1 files changed, 108 insertions, 0 deletions
diff --git a/listen/arpdump.c b/listen/arpdump.c
new file mode 100644
index 0000000..a80716a
--- /dev/null
+++ b/listen/arpdump.c
@@ -0,0 +1,108 @@
+/* @(#) $Header: arpdump.c,v 1.5 91/03/28 19:38:59 deyke Exp $ */
+
+/* ARP packet tracing routines
+ * Copyright 1991 Phil Karn, KA9Q
+ */
+#include <stdio.h>
+#include "listen.h"
+
+#define	ARP_REQUEST	1
+#define	ARP_REPLY	2
+#define	REVARP_REQUEST	3
+#define	REVARP_REPLY	4
+
+#define	ARP_AX25	3
+
+#define	AXALEN		7
+
+#define	PID_IP		0xCC
+
+void arp_dump(unsigned char *data, int length)
+{
+	int is_ip = 0;
+	int hardware;
+	int protocol;
+	int hwlen;
+	int pralen;
+	int operation;
+	unsigned char *shwaddr, *sprotaddr;
+	unsigned char *thwaddr, *tprotaddr;
+	char tmp[25];
+
+	lprintf(T_PROTOCOL, "ARP: ");
+	lprintf(T_IPHDR, "len %d", length);
+	if (length < 16)
+	{
+		lprintf(T_ERROR, " bad packet\n");
+		return;
+	}
+
+	hardware  = get16(data + 0);
+	protocol  = get16(data + 2);
+	hwlen     = data[4];
+	pralen    = data[5];
+	operation = get16(data + 6);
+	
+	if (hardware != ARP_AX25)
+	{
+		lprintf(T_IPHDR, " non-AX25 ARP packet\n");
+		return;
+	}
+
+	lprintf(T_IPHDR, " hwtype AX25");
+
+	/* Print hardware length only if it doesn't match
+	 * the length in the known types table
+	 */
+	if (hwlen != AXALEN)
+		lprintf(T_IPHDR, " hwlen %d", hwlen);
+
+	if (protocol == PID_IP)
+	{
+		lprintf(T_IPHDR, " prot IP");
+		is_ip = 1;
+	}
+	else
+	{
+		lprintf(T_IPHDR, " prot 0x%x prlen %d", protocol, pralen);
+	}
+
+	switch (operation)
+	{
+	case ARP_REQUEST:
+		lprintf(T_IPHDR, " op REQUEST");
+		break;
+	case ARP_REPLY:
+		lprintf(T_IPHDR, " op REPLY");
+		break;
+	case REVARP_REQUEST:
+		lprintf(T_IPHDR, " op REVERSE REQUEST");
+		break;
+	case REVARP_REPLY:
+		lprintf(T_IPHDR, " op REVERSE REPLY");
+		break;
+	default:
+		lprintf(T_IPHDR, " op %d", operation);
+		break;
+	}
+	
+	shwaddr   = data + 8;
+	sprotaddr = shwaddr + hwlen;
+	
+	thwaddr   = sprotaddr + pralen;
+	tprotaddr = thwaddr + hwlen; 
+	
+	lprintf(T_IPHDR, "\nsender");
+	if (is_ip) lprintf(T_ADDR, " IPaddr %d.%d.%d.%d",
+			sprotaddr[0], sprotaddr[1],
+			sprotaddr[2], sprotaddr[3]);
+	lprintf(T_IPHDR, " hwaddr %s\n", pax25(tmp, shwaddr));
+
+	lprintf(T_IPHDR,"target");
+	if (is_ip) lprintf(T_ADDR, " IPaddr %d.%d.%d.%d",
+			tprotaddr[0], tprotaddr[1],
+			tprotaddr[2], tprotaddr[3]);
+	if (*thwaddr != 0)
+		lprintf(T_ADDR, " hwaddr %s", pax25(tmp, thwaddr));
+	lprintf(T_IPHDR, "\n");
+}