index/maildir/maildir-storage.c

	maildir-storage.c revision 8a450b60d44b92cb6b085d5aba69d627f848461a
/* Copyright (C) 2002-2003 Timo Sirainen */

#include "lib.h"
#include "hostpid.h"
#include "home-expand.h"
#include "mkdir-parents.h"
#include "unlink-directory.h"
#include "subscription-file/subscription-file.h"
#include "maildir-storage.h"
#include "maildir-uidlist.h"

#include <stdio.h>
#include <stdlib.h>
#include <unistd.h>
#include <sys/stat.h>

#define CREATE_MODE 0770 /* umask() should limit it more */

struct rename_context {
    int found;
    size_t oldnamelen;
    const char *newname;
};

extern struct mail_storage maildir_storage;
extern struct mailbox maildir_mailbox;

static const char *maildirs[] = { "cur", "new", "tmp", NULL  };

static int verify_inbox(struct index_storage *storage);

static struct mail_storage *
maildir_create(const char *data, const char *user)
{
    struct index_storage *storage;
    const char *root_dir, *inbox_dir, *index_dir, *control_dir;
    const char *home, *path, *p;
    size_t len;

    inbox_dir = root_dir = index_dir = control_dir = NULL;

    if (data == NULL || *data == '\0') {
        /* we'll need to figure out the maildir location ourself.
           it's either root dir if we've already chroot()ed, or
           $HOME/Maildir otherwise */
        if (access("/cur", R_OK|W_OK|X_OK) == 0)
            root_dir = "/";
        else {
            home = getenv("HOME");
            if (home != NULL) {
                path = t_strconcat(home, "/Maildir", NULL);
                if (access(path, R_OK|W_OK|X_OK) == 0)
                    root_dir = path;
            }
        }
    } else {
        /* <Maildir> [:INBOX=<dir>] [:INDEX=<dir>] [:CONTROL=<dir>] */
        p = strchr(data, ':');
        if (p == NULL)
            root_dir = data;
        else {
            root_dir = t_strdup_until(data, p);

            do {
                p++;
                if (strncmp(p, "INBOX=", 6) == 0)
                    inbox_dir = t_strcut(p+6, ':');
                else if (strncmp(p, "INDEX=", 6) == 0)
                    index_dir = t_strcut(p+6, ':');
                else if (strncmp(p, "CONTROL=", 8) == 0)
                    control_dir = t_strcut(p+8, ':');
                p = strchr(p, ':');
            } while (p != NULL);
        }
    }

    if (root_dir == NULL)
        return NULL;

    /* strip trailing '/' */
    len = strlen(root_dir);
    if (root_dir[len-1] == '/')
        root_dir = t_strndup(root_dir, len-1);

    if (index_dir == NULL)
        index_dir = root_dir;
    else if (strcmp(index_dir, "MEMORY") == 0)
        index_dir = NULL;

    storage = i_new(struct index_storage, 1);
    storage->storage = maildir_storage;

    /* the default ".temp.xxx" prefix would be treated as directory */
    storage->temp_prefix =
        i_strconcat("temp.", my_hostname, ".", my_pid, ".", NULL);

    storage->dir = i_strdup(home_expand(root_dir));
    storage->inbox_path = i_strdup(home_expand(inbox_dir));
    storage->index_dir = i_strdup(home_expand(index_dir));
    storage->control_dir = i_strdup(home_expand(control_dir));
    storage->user = i_strdup(user);
    storage->callbacks = i_new(struct mail_storage_callbacks, 1);
    index_storage_init(storage);

