ncpfs: Support interacting with multiple user namespaces

ncpfs does not natively support uids and gids so this conversion was
simply a matter of updating the the type of the mounteduid, the uid
and the gid on the superblock. Fixing the ioctls that read them,
updating the mount option parser and the mount option printer.

Cc: Petr Vandrovec <petr@vandrovec.name>
Acked-by: Serge Hallyn <serge.hallyn@canonical.com>
Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>

1 files changed, 33 insertions, 22 deletions

diff --git a/fs/ncpfs/inode.c b/fs/ncpfs/inode.c
index 1acdad7..e2be336 100644
--- a/fs/ncpfs/inode.c
+++ b/fs/ncpfs/inode.c
@@ -331,12 +331,15 @@ static int  ncp_show_options(struct seq_file *seq, struct dentry *root)
 	struct ncp_server *server = NCP_SBP(root->d_sb);
 	unsigned int tmp;
 
-	if (server->m.uid != 0)
-		seq_printf(seq, ",uid=%u", server->m.uid);
-	if (server->m.gid != 0)
-		seq_printf(seq, ",gid=%u", server->m.gid);
-	if (server->m.mounted_uid != 0)
-		seq_printf(seq, ",owner=%u", server->m.mounted_uid);
+	if (!uid_eq(server->m.uid, GLOBAL_ROOT_UID))
+		seq_printf(seq, ",uid=%u",
+			   from_kuid_munged(&init_user_ns, server->m.uid));
+	if (!gid_eq(server->m.gid, GLOBAL_ROOT_GID))
+		seq_printf(seq, ",gid=%u",
+			   from_kgid_munged(&init_user_ns, server->m.gid));
+	if (!uid_eq(server->m.mounted_uid, GLOBAL_ROOT_UID))
+		seq_printf(seq, ",owner=%u",
+			   from_kuid_munged(&init_user_ns, server->m.mounted_uid));
 	tmp = server->m.file_mode & S_IALLUGO;
 	if (tmp != NCP_DEFAULT_FILE_MODE)
 		seq_printf(seq, ",mode=0%o", tmp);
@@ -381,13 +384,13 @@ static int ncp_parse_options(struct ncp_mount_data_kernel *data, char *options)
 
 	data->flags = 0;
 	data->int_flags = 0;
-	data->mounted_uid = 0;
+	data->mounted_uid = GLOBAL_ROOT_UID;
 	data->wdog_pid = NULL;
 	data->ncp_fd = ~0;
 	data->time_out = NCP_DEFAULT_TIME_OUT;
 	data->retry_count = NCP_DEFAULT_RETRY_COUNT;
-	data->uid = 0;
-	data->gid = 0;
+	data->uid = GLOBAL_ROOT_UID;
+	data->gid = GLOBAL_ROOT_GID;
 	data->file_mode = NCP_DEFAULT_FILE_MODE;
 	data->dir_mode = NCP_DEFAULT_DIR_MODE;
 	data->info_fd = -1;
@@ -399,13 +402,19 @@ static int ncp_parse_options(struct ncp_mount_data_kernel *data, char *options)
 			goto err;
 		switch (optval) {
 			case 'u':
-				data->uid = optint;
+				data->uid = make_kuid(current_user_ns(), optint);
+				if (!uid_valid(data->uid))
+					goto err;
 				break;
 			case 'g':
-				data->gid = optint;
+				data->gid = make_kgid(current_user_ns(), optint);
+				if (!gid_valid(data->gid))
+					goto err;
 				break;
 			case 'o':
-				data->mounted_uid = optint;
+				data->mounted_uid = make_kuid(current_user_ns(), optint);
+				if (!uid_valid(data->mounted_uid))
+					goto err;
 				break;
 			case 'm':
 				data->file_mode = optint;
@@ -480,13 +489,13 @@ static int ncp_fill_super(struct super_block *sb, void *raw_data, int silent)
 
 				data.flags = md->flags;
 				data.int_flags = NCP_IMOUNT_LOGGEDIN_POSSIBLE;
-				data.mounted_uid = md->mounted_uid;
+				data.mounted_uid = make_kuid(current_user_ns(), md->mounted_uid);
 				data.wdog_pid = find_get_pid(md->wdog_pid);
 				data.ncp_fd = md->ncp_fd;
 				data.time_out = md->time_out;
 				data.retry_count = md->retry_count;
-				data.uid = md->uid;
-				data.gid = md->gid;
+				data.uid = make_kuid(current_user_ns(), md->uid);
+				data.gid = make_kgid(current_user_ns(), md->gid);
 				data.file_mode = md->file_mode;
 				data.dir_mode = md->dir_mode;
 				data.info_fd = -1;
@@ -499,13 +508,13 @@ static int ncp_fill_super(struct super_block *sb, void *raw_data, int silent)
 				struct ncp_mount_data_v4* md = (struct ncp_mount_data_v4*)raw_data;
 
 				data.flags = md->flags;
-				data.mounted_uid = md->mounted_uid;
+				data.mounted_uid = make_kuid(current_user_ns(), md->mounted_uid);
 				data.wdog_pid = find_get_pid(md->wdog_pid);
 				data.ncp_fd = md->ncp_fd;
 				data.time_out = md->time_out;
 				data.retry_count = md->retry_count;
-				data.uid = md->uid;
-				data.gid = md->gid;
+				data.uid = make_kuid(current_user_ns(), md->uid);
+				data.gid = make_kgid(current_user_ns(), md->gid);
 				data.file_mode = md->file_mode;
 				data.dir_mode = md->dir_mode;
 				data.info_fd = -1;
@@ -520,6 +529,10 @@ static int ncp_fill_super(struct super_block *sb, void *raw_data, int silent)
 				goto out;
 			break;
 	}
+	error = -EINVAL;
+	if (!uid_valid(data.mounted_uid) || !uid_valid(data.uid) ||
+	    !gid_valid(data.gid))
+		goto out;
 	error = -EBADF;
 	ncp_filp = fget(data.ncp_fd);
 	if (!ncp_filp)
@@ -886,12 +899,10 @@ int ncp_notify_change(struct dentry *dentry, struct iattr *attr)
 		goto out;
 
 	result = -EPERM;
-	if (((attr->ia_valid & ATTR_UID) &&
-	     (attr->ia_uid != server->m.uid)))
+	if ((attr->ia_valid & ATTR_UID) && !uid_eq(attr->ia_uid, server->m.uid))
 		goto out;
 
-	if (((attr->ia_valid & ATTR_GID) &&
-	     (attr->ia_gid != server->m.gid)))
+	if ((attr->ia_valid & ATTR_GID) && !gid_eq(attr->ia_gid, server->m.gid))
 		goto out;
 
 	if (((attr->ia_valid & ATTR_MODE) &&