src/external_acl.cc

   1 /*
   2  * Copyright (C) 1996-2016 The Squid Software Foundation and contributors
   3  *
   4  * Squid software is distributed under GPLv2+ license and includes
   5  * contributions from numerous individuals and organizations.
   6  * Please see the COPYING and CONTRIBUTORS files for details.
   7  */
   8
   9 /* DEBUG: section 82    External ACL */
  10
  11 #include "squid.h"
  12 #include "acl/Acl.h"
  13 #include "acl/FilledChecklist.h"
  14 #include "cache_cf.h"
  15 #include "client_side.h"
  16 #include "client_side_request.h"
  17 #include "comm/Connection.h"
  18 #include "ConfigParser.h"
  19 #include "ExternalACL.h"
  20 #include "ExternalACLEntry.h"
  21 #include "fde.h"
  22 #include "format/Token.h"
  23 #include "helper.h"
  24 #include "helper/Reply.h"
  25 #include "http/Stream.h"
  26 #include "HttpHeaderTools.h"
  27 #include "HttpReply.h"
  28 #include "HttpRequest.h"
  29 #include "ip/tools.h"
  30 #include "MemBuf.h"
  31 #include "mgr/Registration.h"
  32 #include "rfc1738.h"
  33 #include "SquidConfig.h"
  34 #include "SquidString.h"
  35 #include "SquidTime.h"
  36 #include "Store.h"
  37 #include "tools.h"
  38 #include "URL.h"
  39 #include "wordlist.h"
  40 #if USE_OPENSSL
  41 #include "ssl/ServerBump.h"
  42 #include "ssl/support.h"
  43 #endif
  44 #if USE_AUTH
  45 #include "auth/Acl.h"
  46 #include "auth/Gadgets.h"
  47 #include "auth/UserRequest.h"
  48 #endif
  49 #if USE_IDENT
  50 #include "ident/AclIdent.h"
  51 #endif
  52
  53 #ifndef DEFAULT_EXTERNAL_ACL_TTL
  54 #define DEFAULT_EXTERNAL_ACL_TTL 1 * 60 * 60
  55 #endif
  56 #ifndef DEFAULT_EXTERNAL_ACL_CHILDREN
  57 #define DEFAULT_EXTERNAL_ACL_CHILDREN 5
  58 #endif
  59
  60 static char *makeExternalAclKey(ACLFilledChecklist * ch, external_acl_data * acl_data);
  61 static void external_acl_cache_delete(external_acl * def, const ExternalACLEntryPointer &entry);
  62 static int external_acl_entry_expired(external_acl * def, const ExternalACLEntryPointer &entry);
  63 static int external_acl_grace_expired(external_acl * def, const ExternalACLEntryPointer &entry);
  64 static void external_acl_cache_touch(external_acl * def, const ExternalACLEntryPointer &entry);
  65 static ExternalACLEntryPointer external_acl_cache_add(external_acl * def, const char *key, ExternalACLEntryData const &data);
  66
  67 /******************************************************************
  68  * external_acl directive
  69  */
  70
  71 class external_acl
  72 {
  73     /* FIXME: These are not really cbdata, but it is an easy way
  74      * to get them pooled, refcounted, accounted and freed properly...
  75      */
  76     CBDATA_CLASS(external_acl);
  77
  78 public:
  79     external_acl();
  80     ~external_acl();
  81
  82     external_acl *next;
  83
  84     void add(const ExternalACLEntryPointer &);
  85
  86     void trimCache();
  87
  88     int ttl;
  89
  90     int negative_ttl;
  91
  92     int grace;
  93
  94     char *name;
  95
  96     Format::Format format;
  97
  98     wordlist *cmdline;
  99
 100     Helper::ChildConfig children;
 101
 102     helper *theHelper;
 103
 104     hash_table *cache;
 105
 106     dlink_list lru_list;
 107
 108     int cache_size;
 109
 110     int cache_entries;
 111
 112     dlink_list queue;
 113
 114 #if USE_AUTH
 115     /**
 116      * Configuration flag. May only be altered by the configuration parser.
 117      *
 118      * Indicates that all uses of this external_acl_type helper require authentication
 119      * details to be processed. If none are available its a fail match.
