src/lib-storage/mail-storage.c

	mail-storage.c revision 02f884382018f4435407374a059407caa44c9239
2454dfa32c93c20a8522c6ed42fe057baaac9f9aStephan Bosch/* Copyright (c) 2002-2012 Dovecot authors, see the included COPYING file */
dc9bfb7dc057964238e181d3d8b08751527bb08aTimo Sirainen
08d6658a4e2ec8104cd1307f6baa75fdb07a24f8Mark Washenberger#include "lib.h"
7a60e1dc9e93ef3f7c7fe1af6385a0bfa1e31bc3Timo Sirainen#include "ioloop.h"
31a12066e4cd9310d64091c81b59fb8eb1986023Timo Sirainen#include "array.h"
44cf91b7a701a9b4d9f59a990552eab4f7f64fbcTimo Sirainen#include "llist.h"
dc9bfb7dc057964238e181d3d8b08751527bb08aTimo Sirainen#include "unichar.h"
dc9bfb7dc057964238e181d3d8b08751527bb08aTimo Sirainen#include "istream.h"
dc9bfb7dc057964238e181d3d8b08751527bb08aTimo Sirainen#include "eacces-error.h"
dc9bfb7dc057964238e181d3d8b08751527bb08aTimo Sirainen#include "mkdir-parents.h"
dc9bfb7dc057964238e181d3d8b08751527bb08aTimo Sirainen#include "time-util.h"
dc9bfb7dc057964238e181d3d8b08751527bb08aTimo Sirainen#include "var-expand.h"
7ace5117d5f2395bd66f20b09e77dac05492f7ceTimo Sirainen#include "mail-index-private.h"
7ace5117d5f2395bd66f20b09e77dac05492f7ceTimo Sirainen#include "mail-index-alloc-cache.h"
7ace5117d5f2395bd66f20b09e77dac05492f7ceTimo Sirainen#include "mailbox-list-private.h"
7ace5117d5f2395bd66f20b09e77dac05492f7ceTimo Sirainen#include "mail-storage-private.h"
7ace5117d5f2395bd66f20b09e77dac05492f7ceTimo Sirainen#include "mail-storage-settings.h"
9ed2951bd0bb1878a27437d7c00611b2baadd614Timo Sirainen#include "mail-namespace.h"
7ace5117d5f2395bd66f20b09e77dac05492f7ceTimo Sirainen#include "mail-search.h"
7ace5117d5f2395bd66f20b09e77dac05492f7ceTimo Sirainen#include "mail-search-register.h"
7ace5117d5f2395bd66f20b09e77dac05492f7ceTimo Sirainen#include "mailbox-search-result-private.h"
6cbe2facd40ea3461620571a1c168ce9884be3b3Timo Sirainen#include "mailbox-guid-cache.h"
7ace5117d5f2395bd66f20b09e77dac05492f7ceTimo Sirainen
6135260095e1704ed6edff9d00bdfc043c11429cTimo Sirainen#include <stdlib.h>
7ace5117d5f2395bd66f20b09e77dac05492f7ceTimo Sirainen#include <ctype.h>
7ace5117d5f2395bd66f20b09e77dac05492f7ceTimo Sirainen
90cf976e328e093da91a8332d96182201f4ef6c1Timo Sirainen#define MAILBOX_DELETE_RETRY_SECS (60*5)
90cf976e328e093da91a8332d96182201f4ef6c1Timo Sirainen
90cf976e328e093da91a8332d96182201f4ef6c1Timo Sirainenextern struct mail_search_register *mail_search_register_imap;
90cf976e328e093da91a8332d96182201f4ef6c1Timo Sirainenextern struct mail_search_register *mail_search_register_human;
90cf976e328e093da91a8332d96182201f4ef6c1Timo Sirainen
44cf91b7a701a9b4d9f59a990552eab4f7f64fbcTimo Sirainenstruct mail_storage_module_register mail_storage_module_register = { 0 };
90cf976e328e093da91a8332d96182201f4ef6c1Timo Sirainenstruct mail_module_register mail_module_register = { 0 };
90cf976e328e093da91a8332d96182201f4ef6c1Timo Sirainen
90cf976e328e093da91a8332d96182201f4ef6c1Timo Sirainenstruct mail_storage_mail_index_module mail_storage_mail_index_module =
90cf976e328e093da91a8332d96182201f4ef6c1Timo Sirainen    MODULE_CONTEXT_INIT(&mail_index_module_register);
90cf976e328e093da91a8332d96182201f4ef6c1Timo SirainenARRAY_TYPE(mail_storage) mail_storage_classes;
90cf976e328e093da91a8332d96182201f4ef6c1Timo Sirainen
90cf976e328e093da91a8332d96182201f4ef6c1Timo Sirainenvoid mail_storage_init(void)
44cf91b7a701a9b4d9f59a990552eab4f7f64fbcTimo Sirainen{
90cf976e328e093da91a8332d96182201f4ef6c1Timo Sirainen    mailbox_lists_init();
90cf976e328e093da91a8332d96182201f4ef6c1Timo Sirainen    mail_storage_hooks_init();
90cf976e328e093da91a8332d96182201f4ef6c1Timo Sirainen    i_array_init(&mail_storage_classes, 8);
90cf976e328e093da91a8332d96182201f4ef6c1Timo Sirainen}
90cf976e328e093da91a8332d96182201f4ef6c1Timo Sirainen
44cf91b7a701a9b4d9f59a990552eab4f7f64fbcTimo Sirainenvoid mail_storage_deinit(void)
90cf976e328e093da91a8332d96182201f4ef6c1Timo Sirainen{
90cf976e328e093da91a8332d96182201f4ef6c1Timo Sirainen    if (mail_search_register_human != NULL)
90cf976e328e093da91a8332d96182201f4ef6c1Timo Sirainen        mail_search_register_deinit(&mail_search_register_human);
90cf976e328e093da91a8332d96182201f4ef6c1Timo Sirainen    if (mail_search_register_imap != NULL)
90cf976e328e093da91a8332d96182201f4ef6c1Timo Sirainen        mail_search_register_deinit(&mail_search_register_imap);
90cf976e328e093da91a8332d96182201f4ef6c1Timo Sirainen    if (array_is_created(&mail_storage_classes))
6ef7e31619edfaa17ed044b45861d106a86191efTimo Sirainen        array_free(&mail_storage_classes);
6ef7e31619edfaa17ed044b45861d106a86191efTimo Sirainen    mail_storage_hooks_deinit();
5bb7c9863cbb62c41b13e7f42e04f1d57b4634f8Timo Sirainen    mailbox_lists_deinit();
dc9bfb7dc057964238e181d3d8b08751527bb08aTimo Sirainen}
dc9bfb7dc057964238e181d3d8b08751527bb08aTimo Sirainen
8759adc67109b5a12a7af3ed717c7040622a0a04Timo Sirainenvoid mail_storage_class_register(struct mail_storage *storage_class)
6ef7e31619edfaa17ed044b45861d106a86191efTimo Sirainen{
90cf976e328e093da91a8332d96182201f4ef6c1Timo Sirainen    i_assert(mail_storage_find_class(storage_class->name) == NULL);
dc9bfb7dc057964238e181d3d8b08751527bb08aTimo Sirainen
d31c77e63713a6cf3687a4b38ff8daf6d6c7a3ddTimo Sirainen    /* append it after the list, so the autodetection order is correct */
dc9bfb7dc057964238e181d3d8b08751527bb08aTimo Sirainen    array_append(&mail_storage_classes, &storage_class, 1);
dc9bfb7dc057964238e181d3d8b08751527bb08aTimo Sirainen}
90cf976e328e093da91a8332d96182201f4ef6c1Timo Sirainen
90cf976e328e093da91a8332d96182201f4ef6c1Timo Sirainenvoid mail_storage_class_unregister(struct mail_storage *storage_class)
dc9bfb7dc057964238e181d3d8b08751527bb08aTimo Sirainen{
dc9bfb7dc057964238e181d3d8b08751527bb08aTimo Sirainen    struct mail_storage *const *classes;
dc9bfb7dc057964238e181d3d8b08751527bb08aTimo Sirainen    unsigned int i, count;
dc9bfb7dc057964238e181d3d8b08751527bb08aTimo Sirainen
6135260095e1704ed6edff9d00bdfc043c11429cTimo Sirainen    classes = array_get(&mail_storage_classes, &count);
dc9bfb7dc057964238e181d3d8b08751527bb08aTimo Sirainen    for (i = 0; i < count; i++) {
dc9bfb7dc057964238e181d3d8b08751527bb08aTimo Sirainen        if (classes[i] == storage_class) {
dc9bfb7dc057964238e181d3d8b08751527bb08aTimo Sirainen            array_delete(&mail_storage_classes, i, 1);
dc9bfb7dc057964238e181d3d8b08751527bb08aTimo Sirainen            break;
7a60e1dc9e93ef3f7c7fe1af6385a0bfa1e31bc3Timo Sirainen        }
3ab7783791bd46cdd46e9b9de3e98e8efcb6c6bfTimo Sirainen    }
dc9bfb7dc057964238e181d3d8b08751527bb08aTimo Sirainen}
3ab7783791bd46cdd46e9b9de3e98e8efcb6c6bfTimo Sirainen
3ab7783791bd46cdd46e9b9de3e98e8efcb6c6bfTimo Sirainenstruct mail_storage *mail_storage_find_class(const char *name)
6135260095e1704ed6edff9d00bdfc043c11429cTimo Sirainen{
6135260095e1704ed6edff9d00bdfc043c11429cTimo Sirainen    struct mail_storage *const *classes;
24d7c5fc9fa1cb1f49402ec796654113199ba4e6Timo Sirainen    unsigned int i, count;
24d7c5fc9fa1cb1f49402ec796654113199ba4e6Timo Sirainen
24d7c5fc9fa1cb1f49402ec796654113199ba4e6Timo Sirainen    i_assert(name != NULL);
24d7c5fc9fa1cb1f49402ec796654113199ba4e6Timo Sirainen
