postlicyd/strlist.c

   1 /******************************************************************************/
   2 /*          pfixtools: a collection of postfix related tools                  */
   3 /*          ~~~~~~~~~                                                         */
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   5 /*                                                                            */
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  17 /*     permission.                                                            */
  18 /*                                                                            */
  19 /*  THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND   */
  20 /*  ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE     */
  21 /*  IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR        */
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  28 /*  ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF    */
  29 /*  THE POSSIBILITY OF SUCH DAMAGE.                                           */
  30 /******************************************************************************/
  31
  32 /*
  33  * Copyright © 2008 Florent Bruneau
  34  */
  35
  36 #include "filter.h"
  37 #include "trie.h"
  38 #include "file.h"
  39 #include "str.h"
  40 #include "rbl.h"
  41 #include "policy_tokens.h"
  42
  43 typedef struct strlist_config_t {
  44     PA(trie_t) tries;
  45     A(int)     weights;
  46     A(bool)    reverses;
  47     A(bool)    partiales;
  48
  49     A(char)     hosts;
  50     A(int)      host_offsets;
  51     A(int)      host_weights;
  52
  53     int soft_threshold;
  54     int hard_threshold;
  55
  56     unsigned is_email         :1;
  57     unsigned is_hostname      :1;
  58
  59     unsigned match_sender     :1;
  60     unsigned match_recipient  :1;
  61
  62     unsigned match_helo       :1;
  63     unsigned match_client     :1;
  64     unsigned match_reverse    :1;
  65 } strlist_config_t;
  66
  67 typedef struct strlist_async_data_t {
  68     A(rbl_result_t) results;
  69     int awaited;
  70     uint32_t sum;
  71     bool error;
  72 } strlist_async_data_t;
  73
  74 static filter_type_t filter_type = FTK_UNKNOWN;
  75
  76
  77 static strlist_config_t *strlist_config_new(void)
  78 {
  79     return p_new(strlist_config_t, 1);
  80 }
  81
  82 static void strlist_config_delete(strlist_config_t **config)
  83 {
  84     if (*config) {
  85         array_deep_wipe((*config)->tries, trie_delete);
  86         array_wipe((*config)->weights);
  87         array_wipe((*config)->reverses);
  88         array_wipe((*config)->partiales);
  89         array_wipe((*config)->hosts);
  90         array_wipe((*config)->host_offsets);
  91         array_wipe((*config)->host_weights);
  92         p_delete(config);
  93     }
  94 }
  95
  96 static inline void strlist_copy(char *dest, const char *str, ssize_t str_len,
  97                                 bool reverse)
  98 {
  99     if (str_len > 0) {
 100         if (reverse) {
 101             for (const char *src = str + str_len - 1 ; src >= str ; --src) {
 102                 *dest = ascii_tolower(*src);
 103                 ++dest;
 104             }
 105         } else {
 106             for (int i = 0 ; i < str_len ; ++i) {
 107                 *dest = ascii_tolower(str[i]);
 108                 ++dest;
 109             }
 110         }
 111     }
 112     *dest = '\0';
 113 }
 114
 115
 116 static trie_t *strlist_create(const char *file, bool reverse, bool lock)
 117 {
 118     trie_t *db;
 119     file_map_t map;
 120     const char *p, *end;
 121     char line[BUFSIZ];
 122
 123     if (!file_map_open(&map, file, false)) {
 124         return NULL;
 125     }
 126     p   = map.map;
 127     end = map.end;
 128     while (end > p && end[-1] != '\n') {
 129         --end;
 130     }
 131     if (end != map.end) {
 132         warn("file %s miss a final \\n, ignoring last line",
 133              file);
 134     }
 135
 136     db = trie_new();
 137     while (p < end && p != NULL) {
 138         const char *eol = (char *)memchr(p, '\n', end - p);
 139         if (eol == NULL) {
 140             eol = end;
 141         }
 142         if (eol - p >= BUFSIZ) {
 143             err("unreasonnable long line");
 144             file_map_close(&map);
 145             trie_delete(&db);
 146             return NULL;
 147         }
 148         if (*p != '#') {
 149             const char *eos = eol;