 120      */
 121     bool require_auth;
 122 #endif
 123
 124     Format::Quoting quote; // default quoting to use, set by protocol= parameter
 125
 126     Ip::Address local_addr;
 127 };
 128
 129 CBDATA_CLASS_INIT(external_acl);
 130
 131 external_acl::external_acl() :
 132     next(NULL),
 133     ttl(DEFAULT_EXTERNAL_ACL_TTL),
 134     negative_ttl(-1),
 135     grace(1),
 136     name(NULL),
 137     format("external_acl_type"),
 138     cmdline(NULL),
 139     children(DEFAULT_EXTERNAL_ACL_CHILDREN),
 140     theHelper(NULL),
 141     cache(NULL),
 142     cache_size(256*1024),
 143     cache_entries(0),
 144 #if USE_AUTH
 145     require_auth(0),
 146 #endif
 147     quote(Format::LOG_QUOTE_URL)
 148 {
 149     local_addr.setLocalhost();
 150 }
 151
 152 external_acl::~external_acl()
 153 {
 154     xfree(name);
 155     wordlistDestroy(&cmdline);
 156
 157     if (theHelper) {
 158         helperShutdown(theHelper);
 159         delete theHelper;
 160         theHelper = NULL;
 161     }
 162
 163     while (lru_list.tail) {
 164         ExternalACLEntryPointer e(static_cast<ExternalACLEntry *>(lru_list.tail->data));
 165         external_acl_cache_delete(this, e);
 166     }
 167     if (cache)
 168         hashFreeMemory(cache);
 169
 170     while (next) {
 171         external_acl *node = next;
 172         next = node->next;
 173         node->next = NULL; // prevent recursion
 174         delete node;
 175     }
 176 }
 177
 178 void
 179 parse_externalAclHelper(external_acl ** list)
 180 {
 181     char *token = ConfigParser::NextToken();
 182
 183     if (!token) {
 184         self_destruct();
 185         return;
 186     }
 187
 188     external_acl *a = new external_acl;
 189     a->name = xstrdup(token);
 190
 191     // Allow supported %macros inside quoted tokens
 192     ConfigParser::EnableMacros();
 193     token = ConfigParser::NextToken();
 194
 195     /* Parse options */
 196     while (token) {
 197         if (strncmp(token, "ttl=", 4) == 0) {
 198             a->ttl = atoi(token + 4);
 199         } else if (strncmp(token, "negative_ttl=", 13) == 0) {
 200             a->negative_ttl = atoi(token + 13);
 201         } else if (strncmp(token, "children=", 9) == 0) {
 202             a->children.n_max = atoi(token + 9);
 203             debugs(0, DBG_CRITICAL, "WARNING: external_acl_type option children=N has been deprecated in favor of children-max=N and children-startup=N");
 204         } else if (strncmp(token, "children-max=", 13) == 0) {
 205             a->children.n_max = atoi(token + 13);
 206         } else if (strncmp(token, "children-startup=", 17) == 0) {
 207             a->children.n_startup = atoi(token + 17);
 208         } else if (strncmp(token, "children-idle=", 14) == 0) {
 209             a->children.n_idle = atoi(token + 14);
 210         } else if (strncmp(token, "concurrency=", 12) == 0) {
 211             a->children.concurrency = atoi(token + 12);
 212         } else if (strncmp(token, "queue-size=", 11) == 0) {
 213             a->children.queue_size = atoi(token + 11);
 214             a->children.defaultQueueSize = false;
 215         } else if (strncmp(token, "cache=", 6) == 0) {
 216             a->cache_size = atoi(token + 6);
 217         } else if (strncmp(token, "grace=", 6) == 0) {
 218             a->grace = atoi(token + 6);
 219         } else if (strcmp(token, "protocol=2.5") == 0) {
 220             a->quote = Format::LOG_QUOTE_SHELL;
 221         } else if (strcmp(token, "protocol=3.0") == 0) {
 222             debugs(3, DBG_PARSE_NOTE(2), "WARNING: external_acl_type option protocol=3.0 is deprecated. Remove this from your config.");
 223             a->quote = Format::LOG_QUOTE_URL;
 224         } else if (strcmp(token, "quote=url") == 0) {
 225             debugs(3, DBG_PARSE_NOTE(2), "WARNING: external_acl_type option quote=url is deprecated. Remove this from your config.");
 226             a->quote = Format::LOG_QUOTE_URL;
 227         } else if (strcmp(token, "quote=shell") == 0) {
 228             debugs(3, DBG_PARSE_NOTE(2), "WARNING: external_acl_type option quote=shell is deprecated. Use protocol=2.5 if still needed.");
 229             a->quote = Format::LOG_QUOTE_SHELL;
 230
 231             /* INET6: allow admin to configure some helpers explicitly to
 232                       bind to IPv4/v6 localhost port. */
 233         } else if (strcmp(token, "ipv4") == 0) {
 234             if ( !a->local_addr.setIPv4() ) {
 235                 debugs(3, DBG_CRITICAL, "WARNING: Error converting " << a->local_addr << " to IPv4 in " << a->name );
 236             }
 237         } else if (strcmp(token, "ipv6") == 0) {
 238             if (!Ip::EnableIpv6)
 239                 debugs(3, DBG_CRITICAL, "WARNING: --enable-ipv6 required for external ACL helpers to use IPv6: " << a->name );
 240             // else nothing to do.
 241         } else {
 242             break;
 243         }
 244
 245         token = ConfigParser::NextToken();
 246     }
 247     ConfigParser::DisableMacros();
 248
 249     /* check that child startup value is sane. */
 250     if (a->children.n_startup > a->children.n_max)
 251         a->children.n_startup = a->children.n_max;
 252
 253     /* check that child idle value is sane. */
 254     if (a->children.n_idle > a->children.n_max)
 255         a->children.n_idle = a->children.n_max;
 256     if (a->children.n_idle < 1)
 257         a->children.n_idle = 1;
 258
 259     if (a->negative_ttl == -1)
 260         a->negative_ttl = a->ttl;
 261
 262     if (a->children.defaultQueueSize)
 263         a->children.queue_size = 2 * a->children.n_max;
 264
 265     /* Legacy external_acl_type format parser.
 266      * Handles a series of %... tokens where any non-% means
 267      * the start of another parameter field (ie the path to binary).
 268      */
 269     enum Format::Quoting quote = Format::LOG_QUOTE_NONE;
 270     Format::Token **fmt = &a->format.format;
 271     bool data_used = false;
 272     while (token) {
 273         /* stop on first non-% token found */
 274         if (*token != '%')
 275             break;
 276
 277         *fmt = new Format::Token;
 278         // these tokens are whitespace delimited
 279         (*fmt)->space = true;
 280
 281         // set the default encoding to match the protocol= config
 282         // this will be overridden by explicit %macro attributes
 283         (*fmt)->quote = a->quote;
 284
 285         // compatibility for old tokens incompatible with Format::Token syntax
 286 #if USE_OPENSSL // dont bother if we dont have to.
