* Add dkim check plugin.

src/plugins/dkim_check.c

@@ -0,0 +1,247 @@
+/* Copyright (c) 2010-2011, Vsevolod Stakhov
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions are met:
+ *       * Redistributions of source code must retain the above copyright
+ *         notice, this list of conditions and the following disclaimer.
+ *       * Redistributions in binary form must reproduce the above copyright
+ *         notice, this list of conditions and the following disclaimer in the
+ *         documentation and/or other materials provided with the distribution.
+ *
+ * THIS SOFTWARE IS PROVIDED ''AS IS'' AND ANY
+ * EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
+ * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
+ * DISCLAIMED. IN NO EVENT SHALL AUTHOR BE LIABLE FOR ANY
+ * DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
+ * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
+ * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
+ * ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+ * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
+ * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ */
+
+
+/***MODULE:spf
+ * rspamd module that checks spf records of incoming email
+ *
+ * Allowed options:
+ * - symbol_allow (string): symbol to insert (default: 'R_SPF_ALLOW')
+ * - symbol_fail (string): symbol to insert (default: 'R_SPF_FAIL')
+ * - symbol_softfail (string): symbol to insert (default: 'R_SPF_SOFTFAIL')
+ * - whitelist (map): map of whitelisted networks
+ */
+
+#include "config.h"
+#include "main.h"
+#include "message.h"
+#include "cfg_file.h"
+#include "expressions.h"
+#include "util.h"
+#include "view.h"
+#include "map.h"
+#include "dkim.h"
+#include "cfg_xml.h"
+#include "hash.h"
+
+#define DEFAULT_SYMBOL_REJECT "R_DKIM_REJECT"
+#define DEFAULT_SYMBOL_TEMPFAIL "R_DKIM_TEMPFAIL"
+#define DEFAULT_SYMBOL_ALLOW "R_DKIM_ALLOW"
+#define DEFAULT_CACHE_SIZE 2048
+#define DEFAULT_CACHE_MAXAGE 86400
+
+struct dkim_ctx {
+	gint                            (*filter) (struct worker_task * task);
+	gchar                           *symbol_reject;
+	gchar                           *symbol_tempfail;
+	gchar                           *symbol_allow;
+
+	memory_pool_t                   *dkim_pool;
+	radix_tree_t                    *whitelist_ip;
+	GHashTable						*dkim_domains;
+	rspamd_lru_hash_t               *dkim_hash;
+};
+
+static struct dkim_ctx        *dkim_module_ctx = NULL;
+
+static void                   dkim_symbol_callback (struct worker_task *task, void *unused);
+
+/* Initialization */
+gint dkim_module_init (struct config_file *cfg, struct module_ctx **ctx);
+gint dkim_module_config (struct config_file *cfg);
+gint dkim_module_reconfig (struct config_file *cfg);
+
+module_t dkim_module = {
+	"dkim",
+	dkim_module_init,
+	dkim_module_config,
+	dkim_module_reconfig
+};
+
+gint
+dkim_module_init (struct config_file *cfg, struct module_ctx **ctx)
+{
+	dkim_module_ctx = g_malloc0 (sizeof (struct dkim_ctx));
+
+	dkim_module_ctx->dkim_pool = memory_pool_new (memory_pool_get_size ());
+
+	*ctx = (struct module_ctx *)dkim_module_ctx;
+	register_module_opt ("dkim", "symbol_reject", MODULE_OPT_TYPE_STRING);
+	register_module_opt ("dkim", "symbol_tempfail", MODULE_OPT_TYPE_STRING);
+	register_module_opt ("dkim", "symbol_allow", MODULE_OPT_TYPE_STRING);
+	register_module_opt ("dkim", "dkim_cache_size", MODULE_OPT_TYPE_UINT);
+	register_module_opt ("dkim", "dkim_cache_expire", MODULE_OPT_TYPE_TIME);
+	register_module_opt ("dkim", "whitelist", MODULE_OPT_TYPE_MAP);
+	register_module_opt ("dkim", "domains", MODULE_OPT_TYPE_MAP);
+
+	return 0;
+}
+
+gint
+dkim_module_config (struct config_file *cfg)
+{
+	gchar                          *value;
+	gint                            res = TRUE;
+	guint                           cache_size, cache_expire;
+
+	dkim_module_ctx->whitelist_ip = radix_tree_create ();
+
+	if ((value = get_module_opt (cfg, "dkim", "symbol_reject")) != NULL) {
+		dkim_module_ctx->symbol_reject = memory_pool_strdup (dkim_module_ctx->dkim_pool, value);
+	}
+	else {
+		dkim_module_ctx->symbol_reject = DEFAULT_SYMBOL_REJECT;
+	}
+	if ((value = get_module_opt (cfg, "dkim", "symbol_tempfail")) != NULL) {
+		dkim_module_ctx->symbol_tempfail = memory_pool_strdup (dkim_module_ctx->dkim_pool, value);
+	}
+	else {
