1 files changed, 379 insertions, 0 deletions
diff --git a/ANDROID_3.4.5/fs/ecryptfs/file.c b/ANDROID_3.4.5/fs/ecryptfs/file.c
new file mode 100644
index 00000000..2b17f2f9
--- /dev/null
+++ b/ANDROID_3.4.5/fs/ecryptfs/file.c
@@ -0,0 +1,379 @@
+/**
+ * eCryptfs: Linux filesystem encryption layer
+ *
+ * Copyright (C) 1997-2004 Erez Zadok
+ * Copyright (C) 2001-2004 Stony Brook University
+ * Copyright (C) 2004-2007 International Business Machines Corp.
+ *   Author(s): Michael A. Halcrow <mhalcrow@us.ibm.com>
+ *   		Michael C. Thompson <mcthomps@us.ibm.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.
+ *
+ * This program is distributed in the hope that it will be useful, but
+ * WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA
+ * 02111-1307, USA.
+ */
+
+#include <linux/file.h>
+#include <linux/poll.h>
+#include <linux/slab.h>
+#include <linux/mount.h>
+#include <linux/pagemap.h>
+#include <linux/security.h>
+#include <linux/compat.h>
+#include <linux/fs_stack.h>
+#include "ecryptfs_kernel.h"
+
+/**
+ * ecryptfs_read_update_atime
+ *
+ * generic_file_read updates the atime of upper layer inode.  But, it
+ * doesn't give us a chance to update the atime of the lower layer
+ * inode.  This function is a wrapper to generic_file_read.  It
+ * updates the atime of the lower level inode if generic_file_read
+ * returns without any errors. This is to be used only for file reads.
+ * The function to be used for directory reads is ecryptfs_read.
+ */
+static ssize_t ecryptfs_read_update_atime(struct kiocb *iocb,
+				const struct iovec *iov,
+				unsigned long nr_segs, loff_t pos)
+{
+	ssize_t rc;
+	struct path lower;
+	struct file *file = iocb->ki_filp;
+
+	rc = generic_file_aio_read(iocb, iov, nr_segs, pos);
+	/*
+	 * Even though this is a async interface, we need to wait
+	 * for IO to finish to update atime
+	 */
+	if (-EIOCBQUEUED == rc)
+		rc = wait_on_sync_kiocb(iocb);
+	if (rc >= 0) {
+		lower.dentry = ecryptfs_dentry_to_lower(file->f_path.dentry);
+		lower.mnt = ecryptfs_dentry_to_lower_mnt(file->f_path.dentry);
+		touch_atime(&lower);
+	}
+	return rc;
+}
+
+struct ecryptfs_getdents_callback {
+	void *dirent;
+	struct dentry *dentry;
+	filldir_t filldir;
+	int filldir_called;
+	int entries_written;
+};
+
+/* Inspired by generic filldir in fs/readdir.c */
+static int
+ecryptfs_filldir(void *dirent, const char *lower_name, int lower_namelen,
+		 loff_t offset, u64 ino, unsigned int d_type)
+{
+	struct ecryptfs_getdents_callback *buf =
+	    (struct ecryptfs_getdents_callback *)dirent;
+	size_t name_size;
+	char *name;
+	int rc;
+
+	buf->filldir_called++;
+	rc = ecryptfs_decode_and_decrypt_filename(&name, &name_size,
+						  buf->dentry, lower_name,
+						  lower_namelen);
+	if (rc) {
+		printk(KERN_ERR "%s: Error attempting to decode and decrypt "
+		       "filename [%s]; rc = [%d]\n", __func__, lower_name,
+		       rc);
+		goto out;
+	}
+	rc = buf->filldir(buf->dirent, name, name_size, offset, ino, d_type);
+	kfree(name);
+	if (rc >= 0)
+		buf->entries_written++;
+out:
+	return rc;
+}
+
+/**
+ * ecryptfs_readdir
+ * @file: The eCryptfs directory file
+ * @dirent: Directory entry handle
+ * @filldir: The filldir callback function
+ */
+static int ecryptfs_readdir(struct file *file, void *dirent, filldir_t filldir)
+{
+	int rc;
+	struct file *lower_file;
+	struct inode *inode;
+	struct ecryptfs_getdents_callback buf;
+
+	lower_file = ecryptfs_file_to_lower(file);
+	lower_file->f_pos = file->f_pos;
+	inode = file->f_path.dentry->d_inode;
+	memset(&buf, 0, sizeof(buf));
+	buf.dirent = dirent;
+	buf.dentry = file->f_path.dentry;
+	buf.filldir = filldir;
+	buf.filldir_called = 0;
+	buf.entries_written = 0;
+	rc = vfs_readdir(lower_file, ecryptfs_filldir, (void *)&buf);
+	file->f_pos = lower_file->f_pos;
+	if (rc < 0)
+		goto out;
+	if (buf.filldir_called && !buf.entries_written)
+		goto out;
+	if (rc >= 0)
+		fsstack_copy_attr_atime(inode,
+					lower_file->f_path.dentry->d_inode);
+out:
+	return rc;
+}
+
+static void ecryptfs_vma_close(struct vm_area_struct *vma)
+{
+	filemap_write_and_wait(vma->vm_file->f_mapping);
+}
+
+static const struct vm_operations_struct ecryptfs_file_vm_ops = {
+	.close		= ecryptfs_vma_close,
+	.fault		= filemap_fault,
+};
+
+static int ecryptfs_file_mmap(struct file *file, struct vm_area_struct *vma)
+{
+	int rc;
+
+	rc = generic_file_mmap(file, vma);
+	if (!rc)
+		vma->vm_ops = &ecryptfs_file_vm_ops;
+
+	return rc;
+}
+
+struct kmem_cache *ecryptfs_file_info_cache;
+
+/**
+ * ecryptfs_open
+ * @inode: inode speciying file to open
+ * @file: Structure to return filled in
+ *
+ * Opens the file specified by inode.