    (void)verify_inbox(storage);
    return &storage->storage;
}

static void maildir_free(struct mail_storage *_storage)
{
    struct index_storage *storage = (struct index_storage *) _storage;

    index_storage_deinit(storage);

    i_free(storage->temp_prefix);
    i_free(storage->dir);
    i_free(storage->inbox_path);
    i_free(storage->index_dir);
    i_free(storage->control_dir);
    i_free(storage->user);
    i_free(storage->callbacks);
    i_free(storage);
}

static int maildir_autodetect(const char *data)
{
    struct stat st;

    data = t_strcut(data, ':');

    return stat(t_strconcat(data, "/cur", NULL), &st) == 0 &&
        S_ISDIR(st.st_mode);
}

static int maildir_is_valid_create_name(const char *name)
{
    size_t len;

    len = strlen(name);
    if (len == 0 || name[0] == MAILDIR_FS_SEP ||
        name[len-1] == MAILDIR_FS_SEP ||
        strchr(name, '*') != NULL || strchr(name, '%') != NULL)
        return FALSE;

    if (full_filesystem_access)
        return TRUE;

    if (*name == '~' || strchr(name, '/') != NULL)
        return FALSE;

    return TRUE;
}

static int maildir_is_valid_existing_name(const char *name)
{
    if (name[0] == '\0' || name[strlen(name)-1] == '/')
        return FALSE;

    if (full_filesystem_access)
        return TRUE;

    if (*name == '~' || strchr(name, '/') != NULL)
        return FALSE;

    return TRUE;
}

static const char *maildir_get_absolute_path(const char *name, int unlink)
{
    const char *p;

    name = home_expand(name);

    p = strrchr(name, '/');
    if (p == NULL)
        return name;
    return t_strconcat(t_strdup_until(name, p+1),
               unlink ? MAILDIR_FS_SEP_S MAILDIR_FS_SEP_S :
               MAILDIR_FS_SEP_S, p+1, NULL);
}

const char *maildir_get_path(struct index_storage *storage, const char *name)
{
    if (full_filesystem_access && (*name == '/' || *name == '~'))
        return maildir_get_absolute_path(name, FALSE);

    if (strcmp(name, "INBOX") == 0) {
        return storage->inbox_path != NULL ?
            storage->inbox_path : storage->dir;
    }

    return t_strconcat(storage->dir, "/"MAILDIR_FS_SEP_S, name, NULL);
}

static const char *
maildir_get_unlink_path(struct index_storage *storage, const char *name)
{
    if (full_filesystem_access && (*name == '/' || *name == '~'))
        return maildir_get_absolute_path(name, TRUE);

    return maildir_get_path(storage,
                t_strconcat(MAILDIR_FS_SEP_S, name, NULL));
}

static const char *maildir_get_index_path(struct index_storage *storage,
                      const char *name)
{
    if (storage->index_dir == NULL)
        return NULL;

    if (strcmp(name, "INBOX") == 0 &&
        strcmp(storage->index_dir, storage->dir) == 0)
        return storage->dir;

    if (full_filesystem_access && (*name == '/' || *name == '~'))
        return maildir_get_absolute_path(name, FALSE);

    return t_strconcat(storage->index_dir, "/"MAILDIR_FS_SEP_S, name, NULL);
}

static const char *maildir_get_control_path(struct index_storage *storage,
                        const char *name)
{
    if (storage->control_dir == NULL)
        return maildir_get_path(storage, name);

    if (full_filesystem_access && (*name == '/' || *name == '~'))
        return maildir_get_absolute_path(name, FALSE);

    return t_strconcat(storage->control_dir, "/"MAILDIR_FS_SEP_S,
               name, NULL);
}

static int mkdir_verify(struct index_storage *storage,
            const char *dir, int verify)
{
    struct stat st;

    if (verify) {
        if (lstat(dir, &st) == 0)
            return 0;

        if (errno != ENOENT) {
            mail_storage_set_critical(&storage->storage,
                          "lstat(%s) failed: %m", dir);
            return -1;
        }
    }

    if (mkdir_parents(dir, CREATE_MODE) < 0 && (errno != EEXIST || !verify)) {
        if (errno != EEXIST && (!verify || errno != ENOENT)) {
            mail_storage_set_critical(&storage->storage,
                          "mkdir(%s) failed: %m", dir);
        }
        return -1;
    }

    return 0;
}

/* create or fix maildir, ignore if it already exists */
static int create_maildir(struct index_storage *storage,
              const char *dir, int verify)
{
    const char **tmp, *path;

    if (!verify && mkdir_verify(storage, dir, verify) < 0)
        return -1;

    for (tmp = maildirs; *tmp != NULL; tmp++) {
        path = t_strconcat(dir, "/", *tmp, NULL);

        if (mkdir_verify(storage, path, verify) < 0) {
            if (!verify || errno != ENOENT)
                return -1;

