From 1db62753d9e3b5d71018889c8ef0a3722a307455 Mon Sep 17 00:00:00 2001
From: Timo Sirainen <tss@iki.fi>
Date: Thu, 27 May 2010 19:59:39 +0100
Subject: [PATCH] doveadm: mail commands can now be extended more easily by
 plugins. Also plugins can now override the list of -A users.

--HG--
branch : HEAD
---
 src/doveadm/doveadm-mail-altmove.c | 22 +++-----
 src/doveadm/doveadm-mail-expunge.c | 22 +++-----
 src/doveadm/doveadm-mail-fetch.c   | 16 +++---
 src/doveadm/doveadm-mail-mailbox.c | 24 ++++-----
 src/doveadm/doveadm-mail-search.c  | 22 +++-----
 src/doveadm/doveadm-mail.c         | 87 ++++++++++++++++++++----------
 src/doveadm/doveadm-mail.h         | 34 ++++++++++--
 src/doveadm/doveadm-settings.c     |  5 +-
 src/doveadm/doveadm-settings.h     |  2 +
 src/doveadm/doveadm.c              | 16 ++++++
 src/doveadm/doveadm.h              |  1 +
 11 files changed, 153 insertions(+), 98 deletions(-)

diff --git a/src/doveadm/doveadm-mail-altmove.c b/src/doveadm/doveadm-mail-altmove.c
index 4505eadb09..f4631d808a 100644
--- a/src/doveadm/doveadm-mail-altmove.c
+++ b/src/doveadm/doveadm-mail-altmove.c
@@ -9,11 +9,6 @@
 #include "doveadm-mail-iter.h"
 #include "doveadm-mail.h"
 
-struct altmove_cmd_context {
-	struct doveadm_mail_cmd_context ctx;
-	struct mail_search_args *search_args;
-};
-
 static int
 cmd_altmove_box(const struct mailbox_info *info,
 		struct mail_search_args *search_args)
@@ -47,9 +42,8 @@ static void ns_purge(struct mail_namespace *ns)
 }
 
 static void
-cmd_altmove_run(struct doveadm_mail_cmd_context *_ctx, struct mail_user *user)
+cmd_altmove_run(struct doveadm_mail_cmd_context *ctx, struct mail_user *user)
 {
-	struct altmove_cmd_context *ctx = (struct altmove_cmd_context *)_ctx;
 	const enum mailbox_list_iter_flags iter_flags =
 		MAILBOX_LIST_ITER_RAW_LIST |
 		MAILBOX_LIST_ITER_VIRTUAL_NAMES |
@@ -94,11 +88,9 @@ cmd_altmove_run(struct doveadm_mail_cmd_context *_ctx, struct mail_user *user)
 	}
 }
 
-static void cmd_altmove_init(struct doveadm_mail_cmd_context *_ctx,
+static void cmd_altmove_init(struct doveadm_mail_cmd_context *ctx,
 			     const char *const args[])
 {
-	struct altmove_cmd_context *ctx = (struct altmove_cmd_context *)_ctx;
-
 	if (args[0] == NULL)
 		doveadm_mail_help_name("altmove");
 	ctx->search_args = doveadm_mail_build_search_args(args);
@@ -106,12 +98,12 @@ static void cmd_altmove_init(struct doveadm_mail_cmd_context *_ctx,
 
 static struct doveadm_mail_cmd_context *cmd_altmove_alloc(void)
 {
-	struct altmove_cmd_context *ctx;
+	struct doveadm_mail_cmd_context *ctx;
 
-	ctx = doveadm_mail_cmd_alloc(struct altmove_cmd_context);
-	ctx->ctx.init = cmd_altmove_init;
-	ctx->ctx.run = cmd_altmove_run;
-	return &ctx->ctx;
+	ctx = doveadm_mail_cmd_alloc(struct doveadm_mail_cmd_context);
+	ctx->v.init = cmd_altmove_init;
+	ctx->v.run = cmd_altmove_run;
+	return ctx;
 }
 
 struct doveadm_mail_cmd cmd_altmove = {
diff --git a/src/doveadm/doveadm-mail-expunge.c b/src/doveadm/doveadm-mail-expunge.c
index bc063c5443..2e74e448a4 100644
--- a/src/doveadm/doveadm-mail-expunge.c
+++ b/src/doveadm/doveadm-mail-expunge.c
@@ -9,11 +9,6 @@
 #include "doveadm-mail-iter.h"
 #include "doveadm-mail.h"
 
