From: itojun <itojun>
Date: Mon, 18 Jun 2001 09:12:27 +0000 (+0000)
Subject: make arp_print() L2 neutral.  from netbsd
X-Git-Tag: tcpdump-3.7.1~181
X-Git-Url: https://git.tcpdump.org/tcpdump/commitdiff_plain/ae68164cc68a352ca4ba7323dd6b3bf547bf5ab5

make arp_print() L2 neutral.  from netbsd

TODO: recover portions that peep L2 src/dst, by passing more args from
L2 printing to arp_print().  the current code can bomb when L2 = arcnet
(because the code assumes that L2 address len == 6), for example.
---

diff --git a/addrtoname.c b/addrtoname.c
index 47a3577f..4af2a2ce 100644
--- a/addrtoname.c
+++ b/addrtoname.c
@@ -23,7 +23,7 @@
  */
 #ifndef lint
 static const char rcsid[] =
-    "@(#) $Header: /tcpdump/master/tcpdump/addrtoname.c,v 1.75 2001-06-15 21:02:10 fenner Exp $ (LBL)";
+    "@(#) $Header: /tcpdump/master/tcpdump/addrtoname.c,v 1.76 2001-06-18 09:12:27 itojun Exp $ (LBL)";
 #endif
 
 #ifdef HAVE_CONFIG_H
@@ -98,11 +98,13 @@ struct enamemem {
 	u_short e_addr2;
 	char *e_name;
 	u_char *e_nsap;			/* used only for nsaptable[] */
+#define e_bs e_nsap			/* for bytestringtable */
 	struct enamemem *e_nxt;
 };
 
 struct enamemem enametable[HASHNAMESIZE];
 struct enamemem nsaptable[HASHNAMESIZE];
+struct enamemem bytestringtable[HASHNAMESIZE];
 
 struct protoidmem {
 	u_int32_t p_oui;
@@ -322,6 +324,51 @@ lookup_emem(const u_char *ep)
 	return tp;
 }
 
+/*
+ * Find the hash node that corresponds to the bytestring 'bs' 
+ * with length 'nlen'
+ */
+
+static inline struct enamemem *
+lookup_bytestring(register const u_char *bs, const int nlen)
+{
+	struct enamemem *tp;
+	register u_int i, j, k;
+
+	if (nlen >= 6) {
+		k = (bs[0] << 8) | bs[1];
+		j = (bs[2] << 8) | bs[3];
+		i = (bs[4] << 8) | bs[5];
+	} else if (nlen >= 4) {
+		k = (bs[0] << 8) | bs[1];
+		j = (bs[2] << 8) | bs[3];
+		i = 0;
+	} else
+		i = j = k = 0;
+
+	tp = &bytestringtable[(i ^ j) & (HASHNAMESIZE-1)];
+	while (tp->e_nxt)
+		if (tp->e_addr0 == i &&
+		    tp->e_addr1 == j &&
+		    tp->e_addr2 == k &&
+		    bcmp((char *)bs, (char *)(tp->e_bs), nlen) == 0)
+			return tp;
+		else
+			tp = tp->e_nxt;
+
+	tp->e_addr0 = i;
+	tp->e_addr1 = j;
+	tp->e_addr2 = k;
+
+	tp->e_bs = (u_char *) calloc(1, nlen + 1);
+	bcopy(bs, tp->e_bs, nlen);
+	tp->e_nxt = (struct enamemem *)calloc(1, sizeof(*tp));
+	if (tp->e_nxt == NULL)
+		error("lookup_bytestring: calloc");
+
+	return tp;
+}
+
 /* Find the hash node that corresponds the NSAP 'nsap' */
 
 static inline struct enamemem *
@@ -428,6 +475,36 @@ etheraddr_string(register const u_char *ep)
 	return (tp->e_name);
 }
 
+char *
+linkaddr_string(const u_char *ep, const int len)
+{
+	register u_int i, j;
+	register char *cp;
+	register struct enamemem *tp;
+
+	if (len == 6)	/* XXX not totally correct... */
+		return etheraddr_string(ep);
+	
+	tp = lookup_bytestring(ep, len);
+	if (tp->e_name)
+		return (tp->e_name);
+
+	tp->e_name = cp = (char *)malloc(len*3);
+	if (tp->e_name == NULL)
+		error("linkaddr_string: malloc");
+	if ((j = *ep >> 4) != 0)
+		*cp++ = hex[j];
+	*cp++ = hex[*ep++ & 0xf];
+	for (i = len-1; i > 0 ; --i) {
+		*cp++ = ':';
+		if ((j = *ep >> 4) != 0)
+			*cp++ = hex[j];
+		*cp++ = hex[*ep++ & 0xf];
+	}
+	*cp = '\0';
+	return (tp->e_name);
+}
+
 char *
 etherproto_string(u_short port)
 {
diff --git a/addrtoname.h b/addrtoname.h
index 33fc07fc..6c170126 100644
--- a/addrtoname.h
+++ b/addrtoname.h
@@ -18,11 +18,12 @@
  * WARRANTIES, INCLUDING, WITHOUT LIMITATION, THE IMPLIED WARRANTIES OF
  * MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE.
  *
- * @(#) $Header: /tcpdump/master/tcpdump/addrtoname.h,v 1.16 1999-10-30 05:11:07 itojun Exp $ (LBL)
+ * @(#) $Header: /tcpdump/master/tcpdump/addrtoname.h,v 1.17 2001-06-18 09:12:28 itojun Exp $ (LBL)
  */
 
