summaryrefslogtreecommitdiff
path: root/src/libsystemd-basic/src/in-addr-util.c
diff options
context:
space:
mode:
Diffstat (limited to 'src/libsystemd-basic/src/in-addr-util.c')
-rw-r--r--src/libsystemd-basic/src/in-addr-util.c449
1 files changed, 449 insertions, 0 deletions
diff --git a/src/libsystemd-basic/src/in-addr-util.c b/src/libsystemd-basic/src/in-addr-util.c
new file mode 100644
index 0000000000..ad9f9fb071
--- /dev/null
+++ b/src/libsystemd-basic/src/in-addr-util.c
@@ -0,0 +1,449 @@
+/***
+ 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 <endian.h>
+#include <errno.h>
+#include <net/if.h>
+#include <stdint.h>
+#include <stdlib.h>
+
+#include "systemd-basic/alloc-util.h"
+#include "systemd-basic/in-addr-util.h"
+#include "systemd-basic/macro.h"
+#include "systemd-basic/parse-util.h"
+#include "systemd-basic/util.h"
+
+bool in4_addr_is_null(const struct in_addr *a) {
+ return a->s_addr == 0;
+}
+
+bool in6_addr_is_null(const struct in6_addr *a) {
+ return
+ a->s6_addr32[0] == 0 &&
+ a->s6_addr32[1] == 0 &&
+ a->s6_addr32[2] == 0 &&
+ a->s6_addr32[3] == 0;
+}
+
+int in_addr_is_null(int family, const union in_addr_union *u) {
+ assert(u);
+
+ if (family == AF_INET)
+ return in4_addr_is_null(&u->in);
+
+ if (family == AF_INET6)
+ return in6_addr_is_null(&u->in6);
+
+ 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) & UINT32_C(0xFFFF0000)) == (UINT32_C(169) << 24 | UINT32_C(254) << 16);
+
+ if (family == AF_INET6)
+ return IN6_IS_ADDR_LINKLOCAL(&u->in6);
+
+ return -EAFNOSUPPORT;
+}
+
+int in_addr_is_localhost(int family, const union in_addr_union *u) {
+ assert(u);
+
+ if (family == AF_INET)
+ /* All of 127.x.x.x is localhost. */
+ return (be32toh(u->in.s_addr) & UINT32_C(0xFF000000)) == UINT32_C(127) << 24;
+
+ if (family == AF_INET6)
+ return IN6_IS_ADDR_LOOPBACK(&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 > 0 ? -errno : -EINVAL;
+ }
+
+ *ret = x;
+ return 0;
+}
+
+int in_addr_ifindex_to_string(int family, const union in_addr_union *u, int ifindex, char **ret) {
+ size_t l;
+ char *x;
+ int r;
+
+ assert(u);
+ assert(ret);
+
+ /* Much like in_addr_to_string(), but optionally appends the zone interface index to the address, to properly
+ * handle IPv6 link-local addresses. */
+
+ if (family != AF_INET6)
+ goto fallback;
+ if (ifindex <= 0)
+ goto fallback;
+
+ r = in_addr_is_link_local(family, u);
+ if (r < 0)
+ return r;
+ if (r == 0)
+ goto fallback;
+
+ l = INET6_ADDRSTRLEN + 1 + DECIMAL_STR_MAX(ifindex) + 1;
+ x = new(char, l);
+ if (!x)
+ return -ENOMEM;
+
+ errno = 0;
+ if (!inet_ntop(family, u, x, l)) {
+ free(x);
+ return errno > 0 ? -errno : -EINVAL;
+ }
+
+ sprintf(strchr(x, 0), "%%%i", ifindex);
+ *ret = x;
+
+ return 0;
+
+fallback:
+ return in_addr_to_string(family, u, ret);
+}
+
+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 > 0 ? -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;
+}
+
+int in_addr_ifindex_from_string_auto(const char *s, int *family, union in_addr_union *ret, int *ifindex) {
+ const char *suffix;
+ int r, ifi = 0;
+
+ assert(s);
+ assert(family);
+ assert(ret);
+
+ /* Similar to in_addr_from_string_auto() but also parses an optionally appended IPv6 zone suffix ("scope id")
+ * if one is found. */
+
+ suffix = strchr(s, '%');
+ if (suffix) {
+
+ if (ifindex) {
+ /* If we shall return the interface index, try to parse it */
+ r = parse_ifindex(suffix + 1, &ifi);
+ if (r < 0) {
+ unsigned u;
+
+ u = if_nametoindex(suffix + 1);
+ if (u <= 0)
+ return -errno;
+
+ ifi = (int) u;
+ }
+ }
+
+ s = strndupa(s, suffix - s);
+ }
+
+ r = in_addr_from_string_auto(s, family, ret);
+ if (r < 0)
+ return r;
+
+ if (ifindex)
+ *ifindex = ifi;
+
+ return r;
+}
+
+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;
+}
generated by cgit v1.2.3 (git 2.25.1) at 2024-06-01 11:37:05 +0000