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/linkage.h>
14#include <linux/namei.h>
15#include <linux/mount.h>
16#include <linux/syscalls.h>
17#include <asm/uaccess.h>
18
19/*
20 * open a file on nfsd fs
21 */
22
23static struct file *do_open(char *name, int flags)
24{
25	struct nameidata nd;
26	int error;
27
28	nd.mnt = do_kern_mount("nfsd", 0, "nfsd", NULL);
29
30	if (IS_ERR(nd.mnt))
31		return (struct file *)nd.mnt;
32
33	nd.dentry = dget(nd.mnt->mnt_root);
34	nd.last_type = LAST_ROOT;
35	nd.flags = 0;
36	nd.depth = 0;
37
38	error = path_walk(name, &nd);
39	if (error)
40		return ERR_PTR(error);
41
42	if (flags == O_RDWR)
43		error = may_open(&nd,MAY_READ|MAY_WRITE,FMODE_READ|FMODE_WRITE);
44	else
45		error = may_open(&nd, MAY_WRITE, FMODE_WRITE);
46
47	if (!error)
48		return dentry_open(nd.dentry, nd.mnt, flags);
49
50	path_release(&nd);
51	return ERR_PTR(error);
52}
53
54static 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
89long
90asmlinkage sys_nfsservctl(int cmd, struct nfsctl_arg __user *arg, 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}
117