nfsctl.c

linux 内核源代码

/*
 * linux/fs/nfsd/nfsctl.c
 *
 * Syscall interface to knfsd.
 *
 * Copyright (C) 1995, 1996 Olaf Kirch <[e-mail]>
 */

#include <linux/module.h>

#include <linux/linkage.h>
#include <linux/time.h>
#include <linux/errno.h>
#include <linux/fs.h>
#include <linux/fcntl.h>
#include <linux/net.h>
#include <linux/in.h>
#include <linux/syscalls.h>
#include <linux/unistd.h>
#include <linux/slab.h>
#include <linux/proc_fs.h>
#include <linux/seq_file.h>
#include <linux/pagemap.h>
#include <linux/init.h>
#include <linux/string.h>
#include <linux/smp_lock.h>
#include <linux/ctype.h>

#include <linux/nfs.h>
#include <linux/nfsd_idmap.h>
#include <linux/lockd/bind.h>
#include <linux/sunrpc/svc.h>
#include <linux/sunrpc/svcsock.h>
#include <linux/nfsd/nfsd.h>
#include <linux/nfsd/cache.h>
#include <linux/nfsd/xdr.h>
#include <linux/nfsd/syscall.h>

#include <asm/uaccess.h>

/*
 *	We have a single directory with 9 nodes in it.
 */
enum {
	NFSD_Root = 1,
	NFSD_Svc,
	NFSD_Add,
	NFSD_Del,
	NFSD_Export,
	NFSD_Unexport,
	NFSD_Getfd,
	NFSD_Getfs,
	NFSD_List,
	NFSD_Fh,
	NFSD_Threads,
	NFSD_Pool_Threads,
	NFSD_Versions,
	NFSD_Ports,
	NFSD_MaxBlkSize,
	/*
	 * The below MUST come last.  Otherwise we leave a hole in nfsd_files[]
	 * with !CONFIG_NFSD_V4 and simple_fill_super() goes oops
	 */
#ifdef CONFIG_NFSD_V4
	NFSD_Leasetime,
	NFSD_RecoveryDir,
#endif
};

/*
 * write() for these nodes.
 */
static ssize_t write_svc(struct file *file, char *buf, size_t size);
static ssize_t write_add(struct file *file, char *buf, size_t size);
static ssize_t write_del(struct file *file, char *buf, size_t size);
static ssize_t write_export(struct file *file, char *buf, size_t size);
static ssize_t write_unexport(struct file *file, char *buf, size_t size);
static ssize_t write_getfd(struct file *file, char *buf, size_t size);
static ssize_t write_getfs(struct file *file, char *buf, size_t size);
static ssize_t write_filehandle(struct file *file, char *buf, size_t size);
static ssize_t write_threads(struct file *file, char *buf, size_t size);
static ssize_t write_pool_threads(struct file *file, char *buf, size_t size);
static ssize_t write_versions(struct file *file, char *buf, size_t size);
static ssize_t write_ports(struct file *file, char *buf, size_t size);
static ssize_t write_maxblksize(struct file *file, char *buf, size_t size);
#ifdef CONFIG_NFSD_V4
static ssize_t write_leasetime(struct file *file, char *buf, size_t size);
static ssize_t write_recoverydir(struct file *file, char *buf, size_t size);
#endif

static ssize_t (*write_op[])(struct file *, char *, size_t) = {
	[NFSD_Svc] = write_svc,
	[NFSD_Add] = write_add,
	[NFSD_Del] = write_del,
	[NFSD_Export] = write_export,
	[NFSD_Unexport] = write_unexport,
	[NFSD_Getfd] = write_getfd,
	[NFSD_Getfs] = write_getfs,
	[NFSD_Fh] = write_filehandle,
	[NFSD_Threads] = write_threads,
	[NFSD_Pool_Threads] = write_pool_threads,
	[NFSD_Versions] = write_versions,
	[NFSD_Ports] = write_ports,
	[NFSD_MaxBlkSize] = write_maxblksize,
#ifdef CONFIG_NFSD_V4
	[NFSD_Leasetime] = write_leasetime,
	[NFSD_RecoveryDir] = write_recoverydir,
#endif
};

