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 2f05c3873d210423c7e61d6b6b4ea92a00e7543c..3cefef33aeb4f8578138e81e49e857b623aa3a9f 100644 (file)
--- a/print-ascii.c
+++ b/print-ascii.c
@@ -36,6 +36,7 @@
  * POSSIBILITY OF SUCH DAMAGE.
  */
 
+#define NETDISSECT_REWORKED
 #ifdef HAVE_CONFIG_H
 #include "config.h"
 #endif
@@ -43,7 +44,6 @@
 #include <tcpdump-stdinc.h>
 #include <stdio.h>
 
-#include "netdissect.h"
 #include "interface.h"
 
 #define ASCII_LINELENGTH 300
@@ -54,11 +54,16 @@
                (HEXDUMP_HEXSTUFF_PER_SHORT * HEXDUMP_SHORTS_PER_LINE)
 
 void
-ascii_print(register const u_char *cp, register u_int length)
+ascii_print(netdissect_options *ndo,
+            const u_char *cp, u_int length)
 {
-       register int s;
+       u_int caplength;
+       register u_char s;
 
-       putchar('\n');
+       caplength = (ndo->ndo_snapend >= cp) ? ndo->ndo_snapend - cp : 0;
+       if (length > caplength)
+               length = caplength;
+       ND_PRINT((ndo, "\n"));
        while (length > 0) {
                s = *cp++;
                length--;
@@ -73,13 +78,13 @@ ascii_print(register const u_char *cp, register u_int length)
                         * In the middle of a line, just print a '.'.
                         */
                        if (length > 1 && *cp != '\n')
-                               putchar('.');
+                               ND_PRINT((ndo, "."));
                } else {
                        if (!ND_ISGRAPH(s) &&
                            (s != '\t' && s != ' ' && s != '\n'))
-                               putchar('.');
+                               ND_PRINT((ndo, "."));
                        else
-                               putchar(s);
+                               ND_PRINT((ndo, "%c", s));
                }
        }
 }
@@ -88,12 +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;
@@ -146,9 +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) {