1 files changed, 242 insertions, 0 deletions
diff --git a/fs/devpts/inode.c b/fs/devpts/inode.c
new file mode 100644
index 000000000000..1571c8d6c232
--- /dev/null
+++ b/fs/devpts/inode.c
@@ -0,0 +1,242 @@
+/* -*- linux-c -*- --------------------------------------------------------- *
+ *
+ * linux/fs/devpts/inode.c
+ *
+ *  Copyright 1998-2004 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/init.h>
+#include <linux/fs.h>
+#include <linux/sched.h>
+#include <linux/namei.h>
+#include <linux/mount.h>
+#include <linux/tty.h>
+#include <linux/devpts_fs.h>
+#include <linux/xattr.h>
+
+#define DEVPTS_SUPER_MAGIC 0x1cd1
+
+extern struct xattr_handler devpts_xattr_security_handler;
+
+static struct xattr_handler *devpts_xattr_handlers[] = {
+#ifdef CONFIG_DEVPTS_FS_SECURITY
+	&devpts_xattr_security_handler,
+#endif
+	NULL
+};
+
+static struct inode_operations devpts_file_inode_operations = {
+#ifdef CONFIG_DEVPTS_FS_XATTR
+	.setxattr	= generic_setxattr,
+	.getxattr	= generic_getxattr,
+	.listxattr	= generic_listxattr,
+	.removexattr	= generic_removexattr,
+#endif
+};
+
+static struct vfsmount *devpts_mnt;
+static struct dentry *devpts_root;
+
+static struct {
+	int setuid;
+	int setgid;
+	uid_t   uid;
+	gid_t   gid;
+	umode_t mode;
+} config = {.mode = 0600};
+
+static int devpts_remount(struct super_block *sb, 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;
+
+	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 {
+			printk("devpts: called with bogus options\n");
+			return -EINVAL;
+		}
+	}
+	config.setuid  = setuid;
+	config.setgid  = setgid;
+	config.uid     = uid;
+	config.gid     = gid;
+	config.mode    = mode;
+
+	return 0;
+}
+
+static struct super_operations devpts_sops = {
+	.statfs		= simple_statfs,
+	.remount_fs	= devpts_remount,
+};
+
+static int
+devpts_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 = DEVPTS_SUPER_MAGIC;
+	s->s_op = &devpts_sops;
+	s->s_xattr = devpts_xattr_handlers;
+	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_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 = &simple_dir_inode_operations;
+	inode->i_fop = &simple_dir_operations;
+	inode->i_nlink = 2;
+
+	devpts_root = s->s_root = d_alloc_root(inode);
+	if (s->s_root)
+		return 0;
+	
+	printk("devpts: get root dentry failed\n");
+	iput(inode);
+fail:
+	return -ENOMEM;
+}
+
+static struct super_block *devpts_get_sb(struct file_system_type *fs_type,
+	int flags, const char *dev_name, void *data)
+{
+	return get_sb_single(fs_type, flags, data, devpts_fill_super);
+}
+
+static struct file_system_type devpts_fs_type = {
+	.owner		= THIS_MODULE,
+	.name		= "devpts",
+	.get_sb		= devpts_get_sb,
+	.kill_sb	= kill_anon_super,
+};
+
+/*
+ * The normal naming convention is simply /dev/pts/<number>; this conforms
+ * to the System V naming convention
+ */
+
+static struct dentry *get_node(int num)
+{
+	char s[12];
+	struct dentry *root = devpts_root;
+	down(&root->d_inode->i_sem);
+	return lookup_one_len(s, root, sprintf(s, "%d", num));
+}
+
+int devpts_pty_new(struct tty_struct *tty)
+{
+	int number = tty->index;
+	struct tty_driver *driver = tty->driver;
+	dev_t device = MKDEV(driver->major, driver->minor_start+number);
+	struct dentry *dentry;
+	struct inode *inode = new_inode(devpts_mnt->mnt_sb);
+
+	/* We're supposed to be given the slave end of a pty */
+	BUG_ON(driver->type != TTY_DRIVER_TYPE_PTY);
+	BUG_ON(driver->subtype != PTY_TYPE_SLAVE);
+
+	if (!inode)
+		return -ENOMEM;
+
+	inode->i_ino = number+2;
+	inode->i_blksize = 1024;
+	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;
+	init_special_inode(inode, S_IFCHR|config.mode, device);
+	inode->i_op = &devpts_file_inode_operations;
+	inode->u.generic_ip = tty;
+
+	dentry = get_node(number);
+	if (!IS_ERR(dentry) && !dentry->d_inode)
+		d_instantiate(dentry, inode);
+
+	up(&devpts_root->d_inode->i_sem);
+
+	return 0;
+}
+
+struct tty_struct *devpts_get_tty(int number)
+{
+	struct dentry *dentry = get_node(number);
+	struct tty_struct *tty;
+
+	tty = NULL;
+	if (!IS_ERR(dentry)) {
+		if (dentry->d_inode)
+			tty = dentry->d_inode->u.generic_ip;
+		dput(dentry);
+	}
+
+	up(&devpts_root->d_inode->i_sem);
+
+	return tty;
+}
+
+void devpts_pty_kill(int number)
+{
+	struct dentry *dentry = get_node(number);
+
+	if (!IS_ERR(dentry)) {
+		struct inode *inode = dentry->d_inode;
+		if (inode) {
+			inode->i_nlink--;
+			d_delete(dentry);
+			dput(dentry);
+		}
+		dput(dentry);
+	}
+	up(&devpts_root->d_inode->i_sem);
+}
+
+static int __init init_devpts_fs(void)
+{
+	int err = register_filesystem(&devpts_fs_type);
+	if (!err) {
+		devpts_mnt = kern_mount(&devpts_fs_type);
+		if (IS_ERR(devpts_mnt))
+			err = PTR_ERR(devpts_mnt);
+	}
+	return err;
+}
+
+static void __exit exit_devpts_fs(void)
+{
+	unregister_filesystem(&devpts_fs_type);
+	mntput(devpts_mnt);
+}
+
+module_init(init_devpts_fs)
+module_exit(exit_devpts_fs)
+MODULE_LICENSE("GPL");