-struct expunge_cmd_context {
-	struct doveadm_mail_cmd_context ctx;
-	struct mail_search_args *search_args;
-};
-
 static int
 cmd_expunge_box(const struct mailbox_info *info,
 		struct mail_search_args *search_args)
@@ -167,9 +162,8 @@ expunge_search_args_is_msgset_ok(struct mail_search_arg *args)
 }
 
 static void
-cmd_expunge_run(struct doveadm_mail_cmd_context *_ctx, struct mail_user *user)
+cmd_expunge_run(struct doveadm_mail_cmd_context *ctx, struct mail_user *user)
 {
-	struct expunge_cmd_context *ctx = (struct expunge_cmd_context *)_ctx;
 	const enum mailbox_list_iter_flags iter_flags =
 		MAILBOX_LIST_ITER_RAW_LIST |
 		MAILBOX_LIST_ITER_VIRTUAL_NAMES |
@@ -195,11 +189,9 @@ cmd_expunge_run(struct doveadm_mail_cmd_context *_ctx, struct mail_user *user)
 	doveadm_mail_list_iter_deinit(&iter);
 }
 
-static void cmd_expunge_init(struct doveadm_mail_cmd_context *_ctx,
+static void cmd_expunge_init(struct doveadm_mail_cmd_context *ctx,
 			     const char *const args[])
 {
-	struct expunge_cmd_context *ctx = (struct expunge_cmd_context *)_ctx;
-
 	if (args[0] == NULL)
 		doveadm_mail_help_name("expunge");
 
@@ -209,12 +201,12 @@ static void cmd_expunge_init(struct doveadm_mail_cmd_context *_ctx,
 
 static struct doveadm_mail_cmd_context *cmd_expunge_alloc(void)
 {
-	struct expunge_cmd_context *ctx;
+	struct doveadm_mail_cmd_context *ctx;
 
-	ctx = doveadm_mail_cmd_alloc(struct expunge_cmd_context);
-	ctx->ctx.init = cmd_expunge_init;
-	ctx->ctx.run = cmd_expunge_run;
-	return &ctx->ctx;
+	ctx = doveadm_mail_cmd_alloc(struct doveadm_mail_cmd_context);
+	ctx->v.init = cmd_expunge_init;
+	ctx->v.run = cmd_expunge_run;
+	return ctx;
 }
 
 struct doveadm_mail_cmd cmd_expunge = {
diff --git a/src/doveadm/doveadm-mail-fetch.c b/src/doveadm/doveadm-mail-fetch.c
index 317e4635c8..4a10e956f0 100644
--- a/src/doveadm/doveadm-mail-fetch.c
+++ b/src/doveadm/doveadm-mail-fetch.c
@@ -20,7 +20,6 @@
 struct fetch_cmd_context {
 	struct doveadm_mail_cmd_context ctx;
 
-	struct mail_search_args *search_args;
 	struct ostream *output;
 	struct mail *mail;
 
@@ -383,7 +382,8 @@ cmd_fetch_box(struct fetch_cmd_context *ctx, const struct mailbox_info *info)
 	struct mail *mail;
 	struct mailbox_header_lookup_ctx *headers = NULL;
 
-	if (doveadm_mail_iter_init(info, ctx->search_args, &trans, &iter) < 0)
+	if (doveadm_mail_iter_init(info, ctx->ctx.search_args,
+				   &trans, &iter) < 0)
 		return -1;
 
 	if (array_count(&ctx->header_fields) > 1) {
@@ -445,7 +445,7 @@ cmd_fetch_run(struct doveadm_mail_cmd_context *_ctx, struct mail_user *user)
 	struct doveadm_mail_list_iter *iter;
 	const struct mailbox_info *info;
 
