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Systemd/src/basic/in-addr-util.c
Zbigniew Jędrzejewski-Szmek 11a1589223 tree-wide: drop license boilerplate 
Files which are installed as-is (any .service and other unit files, .conf
files, .policy files, etc), are left as is. My assumption is that SPDX
identifiers are not yet that well known, so it's better to retain the
extended header to avoid any doubt.

I also kept any copyright lines. We can probably remove them, but it'd nice to
obtain explicit acks from all involved authors before doing that.
2018-04-06 18:58:55 +02:00

579 lines
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/* SPDX-License-Identifier: LGPL-2.1+ */
/***
This file is part of systemd.
Copyright 2014 Lennart Poettering
***/
#include <arpa/inet.h>
#include <endian.h>
#include <errno.h>
#include <net/if.h>
#include <stdint.h>
#include <stdlib.h>
#include "alloc-util.h"
#include "in-addr-util.h"
#include "macro.h"
#include "parse-util.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;
}
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;
}
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) {
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 > 0 ? -errno : -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;
}
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 in4_addr_netmask_to_prefixlen(const struct in_addr *addr) {
assert(addr);
return 32 - 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) {
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)
l = strndupa(p, e - p);
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(
const char *p,
int *ret_family,
union in_addr_union *ret_prefix,
unsigned char *ret_prefixlen) {
union in_addr_union buffer;
const char *e, *l;
unsigned char k;
int family, r;
assert(p);
e = strchr(p, '/');
if (e)
l = strndupa(p, e - p);
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
k = FAMILY_ADDRESS_SIZE(family) * 8;
if (ret_family)
*ret_family = family;
if (ret_prefix)
*ret_prefix = buffer;
if (ret_prefixlen)
*ret_prefixlen = k;
return 0;
}
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