 150             while (p < eos && isspace(*p)) {
 151                 ++p;
 152             }
 153             while (p < eos && isspace(eos[-1])) {
 154                 --eos;
 155             }
 156             if (p < eos) {
 157                 strlist_copy(line, p, eos - p, reverse);
 158                 trie_insert(db, line);
 159             }
 160         }
 161         p = eol + 1;
 162     }
 163     file_map_close(&map);
 164     trie_compile(db, lock);
 165     return db;
 166 }
 167
 168 static bool strlist_create_from_rhbl(const char *file, bool lock,
 169                                      trie_t **phosts, trie_t **pdomains)
 170 {
 171     trie_t *hosts, *domains;
 172     uint32_t host_count, domain_count;
 173     file_map_t map;
 174     const char *p, *end;
 175     char line[BUFSIZ];
 176
 177     if (!file_map_open(&map, file, false)) {
 178         return false;
 179     }
 180     p   = map.map;
 181     end = map.end;
 182     while (end > p && end[-1] != '\n') {
 183         --end;
 184     }
 185     if (end != map.end) {
 186         warn("file %s miss a final \\n, ignoring last line",
 187              file);
 188     }
 189
 190     hosts = trie_new();
 191     host_count = 0;
 192     domains = trie_new();
 193     domain_count = 0;
 194     while (p < end && p != NULL) {
 195         const char *eol = (char *)memchr(p, '\n', end - p);
 196         if (eol == NULL) {
 197             eol = end;
 198         }
 199         if (eol - p >= BUFSIZ) {
 200             err("unreasonnable long line");
 201             file_map_close(&map);
 202             trie_delete(&hosts);
 203             trie_delete(&domains);
 204             return false;
 205         }
 206         if (*p != '#') {
 207             const char *eos = eol;
 208             while (p < eos && isspace(*p)) {
 209                 ++p;
 210             }
 211             while (p < eos && isspace(eos[-1])) {
 212                 --eos;
 213             }
 214             if (p < eos) {
 215                 if (isalnum(*p)) {
 216                     strlist_copy(line, p, eos - p, true);
 217                     trie_insert(hosts, line);
 218                     ++host_count;
 219                 } else if (*p == '*') {
 220                     ++p;
 221                     strlist_copy(line, p, eos - p, true);
 222                     trie_insert(domains, line);
 223                     ++domain_count;
 224                 }
 225             }
 226         }
 227         p = eol + 1;
 228     }
 229     file_map_close(&map);
 230     if (host_count > 0) {
 231         trie_compile(hosts, lock);
 232         *phosts = hosts;
 233     } else {
 234         trie_delete(&hosts);
 235         *phosts = NULL;
 236     }
 237     if (domain_count > 0) {
 238         trie_compile(domains, lock);
 239         *pdomains = domains;
 240     } else {
 241         trie_delete(&domains);
 242         *pdomains = NULL;
 243     }
 244     return hosts != NULL || domains != NULL;
 245
 246 }
 247
 248
 249 static bool strlist_filter_constructor(filter_t *filter)
 250 {
 251     strlist_config_t *config = strlist_config_new();
 252
 253 #define PARSE_CHECK(Expr, Str, ...)                                            \
 254     if (!(Expr)) {                                                             \
 255         err(Str, ##__VA_ARGS__);                                               \
 256         strlist_config_delete(&config);                                        \
 257         return false;                                                          \
 258     }
 259
 260     config->hard_threshold = 1;
 261     config->soft_threshold = 1;
 262     foreach (filter_param_t *param, filter->params) {
 263         switch (param->type) {
 264           /* file parameter is:
 265            *  [no]lock:(partial-)(prefix|suffix):weight:filename
 266            *  valid options are:
 267            *    - lock:   memlock the database in memory.
 268            *    - nolock: don't memlock the database in memory.
 269            *    - prefix: perform "prefix" compression on storage.
 270            *    - suffix  perform "suffix" compression on storage.
 271            *    - \d+:    a number describing the weight to give to the match
 272            *              the given list [mandatory]
 273            *  the file pointed by filename MUST be a valid string list (one string per
 274            *  line, empty lines and lines beginning with a '#' are ignored).
