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
do_open(char * name,int flags)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
SYSCALL_DEFINE3(nfsservctl,int,cmd,struct nfsctl_arg __user *,arg,void __user *,res)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 }
117