xref: /freebsd/contrib/tcpdump/print-ip6opts.c (revision 783d3ff6d7fae619db8a7990b8a6387de0c677b5)
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 
44 static int
45 ip6_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 
85 trunc:
86     return -1;
87 }
88 
89 static int
90 ip6_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 
214 trunc:
215     return -1;
216 }
217 
218 int
219 hbhopt_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 
234 trunc:
235     nd_print_trunc(ndo);
236     return -1;
237 }
238 
239 int
240 dstopt_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 
262 trunc:
263     nd_print_trunc(ndo);
264     return -1;
265 }
266