 275            */
 276           case ATK_FILE: {
 277             bool lock = false;
 278             int  weight = 0;
 279             bool reverse = false;
 280             bool partial = false;
 281             trie_t *trie = NULL;
 282             const char *current = param->value;
 283             const char *p = m_strchrnul(param->value, ':');
 284             char *next = NULL;
 285             for (int i = 0 ; i < 4 ; ++i) {
 286                 PARSE_CHECK(i == 3 || *p,
 287                             "file parameter must contains a locking state "
 288                             "and a weight option");
 289                 switch (i) {
 290                   case 0:
 291                     if ((p - current) == 4 && strncmp(current, "lock", 4) == 0) {
 292                         lock = true;
 293                     } else if ((p - current) == 6 && strncmp(current, "nolock", 6) == 0) {
 294                         lock = false;
 295                     } else {
 296                         PARSE_CHECK(false, "illegal locking state %.*s",
 297                                     (int)(p - current), current);
 298                     }
 299                     break;
 300
 301                   case 1:
 302                     if (p - current > (ssize_t)strlen("partial-")
 303                         && strncmp(current, "partial-", strlen("partial-")) == 0) {
 304                         partial = true;
 305                         current += strlen("partial-");
 306                     }
 307                     if ((p - current) == 6 && strncmp(current, "suffix", 6) == 0) {
 308                         reverse = true;
 309                     } else if ((p - current) == 6 && strncmp(current, "prefix", 6) == 0) {
 310                         reverse = false;
 311                     } else {
 312                         PARSE_CHECK(false, "illegal character order value %.*s",
 313                                     (int)(p - current), current);
 314                     }
 315                     break;
 316
 317                   case 2:
 318                     weight = strtol(current, &next, 10);
 319                     PARSE_CHECK(next == p && weight >= 0 && weight <= 1024,
 320                                 "illegal weight value %.*s",
 321                                 (int)(p - current), current);
 322                     break;
 323
 324                   case 3:
 325                     trie = strlist_create(current, reverse, lock);
 326                     PARSE_CHECK(trie != NULL,
 327                                 "cannot load string list from %s", current);
 328                     array_add(config->tries, trie);
 329                     array_add(config->weights, weight);
 330                     array_add(config->reverses, reverse);
 331                     array_add(config->partiales, partial);
 332                     break;
 333                 }
 334                 if (i != 3) {
 335                     current = p + 1;
 336                     p = m_strchrnul(current, ':');
 337                 }
 338             }
 339           } break;
 340
 341           /* rbldns parameter is:
 342            *  [no]lock::weight:filename
 343            *  valid options are:
 344            *    - lock:   memlock the database in memory.
 345            *    - nolock: don't memlock the database in memory.
 346            *    - \d+:    a number describing the weight to give to the match
 347            *              the given list [mandatory]
 348            *  directly import a file issued from a rhbl in rbldns format.
 349            */
 350           case ATK_RBLDNS: {
 351             bool lock = false;
 352             int  weight = 0;
 353             trie_t *trie_hosts   = NULL;
 354             trie_t *trie_domains = NULL;
 355             const char *current = param->value;
 356             const char *p = m_strchrnul(param->value, ':');
 357             char *next = NULL;
 358             for (int i = 0 ; i < 3 ; ++i) {
 359                 PARSE_CHECK(i == 2 || *p,
 360                             "file parameter must contains a locking state "
 361                             "and a weight option");
 362                 switch (i) {
 363                   case 0:
 364                     if ((p - current) == 4 && strncmp(current, "lock", 4) == 0) {
 365                         lock = true;
 366                     } else if ((p - current) == 6 && strncmp(current, "nolock", 6) == 0) {
 367                         lock = false;
 368                     } else {
 369                         PARSE_CHECK(false, "illegal locking state %.*s",
 370                                     (int)(p - current), current);
 371                     }
 372                     break;
 373
 374                   case 1:
 375                     weight = strtol(current, &next, 10);
 376                     PARSE_CHECK(next == p && weight >= 0 && weight <= 1024,
 377                                 "illegal weight value %.*s",
 378                                 (int)(p - current), current);
 379                     break;
 380
 381                   case 2:
 382                     PARSE_CHECK(strlist_create_from_rhbl(current, lock,
 383                                                          &trie_hosts, &trie_domains),
 384                                 "cannot load string list from rhbl %s", current);
 385                     if (trie_hosts != NULL) {
 386                         array_add(config->tries, trie_hosts);
 387                         array_add(config->weights, weight);
 388                         array_add(config->reverses, true);
 389                         array_add(config->partiales, false);
 390                     }
 391                     if (trie_domains != NULL) {
 392                         array_add(config->tries, trie_domains);
 393                         array_add(config->weights, weight);
 394                         array_add(config->reverses, true);
 395                         array_add(config->partiales, true);
 396                     }
 397                     config->is_hostname = true;
 398                     break;
 399                 }
 400                 if (i != 2) {
 401                     current = p + 1;
 402                     p = m_strchrnul(current, ':');
 403                 }
 404             }
 405           } break;
 406
 407           /* dns parameter.
