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-rw-r--r--src/lookups/redis.c471
1 files changed, 471 insertions, 0 deletions
diff --git a/src/lookups/redis.c b/src/lookups/redis.c
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+/*************************************************
+* Exim - an Internet mail transport agent *
+*************************************************/
+
+/* Copyright (c) University of Cambridge 1995 - 2018 */
+/* Copyright (c) The Exim Maintainers 2020 */
+/* See the file NOTICE for conditions of use and distribution. */
+
+#include "../exim.h"
+
+#ifdef LOOKUP_REDIS
+
+#include "lf_functions.h"
+
+#include <hiredis/hiredis.h>
+
+#ifndef nele
+# define nele(arr) (sizeof(arr) / sizeof(*arr))
+#endif
+
+/* Structure and anchor for caching connections. */
+typedef struct redis_connection {
+ struct redis_connection *next;
+ uschar *server;
+ redisContext *handle;
+} redis_connection;
+
+static redis_connection *redis_connections = NULL;
+
+
+static void *
+redis_open(const uschar * filename, uschar ** errmsg)
+{
+return (void *)(1);
+}
+
+
+void
+redis_tidy(void)
+{
+redis_connection *cn;
+
+/* XXX: Not sure how often this is called!
+ Guess its called after every lookup which probably would mean to just
+ not use the _tidy() function at all and leave with exim exiting to
+ GC connections! */
+
+while ((cn = redis_connections))
+ {
+ redis_connections = cn->next;
+ DEBUG(D_lookup) debug_printf_indent("close REDIS connection: %s\n", cn->server);
+ redisFree(cn->handle);
+ }
+}
+
+
+/* This function is called from the find entry point to do the search for a
+single server.
+
+ Arguments:
+ query the query string
+ server the server string
+ resultptr where to store the result
+ errmsg where to point an error message
+ defer_break TRUE if no more servers are to be tried after DEFER
+ do_cache set false if data is changed
+ opts options
+
+ The server string is of the form "host/dbnumber/password". The host can be
+ host:port. This string is in a nextinlist temporary buffer, so can be
+ overwritten.
+
+ Returns: OK, FAIL, or DEFER
+*/
+
+static int
+perform_redis_search(const uschar *command, uschar *server, uschar **resultptr,
+ uschar **errmsg, BOOL *defer_break, uint *do_cache, const uschar * opts)
+{
+redisContext *redis_handle = NULL; /* Keep compilers happy */
+redisReply *redis_reply = NULL;
+redisReply *entry = NULL;
+redisReply *tentry = NULL;
+redis_connection *cn;
+int yield = DEFER;
+int i, j;
+gstring * result = NULL;
+uschar *server_copy = NULL;
+uschar *sdata[3];
+
+/* Disaggregate the parameters from the server argument.
+The order is host:port(socket)
+We can write to the string, since it is in a nextinlist temporary buffer.
+This copy is also used for debugging output. */
+
+memset(sdata, 0, sizeof(sdata)) /* Set all to NULL */;
+for (int i = 2; i > 0; i--)
+ {
+ uschar *pp = Ustrrchr(server, '/');
+
+ if (!pp)
+ {
+ *errmsg = string_sprintf("incomplete Redis server data: %s",
+ i == 2 ? server : server_copy);
+ *defer_break = TRUE;
+ return DEFER;
+ }
+ *pp++ = 0;
+ sdata[i] = pp;
+ if (i == 2) server_copy = string_copy(server); /* sans password */
+ }
+sdata[0] = server; /* What's left at the start */
+
+/* If the database or password is an empty string, set it NULL */
+if (sdata[1][0] == 0) sdata[1] = NULL;
+if (sdata[2][0] == 0) sdata[2] = NULL;
+
+/* See if we have a cached connection to the server */
+
+for (cn = redis_connections; cn; cn = cn->next)
+ if (Ustrcmp(cn->server, server_copy) == 0)
+ {
+ redis_handle = cn->handle;
+ break;
+ }
+
+if (!cn)
+ {
+ uschar *p;
+ uschar *socket = NULL;
+ int port = 0;
+ /* int redis_err = REDIS_OK; */
+
+ if ((p = Ustrchr(sdata[0], '(')))
+ {
+ *p++ = 0;
+ socket = p;
+ while (*p != 0 && *p != ')') p++;
+ *p = 0;
+ }
+
+ if ((p = Ustrchr(sdata[0], ':')))
+ {
+ *p++ = 0;
+ port = Uatoi(p);
+ }
+ else
+ port = Uatoi("6379");
+
+ if (Ustrchr(server, '/'))
+ {
+ *errmsg = string_sprintf("unexpected slash in Redis server hostname: %s",
+ sdata[0]);
+ *defer_break = TRUE;
+ return DEFER;
+ }
+
+ DEBUG(D_lookup)
