339 lines
9.0 KiB
C
339 lines
9.0 KiB
C
/*-*- Mode: C; c-basic-offset: 8; indent-tabs-mode: nil -*-*/
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/***
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This file is part of systemd.
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Copyright 2014 Lennart Poettering
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systemd is free software; you can redistribute it and/or modify it
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under the terms of the GNU Lesser General Public License as published by
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the Free Software Foundation; either version 2.1 of the License, or
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(at your option) any later version.
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systemd is distributed in the hope that it will be useful, but
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WITHOUT ANY WARRANTY; without even the implied warranty of
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MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
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Lesser General Public License for more details.
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You should have received a copy of the GNU Lesser General Public License
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along with systemd; If not, see <http://www.gnu.org/licenses/>.
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***/
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#include <arpa/inet.h>
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#include "in-addr-util.h"
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int in_addr_is_null(int family, const union in_addr_union *u) {
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assert(u);
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if (family == AF_INET)
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return u->in.s_addr == 0;
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if (family == AF_INET6)
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return
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u->in6.s6_addr32[0] == 0 &&
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u->in6.s6_addr32[1] == 0 &&
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u->in6.s6_addr32[2] == 0 &&
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u->in6.s6_addr32[3] == 0;
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return -EAFNOSUPPORT;
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}
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int in_addr_is_link_local(int family, const union in_addr_union *u) {
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assert(u);
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if (family == AF_INET)
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return (be32toh(u->in.s_addr) & 0xFFFF0000) == (169U << 24 | 254U << 16);
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if (family == AF_INET6)
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return IN6_IS_ADDR_LINKLOCAL(&u->in6);
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return -EAFNOSUPPORT;
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}
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int in_addr_equal(int family, const union in_addr_union *a, const union in_addr_union *b) {
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assert(a);
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assert(b);
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if (family == AF_INET)
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return a->in.s_addr == b->in.s_addr;
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if (family == AF_INET6)
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return
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a->in6.s6_addr32[0] == b->in6.s6_addr32[0] &&
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a->in6.s6_addr32[1] == b->in6.s6_addr32[1] &&
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a->in6.s6_addr32[2] == b->in6.s6_addr32[2] &&
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a->in6.s6_addr32[3] == b->in6.s6_addr32[3];
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return -EAFNOSUPPORT;
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}
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int in_addr_prefix_intersect(
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int family,
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const union in_addr_union *a,
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unsigned aprefixlen,
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const union in_addr_union *b,
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unsigned bprefixlen) {
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unsigned m;
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assert(a);
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assert(b);
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/* Checks whether there are any addresses that are in both
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* networks */
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m = MIN(aprefixlen, bprefixlen);
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if (family == AF_INET) {
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uint32_t x, nm;
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x = be32toh(a->in.s_addr ^ b->in.s_addr);
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nm = (m == 0) ? 0 : 0xFFFFFFFFUL << (32 - m);
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return (x & nm) == 0;
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}
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if (family == AF_INET6) {
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unsigned i;
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if (m > 128)
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m = 128;
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for (i = 0; i < 16; i++) {
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uint8_t x, nm;
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x = a->in6.s6_addr[i] ^ b->in6.s6_addr[i];
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if (m < 8)
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nm = 0xFF << (8 - m);
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else
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nm = 0xFF;
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if ((x & nm) != 0)
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return 0;
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if (m > 8)
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m -= 8;
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else
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m = 0;
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}
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return 1;
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}
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return -EAFNOSUPPORT;
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}
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int in_addr_prefix_next(int family, union in_addr_union *u, unsigned prefixlen) {
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assert(u);
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/* Increases the network part of an address by one. Returns
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* positive it that succeeds, or 0 if this overflows. */
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if (prefixlen <= 0)
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return 0;
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if (family == AF_INET) {
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uint32_t c, n;
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if (prefixlen > 32)
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prefixlen = 32;
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c = be32toh(u->in.s_addr);
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n = c + (1UL << (32 - prefixlen));
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if (n < c)
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return 0;
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n &= 0xFFFFFFFFUL << (32 - prefixlen);
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u->in.s_addr = htobe32(n);
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return 1;
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}
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if (family == AF_INET6) {
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struct in6_addr add = {}, result;
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uint8_t overflow = 0;
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unsigned i;
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if (prefixlen > 128)
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prefixlen = 128;
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/* First calculate what we have to add */
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add.s6_addr[(prefixlen-1) / 8] = 1 << (7 - (prefixlen-1) % 8);
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for (i = 16; i > 0; i--) {
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unsigned j = i - 1;
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result.s6_addr[j] = u->in6.s6_addr[j] + add.s6_addr[j] + overflow;