 287         if (strncmp(token, "%USER_CERT_", 11) == 0) {
 288             (*fmt)->type = Format::LFT_EXT_ACL_USER_CERT;
 289             (*fmt)->data.string = xstrdup(token + 11);
 290             (*fmt)->data.header.header = (*fmt)->data.string;
 291         } else if (strncmp(token, "%USER_CA_CERT_", 14) == 0) {
 292             (*fmt)->type = Format::LFT_EXT_ACL_USER_CA_CERT;
 293             (*fmt)->data.string = xstrdup(token + 14);
 294             (*fmt)->data.header.header = (*fmt)->data.string;
 295         } else if (strncmp(token, "%CA_CERT_", 9) == 0) {
 296             debugs(82, DBG_PARSE_NOTE(DBG_IMPORTANT), "WARNING: external_acl_type %CA_CERT_* code is obsolete. Use %USER_CA_CERT_* instead");
 297             (*fmt)->type = Format::LFT_EXT_ACL_USER_CA_CERT;
 298             (*fmt)->data.string = xstrdup(token + 9);
 299             (*fmt)->data.header.header = (*fmt)->data.string;
 300         } else
 301 #endif
 302         {
 303             // we can use the Format::Token::parse() method since it
 304             // only pulls off one token. Since we already checked
 305             // for '%' prefix above this is guaranteed to be a token.
 306             const size_t len = (*fmt)->parse(token, &quote);
 307             assert(len == strlen(token));
 308         }
 309
 310         // process special token-specific actions (only if necessary)
 311 #if USE_AUTH
 312         if ((*fmt)->type == Format::LFT_USER_LOGIN)
 313             a->require_auth = true;
 314 #endif
 315
 316         if ((*fmt)->type == Format::LFT_EXT_ACL_DATA)
 317             data_used = true;
 318
 319         fmt = &((*fmt)->next);
 320         token = ConfigParser::NextToken();
 321     }
 322
 323     /* There must be at least one format token */
 324     if (!a->format.format) {
 325         delete a;
 326         self_destruct();
 327         return;
 328     }
 329
 330     // format has implicit %DATA on the end if not used explicitly
 331     if (!data_used) {
 332         *fmt = new Format::Token;
 333         (*fmt)->type = Format::LFT_EXT_ACL_DATA;
 334         (*fmt)->quote = Format::LOG_QUOTE_NONE;
 335     }
 336
 337     /* helper */
 338     if (!token) {
 339         delete a;
 340         self_destruct();
 341         return;
 342     }
 343
 344     wordlistAdd(&a->cmdline, token);
 345
 346     /* arguments */
 347     parse_wordlist(&a->cmdline);
 348
 349     while (*list)
 350         list = &(*list)->next;
 351
 352     *list = a;
 353 }
 354
 355 void
 356 dump_externalAclHelper(StoreEntry * sentry, const char *name, const external_acl * list)
 357 {
 358     const external_acl *node;
 359     const wordlist *word;
 360
 361     for (node = list; node; node = node->next) {
 362         storeAppendPrintf(sentry, "%s %s", name, node->name);
 363
 364         if (!node->local_addr.isIPv6())
 365             storeAppendPrintf(sentry, " ipv4");
 366         else
 367             storeAppendPrintf(sentry, " ipv6");
 368
 369         if (node->ttl != DEFAULT_EXTERNAL_ACL_TTL)
 370             storeAppendPrintf(sentry, " ttl=%d", node->ttl);
 371
 372         if (node->negative_ttl != node->ttl)
 373             storeAppendPrintf(sentry, " negative_ttl=%d", node->negative_ttl);
 374
 375         if (node->grace)
 376             storeAppendPrintf(sentry, " grace=%d", node->grace);
 377
 378         if (node->children.n_max != DEFAULT_EXTERNAL_ACL_CHILDREN)
 379             storeAppendPrintf(sentry, " children-max=%d", node->children.n_max);
 380
 381         if (node->children.n_startup != 1)
 382             storeAppendPrintf(sentry, " children-startup=%d", node->children.n_startup);
 383
 384         if (node->children.n_idle != (node->children.n_max + node->children.n_startup) )
 385             storeAppendPrintf(sentry, " children-idle=%d", node->children.n_idle);
 386
 387         if (node->children.concurrency)
 388             storeAppendPrintf(sentry, " concurrency=%d", node->children.concurrency);
 389
 390         if (node->cache)
 391             storeAppendPrintf(sentry, " cache=%d", node->cache_size);
 392
 393         if (node->quote == Format::LOG_QUOTE_SHELL)
 394             storeAppendPrintf(sentry, " protocol=2.5");
 395
 396         node->format.dump(sentry, NULL, false);
 397
 398         for (word = node->cmdline; word; word = word->next)
 399             storeAppendPrintf(sentry, " %s", word->key);
 400
 401         storeAppendPrintf(sentry, "\n");
 402     }
 403 }
 404
 405 void
 406 free_externalAclHelper(external_acl ** list)
 407 {
 408     delete *list;
 409     *list = NULL;
 410 }
 411
 412 static external_acl *
 413 find_externalAclHelper(const char *name)
 414 {
 415     external_acl *node;
 416
 417     for (node = Config.externalAclHelperList; node; node = node->next) {
 418         if (strcmp(node->name, name) == 0)
 419             return node;
 420     }
 421
 422     return NULL;
 423 }
 424
 425 void
 426 external_acl::add(const ExternalACLEntryPointer &anEntry)
 427 {
 428     trimCache();
 429     assert(anEntry != NULL);
 430     assert (anEntry->def == NULL);
 431     anEntry->def = this;
