path: root/plugins/desktop-file/plugin.cpp

/*
 *  Copyright © 2005 Jorn Baayen <jbaayen@gnome.org>
 *  Copyright © 2005 Christian Persch
 *
 *  Based on the work of:
 *
 *  Copyright © 2004 Bastien Nocera <hadess@hadess.net>
 *  Copyright © 2002 David A. Schleef <ds@schleef.org>
 *
 *  This library is free software; you can redistribute it and/or
 *  modify it under the terms of the GNU Library General Public
 *  License as published by the Free Software Foundation; either
 *  version 2 of the License, or (at your option) any later version.
 *
 *  This library 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
 *  Library General Public License for more details.
 *
 *  You should have received a copy of the GNU Library General Public
 *  License along with this library; if not, write to the
 *  Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor,
 *  Boston, MA 02110-1301, USA.
 *
 *  $Id$
 */

#include <xpcom-config.h>
#include "config.h"

#include <string.h>
#include <glib.h>
#include <gtk/gtkwidget.h>
#include <gtk/gtkwindow.h>
#include <gtk/gtkmessagedialog.h>

#include "ephy-stock-icons.h"

#include <npupp.h>
#include <nsCOMPtr.h>
#include <nsIDOMWindow.h>
#include "../../embed/mozilla/EphyUtils.h"

/* NOTE: For simplicity, we use the Epiphany domain for translations,
 * instead of setting up another one for just a few strings. So we
 * don't need gi18n-lib.h here.
 */
#include <glib/gi18n.h>

#define DESKTOP_FILE_MIME_TYPE  "application/x-desktop"
#define URL_FILE_MIME_TYPE_1    "text/x-uri"
#define URL_FILE_MIME_TYPE_2    "application/x-mswinurl"

static const char kDesktopEntry[] = "Desktop Entry";
static const char kInternetShortcut[] = "InternetShortcut";
static const char kInternetShortcutW[] = "InternetShortcut.W";

typedef enum
{
    FORMAT_DESKTOP_FILE,
    FORMAT_URL_FILE
} FileFormat;

typedef struct {
    NPP instance;
    guint format : 2;
    guint handled : 1;
} Plugin;

static NPNetscapeFuncs mozilla_functions;

static char *
parse_desktop_file (const char *filename)
{
    GKeyFile *keyfile = g_key_file_new ();
    if (!g_key_file_load_from_file (keyfile, filename, (GKeyFileFlags) 0, NULL)) {
        /* Not a valid key file */
        g_key_file_free (keyfile);
        return NULL;
    }

    char *group = g_key_file_get_start_group (keyfile);
    if (!group || strcmp (group, kDesktopEntry) != 0) {
        /* Not a valid Desktop file */
        g_free (group);
        g_key_file_free (keyfile);
        return NULL;
    }
    g_free (group);

    char *encoding = g_key_file_get_string (keyfile, kDesktopEntry, "Encoding", NULL);
    if (!encoding || strcmp (encoding, "UTF-8") != 0) {
        /* Not a properly encoded desktop file */
        g_free (encoding);
        g_key_file_free (keyfile);
        return NULL;
    }
    g_free (encoding);

    char *type = g_key_file_get_string (keyfile, kDesktopEntry, "Type", NULL);
    if (!type || strcmp (type, "Link") != 0) {
        /* Not a "Link" file */
        g_free (type);
        g_key_file_free (keyfile);
        return NULL;
    }
    g_free (type);

    char *url = g_key_file_get_string (keyfile, kDesktopEntry, "URL", NULL);
    if (!url || !url[0]) {
        /* Not a valid URL */
        g_free (url);
        g_key_file_free (keyfile);
        return NULL;
    }

    g_key_file_free (keyfile);

    return url;
}

static char *
parse_url_file (const char *filename)
{
    char *contents = NULL;
    gsize len = 0;
    if (!g_file_get_contents (filename, &contents, &len, NULL)) {
        return NULL;
    }

    /* URL files are encoded in MS-ANSI, so convert to UTF-8 first */
    gsize bytes_read, bytes_written;
    char *converted = g_convert (contents, len, "UTF-8", "MS-ANSI",
                     &bytes_read, &bytes_written, NULL);
    g_free (contents);
    if (converted == NULL) {
        return NULL;
    }

    /* Now load as keyfile */
    GKeyFile *keyfile = g_key_file_new ();
    if (!g_key_file_load_from_data (keyfile, converted, strlen (converted), (GKeyFileFlags) 0, NULL)) {
        /* Not a valid key file */
        g_free (converted);
        g_key_file_free (keyfile);
        return NULL;
    }
    g_free (converted);

