tcp: Set read_sock and peek_len proto_ops

In inet_stream_ops we set read_sock to tcp_read_sock and peek_len to
tcp_peek_len (which is just a stub function that calls tcp_inq).
Signed-off-by: Tom Herbert <tom@herbertland.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

include/net/tcp.h

@@ -1848,6 +1848,8 @@ static inline int tcp_inq(struct sock *sk)
 	return answ;
 }
 
+int tcp_peek_len(struct socket *sock);
+
 static inline void tcp_segs_in(struct tcp_sock *tp, const struct sk_buff *skb)
 {
 	u16 segs_in;

net/ipv4/af_inet.c

@@ -916,6 +916,8 @@ const struct proto_ops inet_stream_ops = {
 	.mmap		   = sock_no_mmap,
 	.sendpage	   = inet_sendpage,
 	.splice_read	   = tcp_splice_read,
+	.read_sock	   = tcp_read_sock,
+	.peek_len	   = tcp_peek_len,
 #ifdef CONFIG_COMPAT
 	.compat_setsockopt = compat_sock_common_setsockopt,
 	.compat_getsockopt = compat_sock_common_getsockopt,

net/ipv4/tcp.c

@@ -1570,6 +1570,12 @@ int tcp_read_sock(struct sock *sk, read_descriptor_t *desc,
 }
 EXPORT_SYMBOL(tcp_read_sock);
 
+int tcp_peek_len(struct socket *sock)
+{
+	return tcp_inq(sock->sk);
+}
+EXPORT_SYMBOL(tcp_peek_len);
+
 /*
  *	This routine copies from a sock struct into the user buffer.
  *

net/ipv6/af_inet6.c

@@ -545,6 +545,8 @@ const struct proto_ops inet6_stream_ops = {
 	.mmap		   = sock_no_mmap,
 	.sendpage	   = inet_sendpage,
 	.splice_read	   = tcp_splice_read,
+	.read_sock	   = tcp_read_sock,
+	.peek_len	   = tcp_peek_len,
 #ifdef CONFIG_COMPAT
 	.compat_setsockopt = compat_sock_common_setsockopt,
 	.compat_getsockopt = compat_sock_common_getsockopt,