337fdae152d4aa130606fd100f3131e40d128772
[exim.git] / 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 opts options
67
68 The server string is of the form "host/dbnumber/password". The host can be
69 host:port. This string is in a nextinlist temporary buffer, so can be
70 overwritten.
71
72 Returns: OK, FAIL, or DEFER
73 */
74
75 static int
76 perform_redis_search(const uschar *command, uschar *server, uschar **resultptr,
77 uschar **errmsg, BOOL *defer_break, uint *do_cache, const uschar * opts)
78 {
79 redisContext *redis_handle = NULL; /* Keep compilers happy */
80 redisReply *redis_reply = NULL;
81 redisReply *entry = NULL;
82 redisReply *tentry = NULL;
83 redis_connection *cn;
84 int yield = DEFER;
85 int i, j;
86 gstring * result = NULL;
87 uschar *server_copy = NULL;
88 uschar *sdata[3];
89
90 /* Disaggregate the parameters from the server argument.
91 The order is host:port(socket)
92 We can write to the string, since it is in a nextinlist temporary buffer.
93 This copy is also used for debugging output. */
94
95 memset(sdata, 0, sizeof(sdata)) /* Set all to NULL */;
96 for (int i = 2; i > 0; i--)
97 {
98 uschar *pp = Ustrrchr(server, '/');
99
100 if (!pp)
101 {
102 *errmsg = string_sprintf("incomplete Redis server data: %s",
103 i == 2 ? server : server_copy);
104 *defer_break = TRUE;
105 return DEFER;
106 }
107 *pp++ = 0;
108 sdata[i] = pp;
109 if (i == 2) server_copy = string_copy(server); /* sans password */
110 }
111 sdata[0] = server; /* What's left at the start */
112
113 /* If the database or password is an empty string, set it NULL */
114 if (sdata[1][0] == 0) sdata[1] = NULL;
115 if (sdata[2][0] == 0) sdata[2] = NULL;
116
117 /* See if we have a cached connection to the server */
118
119 for (cn = redis_connections; cn; cn = cn->next)
120 if (Ustrcmp(cn->server, server_copy) == 0)
121 {
122 redis_handle = cn->handle;
123 break;
124 }
125
126 if (!cn)
127 {
128 uschar *p;
129 uschar *socket = NULL;
130 int port = 0;
131 /* int redis_err = REDIS_OK; */
132
133 if ((p = Ustrchr(sdata[0], '(')))
134 {
135 *p++ = 0;
136 socket = p;
137 while (*p != 0 && *p != ')') p++;
138 *p = 0;
139 }
140
141 if ((p = Ustrchr(sdata[0], ':')))
142 {
143 *p++ = 0;
144 port = Uatoi(p);
145 }
146 else
147 port = Uatoi("6379");
148
149 if (Ustrchr(server, '/'))
150 {
151 *errmsg = string_sprintf("unexpected slash in Redis server hostname: %s",
152 sdata[0]);
153 *defer_break = TRUE;
154 return DEFER;
155 }
156
157 DEBUG(D_lookup)
158 debug_printf_indent("REDIS new connection: host=%s port=%d socket=%s database=%s\n",
159 sdata[0], port, socket, sdata[1]);
160
161 /* Get store for a new handle, initialize it, and connect to the server */
162 /* XXX: Use timeouts ? */
163 redis_handle =
164 socket ? redisConnectUnix(CCS socket) : redisConnect(CCS server, port);
165 if (!redis_handle)
166 {
167 *errmsg = US"REDIS connection failed";
168 *defer_break = FALSE;
169 goto REDIS_EXIT;
170 }
171
172 /* Add the connection to the cache */
173 cn = store_get(sizeof(redis_connection), FALSE);
174 cn->server = server_copy;
175 cn->handle = redis_handle;
176 cn->next = redis_connections;
177 redis_connections = cn;
178 }
179 else
180 {
181 DEBUG(D_lookup)
182 debug_printf_indent("REDIS using cached connection for %s\n", server_copy);
183 }
184
185 /* Authenticate if there is a password */
186 if(sdata[2])
187 if (!(redis_reply = redisCommand(redis_handle, "AUTH %s", sdata[2])))
188 {
189 *errmsg = string_sprintf("REDIS Authentication failed: %s\n", redis_handle->errstr);
190 *defer_break = FALSE;
191 goto REDIS_EXIT;
192 }
193
194 /* Select the database if there is a dbnumber passed */
195 if(sdata[1])
196 {
197 if (!(redis_reply = redisCommand(redis_handle, "SELECT %s", sdata[1])))
198 {
199 *errmsg = string_sprintf("REDIS: Selecting database=%s failed: %s\n", sdata[1], redis_handle->errstr);
200 *defer_break = FALSE;
201 goto REDIS_EXIT;
202 }
203 DEBUG(D_lookup) debug_printf_indent("REDIS: Selecting database=%s\n", sdata[1]);
204 }
205
206 /* split string on whitespace into argv */
207 {
208 uschar * argv[32];
