ipv4: Retire UDP-Lite.

We have deprecated IPv6 UDP-Lite sockets.

Let's drop support for IPv4 UDP-Lite sockets as well.

Most of the changes are similar to the IPv6 patch: removing
udplite.c and udp_impl.h, marking most functions in udp_impl.h
as static, moving the prototype for udp_recvmsg() to udp.h, and
adding INDIRECT_CALLABLE_SCOPE for it.

In addition, the INET_DIAG support for UDP-Lite is dropped.

We will remove the remaining dead code in the following patches.

Signed-off-by: Kuniyuki Iwashima <kuniyu@google.com>
Reviewed-by: Willem de Bruijn <willemb@google.com>
Link: https://patch.msgid.link/20260311052020.1213705-5-kuniyu@google.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

3 files changed, 6 insertions, 9 deletions

diff --git a/include/net/sock.h b/include/net/sock.h
index 6c3f1340e8ef..16a1b8895206 100644
--- a/include/net/sock.h
+++ b/include/net/sock.h
@@ -126,14 +126,14 @@ typedef __u64 __bitwise __addrpair;
  *	@skc_bypass_prot_mem: bypass the per-protocol memory accounting for skb
  *	@skc_bound_dev_if: bound device index if != 0
  *	@skc_bind_node: bind hash linkage for various protocol lookup tables
- *	@skc_portaddr_node: second hash linkage for UDP/UDP-Lite protocol
+ *	@skc_portaddr_node: second hash linkage for UDP
  *	@skc_prot: protocol handlers inside a network family
  *	@skc_net: reference to the network namespace of this socket
  *	@skc_v6_daddr: IPV6 destination address
  *	@skc_v6_rcv_saddr: IPV6 source address
  *	@skc_cookie: socket's cookie value
  *	@skc_node: main hash linkage for various protocol lookup tables
- *	@skc_nulls_node: main hash linkage for TCP/UDP/UDP-Lite protocol
+ *	@skc_nulls_node: main hash linkage for TCP
  *	@skc_tx_queue_mapping: tx queue number for this connection
  *	@skc_rx_queue_mapping: rx queue number for this connection
  *	@skc_flags: place holder for sk_flags
diff --git a/include/net/udp.h b/include/net/udp.h
index 05f63e9e00a7..39223e2692e9 100644
--- a/include/net/udp.h
+++ b/include/net/udp.h
@@ -105,7 +105,7 @@ struct udp_table {
 	unsigned int		log;
 };
 extern struct udp_table udp_table;
-void udp_table_init(struct udp_table *, const char *);
+
 static inline struct udp_hslot *udp_hashslot(struct udp_table *table,
 					     const struct net *net,
 					     unsigned int num)
@@ -312,7 +312,7 @@ static inline void udp_drops_inc(struct sock *sk)
 	numa_drop_add(&udp_sk(sk)->drop_counters, 1);
 }
 
-/* hash routines shared between UDPv4/6 and UDP-Litev4/6 */
+/* hash routines shared between UDPv4/6 */
 static inline int udp_lib_hash(struct sock *sk)
 {
 	BUG();
@@ -420,6 +420,8 @@ bool udp_sk_rx_dst_set(struct sock *sk, struct dst_entry *dst);
 int udp_err(struct sk_buff *, u32);
 int udp_abort(struct sock *sk, int err);
 int udp_sendmsg(struct sock *sk, struct msghdr *msg, size_t len);
+INDIRECT_CALLABLE_DECLARE(int udp_recvmsg(struct sock *sk, struct msghdr *msg,
+					  size_t len, int flags));
 void udp_splice_eof(struct socket *sock);
 int udp_push_pending_frames(struct sock *sk);
 void udp_flush_pending_frames(struct sock *sk);
@@ -427,7 +429,6 @@ int udp_cmsg_send(struct sock *sk, struct msghdr *msg, u16 *gso_size);
 void udp4_hwcsum(struct sk_buff *skb, __be32 src, __be32 dst);
 int udp_rcv(struct sk_buff *skb);
 int udp_ioctl(struct sock *sk, int cmd, int *karg);
-int udp_init_sock(struct sock *sk);
 int udp_pre_connect(struct sock *sk, struct sockaddr_unsized *uaddr, int addr_len);
 int __udp_disconnect(struct sock *sk, int flags);
 int udp_disconnect(struct sock *sk, int flags);
diff --git a/include/net/udplite.h b/include/net/udplite.h
index 786919d29f8d..fdd769745ac4 100644
--- a/include/net/udplite.h
+++ b/include/net/udplite.h
@@ -12,9 +12,6 @@
 #define UDPLITE_SEND_CSCOV   10 /* sender partial coverage (as sent)      */
 #define UDPLITE_RECV_CSCOV   11 /* receiver partial coverage (threshold ) */
 
-extern struct proto 		udplite_prot;
-extern struct udp_table		udplite_table;
-
 /*
  *	Checksum computation is all in software, hence simpler getfrag.
  */
@@ -84,5 +81,4 @@ static inline __wsum udplite_csum(struct sk_buff *skb)
 	return skb_checksum(skb, off, len, 0);
 }
 
-void udplite4_register(void);
 #endif	/* _UDPLITE_H */