xref: /onnv-gate/usr/src/lib/libsocket/inet/inet6_rthdr.c (revision 0:68f95e015346)
1*0Sstevel@tonic-gate /*
2*0Sstevel@tonic-gate  * CDDL HEADER START
3*0Sstevel@tonic-gate  *
4*0Sstevel@tonic-gate  * The contents of this file are subject to the terms of the
5*0Sstevel@tonic-gate  * Common Development and Distribution License, Version 1.0 only
6*0Sstevel@tonic-gate  * (the "License").  You may not use this file except in compliance
7*0Sstevel@tonic-gate  * with the License.
8*0Sstevel@tonic-gate  *
9*0Sstevel@tonic-gate  * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
10*0Sstevel@tonic-gate  * or http://www.opensolaris.org/os/licensing.
11*0Sstevel@tonic-gate  * See the License for the specific language governing permissions
12*0Sstevel@tonic-gate  * and limitations under the License.
13*0Sstevel@tonic-gate  *
14*0Sstevel@tonic-gate  * When distributing Covered Code, include this CDDL HEADER in each
15*0Sstevel@tonic-gate  * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
16*0Sstevel@tonic-gate  * If applicable, add the following below this CDDL HEADER, with the
17*0Sstevel@tonic-gate  * fields enclosed by brackets "[]" replaced with your own identifying
18*0Sstevel@tonic-gate  * information: Portions Copyright [yyyy] [name of copyright owner]
19*0Sstevel@tonic-gate  *
20*0Sstevel@tonic-gate  * CDDL HEADER END
21*0Sstevel@tonic-gate  */
22*0Sstevel@tonic-gate /*
23*0Sstevel@tonic-gate  * Copyright 2003 Sun Microsystems, Inc.
24*0Sstevel@tonic-gate  * All rights reserved.  Use is subject to license terms.
25*0Sstevel@tonic-gate  */
26*0Sstevel@tonic-gate 
27*0Sstevel@tonic-gate #pragma ident	"%Z%%M%	%I%	%E% SMI"
28*0Sstevel@tonic-gate 
29*0Sstevel@tonic-gate /*
30*0Sstevel@tonic-gate  * This code is conformant to revision 7 of 2292bis.  Some of these functions
31*0Sstevel@tonic-gate  * were provided (named inet6_rthdr_) in a very similar form in RFC 2292.
32*0Sstevel@tonic-gate  * The RFC 2292 variants are not supported.
33*0Sstevel@tonic-gate  */
34*0Sstevel@tonic-gate 
35*0Sstevel@tonic-gate #include <stdio.h>
36*0Sstevel@tonic-gate #include <ctype.h>
37*0Sstevel@tonic-gate #include <string.h>
38*0Sstevel@tonic-gate #include <stdlib.h>
39*0Sstevel@tonic-gate #include <sys/types.h>
40*0Sstevel@tonic-gate #include <sys/socket.h>
41*0Sstevel@tonic-gate #include <netinet/in.h>
42*0Sstevel@tonic-gate #include <netinet/ip6.h>
43*0Sstevel@tonic-gate #include <unistd.h>
44*0Sstevel@tonic-gate #include <errno.h>
45*0Sstevel@tonic-gate 
46*0Sstevel@tonic-gate #define	MAX_RTHDR0_SEGMENTS 127
47*0Sstevel@tonic-gate 
48*0Sstevel@tonic-gate /*
49*0Sstevel@tonic-gate  * Return amount of space needed to hold N segments for the specified
50*0Sstevel@tonic-gate  * routing type. Does NOT include space for cmsghdr.
51*0Sstevel@tonic-gate  */
52*0Sstevel@tonic-gate socklen_t
inet6_rth_space(int type,int segments)53*0Sstevel@tonic-gate inet6_rth_space(int type, int segments)
54*0Sstevel@tonic-gate {
55*0Sstevel@tonic-gate 	if (type != IPV6_RTHDR_TYPE_0 || segments < 0 ||
56*0Sstevel@tonic-gate 	    segments > MAX_RTHDR0_SEGMENTS)
57*0Sstevel@tonic-gate 		return (0);
58*0Sstevel@tonic-gate 
59*0Sstevel@tonic-gate 	return (sizeof (struct ip6_rthdr0) +
60*0Sstevel@tonic-gate 	    segments * sizeof (struct in6_addr));
61*0Sstevel@tonic-gate }
62*0Sstevel@tonic-gate 
63*0Sstevel@tonic-gate /*
64*0Sstevel@tonic-gate  * Initializes rthdr structure. Verifies the segments against the length of
65*0Sstevel@tonic-gate  * the buffer.
