Put "atm_llc_print()" back - we want to handle the case of the Ethernet

type not being known, *and* have to pass in a non-null
"extracted_ethertype" pointer (otherwise "llc_print()" dumps core), and
we should pass in non-null pointers for the source and destination
addresses.  However, we can get rid of the "ether_type" variable.

Fix up the test for non-LLC packets to test for the first 3 bytes *not*
matching the header of an LLC/SNAP packet, not for them matching.  Add
in a check for RFC 2684 routed NLPID-formatted PDUs.

diff --git a/print-atm.c b/print-atm.c
index 189831a652531db092f79c3a437f7a9ebec26a67..74f19a858b16278ef2de577e66433a351d811a48 100644 (file)
--- a/print-atm.c
+++ b/print-atm.c
@@ -20,7 +20,7 @@
  */
 #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)";
+    "@(#) $Header: /tcpdump/master/tcpdump/print-atm.c,v 1.28 2002-12-09 05:12:25 guy Exp $ (LBL)";
 #endif
 
 #ifdef HAVE_CONFIG_H
@@ -42,6 +42,44 @@ static const char rcsid[] =
 
 #include "ether.h"
 
+/*
+ * Print an RFC 1483 LLC-encapsulated ATM frame.
+ */
+static void
+atm_llc_print(const u_char *p, int length, int caplen)
+{
+       struct ether_header ehdr;
+       u_short extracted_ethertype;
+
+       /*
+        * Fake up an Ethernet header for the benefit of printers that
+        * insist on "packetp" pointing to an Ethernet header.
+        */
+       memset(&ehdr, '\0', sizeof ehdr);
+
+       /*
+        * Some printers want to get back at the ethernet addresses.
+        * Rather than pass it all the way down, we set this global.
+        *
+        * Actually, the only printers that use packetp are print-arp.c
+        * and print-bootp.c, and they assume that packetp points to an
+        * Ethernet header.  The right thing to do is to fix them to know
+        * which link type is in use when they excavate. XXX
+        */
+       packetp = (u_char *)&ehdr;
+
+       if (!llc_print(p, length, caplen, ESRC(&ehdr), EDST(&ehdr),
+           &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);
+       }
+}
+
 /*
  * This is the top level routine of the printer.  'p' points
  * to the LLC/SNAP header of the packet, 'h->ts' is the timestamp,
@@ -53,6 +91,7 @@ atm_if_print(u_char *user _U_, const struct pcap_pkthdr *h, const u_char *p)
 {
        u_int caplen = h->caplen;
        u_int length = h->len;
+       u_int32_t llchdr;
 
        ++infodelay;
        ts_print(&h->ts);
@@ -69,12 +108,16 @@ atm_if_print(u_char *user _U_, const struct pcap_pkthdr *h, const u_char *p)
         */
        snapend = p + caplen;
 
-       if (EXTRACT_24BITS(p) == 0xaaaa03) {
+       /*
+        * 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.
+        */
+       llchdr = EXTRACT_24BITS(p);
+       if (llchdr != 0xaaaa03 && llchdr != 0xfefe03) {
                /*
                 * 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?
                 */
                if (eflag)
                        printf("%08x%08x %08x%08x ",
@@ -86,10 +129,7 @@ atm_if_print(u_char *user _U_, const struct pcap_pkthdr *h, const u_char *p)
                length -= 20;
                caplen -= 20;
        }
-
-        /* lets call into the generic LLC handler */
-       llc_print(p, length, caplen, NULL, NULL, NULL);
-
+       atm_llc_print(p, length, caplen);
        if (xflag)
                default_print(p, caplen);
  out: