path: root/camel/providers/imap/camel-imap-store.c

/* -*- Mode: C; tab-width: 8; indent-tabs-mode: t; c-basic-offset: 8 -*- */
/* camel-imap-store.c : class for an imap store */

/*
 *  Authors: Jeffrey Stedfast <fejj@helixcode.com>
 *
 *  Copyright 2000 Helix Code, Inc. (www.helixcode.com)
 *
 *  This program is free software; you can redistribute it and/or modify
 *  it under the terms of the GNU General Public License as published by
 *  the Free Software Foundation; either version 2 of the License, or
 *  (at your option) any later version.
 *
 *  This program is distributed in the hope that it will be useful,
 *  but WITHOUT ANY WARRANTY; without even the implied warranty of
 *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 *  GNU General Public License for more details.
 *
 *  You should have received a copy of the GNU General Public License
 *  along with this program; if not, write to the Free Software
 *  Foundation, Inc., 59 Temple Street #330, Boston, MA 02111-1307, USA.
 *
 */


#include <config.h>

#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>
#include <errno.h>

#include <gal/util/e-util.h>

#include "camel-imap-store.h"
#include "camel-imap-folder.h"
#include "camel-imap-utils.h"
#include "camel-imap-command.h"
#include "camel-folder.h"
#include "camel-exception.h"
#include "camel-session.h"
#include "camel-stream.h"
#include "camel-stream-buffer.h"
#include "camel-stream-fs.h"
#include "camel-url.h"
#include "camel-sasl.h"
#include "string-utils.h"

#include "camel-imap-private.h"
#include "camel-private.h"

#define d(x) x

/* Specified in RFC 2060 */
#define IMAP_PORT 143

static CamelRemoteStoreClass *remote_store_class = NULL;

static gboolean imap_connect (CamelService *service, CamelException *ex);
static gboolean imap_disconnect (CamelService *service, gboolean clean, CamelException *ex);
static GList *query_auth_types (CamelService *service, gboolean connect, CamelException *ex);
static guint hash_folder_name (gconstpointer key);
static gint compare_folder_name (gconstpointer a, gconstpointer b);
static CamelFolder *get_folder (CamelStore *store, const char *folder_name, guint32 flags, CamelException *ex);
static CamelFolderInfo *create_folder (CamelStore *store, const char *parent_name, const char *folder_name, CamelException *ex);
static CamelFolderInfo *get_folder_info (CamelStore *store, const char *top,
                     gboolean fast, gboolean recursive,
                     gboolean subscribed_only,
                     CamelException *ex);
static gboolean folder_subscribed (CamelStore *store, const char *folder_name);
static void subscribe_folder (CamelStore *store, const char *folder_name,
                  CamelException *ex);
static void unsubscribe_folder (CamelStore *store, const char *folder_name,
                CamelException *ex);
static void imap_keepalive (CamelRemoteStore *store);

static void
camel_imap_store_class_init (CamelImapStoreClass *camel_imap_store_class)
{
    /* virtual method overload */
    CamelServiceClass *camel_service_class =
        CAMEL_SERVICE_CLASS (camel_imap_store_class);
    CamelStoreClass *camel_store_class =
        CAMEL_STORE_CLASS (camel_imap_store_class);
    CamelRemoteStoreClass *camel_remote_store_class =
        CAMEL_REMOTE_STORE_CLASS (camel_imap_store_class);
    
    remote_store_class = CAMEL_REMOTE_STORE_CLASS(camel_type_get_global_classfuncs 
                              (camel_remote_store_get_type ()));
    
    /* virtual method overload */
    camel_service_class->query_auth_types = query_auth_types;
    camel_service_class->connect = imap_connect;
    camel_service_class->disconnect = imap_disconnect;
    
    camel_store_class->hash_folder_name = hash_folder_name;
    camel_store_class->compare_folder_name = compare_folder_name;
    camel_store_class->get_folder = get_folder;
    camel_store_class->create_folder = create_folder;
    camel_store_class->get_folder_info = get_folder_info;
    camel_store_class->free_folder_info = camel_store_free_folder_info_full;

    camel_store_class->folder_subscribed = folder_subscribed;
    camel_store_class->subscribe_folder = subscribe_folder;
    camel_store_class->unsubscribe_folder = unsubscribe_folder;

    camel_remote_store_class->keepalive = imap_keepalive;
}

static gboolean
free_key (gpointer key, gpointer value, gpointer user_data)
{
    g_free (key);
    return TRUE;
}

static void
camel_imap_store_finalize (CamelObject *object)
{
    CamelImapStore *imap_store = CAMEL_IMAP_STORE (object);

