/* SPDX-License-Identifier: GPL-2.0-or-later * Copyright Red Hat * Author: David Gibson * * inany.h - Types and helpers for handling addresses which could be * IPv6 or IPv4 (encoded as IPv4-mapped IPv6 addresses) */ #ifndef INANY_H #define INANY_H /** union inany_addr - Represents either an IPv4 or IPv6 address * @a6: Address as an IPv6 address, may be IPv4-mapped * @v4mapped.zero: All zero-bits for an IPv4 address * @v4mapped.one: All one-bits for an IPv4 address * @v4mapped.a4: If @a6 is an IPv4 mapped address, the IPv4 address * @u64: As an array of u64s (solely for hashing) * * @v4mapped and @u64 shouldn't be accessed except via helpers. */ union inany_addr { struct in6_addr a6; struct { uint8_t zero[10]; uint8_t one[2]; struct in_addr a4; } v4mapped; uint32_t u32[4]; }; static_assert(sizeof(union inany_addr) == sizeof(struct in6_addr), "union inany_addr is larger than an IPv6 address"); static_assert(_Alignof(union inany_addr) == _Alignof(uint32_t), "union inany_addr has unexpected alignment"); /** inany_v4 - Extract IPv4 address, if present, from IPv[46] address * @addr: IPv4 or IPv6 address * * Return: IPv4 address if @addr is IPv4, NULL otherwise */ static inline struct in_addr *inany_v4(const union inany_addr *addr) { if (!IN6_IS_ADDR_V4MAPPED(&addr->a6)) return NULL; return (struct in_addr *)&addr->v4mapped.a4; } /** inany_equals - Compare two IPv[46] addresses * @a, @b: IPv[46] addresses * * Return: true if @a and @b are the same address */ static inline bool inany_equals(const union inany_addr *a, const union inany_addr *b) { return IN6_ARE_ADDR_EQUAL(&a->a6, &b->a6); } /** inany_is_loopback() - Check if address is loopback * @a: IPv[46] address * * Return: true if @a is either ::1 or in 127.0.0.1/8 */ static inline bool inany_is_loopback(const union inany_addr *a) { const struct in_addr *v4 = inany_v4(a); return IN6_IS_ADDR_LOOPBACK(&a->a6) || (v4 && IN4_IS_ADDR_LOOPBACK(v4)); } /** inany_is_unspecified() - Check if address is unspecified * @a: IPv[46] address * * Return: true if @a is either :: or 0.0.0.0 */ static inline bool inany_is_unspecified(const union inany_addr *a) { const struct in_addr *v4 = inany_v4(a); return IN6_IS_ADDR_UNSPECIFIED(&a->a6) || (v4 && IN4_IS_ADDR_UNSPECIFIED(v4)); } /** inany_is_multicast() - Check if address is multicast or broadcast * @a: IPv[46] address * * Return: true if @a is IPv6 multicast or IPv4 multicast or broadcast */ static inline bool inany_is_multicast(const union inany_addr *a) { const struct in_addr *v4 = inany_v4(a); return IN6_IS_ADDR_MULTICAST(&a->a6) || (v4 && (IN4_IS_ADDR_MULTICAST(v4) || IN4_IS_ADDR_BROADCAST(v4))); } /** inany_is_unicast() - Check if address is specified and unicast * @a: IPv[46] address * * Return: true if @a is specified and a unicast address */ /* cppcheck-suppress unusedFunction */ static inline bool inany_is_unicast(const union inany_addr *a) { return !inany_is_unspecified(a) && !inany_is_multicast(a); } /** inany_from_af - Set IPv[46] address from IPv4 or IPv6 address * @aa: Pointer to store IPv[46] address * @af: Address family of @addr * @addr: struct in_addr (IPv4) or struct in6_addr (IPv6) */ static inline void inany_from_af(union inany_addr *aa, sa_family_t af, const void *addr) { if (af == AF_INET6) { aa->a6 = *((struct in6_addr *)addr); } else if (af == AF_INET) { memset(&aa->v4mapped.zero, 0, sizeof(aa->v4mapped.zero)); memset(&aa->v4mapped.one, 0xff, sizeof(aa->v4mapped.one)); aa->v4mapped.a4 = *((struct in_addr *)addr); } else { /* Not valid to call with other address families */ ASSERT(0); } } /** inany_from_sockaddr - Extract IPv[46] address and port number from sockaddr * @aa: Pointer to store IPv[46] address * @port: Pointer to store port number, host order * @addr: struct sockaddr_in (IPv4) or struct sockaddr_in6 (IPv6) */ static inline void inany_from_sockaddr(union inany_addr *aa, in_port_t *port, const void *addr) { const struct sockaddr *sa = (const struct sockaddr *)addr; if (sa->sa_family == AF_INET6) { struct sockaddr_in6 *sa6 = (struct sockaddr_in6 *)sa; inany_from_af(aa, AF_INET6, &sa6->sin6_addr); *port = ntohs(sa6->sin6_port); } else if (sa->sa_family == AF_INET) { struct sockaddr_in *sa4 = (struct sockaddr_in *)sa; inany_from_af(aa, AF_INET, &sa4->sin_addr); *port = ntohs(sa4->sin_port); } else { /* Not valid to call with other address families */ ASSERT(0); } } /** inany_siphash_feed- Fold IPv[46] address into an in-progress siphash * @state: siphash state * @aa: inany to hash */ static inline void inany_siphash_feed(struct siphash_state *state, const union inany_addr *aa) { siphash_feed(state, (uint64_t)aa->u32[0] << 32 | aa->u32[1]); siphash_feed(state, (uint64_t)aa->u32[2] << 32 | aa->u32[3]); } #endif /* INANY_H */