[linux-2.6-block.git] / fs / nfsctl.c

/*
 *	fs/nfsctl.c
 *
 *	This should eventually move to userland.
 *
 */
#include <linux/types.h>
#include <linux/file.h>
#include <linux/fs.h>
#include <linux/sunrpc/svc.h>
#include <linux/nfsd/nfsd.h>
#include <linux/nfsd/syscall.h>
#include <linux/cred.h>
#include <linux/sched.h>
#include <linux/linkage.h>
#include <linux/namei.h>
#include <linux/mount.h>
#include <linux/syscalls.h>
#include <asm/uaccess.h>

/*
 * open a file on nfsd fs
 */

static struct file *do_open(char *name, int flags)
{
	struct nameidata nd;
	struct vfsmount *mnt;
	int error;

	mnt = do_kern_mount("nfsd", 0, "nfsd", NULL);
	if (IS_ERR(mnt))
		return (struct file *)mnt;

	error = vfs_path_lookup(mnt->mnt_root, mnt, name, 0, &nd);
	mntput(mnt);	/* drop do_kern_mount reference */
	if (error)
		return ERR_PTR(error);

	if (flags == O_RDWR)
		error = may_open(&nd.path, MAY_READ|MAY_WRITE,
					   FMODE_READ|FMODE_WRITE);
	else
		error = may_open(&nd.path, MAY_WRITE, FMODE_WRITE);

	if (!error)
		return dentry_open(nd.path.dentry, nd.path.mnt, flags,
				   current_cred());

	path_put(&nd.path);
	return ERR_PTR(error);
}

static struct {
	char *name; int wsize; int rsize;
} map[] = {
	[NFSCTL_SVC] = {
		.name	= ".svc",
		.wsize	= sizeof(struct nfsctl_svc)
	},
	[NFSCTL_ADDCLIENT] = {
		.name	= ".add",
		.wsize	= sizeof(struct nfsctl_client)
	},
	[NFSCTL_DELCLIENT] = {
		.name	= ".del",
		.wsize	= sizeof(struct nfsctl_client)
	},
	[NFSCTL_EXPORT] = {
		.name	= ".export",
		.wsize	= sizeof(struct nfsctl_export)
	},
	[NFSCTL_UNEXPORT] = {
		.name	= ".unexport",
		.wsize	= sizeof(struct nfsctl_export)
	},
	[NFSCTL_GETFD] = {
		.name	= ".getfd",
		.wsize	= sizeof(struct nfsctl_fdparm),
		.rsize	= NFS_FHSIZE
	},
	[NFSCTL_GETFS] = {
		.name	= ".getfs",
		.wsize	= sizeof(struct nfsctl_fsparm),
		.rsize	= sizeof(struct knfsd_fh)
	},
};

SYSCALL_DEFINE3(nfsservctl, int, cmd, struct nfsctl_arg __user *, arg,
		void __user *, res)
{
	struct file *file;
	void __user *p = &arg->u;
	int version;
	int err;

	if (copy_from_user(&version, &arg->ca_version, sizeof(int)))
		return -EFAULT;

	if (version != NFSCTL_VERSION)
		return -EINVAL;

	if (cmd < 0 || cmd >= ARRAY_SIZE(map) || !map[cmd].name)
		return -EINVAL;

