[PATCH bpf-next v1 2/7] inet: add inet_splice_read() and use it in inet_stream_ops/inet6_stream_ops

[Jiayuan Chen]

Add inet_splice_read() which dispatches to sk->sk_prot->splice_read
via INDIRECT_CALL_1. Replace the direct tcp_splice_read reference in
inet_stream_ops and inet6_stream_ops with inet_splice_read.

Signed-off-by: Jiayuan Chen <jiayuan.chen@xxxxxxxxx>
---
 include/net/inet_common.h |  3 +++
 net/ipv4/af_inet.c        | 15 ++++++++++++++-
 net/ipv6/af_inet6.c       |  2 +-
 3 files changed, 18 insertions(+), 2 deletions(-)

diff --git a/include/net/inet_common.h b/include/net/inet_common.h
index 5dd2bf24449e..84f2744d57f8 100644
--- a/include/net/inet_common.h
+++ b/include/net/inet_common.h
@@ -34,6 +34,9 @@ void __inet_accept(struct socket *sock, struct socket *newsock,
 		   struct sock *newsk);
 int inet_send_prepare(struct sock *sk);
 int inet_sendmsg(struct socket *sock, struct msghdr *msg, size_t size);
+ssize_t inet_splice_read(struct socket *sock, loff_t *ppos,
+			 struct pipe_inode_info *pipe, size_t len,
+			 unsigned int flags);
 void inet_splice_eof(struct socket *sock);
 int inet_recvmsg(struct socket *sock, struct msghdr *msg, size_t size,
 		 int flags);
diff --git a/net/ipv4/af_inet.c b/net/ipv4/af_inet.c
index 8036e76aa1e4..2c7b35d9c62d 100644
--- a/net/ipv4/af_inet.c
+++ b/net/ipv4/af_inet.c
@@ -876,6 +876,19 @@ void inet_splice_eof(struct socket *sock)
 }
 EXPORT_SYMBOL_GPL(inet_splice_eof);
 
+ssize_t inet_splice_read(struct socket *sock, loff_t *ppos,
+			 struct pipe_inode_info *pipe, size_t len,
+			 unsigned int flags)
+{
+	struct sock *sk = sock->sk;
+	const struct proto *prot;
+
+	prot = READ_ONCE(sk->sk_prot);
+	return INDIRECT_CALL_1(prot->splice_read, tcp_splice_read, sock,
+			       ppos, pipe, len, flags);
+}
+EXPORT_SYMBOL_GPL(inet_splice_read);
+
 INDIRECT_CALLABLE_DECLARE(int udp_recvmsg(struct sock *, struct msghdr *,
 					  size_t, int, int *));
 int inet_recvmsg(struct socket *sock, struct msghdr *msg, size_t size,
@@ -1079,7 +1092,7 @@ const struct proto_ops inet_stream_ops = {
 	.mmap		   = tcp_mmap,
 #endif
 	.splice_eof	   = inet_splice_eof,
-	.splice_read	   = tcp_splice_read,
+	.splice_read	   = inet_splice_read,
 	.set_peek_off      = sk_set_peek_off,
 	.read_sock	   = tcp_read_sock,
 	.read_skb	   = tcp_read_skb,
diff --git a/net/ipv6/af_inet6.c b/net/ipv6/af_inet6.c
index 23cc9b4cb2f1..12256b0234ff 100644
--- a/net/ipv6/af_inet6.c
+++ b/net/ipv6/af_inet6.c
@@ -705,7 +705,7 @@ const struct proto_ops inet6_stream_ops = {
 #endif
 	.splice_eof	   = inet_splice_eof,
 	.sendmsg_locked    = tcp_sendmsg_locked,
-	.splice_read	   = tcp_splice_read,
+	.splice_read	   = inet_splice_read,
 	.set_peek_off      = sk_set_peek_off,
 	.read_sock	   = tcp_read_sock,
 	.read_skb	   = tcp_read_skb,
-- 
2.43.0