static ssize_t nfsctl_transaction_write(struct file *file, const char __user *buf, size_t size, loff_t *pos)
{
	ino_t ino =  file->f_path.dentry->d_inode->i_ino;
	char *data;
	ssize_t rv;

	if (ino >= ARRAY_SIZE(write_op) || !write_op[ino])
		return -EINVAL;

	data = simple_transaction_get(file, buf, size);
	if (IS_ERR(data))
		return PTR_ERR(data);

	rv =  write_op[ino](file, data, size);
	if (rv >= 0) {
		simple_transaction_set(file, rv);
		rv = size;
	}
	return rv;
}

static ssize_t nfsctl_transaction_read(struct file *file, char __user *buf, size_t size, loff_t *pos)
{
	if (! file->private_data) {
		/* An attempt to read a transaction file without writing
		 * causes a 0-byte write so that the file can return
		 * state information
		 */
		ssize_t rv = nfsctl_transaction_write(file, buf, 0, pos);
		if (rv < 0)
			return rv;
	}
	return simple_transaction_read(file, buf, size, pos);
}

static const struct file_operations transaction_ops = {
	.write		= nfsctl_transaction_write,
	.read		= nfsctl_transaction_read,
	.release	= simple_transaction_release,
};

extern struct seq_operations nfs_exports_op;
static int exports_open(struct inode *inode, struct file *file)
{
	return seq_open(file, &nfs_exports_op);
}

static const struct file_operations exports_operations = {
	.open		= exports_open,
	.read		= seq_read,
	.llseek		= seq_lseek,
	.release	= seq_release,
};

/*----------------------------------------------------------------------------*/
/*
 * payload - write methods
 * If the method has a response, the response should be put in buf,
 * and the length returned.  Otherwise return 0 or and -error.
 */

static ssize_t write_svc(struct file *file, char *buf, size_t size)
{
	struct nfsctl_svc *data;
	if (size < sizeof(*data))
		return -EINVAL;
	data = (struct nfsctl_svc*) buf;
	return nfsd_svc(data->svc_port, data->svc_nthreads);
}

static ssize_t write_add(struct file *file, char *buf, size_t size)
{
	struct nfsctl_client *data;
	if (size < sizeof(*data))
		return -EINVAL;
	data = (struct nfsctl_client *)buf;
	return exp_addclient(data);
}

static ssize_t write_del(struct file *file, char *buf, size_t size)
{
	struct nfsctl_client *data;
	if (size < sizeof(*data))
		return -EINVAL;
	data = (struct nfsctl_client *)buf;
	return exp_delclient(data);
}

static ssize_t write_export(struct file *file, char *buf, size_t size)
{
	struct nfsctl_export *data;
	if (size < sizeof(*data))
		return -EINVAL;
	data = (struct nfsctl_export*)buf;
	return exp_export(data);
}

static ssize_t write_unexport(struct file *file, char *buf, size_t size)
{
	struct nfsctl_export *data;

	if (size < sizeof(*data))
		return -EINVAL;
	data = (struct nfsctl_export*)buf;
	return exp_unexport(data);
}

static ssize_t write_getfs(struct file *file, char *buf, size_t size)
{
	struct nfsctl_fsparm *data;
	struct sockaddr_in *sin;
	struct auth_domain *clp;
	int err = 0;
	struct knfsd_fh *res;

	if (size < sizeof(*data))
		return -EINVAL;
	data = (struct nfsctl_fsparm*)buf;
	err = -EPROTONOSUPPORT;
	if (data->gd_addr.sa_family != AF_INET)
		goto out;
	sin = (struct sockaddr_in *)&data->gd_addr;
	if (data->gd_maxlen > NFS3_FHSIZE)
		data->gd_maxlen = NFS3_FHSIZE;

