test/swfscript.c

   1 /* Swfedit
   2  * Copyright (C) 2007 Benjamin Otte <otte@gnome.org>
   3  *
   4  * This library is free software; you can redistribute it and/or
   5  * modify it under the terms of the GNU Lesser General Public
   6  * License as published by the Free Software Foundation; either
   7  * version 2.1 of the License, or (at your option) any later version.
   8  *
   9  * This library is distributed in the hope that it will be useful,
  10  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  11  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  12  * Lesser General Public License for more details.
  13  *
  14  * You should have received a copy of the GNU Lesser General Public
  15  * License along with this library; if not, write to the Free Software
  16  * Foundation, Inc., 51 Franklin Street, Fifth Floor,
  17  * Boston, MA  02110-1301  USA
  18  */
  19
  20 #ifdef HAVE_CONFIG_H
  21 #include "config.h"
  22 #endif
  23
  24 #include <gtk/gtk.h>
  25 #include "libswfdec/swfdec_script_internal.h"
  26 #include "swfdec_out.h"
  27 #include "swfedit_file.h"
  28
  29 /* the stuff we look for */
  30 guint *add_trace = NULL;
  31
  32 typedef gboolean ( *SwfeditTokenForeachFunc) (SwfeditToken *token, guint idx,
  33     const char *name, SwfeditTokenType type, gconstpointer value, gpointer data);
  34
  35 static gboolean
  36 swfedit_token_foreach (SwfeditToken *token, SwfeditTokenForeachFunc func,
  37     gpointer data)
  38 {
  39   SwfeditTokenEntry *entry;
  40   guint i;
  41
  42   g_return_val_if_fail (SWFEDIT_IS_TOKEN (token), FALSE);
  43   g_return_val_if_fail (func != NULL, FALSE);
  44
  45   for (i = 0; i < token->tokens->len; i++) {
  46     entry = &g_array_index (token->tokens, SwfeditTokenEntry, i);
  47     if (!func (token, i, entry->name, entry->type, entry->value, data))
  48       return FALSE;
  49     if (entry->type == SWFEDIT_TOKEN_OBJECT) {
  50       if (!swfedit_token_foreach (entry->value, func, data))
  51         return FALSE;
  52     }
  53   }
  54   return TRUE;
  55 }
  56
  57 typedef struct {
  58   guint                 offset;                 /* offset in bytes from start of script */
  59   guint                 new_offset;             /* new offset in bytes from start of script */
  60   guint                 new_actions;            /* number of actions in new script */
  61 } Action;
  62
  63 typedef struct {
  64   SwfdecScript *        script;                 /* the original script */
  65   SwfdecOut *           out;                    /* output for new script or NULL when buffer is set */
  66   SwfdecBuffer *        buffer;                 /* buffer containing new script or NULL while constructing */
  67   GArray *              actions;                /* all actions in the script */
  68 } State;
  69
  70 static gboolean
  71 action_in_array (guint *array, guint action)
  72 {
  73   if (array == NULL)
  74     return FALSE;
  75   while (*array != 0) {
  76     if (*array == action)
  77       return TRUE;
  78     array++;
  79   }
  80   return FALSE;
  81 }
  82
  83 static guint
  84 lookup_offset (GArray *array, guint offset)
  85 {
  86   guint i;
  87   for (i = 0; i < array->len; i++) {
  88     Action *action = &g_array_index (array, Action, i);
  89     if (action->offset == offset)
  90       return action->new_offset;
  91   }
  92   g_assert_not_reached ();
  93   return 0;
  94 }
  95
  96 static gboolean
  97 fixup_jumps_foreach (gconstpointer bytecode, guint action,
