Commit 8ff978b8 authored by Riccardo Paolo Bestetti's avatar Riccardo Paolo Bestetti Committed by Jakub Kicinski
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ipv4/raw: support binding to nonlocal addresses 



Add support to inet v4 raw sockets for binding to nonlocal addresses
through the IP_FREEBIND and IP_TRANSPARENT socket options, as well as
the ipv4.ip_nonlocal_bind kernel parameter.

Add helper function to inet_sock.h to check for bind address validity on
the base of the address type and whether nonlocal address are enabled
for the socket via any of the sockopts/sysctl, deduplicating checks in
ipv4/ping.c, ipv4/af_inet.c, ipv6/af_inet6.c (for mapped v4->v6
addresses), and ipv4/raw.c.

Add test cases with IP[V6]_FREEBIND verifying that both v4 and v6 raw
sockets support binding to nonlocal addresses after the change. Add
necessary support for the test cases to nettest.

Signed-off-by: default avatarRiccardo Paolo Bestetti <pbl@bestov.io>
Reviewed-by: default avatarDavid Ahern <dsahern@kernel.org>
Link: https://lore.kernel.org/r/20211117090010.125393-1-pbl@bestov.io


Signed-off-by: default avatarJakub Kicinski <kuba@kernel.org>
parent 75082e7f

include/net/inet_sock.h

+12 −0
Original line number Diff line number Diff line
@@ -372,4 +372,16 @@ static inline bool inet_can_nonlocal_bind(struct net *net, 
		inet->freebind || inet->transparent;

}



static inline bool inet_addr_valid_or_nonlocal(struct net *net,

					       struct inet_sock *inet,

					       __be32 addr,

					       int addr_type)

{

	return inet_can_nonlocal_bind(net, inet) ||

		addr == htonl(INADDR_ANY) ||

		addr_type == RTN_LOCAL ||

		addr_type == RTN_MULTICAST ||

		addr_type == RTN_BROADCAST;

}



#endif	/* _INET_SOCK_H */

net/ipv4/af_inet.c

+2 −5
Original line number Diff line number Diff line
@@ -489,11 +489,8 @@ int __inet_bind(struct sock *sk, struct sockaddr *uaddr, int addr_len, 
	 *  is temporarily down)

	 */

	err = -EADDRNOTAVAIL;

	if (!inet_can_nonlocal_bind(net, inet) &&

	    addr->sin_addr.s_addr != htonl(INADDR_ANY) &&

	    chk_addr_ret != RTN_LOCAL &&

	    chk_addr_ret != RTN_MULTICAST &&

	    chk_addr_ret != RTN_BROADCAST)

	if (!inet_addr_valid_or_nonlocal(net, inet, addr->sin_addr.s_addr,

	                                 chk_addr_ret))

		goto out;



	snum = ntohs(addr->sin_port);

net/ipv4/ping.c

+5 −9
Original line number Diff line number Diff line
@@ -311,15 +311,11 @@ static int ping_check_bind_addr(struct sock *sk, struct inet_sock *isk, 
		pr_debug("ping_check_bind_addr(sk=%p,addr=%pI4,port=%d)\n",

			 sk, &addr->sin_addr.s_addr, ntohs(addr->sin_port));



		if (addr->sin_addr.s_addr == htonl(INADDR_ANY))

			chk_addr_ret = RTN_LOCAL;

		else

		chk_addr_ret = inet_addr_type(net, addr->sin_addr.s_addr);



		if ((!inet_can_nonlocal_bind(net, isk) &&

		     chk_addr_ret != RTN_LOCAL) ||

		    chk_addr_ret == RTN_MULTICAST ||

		    chk_addr_ret == RTN_BROADCAST)

		if (!inet_addr_valid_or_nonlocal(net, inet_sk(sk),

					         addr->sin_addr.s_addr,

	                                         chk_addr_ret))

			return -EADDRNOTAVAIL;



#if IS_ENABLED(CONFIG_IPV6)

net/ipv4/raw.c

+7 −6
Original line number Diff line number Diff line
@@ -717,6 +717,7 @@ static int raw_bind(struct sock *sk, struct sockaddr *uaddr, int addr_len) 
{

	struct inet_sock *inet = inet_sk(sk);

	struct sockaddr_in *addr = (struct sockaddr_in *) uaddr;

	struct net *net = sock_net(sk);

	u32 tb_id = RT_TABLE_LOCAL;

	int ret = -EINVAL;

	int chk_addr_ret;
@@ -725,16 +726,16 @@ static int raw_bind(struct sock *sk, struct sockaddr *uaddr, int addr_len) 
		goto out;



	if (sk->sk_bound_dev_if)

		tb_id = l3mdev_fib_table_by_index(sock_net(sk),

		tb_id = l3mdev_fib_table_by_index(net,

						  sk->sk_bound_dev_if) ? : tb_id;



	chk_addr_ret = inet_addr_type_table(sock_net(sk), addr->sin_addr.s_addr,

					    tb_id);

	chk_addr_ret = inet_addr_type_table(net, addr->sin_addr.s_addr, tb_id);



	ret = -EADDRNOTAVAIL;

	if (addr->sin_addr.s_addr && chk_addr_ret != RTN_LOCAL &&

	    chk_addr_ret != RTN_MULTICAST && chk_addr_ret != RTN_BROADCAST)

	if (!inet_addr_valid_or_nonlocal(net, inet, addr->sin_addr.s_addr,

					 chk_addr_ret))

		goto out;



	inet->inet_rcv_saddr = inet->inet_saddr = addr->sin_addr.s_addr;

	if (chk_addr_ret == RTN_MULTICAST || chk_addr_ret == RTN_BROADCAST)

		inet->inet_saddr = 0;  /* Use device */

net/ipv6/af_inet6.c

+2 −5
Original line number Diff line number Diff line
@@ -337,11 +337,8 @@ static int __inet6_bind(struct sock *sk, struct sockaddr *uaddr, int addr_len, 
		chk_addr_ret = inet_addr_type_dev_table(net, dev, v4addr);

		rcu_read_unlock();



		if (!inet_can_nonlocal_bind(net, inet) &&

		    v4addr != htonl(INADDR_ANY) &&

		    chk_addr_ret != RTN_LOCAL &&

		    chk_addr_ret != RTN_MULTICAST &&

		    chk_addr_ret != RTN_BROADCAST) {

		if (!inet_addr_valid_or_nonlocal(net, inet, v4addr,

						 chk_addr_ret)) {

			err = -EADDRNOTAVAIL;

			goto out;

		}