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/nfsd/syscall.h>
11#include <linux/cred.h>
12#include <linux/sched.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.path, MAY_READ|MAY_WRITE, flags);
40 else
41 error = may_open(&nd.path, MAY_WRITE, flags);
42
43 if (!error)
44 return dentry_open(nd.path.dentry, nd.path.mnt, flags,
45 current_cred());
46
47 path_put(&nd.path);
48 return ERR_PTR(error);
49}
50
51static struct {
52 char *name; int wsize; int rsize;
53} map[] = {
54 [NFSCTL_SVC] = {
55 .name = ".svc",
56 .wsize = sizeof(struct nfsctl_svc)
57 },
58 [NFSCTL_ADDCLIENT] = {
59 .name = ".add",
60 .wsize = sizeof(struct nfsctl_client)
61 },
62 [NFSCTL_DELCLIENT] = {
63 .name = ".del",
64 .wsize = sizeof(struct nfsctl_client)
65 },
66 [NFSCTL_EXPORT] = {
67 .name = ".export",
68 .wsize = sizeof(struct nfsctl_export)
69 },
70 [NFSCTL_UNEXPORT] = {
71 .name = ".unexport",
72 .wsize = sizeof(struct nfsctl_export)
73 },
74 [NFSCTL_GETFD] = {
75 .name = ".getfd",
76 .wsize = sizeof(struct nfsctl_fdparm),
77 .rsize = NFS_FHSIZE
78 },
79 [NFSCTL_GETFS] = {
80 .name = ".getfs",
81 .wsize = sizeof(struct nfsctl_fsparm),
82 .rsize = sizeof(struct knfsd_fh)
83 },
84};
85
86SYSCALL_DEFINE3(nfsservctl, int, cmd, struct nfsctl_arg __user *, arg,
87 void __user *, res)
88{
89 struct file *file;
90 void __user *p = &arg->u;
91 int version;
92 int err;
93
94 if (copy_from_user(&version, &arg->ca_version, sizeof(int)))
95 return -EFAULT;
96
97 if (version != NFSCTL_VERSION)
98 return -EINVAL;
99
100 if (cmd < 0 || cmd >= ARRAY_SIZE(map) || !map[cmd].name)
101 return -EINVAL;
102
103 file = do_open(map[cmd].name, map[cmd].rsize ? O_RDWR : O_WRONLY);
104 if (IS_ERR(file))
105 return PTR_ERR(file);
106 err = file->f_op->write(file, p, map[cmd].wsize, &file->f_pos);
107 if (err >= 0 && map[cmd].rsize)
108 err = file->f_op->read(file, res, map[cmd].rsize, &file->f_pos);
109 if (err >= 0)
110 err = 0;
111 fput(file);
112 return err;
113}