3 files changed, 297 insertions, 0 deletions

diff --git a/fs/devpts/Makefile b/fs/devpts/Makefile
new file mode 100644
index 000000000000..5800df2e50c8
--- /dev/null
+++ b/fs/devpts/Makefile
@@ -0,0 +1,8 @@
+#
+# Makefile for the Linux /dev/pts virtual filesystem.
+#
+
+obj-$(CONFIG_UNIX98_PTYS)               += devpts.o
+
+devpts-$(CONFIG_UNIX98_PTYS)            := inode.o
+devpts-$(CONFIG_DEVPTS_FS_SECURITY)     += xattr_security.o
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");
diff --git a/fs/devpts/xattr_security.c b/fs/devpts/xattr_security.c
new file mode 100644
index 000000000000..864cb5c79baa
--- /dev/null
+++ b/fs/devpts/xattr_security.c
@@ -0,0 +1,47 @@
+/*
+ * Security xattr support for devpts.
+ *
+ * Author: Stephen Smalley <sds@epoch.ncsc.mil>
+ * Copyright (c) 2004 Red Hat, Inc., James Morris <jmorris@redhat.com>
+ *
+ * This program is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License as published by the Free
+ * Software Foundation; either version 2 of the License, or (at your option)
+ * any later version.
+ */
+#include <linux/string.h>
+#include <linux/fs.h>
+#include <linux/security.h>
+#include <linux/xattr.h>
+
+static size_t
+devpts_xattr_security_list(struct inode *inode, char *list, size_t list_len,
+                           const char *name, size_t name_len)
+{
+        return security_inode_listsecurity(inode, list, list_len);
+}
+
+static int
+devpts_xattr_security_get(struct inode *inode, const char *name,
+                          void *buffer, size_t size)
+{
+        if (strcmp(name, "") == 0)
+                return -EINVAL;
+        return security_inode_getsecurity(inode, name, buffer, size);
+}
+
+static int
+devpts_xattr_security_set(struct inode *inode, const char *name,
+                          const void *value, size_t size, int flags)
+{
+        if (strcmp(name, "") == 0)
+                return -EINVAL;
+        return security_inode_setsecurity(inode, name, value, size, flags);
+}
+
+struct xattr_handler devpts_xattr_security_handler = {
+        .prefix = XATTR_SECURITY_PREFIX,
+        .list   = devpts_xattr_security_list,
+        .get    = devpts_xattr_security_get,
+        .set    = devpts_xattr_security_set,
+};