+ debug_printf_indent("REDIS new connection: host=%s port=%d socket=%s database=%s\n",
+ sdata[0], port, socket, sdata[1]);
+
+ /* Get store for a new handle, initialize it, and connect to the server */
+ /* XXX: Use timeouts ? */
+ redis_handle =
+ socket ? redisConnectUnix(CCS socket) : redisConnect(CCS server, port);
+ if (!redis_handle)
+ {
+ *errmsg = US"REDIS connection failed";
+ *defer_break = FALSE;
+ goto REDIS_EXIT;
+ }
+
+ /* Add the connection to the cache */
+ cn = store_get(sizeof(redis_connection), FALSE);
+ cn->server = server_copy;
+ cn->handle = redis_handle;
+ cn->next = redis_connections;
+ redis_connections = cn;
+ }
+else
+ {
+ DEBUG(D_lookup)
+ debug_printf_indent("REDIS using cached connection for %s\n", server_copy);
+}
+
+/* Authenticate if there is a password */
+if(sdata[2])
+ if (!(redis_reply = redisCommand(redis_handle, "AUTH %s", sdata[2])))
+ {
+ *errmsg = string_sprintf("REDIS Authentication failed: %s\n", redis_handle->errstr);
+ *defer_break = FALSE;
+ goto REDIS_EXIT;
+ }
+
+/* Select the database if there is a dbnumber passed */
+if(sdata[1])
+ {
+ if (!(redis_reply = redisCommand(redis_handle, "SELECT %s", sdata[1])))
+ {
+ *errmsg = string_sprintf("REDIS: Selecting database=%s failed: %s\n", sdata[1], redis_handle->errstr);
+ *defer_break = FALSE;
+ goto REDIS_EXIT;
+ }
+ DEBUG(D_lookup) debug_printf_indent("REDIS: Selecting database=%s\n", sdata[1]);
+ }
+
+/* split string on whitespace into argv */
+ {
+ uschar * argv[32];
+ const uschar * s = command;
+ int siz, ptr, i;
+ uschar c;
+
+ while (isspace(*s)) s++;
+
+ for (i = 0; *s && i < nele(argv); i++)
+ {
+ gstring * g;
+
+ for (g = NULL; (c = *s) && !isspace(c); s++)
+ if (c != '\\' || *++s) /* backslash protects next char */
+ g = string_catn(g, s, 1);
+ argv[i] = string_from_gstring(g);
+
+ DEBUG(D_lookup) debug_printf_indent("REDIS: argv[%d] '%s'\n", i, argv[i]);
+ while (isspace(*s)) s++;
+ }
+
+ /* Run the command. We use the argv form rather than plain as that parses
+ into args by whitespace yet has no escaping mechanism. */
+
+ if (!(redis_reply = redisCommandArgv(redis_handle, i, CCSS argv, NULL)))
+ {
+ *errmsg = string_sprintf("REDIS: query failed: %s\n", redis_handle->errstr);
+ *defer_break = FALSE;
+ goto REDIS_EXIT;
+ }
+ }
+
+switch (redis_reply->type)
+ {
+ case REDIS_REPLY_ERROR:
+ *errmsg = string_sprintf("REDIS: lookup result failed: %s\n", redis_reply->str);
+
+ /* trap MOVED cluster responses and follow them */
+ if (Ustrncmp(redis_reply->str, "MOVED", 5) == 0)
+ {
+ DEBUG(D_lookup)
+ debug_printf_indent("REDIS: cluster redirect %s\n", redis_reply->str);
+ /* follow redirect
+ This is cheating, we simply set defer_break = FALSE to move on to
+ the next server in the redis_servers list */
+ *defer_break = FALSE;
+ return DEFER;
+ } else {
+ *defer_break = TRUE;
+ }
+ *do_cache = 0;
+ goto REDIS_EXIT;
+ /* NOTREACHED */
+
+ case REDIS_REPLY_NIL:
+ DEBUG(D_lookup)
+ debug_printf_indent("REDIS: query was not one that returned any data\n");
+ result = string_catn(result, US"", 1);
+ *do_cache = 0;
+ goto REDIS_EXIT;
+ /* NOTREACHED */
+
+ case REDIS_REPLY_INTEGER:
+ result = string_cat(result, redis_reply->integer != 0 ? US"true" : US"false");
+ break;
+
+ case REDIS_REPLY_STRING:
+ case REDIS_REPLY_STATUS:
+ result = string_catn(result, US redis_reply->str, redis_reply->len);
+ break;
+
+ case REDIS_REPLY_ARRAY:
+
+ /* NOTE: For now support 1 nested array result. If needed a limitless
+ result can be parsed */
+
+ for (int i = 0; i < redis_reply->elements; i++)
+ {
+ entry = redis_reply->element[i];
+
+ if (result)
+ result = string_catn(result, US"\n", 1);
+
+ switch (entry->type)
+ {
+ case REDIS_REPLY_INTEGER:
+ result = string_fmt_append(result, "%d", entry->integer);
+ break;
+ case REDIS_REPLY_STRING:
+ result = string_catn(result, US entry->str, entry->len);
+ break;
+ case REDIS_REPLY_ARRAY:
+ for (int j = 0; j < entry->elements; j++)
+ {
+ tentry = entry->element[j];
+
+ if (result)
+ result = string_catn(result, US"\n", 1);
+
+ switch (tentry->type)
+ {
+ case REDIS_REPLY_INTEGER:
+ result = string_fmt_append(result, "%d", tentry->integer);
+ break;