 408            *  weight:hostname.
 409            * define a RBL to use through DNS resolution.
 410            */
 411           case ATK_DNS: {
 412             int  weight = 0;
 413             const char *current = param->value;
 414             const char *p = m_strchrnul(param->value, ':');
 415             char *next = NULL;
 416             for (int i = 0 ; i < 2 ; ++i) {
 417                 PARSE_CHECK(i == 1 || *p,
 418                             "host parameter must contains a weight option");
 419                 switch (i) {
 420                   case 0:
 421                     weight = strtol(current, &next, 10);
 422                     PARSE_CHECK(next == p && weight >= 0 && weight <= 1024,
 423                                 "illegal weight value %.*s",
 424                                 (int)(p - current), current);
 425                     break;
 426
 427                   case 1:
 428                     array_add(config->host_offsets, array_len(config->hosts));
 429                     array_append(config->hosts, current, strlen(current) + 1);
 430                     array_add(config->host_weights, weight);
 431                     break;
 432                 }
 433                 if (i != 1) {
 434                     current = p + 1;
 435                     p = m_strchrnul(current, ':');
 436                 }
 437             }
 438           } break;
 439
 440           /* hard_threshold parameter is an integer.
 441            *  If the matching score is greater or equal than this threshold,
 442            *  the hook "hard_match" is called.
 443            * hard_threshold = 1 means, that all matches are hard matches.
 444            * default is 1;
 445            */
 446           FILTER_PARAM_PARSE_INT(HARD_THRESHOLD, config->hard_threshold);
 447
 448           /* soft_threshold parameter is an integer.
 449            *  if the matching score is greater or equal than this threshold
 450            *  and smaller or equal than the hard_threshold, the hook "soft_match"
 451            *  is called.
 452            * default is 1;
 453            */
 454           FILTER_PARAM_PARSE_INT(SOFT_THRESHOLD, config->soft_threshold);
 455
 456           /* fields to match againes:
 457            *  fields = field_name(,field_name)*
 458            *  field_names are
 459            *    - hostname: helo_name,client_name,reverse_client_name
 460            *    - email: sender,recipient
 461            */
 462           case ATK_FIELDS: {
 463             const char *current = param->value;
 464             const char *p = m_strchrnul(param->value, ',');
 465             do {
 466                 postlicyd_token tok = policy_tokenize(current, p - current);
 467                 switch (tok) {
 468 #define           CASE(Up, Low, Type)                                          \
 469                   case PTK_ ## Up:                                             \
 470                     config->match_ ## Low = true;                              \
 471                     config->is_ ## Type = true;                                \
 472                     break
 473                   CASE(HELO_NAME, helo, hostname);
 474                   CASE(CLIENT_NAME, client, hostname);
 475                   CASE(REVERSE_CLIENT_NAME, reverse, hostname);
 476                   CASE(SENDER_DOMAIN, sender, hostname);
 477                   CASE(RECIPIENT_DOMAIN, recipient, hostname);
 478                   CASE(SENDER, sender, email);
 479                   CASE(RECIPIENT, recipient, email);
 480 #undef CASE
 481                   default:
 482                     PARSE_CHECK(false, "unknown field %.*s", (int)(p - current), current);
 483                     break;
 484                 }
 485                 if (!*p) {
 486                     break;
 487                 }
 488                 current = p + 1;
 489                 p = m_strchrnul(current, ',');
 490             } while (true);
 491           } break;
 492
 493           default: break;
 494         }
 495     }}
 496
 497     PARSE_CHECK(config->is_email != config->is_hostname,
 498                 "matched field MUST be emails XOR hostnames");
 499     PARSE_CHECK(config->tries.len || config->host_offsets.len,
 500                 "no file parameter in the filter %s", filter->name);
 501     filter->data = config;
 502     return true;
 503 }
 504
 505 static void strlist_filter_destructor(filter_t *filter)
 506 {
 507     strlist_config_t *config = filter->data;
 508     strlist_config_delete(&config);
 509     filter->data = config;
 510 }
 511
 512 static void strlist_filter_async(rbl_result_t *result, void *arg)
 513 {
 514     filter_context_t   *context = arg;
 515     const filter_t      *filter = context->current_filter;
 516     const strlist_config_t *data = filter->data;