-	iter = doveadm_mail_list_iter_init(user, ctx->search_args, iter_flags);
+	iter = doveadm_mail_list_iter_init(user, _ctx->search_args, iter_flags);
 	while ((info = doveadm_mail_list_iter_next(iter)) != NULL) T_BEGIN {
 		(void)cmd_fetch_box(ctx, info);
 	} T_END;
@@ -471,11 +471,11 @@ static void cmd_fetch_init(struct doveadm_mail_cmd_context *_ctx,
 		doveadm_mail_help_name("fetch");
 
 	parse_fetch_fields(ctx, fetch_fields);
-	ctx->search_args = doveadm_mail_build_search_args(args + 1);
+	_ctx->search_args = doveadm_mail_build_search_args(args + 1);
 
 	ctx->output = o_stream_create_fd(STDOUT_FILENO, 0, FALSE);
 	ctx->hdr = str_new(default_pool, 512);
-	if (search_args_have_unique_fetch(ctx->search_args))
+	if (search_args_have_unique_fetch(_ctx->search_args))
 		ctx->prefix = "";
 	else {
 		random_fill_weak(prefix_buf, sizeof(prefix_buf));
@@ -492,9 +492,9 @@ static struct doveadm_mail_cmd_context *cmd_fetch_alloc(void)
 	struct fetch_cmd_context *ctx;
 
 	ctx = doveadm_mail_cmd_alloc(struct fetch_cmd_context);
-	ctx->ctx.init = cmd_fetch_init;
-	ctx->ctx.run = cmd_fetch_run;
-	ctx->ctx.deinit = cmd_fetch_deinit;
+	ctx->ctx.v.init = cmd_fetch_init;
+	ctx->ctx.v.run = cmd_fetch_run;
+	ctx->ctx.v.deinit = cmd_fetch_deinit;
 	return &ctx->ctx;
 }
 
diff --git a/src/doveadm/doveadm-mail-mailbox.c b/src/doveadm/doveadm-mail-mailbox.c
index 378213c0c8..7fb9b8e761 100644
--- a/src/doveadm/doveadm-mail-mailbox.c
+++ b/src/doveadm/doveadm-mail-mailbox.c
@@ -96,7 +96,7 @@ doveadm_mailbox_cmd_alloc_size(size_t size)
 
 	ctx = doveadm_mail_cmd_alloc_size(size);
 	ctx->getopt_args = "78s";
-	ctx->parse_arg = cmd_mailbox_parse_arg;
+	ctx->v.parse_arg = cmd_mailbox_parse_arg;
 	return ctx;
 }
 
@@ -166,8 +166,8 @@ static struct doveadm_mail_cmd_context *cmd_mailbox_list_alloc(void)
 	struct list_cmd_context *ctx;
 
 	ctx = doveadm_mailbox_cmd_alloc(struct list_cmd_context);
-	ctx->ctx.ctx.init = cmd_mailbox_list_init;
-	ctx->ctx.ctx.run = cmd_mailbox_list_run;
+	ctx->ctx.ctx.v.init = cmd_mailbox_list_init;
+	ctx->ctx.ctx.v.run = cmd_mailbox_list_run;
 	return &ctx->ctx.ctx;
 }
 
@@ -235,8 +235,8 @@ static struct doveadm_mail_cmd_context *cmd_mailbox_create_alloc(void)
 	struct mailbox_cmd_context *ctx;
 
 	ctx = doveadm_mailbox_cmd_alloc(struct mailbox_cmd_context);
-	ctx->ctx.ctx.init = cmd_mailbox_create_init;
-	ctx->ctx.ctx.run = cmd_mailbox_create_run;
+	ctx->ctx.ctx.v.init = cmd_mailbox_create_init;
+	ctx->ctx.ctx.v.run = cmd_mailbox_create_run;
 	p_array_init(&ctx->mailboxes, ctx->ctx.ctx.pool, 16);
 	return &ctx->ctx.ctx;
 }
@@ -297,8 +297,8 @@ static struct doveadm_mail_cmd_context *cmd_mailbox_delete_alloc(void)
 	struct mailbox_cmd_context *ctx;
 
