--- a/src/lib-imap-client/imapc-client.c	Mon Apr 24 17:58:53 2017 +0300
+++ b/src/lib-imap-client/imapc-client.c	Mon Apr 24 17:59:53 2017 +0300
@@ -31,6 +31,7 @@
 	{ "UNSELECT", IMAPC_CAPABILITY_UNSELECT },
 	{ "ESEARCH", IMAPC_CAPABILITY_ESEARCH },
 	{ "WITHIN", IMAPC_CAPABILITY_WITHIN },
+	{ "QUOTA", IMAPC_CAPABILITY_QUOTA },
 
 	{ "IMAP4REV1", IMAPC_CAPABILITY_IMAP4REV1 },
 	{ NULL, 0 }

--- a/src/lib-imap-client/imapc-client.h	Mon Apr 24 17:58:53 2017 +0300
+++ b/src/lib-imap-client/imapc-client.h	Mon Apr 24 17:59:53 2017 +0300
@@ -31,6 +31,7 @@
 	IMAPC_CAPABILITY_UNSELECT	= 0x400,
 	IMAPC_CAPABILITY_ESEARCH	= 0x800,
 	IMAPC_CAPABILITY_WITHIN		= 0x1000,
+	IMAPC_CAPABILITY_QUOTA		= 0x2000,
 
 	IMAPC_CAPABILITY_IMAP4REV1	= 0x40000000
 };

--- a/src/plugins/quota/Makefile.am	Mon Apr 24 17:58:53 2017 +0300
+++ b/src/plugins/quota/Makefile.am	Mon Apr 24 17:59:53 2017 +0300
@@ -10,9 +10,12 @@
 	-I$(top_srcdir)/src/lib-dict \
 	-I$(top_srcdir)/src/lib-index \
 	-I$(top_srcdir)/src/lib-mail \
+	-I$(top_srcdir)/src/lib-imap \
+	-I$(top_srcdir)/src/lib-imap-client \
 	-I$(top_srcdir)/src/lib-settings \
 	-I$(top_srcdir)/src/lib-storage \
 	-I$(top_srcdir)/src/lib-storage/index \
+	-I$(top_srcdir)/src/lib-storage/index/imapc \
 	-I$(top_srcdir)/src/lib-storage/index/maildir \
 	-I$(top_srcdir)/src/doveadm
 
@@ -29,6 +32,7 @@
 	quota-fs.c \
 	quota-dict.c \
 	quota-dirsize.c \
+	quota-imapc.c \
 	quota-maildir.c \
         quota-plugin.c \
 	quota-storage.c \
@@ -40,6 +44,7 @@
 	quota-fs.lo \
 	quota-dict.lo \
 	quota-dirsize.lo \
+	quota-imapc.lo \
 	quota-maildir.lo \
         quota-plugin.lo \
 	quota-storage.lo \

--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/src/plugins/quota/quota-imapc.c	Mon Apr 24 17:59:53 2017 +0300
@@ -0,0 +1,448 @@
+/* Copyright (c) 2017 Dovecot authors, see the included COPYING file */
+
+#include "lib.h"
+#include "array.h"
+#include "ioloop.h"
+#include "imap-arg.h"
+#include "imapc-storage.h"
+#include "mailbox-list-private.h"
+#include "quota-private.h"
+
+struct imapc_quota_refresh_root {
+	const char *name;
+	unsigned int order;
+
+	uint64_t bytes_cur, count_cur;
+	uint64_t bytes_limit, count_limit;
+};
+
+struct imapc_quota_refresh {
+	pool_t pool;
+	const char *box_name;
+	ARRAY(struct imapc_quota_refresh_root) roots;
+};
+
+struct imapc_quota_root {
+	struct quota_root root;
+	const char *box_name, *root_name;
+
+	struct mail_namespace *imapc_ns;
+	struct imapc_storage_client *client;
+	bool initialized;
+
+	uint64_t bytes_last, count_last;
+
+	struct timeval last_refresh;
+	struct imapc_quota_refresh refresh;
+};
+
+extern struct quota_backend quota_backend_imapc;
+
+static struct quota_root *imapc_quota_alloc(void)
+{
+	struct imapc_quota_root *root;
+
+	root = i_new(struct imapc_quota_root, 1);
+	return &root->root;
+}
+
+static int imapc_quota_init(struct quota_root *_root, const char *args,
+			    const char **error_r)
+{
+	struct imapc_quota_root *root = (struct imapc_quota_root *)_root;