    if (imap_store->subscribed_folders) {
        g_hash_table_foreach_remove (imap_store->subscribed_folders,
                         free_key, NULL);
        g_hash_table_destroy (imap_store->subscribed_folders);
    }
    if (imap_store->authtypes) {
        g_hash_table_foreach_remove (imap_store->authtypes,
                         free_key, NULL);
        g_hash_table_destroy (imap_store->authtypes);
    }
    if (imap_store->namespace)
        g_free (imap_store->namespace);
#ifdef ENABLE_THREADS
    e_mutex_destroy(imap_store->priv->command_lock);
#endif
    g_free(imap_store->priv);
}

static void
camel_imap_store_init (gpointer object, gpointer klass)
{
    CamelRemoteStore *remote_store = CAMEL_REMOTE_STORE (object);
    CamelImapStore *imap_store = CAMEL_IMAP_STORE (object);
    CamelStore *store = CAMEL_STORE (object);
    
    remote_store->default_port = 143;
    remote_store->use_ssl = FALSE;
    
    imap_store->dir_sep = '\0';
    imap_store->current_folder = NULL;

    store->flags = CAMEL_STORE_SUBSCRIPTIONS;
    
    imap_store->connected = FALSE;
    imap_store->subscribed_folders = NULL;

    imap_store->priv = g_malloc0 (sizeof (*imap_store->priv));
#ifdef ENABLE_THREADS
    imap_store->priv->command_lock = e_mutex_new(E_MUTEX_REC);
#endif
}

CamelType
camel_imap_store_get_type (void)
{
    static CamelType camel_imap_store_type = CAMEL_INVALID_TYPE;
    
    if (camel_imap_store_type == CAMEL_INVALID_TYPE)    {
        camel_imap_store_type =
            camel_type_register (CAMEL_REMOTE_STORE_TYPE, "CamelImapStore",
                         sizeof (CamelImapStore),
                         sizeof (CamelImapStoreClass),
                         (CamelObjectClassInitFunc) camel_imap_store_class_init,
                         NULL,
                         (CamelObjectInitFunc) camel_imap_store_init,
                         (CamelObjectFinalizeFunc) camel_imap_store_finalize);
    }
    
    return camel_imap_store_type;
}

static struct {
    const char *name;
    guint32 flag;
} capabilities[] = {
    { "IMAP4",      IMAP_CAPABILITY_IMAP4 },
    { "IMAP4REV1",      IMAP_CAPABILITY_IMAP4REV1 },
    { "STATUS",     IMAP_CAPABILITY_STATUS },
    { "NAMESPACE",      IMAP_CAPABILITY_NAMESPACE },
    { "UIDPLUS",        IMAP_CAPABILITY_UIDPLUS },
    { "LITERAL+",       IMAP_CAPABILITY_LITERALPLUS },
    { NULL, 0 }
};

/* we have remote-store:connect_lock by now */
static gboolean
connect_to_server (CamelService *service, CamelException *ex)
{
    CamelImapStore *store = CAMEL_IMAP_STORE (service);
    CamelImapResponse *response;
    char *result, *buf, *capa, *lasts;
    int i;

    if (!CAMEL_SERVICE_CLASS (remote_store_class)->connect (service, ex))
        return FALSE;

    store->command = 0;

    /* Read the greeting, if any. FIXME: deal with PREAUTH */
    if (camel_remote_store_recv_line (CAMEL_REMOTE_STORE (service),
                      &buf, ex) < 0) {
        return FALSE;
    }
    g_free (buf);
    store->connected = TRUE;
    
    /* Find out the IMAP capabilities */
    store->capabilities = 0;
    store->authtypes = g_hash_table_new (g_str_hash, g_str_equal);
    response = camel_imap_command (store, NULL, ex, "CAPABILITY");
    if (!response)
        return FALSE;
    result = camel_imap_response_extract (response, "CAPABILITY", ex);
    if (!result)
        return FALSE;

    /* Skip over "* CAPABILITY". */
    capa = imap_next_word (result + 2);

    for (capa = strtok_r (capa, " ", &lasts); capa;
         capa = strtok_r (NULL, " ", &lasts)) {
        if (!strncmp (capa, "AUTH=", 5)) {
            g_hash_table_insert (store->authtypes,
                         g_strdup (capa + 5),
                         GINT_TO_POINTER (1));
            continue;
        }
        for (i = 0; capabilities[i].name; i++) {
            if (g_strcasecmp (capa, capabilities[i].name) == 0) {
                store->capabilities |= capabilities[i].flag;
                break;
            }
        }
    }
    g_free (result);

    if (store->capabilities & IMAP_CAPABILITY_IMAP4REV1) {
        store->server_level = IMAP_LEVEL_IMAP4REV1;
        store->capabilities |= IMAP_CAPABILITY_STATUS;
    } else if (store->capabilities & IMAP_CAPABILITY_IMAP4)
        store->server_level = IMAP_LEVEL_IMAP4;
    else
        store->server_level = IMAP_LEVEL_UNKNOWN;

    return TRUE;
}

static CamelServiceAuthType password_authtype = {
    N_("Password"),
    
    N_("This option will connect to the IMAP server using a "
       "plaintext password."),
    
    "",
    TRUE
};

static GList *
query_auth_types (CamelService *service, gboolean connect, CamelException *ex)
{
    CamelImapStore *store = CAMEL_IMAP_STORE (service);
    CamelServiceAuthType *authtype;
    GList *types, *sasl_types, *t;

    if (connect && !connect_to_server (service, ex))
        return NULL;

    types = CAMEL_SERVICE_CLASS (remote_store_class)->query_auth_types (service, connect, ex);

    sasl_types = camel_sasl_authtype_list ();
    if (connect) {
        for (t = types; t; t = t->next) {
            authtype = t->data;

            if (!g_hash_table_lookup (store->authtypes, authtype->authproto)) {
                g_list_remove_link (types, t);
                g_list_free_1 (t);
            }
        }
    }
    types = g_list_concat (types, sasl_types);

    return g_list_prepend (types, &password_authtype);
}

/* call refresh folder directly, bypassing the folder lock */
static void
refresh_folder_info (gpointer key, gpointer value, gpointer data)
{
    CamelFolder *folder = CAMEL_FOLDER (value);

    CAMEL_FOLDER_CLASS (CAMEL_OBJECT_GET_CLASS(folder))->refresh_info(folder, data);
}

/* This is a little 'hack' to avoid the deadlock conditions that would otherwise
   ensue when calling camel_folder_refresh_info from inside a lock */
/* NB: on second thougts this is probably not entirely safe, but it'll do for now */
/* the alternative is to:
   make the camel folder->lock recursive (which should probably be done)
   or remove it from camel_folder_refresh_info, and use another locking mechanism */
static void
imap_store_refresh_folders (CamelRemoteStore *store, CamelException *ex)
{
    CAMEL_STORE_LOCK(store, cache_lock);

    g_hash_table_foreach (CAMEL_STORE (store)->folders, refresh_folder_info, ex);

    CAMEL_STORE_UNLOCK(store, cache_lock);
}   

static gboolean
try_auth (CamelImapStore *store, const char *mech, CamelException *ex)
{
    CamelSasl *sasl;
    CamelImapResponse *response;
    char *resp;
    char *sasl_resp;

    sasl = camel_sasl_new ("imap", mech, CAMEL_SERVICE (store));

    sasl_resp = camel_sasl_challenge_base64 (sasl, NULL, ex);

    CAMEL_IMAP_STORE_LOCK (store, command_lock);
    response = camel_imap_command (store, NULL, ex, "AUTHENTICATE %s%s%s",
                       mech, sasl_resp ? " " : "",
                       sasl_resp ? sasl_resp : "");
    if (!response)
        goto lose;

    while (!camel_sasl_authenticated (sasl)) {
        resp = camel_imap_response_extract_continuation (response, ex);
        if (!resp)
            goto lose;

        sasl_resp = camel_sasl_challenge_base64 (sasl, resp + 2, ex);
        g_free (resp);
        if (camel_exception_is_set (ex))
            goto break_and_lose;

        response = camel_imap_command_continuation (store, ex, sasl_resp);
        g_free (sasl_resp);
        if (!response)
            goto lose;
    }

    resp = camel_imap_response_extract_continuation (response, NULL);
    if (resp) {
        /* Oops. SASL claims we're done, but the IMAP server
         * doesn't think so...
         */
        g_free (resp);
        goto lose;
    }
    
    camel_object_unref (CAMEL_OBJECT (sasl));
    
    CAMEL_IMAP_STORE_UNLOCK (store, command_lock);
    return TRUE;

 break_and_lose:
    /* Get the server out of "waiting for continuation data" mode. */
    response = camel_imap_command_continuation (store, NULL, "*");
    if (response)
        camel_imap_response_free (response);

 lose:
    if (!camel_exception_is_set (ex)) {
        camel_exception_set (ex, CAMEL_EXCEPTION_SERVICE_CANT_AUTHENTICATE,
                     _("Bad authentication response from server."));
    }
    
    camel_object_unref (CAMEL_OBJECT (sasl));
    
    CAMEL_IMAP_STORE_UNLOCK (store, command_lock);
    
    return FALSE;
}

static gboolean
imap_connect (CamelService *service, CamelException *ex)
{
    CamelImapStore *store = CAMEL_IMAP_STORE (service);
    CamelSession *session = camel_service_get_session (service);
    CamelServiceAuthType *authtype = NULL;
    char *result, *errbuf = NULL, *name;
    gboolean authenticated = FALSE;
    CamelImapResponse *response;
    int len, i, flags;
    
    if (!g_strcasecmp (service->url->protocol, "simap")) {
        CamelRemoteStore *rstore = CAMEL_REMOTE_STORE (service);
        
