/*-*- 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; }