src/lib-storage/mail-storage.c

	mail-storage.c revision b365bd121cdc87f63e1dd47c5085a27091118e00
5f08b0309190ec818d46bfe0e497468b30714a93Timo Sirainen/* Copyright (c) 2002-2010 Dovecot authors, see the included COPYING file */
5f08b0309190ec818d46bfe0e497468b30714a93Timo Sirainen
5f08b0309190ec818d46bfe0e497468b30714a93Timo Sirainen#include "lib.h"
5f08b0309190ec818d46bfe0e497468b30714a93Timo Sirainen#include "ioloop.h"
5f08b0309190ec818d46bfe0e497468b30714a93Timo Sirainen#include "array.h"
5f08b0309190ec818d46bfe0e497468b30714a93Timo Sirainen#include "llist.h"
5f08b0309190ec818d46bfe0e497468b30714a93Timo Sirainen#include "istream.h"
5f08b0309190ec818d46bfe0e497468b30714a93Timo Sirainen#include "eacces-error.h"
5f08b0309190ec818d46bfe0e497468b30714a93Timo Sirainen#include "mkdir-parents.h"
5f08b0309190ec818d46bfe0e497468b30714a93Timo Sirainen#include "var-expand.h"
5f08b0309190ec818d46bfe0e497468b30714a93Timo Sirainen#include "mail-index-private.h"
5f08b0309190ec818d46bfe0e497468b30714a93Timo Sirainen#include "mail-index-alloc-cache.h"
5f08b0309190ec818d46bfe0e497468b30714a93Timo Sirainen#include "mailbox-list-private.h"
5f08b0309190ec818d46bfe0e497468b30714a93Timo Sirainen#include "mail-storage-private.h"
5f08b0309190ec818d46bfe0e497468b30714a93Timo Sirainen#include "mail-storage-settings.h"
5f08b0309190ec818d46bfe0e497468b30714a93Timo Sirainen#include "mail-namespace.h"
5f08b0309190ec818d46bfe0e497468b30714a93Timo Sirainen#include "mail-search.h"
5f08b0309190ec818d46bfe0e497468b30714a93Timo Sirainen#include "mail-search-register.h"
5f08b0309190ec818d46bfe0e497468b30714a93Timo Sirainen#include "mailbox-search-result-private.h"
5f08b0309190ec818d46bfe0e497468b30714a93Timo Sirainen
5f08b0309190ec818d46bfe0e497468b30714a93Timo Sirainen#include <stdlib.h>
5f08b0309190ec818d46bfe0e497468b30714a93Timo Sirainen#include <ctype.h>
5f08b0309190ec818d46bfe0e497468b30714a93Timo Sirainen
5f08b0309190ec818d46bfe0e497468b30714a93Timo Sirainen#define MAILBOX_DELETE_RETRY_SECS (60*5)
5f08b0309190ec818d46bfe0e497468b30714a93Timo Sirainen
5f08b0309190ec818d46bfe0e497468b30714a93Timo Sirainenextern struct mail_search_register *mail_search_register_imap;
5f08b0309190ec818d46bfe0e497468b30714a93Timo Sirainenextern struct mail_search_register *mail_search_register_human;
5f08b0309190ec818d46bfe0e497468b30714a93Timo Sirainen
5f08b0309190ec818d46bfe0e497468b30714a93Timo Sirainenstruct mail_storage_module_register mail_storage_module_register = { 0 };
5f08b0309190ec818d46bfe0e497468b30714a93Timo Sirainenstruct mail_module_register mail_module_register = { 0 };
5f08b0309190ec818d46bfe0e497468b30714a93Timo Sirainen
5f08b0309190ec818d46bfe0e497468b30714a93Timo Sirainenstruct mail_storage_mail_index_module mail_storage_mail_index_module =
5f08b0309190ec818d46bfe0e497468b30714a93Timo Sirainen    MODULE_CONTEXT_INIT(&mail_index_module_register);
5f08b0309190ec818d46bfe0e497468b30714a93Timo SirainenARRAY_TYPE(mail_storage) mail_storage_classes;
5f08b0309190ec818d46bfe0e497468b30714a93Timo Sirainen
5f08b0309190ec818d46bfe0e497468b30714a93Timo Sirainenvoid mail_storage_init(void)
{
    mailbox_lists_init();
    mail_storage_hooks_init();
    i_array_init(&mail_storage_classes, 8);
}