	file = do_open(map[cmd].name, map[cmd].rsize ? O_RDWR : O_WRONLY);	
	if (IS_ERR(file))
		return PTR_ERR(file);
	err = file->f_op->write(file, p, map[cmd].wsize, &file->f_pos);
	if (err >= 0 && map[cmd].rsize)
		err = file->f_op->read(file, res, map[cmd].rsize, &file->f_pos);
	if (err >= 0)
		err = 0;
	fput(file);
	return err;
}
Commit	Line	Data
	1	/*
	2	* fs/nfsctl.c
	3	*
	4	* This should eventually move to userland.
	5	*
	6	*/
	7	#include <linux/types.h>
	8	#include <linux/file.h>
	9	#include <linux/fs.h>
	10	#include <linux/sunrpc/svc.h>
	11	#include <linux/nfsd/nfsd.h>
	12	#include <linux/nfsd/syscall.h>
	13	#include <linux/cred.h>
	14	#include <linux/sched.h>
	15	#include <linux/linkage.h>
	16	#include <linux/namei.h>
	17	#include <linux/mount.h>
	18	#include <linux/syscalls.h>
	19	#include <asm/uaccess.h>
	20
	21	/*
	22	* open a file on nfsd fs
	23	*/
	24
	25	static struct file do_open(char name, int flags)
	26	{
	27	struct nameidata nd;
	28	struct vfsmount *mnt;
	29	int error;
	30
	31	mnt = do_kern_mount("nfsd", 0, "nfsd", NULL);
	32	if (IS_ERR(mnt))
	33	return (struct file *)mnt;
	34
	35	error = vfs_path_lookup(mnt->mnt_root, mnt, name, 0, &nd);
	36	mntput(mnt); /* drop do_kern_mount reference */
	37	if (error)
	38	return ERR_PTR(error);
	39
	40	if (flags == O_RDWR)
	41	error = may_open(&nd.path, MAY_READ\|MAY_WRITE,
	42	FMODE_READ\|FMODE_WRITE);
	43	else
	44	error = may_open(&nd.path, MAY_WRITE, FMODE_WRITE);
	45
	46	if (!error)
	47	return dentry_open(nd.path.dentry, nd.path.mnt, flags,
	48	current_cred());
	49
	50	path_put(&nd.path);
	51	return ERR_PTR(error);
	52	}
	53
	54	static struct {
	55	char *name; int wsize; int rsize;
	56	} map[] = {
	57	[NFSCTL_SVC] = {
	58	.name = ".svc",
	59	.wsize = sizeof(struct nfsctl_svc)
	60	},
	61	[NFSCTL_ADDCLIENT] = {
	62	.name = ".add",
	63	.wsize = sizeof(struct nfsctl_client)
	64	},
	65	[NFSCTL_DELCLIENT] = {
	66	.name = ".del",
	67	.wsize = sizeof(struct nfsctl_client)
	68	},
	69	[NFSCTL_EXPORT] = {
	70	.name = ".export",
	71	.wsize = sizeof(struct nfsctl_export)
	72	},
	73	[NFSCTL_UNEXPORT] = {
	74	.name = ".unexport",
	75	.wsize = sizeof(struct nfsctl_export)
	76	},
	77	[NFSCTL_GETFD] = {
	78	.name = ".getfd",
	79	.wsize = sizeof(struct nfsctl_fdparm),
	80	.rsize = NFS_FHSIZE
	81	},
	82	[NFSCTL_GETFS] = {
	83	.name = ".getfs",
	84	.wsize = sizeof(struct nfsctl_fsparm),
	85	.rsize = sizeof(struct knfsd_fh)
	86	},
	87	};
	88
	89	SYSCALL_DEFINE3(nfsservctl, int, cmd, struct nfsctl_arg __user *, arg,
	90	void __user *, res)
	91	{
	92	struct file *file;
	93	void __user *p = &arg->u;
	94	int version;
	95	int err;
	96
	97	if (copy_from_user(&version, &arg->ca_version, sizeof(int)))
	98	return -EFAULT;
	99
	100	if (version != NFSCTL_VERSION)
	101	return -EINVAL;
	102
	103	if (cmd < 0 \|\| cmd >= ARRAY_SIZE(map) \|\| !map[cmd].name)
	104	return -EINVAL;
	105
	106	file = do_open(map[cmd].name, map[cmd].rsize ? O_RDWR : O_WRONLY);
	107	if (IS_ERR(file))
	108	return PTR_ERR(file);
	109	err = file->f_op->write(file, p, map[cmd].wsize, &file->f_pos);
	110	if (err >= 0 && map[cmd].rsize)
	111	err = file->f_op->read(file, res, map[cmd].rsize, &file->f_pos);
	112	if (err >= 0)
	113	err = 0;
	114	fput(file);
	115	return err;
	116	}