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