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/* -*- linux-c -*- --------------------------------------------------------- *

 *

 * linux/fs/devpts/inode.c

 *

 *  Copyright 1998 H. Peter Anvin -- All Rights Reserved

 *

 * This file is part of the Linux kernel and is made available under

 * the terms of the GNU General Public License, version 2, or at your

 * option, any later version, incorporated herein by reference.

 *

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

#include <linux/module.h>

#include <linux/string.h>

#include <linux/fs.h>

#include <linux/init.h>

#include <linux/kdev_t.h>

#include <linux/kernel.h>

#include <linux/locks.h>

#include <linux/major.h>

#include <linux/slab.h>

#include <linux/stat.h>

#include <linux/tty.h>

#include <asm/bitops.h>

#include <asm/uaccess.h>

#include "devpts_i.h"

static struct vfsmount *devpts_mnt;

static void devpts_put_super(struct super_block *sb)

{

        struct devpts_sb_info *sbi = SBI(sb);

        struct inode *inode;

        int i;

        for ( i = 0 ; i < sbi->max_ptys ; i++ ) {

                if ( (inode = sbi->inodes[i]) ) {

                        if ( atomic_read(&inode->i_count) != 1 )

                                printk("devpts_put_super: badness: entry %d count %d\n",

                                       i, atomic_read(&inode->i_count));

                        inode->i_nlink--;

                        iput(inode);

                }

        }

        kfree(sbi->inodes);

        kfree(sbi);

}

static int devpts_statfs(struct super_block *sb, struct statfs *buf);

static int devpts_remount (struct super_block * sb, int * flags, char * data);

static struct super_operations devpts_sops = {

        put_super:      devpts_put_super,

        statfs:         devpts_statfs,

        remount_fs:     devpts_remount,

};

static int devpts_parse_options(char *options, struct devpts_sb_info *sbi)

{

        int setuid = 0;

        int setgid = 0;

        uid_t uid = 0;

        gid_t gid = 0;

        umode_t mode = 0600;

        char *this_char, *value;

        this_char = NULL;

        if ( options )

                this_char = strtok(options,",");

        for ( ; this_char; this_char = strtok(NULL,",")) {

                if ((value = strchr(this_char,'=')) != NULL)

                        *value++ = 0;

                if (!strcmp(this_char,"uid")) {

                        if (!value || !*value)

                                return 1;

                        uid = simple_strtoul(value,&value,0);

                        if (*value)

                                return 1;

                        setuid = 1;

                }

                else if (!strcmp(this_char,"gid")) {

                        if (!value || !*value)

                                return 1;

                        gid = simple_strtoul(value,&value,0);

                        if (*value)

                                return 1;

                        setgid = 1;

                }

                else if (!strcmp(this_char,"mode")) {

                        if (!value || !*value)

                                return 1;

                        mode = simple_strtoul(value,&value,8);

                        if (*value)

                                return 1;

                }

                else

                        return 1;

        }

        sbi->setuid  = setuid;

        sbi->setgid  = setgid;

        sbi->uid     = uid;

        sbi->gid     = gid;

        sbi->mode    = mode & ~S_IFMT;

        return 0;

}

static int devpts_remount(struct super_block * sb, int * flags, char * data)

{

        struct devpts_sb_info *sbi = sb->u.generic_sbp;

        int res = devpts_parse_options(data,sbi);

        if (res) {

                printk("devpts: called with bogus options\n");

                return -EINVAL;

        }

        return 0;

}

struct super_block *devpts_read_super(struct super_block *s, void *data,

                                      int silent)

{

        struct inode * inode;

        struct devpts_sb_info *sbi;

        sbi = (struct devpts_sb_info *) kmalloc(sizeof(struct devpts_sb_info), GFP_KERNEL);

        if ( !sbi )

                goto fail;

        sbi->magic  = DEVPTS_SBI_MAGIC;

        sbi->max_ptys = unix98_max_ptys;

        sbi->inodes = kmalloc(sizeof(struct inode *) * sbi->max_ptys, GFP_KERNEL);

        if ( !sbi->inodes )

                goto fail_free;

        memset(sbi->inodes, 0, sizeof(struct inode *) * sbi->max_ptys);

        if ( devpts_parse_options(data,sbi) && !silent) {

                printk("devpts: called with bogus options\n");

                goto fail_free;