 432     ExternalACLEntry *e = const_cast<ExternalACLEntry *>(anEntry.getRaw()); // XXX: make hash a std::map of Pointer.
 433     hash_join(cache, e);
 434     dlinkAdd(e, &e->lru, &lru_list);
 435     e->lock(); //cbdataReference(e); // lock it on behalf of the hash
 436     ++cache_entries;
 437 }
 438
 439 void
 440 external_acl::trimCache()
 441 {
 442     if (cache_size && cache_entries >= cache_size) {
 443         ExternalACLEntryPointer e(static_cast<ExternalACLEntry *>(lru_list.tail->data));
 444         external_acl_cache_delete(this, e);
 445     }
 446 }
 447
 448 /******************************************************************
 449  * external acl type
 450  */
 451
 452 class external_acl_data
 453 {
 454     CBDATA_CLASS(external_acl_data);
 455
 456 public:
 457     explicit external_acl_data(external_acl *aDef) : def(cbdataReference(aDef)), name(NULL), arguments(NULL) {}
 458     ~external_acl_data();
 459
 460     external_acl *def;
 461     const char *name;
 462     wordlist *arguments;
 463 };
 464
 465 CBDATA_CLASS_INIT(external_acl_data);
 466
 467 external_acl_data::~external_acl_data()
 468 {
 469     xfree(name);
 470     wordlistDestroy(&arguments);
 471     cbdataReferenceDone(def);
 472 }
 473
 474 void
 475 ACLExternal::parse()
 476 {
 477     if (data) {
 478         self_destruct();
 479         return;
 480     }
 481
 482     char *token = ConfigParser::strtokFile();
 483
 484     if (!token) {
 485         self_destruct();
 486         return;
 487     }
 488
 489     data = new external_acl_data(find_externalAclHelper(token));
 490
 491     if (!data->def) {
 492         delete data;
 493         self_destruct();
 494         return;
 495     }
 496
 497     // def->name is the name of the external_acl_type.
 498     // this is the name of the 'acl' directive being tested
 499     data->name = xstrdup(AclMatchedName);
 500
 501     while ((token = ConfigParser::strtokFile())) {
 502         wordlistAdd(&data->arguments, token);
 503     }
 504 }
 505
 506 bool
 507 ACLExternal::valid () const
 508 {
 509 #if USE_AUTH
 510     if (data->def->require_auth) {
 511         if (authenticateSchemeCount() == 0) {
 512             debugs(28, DBG_CRITICAL, "Can't use proxy auth because no authentication schemes were compiled.");
 513             return false;
 514         }
 515
 516         if (authenticateActiveSchemeCount() == 0) {
 517             debugs(28, DBG_CRITICAL, "Can't use proxy auth because no authentication schemes are fully configured.");
 518             return false;
 519         }
 520     }
 521 #endif
 522
 523     return true;
 524 }
 525
 526 bool
 527 ACLExternal::empty () const
 528 {
 529     return false;
 530 }
 531
 532 ACLExternal::~ACLExternal()
 533 {
 534     delete data;
 535     xfree(class_);
 536 }
 537
 538 static void
 539 copyResultsFromEntry(HttpRequest *req, const ExternalACLEntryPointer &entry)
 540 {
 541     if (req) {
 542 #if USE_AUTH
 543         if (entry->user.size())
 544             req->extacl_user = entry->user;
 545
 546         if (entry->password.size())
 547             req->extacl_passwd = entry->password;
 548 #endif
 549         if (!req->tag.size())
 550             req->tag = entry->tag;
 551
 552         if (entry->log.size())
 553             req->extacl_log = entry->log;
 554
 555         if (entry->message.size())
 556             req->extacl_message = entry->message;
 557
 558         // attach the helper kv-pair to the transaction
 559         UpdateRequestNotes(req->clientConnectionManager.get(), *req, entry->notes);
 560     }
 561 }
 562
 563 static allow_t
 564 aclMatchExternal(external_acl_data *acl, ACLFilledChecklist *ch)
 565 {
 566     debugs(82, 9, HERE << "acl=\"" << acl->def->name << "\"");
 567     ExternalACLEntryPointer entry = ch->extacl_entry;
 568
 569     external_acl_message = "MISSING REQUIRED INFORMATION";
 570
 571     if (entry != NULL) {
 572         if (entry->def == acl->def) {
 573             /* Ours, use it.. if the key matches */
 574             const char *key = makeExternalAclKey(ch, acl);
 575             if (!key)
 576                 return ACCESS_DUNNO; // insufficent data to continue
 577             if (strcmp(key, (char*)entry->key) != 0) {
 578                 debugs(82, 9, "entry key='" << (char *)entry->key << "', our key='" << key << "' dont match. Discarded.");
 579                 // too bad. need a new lookup.
