[PATCH 27/33] ipv6: add ip6_sock_set_addr_preferences

Christoph Hellwig
2020-05-20T19:58:17Z

Add a helper to directly set the IPV6_ADD_PREFERENCES sockopt from kernel
space without going through a fake uaccess.

Signed-off-by: Christoph Hellwig <hch@lst.de>
---
include/net/ipv6.h | 67 ++++++++++++++++++++++++++++++++++++++++
net/ipv6/ipv6_sockglue.c | 59 +----------------------------------
net/sunrpc/xprtsock.c | 7 +++--
3 files changed, 72 insertions(+), 61 deletions(-)

diff --git a/include/net/ipv6.h b/include/net/ipv6.h
index 3b02049d2e582..80260cff7e0c0 100644
--- a/include/net/ipv6.h
+++ b/include/net/ipv6.h
@@ -1194,4 +1194,71 @@ static inline void ip6_sock_set_recverr(struct sock *sk)
release_sock(sk);
}

+static inline int __ip6_sock_set_addr_preferences(struct sock *sk, int val)
+{
+ unsigned int pref = 0;
+ unsigned int prefmask = ~0;
+
+ /* check PUBLIC/TMP/PUBTMP_DEFAULT conflicts */
+ switch (val & (IPV6_PREFER_SRC_PUBLIC |
+ IPV6_PREFER_SRC_TMP |
+ IPV6_PREFER_SRC_PUBTMP_DEFAULT)) {
+ case IPV6_PREFER_SRC_PUBLIC:
+ pref |= IPV6_PREFER_SRC_PUBLIC;
+ prefmask &= ~(IPV6_PREFER_SRC_PUBLIC |
+ IPV6_PREFER_SRC_TMP);
+ break;
+ case IPV6_PREFER_SRC_TMP:
+ pref |= IPV6_PREFER_SRC_TMP;
+ prefmask &= ~(IPV6_PREFER_SRC_PUBLIC |
+ IPV6_PREFER_SRC_TMP);
+ break;
+ case IPV6_PREFER_SRC_PUBTMP_DEFAULT:
+ prefmask &= ~(IPV6_PREFER_SRC_PUBLIC |
+ IPV6_PREFER_SRC_TMP);
+ break;
+ case 0:
+ break;
+ default:
+ return -EINVAL;
+ }
+
+ /* check HOME/COA conflicts */
+ switch (val & (IPV6_PREFER_SRC_HOME | IPV6_PREFER_SRC_COA)) {
+ case IPV6_PREFER_SRC_HOME:
+ prefmask &= ~IPV6_PREFER_SRC_COA;
+ break;
+ case IPV6_PREFER_SRC_COA:
+ pref |= IPV6_PREFER_SRC_COA;
+ break;
+ case 0:
+ break;
+ default:
+ return -EINVAL;
+ }
+
+ /* check CGA/NONCGA conflicts */
+ switch (val & (IPV6_PREFER_SRC_CGA|IPV6_PREFER_SRC_NONCGA)) {
+ case IPV6_PREFER_SRC_CGA:
+ case IPV6_PREFER_SRC_NONCGA:
+ case 0:
+ break;
+ default:
+ return -EINVAL;
+ }
+
+ inet6_sk(sk)->srcprefs = (inet6_sk(sk)->srcprefs & prefmask) | pref;
+ return 0;
+}
+
+static inline int ip6_sock_set_addr_preferences(struct sock *sk, bool val)
+{
+ int ret;
+
+ lock_sock(sk);
+ ret = __ip6_sock_set_addr_preferences(sk, val);
+ release_sock(sk);
+ return ret;
+}
+
#endif /* _NET_IPV6_H */
diff --git a/net/ipv6/ipv6_sockglue.c b/net/ipv6/ipv6_sockglue.c
index a0e50cc57e545..6bcd2e0967df9 100644
--- a/net/ipv6/ipv6_sockglue.c
+++ b/net/ipv6/ipv6_sockglue.c
@@ -838,67 +838,10 @@ static int do_ipv6_setsockopt(struct sock *sk, int level, int optname,
break;

case IPV6_ADDR_PREFERENCES:
- {
- unsigned int pref = 0;
- unsigned int prefmask = ~0;
-
if (optlen < sizeof(int))
goto e_inval;
-
- retv = -EINVAL;
-
- /* check PUBLIC/TMP/PUBTMP_DEFAULT conflicts */
- switch (val & (IPV6_PREFER_SRC_PUBLIC|
- IPV6_PREFER_SRC_TMP|
- IPV6_PREFER_SRC_PUBTMP_DEFAULT)) {
- case IPV6_PREFER_SRC_PUBLIC:
- pref |= IPV6_PREFER_SRC_PUBLIC;
- break;
- case IPV6_PREFER_SRC_TMP:
- pref |= IPV6_PREFER_SRC_TMP;
- break;
- case IPV6_PREFER_SRC_PUBTMP_DEFAULT:
- break;
- case 0:
- goto pref_skip_pubtmp;
- default:
- goto e_inval;
- }
-
- prefmask &= ~(IPV6_PREFER_SRC_PUBLIC|
- IPV6_PREFER_SRC_TMP);
-pref_skip_pubtmp:
-
- /* check HOME/COA conflicts */
- switch (val & (IPV6_PREFER_SRC_HOME|IPV6_PREFER_SRC_COA)) {
- case IPV6_PREFER_SRC_HOME:
- break;
- case IPV6_PREFER_SRC_COA:
- pref |= IPV6_PREFER_SRC_COA;
- case 0:
- goto pref_skip_coa;
- default:
- goto e_inval;
- }
-
- prefmask &= ~IPV6_PREFER_SRC_COA;
-pref_skip_coa:
-
- /* check CGA/NONCGA conflicts */
- switch (val & (IPV6_PREFER_SRC_CGA|IPV6_PREFER_SRC_NONCGA)) {
- case IPV6_PREFER_SRC_CGA:
- case IPV6_PREFER_SRC_NONCGA:
- case 0:
- break;
- default:
- goto e_inval;
- }
-
- np->srcprefs = (np->srcprefs & prefmask) | pref;
- retv = 0;
-
+ retv = __ip6_sock_set_addr_preferences(sk, val);
break;
- }
case IPV6_MINHOPCOUNT:
if (optlen < sizeof(int))
goto e_inval;
diff --git a/net/sunrpc/xprtsock.c b/net/sunrpc/xprtsock.c
index 0d3ec055bc12f..3a143e250b9ac 100644
--- a/net/sunrpc/xprtsock.c
+++ b/net/sunrpc/xprtsock.c
@@ -2150,7 +2150,6 @@ static int xs_tcp_finish_connecting(struct rpc_xprt *xprt, struct socket *sock)

if (!transport->inet) {
struct sock *sk = sock->sk;
- unsigned int addr_pref = IPV6_PREFER_SRC_PUBLIC;

/* Avoid temporary address, they are bad for long-lived
* connections such as NFS mounts.
@@ -2159,8 +2158,10 @@ static int xs_tcp_finish_connecting(struct rpc_xprt *xprt, struct socket *sock)
* knowledge about the normal duration of connections,
* MAY override this as appropriate.
*/
- kernel_setsockopt(sock, SOL_IPV6, IPV6_ADDR_PREFERENCES,
- (char *)&addr_pref, sizeof(addr_pref));
+ if (xs_addr(xprt)->sa_family == PF_INET6) {
+ ip6_sock_set_addr_preferences(sk,
+ IPV6_PREFER_SRC_PUBLIC);
+ }

xs_tcp_set_socket_timeouts(xprt, sock);

--
2.26.2