path: root/modules/bogofilter/evolution-bogofilter.c

/*
 * evolution-bogofilter.c
 *
 * This program is free software; you can redistribute it and/or
 * modify it under the terms of the GNU Lesser General Public
 * License as published by the Free Software Foundation; either
 * version 2 of the License, or (at your option) version 3.
 *
 * 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
 * Lesser General Public License for more details.
 *
 * You should have received a copy of the GNU Lesser General Public
 * License along with the program; if not, see <http://www.gnu.org/licenses/>
 *
 */

#ifdef HAVE_CONFIG_H
#include <config.h>
#endif

#include <config.h>
#include <sys/types.h>
#include <sys/wait.h>
#include <glib/gi18n-lib.h>

#include <camel/camel.h>

#include <libemail-engine/e-mail-junk-filter.h>

/* Standard GObject macros */
#define E_TYPE_BOGOFILTER \
    (e_bogofilter_get_type ())
#define E_BOGOFILTER(obj) \
    (G_TYPE_CHECK_INSTANCE_CAST \
    ((obj), E_TYPE_BOGOFILTER, EBogofilter))

#define BOGOFILTER_EXIT_STATUS_SPAM     0
#define BOGOFILTER_EXIT_STATUS_HAM      1
#define BOGOFILTER_EXIT_STATUS_UNSURE       2
#define BOGOFILTER_EXIT_STATUS_ERROR        3

typedef struct _EBogofilter EBogofilter;
typedef struct _EBogofilterClass EBogofilterClass;

struct _EBogofilter {
    EMailJunkFilter parent;
    gboolean convert_to_unicode;
};

struct _EBogofilterClass {
    EMailJunkFilterClass parent_class;
};

enum {
    PROP_0,
    PROP_CONVERT_TO_UNICODE
};

/* Module Entry Points */
void e_module_load (GTypeModule *type_module);
void e_module_unload (GTypeModule *type_module);

/* Forward Declarations */
GType e_bogofilter_get_type (void);
static void e_bogofilter_interface_init (CamelJunkFilterInterface *interface);

G_DEFINE_DYNAMIC_TYPE_EXTENDED (
    EBogofilter,
    e_bogofilter,
    E_TYPE_MAIL_JUNK_FILTER, 0,
    G_IMPLEMENT_INTERFACE_DYNAMIC (
        CAMEL_TYPE_JUNK_FILTER,
        e_bogofilter_interface_init))

#ifdef G_OS_UNIX
static void
bogofilter_cancelled_cb (GCancellable *cancellable,
                         GPid *pid)
{
    /* XXX On UNIX-like systems we can safely assume a GPid is the
     *     process ID and use it to terminate the process via signal. */
    kill (*pid, SIGTERM);
}
#endif

static void
bogofilter_exited_cb (GPid *pid,
                      gint status,
                      gpointer user_data)
{
    struct {
        GMainLoop *loop;
        gint exit_code;
    } *source_data = user_data;

    if (WIFEXITED (status))
        source_data->exit_code = WEXITSTATUS (status);
    else
        source_data->exit_code = BOGOFILTER_EXIT_STATUS_ERROR;

    g_main_loop_quit (source_data->loop);
}

static gint
bogofilter_command (const gchar **argv,
                    CamelMimeMessage *message,
                    GCancellable *cancellable,
                    GError **error)
{
    CamelStream *stream;
    GMainContext *context;
    GSource *source;
    GPid child_pid;
    gssize bytes_written;
    gint standard_input;
    gulong handler_id = 0;
    gboolean success;

    struct {
        GMainLoop *loop;
        gint exit_code;
    } source_data;

