Ethernet: Rework the length checks

[tcpdump] / print-ether.c

diff --git a/print-ether.c b/print-ether.c
index 7a1b42e0b0c65e9e8fbe03df9bd23a9f0a80b2da..954668c4a2b5bf759a4ae478ada2a2f6c7912a03 100644 (file)
--- a/print-ether.c
+++ b/print-ether.c
@@ -27,6 +27,7 @@
 
 #include "netdissect-stdinc.h"
 
 
 #include "netdissect-stdinc.h"
 

+#define ND_LONGJMP_FROM_TCHECK

 #include "netdissect.h"
 #include "extract.h"
 #include "addrtoname.h"
 #include "netdissect.h"
 #include "extract.h"
 #include "addrtoname.h"


@@ -149,14 +150,15 @@ ether_common_print(netdissect_options *ndo, const u_char *p, u_int length,
        int llc_hdrlen;
        struct lladdr_info src, dst;
 
        int llc_hdrlen;
        struct lladdr_info src, dst;
 

+       if (length < caplen) {
+               ND_PRINT("[length %u < caplen %u]", length, caplen);
+               nd_print_invalid(ndo);
+               return length;
+       }

        if (caplen < ETHER_HDRLEN + switch_tag_len) {
                nd_print_trunc(ndo);
                return caplen;
        }
        if (caplen < ETHER_HDRLEN + switch_tag_len) {
                nd_print_trunc(ndo);
                return caplen;
        }

-       if (length < ETHER_HDRLEN + switch_tag_len) {
-               nd_print_trunc(ndo);
-               return length;
-       }

 
        if (print_encap_header != NULL)
                (*print_encap_header)(ndo, encap_header_arg);
 
        if (print_encap_header != NULL)
                (*print_encap_header)(ndo, encap_header_arg);


@@ -474,11 +476,7 @@ netanalyzer_if_print(netdissect_options *ndo, const struct pcap_pkthdr *h,
         * Fail if we don't have enough data for the Hilscher pseudo-header.
         */
        ndo->ndo_protocol = "netanalyzer";
         * Fail if we don't have enough data for the Hilscher pseudo-header.
         */
        ndo->ndo_protocol = "netanalyzer";

-       if (h->caplen < 4) {
-               ndo->ndo_ll_hdr_len += h->caplen;
-               nd_print_trunc(ndo);
-               return;
-       }
+       ND_TCHECK_LEN(p, 4);

 
        /* Skip the pseudo-header. */
        ndo->ndo_ll_hdr_len += 4;
 
        /* Skip the pseudo-header. */
        ndo->ndo_ll_hdr_len += 4;


@@ -506,11 +504,7 @@ netanalyzer_transparent_if_print(netdissect_options *ndo,
         * preamble, and SOF.
         */
        ndo->ndo_protocol = "netanalyzer_transparent";
         * preamble, and SOF.
         */
        ndo->ndo_protocol = "netanalyzer_transparent";

-       if (h->caplen < 12) {
-               ndo->ndo_ll_hdr_len += h->caplen;
-               nd_print_trunc(ndo);
-               return;
-       }
+       ND_TCHECK_LEN(p, 12);

 
        /* Skip the pseudo-header, preamble, and SOF. */
        ndo->ndo_ll_hdr_len += 12;
 
        /* Skip the pseudo-header, preamble, and SOF. */
        ndo->ndo_ll_hdr_len += 12;


@@ -571,6 +565,9 @@ ethertype_print(netdissect_options *ndo,
                        nd_print_trunc(ndo);
                        return (1);
                }
                        nd_print_trunc(ndo);
                        return (1);
                }

+               /* At least one byte is required */
+               /* FIXME: Reference for this byte? */
+               ND_TCHECK_1(p);

                isoclns_print(ndo, p + 1, length - 1);
                return(1);
 
                isoclns_print(ndo, p + 1, length - 1);
                return(1);