debug_trap("neighborsUdpAck: Found non-ICP cache as SIBLING\n");
1111             debug_trap("neighborsUdpAck: non-ICP neighbors must be a PARENT\n");
1112         } else {
1113             mem->ping_reply_callback(p, ntype, AnyP::PROTO_ICP, header, mem->ircb_data);
1114         }
1115     } else if (opcode == ICP_SECHO) {
1116         if (p) {
1117             debugs(15, 1, "Ignoring SECHO from neighbor " << p->host);
1118             neighborCountIgnored(p);
1119         } else {
1120             debugs(15, 1, "Unsolicited SECHO from " << from);
1121         }
1122     } else if (opcode == ICP_DENIED) {
1123         if (p == NULL) {
1124             neighborIgnoreNonPeer(from, opcode);
1125         } else if (p->stats.pings_acked > 100) {
1126             if (100 * p->icp.counts[ICP_DENIED] / p->stats.pings_acked > 95) {
1127                 debugs(15, 0, "95%% of replies from '" << p->host << "' are UDP_DENIED");
1128                 debugs(15, 0, "Disabling '" << p->host << "', please check your configuration.");
1129                 neighborRemove(p);
1130                 p = NULL;
1131             } else {
1132                 neighborCountIgnored(p);
1133             }
1134         }
1135     } else if (opcode == ICP_MISS_NOFETCH) {
1136         mem->ping_reply_callback(p, ntype, AnyP::PROTO_ICP, header, mem->ircb_data);
1137     } else {
1138         debugs(15, 0, "neighborsUdpAck: Unexpected ICP reply: " << opcode_d);
1139     }
1140 }
1141
1142 peer *
1143 peerFindByName(const char *name)
1144 {
1145     peer *p = NULL;
1146
1147     for (p = Config.peers; p; p = p->next) {
1148         if (!strcasecmp(name, p->name))
1149             break;
1150     }
1151
1152     return p;
1153 }
1154
1155 peer *
1156 peerFindByNameAndPort(const char *name, unsigned short port)
1157 {
1158     peer *p = NULL;
1159
1160     for (p = Config.peers; p; p = p->next) {
1161         if (strcasecmp(name, p->name))
1162             continue;
1163
1164         if (port != p->http_port)
1165             continue;
1166
1167         break;
1168     }
1169
1170     return p;
1171 }
1172
1173 int
1174 neighborUp(const peer * p)
1175 {
1176     if (!p->tcp_up) {
1177         if (!peerProbeConnect((peer *) p)) {
1178             debugs(15, 8, "neighborUp: DOWN (probed): " << p->host << " (" << p->in_addr << ")");
1179             return 0;
1180         }
1181     }
1182
1183     /*
1184      * The peer can not be UP if we don't have any IP addresses
1185      * for it.
1186      */
1187     if (0 == p->n_addresses) {
1188         debugs(15, 8, "neighborUp: DOWN (no-ip): " << p->host << " (" << p->in_addr << ")");
1189         return 0;
1190     }
1191
1192     if (p->options.no_query) {
1193         debugs(15, 8, "neighborUp: UP (no-query): " << p->host << " (" << p->in_addr << ")");
1194         return 1;
1195     }
1196
1197     if (p->stats.probe_start != 0 &&
1198             squid_curtime - p->stats.probe_start > Config.Timeout.deadPeer) {
1199         debugs(15, 8, "neighborUp: DOWN (dead): " << p->host << " (" << p->in_addr << ")");
1200         return 0;
1201     }
1202
1203     debugs(15, 8, "neighborUp: UP: " << p->host << " (" << p->in_addr << ")");
1204     return 1;
1205 }
1206
1207 void
1208 peerDestroy(void *data)
1209 {
1210     peer *p = (peer *)data;
1211
1212     if (p == NULL)
1213         return;
1214
1215     struct _domain_ping *nl = NULL;
1216
1217     for (struct _domain_ping *l = p->peer_domain; l; l = nl) {
1218         nl = l->next;
1219         safe_free(l->domain);