    /* Spawn Bogofilter with an open stdin pipe. */
    success = g_spawn_async_with_pipes (
        NULL,
        (gchar **) argv,
        NULL,
        G_SPAWN_DO_NOT_REAP_CHILD |
        G_SPAWN_STDOUT_TO_DEV_NULL,
        NULL, NULL,
        &child_pid,
        &standard_input,
        NULL,
        NULL,
        error);

    if (!success) {
        gchar *command_line;

        command_line = g_strjoinv (" ", (gchar **) argv);
        g_prefix_error (
            error, _("Failed to spawn Bogofilter (%s): "),
            command_line);
        g_free (command_line);

        return BOGOFILTER_EXIT_STATUS_ERROR;
    }

    /* Stream the CamelMimeMessage to Bogofilter. */
    stream = camel_stream_fs_new_with_fd (standard_input);
    bytes_written = camel_data_wrapper_write_to_stream_sync (
        CAMEL_DATA_WRAPPER (message), stream, cancellable, error);
    success = (bytes_written >= 0) &&
        (camel_stream_close (stream, cancellable, error) == 0);
    g_object_unref (stream);

    if (!success) {
        g_spawn_close_pid (child_pid);
        g_prefix_error (
            error, _("Failed to stream mail "
            "message content to Bogofilter: "));
        return BOGOFILTER_EXIT_STATUS_ERROR;
    }

    /* Wait for the Bogofilter process to terminate
     * using GLib's main loop for better portability. */

    context = g_main_context_new ();

    source = g_child_watch_source_new (child_pid);
    g_source_set_callback (
        source, (GSourceFunc)
        bogofilter_exited_cb,
        &source_data, NULL);
    g_source_attach (source, context);
    g_source_unref (source);

    source_data.loop = g_main_loop_new (context, TRUE);
    source_data.exit_code = 0;

#ifdef G_OS_UNIX
    if (G_IS_CANCELLABLE (cancellable))
        handler_id = g_cancellable_connect (
            cancellable,
            G_CALLBACK (bogofilter_cancelled_cb),
            &child_pid, (GDestroyNotify) NULL);
#endif

    g_main_loop_run (source_data.loop);

    if (handler_id > 0)
        g_cancellable_disconnect (cancellable, handler_id);

    g_main_loop_unref (source_data.loop);
    source_data.loop = NULL;

    g_main_context_unref (context);

    /* Clean up. */

    g_spawn_close_pid (child_pid);

    if (g_cancellable_set_error_if_cancelled (cancellable, error))
        source_data.exit_code = BOGOFILTER_EXIT_STATUS_ERROR;

    else if (source_data.exit_code == BOGOFILTER_EXIT_STATUS_ERROR)
        g_set_error_literal (
            error, CAMEL_ERROR, CAMEL_ERROR_GENERIC,
            _("Bogofilter either crashed or "
            "failed to process a mail message"));

    return source_data.exit_code;
}

static void
bogofilter_init_wordlist (EBogofilter *extension)
{
    CamelStream *stream;
    CamelMimeParser *parser;
    CamelMimeMessage *message;

    /* Initialize the Bogofilter database with a welcome message. */

    parser = camel_mime_parser_new ();
    message = camel_mime_message_new ();

    stream = camel_stream_fs_new_with_name (
        WELCOME_MESSAGE, O_RDONLY, 0, NULL);
    camel_mime_parser_init_with_stream (parser, stream, NULL);
    camel_mime_parser_scan_from (parser, FALSE);
    g_object_unref (stream);

    camel_mime_part_construct_from_parser_sync (
        CAMEL_MIME_PART (message), parser, NULL, NULL);

    camel_junk_filter_learn_not_junk (
        CAMEL_JUNK_FILTER (extension), message, NULL, NULL);

    g_object_unref (message);
    g_object_unref (parser);
}

static gboolean
bogofilter_get_convert_to_unicode (EBogofilter *extension)
{
    return extension->convert_to_unicode;
}

static void
bogofilter_set_convert_to_unicode (EBogofilter *extension,
                                   gboolean convert_to_unicode)
{
    if (extension->convert_to_unicode == convert_to_unicode)
        return;

    extension->convert_to_unicode = convert_to_unicode;

    g_object_notify (G_OBJECT (extension), "convert-to-unicode");
}

static void
bogofilter_set_property (GObject *object,
                         guint property_id,
                         const GValue *value,
                         GParamSpec *pspec)
{
    switch (property_id) {
        case PROP_CONVERT_TO_UNICODE:
            bogofilter_set_convert_to_unicode (
                E_BOGOFILTER (object),
                g_value_get_boolean (value));
            return;
    }

