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/* SPDX-License-Identifier: LGPL-2.1+ */
#include <arpa/inet.h>
#include <endian.h>
#include <errno.h>
#include <net/if.h>
#include <stdint.h>
#include <stdio.h>
#include <stdlib.h>
#include "alloc-util.h"
#include "errno-util.h"
#include "in-addr-util.h"
#include "macro.h"
#include "parse-util.h"
#include "random-util.h"
#include "strxcpyx.h"
#include "util.h"
bool in4_addr_is_null(const struct in_addr *a) {
assert(a);
return a->s_addr == 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_IS_ADDR_UNSPECIFIED(&u->in6);
return -EAFNOSUPPORT;
}
bool in4_addr_is_link_local(const struct in_addr *a) {
assert(a);
return (be32toh(a->s_addr) & UINT32_C(0xFFFF0000)) == (UINT32_C(169) << 24 | UINT32_C(254) << 16);
}
int in_addr_is_link_local(int family, const union in_addr_union *u) {
assert(u);
if (family == AF_INET)
return in4_addr_is_link_local(&u->in);
if (family == AF_INET6)
return IN6_IS_ADDR_LINKLOCAL(&u->in6);
return -EAFNOSUPPORT;
}
int in_addr_is_multicast(int family, const union in_addr_union *u) {
assert(u);
if (family == AF_INET)
return IN_MULTICAST(be32toh(u->in.s_addr));
if (family == AF_INET6)
return IN6_IS_ADDR_MULTICAST(&u->in6);
return -EAFNOSUPPORT;
}
bool in4_addr_is_localhost(const struct in_addr *a) {
assert(a);
/* All of 127.x.x.x is localhost. */
return (be32toh(a->s_addr) & UINT32_C(0xFF000000)) == UINT32_C(127) << 24;
}
bool in4_addr_is_non_local(const struct in_addr *a) {
/* Whether the address is not null and not localhost.
*
* As such, it is suitable to configure as DNS/NTP server from DHCP. */
return !in4_addr_is_null(a) &&
!in4_addr_is_localhost(a);
}
int in_addr_is_localhost(int family, const union in_addr_union *u) {
assert(u);
if (family == AF_INET)
return in4_addr_is_localhost(&u->in);
if (family == AF_INET6)
return IN6_IS_ADDR_LOOPBACK(&u->in6);
return -EAFNOSUPPORT;
}
bool in4_addr_equal(const struct in_addr *a, const struct in_addr *b) {
assert(a);
assert(b);
return a->s_addr == b->s_addr;
}
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 in4_addr_equal(&a->in, &b->in);
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_random_prefix(
int family,
union in_addr_union *u,
unsigned prefixlen_fixed_part,
unsigned prefixlen) {
assert(u);
/* Random network part of an address by one. */
if (prefixlen <= 0)
return 0;
if (family == AF_INET) {
uint32_t c, n;
if (prefixlen_fixed_part > 32)
prefixlen_fixed_part = 32;
if (prefixlen > 32)
prefixlen = 32;
if (prefixlen_fixed_part >= prefixlen)
return -EINVAL;
c = be32toh(u->in.s_addr);
c &= ((UINT32_C(1) << prefixlen_fixed_part) - 1) << (32 - prefixlen_fixed_part);
random_bytes(&n, sizeof(n));
n &= ((UINT32_C(1) << (prefixlen - prefixlen_fixed_part)) - 1) << (32 - prefixlen);
u->in.s_addr = htobe32(n | c);
return 1;
}
if (family == AF_INET6) {
struct in6_addr n;
unsigned i, j;
if (prefixlen_fixed_part > 128)
prefixlen_fixed_part = 128;
if (prefixlen > 128)
prefixlen = 128;
if (prefixlen_fixed_part >= prefixlen)
return -EINVAL;
random_bytes(&n, sizeof(n));
for (i = 0; i < 16; i++) {
uint8_t mask_fixed_part = 0, mask = 0;