1220         xfree(l);
1221     }
1222
1223     safe_free(p->host);
1224     safe_free(p->name);
1225     safe_free(p->domain);
1226 #if USE_CACHE_DIGESTS
1227
1228     cbdataReferenceDone(p->digest);
1229 #endif
1230 }
1231
1232 void
1233 peerNoteDigestGone(peer * p)
1234 {
1235 #if USE_CACHE_DIGESTS
1236     cbdataReferenceDone(p->digest);
1237 #endif
1238 }
1239
1240 static void
1241 peerDNSConfigure(const ipcache_addrs *ia, const DnsLookupDetails &, void *data)
1242 {
1243     peer *p = (peer *)data;
1244
1245     int j;
1246
1247     if (p->n_addresses == 0) {
1248         debugs(15, 1, "Configuring " << neighborTypeStr(p) << " " << p->host << "/" << p->http_port << "/" << p->icp.port);
1249
1250         if (p->type == PEER_MULTICAST)
1251             debugs(15, 1, "    Multicast TTL = " << p->mcast.ttl);
1252     }
1253
1254     p->n_addresses = 0;
1255
1256     if (ia == NULL) {
1257         debugs(0, 0, "WARNING: DNS lookup for '" << p->host << "' failed!");
1258         return;
1259     }
1260
1261     if ((int) ia->count < 1) {
1262         debugs(0, 0, "WARNING: No IP address found for '" << p->host << "'!");
1263         return;
1264     }
1265
1266     p->tcp_up = p->connect_fail_limit;
1267
1268     for (j = 0; j < (int) ia->count && j < PEER_MAX_ADDRESSES; j++) {
1269         p->addresses[j] = ia->in_addrs[j];
1270         debugs(15, 2, "--> IP address #" << j << ": " << p->addresses[j]);
1271         p->n_addresses++;
1272     }
1273
1274     p->in_addr.SetEmpty();
1275     p->in_addr = p->addresses[0];
1276     p->in_addr.SetPort(p->icp.port);
1277
1278     if (p->type == PEER_MULTICAST)
1279         peerCountMcastPeersSchedule(p, 10);
1280
1281 #if USE_ICMP
1282     if (p->type != PEER_MULTICAST)
1283         if (!p->options.no_netdb_exchange)
1284             eventAddIsh("netdbExchangeStart", netdbExchangeStart, p, 30.0, 1);
1285 #endif
1286
1287 }
1288
1289 static void
1290 peerRefreshDNS(void *data)
1291 {
1292     peer *p = NULL;
1293
1294     if (eventFind(peerRefreshDNS, NULL))
1295         eventDelete(peerRefreshDNS, NULL);
1296
1297     if (!data && 0 == stat5minClientRequests()) {
1298         /* no recent client traffic, wait a bit */
1299         eventAddIsh("peerRefreshDNS", peerRefreshDNS, NULL, 180.0, 1);
1300         return;
1301     }
1302
1303     for (p = Config.peers; p; p = p->next)
1304         ipcache_nbgethostbyname(p->host, peerDNSConfigure, p);
1305
1306     /* Reconfigure the peers every hour */
1307     eventAddIsh("peerRefreshDNS", peerRefreshDNS, NULL, 3600.0, 1);
1308 }
1309
1310 static void
1311 peerConnectFailedSilent(peer * p)
1312 {
1313     p->stats.last_connect_failure = squid_curtime;
1314
1315     if (!p->tcp_up) {
1316         debugs(15, 2, "TCP connection to " << p->host << "/" << p->http_port <<
1317                " dead");
1318         return;
1319     }
1320
1321     p->tcp_up--;
1322
1323     if (!p->tcp_up) {
1324         debugs(15, 1, "Detected DEAD " << neighborTypeStr(p) << ": " << p->name);
1325         p->stats.logged_state = PEER_DEAD;
1326     }
1327 }
1328
1329 void
1330 peerConnectFailed(peer *p)
1331 {
1332     debugs(15, 1, "TCP connection to " << p->host << "/" << p->http_port << " failed");
1333     peerConnectFailedSilent(p);
1334 }
1335
1336 void
1337 peerConnectSucceded(peer * p)
1338 {
1339     if (!p->tcp_up) {
1340         debugs(15, 2, "TCP connection to " << p->host << "/" << p->http_port << " succeded");
1341         p->tcp_up = p->connect_fail_limit; // NP: so peerAlive(p) works properly.
