Skip the LLC and SNAP headers with -x.

[tcpdump] / print-sll.c

diff --git a/print-sll.c b/print-sll.c
index e15afa9e44663b665eeaf6cae0df56d1236b4e59..916946938fddf734f1ccf46ddcae07df3dc4540c 100644 (file)
--- a/print-sll.c
+++ b/print-sll.c
@@ -197,6 +197,8 @@ sll_if_print(netdissect_options *ndo, const struct pcap_pkthdr *h, const u_char
        u_int length = h->len;
        register const struct sll_header *sllp;
        u_short ether_type;
+       int llc_hdrlen;
+       u_int hdrlen;
 
        if (caplen < SLL_HDR_LEN) {
                /*
@@ -219,6 +221,7 @@ sll_if_print(netdissect_options *ndo, const struct pcap_pkthdr *h, const u_char
        length -= SLL_HDR_LEN;
        caplen -= SLL_HDR_LEN;
        p += SLL_HDR_LEN;
+       hdrlen = SLL_HDR_LEN;
 
        ether_type = EXTRACT_16BITS(&sllp->sll_protocol);
 
@@ -245,8 +248,10 @@ recurse:
                         * 802.2.
                         * Try to print the LLC-layer header & higher layers.
                         */
-                       if (llc_print(ndo, p, length, caplen, NULL, NULL) == 0)
+                       llc_hdrlen = llc_print(ndo, p, length, caplen, NULL, NULL);
+                       if (llc_hdrlen < 0)
                                goto unknown;   /* unknown LLC type */
+                       hdrlen += llc_hdrlen;
                        break;
 
                default:
@@ -263,9 +268,13 @@ recurse:
                 * Print VLAN information, and then go back and process
                 * the enclosed type field.
                 */
-               if (caplen < 4 || length < 4) {
+               if (caplen < 4) {
                        ND_PRINT((ndo, "[|vlan]"));
-                       return (SLL_HDR_LEN);
+                       return (hdrlen + caplen);
+               }
+               if (length < 4) {
+                       ND_PRINT((ndo, "[|vlan]"));
+                       return (hdrlen + length);
                }
                if (ndo->ndo_eflag) {
                        uint16_t tag = EXTRACT_16BITS(p);
@@ -283,6 +292,7 @@ recurse:
                p += 4;
                length -= 4;
                caplen -= 4;
+               hdrlen += 4;
                goto recurse;
        } else {
                if (ethertype_print(ndo, ether_type, p, length, caplen) == 0) {
@@ -294,5 +304,5 @@ recurse:
                }
        }
 
-       return (SLL_HDR_LEN);
+       return (hdrlen);
 }