        rstore->default_port = 993;
        rstore->use_ssl = TRUE;
    }
    
    if (connect_to_server (service, ex) == 0)
        return FALSE;
    
    if (service->url->authmech) {
        if (!g_hash_table_lookup (store->authtypes, service->url->authmech)) {
            camel_exception_setv (ex, CAMEL_EXCEPTION_SERVICE_CANT_AUTHENTICATE,
                          _("IMAP server %s does not support requested "
                        "authentication type %s"),
                          service->url->host,
                          service->url->authmech);
            camel_service_disconnect (service, TRUE, NULL);
            return FALSE;
        }

        authtype = camel_sasl_authtype (service->url->authmech);
        if (!authtype) {
            camel_exception_setv (ex, CAMEL_EXCEPTION_SERVICE_CANT_AUTHENTICATE,
                          _("No support for authentication type %s"),
                          service->url->authmech);
            camel_service_disconnect (service, TRUE, NULL);
            return FALSE;
        }

        if (!authtype->need_password) {
            authenticated = try_auth (store, authtype->authproto, ex);
            if (!authenticated) {
                camel_service_disconnect (service, TRUE, NULL);
                return FALSE;
            }
        }
    }

    while (!authenticated) {
        if (errbuf) {
            /* We need to un-cache the password before prompting again */
            camel_session_query_authenticator (
                session, CAMEL_AUTHENTICATOR_TELL, NULL,
                TRUE, service, "password", ex);
            g_free (service->url->passwd);
            service->url->passwd = NULL;
        }

        if (!service->url->passwd) {
            char *prompt;

            prompt = g_strdup_printf (_("%sPlease enter the IMAP "
                            "password for %s@%s"),
                          errbuf ? errbuf : "",
                          service->url->user,
                          service->url->host);
            service->url->passwd =
                camel_session_query_authenticator (
                    session, CAMEL_AUTHENTICATOR_ASK,
                    prompt, TRUE, service, "password", ex);
            g_free (prompt);
            g_free (errbuf);
            errbuf = NULL;

            if (!service->url->passwd) {
                camel_exception_set (ex, CAMEL_EXCEPTION_USER_CANCEL,
                             _("You didn't enter a password."));
                camel_service_disconnect (service, TRUE, NULL);
                return FALSE;
            }
        }

        if (!store->connected) {
            /* Some servers (eg, courier) will disconnect on
             * a bad password. So reconnect here.
             */
            if (!connect_to_server (service, ex))
                return FALSE;
        }

        if (authtype)
            authenticated = try_auth (store, authtype->authproto, ex);
        else {
            CAMEL_IMAP_STORE_LOCK(store, command_lock);
            response = camel_imap_command (store, NULL, ex,
                               "LOGIN %S %S",
                               service->url->user,
                               service->url->passwd);
            CAMEL_IMAP_STORE_UNLOCK(store, command_lock);
            if (response) {
                camel_imap_response_free (response);
                authenticated = TRUE;
            }
        }
        if (!authenticated) {
            errbuf = g_strdup_printf (_("Unable to authenticate "
                            "to IMAP server.\n%s\n\n"),
                          camel_exception_get_description (ex));
            camel_exception_clear (ex);
        }
    }

    /* Get subscribed folders */
    CAMEL_IMAP_STORE_LOCK (store, command_lock);
    response = camel_imap_command (store, NULL, ex, "LSUB \"\" \"*\"");
    CAMEL_IMAP_STORE_UNLOCK (store, command_lock);
    if (!response)
        return FALSE;
    store->subscribed_folders = g_hash_table_new (g_str_hash, g_str_equal);
    for (i = 0; i < response->untagged->len; i++) {
        result = response->untagged->pdata[i];
        if (!imap_parse_list_response (result, &flags, NULL, &name))
            continue;
        if (flags & (IMAP_LIST_FLAG_MARKED | IMAP_LIST_FLAG_UNMARKED))
            store->useful_lsub = TRUE;
        if (flags & IMAP_LIST_FLAG_NOSELECT) {
            g_free (name);
            continue;
        }
        g_hash_table_insert (store->subscribed_folders, name,
                     GINT_TO_POINTER (1));
    }
    camel_imap_response_free (response);

    /* Get namespace and hierarchy separator */
    if (service->url->path && strlen (service->url->path) > 1)
        store->namespace = g_strdup (service->url->path + 1);
    else if (store->capabilities & IMAP_CAPABILITY_NAMESPACE) {
        CAMEL_IMAP_STORE_LOCK (store, command_lock);
        response = camel_imap_command (store, NULL, ex, "NAMESPACE");
        CAMEL_IMAP_STORE_UNLOCK (store, command_lock);
        if (!response)
            return FALSE;

        result = camel_imap_response_extract (response, "NAMESPACE", ex);
        if (!result)
            return FALSE;

        name = e_strstrcase (result, "NAMESPACE ((");
        if (name) {
            char *sep;

