postlicyd/strlist.c

   1 /******************************************************************************/
   2 /*          pfixtools: a collection of postfix related tools                  */
   3 /*          ~~~~~~~~~                                                         */
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   5 /*                                                                            */
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  14 /*     documentation and/or other materials provided with the distribution.   */
  15 /*  3. The names of its contributors may not be used to endorse or promote    */
  16 /*     products derived from this software without specific prior written     */
  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        */
  22 /*  PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS    */
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  25 /*  SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS  */
  26 /*  INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN   */
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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 "policy_tokens.h"
  41
  42 typedef struct strlist_config_t {
  43     PA(trie_t) tries;
  44     A(int)     weights;
  45     A(bool)    reverses;
  46     A(bool)    partiales;
  47
  48     int soft_threshold;
  49     int hard_threshold;
  50
  51     unsigned is_email         :1;
  52     unsigned is_hostname      :1;
  53
  54     unsigned match_sender     :1;
  55     unsigned match_recipient  :1;
  56
  57     unsigned match_helo       :1;
  58     unsigned match_client     :1;
  59     unsigned match_reverse    :1;
  60 } strlist_config_t;
  61
  62
  63 static strlist_config_t *strlist_config_new(void)
  64 {
  65     return p_new(strlist_config_t, 1);
  66 }
  67
  68 static void strlist_config_delete(strlist_config_t **config)
  69 {
  70     if (*config) {
  71         array_deep_wipe((*config)->tries, trie_delete);
  72         array_wipe((*config)->weights);
  73         array_wipe((*config)->reverses);
  74         array_wipe((*config)->partiales);
  75         p_delete(config);
  76     }
  77 }
  78
  79 static inline void strlist_copy(char *dest, const char *str, ssize_t str_len,
  80                                 bool reverse)
  81 {
  82     if (str_len > 0) {
  83         if (reverse) {
  84             for (const char *src = str + str_len - 1 ; src >= str ; --src) {
  85                 *dest = ascii_tolower(*src);
  86                 ++dest;
  87             }
  88         } else {
  89             for (int i = 0 ; i < str_len ; ++i) {
  90                 *dest = ascii_tolower(str[i]);
  91                 ++dest;
  92             }
  93         }
  94     }
  95     *dest = '\0';
  96 }
  97
  98
  99 static trie_t *strlist_create(const char *file, bool reverse, bool lock)
 100 {
 101     trie_t *db;
 102     file_map_t map;
 103     const char *p, *end;
 104     char line[BUFSIZ];
 105
 106     if (!file_map_open(&map, file, false)) {
 107         return NULL;
 108     }
 109     p   = map.map;
 110     end = map.end;
 111     while (end > p && end[-1] != '\n') {
 112         --end;
 113     }
 114     if (end != map.end) {
 115         warn("file %s miss a final \\n, ignoring last line",
 116              file);
 117     }
 118
 119     db = trie_new();
 120     while (p < end && p != NULL) {
 121         const char *eol = (char *)memchr(p, '\n', end - p);
 122         if (eol == NULL) {
 123             eol = end;
 124         }
 125         if (eol - p >= BUFSIZ) {
 126             err("unreasonnable long line");
 127             file_map_close(&map);
 128             trie_delete(&db);
 129             return NULL;
 130         }
 131         if (*p != '#') {
 132             const char *eos = eol;
 133             while (p < eos && isspace(*p)) {
 134                 ++p;
 135             }
 136             while (p < eos && isspace(eos[-1])) {
 137                 --eos;
 138             }
 139             if (p < eos) {
 140                 strlist_copy(line, p, eos - p, reverse);
 141                 trie_insert(db, line);
 142             }
 143         }
 144         p = eol + 1;
 145     }
 146     file_map_close(&map);
 147     trie_compile(db, lock);
 148     return db;
 149 }
 150
 151
 152 static bool strlist_filter_constructor(filter_t *filter)
 153 {
 154     strlist_config_t *config = strlist_config_new();
 155
 156 #define PARSE_CHECK(Expr, Str, ...)                                            \
 157     if (!(Expr)) {                                                             \
 158         err(Str, ##__VA_ARGS__);                                               \
 159         strlist_config_delete(&config);                                        \
 160         return false;                                                          \
 161     }
 162
 163     config->hard_threshold = 1;
 164     config->soft_threshold = 1;
 165     foreach (filter_param_t *param, filter->params) {
 166         switch (param->type) {
 167           /* file parameter is:
 168            *  [no]lock:(prefix|suffix):weight:filename
 169            *  valid options are:
 170            *    - lock:   memlock the database in memory.