    G_OBJECT_WARN_INVALID_PROPERTY_ID (object, property_id, pspec);
}

static void
bogofilter_get_property (GObject *object,
                         guint property_id,
                         GValue *value,
                         GParamSpec *pspec)
{
    switch (property_id) {
        case PROP_CONVERT_TO_UNICODE:
            g_value_set_boolean (
                value, bogofilter_get_convert_to_unicode (
                E_BOGOFILTER (object)));
            return;
    }

    G_OBJECT_WARN_INVALID_PROPERTY_ID (object, property_id, pspec);
}

static GtkWidget *
bogofilter_new_config_widget (EMailJunkFilter *junk_filter)
{
    GtkWidget *box;
    GtkWidget *widget;
    gchar *markup;

    box = gtk_box_new (GTK_ORIENTATION_VERTICAL, 12);

    markup = g_markup_printf_escaped (
        "<b>%s</b>", _("Bogofilter Options"));
    widget = gtk_label_new (markup);
    gtk_misc_set_alignment (GTK_MISC (widget), 0.0, 0.5);
    gtk_label_set_use_markup (GTK_LABEL (widget), TRUE);
    gtk_box_pack_start (GTK_BOX (box), widget, FALSE, FALSE, 0);
    gtk_widget_show (widget);
    g_free (markup);

    widget = gtk_check_button_new_with_mnemonic (
        _("Convert message text to _Unicode"));
    gtk_widget_set_margin_left (widget, 12);
    gtk_box_pack_start (GTK_BOX (box), widget, FALSE, FALSE, 0);
    gtk_widget_show (widget);

    g_object_bind_property (
        junk_filter, "convert-to-unicode",
        widget, "active",
        G_BINDING_BIDIRECTIONAL |
        G_BINDING_SYNC_CREATE);

    return box;
}

static CamelJunkStatus
bogofilter_classify (CamelJunkFilter *junk_filter,
                     CamelMimeMessage *message,
                     GCancellable *cancellable,
                     GError **error)
{
    EBogofilter *extension = E_BOGOFILTER (junk_filter);
    static gboolean wordlist_initialized = FALSE;
    CamelJunkStatus status;
    gint exit_code;

    const gchar *argv[] = {
        BOGOFILTER_COMMAND,
        NULL,  /* leave room for unicode option */
        NULL
    };

    if (bogofilter_get_convert_to_unicode (extension))
        argv[1] = "--unicode=yes";

retry:
    exit_code = bogofilter_command (argv, message, cancellable, error);

    switch (exit_code) {
        case BOGOFILTER_EXIT_STATUS_SPAM:
            status = CAMEL_JUNK_STATUS_MESSAGE_IS_JUNK;
            break;

        case BOGOFILTER_EXIT_STATUS_HAM:
            status = CAMEL_JUNK_STATUS_MESSAGE_IS_NOT_JUNK;
            break;

        case BOGOFILTER_EXIT_STATUS_UNSURE:
            status = CAMEL_JUNK_STATUS_INCONCLUSIVE;
            break;

        case BOGOFILTER_EXIT_STATUS_ERROR:
            status = CAMEL_JUNK_STATUS_ERROR;
            if (!wordlist_initialized) {
                wordlist_initialized = TRUE;
                bogofilter_init_wordlist (extension);
                goto retry;
            }
            break;

        default:
            g_warning (
                "Bogofilter: Unexpected exit code (%d) "
                "while classifying message", exit_code);
            break;
    }