 	ctx = doveadm_mailbox_cmd_alloc(struct mailbox_cmd_context);
-	ctx->ctx.ctx.init = cmd_mailbox_delete_init;
-	ctx->ctx.ctx.run = cmd_mailbox_delete_run;
+	ctx->ctx.ctx.v.init = cmd_mailbox_delete_init;
+	ctx->ctx.ctx.v.run = cmd_mailbox_delete_run;
 	p_array_init(&ctx->mailboxes, ctx->ctx.ctx.pool, 16);
 	return &ctx->ctx.ctx;
 }
@@ -361,8 +361,8 @@ static struct doveadm_mail_cmd_context *cmd_mailbox_rename_alloc(void)
 	struct rename_cmd_context *ctx;
 
 	ctx = doveadm_mailbox_cmd_alloc(struct rename_cmd_context);
-	ctx->ctx.ctx.init = cmd_mailbox_rename_init;
-	ctx->ctx.ctx.run = cmd_mailbox_rename_run;
+	ctx->ctx.ctx.v.init = cmd_mailbox_rename_init;
+	ctx->ctx.ctx.v.run = cmd_mailbox_rename_run;
 	return &ctx->ctx.ctx;
 }
 
@@ -423,9 +423,9 @@ cmd_mailbox_subscriptions_alloc(bool subscriptions)
 	ctx->ctx.subscriptions = subscriptions;
 
 	ctx->ctx.ctx.getopt_args = "78";
-	ctx->ctx.ctx.parse_arg = cmd_mailbox_parse_arg;
-	ctx->ctx.ctx.init = cmd_mailbox_subscribe_init;
-	ctx->ctx.ctx.run = cmd_mailbox_subscribe_run;
+	ctx->ctx.ctx.v.parse_arg = cmd_mailbox_parse_arg;
+	ctx->ctx.ctx.v.init = cmd_mailbox_subscribe_init;
+	ctx->ctx.ctx.v.run = cmd_mailbox_subscribe_run;
 	p_array_init(&ctx->mailboxes, ctx->ctx.ctx.pool, 16);
 	return &ctx->ctx.ctx;
 }
diff --git a/src/doveadm/doveadm-mail-search.c b/src/doveadm/doveadm-mail-search.c
index eac69d5167..02174acfd5 100644
--- a/src/doveadm/doveadm-mail-search.c
+++ b/src/doveadm/doveadm-mail-search.c
@@ -8,11 +8,6 @@
 
 #include <stdio.h>
 
-struct search_cmd_context {
-	struct doveadm_mail_cmd_context ctx;
-	struct mail_search_args *search_args;
-};
-
 static int
 cmd_search_box(const struct mailbox_info *info,
 	       struct mail_search_args *search_args)
@@ -42,9 +37,8 @@ cmd_search_box(const struct mailbox_info *info,
 }
 
 static void
-cmd_search_run(struct doveadm_mail_cmd_context *_ctx, struct mail_user *user)
+cmd_search_run(struct doveadm_mail_cmd_context *ctx, struct mail_user *user)
 {
-	struct search_cmd_context *ctx = (struct search_cmd_context *)_ctx;
 	const enum mailbox_list_iter_flags iter_flags =
 		MAILBOX_LIST_ITER_RAW_LIST |
 		MAILBOX_LIST_ITER_VIRTUAL_NAMES |
@@ -60,11 +54,9 @@ cmd_search_run(struct doveadm_mail_cmd_context *_ctx, struct mail_user *user)
 	doveadm_mail_list_iter_deinit(&iter);
 }
 
-static void cmd_search_init(struct doveadm_mail_cmd_context *_ctx,
+static void cmd_search_init(struct doveadm_mail_cmd_context *ctx,
 			    const char *const args[])
 {
-	struct search_cmd_context *ctx = (struct search_cmd_context *)_ctx;
-
 	if (args[0] == NULL)
 		doveadm_mail_help_name("search");
 
