diff options
Diffstat (limited to 'src/shared/in-addr-util.c')
| -rw-r--r-- | src/shared/in-addr-util.c | 211 |
1 files changed, 211 insertions, 0 deletions
diff --git a/src/shared/in-addr-util.c b/src/shared/in-addr-util.c new file mode 100644 index 0000000000..98d2446e5d --- /dev/null +++ b/src/shared/in-addr-util.c @@ -0,0 +1,211 @@ +/*-*- 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_null(unsigned family, 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_equal(unsigned family, union in_addr_union *a, 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( + unsigned 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(unsigned 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(unsigned 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(unsigned 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; +} |