src/external_acl.cc

   1 /*
   2  * Copyright (C) 1996-2015 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 "HttpHeaderTools.h"
  26 #include "HttpReply.h"
  27 #include "HttpRequest.h"
  28 #include "ip/tools.h"
  29 #include "MemBuf.h"
  30 #include "mgr/Registration.h"
  31 #include "rfc1738.h"
  32 #include "SquidConfig.h"
  33 #include "SquidString.h"
  34 #include "SquidTime.h"
  35 #include "Store.h"
  36 #include "tools.h"
  37 #include "URL.h"
  38 #include "wordlist.h"
  39 #if USE_OPENSSL
  40 #include "ssl/ServerBump.h"
  41 #include "ssl/support.h"
  42 #endif
  43 #if USE_AUTH
  44 #include "auth/Acl.h"
  45 #include "auth/Gadgets.h"
  46 #include "auth/UserRequest.h"
  47 #endif
  48 #if USE_IDENT
  49 #include "ident/AclIdent.h"
  50 #endif
  51
  52 #ifndef DEFAULT_EXTERNAL_ACL_TTL
  53 #define DEFAULT_EXTERNAL_ACL_TTL 1 * 60 * 60
  54 #endif
  55 #ifndef DEFAULT_EXTERNAL_ACL_CHILDREN
  56 #define DEFAULT_EXTERNAL_ACL_CHILDREN 5
  57 #endif
  58
  59 static char *makeExternalAclKey(ACLFilledChecklist * ch, external_acl_data * acl_data);
  60 static void external_acl_cache_delete(external_acl * def, const ExternalACLEntryPointer &entry);
  61 static int external_acl_entry_expired(external_acl * def, const ExternalACLEntryPointer &entry);
  62 static int external_acl_grace_expired(external_acl * def, const ExternalACLEntryPointer &entry);
  63 static void external_acl_cache_touch(external_acl * def, const ExternalACLEntryPointer &entry);
  64 static ExternalACLEntryPointer external_acl_cache_add(external_acl * def, const char *key, ExternalACLEntryData const &data);
  65
  66 /******************************************************************
  67  * external_acl directive
  68  */
  69
  70 class external_acl
  71 {
  72     /* FIXME: These are not really cbdata, but it is an easy way
  73      * to get them pooled, refcounted, accounted and freed properly...
  74      */
  75     CBDATA_CLASS(external_acl);
  76
  77 public:
  78     external_acl();
  79     ~external_acl();
  80
  81     external_acl *next;
  82
  83     void add(const ExternalACLEntryPointer &);
  84
  85     void trimCache();
  86
  87     int ttl;
  88
  89     int negative_ttl;
  90
  91     int grace;
  92
  93     char *name;
  94
  95     Format::Format format;
  96
  97     wordlist *cmdline;
  98
  99     Helper::ChildConfig children;
 100
 101     helper *theHelper;
 102
 103     hash_table *cache;
 104
 105     dlink_list lru_list;
 106
 107     int cache_size;
 108
 109     int cache_entries;
 110
 111     dlink_list queue;
 112
 113 #if USE_AUTH
 114     /**
 115      * Configuration flag. May only be altered by the configuration parser.
 116      *
 117      * Indicates that all uses of this external_acl_type helper require authentication
 118      * details to be processed. If none are available its a fail match.