 /* Name to address translation routines. */
 
+extern char *linkaddr_string(const u_char *, const int);
 extern char *etheraddr_string(const u_char *);
 extern char *etherproto_string(u_short);
 extern char *tcpport_string(u_short);
diff --git a/print-arp.c b/print-arp.c
index 3ba8a7e6..cbeb47af 100644
--- a/print-arp.c
+++ b/print-arp.c
@@ -21,7 +21,7 @@
 
 #ifndef lint
 static const char rcsid[] =
-    "@(#) $Header: /tcpdump/master/tcpdump/print-arp.c,v 1.49 2000-10-10 05:05:07 guy Exp $ (LBL)";
+    "@(#) $Header: /tcpdump/master/tcpdump/print-arp.c,v 1.50 2001-06-18 09:12:28 itojun Exp $ (LBL)";
 #endif
 
 #ifdef HAVE_CONFIG_H
@@ -56,7 +56,10 @@ struct	arphdr {
 	u_short	ar_hrd;		/* format of hardware address */
 #define ARPHRD_ETHER 	1	/* ethernet hardware format */
 #define ARPHRD_IEEE802	6	/* token-ring hardware format */
+#define ARPHRD_ARCNET	7	/* arcnet hardware format */
 #define ARPHRD_FRELAY 	15	/* frame relay hardware format */
+#define ARPHRD_STRIP 	23	/* Ricochet Starmode Radio hardware format */
+#define ARPHRD_IEEE1394	24	/* IEEE 1394 (FireWire) hardware format */
 	u_short	ar_pro;		/* format of protocol address */
 	u_char	ar_hln;		/* length of hardware address */
 	u_char	ar_pln;		/* length of protocol address */
@@ -77,109 +80,78 @@ struct	arphdr {
 	u_char	ar_tha[];	/* target hardware address */
 	u_char	ar_tpa[];	/* target protocol address */
 #endif
+#define ar_sha(ap)	(((caddr_t)((ap)+1))+0)
+#define ar_spa(ap)	(((caddr_t)((ap)+1))+  (ap)->ar_hln)
+#define ar_tha(ap)	(((caddr_t)((ap)+1))+  (ap)->ar_hln+(ap)->ar_pln)
+#define ar_tpa(ap)	(((caddr_t)((ap)+1))+2*(ap)->ar_hln+(ap)->ar_pln)
 };
 
 #define ARP_HDRLEN	8
 
-/*
- * Ethernet Address Resolution Protocol.
- *
- * See RFC 826 for protocol description.  Structure below is adapted
- * to resolving internet addresses.  Field names used correspond to 
- * RFC 826.
- */
-struct	ether_arp {
-	struct	arphdr ea_hdr;	/* fixed-size header */
-	u_char	arp_sha[6];	/* sender hardware address */
-	u_char	arp_spa[4];	/* sender protocol address */
-	u_char	arp_tha[6];	/* target hardware address */
-	u_char	arp_tpa[4];	/* target protocol address */
-};
-#define	arp_hrd	ea_hdr.ar_hrd
-#define	arp_pro	ea_hdr.ar_pro
-#define	arp_hln	ea_hdr.ar_hln
-#define	arp_pln	ea_hdr.ar_pln
-#define	arp_op	ea_hdr.ar_op
-
-#define ETHER_ARP_HDRLEN	(ARP_HDRLEN + 6 + 4 + 6 + 4)	
-
-#define SHA(ap) ((ap)->arp_sha)
-#define THA(ap) ((ap)->arp_tha)
-#define SPA(ap) ((ap)->arp_spa)
-#define TPA(ap) ((ap)->arp_tpa)
-
-/* Compatibility */
-#ifndef REVARP_REQUEST
-#define REVARP_REQUEST		3
-#endif
-#ifndef REVARP_REPLY
-#define REVARP_REPLY		4
-#endif
+#define HRD(ap) ((ap)->ar_hrd)
+#define HLN(ap) ((ap)->ar_hln)
+#define PLN(ap) ((ap)->ar_pln)
+#define OP(ap)  ((ap)->ar_op)
+#define PRO(ap) ((ap)->ar_pro)
+#define SHA(ap) (ar_sha(ap))
+#define SPA(ap) (ar_spa(ap))
+#define THA(ap) (ar_tha(ap))
+#define TPA(ap) (ar_tpa(ap))
 
