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).

svn path=/trunk/; revision=2392

1 files changed, 12 insertions, 16 deletions

diff --git a/wiretap/snoop.c b/wiretap/snoop.c
index 3d247bce21..14a590136a 100644
--- a/wiretap/snoop.c
+++ b/wiretap/snoop.c
@@ -1,6 +1,6 @@
 /* snoop.c
  *
- * $Id: snoop.c,v 1.29 2000/07/26 00:20:06 guy Exp $
+ * $Id: snoop.c,v 1.30 2000/09/07 05:34:19 gram Exp $
  *
  * Wiretap Library
  * Copyright (c) 1998 by Gilbert Ramirez <gram@xiexie.org>
@@ -55,7 +55,7 @@ struct snooprec_hdr {
 	guint32	ts_usec;	/* timestamp microseconds */
 };
 
-static int snoop_read(wtap *wth, int *err);
+static gboolean snoop_read(wtap *wth, int *err, int *data_offset);
 static int snoop_seek_read(wtap *wth, int seek_off,
     union wtap_pseudo_header *pseudo_header, u_char *pd, int length);
 static int snoop_read_atm_pseudoheader(FILE_T fh,
@@ -206,12 +206,11 @@ int snoop_open(wtap *wth, int *err)
 }
 
 /* Read the next packet */
-static int snoop_read(wtap *wth, int *err)
+static gboolean snoop_read(wtap *wth, int *err, int *data_offset)
 {
 	guint32 rec_size;
 	guint32	packet_size;
 	guint32 orig_size;
-	int	data_offset;
 	int	bytes_read;
 	struct snooprec_hdr hdr;
 	char	padbuf[4];
@@ -223,13 +222,10 @@ static int snoop_read(wtap *wth, int *err)
 	bytes_read = file_read(&hdr, 1, sizeof hdr, wth->fh);
 	if (bytes_read != sizeof hdr) {
 		*err = file_error(wth->fh);
-		if (*err != 0)
-			return -1;
-		if (bytes_read != 0) {
+		if (*err == 0 && bytes_read != 0) {
 			*err = WTAP_ERR_SHORT_READ;
-			return -1;
 		}
-		return 0;
+		return FALSE;
 	}
 	wth->data_offset += sizeof hdr;
 
@@ -244,10 +240,10 @@ static int snoop_read(wtap *wth, int *err)
 		g_message("snoop: File has %u-byte packet, bigger than maximum of %u",
 		    packet_size, WTAP_MAX_PACKET_SIZE);
 		*err = WTAP_ERR_BAD_RECORD;
-		return -1;
+		return FALSE;
 	}
 
-	data_offset = wth->data_offset;
+	*data_offset = wth->data_offset;
 
 	/*
 	 * If this is an ATM packet, the first four bytes are the
@@ -264,11 +260,11 @@ static int snoop_read(wtap *wth, int *err)
 			g_message("snoop: atmsnoop file has a %u-byte packet, too small to have even an ATM pseudo-header\n",
 			    packet_size);
 			*err = WTAP_ERR_BAD_RECORD;
-			return -1;
+			return FALSE;
 		}
 		if (snoop_read_atm_pseudoheader(wth->fh, &wth->pseudo_header,
 		    err) < 0)
-			return -1;	/* Read error */
+			return FALSE;	/* Read error */
 
 		/*
 		 * Don't count the pseudo-header as part of the packet.
@@ -282,7 +278,7 @@ static int snoop_read(wtap *wth, int *err)
 	buffer_assure_space(wth->frame_buffer, packet_size);
 	if (snoop_read_rec_data(wth->fh, buffer_start_ptr(wth->frame_buffer),
 	    packet_size, err) < 0)
-		return -1;	/* Read error */
+		return FALSE;	/* Read error */
 	wth->data_offset += packet_size;
 
 	wth->phdr.ts.tv_sec = ntohl(hdr.ts_sec);
@@ -309,13 +305,13 @@ static int snoop_read(wtap *wth, int *err)
 			*err = file_error(wth->fh);
 			if (*err == 0)
 				*err = WTAP_ERR_SHORT_READ;
-			return -1;
+			return FALSE;
 		}
 		wth->data_offset += bytes_read;
 		padbytes -= bytes_read;
 	}
 
-	return data_offset;
+	return TRUE;
 }
 
 static int