            /* small optimization. if we're verifying, we don't
               check that the root dir actually exists unless we
               fail here. */
            if (mkdir_verify(storage, dir, verify) < 0)
                return -1;
            if (mkdir_verify(storage, path, verify) < 0)
                return -1;
        }
    }

    return 0;
}

static int create_index_dir(struct index_storage *storage, const char *name)
{
    const char *dir;

    if (storage->index_dir == NULL)
        return 0;

    if (strcmp(storage->index_dir, storage->dir) == 0 ||
        (strcmp(name, "INBOX") == 0 && storage->inbox_path != NULL &&
         strcmp(storage->index_dir, storage->inbox_path) == 0))
        return 0;

    dir = t_strconcat(storage->index_dir, "/"MAILDIR_FS_SEP_S, name, NULL);
    if (mkdir_parents(dir, CREATE_MODE) == -1 && errno != EEXIST) {
        mail_storage_set_critical(&storage->storage,
                      "mkdir(%s) failed: %m", dir);
        return -1;
    }

    return 0;
}

static int create_control_dir(struct index_storage *storage, const char *name)
{
    const char *dir;

    if (storage->control_dir == NULL)
        return 0;

    dir = t_strconcat(storage->control_dir, "/"MAILDIR_FS_SEP_S,
              name, NULL);
    if (mkdir_parents(dir, CREATE_MODE) < 0 && errno != EEXIST) {
        mail_storage_set_critical(&storage->storage,
                      "mkdir(%s) failed: %m", dir);
        return -1;
    }

    return 0;
}

static int verify_inbox(struct index_storage *storage)
{
    const char *path;

    path = storage->inbox_path != NULL ?
        storage->inbox_path : storage->dir;

    if (create_maildir(storage, path, TRUE) < 0)
        return -1;

    /* make sure the index directories exist */
    if (create_index_dir(storage, "INBOX") < 0)
        return -1;
    if (create_control_dir(storage, "INBOX") < 0)
        return -1;
    return 0;
}

static int maildir_is_recent(struct index_mailbox *ibox, uint32_t uid)
{
    return maildir_uidlist_is_recent(ibox->uidlist, uid);
}

static struct mailbox *
maildir_open(struct index_storage *storage, const char *name,
         enum mailbox_open_flags flags)
{
    struct index_mailbox *ibox;
    struct mail_index *index;
    const char *path, *index_dir, *control_dir;
    struct stat st;

    path = maildir_get_path(storage, name);
    index_dir = maildir_get_index_path(storage, name);
    control_dir = maildir_get_control_path(storage, name);

    index = index_storage_alloc(index_dir, path, MAILDIR_INDEX_PREFIX);

    ibox = index_storage_mailbox_init(storage, &maildir_mailbox,
                      index, name, flags);
    if (ibox == NULL)
        return NULL;

    ibox->path = i_strdup(path);
    ibox->control_dir = i_strdup(control_dir);

    ibox->mail_interface = &maildir_mail;
    ibox->uidlist = maildir_uidlist_init(ibox);
    ibox->is_recent = maildir_is_recent;

    /* for shared mailboxes get the create mode from the
       permissions of dovecot-shared file */
    if (stat(t_strconcat(path, "/dovecot-shared", NULL), &st) < 0)
        ibox->mail_create_mode = 0600;
    else {
        ibox->mail_create_mode = st.st_mode & 0666;
        ibox->private_flags_mask = MAIL_SEEN;
        mail_index_set_permissions(ibox->index, st.st_mode & 0666,
                       st.st_gid);
    }

    return &ibox->box;
}

static struct mailbox *
maildir_mailbox_open(struct mail_storage *_storage,
             const char *name, enum mailbox_open_flags flags)
{
    struct index_storage *storage = (struct index_storage *)_storage;
    const char *path;
    struct stat st;

