[net-next-2.6.git] / drivers / isdn / capi / capifs.c

/* $Id: capifs.c,v 1.1.2.3 2004/01/16 21:09:26 keil Exp $
 * 
 * Copyright 2000 by Carsten Paeth <calle@calle.de>
 *
 * Heavily based on devpts filesystem from H. Peter Anvin
 * 
 * This software may be used and distributed according to the terms
 * of the GNU General Public License, incorporated herein by reference.
 *
 */

#include <linux/fs.h>
#include <linux/mount.h>
#include <linux/namei.h>
#include <linux/module.h>
#include <linux/init.h>
#include <linux/ctype.h>
#include <linux/sched.h>	/* current */

#include "capifs.h"

MODULE_DESCRIPTION("CAPI4Linux: /dev/capi/ filesystem");
MODULE_AUTHOR("Carsten Paeth");
MODULE_LICENSE("GPL");

/* ------------------------------------------------------------------ */

static char *revision = "$Revision: 1.1.2.3 $";

/* ------------------------------------------------------------------ */

#define CAPIFS_SUPER_MAGIC (('C'<<8)|'N')

static struct vfsmount *capifs_mnt;
static struct dentry *capifs_root;

static struct {
	int setuid;
	int setgid;
	uid_t   uid;
	gid_t   gid;
	umode_t mode;
} config = {.mode = 0600};

/* ------------------------------------------------------------------ */

static int capifs_remount(struct super_block *s, int *flags, char *data)
{
	int setuid = 0;
	int setgid = 0;
	uid_t uid = 0;
	gid_t gid = 0;
	umode_t mode = 0600;
	char *this_char;
	char *new_opt = kstrdup(data, GFP_KERNEL);

	this_char = NULL;
	while ((this_char = strsep(&data, ",")) != NULL) {
		int n;
		char dummy;
		if (!*this_char)
			continue;
		if (sscanf(this_char, "uid=%i%c", &n, &dummy) == 1) {
			setuid = 1;
			uid = n;
		} else if (sscanf(this_char, "gid=%i%c", &n, &dummy) == 1) {
			setgid = 1;
			gid = n;
		} else if (sscanf(this_char, "mode=%o%c", &n, &dummy) == 1)
			mode = n & ~S_IFMT;
		else {
			kfree(new_opt);
			printk("capifs: called with bogus options\n");
			return -EINVAL;
		}
	}

	mutex_lock(&s->s_root->d_inode->i_mutex);

	replace_mount_options(s, new_opt);
	config.setuid  = setuid;
	config.setgid  = setgid;
	config.uid     = uid;
	config.gid     = gid;
	config.mode    = mode;

	mutex_unlock(&s->s_root->d_inode->i_mutex);

	return 0;
}

static const struct super_operations capifs_sops =
{
	.statfs		= simple_statfs,
	.remount_fs	= capifs_remount,
	.show_options	= generic_show_options,
};


static int
capifs_fill_super(struct super_block *s, void *data, int silent)
{
	struct inode * inode;

	s->s_blocksize = 1024;
	s->s_blocksize_bits = 10;
	s->s_magic = CAPIFS_SUPER_MAGIC;
	s->s_op = &capifs_sops;
	s->s_time_gran = 1;

	inode = new_inode(s);
	if (!inode)
		goto fail;
	inode->i_ino = 1;
	inode->i_mtime = inode->i_atime = inode->i_ctime = CURRENT_TIME;
	inode->i_mode = S_IFDIR | S_IRUGO | S_IXUGO | S_IWUSR;
	inode->i_op = &simple_dir_inode_operations;
	inode->i_fop = &simple_dir_operations;
	inode->i_nlink = 2;

	capifs_root = s->s_root = d_alloc_root(inode);
	if (s->s_root)
		return 0;
	
	printk("capifs: get root dentry failed\n");
	iput(inode);
fail:
	return -ENOMEM;
}

static int capifs_get_sb(struct file_system_type *fs_type,
	int flags, const char *dev_name, void *data, struct vfsmount *mnt)
{
	return get_sb_single(fs_type, flags, data, capifs_fill_super, mnt);
}

static struct file_system_type capifs_fs_type = {
	.owner		= THIS_MODULE,
	.name		= "capifs",
	.get_sb		= capifs_get_sb,
	.kill_sb	= kill_anon_super,
};

