1/*
2 * CDDL HEADER START
3 *
4 * The contents of this file are subject to the terms of the
5 * Common Development and Distribution License (the "License").
6 * You may not use this file except in compliance with the License.
7 *
8 * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
9 * or http://www.opensolaris.org/os/licensing.
10 * See the License for the specific language governing permissions
11 * and limitations under the License.
12 *
13 * When distributing Covered Code, include this CDDL HEADER in each
14 * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
15 * If applicable, add the following below this CDDL HEADER, with the
16 * fields enclosed by brackets "[]" replaced with your own identifying
17 * information: Portions Copyright [yyyy] [name of copyright owner]
18 *
19 * CDDL HEADER END
20 */
21/*
22 * Copyright 2007 Sun Microsystems, Inc.  All rights reserved.
23 * Use is subject to license terms.
24 */
25
26#pragma ident	"%Z%%M%	%I%	%E% SMI"
27
28#include <sys/types.h>
29#include <sys/errno.h>
30#include <setjmp.h>
31#include <sys/socket.h>
32#include <net/if.h>
33#include <net/if_arp.h>
34#include <netinet/in_systm.h>
35#include <netinet/in.h>
36#include <netinet/ip.h>
37#include <netinet/if_ether.h>
38#include <netdb.h>
39#include <net/if_types.h>
40
41#include "snoop.h"
42
43extern char *dlc_header;
44extern jmp_buf xdr_err;
45
46static char *printip(unsigned char *);
47static char *addrtoname_align(unsigned char *);
48
49static char unarp_addr[] = "Unknown";
50char *opname[] = {
51	"",
52	"ARP Request",
53	"ARP Reply",
54	"REVARP Request",
55	"REVARP Reply",
56};
57
58void
59interpret_arp(int flags, struct arphdr *ap, int alen)
60{
61	char *line;
62	extern char *src_name, *dst_name;
63	unsigned char *sip, *tip, *sha, *tha;
64	char *smacbuf = NULL, *dmacbuf = NULL;
65	int maclen;
66	ushort_t arpop;
67	boolean_t is_ip = B_FALSE;
68
69	/*
70	 * Check that at least the generic ARP header was received.
71	 */
72	if (sizeof (struct arphdr) > alen)
73		goto short_packet;
74
75	arpop = ntohs(ap->ar_op);
76	maclen = ap->ar_hln;
77	if (ntohs(ap->ar_pro) == ETHERTYPE_IP)
78		is_ip = B_TRUE;
79
80	sha = (unsigned char *)(ap + 1);
81	sip = sha + maclen;
82	tha = sip + ap->ar_pln;
83	tip = tha + maclen;
84
85	/*
86	 * Check that the protocol/hardware addresses were received.
87	 */
88	if ((tip + ap->ar_pln) > ((unsigned char *)ap + alen))
89		goto short_packet;
90
91	if (maclen == 0) {
92		smacbuf = dmacbuf = unarp_addr;
93	} else {
94		if (((flags & F_DTAIL) && is_ip) || (arpop == ARPOP_REPLY)) {
95			smacbuf = _link_ntoa(sha, NULL, maclen, IFT_OTHER);
96			if (smacbuf == NULL)
97				pr_err("Warning: malloc failure");
98		}
99
100		if (((flags & F_DTAIL) && is_ip) || (arpop ==
101		    REVARP_REQUEST) || (arpop == REVARP_REPLY)) {
102			dmacbuf = _link_ntoa(tha, NULL, maclen, IFT_OTHER);
103			if (dmacbuf == NULL)
104				pr_err("Warning: malloc failure");
105		}
106	}
107
108	src_name = addrtoname_align(sip);
109
110	if (flags & F_SUM) {
111
112		line = get_sum_line();
113
114		switch (arpop) {
115		case ARPOP_REQUEST:
116			(void) snprintf(line, MAXLINE, "ARP C Who is %s ?",
117			    printip(tip));
118			break;
119		case ARPOP_REPLY:
120			(void) snprintf(line, MAXLINE, "ARP R %s is %s",
121			    printip(sip), smacbuf);
122			dst_name = addrtoname_align(tip);
123			break;
124		case REVARP_REQUEST:
125			(void) snprintf(line, MAXLINE, "RARP C Who is %s ?",
126			    dmacbuf);
127			break;
128		case REVARP_REPLY:
129			(void) snprintf(line, MAXLINE, "RARP R %s is %s",
130			    dmacbuf, printip(tip));
