From: Florian Westphal <fw@strlen.de>
Date: Mon, 4 May 2020 10:06:06 +0200
Subject: xfrm: expose local_rxpmtu via ipv6_stubs
Patch-mainline: v5.8-rc1
Git-commit: 3e50ddd8b8d5067796fc87cbbb25c71451ccb385
References: bsc#1176447

We cannot call this function from the core kernel unless we would force
CONFIG_IPV6=y.

Therefore expose this via ipv6_stubs so we can call it from net/xfrm
in the followup patch.

Since the call is expected to be unlikely, no extra code for the IPV6=y
case is added and we will always eat the indirection cost.

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/ipv6_stubs.h |    1 +
 include/net/xfrm.h       |    1 +
 net/ipv6/af_inet6.c      |    1 +
 net/ipv6/xfrm6_output.c  |    2 +-
 4 files changed, 4 insertions(+), 1 deletion(-)

--- a/include/net/ipv6_stubs.h
+++ b/include/net/ipv6_stubs.h
@@ -57,6 +57,7 @@ struct ipv6_stub {
 			      const struct in6_addr *solicited_addr,
 			      bool router, bool solicited, bool override, bool inc_opt);
 #if IS_ENABLED(CONFIG_XFRM)
+	void (*xfrm6_local_rxpmtu)(struct sk_buff *skb, u32 mtu);
 	int (*xfrm6_udp_encap_rcv)(struct sock *sk, struct sk_buff *skb);
 	int (*xfrm6_rcv_encap)(struct sk_buff *skb, int nexthdr, __be32 spi,
 			       int encap_type);
--- a/include/net/xfrm.h
+++ b/include/net/xfrm.h
@@ -1608,6 +1608,7 @@ int xfrm6_find_1stfragopt(struct xfrm_st
 			  u8 **prevhdr);
 
 #ifdef CONFIG_XFRM
+void xfrm6_local_rxpmtu(struct sk_buff *skb, u32 mtu);
 int xfrm4_udp_encap_rcv(struct sock *sk, struct sk_buff *skb);
 int xfrm6_udp_encap_rcv(struct sock *sk, struct sk_buff *skb);
 int xfrm_user_policy(struct sock *sk, int optname,
--- a/net/ipv6/af_inet6.c
+++ b/net/ipv6/af_inet6.c
@@ -963,6 +963,7 @@ static const struct ipv6_stub ipv6_stub_
 	.udpv6_encap_enable = udpv6_encap_enable,
 	.ndisc_send_na = ndisc_send_na,
 #if IS_ENABLED(CONFIG_XFRM)
+	.xfrm6_local_rxpmtu = xfrm6_local_rxpmtu,
 	.xfrm6_udp_encap_rcv = xfrm6_udp_encap_rcv,
 	.xfrm6_rcv_encap = xfrm6_rcv_encap,
 #endif
--- a/net/ipv6/xfrm6_output.c
+++ b/net/ipv6/xfrm6_output.c
@@ -40,7 +40,7 @@ static int xfrm6_local_dontfrag(struct s
 	return 0;
 }
 
-static void xfrm6_local_rxpmtu(struct sk_buff *skb, u32 mtu)
+void xfrm6_local_rxpmtu(struct sk_buff *skb, u32 mtu)
 {
 	struct flowi6 fl6;
 	struct sock *sk = skb->sk;