4 files changed, 419 insertions, 159 deletions

diff --git a/security/Kconfig b/security/Kconfig
index dcf04a09185d..64d3f1e9ca85 100644
--- a/security/Kconfig
+++ b/security/Kconfig
@@ -35,6 +35,7 @@ config KEYS_DEBUG_PROC_KEYS
 
 config SECURITY
         bool "Enable different security models"
+        depends on SYSFS
         help
           This allows you to choose different security modules to be
           configured into your kernel.
diff --git a/security/Makefile b/security/Makefile
index 197cc2f3f1ec..8cbbf2f36709 100644
--- a/security/Makefile
+++ b/security/Makefile
@@ -11,7 +11,7 @@ obj-y		+= commoncap.o
 endif
 
 # Object file lists
-obj-$(CONFIG_SECURITY)                  += security.o dummy.o
+obj-$(CONFIG_SECURITY)                  += security.o dummy.o inode.o
 # Must precede capability.o in order to stack properly.
 obj-$(CONFIG_SECURITY_SELINUX)          += selinux/built-in.o
 obj-$(CONFIG_SECURITY_CAPABILITIES)     += commoncap.o capability.o
diff --git a/security/inode.c b/security/inode.c
new file mode 100644
index 000000000000..a5964502ae30
--- /dev/null
+++ b/security/inode.c
@@ -0,0 +1,347 @@
+/*
+ *  inode.c - securityfs
+ *
+ *  Copyright (C) 2005 Greg Kroah-Hartman <gregkh@suse.de>
+ *
+ *      This program is free software; you can redistribute it and/or
+ *      modify it under the terms of the GNU General Public License version
+ *      2 as published by the Free Software Foundation.
+ *
+ *  Based on fs/debugfs/inode.c which had the following copyright notice:
+ *    Copyright (C) 2004 Greg Kroah-Hartman <greg@kroah.com>
+ *    Copyright (C) 2004 IBM Inc.
+ */
+
+/* #define DEBUG */
+#include <linux/config.h>
+#include <linux/module.h>
+#include <linux/fs.h>
+#include <linux/mount.h>
+#include <linux/pagemap.h>
+#include <linux/init.h>
+#include <linux/namei.h>
+#include <linux/security.h>
+
+#define SECURITYFS_MAGIC        0x73636673
+
+static struct vfsmount *mount;
+static int mount_count;
+
+/*
+ * TODO:
+ *   I think I can get rid of these default_file_ops, but not quite sure...
+ */
+static ssize_t default_read_file(struct file *file, char __user *buf,
+                                 size_t count, loff_t *ppos)
+{
+        return 0;
+}
+
+static ssize_t default_write_file(struct file *file, const char __user *buf,
+                                   size_t count, loff_t *ppos)
+{
+        return count;
+}
+
+static int default_open(struct inode *inode, struct file *file)
+{
+        if (inode->u.generic_ip)
+                file->private_data = inode->u.generic_ip;
+
+        return 0;
+}
+
+static struct file_operations default_file_ops = {
+        .read =         default_read_file,
+        .write =        default_write_file,
+        .open =         default_open,
+};
+
+static struct inode *get_inode(struct super_block *sb, int mode, dev_t dev)
+{
+        struct inode *inode = new_inode(sb);
+
+        if (inode) {
+                inode->i_mode = mode;
+                inode->i_uid = 0;
+                inode->i_gid = 0;
+                inode->i_blksize = PAGE_CACHE_SIZE;
+                inode->i_blocks = 0;
+                inode->i_atime = inode->i_mtime = inode->i_ctime = CURRENT_TIME;
+                switch (mode & S_IFMT) {
+                default:
+                        init_special_inode(inode, mode, dev);
+                        break;
+                case S_IFREG:
+                        inode->i_fop = &default_file_ops;
+                        break;
+                case S_IFDIR:
+                        inode->i_op = &simple_dir_inode_operations;
+                        inode->i_fop = &simple_dir_operations;
+
+                        /* directory inodes start off with i_nlink == 2 (for "." entry) */
+                        inode->i_nlink++;
+                        break;
+                }
+        }
+        return inode;
+}
+
+/* SMP-safe */
+static int mknod(struct inode *dir, struct dentry *dentry,
+                         int mode, dev_t dev)
+{
+        struct inode *inode;
+        int error = -EPERM;
+
+        if (dentry->d_inode)
+                return -EEXIST;
+
+        inode = get_inode(dir->i_sb, mode, dev);
+        if (inode) {
+                d_instantiate(dentry, inode);
+                dget(dentry);
+                error = 0;
+        }
+        return error;
+}
+
+static int mkdir(struct inode *dir, struct dentry *dentry, int mode)
+{
+        int res;
+
+        mode = (mode & (S_IRWXUGO | S_ISVTX)) | S_IFDIR;
+        res = mknod(dir, dentry, mode, 0);
+        if (!res)
+                dir->i_nlink++;
+        return res;
+}
+
+static int create(struct inode *dir, struct dentry *dentry, int mode)
+{
+        mode = (mode & S_IALLUGO) | S_IFREG;
+        return mknod(dir, dentry, mode, 0);
+}
+
+static inline int positive(struct dentry *dentry)
+{
+        return dentry->d_inode && !d_unhashed(dentry);
+}
+
+static int fill_super(struct super_block *sb, void *data, int silent)
+{
+        static struct tree_descr files[] = {{""}};
+
+        return simple_fill_super(sb, SECURITYFS_MAGIC, files);
+}
+
+static struct super_block *get_sb(struct file_system_type *fs_type,
+                                        int flags, const char *dev_name,
+                                        void *data)
+{
+        return get_sb_single(fs_type, flags, data, fill_super);
+}
+
+static struct file_system_type fs_type = {
+        .owner =        THIS_MODULE,
+        .name =         "securityfs",
+        .get_sb =       get_sb,
+        .kill_sb =      kill_litter_super,
+};
+
+static int create_by_name(const char *name, mode_t mode,
+                          struct dentry *parent,
+                          struct dentry **dentry)
+{
+        int error = 0;
+
+        *dentry = NULL;
+
+        /* If the parent is not specified, we create it in the root.
+         * We need the root dentry to do this, which is in the super
+         * block. A pointer to that is in the struct vfsmount that we
+         * have around.
+         */
+        if (!parent ) {
+                if (mount && mount->mnt_sb) {
+                        parent = mount->mnt_sb->s_root;
+                }
+        }
+        if (!parent) {
+                pr_debug("securityfs: Ah! can not find a parent!\n");
+                return -EFAULT;
+        }
+
+        down(&parent->d_inode->i_sem);
+        *dentry = lookup_one_len(name, parent, strlen(name));
+        if (!IS_ERR(dentry)) {
+                if ((mode & S_IFMT) == S_IFDIR)
