Change wtap_read() API so that the data offset is set via a pointer, and

a "keep reading" boolean value is returned from the function.
This avoids having to hack around the fact that some file formats truly
do have records that start at offset 0. (i4btrace and csids have no
file header. Neither does the pppdump-style file that I'm looking at right now).


git-svn-id: http://anonsvn.wireshark.org/wireshark/trunk@2392 f5534014-38df-0310-8fa8-9805f1628bb7

1 files changed, 9 insertions, 30 deletions

diff --git a/wiretap/csids.c b/wiretap/csids.c
index 419db2af02..fbe2d946bd 100644
--- a/wiretap/csids.c
+++ b/wiretap/csids.c
@@ -1,6 +1,6 @@
 /* csids.c
  *
- * $Id: csids.c,v 1.3 2000/08/31 16:44:47 gram Exp $
+ * $Id: csids.c,v 1.4 2000/09/07 05:34:07 gram Exp $
  *
  * Copyright (c) 2000 by Mike Hall <mlh@io.com>
  * Copyright (c) 2000 by Cisco Systems
@@ -44,7 +44,7 @@
  *
  */
 
-static int csids_read(wtap *wth, int *err);
+static gboolean csids_read(wtap *wth, int *err, int *data_offset);
 static int csids_seek_read(wtap *wth, int seek_off,
 	union wtap_pseudo_header *pseudo_header, guint8 *pd, int len);
 
@@ -140,21 +140,18 @@ int csids_open(wtap *wth, int *err)
 }
 
 /* Find the next packet and parse it; called from wtap_loop(). */
-static int csids_read(wtap *wth, int *err)
+static gboolean csids_read(wtap *wth, int *err, int *data_offset)
 {
   guint8 *buf;
   int bytesRead = 0;
   struct csids_header hdr;
-  int packet_offset = wth->data_offset;
+
+  *data_offset = wth->data_offset;
 
   bytesRead = file_read( &hdr, 1, sizeof( struct csids_header) , wth->fh );
   if( bytesRead != sizeof( struct csids_header) ) {
     *err = file_error( wth->fh );
-    if( *err != 0 ) {
-      return -1;
-    } else {
-      return 0;
-    }
+    return FALSE;
   }
   hdr.seconds = pntohl(&hdr.seconds);
   hdr.caplen = pntohs(&hdr.caplen);
@@ -168,9 +165,7 @@ static int csids_read(wtap *wth, int *err)
   bytesRead = file_read( buf, 1, hdr.caplen, wth->fh );
   if( bytesRead != hdr.caplen ) {
     *err = file_error( wth->fh );
-    if( *err != 0 ) {
-      return -1;
-    }       
+    return FALSE;
   }
   
   wth->data_offset += hdr.caplen;
@@ -188,12 +183,7 @@ static int csids_read(wtap *wth, int *err)
     *(++swap) = BSWAP16(*swap); /* ip flags and fragoff */
   }
 
-  /* This is a hack to fix the fact that have to atleast return 1 
-   * or we stop processing. csids has no file header. We recover from 
-   * this hack in csids_seek_read by checking the seek_off == 1 and 
-   * setting it back to 0.
-   */
-  return packet_offset ? packet_offset : 1;
+  return TRUE;
 }
 
 /* Used to read packets in random-access fashion */
@@ -208,18 +198,7 @@ csids_seek_read (wtap *wth,
   int bytesRead = 0;
   struct csids_header hdr;
 
-  /* hack to fix a problem with the way error checking is done. If the 
-   * the return value from csids_read is 0 for the first packet, then
-   * we stop there. So I return 1. But that messes up the offset for 
-   * the seek_off on this call. So if seek_off is 1 then make it 0 and 
-   * if it is not 1 leave it alone. --mlh 
-   */
-  int real_seek_off = seek_off;
-  if( real_seek_off == 1 ) {
-    real_seek_off = 0;
-  }
-
-  file_seek(wth->random_fh, real_seek_off , SEEK_SET);
+  file_seek(wth->random_fh, seek_off , SEEK_SET);
 
   bytesRead = file_read( &hdr, 1, sizeof( struct csids_header) , wth->random_fh );
   if( bytesRead != sizeof( struct csids_header) ) {