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