1342         peerAlive(p);
1343         if (!p->n_addresses)
1344             ipcache_nbgethostbyname(p->host, peerDNSConfigure, p);
1345     } else
1346         p->tcp_up = p->connect_fail_limit;
1347 }
1348
1349 /// called by Comm when test_fd is closed while connect is in progress
1350 static void
1351 peerProbeClosed(int fd, void *data)
1352 {
1353     peer *p = (peer*)data;
1354     p->test_fd = -1;
1355     // it is a failure because we failed to connect
1356     peerConnectFailedSilent(p);
1357 }
1358
1359 static void
1360 peerProbeConnectTimeout(int fd, void *data)
1361 {
1362     peer * p = (peer *)data;
1363     comm_remove_close_handler(fd, &peerProbeClosed, p);
1364     comm_close(fd);
1365     p->test_fd = -1;
1366     peerConnectFailedSilent(p);
1367 }
1368
1369 /*
1370 * peerProbeConnect will be called on dead peers by neighborUp
1371 */
1372 static int
1373 peerProbeConnect(peer * p)
1374 {
1375     int fd;
1376     time_t ctimeout = p->connect_timeout > 0 ? p->connect_timeout
1377                       : Config.Timeout.peer_connect;
1378     int ret = squid_curtime - p->stats.last_connect_failure > ctimeout * 10;
1379
1380     if (p->test_fd != -1)
1381         return ret;/* probe already running */
1382
1383     if (squid_curtime - p->stats.last_connect_probe == 0)
1384         return ret;/* don't probe to often */
1385
1386     Ip::Address temp(getOutgoingAddr(NULL,p));
1387
1388     // if IPv6 is disabled try to force IPv4-only outgoing.
1389     if (!Ip::EnableIpv6 && !temp.SetIPv4()) {
1390         debugs(50, DBG_IMPORTANT, "WARNING: IPv6 is disabled. Failed to use " << temp << " to probe " << p->host);
1391         return ret;
1392     }
1393
1394     // if IPv6 is split-stack, prefer IPv4
1395     if (Ip::EnableIpv6&IPV6_SPECIAL_SPLITSTACK) {
1396         // NP: This is not a great choice of default,
1397         // but with the current Internet being IPv4-majority has a higher success rate.
1398         // if setting to IPv4 fails we dont care, that just means to use IPv6 outgoing.
1399         temp.SetIPv4();
1400     }
1401
1402     fd = comm_open(SOCK_STREAM, IPPROTO_TCP, temp, COMM_NONBLOCKING, p->host);
1403
1404     if (fd < 0)
1405         return ret;
1406
1407     comm_add_close_handler(fd, &peerProbeClosed, p);
1408     commSetTimeout(fd, ctimeout, peerProbeConnectTimeout, p);
1409
1410     p->test_fd = fd;
1411
1412     p->stats.last_connect_probe = squid_curtime;
1413
1414     commConnectStart(p->test_fd,
1415                      p->host,
1416                      p->http_port,
1417                      peerProbeConnectDone,
1418                      p);
1419
1420     return ret;
1421 }
1422
1423 static void
1424 peerProbeConnectDone(int fd, const DnsLookupDetails &, comm_err_t status, int xerrno, void *data)
1425 {
1426     peer *p = (peer*)data;
1427
1428     if (status == COMM_OK) {
1429         peerConnectSucceded(p);
1430     } else {
1431         peerConnectFailedSilent(p);
1432     }
1433
1434     comm_remove_close_handler(fd, &peerProbeClosed, p);
1435     comm_close(fd);
1436     p->test_fd = -1;
1437     return;
1438 }
1439
1440 static void
1441 peerCountMcastPeersSchedule(peer * p, time_t when)
1442 {
1443     if (p->mcast.flags.count_event_pending)
1444         return;
1445
1446     eventAdd("peerCountMcastPeersStart",
1447              peerCountMcastPeersStart,
1448              p,
1449              (double) when, 1);
1450
1451     p->mcast.flags.count_event_pending = 1;
1452 }
1453
1454 static void
1455 peerCountMcastPeersStart(void *data)
1456 {
1457     peer *p = (peer *)data;
1458     ps_state *psstate;
1459     StoreEntry *fake;
1460     MemObject *mem;
1461     icp_common_t *query;
1462     int reqnum;
1463     LOCAL_ARRAY(char, url, MAX_URL);
