Broadcom LI: Modernize packet parsing style.

Enable ND_LONGJMP_FROM_TCHECK. Add and use a standard invalid section.
Test bounds if not decoding the packet fully. Lose a variable, fixup
indentation and simplify some code.

diff --git a/print-bcm-li.c b/print-bcm-li.c
index b6877e231d468a6817fa3d9ccbeb4e0253ecd459..12b1ebbe20ccbb0b2934faacffab30fffb2d50dd 100644 (file)
--- a/print-bcm-li.c
+++ b/print-bcm-li.c
@@ -27,6 +27,7 @@
 
 #include "netdissect-stdinc.h"
 
+#define ND_LONGJMP_FROM_TCHECK
 #include "netdissect.h"
 #include "addrtoname.h"
 #include "extract.h"
@@ -61,16 +62,17 @@ static const struct tok bcm_li_pkt_subtype_values[] = {
 };
 
 void
-bcm_li_print(netdissect_options *ndo, const u_char *p, u_int length)
+bcm_li_print(netdissect_options *ndo,
+             const u_char *bp, u_int length)
 {
-    u_int shim, direction, pkt_type, pkt_subtype, li_id;
-       const u_char *bp = p;
+       u_int shim, direction, pkt_type, pkt_subtype, li_id;
 
        ndo->ndo_protocol = "bcm_li";
-       if (length < BCM_LI_SHIM_LEN)
-               goto trunc;
-       ND_TCHECK_LEN(p, BCM_LI_SHIM_LEN);
-       shim = GET_BE_U_4(p);
+       if (length < BCM_LI_SHIM_LEN) {
+           ND_PRINT(" (length %u < %u)", length, BCM_LI_SHIM_LEN);
+           goto invalid;
+       }
+       shim = GET_BE_U_4(bp);
 
        direction = (shim >> 29) & 0x7;
        pkt_type = (shim >> 25) & 0xf;
@@ -80,16 +82,16 @@ bcm_li_print(netdissect_options *ndo, const u_char *p, u_int length)
        length -= BCM_LI_SHIM_LEN;
        bp += BCM_LI_SHIM_LEN;
 
-       ND_PRINT("%sBCM-LI-SHIM: direction %s, pkt-type %s, pkt-subtype %s, li-id %u",
+       ND_PRINT("%sBCM-LI-SHIM: direction %s, pkt-type %s, pkt-subtype %s, li-id %u%s",
                 ndo->ndo_vflag ? "\n    " : "",
                 tok2str(bcm_li_direction_values, "unknown", direction),
                 tok2str(bcm_li_pkt_type_values, "unknown", pkt_type),
                 tok2str(bcm_li_pkt_subtype_values, "unknown", pkt_subtype),
-                li_id);
+                li_id,
+                ndo->ndo_vflag ? "\n    ": "");
 
-       if (ndo->ndo_vflag) {
-           ND_PRINT("\n    ");
-       } else {
+       if (!ndo->ndo_vflag) {
+           ND_TCHECK_LEN(bp, length);
            return;
        }
 
@@ -118,11 +120,11 @@ bcm_li_print(netdissect_options *ndo, const u_char *p, u_int length)
            break;
 
        default:
-           break;
+           goto invalid;
        }
 
        return;
-trunc:
-       nd_print_trunc(ndo);
+invalid:
+       nd_print_invalid(ndo);
 }