@@ -73,12 +65,12 @@ static void cmd_search_init(struct doveadm_mail_cmd_context *_ctx,
 
 static struct doveadm_mail_cmd_context *cmd_search_alloc(void)
 {
-	struct search_cmd_context *ctx;
+	struct doveadm_mail_cmd_context *ctx;
 
-	ctx = doveadm_mail_cmd_alloc(struct search_cmd_context);
-	ctx->ctx.init = cmd_search_init;
-	ctx->ctx.run = cmd_search_run;
-	return &ctx->ctx;
+	ctx = doveadm_mail_cmd_alloc(struct doveadm_mail_cmd_context);
+	ctx->v.init = cmd_search_init;
+	ctx->v.run = cmd_search_run;
+	return ctx;
 }
 
 struct doveadm_mail_cmd cmd_search = {
diff --git a/src/doveadm/doveadm-mail.c b/src/doveadm/doveadm-mail.c
index 07792f6930..216b69247d 100644
--- a/src/doveadm/doveadm-mail.c
+++ b/src/doveadm/doveadm-mail.c
@@ -21,6 +21,9 @@
 #include <stdlib.h>
 
 ARRAY_TYPE(doveadm_mail_cmd) doveadm_mail_cmds;
+void (*hook_doveadm_mail_init)(struct doveadm_mail_cmd_context *ctx);
+struct doveadm_mail_cmd_module_register
+	doveadm_mail_cmd_module_register = { 0 };
 
 static int killed_signo = 0;
 
@@ -60,7 +63,7 @@ static struct doveadm_mail_cmd_context *cmd_purge_alloc(void)
 	struct doveadm_mail_cmd_context *ctx;
 
 	ctx = doveadm_mail_cmd_alloc(struct doveadm_mail_cmd_context);
-	ctx->run = cmd_purge_run;
+	ctx->v.run = cmd_purge_run;
 	return ctx;
 }
 
@@ -156,14 +159,13 @@ static struct doveadm_mail_cmd_context *cmd_force_resync_alloc(void)
 	struct force_resync_cmd_context *ctx;
 
 	ctx = doveadm_mail_cmd_alloc(struct force_resync_cmd_context);
-	ctx->ctx.init = cmd_force_resync_init;
-	ctx->ctx.run = cmd_force_resync_run;
+	ctx->ctx.v.init = cmd_force_resync_init;
+	ctx->ctx.v.run = cmd_force_resync_run;
 	return &ctx->ctx;
 }
 
 static int
 doveadm_mail_next_user(struct doveadm_mail_cmd_context *ctx,
-		       struct mail_storage_service_ctx *storage_service,
 		       const struct mail_storage_service_input *input,
 		       const char **error_r)
 {
@@ -173,7 +175,8 @@ doveadm_mail_next_user(struct doveadm_mail_cmd_context *ctx,
 	int ret;
 
 	i_set_failure_prefix(t_strdup_printf("doveadm(%s): ", input->username));
-	ret = mail_storage_service_lookup(storage_service, input,
+
+	ret = mail_storage_service_lookup(ctx->storage_service, input,
 					  &service_user, &error);
 	if (ret <= 0) {
 		if (ret < 0) {
@@ -183,7 +186,7 @@ doveadm_mail_next_user(struct doveadm_mail_cmd_context *ctx,
 		return ret;
 	}
 
-	ret = mail_storage_service_next(storage_service, service_user,
+	ret = mail_storage_service_next(ctx->storage_service, service_user,
 					&mail_user);
 	if (ret < 0) {
 		*error_r = "User init failed";
@@ -191,9 +194,9 @@ doveadm_mail_next_user(struct doveadm_mail_cmd_context *ctx,
 		return ret;
 	}
 
-	ctx->run(ctx, mail_user);
-	mail_storage_service_user_free(&service_user);
+	ctx->v.run(ctx, mail_user);
 	mail_user_unref(&mail_user);
+	mail_storage_service_user_free(&service_user);
 	return 1;
 }
 
