xref: /openbsd/usr.sbin/tcpdump/print-ip6opts.c (revision 905646f0)
1 /*	$OpenBSD: print-ip6opts.c,v 1.7 2020/01/24 22:46:37 procter Exp $	*/
2 
3 /*
4  * Copyright (C) 1998 WIDE Project.
5  * All rights reserved.
6  *
7  * Redistribution and use in source and binary forms, with or without
8  * modification, are permitted provided that the following conditions
9  * are met:
10  * 1. Redistributions of source code must retain the above copyright
11  *    notice, this list of conditions and the following disclaimer.
12  * 2. Redistributions in binary form must reproduce the above copyright
13  *    notice, this list of conditions and the following disclaimer in the
14  *    documentation and/or other materials provided with the distribution.
15  * 3. Neither the name of the project nor the names of its contributors
16  *    may be used to endorse or promote products derived from this software
17  *    without specific prior written permission.
18  *
19  * THIS SOFTWARE IS PROVIDED BY THE PROJECT AND CONTRIBUTORS ``AS IS'' AND
20  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
21  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
22  * ARE DISCLAIMED.  IN NO EVENT SHALL THE PROJECT OR CONTRIBUTORS BE LIABLE
23  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
24  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
25  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
26  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
27  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
28  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
29  * SUCH DAMAGE.
30  */
31 
32 #include <sys/time.h>
33 #include <sys/types.h>
34 #include <sys/socket.h>
35 
36 #include <netinet/in.h>
37 #include <netinet/ip6.h>
38 
39 #include <stdio.h>
40 
41 #include "interface.h"
42 #include "addrtoname.h"
43 
44 void
45 ip6_opt_print(const u_char *bp, int len)
46 {
47     int i;
48     int optlen;
49 
50     for (i = 0; i < len; i += optlen) {
51 	switch (bp[i]) {
52 	case IP6OPT_PAD1:
53 	    optlen = 1;
54 	    break;
55 	case IP6OPT_PADN:
56 	    if (len - i < IP6OPT_MINLEN) {
57 		printf("(padn: trunc)");
58 		goto trunc;
59 	    }
60 	    optlen = bp[i + 1] + 2;
61 	    break;
62 	case IP6OPT_ROUTER_ALERT:
63 	    if (len - i < IP6OPT_RTALERT_LEN) {
64 		printf("(rtalert: trunc)");
65 		goto trunc;
66 	    }
67 	    if (bp[i + 1] != IP6OPT_RTALERT_LEN - 2) {
68 		printf("(rtalert: invalid len %d)", bp[i + 1]);
69 		goto trunc;
70 	    }
71 	    printf("(rtalert: 0x%04x) ", ntohs(*(u_short *)&bp[i + 2]));
72 	    optlen = IP6OPT_RTALERT_LEN;
73 	    break;
74 	case IP6OPT_JUMBO:
75 	    if (len - i < IP6OPT_JUMBO_LEN) {
76 		printf("(jumbo: trunc)");
77 		goto trunc;
78 	    }
79 	    if (bp[i + 1] != IP6OPT_JUMBO_LEN - 2) {
80 		printf("(jumbo: invalid len %d)", bp[i + 1]);
81 		goto trunc;
82 	    }
83 	    printf("(jumbo: %u) ", (u_int32_t)ntohl(*(u_int *)&bp[i + 2]));
84 	    optlen = IP6OPT_JUMBO_LEN;
85 	    break;
86 	default:
87 	    if (len - i < IP6OPT_MINLEN) {
88 		printf("(type %d: trunc)", bp[i]);
89 		goto trunc;
90 	    }
91 	    printf("(type 0x%02x: len=%d) ", bp[i], bp[i + 1]);
92 	    optlen = bp[i + 1] + 2;
93 	    break;
94 	}
95     }
96 
97 #if 0
98 end:
99 #endif
100     return;
101 
102 trunc:
103     printf("[trunc] ");
104 }
105 
106 int
107 hbhopt_print(const u_char *bp)
108 {
109     const struct ip6_hbh *dp = (struct ip6_hbh *)bp;
110     const u_char *ep;
111     int hbhlen = 0;
112 
113     /* 'ep' points to the end of avaible data. */
114     ep = snapend;
115     TCHECK(dp->ip6h_len);
116     hbhlen = (int)((dp->ip6h_len + 1) << 3);
117     TCHECK2(*dp, hbhlen);
118     printf("HBH ");
119     if (vflag)
120 	ip6_opt_print((const u_char *)dp + sizeof(*dp), hbhlen - sizeof(*dp));
121 
122     return(hbhlen);
123 
124   trunc:
125     printf("[|HBH]");
126     return(hbhlen);
127 }
128 
129 int
130 dstopt_print(const u_char *bp)
131 {
132     const struct ip6_dest *dp = (struct ip6_dest *)bp;
133     const u_char *ep;
134     int dstoptlen = 0;
135 
136     /* 'ep' points to the end of avaible data. */
137     ep = snapend;
138     TCHECK(dp->ip6d_len);
139     dstoptlen = (int)((dp->ip6d_len + 1) << 3);
140     TCHECK2(*dp, dstoptlen);
141     printf("DSTOPT ");
142     if (vflag) {
143 	ip6_opt_print((const u_char *)dp + sizeof(*dp),
144 	    dstoptlen - sizeof(*dp));
145     }
146 
147     return(dstoptlen);
148 
149   trunc:
150     printf("[|DSTOPT]");
151     return(dstoptlen);
152 }
153