net: ipv4: Move ip_options_fragment() out of loop

The ip_options_fragment() only called when iter->offset is equal to zero,
so move it out of loop, and inline 'Copy the flags to each fragment.'
As also, remove the unused parameter in ip_frag_ipcb().
Signed-off-by: Yajun Deng <yajun.deng@linux.dev>
Signed-off-by: David S. Miller <davem@davemloft.net>

net/ipv4/ip_output.c

@@ -606,18 +606,6 @@ void ip_fraglist_init(struct sk_buff *skb, struct iphdr *iph,
 }
 EXPORT_SYMBOL(ip_fraglist_init);
 
-static void ip_fraglist_ipcb_prepare(struct sk_buff *skb,
-				     struct ip_fraglist_iter *iter)
-{
-	struct sk_buff *to = iter->frag;
-
-	/* Copy the flags to each fragment. */
-	IPCB(to)->flags = IPCB(skb)->flags;
-
-	if (iter->offset == 0)
-		ip_options_fragment(to);
-}
-
 void ip_fraglist_prepare(struct sk_buff *skb, struct ip_fraglist_iter *iter)
 {
 	unsigned int hlen = iter->hlen;
@@ -663,7 +651,7 @@ void ip_frag_init(struct sk_buff *skb, unsigned int hlen,
 EXPORT_SYMBOL(ip_frag_init);
 
 static void ip_frag_ipcb(struct sk_buff *from, struct sk_buff *to,
-			 bool first_frag, struct ip_frag_state *state)
+			 bool first_frag)
 {
 	/* Copy the flags to each fragment. */
 	IPCB(to)->flags = IPCB(from)->flags;
@@ -837,12 +825,13 @@ int ip_do_fragment(struct net *net, struct sock *sk, struct sk_buff *skb,
 
 		/* Everything is OK. Generate! */
 		ip_fraglist_init(skb, iph, hlen, &iter);
+		ip_options_fragment(iter.frag);
 
 		for (;;) {
 			/* Prepare header of the next frame,
 			 * before previous one went down. */
 			if (iter.frag) {
-				ip_fraglist_ipcb_prepare(skb, &iter);
+				IPCB(iter.frag)->flags = IPCB(skb)->flags;
 				ip_fraglist_prepare(skb, &iter);
 			}
 
@@ -897,7 +886,7 @@ int ip_do_fragment(struct net *net, struct sock *sk, struct sk_buff *skb,
 			err = PTR_ERR(skb2);
 			goto fail;
 		}
-		ip_frag_ipcb(skb, skb2, first_frag, &state);
+		ip_frag_ipcb(skb, skb2, first_frag);
 
 		/*
 		 *	Put this fragment into the sending queue.