/* SPDX-License-Identifier: BSD-2-Clause */
/*
* Socket Address handling for dhcpcd
* Copyright (c) 2015-2021 Roy Marples <roy@marples.name>
* 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.
*
* THIS SOFTWARE IS PROVIDED BY THE AUTHOR 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 AUTHOR 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/socket.h>
#include <sys/types.h>
#include <arpa/inet.h>
#ifdef AF_LINK
#include <net/if_dl.h>
#elif defined(AF_PACKET)
#include <linux/if_packet.h>
#endif
#include <assert.h>
#include <errno.h>
#include <stdbool.h>
#include <stddef.h>
#include <stdio.h>
#include <stdint.h>
#include <string.h>
#include "config.h"
#include "common.h"
#include "sa.h"
#ifndef NDEBUG
static bool sa_inprefix;
#endif
socklen_t
sa_addroffset(const struct sockaddr *sa)
{
assert(sa != NULL);
switch(sa->sa_family) {
#ifdef INET
case AF_INET:
return offsetof(struct sockaddr_in, sin_addr) +
offsetof(struct in_addr, s_addr);
#endif /* INET */
#ifdef INET6
case AF_INET6:
return offsetof(struct sockaddr_in6, sin6_addr) +
offsetof(struct in6_addr, s6_addr);
#endif /* INET6 */
default:
errno = EAFNOSUPPORT;
return 0;
}
}
socklen_t
sa_addrlen(const struct sockaddr *sa)
{
#define membersize(type, member) sizeof(((type *)0)->member)
assert(sa != NULL);
switch(sa->sa_family) {
#ifdef INET
case AF_INET:
return membersize(struct in_addr, s_addr);
#endif /* INET */
#ifdef INET6
case AF_INET6:
return membersize(struct in6_addr, s6_addr);
#endif /* INET6 */
default:
errno = EAFNOSUPPORT;
return 0;
}
}
#ifndef HAVE_SA_LEN
socklen_t
sa_len(const struct sockaddr *sa)
{
switch (sa->sa_family) {
#ifdef AF_LINK
case AF_LINK:
return sizeof(struct sockaddr_dl);
#endif
#ifdef AF_PACKET
case AF_PACKET:
return sizeof(struct sockaddr_ll);
#endif
case AF_INET:
return sizeof(struct sockaddr_in);
case AF_INET6:
return sizeof(struct sockaddr_in6);
default:
return sizeof(struct sockaddr);
}
}
#endif
bool
sa_is_unspecified(const struct sockaddr *sa)
{
assert(sa != NULL);
switch(sa->sa_family) {
case AF_UNSPEC:
return true;
#ifdef INET
case AF_INET:
return satocsin(sa)->sin_addr.s_addr == INADDR_ANY;
#endif /* INET */
#ifdef INET6
case AF_INET6:
return IN6_IS_ADDR_UNSPECIFIED(&satocsin6(sa)->sin6_addr);
#endif /* INET6 */
default:
errno = EAFNOSUPPORT;
return false;
}
}
#ifdef INET6
#ifndef IN6MASK128
#define IN6MASK128 {{{ 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, \
0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff }}}
#endif
static const struct in6_addr in6allones = IN6MASK128;
#endif
bool
sa_is_allones(const struct sockaddr *sa)
{
assert(sa != NULL);
switch(sa->sa_family) {
case AF_UNSPEC:
return false;
#ifdef INET
case AF_INET:
{
const struct sockaddr_in *sin;
sin = satocsin(sa);
return sin->sin_addr.s_addr == INADDR_BROADCAST;
}
#endif /* INET */
