ipv6: add ip6_sock_set_addr_preferences

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>
Signed-off-by: David S. Miller <davem@davemloft.net>

diff --git a/include/net/ipv6.h b/include/net/ipv6.h
index 49c4abf..9a90759 100644 (file)
--- a/include/net/ipv6.h
+++ b/include/net/ipv6.h
@@ -1195,4 +1195,71 @@ 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 e10258c..adbfed6 100644 (file)
--- a/net/ipv6/ipv6_sockglue.c
+++ b/net/ipv6/ipv6_sockglue.c
@@ -845,67 +845,10 @@ done:
                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 0d3ec05..3a143e2 100644 (file)
--- 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);