  98         const guint8 *data, guint len, gpointer user_data)
  99 {
 100   State *state = user_data;
 101
 102   if (action == 0x99 || action == 0x9d) {
 103     guint offset = (guint8 *) bytecode - state->script->buffer->data;
 104     guint jump_offset = offset + 5 + GINT16_FROM_LE (*((gint16 *) data));
 105     offset = lookup_offset (state->actions, offset);
 106     jump_offset = lookup_offset (state->actions, jump_offset);
 107     *((gint16 *) &state->buffer->data[offset + 3]) =
 108       GINT16_TO_LE (jump_offset - offset - 5);
 109   }
 110   if (action == 0x8a || action == 0x8d) {
 111     Action *cur = NULL; /* silence gcc */
 112     guint id = action == 0x8a ? 2 : 0;
 113     guint i, count;
 114     guint offset = (guint8 *) bytecode - state->script->buffer->data;
 115     for (i = 0; i < state->actions->len; i++) {
 116       cur = &g_array_index (state->actions, Action, i);
 117       if (cur->offset == offset) {
 118         offset = cur->new_offset;
 119         break;
 120       }
 121     }
 122     g_assert (i < state->actions->len);
 123     i = data[id];
 124     count = cur->new_actions - 1; /* FIXME: only works as long as we append actions */
 125     while (i > 0) {
 126       cur++;
 127       count += cur->new_actions;
 128       i--;
 129     }
 130     g_assert (count < 256);
 131     state->buffer->data[offset + 3 + id] = count;
 132   }
 133   return TRUE;
 134 }
 135
 136 static gboolean
 137 modify_script_foreach (gconstpointer bytecode, guint action,
 138         const guint8 *data, guint len, gpointer user_data)
 139 {
 140   Action next;
 141   State *state = user_data;
 142
 143   next.offset = (guint8 *) bytecode - state->script->buffer->data;
 144   next.new_offset = swfdec_out_get_bits (state->out) / 8;
 145   next.new_actions = 1;
 146   swfdec_out_put_u8 (state->out, action);
 147   if (action & 0x80) {
 148     swfdec_out_put_u16 (state->out, len);
 149     swfdec_out_put_data (state->out, data, len);
 150   }
 151   if (action_in_array (add_trace, action)) {
 152     swfdec_out_put_u8 (state->out, 0x4c); /* PushDuplicate */
 153     swfdec_out_put_u8 (state->out, 0x26); /* Trace */
 154     next.new_actions += 2;
 155   }
 156   g_array_append_val (state->actions, next);
 157   return TRUE;
 158 }
 159
 160 static gboolean
 161 modify_file (SwfeditToken *token, guint idx, const char *name,
 162     SwfeditTokenType type, gconstpointer value, gpointer data)
 163 {
 164   Action end;
 165   SwfdecScript *script;
 166   State state;
 167
 168   if (type != SWFEDIT_TOKEN_SCRIPT)
 169     return TRUE;
 170
 171   state.script = (SwfdecScript *) value;
 172   state.out = swfdec_out_open ();
 173   state.buffer = NULL;
 174   state.actions = g_array_new (FALSE, FALSE, sizeof (Action));
 175   swfdec_script_foreach (state.script, modify_script_foreach, &state);
 176   /* compute end offset */
 177   end.offset = g_array_index (state.actions, Action, state.actions->len - 1).offset;
 178   if (state.script->buffer->data[end.offset] & 0x80) {
 179     end.offset += GUINT16_FROM_LE (*((guint16* ) &state.script->buffer->data[end.offset + 1])) + 3;
 180   } else {
 181     end.offset++;
 182   }
 183   end.new_offset = swfdec_out_get_bits (state.out) / 8;
 184   end.new_actions = 0;
 185   g_array_append_val (state.actions, end);
 186 #if 0
 187   {
 188     guint i;
 189     for (i = 0; i < state.actions->len; i++) {
 190       Action *action = &g_array_index (state.actions, Action, i);
