/* SPDX-License-Identifier: LGPL-2.1-or-later */ #include #include #include #include #include #include #include #include "alloc-util.h" #include "errno-util.h" #include "in-addr-util.h" #include "logarithm.h" #include "macro.h" #include "parse-util.h" #include "random-util.h" #include "stdio-util.h" #include "string-util.h" #include "strxcpyx.h" bool in4_addr_is_null(const struct in_addr *a) { assert(a); return a->s_addr == 0; } bool in6_addr_is_null(const struct in6_addr *a) { assert(a); return IN6_IS_ADDR_UNSPECIFIED(a); } 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_addr_is_null(&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); } bool in4_addr_is_link_local_dynamic(const struct in_addr *a) { assert(a); if (!in4_addr_is_link_local(a)) return false; /* 169.254.0.0/24 and 169.254.255.0/24 must not be used for the dynamic IPv4LL assignment. * See RFC 3927 Section 2.1: * The IPv4 prefix 169.254/16 is registered with the IANA for this purpose. The first 256 and last * 256 addresses in the 169.254/16 prefix are reserved for future use and MUST NOT be selected by a * host using this dynamic configuration mechanism. */ return !IN_SET(be32toh(a->s_addr) & 0x0000FF00U, 0x0000U, 0xFF00U); } bool in6_addr_is_link_local(const struct in6_addr *a) { assert(a); return IN6_IS_ADDR_LINKLOCAL(a); } 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_addr_is_link_local(&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); } bool in4_addr_is_multicast(const struct in_addr *a) { assert(a); return IN_MULTICAST(be32toh(a->s_addr)); } bool in6_addr_is_multicast(const struct in6_addr *a) { assert(a); return IN6_IS_ADDR_MULTICAST(a); } int in_addr_is_multicast(int family, const union in_addr_union *u) { assert(u); if (family == AF_INET) return in4_addr_is_multicast(&u->in); if (family == AF_INET6) return in6_addr_is_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; } int in_addr_is_localhost_one(int family, const union in_addr_union *u) { assert(u); if (family == AF_INET) /* 127.0.0.1 */ return be32toh(u->in.s_addr) == UINT32_C(0x7F000001); if (family == AF_INET6) return IN6_IS_ADDR_LOOPBACK(&u->in6); return -EAFNOSUPPORT; } bool in6_addr_is_ipv4_mapped_address(const struct in6_addr *a) { return a->s6_addr32[0] == 0 && a->s6_addr32[1] == 0 && a->s6_addr32[2] == htobe32(UINT32_C(0x0000ffff)); } 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; } bool in6_addr_equal(const struct in6_addr *a, const struct in6_addr *b) { assert(a); assert(b); return IN6_ARE_ADDR_EQUAL(a, b); } 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_addr_equal(&a->in6, &b->in6); return -EAFNOSUPPORT; } bool in4_addr_prefix_intersect( const struct in_addr *a, unsigned aprefixlen, const struct in_addr *b, unsigned bprefixlen) { assert(a); assert(b); unsigned m = MIN3(aprefixlen, bprefixlen, (unsigned) (sizeof(struct in_addr) * 8)); if (m == 0) return true; /* Let's return earlier, to avoid shift by 32. */ uint32_t x = be32toh(a->s_addr ^ b->s_addr); uint32_t n = 0xFFFFFFFFUL << (32 - m); return (x & n) == 0; } bool in6_addr_prefix_intersect( const struct in6_addr *a, unsigned aprefixlen, const struct in6_addr *b, unsigned bprefixlen) { assert(a); assert(b); unsigned m = MIN3(aprefixlen, bprefixlen, (unsigned) (sizeof(struct in6_addr) * 8)); if (m == 0) return true; for (size_t i = 0; i < sizeof(struct in6_addr); i++) { uint8_t x = a->s6_addr[i] ^ b->s6_addr[i]; uint8_t n = m < 8 ? (0xFF << (8 - m)) : 0xFF; if ((x & n) != 0) return false; if (m <= 8) break; m -= 8; } return true; } int in_addr_prefix_intersect( int family, const union in_addr_union *a, unsigned aprefixlen, const union in_addr_union *b, unsigned bprefixlen) { assert(a); assert(b); /* Checks whether there are any addresses that are in both networks. */ if (family == AF_INET) return in4_addr_prefix_intersect(&a->in, aprefixlen, &b->in, bprefixlen); if (family == AF_INET6) return in6_addr_prefix_intersect(&a->in6, aprefixlen, &b->in6, bprefixlen); 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 0 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 0 will be returned and the calculated prefix will be available in * u. 