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, 43 insertions, 26 deletions

diff --git a/wiretap/wtap.c b/wiretap/wtap.c
index 4a79760390..dd6a34e39e 100644
--- a/wiretap/wtap.c
+++ b/wiretap/wtap.c
@@ -1,6 +1,6 @@
 /* wtap.c
  *
- * $Id: wtap.c,v 1.46 2000/08/19 18:31:23 deniel Exp $
+ * $Id: wtap.c,v 1.47 2000/09/07 05:34:22 gram Exp $
  *
  * Wiretap Library
  * Copyright (c) 1998 by Gilbert Ramirez <gram@xiexie.org>
@@ -30,27 +30,32 @@
 #include "file_wrappers.h"
 #include "buffer.h"
 
-FILE* wtap_file(wtap *wth)
+FILE*
+wtap_file(wtap *wth)
 {
 	return wth->fh;
 }
 
-int wtap_fd(wtap *wth)
+int
+wtap_fd(wtap *wth)
 {
 	return wth->fd;
 }
 
-int wtap_file_type(wtap *wth)
+int
+wtap_file_type(wtap *wth)
 {
 	return wth->file_type;
 }
 
-int wtap_snapshot_length(wtap *wth)
+int
+wtap_snapshot_length(wtap *wth)
 {
 	return wth->snapshot_length;
 }
 
-int wtap_file_encap(wtap *wth)
+int
+wtap_file_encap(wtap *wth)
 {
 	return wth->file_encap;
 }
@@ -113,7 +118,8 @@ const static struct encap_type_info {
 };
 
 /* Name that should be somewhat descriptive. */
-const char *wtap_encap_string(int encap)
+const char
+*wtap_encap_string(int encap)
 {
 	if (encap < 0 || encap >= WTAP_NUM_ENCAP_TYPES)
 		return NULL;
@@ -122,7 +128,8 @@ const char *wtap_encap_string(int encap)
 }
 
 /* Name to use in, say, a command-line flag specifying the type. */
-const char *wtap_encap_short_string(int encap)
+const char
+*wtap_encap_short_string(int encap)
 {
 	if (encap < 0 || encap >= WTAP_NUM_ENCAP_TYPES)
 		return NULL;
@@ -131,7 +138,8 @@ const char *wtap_encap_short_string(int encap)
 }
 
 /* Translate a short name to a capture file type. */
-int wtap_short_string_to_encap(const char *short_name)
+int
+wtap_short_string_to_encap(const char *short_name)
 {
 	int encap;
 
@@ -162,7 +170,8 @@ static const char *wtap_errlist[] = {
 };
 #define	WTAP_ERRLIST_SIZE	(sizeof wtap_errlist / sizeof wtap_errlist[0])
 
-const char *wtap_strerror(int err)
+const char
+*wtap_strerror(int err)
 {
 	static char errbuf[128];
 	int wtap_errlist_index;
@@ -196,7 +205,8 @@ const char *wtap_strerror(int err)
    
    Instead, if the subtype has a "sequential close" function, we call it,
    to free up stuff used only by the sequential side. */
-void wtap_sequential_close(wtap *wth)
+void
+wtap_sequential_close(wtap *wth)
 {
 	if (wth->subtype_sequential_close != NULL)
 		(*wth->subtype_sequential_close)(wth);
@@ -213,7 +223,8 @@ void wtap_sequential_close(wtap *wth)
 	}
 }
 
-void wtap_close(wtap *wth)
+void
+wtap_close(wtap *wth)
 {
 	wtap_sequential_close(wth);
 
@@ -226,47 +237,53 @@ void wtap_close(wtap *wth)
 	g_free(wth);
 }
 
-int wtap_read(wtap *wth, int *err)
+gboolean
+wtap_read(wtap *wth, int *err, int *data_offset)
 {
-	return wth->subtype_read(wth, err);
+	return wth->subtype_read(wth, err, data_offset);
 }
 
-struct wtap_pkthdr *wtap_phdr(wtap *wth)
+struct wtap_pkthdr*
+wtap_phdr(wtap *wth)
 {
 	return &wth->phdr;
 }
 
-union wtap_pseudo_header *wtap_pseudoheader(wtap *wth)
+union wtap_pseudo_header*
+wtap_pseudoheader(wtap *wth)
 {
 	return &wth->pseudo_header;
 }
 
-guint8 *wtap_buf_ptr(wtap *wth)
+guint8*
+wtap_buf_ptr(wtap *wth)
 {
 	return buffer_start_ptr(wth->frame_buffer);
 }
 
-int wtap_loop(wtap *wth, int count, wtap_handler callback, u_char* user,
-	int *err)
+gboolean
+wtap_loop(wtap *wth, int count, wtap_handler callback, u_char* user, int *err)
 {
-	int data_offset, loop = 0;
+	int		data_offset, loop = 0;
 
-	/* Start be clearing error flag */
+	/* Start by clearing error flag */
 	*err = 0;
 
-	while ((data_offset = wtap_read(wth, err)) > 0) {
+	while ( (wtap_read(wth, err, &data_offset)) ) {
 		callback(user, &wth->phdr, data_offset,
 		    &wth->pseudo_header, buffer_start_ptr(wth->frame_buffer));
 		if (count > 0 && ++loop >= count)
 			break;
 	}
-	if (data_offset < 0)
-		return FALSE;	/* failure */
-	else
+
+	if (*err == 0)
 		return TRUE;	/* success */
+	else
+		return FALSE;	/* failure */
 }
 
-int wtap_seek_read(wtap *wth, int seek_off,
+int
+wtap_seek_read(wtap *wth, int seek_off,
 	union wtap_pseudo_header *pseudo_header, guint8 *pd, int len)
 {
 	return wth->subtype_seek_read(wth, seek_off, pseudo_header, pd, len);