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(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 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 (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("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 = string_sprintf("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));
 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("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("REDIS: Selecting database=%s\n", sdata[1]);
 203   }
 204
 205 /* split string on whitespace into argv */
 206   {
 207   uschar * argv[32];
 208   int i;
 209   const uschar * s = command;
 210   int siz, ptr;
 211   uschar c;
 212
 213   while (isspace(*s)) s++;
 214
 215   for (i = 0; *s && i < nele(argv); i++)
 216     {
 217     gstring * g;
 218
 219     for (g = NULL; (c = *s) && !isspace(c); s++)
 220       if (c != '\\' || *++s)            /* backslash protects next char */
 221         g = string_catn(g, s, 1);
 222     argv[i] = string_from_gstring(g);
 223
 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
 245     /* trap MOVED cluster responses and follow them */
 246     if (Ustrncmp(redis_reply->str, "MOVED", 5))
 247       {
 248       DEBUG(D_lookup)
 249         debug_printf("REDIS: cluster redirect %s\n", redis_reply->str);
 250       /* follow redirect
 251       This is cheating, we simply set defer_break = TRUE to move on to
 252       the next server in the redis_servers list */
 253       *defer_break = TRUE;
 254       return DEFER;
 255       } else {
 256       *defer_break = FALSE;
 257       }
 258     *do_cache = 0;
 259     goto REDIS_EXIT;
 260     /* NOTREACHED */
 261
 262   case REDIS_REPLY_NIL:
 263     DEBUG(D_lookup)
 264       debug_printf("REDIS: query was not one that returned any data\n");
 265     result = string_catn(result, US"", 1);
 266     *do_cache = 0;
 267     goto REDIS_EXIT;
 268     /* NOTREACHED */
 269
 270   case REDIS_REPLY_INTEGER:
 271     result = string_cat(result, redis_reply->integer != 0 ? US"true" : US"false");
 272     break;
 273
 274   case REDIS_REPLY_STRING:
 275   case REDIS_REPLY_STATUS:
 276     result = string_catn(result, US redis_reply->str, redis_reply->len);
 277     break;
 278
 279   case REDIS_REPLY_ARRAY:
 280
 281     /* NOTE: For now support 1 nested array result. If needed a limitless
 282     result can be parsed */
 283
 284     for (i = 0; i < redis_reply->elements; i++)
 285       {
 286       entry = redis_reply->element[i];
 287
 288       if (result)
 289         result = string_catn(result, US"\n", 1);
 290
 291       switch (entry->type)
 292         {
 293         case REDIS_REPLY_INTEGER:
 294           result = string_cat(result, string_sprintf("%d", entry->integer));
 295           break;
 296         case REDIS_REPLY_STRING:
 297           result = string_catn(result, US entry->str, entry->len);
 298           break;
 299         case REDIS_REPLY_ARRAY:
 300           for (j = 0; j < entry->elements; j++)
 301             {
 302             tentry = entry->element[j];
 303
 304             if (result)
 305               result = string_catn(result, US"\n", 1);
 306
 307             switch (tentry->type)
 308               {
 309               case REDIS_REPLY_INTEGER:
 310                 result = string_cat(result, string_sprintf("%d", tentry->integer));
 311                 break;
 312               case REDIS_REPLY_STRING:
 313                 result = string_catn(result, US tentry->str, tentry->len);
 314                 break;
 315               case REDIS_REPLY_ARRAY:
 316                 DEBUG(D_lookup)
 317                   debug_printf("REDIS: result has nesting of arrays which"
 318                     " is not supported. Ignoring!\n");
 319                 break;
 320               default:
 321                 DEBUG(D_lookup) debug_printf(
 322                           "REDIS: result has unsupported type. Ignoring!\n");
 323                 break;
 324               }
 325             }
 326             break;
 327           default:
 328             DEBUG(D_lookup) debug_printf("REDIS: query returned unsupported type\n");
 329             break;
 330           }
 331         }
 332       break;
 333   }
 334
 335
 336 if (result)
 337   store_reset(result->s + result->ptr + 1);
 338 else
 339   {
 340   yield = FAIL;
 341   *errmsg = US"REDIS: no data found";
 342   }
 343
 344 REDIS_EXIT:
 345
 346 /* Free store for any result that was got; don't close the connection,
 347 as it is cached. */
 348
 349 if (redis_reply) freeReplyObject(redis_reply);
 350
 351 /* Non-NULL result indicates a successful result */
 352
 353 if (result)
 354   {
 355   *resultptr = string_from_gstring(result);
 356   return OK;
 357   }
 358 else
 359   {
 360   DEBUG(D_lookup) debug_printf("%s\n", *errmsg);
 361   /* NOTE: Required to close connection since it needs to be reopened */
 362   return yield;      /* FAIL or DEFER */
 363   }
 364 }
 365
 366
 367
 368 /*************************************************
 369 *               Find entry point                 *
 370 *************************************************/
 371 /*
 372  * See local README for interface description. The handle and filename
 373  * arguments are not used. The code to loop through a list of servers while the
 374  * query is deferred with a retryable error is now in a separate function that is
 375  * shared with other noSQL lookups.