 580                 entry = ch->extacl_entry = NULL;
 581             }
 582         } else {
 583             /* Not ours.. get rid of it */
 584             debugs(82, 9, "entry " << entry << " not valid or not ours. Discarded.");
 585             if (entry != NULL) {
 586                 debugs(82, 9, "entry def=" << entry->def << ", our def=" << acl->def);
 587                 const char *key = makeExternalAclKey(ch, acl); // may be nil
 588                 debugs(82, 9, "entry key='" << (char *)entry->key << "', our key='" << key << "'");
 589             }
 590             entry = ch->extacl_entry = NULL;
 591         }
 592     }
 593
 594     if (!entry) {
 595         debugs(82, 9, HERE << "No helper entry available");
 596 #if USE_AUTH
 597         if (acl->def->require_auth) {
 598             /* Make sure the user is authenticated */
 599             debugs(82, 3, HERE << acl->def->name << " check user authenticated.");
 600             const allow_t ti = AuthenticateAcl(ch);
 601             if (ti != ACCESS_ALLOWED) {
 602                 debugs(82, 2, HERE << acl->def->name << " user not authenticated (" << ti << ")");
 603                 return ti;
 604             }
 605             debugs(82, 3, HERE << acl->def->name << " user is authenticated.");
 606         }
 607 #endif
 608         const char *key = makeExternalAclKey(ch, acl);
 609
 610         if (!key) {
 611             /* Not sufficient data to process */
 612             return ACCESS_DUNNO;
 613         }
 614
 615         entry = static_cast<ExternalACLEntry *>(hash_lookup(acl->def->cache, key));
 616
 617         const ExternalACLEntryPointer staleEntry = entry;
 618         if (entry != NULL && external_acl_entry_expired(acl->def, entry))
 619             entry = NULL;
 620
 621         if (entry != NULL && external_acl_grace_expired(acl->def, entry)) {
 622             // refresh in the background
 623             ExternalACLLookup::Start(ch, acl, true);
 624             debugs(82, 4, HERE << "no need to wait for the refresh of '" <<
 625                    key << "' in '" << acl->def->name << "' (ch=" << ch << ").");
 626         }
 627
 628         if (!entry) {
 629             debugs(82, 2, HERE << acl->def->name << "(\"" << key << "\") = lookup needed");
 630
 631             if (!acl->def->theHelper->queueFull()) {
 632                 debugs(82, 2, HERE << "\"" << key << "\": queueing a call.");
 633                 if (!ch->goAsync(ExternalACLLookup::Instance()))
 634                     debugs(82, 2, "\"" << key << "\": no async support!");
 635                 debugs(82, 2, HERE << "\"" << key << "\": return -1.");
 636                 return ACCESS_DUNNO; // expired cached or simply absent entry
 637             } else {
 638                 if (!staleEntry) {
 639                     debugs(82, DBG_IMPORTANT, "WARNING: external ACL '" << acl->def->name <<
 640                            "' queue overload. Request rejected '" << key << "'.");
 641                     external_acl_message = "SYSTEM TOO BUSY, TRY AGAIN LATER";
 642                     return ACCESS_DUNNO;
 643                 } else {
 644                     debugs(82, DBG_IMPORTANT, "WARNING: external ACL '" << acl->def->name <<
 645                            "' queue overload. Using stale result. '" << key << "'.");
 646                     entry = staleEntry;
 647                     /* Fall thru to processing below */
 648                 }
 649             }
 650         }
 651     }
 652
 653     debugs(82, 4, HERE << "entry = { date=" <<
 654            (long unsigned int) entry->date <<
 655            ", result=" << entry->result <<
 656            " tag=" << entry->tag <<
 657            " log=" << entry->log << " }");
 658 #if USE_AUTH
 659     debugs(82, 4, HERE << "entry user=" << entry->user);
 660 #endif
 661
 662     external_acl_cache_touch(acl->def, entry);
 663     external_acl_message = entry->message.termedBuf();
 664
 665     debugs(82, 2, HERE << acl->def->name << " = " << entry->result);
 666     copyResultsFromEntry(ch->request, entry);
 667     return entry->result;
 668 }
 669
 670 int
 671 ACLExternal::match(ACLChecklist *checklist)
 672 {
 673     allow_t answer = aclMatchExternal(data, Filled(checklist));
 674
 675     // convert to tri-state ACL match 1,0,-1
 676     switch (answer) {
 677     case ACCESS_ALLOWED:
 678         return 1; // match
 679
 680     case ACCESS_DENIED:
 681         return 0; // non-match
 682
 683     case ACCESS_DUNNO:
 684     case ACCESS_AUTH_REQUIRED:
 685     default:
 686         // If the answer is not allowed or denied (matches/not matches) and
 687         // async authentication is not in progress, then we are done.
 688         if (checklist->keepMatching())
 689             checklist->markFinished(answer, "aclMatchExternal exception");
 690         return -1; // other
 691     }
 692 }
 693
 694 SBufList
 695 ACLExternal::dump() const
 696 {
 697     external_acl_data const *acl = data;
 698     SBufList rv;
 699     rv.push_back(SBuf(acl->def->name));
 700
 701     for (wordlist *arg = acl->arguments; arg; arg = arg->next) {
 702         SBuf s;
 703         s.Printf(" %s", arg->key);
 704         rv.push_back(s);
 705     }
 706
 707     return rv;
 708 }
 709
 710 /******************************************************************
 711  * external_acl cache
 712  */
 713
 714 static void
 715 external_acl_cache_touch(external_acl * def, const ExternalACLEntryPointer &entry)
 716 {
 717     // this must not be done when nothing is being cached.