24d7c5fc9fa1cb1f49402ec796654113199ba4e6Timo Sirainen    classes = array_get(&mail_storage_classes, &count);
ef4ca21b9195a2aca07a4965ea2d1d97c850b89amanuel    for (i = 0; i < count; i++) {
ef4ca21b9195a2aca07a4965ea2d1d97c850b89amanuel        if (strcasecmp(classes[i]->name, name) == 0)
ef4ca21b9195a2aca07a4965ea2d1d97c850b89amanuel            return classes[i];
24d7c5fc9fa1cb1f49402ec796654113199ba4e6Timo Sirainen    }
145d2eef238ed8bbff635e3b06951a83f0ee5a03Timo Sirainen    return NULL;
145d2eef238ed8bbff635e3b06951a83f0ee5a03Timo Sirainen}
145d2eef238ed8bbff635e3b06951a83f0ee5a03Timo Sirainen
145d2eef238ed8bbff635e3b06951a83f0ee5a03Timo Sirainenstatic struct mail_storage *
145d2eef238ed8bbff635e3b06951a83f0ee5a03Timo Sirainenmail_storage_autodetect(const struct mail_namespace *ns,
24d7c5fc9fa1cb1f49402ec796654113199ba4e6Timo Sirainen            struct mailbox_list_settings *set)
24d7c5fc9fa1cb1f49402ec796654113199ba4e6Timo Sirainen{
24d7c5fc9fa1cb1f49402ec796654113199ba4e6Timo Sirainen    struct mail_storage *const *classes;
8759adc67109b5a12a7af3ed717c7040622a0a04Timo Sirainen    unsigned int i, count;
8759adc67109b5a12a7af3ed717c7040622a0a04Timo Sirainen
8759adc67109b5a12a7af3ed717c7040622a0a04Timo Sirainen    classes = array_get(&mail_storage_classes, &count);
24d7c5fc9fa1cb1f49402ec796654113199ba4e6Timo Sirainen    for (i = 0; i < count; i++) {
24d7c5fc9fa1cb1f49402ec796654113199ba4e6Timo Sirainen        if (classes[i]->v.autodetect != NULL) {
553308791c097219e8eb31cbd03a29e9e1333848Timo Sirainen            if (classes[i]->v.autodetect(ns, set))
24d7c5fc9fa1cb1f49402ec796654113199ba4e6Timo Sirainen                return classes[i];
dc9bfb7dc057964238e181d3d8b08751527bb08aTimo Sirainen        }
dc9bfb7dc057964238e181d3d8b08751527bb08aTimo Sirainen    }
dc9bfb7dc057964238e181d3d8b08751527bb08aTimo Sirainen    return NULL;
dc9bfb7dc057964238e181d3d8b08751527bb08aTimo Sirainen}
dc9bfb7dc057964238e181d3d8b08751527bb08aTimo Sirainen
6ef7e31619edfaa17ed044b45861d106a86191efTimo Sirainenstatic void
6ef7e31619edfaa17ed044b45861d106a86191efTimo Sirainenmail_storage_set_autodetection(const char **data, const char **driver)
6ef7e31619edfaa17ed044b45861d106a86191efTimo Sirainen{
6ef7e31619edfaa17ed044b45861d106a86191efTimo Sirainen    const char *p;
6ef7e31619edfaa17ed044b45861d106a86191efTimo Sirainen
dc9bfb7dc057964238e181d3d8b08751527bb08aTimo Sirainen    /* check if data is in driver:data format (eg. mbox:~/mail) */
dc9bfb7dc057964238e181d3d8b08751527bb08aTimo Sirainen    p = *data;
8759adc67109b5a12a7af3ed717c7040622a0a04Timo Sirainen    while (i_isalnum(*p)) p++;
90cf976e328e093da91a8332d96182201f4ef6c1Timo Sirainen
dc9bfb7dc057964238e181d3d8b08751527bb08aTimo Sirainen    if (*p == ':' && p != *data) {
d31c77e63713a6cf3687a4b38ff8daf6d6c7a3ddTimo Sirainen        /* no autodetection if the storage driver is given. */
dc9bfb7dc057964238e181d3d8b08751527bb08aTimo Sirainen        *driver = t_strdup_until(*data, p);
dc9bfb7dc057964238e181d3d8b08751527bb08aTimo Sirainen        *data = p + 1;
90cf976e328e093da91a8332d96182201f4ef6c1Timo Sirainen    }
90cf976e328e093da91a8332d96182201f4ef6c1Timo Sirainen}
dc9bfb7dc057964238e181d3d8b08751527bb08aTimo Sirainen
dc9bfb7dc057964238e181d3d8b08751527bb08aTimo Sirainenstatic struct mail_storage *
dc9bfb7dc057964238e181d3d8b08751527bb08aTimo Sirainenmail_storage_get_class(struct mail_namespace *ns, const char *driver,
dc9bfb7dc057964238e181d3d8b08751527bb08aTimo Sirainen               struct mailbox_list_settings *list_set,
a3dd97fb6d92a89c3de0597fed2d4b044c7aeb84Timo Sirainen               enum mail_storage_flags flags, const char **error_r)
a3dd97fb6d92a89c3de0597fed2d4b044c7aeb84Timo Sirainen{
dc9bfb7dc057964238e181d3d8b08751527bb08aTimo Sirainen    struct mail_storage *storage_class = NULL;
dc9bfb7dc057964238e181d3d8b08751527bb08aTimo Sirainen    const char *home;
dc9bfb7dc057964238e181d3d8b08751527bb08aTimo Sirainen
dc9bfb7dc057964238e181d3d8b08751527bb08aTimo Sirainen    if (driver == NULL) {
7a60e1dc9e93ef3f7c7fe1af6385a0bfa1e31bc3Timo Sirainen        /* no mail_location, autodetect */
553308791c097219e8eb31cbd03a29e9e1333848Timo Sirainen    } else if (strcmp(driver, "auto") == 0) {
dc9bfb7dc057964238e181d3d8b08751527bb08aTimo Sirainen        /* explicit autodetection with "auto" driver. */
a3dd97fb6d92a89c3de0597fed2d4b044c7aeb84Timo Sirainen        if (list_set->root_dir != NULL &&
7dcb5545370faa9d4ff83b3ede65a69fc3dd4b65Timo Sirainen            *list_set->root_dir == '\0') {
a3dd97fb6d92a89c3de0597fed2d4b044c7aeb84Timo Sirainen            /* handle the same as with driver=NULL */
cc0495b3bbe3c3e41c512274b302d6f0fa028187Timo Sirainen            list_set->root_dir = NULL;
dc9bfb7dc057964238e181d3d8b08751527bb08aTimo Sirainen        }
dc9bfb7dc057964238e181d3d8b08751527bb08aTimo Sirainen    } else {
dc9bfb7dc057964238e181d3d8b08751527bb08aTimo Sirainen        storage_class = mail_storage_find_class(driver);
a64adf62fa33f2463a86f990217b0c9078531a40Timo Sirainen        if (storage_class == NULL) {
dc9bfb7dc057964238e181d3d8b08751527bb08aTimo Sirainen            *error_r = t_strdup_printf(
31a12066e4cd9310d64091c81b59fb8eb1986023Timo Sirainen                "Unknown mail storage driver %s", driver);
31a12066e4cd9310d64091c81b59fb8eb1986023Timo Sirainen            return NULL;
a64adf62fa33f2463a86f990217b0c9078531a40Timo Sirainen        }
dc9bfb7dc057964238e181d3d8b08751527bb08aTimo Sirainen    }
dc9bfb7dc057964238e181d3d8b08751527bb08aTimo Sirainen
31a12066e4cd9310d64091c81b59fb8eb1986023Timo Sirainen    if (list_set->root_dir == NULL || *list_set->root_dir == '\0') {
31a12066e4cd9310d64091c81b59fb8eb1986023Timo Sirainen        /* no root directory given. is this allowed? */
47a5a7e8296f3b8f2fac9a0659d4de3f2723ba4aMartti Rannanjärvi        const struct mailbox_list *list;
31a12066e4cd9310d64091c81b59fb8eb1986023Timo Sirainen
47a5a7e8296f3b8f2fac9a0659d4de3f2723ba4aMartti Rannanjärvi        list = list_set->layout == NULL ? NULL :
31a12066e4cd9310d64091c81b59fb8eb1986023Timo Sirainen            mailbox_list_find_class(list_set->layout);
31a12066e4cd9310d64091c81b59fb8eb1986023Timo Sirainen        if (storage_class == NULL &&
61618d4c58080570f689614fec204ae14e90cef2Timo Sirainen            (flags & MAIL_STORAGE_FLAG_NO_AUTODETECTION) == 0) {
a64adf62fa33f2463a86f990217b0c9078531a40Timo Sirainen            /* autodetection should take care of this */
dc9bfb7dc057964238e181d3d8b08751527bb08aTimo Sirainen        } else if (storage_class != NULL &&
dc9bfb7dc057964238e181d3d8b08751527bb08aTimo Sirainen               (storage_class->class_flags & MAIL_STORAGE_CLASS_FLAG_NO_ROOT) != 0) {
dc9bfb7dc057964238e181d3d8b08751527bb08aTimo Sirainen            /* root not required for this storage */
dc9bfb7dc057964238e181d3d8b08751527bb08aTimo Sirainen        } else if (list != NULL &&
8ef7c24178fd798c3e0301c5b8afa1a9bdedd27fTimo Sirainen               (list->props & MAILBOX_LIST_PROP_NO_ROOT) != 0) {
d5cebe7f98e63d4e2822863ef2faa4971e8b3a5dTimo Sirainen            /* root not required for this layout */
dc9bfb7dc057964238e181d3d8b08751527bb08aTimo Sirainen        } else {
            *error_r = "Root mail directory not given";
            return NULL;
        }
    }

