[PATCH] xfrm: Fix inter family IPsec tunnel handling again

[Steffen Klassert <steffen.klassert@secunet.com>]

Move the selector family initialization behind the check for AF_UNSPEC
and call xfrm_ip2inner_mode() in any case. So the selector family is
intitalized in any case and we can choose for the right inner_mode.
Also check for IPPROTO_IPIP and IPPROTO_IPV6 in xfrm{4,6}_mode_tunnel_input()
to remove the right header.

Signed-off-by: Steffen Klassert <steffen.klassert@secunet.com>
---
 net/ipv4/xfrm4_mode_tunnel.c |   20 +++++++++++++++-----
 net/ipv6/xfrm6_mode_tunnel.c |   14 +++++++++++---
 net/xfrm/xfrm_input.c        |   19 ++++---------------
 net/xfrm/xfrm_state.c        |    2 ++
 net/xfrm/xfrm_user.c         |    4 ----
 5 files changed, 32 insertions(+), 27 deletions(-)

diff --git a/net/ipv4/xfrm4_mode_tunnel.c b/net/ipv4/xfrm4_mode_tunnel.c
index 7135279..5fabea3 100644
--- a/net/ipv4/xfrm4_mode_tunnel.c
+++ b/net/ipv4/xfrm4_mode_tunnel.c
@@ -68,11 +68,21 @@ static int xfrm4_mode_tunnel_input(struct xfrm_state *x, struct sk_buff *skb)
 	const unsigned char *old_mac;
 	int err = -EINVAL;
 
-	if (XFRM_MODE_SKB_CB(skb)->protocol != IPPROTO_IPIP)
-		goto out;
-
-	if (!pskb_may_pull(skb, sizeof(struct iphdr)))
-		goto out;
+        switch (XFRM_MODE_SKB_CB(skb)->protocol) {
+        case IPPROTO_IPIP:
+                if (!pskb_may_pull(skb, sizeof(struct iphdr)))
+                        goto out;
+                break;
+#if defined(CONFIG_IPV6) || defined (CONFIG_IPV6_MODULE)
+        case IPPROTO_IPV6:
+                if (!pskb_may_pull(skb, sizeof(struct ipv6hdr)))
+                        goto out;
+                break;
+#endif
+        default:
+                goto out;
+	}
+	
 
 	if (skb_cloned(skb) &&
 	    (err = pskb_expand_head(skb, 0, 0, GFP_ATOMIC)))
diff --git a/net/ipv6/xfrm6_mode_tunnel.c b/net/ipv6/xfrm6_mode_tunnel.c
index e20529b..440f064 100644
--- a/net/ipv6/xfrm6_mode_tunnel.c
+++ b/net/ipv6/xfrm6_mode_tunnel.c
@@ -63,10 +63,18 @@ static int xfrm6_mode_tunnel_input(struct xfrm_state *x, struct sk_buff *skb)
 	int err = -EINVAL;
 	const unsigned char *old_mac;
 
-	if (XFRM_MODE_SKB_CB(skb)->protocol != IPPROTO_IPV6)
-		goto out;
-	if (!pskb_may_pull(skb, sizeof(struct ipv6hdr)))
+	switch (XFRM_MODE_SKB_CB(skb)->protocol) {
+	case IPPROTO_IPIP:
+		if (!pskb_may_pull(skb, sizeof(struct iphdr)))
+			goto out;
+		break;
+	case IPPROTO_IPV6:
+		if (!pskb_may_pull(skb, sizeof(struct ipv6hdr)))
+			goto out;
+		break;	
+	default:
 		goto out;
+	}
 
 	if (skb_cloned(skb) &&
 	    (err = pskb_expand_head(skb, 0, 0, GFP_ATOMIC)))
diff --git a/net/xfrm/xfrm_input.c b/net/xfrm/xfrm_input.c
index 7527940..d220ecf 100644
--- a/net/xfrm/xfrm_input.c
+++ b/net/xfrm/xfrm_input.c
@@ -91,11 +91,9 @@ int xfrm_prepare_input(struct xfrm_state *x, struct sk_buff *skb)
 	if (err)
 		return err;
 
-	if (x->sel.family == AF_UNSPEC) {
-		inner_mode = xfrm_ip2inner_mode(x, XFRM_MODE_SKB_CB(skb)->protocol);
-		if (inner_mode == NULL)
-			return -EAFNOSUPPORT;
-	}
+	inner_mode = xfrm_ip2inner_mode(x, XFRM_MODE_SKB_CB(skb)->protocol);
+	if (inner_mode == NULL)
+		return -EAFNOSUPPORT;
 
 	skb->protocol = inner_mode->afinfo->eth_proto;
 	return inner_mode->input2(x, skb);
@@ -108,7 +106,6 @@ int xfrm_input(struct sk_buff *skb, int nexthdr, __be32 spi, int encap_type)
 	__be32 seq;
 	struct xfrm_state *x;
 	xfrm_address_t *daddr;
-	struct xfrm_mode *inner_mode;
 	unsigned int family;
 	int decaps = 0;
 	int async = 0;
@@ -215,15 +212,7 @@ resume:
 
 		XFRM_MODE_SKB_CB(skb)->protocol = nexthdr;
 
-		inner_mode = x->inner_mode;
-
-		if (x->sel.family == AF_UNSPEC) {
-			inner_mode = xfrm_ip2inner_mode(x, XFRM_MODE_SKB_CB(skb)->protocol);
-			if (inner_mode == NULL)
-				goto drop;
-		}
-
-		if (inner_mode->input(x, skb)) {
+		if (x->inner_mode->input(x, skb)) {
 			XFRM_INC_STATS(LINUX_MIB_XFRMINSTATEMODEERROR);
 			goto drop;
 		}
diff --git a/net/xfrm/xfrm_state.c b/net/xfrm/xfrm_state.c
index 72fddaf..9ea1008 100644
--- a/net/xfrm/xfrm_state.c
+++ b/net/xfrm/xfrm_state.c
@@ -2030,6 +2030,8 @@ int xfrm_init_state(struct xfrm_state *x)
 			x->inner_mode = inner_mode_iaf;
 			x->inner_mode_iaf = inner_mode;
 		}
+
+		x->sel.family = family;
 	}
 
 	x->type = xfrm_get_type(x->id.proto, family);
diff --git a/net/xfrm/xfrm_user.c b/net/xfrm/xfrm_user.c
index b976d9e..dae0956 100644
--- a/net/xfrm/xfrm_user.c
+++ b/net/xfrm/xfrm_user.c
@@ -276,10 +276,6 @@ static void copy_from_user_state(struct xfrm_state *x, struct xfrm_usersa_info *
 	x->props.family = p->family;
 	memcpy(&x->props.saddr, &p->saddr, sizeof(x->props.saddr));
 	x->props.flags = p->flags;
-
-	if (!x->sel.family)
-		x->sel.family = p->family;
-
 }
 
 /*
-- 
1.5.3