 718     if (def->cache_size <= 0 || (def->ttl <= 0 && entry->result == 1) || (def->negative_ttl <= 0 && entry->result != 1))
 719         return;
 720
 721     dlinkDelete(&entry->lru, &def->lru_list);
 722     ExternalACLEntry *e = const_cast<ExternalACLEntry *>(entry.getRaw()); // XXX: make hash a std::map of Pointer.
 723     dlinkAdd(e, &entry->lru, &def->lru_list);
 724 }
 725
 726 static char *
 727 makeExternalAclKey(ACLFilledChecklist * ch, external_acl_data * acl_data)
 728 {
 729     static MemBuf mb;
 730     mb.reset();
 731
 732     // check for special case tokens in the format
 733     for (Format::Token *t = acl_data->def->format.format; t ; t = t->next) {
 734
 735         if (t->type == Format::LFT_EXT_ACL_NAME) {
 736             // setup for %ACL
 737             safe_free(ch->al->lastAclName);
 738             ch->al->lastAclName = xstrdup(acl_data->name);
 739         }
 740
 741         if (t->type == Format::LFT_EXT_ACL_DATA) {
 742             // setup string for %DATA
 743             SBuf sb;
 744             for (auto arg = acl_data->arguments; arg; arg = arg->next) {
 745                 if (sb.length())
 746                     sb.append(" ", 1);
 747
 748                 if (acl_data->def->quote == Format::LOG_QUOTE_URL) {
 749                     const char *quoted = rfc1738_escape(arg->key);
 750                     sb.append(quoted, strlen(quoted));
 751                 } else {
 752                     static MemBuf mb2;
 753                     mb2.init();
 754                     strwordquote(&mb2, arg->key);
 755                     sb.append(mb2.buf, mb2.size);
 756                     mb2.clean();
 757                 }
 758             }
 759
 760             ch->al->lastAclData = sb;
 761         }
 762
 763 #if USE_IDENT
 764         if (t->type == Format::LFT_USER_IDENT) {
 765             if (!*ch->rfc931) {
 766                 // if we fail to go async, we still return NULL and the caller
 767                 // will detect the failure in ACLExternal::match().
 768                 (void)ch->goAsync(IdentLookup::Instance());
 769                 return NULL;
 770             }
 771         }
 772 #endif
 773     }
 774
 775     // assemble the full helper lookup string
 776     acl_data->def->format.assemble(mb, ch->al, 0);
 777
 778     return mb.buf;
 779 }
 780
 781 static int
 782 external_acl_entry_expired(external_acl * def, const ExternalACLEntryPointer &entry)
 783 {
 784     if (def->cache_size <= 0)
 785         return 1;
 786
 787     if (entry->date + (entry->result == 1 ? def->ttl : def->negative_ttl) < squid_curtime)
 788         return 1;
 789     else
 790         return 0;
 791 }
 792
 793 static int
 794 external_acl_grace_expired(external_acl * def, const ExternalACLEntryPointer &entry)
 795 {
 796     if (def->cache_size <= 0)
 797         return 1;
 798
 799     int ttl;
 800     ttl = entry->result == 1 ? def->ttl : def->negative_ttl;
 801     ttl = (ttl * (100 - def->grace)) / 100;
 802
 803     if (entry->date + ttl <= squid_curtime)
 804         return 1;
 805     else
 806         return 0;
 807 }
 808
 809 static ExternalACLEntryPointer
 810 external_acl_cache_add(external_acl * def, const char *key, ExternalACLEntryData const & data)
 811 {
 812     ExternalACLEntryPointer entry;
 813
 814     // do not bother caching this result if TTL is going to expire it immediately
 815     if (def->cache_size <= 0 || (def->ttl <= 0 && data.result == 1) || (def->negative_ttl <= 0 && data.result != 1)) {
 816         debugs(82,6, HERE);
 817         entry = new ExternalACLEntry;
 818         entry->key = xstrdup(key);
 819         entry->update(data);
 820         entry->def = def;
 821         return entry;
 822     }
 823
 824     entry = static_cast<ExternalACLEntry *>(hash_lookup(def->cache, key));
 825     debugs(82, 2, "external_acl_cache_add: Adding '" << key << "' = " << data.result);
 826
 827     if (entry != NULL) {
 828         debugs(82, 3, "updating existing entry");
 829         entry->update(data);
 830         external_acl_cache_touch(def, entry);
 831         return entry;
 832     }
 833
 834     entry = new ExternalACLEntry;
 835     entry->key = xstrdup(key);
 836     entry->update(data);
 837
 838     def->add(entry);
 839
 840     return entry;
 841 }
 842
 843 static void
 844 external_acl_cache_delete(external_acl * def, const ExternalACLEntryPointer &entry)
 845 {
 846     assert(entry != NULL);
 847     assert(def->cache_size > 0 && entry->def == def);
 848     ExternalACLEntry *e = const_cast<ExternalACLEntry *>(entry.getRaw()); // XXX: make hash a std::map of Pointer.
 849     hash_remove_link(def->cache, e);
 850     dlinkDelete(&e->lru, &def->lru_list);
 851     e->unlock(); // unlock on behalf of the hash
 852     def->cache_entries -= 1;
 853 }
 854
 855 /******************************************************************
 856  * external_acl helpers
 857  */
 858
 859 class externalAclState
 860 {
 861     CBDATA_CLASS(externalAclState);
 862
 863 public:
 864     externalAclState(external_acl* aDef, const char *aKey) :
 865         callback(NULL),
 866         callback_data(NULL),
 867         key(xstrdup(aKey)),
 868         def(cbdataReference(aDef)),
 869         queue(NULL)
 870     {}
 871     ~externalAclState();
 872
 873     EAH *callback;
 874     void *callback_data;
 875     char *key;
 876     external_acl *def;
 877     dlink_node list;
 878     externalAclState *queue;
 879 };
 880
 881 CBDATA_CLASS_INIT(externalAclState);
 882
 883 externalAclState::~externalAclState()
 884 {
 885     xfree(key);
 886     cbdataReferenceDone(callback_data);
 887     cbdataReferenceDone(def);
 888 }
 889
 890 /*
 891  * The helper program receives queries on stdin, one
 892  * per line, and must return the result on on stdout
 893  *
 894  * General result syntax:
 895  *
 896  *   OK/ERR keyword=value ...