+ *
+ * Returns zero on success; non-zero otherwise
+ */
+static int ecryptfs_open(struct inode *inode, struct file *file)
+{
+	int rc = 0;
+	struct ecryptfs_crypt_stat *crypt_stat = NULL;
+	struct ecryptfs_mount_crypt_stat *mount_crypt_stat;
+	struct dentry *ecryptfs_dentry = file->f_path.dentry;
+	/* Private value of ecryptfs_dentry allocated in
+	 * ecryptfs_lookup() */
+	struct dentry *lower_dentry;
+	struct ecryptfs_file_info *file_info;
+
+	mount_crypt_stat = &ecryptfs_superblock_to_private(
+		ecryptfs_dentry->d_sb)->mount_crypt_stat;
+	if ((mount_crypt_stat->flags & ECRYPTFS_ENCRYPTED_VIEW_ENABLED)
+	    && ((file->f_flags & O_WRONLY) || (file->f_flags & O_RDWR)
+		|| (file->f_flags & O_CREAT) || (file->f_flags & O_TRUNC)
+		|| (file->f_flags & O_APPEND))) {
+		printk(KERN_WARNING "Mount has encrypted view enabled; "
+		       "files may only be read\n");
+		rc = -EPERM;
+		goto out;
+	}
+	/* Released in ecryptfs_release or end of function if failure */
+	file_info = kmem_cache_zalloc(ecryptfs_file_info_cache, GFP_KERNEL);
+	ecryptfs_set_file_private(file, file_info);
+	if (!file_info) {
+		ecryptfs_printk(KERN_ERR,
+				"Error attempting to allocate memory\n");
+		rc = -ENOMEM;
+		goto out;
+	}
+	lower_dentry = ecryptfs_dentry_to_lower(ecryptfs_dentry);
+	crypt_stat = &ecryptfs_inode_to_private(inode)->crypt_stat;
+	mutex_lock(&crypt_stat->cs_mutex);
+	if (!(crypt_stat->flags & ECRYPTFS_POLICY_APPLIED)) {
+		ecryptfs_printk(KERN_DEBUG, "Setting flags for stat...\n");
+		/* Policy code enabled in future release */
+		crypt_stat->flags |= (ECRYPTFS_POLICY_APPLIED
+				      | ECRYPTFS_ENCRYPTED);
+	}
+	mutex_unlock(&crypt_stat->cs_mutex);
+	rc = ecryptfs_get_lower_file(ecryptfs_dentry, inode);
+	if (rc) {
+		printk(KERN_ERR "%s: Error attempting to initialize "
+			"the lower file for the dentry with name "
+			"[%s]; rc = [%d]\n", __func__,
+			ecryptfs_dentry->d_name.name, rc);
+		goto out_free;
+	}
+	if ((ecryptfs_inode_to_private(inode)->lower_file->f_flags & O_ACCMODE)
+	    == O_RDONLY && (file->f_flags & O_ACCMODE) != O_RDONLY) {
+		rc = -EPERM;
+		printk(KERN_WARNING "%s: Lower file is RO; eCryptfs "
+		       "file must hence be opened RO\n", __func__);
+		goto out_put;
+	}
+	ecryptfs_set_file_lower(
+		file, ecryptfs_inode_to_private(inode)->lower_file);
+	if (S_ISDIR(ecryptfs_dentry->d_inode->i_mode)) {
+		ecryptfs_printk(KERN_DEBUG, "This is a directory\n");
+		mutex_lock(&crypt_stat->cs_mutex);
+		crypt_stat->flags &= ~(ECRYPTFS_ENCRYPTED);
+		mutex_unlock(&crypt_stat->cs_mutex);
+		rc = 0;
+		goto out;
+	}
+	mutex_lock(&crypt_stat->cs_mutex);
+	if (!(crypt_stat->flags & ECRYPTFS_POLICY_APPLIED)
+	    || !(crypt_stat->flags & ECRYPTFS_KEY_VALID)) {
+		rc = ecryptfs_read_metadata(ecryptfs_dentry);
+		if (rc) {
+			ecryptfs_printk(KERN_DEBUG,
+					"Valid headers not found\n");
+			if (!(mount_crypt_stat->flags
+			      & ECRYPTFS_PLAINTEXT_PASSTHROUGH_ENABLED)) {
+				rc = -EIO;
+				printk(KERN_WARNING "Either the lower file "
+				       "is not in a valid eCryptfs format, "
+				       "or the key could not be retrieved. "
+				       "Plaintext passthrough mode is not "
+				       "enabled; returning -EIO\n");
+				mutex_unlock(&crypt_stat->cs_mutex);
+				goto out_put;
+			}
+			rc = 0;