+                        error = mkdir(parent->d_inode, *dentry, mode);
+                else
+                        error = create(parent->d_inode, *dentry, mode);
+        } else
+                error = PTR_ERR(dentry);
+        up(&parent->d_inode->i_sem);
+
+        return error;
+}
+
+/**
+ * securityfs_create_file - create a file in the securityfs filesystem
+ *
+ * @name: a pointer to a string containing the name of the file to create.
+ * @mode: the permission that the file should have
+ * @parent: a pointer to the parent dentry for this file.  This should be a
+ *          directory dentry if set.  If this paramater is NULL, then the
+ *          file will be created in the root of the securityfs filesystem.
+ * @data: a pointer to something that the caller will want to get to later
+ *        on.  The inode.u.generic_ip pointer will point to this value on
+ *        the open() call.
+ * @fops: a pointer to a struct file_operations that should be used for
+ *        this file.
+ *
+ * This is the basic "create a file" function for securityfs.  It allows for a
+ * wide range of flexibility in createing a file, or a directory (if you
+ * want to create a directory, the securityfs_create_dir() function is
+ * recommended to be used instead.)
+ *
+ * This function will return a pointer to a dentry if it succeeds.  This
+ * pointer must be passed to the securityfs_remove() function when the file is
+ * to be removed (no automatic cleanup happens if your module is unloaded,
+ * you are responsible here.)  If an error occurs, NULL will be returned.
+ *
+ * If securityfs is not enabled in the kernel, the value -ENODEV will be
+ * returned.  It is not wise to check for this value, but rather, check for
+ * NULL or !NULL instead as to eliminate the need for #ifdef in the calling
+ * code.
+ */
+struct dentry *securityfs_create_file(const char *name, mode_t mode,
+                                   struct dentry *parent, void *data,
+                                   struct file_operations *fops)
+{
+        struct dentry *dentry = NULL;
+        int error;
+
+        pr_debug("securityfs: creating file '%s'\n",name);
+
+        error = simple_pin_fs("securityfs", &mount, &mount_count);
+        if (error) {
+                dentry = ERR_PTR(error);
+                goto exit;
+        }
+
+        error = create_by_name(name, mode, parent, &dentry);
+        if (error) {
+                dentry = ERR_PTR(error);
+                simple_release_fs(&mount, &mount_count);
+                goto exit;
+        }
+
+        if (dentry->d_inode) {
+                if (fops)
+                        dentry->d_inode->i_fop = fops;
+                if (data)
+                        dentry->d_inode->u.generic_ip = data;
+        }
+exit:
+        return dentry;
+}
+EXPORT_SYMBOL_GPL(securityfs_create_file);
+
+/**
+ * securityfs_create_dir - create a directory in the securityfs filesystem
+ *
+ * @name: a pointer to a string containing the name of the directory to
+ *        create.
+ * @parent: a pointer to the parent dentry for this file.  This should be a
+ *          directory dentry if set.  If this paramater is NULL, then the
+ *          directory will be created in the root of the securityfs filesystem.
+ *
+ * This function creates a directory in securityfs with the given name.
+ *
+ * This function will return a pointer to a dentry if it succeeds.  This
+ * pointer must be passed to the securityfs_remove() function when the file is
+ * to be removed (no automatic cleanup happens if your module is unloaded,
+ * you are responsible here.)  If an error occurs, NULL will be returned.
+ *
+ * If securityfs is not enabled in the kernel, the value -ENODEV will be
+ * returned.  It is not wise to check for this value, but rather, check for
+ * NULL or !NULL instead as to eliminate the need for #ifdef in the calling
+ * code.
+ */
+struct dentry *securityfs_create_dir(const char *name, struct dentry *parent)
+{
+        return securityfs_create_file(name,
+                                      S_IFDIR | S_IRWXU | S_IRUGO | S_IXUGO,
+                                      parent, NULL, NULL);
+}
+EXPORT_SYMBOL_GPL(securityfs_create_dir);
+
+/**
+ * securityfs_remove - removes a file or directory from the securityfs filesystem
+ *
+ * @dentry: a pointer to a the dentry of the file or directory to be
+ *          removed.
+ *
+ * This function removes a file or directory in securityfs that was previously
+ * created with a call to another securityfs function (like
+ * securityfs_create_file() or variants thereof.)
+ *
+ * This function is required to be called in order for the file to be
+ * removed, no automatic cleanup of files will happen when a module is
+ * removed, you are responsible here.
+ */
+void securityfs_remove(struct dentry *dentry)
+{
+        struct dentry *parent;
+
+        if (!dentry)
+                return;
+
+        parent = dentry->d_parent;
+        if (!parent || !parent->d_inode)
+                return;
+
+        down(&parent->d_inode->i_sem);
+        if (positive(dentry)) {
+                if (dentry->d_inode) {
+                        if (S_ISDIR(dentry->d_inode->i_mode))
+                                simple_rmdir(parent->d_inode, dentry);
+                        else
+                                simple_unlink(parent->d_inode, dentry);
+                        dput(dentry);
+                }
+        }
+        up(&parent->d_inode->i_sem);
+        simple_release_fs(&mount, &mount_count);
+}
+EXPORT_SYMBOL_GPL(securityfs_remove);
+
+static decl_subsys(security, NULL, NULL);
+
+static int __init securityfs_init(void)
+{
+        int retval;
+
+        kset_set_kset_s(&security_subsys, kernel_subsys);
+        retval = subsystem_register(&security_subsys);
+        if (retval)
+                return retval;
+
+        retval = register_filesystem(&fs_type);
+        if (retval)
+                subsystem_unregister(&security_subsys);
+        return retval;
+}
+
+static void __exit securityfs_exit(void)
+{
+        simple_release_fs(&mount, &mount_count);
+        unregister_filesystem(&fs_type);
+        subsystem_unregister(&security_subsys);
+}
+
+core_initcall(securityfs_init);
+module_exit(securityfs_exit);
+MODULE_LICENSE("GPL");
+
diff --git a/security/seclvl.c b/security/seclvl.c
index 96b1f2122f67..dc4e17b6eaf6 100644
--- a/security/seclvl.c
+++ b/security/seclvl.c
@@ -119,69 +119,6 @@ MODULE_PARM_DESC(hideHash, "When set to 0, reading seclvl/passwd from sysfs "
         } while (0)
 
