src/src/lookups/redis.c

   1 /*************************************************
   2 *     Exim - an Internet mail transport agent    *
   3 *************************************************/
   4
   5 /* Copyright (c) University of Cambridge 1995 - 2018 */
   6 /* See the file NOTICE for conditions of use and distribution. */
   7
   8 #include "../exim.h"
   9
  10 #ifdef LOOKUP_REDIS
  11
  12 #include "lf_functions.h"
  13
  14 #include <hiredis/hiredis.h>
  15
  16 #ifndef nele
  17 # define nele(arr) (sizeof(arr) / sizeof(*arr))
  18 #endif
  19
  20 /* Structure and anchor for caching connections. */
  21 typedef struct redis_connection {
  22   struct redis_connection *next;
  23   uschar  *server;
  24   redisContext    *handle;
  25 } redis_connection;
  26
  27 static redis_connection *redis_connections = NULL;
  28
  29
  30 static void *
  31 redis_open(const uschar * filename, uschar ** errmsg)
  32 {
  33 return (void *)(1);
  34 }
  35
  36
  37 void
  38 redis_tidy(void)
  39 {
  40 redis_connection *cn;
  41
  42 /* XXX: Not sure how often this is called!
  43  Guess its called after every lookup which probably would mean to just
  44  not use the _tidy() function at all and leave with exim exiting to
  45  GC connections!  */
  46
  47 while ((cn = redis_connections))
  48   {
  49   redis_connections = cn->next;
  50   DEBUG(D_lookup) debug_printf_indent("close REDIS connection: %s\n", cn->server);
  51   redisFree(cn->handle);
  52   }
  53 }
  54
  55
  56 /* This function is called from the find entry point to do the search for a
  57 single server.
  58
  59     Arguments:
  60       query        the query string
  61       server       the server string
  62       resultptr    where to store the result
  63       errmsg       where to point an error message
  64       defer_break  TRUE if no more servers are to be tried after DEFER
  65       do_cache     set false if data is changed
  66
  67     The server string is of the form "host/dbnumber/password". The host can be
  68     host:port. This string is in a nextinlist temporary buffer, so can be
  69     overwritten.
  70
  71     Returns:       OK, FAIL, or DEFER
  72 */
  73
  74 static int
  75 perform_redis_search(const uschar *command, uschar *server, uschar **resultptr,
  76   uschar **errmsg, BOOL *defer_break, uint *do_cache)
  77 {
  78 redisContext *redis_handle = NULL;        /* Keep compilers happy */
  79 redisReply *redis_reply = NULL;
  80 redisReply *entry = NULL;
  81 redisReply *tentry = NULL;
  82 redis_connection *cn;
  83 int yield = DEFER;
  84 int i, j;
  85 gstring * result = NULL;
  86 uschar *server_copy = NULL;
  87 uschar *sdata[3];
  88
  89 /* Disaggregate the parameters from the server argument.
