From: Michal Kubecek <mkubecek@suse.cz>
Date: Mon, 31 Aug 2020 22:05:44 +0200
Subject: kabi: mask changes to struct ipv6_stub
Patch-mainline: Never, kabi workaround
References: bsc#1165629

Backport of mainline commit 6c8991f41546 ("net: ipv6_stub: use
ip6_dst_lookup_flow instead of ip6_dst_lookup") replaces callback
->ipv6_dst_lookup() in struct ipv6_stub with a ->ipv6_dst_lookup_flow().

As there are only two instances of the structure and both are static
function in kernel code (and only one is actually used as we don't build
IPv6 support as a module any more), we can safely add new members at the
end of the structure.

Move ->ipv6_dst_lookup_flow() callbac to the end of the function, hide it
from kabi checker and restore ->ipv6_dst_lookup() for potential callers in
out of tree modules built against previous kernels.

Signed-off-by: Michal Kubecek <mkubecek@suse.cz>
---
 include/net/addrconf.h   | 12 ++++++++----
 net/ipv6/addrconf_core.c |  8 ++++++++
 net/ipv6/af_inet6.c      |  3 ++-
 3 files changed, 18 insertions(+), 5 deletions(-)

--- a/include/net/addrconf.h
+++ b/include/net/addrconf.h
@@ -223,15 +223,19 @@ struct ipv6_stub {
 				 const struct in6_addr *addr);
 	int (*ipv6_sock_mc_drop)(struct sock *sk, int ifindex,
 				 const struct in6_addr *addr);
-	struct dst_entry *(*ipv6_dst_lookup_flow)(struct net *net,
-						  const struct sock *sk,
-						  struct flowi6 *fl6,
-						  const struct in6_addr *final_dst);
+	int (*ipv6_dst_lookup)(struct net *net, struct sock *sk,
+			       struct dst_entry **dst, struct flowi6 *fl6);
 	void (*udpv6_encap_enable)(void);
 	void (*ndisc_send_na)(struct net_device *dev, const struct in6_addr *daddr,
 			      const struct in6_addr *solicited_addr,
 			      bool router, bool solicited, bool override, bool inc_opt);
 	struct neigh_table *nd_tbl;
+#ifndef __GENKSYMS__
+	struct dst_entry *(*ipv6_dst_lookup_flow)(struct net *net,
+						  const struct sock *sk,
+						  struct flowi6 *fl6,
+						  const struct in6_addr *final_dst);
+#endif /* __GENKSYMS__ */
 };
 extern const struct ipv6_stub *ipv6_stub __read_mostly;
 
--- a/net/ipv6/addrconf_core.c
+++ b/net/ipv6/addrconf_core.c
@@ -127,6 +127,13 @@ int inet6addr_validator_notifier_call_chain(unsigned long val, void *v)
 }
 EXPORT_SYMBOL(inet6addr_validator_notifier_call_chain);
 
+static int eafnosupport_ipv6_dst_lookup(struct net *net, struct sock *u1,
+					struct dst_entry **u2,
+					struct flowi6 *u3)
+{
+	return -EAFNOSUPPORT;
+}
+
 static struct dst_entry *eafnosupport_ipv6_dst_lookup_flow(struct net *net,
 							   const struct sock *sk,
 							   struct flowi6 *fl6,
@@ -136,6 +143,7 @@ static struct dst_entry *eafnosupport_ipv6_dst_lookup_flow(struct net *net,
 }
 
 const struct ipv6_stub *ipv6_stub __read_mostly = &(struct ipv6_stub) {
+	.ipv6_dst_lookup = eafnosupport_ipv6_dst_lookup,
 	.ipv6_dst_lookup_flow = eafnosupport_ipv6_dst_lookup_flow,
 };
 EXPORT_SYMBOL_GPL(ipv6_stub);
--- a/net/ipv6/af_inet6.c
+++ b/net/ipv6/af_inet6.c
@@ -899,10 +899,11 @@ static struct pernet_operations inet6_net_ops = {
 static const struct ipv6_stub ipv6_stub_impl = {
 	.ipv6_sock_mc_join = ipv6_sock_mc_join,
 	.ipv6_sock_mc_drop = ipv6_sock_mc_drop,
-	.ipv6_dst_lookup_flow = ip6_dst_lookup_flow__net,
+	.ipv6_dst_lookup = ip6_dst_lookup,
 	.udpv6_encap_enable = udpv6_encap_enable,
 	.ndisc_send_na = ndisc_send_na,
 	.nd_tbl	= &nd_tbl,
+	.ipv6_dst_lookup_flow = ip6_dst_lookup_flow__net,
 };
 
 static const struct ipv6_bpf_stub ipv6_bpf_stub_impl = {