1 /* SPDX-License-Identifier: LGPL-2.1+ */
10 #include "alloc-util.h"
11 #include "in-addr-util.h"
13 #include "parse-util.h"
16 bool in4_addr_is_null(const struct in_addr
*a
) {
19 return a
->s_addr
== 0;
22 int in_addr_is_null(int family
, const union in_addr_union
*u
) {
25 if (family
== AF_INET
)
26 return in4_addr_is_null(&u
->in
);
28 if (family
== AF_INET6
)
29 return IN6_IS_ADDR_UNSPECIFIED(&u
->in6
);
34 bool in4_addr_is_link_local(const struct in_addr
*a
) {
37 return (be32toh(a
->s_addr
) & UINT32_C(0xFFFF0000)) == (UINT32_C(169) << 24 | UINT32_C(254) << 16);
40 int in_addr_is_link_local(int family
, const union in_addr_union
*u
) {
43 if (family
== AF_INET
)
44 return in4_addr_is_link_local(&u
->in
);
46 if (family
== AF_INET6
)
47 return IN6_IS_ADDR_LINKLOCAL(&u
->in6
);
52 int in_addr_is_multicast(int family
, const union in_addr_union
*u
) {
55 if (family
== AF_INET
)
56 return IN_MULTICAST(be32toh(u
->in
.s_addr
));
58 if (family
== AF_INET6
)
59 return IN6_IS_ADDR_MULTICAST(&u
->in6
);
64 bool in4_addr_is_localhost(const struct in_addr
*a
) {
67 /* All of 127.x.x.x is localhost. */
68 return (be32toh(a
->s_addr
) & UINT32_C(0xFF000000)) == UINT32_C(127) << 24;
71 bool in4_addr_is_non_local(const struct in_addr
*a
) {
72 /* Whether the address is not null and not localhost.
74 * As such, it is suitable to configure as DNS/NTP server from DHCP. */
75 return !in4_addr_is_null(a
) &&
76 !in4_addr_is_localhost(a
);
79 int in_addr_is_localhost(int family
, const union in_addr_union
*u
) {
82 if (family
== AF_INET
)
83 return in4_addr_is_localhost(&u
->in
);
85 if (family
== AF_INET6
)
86 return IN6_IS_ADDR_LOOPBACK(&u
->in6
);
91 int in_addr_equal(int family
, const union in_addr_union
*a
, const union in_addr_union
*b
) {
95 if (family
== AF_INET
)
96 return a
->in
.s_addr
== b
->in
.s_addr
;
98 if (family
== AF_INET6
)
100 a
->in6
.s6_addr32
[0] == b
->in6
.s6_addr32
[0] &&
101 a
->in6
.s6_addr32
[1] == b
->in6
.s6_addr32
[1] &&
102 a
->in6
.s6_addr32
[2] == b
->in6
.s6_addr32
[2] &&
103 a
->in6
.s6_addr32
[3] == b
->in6
.s6_addr32
[3];
105 return -EAFNOSUPPORT
;
108 int in_addr_prefix_intersect(
110 const union in_addr_union
*a
,
112 const union in_addr_union
*b
,
113 unsigned bprefixlen
) {
120 /* Checks whether there are any addresses that are in both
123 m
= MIN(aprefixlen
, bprefixlen
);
125 if (family
== AF_INET
) {
128 x
= be32toh(a
->in
.s_addr
^ b
->in
.s_addr
);
129 nm
= (m
== 0) ? 0 : 0xFFFFFFFFUL
<< (32 - m
);
131 return (x
& nm
) == 0;
134 if (family
== AF_INET6
) {
140 for (i
= 0; i
< 16; i
++) {
143 x
= a
->in6
.s6_addr
[i
] ^ b
->in6
.s6_addr
[i
];
146 nm
= 0xFF << (8 - m
);
162 return -EAFNOSUPPORT
;
165 int in_addr_prefix_next(int family
, union in_addr_union
*u
, unsigned prefixlen
) {
168 /* Increases the network part of an address by one. Returns
169 * positive it that succeeds, or 0 if this overflows. */
174 if (family
== AF_INET
) {
180 c
= be32toh(u
->in
.s_addr
);
181 n
= c
+ (1UL << (32 - prefixlen
));
184 n
&= 0xFFFFFFFFUL
<< (32 - prefixlen
);
186 u
->in
.s_addr
= htobe32(n
);
190 if (family
== AF_INET6
) {
191 struct in6_addr add