209 const uschar * s = command;
210 int siz, ptr, i;
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_indent("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 if (!(redis_reply = redisCommandArgv(redis_handle, i, CCSS argv, NULL)))
232 {
233 *errmsg = string_sprintf("REDIS: query failed: %s\n", redis_handle->errstr);
234 *defer_break = FALSE;
235 goto REDIS_EXIT;
236 }
237 }
238
239 switch (redis_reply->type)
240 {
241 case REDIS_REPLY_ERROR:
242 *errmsg = string_sprintf("REDIS: lookup result failed: %s\n", redis_reply->str);
243
244 /* trap MOVED cluster responses and follow them */
245 if (Ustrncmp(redis_reply->str, "MOVED", 5) == 0)
246 {
247 DEBUG(D_lookup)
248 debug_printf_indent("REDIS: cluster redirect %s\n", redis_reply->str);
249 /* follow redirect
250 This is cheating, we simply set defer_break = FALSE to move on to
251 the next server in the redis_servers list */
252 *defer_break = FALSE;
253 return DEFER;
254 } else {
255 *defer_break = TRUE;
256 }
257 *do_cache = 0;
258 goto REDIS_EXIT;
259 /* NOTREACHED */
260
261 case REDIS_REPLY_NIL:
262 DEBUG(D_lookup)
263 debug_printf_indent("REDIS: query was not one that returned any data\n");
264 result = string_catn(result, US"", 1);
265 *do_cache = 0;
266 goto REDIS_EXIT;
267 /* NOTREACHED */
268
269 case REDIS_REPLY_INTEGER:
270 result = string_cat(result, redis_reply->integer != 0 ? US"true" : US"false");
271 break;
272
273 case REDIS_REPLY_STRING:
274 case REDIS_REPLY_STATUS:
275 result = string_catn(result, US redis_reply->str, redis_reply->len);
276 break;
277
278 case REDIS_REPLY_ARRAY:
279
280 /* NOTE: For now support 1 nested array result. If needed a limitless
281 result can be parsed */
282
283 for (int i = 0; i < redis_reply->elements; i++)
284 {
285 entry = redis_reply->element[i];
286
287 if (result)
288 result = string_catn(result, US"\n", 1);
289
290 switch (entry->type)
291 {
292 case REDIS_REPLY_INTEGER:
293 result = string_fmt_append(result, "%d", entry->integer);
294 break;
295 case REDIS_REPLY_STRING:
296 result = string_catn(result, US entry->str, entry->len);
297 break;
298 case REDIS_REPLY_ARRAY:
299 for (int j = 0; j < entry->elements; j++)
300 {
301 tentry = entry->element[j];
302
303 if (result)
304 result = string_catn(result, US"\n", 1);
305
306 switch (tentry->type)
307 {
308 case REDIS_REPLY_INTEGER:
309 result = string_fmt_append(result, "%d", tentry->integer);
310 break;
311 case REDIS_REPLY_STRING:
312 result = string_catn(result, US tentry->str, tentry->len);
313 break;
314 case REDIS_REPLY_ARRAY:
315 DEBUG(D_lookup)
316 debug_printf_indent("REDIS: result has nesting of arrays which"
317 " is not supported. Ignoring!\n");
318 break;
319 default:
320 DEBUG(D_lookup) debug_printf_indent(
321 "REDIS: result has unsupported type. Ignoring!\n");
322 break;
323 }
324 }
325 break;
326 default:
327 DEBUG(D_lookup) debug_printf_indent("REDIS: query returned unsupported type\n");
328 break;
329 }
330 }
331 break;
332 }
333
334
335 if (result)
336 gstring_release_unused(result);
337 else
338 {
339 yield = FAIL;
340 *errmsg = US"REDIS: no data found";
341 }
342
343 REDIS_EXIT:
344
345 /* Free store for any result that was got; don't close the connection,
346 as it is cached. */
347
348 if (redis_reply) freeReplyObject(redis_reply);
349
350 /* Non-NULL result indicates a successful result */
351
352 if (result)
353 {
354 *resultptr = string_from_gstring(result);
355 return OK;
356 }
357 else
358 {
359 DEBUG(D_lookup) debug_printf_indent("%s\n", *errmsg);
360 /* NOTE: Required to close connection since it needs to be reopened */
361 return yield; /* FAIL or DEFER */
362 }
363 }
364
365
366
367 /*************************************************
368 * Find entry point *
369 *************************************************/
370 /*
371 * See local README for interface description. The handle and filename
372 * arguments are not used. The code to loop through a list of servers while the
373 * query is deferred with a retryable error is now in a separate function that is
374 * shared with other noSQL lookups.