#ifdef INET6
case AF_INET6:
{
const struct sockaddr_in6 *sin6;
sin6 = satocsin6(sa);
return IN6_ARE_ADDR_EQUAL(&sin6->sin6_addr, &in6allones);
}
#endif /* INET6 */
default:
errno = EAFNOSUPPORT;
return false;
}
}
bool
sa_is_loopback(const struct sockaddr *sa)
{
assert(sa != NULL);
switch(sa->sa_family) {
case AF_UNSPEC:
return false;
#ifdef INET
case AF_INET:
{
const struct sockaddr_in *sin;
sin = satocsin(sa);
return sin->sin_addr.s_addr == htonl(INADDR_LOOPBACK);
}
#endif /* INET */
#ifdef INET6
case AF_INET6:
{
const struct sockaddr_in6 *sin6;
sin6 = satocsin6(sa);
return IN6_IS_ADDR_LOOPBACK(&sin6->sin6_addr);
}
#endif /* INET6 */
default:
errno = EAFNOSUPPORT;
return false;
}
}
int
sa_toprefix(const struct sockaddr *sa)
{
int prefix;
assert(sa != NULL);
switch(sa->sa_family) {
#ifdef INET
case AF_INET:
{
const struct sockaddr_in *sin;
uint32_t mask;
sin = satocsin(sa);
if (sin->sin_addr.s_addr == INADDR_ANY) {
prefix = 0;
break;
}
mask = ntohl(sin->sin_addr.s_addr);
prefix = 33 - ffs((int)mask); /* 33 - (1 .. 32) -> 32 .. 1 */
if (prefix < 32) { /* more than 1 bit in mask */
/* check for non-contig netmask */
if ((mask^(((1U << prefix)-1) << (32 - prefix))) != 0) {
errno = EINVAL;
return -1; /* noncontig, no pfxlen */
}
}
break;
}
#endif
#ifdef INET6
case AF_INET6:
{
const struct sockaddr_in6 *sin6;
int x, y;
const uint8_t *lim, *p;
sin6 = satocsin6(sa);
p = (const uint8_t *)sin6->sin6_addr.s6_addr;
lim = p + sizeof(sin6->sin6_addr.s6_addr);
for (x = 0; p < lim; x++, p++) {
if (*p != 0xff)
break;
}
y = 0;
if (p < lim) {
for (y = 0; y < NBBY; y++) {
if ((*p & (0x80 >> y)) == 0)
break;
}
}
/*
* when the limit pointer is given, do a stricter check on the
* remaining bits.
*/
if (p < lim) {
if (y != 0 && (*p & (0x00ff >> y)) != 0)
return 0;
for (p = p + 1; p < lim; p++)
if (*p != 0)
return 0;
}
prefix = x * NBBY + y;
break;
}
#endif
default:
errno = EAFNOSUPPORT;
return -1;
}
#ifndef NDEBUG
/* Ensure the calculation is correct */
if (!sa_inprefix) {
union sa_ss ss = { .sa = { .sa_family = sa->sa_family } };
sa_inprefix = true;
sa_fromprefix(&ss.sa, prefix);
assert(sa_cmp(sa, &ss.sa) == 0);
sa_inprefix = false;
}
#endif
return prefix;
}
int
sa_fromprefix(struct sockaddr *sa, int prefix)
{
uint8_t *ap;
int max_prefix, bytes, bits, i;
switch (sa->sa_family) {
#ifdef INET
case AF_INET:
max_prefix = 32;
#ifdef HAVE_SA_LEN
sa->sa_len = sizeof(struct sockaddr_in);
#endif
break;
#endif
#ifdef INET6
case AF_INET6:
max_prefix = 128;
#ifdef HAVE_SA_LEN
sa->sa_len = sizeof(struct sockaddr_in6);
#endif
break;
#endif
default:
errno = EAFNOSUPPORT;
return -1;
}
bytes = prefix / NBBY;
bits = prefix % NBBY;
ap = (uint8_t *)sa + sa_addroffset(sa);
for (i = 0; i < bytes; i++)
*ap++ = 0xff;
if (bits) {
uint8_t a;
a = 0xff;
a = (uint8_t)(a << (8 - bits));
*ap++ = a;
}