    mail_storage_clear_error(_storage);

    if (strcmp(name, "INBOX") == 0) {
        if (verify_inbox(storage) < 0)
            return NULL;
        return maildir_open(storage, "INBOX", flags);
    }

    if (!maildir_is_valid_existing_name(name)) {
        mail_storage_set_error(_storage, "Invalid mailbox name");
        return NULL;
    }

    path = maildir_get_path(storage, name);
    if (stat(path, &st) == 0) {
        /* exists - make sure the required directories are also there */
        if (create_maildir(storage, path, TRUE) < 0 ||
            create_index_dir(storage, name) < 0 ||
            create_control_dir(storage, name) < 0)
            return NULL;

        return maildir_open(storage, name, flags);
    } else if (errno == ENOENT) {
        mail_storage_set_error(_storage, "Mailbox doesn't exist: %s",
                       name);
        return NULL;
    } else {
        mail_storage_set_critical(_storage, "stat(%s) failed: %m",
                      path);
        return NULL;
    }
}

static int maildir_mailbox_create(struct mail_storage *_storage,
                  const char *name,
                  int directory __attr_unused__)
{
    struct index_storage *storage = (struct index_storage *)_storage;
    const char *path;

    mail_storage_clear_error(_storage);

    if (!maildir_is_valid_create_name(name)) {
        mail_storage_set_error(_storage, "Invalid mailbox name");
        return -1;
    }

    path = maildir_get_path(storage, name);
    if (create_maildir(storage, path, FALSE) < 0) {
        if (errno == EEXIST) {
            mail_storage_set_error(_storage,
                           "Mailbox already exists");
        }
        return -1;
    }

    return 0;
}

static int maildir_mailbox_delete(struct mail_storage *_storage,
                  const char *name)
{
    struct index_storage *storage = (struct index_storage *)_storage;
    struct stat st;
    const char *src, *dest, *index_dir;
    int count;

    mail_storage_clear_error(_storage);

    if (strcmp(name, "INBOX") == 0) {
        mail_storage_set_error(_storage, "INBOX can't be deleted.");
        return -1;
    }

    if (!maildir_is_valid_existing_name(name)) {
        mail_storage_set_error(_storage, "Invalid mailbox name");
        return -1;
    }

    /* rename the .maildir into ..maildir which marks it as being
       deleted. delete indexes before the actual maildir. this way we
       never see partially deleted mailboxes. */
    src = maildir_get_path(storage, name);
    dest = maildir_get_unlink_path(storage, name);
    if (stat(src, &st) != 0 && errno == ENOENT) {
        mail_storage_set_error(_storage, "Mailbox doesn't exist: %s",
                       name);
        return -1;
    }

    if (storage->index_dir != NULL && *name != '/' && *name != '~' &&
        strcmp(storage->index_dir, storage->dir) != 0) {
        index_dir = t_strconcat(storage->index_dir,
                    "/"MAILDIR_FS_SEP_S, name, NULL);
        index_storage_destroy_unrefed();

        /* it can fail with some NFS implementations if indexes are
           opened by another session.. can't really help it. */
        if (unlink_directory(index_dir, TRUE) < 0 &&
            errno != ENOTEMPTY) {
            mail_storage_set_critical(_storage,
                "unlink_directory(%s) failed: %m", index_dir);
            return -1;
        }
    }

    count = 0;
    while (rename(src, dest) < 0 && count < 2) {
        if (errno != EEXIST && errno != ENOTEMPTY) {
            mail_storage_set_critical(_storage,
                "rename(%s, %s) failed: %m", src, dest);
            return -1;
        }

        /* ..dir already existed? delete it and try again */
        if (unlink_directory(dest, TRUE) < 0) {
            mail_storage_set_critical(_storage,
                "unlink_directory(%s) failed: %m", dest);
            return -1;
        }
        count++;
    }

    if (unlink_directory(dest, TRUE) < 0 && errno != ENOTEMPTY) {
        mail_storage_set_critical(_storage,
            "unlink_directory(%s) failed: %m", dest);