 119      */
 120     bool require_auth;
 121 #endif
 122
 123     enum {
 124         QUOTE_METHOD_SHELL = 1,
 125         QUOTE_METHOD_URL
 126     } quote;
 127
 128     Ip::Address local_addr;
 129 };
 130
 131 CBDATA_CLASS_INIT(external_acl);
 132
 133 external_acl::external_acl() :
 134     next(NULL),
 135     ttl(DEFAULT_EXTERNAL_ACL_TTL),
 136     negative_ttl(-1),
 137     grace(1),
 138     name(NULL),
 139     format("external_acl_type"),
 140     cmdline(NULL),
 141     children(DEFAULT_EXTERNAL_ACL_CHILDREN),
 142     theHelper(NULL),
 143     cache(NULL),
 144     cache_size(256*1024),
 145     cache_entries(0),
 146 #if USE_AUTH
 147     require_auth(0),
 148 #endif
 149     quote(external_acl::QUOTE_METHOD_URL)
 150 {
 151     local_addr.setLocalhost();
 152 }
 153
 154 external_acl::~external_acl()
 155 {
 156     xfree(name);
 157     wordlistDestroy(&cmdline);
 158
 159     if (theHelper) {
 160         helperShutdown(theHelper);
 161         delete theHelper;
 162         theHelper = NULL;
 163     }
 164
 165     while (lru_list.tail) {
 166         ExternalACLEntryPointer e(static_cast<ExternalACLEntry *>(lru_list.tail->data));
 167         external_acl_cache_delete(this, e);
 168     }
 169     if (cache)
 170         hashFreeMemory(cache);
 171
 172     while (next) {
 173         external_acl *node = next;
 174         next = node->next;
 175         node->next = NULL; // prevent recursion
 176         delete node;
 177     }
 178 }
 179
 180 void
 181 parse_externalAclHelper(external_acl ** list)
 182 {
 183     external_acl *a = new external_acl;
 184     char *token = ConfigParser::NextToken();
 185
 186     if (!token)
 187         self_destruct();
 188
 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 = external_acl::QUOTE_METHOD_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 = external_acl::QUOTE_METHOD_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 = external_acl::QUOTE_METHOD_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 = external_acl::QUOTE_METHOD_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         // compatibility for old tokens incompatible with Format::Token syntax
 282 #if USE_OPENSSL // dont bother if we dont have to.
 283         if (strncmp(token, "%USER_CERT_", 11) == 0) {
 284             (*fmt)->type = Format::LFT_EXT_ACL_USER_CERT;
 285             (*fmt)->data.string = xstrdup(token + 11);
 286             (*fmt)->data.header.header = (*fmt)->data.string;
 287         } else if (strncmp(token, "%USER_CA_CERT_", 14) == 0) {
 288             (*fmt)->type = Format::LFT_EXT_ACL_USER_CA_CERT;
 289             (*fmt)->data.string = xstrdup(token + 14);
 290             (*fmt)->data.header.header = (*fmt)->data.string;
 291         } else if (strncmp(token, "%CA_CERT_", 9) == 0) {
 292             debugs(82, DBG_PARSE_NOTE(DBG_IMPORTANT), "WARNING: external_acl_type %CA_CERT_* code is obsolete. Use %USER_CA_CERT_* instead");
 293             (*fmt)->type = Format::LFT_EXT_ACL_USER_CA_CERT;
 294             (*fmt)->data.string = xstrdup(token + 9);
 295             (*fmt)->data.header.header = (*fmt)->data.string;
 296         } else
 297 #endif
 298         {
 299             // we can use the Format::Token::parse() method since it
 300             // only pulls off one token. Since we already checked
 301             // for '%' prefix above this is guaranteed to be a token.
