NFS: Introduce nfs4_validate_mount_options

Refactor NFSv4 mount processing to break out mount data validation
in the same way it's broken out in the NFSv2/v3 mount path.

Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>

1 files changed, 89 insertions, 64 deletions

diff --git a/fs/nfs/super.c b/fs/nfs/super.c
index baf75e9bd3fe..ed3ec4477a0f 100644
--- a/fs/nfs/super.c
+++ b/fs/nfs/super.c
@@ -814,6 +814,89 @@ static void nfs4_fill_super(struct super_block *sb)
 }
 
 /*
+ * Validate NFSv4 mount options
+ */
+static int nfs4_validate_mount_data(struct nfs4_mount_data **options,
+                                    const char *dev_name,
+                                    struct sockaddr_in *addr,
+                                    rpc_authflavor_t *authflavour,
+                                    char **hostname,
+                                    char **mntpath,
+                                    char **ip_addr)
+{
+        struct nfs4_mount_data *data = *options;
+        char *c;
+
+        if (data == NULL)
+                goto out_no_data;
+
+        switch (data->version) {
+        case 1:
+                if (data->host_addrlen != sizeof(*addr))
+                        goto out_no_address;
+                if (copy_from_user(addr, data->host_addr, sizeof(*addr)))
+                        return -EFAULT;
+                if (addr->sin_port == 0)
+                        addr->sin_port = htons(NFS_PORT);
+                if (!nfs_verify_server_address((struct sockaddr *) addr))
+                        goto out_no_address;
+
+                switch (data->auth_flavourlen) {
+                case 0:
+                        *authflavour = RPC_AUTH_UNIX;
+                        break;
+                case 1:
+                        if (copy_from_user(authflavour, data->auth_flavours,
+                                           sizeof(*authflavour)))
+                                return -EFAULT;
+                        break;
+                default:
+                        goto out_inval_auth;
+                }
+
+                c = strndup_user(data->hostname.data, NFS4_MAXNAMLEN);
+                if (IS_ERR(c))
+                        return PTR_ERR(c);
+                *hostname = c;
+
+                c = strndup_user(data->mnt_path.data, NFS4_MAXPATHLEN);
+                if (IS_ERR(c))
+                        return PTR_ERR(c);
+                *mntpath = c;
+                dfprintk(MOUNT, "NFS: MNTPATH: '%s'\n", *mntpath);
+
+                c = strndup_user(data->client_addr.data, 16);
+                if (IS_ERR(c))
+                        return PTR_ERR(c);
+                *ip_addr = c;
+
+                break;
+        default:
+                goto out_bad_version;
+        }
+
+        return 0;
+
+out_no_data:
+        dfprintk(MOUNT, "NFS4: mount program didn't pass any mount data\n");
+        return -EINVAL;
+
+out_inval_auth:
+        dfprintk(MOUNT, "NFS4: Invalid number of RPC auth flavours %d\n",
+                 data->auth_flavourlen);
+        return -EINVAL;
+
+out_no_address:
+        dfprintk(MOUNT, "NFS4: mount program didn't pass remote address\n");
+        return -EINVAL;
+
+out_bad_version:
+        dfprintk(MOUNT, "NFS4: bad nfs_mount_data version %d\n",
+                 data->version);
+        return -EINVAL;
+}
+
+/*
  * Get the superblock for an NFS4 mountpoint
  */
 static int nfs4_get_sb(struct file_system_type *fs_type,
@@ -826,68 +909,14 @@ static int nfs4_get_sb(struct file_system_type *fs_type,
         rpc_authflavor_t authflavour;
         struct nfs_fh mntfh;
         struct dentry *mntroot;
-        char *p, *mntpath = NULL, *hostname = NULL, *ip_addr = NULL;
+        char *mntpath = NULL, *hostname = NULL, *ip_addr = NULL;
         int error;
 
-        if (data == NULL) {
-                dprintk("%s: missing data argument\n", __FUNCTION__);
-                return -EINVAL;
-        }
-        if (data->version <= 0 || data->version > NFS4_MOUNT_VERSION) {
-                dprintk("%s: bad mount version\n", __FUNCTION__);
-                return -EINVAL;
-        }
-
-        /* We now require that the mount process passes the remote address */
-        if (data->host_addrlen != sizeof(addr))
-                return -EINVAL;
-
-        if (copy_from_user(&addr, data->host_addr, sizeof(addr)))
-                return -EFAULT;
-
-        if (!nfs_verify_server_address((struct sockaddr *) &addr)) {
-                dprintk("%s: mount program didn't pass remote IP address!\n",
-                                __FUNCTION__);
-                return -EINVAL;
-        }
-
-        /* RFC3530: The default port for NFS is 2049 */
-        if (addr.sin_port == 0)
-                addr.sin_port = htons(NFS_PORT);
-
-        /* Grab the authentication type */
-        authflavour = RPC_AUTH_UNIX;
-        if (data->auth_flavourlen != 0) {
-                if (data->auth_flavourlen != 1) {
-                        dprintk("%s: Invalid number of RPC auth flavours %d.\n",
-                                        __FUNCTION__, data->auth_flavourlen);
-                        error = -EINVAL;
-                        goto out;
-                }
-
-                if (copy_from_user(&authflavour, data->auth_flavours,
-                                   sizeof(authflavour))) {
-                        error = -EFAULT;
-                        goto out;
-                }
-        }
-
-        p = strndup_user(data->hostname.data, NFS4_MAXNAMLEN);
-        if (IS_ERR(p))
-                goto out_err;
-        hostname = p;
-
-        p = strndup_user(data->mnt_path.data, NFS4_MAXPATHLEN);
-        if (IS_ERR(p))
-                goto out_err;
-        mntpath = p;
-
-        dprintk("MNTPATH: %s\n", mntpath);
-
-        p = strndup_user(data->client_addr.data, 16);
-        if (IS_ERR(p))
-                goto out_err;
-        ip_addr = p;
+        /* Validate the mount data */
+        error = nfs4_validate_mount_data(&data, dev_name, &addr, &authflavour,
+                                         &hostname, &mntpath, &ip_addr);
+        if (error < 0)
+                goto out;
 
         /* Get a volume representation */
         server = nfs4_create_server(data, hostname, &addr, mntpath, ip_addr,
@@ -932,10 +961,6 @@ out:
         kfree(hostname);
         return error;
 
-out_err:
-        error = PTR_ERR(p);
-        goto out;
-
 out_free:
         nfs_free_server(server);
         goto out;