66*0Sstevel@tonic-gate  * Note that a routing header can only hold 127 segments since the length field
67*0Sstevel@tonic-gate  * in the header is just a byte.
68*0Sstevel@tonic-gate  */
69*0Sstevel@tonic-gate void *
inet6_rth_init(void * bp,socklen_t bp_len,int type,int segments)70*0Sstevel@tonic-gate inet6_rth_init(void *bp, socklen_t bp_len, int type, int segments)
71*0Sstevel@tonic-gate {
72*0Sstevel@tonic-gate 	struct ip6_rthdr0 *rthdr;
73*0Sstevel@tonic-gate 
74*0Sstevel@tonic-gate 	if (type != IPV6_RTHDR_TYPE_0 || segments < 0 ||
75*0Sstevel@tonic-gate 	    segments > MAX_RTHDR0_SEGMENTS)
76*0Sstevel@tonic-gate 		return (NULL);
77*0Sstevel@tonic-gate 
78*0Sstevel@tonic-gate 	if (bp_len < sizeof (struct ip6_rthdr0) +
79*0Sstevel@tonic-gate 	    segments * sizeof (struct in6_addr))
80*0Sstevel@tonic-gate 		return (NULL);
81*0Sstevel@tonic-gate 
82*0Sstevel@tonic-gate 	rthdr = (struct ip6_rthdr0 *)bp;
83*0Sstevel@tonic-gate 	rthdr->ip6r0_nxt = 0;
84*0Sstevel@tonic-gate 	rthdr->ip6r0_len = (segments * 2);
85*0Sstevel@tonic-gate 	rthdr->ip6r0_type = type;
86*0Sstevel@tonic-gate 	rthdr->ip6r0_segleft = 0;	/* Incremented by rthdr_add */
87*0Sstevel@tonic-gate 	*(uint32_t *)&rthdr->ip6r0_reserved = 0;
88*0Sstevel@tonic-gate 	return (bp);
89*0Sstevel@tonic-gate }
90*0Sstevel@tonic-gate 
91*0Sstevel@tonic-gate /*
92*0Sstevel@tonic-gate  * Add one more address to the routing header. Fails when there is no more
93*0Sstevel@tonic-gate  * room.
94*0Sstevel@tonic-gate  */
95*0Sstevel@tonic-gate int
inet6_rth_add(void * bp,const struct in6_addr * addr)96*0Sstevel@tonic-gate inet6_rth_add(void *bp, const struct in6_addr *addr)
97*0Sstevel@tonic-gate {
98*0Sstevel@tonic-gate 	struct ip6_rthdr0 *rthdr;
99*0Sstevel@tonic-gate 	struct in6_addr *addrs;
100*0Sstevel@tonic-gate 
101*0Sstevel@tonic-gate 	rthdr = (struct ip6_rthdr0 *)bp;
102*0Sstevel@tonic-gate 	if ((rthdr->ip6r0_segleft + 1) * 2 > rthdr->ip6r0_len) {
103*0Sstevel@tonic-gate 		/* Not room for one more */
104*0Sstevel@tonic-gate 		return (-1);
105*0Sstevel@tonic-gate 	}
106*0Sstevel@tonic-gate 	addrs = (struct in6_addr *)((char *)rthdr + sizeof (*rthdr));
107*0Sstevel@tonic-gate 	addrs[rthdr->ip6r0_segleft++] = *addr;
108*0Sstevel@tonic-gate 	return (0);
109*0Sstevel@tonic-gate }
110*0Sstevel@tonic-gate 
111*0Sstevel@tonic-gate /*
112*0Sstevel@tonic-gate  * Reverse a source route. Both arguments can point to the same buffer.