1464     assert(p->type == PEER_MULTICAST);
1465     p->mcast.flags.count_event_pending = 0;
1466     snprintf(url, MAX_URL, "http://");
1467     p->in_addr.ToURL(url+7, MAX_URL -8 );
1468     strcat(url, "/");
1469     fake = storeCreateEntry(url, url, request_flags(), METHOD_GET);
1470     HttpRequest *req = HttpRequest::CreateFromUrl(url);
1471     psstate = new ps_state;
1472     psstate->request = HTTPMSGLOCK(req);
1473     psstate->entry = fake;
1474     psstate->callback = NULL;
1475     psstate->callback_data = cbdataReference(p);
1476     psstate->ping.start = current_time;
1477     mem = fake->mem_obj;
1478     mem->request = HTTPMSGLOCK(psstate->request);
1479     mem->start_ping = current_time;
1480     mem->ping_reply_callback = peerCountHandleIcpReply;
1481     mem->ircb_data = psstate;
1482     mcastSetTtl(theOutIcpConnection, p->mcast.ttl);
1483     p->mcast.id = mem->id;
1484     reqnum = icpSetCacheKey((const cache_key *)fake->key);
1485     query = _icp_common_t::createMessage(ICP_QUERY, 0, url, reqnum, 0);
1486     icpUdpSend(theOutIcpConnection,
1487                p->in_addr,
1488                query,
1489                LOG_ICP_QUERY,
1490                0);
1491     fake->ping_status = PING_WAITING;
1492     eventAdd("peerCountMcastPeersDone",
1493              peerCountMcastPeersDone,
1494              psstate,
1495              Config.Timeout.mcast_icp_query / 1000.0, 1);
1496     p->mcast.flags.counting = 1;
1497     peerCountMcastPeersSchedule(p, MCAST_COUNT_RATE);
1498 }
1499
1500 static void
1501 peerCountMcastPeersDone(void *data)
1502 {
1503     ps_state *psstate = (ps_state *)data;
1504     StoreEntry *fake = psstate->entry;
1505
1506     if (cbdataReferenceValid(psstate->callback_data)) {
1507         peer *p = (peer *)psstate->callback_data;
1508         p->mcast.flags.counting = 0;
1509         p->mcast.avg_n_members = Math::doubleAverage(p->mcast.avg_n_members, (double) psstate->ping.n_recv, ++p->mcast.n_times_counted, 10);
1510         debugs(15, 1, "Group " << p->host  << ": " << psstate->ping.n_recv  <<
1511                " replies, "<< std::setw(4)<< std::setprecision(2) <<
1512                p->mcast.avg_n_members <<" average, RTT " << p->stats.rtt);
1513         p->mcast.n_replies_expected = (int) p->mcast.avg_n_members;
1514     }
1515
1516     cbdataReferenceDone(psstate->callback_data);
1517
1518     EBIT_SET(fake->flags, ENTRY_ABORTED);
1519     HTTPMSGUNLOCK(fake->mem_obj->request);
1520     fake->releaseRequest();
1521     fake->unlock();
1522     HTTPMSGUNLOCK(psstate->request);
1523     cbdataFree(psstate);
1524 }
1525
1526 static void
1527 peerCountHandleIcpReply(peer * p, peer_t type, AnyP::ProtocolType proto, void *hdrnotused, void *data)
1528 {
1529     int rtt_av_factor;
1530
1531     ps_state *psstate = (ps_state *)data;
1532     StoreEntry *fake = psstate->entry;
1533     MemObject *mem = fake->mem_obj;
1534     int rtt = tvSubMsec(mem->start_ping, current_time);
1535     assert(proto == AnyP::PROTO_ICP);
1536     assert(fake);
1537     assert(mem);
1538     psstate->ping.n_recv++;
1539     rtt_av_factor = RTT_AV_FACTOR;
1540
1541     if (p->options.weighted_roundrobin)
1542         rtt_av_factor = RTT_BACKGROUND_AV_FACTOR;
1543
1544     p->stats.rtt = Math::intAverage(p->stats.rtt, rtt, psstate->ping.n_recv, rtt_av_factor);
1545 }
1546
1547 static void
1548 neighborDumpPeers(StoreEntry * sentry)
1549 {
1550     dump_peers(sentry, Config.peers);
1551 }
1552
1553 static void
1554 neighborDumpNonPeers(StoreEntry * sentry)
1555 {
1556     dump_peers(sentry, non_peers);
1557 }
1558
1559 void
1560 dump_peer_options(StoreEntry * sentry, peer * p)
1561 {
1562     if (p->options.proxy_only)
1563         storeAppendPrintf(sentry, " proxy-only");
1564
1565     if (p->options.no_query)