struct dentry *capifs_new_ncci(unsigned int number, dev_t device)
{
	struct dentry *dentry;
	struct inode *inode;
	char name[10];
	int namelen;

	mutex_lock(&capifs_root->d_inode->i_mutex);

	namelen = sprintf(name, "%d", number);
	dentry = lookup_one_len(name, capifs_root, namelen);
	if (IS_ERR(dentry)) {
		dentry = NULL;
		goto unlock_out;
	}

	if (dentry->d_inode) {
		dput(dentry);
		dentry = NULL;
		goto unlock_out;
	}

	inode = new_inode(capifs_mnt->mnt_sb);
	if (!inode) {
		dput(dentry);
		dentry = NULL;
		goto unlock_out;
	}

	/* config contents is protected by root's i_mutex */
	inode->i_uid = config.setuid ? config.uid : current_fsuid();
	inode->i_gid = config.setgid ? config.gid : current_fsgid();
	inode->i_mtime = inode->i_atime = inode->i_ctime = CURRENT_TIME;
	inode->i_ino = number + 2;
	init_special_inode(inode, S_IFCHR|config.mode, device);

	d_instantiate(dentry, inode);
	dget(dentry);

unlock_out:
	mutex_unlock(&capifs_root->d_inode->i_mutex);

	return dentry;
}

void capifs_free_ncci(struct dentry *dentry)
{
	struct inode *inode;

	if (!dentry)
		return;

	mutex_lock(&capifs_root->d_inode->i_mutex);

	inode = dentry->d_inode;
	if (inode) {
		drop_nlink(inode);
		d_delete(dentry);
		dput(dentry);
	}
	dput(dentry);

	mutex_unlock(&capifs_root->d_inode->i_mutex);
}

static int __init capifs_init(void)
{
	char rev[32];
	char *p;
	int err;

	if ((p = strchr(revision, ':')) != NULL && p[1]) {
		strlcpy(rev, p + 2, sizeof(rev));
		if ((p = strchr(rev, '$')) != NULL && p > rev)
		   *(p-1) = 0;
	} else
		strcpy(rev, "1.0");

	err = register_filesystem(&capifs_fs_type);
	if (!err) {
		capifs_mnt = kern_mount(&capifs_fs_type);
		if (IS_ERR(capifs_mnt)) {
			err = PTR_ERR(capifs_mnt);
			unregister_filesystem(&capifs_fs_type);
		}
	}
	if (!err)
		printk(KERN_NOTICE "capifs: Rev %s\n", rev);
	return err;
}

static void __exit capifs_exit(void)
{
	unregister_filesystem(&capifs_fs_type);
	mntput(capifs_mnt);
}

EXPORT_SYMBOL(capifs_new_ncci);
EXPORT_SYMBOL(capifs_free_ncci);