+	const char *const *tmp;
+
+	if (args == NULL)
+		args = "";
+	for (tmp = t_strsplit(args, ":"); *tmp != NULL; tmp++) {
+		if (strncmp(*tmp, "ns=", 3) == 0)
+			_root->ns_prefix = p_strdup(_root->pool, *tmp + 3);
+		else if (strncmp(*tmp, "box=", 4) == 0)
+			root->box_name = p_strdup(_root->pool, *tmp + 4);
+		else if (strncmp(*tmp, "root=", 5) == 0)
+			root->root_name = p_strdup(_root->pool, *tmp + 5);
+		else {
+			*error_r = t_strdup_printf("Invalid parameter: %s", *tmp);
+			return -1;
+		}
+	}
+	if (root->box_name == NULL && root->root_name == NULL)
+		root->box_name = "INBOX";
+	return 0;
+}
+
+static void imapc_quota_deinit(struct quota_root *_root)
+{
+	i_free(_root);
+}
+
+static void
+imapc_quota_root_namespace_added(struct quota_root *_root,
+				 struct mail_namespace *ns)
+{
+	struct imapc_quota_root *root = (struct imapc_quota_root *)_root;
+
+	if (root->imapc_ns == NULL)
+		root->imapc_ns = ns;
+}
+
+static struct imapc_quota_refresh *
+imapc_quota_root_refresh_find(struct imapc_storage_client *client)
+{
+	struct imapc_storage *storage = client->_storage;
+	struct quota *quota;
+	struct quota_root *const *rootp;
+
+	i_assert(storage != NULL);
+	quota = quota_get_mail_user_quota(storage->storage.user);
+	i_assert(quota != NULL);
+
+	/* find the quota root that is being refreshed */
+	array_foreach(&quota->roots, rootp) {
+		if ((*rootp)->backend.name == quota_backend_imapc.name) {
+			struct imapc_quota_root *root =
+				(struct imapc_quota_root *)*rootp;
+
+			if (root->refresh.pool != NULL)
+				return &root->refresh;
+		}
+	}
+	return NULL;
+}
+
+static struct imapc_quota_refresh_root *
+imapc_quota_refresh_root_get(struct imapc_quota_refresh *refresh,
+			     const char *root_name)
+{
+	struct imapc_quota_refresh_root *refresh_root;
+
+	array_foreach_modifiable(&refresh->roots, refresh_root) {
+		if (strcmp(refresh_root->name, root_name) == 0)
+			return refresh_root;
+	}
+
+	refresh_root = array_append_space(&refresh->roots);
+	refresh_root->order = UINT_MAX;
+	refresh_root->name = p_strdup(refresh->pool, root_name);
+	refresh_root->bytes_limit = (uint64_t)-1;
+	refresh_root->count_limit = (uint64_t)-1;
+	return refresh_root;
+}
+
+static void imapc_untagged_quotaroot(const struct imapc_untagged_reply *reply,
+				     struct imapc_storage_client *client)
+{
+	struct imapc_quota_refresh *refresh;
+	struct imapc_quota_refresh_root *refresh_root;
+	const char *mailbox_name, *root_name;
+	unsigned int i;
+
+	if (!imap_arg_get_astring(&reply->args[0], &mailbox_name))
+		return;
+
+	if ((refresh = imapc_quota_root_refresh_find(client)) == NULL ||
+	    refresh->box_name == NULL ||
+	    strcmp(refresh->box_name, mailbox_name) != 0) {
+		/* unsolicited QUOTAROOT reply - ignore */
+		return;
+	}
+	if (array_count(&refresh->roots) > 0) {
+		/* duplicate QUOTAROOT reply - ignore */
+		return;
+	}
+
+	i = 1;
+	while (imap_arg_get_astring(&reply->args[i], &root_name)) {
+		refresh_root = imapc_quota_refresh_root_get(refresh, root_name);