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overflow = (result.s6_addr[j] < u->in6.s6_addr[j]);
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}
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if (overflow)
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return 0;
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u->in6 = result;
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return 1;
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}
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return -EAFNOSUPPORT;
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}
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int in_addr_to_string(int family, const union in_addr_union *u, char **ret) {
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char *x;
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size_t l;
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assert(u);
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assert(ret);
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if (family == AF_INET)
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l = INET_ADDRSTRLEN;
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else if (family == AF_INET6)
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l = INET6_ADDRSTRLEN;
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else
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return -EAFNOSUPPORT;
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x = new(char, l);
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if (!x)
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return -ENOMEM;
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errno = 0;
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if (!inet_ntop(family, u, x, l)) {
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free(x);
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return errno ? -errno : -EINVAL;
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}
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*ret = x;
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return 0;
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}
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int in_addr_from_string(int family, const char *s, union in_addr_union *ret) {
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assert(s);
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assert(ret);
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if (!IN_SET(family, AF_INET, AF_INET6))
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return -EAFNOSUPPORT;
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errno = 0;
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if (inet_pton(family, s, ret) <= 0)
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return errno ? -errno : -EINVAL;
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return 0;
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}
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int in_addr_from_string_auto(const char *s, int *family, union in_addr_union *ret) {
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int r;
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assert(s);
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assert(family);
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assert(ret);
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r = in_addr_from_string(AF_INET, s, ret);
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if (r >= 0) {
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*family = AF_INET;
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return 0;
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}
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r = in_addr_from_string(AF_INET6, s, ret);
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if (r >= 0) {
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*family = AF_INET6;
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return 0;
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}
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return -EINVAL;
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}
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unsigned char in_addr_netmask_to_prefixlen(const struct in_addr *addr) {
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assert(addr);
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return 32 - u32ctz(be32toh(addr->s_addr));
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}
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struct in_addr* in_addr_prefixlen_to_netmask(struct in_addr *addr, unsigned char prefixlen) {
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assert(addr);
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assert(prefixlen <= 32);
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/* Shifting beyond 32 is not defined, handle this specially. */
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if (prefixlen == 0)
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addr->s_addr = 0;
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else
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addr->s_addr = htobe32((0xffffffff << (32 - prefixlen)) & 0xffffffff);
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return addr;
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}
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int in_addr_default_prefixlen(const struct in_addr *addr, unsigned char *prefixlen) {
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uint8_t msb_octet = *(uint8_t*) addr;
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/* addr may not be aligned, so make sure we only access it byte-wise */
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assert(addr);
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assert(prefixlen);
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if (msb_octet < 128)
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/* class A, leading bits: 0 */
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*prefixlen = 8;
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else if (msb_octet < 192)
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/* class B, leading bits 10 */
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*prefixlen = 16;
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else if (msb_octet < 224)
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/* class C, leading bits 110 */
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*prefixlen = 24;
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else
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/* class D or E, no default prefixlen */
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return -ERANGE;
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return 0;
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}
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int in_addr_default_subnet_mask(const struct in_addr *addr, struct in_addr *mask) {
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unsigned char prefixlen;
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int r;
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assert(addr);
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assert(mask);
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r = in_addr_default_prefixlen(addr, &prefixlen);
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if (r < 0)
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return r;
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in_addr_prefixlen_to_netmask(mask, prefixlen);
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return 0;
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}
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int in_addr_mask(int family, union in_addr_union *addr, unsigned char prefixlen) {
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assert(addr);
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if (family == AF_INET) {
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struct in_addr mask;
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if (!in_addr_prefixlen_to_netmask(&mask, prefixlen))
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return -EINVAL;
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addr->in.s_addr &= mask.s_addr;
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return 0;
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}
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if (family == AF_INET6) {
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unsigned i;
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for (i = 0; i < 16; i++) {
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uint8_t mask;
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if (prefixlen >= 8) {
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mask = 0xFF;
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prefixlen -= 8;
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} else {
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mask = 0xFF << (8 - prefixlen);
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prefixlen = 0;
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}
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addr->in6.s6_addr[i] &= mask;
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}
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return 0;
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}
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return -EAFNOSUPPORT;
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}
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