+		dkim_module_ctx->symbol_tempfail = DEFAULT_SYMBOL_TEMPFAIL;
+	}
+	if ((value = get_module_opt (cfg, "dkim", "symbol_allow")) != NULL) {
+		dkim_module_ctx->symbol_allow = memory_pool_strdup (dkim_module_ctx->dkim_pool, value);
+	}
+	else {
+		dkim_module_ctx->symbol_allow = DEFAULT_SYMBOL_ALLOW;
+	}
+	if ((value = get_module_opt (cfg, "dkim", "dkim_cache_size")) != NULL) {
+		cache_size = strtoul (value, NULL, 10);
+	}
+	else {
+		cache_size = DEFAULT_CACHE_SIZE;
+	}
+	if ((value = get_module_opt (cfg, "dkim", "dkim_cache_expire")) != NULL) {
+		cache_expire = cfg_parse_time (value, TIME_SECONDS) / 1000;
+	}
+	else {
+		cache_expire = DEFAULT_CACHE_MAXAGE;
+	}
+	if ((value = get_module_opt (cfg, "dkim", "whitelist")) != NULL) {
+		if (! add_map (value, read_radix_list, fin_radix_list, (void **)&dkim_module_ctx->whitelist_ip)) {
+			msg_warn ("cannot load whitelist from %s", value);
+		}
+	}
+	if ((value = get_module_opt (cfg, "dkim", "domains")) != NULL) {
+		if (! add_map (value, read_host_list, fin_host_list, (void **)&dkim_module_ctx->dkim_domains)) {
+			msg_warn ("cannot load domains list from %s", value);
+		}
+	}
+
+	register_symbol (&cfg->cache, dkim_module_ctx->symbol_reject, 1, dkim_symbol_callback, NULL);
+	register_virtual_symbol (&cfg->cache, dkim_module_ctx->symbol_tempfail, 1);
+	register_virtual_symbol (&cfg->cache, dkim_module_ctx->symbol_allow, 1);
+
+	dkim_module_ctx->dkim_hash = rspamd_lru_hash_new (rspamd_strcase_hash, rspamd_strcase_equal,
+			cache_size, cache_expire, g_free, (GDestroyNotify)rspamd_dkim_key_free);
+
+	return res;
+}
+
+gint
+dkim_module_reconfig (struct config_file *cfg)
+{
+	memory_pool_delete (dkim_module_ctx->dkim_pool);
+	radix_tree_free (dkim_module_ctx->whitelist_ip);
+	if (dkim_module_ctx->dkim_domains) {
+		g_hash_table_destroy (dkim_module_ctx->dkim_domains);
+	}
+	dkim_module_ctx->dkim_pool = memory_pool_new (memory_pool_get_size ());
+
+	return dkim_module_config (cfg);
+}
+
+static void
+dkim_module_check (struct worker_task *task, rspamd_dkim_context_t *ctx, rspamd_dkim_key_t *key)
+{
+	gint								 res;
+
+	msg_debug ("check dkim signature for %s domain", ctx->dns_key);
+	res = rspamd_dkim_check (ctx, key, task);
+
+	if (res == DKIM_REJECT) {
+		insert_result (task, dkim_module_ctx->symbol_reject, 1, NULL);
+	}
+	else if (res == DKIM_TRYAGAIN) {
+		insert_result (task, dkim_module_ctx->symbol_tempfail, 1, NULL);
+	}
+	else if (res == DKIM_CONTINUE) {
+		insert_result (task, dkim_module_ctx->symbol_allow, 1, NULL);
+	}
+}
+
+static void
+dkim_module_key_handler (rspamd_dkim_key_t *key, gsize keylen, rspamd_dkim_context_t *ctx, gpointer ud, GError *err)
+{
+	struct worker_task					*task = ud;
+
+
+	if (key != NULL) {
+		/* Add new key to the lru cache */
+		rspamd_lru_hash_insert (dkim_module_ctx->dkim_hash, g_strdup (ctx->dns_key), key, task->tv.tv_sec);
+		dkim_module_check (task, ctx, key);
+	}
+	else {
+		/* Insert tempfail symbol */
+		insert_result (task, dkim_module_ctx->symbol_tempfail, 1, NULL);
+	}
+}
+
+static void
+dkim_symbol_callback (struct worker_task *task, void *unused)
+{
+	GList								*hlist;
+	rspamd_dkim_context_t				*ctx;
+	rspamd_dkim_key_t					*key;
+	GError								*err = NULL;
+	/* First check if a message has its signature */
+
+	hlist = message_get_header (task->task_pool, task->message, DKIM_SIGNHEADER, FALSE);
+	if (hlist != NULL) {
+		/* Check whitelist */
+		msg_debug ("dkim signature found");
+#ifdef HAVE_INET_PTON
+		if (!task->from_addr.has_addr ||
+				radix32tree_find (dkim_module_ctx->whitelist_ip, ntohl (task->from_addr.d.in4.s_addr)) == RADIX_NO_VALUE) {
+#else
+		if (radix32tree_find (dkim_module_ctx->whitelist_ip, ntohl (task->from_addr.s_addr)) == RADIX_NO_VALUE) {
+#endif
+			/* Parse signature */
+			msg_debug ("create dkim signature");
+			ctx = rspamd_create_dkim_context (hlist->data, task->task_pool, &err);
+			if (ctx == NULL) {
+				msg_info ("cannot parse DKIM context: %s", err->message);
+				g_error_free (err);
+			}
+			else {
+				/* Get key */
+				key = rspamd_lru_hash_lookup (dkim_module_ctx->dkim_hash, ctx->dns_key, task->tv.tv_sec);
+				if (key != NULL) {
+					dkim_module_check (task, ctx, key);
+				}
+				else {
+					rspamd_get_dkim_key (ctx, task->resolver, task->s, dkim_module_key_handler, task);
+				}
+			}
+		}
+	}
+}