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 0, writes 192.168.2.0 to u * - in_addr_prefix_nth(AF_INET, 192.168.0.0, 24, 0), returns 0, 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 0, 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 (family == AF_INET) { uint32_t c, n, t; if (prefixlen > 32) return -ERANGE; 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 0; } if (family == AF_INET6) { bool overflow = false; if (prefixlen > 128) return -ERANGE; for (unsigned i = 16; i > 0; i--) { unsigned t, j = i - 1, p = j * 8; if (p >= prefixlen) { u->in6.s6_addr[j] = 0; continue; } if (prefixlen - p < 8) { u->in6.s6_addr[j] &= 0xff << (8 - (prefixlen - p)); t = u->in6.s6_addr[j] + ((nth & 0xff) << (8 - (prefixlen - p))); nth >>= prefixlen - p; } else { t = u->in6.s6_addr[j] + (nth & 0xff) + overflow; nth >>= 8; } overflow = t > UINT8_MAX; u->in6.s6_addr[j] = (uint8_t) (t & 0xff); } if (overflow || nth != 0) return -ERANGE; return 0; } 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_prefix_range( int family, const union in_addr_union *in, unsigned prefixlen, union in_addr_union *ret_start, union in_addr_union *ret_end) { union in_addr_union start, end; int r; assert(in); if (!IN_SET(family, AF_INET, AF_INET6)) return -EAFNOSUPPORT; if (ret_start) { start = *in; r = in_addr_prefix_nth(family, &start, prefixlen, 0); if (r < 0) return r; } if (ret_end) { end = *in; r = in_addr_prefix_nth(family, &end, prefixlen, 1); if (r < 0) return r; } if (ret_start) *ret_start = start; if (ret_end) *ret_end = end; return 0; } 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 (!typesafe_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 *buf, size_t buf_len) { assert(u); assert(buf); if (!IN_SET(family, AF_INET, AF_INET6)) return -EAFNOSUPPORT; errno = 0; if (!typesafe_inet_ntop(family, u, buf, buf_len)) return errno_or_else(ENOSPC); size_t l = strlen(buf); if (!snprintf_ok(buf + l, buf_len - l, "/%u", prefixlen)) return -ENOSPC; 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)); } /* Calculate an IPv4 netmask from prefix length, for example /8 -> 255.0.0.0. */ 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; } /* Calculate an IPv6 netmask from prefix length, for example /16 -> ffff::. */ struct in6_addr* in6_addr_prefixlen_to_netmask(struct in6_addr *addr, unsigned char prefixlen) { assert(addr); assert(prefixlen <= 128); for (unsigned i = 0; i < 16; i++) { uint8_t mask; if (prefixlen >= 8) { mask = 0xFF; prefixlen -= 8; } else if (prefixlen > 0) { mask = 0xFF << (8 - prefixlen); prefixlen = 0; } else { assert(prefixlen == 0); mask = 0; } addr->s6_addr[i] = mask; } return addr; } /* Calculate an IPv4 or IPv6 netmask from prefix length, for example /8 -> 255.0.0.0 or /16 -> ffff::. */ int in_addr_prefixlen_to_netmask(int family, union in_addr_union *addr, unsigned char prefixlen) { assert(addr); switch (family) { case AF_INET: in4_addr_prefixlen_to_netmask(&addr->in, prefixlen); return 0; case AF_INET6: in6_addr_prefixlen_to_netmask(&addr->in6, prefixlen); return 0; default: return -EAFNOSUPPORT; } } 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 in4_addr_mask(struct in_addr *addr, unsigned char