 897  *
 898  * Keywords:
 899  *
 900  *   user=      The users name (login)
 901  *   message=   Message describing the reason
 902  *   tag=   A string tag to be applied to the request that triggered the acl match.
 903  *          applies to both OK and ERR responses.
 904  *          Won't override existing request tags.
 905  *   log=   A string to be used in access logging
 906  *
 907  * Other keywords may be added to the protocol later
 908  *
 909  * value needs to be URL-encoded or enclosed in double quotes (")
 910  * with \-escaping on any whitespace, quotes, or slashes (\).
 911  */
 912 static void
 913 externalAclHandleReply(void *data, const Helper::Reply &reply)
 914 {
 915     externalAclState *state = static_cast<externalAclState *>(data);
 916     externalAclState *next;
 917     ExternalACLEntryData entryData;
 918     entryData.result = ACCESS_DENIED;
 919
 920     debugs(82, 2, HERE << "reply=" << reply);
 921
 922     if (reply.result == Helper::Okay)
 923         entryData.result = ACCESS_ALLOWED;
 924     // XXX: handle other non-DENIED results better
 925
 926     // XXX: make entryData store a proper Helper::Reply object instead of copying.
 927
 928     entryData.notes.append(&reply.notes);
 929
 930     const char *label = reply.notes.findFirst("tag");
 931     if (label != NULL && *label != '\0')
 932         entryData.tag = label;
 933
 934     label = reply.notes.findFirst("message");
 935     if (label != NULL && *label != '\0')
 936         entryData.message = label;
 937
 938     label = reply.notes.findFirst("log");
 939     if (label != NULL && *label != '\0')
 940         entryData.log = label;
 941
 942 #if USE_AUTH
 943     label = reply.notes.findFirst("user");
 944     if (label != NULL && *label != '\0')
 945         entryData.user = label;
 946
 947     label = reply.notes.findFirst("password");
 948     if (label != NULL && *label != '\0')
 949         entryData.password = label;
 950 #endif
 951
 952     dlinkDelete(&state->list, &state->def->queue);
 953
 954     ExternalACLEntryPointer entry;
 955     if (cbdataReferenceValid(state->def)) {
 956         // only cache OK and ERR results.
 957         if (reply.result == Helper::Okay || reply.result == Helper::Error)
 958             entry = external_acl_cache_add(state->def, state->key, entryData);
 959         else {
 960             const ExternalACLEntryPointer oldentry = static_cast<ExternalACLEntry *>(hash_lookup(state->def->cache, state->key));
 961
 962             if (oldentry != NULL)
 963                 external_acl_cache_delete(state->def, oldentry);
 964         }
 965     }
 966
 967     do {
 968         void *cbdata;
 969         if (state->callback && cbdataReferenceValidDone(state->callback_data, &cbdata))
 970             state->callback(cbdata, entry);
 971
 972         next = state->queue;
 973         state->queue = NULL;
 974
 975         delete state;
 976
 977         state = next;
 978     } while (state);
 979 }
 980
 981 void
 982 ACLExternal::ExternalAclLookup(ACLChecklist *checklist, ACLExternal * me)
 983 {
 984     ExternalACLLookup::Start(checklist, me->data, false);
 985 }
 986
 987 void
 988 ExternalACLLookup::Start(ACLChecklist *checklist, external_acl_data *acl, bool inBackground)
 989 {
 990     external_acl *def = acl->def;
 991
 992     ACLFilledChecklist *ch = Filled(checklist);
 993     const char *key = makeExternalAclKey(ch, acl);
 994     assert(key); // XXX: will fail if EXT_ACL_IDENT case needs an async lookup
 995
 996     debugs(82, 2, HERE << (inBackground ? "bg" : "fg") << " lookup in '" <<
 997            def->name << "' for '" << key << "'");
 998
 999     /* Check for a pending lookup to hook into */
1000     // only possible if we are caching results.
1001     externalAclState *oldstate = NULL;
1002     if (def->cache_size > 0) {
1003         for (dlink_node *node = def->queue.head; node; node = node->next) {
1004             externalAclState *oldstatetmp = static_cast<externalAclState *>(node->data);
1005
1006             if (strcmp(key, oldstatetmp->key) == 0) {
1007                 oldstate = oldstatetmp;
1008                 break;
1009             }
1010         }
1011     }
1012
1013     // A background refresh has no need to piggiback on a pending request:
1014     // When the pending request completes, the cache will be refreshed anyway.