+ case REDIS_REPLY_STRING:
+ result = string_catn(result, US tentry->str, tentry->len);
+ break;
+ case REDIS_REPLY_ARRAY:
+ DEBUG(D_lookup)
+ debug_printf_indent("REDIS: result has nesting of arrays which"
+ " is not supported. Ignoring!\n");
+ break;
+ default:
+ DEBUG(D_lookup) debug_printf_indent(
+ "REDIS: result has unsupported type. Ignoring!\n");
+ break;
+ }
+ }
+ break;
+ default:
+ DEBUG(D_lookup) debug_printf_indent("REDIS: query returned unsupported type\n");
+ break;
+ }
+ }
+ break;
+ }
+
+
+if (result)
+ gstring_release_unused(result);
+else
+ {
+ yield = FAIL;
+ *errmsg = US"REDIS: no data found";
+ }
+
+REDIS_EXIT:
+
+/* Free store for any result that was got; don't close the connection,
+as it is cached. */
+
+if (redis_reply) freeReplyObject(redis_reply);
+
+/* Non-NULL result indicates a successful result */
+
+if (result)
+ {
+ *resultptr = string_from_gstring(result);
+ return OK;
+ }
+else
+ {
+ DEBUG(D_lookup) debug_printf_indent("%s\n", *errmsg);
+ /* NOTE: Required to close connection since it needs to be reopened */
+ return yield; /* FAIL or DEFER */
+ }
+}
+
+
+
+/*************************************************
+* Find entry point *
+*************************************************/
+/*
+ * See local README for interface description. The handle and filename
+ * arguments are not used. The code to loop through a list of servers while the
+ * query is deferred with a retryable error is now in a separate function that is
+ * shared with other noSQL lookups.
+ */
+
+static int
+redis_find(void * handle __attribute__((unused)),
+ const uschar * filename __attribute__((unused)),
+ const uschar * command, int length, uschar ** result, uschar ** errmsg,
+ uint * do_cache, const uschar * opts)
+{
+return lf_sqlperform(US"Redis", US"redis_servers", redis_servers, command,
+ result, errmsg, do_cache, opts, perform_redis_search);
+}
+
+
+
+/*************************************************
+* Quote entry point *
+*************************************************/
+
+/* Prefix any whitespace, or backslash, with a backslash.
+This is not a Redis thing but instead to let the argv splitting
+we do to split on whitespace, yet provide means for getting
+whitespace into an argument.
+
+Arguments:
+ s the string to be quoted
+ opt additional option text or NULL if none
+
+Returns: the processed string or NULL for a bad option
+*/
+
+static uschar *
+redis_quote(uschar *s, uschar *opt)
+{
+register int c;
+int count = 0;
+uschar *t = s;
+uschar *quoted;
+
+if (opt) return NULL; /* No options recognized */
+
+while ((c = *t++) != 0)
+ if (isspace(c) || c == '\\') count++;
+
+if (count == 0) return s;
+t = quoted = store_get(Ustrlen(s) + count + 1, is_tainted(s));
+
+while ((c = *s++) != 0)
+ {
+ if (isspace(c) || c == '\\') *t++ = '\\';
+ *t++ = c;
+ }
+
+*t = 0;
+return quoted;
+}
+
+
+/*************************************************
+* Version reporting entry point *
+*************************************************/
+#include "../version.h"
+
+void
+redis_version_report(FILE *f)
+{
+fprintf(f, "Library version: REDIS: Compile: %d [%d]\n",
+ HIREDIS_MAJOR, HIREDIS_MINOR);
+#ifdef DYNLOOKUP
+fprintf(f, " Exim version %s\n", EXIM_VERSION_STR);
+#endif
+}
+
+
+
+/* These are the lookup_info blocks for this driver */
+static lookup_info redis_lookup_info = {
+ .name = US"redis", /* lookup name */
+ .type = lookup_querystyle, /* query-style lookup */
+ .open = redis_open, /* open function */
+ .check = NULL, /* no check function */
+ .find = redis_find, /* find function */
+ .close = NULL, /* no close function */
+ .tidy = redis_tidy, /* tidy function */
+ .quote = redis_quote, /* quoting function */
+ .version_report = redis_version_report /* version reporting */
+};
+
+#ifdef DYNLOOKUP
+# define redis_lookup_module_info _lookup_module_info
+#endif /* DYNLOOKUP */
+
+static lookup_info *_lookup_list[] = { &redis_lookup_info };
+lookup_module_info redis_lookup_module_info = { LOOKUP_MODULE_INFO_MAGIC, _lookup_list, 1 };
+
+#endif /* LOOKUP_REDIS */
+/* End of lookups/redis.c */
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