Don't run past the snapshot length when doing hex/ASCII dumps.

[tcpdump] / print-ascii.c

diff --git a/print-ascii.c b/print-ascii.c
index f83d401a801f05e85352823bb22f1fc89108549a..3cefef33aeb4f8578138e81e49e857b623aa3a9f 100644 (file)
--- a/print-ascii.c
+++ b/print-ascii.c
@@ -55,10 +55,14 @@
 
 void
 ascii_print(netdissect_options *ndo,
-            register const u_char *cp, register u_int length)
+            const u_char *cp, u_int length)
 {
+       u_int caplength;
        register u_char s;
 
+       caplength = (ndo->ndo_snapend >= cp) ? ndo->ndo_snapend - cp : 0;
+       if (length > caplength)
+               length = caplength;
        ND_PRINT((ndo, "\n"));
        while (length > 0) {
                s = *cp++;
@@ -89,12 +93,16 @@ void
 hex_and_ascii_print_with_offset(netdissect_options *ndo, register const char *ident,
     register const u_char *cp, register u_int length, register u_int oset)
 {
+       u_int caplength;
        register u_int i;
        register int s1, s2;
        register int nshorts;
        char hexstuff[HEXDUMP_SHORTS_PER_LINE*HEXDUMP_HEXSTUFF_PER_SHORT+1], *hsp;
        char asciistuff[ASCII_LINELENGTH+1], *asp;
 
+       caplength = (ndo->ndo_snapend >= cp) ? ndo->ndo_snapend - cp : 0;
+       if (length > caplength)
+               length = caplength;
        nshorts = length / sizeof(u_short);
        i = 0;
        hsp = hexstuff; asp = asciistuff;
@@ -147,9 +155,13 @@ hex_print_with_offset(netdissect_options *ndo,
                       const char *ident, const u_char *cp, u_int length,
                      u_int oset)
 {
+       u_int caplength;
        register u_int i, s;
        register int nshorts;
 
+       caplength = (ndo->ndo_snapend >= cp) ? ndo->ndo_snapend - cp : 0;
+       if (length > caplength)
+               length = caplength;
        nshorts = (u_int) length / sizeof(u_short);
        i = 0;
        while (--nshorts >= 0) {