 302             const size_t len = (*fmt)->parse(token, &quote);
 303             assert(len == strlen(token));
 304         }
 305
 306         // process special token-specific actions (only if necessary)
 307 #if USE_AUTH
 308         if ((*fmt)->type == Format::LFT_USER_LOGIN)
 309             a->require_auth = true;
 310 #endif
 311
 312        if ((*fmt)->type == Format::LFT_EXT_ACL_DATA)
 313            data_used = true;
 314
 315         fmt = &((*fmt)->next);
 316         token = ConfigParser::NextToken();
 317     }
 318
 319     /* There must be at least one format token */
 320     if (!a->format.format)
 321         self_destruct();
 322
 323     // format has implicit %DATA on the end if not used explicitly
 324     if (!data_used) {
 325         *fmt = new Format::Token;
 326         (*fmt)->type = Format::LFT_EXT_ACL_DATA;
 327     }
 328
 329     /* helper */
 330     if (!token)
 331         self_destruct();
 332
 333     wordlistAdd(&a->cmdline, token);
 334
 335     /* arguments */
 336     parse_wordlist(&a->cmdline);
 337
 338     while (*list)
 339         list = &(*list)->next;
 340
 341     *list = a;
 342 }
 343
 344 void
 345 dump_externalAclHelper(StoreEntry * sentry, const char *name, const external_acl * list)
 346 {
 347     const external_acl *node;
 348     const wordlist *word;
 349
 350     for (node = list; node; node = node->next) {
 351         storeAppendPrintf(sentry, "%s %s", name, node->name);
 352
 353         if (!node->local_addr.isIPv6())
 354             storeAppendPrintf(sentry, " ipv4");
 355         else
 356             storeAppendPrintf(sentry, " ipv6");
 357
 358         if (node->ttl != DEFAULT_EXTERNAL_ACL_TTL)
 359             storeAppendPrintf(sentry, " ttl=%d", node->ttl);
 360
 361         if (node->negative_ttl != node->ttl)
 362             storeAppendPrintf(sentry, " negative_ttl=%d", node->negative_ttl);
 363
 364         if (node->grace)
 365             storeAppendPrintf(sentry, " grace=%d", node->grace);
 366
 367         if (node->children.n_max != DEFAULT_EXTERNAL_ACL_CHILDREN)
 368             storeAppendPrintf(sentry, " children-max=%d", node->children.n_max);
 369
 370         if (node->children.n_startup != 1)
 371             storeAppendPrintf(sentry, " children-startup=%d", node->children.n_startup);
 372
 373         if (node->children.n_idle != (node->children.n_max + node->children.n_startup) )
 374             storeAppendPrintf(sentry, " children-idle=%d", node->children.n_idle);
 375
 376         if (node->children.concurrency)
 377             storeAppendPrintf(sentry, " concurrency=%d", node->children.concurrency);
 378
 379         if (node->cache)
 380             storeAppendPrintf(sentry, " cache=%d", node->cache_size);
 381
 382         if (node->quote == external_acl::QUOTE_METHOD_SHELL)
 383             storeAppendPrintf(sentry, " protocol=2.5");
 384
 385         node->format.dump(sentry, NULL, false);
 386
 387         for (word = node->cmdline; word; word = word->next)
 388             storeAppendPrintf(sentry, " %s", word->key);
 389
 390         storeAppendPrintf(sentry, "\n");
 391     }
 392 }
 393
 394 void
 395 free_externalAclHelper(external_acl ** list)
 396 {
 397     delete *list;
 398     *list = NULL;
 399 }
 400
 401 static external_acl *
 402 find_externalAclHelper(const char *name)
 403 {
 404     external_acl *node;
 405
 406     for (node = Config.externalAclHelperList; node; node = node->next) {
 407         if (strcmp(node->name, name) == 0)
 408             return node;
 409     }
 410
 411     return NULL;
 412 }
 413
 414 void
 415 external_acl::add(const ExternalACLEntryPointer &anEntry)
 416 {
 417     trimCache();
 418     assert(anEntry != NULL);
 419     assert (anEntry->def == NULL);
 420     anEntry->def = this;
 421     ExternalACLEntry *e = const_cast<ExternalACLEntry *>(anEntry.getRaw()); // XXX: make hash a std::map of Pointer.
 422     hash_join(cache, e);
 423     dlinkAdd(e, &e->lru, &lru_list);
 424     e->lock(); //cbdataReference(e); // lock it on behalf of the hash
 425     ++cache_entries;
 426 }
 427
 428 void
 429 external_acl::trimCache()
 430 {
 431     if (cache_size && cache_entries >= cache_size) {
 432         ExternalACLEntryPointer e(static_cast<ExternalACLEntry *>(lru_list.tail->data));
 433         external_acl_cache_delete(this, e);
 434     }
 435 }
 436
 437 /******************************************************************
 438  * external acl type
 439  */
 440
 441 class external_acl_data
 442 {
 443     CBDATA_CLASS(external_acl_data);
 444
 445 public:
 446     explicit external_acl_data(external_acl *aDef) : def(cbdataReference(aDef)), name(NULL), arguments(NULL) {}
 447     ~external_acl_data();
 448
 449     external_acl *def;
 450     const char *name;
 451     wordlist *arguments;
 452 };
 453
 454 CBDATA_CLASS_INIT(external_acl_data);
 455
 456 external_acl_data::~external_acl_data()
 457 {
 458     xfree(name);
 459     wordlistDestroy(&arguments);
 460     cbdataReferenceDone(def);
 461 }
 462
 463 void
 464 ACLExternal::parse()
 465 {
 466     if (data)
 467         self_destruct();
 468
 469     char *token = ConfigParser::strtokFile();
 470
 471     if (!token)
 472         self_destruct();
 473
 474     data = new external_acl_data(find_externalAclHelper(token));
 475
 476     if (!data->def)
 477         self_destruct();
 478
 479     // def->name is the name of the external_acl_type.
