udp6: pass flow in ip6_make_skb together with cork

Another preparation patch. inet_cork_full already contains a field for
iflow, so we can avoid passing a separate struct iflow6 into
__ip6_append_data() and ip6_make_skb(), and use the flow stored in
inet_cork_full. Make sure callers set cork->fl, i.e. we init it in
ip6_append_data() and before calling ip6_make_skb().

Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
Reviewed-by: Willem de Bruijn <willemb@google.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

include/net/ipv6.h

@@ -1020,7 +1020,7 @@ struct sk_buff *ip6_make_skb(struct sock *sk,
 			     int getfrag(void *from, char *to, int offset,
 					 int len, int odd, struct sk_buff *skb),
 			     void *from, int length, int transhdrlen,
-			     struct ipcm6_cookie *ipc6, struct flowi6 *fl6,
+			     struct ipcm6_cookie *ipc6,
 			     struct rt6_info *rt, unsigned int flags,
 			     struct inet_cork_full *cork);
 

net/ipv6/ip6_output.c

@@ -1350,7 +1350,7 @@ static void ip6_append_data_mtu(unsigned int *mtu,
 
 static int ip6_setup_cork(struct sock *sk, struct inet_cork_full *cork,
 			  struct inet6_cork *v6_cork, struct ipcm6_cookie *ipc6,
-			  struct rt6_info *rt, struct flowi6 *fl6)
+			  struct rt6_info *rt)
 {
 	struct ipv6_pinfo *np = inet6_sk(sk);
 	unsigned int mtu;
@@ -1391,7 +1391,6 @@ static int ip6_setup_cork(struct sock *sk, struct inet_cork_full *cork,
 	}
 	dst_hold(&rt->dst);
 	cork->base.dst = &rt->dst;
-	cork->fl.u.ip6 = *fl6;
 	v6_cork->hop_limit = ipc6->hlimit;
 	v6_cork->tclass = ipc6->tclass;
 	if (rt->dst.flags & DST_XFRM_TUNNEL)
@@ -1422,7 +1421,6 @@ static int ip6_setup_cork(struct sock *sk, struct inet_cork_full *cork,
 }
 
 static int __ip6_append_data(struct sock *sk,
-			     struct flowi6 *fl6,
 			     struct sk_buff_head *queue,
 			     struct inet_cork_full *cork_full,
 			     struct inet6_cork *v6_cork,
@@ -1434,6 +1432,7 @@ static int __ip6_append_data(struct sock *sk,
 {
 	struct sk_buff *skb, *skb_prev = NULL;
 	struct inet_cork *cork = &cork_full->base;
+	struct flowi6 *fl6 = &cork_full->fl.u.ip6;
 	unsigned int maxfraglen, fragheaderlen, mtu, orig_mtu, pmtu;
 	struct ubuf_info *uarg = NULL;
 	int exthdrlen = 0;
@@ -1786,19 +1785,19 @@ int ip6_append_data(struct sock *sk,
 		 * setup for corking
 		 */
 		err = ip6_setup_cork(sk, &inet->cork, &np->cork,
-				     ipc6, rt, fl6);
+				     ipc6, rt);
 		if (err)
 			return err;
 
+		inet->cork.fl.u.ip6 = *fl6;
 		exthdrlen = (ipc6->opt ? ipc6->opt->opt_flen : 0);
 		length += exthdrlen;
 		transhdrlen += exthdrlen;
 	} else {
-		fl6 = &inet->cork.fl.u.ip6;
 		transhdrlen = 0;
 	}
 
-	return __ip6_append_data(sk, fl6, &sk->sk_write_queue, &inet->cork,
+	return __ip6_append_data(sk, &sk->sk_write_queue, &inet->cork,
 				 &np->cork, sk_page_frag(sk), getfrag,
 				 from, length, transhdrlen, flags, ipc6);
 }
@@ -1967,9 +1966,8 @@ struct sk_buff *ip6_make_skb(struct sock *sk,
 			     int getfrag(void *from, char *to, int offset,
 					 int len, int odd, struct sk_buff *skb),
 			     void *from, int length, int transhdrlen,
-			     struct ipcm6_cookie *ipc6, struct flowi6 *fl6,
-			     struct rt6_info *rt, unsigned int flags,
-			     struct inet_cork_full *cork)
+			     struct ipcm6_cookie *ipc6, struct rt6_info *rt,
+			     unsigned int flags, struct inet_cork_full *cork)
 {
 	struct inet6_cork v6_cork;
 	struct sk_buff_head queue;
@@ -1986,15 +1984,15 @@ struct sk_buff *ip6_make_skb(struct sock *sk,
 	cork->base.opt = NULL;
 	cork->base.dst = NULL;
 	v6_cork.opt = NULL;
-	err = ip6_setup_cork(sk, cork, &v6_cork, ipc6, rt, fl6);
+	err = ip6_setup_cork(sk, cork, &v6_cork, ipc6, rt);
 	if (err) {
 		ip6_cork_release(cork, &v6_cork);
 		return ERR_PTR(err);
 	}
 	if (ipc6->dontfrag < 0)
 		ipc6->dontfrag = inet6_sk(sk)->dontfrag;
 
-	err = __ip6_append_data(sk, fl6, &queue, cork, &v6_cork,
+	err = __ip6_append_data(sk, &queue, cork, &v6_cork,
 				&current->task_frag, getfrag, from,
 				length + exthdrlen, transhdrlen + exthdrlen,
 				flags, ipc6);

net/ipv6/udp.c

@@ -1533,9 +1533,11 @@ int udpv6_sendmsg(struct sock *sk, struct msghdr *msg, size_t len)
 		struct inet_cork_full cork;
 		struct sk_buff *skb;
 
+		cork.fl.u.ip6 = fl6;
+
 		skb = ip6_make_skb(sk, getfrag, msg, ulen,
 				   sizeof(struct udphdr), &ipc6,
-				   &fl6, (struct rt6_info *)dst,
+				   (struct rt6_info *)dst,
 				   msg->msg_flags, &cork);
 		err = PTR_ERR(skb);
 		if (!IS_ERR_OR_NULL(skb))