= {}, result
;
192 uint8_t overflow
= 0;
198 /* First calculate what we have to add */
199 add
.s6_addr
[(prefixlen
-1) / 8] = 1 << (7 - (prefixlen
-1) % 8);
201 for (i
= 16; i
> 0; i
--) {
204 result
.s6_addr
[j
] = u
->in6
.s6_addr
[j
] + add
.s6_addr
[j
] + overflow
;
205 overflow
= (result
.s6_addr
[j
] < u
->in6
.s6_addr
[j
]);
215 return -EAFNOSUPPORT
;
218 int in_addr_to_string(int family
, const union in_addr_union
*u
, char **ret
) {
225 if (family
== AF_INET
)
227 else if (family
== AF_INET6
)
228 l
= INET6_ADDRSTRLEN
;
230 return -EAFNOSUPPORT
;
237 if (!inet_ntop(family
, u
, x
, l
)) {
239 return errno
> 0 ? -errno
: -EINVAL
;
246 int in_addr_ifindex_to_string(int family
, const union in_addr_union
*u
, int ifindex
, char **ret
) {
254 /* Much like in_addr_to_string(), but optionally appends the zone interface index to the address, to properly
255 * handle IPv6 link-local addresses. */
257 if (family
!= AF_INET6
)
262 r
= in_addr_is_link_local(family
, u
);
268 l
= INET6_ADDRSTRLEN
+ 1 + DECIMAL_STR_MAX(ifindex
) + 1;
274 if (!inet_ntop(family
, u
, x
, l
)) {
276 return errno
> 0 ? -errno
: -EINVAL
;
279 sprintf(strchr(x
, 0), "%%%i", ifindex
);
285 return in_addr_to_string(family
, u
, ret
);
288 int in_addr_from_string(int family
, const char *s
, union in_addr_union
*ret
) {
289 union in_addr_union buffer
;
292 if (!IN_SET(family
, AF_INET
, AF_INET6
))
293 return -EAFNOSUPPORT
;
296 if (inet_pton(family
, s
, ret
?: &buffer
) <= 0)
297 return errno
> 0 ? -errno
: -EINVAL
;
302 int in_addr_from_string_auto(const char *s
, int *ret_family
, union in_addr_union
*ret
) {
307 r
= in_addr_from_string(AF_INET
, s
, ret
);
310 *ret_family
= AF_INET
;
314 r
= in_addr_from_string(AF_INET6
, s
, ret
);
317 *ret_family
= AF_INET6
;
324 int in_addr_ifindex_from_string_auto(const char *s
, int *family
, union in_addr_union
*ret
, int *ifindex
) {
325 _cleanup_free_
char *buf
= NULL
;
333 /* Similar to in_addr_from_string_auto() but also parses an optionally appended IPv6 zone suffix ("scope id")
334 * if one is found. */
336 suffix
= strchr(s
, '%');
340 /* If we shall return the interface index, try to parse it */
341 r
= parse_ifindex(suffix
+ 1, &ifi
);
345 u
= if_nametoindex(suffix
+ 1);
353 buf
= strndup(s
, suffix
- s
);
360 r
= in_addr_from_string_auto(s
, family
, ret
);
370 unsigned char in4_addr_netmask_to_prefixlen(const struct in_addr
*addr
) {
373 return 32U - u32ctz(be32toh(addr
->s_addr
));
376 struct in_addr
* in4_addr_prefixlen_to_netmask(struct in_addr
*addr
, unsigned char prefixlen
) {
378 assert(prefixlen
<= 32);
380 /* Shifting beyond 32 is not defined, handle this specially. */
384 addr
->s_addr
= htobe32((0xffffffff << (32 - prefixlen
)) & 0xffffffff);
389 int in4_addr_default_prefixlen(const struct in_addr
*addr
, unsigned char *prefixlen
) {
390 uint8_t msb_octet
= *(uint8_t*) addr
;
392 /* addr may not be aligned, so make sure we only access it byte-wise */
398 /* class A, leading bits: 0 */
400 else if (msb_octet
< 192)
401 /* class B, leading bits 10 */
403 else if (msb_octet
< 224)
404 /* class C, leading bits 110 */
407 /* class D or E, no default prefixlen */