  90 The order is host:port(socket)
  91 We can write to the string, since it is in a nextinlist temporary buffer.
  92 This copy is also used for debugging output.  */
  93
  94 memset(sdata, 0, sizeof(sdata)) /* Set all to NULL */;
  95 for (int i = 2; i > 0; i--)
  96   {
  97   uschar *pp = Ustrrchr(server, '/');
  98
  99   if (!pp)
 100     {
 101     *errmsg = string_sprintf("incomplete Redis server data: %s",
 102       i == 2 ? server : server_copy);
 103     *defer_break = TRUE;
 104     return DEFER;
 105     }
 106   *pp++ = 0;
 107   sdata[i] = pp;
 108   if (i == 2) server_copy = string_copy(server);  /* sans password */
 109   }
 110 sdata[0] = server;   /* What's left at the start */
 111
 112 /* If the database or password is an empty string, set it NULL */
 113 if (sdata[1][0] == 0) sdata[1] = NULL;
 114 if (sdata[2][0] == 0) sdata[2] = NULL;
 115
 116 /* See if we have a cached connection to the server */
 117
 118 for (cn = redis_connections; cn; cn = cn->next)
 119   if (Ustrcmp(cn->server, server_copy) == 0)
 120     {
 121     redis_handle = cn->handle;
 122     break;
 123     }
 124
 125 if (!cn)
 126   {
 127   uschar *p;
 128   uschar *socket = NULL;
 129   int port = 0;
 130   /* int redis_err = REDIS_OK; */
 131
 132   if ((p = Ustrchr(sdata[0], '(')))
 133     {
 134     *p++ = 0;
 135     socket = p;
 136     while (*p != 0 && *p != ')') p++;
 137     *p = 0;
 138     }
 139
 140   if ((p = Ustrchr(sdata[0], ':')))
 141     {
 142     *p++ = 0;
 143     port = Uatoi(p);
 144     }
 145   else
 146     port = Uatoi("6379");
 147
 148   if (Ustrchr(server, '/'))
 149     {
 150     *errmsg = string_sprintf("unexpected slash in Redis server hostname: %s",
 151       sdata[0]);
 152     *defer_break = TRUE;
 153     return DEFER;
 154     }
 155
 156   DEBUG(D_lookup)
 157     debug_printf_indent("REDIS new connection: host=%s port=%d socket=%s database=%s\n",
 158       sdata[0], port, socket, sdata[1]);
 159
 160   /* Get store for a new handle, initialize it, and connect to the server */
 161   /* XXX: Use timeouts ? */
 162   redis_handle =
 163     socket ? redisConnectUnix(CCS socket) : redisConnect(CCS server, port);
 164   if (!redis_handle)
 165     {
 166     *errmsg = US"REDIS connection failed";
 167     *defer_break = FALSE;
 168     goto REDIS_EXIT;
 169     }
 170
 171   /* Add the connection to the cache */
 172   cn = store_get(sizeof(redis_connection), FALSE);
 173   cn->server = server_copy;
 174   cn->handle = redis_handle;
 175   cn->next = redis_connections;
 176   redis_connections = cn;
 177   }
 178 else
 179   {
 180   DEBUG(D_lookup)
 181     debug_printf_indent("REDIS using cached connection for %s\n", server_copy);
 182 }
 183
 184 /* Authenticate if there is a password */
 185 if(sdata[2])
 186   if (!(redis_reply = redisCommand(redis_handle, "AUTH %s", sdata[2])))
 187     {
 188     *errmsg = string_sprintf("REDIS Authentication failed: %s\n", redis_handle->errstr);
 189     *defer_break = FALSE;
 190     goto REDIS_EXIT;
 191     }
 192
 193 /* Select the database if there is a dbnumber passed */
 194 if(sdata[1])
 195   {
 196   if (!(redis_reply = redisCommand(redis_handle, "SELECT %s", sdata[1])))
 197     {
 198     *errmsg = string_sprintf("REDIS: Selecting database=%s failed: %s\n", sdata[1], redis_handle->errstr);
 199     *defer_break = FALSE;
 200     goto REDIS_EXIT;
 201     }
 202   DEBUG(D_lookup) debug_printf_indent("REDIS: Selecting database=%s\n", sdata[1]);
 203   }
 204
 205 /* split string on whitespace into argv */
 206   {
 207   uschar * argv[32];
 208   const uschar * s = command;
 209   int siz, ptr, i;
 210   uschar c;
 211
 212   while (isspace(*s)) s++;
 213
 214   for (i = 0; *s && i < nele(argv); i++)
 215     {
 216     gstring * g;
 217
 218     for (g = NULL; (c = *s) && !isspace(c); s++)
 219       if (c != '\\' || *++s)            /* backslash protects next char */
 220         g = string_catn(g, s, 1);
 221     argv[i] = string_from_gstring(g);
 222
 223     DEBUG(D_lookup) debug_printf_indent("REDIS: argv[%d] '%s'\n", i, argv[i]);
 224     while (isspace(*s)) s++;
 225     }
 226
 227   /* Run the command. We use the argv form rather than plain as that parses
 228   into args by whitespace yet has no escaping mechanism. */
 229
 230   if (!(redis_reply = redisCommandArgv(redis_handle, i, CCSS argv, NULL)))
 231     {
 232     *errmsg = string_sprintf("REDIS: query failed: %s\n", redis_handle->errstr);
 233     *defer_break = FALSE;
 234     goto REDIS_EXIT;
 235     }
 236   }
 237
