[PATCH 20/28] ipv4: add ip_sock_set_recverr

[Christoph Hellwig]

Add a helper to directly set the IP_RECVERR sockopt from kernel space
without going through a fake uaccess.

Signed-off-by: Christoph Hellwig <hch@xxxxxx>
Reviewed-by: David Howells <dhowells@xxxxxxxxxx>
---
 include/net/ip.h         | 1 +
 net/ipv4/ip_sockglue.c   | 8 ++++++++
 net/rxrpc/local_object.c | 8 +-------
 3 files changed, 10 insertions(+), 7 deletions(-)

diff --git a/include/net/ip.h b/include/net/ip.h
index 5f5d8226b6abc..f063a491b9063 100644
--- a/include/net/ip.h
+++ b/include/net/ip.h
@@ -766,6 +766,7 @@ static inline bool inetdev_valid_mtu(unsigned int mtu)
 }
 
 void ip_sock_set_freebind(struct sock *sk);
+void ip_sock_set_recverr(struct sock *sk);
 void ip_sock_set_tos(struct sock *sk, int val);
 
 #endif	/* _IP_H */
diff --git a/net/ipv4/ip_sockglue.c b/net/ipv4/ip_sockglue.c
index 767838d2030d8..aca6b81da9bae 100644
--- a/net/ipv4/ip_sockglue.c
+++ b/net/ipv4/ip_sockglue.c
@@ -589,6 +589,14 @@ void ip_sock_set_freebind(struct sock *sk)
 }
 EXPORT_SYMBOL(ip_sock_set_freebind);
 
+void ip_sock_set_recverr(struct sock *sk)
+{
+	lock_sock(sk);
+	inet_sk(sk)->recverr = true;
+	release_sock(sk);
+}
+EXPORT_SYMBOL(ip_sock_set_recverr);
+
 /*
  *	Socket option code for IP. This is the end of the line after any
  *	TCP,UDP etc options on an IP socket.
diff --git a/net/rxrpc/local_object.c b/net/rxrpc/local_object.c
index 5ea2bd01fdd59..4c0e8fe5ec1fb 100644
--- a/net/rxrpc/local_object.c
+++ b/net/rxrpc/local_object.c
@@ -171,13 +171,7 @@ static int rxrpc_open_socket(struct rxrpc_local *local, struct net *net)
 		/* Fall through */
 	case AF_INET:
 		/* we want to receive ICMP errors */
-		opt = 1;
-		ret = kernel_setsockopt(local->socket, SOL_IP, IP_RECVERR,
-					(char *) &opt, sizeof(opt));
-		if (ret < 0) {
-			_debug("setsockopt failed");
-			goto error;
-		}
+		ip_sock_set_recverr(local->socket->sk);
 
 		/* we want to set the don't fragment bit */
 		opt = IP_PMTUDISC_DO;
-- 
2.26.2