freebsd-skq/lib/libc/net/rthdr.c
mtm b79eceb7f3 Make inet6_rth_* family of functions more compliant with RFC3542:
1. CMSG_NXTHDR(mhdr, cmsg) is supposed to dereference cmsg and return
   the next header in the chain. If cmsg is NULL it should return
   the first header, behaving essentially like CMSG_FIRSTHDR().
2. inet6_rth_(space|init|add) should do basic checking on their input
   to verify that the number of headers (segments) is
   between 0 and 127 inclusive.

MFC-After: 1 month
2007-04-19 15:48:16 +00:00

451 lines
9.8 KiB
C

/* $KAME: rthdr.c,v 1.19 2003/06/06 10:48:51 itojun Exp $ */
/*
* Copyright (C) 1995, 1996, 1997, and 1998 WIDE Project.
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
* 3. Neither the name of the project nor the names of its contributors
* may be used to endorse or promote products derived from this software
* without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE PROJECT AND CONTRIBUTORS ``AS IS'' AND
* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL THE PROJECT OR CONTRIBUTORS BE LIABLE
* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGE.
*/
#include <sys/cdefs.h>
__FBSDID("$FreeBSD$");
#include <sys/param.h>
#include <sys/types.h>
#include <sys/socket.h>
#include <netinet/in.h>
#include <netinet/ip6.h>
#include <string.h>
#include <stdio.h>
/*
* RFC2292 API
*/
size_t
inet6_rthdr_space(type, seg)
int type, seg;
{
switch (type) {
case IPV6_RTHDR_TYPE_0:
if (seg < 1 || seg > 23)
return (0);
#ifdef COMPAT_RFC2292
return (CMSG_SPACE(sizeof(struct in6_addr) * (seg - 1) +
sizeof(struct ip6_rthdr0)));
#else
return (CMSG_SPACE(sizeof(struct in6_addr) * seg +
sizeof(struct ip6_rthdr0)));
#endif
default:
return (0);
}
}
struct cmsghdr *
inet6_rthdr_init(bp, type)
void *bp;
int type;
{
struct cmsghdr *ch = (struct cmsghdr *)bp;
struct ip6_rthdr *rthdr;
rthdr = (struct ip6_rthdr *)CMSG_DATA(ch);
ch->cmsg_level = IPPROTO_IPV6;
ch->cmsg_type = IPV6_RTHDR;
switch (type) {
case IPV6_RTHDR_TYPE_0:
#ifdef COMPAT_RFC2292
ch->cmsg_len = CMSG_LEN(sizeof(struct ip6_rthdr0) -
sizeof(struct in6_addr));
#else
ch->cmsg_len = CMSG_LEN(sizeof(struct ip6_rthdr0));
#endif
bzero(rthdr, sizeof(struct ip6_rthdr0));
rthdr->ip6r_type = IPV6_RTHDR_TYPE_0;
return (ch);
default:
return (NULL);
}
}
/* ARGSUSED */
int
inet6_rthdr_add(cmsg, addr, flags)
struct cmsghdr *cmsg;
const struct in6_addr *addr;
u_int flags;
{
struct ip6_rthdr *rthdr;
rthdr = (struct ip6_rthdr *)CMSG_DATA(cmsg);
switch (rthdr->ip6r_type) {
case IPV6_RTHDR_TYPE_0:
{
struct ip6_rthdr0 *rt0 = (struct ip6_rthdr0 *)rthdr;
if (flags != IPV6_RTHDR_LOOSE && flags != IPV6_RTHDR_STRICT)
return (-1);
if (rt0->ip6r0_segleft == 23)
return (-1);
#ifdef COMPAT_RFC1883 /* XXX */
if (flags == IPV6_RTHDR_STRICT) {
int c, b;
c = rt0->ip6r0_segleft / 8;
b = rt0->ip6r0_segleft % 8;
rt0->ip6r0_slmap[c] |= (1 << (7 - b));
}
#else
if (flags != IPV6_RTHDR_LOOSE)
return (-1);
#endif
rt0->ip6r0_segleft++;
bcopy(addr, (caddr_t)rt0 + ((rt0->ip6r0_len + 1) << 3),