1566         storeAppendPrintf(sentry, " no-query");
1567
1568     if (p->options.background_ping)
1569         storeAppendPrintf(sentry, " background-ping");
1570
1571     if (p->options.no_digest)
1572         storeAppendPrintf(sentry, " no-digest");
1573
1574     if (p->options.default_parent)
1575         storeAppendPrintf(sentry, " default");
1576
1577     if (p->options.roundrobin)
1578         storeAppendPrintf(sentry, " round-robin");
1579
1580     if (p->options.carp)
1581         storeAppendPrintf(sentry, " carp");
1582 #if USE_AUTH
1583     if (p->options.userhash)
1584         storeAppendPrintf(sentry, " userhash");
1585
1586     if (p->options.userhash)
1587         storeAppendPrintf(sentry, " sourcehash");
1588 #endif
1589     if (p->options.weighted_roundrobin)
1590         storeAppendPrintf(sentry, " weighted-round-robin");
1591
1592     if (p->options.mcast_responder)
1593         storeAppendPrintf(sentry, " multicast-responder");
1594
1595 #if PEER_MULTICAST_SIBLINGS
1596     if (p->options.mcast_siblings)
1597         storeAppendPrintf(sentry, " multicast-siblings");
1598 #endif
1599
1600     if (p->weight != 1)
1601         storeAppendPrintf(sentry, " weight=%d", p->weight);
1602
1603     if (p->options.closest_only)
1604         storeAppendPrintf(sentry, " closest-only");
1605
1606 #if USE_HTCP
1607     if (p->options.htcp) {
1608         storeAppendPrintf(sentry, " htcp");
1609         if (p->options.htcp_oldsquid || p->options.htcp_no_clr || p->options.htcp_no_purge_clr || p->options.htcp_only_clr) {
1610             int doneopts=0;
1611             if (p->options.htcp_oldsquid)
1612                 storeAppendPrintf(sentry, "%soldsquid",(doneopts++>0?",":"="));
1613             if (p->options.htcp_no_clr)
1614                 storeAppendPrintf(sentry, "%sno-clr",(doneopts++>0?",":"="));
1615             if (p->options.htcp_no_purge_clr)
1616                 storeAppendPrintf(sentry, "%sno-purge-clr",(doneopts++>0?",":"="));
1617             if (p->options.htcp_only_clr)
1618                 storeAppendPrintf(sentry, "%sonly-clr",(doneopts++>0?",":"="));
1619         }
1620     }
1621 #endif
1622
1623     if (p->options.no_netdb_exchange)
1624         storeAppendPrintf(sentry, " no-netdb-exchange");
1625
1626 #if USE_DELAY_POOLS
1627     if (p->options.no_delay)
1628         storeAppendPrintf(sentry, " no-delay");
1629 #endif
1630
1631     if (p->login)
1632         storeAppendPrintf(sentry, " login=%s", p->login);
1633
1634     if (p->mcast.ttl > 0)
1635         storeAppendPrintf(sentry, " ttl=%d", p->mcast.ttl);
1636
1637     if (p->connect_timeout > 0)
1638         storeAppendPrintf(sentry, " connect-timeout=%d", (int) p->connect_timeout);
1639
1640     if (p->connect_fail_limit != PEER_TCP_MAGIC_COUNT)
1641         storeAppendPrintf(sentry, " connect-fail-limit=%d", p->connect_fail_limit);
1642
1643 #if USE_CACHE_DIGESTS
1644
1645     if (p->digest_url)
1646         storeAppendPrintf(sentry, " digest-url=%s", p->digest_url);
1647
1648 #endif
1649
1650     if (p->options.allow_miss)
1651         storeAppendPrintf(sentry, " allow-miss");
1652
1653     if (p->options.no_tproxy)
1654         storeAppendPrintf(sentry, " no-tproxy");
1655
1656     if (p->max_conn > 0)
1657         storeAppendPrintf(sentry, " max-conn=%d", p->max_conn);
1658
1659     if (p->options.originserver)
1660         storeAppendPrintf(sentry, " originserver");
1661
1662     if (p->domain)
1663         storeAppendPrintf(sentry, " forceddomain=%s", p->domain);
1664
1665     if (p->connection_auth == 0)
1666         storeAppendPrintf(sentry, " connection-auth=off");
1667     else if (p->connection_auth == 1)
1668         storeAppendPrintf(sentry, " connection-auth=on");
1669     else if (p->connection_auth == 2)