	res = (struct knfsd_fh*)buf;

	exp_readlock();
	if (!(clp = auth_unix_lookup(sin->sin_addr)))
		err = -EPERM;
	else {
		err = exp_rootfh(clp, data->gd_path, res, data->gd_maxlen);
		auth_domain_put(clp);
	}
	exp_readunlock();
	if (err == 0)
		err = res->fh_size + offsetof(struct knfsd_fh, fh_base);
 out:
	return err;
}

static ssize_t write_getfd(struct file *file, char *buf, size_t size)
{
	struct nfsctl_fdparm *data;
	struct sockaddr_in *sin;
	struct auth_domain *clp;
	int err = 0;
	struct knfsd_fh fh;
	char *res;

	if (size < sizeof(*data))
		return -EINVAL;
	data = (struct nfsctl_fdparm*)buf;
	err = -EPROTONOSUPPORT;
	if (data->gd_addr.sa_family != AF_INET)
		goto out;
	err = -EINVAL;
	if (data->gd_version < 2 || data->gd_version > NFSSVC_MAXVERS)
		goto out;

	res = buf;
	sin = (struct sockaddr_in *)&data->gd_addr;
	exp_readlock();
	if (!(clp = auth_unix_lookup(sin->sin_addr)))
		err = -EPERM;
	else {
		err = exp_rootfh(clp, data->gd_path, &fh, NFS_FHSIZE);
		auth_domain_put(clp);
	}
	exp_readunlock();

	if (err == 0) {
		memset(res,0, NFS_FHSIZE);
		memcpy(res, &fh.fh_base, fh.fh_size);
		err = NFS_FHSIZE;
	}
 out:
	return err;
}

static ssize_t write_filehandle(struct file *file, char *buf, size_t size)
{
	/* request is:
	 *   domain path maxsize
	 * response is
	 *   filehandle
	 *
	 * qword quoting is used, so filehandle will be \x....
	 */
	char *dname, *path;
	int uninitialized_var(maxsize);
	char *mesg = buf;
	int len;
	struct auth_domain *dom;
	struct knfsd_fh fh;

	if (buf[size-1] != '\n')
		return -EINVAL;
	buf[size-1] = 0;

	dname = mesg;
	len = qword_get(&mesg, dname, size);
	if (len <= 0) return -EINVAL;
	
	path = dname+len+1;
	len = qword_get(&mesg, path, size);
	if (len <= 0) return -EINVAL;

	len = get_int(&mesg, &maxsize);
	if (len)
		return len;

	if (maxsize < NFS_FHSIZE)
		return -EINVAL;
	if (maxsize > NFS3_FHSIZE)
		maxsize = NFS3_FHSIZE;

	if (qword_get(&mesg, mesg, size)>0)
		return -EINVAL;

	/* we have all the words, they are in buf.. */
	dom = unix_domain_find(dname);
	if (!dom)
		return -ENOMEM;

	len = exp_rootfh(dom, path, &fh,  maxsize);
	auth_domain_put(dom);
	if (len)
		return len;
	
	mesg = buf; len = SIMPLE_TRANSACTION_LIMIT;
	qword_addhex(&mesg, &len, (char*)&fh.fh_base, fh.fh_size);
	mesg[-1] = '\n';
	return mesg - buf;	
}

extern int nfsd_nrthreads(void);

static ssize_t write_threads(struct file *file, char *buf, size_t size)
{
	/* if size > 0, look for a number of threads and call nfsd_svc
	 * then write out number of threads as reply
	 */
	char *mesg = buf;
	int rv;
	if (size > 0) {
		int newthreads;
		rv = get_int(&mesg, &newthreads);
		if (rv)
			return rv;
		if (newthreads <0)
			return -EINVAL;
		rv = nfsd_svc(2049, newthreads);