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/*
* CDDL HEADER START
*
* The contents of this file are subject to the terms of the
* Common Development and Distribution License (the "License").
* You may not use this file except in compliance with the License.
*
* You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
* or http://www.opensolaris.org/os/licensing.
* See the License for the specific language governing permissions
* and limitations under the License.
*
* When distributing Covered Code, include this CDDL HEADER in each
* file and include the License file at usr/src/OPENSOLARIS.LICENSE.
* If applicable, add the following below this CDDL HEADER, with the
* fields enclosed by brackets "[]" replaced with your own identifying
* information: Portions Copyright [yyyy] [name of copyright owner]
*
* CDDL HEADER END
*/
/*
* Copyright (c) 2009, 2010, Oracle and/or its affiliates. All rights reserved.
*/
#include <unistd.h>
#include <netinet/in.h>
#include <libinetutil.h>
#include <inet/ip.h>
#include <strings.h>
#include <stddef.h>
#include <errno.h>
#include <libsocket_priv.h>
/*
* Internet utility functions.
*/
/*
* Given a host-order address, calculate client's default net mask.
* Consult netmasks database to see if net is further subnetted.
* We'll only snag the first netmask that matches our criteria.
* We return the resultant netmask in host order.
*/
void
get_netmask4(const struct in_addr *n_addrp, struct in_addr *s_addrp)
{
struct in_addr hp, tp;
/*
* First check if VLSM is in use.
*/
hp.s_addr = htonl(n_addrp->s_addr);
if (getnetmaskbyaddr(hp, &tp) == 0) {
s_addrp->s_addr = ntohl(tp.s_addr);
return;
}
/*
* Fall back on standard classed networks.
*/
if (IN_CLASSA(n_addrp->s_addr))
s_addrp->s_addr = IN_CLASSA_NET;
else if (IN_CLASSB(n_addrp->s_addr))
s_addrp->s_addr = IN_CLASSB_NET;
else if (IN_CLASSC(n_addrp->s_addr))
s_addrp->s_addr = IN_CLASSC_NET;
else
s_addrp->s_addr = IN_CLASSE_NET;
}
/*
* Checks if the IP addresses `ssp1' and `ssp2' are equal.
*/
boolean_t
sockaddrcmp(const struct sockaddr_storage *ssp1,
const struct sockaddr_storage *ssp2)
{
struct in_addr addr1, addr2;
const struct in6_addr *addr6p1, *addr6p2;
if (ssp1->ss_family != ssp2->ss_family)
return (B_FALSE);
if (ssp1 == ssp2)
return (B_TRUE);
switch (ssp1->ss_family) {
case AF_INET:
addr1 = ((const struct sockaddr_in *)ssp1)->sin_addr;
addr2 = ((const struct sockaddr_in *)ssp2)->sin_addr;
return (addr1.s_addr == addr2.s_addr);
case AF_INET6:
addr6p1 = &((const struct sockaddr_in6 *)ssp1)->sin6_addr;
addr6p2 = &((const struct sockaddr_in6 *)ssp2)->sin6_addr;
return (IN6_ARE_ADDR_EQUAL(addr6p1, addr6p2));
}
return (B_FALSE);
}
/*
* Stores the netmask in `mask' for the given prefixlen `plen' and also sets
* `sa_family' in `mask'. Because this function does not require aligned
* access to the data inside of the sockaddr_in/6 structures, the code can
* use offsetof() to find the right place in the incoming structure. Why is
* using that beneficial? Less issues with lint. When using a direct cast
* of the struct sockaddr_storage structure to sockaddr_in6, a lint warning
* is generated because the former is composed of 16bit & 8bit elements whilst
* sockaddr_in6 has a 32bit alignment requirement.
*/
int
plen2mask(uint_t prefixlen, sa_family_t af, struct sockaddr *mask)
{
uint8_t *addr;
if (af == AF_INET) {
if (prefixlen > IP_ABITS)
return (EINVAL);
bzero(mask, sizeof (struct sockaddr_in));
addr = (uint8_t *)mask;
addr += offsetof(struct sockaddr_in, sin_addr);
} else {
if (prefixlen > IPV6_ABITS)
return (EINVAL);
bzero(mask, sizeof (struct sockaddr_in6));
addr = (uint8_t *)mask;
addr += offsetof(struct sockaddr_in6, sin6_addr);
}
mask->sa_family = af;
while (prefixlen > 0) {
if (prefixlen >= 8) {
*addr++ = 0xFF;
prefixlen -= 8;
continue;
}
*addr |= 1 << (8 - prefixlen);
prefixlen--;
}
return (0);
}
/*
* Convert a mask to a prefix length.
* Returns prefix length on success, -1 otherwise.
* The comments (above) for plen2mask about the use of `mask' also apply
* to this function and the choice to use offsetof here too.
*/
int
mask2plen(const struct sockaddr *mask)
{
int rc = 0;
uint8_t last;
uint8_t *addr;
int limit;
if (mask->sa_family == AF_INET) {
limit = IP_ABITS;
addr = (uint8_t *)mask;
addr += offsetof(struct sockaddr_in, sin_addr);
} else {
limit = IPV6_ABITS;
addr = (uint8_t *)mask;
addr += offsetof(struct sockaddr_in6, sin6_addr);
}
while (*addr == 0xff) {
rc += 8;
if (rc == limit)
return (limit);
addr++;
}
last = *addr;
while (last != 0) {
rc++;
last = (last << 1) & 0xff;
}
return (rc);
}
/*
* Returns B_TRUE if the address in `ss' is INADDR_ANY for IPv4 or
* :: for IPv6. Otherwise, returns B_FALSE.
*/
boolean_t
sockaddrunspec(const struct sockaddr *ss)
{
struct sockaddr_storage data;
switch (ss->sa_family) {
case AF_INET:
(void) memcpy(&data, ss, sizeof (struct sockaddr_in));
return (((struct sockaddr_in *)&data)->sin_addr.s_addr ==
INADDR_ANY);
case AF_INET6:
(void) memcpy(&data, ss, sizeof (struct sockaddr_in6));
return (IN6_IS_ADDR_UNSPECIFIED(
&((struct sockaddr_in6 *)&data)->sin6_addr));
}
return (B_FALSE);
}
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