 /**
- * kobject stuff
- */
-
-struct subsystem seclvl_subsys;
-
-struct seclvl_obj {
-        char *name;
-        struct list_head slot_list;
-        struct kobject kobj;
-};
-
-/**
- * There is a seclvl_attribute struct for each file in sysfs.
- *
- * In our case, we have one of these structs for "passwd" and another
- * for "seclvl".
- */
-struct seclvl_attribute {
-        struct attribute attr;
-        ssize_t(*show) (struct seclvl_obj *, char *);
-        ssize_t(*store) (struct seclvl_obj *, const char *, size_t);
-};
-
-/**
- * When this function is called, one of the files in sysfs is being
- * written to.  attribute->store is a function pointer to whatever the
- * struct seclvl_attribute store function pointer points to.  It is
- * unique for "passwd" and "seclvl".
- */
-static ssize_t
-seclvl_attr_store(struct kobject *kobj,
-                  struct attribute *attr, const char *buf, size_t len)
-{
-        struct seclvl_obj *obj = container_of(kobj, struct seclvl_obj, kobj);
-        struct seclvl_attribute *attribute =
-            container_of(attr, struct seclvl_attribute, attr);
-        return attribute->store ? attribute->store(obj, buf, len) : -EIO;
-}
-
-static ssize_t
-seclvl_attr_show(struct kobject *kobj, struct attribute *attr, char *buf)
-{
-        struct seclvl_obj *obj = container_of(kobj, struct seclvl_obj, kobj);
-        struct seclvl_attribute *attribute =
-            container_of(attr, struct seclvl_attribute, attr);
-        return attribute->show ? attribute->show(obj, buf) : -EIO;
-}
-
-/**
- * Callback function pointers for show and store
- */
-static struct sysfs_ops seclvlfs_sysfs_ops = {
-        .show = seclvl_attr_show,
-        .store = seclvl_attr_store,
-};
-
-static struct kobj_type seclvl_ktype = {
-        .sysfs_ops = &seclvlfs_sysfs_ops
-};
-
-decl_subsys(seclvl, &seclvl_ktype, NULL);
-
-/**
  * The actual security level.  Ranges between -1 and 2 inclusive.
  */
 static int seclvl;
@@ -213,97 +150,44 @@ static int seclvl_sanity(int reqlvl)
 }
 
