lmtp: Load all globally-defined mail_plugins at client connect.

Before, this was not performed until after a user lookup was performed for a
recipient. That is not acceptable when plugins need to modify the LMTP protocol
itself.

src/lmtp/Makefile.am

@@ -16,6 +16,7 @@ AM_CPPFLAGS = \
 	-I$(top_srcdir)/src/lib-storage \
 	-I$(top_srcdir)/src/lib-storage/index \
 	-I$(top_srcdir)/src/lib-storage/index/raw \
+	-DMODULEDIR=\""$(moduledir)"\" \
 	$(BINARY_CFLAGS)
 
 lmtp_LDFLAGS = -export-dynamic \

src/lmtp/lmtp-client.c

@@ -10,6 +10,7 @@
 #include "hostpid.h"
 #include "process-title.h"
 #include "var-expand.h"
+#include "module-dir.h"
 #include "master-service-ssl.h"
 #include "master-service-settings.h"
 #include "iostream-ssl.h"
@@ -74,6 +75,24 @@ static void refresh_proctitle(void)
 	process_title_set(str_c(title));
 }
 
+static void client_load_modules(struct client *client)
+{
+        struct module_dir_load_settings mod_set;
+
+        i_zero(&mod_set);
+        mod_set.abi_version = DOVECOT_ABI_VERSION;
+        mod_set.require_init_funcs = TRUE;
+        mod_set.binary_name = "lmtp";
+
+        /* pre-load all configured mail plugins */
+        mail_storage_service_modules =
+                module_dir_load_missing(mail_storage_service_modules,
+                                        client->lmtp_set->mail_plugin_dir,
+                                        client->lmtp_set->mail_plugins,
+                                        &mod_set);
+	module_dir_init(mail_storage_service_modules);
+}
+
 static void client_raw_user_create(struct client *client)
 {
 	void **sets;
@@ -137,6 +156,7 @@ struct client *client_create(int fd_in, int fd_out,
 
 	client_read_settings(client, conn->ssl);
 	client_raw_user_create(client);
+	client_load_modules(client);
 	client->my_domain = client->unexpanded_lda_set->hostname;
 
 	if (client->service_set->verbose_proctitle)

src/lmtp/lmtp-settings.c

@@ -70,6 +70,9 @@ static const struct setting_define lmtp_setting_defines[] = {
 	DEF(SET_STR_VARS, login_greeting),
 	DEF(SET_STR, login_trusted_networks),
 
+	DEF(SET_STR, mail_plugins),
+	DEF(SET_STR, mail_plugin_dir),
+
 	SETTING_DEFINE_LIST_END
 };
 
@@ -83,7 +86,10 @@ static const struct lmtp_settings lmtp_default_settings = {
 	.lmtp_proxy_rawlog_dir = "",
 
 	.login_greeting = PACKAGE_NAME" ready.",
-	.login_trusted_networks = ""
+	.login_trusted_networks = "",
+
+	.mail_plugins = "",
+	.mail_plugin_dir = MODULEDIR,
 };
 
 static const struct setting_parser_info *lmtp_setting_dependencies[] = {

src/lmtp/lmtp-settings.h

@@ -24,6 +24,9 @@ struct lmtp_settings {
 	const char *login_greeting;
 	const char *login_trusted_networks;
 
+	const char *mail_plugins;
+	const char *mail_plugin_dir;
+
 	enum lmtp_hdr_delivery_address parsed_lmtp_hdr_delivery_address;
 };