@@ -202,7 +205,6 @@ doveadm_mail_single_user(struct doveadm_mail_cmd_context *ctx,
 			 const char *username,
 			 enum mail_storage_service_flags service_flags)
 {
-	struct mail_storage_service_ctx *storage_service;
 	struct mail_storage_service_input input;
 	const char *error;
 	int ret;
@@ -213,14 +215,17 @@ doveadm_mail_single_user(struct doveadm_mail_cmd_context *ctx,
 	memset(&input, 0, sizeof(input));
 	input.username = username;
 
-	storage_service = mail_storage_service_init(master_service, NULL,
-						    service_flags);
-	ret = doveadm_mail_next_user(ctx, storage_service, &input, &error);
+	ctx->storage_service = mail_storage_service_init(master_service, NULL,
+							 service_flags);
+	if (hook_doveadm_mail_init != NULL)
+		hook_doveadm_mail_init(ctx);
+
+	ret = doveadm_mail_next_user(ctx, &input, &error);
 	if (ret < 0)
 		i_fatal("%s", error);
 	else if (ret == 0)
 		i_fatal("User no longer exists");
-	mail_storage_service_deinit(&storage_service);
+	mail_storage_service_deinit(&ctx->storage_service);
 }
 
 static void sig_die(const siginfo_t *si, void *context ATTR_UNUSED)
@@ -233,7 +238,6 @@ doveadm_mail_all_users(struct doveadm_mail_cmd_context *ctx,
 		       enum mail_storage_service_flags service_flags)
 {
 	struct mail_storage_service_input input;
-	struct mail_storage_service_ctx *storage_service;
 	unsigned int user_idx, user_count, interval, n;
 	const char *user, *error;
 	int ret;
@@ -243,24 +247,24 @@ doveadm_mail_all_users(struct doveadm_mail_cmd_context *ctx,
 	memset(&input, 0, sizeof(input));
 	input.service = "doveadm";
 
-	storage_service = mail_storage_service_init(master_service, NULL,
-						    service_flags);
-
+	ctx->storage_service = mail_storage_service_init(master_service, NULL,
+							 service_flags);
         lib_signals_set_handler(SIGINT, FALSE, sig_die, NULL);
 	lib_signals_set_handler(SIGTERM, FALSE, sig_die, NULL);
 
-	user_count = mail_storage_service_all_init(storage_service);
+	if (hook_doveadm_mail_init != NULL)
+		hook_doveadm_mail_init(ctx);
+
+	user_count = mail_storage_service_all_init(ctx->storage_service);
 	n = user_count / 10000;
 	for (interval = 10; n > 0 && interval < 1000; interval *= 10)
 		n /= 10;
 	
 	user_idx = 0;
-	while ((ret = mail_storage_service_all_next(storage_service,
-						    &user)) > 0) {
+	while ((ret = ctx->v.get_next_user(ctx, &user)) > 0) {
 		input.username = user;
 		T_BEGIN {
-			ret = doveadm_mail_next_user(ctx, storage_service,
-						     &input, &error);
+			ret = doveadm_mail_next_user(ctx, &input, &error);
 			if (ret < 0)
 				i_error("%s", error);
 			else if (ret == 0)
@@ -285,7 +289,25 @@ doveadm_mail_all_users(struct doveadm_mail_cmd_context *ctx,
 	i_set_failure_prefix("doveadm: ");
 	if (ret < 0)
 		i_error("Failed to iterate through some users");
-	mail_storage_service_deinit(&storage_service);
+	mail_storage_service_deinit(&ctx->storage_service);
+}
+
+static void
+doveadm_mail_cmd_init_noop(struct doveadm_mail_cmd_context *ctx ATTR_UNUSED,
+			   const char *const args[] ATTR_UNUSED)
+{
+}
+
+static int
+doveadm_mail_cmd_get_next_user(struct doveadm_mail_cmd_context *ctx,
+			       const char **username_r)
+{
+	return mail_storage_service_all_next(ctx->storage_service, username_r);
+}
+
+static void
+doveadm_mail_cmd_deinit_noop(struct doveadm_mail_cmd_context *ctx ATTR_UNUSED)
+{
 }
 
