If the Windows Sniffer writes out one of its ATM capture files in DOS

Sniffer format, it doesn't distinguish between LE Control and LANE
encapsulated LAN frames, so we can't rely on the ATM subtype being
correct even when reading DOS Sniffer captures - we force it to
TRAF_ST_LANE_LE_CTRL for LANE frames that begin with 0xff 0x00.

Move the calls to "infer_pkt_encap()" into "fix_pseudo_header()".

svn path=/trunk/; revision=6869

1 files changed, 57 insertions, 52 deletions

diff --git a/wiretap/ngsniffer.c b/wiretap/ngsniffer.c
index f3f707ca99..24aa93383a 100644
--- a/wiretap/ngsniffer.c
+++ b/wiretap/ngsniffer.c
@@ -1,6 +1,6 @@
 /* ngsniffer.c
  *
- * $Id: ngsniffer.c,v 1.100 2003/01/06 00:03:43 guy Exp $
+ * $Id: ngsniffer.c,v 1.101 2003/01/07 06:46:50 guy Exp $
  *
  * Wiretap Library
  * Copyright (c) 1998 by Gilbert Ramirez <gram@alumni.rice.edu>
@@ -64,6 +64,7 @@
 #include "wtap-int.h"
 #include "file_wrappers.h"
 #include "buffer.h"
+#include "atm.h"
 #include "ngsniffer.h"
 
 /* Magic number in Sniffer files. */
@@ -379,7 +380,8 @@ static void set_pseudo_header_frame6(union wtap_pseudo_header *pseudo_header,
 static gboolean ngsniffer_read_rec_data(wtap *wth, gboolean is_random,
     guchar *pd, int length, int *err);
 static int infer_pkt_encap(const guint8 *pd, int len);
-static void fix_pseudo_header(int, union wtap_pseudo_header *pseudo_header);
+static int fix_pseudo_header(int encap, const guint8 *pd, int len,
+    union wtap_pseudo_header *pseudo_header);
 static void ngsniffer_sequential_close(wtap *wth);
 static void ngsniffer_close(wtap *wth);
 static gboolean ngsniffer_dump(wtap_dumper *wdh, const struct wtap_pkthdr *phdr,
@@ -987,21 +989,9 @@ found:
 		return FALSE;	/* Read error */
 	wth->data_offset += length;
 
+	pkt_encap = fix_pseudo_header(pkt_encap, pd, length,
+	    &wth->pseudo_header);
 	wth->phdr.pkt_encap = pkt_encap;
-	if (pkt_encap == WTAP_ENCAP_PER_PACKET) {
-		/*
-		 * Infer the packet type from the first byte.
-		 */
-		wth->phdr.pkt_encap = infer_pkt_encap(pd, length);
-
-		/*
-		 * Fix up the pseudo-header; we may have set
-		 * "x25.flags", but, for some traffic, we should
-		 * set "isdn.uton" instead, and set the channel
-		 * number.
-		 */
-		fix_pseudo_header(wth->phdr.pkt_encap, &wth->pseudo_header);
-	}
 
 	t = t/1000000.0 * wth->capture.ngsniffer->timeunit; /* t = # of secs */
 	t += wth->capture.ngsniffer->start;
@@ -1088,20 +1078,7 @@ static gboolean ngsniffer_seek_read(wtap *wth, long seek_off,
 	if (!ngsniffer_read_rec_data(wth, TRUE, pd, packet_size, err))
 		return FALSE;
 
-	if (pkt_encap == WTAP_ENCAP_PER_PACKET) {
-		/*
-		 * Infer the packet type from the first two bytes.
-		 */
-		pkt_encap = infer_pkt_encap(pd, packet_size);
-
-		/*
-		 * Fix up the pseudo-header; we may have set
-		 * "x25.flags", but, for some traffic, we should
-		 * set "isdn.uton" instead, and set the channel
-		 * number.
-		 */
-		fix_pseudo_header(pkt_encap, pseudo_header);
-	}
+	fix_pseudo_header(pkt_encap, pd, packet_size, pseudo_header);
 
 	return TRUE;
 }
@@ -1632,38 +1609,66 @@ static int infer_pkt_encap(const guint8 *pd, int len)
 	}
 }
 
-static void fix_pseudo_header(int encap,
+static int fix_pseudo_header(int encap, const guint8 *pd, int len,
     union wtap_pseudo_header *pseudo_header)
 {
 	switch (encap) {
 
-	case WTAP_ENCAP_WFLEET_HDLC:
-	case WTAP_ENCAP_CHDLC:
-	case WTAP_ENCAP_PPP_WITH_PHDR:
-		if (pseudo_header->x25.flags == 0)
-			pseudo_header->p2p.sent = TRUE;
-		else
-			pseudo_header->p2p.sent = FALSE;
-		break;
+	case WTAP_ENCAP_PER_PACKET:
+		/*
+		 * Infer the packet type from the first two bytes.
+		 */
+		encap = infer_pkt_encap(pd, len);
 
-	case WTAP_ENCAP_ISDN:
-		if (pseudo_header->x25.flags == 0x00)
-			pseudo_header->isdn.uton = FALSE;
-		else
-			pseudo_header->isdn.uton = TRUE;
+		/*
+		 * Fix up the pseudo-header to match the new
+		 * encapsulation type.
+		 */
+		switch (encap) {
+
+		case WTAP_ENCAP_WFLEET_HDLC:
+		case WTAP_ENCAP_CHDLC:
+		case WTAP_ENCAP_PPP_WITH_PHDR:
+			if (pseudo_header->x25.flags == 0)
+				pseudo_header->p2p.sent = TRUE;
+			else
+				pseudo_header->p2p.sent = FALSE;
+			break;
+
+		case WTAP_ENCAP_ISDN:
+			if (pseudo_header->x25.flags == 0x00)
+				pseudo_header->isdn.uton = FALSE;
+			else
+				pseudo_header->isdn.uton = TRUE;
+
+			/*
+			 * XXX - this is currently a per-packet
+			 * encapsulation type, and we can't determine
+			 * whether a capture is an ISDN capture before
+			 * seeing any packets, and B-channel PPP packets
+			 * look like PPP packets and are given
+			 * WTAP_ENCAP_PPP_WITH_PHDR, not WTAP_ENCAP_ISDN,
+			 * so we assume this is a D-channel packet and
+			 * thus give it a channel number of 0.
+			 */
+			pseudo_header->isdn.channel = 0;
+			break;
+		}
+		break;
 
+	case WTAP_ENCAP_ATM_PDUS:
 		/*
-		 * XXX - this is currently a per-packet encapsulation
-		 * type, and we can't determine whether a capture is
-		 * an ISDN capture before seeing any packets, and
-		 * B-channel PPP packets look like PPP packets and
-		 * are given WTAP_ENCAP_PPP_WITH_PHDR, not
-		 * WTAP_ENCAP_ISDN, so we assume this is a D-channel
-		 * packet and thus give it a channel number of 0.
+		 * If the Windows Sniffer writes out one of its ATM
+		 * capture files in DOS Sniffer format, it doesn't
+		 * distinguish between LE Control and LANE encapsulated
+		 * LAN frames, so we fix that up here.
 		 */
-		pseudo_header->isdn.channel = 0;
+		if (pseudo_header->atm.type == TRAF_LANE && len >= 2 &&
+		    pd[0] == 0xff && pd[1] == 0x00)
+			pseudo_header->atm.subtype = TRAF_ST_LANE_LE_CTRL;
 		break;
 	}
+	return encap;
 }
 
 /* Throw away the buffers used by the sequential I/O stream, but not