    /* Check that the return value and GError agree. */
    if (status != CAMEL_JUNK_STATUS_ERROR)
        g_warn_if_fail (error == NULL || *error == NULL);
    else
        g_warn_if_fail (error == NULL || *error != NULL);

    return status;
}

static gboolean
bogofilter_learn_junk (CamelJunkFilter *junk_filter,
                       CamelMimeMessage *message,
                       GCancellable *cancellable,
                       GError **error)
{
    EBogofilter *extension = E_BOGOFILTER (junk_filter);
    gint exit_code;

    const gchar *argv[] = {
        BOGOFILTER_COMMAND,
        "--register-spam",
        NULL,  /* leave room for unicode option */
        NULL
    };

    if (bogofilter_get_convert_to_unicode (extension))
        argv[2] = "--unicode=yes";

    exit_code = bogofilter_command (argv, message, cancellable, error);

    if (exit_code != 0)
        g_warning (
            "Bogofilter: Unexpected exit code (%d) "
            "while registering spam", exit_code);

    /* Check that the return value and GError agree. */
    if (exit_code != BOGOFILTER_EXIT_STATUS_ERROR)
        g_warn_if_fail (error == NULL || *error == NULL);
    else
        g_warn_if_fail (error == NULL || *error != NULL);

    return (exit_code != BOGOFILTER_EXIT_STATUS_ERROR);
}

static gboolean
bogofilter_learn_not_junk (CamelJunkFilter *junk_filter,
                           CamelMimeMessage *message,
                           GCancellable *cancellable,
                           GError **error)
{
    EBogofilter *extension = E_BOGOFILTER (junk_filter);
    gint exit_code;

    const gchar *argv[] = {
        BOGOFILTER_COMMAND,
        "--register-ham",
        NULL,  /* leave room for unicode option */
        NULL
    };

    if (bogofilter_get_convert_to_unicode (extension))
        argv[2] = "--unicode=yes";

    exit_code = bogofilter_command (argv, message, cancellable, error);

    if (exit_code != 0)
        g_warning (
            "Bogofilter: Unexpected exit code (%d) "
            "while registering ham", exit_code);

    /* Check that the return value and GError agree. */
    if (exit_code != BOGOFILTER_EXIT_STATUS_ERROR)
        g_warn_if_fail (error == NULL || *error == NULL);
    else
        g_warn_if_fail (error == NULL || *error != NULL);

    return (exit_code != BOGOFILTER_EXIT_STATUS_ERROR);
}

static void
e_bogofilter_class_init (EBogofilterClass *class)
{
    GObjectClass *object_class;
    EMailJunkFilterClass *junk_filter_class;

    object_class = G_OBJECT_CLASS (class);
    object_class->set_property = bogofilter_set_property;
    object_class->get_property = bogofilter_get_property;

    junk_filter_class = E_MAIL_JUNK_FILTER_CLASS (class);
    junk_filter_class->filter_name = "Bogofilter";
    junk_filter_class->display_name = _("Bogofilter");
    junk_filter_class->new_config_widget = bogofilter_new_config_widget;

    g_object_class_install_property (
        object_class,
        PROP_CONVERT_TO_UNICODE,
        g_param_spec_boolean (
            "convert-to-unicode",
            "Convert to Unicode",
            "Convert message text to Unicode",
            TRUE,
            G_PARAM_READWRITE));
}

static void
e_bogofilter_class_finalize (EBogofilterClass *class)
{
}

static void
e_bogofilter_interface_init (CamelJunkFilterInterface *interface)
{
    interface->classify = bogofilter_classify;
    interface->learn_junk = bogofilter_learn_junk;
    interface->learn_not_junk = bogofilter_learn_not_junk;
}

static void
e_bogofilter_init (EBogofilter *extension)
{
    GSettings *settings;

    settings = g_settings_new ("org.gnome.evolution.bogofilter");
    g_settings_bind (
        settings, "utf8-for-spam-filter",
        G_OBJECT (extension), "convert-to-unicode",
        G_SETTINGS_BIND_DEFAULT);
    g_object_unref (settings);
}

G_MODULE_EXPORT void
e_module_load (GTypeModule *type_module)
{
    e_bogofilter_register_type (type_module);
}

G_MODULE_EXPORT void
e_module_unload (GTypeModule *type_module)
{
}