NFSv4: test SECINFO RPC_AUTH_GSS pseudoflavors for support
Fix nfs4_negotiate_security to create an rpc_clnt used to test each SECINFO
returned pseudoflavor. Check credential creation (and gss_context creation)
which is important for RPC_AUTH_GSS pseudoflavors which can fail for multiple
reasons including mis-configuration.
Don't call nfs4_negotiate in nfs4_submount as it was just called by
nfs4_proc_lookup_mountpoint (nfs4_proc_lookup_common)
Signed-off-by: Andy Adamson <andros@netapp.com>
[Trond: fix corrupt return value from nfs_find_best_sec()]
Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com>
diff --git a/fs/nfs/nfs4namespace.c b/fs/nfs/nfs4namespace.c
index fd4dcb6..3d83cb1 100644
--- a/fs/nfs/nfs4namespace.c
+++ b/fs/nfs/nfs4namespace.c
@@ -139,17 +139,22 @@
* @server: NFS server struct
* @flavors: List of security tuples returned by SECINFO procedure
*
- * Return the pseudoflavor of the first security mechanism in
- * "flavors" that is locally supported. The "flavors" array
+ * Return an rpc client that uses the first security mechanism in
+ * "flavors" that is locally supported. The "flavors" array
* is searched in the order returned from the server, per RFC 3530
- * recommendation.
+ * recommendation and each flavor is checked for membership in the
+ * sec= mount option list if it exists.
*
* Return -EPERM if no matching flavor is found in the array.
+ *
+ * Please call rpc_shutdown_client() when you are done with this rpc client.
+ *
*/
-static rpc_authflavor_t nfs_find_best_sec(struct nfs_server *server,
+static struct rpc_clnt *nfs_find_best_sec(struct rpc_clnt *clnt,
+ struct nfs_server *server,
struct nfs4_secinfo_flavors *flavors)
{
- rpc_authflavor_t pseudoflavor;
+ rpc_authflavor_t pflavor;
struct nfs4_secinfo4 *secinfo;
unsigned int i;
@@ -160,58 +165,73 @@
case RPC_AUTH_NULL:
case RPC_AUTH_UNIX:
case RPC_AUTH_GSS:
- pseudoflavor = rpcauth_get_pseudoflavor(secinfo->flavor,
+ pflavor = rpcauth_get_pseudoflavor(secinfo->flavor,
&secinfo->flavor_info);
- /* make sure pseudoflavor matches sec= mount opt */
- if (pseudoflavor != RPC_AUTH_MAXFLAVOR &&
- nfs_auth_info_match(&server->auth_info,
- pseudoflavor))
- return pseudoflavor;
- break;
+ /* does the pseudoflavor match a sec= mount opt? */
+ if (pflavor != RPC_AUTH_MAXFLAVOR &&
+ nfs_auth_info_match(&server->auth_info, pflavor)) {
+ struct rpc_clnt *new;
+ struct rpc_cred *cred;
+
+ /* Cloning creates an rpc_auth for the flavor */
+ new = rpc_clone_client_set_auth(clnt, pflavor);
+ if (IS_ERR(new))
+ continue;
+ /**
+ * Check that the user actually can use the
+ * flavor. This is mostly for RPC_AUTH_GSS
+ * where cr_init obtains a gss context
+ */
+ cred = rpcauth_lookupcred(new->cl_auth, 0);
+ if (IS_ERR(cred)) {
+ rpc_shutdown_client(new);
+ continue;
+ }
+ put_rpccred(cred);
+ return new;
+ }
}
}
-
- return -EPERM;
+ return ERR_PTR(-EPERM);
}
-static rpc_authflavor_t nfs4_negotiate_security(struct inode *inode, struct qstr *name)
+/**
+ * nfs4_negotiate_security - in response to an NFS4ERR_WRONGSEC on lookup,
+ * return an rpc_clnt that uses the best available security flavor with
+ * respect to the secinfo flavor list and the sec= mount options.
+ *
+ * @clnt: RPC client to clone
+ * @inode: directory inode
+ * @name: lookup name
+ *
+ * Please call rpc_shutdown_client() when you are done with this rpc client.
+ */
+struct rpc_clnt *
+nfs4_negotiate_security(struct rpc_clnt *clnt, struct inode *inode,
+ struct qstr *name)
{
struct page *page;
struct nfs4_secinfo_flavors *flavors;
- rpc_authflavor_t flavor;
+ struct rpc_clnt *new;
int err;
page = alloc_page(GFP_KERNEL);
if (!page)
- return -ENOMEM;
+ return ERR_PTR(-ENOMEM);
+
flavors = page_address(page);
err = nfs4_proc_secinfo(inode, name, flavors);
if (err < 0) {
- flavor = err;
+ new = ERR_PTR(err);
goto out;
}
- flavor = nfs_find_best_sec(NFS_SERVER(inode), flavors);
+ new = nfs_find_best_sec(clnt, NFS_SERVER(inode), flavors);
out:
put_page(page);
- return flavor;
-}
-
-/*
- * Please call rpc_shutdown_client() when you are done with this client.
- */
-struct rpc_clnt *nfs4_create_sec_client(struct rpc_clnt *clnt, struct inode *inode,
- struct qstr *name)
-{
- rpc_authflavor_t flavor;
-
- flavor = nfs4_negotiate_security(inode, name);
- if ((int)flavor < 0)
- return ERR_PTR((int)flavor);
-
- return rpc_clone_client_set_auth(clnt, flavor);
+ return new;
}
static struct vfsmount *try_location(struct nfs_clone_mount *mountdata,
@@ -394,14 +414,6 @@
if (client->cl_auth->au_flavor != flavor)
flavor = client->cl_auth->au_flavor;
- else {
- rpc_authflavor_t new = nfs4_negotiate_security(dir, name);
- if ((int)new < 0) {
- mnt = ERR_PTR((int)new);
- goto out;
- }
- flavor = new;
- }
mnt = nfs_do_submount(dentry, fh, fattr, flavor);
out:
rpc_shutdown_client(client);