void mail_storage_deinit(void)
{
    if (mail_search_register_human != NULL)
        mail_search_register_deinit(&mail_search_register_human);
    if (mail_search_register_imap != NULL)
        mail_search_register_deinit(&mail_search_register_imap);
    if (array_is_created(&mail_storage_classes))
        array_free(&mail_storage_classes);
    mail_storage_hooks_deinit();
    mailbox_lists_deinit();
}

void mail_storage_class_register(struct mail_storage *storage_class)
{
    i_assert(mail_storage_find_class(storage_class->name) == NULL);

    /* append it after the list, so the autodetection order is correct */
    array_append(&mail_storage_classes, &storage_class, 1);
}

void mail_storage_class_unregister(struct mail_storage *storage_class)
{
    struct mail_storage *const *classes;
    unsigned int i, count;

    classes = array_get(&mail_storage_classes, &count);
    for (i = 0; i < count; i++) {
        if (classes[i] == storage_class) {
            array_delete(&mail_storage_classes, i, 1);
            break;
        }
    }
}

struct mail_storage *mail_storage_find_class(const char *name)
{
    struct mail_storage *const *classes;
    unsigned int i, count;

    i_assert(name != NULL);

    classes = array_get(&mail_storage_classes, &count);
    for (i = 0; i < count; i++) {
        if (strcasecmp(classes[i]->name, name) == 0)
            return classes[i];
    }
    return NULL;
}

static struct mail_storage *
mail_storage_autodetect(const struct mail_namespace *ns,
            struct mailbox_list_settings *set)
{
    struct mail_storage *const *classes;
    unsigned int i, count;

    classes = array_get(&mail_storage_classes, &count);
    for (i = 0; i < count; i++) {
        if (classes[i]->v.autodetect != NULL) {
            if (classes[i]->v.autodetect(ns, set))
                return classes[i];
        }
    }
    return NULL;
}

static void
mail_storage_set_autodetection(const char **data, const char **driver)
{
    const char *p;

    /* check if data is in driver:data format (eg. mbox:~/mail) */
    p = *data;
    while (i_isalnum(*p)) p++;

    if (*p == ':' && p != *data) {
        /* no autodetection if the storage driver is given. */
        *driver = t_strdup_until(*data, p);
        *data = p + 1;
    }
}

static struct mail_storage *
mail_storage_get_class(struct mail_namespace *ns, const char *driver,
               struct mailbox_list_settings *list_set,
               enum mail_storage_flags flags, const char **error_r)
{
    struct mail_storage *storage_class = NULL;
    const char *home;

    if (driver != NULL) {
        storage_class = mail_storage_find_class(driver);
        if (storage_class == NULL) {
            *error_r = t_strdup_printf(
                "Unknown mail storage driver %s", driver);
            return NULL;
        }
    }

    if (list_set->root_dir == NULL || *list_set->root_dir == '\0') {
        /* no root directory given. is this allowed? */
        const struct mailbox_list *list;

        list = list_set->layout == NULL ? NULL :
            mailbox_list_find_class(list_set->layout);
        if (storage_class == NULL &&
            (flags & MAIL_STORAGE_FLAG_NO_AUTODETECTION) == 0) {
            /* autodetection should take care of this */
        } else if (list != NULL &&
               (list->props & MAILBOX_LIST_PROP_NO_ROOT) != 0) {
            /* root not required for this layout */
        } 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;

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

        *error_r = t_strdup_printf(
            "Mail storage autodetection failed with home=%s", 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_create_root(struct mailbox_list *list,
             enum mail_storage_flags flags, const char **error_r)
{
    const char *root_dir, *origin;
    struct stat st;
    mode_t mode;
    gid_t gid;