1670         storeAppendPrintf(sentry, " connection-auth=auto");
1671
1672     storeAppendPrintf(sentry, "\n");
1673 }
1674
1675 static void
1676 dump_peers(StoreEntry * sentry, peer * peers)
1677 {
1678     peer *e = NULL;
1679     char ntoabuf[MAX_IPSTRLEN];
1680     struct _domain_ping *d = NULL;
1681     icp_opcode op;
1682     int i;
1683
1684     if (peers == NULL)
1685         storeAppendPrintf(sentry, "There are no neighbors installed.\n");
1686
1687     for (e = peers; e; e = e->next) {
1688         assert(e->host != NULL);
1689         storeAppendPrintf(sentry, "\n%-11.11s: %s\n",
1690                           neighborTypeStr(e),
1691                           e->name);
1692         storeAppendPrintf(sentry, "Host       : %s/%d/%d\n",
1693                           e->host,
1694                           e->http_port,
1695                           e->icp.port);
1696         storeAppendPrintf(sentry, "Flags      :");
1697         dump_peer_options(sentry, e);
1698
1699         for (i = 0; i < e->n_addresses; i++) {
1700             storeAppendPrintf(sentry, "Address[%d] : %s\n", i,
1701                               e->addresses[i].NtoA(ntoabuf,MAX_IPSTRLEN) );
1702         }
1703
1704         storeAppendPrintf(sentry, "Status     : %s\n",
1705                           neighborUp(e) ? "Up" : "Down");
1706         storeAppendPrintf(sentry, "FETCHES    : %d\n", e->stats.fetches);
1707         storeAppendPrintf(sentry, "OPEN CONNS : %d\n", e->stats.conn_open);
1708         storeAppendPrintf(sentry, "AVG RTT    : %d msec\n", e->stats.rtt);
1709
1710         if (!e->options.no_query) {
1711             storeAppendPrintf(sentry, "LAST QUERY : %8d seconds ago\n",
1712                               (int) (squid_curtime - e->stats.last_query));
1713
1714             if (e->stats.last_reply > 0)
1715                 storeAppendPrintf(sentry, "LAST REPLY : %8d seconds ago\n",
1716                                   (int) (squid_curtime - e->stats.last_reply));
1717             else
1718                 storeAppendPrintf(sentry, "LAST REPLY : none received\n");
1719
1720             storeAppendPrintf(sentry, "PINGS SENT : %8d\n", e->stats.pings_sent);
1721
1722             storeAppendPrintf(sentry, "PINGS ACKED: %8d %3d%%\n",
1723                               e->stats.pings_acked,
1724                               Math::intPercent(e->stats.pings_acked, e->stats.pings_sent));
1725         }
1726
1727         storeAppendPrintf(sentry, "IGNORED    : %8d %3d%%\n", e->stats.ignored_replies, Math::intPercent(e->stats.ignored_replies, e->stats.pings_acked));
1728
1729         if (!e->options.no_query) {
1730             storeAppendPrintf(sentry, "Histogram of PINGS ACKED:\n");
1731 #if USE_HTCP
1732
1733             if (e->options.htcp) {
1734                 storeAppendPrintf(sentry, "\tMisses\t%8d %3d%%\n",
1735                                   e->htcp.counts[0],
1736                                   Math::intPercent(e->htcp.counts[0], e->stats.pings_acked));
1737                 storeAppendPrintf(sentry, "\tHits\t%8d %3d%%\n",
1738                                   e->htcp.counts[1],
1739                                   Math::intPercent(e->htcp.counts[1], e->stats.pings_acked));
1740             } else {
1741 #endif
1742
1743                 for (op = ICP_INVALID; op < ICP_END; ++op) {
1744                     if (e->icp.counts[op] == 0)
1745                         continue;
1746
1747                     storeAppendPrintf(sentry, "    %12.12s : %8d %3d%%\n",
1748                                       icp_opcode_str[op],
1749                                       e->icp.counts[op],
1750                                       Math::intPercent(e->icp.counts[op], e->stats.pings_acked));
1751                 }
1752