 480     // this is the name of the 'acl' directive being tested
 481     data->name = xstrdup(AclMatchedName);
 482
 483     while ((token = ConfigParser::strtokFile())) {
 484         wordlistAdd(&data->arguments, token);
 485     }
 486 }
 487
 488 bool
 489 ACLExternal::valid () const
 490 {
 491 #if USE_AUTH
 492     if (data->def->require_auth) {
 493         if (authenticateSchemeCount() == 0) {
 494             debugs(28, DBG_CRITICAL, "Can't use proxy auth because no authentication schemes were compiled.");
 495             return false;
 496         }
 497
 498         if (authenticateActiveSchemeCount() == 0) {
 499             debugs(28, DBG_CRITICAL, "Can't use proxy auth because no authentication schemes are fully configured.");
 500             return false;
 501         }
 502     }
 503 #endif
 504
 505     return true;
 506 }
 507
 508 bool
 509 ACLExternal::empty () const
 510 {
 511     return false;
 512 }
 513
 514 ACLExternal::~ACLExternal()
 515 {
 516     delete data;
 517     xfree(class_);
 518 }
 519
 520 static void
 521 copyResultsFromEntry(HttpRequest *req, const ExternalACLEntryPointer &entry)
 522 {
 523     if (req) {
 524 #if USE_AUTH
 525         if (entry->user.size())
 526             req->extacl_user = entry->user;
 527
 528         if (entry->password.size())
 529             req->extacl_passwd = entry->password;
 530 #endif
 531         if (!req->tag.size())
 532             req->tag = entry->tag;
 533
 534         if (entry->log.size())
 535             req->extacl_log = entry->log;
 536
 537         if (entry->message.size())
 538             req->extacl_message = entry->message;
 539
 540         // attach the helper kv-pair to the transaction
 541         UpdateRequestNotes(req->clientConnectionManager.get(), *req, entry->notes);
 542     }
 543 }
 544
 545 static allow_t
 546 aclMatchExternal(external_acl_data *acl, ACLFilledChecklist *ch)
 547 {
 548     debugs(82, 9, HERE << "acl=\"" << acl->def->name << "\"");
 549     ExternalACLEntryPointer entry = ch->extacl_entry;
 550
 551     external_acl_message = "MISSING REQUIRED INFORMATION";
 552
 553     if (entry != NULL) {
 554         if (entry->def == acl->def) {
 555             /* Ours, use it.. if the key matches */
 556             const char *key = makeExternalAclKey(ch, acl);
 557             if (!key)
 558                 return ACCESS_DUNNO; // insufficent data to continue
 559             if (strcmp(key, (char*)entry->key) != 0) {
 560                 debugs(82, 9, "entry key='" << (char *)entry->key << "', our key='" << key << "' dont match. Discarded.");
 561                 // too bad. need a new lookup.