 517     strlist_async_data_t  *async = context->contexts[filter_type];
 518
 519     if (*result != RBL_ERROR) {
 520         async->error = false;
 521     }
 522     --async->awaited;
 523
 524     debug("got asynchronous request result for filter %s, rbl %d, still awaiting %d answers",
 525           filter->name, (int)(result - array_ptr(async->results, 0)), async->awaited);
 526
 527     if (async->awaited == 0) {
 528         filter_result_t res = HTK_FAIL;
 529         if (async->error) {
 530             res = HTK_ERROR;
 531         } else {
 532             uint32_t j = 0;
 533 #define DO_SUM(Field)                                                          \
 534         if (data->match_ ## Field) {                                           \
 535             for (uint32_t i = 0 ; i < array_len(data->host_offsets) ; ++i) {   \
 536                 int weight = array_elt(data->host_weights, i);                 \
 537                                                                                \
 538                 switch (array_elt(async->results, j)) {                        \
 539                   case RBL_ASYNC:                                              \
 540                     crit("no more awaited answer but result is ASYNC");        \
 541                     abort();                                                   \
 542                   case RBL_FOUND:                                              \
 543                     async->sum += weight;                                      \
 544                     break;                                                     \
 545                   default:                                                     \
 546                     break;                                                     \
 547                 }                                                              \
 548                 ++j;                                                           \
 549             }                                                                  \
 550         }
 551             DO_SUM(helo);
 552             DO_SUM(client);
 553             DO_SUM(reverse);
 554             DO_SUM(recipient);
 555             DO_SUM(sender);
 556 #undef DO_SUM
 557             debug("score is %d", async->sum);
 558             if (async->sum >= (uint32_t)data->hard_threshold) {
 559                 res = HTK_HARD_MATCH;
 560             } else if (async->sum >= (uint32_t)data->soft_threshold) {
 561                 res = HTK_SOFT_MATCH;
 562             }
 563         }
 564         debug("answering to filter %s", filter->name);
 565         filter_post_async_result(context, res);
 566     }
 567 }
 568
 569
 570 static filter_result_t strlist_filter(const filter_t *filter, const query_t *query,
 571                                       filter_context_t *context)
 572 {
 573     char reverse[BUFSIZ];
 574     char normal[BUFSIZ];
 575     const strlist_config_t *config = filter->data;
 576     strlist_async_data_t *async = context->contexts[filter_type];
 577     int result_pos = 0;
 578     async->sum = 0;
 579     async->error = true;
 580     array_ensure_exact_capacity(async->results, (config->match_client
 581                                 + config->match_sender + config->match_helo
 582                                 + config->match_recipient + config->match_reverse)
 583                                 * array_len(config->host_offsets));
 584     async->awaited = 0;
 585
 586
 587     if (config->is_email &&
 588         ((config->match_sender && query->state < SMTP_MAIL)
 589         || (config->match_recipient && query->state != SMTP_RCPT))) {
 590         warn("trying to match an email against a field that is not "
 591              "available in current protocol state");
 592         return HTK_ABORT;
 593     } else if (config->is_hostname && config->match_helo && query->state < SMTP_HELO) {
 594         warn("trying to match hostname against helo before helo is received");
 595         return HTK_ABORT;
 596     }
 597 #define LOOKUP(Flag, Field)                                                    \
 598     if (config->match_ ## Flag) {                                              \
 599         const int len = m_strlen(query->Field);                                \
 600         strlist_copy(normal, query->Field, len, false);                        \
 601         strlist_copy(reverse, query->Field, len, true);                        \
 602         for (uint32_t i = 0 ; i < config->tries.len ; ++i) {                   \
 603             const int weight   = array_elt(config->weights, i);                \
 604             const trie_t *trie = array_elt(config->tries, i);                  \
 605             const bool rev     = array_elt(config->reverses, i);               \
 606             const bool part    = array_elt(config->partiales, i);              \