    if (storage_class != NULL) {
        storage_class->v.get_list_settings(ns, list_set);
        return storage_class;
    }

    storage_class = mail_storage_autodetect(ns, list_set);
    if (storage_class != NULL)
        return storage_class;

    (void)mail_user_get_home(ns->user, &home);
    if (home == NULL || *home == '\0') home = "(not set)";

    if (ns->set->location == NULL || *ns->set->location == '\0') {
        *error_r = t_strdup_printf(
            "Mail storage autodetection failed with home=%s", home);
    } else if (strncmp(ns->set->location, "auto:", 5) == 0) {
        *error_r = t_strdup_printf(
            "Autodetection failed for %s (home=%s)",
            ns->set->location, home);
    } else {
        *error_r = t_strdup_printf(
            "Ambiguous mail location setting, "
            "don't know what to do with it: %s "
            "(try prefixing it with mbox: or maildir:)",
            ns->set->location);
    }
    return NULL;
}

static int
mail_storage_verify_root(const char *root_dir, bool autocreate,
             const char **error_r)
{
    struct stat st;

    if (stat(root_dir, &st) == 0) {
        /* exists */
        return 1;
    } else if (errno == EACCES) {
        *error_r = mail_error_eacces_msg("stat", root_dir);
        return -1;
    } else if (errno != ENOENT && errno != ENOTDIR) {
        *error_r = t_strdup_printf("stat(%s) failed: %m", root_dir);
        return -1;
    } else if (!autocreate) {
        *error_r = t_strdup_printf(
            "Root mail directory doesn't exist: %s", root_dir);
        return -1;
    } else {
        /* doesn't exist */
        return 0;
    }
}

static int
mail_storage_create_root(struct mailbox_list *list,
             enum mail_storage_flags flags, const char **error_r)
{
    const char *root_dir, *error;
    bool autocreate;
    int ret;

    root_dir = mailbox_list_get_path(list, NULL,
                     MAILBOX_LIST_PATH_TYPE_MAILBOX);
    if (root_dir == NULL) {
        /* storage doesn't use directories (e.g. shared root) */
        return 0;
    }

    if ((flags & MAIL_STORAGE_FLAG_NO_AUTOVERIFY) != 0) {
        if (!list->mail_set->mail_debug)
            return 0;

        /* we don't need to verify, but since debugging is
           enabled, check and log if the root doesn't exist */
        if (mail_storage_verify_root(root_dir, FALSE, &error) < 0) {
            i_debug("Namespace %s: Creating storage despite: %s",
                list->ns->prefix, error);
        }
        return 0;
    }

    autocreate = (flags & MAIL_STORAGE_FLAG_NO_AUTOCREATE) == 0;
    ret = mail_storage_verify_root(root_dir, autocreate, error_r);
    if (ret == 0) {
        ret = mailbox_list_mkdir_root(list, root_dir,
                          MAILBOX_LIST_PATH_TYPE_MAILBOX,
                          error_r);
    }
    return ret < 0 ? -1 : 0;
}

static bool
mail_storage_match_class(struct mail_storage *storage,
             const struct mail_storage *storage_class,
             const struct mailbox_list_settings *set)
{
    if (strcmp(storage->name, storage_class->name) != 0)
        return FALSE;

    if ((storage->class_flags & MAIL_STORAGE_CLASS_FLAG_UNIQUE_ROOT) != 0 &&
        strcmp(storage->unique_root_dir, set->root_dir) != 0)
        return FALSE;

    if (strcmp(storage->name, "shared") == 0) {
        /* allow multiple independent shared namespaces */
        return FALSE;
    }
    return TRUE;
}

static struct mail_storage *
mail_storage_find(struct mail_user *user,
          const struct mail_storage *storage_class,
          const struct mailbox_list_settings *set)
{
    struct mail_storage *storage = user->storages;

    for (; storage != NULL; storage = storage->next) {
        if (mail_storage_match_class(storage, storage_class, set))
            return storage;
    }
    return NULL;
}

int mail_storage_create(struct mail_namespace *ns, const char *driver,
            enum mail_storage_flags flags, const char **error_r)
{
    struct mail_storage *storage_class, *storage = NULL;
    struct mailbox_list *list;
    struct mailbox_list_settings list_set;
    enum mailbox_list_flags list_flags = 0;
    const char *data = ns->set->location;
    const char *p;

    if ((flags & MAIL_STORAGE_FLAG_KEEP_HEADER_MD5) == 0 &&
        ns->mail_set->pop3_uidl_format != NULL) {
        /* if pop3_uidl_format contains %m, we want to keep the
           header MD5 sums stored even if we're not running POP3
           right now. */
        p = ns->mail_set->pop3_uidl_format;
        while ((p = strchr(p, '%')) != NULL) {
            if (p[1] == '%')
                p += 2;
            else if (var_get_key(++p) == 'm') {
                flags |= MAIL_STORAGE_FLAG_KEEP_HEADER_MD5;
                break;
            }
        }
    }

    memset(&list_set, 0, sizeof(list_set));
    list_set.mailbox_dir_name = "";
    list_set.maildir_name = "";
    if (data == NULL) {
        /* autodetect */
    } else if (driver != NULL && strcmp(driver, "shared") == 0) {
        /* internal shared namespace */
        list_set.root_dir = ns->user->set->base_dir;
    } else {
        if (driver == NULL)
            mail_storage_set_autodetection(&data, &driver);
        if (mailbox_list_settings_parse(ns->user, data, &list_set,
                        error_r) < 0)
            return -1;
    }

    storage_class = mail_storage_get_class(ns, driver, &list_set, flags,
                           error_r);
    if (storage_class == NULL)
        return -1;
    i_assert(list_set.layout != NULL);

    if (ns->list == NULL) {
        /* first storage for namespace */
        if (mail_storage_is_mailbox_file(storage_class))
            list_flags |= MAILBOX_LIST_FLAG_MAILBOX_FILES;
        if (mailbox_list_create(list_set.layout, ns, &list_set,
                    list_flags, &list, error_r) < 0) {
            *error_r = t_strdup_printf("Mailbox list driver %s: %s",
                           list_set.layout, *error_r);
            return -1;
        }
        if (mail_storage_create_root(ns->list, flags, error_r) < 0)
            return -1;
    }

    storage = mail_storage_find(ns->user, storage_class, &list_set);
    if (storage != NULL) {
        /* using an existing storage */
        storage->refcount++;
        mail_namespace_add_storage(ns, storage);
        return 0;
    }

    storage = storage_class->v.alloc();
    storage->refcount = 1;
    storage->storage_class = storage_class;
    storage->user = ns->user;
    storage->set = ns->mail_set;
    storage->flags = flags;
    p_array_init(&storage->module_contexts, storage->pool, 5);

    if (storage->v.create != NULL &&
        storage->v.create(storage, ns, error_r) < 0) {
        *error_r = t_strdup_printf("%s: %s", storage->name, *error_r);
        pool_unref(&storage->pool);
        return -1;
    }