            name += 12;
            store->namespace = imap_parse_string (&name, &len);
            if (name && *name++ == ' ') {
                sep = imap_parse_string (&name, &len);
                if (sep) {
                    store->dir_sep = *sep;
                    g_free (sep);
                }
            }
        }
        g_free (result);
    }
    if (!store->namespace)
        store->namespace = g_strdup ("");

    if (!store->dir_sep) {
        CAMEL_IMAP_STORE_LOCK(store, command_lock);
        if (store->server_level >= IMAP_LEVEL_IMAP4REV1) {
            /* This idiom means "tell me the hierarchy separator
             * for the given path, even if that path doesn't exist.
             */
            response = camel_imap_command (store, NULL, ex,
                               "LIST %S \"\"",
                               store->namespace);
        } else {
            /* Plain IMAP4 doesn't have that idiom, so we fall back
             * to "tell me about this folder", which will fail if
             * the folder doesn't exist (eg, if namespace is "").
             */
            response = camel_imap_command (store, NULL, ex,
                               "LIST \"\" %S",
                               store->namespace);
        }
        CAMEL_IMAP_STORE_UNLOCK(store, command_lock);

        if (!response)
            return FALSE;

        result = camel_imap_response_extract (response, "LIST", NULL);
        if (result) {
            imap_parse_list_response (result, NULL, &store->dir_sep, NULL);
            g_free (result);
        }
        if (!store->dir_sep)
            store->dir_sep = '/';   /* Guess */
    }

    /* Generate base URL */
    store->base_url = camel_url_to_string (service->url, FALSE);
    len = strlen (store->base_url);
    if (service->url->path)
        store->base_url[len - strlen (service->url->path) + 1] = '\0';
    else {
        store->base_url = g_realloc (store->base_url, len + 2);
        store->base_url[len] = '/';
        store->base_url[len + 1] = '\0';
    }

    /* Find our storage path. */
    if (!store->storage_path) {
        store->storage_path =
            camel_session_get_storage_path (session, service, ex);
        if (camel_exception_is_set (ex)) 
            return FALSE;
    }

    imap_store_refresh_folders (CAMEL_REMOTE_STORE (store), ex);

    return !camel_exception_is_set (ex);
}

static gboolean
imap_disconnect (CamelService *service, gboolean clean, CamelException *ex)
{
    CamelImapStore *store = CAMEL_IMAP_STORE (service);
    CamelImapResponse *response;
    
    if (store->connected && clean) {
        /* send the logout command */

        /* NB: this lock probably isn't required */
        CAMEL_IMAP_STORE_LOCK(store, command_lock);
        response = camel_imap_command (store, NULL, ex, "LOGOUT");
        CAMEL_IMAP_STORE_UNLOCK(store, command_lock);
        camel_imap_response_free (response);
    }
    store->connected = FALSE;
    store->current_folder = NULL;

    if (store->subscribed_folders) {
        g_hash_table_foreach_remove (store->subscribed_folders,
                         free_key, NULL);
        g_hash_table_destroy (store->subscribed_folders);
        store->subscribed_folders = NULL;
    }

    if (store->namespace) {
        g_free (store->namespace);
        store->namespace = NULL;
    }

    return CAMEL_SERVICE_CLASS (remote_store_class)->disconnect (service, clean, ex);
}

/* NOTE: Must have imap_store::command_lock before calling this */
static gboolean
imap_folder_exists (CamelImapStore *store, const char *folder_name,
            gboolean *selectable, char **short_name,
            CamelException *ex)
{
    CamelImapResponse *response;
    char *result, sep;
    int flags;

    if (!g_strcasecmp (folder_name, "INBOX")) {
        if (selectable)
            *selectable = TRUE;
        if (short_name)
            *short_name = g_strdup ("INBOX");
        return TRUE;
    }

    response = camel_imap_command (store, NULL, ex, "LIST \"\" %S",
                       folder_name);
    if (!response)
        return FALSE;
    result = camel_imap_response_extract (response, "LIST", ex);
    if (!result)
        return FALSE;

    if (!imap_parse_list_response (result, &flags, &sep, NULL))
        return FALSE;

    if (selectable)
        *selectable = !(flags & IMAP_LIST_FLAG_NOSELECT);
    if (short_name) {
        *short_name = strrchr (folder_name, sep);
        if (*short_name)
            *short_name = g_strdup (*short_name + 1);
        else
            *short_name = g_strdup (folder_name);
    }

    return TRUE;
}

/* NOTE: Must have imap_store::command_lock before calling this */
static gboolean
imap_create (CamelImapStore *store, const char *folder_name,
         CamelException *ex)
{
    CamelImapResponse *response;

    response = camel_imap_command (store, NULL, ex, "CREATE %S",
                       folder_name);
    camel_imap_response_free (response);