 /**
- * Called whenever the user reads the sysfs handle to this kernel
- * object
- */
-static ssize_t seclvl_read_file(struct seclvl_obj *obj, char *buff)
-{
-        return snprintf(buff, PAGE_SIZE, "%d\n", seclvl);
-}
-
-/**
  * security level advancement rules:
  *   Valid levels are -1 through 2, inclusive.
  *   From -1, stuck.  [ in case compiled into kernel ]
  *   From 0 or above, can only increment.
  */
-static int do_seclvl_advance(int newlvl)
+static void do_seclvl_advance(void *data, u64 val)
 {
-        if (newlvl <= seclvl) {
-                seclvl_printk(1, KERN_WARNING, "Cannot advance to seclvl "
-                              "[%d]\n", newlvl);
-                return -EINVAL;
-        }
+        int ret;
+        int newlvl = (int)val;
+
+        ret = seclvl_sanity(newlvl);
+        if (ret)
+                return;
+
         if (newlvl > 2) {
                 seclvl_printk(1, KERN_WARNING, "Cannot advance to seclvl "
                               "[%d]\n", newlvl);
-                return -EINVAL;
+                return;
         }
         if (seclvl == -1) {
                 seclvl_printk(1, KERN_WARNING, "Not allowed to advance to "
                               "seclvl [%d]\n", seclvl);
-                return -EPERM;
+                return;
         }
-        seclvl = newlvl;
-        return 0;
+        seclvl = newlvl;  /* would it be more "correct" to set *data? */
+        return;
 }
 