    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 (stat(root_dir, &st) == 0) {
        /* ok */
        return 0;
    } 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 (list->ns->type == NAMESPACE_SHARED) {
        /* can't create a new user, but we don't want to fail
           the storage creation. */
    } else if ((flags & MAIL_STORAGE_FLAG_NO_AUTOCREATE) != 0) {
        *error_r = t_strdup_printf(
            "Root mail directory doesn't exist: %s", root_dir);
        return -1;
    }

    /* we need to create the root directory. */
    mailbox_list_get_dir_permissions(list, NULL, &mode, &gid, &origin);
    if (mkdir_parents_chgrp(root_dir, mode, gid, origin) < 0 &&
        errno != EEXIST) {
        *error_r = mail_error_create_eacces_msg("mkdir", root_dir);
        return -1;
    } else {
        /* created */
        return 0;
    }
}

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 (strcmp(storage->name, storage_class->name) == 0 &&
            ((storage->class_flags &
              MAIL_STORAGE_CLASS_FLAG_UNIQUE_ROOT) == 0 ||
             strcmp(storage->unique_root_dir, set->root_dir) == 0))
            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_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));
    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, 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->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);

    storage->obj_refcount++;
}

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

    storage->obj_refcount--;
}

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)
{
    struct tm *tm;
    char str[256];

    tm = localtime(&ioloop_time);

    i_free(storage->error_string);
    storage->error_string =
        strftime(str, sizeof(str),
             MAIL_ERRSTR_CRITICAL_MSG_STAMP, tm) > 0 ?
        i_strdup(str) : i_strdup(MAIL_ERRSTR_CRITICAL_MSG);
    storage->error = MAIL_ERROR_TEMP;
}

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

    mail_storage_clear_error(storage);
    if (fmt != NULL) {
        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;
}

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;
}

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

    if (mailbox_list_get_storage(&new_list, &name, &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, name, flags);
        hook_mailbox_allocated(box);
    } T_END;

    mail_storage_obj_ref(box->storage);
    return box;
}

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

    if (box->opened)
        return 0;

    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 && box->inbox) T_BEGIN {
        /* INBOX should always exist. try to create it and retry. */
        (void)mailbox_create(box, NULL, FALSE);
        mailbox_close(box);
        ret = box->v.open(box);
        if (ret < 0 && !box->storage->user->inbox_open_error_logged) {
            box->storage->user->inbox_open_error_logged = TRUE;
            i_error("Opening INBOX failed: %s",
                mail_storage_get_last_error(box->storage, NULL));
        }
    } 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;
}

int mailbox_open(struct mailbox *box)
{
    return mailbox_open_full(box, NULL);
}

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;
    box->backend_readonly = 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);
    mail_storage_obj_unref(box->storage);
    pool_unref(&box->pool);
}

int mailbox_create(struct mailbox *box, const struct mailbox_update *update,
           bool directory)
{
    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;
    }

    if (box->list->v.create_mailbox_dir(box->list, box->name,
                        directory) < 0) {
        mail_storage_copy_list_error(box->storage, box->list);
        return -1;
    }
    mailbox_refresh_permissions(box);

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

int mailbox_update(struct mailbox *box, const struct mailbox_update *update)
{
    return box->v.update(box, update);
}

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

    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. */
    return mailbox_sync(box, MAILBOX_SYNC_FLAG_FULL_READ);
}

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_delete(struct mailbox *box)
{
    enum mail_error error;
    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) {
        mail_storage_set_error(box->storage, MAIL_ERROR_NOTPOSSIBLE,
                       "INBOX can't be deleted.");
        return -1;
    }

    box->deleting = TRUE;
    if (mailbox_open(box) < 0) {
        (void)mail_storage_get_last_error(box->storage, &error);
        if (error != MAIL_ERROR_NOTFOUND)
            return -1;
        if (!box->mailbox_deleted) {
            /* \noselect mailbox */
        } else {
            /* if deletion happened a long time ago, it means it
               crashed while doing it. undelete the mailbox in
               that case. */
            if (!mailbox_try_undelete(box))
                return -1;

            /* retry */
            if (mailbox_open(box) < 0)
                return -1;
        }
    }

    if (box->opened) {
        if (mailbox_mark_index_deleted(box, TRUE) < 0)
            return -1;
    }
    ret = box->v.delete(box);

