src/src/lookups/redis.c

   1 /*************************************************
   2 *     Exim - an Internet mail transport agent    *
   3 *************************************************/
   4
   5 /* Copyright (c) University of Cambridge 1995 - 2015 */
   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(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("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 ssize = 0;
  84 int offset = 0;
  85 int yield = DEFER;
  86 int i, j;
  87 uschar *result = NULL;
  88 uschar *server_copy = NULL;
  89 uschar *tmp, *ttmp;
  90 uschar *sdata[3];
  91
  92 /* Disaggregate the parameters from the server argument.
  93 The order is host:port(socket)
  94 We can write to the string, since it is in a nextinlist temporary buffer.
  95 This copy is also used for debugging output.  */
  96
  97 memset(sdata, 0, sizeof(sdata)) /* Set all to NULL */;
  98 for (i = 2; i > 0; i--)
  99   {
 100   uschar *pp = Ustrrchr(server, '/');
 101
 102   if (!pp)
 103     {
 104     *errmsg = string_sprintf("incomplete Redis server data: %s",
 105       i == 2 ? server : server_copy);
 106     *defer_break = TRUE;
 107     return DEFER;
 108     }
 109   *pp++ = 0;
 110   sdata[i] = pp;
 111   if (i == 2) server_copy = string_copy(server);  /* sans password */
 112   }
 113 sdata[0] = server;   /* What's left at the start */
 114
 115 /* If the database or password is an empty string, set it NULL */
 116 if (sdata[1][0] == 0) sdata[1] = NULL;
 117 if (sdata[2][0] == 0) sdata[2] = NULL;
 118
 119 /* See if we have a cached connection to the server */
 120
 121 for (cn = redis_connections; cn; cn = cn->next)
 122   if (Ustrcmp(cn->server, server_copy) == 0)
 123     {
 124     redis_handle = cn->handle;
 125     break;
 126     }
 127
 128 if (!cn)
 129   {
 130   uschar *p;
 131   uschar *socket = NULL;
 132   int port = 0;
 133   /* int redis_err = REDIS_OK; */
 134
 135   if ((p = Ustrchr(sdata[0], '(')))
 136     {
 137     *p++ = 0;
 138     socket = p;
 139     while (*p != 0 && *p != ')') p++;
 140     *p = 0;
 141     }
 142
 143   if ((p = Ustrchr(sdata[0], ':')))
 144     {
 145     *p++ = 0;
 146     port = Uatoi(p);
 147     }
 148   else
 149     port = Uatoi("6379");
 150
 151   if (Ustrchr(server, '/'))
 152     {
 153     *errmsg = string_sprintf("unexpected slash in Redis server hostname: %s",
 154       sdata[0]);
 155     *defer_break = TRUE;
 156     return DEFER;
 157     }
 158
 159   DEBUG(D_lookup)
 160     debug_printf("REDIS new connection: host=%s port=%d socket=%s database=%s\n",
 161       sdata[0], port, socket, sdata[1]);
 162
 163   /* Get store for a new handle, initialize it, and connect to the server */
 164   /* XXX: Use timeouts ? */
 165   redis_handle =
 166     socket ? redisConnectUnix(CCS socket) : redisConnect(CCS server, port);
 167   if (!redis_handle)
 168     {
 169     *errmsg = string_sprintf("REDIS connection failed");
 170     *defer_break = FALSE;
 171     goto REDIS_EXIT;
 172     }
 173
 174   /* Add the connection to the cache */
 175   cn = store_get(sizeof(redis_connection));
 176   cn->server = server_copy;
 177   cn->handle = redis_handle;
 178   cn->next = redis_connections;
 179   redis_connections = cn;
 180   }
 181 else
 182   {
 183   DEBUG(D_lookup)
 184     debug_printf("REDIS using cached connection for %s\n", server_copy);
 185 }
 186
 187 /* Authenticate if there is a password */
 188 if(sdata[2])
 189   if (!(redis_reply = redisCommand(redis_handle, "AUTH %s", sdata[2])))
 190     {
 191     *errmsg = string_sprintf("REDIS Authentication failed: %s\n", redis_handle->errstr);
 192     *defer_break = FALSE;
 193     goto REDIS_EXIT;
 194     }
 195
 196 /* Select the database if there is a dbnumber passed */
 197 if(sdata[1])
 198   {
 199   if (!(redis_reply = redisCommand(redis_handle, "SELECT %s", sdata[1])))
 200     {
 201     *errmsg = string_sprintf("REDIS: Selecting database=%s failed: %s\n", sdata[1], redis_handle->errstr);
 202     *defer_break = FALSE;
 203     goto REDIS_EXIT;
 204     }
 205   DEBUG(D_lookup) debug_printf("REDIS: Selecting database=%s\n", sdata[1]);
 206   }
 207
 208 /* split string on whitespace into argv */
 209   {
 210   uschar * argv[32];
 211   int i;
 212   const uschar * s = command;
 213   int siz, ptr;
 214   uschar c;
 215
 216   while (isspace(*s)) s++;
 217
 218   for (i = 0; *s && i < nele(argv); i++)
 219     {
 220     for (argv[i] = NULL, siz = ptr = 0; (c = *s) && !isspace(c); s++)
 221       if (c != '\\' || *++s)            /* backslash protects next char */
 222         argv[i] = string_catn(argv[i], &siz, &ptr, s, 1);
 223     *(argv[i]+ptr) = '\0';
 224     DEBUG(D_lookup) debug_printf("REDIS: argv[%d] '%s'\n", i, argv[i]);
 225     while (isspace(*s)) s++;
 226     }
 227