 562                 entry = ch->extacl_entry = NULL;
 563             }
 564         } else {
 565             /* Not ours.. get rid of it */
 566             debugs(82, 9, "entry " << entry << " not valid or not ours. Discarded.");
 567             if (entry != NULL) {
 568                 debugs(82, 9, "entry def=" << entry->def << ", our def=" << acl->def);
 569                 const char *key = makeExternalAclKey(ch, acl); // may be nil
 570                 debugs(82, 9, "entry key='" << (char *)entry->key << "', our key='" << key << "'");
 571             }
 572             entry = ch->extacl_entry = NULL;
 573         }
 574     }
 575
 576     if (!entry) {
 577         debugs(82, 9, HERE << "No helper entry available");
 578 #if USE_AUTH
 579         if (acl->def->require_auth) {
 580             /* Make sure the user is authenticated */
 581             debugs(82, 3, HERE << acl->def->name << " check user authenticated.");
 582             const allow_t ti = AuthenticateAcl(ch);
 583             if (ti != ACCESS_ALLOWED) {
 584                 debugs(82, 2, HERE << acl->def->name << " user not authenticated (" << ti << ")");
 585                 return ti;
 586             }
 587             debugs(82, 3, HERE << acl->def->name << " user is authenticated.");
 588         }
 589 #endif
 590         const char *key = makeExternalAclKey(ch, acl);
 591
 592         if (!key) {
 593             /* Not sufficient data to process */
 594             return ACCESS_DUNNO;
 595         }
 596
 597         entry = static_cast<ExternalACLEntry *>(hash_lookup(acl->def->cache, key));
 598
 599         const ExternalACLEntryPointer staleEntry = entry;
 600         if (entry != NULL && external_acl_entry_expired(acl->def, entry))
 601             entry = NULL;
 602
 603         if (entry != NULL && external_acl_grace_expired(acl->def, entry)) {
 604             // refresh in the background
 605             ExternalACLLookup::Start(ch, acl, true);
 606             debugs(82, 4, HERE << "no need to wait for the refresh of '" <<
 607                    key << "' in '" << acl->def->name << "' (ch=" << ch << ").");
 608         }
 609
 610         if (!entry) {
 611             debugs(82, 2, HERE << acl->def->name << "(\"" << key << "\") = lookup needed");
 612
 613             if (!acl->def->theHelper->queueFull()) {
 614                 debugs(82, 2, HERE << "\"" << key << "\": queueing a call.");
 615                 if (!ch->goAsync(ExternalACLLookup::Instance()))
 616                     debugs(82, 2, "\"" << key << "\": no async support!");
 617                 debugs(82, 2, HERE << "\"" << key << "\": return -1.");
 618                 return ACCESS_DUNNO; // expired cached or simply absent entry
 619             } else {
 620                 if (!staleEntry) {
 621                     debugs(82, DBG_IMPORTANT, "WARNING: external ACL '" << acl->def->name <<
 622                            "' queue overload. Request rejected '" << key << "'.");
 623                     external_acl_message = "SYSTEM TOO BUSY, TRY AGAIN LATER";
 624                     return ACCESS_DUNNO;
 625                 } else {
 626                     debugs(82, DBG_IMPORTANT, "WARNING: external ACL '" << acl->def->name <<
 627                            "' queue overload. Using stale result. '" << key << "'.");
 628                     entry = staleEntry;
 629                     /* Fall thru to processing below */
 630                 }
 631             }
 632         }
 633     }
 634
 635     debugs(82, 4, HERE << "entry = { date=" <<
 636            (long unsigned int) entry->date <<
 637            ", result=" << entry->result <<
 638            " tag=" << entry->tag <<
 639            " log=" << entry->log << " }");
 640 #if USE_AUTH
 641     debugs(82, 4, HERE << "entry user=" << entry->user);
 642 #endif
 643
 644     external_acl_cache_touch(acl->def, entry);
 645     external_acl_message = entry->message.termedBuf();
 646
 647     debugs(82, 2, HERE << acl->def->name << " = " << entry->result);
 648     copyResultsFromEntry(ch->request, entry);
 649     return entry->result;
 650 }
 651
 652 int
 653 ACLExternal::match(ACLChecklist *checklist)
 654 {
 655     allow_t answer = aclMatchExternal(data, Filled(checklist));
 656
 657     // convert to tri-state ACL match 1,0,-1
 658     switch (answer) {
 659     case ACCESS_ALLOWED:
 660         return 1; // match
 661
 662     case ACCESS_DENIED:
 663         return 0; // non-match
 664
 665     case ACCESS_DUNNO:
 666     case ACCESS_AUTH_REQUIRED:
 667     default:
 668         // If the answer is not allowed or denied (matches/not matches) and
 669         // async authentication is not in progress, then we are done.
