* MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE.
*/
#ifndef lint
-static const char rcsid[] =
- "@(#) $Header: /tcpdump/master/tcpdump/print-atm.c,v 1.27 2002-12-04 19:12:39 hannes Exp $ (LBL)";
+static const char rcsid[] _U_ =
+ "@(#) $Header: /tcpdump/master/tcpdump/print-atm.c,v 1.35 2003-11-16 09:36:13 guy Exp $ (LBL)";
#endif
#ifdef HAVE_CONFIG_H
#include "ethertype.h"
#include "atm.h"
#include "atmuni31.h"
+#include "llc.h"
#include "ether.h"
+/*
+ * Print an RFC 1483 LLC-encapsulated ATM frame.
+ */
+static void
+atm_llc_print(const u_char *p, int length, int caplen)
+{
+ u_short extracted_ethertype;
+
+ if (!llc_print(p, length, caplen, NULL, NULL,
+ &extracted_ethertype)) {
+ /* ether_type not known, print raw packet */
+ if (extracted_ethertype) {
+ printf("(LLC %s) ",
+ etherproto_string(htons(extracted_ethertype)));
+ }
+ if (!xflag && !qflag)
+ default_print(p, caplen);
+ }
+}
+
+/*
+ * Given a SAP value, generate the LLC header value for a UI packet
+ * with that SAP as the source and destination SAP.
+ */
+#define LLC_UI_HDR(sap) ((sap)<<16 | (sap<<8) | 0x03)
+
/*
* This is the top level routine of the printer. 'p' points
* to the LLC/SNAP header of the packet, 'h->ts' is the timestamp,
* 'h->length' is the length of the packet off the wire, and 'h->caplen'
* is the number of bytes actually captured.
*/
-void
-atm_if_print(u_char *user _U_, const struct pcap_pkthdr *h, const u_char *p)
+u_int
+atm_if_print(const struct pcap_pkthdr *h, const u_char *p)
{
u_int caplen = h->caplen;
u_int length = h->len;
-
- ++infodelay;
- ts_print(&h->ts);
+ u_int32_t llchdr;
+ u_int hdrlen = 0;
if (caplen < 8) {
printf("[|atm]");
- goto out;
+ return (caplen);
}
/*
- * Some printers want to check that they're not walking off the
- * end of the packet.
- * Rather than pass it all the way down, we set this global.
+ * Extract the presumed LLC header into a variable, for quick
+ * testing.
+ * Then check for a header that's neither a header for a SNAP
+ * packet nor an RFC 2684 routed NLPID-formatted PDU nor
+ * an 802.2-but-no-SNAP IP packet.
*/
- snapend = p + caplen;
-
- if (EXTRACT_24BITS(p) == 0xaaaa03) {
+ llchdr = EXTRACT_24BITS(p);
+ if (llchdr != LLC_UI_HDR(LLCSAP_SNAP) &&
+ llchdr != LLC_UI_HDR(LLCSAP_ISONS) &&
+ llchdr != LLC_UI_HDR(LLCSAP_IP)) {
/*
* XXX - assume 802.6 MAC header from Fore driver.
- * XXX - should we also assume it's not a MAC header
- * if it begins with 0xfe 0xfe 0x03, for RFC 2684
- * routed NLPID-formatted PDUs?
+ *
+ * Unfortunately, the above list doesn't check for
+ * all known SAPs, doesn't check for headers where
+ * the source and destination SAP aren't the same,
+ * and doesn't check for non-UI frames. It also
+ * runs the risk of an 802.6 MAC header that happens
+ * to begin with one of those values being
+ * incorrectly treated as an 802.2 header.
+ *
+ * So is that Fore driver still around? And, if so,
+ * is it still putting 802.6 MAC headers on ATM
+ * packets? If so, could it be changed to use a
+ * new DLT_IEEE802_6 value if we added it?
*/
if (eflag)
printf("%08x%08x %08x%08x ",
p += 20;
length -= 20;
caplen -= 20;
+ hdrlen += 20;
}
-
- /* lets call into the generic LLC handler */
- llc_print(p, length, caplen, NULL, NULL, NULL);
-
- if (xflag)
- default_print(p, caplen);
- out:
- putchar('\n');
+ atm_llc_print(p, length, caplen);
+ return (hdrlen);
}
/*
if (eflag)
printf("VPI:%u VCI:%u ", vpi, vci);
- /*
- * Some printers want to check that they're not walking off the
- * end of the packet.
- * Rather than pass it all the way down, we set this global.
- */
- snapend = p + caplen;
-
if (vpi == 0) {
switch (vci) {
case PPC:
sig_print(p, caplen);
- goto out;
+ return;
case BCC:
printf("broadcast sig: ");
- goto out;
+ return;
case OAMF4SC:
printf("oamF4(segment): ");
- goto out;
+ return;
case OAMF4EC:
printf("oamF4(end): ");
- goto out;
+ return;
case METAC:
printf("meta: ");
- goto out;
+ return;
case ILMIC:
printf("ilmi: ");
snmp_print(p, length);
- goto out;
+ return;
}
}
default:
/*
* Assumes traffic is LLC if unknown.
- * call into the generic LLC handler
*/
- llc_print(p, length, caplen, NULL, NULL, NULL);
+ atm_llc_print(p, length, caplen);
break;
case ATM_LANE:
lane_print(p, length, caplen);
break;
}
-
-out:
- if (xflag)
- default_print(p, caplen);
}
projects / tcpdump / blobdiff