131			dst_name = addrtoname_align(tip);
132			break;
133		}
134	}
135
136	if (flags & F_DTAIL) {
137		show_header("ARP:  ", "ARP/RARP Frame", alen);
138		show_space();
139		(void) snprintf(get_line(0, 0), get_line_remain(),
140		    "Hardware type = %d (%s)", ntohs(ap->ar_hrd),
141		    arp_htype(ntohs(ap->ar_hrd)));
142		(void) snprintf(get_line(0, 0), get_line_remain(),
143		    "Protocol type = %04x (%s)", ntohs(ap->ar_pro),
144		    print_ethertype(ntohs(ap->ar_pro)));
145		(void) snprintf(get_line(0, 0), get_line_remain(),
146		    "Length of hardware address = %d bytes", ap->ar_hln);
147		(void) snprintf(get_line(0, 0), get_line_remain(),
148		    "Length of protocol address = %d bytes", ap->ar_pln);
149		(void) snprintf(get_line(0, 0), get_line_remain(),
150		    "Opcode %d (%s)", arpop,
151		    (arpop > REVARP_REPLY) ? opname[0] : opname[arpop]);
152
153		if (is_ip) {
154			(void) snprintf(get_line(0, 0), get_line_remain(),
155			    "Sender's hardware address = %s", smacbuf);
156			(void) snprintf(get_line(0, 0), get_line_remain(),
157			    "Sender's protocol address = %s",
158			    printip(sip));
159			(void) snprintf(get_line(0, 0), get_line_remain(),
160			    "Target hardware address = %s",
161			    arpop == ARPOP_REQUEST ? "?" : dmacbuf);
162			(void) snprintf(get_line(0, 0), get_line_remain(),
163			    "Target protocol address = %s",
164			    arpop == REVARP_REQUEST ? "?" :
165			    printip(tip));
166		}
167		show_trailer();
168	}
169
170	if (maclen != 0) {
171		free(smacbuf);
172		free(dmacbuf);
173	}
174	return;
175
176short_packet:
177	if (flags & F_SUM) {
178		(void) snprintf(get_sum_line(), MAXLINE,
179		    "ARP (short packet)");
180	} else if (flags & F_DTAIL) {
181		show_header("ARP:  ", "ARP/RARP Frame", alen);
182		show_space();
183		(void) snprintf(get_line(0, 0), get_line_remain(),
184		    "ARP (short packet)");
185	}
186}
187
188char *
189printip(unsigned char *p)
190{
191	static char buff[MAXHOSTNAMELEN + 32];
192	char *ap, *np;
193	struct in_addr a;
194
195	memcpy(&a, p, 4);
196	ap = (char *)inet_ntoa(a);
197	np = (char *)addrtoname(AF_INET, &a);
198	(void) snprintf(buff, MAXHOSTNAMELEN, "%s, %s", ap, np);
199	return (buff);
200}
201
202char *
203addrtoname_align(unsigned char *p)
204{
205	struct in_addr a;
206
207	memcpy(&a, p, 4);
208	return ((char *)addrtoname(AF_INET, &a));
209}
210
211/*
212 * These numbers are assigned by the IANA.  See the arp-parameters registry.
213 * Only those values that are used within Solaris have #defines.
214 */
215const char *
216arp_htype(int t)
217{
218	switch (t) {
219	case ARPHRD_ETHER:
220		return ("Ethernet (10Mb)");
221	case 2:
222		return ("Experimental Ethernet (3MB)");
223	case 3:
224		return ("Amateur Radio AX.25");
225	case 4:
226		return ("Proteon ProNET Token Ring");
227	case 5:
228		return ("Chaos");
229	case ARPHRD_IEEE802:
230		return ("IEEE 802");
231	case 7:
232		return ("ARCNET");
233	case 8:
234		return ("Hyperchannel");
235	case 9:
236		return ("Lanstar");
237	case 10:
238		return ("Autonet");
239	case 11:
240		return ("LocalTalk");
241	case 12:
242		return ("LocalNet");
243	case 13:
244		return ("Ultra Link");
245	case 14:
246		return ("SMDS");
247	case ARPHRD_FRAME:
248		return ("Frame Relay");
249	case ARPHRD_ATM:
250		return ("ATM");
251	case ARPHRD_HDLC:
252		return ("HDLC");
253	case ARPHRD_FC:
254		return ("Fibre Channel");
255	case ARPHRD_IPATM:
256		return ("IP-ATM");
257	case ARPHRD_TUNNEL:
258		return ("Tunnel");
259	case ARPHRD_IB:
260		return ("IPIB");
261	};
262	return ("UNKNOWN");
263}
264