prefixlen) { struct in_addr mask; assert(addr); if (!in4_addr_prefixlen_to_netmask(&mask, prefixlen)) return -EINVAL; addr->s_addr &= mask.s_addr; return 0; } int in6_addr_mask(struct in6_addr *addr, unsigned char prefixlen) { unsigned i; for (i = 0; i < 16; i++) { uint8_t mask; if (prefixlen >= 8) { mask = 0xFF; prefixlen -= 8; } else if (prefixlen > 0) { mask = 0xFF << (8 - prefixlen); prefixlen = 0; } else { assert(prefixlen == 0); mask = 0; } addr->s6_addr[i] &= mask; } return 0; } int in_addr_mask(int family, union in_addr_union *addr, unsigned char prefixlen) { assert(addr); switch (family) { case AF_INET: return in4_addr_mask(&addr->in, prefixlen); case AF_INET6: return in6_addr_mask(&addr->in6, prefixlen); default: return -EAFNOSUPPORT; } } int in4_addr_prefix_covers_full( const struct in_addr *prefix, unsigned char prefixlen, const struct in_addr *address, unsigned char address_prefixlen) { struct in_addr masked_prefix, masked_address; int r; assert(prefix); assert(address); if (prefixlen > address_prefixlen) return false; masked_prefix = *prefix; r = in4_addr_mask(&masked_prefix, prefixlen); if (r < 0) return r; masked_address = *address; r = in4_addr_mask(&masked_address, prefixlen); if (r < 0) return r; return in4_addr_equal(&masked_prefix, &masked_address); } int in6_addr_prefix_covers_full( const struct in6_addr *prefix, unsigned char prefixlen, const struct in6_addr *address, unsigned char address_prefixlen) { struct in6_addr masked_prefix, masked_address; int r; assert(prefix); assert(address); if (prefixlen > address_prefixlen) return false; masked_prefix = *prefix; r = in6_addr_mask(&masked_prefix, prefixlen); if (r < 0) return r; masked_address = *address; r = in6_addr_mask(&masked_address, prefixlen); if (r < 0) return r; return in6_addr_equal(&masked_prefix, &masked_address); } int in_addr_prefix_covers_full( int family, const union in_addr_union *prefix, unsigned char prefixlen, const union in_addr_union *address, unsigned char address_prefixlen) { assert(prefix); assert(address); switch (family) { case AF_INET: return in4_addr_prefix_covers_full(&prefix->in, prefixlen, &address->in, address_prefixlen); case AF_INET6: return in6_addr_prefix_covers_full(&prefix->in6, prefixlen, &address->in6, address_prefixlen); default: return -EAFNOSUPPORT; } } 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. */ default: assert_not_reached(); } if (ret_family) *ret_family = family; if (ret_prefix) *ret_prefix = buffer; if (ret_prefixlen) *ret_prefixlen = k; return 0; } void in_addr_hash_func(const union in_addr_union *u, int family, struct siphash *state) { assert(u); assert(state); siphash24_compress(u->bytes, FAMILY_ADDRESS_SIZE(family), state); } void in_addr_data_hash_func(const struct in_addr_data *a, struct siphash *state) { assert(a); assert(state); siphash24_compress_typesafe(a->family, state); in_addr_hash_func(&a->address, a->family, state); } int in_addr_data_compare_func(const struct in_addr_data *x, const struct in_addr_data *y) { int r; assert(x); assert(y); 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); DEFINE_HASH_OPS_WITH_KEY_DESTRUCTOR( in_addr_data_hash_ops_free, struct in_addr_data, in_addr_data_hash_func, in_addr_data_compare_func, free); void in6_addr_hash_func(const struct in6_addr *addr, struct siphash *state) { assert(addr); assert(state); siphash24_compress_typesafe(*addr, state); } int in6_addr_compare_func(const struct in6_addr *a, const struct in6_addr *b) { assert(a); assert(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); DEFINE_HASH_OPS_WITH_KEY_DESTRUCTOR( in6_addr_hash_ops_free, struct in6_addr, in6_addr_hash_func, in6_addr_compare_func, free);