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