 171            *    - nolock: don't memlock the database in memory.
 172            *    - prefix: perform "prefix" compression on storage.
 173            *    - suffix  perform "suffix" compression on storage.
 174            *    - \d+:    a number describing the weight to give to the match
 175            *              the given list [mandatory]
 176            *  the file pointed by filename MUST be a valid string list (one string per
 177            *  line, empty lines and lines beginning with a '#' are ignored).
 178            */
 179           case ATK_FILE: {
 180             bool lock = false;
 181             int  weight = 0;
 182             bool reverse = false;
 183             bool partial = false;
 184             trie_t *trie = NULL;
 185             const char *current = param->value;
 186             const char *p = m_strchrnul(param->value, ':');
 187             char *next = NULL;
 188             for (int i = 0 ; i < 4 ; ++i) {
 189                 PARSE_CHECK(i == 3 || *p,
 190                             "file parameter must contains a locking state "
 191                             "and a weight option");
 192                 switch (i) {
 193                   case 0:
 194                     if ((p - current) == 4 && strncmp(current, "lock", 4) == 0) {
 195                         lock = true;
 196                     } else if ((p - current) == 6 && strncmp(current, "nolock", 6) == 0) {
 197                         lock = false;
 198                     } else {
 199                         PARSE_CHECK(false, "illegal locking state %.*s",
 200                                     p - current, current);
 201                     }
 202                     break;
 203
 204                   case 1:
 205                     if (p - current > (ssize_t)strlen("partial-")
 206                         && strncmp(current, "partial-", strlen("partial-")) == 0) {
 207                         partial = true;
 208                         current += strlen("partial-");
 209                     }
 210                     if ((p - current) == 6 && strncmp(current, "suffix", 6) == 0) {
 211                         reverse = true;
 212                     } else if ((p - current) == 6 && strncmp(current, "prefix", 6) == 0) {
 213                         reverse = false;
 214                     } else {
 215                         PARSE_CHECK(false, "illegal character order value %.*s",
 216                                     p - current, current);
 217                     }
 218                     break;
 219
 220                   case 2:
 221                     weight = strtol(current, &next, 10);
 222                     PARSE_CHECK(next == p && weight >= 0 && weight <= 1024,
 223                                 "illegal weight value %.*s",
 224                                 (p - current), current);
 225                     break;
 226
 227                   case 3:
 228                     trie = strlist_create(current, reverse, lock);
 229                     PARSE_CHECK(trie != NULL,
 230                                 "cannot load string list from %s", current);
 231                     array_add(config->tries, trie);
 232                     array_add(config->weights, weight);
 233                     array_add(config->reverses, reverse);
 234                     array_add(config->partiales, partial);
 235                     break;
 236                 }
 237                 if (i != 3) {
 238                     current = p + 1;
 239                     p = m_strchrnul(current, ':');
 240                 }
 241             }
 242           } break;
 243
 244           /* hard_threshold parameter is an integer.
 245            *  If the matching score is greater or equal than this threshold,
 246            *  the hook "hard_match" is called.
 247            * hard_threshold = 1 means, that all matches are hard matches.
 248            * default is 1;
 249            */
 250           FILTER_PARAM_PARSE_INT(HARD_THRESHOLD, config->hard_threshold);
 251
 252           /* soft_threshold parameter is an integer.
 253            *  if the matching score is greater or equal than this threshold
 254            *  and smaller or equal than the hard_threshold, the hook "soft_match"
 255            *  is called.