    return !camel_exception_is_set (ex);
}

static guint
hash_folder_name (gconstpointer key)
{
    if (g_strcasecmp (key, "INBOX") == 0)
        return g_str_hash ("INBOX");
    else
        return g_str_hash (key);
}

static gint
compare_folder_name (gconstpointer a, gconstpointer b)
{
    gconstpointer aname = a, bname = b;

    if (g_strcasecmp (a, "INBOX") == 0)
        aname = "INBOX";
    if (g_strcasecmp (b, "INBOX") == 0)
        bname = "INBOX";
    return g_str_equal (aname, bname);
}

static CamelFolder *
get_folder (CamelStore *store, const char *folder_name, guint32 flags,
        CamelException *ex)
{
    CamelImapStore *imap_store = CAMEL_IMAP_STORE (store);
    CamelFolder *new_folder = NULL;
    char *short_name, *summary_file, *p;
    gboolean selectable;

    if (!camel_remote_store_connected (CAMEL_REMOTE_STORE (store), ex))
        return NULL;

    /* lock around the whole lot to check/create atomically */
    CAMEL_IMAP_STORE_LOCK(imap_store, command_lock);
    if (!imap_folder_exists (imap_store, folder_name,
                 &selectable, &short_name, ex)) {
        if ((flags & CAMEL_STORE_FOLDER_CREATE) == 0
            || (!imap_create (imap_store, folder_name, ex))
            || (!imap_folder_exists (imap_store, folder_name,
                         &selectable, &short_name, ex))) {
            CAMEL_IMAP_STORE_UNLOCK(imap_store, command_lock);
            return NULL;
        }
    }
    CAMEL_IMAP_STORE_UNLOCK(imap_store, command_lock);

    if (!selectable) {
        camel_exception_setv (ex, CAMEL_EXCEPTION_STORE_NO_FOLDER,
                      "%s is not a selectable folder",
                      folder_name);
        g_free (short_name);
        return NULL;
    }

    summary_file = g_strdup_printf ("%s/%s/#summary",
                    imap_store->storage_path,
                    folder_name);
    p = strrchr (summary_file, '/');
    *p = '\0';
    if (e_mkdir_hier (summary_file, S_IRWXU) == 0) {
        *p = '/';
        new_folder = camel_imap_folder_new (store, folder_name,
                            short_name, summary_file,
                            ex);
    } else {
        camel_exception_setv (ex, CAMEL_EXCEPTION_SYSTEM,
                      _("Could not create directory %s: %s"),
                      summary_file, g_strerror (errno));
    }
    g_free (summary_file);
    g_free (short_name);

    if (camel_exception_is_set (ex))
        return NULL;

    return new_folder;
}

static char *
imap_concat (CamelImapStore *imap_store, const char *prefix, const char *suffix)
{
    int len;

    len = strlen (prefix);
    if (len > 0 && prefix[len - 1] == imap_store->dir_sep)
        return g_strdup_printf ("%s%s", prefix, suffix);
    else
        return g_strdup_printf ("%s%c%s", prefix, imap_store->dir_sep, suffix);
}

static CamelFolderInfo *
create_folder (CamelStore *store, const char *parent_name,
           const char *folder_name, CamelException *ex)
{
    CamelImapStore *imap_store = CAMEL_IMAP_STORE (store);
    CamelFolderInfo *fi;
    char *full_name;

    if (!parent_name)
        parent_name = imap_store->namespace;
    full_name = imap_concat (imap_store, parent_name, folder_name);

    imap_create (imap_store, full_name, ex);
    if (camel_exception_is_set (ex)) {
        g_free (full_name);
        return NULL;
    }

    fi = get_folder_info (store, full_name, FALSE, FALSE, FALSE, ex);
    g_free (full_name);
    
    return fi;
}

static CamelFolderInfo *
parse_list_response_as_folder_info (CamelImapStore *imap_store,
                    const char *response)
{
    CamelFolderInfo *fi;
    int flags;
    char sep, *dir, *name = NULL;

    if (!imap_parse_list_response (response, &flags, &sep, &dir))
        return NULL;

    if (sep) {
        name = strrchr (dir, sep);
        if (name && !*++name) {
            g_free (dir);
            return NULL;
        }
    }

    fi = g_new0 (CamelFolderInfo, 1);
    fi->full_name = dir;
    if (sep && name)
        fi->name = g_strdup (name);
    else
        fi->name = g_strdup (dir);
    if (!(flags & IMAP_LIST_FLAG_NOSELECT))
        fi->url = g_strdup_printf ("%s%s", imap_store->base_url, dir);
    if (!(flags & IMAP_LIST_FLAG_UNMARKED))
        fi->unread_message_count = -1;

    return fi;
}

static void
copy_folder_name (gpointer name, gpointer key, gpointer array)
{
    g_ptr_array_add (array, name);
}

