Clean up the code to check the file type.

svn path=/trunk/; revision=10445

diff --git a/wiretap/eyesdn.c b/wiretap/eyesdn.c
index cd4052004315696eb9525b87d33f72c3a07f5414..df82cc26aa1da3ab2e55f868033669cee81c2445 100644 (file)
--- a/wiretap/eyesdn.c
+++ b/wiretap/eyesdn.c
@@ -1,6 +1,6 @@
 /* eyesdn.c
  *
- * $Id: eyesdn.c,v 1.6 2004/03/17 09:24:41 guy Exp $
+ * $Id: eyesdn.c,v 1.7 2004/03/23 00:17:50 guy Exp $
  *
  * Wiretap Library
  * Copyright (c) 1998 by Gilbert Ramirez <gram@alumni.rice.edu>
@@ -132,54 +132,22 @@ static long eyesdn_seek_next_packet(wtap *wth, int *err)
   return -1;
 }
 
-/* Look through the first part of a file to see if this is
- * a eyesdn trace file.
- *
- * Returns TRUE if it is, FALSE if it isn't or if we get an I/O error;
- * if we get an I/O error, "*err" will be set to a non-zero value.
- */
-static gboolean eyesdn_check_file_type(wtap *wth, int *err)
-{
-       char    buf[EYESDN_HDR_MAGIC_SIZE];
-       size_t  i, reclen;
-       guint   level;
-       char    byte;
-
-        reclen=EYESDN_HDR_MAGIC_SIZE;
-        if (file_read(buf, 1, reclen, wth->fh) == reclen) {
-           level = 0;
-           for (i = 0; i < reclen; i++) {
-               byte = buf[i];
-               if (byte == eyesdn_hdr_magic[level]) {
-                   level++;
-                   if (level >= EYESDN_HDR_MAGIC_SIZE) {
-                       return TRUE;
-                   }
-               } else {
-                   level = 0;
-               }
-           }
-       } else {/* EOF or error. */
-           if (file_eof(wth->fh))
-               *err = 0;
-           else
-               *err = file_error(wth->fh);
-           return FALSE;
-       }
-       *err = 0;
-       return FALSE;
-}
-
-
 int eyesdn_open(wtap *wth, int *err, gchar **err_info _U_)
 {
+       int     bytes_read;
+       char    magic[EYESDN_HDR_MAGIC_SIZE];
+
        /* Look for eyesdn header */
-       if (!eyesdn_check_file_type(wth, err)) {
-               if (*err == 0)
-                       return 0;
-               else
+       errno = WTAP_ERR_CANT_READ;
+       bytes_read = file_read(&magic, 1, sizeof magic, wth->fh);
+       if (bytes_read != sizeof magic) {
+               *err = file_error(wth->fh);
+               if (*err != 0)
                        return -1;
+               return 0;
        }
+       if (memcmp(magic, eyesdn_hdr_magic, EYESDN_HDR_MAGIC_SIZE) != 0)
+               return 0;
 
        wth->data_offset = 0;
        wth->file_encap = WTAP_ENCAP_ISDN;