From: Florian Westphal <fw@strlen.de>
Date: Mon, 4 May 2020 10:06:09 +0200
Subject: xfrm: remove output_finish indirection from xfrm_state_afinfo
Patch-mainline: v5.8-rc1
Git-commit: 2ab6096db2f16b3a6adbad252f1be171e649028d
References: bsc#1176447

There are only two implementaions, one for ipv4 and one for ipv6.

Both are almost identical, they clear skb->cb[], set the TRANSFORMED flag
in IP(6)CB and then call the common xfrm_output() function.

By placing the IPCB handling into the common function, we avoid the need
for the output_finish indirection as the output functions can simply
use xfrm_output().

Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Steffen Klassert <steffen.klassert@secunet.com>
Acked-by: Thomas Bogendoerfer <tbogendoerfer@suse.de>
---
 include/net/xfrm.h      |    1 -
 net/ipv4/xfrm4_output.c |   21 +--------------------
 net/ipv4/xfrm4_state.c  |    1 -
 net/ipv6/xfrm6_output.c |   32 ++------------------------------
 net/ipv6/xfrm6_state.c  |    1 -
 net/xfrm/xfrm_output.c  |   16 ++++++++++++++++
 6 files changed, 19 insertions(+), 53 deletions(-)

--- a/include/net/xfrm.h
+++ b/include/net/xfrm.h
@@ -361,7 +361,6 @@ struct xfrm_state_afinfo {
 	const struct xfrm_type		*type_dstopts;
 
 	int			(*output)(struct net *net, struct sock *sk, struct sk_buff *skb);
-	int			(*output_finish)(struct sock *sk, struct sk_buff *skb);
 	int			(*transport_finish)(struct sk_buff *skb,
 						    int async);
 	void			(*local_error)(struct sk_buff *skb, u32 mtu);
--- a/net/ipv4/xfrm4_output.c
+++ b/net/ipv4/xfrm4_output.c
@@ -14,20 +14,9 @@
 #include <net/xfrm.h>
 #include <net/icmp.h>
 
-int xfrm4_output_finish(struct sock *sk, struct sk_buff *skb)
-{
-	memset(IPCB(skb), 0, sizeof(*IPCB(skb)));
-
-	IPCB(skb)->flags |= IPSKB_XFRM_TRANSFORMED;
-
-	return xfrm_output(sk, skb);
-}
-
 static int __xfrm4_output(struct net *net, struct sock *sk, struct sk_buff *skb)
 {
 	struct xfrm_state *x = skb_dst(skb)->xfrm;
-	const struct xfrm_state_afinfo *afinfo;
-	int ret = -EAFNOSUPPORT;
 
 #ifdef CONFIG_NETFILTER
 	if (!x) {
@@ -36,15 +25,7 @@ static int __xfrm4_output(struct net *ne
 	}
 #endif
 
-	rcu_read_lock();
-	afinfo = xfrm_state_afinfo_get_rcu(x->outer_mode.family);
-	if (likely(afinfo))
-		ret = afinfo->output_finish(sk, skb);
-	else
-		kfree_skb(skb);
-	rcu_read_unlock();
-
-	return ret;
+	return xfrm_output(sk, skb);
 }
 
 int xfrm4_output(struct net *net, struct sock *sk, struct sk_buff *skb)
--- a/net/ipv4/xfrm4_state.c
+++ b/net/ipv4/xfrm4_state.c
@@ -14,7 +14,6 @@ static struct xfrm_state_afinfo xfrm4_st
 	.family			= AF_INET,
 	.proto			= IPPROTO_IPIP,
 	.output			= xfrm4_output,
-	.output_finish		= xfrm4_output_finish,
 	.transport_finish	= xfrm4_transport_finish,
 	.local_error		= xfrm4_local_error,
 };
--- a/net/ipv6/xfrm6_output.c
+++ b/net/ipv6/xfrm6_output.c
@@ -47,37 +47,9 @@ void xfrm6_local_error(struct sk_buff *s
 	ipv6_local_error(sk, EMSGSIZE, &fl6, mtu);
 }
 
-int xfrm6_output_finish(struct sock *sk, struct sk_buff *skb)
-{
-	memset(IP6CB(skb), 0, sizeof(*IP6CB(skb)));
-
-	IP6CB(skb)->flags |= IP6SKB_XFRM_TRANSFORMED;
-
-	return xfrm_output(sk, skb);
-}
-
-static int __xfrm6_output_state_finish(struct xfrm_state *x, struct sock *sk,
-				       struct sk_buff *skb)
-{
-	const struct xfrm_state_afinfo *afinfo;
-	int ret = -EAFNOSUPPORT;
-
-	rcu_read_lock();
-	afinfo = xfrm_state_afinfo_get_rcu(x->outer_mode.family);
-	if (likely(afinfo))
-		ret = afinfo->output_finish(sk, skb);
-	else
-		kfree_skb(skb);
-	rcu_read_unlock();
-
-	return ret;
-}
-
 static int __xfrm6_output_finish(struct net *net, struct sock *sk, struct sk_buff *skb)
 {
-	struct xfrm_state *x = skb_dst(skb)->xfrm;
-
-	return __xfrm6_output_state_finish(x, sk, skb);
+	return xfrm_output(sk, skb);
 }
 
 static int __xfrm6_output(struct net *net, struct sock *sk, struct sk_buff *skb)
@@ -119,7 +91,7 @@ static int __xfrm6_output(struct net *ne
 				    __xfrm6_output_finish);
 
 skip_frag:
-	return __xfrm6_output_state_finish(x, sk, skb);
+	return xfrm_output(sk, skb);
 }
 
 int xfrm6_output(struct net *net, struct sock *sk, struct sk_buff *skb)
--- a/net/ipv6/xfrm6_state.c
+++ b/net/ipv6/xfrm6_state.c
@@ -18,7 +18,6 @@ static struct xfrm_state_afinfo xfrm6_st
 	.family			= AF_INET6,
 	.proto			= IPPROTO_IPV6,
 	.output			= xfrm6_output,
-	.output_finish		= xfrm6_output_finish,
 	.transport_finish	= xfrm6_transport_finish,
 	.local_error		= xfrm6_local_error,
 };
--- a/net/xfrm/xfrm_output.c
+++ b/net/xfrm/xfrm_output.c
@@ -571,6 +571,22 @@ int xfrm_output(struct sock *sk, struct
 	struct xfrm_state *x = skb_dst(skb)->xfrm;
 	int err;
 
+	switch (x->outer_mode.family) {
+	case AF_INET:
+		memset(IPCB(skb), 0, sizeof(*IPCB(skb)));
+#ifdef CONFIG_NETFILTER
+		IPCB(skb)->flags |= IPSKB_XFRM_TRANSFORMED;
+#endif
+		break;
+	case AF_INET6:
+		memset(IP6CB(skb), 0, sizeof(*IP6CB(skb)));
+
+#ifdef CONFIG_NETFILTER
+		IP6CB(skb)->flags |= IP6SKB_XFRM_TRANSFORMED;
+#endif
+		break;
+	}
+
 	secpath_reset(skb);
 
 	if (xfrm_dev_offload_ok(skb, x)) {