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 /* 28 * This code is conformant to revision 7 of 2292bis. Some of these functions 29 * were provided (named inet6_rthdr_) in a very similar form in RFC 2292. 30 * The RFC 2292 variants are not supported. 31 */ 32 33 #include <stdio.h> 34 #include <ctype.h> 35 #include <string.h> 36 #include <stdlib.h> 37 #include <sys/types.h> 38 #include <sys/socket.h> 39 #include <netinet/in.h> 40 #include <netinet/ip6.h> 41 #include <unistd.h> 42 #include <errno.h> 43 44 #define MAX_RTHDR0_SEGMENTS 127 45 46 /* 47 * Return amount of space needed to hold N segments for the specified 48 * routing type. Does NOT include space for cmsghdr. 49 */ 50 socklen_t 51 inet6_rth_space(int type, int segments) 52 { 53 if (type != IPV6_RTHDR_TYPE_0 || segments < 0 || 54 segments > MAX_RTHDR0_SEGMENTS) 55 return (0); 56 57 return (sizeof (struct ip6_rthdr0) + 58 segments * sizeof (struct in6_addr)); 59 } 60 61 /* 62 * Initializes rthdr structure. Verifies the segments against the length of 63 * the buffer. 64 * Note that a routing header can only hold 127 segments since the length field 65 * in the header is just a byte. 66 */ 67 void * 68 inet6_rth_init(void *bp, socklen_t bp_len, int type, int segments) 69 { 70 struct ip6_rthdr0 *rthdr; 71 72 if (type != IPV6_RTHDR_TYPE_0 || segments < 0 || 73 segments > MAX_RTHDR0_SEGMENTS) 74 return (NULL); 75 76 if (bp_len < sizeof (struct ip6_rthdr0) + 77 segments * sizeof (struct in6_addr)) 78 return (NULL); 79 80 rthdr = (struct ip6_rthdr0 *)bp; 81 rthdr->ip6r0_nxt = 0; 82 rthdr->ip6r0_len = (segments * 2); 83 rthdr->ip6r0_type = type; 84 rthdr->ip6r0_segleft = 0; /* Incremented by rthdr_add */ 85 *(uint32_t *)&rthdr->ip6r0_reserved = 0; 86 return (bp); 87 } 88 89 /* 90 * Add one more address to the routing header. Fails when there is no more 91 * room. 92 */ 93 int 94 inet6_rth_add(void *bp, const struct in6_addr *addr) 95 { 96 struct ip6_rthdr0 *rthdr; 97 struct in6_addr *addrs; 98 99 rthdr = (struct ip6_rthdr0 *)bp; 100 if ((rthdr->ip6r0_segleft + 1) * 2 > rthdr->ip6r0_len) { 101 /* Not room for one more */ 102 return (-1); 103 } 104 addrs = (struct in6_addr *)((char *)rthdr + sizeof (*rthdr)); 105 addrs[rthdr->ip6r0_segleft++] = *addr; 106 return (0); 107 } 108 109 /* 110 * Reverse a source route. Both arguments can point to the same buffer. 111 */ 112 int 113 inet6_rth_reverse(const void *in, void *out) 114 { 115 struct ip6_rthdr0 *rtin, *rtout; 116 int i, segments; 117 struct in6_addr tmp; 118 struct in6_addr *rtout_addrs; 119 struct in6_addr *rtin_addrs; 120 121 rtin = (struct ip6_rthdr0 *)in; 122 rtout = (struct ip6_rthdr0 *)out; 123 124 if (rtout->ip6r0_type != 0 || rtin->ip6r0_type != 0 || 125 rtout->ip6r0_len > MAX_RTHDR0_SEGMENTS * 2 || 126 rtin->ip6r0_len > MAX_RTHDR0_SEGMENTS * 2 || 127 rtout->ip6r0_len != rtin->ip6r0_len) 128 return (-1); 129 130 segments = rtin->ip6r0_len / 2; 131 rtout_addrs = (struct in6_addr *)((char *)rtout + sizeof (*rtout)); 132 rtin_addrs = (struct in6_addr *)((char *)rtin + sizeof (*rtin)); 133 for (i = 0; i < (segments + 1)/2; i++) { 134 tmp = rtin_addrs[i]; 135 rtout_addrs[i] = rtin_addrs[segments - 1 - i]; 136 rtout_addrs[segments - 1 - i] = tmp; 137 } 138 rtout->ip6r0_segleft = segments; 139 return (0); 140 } 141 142 /* 143 * Return the number of segments in the routing header. 144 */ 145 int 146 inet6_rth_segments(const void *bp) 147 { 148 struct ip6_rthdr0 *rthdr; 149 150 rthdr = (struct ip6_rthdr0 *)bp; 151 if (rthdr->ip6r0_type == 0) { 152 if (rthdr->ip6r0_len > MAX_RTHDR0_SEGMENTS * 2) { 153 return (-1); 154 } else { 155 return (rthdr->ip6r0_len / 2); 156 } 157 } else { 158 return (-1); 159 } 160 } 161 162 /* 163 * Return a pointer to an element in the source route. 164 * This uses the C convention for index [0, size-1]. 165 */ 166 struct in6_addr * 167 inet6_rth_getaddr(const void *bp, int index) 168 { 169 struct ip6_rthdr0 *rthdr; 170 struct in6_addr *rv; 171 172 rthdr = (struct ip6_rthdr0 *)bp; 173 if (index >= rthdr->ip6r0_len/2 || index < 0) 174 return (NULL); 175 176 rv = (struct in6_addr *)((char *)rthdr + sizeof (*rthdr)); 177 return (&rv[index]); 178 } 179