1/*
2 * Copyright (C) 1998 WIDE Project.
3 * All rights reserved.
4 *
5 * Redistribution and use in source and binary forms, with or without
6 * modification, are permitted provided that the following conditions
7 * are met:
8 * 1. Redistributions of source code must retain the above copyright
9 *    notice, this list of conditions and the following disclaimer.
10 * 2. Redistributions in binary form must reproduce the above copyright
11 *    notice, this list of conditions and the following disclaimer in the
12 *    documentation and/or other materials provided with the distribution.
13 * 3. Neither the name of the project nor the names of its contributors
14 *    may be used to endorse or promote products derived from this software
15 *    without specific prior written permission.
16 *
17 * THIS SOFTWARE IS PROVIDED BY THE PROJECT AND CONTRIBUTORS ``AS IS'' AND
18 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
19 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
20 * ARE DISCLAIMED.  IN NO EVENT SHALL THE PROJECT OR CONTRIBUTORS BE LIABLE
21 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
22 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
23 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
24 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
25 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
26 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
27 * SUCH DAMAGE.
28 */
29
30/* \summary: IPv6 header option printer */
31
32#ifdef HAVE_CONFIG_H
33#include <config.h>
34#endif
35
36#include "netdissect-stdinc.h"
37
38#include "netdissect.h"
39#include "addrtoname.h"
40#include "extract.h"
41
42#include "ip6.h"
43
44static int
45ip6_sopt_print(netdissect_options *ndo, const u_char *bp, int len)
46{
47    int i;
48    int optlen;
49
50    for (i = 0; i < len; i += optlen) {
51	if (GET_U_1(bp + i) == IP6OPT_PAD1)
52	    optlen = 1;
53	else {
54	    if (i + 1 < len)
55		optlen = GET_U_1(bp + i + 1) + 2;
56	    else
57		goto trunc;
58	}
59	if (i + optlen > len)
60	    goto trunc;
61
62	switch (GET_U_1(bp + i)) {
63	case IP6OPT_PAD1:
64            ND_PRINT(", pad1");
65	    break;
66	case IP6OPT_PADN:
67	    if (len - i < IP6OPT_MINLEN) {
68		ND_PRINT(", padn: trunc");
69		goto trunc;
70	    }
71            ND_PRINT(", padn");
72	    break;
73	default:
74	    if (len - i < IP6OPT_MINLEN) {
75		ND_PRINT(", sopt_type %u: trunc)", GET_U_1(bp + i));
76		goto trunc;
77	    }
78	    ND_PRINT(", sopt_type 0x%02x: len=%u", GET_U_1(bp + i),
79                     GET_U_1(bp + i + 1));
80	    break;
81	}
82    }
83    return 0;
84
85trunc:
86    return -1;
87}
88
89static int
90ip6_opt_process(netdissect_options *ndo, const u_char *bp, int len,
91		int *found_jumbop, uint32_t *payload_len)
92{
93    int i;
94    int optlen = 0;
95    int found_jumbo = 0;
96    uint32_t jumbolen = 0;
97
98    if (len == 0)
99        return 0;
100    for (i = 0; i < len; i += optlen) {
101	if (GET_U_1(bp + i) == IP6OPT_PAD1)
102	    optlen = 1;
103	else {
104	    if (i + 1 < len)
105		optlen = GET_U_1(bp + i + 1) + 2;
106	    else
107		goto trunc;
108	}
109	if (i + optlen > len)
110	    goto trunc;
111
112	switch (GET_U_1(bp + i)) {
113	case IP6OPT_PAD1:
114	    if (ndo->ndo_vflag)
115                ND_PRINT("(pad1)");
116	    break;
117	case IP6OPT_PADN:
118	    if (len - i < IP6OPT_MINLEN) {
119		ND_PRINT("(padn: trunc)");
120		goto trunc;
121	    }
122	    if (ndo->ndo_vflag)
123                ND_PRINT("(padn)");
124	    break;
125	case IP6OPT_ROUTER_ALERT:
126	    if (len - i < IP6OPT_RTALERT_LEN) {
127		ND_PRINT("(rtalert: trunc)");
128		goto trunc;
129	    }
130	    if (GET_U_1(bp + i + 1) != IP6OPT_RTALERT_LEN - 2) {
131		ND_PRINT("(rtalert: invalid len %u)", GET_U_1(bp + i + 1));
132		goto trunc;
133	    }
134	    if (ndo->ndo_vflag)
135		ND_PRINT("(rtalert: 0x%04x) ", GET_BE_U_2(bp + i + 2));
136	    break;
137	case IP6OPT_JUMBO:
138	    if (len - i < IP6OPT_JUMBO_LEN) {
139		ND_PRINT("(jumbo: trunc)");
140		goto trunc;
141	    }
142	    if (GET_U_1(bp + i + 1) != IP6OPT_JUMBO_LEN - 2) {
143		ND_PRINT("(jumbo: invalid len %u)", GET_U_1(bp + i + 1));
144		goto trunc;
145	    }
146	    jumbolen = GET_BE_U_4(bp + i + 2);
147	    if (found_jumbo) {
148		/* More than one Jumbo Payload option */
149		if (ndo->ndo_vflag)
150		    ND_PRINT("(jumbo: %u - already seen) ", jumbolen);
151	    } else {
152		found_jumbo = 1;
153		if (payload_len == NULL) {
154		    /* Not a hop-by-hop option - not valid */
155		    if (ndo->ndo_vflag)
156			ND_PRINT("(jumbo: %u - not a hop-by-hop option) ", jumbolen);
157		} else if (*payload_len != 0) {
158		    /* Payload length was non-zero - not valid */
159		    if (ndo->ndo_vflag)
160			ND_PRINT("(jumbo: %u - payload len != 0) ", jumbolen);
161		} else {
162		    /*
163		     * This is a hop-by-hop option, and Payload length
164		     * was zero in the IPv6 header.