    /* First try the [InternetShortcut.W] section */
    if (g_key_file_has_group (keyfile, kInternetShortcutW))
    {
        char *entry = g_key_file_get_string (keyfile, kInternetShortcutW, "URL", NULL);
        if (!entry || !entry[0]) {
            g_free (entry);
            g_key_file_free (keyfile);
            return NULL;
        }

        /* The URL is encoded in UTF-7 */
        char *url = g_convert (entry, strlen (entry), "UTF-8", "UTF-7",
                       &bytes_read, &bytes_written, NULL);
        g_free (entry);
        if (!url || !url[0]) {
            g_free (url);
            g_key_file_free (keyfile);
            return NULL;
        }

        g_key_file_free (keyfile);

        return url;
    }

    /* No [InternetShortcut.W] section, fallback to [InternetShortcut] */
    if (g_key_file_has_group (keyfile, kInternetShortcut))
    {
        char *url = g_key_file_get_string (keyfile, kInternetShortcut, "URL", NULL);
        if (!url || !url[0]) {
            g_free (url);
            g_key_file_free (keyfile);
            return NULL;
        }

        return url;
    }

    g_key_file_free (keyfile);
    return NULL;
}

static void
show_error_dialog (NPP instance,
           const char *primary_text,
           const char *secondary_text)
{
    GtkWidget *dialog, *parent;

    nsCOMPtr<nsIDOMWindow> domWin;
    mozilla_functions.getvalue (instance, NPNVDOMWindow,
                    static_cast<nsIDOMWindow **>(getter_AddRefs (domWin)));
    parent = EphyUtils::FindGtkParent (domWin);

    dialog = gtk_message_dialog_new (GTK_WINDOW (parent),
                     (GtkDialogFlags) (GTK_DIALOG_MODAL | GTK_DIALOG_DESTROY_WITH_PARENT),
                     GTK_MESSAGE_ERROR, GTK_BUTTONS_OK,
                     primary_text, NULL);

    gtk_message_dialog_format_secondary_text (GTK_MESSAGE_DIALOG (dialog),
                          secondary_text);
    gtk_window_set_icon_name (GTK_WINDOW (dialog), EPHY_STOCK_EPHY);

    gtk_dialog_set_default_response (GTK_DIALOG (dialog), GTK_RESPONSE_OK);

    g_signal_connect (dialog, "response",
              G_CALLBACK (gtk_widget_destroy), NULL);

    if (parent && GTK_WINDOW (parent)->group) {
        gtk_window_group_add_window (GTK_WINDOW (parent)->group,
                         GTK_WINDOW (dialog));
    }

    gtk_widget_show (dialog);
}

/* Check for unsafe protocols. See:
 * http://www.mozilla.org/projects/security/components/reviewguide.html
 */

#define JAVASCRIPT_PROTOCOL "javascript:"
#define DATA_PROTOCOL       "data:"

static gboolean
is_safe_url (char *url)
{
    /* FIXME: when we allow non-file: .desktop files, add a security check here,
     * like the one HTPP protocol handler does on redirect.
     */

    url = g_strstrip (url);

    return (g_ascii_strncasecmp (url, JAVASCRIPT_PROTOCOL,
                         strlen (JAVASCRIPT_PROTOCOL)) != 0 &&
            g_ascii_strncasecmp (url, DATA_PROTOCOL,
                         strlen (DATA_PROTOCOL)) != 0);
}

static NPError
plugin_new_instance (NPMIMEType mime_type,
             NPP instance,
             guint16 mode,
             gint16 argc,
             char **argn,
             char **argv,
             NPSavedData *saved)
{
    if (instance == NULL)
        return NPERR_INVALID_INSTANCE_ERROR;

    /* We don't do embedded */
    if (mode != NP_FULL)
        return NPERR_INVALID_PARAM;

    /* FIXME: Until I've thought more about security when loading .desktop
     * files from non-file: locations, only allow local desktop files.
    */
    PRBool isSafe = PR_FALSE;
    for (gint16 i = 0; i < argc; ++i) {
        if (argn[i] && g_ascii_strcasecmp (argn[i], "src") == 0) {
            isSafe = argv[i] && g_ascii_strncasecmp (argv[i], "file:/", strlen ("file:/")) == 0;
            break;
        }
    }

    if (!isSafe)
        return NPERR_INVALID_URL;

    instance->pdata = mozilla_functions.memalloc (sizeof (Plugin));

    Plugin *plugin = (Plugin *) instance->pdata;
    if (plugin == NULL)
        return NPERR_OUT_OF_MEMORY_ERROR;

    memset (plugin, 0, sizeof (Plugin));

    plugin->instance = instance;

    mozilla_functions.setvalue (plugin->instance, NPPVpluginWindowBool,
                    GINT_TO_POINTER (FALSE));

    return NPERR_NO_ERROR;
}

static NPError
plugin_destroy_instance (NPP instance,
             NPSavedData **save)
{
    if (instance == NULL)
        return NPERR_INVALID_INSTANCE_ERROR;