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

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

    if (strcmp(storage1->name, storage2->name) != 0)
        return FALSE;
    if ((storage1->class_flags & MAIL_STORAGE_CLASS_FLAG_UNIQUE_ROOT) != 0)
        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)
{
    return nullequals(list1->set.alt_dir, list2->set.alt_dir) &&
        nullequals(list1->set.index_dir, list2->set.index_dir) &&
        nullequals(list1->set.control_dir, list2->set.control_dir);
}

int mailbox_rename(struct mailbox *src, struct mailbox *dest,
           bool rename_children)
{
    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) ||
        !mailbox_lists_rename_compatible(src->list, dest->list)) {
        mail_storage_set_error(src->storage, MAIL_ERROR_NOTPOSSIBLE,
            "Can't rename mailboxes across specified storages.");
        return -1;
    }
    if (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);
}

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_allow_new_keywords(struct mailbox *box)
{
    return box->v.allow_new_keywords(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;
}

void mailbox_get_status(struct mailbox *box,
            enum mailbox_status_items items,
            struct mailbox_status *status_r)
{
    box->v.get_status(box, items, status_r);
}

int mailbox_get_guid(struct mailbox *box, uint8_t guid[MAIL_GUID_128_SIZE])
{
    if (box->v.get_guid == NULL) {
        mail_storage_set_error(box->storage, MAIL_ERROR_NOTPOSSIBLE,
                       "Storage doesn't support mailbox GUIDs");
    }
    if (!box->opened) {
        if (mailbox_open(box) < 0)
            return -1;
    }
    if (box->v.get_guid(box, guid) < 0)
        return -1;

    i_assert(!mail_guid_128_is_empty(guid));
    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 &&
        !box->storage->user->inbox_open_error_logged) {
        errormsg = mail_storage_get_last_error(box->storage, &error);
        if (error == MAIL_ERROR_NOTPOSSIBLE) {
            box->storage->user->inbox_open_error_logged = TRUE;
            i_error("Syncing INBOX failed: %s", errormsg);
        }
    }
    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, unsigned int min_interval,
                mailbox_notify_callback_t *callback, void *context)
{
    box->notify_min_interval = min_interval;
    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, 0, NULL, NULL);
}

int mailbox_keywords_create(struct mailbox *box, const char *const keywords[],
                struct mail_keywords **keywords_r)
{
    const char *empty_keyword_list = NULL;

    if (keywords == NULL)
        keywords = &empty_keyword_list;
    return box->v.keywords_create(box, keywords, keywords_r, FALSE);
}

struct mail_keywords *
mailbox_keywords_create_valid(struct mailbox *box,
                  const char *const keywords[])
{
    const char *empty_keyword_list = NULL;
    struct mail_keywords *kw;

    if (keywords == NULL)
        keywords = &empty_keyword_list;
    if (box->v.keywords_create(box, keywords, &kw, TRUE) < 0)
        i_unreached();
    return kw;
}

struct mail_keywords *
mailbox_keywords_create_from_indexes(struct mailbox *box,
                     const ARRAY_TYPE(keyword_indexes) *idx)
{
    return box->v.keywords_create_from_indexes(box, idx);
}

void mailbox_keywords_ref(struct mailbox *box, struct mail_keywords *keywords)
{
    box->v.keywords_ref(keywords);
}

void mailbox_keywords_unref(struct mailbox *box,
                struct mail_keywords **_keywords)
{
    struct mail_keywords *keywords = *_keywords;

