From bd5eb35f16a9c55afcf5eb1c920cbbaf09747369 Mon Sep 17 00:00:00 2001
From: Eric Dumazet <edumazet@google.com>
Date: Mon, 7 Dec 2015 08:53:17 -0800
Subject: [PATCH] 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: ca6fb0651883 ("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>
---
include/net/inet_sock.h | 27 +++++++++++++++++++++++----
net/xfrm/xfrm_policy.c | 2 ++
2 files changed, 25 insertions(+), 4 deletions(-)
diff --git a/include/net/inet_sock.h b/include/net/inet_sock.h
index 2134e6d815bcb..625bdf95d673d 100644
--- a/include/net/inet_sock.h
+++ b/include/net/inet_sock.h
@@ -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;
diff --git a/net/xfrm/xfrm_policy.c b/net/xfrm/xfrm_policy.c
index 09bfcbac63bb3..18276f0cc32b5 100644
--- a/net/xfrm/xfrm_policy.c
+++ b/net/xfrm/xfrm_policy.c
@@ -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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