+		refresh_root->order = i;
+		i++;
+	}
+}
+
+static void imapc_untagged_quota(const struct imapc_untagged_reply *reply,
+				 struct imapc_storage_client *client)
+{
+	const struct imap_arg *list;
+	struct imapc_quota_refresh *refresh;
+	struct imapc_quota_refresh_root *refresh_root;
+	const char *root_name, *resource, *value_str, *limit_str;
+	uint64_t value, limit;
+	unsigned int i;
+
+	if (!imap_arg_get_astring(&reply->args[0], &root_name) ||
+	    !imap_arg_get_list(&reply->args[1], &list))
+		return;
+
+	if ((refresh = imapc_quota_root_refresh_find(client)) == NULL) {
+		/* unsolicited QUOTA reply - ignore */
+		return;
+	}
+	refresh_root = imapc_quota_refresh_root_get(refresh, root_name);
+
+	for (i = 0; list[i].type != IMAP_ARG_EOL; i += 3) {
+		if (!imap_arg_get_atom(&list[i], &resource) ||
+		    !imap_arg_get_atom(&list[i+1], &value_str) ||
+		    !imap_arg_get_atom(&list[i+2], &limit_str) ||
+		    /* RFC2087 uses 32bit number, but be ready for future */
+		    str_to_uint64(value_str, &value) < 0 ||
+		    str_to_uint64(limit_str, &limit) < 0)
+			return;
+
+		if (strcasecmp(resource, QUOTA_NAME_STORAGE_KILOBYTES) == 0) {
+			refresh_root->bytes_cur = value * 1024;
+			refresh_root->bytes_limit = limit * 1024;
+		} else if (strcasecmp(resource, QUOTA_NAME_MESSAGES) == 0) {
+			refresh_root->count_cur = value;
+			refresh_root->count_limit = limit;
+		}
+	}
+}
+
+static bool imapc_quota_client_init(struct imapc_quota_root *root)
+{
+	struct mailbox_list *list;
+	struct mail_storage *storage;
+
+	if (root->initialized)
+		return root->client != NULL;
+	root->initialized = TRUE;
+
+	list = root->imapc_ns->list;
+	if (mailbox_list_get_storage(&list, "", &storage) == 0 &&
+	    strcmp(storage->name, IMAPC_STORAGE_NAME) != 0) {
+		/* non-imapc namespace, skip */
+		if ((storage->class_flags &
+		     MAIL_STORAGE_CLASS_FLAG_NOQUOTA) == 0) {
+			i_warning("quota: Namespace '%s' is not imapc, "
+				  "skipping for imapc quota",
+				  root->imapc_ns->prefix);
+		}
+		return FALSE;
+	}
+	root->client = ((struct imapc_storage *)storage)->client;
+
+	imapc_storage_client_register_untagged(root->client, "QUOTAROOT",
+					       imapc_untagged_quotaroot);
+	imapc_storage_client_register_untagged(root->client, "QUOTA",
+					       imapc_untagged_quota);
+	return TRUE;
+}
+
+static void imapc_quota_refresh_init(struct imapc_quota_refresh *refresh)
+{
+	i_assert(refresh->pool == NULL);
+
+	refresh->pool = pool_alloconly_create("imapc quota refresh", 256);
+	p_array_init(&refresh->roots, refresh->pool, 4);
+}
+
+static void
+imapc_quota_refresh_update(struct quota *quota,
+			   struct imapc_quota_refresh *refresh)
+{
+	struct quota_root *const *rootp;
+	const struct imapc_quota_refresh_root *refresh_root;
+
+	if (array_count(&refresh->roots) == 0) {
+		i_error("quota: imapc didn't return any QUOTA results");
+		return;
+	}
+	/* use the first quota root for everything */
+	refresh_root = array_idx(&refresh->roots, 0);
