120 строки
2.5 KiB
C
120 строки
2.5 KiB
C
/*
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* fs/nfsctl.c
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*
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* This should eventually move to userland.
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*
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*/
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#include <linux/config.h>
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#include <linux/types.h>
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#include <linux/file.h>
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#include <linux/fs.h>
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#include <linux/sunrpc/svc.h>
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#include <linux/nfsd/nfsd.h>
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#include <linux/nfsd/syscall.h>
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#include <linux/linkage.h>
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#include <linux/namei.h>
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#include <linux/mount.h>
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#include <linux/syscalls.h>
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#include <asm/uaccess.h>
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/*
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* open a file on nfsd fs
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*/
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static struct file *do_open(char *name, int flags)
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{
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struct nameidata nd;
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int error;
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nd.mnt = do_kern_mount("nfsd", 0, "nfsd", NULL);
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if (IS_ERR(nd.mnt))
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return (struct file *)nd.mnt;
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nd.dentry = dget(nd.mnt->mnt_root);
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nd.last_type = LAST_ROOT;
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nd.flags = 0;
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nd.depth = 0;
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error = path_walk(name, &nd);
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if (error)
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return ERR_PTR(error);
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if (flags == O_RDWR)
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error = may_open(&nd,MAY_READ|MAY_WRITE,FMODE_READ|FMODE_WRITE);
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else
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error = may_open(&nd, MAY_WRITE, FMODE_WRITE);
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if (!error)
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return dentry_open(nd.dentry, nd.mnt, flags);
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path_release(&nd);
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return ERR_PTR(error);
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}
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static struct {
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char *name; int wsize; int rsize;
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} map[] = {
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[NFSCTL_SVC] = {
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.name = ".svc",
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.wsize = sizeof(struct nfsctl_svc)
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},
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[NFSCTL_ADDCLIENT] = {
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.name = ".add",
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.wsize = sizeof(struct nfsctl_client)
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},
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[NFSCTL_DELCLIENT] = {
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.name = ".del",
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.wsize = sizeof(struct nfsctl_client)
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},
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[NFSCTL_EXPORT] = {
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.name = ".export",
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.wsize = sizeof(struct nfsctl_export)
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},
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[NFSCTL_UNEXPORT] = {
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.name = ".unexport",
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.wsize = sizeof(struct nfsctl_export)
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},
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[NFSCTL_GETFD] = {
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.name = ".getfd",
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.wsize = sizeof(struct nfsctl_fdparm),
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.rsize = NFS_FHSIZE
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},
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[NFSCTL_GETFS] = {
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.name = ".getfs",
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.wsize = sizeof(struct nfsctl_fsparm),
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.rsize = sizeof(struct knfsd_fh)
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},
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};
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long
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asmlinkage sys_nfsservctl(int cmd, struct nfsctl_arg __user *arg, void __user *res)
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{
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struct file *file;
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void __user *p = &arg->u;
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int version;
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int err;
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if (copy_from_user(&version, &arg->ca_version, sizeof(int)))
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return -EFAULT;
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if (version != NFSCTL_VERSION) {
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printk(KERN_WARNING "nfsd: incompatible version in syscall.\n");
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return -EINVAL;
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}
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if (cmd < 0 || cmd >= sizeof(map)/sizeof(map[0]) || !map[cmd].name)
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return -EINVAL;
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file = do_open(map[cmd].name, map[cmd].rsize ? O_RDWR : O_WRONLY);
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if (IS_ERR(file))
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return PTR_ERR(file);
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err = file->f_op->write(file, p, map[cmd].wsize, &file->f_pos);
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if (err >= 0 && map[cmd].rsize)
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err = file->f_op->read(file, res, map[cmd].rsize, &file->f_pos);
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if (err >= 0)
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err = 0;
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fput(file);
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return err;
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}
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