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author | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-27 13:00:47 +0000 |
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committer | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-27 13:00:47 +0000 |
commit | 2cb7e0aaedad73b076ea18c6900b0e86c5760d79 (patch) | |
tree | da68ca54bb79f4080079bf0828acda937593a4e1 /src/basic/in-addr-util.c | |
parent | Initial commit. (diff) | |
download | systemd-upstream.tar.xz systemd-upstream.zip |
Adding upstream version 247.3.upstream/247.3upstream
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to 'src/basic/in-addr-util.c')
-rw-r--r-- | src/basic/in-addr-util.c | 784 |
1 files changed, 784 insertions, 0 deletions
diff --git a/src/basic/in-addr-util.c b/src/basic/in-addr-util.c new file mode 100644 index 0000000..a4f13b6 --- /dev/null +++ b/src/basic/in-addr-util.c @@ -0,0 +1,784 @@ +/* SPDX-License-Identifier: LGPL-2.1-or-later */ + +#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 "string-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; +} + +bool in6_addr_is_link_local_all_nodes(const struct in6_addr *a) { + assert(a); + + /* ff02::1 */ + return be32toh(a->s6_addr32[0]) == UINT32_C(0xff020000) && + a->s6_addr32[1] == 0 && + a->s6_addr32[2] == 0 && + be32toh(a->s6_addr32[3]) == UINT32_C(0x00000001); +} + +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_local_multicast(const struct in_addr *a) { + assert(a); + + return (be32toh(a->s_addr) & UINT32_C(0xffffff00)) == UINT32_C(0xe0000000); +} + +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 IN6_ARE_ADDR_EQUAL(&a->in6, &b->in6); + + 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 if that succeeds, or -ERANGE if this overflows. */ + + return in_addr_prefix_nth(family, u, prefixlen, 1); +} + +/* + * Calculates the nth prefix of size prefixlen starting from the address denoted by u. + * + * On success 1 will be returned and the calculated prefix will be available in + * u. In the case nth == 0 the input will be left unchanged and 1 will be returned. + * In case the calculation cannot be performed (invalid prefix length, + * overflows would occur) -ERANGE is returned. If the address family given isn't + * supported -EAFNOSUPPORT will be returned. + * + * + * Examples: + * - in_addr_prefix_nth(AF_INET, 192.168.0.0, 24, 2), returns 1, writes 192.168.2.0 to u + * - in_addr_prefix_nth(AF_INET, 192.168.0.0, 24, 0), returns 1, no data written + * - in_addr_prefix_nth(AF_INET, 255.255.255.0, 24, 1), returns -ERANGE, no data written + * - in_addr_prefix_nth(AF_INET, 255.255.255.0, 0, 1), returns -ERANGE, no data written + * - in_addr_prefix_nth(AF_INET6, 2001:db8, 64, 0xff00) returns 1, writes 2001:0db8:0000:ff00:: to u + */ +int in_addr_prefix_nth(int family, union in_addr_union *u, unsigned prefixlen, uint64_t nth) { + assert(u); + + if (prefixlen <= 0) + return -ERANGE; + + if (nth == 0) + return 1; + + if (family == AF_INET) { + uint32_t c, n, t; + if (prefixlen > 32) + prefixlen = 32; + + c = be32toh(u->in.s_addr); + + t = nth << (32 - prefixlen); + + /* Check for wrap */ + if (c > UINT32_MAX - t) + return -ERANGE; + + n = c + t; + + n &= UINT32_C(0xFFFFFFFF) << (32 - prefixlen); + u->in.s_addr = htobe32(n); + return 1; + } + + if (family == AF_INET6) { + struct in6_addr result = {}; + uint8_t overflow = 0; + uint64_t delta; /* this assumes that we only ever have to up to 1<<64 subnets */ + unsigned start_byte = (prefixlen - 1) / 8; + + if (prefixlen > 128) + prefixlen = 128; + + /* First calculate what we have to add */ + delta = nth << ((128 - prefixlen) % 8); + + for (unsigned i = 16; i > 0; i--) { + unsigned j = i - 1; + unsigned d = 0; + + if (j <= start_byte) { + int16_t t; + + d = delta & 0xFF; + delta >>= 8; + + t = u->in6.s6_addr[j] + d + overflow; + overflow = t > UINT8_MAX ? t - UINT8_MAX : 0; + + result.s6_addr[j] = (uint8_t)t; + } else + result.s6_addr[j] = u->in6.s6_addr[j]; + } + + if (overflow || delta != 0) + return -ERANGE; + + 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_port_ifindex_name_to_string(int family, const union in_addr_union *u, uint16_t port, int ifindex, const char *server_name, char **ret) { + _cleanup_free_ char *ip_str = NULL, *x = NULL; + int r; + + assert(IN_SET(family, AF_INET, AF_INET6)); + 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. */ + + r = in_addr_to_string(family, u, &ip_str); + if (r < 0) + return r; + + if (family == AF_INET6) { + r = in_addr_is_link_local(family, u); + if (r < 0) + return r; + if (r == 0) + ifindex = 0; + } else + ifindex = 0; /* For IPv4 address, ifindex is always ignored. */ + + if (port == 0 && ifindex == 0 && isempty(server_name)) { + *ret = TAKE_PTR(ip_str); + return 0; + } + + const char *separator = isempty(server_name) ? "" : "#"; + server_name = strempty(server_name); + + if (port > 0) { + if (family == AF_INET6) { + if (ifindex > 0) + r = asprintf(&x, "[%s]:%"PRIu16"%%%i%s%s", ip_str, port, ifindex, separator, server_name); + else + r = asprintf(&x, "[%s]:%"PRIu16"%s%s", ip_str, port, separator, server_name); + } else + r = asprintf(&x, "%s:%"PRIu16"%s%s", ip_str, port, separator, server_name); + } else { + if (ifindex > 0) + r = asprintf(&x, "%s%%%i%s%s", ip_str, ifindex, separator, server_name); + else { + x = strjoin(ip_str, separator, server_name); + r = x ? 0 : -ENOMEM; + } + } + if (r < 0) + return -ENOMEM; + + *ret = TAKE_PTR(x); + return 0; +} + +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); + +void in6_addr_hash_func(const struct in6_addr *addr, struct siphash *state) { + assert(addr); + + siphash24_compress(addr, sizeof(*addr), state); +} + +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); |