375 */
376
377 static int
378 redis_find(void * handle __attribute__((unused)),
379 const uschar * filename __attribute__((unused)),
380 const uschar * command, int length, uschar ** result, uschar ** errmsg,
381 uint * do_cache, const uschar * opts)
382 {
383 return lf_sqlperform(US"Redis", US"redis_servers", redis_servers, command,
384 result, errmsg, do_cache, opts, perform_redis_search);
385 }
386
387
388
389 /*************************************************
390 * Quote entry point *
391 *************************************************/
392
393 /* Prefix any whitespace, or backslash, with a backslash.
394 This is not a Redis thing but instead to let the argv splitting
395 we do to split on whitespace, yet provide means for getting
396 whitespace into an argument.
397
398 Arguments:
399 s the string to be quoted
400 opt additional option text or NULL if none
401
402 Returns: the processed string or NULL for a bad option
403 */
404
405 static uschar *
406 redis_quote(uschar *s, uschar *opt)
407 {
408 register int c;
409 int count = 0;
410 uschar *t = s;
411 uschar *quoted;
412
413 if (opt) return NULL; /* No options recognized */
414
415 while ((c = *t++) != 0)
416 if (isspace(c) || c == '\\') count++;
417
418 if (count == 0) return s;
419 t = quoted = store_get(Ustrlen(s) + count + 1, is_tainted(s));
420
421 while ((c = *s++) != 0)
422 {
423 if (isspace(c) || c == '\\') *t++ = '\\';
424 *t++ = c;
425 }
426
427 *t = 0;
428 return quoted;
429 }
430
431
432 /*************************************************
433 * Version reporting entry point *
434 *************************************************/
435 #include "../version.h"
436
437 void
438 redis_version_report(FILE *f)
439 {
440 fprintf(f, "Library version: REDIS: Compile: %d [%d]\n",
441 HIREDIS_MAJOR, HIREDIS_MINOR);
442 #ifdef DYNLOOKUP
443 fprintf(f, " Exim version %s\n", EXIM_VERSION_STR);
444 #endif
445 }
446
447
448
449 /* These are the lookup_info blocks for this driver */
450 static lookup_info redis_lookup_info = {
451 US"redis", /* lookup name */
452 lookup_querystyle, /* query-style lookup */
453 redis_open, /* open function */
454 NULL, /* no check function */
455 redis_find, /* find function */
456 NULL, /* no close function */
457 redis_tidy, /* tidy function */
458 redis_quote, /* quoting function */
459 redis_version_report /* version reporting */
460 };
461
462 #ifdef DYNLOOKUP
463 # define redis_lookup_module_info _lookup_module_info
464 #endif /* DYNLOOKUP */
465
466 static lookup_info *_lookup_list[] = { &redis_lookup_info };
467 lookup_module_info redis_lookup_module_info = { LOOKUP_MODULE_INFO_MAGIC, _lookup_list, 1 };
468
469 #endif /* LOOKUP_REDIS */
470 /* End of lookups/redis.c */