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git.ipfire.org Git - thirdparty/systemd.git/blob - src/basic/in-addr-util.c
2 This file is part of systemd.
4 Copyright 2014 Lennart Poettering
6 systemd is free software; you can redistribute it and/or modify it
7 under the terms of the GNU Lesser General Public License as published by
8 the Free Software Foundation; either version 2.1 of the License, or
9 (at your option) any later version.
11 systemd is distributed in the hope that it will be useful, but
12 WITHOUT ANY WARRANTY; without even the implied warranty of
13 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
14 Lesser General Public License for more details.
16 You should have received a copy of the GNU Lesser General Public License
17 along with systemd; If not, see <http://www.gnu.org/licenses/>.
20 #include <arpa/inet.h>
27 #include "alloc-util.h"
28 #include "in-addr-util.h"
30 #include "parse-util.h"
33 bool in4_addr_is_null(const struct in_addr
*a
) {
36 return a
->s_addr
== 0;
39 int in_addr_is_null(int family
, const union in_addr_union
*u
) {
42 if (family
== AF_INET
)
43 return in4_addr_is_null(&u
->in
);
45 if (family
== AF_INET6
)
46 return IN6_IS_ADDR_UNSPECIFIED(&u
->in6
);
51 bool in4_addr_is_link_local(const struct in_addr
*a
) {
54 return (be32toh(a
->s_addr
) & UINT32_C(0xFFFF0000)) == (UINT32_C(169) << 24 | UINT32_C(254) << 16);
57 int in_addr_is_link_local(int family
, const union in_addr_union
*u
) {
60 if (family
== AF_INET
)
61 return in4_addr_is_link_local(&u
->in
);
63 if (family
== AF_INET6
)
64 return IN6_IS_ADDR_LINKLOCAL(&u
->in6
);
69 int in_addr_is_multicast(int family
, const union in_addr_union
*u
) {
72 if (family
== AF_INET
)
73 return IN_MULTICAST(be32toh(u
->in
.s_addr
));
75 if (family
== AF_INET6
)
76 return IN6_IS_ADDR_MULTICAST(&u
->in6
);
81 bool in4_addr_is_localhost(const struct in_addr
*a
) {
84 /* All of 127.x.x.x is localhost. */
85 return (be32toh(a
->s_addr
) & UINT32_C(0xFF000000)) == UINT32_C(127) << 24;
88 int in_addr_is_localhost(int family
, const union in_addr_union
*u
) {
91 if (family
== AF_INET
)
92 return in4_addr_is_localhost(&u
->in
);
94 if (family
== AF_INET6
)
95 return IN6_IS_ADDR_LOOPBACK(&u
->in6
);
100 int in_addr_equal(int family
, const union in_addr_union
*a
, const union in_addr_union
*b
) {
104 if (family
== AF_INET
)
105 return a
->in
.s_addr
== b
->in
.s_addr
;
107 if (family
== AF_INET6
)
109 a
->in6
.s6_addr32
[0] == b
->in6
.s6_addr32
[0] &&
110 a
->in6
.s6_addr32
[1] == b
->in6
.s6_addr32
[1] &&
111 a
->in6
.s6_addr32
[2] == b
->in6
.s6_addr32
[2] &&
112 a
->in6
.s6_addr32
[3] == b
->in6
.s6_addr32
[3];
114 return -EAFNOSUPPORT
;
117 int in_addr_prefix_intersect(
119 const union in_addr_union
*a
,
121 const union in_addr_union
*b
,
122 unsigned bprefixlen
) {
129 /* Checks whether there are any addresses that are in both
132 m
= MIN(aprefixlen
, bprefixlen
);
134 if (family
== AF_INET
) {
137 x
= be32toh(a
->in
.s_addr
^ b
->in
.s_addr
);
138 nm
= (m
== 0) ? 0 : 0xFFFFFFFFUL
<< (32 - m
);
140 return (x
& nm
) == 0;
143 if (family
== AF_INET6
) {
149 for (i
= 0; i
< 16; i
++) {
152 x
= a
->in6
.s6_addr
[i
] ^ b
->in6
.s6_addr
[i
];
155 nm
= 0xFF << (8 - m
);
171 return -EAFNOSUPPORT
;
174 int in_addr_prefix_next(int family
, union in_addr_union
*u
, unsigned prefixlen
) {
177 /* Increases the network part of an address by one. Returns
178 * positive it that succeeds, or 0 if this overflows. */
183 if (family
== AF_INET
) {
189 c
= be32toh(u
->in
.s_addr
);
190 n
= c
+ (1UL << (32 - prefixlen
));
193 n
&= 0xFFFFFFFFUL
<< (32 - prefixlen
);
195 u
->in
.s_addr
= htobe32(n
);
199 if (family
== AF_INET6
) {
200 struct in6_addr add
= {}, result
;
201 uint8_t overflow
= 0;
207 /* First calculate what we have to add */
208 add
.s6_addr
[(prefixlen
-1) / 8] = 1 << (7 - (prefixlen
-1) % 8);
210 for (i
= 16; i
> 0; i
--) {
213 result
.s6_addr