 376  */
 377
 378 static int
 379 redis_find(void *handle __attribute__((unused)),
 380   uschar *filename __attribute__((unused)),
 381   const uschar *command, int length, uschar **result, uschar **errmsg,
 382   uint *do_cache)
 383 {
 384 return lf_sqlperform(US"Redis", US"redis_servers", redis_servers, command,
 385   result, errmsg, do_cache, perform_redis_search);
 386 }
 387
 388
 389
 390 /*************************************************
 391 *               Quote entry point                *
 392 *************************************************/
 393
 394 /* Prefix any whitespace, or backslash, with a backslash.
 395 This is not a Redis thing but instead to let the argv splitting
 396 we do to split on whitespace, yet provide means for getting
 397 whitespace into an argument.
 398
 399 Arguments:
 400   s          the string to be quoted
 401   opt        additional option text or NULL if none
 402
 403 Returns:     the processed string or NULL for a bad option
 404 */
 405
 406 static uschar *
 407 redis_quote(uschar *s, uschar *opt)
 408 {
 409 register int c;
 410 int count = 0;
 411 uschar *t = s;
 412 uschar *quoted;
 413
 414 if (opt) return NULL;     /* No options recognized */
 415
 416 while ((c = *t++) != 0)
 417   if (isspace(c) || c == '\\') count++;
 418
 419 if (count == 0) return s;
 420 t = quoted = store_get(Ustrlen(s) + count + 1);
 421
 422 while ((c = *s++) != 0)
 423   {
 424   if (isspace(c) || c == '\\') *t++ = '\\';
 425   *t++ = c;
 426   }
 427
 428 *t = 0;
 429 return quoted;
 430 }
 431
 432
 433 /*************************************************
 434 *         Version reporting entry point          *
 435 *************************************************/
 436 #include "../version.h"
 437
 438 void
 439 redis_version_report(FILE *f)
 440 {
 441 fprintf(f, "Library version: REDIS: Compile: %d [%d]\n",
 442                HIREDIS_MAJOR, HIREDIS_MINOR);
 443 #ifdef DYNLOOKUP
 444 fprintf(f, "                        Exim version %s\n", EXIM_VERSION_STR);
 445 #endif
 446 }
 447
 448
 449
 450 /* These are the lookup_info blocks for this driver */
 451 static lookup_info redis_lookup_info = {
 452   US"redis",                     /* lookup name */
 453   lookup_querystyle,             /* query-style lookup */
 454   redis_open,                    /* open function */
 455   NULL,                          /* no check function */
 456   redis_find,                    /* find function */
 457   NULL,                          /* no close function */
 458   redis_tidy,                    /* tidy function */
 459   redis_quote,                   /* quoting function */
 460   redis_version_report           /* version reporting */
 461 };
 462
 463 #ifdef DYNLOOKUP
 464 # define redis_lookup_module_info _lookup_module_info
 465 #endif /* DYNLOOKUP */
 466
 467 static lookup_info *_lookup_list[] = { &redis_lookup_info };
 468 lookup_module_info redis_lookup_module_info = { LOOKUP_MODULE_INFO_MAGIC, _lookup_list, 1 };
 469
 470 #endif /* LOOKUP_REDIS */
 471 /* End of lookups/redis.c */