 static void
@@ -302,6 +324,15 @@ doveadm_mail_cmd(const struct doveadm_mail_cmd *cmd, int argc, char *argv[])
 		service_flags |= MAIL_STORAGE_SERVICE_FLAG_DEBUG;
 
 	ctx = cmd->alloc();
+	if (ctx->v.init == NULL)
+		ctx->v.init = doveadm_mail_cmd_init_noop;
+	if (ctx->v.get_next_user == NULL)
+		ctx->v.get_next_user = doveadm_mail_cmd_get_next_user;
+	if (ctx->v.deinit == NULL)
+		ctx->v.deinit = doveadm_mail_cmd_deinit_noop;
+
+	p_array_init(&ctx->module_contexts, ctx->pool, 5);
+
 	getopt_args = t_strconcat("Au:", ctx->getopt_args, NULL);
 	username = getenv("USER");
 	while ((c = getopt(argc, argv, getopt_args)) > 0) {
@@ -315,7 +346,8 @@ doveadm_mail_cmd(const struct doveadm_mail_cmd *cmd, int argc, char *argv[])
 			username = optarg;
 			break;
 		default:
-			if (ctx->parse_arg == NULL || !ctx->parse_arg(ctx, c))
+			if (ctx->v.parse_arg == NULL ||
+			    !ctx->v.parse_arg(ctx, c))
 				doveadm_mail_help(cmd);
 		}
 	}
@@ -326,16 +358,15 @@ doveadm_mail_cmd(const struct doveadm_mail_cmd *cmd, int argc, char *argv[])
 			cmd->name, argv[0]);
 	}
 
-	if (ctx->init != NULL)
-		ctx->init(ctx, (const void *)argv);
+	ctx->v.init(ctx, (const void *)argv);
+
 	if (!all_users) {
 		doveadm_mail_single_user(ctx, username, service_flags);
 	} else {
 		service_flags |= MAIL_STORAGE_SERVICE_FLAG_TEMP_PRIV_DROP;
 		doveadm_mail_all_users(ctx, service_flags);
 	}
-	if (ctx->deinit != NULL)
-		ctx->deinit(ctx);
+	ctx->v.deinit(ctx);
 }
 
 static bool
diff --git a/src/doveadm/doveadm-mail.h b/src/doveadm/doveadm-mail.h
index 234ddcab8b..bd629b5ba6 100644
--- a/src/doveadm/doveadm-mail.h
+++ b/src/doveadm/doveadm-mail.h
@@ -2,22 +2,46 @@
 #define DOVEADM_MAIL_H
 
 #include "doveadm.h"
+#include "module-context.h"
 
 struct mail_user;
+struct mail_storage_service_ctx;
+struct mail_storage_service_input;
+struct mail_storage_service_user;
 struct doveadm_mail_cmd_context;
 
-struct doveadm_mail_cmd_context {
-	pool_t pool;
-	const char *getopt_args;
-
+struct doveadm_mail_cmd_vfuncs {
 	bool (*parse_arg)(struct doveadm_mail_cmd_context *ctx,int c);
 	void (*init)(struct doveadm_mail_cmd_context *ctx,
 		     const char *const args[]);
+	int (*get_next_user)(struct doveadm_mail_cmd_context *ctx,
+			     const char **username_r);
 	void (*run)(struct doveadm_mail_cmd_context *ctx,
 		    struct mail_user *mail_user);
 	void (*deinit)(struct doveadm_mail_cmd_context *ctx);
 };
 
+struct doveadm_mail_cmd_module_register {
+	unsigned int id;
+};
+
+union doveadm_mail_cmd_module_context {
+        struct doveadm_mail_cmd_vfuncs super;
+	struct doveadm_mail_cmd_module_register *reg;
+};
+
+struct doveadm_mail_cmd_context {
+	pool_t pool;
+	const char *getopt_args;
+	struct mail_storage_service_ctx *storage_service;
+	/* search args aren't set for all mail commands */
+	struct mail_search_args *search_args;
+
+	struct doveadm_mail_cmd_vfuncs v;
+
+	ARRAY_DEFINE(module_contexts, union doveadm_mail_cmd_module_context *);
+};
+
 struct doveadm_mail_cmd {
 	struct doveadm_mail_cmd_context *(*alloc)(void);
 	const char *name;
@@ -26,6 +50,8 @@ struct doveadm_mail_cmd {
 ARRAY_DEFINE_TYPE(doveadm_mail_cmd, struct doveadm_mail_cmd);
 
