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 9315edd2e3278fcd469d371e257d92286a8b0dd4..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
@@ -54,32 +54,55 @@
                (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--;
-               if (!isgraph(s) &&
-                   (s != '\t' && s != ' ' && s != '\n' && s != '\r'))
-                       putchar('.');
-               else
-                       putchar(s);
+               if (s == '\r') {
+                       /*
+                        * Don't print CRs at the end of the line; they
+                        * don't belong at the ends of lines on UN*X,
+                        * and the standard I/O library will give us one
+                        * on Windows so we don't need to print one
+                        * ourselves.
+                        *
+                        * In the middle of a line, just print a '.'.
+                        */
+                       if (length > 1 && *cp != '\n')
+                               ND_PRINT((ndo, "."));
+               } else {
+                       if (!ND_ISGRAPH(s) &&
+                           (s != '\t' && s != ' ' && s != '\n'))
+                               ND_PRINT((ndo, "."));
+                       else
+                               ND_PRINT((ndo, "%c", s));
+               }
        }
 }
 
 void
-hex_and_ascii_print_with_offset(register const char *ident,
+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;
@@ -89,14 +112,14 @@ hex_and_ascii_print_with_offset(register const char *ident,
                (void)snprintf(hsp, sizeof(hexstuff) - (hsp - hexstuff),
                    " %02x%02x", s1, s2);
                hsp += HEXDUMP_HEXSTUFF_PER_SHORT;
-               *(asp++) = (isgraph(s1) ? s1 : '.');
-               *(asp++) = (isgraph(s2) ? s2 : '.');
+               *(asp++) = (ND_ISGRAPH(s1) ? s1 : '.');
+               *(asp++) = (ND_ISGRAPH(s2) ? s2 : '.');
                i++;
                if (i >= HEXDUMP_SHORTS_PER_LINE) {
                        *hsp = *asp = '\0';
-                       (void)printf("%s0x%04x: %-*s  %s",
+                       ND_PRINT((ndo, "%s0x%04x: %-*s  %s",
                            ident, oset, HEXDUMP_HEXSTUFF_PER_LINE,
-                           hexstuff, asciistuff);
+                           hexstuff, asciistuff));
                        i = 0; hsp = hexstuff; asp = asciistuff;
                        oset += HEXDUMP_BYTES_PER_LINE;
                }
@@ -106,22 +129,22 @@ hex_and_ascii_print_with_offset(register const char *ident,
                (void)snprintf(hsp, sizeof(hexstuff) - (hsp - hexstuff),
                    " %02x", s1);
                hsp += 3;
-               *(asp++) = (isgraph(s1) ? s1 : '.');
+               *(asp++) = (ND_ISGRAPH(s1) ? s1 : '.');
                ++i;
        }
        if (i > 0) {
                *hsp = *asp = '\0';
-               (void)printf("%s0x%04x: %-*s  %s",
+               ND_PRINT((ndo, "%s0x%04x: %-*s  %s",
                     ident, oset, HEXDUMP_HEXSTUFF_PER_LINE,
-                    hexstuff, asciistuff);
+                    hexstuff, asciistuff));
        }
 }
 
 void
-hex_and_ascii_print(register const char *ident, register const u_char *cp,
-    register u_int length)
+hex_and_ascii_print(netdissect_options *ndo, register const char *ident,
+    register const u_char *cp, register u_int length)
 {
-       hex_and_ascii_print_with_offset(ident, cp, length, 0);
+       hex_and_ascii_print_with_offset(ndo, ident, cp, length, 0);
 }
 
 /*
@@ -132,23 +155,27 @@ 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) {
                if ((i++ % 8) == 0) {
-                  (void)ND_PRINT((ndo,"%s0x%04x: ", ident, oset));
-                  oset += HEXDUMP_BYTES_PER_LINE;
+                       ND_PRINT((ndo,"%s0x%04x: ", ident, oset));
+                       oset += HEXDUMP_BYTES_PER_LINE;
                }
                s = *cp++;
-               (void)ND_PRINT((ndo," %02x%02x", s, *cp++));
+               ND_PRINT((ndo," %02x%02x", s, *cp++));
        }
        if (length & 1) {
                if ((i % 8) == 0)
-                  (void)ND_PRINT((ndo,"%s0x%04x: ", ident, oset));
-               (void)ND_PRINT((ndo," %02x", *cp));
+                       ND_PRINT((ndo,"%s0x%04x: ", ident, oset));
+               ND_PRINT((ndo," %02x", *cp));
        }
 }