        }

        inode = new_inode(s);

        if (!inode)

                goto fail_free;

        inode->i_ino = 1;

        inode->i_mtime = inode->i_atime = inode->i_ctime = CURRENT_TIME;

        inode->i_blocks = 0;

        inode->i_blksize = 1024;

        inode->i_uid = inode->i_gid = 0;

        inode->i_mode = S_IFDIR | S_IRUGO | S_IXUGO | S_IWUSR;

        inode->i_op = &devpts_root_inode_operations;

        inode->i_fop = &devpts_root_operations;

        inode->i_nlink = 2;

        s->u.generic_sbp = (void *) sbi;

        s->s_blocksize = 1024;

        s->s_blocksize_bits = 10;

        s->s_magic = DEVPTS_SUPER_MAGIC;

        s->s_op = &devpts_sops;

        s->s_root = d_alloc_root(inode);

        if (s->s_root)

                return s;

        printk("devpts: get root dentry failed\n");

        iput(inode);

fail_free:

        kfree(sbi);

fail:

        return NULL;

}

static int devpts_statfs(struct super_block *sb, struct statfs *buf)

{

        buf->f_type = DEVPTS_SUPER_MAGIC;

        buf->f_bsize = 1024;

        buf->f_namelen = NAME_MAX;

        return 0;

}

static DECLARE_FSTYPE(devpts_fs_type, "devpts", devpts_read_super, FS_SINGLE);

void devpts_pty_new(int number, kdev_t device)

{

        struct super_block *sb = devpts_mnt->mnt_sb;

        struct devpts_sb_info *sbi = SBI(sb);

        struct inode *inode;

        if ( sbi->inodes[number] )

                return; /* Already registered, this does happen */

        inode = new_inode(sb);

        if (!inode)

                return;

        inode->i_ino = number+2;

        inode->i_blocks = 0;

        inode->i_blksize = 1024;

        inode->i_uid = sbi->setuid ? sbi->uid : current->fsuid;

        inode->i_gid = sbi->setgid ? sbi->gid : current->fsgid;

        inode->i_mtime = inode->i_atime = inode->i_ctime = CURRENT_TIME;

        init_special_inode(inode, S_IFCHR|sbi->mode, kdev_t_to_nr(device));

        if ( sbi->inodes[number] ) {

                iput(inode);

                return;

        }

        sbi->inodes[number] = inode;

}

void devpts_pty_kill(int number)

{

        struct super_block *sb = devpts_mnt->mnt_sb;

        struct devpts_sb_info *sbi = SBI(sb);

        struct inode *inode = sbi->inodes[number];

        if ( inode ) {

                sbi->inodes[number] = NULL;

                inode->i_nlink--;

                iput(inode);

        }

}

static int __init init_devpts_fs(void)

{

        int err = register_filesystem(&devpts_fs_type);

        if (!err) {

                devpts_mnt = kern_mount(&devpts_fs_type);

                err = PTR_ERR(devpts_mnt);

                if (!IS_ERR(devpts_mnt))

                        err = 0;

#ifdef MODULE

                if ( !err ) {

                        devpts_upcall_new  = devpts_pty_new;

                        devpts_upcall_kill = devpts_pty_kill;

                }

#endif

        }

        return err;

}

static void __exit exit_devpts_fs(void)

{

#ifdef MODULE

        devpts_upcall_new  = NULL;

        devpts_upcall_kill = NULL;

#endif

        unregister_filesystem(&devpts_fs_type);

        kern_umount(devpts_mnt);

}

module_init(init_devpts_fs)

module_exit(exit_devpts_fs)

MODULE_LICENSE("GPL");