 256            * default is 1;
 257            */
 258           FILTER_PARAM_PARSE_INT(SOFT_THRESHOLD, config->soft_threshold);
 259
 260           /* fields to match againes:
 261            *  fields = field_name(,field_name)*
 262            *  field_names are
 263            *    - hostname: helo_name,client_name,reverse_client_name
 264            *    - email: sender,recipient
 265            */
 266           case ATK_FIELDS: {
 267             const char *current = param->value;
 268             const char *p = m_strchrnul(param->value, ',');
 269             do {
 270                 postlicyd_token tok = policy_tokenize(current, p - current);
 271                 switch (tok) {
 272 #define           CASE(Up, Low, Type)                                          \
 273                   case PTK_ ## Up:                                             \
 274                     config->match_ ## Low = true;                              \
 275                     config->is_ ## Type = true;                                \
 276                     break
 277                   CASE(HELO_NAME, helo, hostname);
 278                   CASE(CLIENT_NAME, client, hostname);
 279                   CASE(REVERSE_CLIENT_NAME, reverse, hostname);
 280                   CASE(SENDER_DOMAIN, sender, hostname);
 281                   CASE(RECIPIENT_DOMAIN, recipient, hostname);
 282                   CASE(SENDER, sender, email);
 283                   CASE(RECIPIENT, recipient, email);
 284 #undef CASE
 285                   default:
 286                     PARSE_CHECK(false, "unknown field %.*s", p - current, current);
 287                     break;
 288                 }
 289                 if (!*p) {
 290                     break;
 291                 }
 292                 current = p + 1;
 293                 p = m_strchrnul(current, ',');
 294             } while (true);
 295           } break;
 296
 297           default: break;
 298         }
 299     }}
 300
 301     PARSE_CHECK(config->is_email != config->is_hostname,
 302                 "matched field MUST be emails XOR hostnames");
 303     PARSE_CHECK(config->tries.len,
 304                 "no file parameter in the filter %s", filter->name);
 305     filter->data = config;
 306     return true;
 307 }
 308
 309 static void strlist_filter_destructor(filter_t *filter)
 310 {
 311     strlist_config_t *config = filter->data;
 312     strlist_config_delete(&config);
 313     filter->data = config;
 314 }
 315
 316 static filter_result_t strlist_filter(const filter_t *filter, const query_t *query)
 317 {
 318     char reverse[BUFSIZ];
 319     char normal[BUFSIZ];
 320     const strlist_config_t *config = filter->data;
 321     int sum = 0;
 322     if (config->is_email &&
 323         ((config->match_sender && query->state < SMTP_MAIL)
 324         || (config->match_recipient && query->state != SMTP_RCPT))) {
 325         warn("trying to match an email against a field that is not "
 326              "available in current protocol state");
 327         return HTK_ABORT;
 328     } else if (config->is_hostname && config->match_helo && query->state < SMTP_HELO) {
 329         warn("trying to match hostname against helo before helo is received");
 330         return HTK_ABORT;
 331     }
 332 #define LOOKUP(Flag, Field)                                                    \
 333     if (config->match_ ## Flag) {                                              \
 334         const int len = m_strlen(query->Field);                                \
 335         strlist_copy(normal, query->Field, len, false);                        \
 336         strlist_copy(reverse, query->Field, len, true);                        \
 337         for (uint32_t i = 0 ; i < config->tries.len ; ++i) {                   \
 338             const int weight   = array_elt(config->weights, i);                \
 339             const trie_t *trie = array_elt(config->tries, i);                  \
 340             const bool rev     = array_elt(config->reverses, i);               \
 341             const bool part    = array_elt(config->partiales, i);              \
 342             if ((!part && trie_lookup(trie, rev ? reverse : normal))           \
 343                 || (part && trie_prefix(trie, rev ? reverse : normal))) {      \
 344                 sum += weight;                                                 \
 345                 if (sum >= config->hard_threshold) {                           \
 346                     return HTK_HARD_MATCH;                                     \
 347                 }                                                              \
 348             }                                                                  \
 349         }                                                                      \
 350     }
 351     if (config->is_email) {
 352         LOOKUP(sender, sender);
 353         LOOKUP(recipient, recipient);
 354     } else if (config->is_hostname) {
 355         LOOKUP(helo, helo_name);
 356         LOOKUP(client, client_name);
 357         LOOKUP(reverse, reverse_client_name);
 358         LOOKUP(recipient, recipient_domain);
 359         LOOKUP(sender, sender_domain);
 360     }
 361 #undef  LOOKUP
 362     if (sum >= config->hard_threshold) {
 363         return HTK_HARD_MATCH;
 364     } else if (sum >= config->soft_threshold) {
 365         return HTK_SOFT_MATCH;
 366     } else {
 367         return HTK_FAIL;
 368     }
 369 }
 370
 371 static int strlist_init(void)
 372 {
 373     filter_type_t type =  filter_register("strlist", strlist_filter_constructor,
 374                                           strlist_filter_destructor, strlist_filter);
 375     /* Hooks.
 376      */
 377     (void)filter_hook_register(type, "abort");
 378     (void)filter_hook_register(type, "error");
 379     (void)filter_hook_register(type, "fail");
 380     (void)filter_hook_register(type, "hard_match");
 381     (void)filter_hook_register(type, "soft_match");
 382
 383     /* Parameters.
 384      */
 385     (void)filter_param_register(type, "file");
 386     (void)filter_param_register(type, "hard_threshold");
 387     (void)filter_param_register(type, "soft_threshold");
 388     (void)filter_param_register(type, "fields");
 389     return 0;
 390 }
 391 module_init(strlist_init);