        /* it's already renamed to ..dir, which means it's deleted
           as far as client is concerned. Report success. */
    }

    return 0;
}

static int rename_indexes(struct index_storage *storage,
              const char *oldname, const char *newname)
{
    const char *oldpath, *newpath;

    if (storage->index_dir == NULL ||
        strcmp(storage->index_dir, storage->dir) == 0)
        return 0;

    /* Rename it's index. */
    oldpath = t_strconcat(storage->index_dir, "/"MAILDIR_FS_SEP_S,
                  oldname, NULL);
    newpath = t_strconcat(storage->index_dir, "/"MAILDIR_FS_SEP_S,
                  newname, NULL);

    if (rename(oldpath, newpath) < 0 && errno != ENOENT) {
        mail_storage_set_critical(&storage->storage,
                      "rename(%s, %s) failed: %m",
                      oldpath, newpath);
        return -1;
    }

    return 0;
}

static int rename_subfolders(struct index_storage *storage,
                 const char *oldname, const char *newname)
{
    struct mailbox_list_context *ctx;
        struct mailbox_list *list;
    const char *oldpath, *newpath, *new_listname;
    size_t oldnamelen;
    int ret;

    ret = 0;
    oldnamelen = strlen(oldname);

    ctx = maildir_mailbox_list_init(&storage->storage, oldname, "*",
                    MAILBOX_LIST_FAST_FLAGS);
    while ((list = maildir_mailbox_list_next(ctx)) != NULL) {
        t_push();

        i_assert(oldnamelen <= strlen(list->name));

        new_listname = t_strconcat(newname,
                       list->name + oldnamelen, NULL);
        oldpath = maildir_get_path(storage, list->name);
        newpath = maildir_get_path(storage, new_listname);

        /* FIXME: it's possible to merge two folders if either one of
           them doesn't have existing root folder. We could check this
           but I'm not sure if it's worth it. It could be even
           considered as a feature.

           Anyway, the bug with merging is that if both folders have
           identically named subfolder they conflict. Just ignore those
           and leave them under the old folder. */
        if (rename(oldpath, newpath) == 0 ||
            errno == EEXIST || errno == ENOTEMPTY)
            ret = 1;
        else {
            mail_storage_set_critical(&storage->storage,
                          "rename(%s, %s) failed: %m",
                          oldpath, newpath);
            ret = -1;
            t_pop();
            break;
        }

        (void)rename_indexes(storage, list->name, new_listname);
        t_pop();
    }

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

static int maildir_mailbox_rename(struct mail_storage *_storage,
                  const char *oldname, const char *newname)
{
    struct index_storage *storage = (struct index_storage *)_storage;
    const char *oldpath, *newpath;
    int ret, found;

    mail_storage_clear_error(_storage);

    if (!maildir_is_valid_existing_name(oldname) ||
        !maildir_is_valid_create_name(newname)) {
        mail_storage_set_error(_storage, "Invalid mailbox name");
        return -1;
    }

    if (strcmp(oldname, "INBOX") == 0) {
        mail_storage_set_error(_storage,
                       "Renaming INBOX isn't supported.");
        return -1;
    }

    /* NOTE: it's possible to rename a nonexisting folder which has
       subfolders. In that case we should ignore the rename() error. */
    oldpath = maildir_get_path(storage, oldname);
    newpath = maildir_get_path(storage, newname);

    ret = rename(oldpath, newpath);
    if (ret == 0 || errno == ENOENT) {
        (void)rename_indexes(storage, oldname, newname);

        found = ret == 0;
        ret = rename_subfolders(storage, oldname, newname);
        if (ret < 0)
            return -1;
        if (!found && ret == 0) {
            mail_storage_set_error(_storage,
                           "Mailbox doesn't exist");
            return -1;
        }

        return 0;
    }

    if (errno == EEXIST) {
        mail_storage_set_error(_storage,
                       "Target mailbox already exists");
        return -1;
    } else {
        mail_storage_set_critical(_storage, "rename(%s, %s) failed: %m",
                      oldpath, newpath);
        return -1;
    }
}