module_init(capifs_init);
module_exit(capifs_exit);
Commit	Line	Data
1da177e4 LT	1	/* $Id: capifs.c,v 1.1.2.3 2004/01/16 21:09:26 keil Exp $
	2	*
	3	* Copyright 2000 by Carsten Paeth <calle@calle.de>
	4	*
	5	* Heavily based on devpts filesystem from H. Peter Anvin
	6	*
	7	* This software may be used and distributed according to the terms
	8	* of the GNU General Public License, incorporated herein by reference.
	9	*
	10	*/
	11
	12	#include <linux/fs.h>
	13	#include <linux/mount.h>
	14	#include <linux/namei.h>
	15	#include <linux/module.h>
	16	#include <linux/init.h>
	17	#include <linux/ctype.h>
4e57b681	18	#include <linux/sched.h> /* current */
1da177e4	19
6e21bd9a AB	20	#include "capifs.h"
6e21bd9a AB	21
1da177e4 LT	22	MODULE_DESCRIPTION("CAPI4Linux: /dev/capi/ filesystem");
	23	MODULE_AUTHOR("Carsten Paeth");
	24	MODULE_LICENSE("GPL");
	25
	26	/* ------------------------------------------------------------------ */
	27
	28	static char *revision = "$Revision: 1.1.2.3 $";
	29
	30	/* ------------------------------------------------------------------ */
	31
	32	#define CAPIFS_SUPER_MAGIC (('C'<<8)\|'N')
	33
	34	static struct vfsmount *capifs_mnt;
	35	static struct dentry *capifs_root;
	36
	37	static struct {
	38	int setuid;
	39	int setgid;
	40	uid_t uid;
	41	gid_t gid;
	42	umode_t mode;
	43	} config = {.mode = 0600};
	44
	45	/* ------------------------------------------------------------------ */
	46
	47	static int capifs_remount(struct super_block s, int flags, char *data)
	48	{
	49	int setuid = 0;
	50	int setgid = 0;
	51	uid_t uid = 0;
	52	gid_t gid = 0;
	53	umode_t mode = 0600;
	54	char *this_char;
e55e212c	55	char *new_opt = kstrdup(data, GFP_KERNEL);
1da177e4 LT	56
	57	this_char = NULL;
	58	while ((this_char = strsep(&data, ",")) != NULL) {
	59	int n;
	60	char dummy;
	61	if (!*this_char)
	62	continue;
	63	if (sscanf(this_char, "uid=%i%c", &n, &dummy) == 1) {
	64	setuid = 1;
	65	uid = n;
	66	} else if (sscanf(this_char, "gid=%i%c", &n, &dummy) == 1) {
	67	setgid = 1;
	68	gid = n;
	69	} else if (sscanf(this_char, "mode=%o%c", &n, &dummy) == 1)
	70	mode = n & ~S_IFMT;
	71	else {
c24e9b3f	72	kfree(new_opt);
1da177e4 LT	73	printk("capifs: called with bogus options\n");
	74	return -EINVAL;
	75	}
	76	}
e55e212c	77
b0c4f322	78	mutex_lock(&s->s_root->d_inode->i_mutex);
e55e212c	79
b0c4f322	80	replace_mount_options(s, new_opt);
1da177e4 LT	81	config.setuid = setuid;
	82	config.setgid = setgid;
	83	config.uid = uid;
	84	config.gid = gid;
	85	config.mode = mode;
e55e212c	86
b0c4f322 AV	87	mutex_unlock(&s->s_root->d_inode->i_mutex);
b0c4f322 AV	88
1da177e4 LT	89	return 0;
	90	}
	91
b87221de	92	static const struct super_operations capifs_sops =
1da177e4 LT	93	{
	94	.statfs = simple_statfs,
	95	.remount_fs = capifs_remount,
e55e212c	96	.show_options = generic_show_options,
1da177e4 LT	97	};
	98
	99
	100	static int
	101	capifs_fill_super(struct super_block s, void data, int silent)
	102	{
	103	struct inode * inode;
	104
	105	s->s_blocksize = 1024;
	106	s->s_blocksize_bits = 10;
	107	s->s_magic = CAPIFS_SUPER_MAGIC;
	108	s->s_op = &capifs_sops;
	109	s->s_time_gran = 1;
	110
	111	inode = new_inode(s);
	112	if (!inode)
	113	goto fail;
	114	inode->i_ino = 1;
	115	inode->i_mtime = inode->i_atime = inode->i_ctime = CURRENT_TIME;
1da177e4 LT	116	inode->i_mode = S_IFDIR \| S_IRUGO \| S_IXUGO \| S_IWUSR;
	117	inode->i_op = &simple_dir_inode_operations;
	118	inode->i_fop = &simple_dir_operations;
	119	inode->i_nlink = 2;
	120
	121	capifs_root = s->s_root = d_alloc_root(inode);
	122	if (s->s_root)