 238 switch (redis_reply->type)
 239   {
 240   case REDIS_REPLY_ERROR:
 241     *errmsg = string_sprintf("REDIS: lookup result failed: %s\n", redis_reply->str);
 242
 243     /* trap MOVED cluster responses and follow them */
 244     if (Ustrncmp(redis_reply->str, "MOVED", 5) == 0)
 245       {
 246       DEBUG(D_lookup)
 247         debug_printf_indent("REDIS: cluster redirect %s\n", redis_reply->str);
 248       /* follow redirect
 249       This is cheating, we simply set defer_break = FALSE to move on to
 250       the next server in the redis_servers list */
 251       *defer_break = FALSE;
 252       return DEFER;
 253       } else {
 254       *defer_break = TRUE;
 255       }
 256     *do_cache = 0;
 257     goto REDIS_EXIT;
 258     /* NOTREACHED */
 259
 260   case REDIS_REPLY_NIL:
 261     DEBUG(D_lookup)
 262       debug_printf_indent("REDIS: query was not one that returned any data\n");
 263     result = string_catn(result, US"", 1);
 264     *do_cache = 0;
 265     goto REDIS_EXIT;
 266     /* NOTREACHED */
 267
 268   case REDIS_REPLY_INTEGER:
 269     result = string_cat(result, redis_reply->integer != 0 ? US"true" : US"false");
 270     break;
 271
 272   case REDIS_REPLY_STRING:
 273   case REDIS_REPLY_STATUS:
 274     result = string_catn(result, US redis_reply->str, redis_reply->len);
 275     break;
 276
 277   case REDIS_REPLY_ARRAY:
 278
 279     /* NOTE: For now support 1 nested array result. If needed a limitless
 280     result can be parsed */
 281
 282     for (int i = 0; i < redis_reply->elements; i++)
 283       {
 284       entry = redis_reply->element[i];
 285
 286       if (result)
 287         result = string_catn(result, US"\n", 1);
 288
 289       switch (entry->type)
 290         {
 291         case REDIS_REPLY_INTEGER:
 292           result = string_fmt_append(result, "%d", entry->integer);
 293           break;
 294         case REDIS_REPLY_STRING:
 295           result = string_catn(result, US entry->str, entry->len);
 296           break;
 297         case REDIS_REPLY_ARRAY:
 298           for (int j = 0; j < entry->elements; j++)
 299             {
 300             tentry = entry->element[j];
 301
 302             if (result)
 303               result = string_catn(result, US"\n", 1);
 304
 305             switch (tentry->type)
 306               {
 307               case REDIS_REPLY_INTEGER:
 308                 result = string_fmt_append(result, "%d", tentry->integer);
 309                 break;
 310               case REDIS_REPLY_STRING:
 311                 result = string_catn(result, US tentry->str, tentry->len);
 312                 break;
 313               case REDIS_REPLY_ARRAY:
 314                 DEBUG(D_lookup)
 315                   debug_printf_indent("REDIS: result has nesting of arrays which"
 316                     " is not supported. Ignoring!\n");
 317                 break;
 318               default:
 319                 DEBUG(D_lookup) debug_printf_indent(
 320                           "REDIS: result has unsupported type. Ignoring!\n");
 321                 break;
 322               }
 323             }
 324             break;
 325           default:
 326             DEBUG(D_lookup) debug_printf_indent("REDIS: query returned unsupported type\n");
 327             break;
 328           }
 329         }
 330       break;
 331   }
 332
 333
 334 if (result)
 335   gstring_release_unused(result);
 336 else
 337   {
 338   yield = FAIL;
 339   *errmsg = US"REDIS: no data found";
 340   }
 341
 342 REDIS_EXIT:
 343
 344 /* Free store for any result that was got; don't close the connection,
 345 as it is cached. */
 346
 347 if (redis_reply) freeReplyObject(redis_reply);
 348
 349 /* Non-NULL result indicates a successful result */
 350
 351 if (result)
 352   {
 353   *resultptr = string_from_gstring(result);
 354   return OK;
 355   }
 356 else
 357   {
 358   DEBUG(D_lookup) debug_printf_indent("%s\n", *errmsg);
 359   /* NOTE: Required to close connection since it needs to be reopened */
 360   return yield;      /* FAIL or DEFER */
 361   }
 362 }
 363
 364
 365
 366 /*************************************************
 367 *               Find entry point                 *
 368 *************************************************/
 369 /*
 370  * See local README for interface description. The handle and filename
 371  * arguments are not used. The code to loop through a list of servers while the
 372  * query is deferred with a retryable error is now in a separate function that is
 373  * shared with other noSQL lookups.