 extern ARRAY_TYPE(doveadm_mail_cmd) doveadm_mail_cmds;
+extern void (*hook_doveadm_mail_init)(struct doveadm_mail_cmd_context *ctx);
+extern struct doveadm_mail_cmd_module_register doveadm_mail_cmd_module_register;
 
 bool doveadm_mail_try_run(const char *cmd_name, int argc, char *argv[]);
 void doveadm_mail_register_cmd(const struct doveadm_mail_cmd *cmd);
diff --git a/src/doveadm/doveadm-settings.c b/src/doveadm/doveadm-settings.c
index 7d086752c3..120c97c661 100644
--- a/src/doveadm/doveadm-settings.c
+++ b/src/doveadm/doveadm-settings.c
@@ -12,6 +12,7 @@ static const struct setting_define doveadm_setting_defines[] = {
 	DEF(SET_STR, base_dir),
 	DEF(SET_STR, mail_plugins),
 	DEF(SET_STR, mail_plugin_dir),
+	{ SET_STRLIST, "plugin", offsetof(struct doveadm_settings, plugin_envs), NULL },
 
 	SETTING_DEFINE_LIST_END
 };
@@ -19,7 +20,9 @@ static const struct setting_define doveadm_setting_defines[] = {
 const struct doveadm_settings doveadm_default_settings = {
 	.base_dir = PKG_RUNDIR,
 	.mail_plugins = "",
-	.mail_plugin_dir = MODULEDIR
+	.mail_plugin_dir = MODULEDIR,
+
+	.plugin_envs = ARRAY_INIT
 };
 
 const struct setting_parser_info doveadm_setting_parser_info = {
diff --git a/src/doveadm/doveadm-settings.h b/src/doveadm/doveadm-settings.h
index 622ab46d7f..e01c99b3d8 100644
--- a/src/doveadm/doveadm-settings.h
+++ b/src/doveadm/doveadm-settings.h
@@ -5,6 +5,8 @@ struct doveadm_settings {
 	const char *base_dir;
 	const char *mail_plugins;
 	const char *mail_plugin_dir;
+
+	ARRAY_DEFINE(plugin_envs, const char *);
 };
 
 extern const struct setting_parser_info doveadm_setting_parser_info;
diff --git a/src/doveadm/doveadm.c b/src/doveadm/doveadm.c
index f069021454..c3a76d0b65 100644
--- a/src/doveadm/doveadm.c
+++ b/src/doveadm/doveadm.c
@@ -57,6 +57,22 @@ const char *unixdate2str(time_t timestamp)
 	return buf;
 }
 
+const char *doveadm_plugin_getenv(const char *name)
+{
+	const char *const *envs;
+	unsigned int i, count;
+
+	if (!array_is_created(&doveadm_settings->plugin_envs))
+		return NULL;
+
+	envs = array_get(&doveadm_settings->plugin_envs, &count);
+	for (i = 0; i < count; i += 2) {
+		if (strcmp(envs[i], name) == 0)
+			return envs[i+1];
+	}
+	return NULL;
+}
+
 static void cmd_help(int argc, char *argv[])
 {
 	const struct doveadm_cmd *cmd;
diff --git a/src/doveadm/doveadm.h b/src/doveadm/doveadm.h
index 7579cb7994..afe8f4505f 100644
--- a/src/doveadm/doveadm.h
+++ b/src/doveadm/doveadm.h
@@ -31,6 +31,7 @@ void usage(void) ATTR_NORETURN;
 void help(const struct doveadm_cmd *cmd);
 
 const char *unixdate2str(time_t timestamp);
+const char *doveadm_plugin_getenv(const char *name);
 void doveadm_register_director_commands(void);
 
 #endif
-- 
2.47.3