if (i < (prefixlen_fixed_part + 7) / 8) {
if (i < prefixlen_fixed_part / 8)
mask_fixed_part = 0xffu;
else {
j = prefixlen_fixed_part % 8;
mask_fixed_part = ((UINT8_C(1) << (j + 1)) - 1) << (8 - j);
}
}
if (i < (prefixlen + 7) / 8) {
if (i < prefixlen / 8)
mask = 0xffu ^ mask_fixed_part;
else {
j = prefixlen % 8;
mask = (((UINT8_C(1) << (j + 1)) - 1) << (8 - j)) ^ mask_fixed_part;
}
}
u->in6.s6_addr[i] &= mask_fixed_part;
u->in6.s6_addr[i] |= n.s6_addr[i] & mask;
}
return 1;
}
return -EAFNOSUPPORT;
}
int in_addr_to_string(int family, const union in_addr_union *u, char **ret) {
_cleanup_free_ char *x = NULL;
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))
return errno_or_else(EINVAL);
*ret = TAKE_PTR(x);
return 0;
}
int in_addr_prefix_to_string(int family, const union in_addr_union *u, unsigned prefixlen, char **ret) {
_cleanup_free_ char *x = NULL;
char *p;
size_t l;
assert(u);
assert(ret);
if (family == AF_INET)
l = INET_ADDRSTRLEN + 3;
else if (family == AF_INET6)
l = INET6_ADDRSTRLEN + 4;
else
return -EAFNOSUPPORT;
if (prefixlen > FAMILY_ADDRESS_SIZE(family) * 8)
return -EINVAL;
x = new(char, l);
if (!x)
return -ENOMEM;
errno = 0;
if (!inet_ntop(family, u, x, l))
return errno_or_else(EINVAL);
p = x + strlen(x);
l -= strlen(x);
(void) strpcpyf(&p, l, "/%u", prefixlen);
*ret = TAKE_PTR(x);
return 0;
}
int in_addr_ifindex_to_string(int family, const union in_addr_union *u, int ifindex, char **ret) {
_cleanup_free_ char *x = NULL;
size_t l;
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))
return errno_or_else(EINVAL);
sprintf(strchr(x, 0), "%%%i", ifindex);
*ret = TAKE_PTR(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) {
union in_addr_union buffer;
assert(s);
if (!IN_SET(family, AF_INET, AF_INET6))
return -EAFNOSUPPORT;
errno = 0;
if (inet_pton(family, s, ret ?: &buffer) <= 0)
return errno_or_else(EINVAL);
return 0;
}
int in_addr_from_string_auto(const char *s, int *ret_family, union in_addr_union *ret) {
int r;
assert(s);
r = in_addr_from_string(AF_INET, s, ret);
if (r >= 0) {
if (ret_family)
*ret_family = AF_INET;
return 0;
}
r = in_addr_from_string(AF_INET6, s, ret);
if (r >= 0) {
if (ret_family)
*ret_family = AF_INET6;
return 0;
}
return -EINVAL;
}
unsigned char in4_addr_netmask_to_prefixlen(const struct in_addr *addr) {
assert(addr);
return 32U - u32ctz(be32toh(addr->s_addr));
}
struct in_addr* in4_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 in4_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 in4_addr_default_subnet_mask(const struct in_addr *addr, struct in_addr *mask) {
unsigned char prefixlen;
int r;
assert(addr);
assert(mask);
r = in4_addr_default_prefixlen(addr, &prefixlen);
if (r < 0)
return r;
in4_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 (!in4_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;
}
int in_addr_prefix_covers(int family,
const union in_addr_union *prefix,
unsigned char prefixlen,
const union in_addr_union *address) {
union in_addr_union masked_prefix, masked_address;
int r;
assert(prefix);
assert(address);
masked_prefix = *prefix;
r = in_addr_mask(family, &masked_prefix, prefixlen);