-/**
- * Called whenever the user writes to the sysfs handle to this kernel
- * object (seclvl/seclvl).  It expects a single-digit number.
- */
-static ssize_t
-seclvl_write_file(struct seclvl_obj *obj, const char *buff, size_t count)
+static u64 seclvl_int_get(void *data)
 {
-        unsigned long val;
-        if (count > 2 || (count == 2 && buff[1] != '\n')) {
-                seclvl_printk(1, KERN_WARNING, "Invalid value passed to "
-                              "seclvl: [%s]\n", buff);
-                return -EINVAL;
-        }
-        val = buff[0] - 48;
-        if (seclvl_sanity(val)) {
-                seclvl_printk(1, KERN_WARNING, "Illegal secure level "
-                              "requested: [%d]\n", (int)val);
-                return -EPERM;
-        }
-        if (do_seclvl_advance(val)) {
-                seclvl_printk(0, KERN_ERR, "Failure advancing security level "
-                              "to %lu\n", val);
-        }
-        return count;
+        return *(int *)data;
 }
 
-/* Generate sysfs_attr_seclvl */
-static struct seclvl_attribute sysfs_attr_seclvl =
-__ATTR(seclvl, (S_IFREG | S_IRUGO | S_IWUSR), seclvl_read_file,
-       seclvl_write_file);
+DEFINE_SIMPLE_ATTRIBUTE(seclvl_file_ops, seclvl_int_get, do_seclvl_advance, "%lld\n");
 
 static unsigned char hashedPassword[SHA1_DIGEST_SIZE];
 
 /**
- * Called whenever the user reads the sysfs passwd handle.
- */
-static ssize_t seclvl_read_passwd(struct seclvl_obj *obj, char *buff)
-{
-        /* So just how good *is* your password? :-) */
-        char tmp[3];
-        int i = 0;
-        buff[0] = '\0';
-        if (hideHash) {
-                /* Security through obscurity */
-                return 0;
-        }
-        while (i < SHA1_DIGEST_SIZE) {
-                snprintf(tmp, 3, "%02x", hashedPassword[i]);
-                strncat(buff, tmp, 2);
-                i++;
-        }
-        strcat(buff, "\n");
-        return ((SHA1_DIGEST_SIZE * 2) + 1);
-}
-
-/**
  * Converts a block of plaintext of into its SHA1 hashed value.
  *
  * It would be nice if crypto had a wrapper to do this for us linear
@@ -347,12 +231,15 @@ plaintext_to_sha1(unsigned char *hash, const char *plaintext, int len)
  * object.  It hashes the password and compares the hashed results.
  */
 static ssize_t
-seclvl_write_passwd(struct seclvl_obj *obj, const char *buff, size_t count)
+passwd_write_file(struct file * file, const char __user * buf,
+                                size_t count, loff_t *ppos)
 {
         int i;
         unsigned char tmp[SHA1_DIGEST_SIZE];
+        char *page;
         int rc;
         int len;
+
         if (!*passwd && !*sha1_passwd) {
                 seclvl_printk(0, KERN_ERR, "Attempt to password-unlock the "
                               "seclvl module, but neither a plain text "
@@ -363,13 +250,26 @@ seclvl_write_passwd(struct seclvl_obj *obj, const char *buff, size_t count)
                               "maintainer about this event.\n");
                 return -EINVAL;
         }
-        len = strlen(buff);
+
+        if (count < 0 || count >= PAGE_SIZE)
+                return -ENOMEM;
+        if (*ppos != 0) {
+                return -EINVAL;
+        }
+        page = (char *)get_zeroed_page(GFP_KERNEL);
+        if (!page)
+                return -ENOMEM;
+        len = -EFAULT;
+        if (copy_from_user(page, buf, count))
+                goto out;
+        
+        len = strlen(page);
         /* ``echo "secret" > seclvl/passwd'' includes a newline */
-        if (buff[len - 1] == '\n') {
+        if (page[len - 1] == '\n') {
                 len--;
         }
         /* Hash the password, then compare the hashed values */
-        if ((rc = plaintext_to_sha1(tmp, buff, len))) {
+        if ((rc = plaintext_to_sha1(tmp, page, len))) {
                 seclvl_printk(0, KERN_ERR, "Error hashing password: rc = "
                               "[%d]\n", rc);
                 return rc;
@@ -382,13 +282,16 @@ seclvl_write_passwd(struct seclvl_obj *obj, const char *buff, size_t count)
         seclvl_printk(0, KERN_INFO,
                       "Password accepted; seclvl reduced to 0.\n");
         seclvl = 0;
-        return count;
+        len = count;
+
+out:
+        free_page((unsigned long)page);
+        return len;
 }
 