1753 #if USE_HTCP
1754
1755             }
1756
1757 #endif
1758
1759         }
1760
1761         if (e->stats.last_connect_failure) {
1762             storeAppendPrintf(sentry, "Last failed connect() at: %s\n",
1763                               Time::FormatHttpd(e->stats.last_connect_failure));
1764         }
1765
1766         if (e->peer_domain != NULL) {
1767             storeAppendPrintf(sentry, "DOMAIN LIST: ");
1768
1769             for (d = e->peer_domain; d; d = d->next) {
1770                 storeAppendPrintf(sentry, "%s%s ",
1771                                   d->do_ping ? null_string : "!", d->domain);
1772             }
1773
1774             storeAppendPrintf(sentry, "\n");
1775         }
1776
1777         storeAppendPrintf(sentry, "keep-alive ratio: %d%%\n", Math::intPercent(e->stats.n_keepalives_recv, e->stats.n_keepalives_sent));
1778     }
1779 }
1780
1781 #if USE_HTCP
1782 void
1783 neighborsHtcpReply(const cache_key * key, htcpReplyData * htcp, const Ip::Address &from)
1784 {
1785     StoreEntry *e = Store::Root().get(key);
1786     MemObject *mem = NULL;
1787     peer *p;
1788     peer_t ntype = PEER_NONE;
1789     debugs(15, 6, "neighborsHtcpReply: " <<
1790            (htcp->hit ? "HIT" : "MISS") << " " <<
1791            storeKeyText(key)  );
1792
1793     if (NULL != e)
1794         mem = e->mem_obj;
1795
1796     if ((p = whichPeer(from)))
1797         neighborAliveHtcp(p, mem, htcp);
1798
1799     /* Does the entry exist? */
1800     if (NULL == e) {
1801         debugs(12, 3, "neighyborsHtcpReply: Cache key '" << storeKeyText(key) << "' not found");
1802         neighborCountIgnored(p);
1803         return;
1804     }
1805
1806     /* check if someone is already fetching it */
1807     if (EBIT_TEST(e->flags, ENTRY_DISPATCHED)) {
1808         debugs(15, 3, "neighborsUdpAck: '" << storeKeyText(key) << "' already being fetched.");
1809         neighborCountIgnored(p);
1810         return;
1811     }
1812
1813     if (mem == NULL) {
1814         debugs(15, 2, "Ignoring reply for missing mem_obj: " << storeKeyText(key));
1815         neighborCountIgnored(p);
1816         return;
1817     }
1818
1819     if (e->ping_status != PING_WAITING) {
1820         debugs(15, 2, "neighborsUdpAck: Entry " << storeKeyText(key) << " is not PING_WAITING");
1821         neighborCountIgnored(p);
1822         return;
1823     }
1824
1825     if (e->lock_count == 0) {
1826         debugs(12, 1, "neighborsUdpAck: '" << storeKeyText(key) << "' has no locks");
1827         neighborCountIgnored(p);
1828         return;
1829     }
1830
1831     if (p) {
1832         ntype = neighborType(p, mem->request);
1833         neighborUpdateRtt(p, mem);
1834     }
1835
1836     if (ignoreMulticastReply(p, mem)) {
1837         neighborCountIgnored(p);
1838         return;
1839     }
1840
1841     debugs(15, 3, "neighborsHtcpReply: e = " << e);
1842     mem->ping_reply_callback(p, ntype, AnyP::PROTO_HTCP, htcp, mem->ircb_data);
1843 }
1844
1845 /*
1846  * Send HTCP CLR messages to all peers configured to receive them.
1847  */
1848 void
1849 neighborsHtcpClear(StoreEntry * e, const char *uri, HttpRequest * req, const HttpRequestMethod &method, htcp_clr_reason reason)
1850 {
1851     peer *p;
1852     char buf[128];
1853
1854     for (p = Config.peers; p; p = p->next) {
1855         if (!p->options.htcp) {
1856             continue;
1857         }
1858         if (p->options.htcp_no_clr) {
1859             continue;
1860         }
1861         if (p->options.htcp_no_purge_clr && reason == HTCP_CLR_PURGE) {
1862             continue;
1863         }
1864         debugs(15, 3, "neighborsHtcpClear: sending CLR to " << p->in_addr.ToURL(buf, 128));
1865         htcpClear(e, uri, req, method, p, reason);
1866     }
1867 }
1868
1869 #endif