 static u_char ezero[6];
 
 void
-arp_print(register const u_char *bp, u_int length, u_int caplen)
+arp_print(const u_char *bp, u_int length, u_int caplen)
 {
-	register const struct ether_arp *ap;
-	register const struct ether_header *eh;
-	register u_short pro, hrd, op;
+	const struct arphdr *ap;
+	u_short pro, hrd, op;
 
-	ap = (struct ether_arp *)bp;
-	if ((u_char *)(ap + 1) > snapend) {
+	ap = (struct arphdr *)bp;
+	if ((u_char *)(ap + 1) > snapend)  {
 		printf("[|arp]");
 		return;
 	}
-	if (length < ETHER_ARP_HDRLEN) {
+	if ((u_char *)(ar_tpa(ap) + PLN(ap)) > snapend) {
 		(void)printf("truncated-arp");
 		default_print((u_char *)ap, length);
 		return;
 	}
 
-	pro = EXTRACT_16BITS(&ap->arp_pro);
-	hrd = EXTRACT_16BITS(&ap->arp_hrd);
-	op = EXTRACT_16BITS(&ap->arp_op);
+	pro = EXTRACT_16BITS(&PRO(ap));
+	hrd = EXTRACT_16BITS(&HRD(ap));
+	op = EXTRACT_16BITS(&OP(ap));
 
-	if ((pro != ETHERTYPE_IP && pro != ETHERTYPE_TRAIL)
-	    || ap->arp_hln != sizeof(SHA(ap))
-	    || ap->arp_pln != sizeof(SPA(ap))) {
+	if (pro != ETHERTYPE_IP && pro != ETHERTYPE_TRAIL) {
 		(void)printf("arp-#%d for proto #%d (%d) hardware #%d (%d)",
-				op, pro, ap->arp_pln,
-				hrd, ap->arp_hln);
+				op, pro, PLN(ap), hrd, HLN(ap));
 		return;
 	}
 	if (pro == ETHERTYPE_TRAIL)
 		(void)printf("trailer-");
-	eh = (struct ether_header *)packetp;
 	switch (op) {
 
 	case ARPOP_REQUEST:
 		(void)printf("arp who-has %s", ipaddr_string(TPA(ap)));
-		if (memcmp((char *)ezero, (char *)THA(ap), 6) != 0)
-			(void)printf(" (%s)", etheraddr_string(THA(ap)));
+		if (memcmp((char *)ezero, (char *)THA(ap), HLN(ap)) != 0)
+			(void)printf(" (%s)",
+			    linkaddr_string(THA(ap), HLN(ap)));
 		(void)printf(" tell %s", ipaddr_string(SPA(ap)));
-		if (memcmp((char *)ESRC(eh), (char *)SHA(ap), 6) != 0)
-			(void)printf(" (%s)", etheraddr_string(SHA(ap)));
 		break;
 
 	case ARPOP_REPLY:
 		(void)printf("arp reply %s", ipaddr_string(SPA(ap)));
-		if (memcmp((char *)ESRC(eh), (char *)SHA(ap), 6) != 0)
-			(void)printf(" (%s)", etheraddr_string(SHA(ap)));
-		(void)printf(" is-at %s", etheraddr_string(SHA(ap)));
-		if (memcmp((char *)EDST(eh), (char *)THA(ap), 6) != 0)
-			(void)printf(" (%s)", etheraddr_string(THA(ap)));
+		(void)printf(" is-at %s", linkaddr_string(SHA(ap), HLN(ap)));
 		break;
 
-	case REVARP_REQUEST:
+	case ARPOP_REVREQUEST:
 		(void)printf("rarp who-is %s tell %s",
-			etheraddr_string(THA(ap)),
-			etheraddr_string(SHA(ap)));
+			linkaddr_string(THA(ap), HLN(ap)),
+			linkaddr_string(SHA(ap), HLN(ap)));
 		break;
 
-	case REVARP_REPLY:
+	case ARPOP_REVREPLY:
 		(void)printf("rarp reply %s at %s",
-			etheraddr_string(THA(ap)),
+			linkaddr_string(THA(ap), HLN(ap)),
 			ipaddr_string(TPA(ap)));
 		break;