NULL/LOOP: Add a bounds check

[tcpdump] / print-null.c

diff --git a/print-null.c b/print-null.c
index 22754f587f42919b35ca796cbd3a4ed2a8a6fcd4..f1067ff5ca1d673560b0a7aad96b0026f786e125 100644 (file)
--- a/print-null.c
+++ b/print-null.c
@@ -19,24 +19,22 @@
  * MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE.
  */
 
+/* \summary: BSD loopback device printer */
+
 #ifdef HAVE_CONFIG_H
-#include "config.h"
+#include <config.h>
 #endif
 
-#include <tcpdump-stdinc.h>
+#include "netdissect-stdinc.h"
 
-#include <pcap.h>
-#include <stdio.h>
 #include <string.h>
 
-#include "interface.h"
-
-#include "ip.h"
-#ifdef INET6
-#include "ip6.h"
-#endif
+#include "netdissect.h"
+#include "extract.h"
 #include "af.h"
 
+static const char tstr[] = " [|null]";
+
 /*
  * The DLT_NULL packet header is 4 bytes long. It contains a host-byte-order
  * 32-bit integer that specifies the family, e.g. AF_INET.
@@ -57,18 +55,18 @@
 #define        SWAPLONG(y) \
 ((((y)&0xff)<<24) | (((y)&0xff00)<<8) | (((y)&0xff0000)>>8) | (((y)>>24)&0xff))
 
-static inline void
-null_hdr_print(u_int family, u_int length)
+static void
+null_hdr_print(netdissect_options *ndo, u_int family, u_int length)
 {
-       if (!qflag) {
-               (void)printf("AF %s (%u)",
+       if (!ndo->ndo_qflag) {
+               ND_PRINT("AF %s (%u)",
                        tok2str(bsd_af_values,"Unknown",family),family);
        } else {
-               (void)printf("%s",
+               ND_PRINT("%s",
                        tok2str(bsd_af_values,"Unknown AF %u",family));
        }
 
-       (void)printf(", length %u: ", length);
+       ND_PRINT(", length %u: ", length);
 }
 
 /*
@@ -78,18 +76,17 @@ null_hdr_print(u_int family, u_int length)
  * is the number of bytes actually captured.
  */
 u_int
-null_if_print(const struct pcap_pkthdr *h, const u_char *p)
+null_if_print(netdissect_options *ndo, const struct pcap_pkthdr *h, const u_char *p)
 {
        u_int length = h->len;
        u_int caplen = h->caplen;
-       u_int family;
+       uint32_t family;
 
-       if (caplen < NULL_HDRLEN) {
-               printf("[|null]");
-               return (NULL_HDRLEN);
-       }
+       if (caplen < NULL_HDRLEN)
+               goto trunc;
 
-       memcpy((char *)&family, (char *)p, sizeof(family));
+       ND_TCHECK_4(p);
+       memcpy((char *)&family, (const char *)p, sizeof(family));
 
        /*
         * This isn't necessarily in our host byte order; if this is
@@ -102,8 +99,8 @@ null_if_print(const struct pcap_pkthdr *h, const u_char *p)
        if ((family & 0xFFFF0000) != 0)
                family = SWAPLONG(family);
 
-       if (eflag)
-               null_hdr_print(family, length);
+       if (ndo->ndo_eflag)
+               null_hdr_print(ndo, family, length);
 
        length -= NULL_HDRLEN;
        caplen -= NULL_HDRLEN;
@@ -112,37 +109,38 @@ null_if_print(const struct pcap_pkthdr *h, const u_char *p)
        switch (family) {
 
        case BSD_AFNUM_INET:
-               ip_print(gndo, p, length);
+               ip_print(ndo, p, length);
                break;
 
-#ifdef INET6
        case BSD_AFNUM_INET6_BSD:
        case BSD_AFNUM_INET6_FREEBSD:
        case BSD_AFNUM_INET6_DARWIN:
-               ip6_print(gndo, p, length);
+               ip6_print(ndo, p, length);
                break;
-#endif
 
        case BSD_AFNUM_ISO:
-               isoclns_print(p, length, caplen);
+               isoclns_print(ndo, p, length);
                break;
 
        case BSD_AFNUM_APPLETALK:
-               atalk_print(p, length);
+               atalk_print(ndo, p, length);
                break;
 
        case BSD_AFNUM_IPX:
-               ipx_print(p, length);
+               ipx_print(ndo, p, length);
                break;
 
        default:
                /* unknown AF_ value */
-               if (!eflag)
-                       null_hdr_print(family, length + NULL_HDRLEN);
-               if (!suppress_default_print)
-                       default_print(p, caplen);
+               if (!ndo->ndo_eflag)
+                       null_hdr_print(ndo, family, length + NULL_HDRLEN);
+               if (!ndo->ndo_suppress_default_print)
+                       ND_DEFAULTPRINT(p, caplen);
        }
 
+       return (NULL_HDRLEN);
+trunc:
+       ND_PRINT("%s", tstr);
        return (NULL_HDRLEN);
 }