 191       g_print ("%u  %u => %u  (%u actions)\n", i, action->offset,
 192           action->new_offset, action->new_actions);
 193     }
 194   }
 195 #endif
 196   /* maybe append 0 byte */
 197   if (end.offset + 1 == state.script->buffer->length) {
 198     swfdec_out_put_u8 (state.out, 0);
 199   } else {
 200     g_assert (end.offset == state.script->buffer->length);
 201   }
 202   state.buffer = swfdec_out_close (state.out);
 203   state.out = NULL;
 204   swfdec_script_foreach (state.script, fixup_jumps_foreach, &state);
 205   g_array_free (state.actions, TRUE);
 206 #if 0
 207   g_print ("got a new script in %u bytes - old script was %u bytes\n",
 208       state.buffer->length, state.script->buffer->length);
 209 #endif
 210   script = swfdec_script_new (state.buffer, state.script->name, state.script->version);
 211   g_assert (script);
 212   swfedit_token_set (token, idx, script);
 213
 214   return TRUE;
 215 }
 216
 217 static guint *
 218 string_to_action_list (const char *list)
 219 {
 220   char **actions = g_strsplit (list, ",", -1);
 221   guint *ret;
 222   guint i, len;
 223
 224   len = g_strv_length (actions);
 225   ret = g_new (guint, len + 1);
 226   ret[len] = 0;
 227   for (i = 0; i < len; i++) {
 228     ret[i] = swfdec_action_get_from_name (actions[i]);
 229     if (ret[i] == 0) {
 230       g_printerr ("No such action \"%s\"\n", actions[i]);
 231       g_free (actions);
 232       g_free (ret);
 233       return NULL;
 234     }
 235   }
 236   g_free (actions);
 237   return ret;
 238 }
 239
 240 int
 241 main (int argc, char **argv)
 242 {
 243   SwfeditFile *file;
 244   GError *error = NULL;
 245   char *add_trace_s = NULL;
 246   GOptionEntry options[] = {
 247     { "add-trace", 't', 0, G_OPTION_ARG_STRING, &add_trace_s, "list of actions to trace", "ACTION, ACTION" },
 248     { NULL }
 249   };
 250   GOptionContext *ctx;
 251
 252   ctx = g_option_context_new ("");
 253   g_option_context_add_main_entries (ctx, options, "options");
 254   g_option_context_add_group (ctx, gtk_get_option_group (TRUE));
 255   g_option_context_parse (ctx, &argc, &argv, &error);
 256   g_option_context_free (ctx);
 257   if (error) {
 258     g_printerr ("error parsing arguments: %s\n", error->message);
 259     g_error_free (error);
 260     return 1;
 261   }
 262
 263   if (argc < 2) {
 264     g_printerr ("Usage: %s FILENAME [OUTPUT-FILENAME]\n", argv[0]);
 265     return 1;
 266   }
 267   if (add_trace_s) {
 268     add_trace = string_to_action_list (add_trace_s);
 269     g_free (add_trace_s);
 270     if (add_trace == NULL)
 271       return 1;
 272   }
 273   file = swfedit_file_new (argv[1], &error);
 274   if (file == NULL) {
 275     g_printerr ("error opening file %s: %s\n", argv[1], error->message);
 276     g_error_free (error);
 277     return 1;
 278   }
 279   if (!swfedit_token_foreach (SWFEDIT_TOKEN (file), modify_file, NULL)) {
 280     g_printerr ("modifying file %s failed.\n", argv[1]);
 281     g_object_unref (file);
 282     return 1;
 283   }
 284   g_free (file->filename);
 285   if (argc > 2) {
 286     file->filename = g_strdup (argv[2]);
 287   } else {
 288     file->filename = g_strdup_printf ("%s.out.swf", argv[1]);
 289   }
 290   if (!swfedit_file_save (file, &error)) {
 291     g_printerr ("Error saving file: %s\n", error->message);
 292     g_error_free (error);
 293   }
 294   g_print ("saved modified file to %s\n", file->filename);
 295   g_object_unref (file);
 296   return 0;
 297 }
 298