-/* Generate sysfs_attr_passwd */
-static struct seclvl_attribute sysfs_attr_passwd =
-__ATTR(passwd, (S_IFREG | S_IRUGO | S_IWUSR), seclvl_read_passwd,
-       seclvl_write_passwd);
+static struct file_operations passwd_file_ops = {
+        .write = passwd_write_file,
+};
 
 /**
  * Explicitely disallow ptrace'ing the init process.
@@ -647,22 +550,34 @@ static int processPassword(void)
 }
 
 /**
- * Sysfs registrations
+ * securityfs registrations
  */
-static int doSysfsRegistrations(void)
+struct dentry *dir_ino, *seclvl_ino, *passwd_ino;
+
+static int seclvlfs_register(void)
 {
-        int rc = 0;
-        if ((rc = subsystem_register(&seclvl_subsys))) {
-                seclvl_printk(0, KERN_WARNING,
-                              "Error [%d] registering seclvl subsystem\n", rc);
-                return rc;
-        }
-        sysfs_create_file(&seclvl_subsys.kset.kobj, &sysfs_attr_seclvl.attr);
+        dir_ino = securityfs_create_dir("seclvl", NULL);
+        if (!dir_ino)
+                return -EFAULT;
+
+        seclvl_ino = securityfs_create_file("seclvl", S_IRUGO | S_IWUSR,
+                                dir_ino, &seclvl, &seclvl_file_ops);
+        if (!seclvl_ino)
+                goto out_deldir;
         if (*passwd || *sha1_passwd) {
-                sysfs_create_file(&seclvl_subsys.kset.kobj,
-                                  &sysfs_attr_passwd.attr);
+                passwd_ino = securityfs_create_file("passwd", S_IRUGO | S_IWUSR,
+                                dir_ino, NULL, &passwd_file_ops);
+                if (!passwd_ino)
+                        goto out_delf;
         }
         return 0;
+
+out_deldir:
+        securityfs_remove(dir_ino);
+out_delf:
+        securityfs_remove(seclvl_ino);
+
+        return -EFAULT;
 }
 
 /**
@@ -677,8 +592,6 @@ static int __init seclvl_init(void)
                 rc = -EINVAL;
                 goto exit;
         }
-        sysfs_attr_seclvl.attr.owner = THIS_MODULE;
-        sysfs_attr_passwd.attr.owner = THIS_MODULE;
         if (initlvl < -1 || initlvl > 2) {
                 seclvl_printk(0, KERN_ERR, "Error: bad initial securelevel "
                               "[%d].\n", initlvl);
@@ -706,7 +619,7 @@ static int __init seclvl_init(void)
                 }               /* if primary module registered */
                 secondary = 1;
         }                       /* if we registered ourselves with the security framework */
-        if ((rc = doSysfsRegistrations())) {
+        if ((rc = seclvlfs_register())) {
                 seclvl_printk(0, KERN_ERR, "Error registering with sysfs\n");
                 goto exit;
         }
@@ -724,12 +637,11 @@ static int __init seclvl_init(void)
  */
 static void __exit seclvl_exit(void)
 {
-        sysfs_remove_file(&seclvl_subsys.kset.kobj, &sysfs_attr_seclvl.attr);
+        securityfs_remove(seclvl_ino);
         if (*passwd || *sha1_passwd) {
-                sysfs_remove_file(&seclvl_subsys.kset.kobj,
-                                  &sysfs_attr_passwd.attr);
+                securityfs_remove(passwd_ino);
         }
-        subsystem_unregister(&seclvl_subsys);
+        securityfs_remove(dir_ino);
         if (secondary == 1) {
                 mod_unreg_security(MY_NAME, &seclvl_ops);
         } else if (unregister_security(&seclvl_ops)) {