 670         if (checklist->keepMatching())
 671             checklist->markFinished(answer, "aclMatchExternal exception");
 672         return -1; // other
 673     }
 674 }
 675
 676 SBufList
 677 ACLExternal::dump() const
 678 {
 679     external_acl_data const *acl = data;
 680     SBufList rv;
 681     rv.push_back(SBuf(acl->def->name));
 682
 683     for (wordlist *arg = acl->arguments; arg; arg = arg->next) {
 684         SBuf s;
 685         s.Printf(" %s", arg->key);
 686         rv.push_back(s);
 687     }
 688
 689     return rv;
 690 }
 691
 692 /******************************************************************
 693  * external_acl cache
 694  */
 695
 696 static void
 697 external_acl_cache_touch(external_acl * def, const ExternalACLEntryPointer &entry)
 698 {
 699     // this must not be done when nothing is being cached.
 700     if (def->cache_size <= 0 || (def->ttl <= 0 && entry->result == 1) || (def->negative_ttl <= 0 && entry->result != 1))
 701         return;
 702
 703     dlinkDelete(&entry->lru, &def->lru_list);
 704     ExternalACLEntry *e = const_cast<ExternalACLEntry *>(entry.getRaw()); // XXX: make hash a std::map of Pointer.
 705     dlinkAdd(e, &entry->lru, &def->lru_list);
 706 }
 707
 708 static char *
 709 makeExternalAclKey(ACLFilledChecklist * ch, external_acl_data * acl_data)
 710 {
 711     static MemBuf mb;
 712     mb.reset();
 713
 714     // check for special case tokens in the format
 715     for (Format::Token *t = acl_data->def->format.format; t ; t = t->next) {
 716
 717         if (t->type == Format::LFT_EXT_ACL_NAME) {
 718             // setup for %ACL
 719             safe_free(ch->al->_private.lastAclName);
 720             ch->al->_private.lastAclName = xstrdup(acl_data->name);
 721         }
 722
 723         if (t->type == Format::LFT_EXT_ACL_NAME) {
 724             // setup string for %DATA
 725             SBuf sb;
 726             bool first = true;
 727             for (auto arg = acl_data->arguments; arg; arg = arg->next) {
 728                 if (!first)
 729                     sb.append(" ", 1);
 730
 731                 if (acl_data->def->quote == external_acl::QUOTE_METHOD_URL) {
 732                     const char *quoted = rfc1738_escape(arg->key);
 733                     sb.append(quoted, strlen(quoted));
 734                 } else {
 735                     static MemBuf mb2;
 736                     mb2.init();
 737                     strwordquote(&mb2, arg->key);
 738                     sb.append(mb2.buf, mb2.size);
 739                     mb2.clean();
 740                 }
 741
 742                 first = false;
 743             }
 744         }
 745
 746         if (t->type == Format::LFT_USER_IDENT) {
 747             if (!*ch->rfc931) {
 748                 // if we fail to go async, we still return NULL and the caller
 749                 // will detect the failure in ACLExternal::match().
 750                 (void)ch->goAsync(IdentLookup::Instance());
 751                 return NULL;
 752             }
 753         }
 754     }
 755
 756     // generate %DATA token value  of this acl lookup
 757     SBuf sb;
 758     for (auto arg = acl_data->arguments; arg; arg = arg->next) {
 759         if (sb.length())
 760             sb.append(" ", 1);
 761
 762         if (acl_data->def->quote == external_acl::QUOTE_METHOD_URL) {
 763             const char *quoted = rfc1738_escape(arg->key);
 764             sb.append(quoted, strlen(quoted));
 765         } else {
 766             static MemBuf mb2;
 767             mb2.init();
 768             strwordquote(&mb2, arg->key);
 769             sb.append(mb2.buf, mb2.size);
 770             mb2.clean();
 771         }
 772     }
 773     ch->al->_private.lastAclData = sb.c_str();
 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