bytes = (max_prefix - prefix) / NBBY;
for (i = 0; i < bytes; i++)
*ap++ = 0x00;
#ifndef NDEBUG
/* Ensure the calculation is correct */
if (!sa_inprefix) {
sa_inprefix = true;
assert(sa_toprefix(sa) == prefix);
sa_inprefix = false;
}
#endif
return 0;
}
/* inet_ntop, but for sockaddr. */
const char *
sa_addrtop(const struct sockaddr *sa, char *buf, socklen_t len)
{
const void *addr;
assert(buf != NULL);
assert(len > 0);
if (sa->sa_family == 0) {
*buf = '\0';
return NULL;
}
#ifdef AF_LINK
#ifndef CLLADDR
#define CLLADDR(sdl) (const void *)((sdl)->sdl_data + (sdl)->sdl_nlen)
#endif
if (sa->sa_family == AF_LINK) {
const struct sockaddr_dl *sdl;
sdl = (const void *)sa;
if (sdl->sdl_alen == 0) {
if (snprintf(buf, len, "link#%d", sdl->sdl_index) == -1)
return NULL;
return buf;
}
return hwaddr_ntoa(CLLADDR(sdl), sdl->sdl_alen, buf, len);
}
#elif defined(AF_PACKET)
if (sa->sa_family == AF_PACKET) {
const struct sockaddr_ll *sll;
sll = (const void *)sa;
return hwaddr_ntoa(sll->sll_addr, sll->sll_halen, buf, len);
}
#endif
addr = (const char *)sa + sa_addroffset(sa);
return inet_ntop(sa->sa_family, addr, buf, len);
}
int
sa_cmp(const struct sockaddr *sa1, const struct sockaddr *sa2)
{
socklen_t offset, len;
assert(sa1 != NULL);
assert(sa2 != NULL);
/* Treat AF_UNSPEC as the unspecified address. */
if ((sa1->sa_family == AF_UNSPEC || sa2->sa_family == AF_UNSPEC) &&
sa_is_unspecified(sa1) && sa_is_unspecified(sa2))
return 0;
if (sa1->sa_family != sa2->sa_family)
return sa1->sa_family - sa2->sa_family;
#ifdef HAVE_SA_LEN
len = MIN(sa1->sa_len, sa2->sa_len);
#endif
switch (sa1->sa_family) {
#ifdef INET
case AF_INET:
offset = offsetof(struct sockaddr_in, sin_addr);
#ifdef HAVE_SA_LEN
len -= offset;
len = MIN(len, sizeof(struct in_addr));
#else
len = sizeof(struct in_addr);
#endif
break;
#endif
#ifdef INET6
case AF_INET6:
offset = offsetof(struct sockaddr_in6, sin6_addr);
#ifdef HAVE_SA_LEN
len -= offset;
len = MIN(len, sizeof(struct in6_addr));
#else
len = sizeof(struct in6_addr);
#endif
break;
#endif
default:
offset = 0;
#ifndef HAVE_SA_LEN
len = sizeof(struct sockaddr);
#endif
break;
}
return memcmp((const char *)sa1 + offset,
(const char *)sa2 + offset,
len);
}
#ifdef INET
void
sa_in_init(struct sockaddr *sa, const struct in_addr *addr)
{
struct sockaddr_in *sin;
assert(sa != NULL);
assert(addr != NULL);
sin = satosin(sa);
sin->sin_family = AF_INET;
#ifdef HAVE_SA_LEN
sin->sin_len = sizeof(*sin);
#endif
sin->sin_addr.s_addr = addr->s_addr;
}
#endif
#ifdef INET6
void
sa_in6_init(struct sockaddr *sa, const struct in6_addr *addr)
{
struct sockaddr_in6 *sin6;
assert(sa != NULL);
assert(addr != NULL);
sin6 = satosin6(sa);
sin6->sin6_family = AF_INET6;
#ifdef HAVE_SA_LEN
sin6->sin6_len = sizeof(*sin6);
#endif
memcpy(&sin6->sin6_addr.s6_addr, &addr->s6_addr,
sizeof(sin6->sin6_addr.s6_addr));
}
#endif