if (r < 0)
return r;
masked_address = *address;
r = in_addr_mask(family, &masked_address, prefixlen);
if (r < 0)
return r;
return in_addr_equal(family, &masked_prefix, &masked_address);
}
int in_addr_parse_prefixlen(int family, const char *p, unsigned char *ret) {
uint8_t u;
int r;
if (!IN_SET(family, AF_INET, AF_INET6))
return -EAFNOSUPPORT;
r = safe_atou8(p, &u);
if (r < 0)
return r;
if (u > FAMILY_ADDRESS_SIZE(family) * 8)
return -ERANGE;
*ret = u;
return 0;
}
int in_addr_prefix_from_string(
const char *p,
int family,
union in_addr_union *ret_prefix,
unsigned char *ret_prefixlen) {
_cleanup_free_ char *str = NULL;
union in_addr_union buffer;
const char *e, *l;
unsigned char k;
int r;
assert(p);
if (!IN_SET(family, AF_INET, AF_INET6))
return -EAFNOSUPPORT;
e = strchr(p, '/');
if (e) {
str = strndup(p, e - p);
if (!str)
return -ENOMEM;
l = str;
} else
l = p;
r = in_addr_from_string(family, l, &buffer);
if (r < 0)
return r;
if (e) {
r = in_addr_parse_prefixlen(family, e+1, &k);
if (r < 0)
return r;
} else
k = FAMILY_ADDRESS_SIZE(family) * 8;
if (ret_prefix)
*ret_prefix = buffer;
if (ret_prefixlen)
*ret_prefixlen = k;
return 0;
}
int in_addr_prefix_from_string_auto_internal(
const char *p,
InAddrPrefixLenMode mode,
int *ret_family,
union in_addr_union *ret_prefix,
unsigned char *ret_prefixlen) {
_cleanup_free_ char *str = NULL;
union in_addr_union buffer;
const char *e, *l;
unsigned char k;
int family, r;
assert(p);
e = strchr(p, '/');
if (e) {
str = strndup(p, e - p);
if (!str)
return -ENOMEM;
l = str;
} else
l = p;
r = in_addr_from_string_auto(l, &family, &buffer);
if (r < 0)
return r;
if (e) {
r = in_addr_parse_prefixlen(family, e+1, &k);
if (r < 0)
return r;
} else
switch (mode) {
case PREFIXLEN_FULL:
k = FAMILY_ADDRESS_SIZE(family) * 8;
break;
case PREFIXLEN_REFUSE:
return -ENOANO; /* To distinguish this error from others. */
case PREFIXLEN_LEGACY:
if (family == AF_INET) {
r = in4_addr_default_prefixlen(&buffer.in, &k);
if (r < 0)
return r;
} else
k = 0;
break;
default:
assert_not_reached("Invalid prefixlen mode");
}
if (ret_family)
*ret_family = family;
if (ret_prefix)
*ret_prefix = buffer;
if (ret_prefixlen)
*ret_prefixlen = k;
return 0;
}
static void in_addr_data_hash_func(const struct in_addr_data *a, struct siphash *state) {
siphash24_compress(&a->family, sizeof(a->family), state);
siphash24_compress(&a->address, FAMILY_ADDRESS_SIZE(a->family), state);
}
static int in_addr_data_compare_func(const struct in_addr_data *x, const struct in_addr_data *y) {
int r;
r = CMP(x->family, y->family);
if (r != 0)
return r;
return memcmp(&x->address, &y->address, FAMILY_ADDRESS_SIZE(x->family));
}
DEFINE_HASH_OPS(in_addr_data_hash_ops, struct in_addr_data, in_addr_data_hash_func, in_addr_data_compare_func);
static void in6_addr_hash_func(const struct in6_addr *addr, struct siphash *state) {
assert(addr);
siphash24_compress(addr, sizeof(*addr), state);
}
static int in6_addr_compare_func(const struct in6_addr *a, const struct in6_addr *b) {
return memcmp(a, b, sizeof(*a));
}
DEFINE_HASH_OPS(in6_addr_hash_ops, struct in6_addr, in6_addr_hash_func, in6_addr_compare_func);