1015     if (oldstate && inBackground) {
1016         debugs(82, 7, HERE << "'" << def->name << "' queue is already being refreshed (ch=" << ch << ")");
1017         return;
1018     }
1019
1020     externalAclState *state = new externalAclState(def, key);
1021
1022     if (!inBackground) {
1023         state->callback = &ExternalACLLookup::LookupDone;
1024         state->callback_data = cbdataReference(checklist);
1025     }
1026
1027     if (oldstate) {
1028         /* Hook into pending lookup */
1029         state->queue = oldstate->queue;
1030         oldstate->queue = state;
1031     } else {
1032         /* No pending lookup found. Sumbit to helper */
1033
1034         MemBuf buf;
1035         buf.init();
1036         buf.appendf("%s\n", key);
1037         debugs(82, 4, "externalAclLookup: looking up for '" << key << "' in '" << def->name << "'.");
1038
1039         if (!def->theHelper->trySubmit(buf.buf, externalAclHandleReply, state)) {
1040             debugs(82, 7, HERE << "'" << def->name << "' submit to helper failed");
1041             assert(inBackground); // or the caller should have checked
1042             delete state;
1043             return;
1044         }
1045
1046         dlinkAdd(state, &state->list, &def->queue);
1047
1048         buf.clean();
1049     }
1050
1051     debugs(82, 4, "externalAclLookup: will wait for the result of '" << key <<
1052            "' in '" << def->name << "' (ch=" << ch << ").");
1053 }
1054
1055 static void
1056 externalAclStats(StoreEntry * sentry)
1057 {
1058     for (external_acl *p = Config.externalAclHelperList; p; p = p->next) {
1059         storeAppendPrintf(sentry, "External ACL Statistics: %s\n", p->name);
1060         storeAppendPrintf(sentry, "Cache size: %d\n", p->cache->count);
1061         assert(p->theHelper);
1062         p->theHelper->packStatsInto(sentry);
1063         storeAppendPrintf(sentry, "\n");
1064     }
1065 }
1066
1067 static void
1068 externalAclRegisterWithCacheManager(void)
1069 {
1070     Mgr::RegisterAction("external_acl",
1071                         "External ACL stats",
1072                         externalAclStats, 0, 1);
1073 }
1074
1075 void
1076 externalAclInit(void)
1077 {
1078     for (external_acl *p = Config.externalAclHelperList; p; p = p->next) {
1079         if (!p->cache)
1080             p->cache = hash_create((HASHCMP *) strcmp, hashPrime(1024), hash4);
1081
1082         if (!p->theHelper)
1083             p->theHelper = new helper(p->name);
1084
1085         p->theHelper->cmdline = p->cmdline;
1086
1087         p->theHelper->childs.updateLimits(p->children);
1088
1089         p->theHelper->ipc_type = IPC_TCP_SOCKET;
1090
1091         p->theHelper->addr = p->local_addr;
1092
1093         helperOpenServers(p->theHelper);
1094     }
1095
1096     externalAclRegisterWithCacheManager();
1097 }
1098
1099 void
1100 externalAclShutdown(void)
1101 {
1102     external_acl *p;
1103
1104     for (p = Config.externalAclHelperList; p; p = p->next) {
1105         helperShutdown(p->theHelper);
1106     }
1107 }
1108
1109 ExternalACLLookup ExternalACLLookup::instance_;
1110 ExternalACLLookup *
1111 ExternalACLLookup::Instance()
1112 {
1113     return &instance_;
1114 }
1115
1116 void
1117 ExternalACLLookup::checkForAsync(ACLChecklist *checklist)const
1118 {
1119     /* TODO: optimise this - we probably have a pointer to this
1120      * around somewhere */
1121     ACL *acl = ACL::FindByName(AclMatchedName);
1122     assert(acl);
1123     ACLExternal *me = dynamic_cast<ACLExternal *> (acl);
1124     assert (me);
1125     ACLExternal::ExternalAclLookup(checklist, me);
1126 }
1127
1128 /// Called when an async lookup returns
1129 void
1130 ExternalACLLookup::LookupDone(void *data, const ExternalACLEntryPointer &result)
1131 {
1132     ACLFilledChecklist *checklist = Filled(static_cast<ACLChecklist*>(data));
1133     checklist->extacl_entry = result;
1134     checklist->resumeNonBlockingCheck(ExternalACLLookup::Instance());
1135 }
1136
1137 /* This registers "external" in the registry. To do dynamic definitions
1138  * of external ACL's, rather than a static prototype, have a Prototype instance
1139  * prototype in the class that defines each external acl 'class'.
1140  * Then, then the external acl instance is created, it self registers under
1141  * it's name.
1142  * Be sure that clone is fully functional for that acl class though!
1143  */
1144 ACL::Prototype ACLExternal::RegistryProtoype(&ACLExternal::RegistryEntry_, "external");
1145
1146 ACLExternal ACLExternal::RegistryEntry_("external");
1147
1148 ACL *
1149 ACLExternal::clone() const
1150 {
1151     return new ACLExternal(*this);
1152 }
1153
1154 ACLExternal::ACLExternal(char const *theClass) : data(NULL), class_(xstrdup(theClass))
1155 {}
1156
1157 ACLExternal::ACLExternal(ACLExternal const & old) : data(NULL), class_(old.class_ ? xstrdup(old.class_) : NULL)
1158 {
1159     /* we don't have copy constructors for the data yet */
1160     assert(!old.data);
1161 }
1162
1163 char const *
1164 ACLExternal::typeString() const
1165 {
1166     return class_;
1167 }
1168
1169 bool
1170 ACLExternal::isProxyAuth() const
1171 {
1172 #if USE_AUTH
1173     return data->def->require_auth;
1174 #else
1175     return false;
1176 #endif
1177 }
1178