 228   /* Run the command. We use the argv form rather than plain as that parses
 229   into args by whitespace yet has no escaping mechanism. */
 230
 231   redis_reply = redisCommandArgv(redis_handle, i, (const char **) argv, NULL);
 232   if (!redis_reply)
 233     {
 234     *errmsg = string_sprintf("REDIS: query failed: %s\n", redis_handle->errstr);
 235     *defer_break = FALSE;
 236     goto REDIS_EXIT;
 237     }
 238   }
 239
 240 switch (redis_reply->type)
 241   {
 242   case REDIS_REPLY_ERROR:
 243     *errmsg = string_sprintf("REDIS: lookup result failed: %s\n", redis_reply->str);
 244     *defer_break = FALSE;
 245     *do_cache = 0;
 246     goto REDIS_EXIT;
 247     /* NOTREACHED */
 248
 249   case REDIS_REPLY_NIL:
 250     DEBUG(D_lookup)
 251       debug_printf("REDIS: query was not one that returned any data\n");
 252     result = string_sprintf("");
 253     *do_cache = 0;
 254     goto REDIS_EXIT;
 255     /* NOTREACHED */
 256
 257   case REDIS_REPLY_INTEGER:
 258     ttmp = (redis_reply->integer != 0) ? US"true" : US"false";
 259     result = string_cat(result, &ssize, &offset, US ttmp);
 260     break;
 261
 262   case REDIS_REPLY_STRING:
 263   case REDIS_REPLY_STATUS:
 264     result = string_catn(result, &ssize, &offset,
 265                         US redis_reply->str, redis_reply->len);
 266     break;
 267
 268   case REDIS_REPLY_ARRAY:
 269
 270     /* NOTE: For now support 1 nested array result. If needed a limitless
 271     result can be parsed */
 272
 273     for (i = 0; i < redis_reply->elements; i++)
 274       {
 275       entry = redis_reply->element[i];
 276
 277       if (result)
 278         result = string_catn(result, &ssize, &offset, US"\n", 1);
 279
 280       switch (entry->type)
 281         {
 282         case REDIS_REPLY_INTEGER:
 283           tmp = string_sprintf("%d", entry->integer);
 284           result = string_cat(result, &ssize, &offset, US tmp);
 285           break;
 286         case REDIS_REPLY_STRING:
 287           result = string_catn(result, &ssize, &offset,
 288                               US entry->str, entry->len);
 289           break;
 290         case REDIS_REPLY_ARRAY:
 291           for (j = 0; j < entry->elements; j++)
 292             {
 293             tentry = entry->element[j];
 294
 295             if (result)
 296               result = string_catn(result, &ssize, &offset, US"\n", 1);
 297
 298             switch (tentry->type)
 299               {
 300               case REDIS_REPLY_INTEGER:
 301                 ttmp = string_sprintf("%d", tentry->integer);
 302                 result = string_cat(result, &ssize, &offset, US ttmp);
 303                 break;
 304               case REDIS_REPLY_STRING:
 305                 result = string_catn(result, &ssize, &offset,
 306                                     US tentry->str, tentry->len);
 307                 break;
 308               case REDIS_REPLY_ARRAY:
 309                 DEBUG(D_lookup)
 310                   debug_printf("REDIS: result has nesting of arrays which"
 311                     " is not supported. Ignoring!\n");
 312                 break;
 313               default:
 314                 DEBUG(D_lookup) debug_printf(
 315                           "REDIS: result has unsupported type. Ignoring!\n");
 316                 break;
 317               }
 318             }
 319             break;
 320           default:
 321             DEBUG(D_lookup) debug_printf("REDIS: query returned unsupported type\n");
 322             break;
 323           }
 324         }
 325       break;
 326   }
 327
 328
 329 if (result)
 330   {
 331   result[offset] = 0;
 332   store_reset(result + offset + 1);
 333   }
 334 else
 335   {
 336   yield = FAIL;
 337   *errmsg = US"REDIS: no data found";
 338   }
 339
 340 REDIS_EXIT:
 341
 342 /* Free store for any result that was got; don't close the connection,
 343 as it is cached. */
 344
 345 if (redis_reply) freeReplyObject(redis_reply);
 346
 347 /* Non-NULL result indicates a sucessful result */
 348
 349 if (result)
 350   {
 351   *resultptr = result;
 352   return OK;
 353   }
 354 else
 355   {
 356   DEBUG(D_lookup) debug_printf("%s\n", *errmsg);
 357   /* NOTE: Required to close connection since it needs to be reopened */
 358   return yield;      /* FAIL or DEFER */
 359   }
 360 }
 361
 362
 363
 364 /*************************************************
 365 *               Find entry point                 *
 366 *************************************************/
 367 /*
 368  * See local README for interface description. The handle and filename
 369  * arguments are not used. The code to loop through a list of servers while the
 370  * query is deferred with a retryable error is now in a separate function that is
 371  * shared with other noSQL lookups.
