Commit bd5eb35f authored by Eric Dumazet's avatar Eric Dumazet Committed by David S. Miller
Browse files

xfrm: take care of request sockets 



TCP SYNACK messages might now be attached to request sockets.

XFRM needs to get back to a listener socket.

Adds new helpers that might be used elsewhere :
sk_to_full_sk() and sk_const_to_full_sk()

Note: We also need to add RCU protection for xfrm lookups,
now TCP/DCCP have lockless listener processing. This will
be addressed in separate patches.

Fixes: ca6fb065 ("tcp: attach SYNACK messages to request sockets instead of listener")
Reported-by: default avatarDave Jones <davej@codemonkey.org.uk>
Signed-off-by: default avatarEric Dumazet <edumazet@google.com>
Cc: Steffen Klassert <steffen.klassert@secunet.com>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
parent 69ce6487

include/net/inet_sock.h

+23 −4
Original line number Diff line number Diff line
@@ -210,18 +210,37 @@ struct inet_sock { 
#define IP_CMSG_ORIGDSTADDR	BIT(6)

#define IP_CMSG_CHECKSUM	BIT(7)



/* SYNACK messages might be attached to request sockets.

/**

 * sk_to_full_sk - Access to a full socket

 * @sk: pointer to a socket

 *

 * SYNACK messages might be attached to request sockets.

 * Some places want to reach the listener in this case.

 */

static inline struct sock *skb_to_full_sk(const struct sk_buff *skb)

static inline struct sock *sk_to_full_sk(struct sock *sk)

{

	struct sock *sk = skb->sk;



#ifdef CONFIG_INET

	if (sk && sk->sk_state == TCP_NEW_SYN_RECV)

		sk = inet_reqsk(sk)->rsk_listener;

#endif

	return sk;

}



/* sk_to_full_sk() variant with a const argument */

static inline const struct sock *sk_const_to_full_sk(const struct sock *sk)

{

#ifdef CONFIG_INET

	if (sk && sk->sk_state == TCP_NEW_SYN_RECV)

		sk = ((const struct request_sock *)sk)->rsk_listener;

#endif

	return sk;

}



static inline struct sock *skb_to_full_sk(const struct sk_buff *skb)

{

	return sk_to_full_sk(skb->sk);

}



static inline struct inet_sock *inet_sk(const struct sock *sk)

{

	return (struct inet_sock *)sk;

net/xfrm/xfrm_policy.c

+2 −0
Original line number Diff line number Diff line
@@ -2198,6 +2198,7 @@ struct dst_entry *xfrm_lookup(struct net *net, struct dst_entry *dst_orig, 
	xdst = NULL;

	route = NULL;



	sk = sk_const_to_full_sk(sk);

	if (sk && sk->sk_policy[XFRM_POLICY_OUT]) {

		num_pols = 1;

		pols[0] = xfrm_sk_policy_lookup(sk, XFRM_POLICY_OUT, fl);
@@ -2477,6 +2478,7 @@ int __xfrm_policy_check(struct sock *sk, int dir, struct sk_buff *skb, 
	}



	pol = NULL;

	sk = sk_to_full_sk(sk);

	if (sk && sk->sk_policy[dir]) {

		pol = xfrm_sk_policy_lookup(sk, dir, &fl);

		if (IS_ERR(pol)) {

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