static int maildir_set_subscribed(struct mail_storage *_storage,
                  const char *name, int set)
{
    struct index_storage *storage = (struct index_storage *)_storage;
    const char *path;

    path = t_strconcat(storage->control_dir != NULL ?
               storage->control_dir : storage->dir,
               "/" SUBSCRIPTION_FILE_NAME, NULL);

    return subsfile_set_subscribed(_storage, path, storage->temp_prefix,
                       name, set);
}

static int maildir_get_mailbox_name_status(struct mail_storage *_storage,
                       const char *name,
                       enum mailbox_name_status *status)
{
    struct index_storage *storage = (struct index_storage *)_storage;
    struct stat st;
    const char *path;

    mail_storage_clear_error(_storage);

    if (!maildir_is_valid_existing_name(name)) {
        *status = MAILBOX_NAME_INVALID;
        return 0;
    }

    path = maildir_get_path(storage, name);
    if (strcmp(name, "INBOX") == 0 || stat(path, &st) == 0) {
        *status = MAILBOX_NAME_EXISTS;
        return 0;
    }

    if (!maildir_is_valid_create_name(name)) {
        *status = MAILBOX_NAME_INVALID;
        return 0;
    }

    if (errno == ENOENT) {
        *status = MAILBOX_NAME_VALID;
        return 0;
    } else {
        mail_storage_set_critical(_storage, "stat(%s) failed: %m",
                      path);
        return -1;
    }
}

static int maildir_storage_close(struct mailbox *box)
{
    struct index_mailbox *ibox = (struct index_mailbox *)box;
    int ret = 0;

    /*FIXME:if (!maildir_try_flush_dirty_flags(ibox->index, TRUE)) {
        mail_storage_set_index_error(ibox);
        ret = -1;
    }*/

    maildir_uidlist_deinit(ibox->uidlist);
        index_storage_mailbox_free(box);
    return ret;
}

static void
maildir_notify_changes(struct mailbox *box, unsigned int min_interval,
               mailbox_notify_callback_t *callback, void *context)
{
    struct index_mailbox *ibox = (struct index_mailbox *)box;

    ibox->min_notify_interval = min_interval;
    ibox->notify_callback = callback;
    ibox->notify_context = context;

    if (callback == NULL) {
        index_mailbox_check_remove_all(ibox);
        return;
    }

    index_mailbox_check_add(ibox,
        t_strconcat(ibox->storage->dir, "/new", NULL), TRUE);
    index_mailbox_check_add(ibox,
        t_strconcat(ibox->storage->dir, "/cur", NULL), TRUE);
}

struct mail_storage maildir_storage = {
    "maildir", /* name */

    '.', /* hierarchy separator */

    maildir_create,
    maildir_free,
    maildir_autodetect,
    index_storage_set_callbacks,
    maildir_mailbox_open,
    maildir_mailbox_create,
    maildir_mailbox_delete,
    maildir_mailbox_rename,
    maildir_mailbox_list_init,
    maildir_mailbox_list_next,
    maildir_mailbox_list_deinit,
    maildir_set_subscribed,
    maildir_get_mailbox_name_status,
    index_storage_get_last_error,

    NULL,
    0
};

struct mailbox maildir_mailbox = {
    NULL, /* name */
    NULL, /* storage */

    index_storage_is_readonly,
        index_storage_allow_new_keywords,
    maildir_storage_close,
    index_storage_get_status,
    maildir_storage_sync_init,
    index_mailbox_sync_next,
    index_mailbox_sync_deinit,
    maildir_notify_changes,
    maildir_transaction_begin,
    maildir_transaction_commit,
    maildir_transaction_rollback,
    index_storage_fetch,
    index_storage_get_uids,
    index_header_lookup_init,
        index_header_lookup_deinit,
    index_storage_search_get_sorting,
    index_storage_search_init,
    index_storage_search_deinit,
    index_storage_search_next,
    maildir_save_init,
    maildir_save_continue,
    maildir_save_finish,
    maildir_save_cancel,
    maildir_copy,
    index_storage_is_inconsistent
};