sizeof(struct in6_addr));
rt0->ip6r0_len += sizeof(struct in6_addr) >> 3;
cmsg->cmsg_len = CMSG_LEN((rt0->ip6r0_len + 1) << 3);
break;
}
default:
return (-1);
}
return (0);
}
/* ARGSUSED */
int
inet6_rthdr_lasthop(cmsg, flags)
struct cmsghdr *cmsg;
unsigned int flags;
{
struct ip6_rthdr *rthdr;
rthdr = (struct ip6_rthdr *)CMSG_DATA(cmsg);
switch (rthdr->ip6r_type) {
case IPV6_RTHDR_TYPE_0:
{
struct ip6_rthdr0 *rt0 = (struct ip6_rthdr0 *)rthdr;
#ifdef COMPAT_RFC1883 /* XXX */
if (flags != IPV6_RTHDR_LOOSE && flags != IPV6_RTHDR_STRICT)
return (-1);
#endif /* COMPAT_RFC1883 */
if (rt0->ip6r0_segleft > 23)
return (-1);
#ifdef COMPAT_RFC1883 /* XXX */
if (flags == IPV6_RTHDR_STRICT) {
int c, b;
c = rt0->ip6r0_segleft / 8;
b = rt0->ip6r0_segleft % 8;
rt0->ip6r0_slmap[c] |= (1 << (7 - b));
}
#else
if (flags != IPV6_RTHDR_LOOSE)
return (-1);
#endif /* COMPAT_RFC1883 */
break;
}
default:
return (-1);
}
return (0);
}
#if 0
int
inet6_rthdr_reverse(in, out)
const struct cmsghdr *in;
struct cmsghdr *out;
{
return (-1);
}
#endif
int
inet6_rthdr_segments(cmsg)
const struct cmsghdr *cmsg;
{
struct ip6_rthdr *rthdr;
rthdr = (struct ip6_rthdr *)CMSG_DATA(cmsg);
switch (rthdr->ip6r_type) {
case IPV6_RTHDR_TYPE_0:
{
struct ip6_rthdr0 *rt0 = (struct ip6_rthdr0 *)rthdr;
if (rt0->ip6r0_len % 2 || 46 < rt0->ip6r0_len)
return (-1);
return (rt0->ip6r0_len * 8) / sizeof(struct in6_addr);
}
default:
return (-1);
}
}
struct in6_addr *
inet6_rthdr_getaddr(cmsg, idx)
struct cmsghdr *cmsg;
int idx;
{
struct ip6_rthdr *rthdr;
rthdr = (struct ip6_rthdr *)CMSG_DATA(cmsg);
switch (rthdr->ip6r_type) {
case IPV6_RTHDR_TYPE_0:
{
struct ip6_rthdr0 *rt0 = (struct ip6_rthdr0 *)rthdr;
int naddr;
if (rt0->ip6r0_len % 2 || 46 < rt0->ip6r0_len)
return NULL;
naddr = (rt0->ip6r0_len * 8) / sizeof(struct in6_addr);
if (idx <= 0 || naddr < idx)
return NULL;
#ifdef COMPAT_RFC2292
return (((struct in6_addr *)(rt0 + 1)) + idx - 1);
#else
return (((struct in6_addr *)(rt0 + 1)) + idx);
#endif
}
default:
return NULL;
}
}
int
inet6_rthdr_getflags(cmsg, idx)
const struct cmsghdr *cmsg;
int idx;
{
struct ip6_rthdr *rthdr;
rthdr = (struct ip6_rthdr *)CMSG_DATA(cmsg);
switch (rthdr->ip6r_type) {
case IPV6_RTHDR_TYPE_0:
{
struct ip6_rthdr0 *rt0 = (struct ip6_rthdr0 *)rthdr;
int naddr;
if (rt0->ip6r0_len % 2 || 46 < rt0->ip6r0_len)
return (-1);
naddr = (rt0->ip6r0_len * 8) / sizeof(struct in6_addr);
if (idx < 0 || naddr < idx)
return (-1);
#ifdef COMPAT_RFC1883 /* XXX */
if (rt0->ip6r0_slmap[idx / 8] & (0x80 >> (idx % 8)))
return IPV6_RTHDR_STRICT;
else
return IPV6_RTHDR_LOOSE;
#else
return IPV6_RTHDR_LOOSE;
#endif /* COMPAT_RFC1883 */
}
default:
return (-1);
}
}
/*
* RFC3542 API
*/
socklen_t
inet6_rth_space(int type, int segments)
{
switch (type) {
case IPV6_RTHDR_TYPE_0:
if ((segments >= 0) && (segments <= 127))
return (((segments * 2) + 1) << 3);
/* FALLTHROUGH */
default:
return (0); /* type not suppported */
}
}
void *
inet6_rth_init(void *bp, socklen_t bp_len, int type, int segments)