    T_BEGIN {
        hook_mail_storage_created(storage);
    } T_END;

    DLLIST_PREPEND(&ns->user->storages, storage);
        mail_namespace_add_storage(ns, storage);
    return 0;
}

void mail_storage_unref(struct mail_storage **_storage)
{
    struct mail_storage *storage = *_storage;

    i_assert(storage->refcount > 0);

    /* set *_storage=NULL only after calling destroy() callback.
       for example mdbox wants to access ns->storage */
    if (--storage->refcount > 0) {
        *_storage = NULL;
        return;
    }

    if (storage->mailboxes != NULL) {
        i_panic("Trying to deinit storage without freeing mailbox %s",
            storage->mailboxes->vname);
    }
    if (storage->obj_refcount != 0)
        i_panic("Trying to deinit storage before freeing its objects");

    DLLIST_REMOVE(&storage->user->storages, storage);

    if (storage->v.destroy != NULL)
        storage->v.destroy(storage);
    i_free(storage->error_string);

    *_storage = NULL;
    pool_unref(&storage->pool);

    mail_index_alloc_cache_destroy_unrefed();
}

void mail_storage_obj_ref(struct mail_storage *storage)
{
    i_assert(storage->refcount > 0);

    if (storage->obj_refcount++ == 0)
        mail_user_ref(storage->user);
}

void mail_storage_obj_unref(struct mail_storage *storage)
{
    i_assert(storage->refcount > 0);
    i_assert(storage->obj_refcount > 0);

    if (--storage->obj_refcount == 0) {
        struct mail_user *user = storage->user;
        mail_user_unref(&user);
    }
}

void mail_storage_clear_error(struct mail_storage *storage)
{
    i_free_and_null(storage->error_string);

    storage->error = MAIL_ERROR_NONE;
}

void mail_storage_set_error(struct mail_storage *storage,
                enum mail_error error, const char *string)
{
    i_free(storage->error_string);
    storage->error_string = i_strdup(string);
    storage->error = error;
}

void mail_storage_set_internal_error(struct mail_storage *storage)
{
    const char *str;

    str = t_strflocaltime(MAIL_ERRSTR_CRITICAL_MSG_STAMP, ioloop_time);

    i_free(storage->error_string);
    storage->error_string = i_strdup(str);
    storage->error = MAIL_ERROR_TEMP;
}

void mail_storage_set_critical(struct mail_storage *storage,
                   const char *fmt, ...)
{
    va_list va;

    va_start(va, fmt);
    i_error("%s", t_strdup_vprintf(fmt, va));
    va_end(va);

    /* critical errors may contain sensitive data, so let user
       see only "Internal error" with a timestamp to make it
       easier to look from log files the actual error message. */
    mail_storage_set_internal_error(storage);
}

void mail_storage_copy_list_error(struct mail_storage *storage,
                  struct mailbox_list *list)
{
    const char *str;
    enum mail_error error;

    str = mailbox_list_get_last_error(list, &error);
    mail_storage_set_error(storage, error, str);
}

void mail_storage_set_index_error(struct mailbox *box)
{
    if (mail_index_is_deleted(box->index))
        mailbox_set_deleted(box);
    else
        mail_storage_set_internal_error(box->storage);
    mail_index_reset_error(box->index);
}

const struct mail_storage_settings *
mail_storage_get_settings(struct mail_storage *storage)
{
    return storage->set;
}

struct mail_user *mail_storage_get_user(struct mail_storage *storage)
{
    return storage->user;
}

void mail_storage_set_callbacks(struct mail_storage *storage,
                struct mail_storage_callbacks *callbacks,
                void *context)
{
    storage->callbacks = *callbacks;
    storage->callback_context = context;
}

int mail_storage_purge(struct mail_storage *storage)
{
    return storage->v.purge == NULL ? 0 :
        storage->v.purge(storage);
}

const char *mail_storage_get_last_error(struct mail_storage *storage,
                    enum mail_error *error_r)
{
    /* We get here only in error situations, so we have to return some
       error. If storage->error is NONE, it means we forgot to set it at
       some point.. */
    if (storage->error == MAIL_ERROR_NONE) {
        if (error_r != NULL)
            *error_r = MAIL_ERROR_TEMP;
        return storage->error_string != NULL ? storage->error_string :
            "BUG: Unknown internal error";
    }

    if (storage->error_string == NULL) {
        /* This shouldn't happen.. */
        storage->error_string =
            i_strdup_printf("BUG: Unknown 0x%x error",
                    storage->error);
    }

    if (error_r != NULL)
        *error_r = storage->error;
    return storage->error_string;
}

const char *mailbox_get_last_error(struct mailbox *box,
                   enum mail_error *error_r)
{
    return mail_storage_get_last_error(box->storage, error_r);
}

enum mail_error mailbox_get_last_mail_error(struct mailbox *box)
{
    enum mail_error error;

    (void)mail_storage_get_last_error(box->storage, &error);
    return error;
}

bool mail_storage_is_mailbox_file(struct mail_storage *storage)
{
    return (storage->class_flags &
        MAIL_STORAGE_CLASS_FLAG_MAILBOX_IS_FILE) != 0;
}

bool mail_storage_set_error_from_errno(struct mail_storage *storage)
{
    const char *error_string;
    enum mail_error error;

    if (!mail_error_from_errno(&error, &error_string))
        return FALSE;
    if (storage->set->mail_debug && error != MAIL_ERROR_NOTFOUND) {
        /* debugging is enabled - admin may be debugging a
           (permission) problem, so return FALSE to get the caller to
           log the full error message. */
        return FALSE;
    }

    mail_storage_set_error(storage, error, error_string);
    return TRUE;
}

const struct mailbox_settings *
mailbox_settings_find(struct mail_user *user, const char *vname)
{
    struct mailbox_settings *const *box_set;
    struct mail_namespace *ns;

    ns = mail_namespace_find(user->namespaces, vname);
    if (ns == NULL)
        return NULL;
    if (!array_is_created(&ns->set->mailboxes))
        return NULL;

    if (ns->prefix_len > 0 &&
        strncmp(ns->prefix, vname, ns->prefix_len-1) == 0) {
        if (vname[ns->prefix_len-1] == mail_namespace_get_sep(ns))
            vname += ns->prefix_len;
        else if (vname[ns->prefix_len-1] == '\0') {
            /* namespace prefix itself */
            vname = "";
        }
    }
    array_foreach(&ns->set->mailboxes, box_set) {
        if (strcmp((*box_set)->name, vname) == 0)
            return *box_set;
    }
    return NULL;
}

struct mailbox *mailbox_alloc(struct mailbox_list *list, const char *vname,
                  enum mailbox_flags flags)
{
    struct mailbox_list *new_list = list;
    struct mail_storage *storage;
    struct mailbox *box;

    i_assert(uni_utf8_str_is_valid(vname));

    if ((list->ns->flags & NAMESPACE_FLAG_INBOX_USER) != 0 &&
        strncasecmp(vname, "INBOX", 5) == 0 &&
        strncmp(vname, "INBOX", 5) != 0) {
        /* make sure INBOX shows up in uppercase everywhere */
        if (vname[5] == '\0')
            vname = "INBOX";
        else if (vname[5] == mail_namespace_get_sep(list->ns))
            vname = t_strconcat("INBOX", vname + 5, NULL);
    }

    if (mailbox_list_get_storage(&new_list, vname, &storage) < 0) {
        /* just use the first storage. FIXME: does this break? */
        storage = list->ns->storage;
    }

    T_BEGIN {
        box = storage->v.mailbox_alloc(storage, new_list, vname, flags);
        box->set = mailbox_settings_find(storage->user, vname);
        hook_mailbox_allocated(box);
    } T_END;