+
+	array_foreach(&quota->roots, rootp) {
+		if ((*rootp)->backend.name == quota_backend_imapc.name) {
+			struct imapc_quota_root *root =
+				(struct imapc_quota_root *)*rootp;
+
+			root->bytes_last = refresh_root->bytes_cur;
+			root->count_last = refresh_root->count_cur;
+			root->root.bytes_limit = refresh_root->bytes_limit;
+			root->root.count_limit = refresh_root->count_limit;
+		}
+	}
+}
+
+static void
+imapc_quota_refresh_deinit(struct quota *quota,
+			   struct imapc_quota_refresh *refresh, bool success)
+{
+	if (success)
+		imapc_quota_refresh_update(quota, refresh);
+	pool_unref(&refresh->pool);
+	i_zero(refresh);
+}
+
+static int
+imapc_quota_refresh_root_order_cmp(const struct imapc_quota_refresh_root *root1,
+				   const struct imapc_quota_refresh_root *root2)
+{
+	if (root1->order < root2->order)
+		return -1;
+	else if (root1->order > root2->order)
+		return 1;
+	else
+		return 0;
+}
+
+static int imapc_quota_refresh_mailbox(struct imapc_quota_root *root)
+{
+	struct imapc_simple_context sctx;
+	struct imapc_command *cmd;
+
+	i_assert(root->box_name != NULL);
+
+	/* ask quotas for the configured mailbox */
+	imapc_quota_refresh_init(&root->refresh);
+	root->refresh.box_name = root->box_name;
+
+	imapc_simple_context_init(&sctx, root->client);
+	cmd = imapc_client_cmd(root->client->client,
+			       imapc_simple_callback, &sctx);
+	imapc_command_sendf(cmd, "GETQUOTAROOT %s", root->box_name);
+	imapc_simple_run(&sctx);
+
+	/* if there are multiple quota roots, use the first one returned by
+	   the QUOTAROOT */
+	array_sort(&root->refresh.roots, imapc_quota_refresh_root_order_cmp);
+	imapc_quota_refresh_deinit(root->root.quota, &root->refresh,
+				   sctx.ret == 0);
+	return sctx.ret;
+}
+
+static int imapc_quota_refresh_root(struct imapc_quota_root *root)
+{
+	struct imapc_simple_context sctx;
+	struct imapc_command *cmd;
+
+	i_assert(root->root_name != NULL);
+
+	/* ask quotas for the configured quota root */
+	imapc_quota_refresh_init(&root->refresh);
+
+	imapc_simple_context_init(&sctx, root->client);
+	cmd = imapc_client_cmd(root->client->client,
+			       imapc_simple_callback, &sctx);
+	imapc_command_sendf(cmd, "GETQUOTA %s", root->root_name);
+	imapc_simple_run(&sctx);
+
+	/* there shouldn't be more than one QUOTA reply, but ignore anyway
+	   anything we didn't expect. */
+	while (array_count(&root->refresh.roots) > 0) {
+		const struct imapc_quota_refresh_root *refresh_root =
+			array_idx(&root->refresh.roots, 0);
+		if (strcmp(refresh_root->name, root->root_name) == 0)
+			break;
+		array_delete(&root->refresh.roots, 0, 1);
+	}
+	imapc_quota_refresh_deinit(root->root.quota, &root->refresh,
+				   sctx.ret == 0);
+	return sctx.ret;
+}
+
+static int imapc_quota_refresh(struct imapc_quota_root *root)
+{
+	enum imapc_capability capa;
+
+	if (root->imapc_ns == NULL) {
+		/* imapc namespace is missing - disable this quota backend */
+		return 0;
+	}
+	if (root->last_refresh.tv_sec == ioloop_timeval.tv_sec &&