	123	return 0;
	124
	125	printk("capifs: get root dentry failed\n");
	126	iput(inode);
	127	fail:
	128	return -ENOMEM;
	129	}
	130
454e2398 DH	131	static int capifs_get_sb(struct file_system_type *fs_type,
454e2398 DH	132	int flags, const char dev_name, void data, struct vfsmount *mnt)
1da177e4	133	{
454e2398	134	return get_sb_single(fs_type, flags, data, capifs_fill_super, mnt);
1da177e4 LT	135	}
	136
	137	static struct file_system_type capifs_fs_type = {
	138	.owner = THIS_MODULE,
	139	.name = "capifs",
	140	.get_sb = capifs_get_sb,
	141	.kill_sb = kill_anon_super,
	142	};
	143
90926f0e	144	struct dentry *capifs_new_ncci(unsigned int number, dev_t device)
1da177e4 LT	145	{
1da177e4 LT	146	struct dentry *dentry;
c947862f	147	struct inode *inode;
90926f0e JK	148	char name[10];
90926f0e JK	149	int namelen;
b0c4f322	150
90926f0e JK	151	mutex_lock(&capifs_root->d_inode->i_mutex);
	152
	153	namelen = sprintf(name, "%d", number);
	154	dentry = lookup_one_len(name, capifs_root, namelen);
	155	if (IS_ERR(dentry)) {
	156	dentry = NULL;
c947862f	157	goto unlock_out;
90926f0e	158	}
c947862f JK	159
	160	if (dentry->d_inode) {
	161	dput(dentry);
90926f0e	162	dentry = NULL;
c947862f JK	163	goto unlock_out;
	164	}
	165
	166	inode = new_inode(capifs_mnt->mnt_sb);
	167	if (!inode) {
	168	dput(dentry);
90926f0e	169	dentry = NULL;
c947862f JK	170	goto unlock_out;
c947862f JK	171	}
b0c4f322 AV	172
b0c4f322 AV	173	/* config contents is protected by root's i_mutex */
0e164b68 DH	174	inode->i_uid = config.setuid ? config.uid : current_fsuid();
0e164b68 DH	175	inode->i_gid = config.setgid ? config.gid : current_fsgid();
1da177e4	176	inode->i_mtime = inode->i_atime = inode->i_ctime = CURRENT_TIME;
c947862f	177	inode->i_ino = number + 2;
1da177e4	178	init_special_inode(inode, S_IFCHR\|config.mode, device);
1da177e4	179
c947862f	180	d_instantiate(dentry, inode);
90926f0e	181	dget(dentry);
c947862f JK	182
c947862f JK	183	unlock_out:
1b1dcc1b	184	mutex_unlock(&capifs_root->d_inode->i_mutex);
90926f0e JK	185
90926f0e JK	186	return dentry;
1da177e4 LT	187	}
1da177e4 LT	188
90926f0e	189	void capifs_free_ncci(struct dentry *dentry)
1da177e4	190	{
90926f0e JK	191	struct inode *inode;
	192
	193	if (!dentry)
	194	return;
	195
	196	mutex_lock(&capifs_root->d_inode->i_mutex);
	197
	198	inode = dentry->d_inode;
	199	if (inode) {
	200	drop_nlink(inode);
	201	d_delete(dentry);
1da177e4 LT	202	dput(dentry);
1da177e4 LT	203	}
90926f0e JK	204	dput(dentry);
90926f0e JK	205
1b1dcc1b	206	mutex_unlock(&capifs_root->d_inode->i_mutex);
1da177e4 LT	207	}
	208
	209	static int __init capifs_init(void)
	210	{
	211	char rev[32];
	212	char *p;
	213	int err;
	214
2f9e9b6d	215	if ((p = strchr(revision, ':')) != NULL && p[1]) {
1da177e4	216	strlcpy(rev, p + 2, sizeof(rev));
2f9e9b6d	217	if ((p = strchr(rev, '$')) != NULL && p > rev)
1da177e4 LT	218	*(p-1) = 0;
	219	} else
	220	strcpy(rev, "1.0");
	221
	222	err = register_filesystem(&capifs_fs_type);
	223	if (!err) {
	224	capifs_mnt = kern_mount(&capifs_fs_type);
820d220d	225	if (IS_ERR(capifs_mnt)) {
1da177e4	226	err = PTR_ERR(capifs_mnt);
820d220d JM	227	unregister_filesystem(&capifs_fs_type);
820d220d JM	228	}
1da177e4 LT	229	}
	230	if (!err)
	231	printk(KERN_NOTICE "capifs: Rev %s\n", rev);
	232	return err;
	233	}
	234
	235	static void __exit capifs_exit(void)
	236	{
	237	unregister_filesystem(&capifs_fs_type);
	238	mntput(capifs_mnt);
	239	}
	240
	241	EXPORT_SYMBOL(capifs_new_ncci);
	242	EXPORT_SYMBOL(capifs_free_ncci);
	243
	244	module_init(capifs_init);
	245	module_exit(capifs_exit);