 372  */
 373
 374 static int
 375 redis_find(void *handle __attribute__((unused)),
 376   uschar *filename __attribute__((unused)),
 377   const uschar *command, int length, uschar **result, uschar **errmsg,
 378   uint *do_cache)
 379 {
 380 return lf_sqlperform(US"Redis", US"redis_servers", redis_servers, command,
 381   result, errmsg, do_cache, perform_redis_search);
 382 }
 383
 384
 385
 386 /*************************************************
 387 *               Quote entry point                *
 388 *************************************************/
 389
 390 /* Prefix any whitespace, or backslash, with a backslash.
 391 This is not a Redis thing but instead to let the argv splitting
 392 we do to split on whitespace, yet provide means for getting
 393 whitespace into an argument.
 394
 395 Arguments:
 396   s          the string to be quoted
 397   opt        additional option text or NULL if none
 398
 399 Returns:     the processed string or NULL for a bad option
 400 */
 401
 402 static uschar *
 403 redis_quote(uschar *s, uschar *opt)
 404 {
 405 register int c;
 406 int count = 0;
 407 uschar *t = s;
 408 uschar *quoted;
 409
 410 if (opt) return NULL;     /* No options recognized */
 411
 412 while ((c = *t++) != 0)
 413   if (isspace(c) || c == '\\') count++;
 414
 415 if (count == 0) return s;
 416 t = quoted = store_get(Ustrlen(s) + count + 1);
 417
 418 while ((c = *s++) != 0)
 419   {
 420   if (isspace(c) || c == '\\') *t++ = '\\';
 421   *t++ = c;
 422   }
 423
 424 *t = 0;
 425 return quoted;
 426 }
 427
 428
 429 /*************************************************
 430 *         Version reporting entry point          *
 431 *************************************************/
 432 #include "../version.h"
 433
 434 void
 435 redis_version_report(FILE *f)
 436 {
 437 fprintf(f, "Library version: REDIS: Compile: %d [%d]\n",
 438                HIREDIS_MAJOR, HIREDIS_MINOR);
 439 #ifdef DYNLOOKUP
 440 fprintf(f, "                        Exim version %s\n", EXIM_VERSION_STR);
 441 #endif
 442 }
 443
 444
 445
 446 /* These are the lookup_info blocks for this driver */
 447 static lookup_info redis_lookup_info = {
 448   US"redis",                     /* lookup name */
 449   lookup_querystyle,             /* query-style lookup */
 450   redis_open,                    /* open function */
 451   NULL,                          /* no check function */
 452   redis_find,                    /* find function */
 453   NULL,                          /* no close function */
 454   redis_tidy,                    /* tidy function */
 455   redis_quote,                   /* quoting function */
 456   redis_version_report           /* version reporting */
 457 };
 458
 459 #ifdef DYNLOOKUP
 460 # define redis_lookup_module_info _lookup_module_info
 461 #endif /* DYNLOOKUP */
 462
 463 static lookup_info *_lookup_list[] = { &redis_lookup_info };
 464 lookup_module_info redis_lookup_module_info = { LOOKUP_MODULE_INFO_MAGIC, _lookup_list, 1 };
 465
 466 #endif /* LOOKUP_REDIS */
 467 /* End of lookups/redis.c */