413 int in4_addr_default_subnet_mask(const struct in_addr
*addr
, struct in_addr
*mask
) {
414 unsigned char prefixlen
;
420 r
= in4_addr_default_prefixlen(addr
, &prefixlen
);
424 in4_addr_prefixlen_to_netmask(mask
, prefixlen
);
428 int in_addr_mask(int family
, union in_addr_union
*addr
, unsigned char prefixlen
) {
431 if (family
== AF_INET
) {
434 if (!in4_addr_prefixlen_to_netmask(&mask
, prefixlen
))
437 addr
->in
.s_addr
&= mask
.s_addr
;
441 if (family
== AF_INET6
) {
444 for (i
= 0; i
< 16; i
++) {
447 if (prefixlen
>= 8) {
451 mask
= 0xFF << (8 - prefixlen
);
455 addr
->in6
.s6_addr
[i
] &= mask
;
461 return -EAFNOSUPPORT
;
464 int in_addr_prefix_covers(int family
,
465 const union in_addr_union
*prefix
,
466 unsigned char prefixlen
,
467 const union in_addr_union
*address
) {
469 union in_addr_union masked_prefix
, masked_address
;
475 masked_prefix
= *prefix
;
476 r
= in_addr_mask(family
, &masked_prefix
, prefixlen
);
480 masked_address
= *address
;
481 r
= in_addr_mask(family
, &masked_address
, prefixlen
);
485 return in_addr_equal(family
, &masked_prefix
, &masked_address
);
488 int in_addr_parse_prefixlen(int family
, const char *p
, unsigned char *ret
) {
492 if (!IN_SET(family
, AF_INET
, AF_INET6
))
493 return -EAFNOSUPPORT
;
495 r
= safe_atou8(p
, &u
);
499 if (u
> FAMILY_ADDRESS_SIZE(family
) * 8)
506 int in_addr_prefix_from_string(
509 union in_addr_union
*ret_prefix
,
510 unsigned char *ret_prefixlen
) {
512 _cleanup_free_
char *str
= NULL
;
513 union in_addr_union buffer
;
520 if (!IN_SET(family
, AF_INET
, AF_INET6
))
521 return -EAFNOSUPPORT
;
525 str
= strndup(p
, e
- p
);
533 r
= in_addr_from_string(family
, l
, &buffer
);
538 r
= in_addr_parse_prefixlen(family
, e
+1, &k
);
542 k
= FAMILY_ADDRESS_SIZE(family
) * 8;
545 *ret_prefix
= buffer
;
552 int in_addr_prefix_from_string_auto_internal(
554 InAddrPrefixLenMode mode
,
556 union in_addr_union
*ret_prefix
,
557 unsigned char *ret_prefixlen
) {
559 _cleanup_free_
char *str
= NULL
;
560 union in_addr_union buffer
;
569 str
= strndup(p
, e
- p
);
577 r
= in_addr_from_string_auto(l
, &family
, &buffer
);
582 r
= in_addr_parse_prefixlen(family
, e
+1, &k
);
588 k
= FAMILY_ADDRESS_SIZE(family
) * 8;
590 case PREFIXLEN_REFUSE
:
591 return -ENOANO
; /* To distinguish this error from others. */
592 case PREFIXLEN_LEGACY
:
593 if (family
== AF_INET
) {
594 r
= in4_addr_default_prefixlen(&buffer
.in
, &k
);
601 assert_not_reached("Invalid prefixlen mode");
605 *ret_family
= family
;
607 *ret_prefix
= buffer
;
615 static void in_addr_data_hash_func(const struct in_addr_data
*a
, struct siphash
*state
) {
616 siphash24_compress(&a
->family
, sizeof(a
->family
), state
);
617 siphash24_compress(&a
->address
, FAMILY_ADDRESS_SIZE(a
->family
), state
);
620 static int in_addr_data_compare_func(const struct in_addr_data
*x
, const struct in_addr_data
*y
) {
623 r
= CMP(x
->family
, y
->family
);
627 return memcmp(&x
->address
, &y
->address
, FAMILY_ADDRESS_SIZE(x
->family
));
630 DEFINE_HASH_OPS(in_addr_data_hash_ops
, struct in_addr_data
, in_addr_data_hash_func
, in_addr_data_compare_func
);