217 lines
4.9 KiB
C
217 lines
4.9 KiB
C
/* $OpenBSD: inet_nat64.c,v 1.2 2015/03/14 03:38:51 jsg Exp $ */
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/* $vantronix: inet_nat64.c,v 1.2 2011/02/28 14:57:58 mike Exp $ */
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/*
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* Copyright (c) 2011 Reyk Floeter <reyk@vantronix.net>
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*
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* Permission to use, copy, modify, and distribute this software for any
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* purpose with or without fee is hereby granted, provided that the above
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* copyright notice and this permission notice appear in all copies.
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*
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* THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
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* WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
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* MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
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* ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
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* WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
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* ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
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* OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
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*/
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#include <sys/param.h>
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#include <sys/socket.h>
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#ifdef _KERNEL
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#include <sys/mbuf.h>
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#else
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#include <errno.h>
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#endif
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union inet_nat64_addr {
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u_int32_t u32[4];
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u_int8_t u8[16];
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};
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u_int32_t inet_nat64_mask(u_int32_t, u_int32_t, u_int8_t);
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int inet_nat64(int, const void *, void *, const void *, u_int8_t);
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int inet_nat64_inet(const void *, void *, const void *, u_int8_t);
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int inet_nat64_inet6(const void *, void *, const void *, u_int8_t);
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int inet_nat46(int, const void *, void *, const void *, u_int8_t);
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int inet_nat46_inet(const void *, void *, const void *, u_int8_t);
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int inet_nat46_inet6(const void *, void *, const void *, u_int8_t);
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u_int32_t
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inet_nat64_mask(u_int32_t src, u_int32_t pfx, u_int8_t pfxlen)
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{
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u_int32_t u32;
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if (pfxlen == 0)
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return (src);
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else if (pfxlen > 32)
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pfxlen = 32;
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u32 =
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(src & ~htonl(0xffffffff << (32 - pfxlen))) |
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(pfx & htonl(0xffffffff << (32 - pfxlen)));
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return (u32);
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}
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int
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inet_nat64(int af, const void *src, void *dst,
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const void *pfx, u_int8_t pfxlen)
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{
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switch (af) {
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case AF_INET:
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return (inet_nat64_inet(src, dst, pfx, pfxlen));
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case AF_INET6:
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return (inet_nat64_inet6(src, dst, pfx, pfxlen));
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default:
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#ifndef _KERNEL
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errno = EAFNOSUPPORT;
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#endif
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return (-1);
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}
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/* NOTREACHED */
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}
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int
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inet_nat64_inet(const void *src, void *dst, const void *pfx, u_int8_t pfxlen)
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{
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const union inet_nat64_addr *s = src;
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const union inet_nat64_addr *p = pfx;
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union inet_nat64_addr *d = dst;
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int i, j;
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switch (pfxlen) {
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case 32:
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case 40:
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case 48:
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case 56:
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case 64:
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case 96:
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i = pfxlen / 8;
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break;
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default:
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if (pfxlen < 96 || pfxlen > 128) {
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#ifndef _KERNEL
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errno = EINVAL;
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#endif
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return (-1);
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}
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/* as an extension, mask out any other bits */
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d->u32[0] = inet_nat64_mask(s->u32[3], p->u32[3],
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(u_int8_t)(32 - (128 - pfxlen)));
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return (0);
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}
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/* fill the octets with the source and skip reserved octet 8 */
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for (j = 0; j < 4; j++) {
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if (i == 8)
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i++;
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d->u8[j] = s->u8[i++];
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}
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return (0);
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}
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int
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inet_nat64_inet6(const void *src, void *dst, const void *pfx, u_int8_t pfxlen)
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{
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const union inet_nat64_addr *s = src;
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const union inet_nat64_addr *p = pfx;
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union inet_nat64_addr *d = dst;
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int i, j;
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/* first copy the prefix octets to the destination */
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*d = *p;
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switch (pfxlen) {
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case 32:
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case 40:
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case 48:
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case 56:
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case 64:
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case 96:
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i = pfxlen / 8;
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break;
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default:
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if (pfxlen < 96 || pfxlen > 128) {
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#ifndef _KERNEL
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errno = EINVAL;
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#endif
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return (-1);
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}
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/* as an extension, mask out any other bits */
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d->u32[3] = inet_nat64_mask(s->u32[0], p->u32[3],
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(u_int8_t)(32 - (128 - pfxlen)));
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return (0);
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}
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/* octet 8 is reserved and must be set to zero */
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d->u8[8] = 0;
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/* fill the other octets with the source and skip octet 8 */
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for (j = 0; j < 4; j++) {
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if (i == 8)
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i++;
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d->u8[i++] = s->u8[j];
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}
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return (0);
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}
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int
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inet_nat46(int af, const void *src, void *dst,
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const void *pfx, u_int8_t pfxlen)
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{
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if (pfxlen > 32) {
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#ifndef _KERNEL
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errno = EINVAL;
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#endif
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return (-1);
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}
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switch (af) {
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case AF_INET:
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return (inet_nat46_inet(src, dst, pfx, pfxlen));
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case AF_INET6:
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return (inet_nat46_inet6(src, dst, pfx, pfxlen));
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default:
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#ifndef _KERNEL
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errno = EAFNOSUPPORT;
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#endif
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return (-1);
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}
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/* NOTREACHED */
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}
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int
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inet_nat46_inet(const void *src, void *dst, const void *pfx, u_int8_t pfxlen)
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{
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const union inet_nat64_addr *s = src;
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const union inet_nat64_addr *p = pfx;
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union inet_nat64_addr *d = dst;
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/* set the remaining bits to the source */
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d->u32[0] = inet_nat64_mask(s->u32[3], p->u32[0], pfxlen);
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return (0);
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}
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int
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inet_nat46_inet6(const void *src, void *dst, const void *pfx, u_int8_t pfxlen)
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{
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const union inet_nat64_addr *s = src;
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const union inet_nat64_addr *p = pfx;
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union inet_nat64_addr *d = dst;
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/* set the initial octets to zero */
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d->u32[0] = d->u32[1] = d->u32[2] = 0;
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/* now set the remaining bits to the source */
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d->u32[3] = inet_nat64_mask(s->u32[0], p->u32[0], pfxlen);
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return (0);
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}
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