    DLLIST_PREPEND(&box->storage->mailboxes, box);
    mail_storage_obj_ref(box->storage);
    return box;
}

struct mailbox *mailbox_alloc_guid(struct mailbox_list *list,
                   const guid_128_t guid,
                   enum mailbox_flags flags)
{
    struct mailbox *box = NULL;
    struct mailbox_metadata metadata;
    enum mail_error open_error = MAIL_ERROR_TEMP;
    const char *vname;

    if (mailbox_guid_cache_find(list, guid, &vname) < 0) {
        vname = NULL;
    } else if (vname != NULL) {
        box = mailbox_alloc(list, vname, flags);
        if (mailbox_get_metadata(box, MAILBOX_METADATA_GUID,
                     &metadata) < 0) {
        } else if (memcmp(metadata.guid, guid,
                  sizeof(metadata.guid)) != 0) {
            /* GUID mismatch, refresh cache and try again */
            mailbox_free(&box);
            mailbox_guid_cache_refresh(list);
            return mailbox_alloc_guid(list, guid, flags);
        } else {
            /* successfully opened the correct mailbox */
            return box;
        }
        i_error("mailbox_alloc_guid(%s): "
            "Couldn't verify mailbox GUID: %s",
            guid_128_to_string(guid),
            mailbox_get_last_error(box, NULL));
        vname = NULL;
        mailbox_free(&box);
    } else {
        vname = t_strdup_printf("(nonexistent mailbox with GUID=%s)",
                    guid_128_to_string(guid));
        open_error = MAIL_ERROR_NOTFOUND;
    }

    if (vname == NULL) {
        vname = t_strdup_printf("(error in mailbox with GUID=%s)",
                    guid_128_to_string(guid));
    }
    box = mailbox_alloc(list, vname, flags);
    box->open_error = open_error;
    return box;
}

static bool have_listable_namespace_prefix(struct mail_namespace *ns,
                       const char *name)
{
    unsigned int name_len = strlen(name);

    for (; ns != NULL; ns = ns->next) {
        if ((ns->flags & (NAMESPACE_FLAG_LIST_PREFIX |
                  NAMESPACE_FLAG_LIST_CHILDREN)) == 0)
            continue;

        if (ns->prefix_len <= name_len)
            continue;

        /* if prefix has multiple hierarchies, match
           any of the hierarchies */
        if (strncmp(ns->prefix, name, name_len) == 0 &&
            ns->prefix[name_len] == mail_namespace_get_sep(ns))
            return TRUE;
    }
    return FALSE;
}

static bool mailbox_is_autocreated(struct mailbox *box)
{
    if (box->inbox_user)
        return TRUE;
    return box->set != NULL &&
        strcmp(box->set->autocreate, MAILBOX_SET_AUTO_NO) != 0;
}

int mailbox_exists(struct mailbox *box, bool auto_boxes,
           enum mailbox_existence *existence_r)
{
    switch (box->open_error) {
    case 0:
        break;
    case MAIL_ERROR_NOTFOUND:
        *existence_r = MAILBOX_EXISTENCE_NONE;
        return 0;
    default:
        /* unsure if this exists or not */
        return -1;
    }
    if (!mailbox_list_is_valid_existing_name(box->list, box->name)) {
        /* report it as not selectable, since it exists but we won't
           let it be opened. */
        *existence_r = MAILBOX_EXISTENCE_NOSELECT;
        return 0;
    }

    if (auto_boxes && box->set != NULL && mailbox_is_autocreated(box)) {
        *existence_r = MAILBOX_EXISTENCE_SELECT;
        return 0;
    }

    if (box->v.exists(box, auto_boxes, existence_r) < 0)
        return -1;

    if (!box->inbox_user && *existence_r == MAILBOX_EXISTENCE_NOSELECT &&
        have_listable_namespace_prefix(box->storage->user->namespaces,
                       box->vname)) {
           /* listable namespace prefix always exists. */
        *existence_r = MAILBOX_EXISTENCE_NOSELECT;
        return 0;
    }

    /* if this is a shared namespace with only INBOX and
       mail_shared_explicit_inbox=no, we'll need to mark the namespace as
       usable here since nothing else will. */
    box->list->ns->flags |= NAMESPACE_FLAG_USABLE;
    return 0;
}

static int mailbox_check_mismatching_separators(struct mailbox *box)
{
    struct mail_namespace *ns = box->list->ns;
    const char *p, *vname = box->vname;
    char list_sep, ns_sep;

    if (box->inbox_user) {
        /* this is INBOX - don't bother with further checks */
        return 0;
    }

    list_sep = mailbox_list_get_hierarchy_sep(box->list);
    ns_sep = mail_namespace_get_sep(ns);

    if (ns->prefix_len > 0) {
        /* vname is either "namespace/box" or "namespace" */
        i_assert(strncmp(vname, ns->prefix, ns->prefix_len-1) == 0);
        vname += ns->prefix_len - 1;
        if (vname[0] != '\0') {
            i_assert(vname[0] == ns->prefix[ns->prefix_len-1]);
            vname++;

            if (vname[0] == '\0') {
                /* "namespace/" isn't a valid mailbox name. */
                mail_storage_set_error(box->storage,
                               MAIL_ERROR_PARAMS,
                               "Invalid mailbox name");
                return -1;
            }
        }
    }

    if (ns_sep == list_sep || box->list->set.escape_char != '\0')
        return 0;

    for (p = vname; *p != '\0'; p++) {
        if (*p == list_sep) {
            mail_storage_set_error(box->storage, MAIL_ERROR_PARAMS,
                t_strdup_printf("Character not allowed "
                        "in mailbox name: '%c'",
                        list_sep));
            return -1;
        }
    }
    return 0;
}

static void mailbox_autocreate(struct mailbox *box)
{
    const char *errstr;
    enum mail_error error;

    if (mailbox_create(box, NULL, FALSE) < 0) {
        errstr = mailbox_get_last_error(box, &error);
        if (error != MAIL_ERROR_NOTFOUND && !box->inbox_user) {
            mail_storage_set_critical(box->storage,
                "Failed to autocreate mailbox %s: %s",
                box->vname, errstr);
        }
    } else if (box->set != NULL &&
           strcmp(box->set->autocreate,
              MAILBOX_SET_AUTO_SUBSCRIBE) == 0) {
        if (mailbox_set_subscribed(box, TRUE) < 0) {
            mail_storage_set_critical(box->storage,
                "Failed to autosubscribe to mailbox %s: %s",
                box->vname, mailbox_get_last_error(box, NULL));
        }
    }
}

static int mailbox_autocreate_and_reopen(struct mailbox *box)
{
    int ret;

    mailbox_autocreate(box);
    mailbox_close(box);

    ret = box->v.open(box);
    if (ret < 0 && box->inbox_user &&
        !box->storage->user->inbox_open_error_logged) {
        box->storage->user->inbox_open_error_logged = TRUE;
        mail_storage_set_critical(box->storage,
            "Opening INBOX failed: %s",
            mailbox_get_last_error(box, NULL));
    }
    return ret;
}

static int mailbox_open_full(struct mailbox *box, struct istream *input)
{
    int ret;

    if (box->opened)
        return 0;
    switch (box->open_error) {
    case 0:
        break;
    case MAIL_ERROR_NOTFOUND:
        mail_storage_set_error(box->storage, MAIL_ERROR_NOTFOUND,
            T_MAIL_ERR_MAILBOX_NOT_FOUND(box->vname));
        return -1;
    default:
        mail_storage_set_internal_error(box->storage);
        box->storage->error = box->open_error;
        return -1;
    }

    if (mailbox_check_mismatching_separators(box) < 0)
        return -1;
    if (!mailbox_list_is_valid_existing_name(box->list, box->name)) {
        mail_storage_set_error(box->storage, MAIL_ERROR_PARAMS,
                       "Invalid mailbox name");
        return -1;
    }

    if (input != NULL) {
        if ((box->storage->class_flags &
             MAIL_STORAGE_CLASS_FLAG_OPEN_STREAMS) == 0) {
            mail_storage_set_critical(box->storage,
                "Storage doesn't support streamed mailboxes");
            return -1;
        }
        box->input = input;
        box->flags |= MAILBOX_FLAG_READONLY;
        i_stream_ref(box->input);
    }

    T_BEGIN {
        ret = box->v.open(box);
    } T_END;

    if (ret < 0 && box->storage->error == MAIL_ERROR_NOTFOUND &&
        box->input == NULL && mailbox_is_autocreated(box)) T_BEGIN {
        ret = mailbox_autocreate_and_reopen(box);
    } T_END;

    if (ret < 0) {
        if (box->input != NULL)
            i_stream_unref(&box->input);
        return -1;
    }

    box->list->ns->flags |= NAMESPACE_FLAG_USABLE;
    return 0;
}

static bool mailbox_try_undelete(struct mailbox *box)
{
    time_t mtime;

    if (mail_index_get_modification_time(box->index, &mtime) < 0)
        return FALSE;
    if (mtime + MAILBOX_DELETE_RETRY_SECS > time(NULL))
        return FALSE;

    if (mailbox_mark_index_deleted(box, FALSE) < 0)
        return FALSE;
    box->mailbox_deleted = FALSE;
    return TRUE;
}

int mailbox_open(struct mailbox *box)
{
    if (mailbox_open_full(box, NULL) < 0) {
        if (!box->mailbox_deleted)
            return -1;