    Plugin *plugin = (Plugin *) instance->pdata;
    if (plugin == NULL)
        return NPERR_NO_ERROR;

    mozilla_functions.memfree (instance->pdata);
    instance->pdata = NULL;

    return NPERR_NO_ERROR;
}

static NPError
plugin_new_stream (NPP instance,
           NPMIMEType type,
           NPStream *stream_ptr,
           NPBool seekable,
           guint16 *stype)
{
    if (instance == NULL || type == NULL)
        return NPERR_INVALID_INSTANCE_ERROR;

    Plugin *plugin = (Plugin *) instance->pdata;
    if (plugin == NULL)
        return NPERR_INVALID_INSTANCE_ERROR;

    if (type && strcmp (type, DESKTOP_FILE_MIME_TYPE) == 0) {
        plugin->format = FORMAT_DESKTOP_FILE;
    }
    else if (type && (strcmp (type, URL_FILE_MIME_TYPE_1) == 0 ||
              strcmp (type, URL_FILE_MIME_TYPE_2) == 0)) {
        plugin->format = FORMAT_URL_FILE;
    }
    else
    {
        return NPERR_INVALID_PARAM;
    }

    *stype = NP_ASFILEONLY;

    plugin->handled = FALSE;

    return NPERR_NO_ERROR;
}

static NPError
plugin_stream_as_file (NPP instance,
               NPStream* stream,
               const char *filename)
{
    if (instance == NULL)
        return NPERR_INVALID_INSTANCE_ERROR;

    Plugin *plugin = (Plugin *) instance->pdata;
    if (plugin == NULL)
        return NPERR_INVALID_INSTANCE_ERROR;

    if (!filename)
        return NPERR_INVALID_PARAM;

    char *url = NULL;
    if (plugin->format == FORMAT_DESKTOP_FILE) {
        url = parse_desktop_file (filename);
    } else if (plugin->format == FORMAT_URL_FILE) {
        url = parse_url_file (filename);
    }

    if (!url) {
        return NPERR_GENERIC_ERROR;
    }

    plugin->handled = TRUE;

    if (is_safe_url (url)) {
        mozilla_functions.geturl (instance, url, "_top");
    } else {
        /* Load blank page, so that further drags to the embed work */
        mozilla_functions.geturl (instance, "about:blank", "_top");

        show_error_dialog (instance,
                   _("Unsafe protocol."),
                   _("The address has not been "
                     "loaded, because it refers to an "
                     "unsafe protocol and thereby presents "
                     "a security risk to your system."));
    }

    g_free (url);

    return NPERR_NO_ERROR;
}

static NPError
plugin_destroy_stream (NPP instance,
               NPStream *stream,
               NPError reason)
{
    if (instance == NULL)
        return NPERR_INVALID_INSTANCE_ERROR;

    Plugin *plugin = (Plugin *) instance->pdata;
    if (plugin == NULL)
        return NPERR_INVALID_INSTANCE_ERROR;

    if (!plugin->handled) {
        /* Load blank page, so that further drags to the embed work */
        mozilla_functions.geturl (instance, "about:blank", "_top");

        show_error_dialog (instance,
                   _("No address found."),
                   _("No web address could be found in this file."));
    }

    return NPERR_NO_ERROR;
}

static int32
plugin_write_ready (NPP instance,
            NPStream *stream)
{
    /* Ready to read 8 KB - should do. Can always get more. */
    return 8192;
}

static int32
plugin_write (NPP instance,
          NPStream *stream,
          int32 offset,
          int32 len,
          gpointer buffer)
{
    /* FIXME */
    return len;
}

static NPError
plugin_get_value (NPP instance,
          NPPVariable variable,
          gpointer value)
{
    NPError err = NPERR_NO_ERROR;

    switch (variable) {
    case NPPVpluginNameString:
        /* Translators: "Desktop File" refers to .desktop files containing a link */
        *((char **) value) = _("Epiphany Desktop File Plugin");
        break;

    case NPPVpluginDescriptionString:
        *((char **) value) = _("This plugin handles “.desktop” and “.url” files containing web links.");
        break;

    case NPPVpluginNeedsXEmbed:
        *((NPBool *) value) = PR_FALSE;
        break;

    default:
        err = NPERR_INVALID_PARAM;
        break;
    }

    return err;
}

NPError
NP_GetValue (void *future,
         NPPVariable variable,
         gpointer value)
{
    return plugin_get_value (NULL, variable, value);
}

char *
NP_GetMIMEDescription (void)
{
    return DESKTOP_FILE_MIME_TYPE ":desktop:desktop link file;"
           URL_FILE_MIME_TYPE_1 ":url:URL file;"
           URL_FILE_MIME_TYPE_2 "::URL file;";
}

