net: relax PKTINFO non local ipv6 udp xmit check

Allow transparent sockets to be less restrictive about
the source ip of ipv6 udp packets being sent.

Google-Bug-Id: 5018138
Signed-off-by: Maciej Żenczykowski <maze@google.com>
CC: "Erik Kline" <ek@google.com>
CC: "Lorenzo Colitti" <lorenzo@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/net/ipv6/ip6_flowlabel.c b/net/ipv6/ip6_flowlabel.c
index f3caf1b..5430394 100644
--- a/net/ipv6/ip6_flowlabel.c
+++ b/net/ipv6/ip6_flowlabel.c
@@ -322,8 +322,8 @@
 }
 
 static struct ip6_flowlabel *
-fl_create(struct net *net, struct in6_flowlabel_req *freq, char __user *optval,
-	  int optlen, int *err_p)
+fl_create(struct net *net, struct sock *sk, struct in6_flowlabel_req *freq,
+	  char __user *optval, int optlen, int *err_p)
 {
 	struct ip6_flowlabel *fl = NULL;
 	int olen;
@@ -360,7 +360,7 @@
 		msg.msg_control = (void*)(fl->opt+1);
 		memset(&flowi6, 0, sizeof(flowi6));
 
-		err = datagram_send_ctl(net, &msg, &flowi6, fl->opt, &junk,
+		err = datagram_send_ctl(net, sk, &msg, &flowi6, fl->opt, &junk,
 					&junk, &junk);
 		if (err)
 			goto done;
@@ -528,7 +528,7 @@
 		if (freq.flr_label & ~IPV6_FLOWLABEL_MASK)
 			return -EINVAL;
 
-		fl = fl_create(net, &freq, optval, optlen, &err);
+		fl = fl_create(net, sk, &freq, optval, optlen, &err);
 		if (fl == NULL)
 			return err;
 		sfl1 = kmalloc(sizeof(*sfl1), GFP_KERNEL);