        /* mailbox has been marked as deleted. if this deletion
           started (and crashed) a long time ago, it can be confusing
           to user that the mailbox can't be opened. so we'll just
           undelete it and reopen. */
        if(!mailbox_try_undelete(box))
            return -1;
        if (mailbox_open_full(box, NULL) < 0)
            return -1;
    }
    return 0;
}

int mailbox_open_stream(struct mailbox *box, struct istream *input)
{
    return mailbox_open_full(box, input);
}

int mailbox_enable(struct mailbox *box, enum mailbox_feature features)
{
    return box->v.enable(box, features);
}

enum mailbox_feature mailbox_get_enabled_features(struct mailbox *box)
{
    return box->enabled_features;
}

void mailbox_close(struct mailbox *box)
{
    if (!box->opened)
        return;

    if (box->transaction_count != 0) {
        i_panic("Trying to close mailbox %s with open transactions",
            box->name);
    }
    box->v.close(box);

    box->opened = FALSE;
    box->mailbox_deleted = FALSE;
    array_clear(&box->search_results);
}

void mailbox_free(struct mailbox **_box)
{
    struct mailbox *box = *_box;

    *_box = NULL;

    mailbox_close(box);
    box->v.free(box);

    DLLIST_REMOVE(&box->storage->mailboxes, box);
    mail_storage_obj_unref(box->storage);
    if (box->metadata_pool != NULL)
        pool_unref(&box->metadata_pool);
    pool_unref(&box->pool);
}

int mailbox_create(struct mailbox *box, const struct mailbox_update *update,
           bool directory)
{
    enum mailbox_dir_create_type type;
    int ret;

    if (!mailbox_list_is_valid_create_name(box->list, box->name)) {
        mail_storage_set_error(box->storage, MAIL_ERROR_PARAMS,
                       "Invalid mailbox name");
        return -1;
    }

    type = directory ? MAILBOX_DIR_CREATE_TYPE_TRY_NOSELECT :
        MAILBOX_DIR_CREATE_TYPE_MAILBOX;
    if (box->list->v.create_mailbox_dir(box->list, box->name, type) < 0) {
        mail_storage_copy_list_error(box->storage, box->list);
        if (directory ||
            mailbox_get_last_mail_error(box) != MAIL_ERROR_EXISTS)
            return -1;
        /* the directory already exists, but the mailbox might not */
    }
    mailbox_refresh_permissions(box);

    box->creating = TRUE;
    ret = box->v.create(box, update, directory);
    box->creating = FALSE;
    return ret;
}

int mailbox_update(struct mailbox *box, const struct mailbox_update *update)
{
    i_assert(update->min_next_uid == 0 ||
         update->min_first_recent_uid == 0 ||
         update->min_first_recent_uid <= update->min_next_uid);

    return box->v.update(box, update);
}

int mailbox_mark_index_deleted(struct mailbox *box, bool del)
{
    struct mail_index_transaction *trans;
    enum mail_index_transaction_flags trans_flags = 0;
    enum mailbox_flags old_flag;
    int ret;

    if (box->marked_deleted && del) {
        /* we already marked it deleted. this allows plugins to
           "lock" the deletion earlier. */
        return 0;
    }

    old_flag = box->flags & MAILBOX_FLAG_OPEN_DELETED;
    box->flags |= MAILBOX_FLAG_OPEN_DELETED;
    ret = mailbox_open(box);
    box->flags = (box->flags & ~MAILBOX_FLAG_OPEN_DELETED) | old_flag;
    if (ret < 0)
        return -1;

    trans_flags = del ? 0 : MAIL_INDEX_TRANSACTION_FLAG_EXTERNAL;
    trans = mail_index_transaction_begin(box->view, trans_flags);
    if (del)
        mail_index_set_deleted(trans);
    else
        mail_index_set_undeleted(trans);
    if (mail_index_transaction_commit(&trans) < 0) {
        mail_storage_set_index_error(box);
        return -1;
    }

    /* sync the mailbox. this finishes the index deletion and it can
       succeed only for a single session. we do it here, so the rest of
       the deletion code doesn't have to worry about race conditions. */
    if (mailbox_sync(box, MAILBOX_SYNC_FLAG_FULL_READ) < 0)
        return -1;

    box->marked_deleted = del;
    return 0;
}

int mailbox_delete(struct mailbox *box)
{
    int ret;

    if (*box->name == '\0') {
        mail_storage_set_error(box->storage, MAIL_ERROR_PARAMS,
                       "Storage root can't be deleted");
        return -1;
    }
    if (box->inbox_any) {
        mail_storage_set_error(box->storage, MAIL_ERROR_NOTPOSSIBLE,
                       "INBOX can't be deleted.");
        return -1;
    }

    box->deleting = TRUE;
    if (mailbox_open(box) < 0) {
        if (mailbox_get_last_mail_error(box) != MAIL_ERROR_NOTFOUND)
            return -1;
        /* \noselect mailbox */
    }

    ret = box->v.delete(box);
    if (ret < 0 && box->marked_deleted) {
        /* deletion failed. revert the mark so it can maybe be
           tried again later. */
        if (mailbox_mark_index_deleted(box, FALSE) < 0)
            return -1;
    }

    box->deleting = FALSE;
    mailbox_close(box);
    return ret;
}

int mailbox_delete_empty(struct mailbox *box)
{
    int ret;

    /* FIXME: should be a parameter to delete(), but since it changes API
       don't do it for now */
    box->deleting_must_be_empty = TRUE;
    ret = mailbox_delete(box);
    box->deleting_must_be_empty = FALSE;
    return ret;
}

static bool
mail_storages_rename_compatible(struct mail_storage *storage1,
                struct mail_storage *storage2,
                const char **error_r)
{
    if (storage1 == storage2)
        return TRUE;

    if (strcmp(storage1->name, storage2->name) != 0) {
        *error_r = t_strdup_printf("storage %s != %s",
                       storage1->name, storage2->name);
        return FALSE;
    }
    if ((storage1->class_flags & MAIL_STORAGE_CLASS_FLAG_UNIQUE_ROOT) != 0) {
        /* e.g. mdbox where all mails are in storage/ directory and
           they can't be easily moved from there. */
        *error_r = t_strdup_printf("storage %s uses unique root",
                       storage1->name);
        return FALSE;
    }
    return TRUE;
}

static bool nullequals(const void *p1, const void *p2)
{
    return (p1 == NULL && p2 == NULL) || (p1 != NULL && p2 != NULL);
}

static bool
mailbox_lists_rename_compatible(struct mailbox_list *list1,
                struct mailbox_list *list2,
                const char **error_r)
{
    if (!nullequals(list1->set.alt_dir, list2->set.alt_dir)) {
        *error_r = "one namespace has alt dir and another doesn't";
        return FALSE;
    }
    if (!nullequals(list1->set.index_dir, list2->set.index_dir)) {
        *error_r = "one namespace has index dir and another doesn't";
        return FALSE;
    }
    if (!nullequals(list1->set.control_dir, list2->set.control_dir)) {
        *error_r = "one namespace has control dir and another doesn't";
        return FALSE;
    }
    return TRUE;
}

int mailbox_rename(struct mailbox *src, struct mailbox *dest,
           bool rename_children)
{
    const char *error = NULL;

    if (!mailbox_list_is_valid_existing_name(src->list, src->name) ||
        *src->name == '\0' ||
        !mailbox_list_is_valid_create_name(dest->list, dest->name)) {
        mail_storage_set_error(src->storage, MAIL_ERROR_PARAMS,
                       "Invalid mailbox name");
        return -1;
    }
    if (!mail_storages_rename_compatible(src->storage,
                         dest->storage, &error) ||
        !mailbox_lists_rename_compatible(src->list,
                         dest->list, &error)) {
        if (src->storage->set->mail_debug) {
            i_debug("Can't rename '%s' to '%s': %s",
                src->vname, dest->vname, error);
        }
        mail_storage_set_error(src->storage, MAIL_ERROR_NOTPOSSIBLE,
            "Can't rename mailboxes across specified storages.");
        return -1;
    }
    if (src->list != dest->list &&
        (src->list->ns->type != NAMESPACE_PRIVATE ||
         dest->list->ns->type != NAMESPACE_PRIVATE)) {
        mail_storage_set_error(src->storage, MAIL_ERROR_NOTPOSSIBLE,
            "Renaming not supported across non-private namespaces.");
        return -1;
    }

    return src->v.rename(src, dest, rename_children);
}

int mailbox_set_subscribed(struct mailbox *box, bool set)
{
    if (!mailbox_list_is_valid_existing_name(box->list, box->name)) {
        mail_storage_set_error(box->storage, MAIL_ERROR_PARAMS,
                       "Invalid mailbox name");
        return -1;
    }

    return box->v.set_subscribed(box, set);
}

struct mail_storage *mailbox_get_storage(const struct mailbox *box)
{
    return box->storage;
}

struct mail_namespace *
mailbox_get_namespace(const struct mailbox *box)
{
    return box->list->ns;
}

const struct mail_storage_settings *mailbox_get_settings(struct mailbox *box)
{
    return box->storage->set;
}

const char *mailbox_get_name(const struct mailbox *box)
{
    return box->name;
}

const char *mailbox_get_vname(const struct mailbox *box)
{
    return box->vname;
}

bool mailbox_is_readonly(struct mailbox *box)
{
    return box->v.is_readonly(box);
}

