X-Git-Url: https://git.tcpdump.org/tcpdump/blobdiff_plain/cf53dc05f1c854cc8cb94afd3409bbf033a055ed..refs/heads/master:/print-null.c

diff --git a/print-null.c b/print-null.c
index d4affbbf..725d5839 100644
--- a/print-null.c
+++ b/print-null.c
@@ -19,122 +19,118 @@
  * MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE.
  */
 
-#ifndef lint
-static const char rcsid[] =
-    "@(#) $Header: /tcpdump/master/tcpdump/print-null.c,v 1.36 2000-09-29 04:58:44 guy Exp $ (LBL)";
-#endif
+/* \summary: BSD loopback device printer */
 
-#ifdef HAVE_CONFIG_H
-#include "config.h"
-#endif
+#include <config.h>
 
-#include <sys/param.h>
-#include <sys/time.h>
-#include <sys/socket.h>
-#include <sys/file.h>
-#include <sys/ioctl.h>
+#include "netdissect-stdinc.h"
 
-struct mbuf;
-struct rtentry;
+#define ND_LONGJMP_FROM_TCHECK
+#include "netdissect.h"
+#include "extract.h"
+#include "af.h"
 
-#include <netinet/in.h>
-
-#include <pcap.h>
-#include <stdio.h>
-#include <string.h>
-
-#ifdef INET6
-#include <netinet/ip6.h>
-#endif
-
-#include "interface.h"
-#include "addrtoname.h"
-
-#include "ip.h"
-
-#ifndef AF_NS
-#define AF_NS		6		/* XEROX NS protocols */
-#endif
 
 /*
- * The DLT_NULL packet header is 4 bytes long. It contains a network
- * order 32 bit integer that specifies the family, e.g. AF_INET
+ * 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.
+ *
+ * Note here that "host" refers to the host on which the packets were
+ * captured; that isn't necessarily *this* host.
+ *
+ * The OpenBSD DLT_LOOP packet header is the same, except that the integer
+ * is in network byte order.
  */
 #define	NULL_HDRLEN 4
 
+/*
+ * Byte-swap a 32-bit number.
+ * ("htonl()" or "ntohl()" won't work - we want to byte-swap even on
+ * big-endian platforms.)
+ */
+#define	SWAPLONG(y) \
+((((y)&0xff)<<24) | (((y)&0xff00)<<8) | (((y)&0xff0000)>>8) | (((y)>>24)&0xff))
+
 static void
-null_print(const u_char *p, const struct ip *ip, u_int length)
+null_hdr_print(netdissect_options *ndo, uint32_t family, u_int length)
 {
-	u_int family;
-
-	memcpy((char *)&family, (char *)p, sizeof(family));
-
-	if (nflag) {
-		/* XXX just dump the header */
-		return;
+	if (!ndo->ndo_qflag) {
+		ND_PRINT("AF %s (%u)",
+			tok2str(bsd_af_values,"Unknown",family),family);
+	} else {
+		ND_PRINT("%s",
+			tok2str(bsd_af_values,"Unknown AF %u",family));
 	}
-	switch (family) {
-
-	case AF_INET:
-		printf("ip: ");
-		break;
-
-#ifdef INET6
-	case AF_INET6:
-		printf("ip6: ");
-		break;
-#endif
-
-	case AF_NS:
-		printf("ns: ");
-		break;
 
-	default:
-		printf("AF %d: ", family);
-		break;
-	}
+	ND_PRINT(", length %u: ", length);
 }
 
+/*
+ * This is the top level routine of the printer.  'p' points
+ * to the ether header of the packet, 'h->ts' is the timestamp,
+ * 'h->len' is the length of the packet off the wire, and 'h->caplen'
+ * is the number of bytes actually captured.
+ */
 void
-null_if_print(u_char *user, 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;
-	const struct ip *ip;
+	uint32_t family;
 
-	ts_print(&h->ts);
+	ndo->ndo_protocol = "null";
+	ND_TCHECK_LEN(p, NULL_HDRLEN);
+	ndo->ndo_ll_hdr_len += NULL_HDRLEN;
+
+	family = GET_HE_U_4(p);
 
 	/*
-	 * Some printers want to get back at the link level addresses,
-	 * and/or check that they're not walking off the end of the packet.
-	 * Rather than pass them all the way down, we set these globals.
+	 * This isn't necessarily in our host byte order; if this is
+	 * a DLT_LOOP capture, it's in network byte order, and if
+	 * this is a DLT_NULL capture from a machine with the opposite
+	 * byte-order, it's in the opposite byte order from ours.
+	 *
+	 * If the upper 16 bits aren't all zero, assume it's byte-swapped.
 	 */
-	packetp = p;
-	snapend = p + caplen;
+	if ((family & 0xFFFF0000) != 0)
+		family = SWAPLONG(family);
+
+	if (ndo->ndo_eflag)
+		null_hdr_print(ndo, family, length);
 
 	length -= NULL_HDRLEN;
+	caplen -= NULL_HDRLEN;
+	p += NULL_HDRLEN;
+
+	switch (family) {
 
-	ip = (struct ip *)(p + NULL_HDRLEN);
+	case BSD_AF_INET:
+		ip_print(ndo, p, length);
+		break;
 
-	if (eflag)
-		null_print(p, ip, length);
+	case BSD_AF_INET6_BSD:
+	case BSD_AF_INET6_FREEBSD:
+	case BSD_AF_INET6_DARWIN:
+		ip6_print(ndo, p, length);
+		break;
 
-	switch (ip->ip_v) {
-	case 4:
-		ip_print((const u_char *)ip, length);
+	case BSD_AF_ISO:
+		isoclns_print(ndo, p, length);
 		break;
-#ifdef INET6
-	case 6:
-		ip6_print((const u_char *)ip, length);
+
+	case BSD_AF_APPLETALK:
+		atalk_print(ndo, p, length);
 		break;
-#endif /* INET6 */
-	default:
-		printf("ip v%d", ip->ip_v);
+
+	case BSD_AF_IPX:
+		ipx_print(ndo, p, length);
 		break;
-	}
 
-	if (xflag)
-		default_print((const u_char *)ip, caplen - NULL_HDRLEN);
-	putchar('\n');
+	default:
+		/* unknown AF_ value */
+		if (!ndo->ndo_eflag)
+			null_hdr_print(ndo, family, length + NULL_HDRLEN);
+		if (!ndo->ndo_suppress_default_print)
+			ND_DEFAULTPRINT(p, caplen);
+	}
 }
-