 374  */
 375
 376 static int
 377 redis_find(void * handle __attribute__((unused)),
 378   const uschar * filename __attribute__((unused)),
 379   const uschar * command, int length, uschar ** result, uschar ** errmsg,
 380   uint * do_cache)
 381 {
 382 return lf_sqlperform(US"Redis", US"redis_servers", redis_servers, command,
 383   result, errmsg, do_cache, perform_redis_search);
 384 }
 385
 386
 387
 388 /*************************************************
 389 *               Quote entry point                *
 390 *************************************************/
 391
 392 /* Prefix any whitespace, or backslash, with a backslash.
 393 This is not a Redis thing but instead to let the argv splitting
 394 we do to split on whitespace, yet provide means for getting
 395 whitespace into an argument.
 396
 397 Arguments:
 398   s          the string to be quoted
 399   opt        additional option text or NULL if none
 400
 401 Returns:     the processed string or NULL for a bad option
 402 */
 403
 404 static uschar *
 405 redis_quote(uschar *s, uschar *opt)
 406 {
 407 register int c;
 408 int count = 0;
 409 uschar *t = s;
 410 uschar *quoted;
 411
 412 if (opt) return NULL;     /* No options recognized */
 413
 414 while ((c = *t++) != 0)
 415   if (isspace(c) || c == '\\') count++;
 416
 417 if (count == 0) return s;
 418 t = quoted = store_get(Ustrlen(s) + count + 1, is_tainted(s));
 419
 420 while ((c = *s++) != 0)
 421   {
 422   if (isspace(c) || c == '\\') *t++ = '\\';
 423   *t++ = c;
 424   }
 425
 426 *t = 0;
 427 return quoted;
 428 }
 429
 430
 431 /*************************************************
 432 *         Version reporting entry point          *
 433 *************************************************/
 434 #include "../version.h"
 435
 436 void
 437 redis_version_report(FILE *f)
 438 {
 439 fprintf(f, "Library version: REDIS: Compile: %d [%d]\n",
 440                HIREDIS_MAJOR, HIREDIS_MINOR);
 441 #ifdef DYNLOOKUP
 442 fprintf(f, "                        Exim version %s\n", EXIM_VERSION_STR);
 443 #endif
 444 }
 445
 446
 447
 448 /* These are the lookup_info blocks for this driver */
 449 static lookup_info redis_lookup_info = {
 450   US"redis",                     /* lookup name */
 451   lookup_querystyle,             /* query-style lookup */
 452   redis_open,                    /* open function */
 453   NULL,                          /* no check function */
 454   redis_find,                    /* find function */
 455   NULL,                          /* no close function */
 456   redis_tidy,                    /* tidy function */
 457   redis_quote,                   /* quoting function */
 458   redis_version_report           /* version reporting */
 459 };
 460
 461 #ifdef DYNLOOKUP
 462 # define redis_lookup_module_info _lookup_module_info
 463 #endif /* DYNLOOKUP */
 464
 465 static lookup_info *_lookup_list[] = { &redis_lookup_info };
 466 lookup_module_info redis_lookup_module_info = { LOOKUP_MODULE_INFO_MAGIC, _lookup_list, 1 };
 467
 468 #endif /* LOOKUP_REDIS */
 469 /* End of lookups/redis.c */