+	    root->last_refresh.tv_usec == ioloop_timeval.tv_usec)
+		return 0;
+	if (!imapc_quota_client_init(root))
+		return 0;
+
+	if (imapc_client_get_capabilities(root->client->client, &capa) < 0)
+		return -1;
+	if ((capa & IMAPC_CAPABILITY_QUOTA) == 0) {
+		/* no QUOTA capability - disable quota */
+		i_warning("quota: Remote IMAP server doesn't support QUOTA - disabling");
+		root->client = NULL;
+		return 0;
+	}
+
+	root->last_refresh = ioloop_timeval;
+	if (root->root_name == NULL)
+		return imapc_quota_refresh_mailbox(root);
+	else
+		return imapc_quota_refresh_root(root);
+}
+
+static int imapc_quota_init_limits(struct quota_root *_root)
+{
+	struct imapc_quota_root *root = (struct imapc_quota_root *)_root;
+
+	return imapc_quota_refresh(root);
+}
+
+static void
+imapc_quota_namespace_added(struct quota *quota, struct mail_namespace *ns)
+{
+	struct quota_root **roots;
+	unsigned int i, count;
+
+	roots = array_get_modifiable(&quota->roots, &count);
+	for (i = 0; i < count; i++) {
+		if (roots[i]->backend.name == quota_backend_imapc.name &&
+		    ((roots[i]->ns_prefix == NULL &&
+		      ns->type == MAIL_NAMESPACE_TYPE_PRIVATE) ||
+		     roots[i]->ns == ns))
+			imapc_quota_root_namespace_added(roots[i], ns);
+	}
+}
+
+static const char *const *
+imapc_quota_root_get_resources(struct quota_root *root ATTR_UNUSED)
+{
+	static const char *resources_both[] = {
+		QUOTA_NAME_STORAGE_KILOBYTES,
+		QUOTA_NAME_MESSAGES,
+		NULL
+	};
+	return resources_both;
+}
+
+static int
+imapc_quota_get_resource(struct quota_root *_root, const char *name,
+			 uint64_t *value_r)
+{
+	struct imapc_quota_root *root = (struct imapc_quota_root *)_root;
+
+	if (imapc_quota_refresh(root) < 0)
+		return -1;
+
+	if (strcmp(name, QUOTA_NAME_STORAGE_BYTES) == 0)
+		*value_r = root->bytes_last;
+	else if (strcmp(name, QUOTA_NAME_MESSAGES) == 0)
+		*value_r = root->count_last;
+	else
+		return 0;
+	return 1;
+}
+
+static int 
+imapc_quota_update(struct quota_root *root ATTR_UNUSED,
+		   struct quota_transaction_context *ctx ATTR_UNUSED)
+{
+	return 0;
+}
+
+struct quota_backend quota_backend_imapc = {
+	"imapc",
+
+	{
+		imapc_quota_alloc,
+		imapc_quota_init,
+		imapc_quota_deinit,
+		NULL,
+		imapc_quota_init_limits,
+		imapc_quota_namespace_added,
+		imapc_quota_root_get_resources,
+		imapc_quota_get_resource,
+		imapc_quota_update,
+		NULL,
+		NULL
+	}
+};

--- a/src/plugins/quota/quota.c	Mon Apr 24 17:58:53 2017 +0300
+++ b/src/plugins/quota/quota.c	Mon Apr 24 17:59:53 2017 +0300
@@ -39,6 +39,7 @@
 extern struct quota_backend quota_backend_dict;
 extern struct quota_backend quota_backend_dirsize;
 extern struct quota_backend quota_backend_fs;
+extern struct quota_backend quota_backend_imapc;
 extern struct quota_backend quota_backend_maildir;
 
 static const struct quota_backend *quota_internal_backends[] = {
@@ -48,6 +49,7 @@
 	&quota_backend_count,
 	&quota_backend_dict,
 	&quota_backend_dirsize,
+	&quota_backend_imapc,
 	&quota_backend_maildir
 };