+			crypt_stat->flags &= ~(ECRYPTFS_I_SIZE_INITIALIZED
+					       | ECRYPTFS_ENCRYPTED);
+			mutex_unlock(&crypt_stat->cs_mutex);
+			goto out;
+		}
+	}
+	mutex_unlock(&crypt_stat->cs_mutex);
+	ecryptfs_printk(KERN_DEBUG, "inode w/ addr = [0x%p], i_ino = "
+			"[0x%.16lx] size: [0x%.16llx]\n", inode, inode->i_ino,
+			(unsigned long long)i_size_read(inode));
+	goto out;
+out_put:
+	ecryptfs_put_lower_file(inode);
+out_free:
+	kmem_cache_free(ecryptfs_file_info_cache,
+			ecryptfs_file_to_private(file));
+out:
+	return rc;
+}
+
+static int ecryptfs_flush(struct file *file, fl_owner_t td)
+{
+	return file->f_mode & FMODE_WRITE
+	       ? filemap_write_and_wait(file->f_mapping) : 0;
+}
+
+static int ecryptfs_release(struct inode *inode, struct file *file)
+{
+	ecryptfs_put_lower_file(inode);
+	kmem_cache_free(ecryptfs_file_info_cache,
+			ecryptfs_file_to_private(file));
+	return 0;
+}
+
+static int
+ecryptfs_fsync(struct file *file, loff_t start, loff_t end, int datasync)
+{
+	int rc = 0;
+
+	rc = generic_file_fsync(file, start, end, datasync);
+	if (rc)
+		goto out;
+	rc = vfs_fsync_range(ecryptfs_file_to_lower(file), start, end,
+			     datasync);
+out:
+	return rc;
+}
+
+static int ecryptfs_fasync(int fd, struct file *file, int flag)
+{
+	int rc = 0;
+	struct file *lower_file = NULL;
+
+	lower_file = ecryptfs_file_to_lower(file);
+	if (lower_file->f_op && lower_file->f_op->fasync)
+		rc = lower_file->f_op->fasync(fd, lower_file, flag);
+	return rc;
+}
+
+static long
+ecryptfs_unlocked_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
+{
+	struct file *lower_file = NULL;
+	long rc = -ENOTTY;
+
+	if (ecryptfs_file_to_private(file))
+		lower_file = ecryptfs_file_to_lower(file);
+	if (lower_file && lower_file->f_op && lower_file->f_op->unlocked_ioctl)
+		rc = lower_file->f_op->unlocked_ioctl(lower_file, cmd, arg);
+	return rc;
+}
+
+#ifdef CONFIG_COMPAT
+static long
+ecryptfs_compat_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
+{
+	struct file *lower_file = NULL;
+	long rc = -ENOIOCTLCMD;
+
+	if (ecryptfs_file_to_private(file))
+		lower_file = ecryptfs_file_to_lower(file);
+	if (lower_file && lower_file->f_op && lower_file->f_op->compat_ioctl)
+		rc = lower_file->f_op->compat_ioctl(lower_file, cmd, arg);
+	return rc;
+}
+#endif
+
+const struct file_operations ecryptfs_dir_fops = {
+	.readdir = ecryptfs_readdir,
+	.read = generic_read_dir,
+	.unlocked_ioctl = ecryptfs_unlocked_ioctl,
+#ifdef CONFIG_COMPAT
+	.compat_ioctl = ecryptfs_compat_ioctl,
+#endif
+	.open = ecryptfs_open,
+	.flush = ecryptfs_flush,
+	.release = ecryptfs_release,
+	.fsync = ecryptfs_fsync,
+	.fasync = ecryptfs_fasync,
+	.splice_read = generic_file_splice_read,
+	.llseek = default_llseek,
+};
+
+const struct file_operations ecryptfs_main_fops = {
+	.llseek = generic_file_llseek,
+	.read = do_sync_read,
+	.aio_read = ecryptfs_read_update_atime,
+	.write = do_sync_write,
+	.aio_write = generic_file_aio_write,
+	.readdir = ecryptfs_readdir,
+	.unlocked_ioctl = ecryptfs_unlocked_ioctl,
+#ifdef CONFIG_COMPAT
+	.compat_ioctl = ecryptfs_compat_ioctl,
+#endif
+	.mmap = ecryptfs_file_mmap,
+	.open = ecryptfs_open,
+	.flush = ecryptfs_flush,
+	.release = ecryptfs_release,
+	.fsync = ecryptfs_fsync,
+	.fasync = ecryptfs_fasync,
+	.splice_read = generic_file_splice_read,
+};