{
struct ip6_rthdr *rth = (struct ip6_rthdr *)bp;
struct ip6_rthdr0 *rth0;
switch (type) {
case IPV6_RTHDR_TYPE_0:
/* length validation */
if (bp_len < inet6_rth_space(IPV6_RTHDR_TYPE_0, segments))
return (NULL);
/* segment validation */
if ((segments < 0) || (segments > 127))
return (NULL);
memset(bp, 0, bp_len);
rth0 = (struct ip6_rthdr0 *)rth;
rth0->ip6r0_len = segments * 2;
rth0->ip6r0_type = IPV6_RTHDR_TYPE_0;
rth0->ip6r0_segleft = 0;
rth0->ip6r0_reserved = 0;
break;
default:
return (NULL); /* type not supported */
}
return (bp);
}
int
inet6_rth_add(void *bp, const struct in6_addr *addr)
{
struct ip6_rthdr *rth = (struct ip6_rthdr *)bp;
struct ip6_rthdr0 *rth0;
struct in6_addr *nextaddr;
switch (rth->ip6r_type) {
case IPV6_RTHDR_TYPE_0:
rth0 = (struct ip6_rthdr0 *)rth;
/* Don't exceed the number of stated segments */
if (rth0->ip6r0_segleft == (rth0->ip6r0_len / 2))
return (-1);
nextaddr = (struct in6_addr *)(rth0 + 1) + rth0->ip6r0_segleft;
*nextaddr = *addr;
rth0->ip6r0_segleft++;
break;
default:
return (-1); /* type not supported */
}
return (0);
}
int
inet6_rth_reverse(const void *in, void *out)
{
struct ip6_rthdr *rth_in = (struct ip6_rthdr *)in;
struct ip6_rthdr0 *rth0_in, *rth0_out;
int i, segments;
switch (rth_in->ip6r_type) {
case IPV6_RTHDR_TYPE_0:
rth0_in = (struct ip6_rthdr0 *)in;
rth0_out = (struct ip6_rthdr0 *)out;
/* parameter validation XXX too paranoid? */
if (rth0_in->ip6r0_len % 2)
return (-1);
segments = rth0_in->ip6r0_len / 2;
/* we can't use memcpy here, since in and out may overlap */
memmove((void *)rth0_out, (void *)rth0_in,
((rth0_in->ip6r0_len) + 1) << 3);
rth0_out->ip6r0_segleft = segments;
/* reverse the addresses */
for (i = 0; i < segments / 2; i++) {
struct in6_addr addr_tmp, *addr1, *addr2;
addr1 = (struct in6_addr *)(rth0_out + 1) + i;
addr2 = (struct in6_addr *)(rth0_out + 1) +
(segments - i - 1);
addr_tmp = *addr1;
*addr1 = *addr2;
*addr2 = addr_tmp;
}
break;
default:
return (-1); /* type not supported */
}
return (0);
}
int
inet6_rth_segments(const void *bp)
{
struct ip6_rthdr *rh = (struct ip6_rthdr *)bp;
struct ip6_rthdr0 *rh0;
int addrs;
switch (rh->ip6r_type) {
case IPV6_RTHDR_TYPE_0:
rh0 = (struct ip6_rthdr0 *)bp;
/*
* Validation for a type-0 routing header.
* Is this too strict?
*/
if ((rh0->ip6r0_len % 2) != 0 ||
(addrs = (rh0->ip6r0_len >> 1)) < rh0->ip6r0_segleft)
return (-1);
return (addrs);
default:
return (-1); /* unknown type */
}
}
struct in6_addr *
inet6_rth_getaddr(const void *bp, int idx)
{
struct ip6_rthdr *rh = (struct ip6_rthdr *)bp;
struct ip6_rthdr0 *rh0;
int addrs;
switch (rh->ip6r_type) {
case IPV6_RTHDR_TYPE_0:
rh0 = (struct ip6_rthdr0 *)bp;
/*
* Validation for a type-0 routing header.
* Is this too strict?
*/
if ((rh0->ip6r0_len % 2) != 0 ||
(addrs = (rh0->ip6r0_len >> 1)) < rh0->ip6r0_segleft)
return (NULL);
if (idx < 0 || addrs <= idx)
return (NULL);
return (((struct in6_addr *)(rh0 + 1)) + idx);
default:
return (NULL); /* unknown type */
break;
}
}