[PATCH 24/33] ipv4: add ip_sock_set_pktinfo

Christoph Hellwig
2020-05-20T19:58:01Z

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

Signed-off-by: Christoph Hellwig <hch@lst.de>
---
include/net/ip.h | 1 +
net/ipv4/ip_sockglue.c | 8 ++++++++
net/sunrpc/svcsock.c | 5 ++---
3 files changed, 11 insertions(+), 3 deletions(-)

diff --git a/include/net/ip.h b/include/net/ip.h
index d3649c49dd333..04ebe7bf54c6a 100644
--- a/include/net/ip.h
+++ b/include/net/ip.h
@@ -767,6 +767,7 @@ static inline bool inetdev_valid_mtu(unsigned int mtu)

void ip_sock_set_freebind(struct sock *sk);
int ip_sock_set_mtu_discover(struct sock *sk, int val);
+void ip_sock_set_pktinfo(struct sock *sk);
void ip_sock_set_recverr(struct sock *sk);
void ip_sock_set_tos(struct sock *sk, int val);

diff --git a/net/ipv4/ip_sockglue.c b/net/ipv4/ip_sockglue.c
index a3c46ec95a756..55fd4794a7975 100644
--- a/net/ipv4/ip_sockglue.c
+++ b/net/ipv4/ip_sockglue.c
@@ -608,6 +608,14 @@ int ip_sock_set_mtu_discover(struct sock *sk, int val)
}
EXPORT_SYMBOL(ip_sock_set_mtu_discover);

+void ip_sock_set_pktinfo(struct sock *sk)
+{
+ lock_sock(sk);
+ inet_sk(sk)->cmsg_flags |= IP_CMSG_PKTINFO;
+ release_sock(sk);
+}
+EXPORT_SYMBOL(ip_sock_set_pktinfo);
+
/*
* 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/sunrpc/svcsock.c b/net/sunrpc/svcsock.c
index 6773dacc64d8e..7a805d165689c 100644
--- a/net/sunrpc/svcsock.c
+++ b/net/sunrpc/svcsock.c
@@ -616,9 +616,8 @@ static void svc_udp_init(struct svc_sock *svsk, struct svc_serv *serv)
/* make sure we get destination address info */
switch (svsk->sk_sk->sk_family) {
case AF_INET:
- level = SOL_IP;
- optname = IP_PKTINFO;
- break;
+ ip_sock_set_pktinfo(svsk->sk_sock->sk);
+ return;
case AF_INET6:
level = SOL_IPV6;
optname = IPV6_RECVPKTINFO;
--
2.26.2