tjh.dev
Linux kernel mirror (for testing)
git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
kernel
os
linux
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 struct vfsmount *mnt;
27 int error;
28
29 mnt = do_kern_mount("nfsd", 0, "nfsd", NULL);
30 if (IS_ERR(mnt))
31 return (struct file *)mnt;
32
33 error = vfs_path_lookup(mnt->mnt_root, mnt, name, 0, &nd);
34 mntput(mnt); /* drop do_kern_mount reference */
35 if (error)
36 return ERR_PTR(error);
37
38 if (flags == O_RDWR)
39 error = may_open(&nd,MAY_READ|MAY_WRITE,FMODE_READ|FMODE_WRITE);
40 else
41 error = may_open(&nd, MAY_WRITE, FMODE_WRITE);
42
43 if (!error)
44 return dentry_open(nd.path.dentry, nd.path.mnt, flags);
45
46 path_put(&nd.path);
47 return ERR_PTR(error);
48}
49
50static struct {
51 char *name; int wsize; int rsize;
52} map[] = {
53 [NFSCTL_SVC] = {
54 .name = ".svc",
55 .wsize = sizeof(struct nfsctl_svc)
56 },
57 [NFSCTL_ADDCLIENT] = {
58 .name = ".add",
59 .wsize = sizeof(struct nfsctl_client)
60 },
61 [NFSCTL_DELCLIENT] = {
62 .name = ".del",
63 .wsize = sizeof(struct nfsctl_client)
64 },
65 [NFSCTL_EXPORT] = {
66 .name = ".export",
67 .wsize = sizeof(struct nfsctl_export)
68 },
69 [NFSCTL_UNEXPORT] = {
70 .name = ".unexport",
71 .wsize = sizeof(struct nfsctl_export)
72 },
73 [NFSCTL_GETFD] = {
74 .name = ".getfd",
75 .wsize = sizeof(struct nfsctl_fdparm),
76 .rsize = NFS_FHSIZE
77 },
78 [NFSCTL_GETFS] = {
79 .name = ".getfs",
80 .wsize = sizeof(struct nfsctl_fsparm),
81 .rsize = sizeof(struct knfsd_fh)
82 },
83};
84
85long
86asmlinkage sys_nfsservctl(int cmd, struct nfsctl_arg __user *arg, void __user *res)
87{
88 struct file *file;
89 void __user *p = &arg->u;
90 int version;
91 int err;
92
93 if (copy_from_user(&version, &arg->ca_version, sizeof(int)))
94 return -EFAULT;
95
96 if (version != NFSCTL_VERSION)
97 return -EINVAL;
98
99 if (cmd < 0 || cmd >= ARRAY_SIZE(map) || !map[cmd].name)
100 return -EINVAL;
101
102 file = do_open(map[cmd].name, map[cmd].rsize ? O_RDWR : O_WRONLY);
103 if (IS_ERR(file))
104 return PTR_ERR(file);
105 err = file->f_op->write(file, p, map[cmd].wsize, &file->f_pos);
106 if (err >= 0 && map[cmd].rsize)
107 err = file->f_op->read(file, res, map[cmd].rsize, &file->f_pos);
108 if (err >= 0)
109 err = 0;
110 fput(file);
111 return err;
112}