    *_keywords = NULL;
    box->v.keywords_unref(keywords);
}

bool mailbox_keyword_is_valid(struct mailbox *box, const char *keyword,
                  const char **error_r)
{
    return box->v.keyword_is_valid(box, keyword, error_r);
}

void mailbox_get_seq_range(struct mailbox *box, uint32_t uid1, uint32_t uid2,
               uint32_t *seq1_r, uint32_t *seq2_r)
{
    box->v.get_seq_range(box, uid1, uid2, seq1_r, seq2_r);
}

void mailbox_get_uid_range(struct mailbox *box,
               const ARRAY_TYPE(seq_range) *seqs,
               ARRAY_TYPE(seq_range) *uids)
{
    box->v.get_uid_range(box, seqs, uids);
}

bool mailbox_get_expunges(struct mailbox *box, uint64_t prev_modseq,
              const ARRAY_TYPE(seq_range) *uids_filter,
              ARRAY_TYPE(mailbox_expunge_rec) *expunges)
{
    return box->v.get_expunges(box, prev_modseq,
                   uids_filter, expunges);
}

bool mailbox_get_virtual_uid(struct mailbox *box, const char *backend_mailbox,
                 uint32_t backend_uidvalidity,
                 uint32_t backend_uid, uint32_t *uid_r)
{
    if (box->v.get_virtual_uid == NULL)
        return FALSE;
    return box->v.get_virtual_uid(box, backend_mailbox, backend_uidvalidity,
                      backend_uid, uid_r);
}

void mailbox_get_virtual_backend_boxes(struct mailbox *box,
                       ARRAY_TYPE(mailboxes) *mailboxes,
                       bool only_with_msgs)
{
    if (box->v.get_virtual_backend_boxes == NULL)
        array_append(mailboxes, &box, 1);
    else
        box->v.get_virtual_backend_boxes(box, mailboxes, only_with_msgs);
}

void mailbox_get_virtual_box_patterns(struct mailbox *box,
                ARRAY_TYPE(mailbox_virtual_patterns) *includes,
                ARRAY_TYPE(mailbox_virtual_patterns) *excludes)
{
    if (box->v.get_virtual_box_patterns == NULL) {
        struct mailbox_virtual_pattern pat;

        memset(&pat, 0, sizeof(pat));
        pat.ns = box->list->ns;
        pat.pattern = box->name;
        array_append(includes, &pat, 1);
    } else {
        box->v.get_virtual_box_patterns(box, includes, excludes);
    }
}

struct mailbox_header_lookup_ctx *
mailbox_header_lookup_init(struct mailbox *box, const char *const headers[])
{
    return box->v.header_lookup_init(box, headers);
}

void mailbox_header_lookup_ref(struct mailbox_header_lookup_ctx *ctx)
{
    i_assert(ctx->refcount > 0);
    ctx->refcount++;
}

void mailbox_header_lookup_unref(struct mailbox_header_lookup_ctx **_ctx)
{
    struct mailbox_header_lookup_ctx *ctx = *_ctx;

    *_ctx = NULL;

    i_assert(ctx->refcount > 0);
    if (--ctx->refcount > 0)
        return;

    ctx->box->v.header_lookup_deinit(ctx);
}

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

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)
{
    bool tryagain;

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

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

    if (!box->v.search_next_nonblock(ctx, mail, tryagain_r))
        return FALSE;
    else {
        mailbox_search_results_add(ctx, mail->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);
    *result_r = mailbox_search_result_save(ctx, flags);
    mail = mail_alloc(t, 0, NULL);
    while (mailbox_search_next(ctx, mail)) ;
    mail_free(&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. */
    ret = mailbox_transaction_commit_get_changes(t, &changes);
    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)
{
    t->box->v.transaction_set_max_modseq(t, 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(ctx->transaction->box, 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_free(ctx->pop3_uidl);
    ctx->pop3_uidl = i_strdup(uidl);
}

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 (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(box, &keywords);
    return ret;
}

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

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

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(box, &keywords);
    return ret;
}

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;
}

void mailbox_refresh_permissions(struct mailbox *box)
{
    const char *origin, *dir_origin;
    gid_t dir_gid;

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

    mailbox_list_get_permissions(box->list, box->name,
                     &box->file_create_mode,
                     &box->file_create_gid, &origin);

    box->file_create_gid_origin = p_strdup(box->pool, origin);
    mailbox_list_get_dir_permissions(box->list, box->name,
                     &box->dir_create_mode,
                     &dir_gid, &dir_origin);
}

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

    i_assert(box->file_create_mode != 0);
    i_assert((flags & O_CREAT) != 0);

    *fd_r = -1;

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