inet: add indirect call wrapper for getfrag() calls

UDP send path suffers from one indirect call to ip_generic_getfrag()

We can use INDIRECT_CALL_1() to avoid it.

Signed-off-by: Eric Dumazet <edumazet@google.com>
Reviewed-by: Willem de Bruijn <willemb@google.com>
Reviewed-by: Brian Vazquez <brianvv@google.com>
Link: https://patch.msgid.link/20241203173617.2595451-1-edumazet@google.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

net/ipv4/ip_output.c

@@ -1169,7 +1169,10 @@ static int __ip_append_data(struct sock *sk,
 			/* [!] NOTE: copy will be negative if pagedlen>0
 			 * because then the equation reduces to -fraggap.
 			 */
-			if (copy > 0 && getfrag(from, data + transhdrlen, offset, copy, fraggap, skb) < 0) {
+			if (copy > 0 &&
+			    INDIRECT_CALL_1(getfrag, ip_generic_getfrag,
+					    from, data + transhdrlen, offset,
+					    copy, fraggap, skb) < 0) {
 				err = -EFAULT;
 				kfree_skb(skb);
 				goto error;
@@ -1213,8 +1216,9 @@ static int __ip_append_data(struct sock *sk,
 			unsigned int off;
 
 			off = skb->len;
-			if (getfrag(from, skb_put(skb, copy),
-					offset, copy, off, skb) < 0) {
+			if (INDIRECT_CALL_1(getfrag, ip_generic_getfrag,
+					    from, skb_put(skb, copy),
+					    offset, copy, off, skb) < 0) {
 				__skb_trim(skb, off);
 				err = -EFAULT;
 				goto error;
@@ -1252,7 +1256,8 @@ static int __ip_append_data(struct sock *sk,
 				get_page(pfrag->page);
 			}
 			copy = min_t(int, copy, pfrag->size - pfrag->offset);
-			if (getfrag(from,
+			if (INDIRECT_CALL_1(getfrag, ip_generic_getfrag,
+				    from,
 				    page_address(pfrag->page) + pfrag->offset,
 				    offset, copy, skb->len, skb) < 0)
 				goto error_efault;

net/ipv6/ip6_output.c

@@ -1697,8 +1697,9 @@ static int __ip6_append_data(struct sock *sk,
 				pskb_trim_unique(skb_prev, maxfraglen);
 			}
 			if (copy > 0 &&
-			    getfrag(from, data + transhdrlen, offset,
-				    copy, fraggap, skb) < 0) {
+			    INDIRECT_CALL_1(getfrag, ip_generic_getfrag,
+					   from, data + transhdrlen, offset,
+					   copy, fraggap, skb) < 0) {
 				err = -EFAULT;
 				kfree_skb(skb);
 				goto error;
@@ -1742,8 +1743,9 @@ static int __ip6_append_data(struct sock *sk,
 			unsigned int off;
 
 			off = skb->len;
-			if (getfrag(from, skb_put(skb, copy),
-						offset, copy, off, skb) < 0) {
+			if (INDIRECT_CALL_1(getfrag, ip_generic_getfrag,
+					    from, skb_put(skb, copy),
+					    offset, copy, off, skb) < 0) {
 				__skb_trim(skb, off);
 				err = -EFAULT;
 				goto error;
@@ -1781,7 +1783,8 @@ static int __ip6_append_data(struct sock *sk,
 				get_page(pfrag->page);
 			}
 			copy = min_t(int, copy, pfrag->size - pfrag->offset);
-			if (getfrag(from,
+			if (INDIRECT_CALL_1(getfrag, ip_generic_getfrag,
+				    from,
 				    page_address(pfrag->page) + pfrag->offset,
 				    offset, copy, skb->len, skb) < 0)
 				goto error_efault;