ipv6: change ipv6_stub_impl.ipv6_dst_lookup to take net argument

This patch adds net argument to ipv6_stub_impl.ipv6_dst_lookup
for use cases where sk is not available (like mpls).
sk appears to be needed to get the namespace 'net' and is optional
otherwise. This patch series changes ipv6_stub_impl.ipv6_dst_lookup
to take net argument. sk remains optional.

All callers of ipv6_stub_impl.ipv6_dst_lookup have been modified
to pass net. I have modified them to use already available
'net' in the scope of the call. I can change them to
sock_net(sk) to avoid any unintended change in behaviour if sock
namespace is different. They dont seem to be from code inspection.

Signed-off-by: Roopa Prabhu <roopa@cumulusnetworks.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

drivers/net/vxlan.c

@@ -2034,7 +2034,7 @@ static void vxlan_xmit_one(struct sk_buff *skb, struct net_device *dev,
 		fl6.flowi6_mark = skb->mark;
 		fl6.flowi6_proto = IPPROTO_UDP;
 
-		if (ipv6_stub->ipv6_dst_lookup(sk, &ndst, &fl6)) {
+		if (ipv6_stub->ipv6_dst_lookup(vxlan->net, sk, &ndst, &fl6)) {
 			netdev_dbg(dev, "no route to %pI6\n",
 				   &dst->sin6.sin6_addr);
 			dev->stats.tx_carrier_errors++;

include/net/addrconf.h

@@ -158,8 +158,8 @@ struct ipv6_stub {
 				 const struct in6_addr *addr);
 	int (*ipv6_sock_mc_drop)(struct sock *sk, int ifindex,
 				 const struct in6_addr *addr);
-	int (*ipv6_dst_lookup)(struct sock *sk, struct dst_entry **dst,
-				struct flowi6 *fl6);
+	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, struct neighbour *neigh,
 			      const struct in6_addr *daddr,

include/net/ipv6.h

@@ -813,7 +813,8 @@ static inline struct sk_buff *ip6_finish_skb(struct sock *sk)
 			      &inet6_sk(sk)->cork);
 }
 
-int ip6_dst_lookup(struct sock *sk, struct dst_entry **dst, struct flowi6 *fl6);
+int ip6_dst_lookup(struct net *net, struct sock *sk, struct dst_entry **dst,
+		   struct flowi6 *fl6);
 struct dst_entry *ip6_dst_lookup_flow(struct sock *sk, struct flowi6 *fl6,
 				      const struct in6_addr *final_dst);
 struct dst_entry *ip6_sk_dst_lookup_flow(struct sock *sk, struct flowi6 *fl6,

net/ipv6/addrconf_core.c

@@ -107,7 +107,16 @@ int inet6addr_notifier_call_chain(unsigned long val, void *v)
 }
 EXPORT_SYMBOL(inet6addr_notifier_call_chain);
 
-const struct ipv6_stub *ipv6_stub __read_mostly;
+static int eafnosupport_ipv6_dst_lookup(struct net *net, struct sock *u1,
+					struct dst_entry **u2,
+					struct flowi6 *u3)
+{
+	return -EAFNOSUPPORT;
+}
+
+const struct ipv6_stub *ipv6_stub __read_mostly = &(struct ipv6_stub) {
+	.ipv6_dst_lookup = eafnosupport_ipv6_dst_lookup,
+};
 EXPORT_SYMBOL_GPL(ipv6_stub);
 
 /* IPv6 Wildcard Address and Loopback Address defined by RFC2553 */

net/ipv6/icmp.c

@@ -329,7 +329,7 @@ static struct dst_entry *icmpv6_route_lookup(struct net *net,
 	struct flowi6 fl2;
 	int err;
 
-	err = ip6_dst_lookup(sk, &dst, fl6);
+	err = ip6_dst_lookup(net, sk, &dst, fl6);
 	if (err)
 		return ERR_PTR(err);
 
@@ -361,7 +361,7 @@ static struct dst_entry *icmpv6_route_lookup(struct net *net,
 	if (err)
 		goto relookup_failed;
 
-	err = ip6_dst_lookup(sk, &dst2, &fl2);
+	err = ip6_dst_lookup(net, sk, &dst2, &fl2);
 	if (err)
 		goto relookup_failed;
 
@@ -591,7 +591,7 @@ static void icmpv6_echo_reply(struct sk_buff *skb)
 	else if (!fl6.flowi6_oif)
 		fl6.flowi6_oif = np->ucast_oif;
 
-	err = ip6_dst_lookup(sk, &dst, &fl6);
+	err = ip6_dst_lookup(net, sk, &dst, &fl6);
 	if (err)
 		goto out;
 	dst = xfrm_lookup(net, dst, flowi6_to_flowi(&fl6), sk, 0);

net/ipv6/ip6_output.c

@@ -881,10 +881,9 @@ out:
 	return dst;
 }
 
-static int ip6_dst_lookup_tail(struct sock *sk,
+static int ip6_dst_lookup_tail(struct net *net, struct sock *sk,
 			       struct dst_entry **dst, struct flowi6 *fl6)
 {
-	struct net *net = sock_net(sk);
 #ifdef CONFIG_IPV6_OPTIMISTIC_DAD
 	struct neighbour *n;
 	struct rt6_info *rt;
@@ -994,10 +993,11 @@ out_err_release:
  *
  *	It returns zero on success, or a standard errno code on error.
  */
-int ip6_dst_lookup(struct sock *sk, struct dst_entry **dst, struct flowi6 *fl6)
+int ip6_dst_lookup(struct net *net, struct sock *sk, struct dst_entry **dst,
+		   struct flowi6 *fl6)
 {
 	*dst = NULL;
-	return ip6_dst_lookup_tail(sk, dst, fl6);
+	return ip6_dst_lookup_tail(net, sk, dst, fl6);
 }
 EXPORT_SYMBOL_GPL(ip6_dst_lookup);
 
@@ -1018,7 +1018,7 @@ struct dst_entry *ip6_dst_lookup_flow(struct sock *sk, struct flowi6 *fl6,
 	struct dst_entry *dst = NULL;
 	int err;
 
-	err = ip6_dst_lookup_tail(sk, &dst, fl6);
+	err = ip6_dst_lookup_tail(sock_net(sk), sk, &dst, fl6);
 	if (err)
 		return ERR_PTR(err);
 	if (final_dst)
@@ -1052,7 +1052,7 @@ struct dst_entry *ip6_sk_dst_lookup_flow(struct sock *sk, struct flowi6 *fl6,
 
 	dst = ip6_sk_dst_check(sk, dst, fl6);
 
-	err = ip6_dst_lookup_tail(sk, &dst, fl6);
+	err = ip6_dst_lookup_tail(sock_net(sk), sk, &dst, fl6);
 	if (err)
 		return ERR_PTR(err);
 	if (final_dst)

net/tipc/udp_media.c

@@ -194,7 +194,8 @@ static int tipc_udp_send_msg(struct net *net, struct sk_buff *skb,
 			.saddr = src->ipv6,
 			.flowi6_proto = IPPROTO_UDP
 		};
-		err = ipv6_stub->ipv6_dst_lookup(ub->ubsock->sk, &ndst, &fl6);
+		err = ipv6_stub->ipv6_dst_lookup(net, ub->ubsock->sk, &ndst,
+						 &fl6);
 		if (err)
 			goto tx_error;
 		ttl = ip6_dst_hoplimit(ndst);