[j
] = u
->in6
.s6_addr
[j
] + add
.s6_addr
[j
] + overflow
;
214 overflow
= (result
.s6_addr
[j
] < u
->in6
.s6_addr
[j
]);
224 return -EAFNOSUPPORT
;
227 int in_addr_to_string(int family
, const union in_addr_union
*u
, char **ret
) {
234 if (family
== AF_INET
)
236 else if (family
== AF_INET6
)
237 l
= INET6_ADDRSTRLEN
;
239 return -EAFNOSUPPORT
;
246 if (!inet_ntop(family
, u
, x
, l
)) {
248 return errno
> 0 ? -errno
: -EINVAL
;
255 int in_addr_ifindex_to_string(int family
, const union in_addr_union
*u
, int ifindex
, char **ret
) {
263 /* Much like in_addr_to_string(), but optionally appends the zone interface index to the address, to properly
264 * handle IPv6 link-local addresses. */
266 if (family
!= AF_INET6
)
271 r
= in_addr_is_link_local(family
, u
);
277 l
= INET6_ADDRSTRLEN
+ 1 + DECIMAL_STR_MAX(ifindex
) + 1;
283 if (!inet_ntop(family
, u
, x
, l
)) {
285 return errno
> 0 ? -errno
: -EINVAL
;
288 sprintf(strchr(x
, 0), "%%%i", ifindex
);
294 return in_addr_to_string(family
, u
, ret
);
297 int in_addr_from_string(int family
, const char *s
, union in_addr_union
*ret
) {
298 union in_addr_union buffer
;
301 if (!IN_SET(family
, AF_INET
, AF_INET6
))
302 return -EAFNOSUPPORT
;
305 if (inet_pton(family
, s
, ret
?: &buffer
) <= 0)
306 return errno
> 0 ? -errno
: -EINVAL
;
311 int in_addr_from_string_auto(const char *s
, int *family
, union in_addr_union
*ret
) {
316 r
= in_addr_from_string(AF_INET
, s
, ret
);
323 r
= in_addr_from_string(AF_INET6
, s
, ret
);
333 int in_addr_ifindex_from_string_auto(const char *s
, int *family
, union in_addr_union
*ret
, int *ifindex
) {
341 /* Similar to in_addr_from_string_auto() but also parses an optionally appended IPv6 zone suffix ("scope id")
342 * if one is found. */
344 suffix
= strchr(s
, '%');
348 /* If we shall return the interface index, try to parse it */
349 r
= parse_ifindex(suffix
+ 1, &ifi
);
353 u
= if_nametoindex(suffix
+ 1);
361 s
= strndupa(s
, suffix
- s
);
364 r
= in_addr_from_string_auto(s
, family
, ret
);
374 unsigned char in_addr_netmask_to_prefixlen(const struct in_addr
*addr
) {
377 return 32 - u32ctz(be32toh(addr
->s_addr
));
380 struct in_addr
* in_addr_prefixlen_to_netmask(struct in_addr
*addr
, unsigned char prefixlen
) {
382 assert(prefixlen
<= 32);
384 /* Shifting beyond 32 is not defined, handle this specially. */
388 addr
->s_addr
= htobe32((0xffffffff << (32 - prefixlen
)) & 0xffffffff);
393 int in_addr_default_prefixlen(const struct in_addr
*addr
, unsigned char *prefixlen
) {
394 uint8_t msb_octet
= *(uint8_t*) addr
;
396 /* addr may not be aligned, so make sure we only access it byte-wise */
402 /* class A, leading bits: 0 */
404 else if (msb_octet
< 192)
405 /* class B, leading bits 10 */
407 else if (msb_octet
< 224)
408 /* class C, leading bits 110 */
411 /* class D or E, no default prefixlen */
417 int in_addr_default_subnet_mask(const struct in_addr
*addr
, struct in_addr
*mask
) {
418 unsigned char prefixlen
;
424 r
= in_addr_default_prefixlen(addr
, &prefixlen
);
428 in_addr_prefixlen_to_netmask(mask
, prefixlen
);
432 int in_addr_mask(int family
, union in_addr_union
*addr
, unsigned char prefixlen
) {
435 if (family
== AF_INET
) {
438 if (!in_addr_prefixlen_to_netmask(&mask
, prefixlen
))
441 addr
->in
.s_addr
&= mask
.s_addr
;
445 if (family
== AF_INET6
) {
448 for (i
= 0; i
< 16; i
++) {
451 if (prefixlen
>= 8) {
455 mask
= 0xFF << (8 - prefixlen
);
459 addr
->in6
.s6_addr
[i
] &= mask
;
465 return -EAFNOSUPPORT
;
468 int in_addr_prefix_from_string(const char *p
, int family
, union in_addr_union
*ret_prefix
, uint8_t *ret_prefixlen
) {
469 union in_addr_union buffer
;
476 if (!IN_SET(family
, AF_INET
, AF_INET6
))
477 return -EAFNOSUPPORT
;
481 l
= strndupa(p
, e
- p
);
485 r
= in_addr_from_string(family
, l
, &buffer
);
489 k
= FAMILY_ADDRESS_SIZE(family
) * 8;
494 r
= safe_atou8(e
+ 1, &n
);
504 *ret_prefix
= buffer
;