/* SPDX-License-Identifier: GPL-2.0-or-later
* Copyright Red Hat
* Author: David Gibson <david@gibson.dropbear.id.au>
*
* 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]);
}
#define INANY_ADDRSTRLEN MAX(INET_ADDRSTRLEN, INET6_ADDRSTRLEN)
const char *inany_ntop(const union inany_addr *src, char *dst, socklen_t size);
#endif /* INANY_H */