165		     */
166		    if (jumbolen < 65536) {
167			/* Too short */
168			if (ndo->ndo_vflag)
169			    ND_PRINT("(jumbo: %u - < 65536) ", jumbolen);
170		    } else {
171			/* OK, this is valid */
172			*found_jumbop = 1;
173			*payload_len = jumbolen;
174			if (ndo->ndo_vflag)
175			    ND_PRINT("(jumbo: %u) ", jumbolen);
176		    }
177		}
178	    }
179	    break;
180        case IP6OPT_HOME_ADDRESS:
181	    if (len - i < IP6OPT_HOMEADDR_MINLEN) {
182		ND_PRINT("(homeaddr: trunc)");
183		goto trunc;
184	    }
185	    if (GET_U_1(bp + i + 1) < IP6OPT_HOMEADDR_MINLEN - 2) {
186		ND_PRINT("(homeaddr: invalid len %u)", GET_U_1(bp + i + 1));
187		goto trunc;
188	    }
189	    if (ndo->ndo_vflag) {
190		ND_PRINT("(homeaddr: %s", GET_IP6ADDR_STRING(bp + i + 2));
191		if (GET_U_1(bp + i + 1) > IP6OPT_HOMEADDR_MINLEN - 2) {
192		    if (ip6_sopt_print(ndo, bp + i + IP6OPT_HOMEADDR_MINLEN,
193				       (optlen - IP6OPT_HOMEADDR_MINLEN)) == -1)
194			goto trunc;
195		}
196		ND_PRINT(")");
197	    }
198	    break;
199	default:
200	    if (len - i < IP6OPT_MINLEN) {
201		ND_PRINT("(type %u: trunc)", GET_U_1(bp + i));
202		goto trunc;
203	    }
204	    if (ndo->ndo_vflag)
205		ND_PRINT("(opt_type 0x%02x: len=%u)", GET_U_1(bp + i),
206			 GET_U_1(bp + i + 1));
207	    break;
208	}
209    }
210    if (ndo->ndo_vflag)
211        ND_PRINT(" ");
212    return 0;
213
214trunc:
215    return -1;
216}
217
218int
219hbhopt_process(netdissect_options *ndo, const u_char *bp, int *found_jumbo,
220	       uint32_t *jumbolen)
221{
222    const struct ip6_hbh *dp = (const struct ip6_hbh *)bp;
223    u_int hbhlen = 0;
224
225    ndo->ndo_protocol = "hbhopt";
226    hbhlen = (GET_U_1(dp->ip6h_len) + 1) << 3;
227    ND_TCHECK_LEN(dp, hbhlen);
228    ND_PRINT("HBH ");
229    if (ip6_opt_process(ndo, (const u_char *)dp + sizeof(*dp),
230			hbhlen - sizeof(*dp), found_jumbo, jumbolen) == -1)
231	goto trunc;
232    return hbhlen;
233
234trunc:
235    nd_print_trunc(ndo);
236    return -1;
237}
238
239int
240dstopt_process(netdissect_options *ndo, const u_char *bp)
241{
242    const struct ip6_dest *dp = (const struct ip6_dest *)bp;
243    u_int dstoptlen = 0;
244
245    ndo->ndo_protocol = "dstopt";
246    dstoptlen = (GET_U_1(dp->ip6d_len) + 1) << 3;
247    ND_TCHECK_LEN(dp, dstoptlen);
248    ND_PRINT("DSTOPT ");
249    if (ndo->ndo_vflag) {
250	/*
251	 * The Jumbo Payload option is a hop-by-hop option; we don't
252	 * honor Jumbo Payload destination options, reporting them
253	 * as invalid.
254	 */
255	if (ip6_opt_process(ndo, (const u_char *)dp + sizeof(*dp),
256			    dstoptlen - sizeof(*dp), NULL, NULL) == -1)
257	    goto trunc;
258    }
259
260    return dstoptlen;
261
262trunc:
263    nd_print_trunc(ndo);
264    return -1;
265}
266