 607             if ((!part && trie_lookup(trie, rev ? reverse : normal))           \
 608                 || (part && trie_prefix(trie, rev ? reverse : normal))) {      \
 609                 async->sum += weight;                                          \
 610                 if (async->sum >= (uint32_t)config->hard_threshold) {          \
 611                     return HTK_HARD_MATCH;                                     \
 612                 }                                                              \
 613             }                                                                  \
 614             async->error = false;                                              \
 615         }                                                                      \
 616     }
 617 #define DNS(Flag, Field)                                                       \
 618     if (config->match_ ## Flag) {                                              \
 619         const int len = m_strlen(query->Field);                                \
 620         strlist_copy(normal, query->Field, len, false);                        \
 621         for (uint32_t i = 0 ; len > 0 && i < config->host_offsets.len ; ++i) { \
 622             const char *rbl = array_ptr(config->hosts,                         \
 623                                         array_elt(config->host_offsets, i));   \
 624             debug("running check of field %s (%s) against %s", STR(Field),     \
 625                   normal, rbl);                                                \
 626             if (rhbl_check(rbl, normal, array_ptr(async->results, result_pos), \
 627                            strlist_filter_async, context)) {                   \
 628                 async->error = false;                                          \
 629                 ++async->awaited;                                              \
 630             }                                                                  \
 631             ++result_pos;                                                      \
 632         }                                                                      \
 633     }
 634
 635     if (config->is_email) {
 636         LOOKUP(sender, sender);
 637         LOOKUP(recipient, recipient);
 638         DNS(sender, sender);
 639         DNS(recipient, recipient);
 640     } else if (config->is_hostname) {
 641         LOOKUP(helo, helo_name);
 642         LOOKUP(client, client_name);
 643         LOOKUP(reverse, reverse_client_name);
 644         LOOKUP(recipient, recipient_domain);
 645         LOOKUP(sender, sender_domain);
 646         DNS(helo, helo_name);
 647         DNS(client, client_name);
 648         DNS(reverse, reverse_client_name);
 649         DNS(recipient, recipient_domain);
 650         DNS(sender, sender_domain);
 651     }
 652 #undef  DNS
 653 #undef  LOOKUP
 654     if (async->awaited > 0) {
 655         return HTK_ASYNC;
 656     }
 657     if (async->error) {
 658         err("filter %s: all the rbls returned an error", filter->name);
 659         return HTK_ERROR;
 660     }
 661     if (async->sum >= (uint32_t)config->hard_threshold) {
 662         return HTK_HARD_MATCH;
 663     } else if (async->sum >= (uint32_t)config->soft_threshold) {
 664         return HTK_SOFT_MATCH;
 665     } else {
 666         return HTK_FAIL;
 667     }
 668 }
 669
 670 static void *strlist_context_constructor(void)
 671 {
 672     return p_new(strlist_async_data_t, 1);
 673 }
 674
 675 static void strlist_context_destructor(void *data)
 676 {
 677     strlist_async_data_t *ctx = data;
 678     array_wipe(ctx->results);
 679     p_delete(&ctx);
 680 }
 681
 682 static int strlist_init(void)
 683 {
 684     filter_type =  filter_register("strlist", strlist_filter_constructor,
 685                                    strlist_filter_destructor, strlist_filter,
 686                                    strlist_context_constructor,
 687                                    strlist_context_destructor);
 688     /* Hooks.
 689      */
 690     (void)filter_hook_register(filter_type, "abort");
 691     (void)filter_hook_register(filter_type, "error");
 692     (void)filter_hook_register(filter_type, "fail");
 693     (void)filter_hook_register(filter_type, "hard_match");
 694     (void)filter_hook_register(filter_type, "soft_match");
 695
 696     /* Parameters.
 697      */
 698     (void)filter_param_register(filter_type, "file");
 699     (void)filter_param_register(filter_type, "rbldns");
 700     (void)filter_param_register(filter_type, "dns");
 701     (void)filter_param_register(filter_type, "hard_threshold");
 702     (void)filter_param_register(filter_type, "soft_threshold");
 703     (void)filter_param_register(filter_type, "fields");
 704     return 0;
 705 }
 706 module_init(strlist_init);