static void
get_subscribed_folders_by_hand (CamelImapStore *imap_store, const char *top,
                GPtrArray *folders, CamelException *ex)
{
    GPtrArray *names;
    CamelImapResponse *response;
    CamelFolderInfo *fi;
    char *result;
    int i, toplen = strlen (top);

    names = g_ptr_array_new ();
    g_hash_table_foreach (imap_store->subscribed_folders,
                  copy_folder_name, names);

    for (i = 0; i < names->len; i++) {
        CAMEL_IMAP_STORE_LOCK (imap_store, command_lock);
        response = camel_imap_command (imap_store, NULL, ex,
                           "LIST \"\" %S",
                           names->pdata[i]);
        CAMEL_IMAP_STORE_UNLOCK (imap_store, command_lock);

        if (!response) {
            g_ptr_array_free (names, TRUE);
            return;
        }
        result = camel_imap_response_extract (response, "LIST", NULL);
        if (!result) {
            g_hash_table_remove (imap_store->subscribed_folders,
                         names->pdata[i]);
            g_free (names->pdata[i]);
            g_ptr_array_remove_index_fast (names, i--);
            continue;
        }

        fi = parse_list_response_as_folder_info (imap_store, result);
        if (!fi)
            continue;

        if (strncmp (top, fi->full_name, toplen) != 0) {
            camel_folder_info_free (fi);
            continue;
        }

        g_ptr_array_add (folders, fi);
    }
    g_ptr_array_free (names, TRUE);
}

static void
get_folders (CamelImapStore *imap_store, const char *pattern,
         GPtrArray *folders, gboolean lsub, CamelException *ex)
{
    CamelImapResponse *response;
    CamelFolderInfo *fi;
    char *list;
    int i;

    CAMEL_IMAP_STORE_LOCK (imap_store, command_lock);
    response = camel_imap_command (imap_store, NULL, ex,
                       "%s \"\" %S", lsub ? "LSUB" : "LIST",
                       pattern);
    CAMEL_IMAP_STORE_UNLOCK (imap_store, command_lock);
    if (!response)
        return;

    for (i = 0; i < response->untagged->len; i++) {
        list = response->untagged->pdata[i];
        fi = parse_list_response_as_folder_info (imap_store, list);
        if (!fi)
            continue;
        g_ptr_array_add (folders, fi);
    }
    camel_imap_response_free (response);
}

static CamelFolderInfo *
get_folder_info (CamelStore *store, const char *top, gboolean fast,
         gboolean recursive, gboolean subscribed_only,
         CamelException *ex)
{
    CamelImapStore *imap_store = CAMEL_IMAP_STORE (store);
    gboolean need_inbox = FALSE;
    CamelImapResponse *response;
    GPtrArray *folders;
    const char *name, *p;
    char *pattern, *status;
    CamelFolderInfo *fi;
    int i;

    if (!camel_remote_store_connected (CAMEL_REMOTE_STORE (store), ex))
        return NULL;

    /* Sync flag changes to the server so it has the same ideas about
     * read/unread as we do.
     */
    camel_store_sync (store, ex);
    if (camel_exception_is_set (ex))
        return NULL;

    name = top;
    if (!name) {
        need_inbox = TRUE;
        name = imap_store->namespace;
    }

    folders = g_ptr_array_new ();

    get_folders (imap_store, name, folders, FALSE, ex);
    if (camel_exception_is_set (ex))
        return NULL;
    if (folders->len) {
        fi = folders->pdata[0];
        if (!fi->url)
            g_ptr_array_remove_index (folders, 0);
    }

    if (subscribed_only && !imap_store->useful_lsub)
        get_subscribed_folders_by_hand (imap_store, name, folders, ex);
    else {
        pattern = imap_concat (imap_store, name, recursive ? "*" : "%");
        get_folders (imap_store, pattern, folders, subscribed_only, ex);
        g_free (pattern);
    }
    if (camel_exception_is_set (ex)) {
        for (i = 0; i < folders->len; i++)
            camel_folder_info_free (folders->pdata[i]);
        g_ptr_array_free (folders, TRUE);
        return NULL;
    }

    /* Add INBOX, if necessary */
    if (need_inbox) {
        for (i = 0; i < folders->len; i++) {
            fi = folders->pdata[i];
            if (!g_strcasecmp (fi->full_name, "INBOX")) {
                need_inbox = FALSE;
                break;
            }
        }
    }
    if (need_inbox) {
        fi = g_new0 (CamelFolderInfo, 1);
        fi->full_name = g_strdup ("INBOX");
        fi->name = g_strdup ("INBOX");
        fi->url = g_strdup_printf ("%sINBOX", imap_store->base_url);
        fi->unread_message_count = -1;

        g_ptr_array_add (folders, fi);
    }

    if (!fast) {
        /* Get unread counts */
        for (i = 0; i < folders->len; i++) {
            fi = folders->pdata[i];
            if (!fi->url || fi->unread_message_count != -1)
                continue;

