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: ca6fb06518 ("tcp: attach SYNACK messages to request sockets instead of listener")
Reported-by: Dave Jones <davej@codemonkey.org.uk>
Signed-off-by: Eric Dumazet <edumazet@google.com>
Cc: Steffen Klassert <steffen.klassert@secunet.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
This commit is contained in:
Eric Dumazet 2015-12-07 08:53:17 -08:00 committed by David S. Miller
parent 69ce6487dc
commit bd5eb35f16
2 changed files with 25 additions and 4 deletions

View File

@ -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;

View File

@ -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)) {