NPError
NP_Initialize (NPNetscapeFuncs *moz_funcs,
               NPPluginFuncs *plugin_funcs)
{
    if (moz_funcs == NULL || plugin_funcs == NULL)
        return NPERR_INVALID_FUNCTABLE_ERROR;

    if ((moz_funcs->version >> 8) > NP_VERSION_MAJOR)
        return NPERR_INCOMPATIBLE_VERSION_ERROR;
    if (moz_funcs->size < sizeof (NPNetscapeFuncs))
        return NPERR_INVALID_FUNCTABLE_ERROR;
    if (plugin_funcs->size < sizeof (NPPluginFuncs))
        return NPERR_INVALID_FUNCTABLE_ERROR;

    /*
     * Copy all of the fields of the Mozilla function table into our
     * copy so we can call back into Mozilla later.  Note that we need
     * to copy the fields one by one, rather than assigning the whole
     * structure, because the Mozilla function table could actually be
     * bigger than what we expect.
     */
    mozilla_functions.size             = moz_funcs->size;
    mozilla_functions.version          = moz_funcs->version;
    mozilla_functions.geturl           = moz_funcs->geturl;
    mozilla_functions.posturl          = moz_funcs->posturl;
    mozilla_functions.requestread      = moz_funcs->requestread;
    mozilla_functions.newstream        = moz_funcs->newstream;
    mozilla_functions.write            = moz_funcs->write;
    mozilla_functions.destroystream    = moz_funcs->destroystream;
    mozilla_functions.status           = moz_funcs->status;
    mozilla_functions.uagent           = moz_funcs->uagent;
    mozilla_functions.memalloc         = moz_funcs->memalloc;
    mozilla_functions.memfree          = moz_funcs->memfree;
    mozilla_functions.memflush         = moz_funcs->memflush;
    mozilla_functions.reloadplugins    = moz_funcs->reloadplugins;
    mozilla_functions.getJavaEnv       = moz_funcs->getJavaEnv;
    mozilla_functions.getJavaPeer      = moz_funcs->getJavaPeer;
    mozilla_functions.geturlnotify     = moz_funcs->geturlnotify;
    mozilla_functions.posturlnotify    = moz_funcs->posturlnotify;
    mozilla_functions.getvalue         = moz_funcs->getvalue;
    mozilla_functions.setvalue         = moz_funcs->setvalue;
    mozilla_functions.invalidaterect   = moz_funcs->invalidaterect;
    mozilla_functions.invalidateregion = moz_funcs->invalidateregion;
    mozilla_functions.forceredraw      = moz_funcs->forceredraw;
    mozilla_functions.geturl           = moz_funcs->geturl;

    /*
     * Set up a plugin function table that Mozilla will use to call
     * into us.  Mozilla needs to know about our version and size and
     * have a UniversalProcPointer for every function we implement.
     */

    plugin_funcs->size = sizeof (NPPluginFuncs);
    plugin_funcs->version = (NP_VERSION_MAJOR << 8) + NP_VERSION_MINOR;
    plugin_funcs->newp = NewNPP_NewProc (plugin_new_instance);
    plugin_funcs->destroy = NewNPP_DestroyProc (plugin_destroy_instance);
    plugin_funcs->setwindow = NewNPP_SetWindowProc (NULL);
    plugin_funcs->newstream = NewNPP_NewStreamProc (plugin_new_stream);
    plugin_funcs->destroystream = NewNPP_DestroyStreamProc (plugin_destroy_stream);
    plugin_funcs->asfile = NewNPP_StreamAsFileProc (plugin_stream_as_file);
    plugin_funcs->writeready = NewNPP_WriteReadyProc (plugin_write_ready);
    plugin_funcs->write = NewNPP_WriteProc (plugin_write);
    plugin_funcs->print = NewNPP_PrintProc (NULL);
    plugin_funcs->event = NewNPP_HandleEventProc (NULL);
    plugin_funcs->urlnotify = NewNPP_URLNotifyProc (NULL);
    plugin_funcs->javaClass = NULL;
    plugin_funcs->getvalue = NewNPP_GetValueProc (plugin_get_value);
    plugin_funcs->setvalue = NewNPP_SetValueProc (NULL);

    return NPERR_NO_ERROR;
}

NPError
NP_Shutdown (void)
{
    return NPERR_NO_ERROR;
}