bool mailbox_backends_equal(const struct mailbox *box1,
                const struct mailbox *box2)
{
    struct mail_namespace *ns1 = box1->list->ns, *ns2 = box2->list->ns;

    if (strcmp(box1->name, box2->name) != 0)
        return FALSE;

    while (ns1->alias_for != NULL)
        ns1 = ns1->alias_for;
    while (ns2->alias_for != NULL)
        ns2 = ns2->alias_for;
    return ns1 == ns2;
}

int mailbox_get_status(struct mailbox *box,
               enum mailbox_status_items items,
               struct mailbox_status *status_r)
{
    memset(status_r, 0, sizeof(*status_r));
    return box->v.get_status(box, items, status_r);
}

void mailbox_get_open_status(struct mailbox *box,
                 enum mailbox_status_items items,
                 struct mailbox_status *status_r)
{
    i_assert(box->opened);

    memset(status_r, 0, sizeof(*status_r));
    if (box->v.get_status(box, items, status_r) < 0)
        i_unreached();
}

int mailbox_get_metadata(struct mailbox *box, enum mailbox_metadata_items items,
             struct mailbox_metadata *metadata_r)
{
    memset(metadata_r, 0, sizeof(*metadata_r));

    if (box->metadata_pool != NULL)
        p_clear(box->metadata_pool);

    if (box->v.get_metadata(box, items, metadata_r) < 0)
        return -1;

    i_assert((items & MAILBOX_METADATA_GUID) == 0 ||
         !guid_128_is_empty(metadata_r->guid));
    return 0;
}

enum mail_flags mailbox_get_private_flags_mask(struct mailbox *box)
{
    if (box->v.get_private_flags_mask != NULL)
        return box->v.get_private_flags_mask(box);
    else if (box->list->set.index_pvt_dir != NULL)
        return MAIL_SEEN; /* FIXME */
    else
        return 0;
}

struct mailbox_sync_context *
mailbox_sync_init(struct mailbox *box, enum mailbox_sync_flags flags)
{
    struct mailbox_sync_context *ctx;

    if (box->transaction_count != 0) {
        i_panic("Trying to sync mailbox %s with open transactions",
            box->name);
    }
    T_BEGIN {
        ctx = box->v.sync_init(box, flags);
    } T_END;
    return ctx;
}

bool mailbox_sync_next(struct mailbox_sync_context *ctx,
               struct mailbox_sync_rec *sync_rec_r)
{
    return ctx->box->v.sync_next(ctx, sync_rec_r);
}

int mailbox_sync_deinit(struct mailbox_sync_context **_ctx,
            struct mailbox_sync_status *status_r)
{
    struct mailbox_sync_context *ctx = *_ctx;
    struct mailbox *box = ctx->box;
    const char *errormsg;
    enum mail_error error;
    int ret;

    *_ctx = NULL;

    memset(status_r, 0, sizeof(*status_r));
    ret = box->v.sync_deinit(ctx, status_r);
    if (ret < 0 && box->inbox_user &&
        !box->storage->user->inbox_open_error_logged) {
        errormsg = mailbox_get_last_error(box, &error);
        if (error == MAIL_ERROR_NOTPOSSIBLE) {
            box->storage->user->inbox_open_error_logged = TRUE;
            i_error("Syncing INBOX failed: %s", errormsg);
        }
    }
    if (ret == 0)
        box->synced = TRUE;
    return ret;
}

int mailbox_sync(struct mailbox *box, enum mailbox_sync_flags flags)
{
    struct mailbox_sync_context *ctx;
    struct mailbox_sync_status status;

    if (array_count(&box->search_results) == 0) {
        /* we don't care about mailbox's current state, so we might
           as well fix inconsistency state */
        flags |= MAILBOX_SYNC_FLAG_FIX_INCONSISTENT;
    }

    ctx = mailbox_sync_init(box, flags);
    return mailbox_sync_deinit(&ctx, &status);
}

#undef mailbox_notify_changes
void mailbox_notify_changes(struct mailbox *box,
                mailbox_notify_callback_t *callback, void *context)
{
    box->notify_callback = callback;
    box->notify_context = context;

    box->v.notify_changes(box);
}

void mailbox_notify_changes_stop(struct mailbox *box)
{
    mailbox_notify_changes(box, NULL, NULL);
}

struct mail_search_context *
mailbox_search_init(struct mailbox_transaction_context *t,
            struct mail_search_args *args,
            const enum mail_sort_type *sort_program,
            enum mail_fetch_field wanted_fields,
            struct mailbox_header_lookup_ctx *wanted_headers)
{
    mail_search_args_ref(args);
    if (!args->simplified)
        mail_search_args_simplify(args);
    return t->box->v.search_init(t, args, sort_program,
                     wanted_fields, wanted_headers);
}

int mailbox_search_deinit(struct mail_search_context **_ctx)
{
    struct mail_search_context *ctx = *_ctx;
    struct mail_search_args *args = ctx->args;
    int ret;

    *_ctx = NULL;
    mailbox_search_results_initial_done(ctx);
    ret = ctx->transaction->box->v.search_deinit(ctx);
    mail_search_args_unref(&args);
    return ret;
}

bool mailbox_search_next(struct mail_search_context *ctx, struct mail **mail_r)
{
    bool tryagain;

    while (!mailbox_search_next_nonblock(ctx, mail_r, &tryagain)) {
        if (!tryagain)
            return FALSE;
    }
    return TRUE;
}

bool mailbox_search_next_nonblock(struct mail_search_context *ctx,
                  struct mail **mail_r, bool *tryagain_r)
{
    struct mailbox *box = ctx->transaction->box;

    *mail_r = NULL;

    if (!box->v.search_next_nonblock(ctx, mail_r, tryagain_r))
        return FALSE;
    else {
        mailbox_search_results_add(ctx, (*mail_r)->uid);
        return TRUE;
    }
}

bool mailbox_search_seen_lost_data(struct mail_search_context *ctx)
{
    return ctx->seen_lost_data;
}

int mailbox_search_result_build(struct mailbox_transaction_context *t,
                struct mail_search_args *args,
                enum mailbox_search_result_flags flags,
                struct mail_search_result **result_r)
{
    struct mail_search_context *ctx;
    struct mail *mail;
    int ret;

    ctx = mailbox_search_init(t, args, NULL, 0, NULL);
    *result_r = mailbox_search_result_save(ctx, flags);
    while (mailbox_search_next(ctx, &mail)) ;

    ret = mailbox_search_deinit(&ctx);
    if (ret < 0)
        mailbox_search_result_free(result_r);
    return ret;
}

struct mailbox_transaction_context *
mailbox_transaction_begin(struct mailbox *box,
              enum mailbox_transaction_flags flags)
{
    struct mailbox_transaction_context *trans;

    box->transaction_count++;
    trans = box->v.transaction_begin(box, flags);
    trans->flags = flags;
    return trans;
}

int mailbox_transaction_commit(struct mailbox_transaction_context **t)
{
    struct mail_transaction_commit_changes changes;
    int ret;

    /* Store changes temporarily so that plugins overriding
       transaction_commit() can look at them. */
    changes.pool = NULL;
    ret = mailbox_transaction_commit_get_changes(t, &changes);
    if (changes.pool != NULL)
        pool_unref(&changes.pool);
    return ret;
}

int mailbox_transaction_commit_get_changes(
    struct mailbox_transaction_context **_t,
    struct mail_transaction_commit_changes *changes_r)
{
    struct mailbox_transaction_context *t = *_t;
    int ret;

    t->box->transaction_count--;

    *_t = NULL;
    T_BEGIN {
        ret = t->box->v.transaction_commit(t, changes_r);
    } T_END;
    return ret;
}

void mailbox_transaction_rollback(struct mailbox_transaction_context **_t)
{
    struct mailbox_transaction_context *t = *_t;

    t->box->transaction_count--;

