path: root/net/ipv4/inet_connection_sock.c

// SPDX-License-Identifier: GPL-2.0-or-later
/*
 * INET		An implementation of the TCP/IP protocol suite for the LINUX
 *		operating system.  INET is implemented using the  BSD Socket
 *		interface as the means of communication with the user level.
 *
 *		Support for INET connection oriented protocols.
 *
 * Authors:	See the TCP sources
 */

#include <linux/module.h>
#include <linux/jhash.h>

#include <net/inet_connection_sock.h>
#include <net/inet_hashtables.h>
#include <net/inet_timewait_sock.h>
#include <net/ip.h>
#include <net/route.h>
#include <net/tcp_states.h>
#include <net/xfrm.h>
#include <net/tcp.h>
#include <net/sock_reuseport.h>
#include <net/addrconf.h>

#if IS_ENABLED(CONFIG_IPV6)
/* match_sk*_wildcard == true:  IPV6_ADDR_ANY equals to any IPv6 addresses
 *				if IPv6 only, and any IPv4 addresses
 *				if not IPv6 only
 * match_sk*_wildcard == false: addresses must be exactly the same, i.e.
 *				IPV6_ADDR_ANY only equals to IPV6_ADDR_ANY,
 *				and 0.0.0.0 equals to 0.0.0.0 only
 */
static bool ipv6_rcv_saddr_equal(const struct in6_addr *sk1_rcv_saddr6,
				 const struct in6_addr *sk2_rcv_saddr6,
				 __be32 sk1_rcv_saddr, __be32 sk2_rcv_saddr,
				 bool sk1_ipv6only, bool sk2_ipv6only,
				 bool match_sk1_wildcard,
				 bool match_sk2_wildcard)
{
	int addr_type = ipv6_addr_type(sk1_rcv_saddr6);
	int addr_type2 = sk2_rcv_saddr6 ? ipv6_addr_type(sk2_rcv_saddr6) : IPV6_ADDR_MAPPED;

	/* if both are mapped, treat as IPv4 */
	if (addr_type == IPV6_ADDR_MAPPED && addr_type2 == IPV6_ADDR_MAPPED) {
		if (!sk2_ipv6only) {
			if (sk1_rcv_saddr == sk2_rcv_saddr)
				return true;
			return (match_sk1_wildcard && !sk1_rcv_saddr) ||
				(match_sk2_wildcard && !sk2_rcv_saddr);
		}
		return false;
	}

	if (addr_type == IPV6_ADDR_ANY && addr_type2 == IPV6_ADDR_ANY)
		return true;

	if (addr_type2 == IPV6_ADDR_ANY && match_sk2_wildcard &&
	    !(sk2_ipv6only && addr_type == IPV6_ADDR_MAPPED))
		return true;

	if (addr_type == IPV6_ADDR_ANY && match_sk1_wildcard &&
	    !(sk1_ipv6only && addr_type2 == IPV6_ADDR_MAPPED))
		return true;

	if (sk2_rcv_saddr6 &&
	    ipv6_addr_equal(sk1_rcv_saddr6, sk2_rcv_saddr6))
		return true;

	return false;
}
#endif

/* match_sk*_wildcard == true:  0.0.0.0 equals to any IPv4 addresses
 * match_sk*_wildcard == false: addresses must be exactly the same, i.e.
 *				0.0.0.0 only equals to 0.0.0.0
 */
static bool ipv4_rcv_saddr_equal(__be32 sk1_rcv_saddr, __be32 sk2_rcv_saddr,
				 bool sk2_ipv6only, bool match_sk1_wildcard,
				 bool match_sk2_wildcard)
{
	if (!sk2_ipv6only) {
		if (sk1_rcv_saddr == sk2_rcv_saddr)
			return true;
		return (match_sk1_wildcard && !sk1_rcv_saddr) ||
			(match_sk2_wildcard && !sk2_rcv_saddr);
	}
	return false;
}

bool inet_rcv_saddr_equal(const struct sock *sk, const struct sock *sk2,
			  bool match_wildcard)
{
#if IS_ENABLED(CONFIG_IPV6)
	if (sk->sk_family == AF_INET6)
		return ipv6_rcv_saddr_equal(&sk->sk_v6_rcv_saddr,
					    inet6_rcv_saddr(sk2),
					    sk->sk_rcv_saddr,
					    sk2->sk_rcv_saddr,
					    ipv6_only_sock(sk),
					    ipv6_only_sock(sk2),
					    match_wildcard,
					    match_wildcard);
#endif
	return ipv4_rcv_saddr_equal(sk->