diff options
| -rw-r--r-- | fs/ecryptfs/inode.c | 100 |
1 files changed, 52 insertions, 48 deletions
diff --git a/fs/ecryptfs/inode.c b/fs/ecryptfs/inode.c index ddbd096c7406..605f514f3b47 100644 --- a/fs/ecryptfs/inode.c +++ b/fs/ecryptfs/inode.c @@ -648,38 +648,17 @@ out_lock: return rc; } -static int -ecryptfs_readlink(struct dentry *dentry, char __user *buf, int bufsiz) +static int ecryptfs_readlink_lower(struct dentry *dentry, char **buf, + size_t *bufsiz) { + struct dentry *lower_dentry = ecryptfs_dentry_to_lower(dentry); char *lower_buf; - size_t lower_bufsiz; - struct dentry *lower_dentry; - struct ecryptfs_mount_crypt_stat *mount_crypt_stat; - char *plaintext_name; - size_t plaintext_name_size; + size_t lower_bufsiz = PATH_MAX; mm_segment_t old_fs; int rc; - lower_dentry = ecryptfs_dentry_to_lower(dentry); - if (!lower_dentry->d_inode->i_op->readlink) { - rc = -EINVAL; - goto out; - } - mount_crypt_stat = &ecryptfs_superblock_to_private( - dentry->d_sb)->mount_crypt_stat; - /* - * If the lower filename is encrypted, it will result in a significantly - * longer name. If needed, truncate the name after decode and decrypt. - */ - if (mount_crypt_stat->flags & ECRYPTFS_GLOBAL_ENCRYPT_FILENAMES) - lower_bufsiz = PATH_MAX; - else - lower_bufsiz = bufsiz; - /* Released in this function */ lower_buf = kmalloc(lower_bufsiz, GFP_KERNEL); - if (lower_buf == NULL) { - printk(KERN_ERR "%s: Out of memory whilst attempting to " - "kmalloc [%zd] bytes\n", __func__, lower_bufsiz); + if (!lower_buf) { rc = -ENOMEM; goto out; } @@ -689,29 +668,31 @@ ecryptfs_readlink(struct dentry *dentry, char __user *buf, int bufsiz) (char __user *)lower_buf, lower_bufsiz); set_fs(old_fs); - if (rc >= 0) { - rc = ecryptfs_decode_and_decrypt_filename(&plaintext_name, - &plaintext_name_size, - dentry, lower_buf, - rc); - if (rc) { - printk(KERN_ERR "%s: Error attempting to decode and " - "decrypt filename; rc = [%d]\n", __func__, - rc); - goto out_free_lower_buf; - } - /* Check for bufsiz <= 0 done in sys_readlinkat() */ - rc = copy_to_user(buf, plaintext_name, - min((size_t) bufsiz, plaintext_name_size)); - if (rc) - rc = -EFAULT; - else - rc = plaintext_name_size; - kfree(plaintext_name); - fsstack_copy_attr_atime(dentry->d_inode, lower_dentry->d_inode); - } -out_free_lower_buf: + if (rc < 0) + goto out; + lower_bufsiz = rc; + rc = ecryptfs_decode_and_decrypt_filename(buf, bufsiz, dentry, + lower_buf, lower_bufsiz); +out: kfree(lower_buf); + return rc; +} + +static int +ecryptfs_readlink(struct dentry *dentry, char __user *buf, int bufsiz) +{ + char *kbuf; + size_t kbufsiz, copied; + int rc; + + rc = ecryptfs_readlink_lower(dentry, &kbuf, &kbufsiz); + if (rc) + goto out; + copied = min_t(size_t, bufsiz, kbufsiz); + rc = copy_to_user(buf, kbuf, copied) ? -EFAULT : copied; + kfree(kbuf); + fsstack_copy_attr_atime(dentry->d_inode, + ecryptfs_dentry_to_lower(dentry)->d_inode); out: return rc; } @@ -1016,6 +997,28 @@ out: return rc; } +int ecryptfs_getattr_link(struct vfsmount *mnt, struct dentry *dentry, + struct kstat *stat) +{ + struct ecryptfs_mount_crypt_stat *mount_crypt_stat; + int rc = 0; + + mount_crypt_stat = &ecryptfs_superblock_to_private( + dentry->d_sb)->mount_crypt_stat; + generic_fillattr(dentry->d_inode, stat); + if (mount_crypt_stat->flags & ECRYPTFS_GLOBAL_ENCRYPT_FILENAMES) { + char *target; + size_t targetsiz; + + rc = ecryptfs_readlink_lower(dentry, &target, &targetsiz); + if (!rc) { + kfree(target); + stat->size = targetsiz; + } + } + return rc; +} + int ecryptfs_getattr(struct vfsmount *mnt, struct dentry *dentry, struct kstat *stat) { @@ -1133,6 +1136,7 @@ const struct inode_operations ecryptfs_symlink_iops = { .put_link = ecryptfs_put_link, .permission = ecryptfs_permission, .setattr = ecryptfs_setattr, + .getattr = ecryptfs_getattr_link, .setxattr = ecryptfs_setxattr, .getxattr = ecryptfs_getxattr, .listxattr = ecryptfs_listxattr, |