    *_t = NULL;
    t->box->v.transaction_rollback(t);
}

unsigned int mailbox_transaction_get_count(const struct mailbox *box)
{
    return box->transaction_count;
}

void mailbox_transaction_set_max_modseq(struct mailbox_transaction_context *t,
                    uint64_t max_modseq,
                    ARRAY_TYPE(seq_range) *seqs)
{
    mail_index_transaction_set_max_modseq(t->itrans, max_modseq, seqs);
}

struct mailbox *
mailbox_transaction_get_mailbox(const struct mailbox_transaction_context *t)
{
    return t->box;
}

struct mail_save_context *
mailbox_save_alloc(struct mailbox_transaction_context *t)
{
    struct mail_save_context *ctx;

    ctx = t->box->v.save_alloc(t);
    ctx->received_date = (time_t)-1;
    ctx->save_date = (time_t)-1;
    return ctx;
}

void mailbox_save_set_flags(struct mail_save_context *ctx,
                enum mail_flags flags,
                struct mail_keywords *keywords)
{
    ctx->flags = flags;
    ctx->keywords = keywords;
    if (keywords != NULL)
        mailbox_keywords_ref(keywords);
}

void mailbox_save_copy_flags(struct mail_save_context *ctx, struct mail *mail)
{
    const char *const *keywords_list;

    keywords_list = mail_get_keywords(mail);
    ctx->keywords = str_array_length(keywords_list) == 0 ? NULL :
        mailbox_keywords_create_valid(ctx->transaction->box,
                          keywords_list);
    ctx->flags = mail_get_flags(mail);
}

void mailbox_save_set_min_modseq(struct mail_save_context *ctx,
                 uint64_t min_modseq)
{
    ctx->min_modseq = min_modseq;
}

void mailbox_save_set_received_date(struct mail_save_context *ctx,
                    time_t received_date, int timezone_offset)
{
    ctx->received_date = received_date;
    ctx->received_tz_offset = timezone_offset;
}

void mailbox_save_set_save_date(struct mail_save_context *ctx,
                time_t save_date)
{
    ctx->save_date = save_date;
}

void mailbox_save_set_from_envelope(struct mail_save_context *ctx,
                    const char *envelope)
{
    i_free(ctx->from_envelope);
    ctx->from_envelope = i_strdup(envelope);
}

void mailbox_save_set_uid(struct mail_save_context *ctx, uint32_t uid)
{
    ctx->uid = uid;
}

void mailbox_save_set_guid(struct mail_save_context *ctx, const char *guid)
{
    i_assert(guid == NULL || *guid != '\0');

    i_free(ctx->guid);
    ctx->guid = i_strdup(guid);
}

void mailbox_save_set_pop3_uidl(struct mail_save_context *ctx, const char *uidl)
{
    i_assert(*uidl != '\0');
    i_assert(strchr(uidl, '\n') == NULL);

    i_free(ctx->pop3_uidl);
    ctx->pop3_uidl = i_strdup(uidl);
}

void mailbox_save_set_pop3_order(struct mail_save_context *ctx,
                 unsigned int order)
{
    i_assert(order > 0);

    ctx->pop3_order = order;
}

void mailbox_save_set_dest_mail(struct mail_save_context *ctx,
                struct mail *mail)
{
    ctx->dest_mail = mail;
}

int mailbox_save_begin(struct mail_save_context **ctx, struct istream *input)
{
    struct mailbox *box = (*ctx)->transaction->box;
    int ret;

    if (mail_index_is_deleted(box->index)) {
        mailbox_set_deleted(box);
        return -1;
    }

    if (!(*ctx)->copying_via_save)
        (*ctx)->saving = TRUE;
    if (box->v.save_begin == NULL) {
        mail_storage_set_error(box->storage, MAIL_ERROR_NOTPOSSIBLE,
                       "Saving messages not supported");
        ret = -1;
    } else {
        ret = box->v.save_begin(*ctx, input);
    }

    if (ret < 0) {
        mailbox_save_cancel(ctx);
        return -1;
    }
    return 0;
}

int mailbox_save_continue(struct mail_save_context *ctx)
{
    return ctx->transaction->box->v.save_continue(ctx);
}

int mailbox_save_finish(struct mail_save_context **_ctx)
{
    struct mail_save_context *ctx = *_ctx;
    struct mailbox *box = ctx->transaction->box;
    struct mail_keywords *keywords = ctx->keywords;
    int ret;

    *_ctx = NULL;
    ret = box->v.save_finish(ctx);
    if (keywords != NULL)
        mailbox_keywords_unref(&keywords);
    return ret;
}

void mailbox_save_cancel(struct mail_save_context **_ctx)
{
    struct mail_save_context *ctx = *_ctx;
    struct mail_keywords *keywords = ctx->keywords;

    *_ctx = NULL;
    ctx->transaction->box->v.save_cancel(ctx);
    if (keywords != NULL)
        mailbox_keywords_unref(&keywords);
}

struct mailbox_transaction_context *
mailbox_save_get_transaction(struct mail_save_context *ctx)
{
    return ctx->transaction;
}

int mailbox_copy(struct mail_save_context **_ctx, struct mail *mail)
{
    struct mail_save_context *ctx = *_ctx;
    struct mailbox *box = ctx->transaction->box;
    struct mail_keywords *keywords = ctx->keywords;
    int ret;

    *_ctx = NULL;

    if (mail_index_is_deleted(box->index)) {
        mailbox_set_deleted(box);
        mailbox_save_cancel(&ctx);
        return -1;
    }

    ret = ctx->transaction->box->v.copy(ctx, mail);
    if (keywords != NULL)
        mailbox_keywords_unref(&keywords);
    return ret;
}

int mailbox_move(struct mail_save_context **_ctx, struct mail *mail)
{
    struct mail_save_context *ctx = *_ctx;

    ctx->moving = TRUE;
    if (mailbox_copy(_ctx, mail) < 0)
        return -1;

    mail_expunge(mail);
    return 0;
}

int mailbox_save_using_mail(struct mail_save_context **ctx, struct mail *mail)
{
    (*ctx)->saving = TRUE;
    return mailbox_copy(ctx, mail);
}

bool mailbox_is_inconsistent(struct mailbox *box)
{
    return box->mailbox_deleted || box->v.is_inconsistent(box);
}

void mailbox_set_deleted(struct mailbox *box)
{
    mail_storage_set_error(box->storage, MAIL_ERROR_NOTFOUND,
                   "Mailbox was deleted under us");
    box->mailbox_deleted = TRUE;
}

const char *mailbox_get_path(struct mailbox *box)
{
    const char *path;

    if (box->_path == NULL) {
        path = mailbox_list_get_path(box->list, box->name,
                         MAILBOX_LIST_PATH_TYPE_MAILBOX);
        box->_path = p_strdup(box->pool, path);
    }
    return box->_path;
}

static void mailbox_get_permissions_if_not_set(struct mailbox *box)
{
    if (box->_perm.file_create_mode != 0)
        return;

    if (box->input != NULL) {
        box->_perm.file_uid = geteuid();
        box->_perm.file_create_mode = 0600;
        box->_perm.dir_create_mode = 0700;
        box->_perm.file_create_gid = (gid_t)-1;
        box->_perm.file_create_gid_origin = "defaults";
        return;
    }

    mailbox_list_get_permissions(box->list, box->name, &box->_perm);
    box->_perm.file_create_gid_origin =
        p_strdup(box->pool, box->_perm.file_create_gid_origin);
}

const struct mailbox_permissions *mailbox_get_permissions(struct mailbox *box)
{
    mailbox_get_permissions_if_not_set(box);

    if (!box->_perm.mail_index_permissions_set && box->index != NULL) {
        box->_perm.mail_index_permissions_set = TRUE;
        mail_index_set_permissions(box->index,
                       box->_perm.file_create_mode,
                       box->_perm.file_create_gid,
                       box->_perm.file_create_gid_origin);
    }
    return &box->_perm;
}

void mailbox_refresh_permissions(struct mailbox *box)
{
    memset(&box->_perm, 0, sizeof(box->_perm));
    (void)mailbox_get_permissions(box);
}

int mailbox_create_fd(struct mailbox *box, const char *path, int flags,
              int *fd_r)
{
    const struct mailbox_permissions *perm = mailbox_get_permissions(box);
    mode_t old_mask;
    int fd;

    i_assert((flags & O_CREAT) != 0);

    *fd_r = -1;

    old_mask = umask(0);
    fd = open(path, flags, perm->file_create_mode);
    umask(old_mask);

    if (fd != -1) {
        /* ok */
    } else if (errno == EEXIST) {
        /* O_EXCL used, caller will handle this error */
        return 0;
    } else if (errno == ENOENT) {
        mailbox_set_deleted(box);
        return -1;
    } else if (errno == ENOTDIR) {
        mail_storage_set_error(box->storage, MAIL_ERROR_NOTPOSSIBLE,
            "Mailbox doesn't allow inferior mailboxes");
        return -1;
    } else if (mail_storage_set_error_from_errno(box->storage)) {
        return -1;
    } else {
        mail_storage_set_critical(box->storage,
            "open(%s, O_CREAT) failed: %m", path);
        return -1;
    }

    if (perm->file_create_gid != (gid_t)-1) {
        if (fchown(fd, (uid_t)-1, perm->file_create_gid) == 0) {
            /* ok */
        } else if (errno == EPERM) {
            mail_storage_set_critical(box->storage, "%s",
                eperm_error_get_chgrp("fchown", path,
                    perm->file_create_gid,
                    perm->file_create_gid_origin));
        } else {
            mail_storage_set_critical(box->storage,
                "fchown(%s) failed: %m", path);
        }
    }
    *fd_r = fd;
    return 1;
}

unsigned int mail_storage_get_lock_timeout(struct mail_storage *storage,
                       unsigned int secs)
{
    return storage->set->mail_max_lock_timeout == 0 ? secs :
        I_MIN(secs, storage->set->mail_max_lock_timeout);
}