bb6bb5649d
passt usually doesn't NAT, but it does do so for the remapping of the gateway address to refer to the host. Currently we perform this NAT with slightly different rules on both IPv4 addresses and IPv6 addresses, but not on IPv4-mapped IPv6 addresses. This means we won't correctly handle the case of an IPv4 connection over an IPv6 socket, which is possible on Linux (and probably other platforms). Refactor tcp_conn_from_sock() to perform the NAT after converting either address family into an inany_addr, so IPv4 and and IPv4-mapped addresses have the same representation. With two new helpers this lets us remove the IPv4 and IPv6 specific paths from tcp_conn_from_sock(). Signed-off-by: David Gibson <david@gibson.dropbear.id.au> Signed-off-by: Stefano Brivio <sbrivio@redhat.com>
94 lines
2.8 KiB
C
94 lines
2.8 KiB
C
/* SPDX-License-Identifier: AGPL-3.0-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)
|
|
*/
|
|
|
|
#include <assert.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
|
|
*
|
|
* @v4mapped 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;
|
|
};
|
|
|
|
/** 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_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, int 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);
|
|
}
|
|
}
|