            /* UW will give cached data for the currently
             * selected folder. Grr. Well, I guess this
             * also potentially saves us one IMAP command.
             */
            if (imap_store->current_folder &&
                !strcmp (imap_store->current_folder->full_name,
                     fi->full_name)) {
                fi->unread_message_count = camel_folder_get_unread_message_count (imap_store->current_folder);
                continue;
            }

            CAMEL_IMAP_STORE_LOCK (imap_store, command_lock);
            response = camel_imap_command (imap_store, NULL, NULL,
                               "STATUS %S (UNSEEN)",
                               fi->full_name);
            CAMEL_IMAP_STORE_UNLOCK (imap_store, command_lock);
            if (!response)
                continue;
            status = camel_imap_response_extract (response, "STATUS", NULL);
            if (!status)
                continue;

            p = e_strstrcase (status, "UNSEEN");
            if (p)
                fi->unread_message_count = strtoul (p + 6, NULL, 10);
            g_free (status);
        }
    }

    /* And assemble. */
    fi = camel_folder_info_build (folders, name, imap_store->dir_sep, TRUE);
    g_ptr_array_free (folders, TRUE);
    return fi;
}

static gboolean
folder_subscribed (CamelStore *store, const char *folder_name)
{
    CamelImapStore *imap_store = CAMEL_IMAP_STORE (store);

    g_return_val_if_fail (imap_store->subscribed_folders != NULL, FALSE);

    return g_hash_table_lookup (imap_store->subscribed_folders,
                    folder_name) != NULL;
}

static void
subscribe_folder (CamelStore *store, const char *folder_name,
          CamelException *ex)
{
    CamelImapStore *imap_store = CAMEL_IMAP_STORE (store);
    CamelImapResponse *response;
    
    if (!camel_remote_store_connected (CAMEL_REMOTE_STORE (store), ex))
        return;

    CAMEL_IMAP_STORE_LOCK(imap_store, command_lock);
    response = camel_imap_command (imap_store, NULL, ex,
                       "SUBSCRIBE %S", folder_name);
    CAMEL_IMAP_STORE_UNLOCK(imap_store, command_lock);
    if (response) {
        CamelFolderInfo *fi;
        char *name;
        
        g_hash_table_insert (imap_store->subscribed_folders,
                     g_strdup (folder_name),
                     GUINT_TO_POINTER (1));
        
        name = strrchr (folder_name, imap_store->dir_sep);
        if (name)
            name++;
        
        fi = g_new0 (CamelFolderInfo, 1);
        fi->full_name = g_strdup (folder_name);
        fi->name = g_strdup (name);
        fi->url = g_strdup_printf ("%s%s", imap_store->base_url, folder_name);
        fi->unread_message_count = -1;
        
        camel_object_trigger_event (CAMEL_OBJECT (store),
                        "folder_created", fi);
        
        camel_folder_info_free (fi);
    }
    camel_imap_response_free (response);
}

static void
unsubscribe_folder (CamelStore *store, const char *folder_name,
            CamelException *ex)
{
    CamelImapStore *imap_store = CAMEL_IMAP_STORE (store);
    CamelImapResponse *response;
    gpointer key, value;
    
    if (!camel_remote_store_connected (CAMEL_REMOTE_STORE (store), ex))
        return;

    CAMEL_IMAP_STORE_LOCK(imap_store, command_lock);
    response = camel_imap_command (imap_store, NULL, ex,
                       "UNSUBSCRIBE %S", folder_name);
    CAMEL_IMAP_STORE_UNLOCK(imap_store, command_lock);
    if (response) {
        CamelFolderInfo *fi;
        char *name;
        
        g_hash_table_lookup_extended (imap_store->subscribed_folders,
                          folder_name, &key, &value);
        g_hash_table_remove (imap_store->subscribed_folders,
                     folder_name);
        g_free (key);
        
        name = strrchr (folder_name, imap_store->dir_sep);
        if (name)
            name++;
        
        fi = g_new0 (CamelFolderInfo, 1);
        fi->full_name = g_strdup (folder_name);
        fi->name = g_strdup (name);
        fi->url = g_strdup_printf ("%s%s", imap_store->base_url, folder_name);
        fi->unread_message_count = -1;
        
        camel_object_trigger_event (CAMEL_OBJECT (store),
                        "folder_deleted", fi);
        
        camel_folder_info_free (fi);
    }
    camel_imap_response_free (response);
}

static void
imap_keepalive (CamelRemoteStore *store)
{
    CamelImapStore *imap_store = CAMEL_IMAP_STORE (store);
    CamelImapResponse *response;

    CAMEL_IMAP_STORE_LOCK(imap_store, command_lock);
    response = camel_imap_command (imap_store, NULL, NULL, "NOOP");
    CAMEL_IMAP_STORE_UNLOCK(imap_store, command_lock);
    camel_imap_response_free (response);
}