113*0Sstevel@tonic-gate  */
114*0Sstevel@tonic-gate int
inet6_rth_reverse(const void * in,void * out)115*0Sstevel@tonic-gate inet6_rth_reverse(const void *in, void *out)
116*0Sstevel@tonic-gate {
117*0Sstevel@tonic-gate 	struct ip6_rthdr0 *rtin, *rtout;
118*0Sstevel@tonic-gate 	int i, segments;
119*0Sstevel@tonic-gate 	struct in6_addr tmp;
120*0Sstevel@tonic-gate 	struct in6_addr *rtout_addrs;
121*0Sstevel@tonic-gate 	struct in6_addr *rtin_addrs;
122*0Sstevel@tonic-gate 
123*0Sstevel@tonic-gate 	rtin = (struct ip6_rthdr0 *)in;
124*0Sstevel@tonic-gate 	rtout = (struct ip6_rthdr0 *)out;
125*0Sstevel@tonic-gate 
126*0Sstevel@tonic-gate 	if (rtout->ip6r0_type != 0 || rtin->ip6r0_type != 0 ||
127*0Sstevel@tonic-gate 	    rtout->ip6r0_len > MAX_RTHDR0_SEGMENTS * 2 ||
128*0Sstevel@tonic-gate 	    rtin->ip6r0_len > MAX_RTHDR0_SEGMENTS * 2 ||
129*0Sstevel@tonic-gate 	    rtout->ip6r0_len != rtin->ip6r0_len)
130*0Sstevel@tonic-gate 		return (-1);
131*0Sstevel@tonic-gate 
132*0Sstevel@tonic-gate 	segments = rtin->ip6r0_len / 2;
133*0Sstevel@tonic-gate 	rtout_addrs = (struct in6_addr *)((char *)rtout + sizeof (*rtout));
134*0Sstevel@tonic-gate 	rtin_addrs = (struct in6_addr *)((char *)rtin + sizeof (*rtin));
135*0Sstevel@tonic-gate 	for (i = 0; i < (segments + 1)/2; i++) {
136*0Sstevel@tonic-gate 		tmp = rtin_addrs[i];
137*0Sstevel@tonic-gate 		rtout_addrs[i] = rtin_addrs[segments - 1 - i];
138*0Sstevel@tonic-gate 		rtout_addrs[segments - 1 - i] = tmp;
139*0Sstevel@tonic-gate 	}
140*0Sstevel@tonic-gate 	rtout->ip6r0_segleft = segments;
141*0Sstevel@tonic-gate 	return (0);
142*0Sstevel@tonic-gate }
143*0Sstevel@tonic-gate 
144*0Sstevel@tonic-gate /*
145*0Sstevel@tonic-gate  * Return the number of segments in the routing header.
146*0Sstevel@tonic-gate  */
147*0Sstevel@tonic-gate int
inet6_rth_segments(const void * bp)148*0Sstevel@tonic-gate inet6_rth_segments(const void *bp)
149*0Sstevel@tonic-gate {
150*0Sstevel@tonic-gate 	struct ip6_rthdr0 *rthdr;
151*0Sstevel@tonic-gate 
152*0Sstevel@tonic-gate 	rthdr = (struct ip6_rthdr0 *)bp;
153*0Sstevel@tonic-gate 	if (rthdr->ip6r0_type == 0) {
154*0Sstevel@tonic-gate 		if (rthdr->ip6r0_len > MAX_RTHDR0_SEGMENTS * 2) {
155*0Sstevel@tonic-gate 			return (-1);
156*0Sstevel@tonic-gate 		} else {
157*0Sstevel@tonic-gate 			return (rthdr->ip6r0_len / 2);
158*0Sstevel@tonic-gate 		}
159*0Sstevel@tonic-gate 	} else {
160*0Sstevel@tonic-gate 		return (-1);
161*0Sstevel@tonic-gate 	}
162*0Sstevel@tonic-gate }
163*0Sstevel@tonic-gate 
164*0Sstevel@tonic-gate /*
165*0Sstevel@tonic-gate  * Return a pointer to an element in the source route.
166*0Sstevel@tonic-gate  * This uses the C convention for index [0, size-1].
167*0Sstevel@tonic-gate  */
168*0Sstevel@tonic-gate struct in6_addr *
inet6_rth_getaddr(const void * bp,int index)169*0Sstevel@tonic-gate inet6_rth_getaddr(const void *bp, int index)
170*0Sstevel@tonic-gate {
171*0Sstevel@tonic-gate 	struct ip6_rthdr0 *rthdr;
172*0Sstevel@tonic-gate 	struct in6_addr *rv;
173*0Sstevel@tonic-gate 
174*0Sstevel@tonic-gate 	rthdr = (struct ip6_rthdr0 *)bp;
175*0Sstevel@tonic-gate 	if (index >= rthdr->ip6r0_len/2 || index < 0)
176*0Sstevel@tonic-gate 		return (NULL);
177*0Sstevel@tonic-gate 
178*0Sstevel@tonic-gate 	rv = (struct in6_addr *)((char *)rthdr + sizeof (*rthdr));
179*0Sstevel@tonic-gate 	return (&rv[index]);
180*0Sstevel@tonic-gate }
181