diff options
Diffstat (limited to 'fs/ecryptfs/mmap.c')
| -rw-r--r-- | fs/ecryptfs/mmap.c | 74 |
1 files changed, 73 insertions, 1 deletions
diff --git a/fs/ecryptfs/mmap.c b/fs/ecryptfs/mmap.c index ba3650d03c48..3386014becc6 100644 --- a/fs/ecryptfs/mmap.c +++ b/fs/ecryptfs/mmap.c @@ -260,6 +260,33 @@ out: ClearPageUptodate(page); return rc; } +/** + * Header Extent: + * Octets 0-7: Unencrypted file size (big-endian) + * Octets 8-15: eCryptfs special marker + * Octets 16-19: Flags + * Octet 16: File format version number (between 0 and 255) + * Octets 17-18: Reserved + * Octet 19: Bit 1 (lsb): Reserved + * Bit 2: Encrypted? + * Bits 3-8: Reserved + * Octets 20-23: Header extent size (big-endian) + * Octets 24-25: Number of header extents at front of file + * (big-endian) + * Octet 26: Begin RFC 2440 authentication token packet set + */ +static void set_header_info(char *page_virt, + struct ecryptfs_crypt_stat *crypt_stat) +{ + size_t written; + int save_num_header_extents_at_front = + crypt_stat->num_header_extents_at_front; + + crypt_stat->num_header_extents_at_front = 1; + ecryptfs_write_header_metadata(page_virt + 20, crypt_stat, &written); + crypt_stat->num_header_extents_at_front = + save_num_header_extents_at_front; +} /** * ecryptfs_readpage @@ -289,10 +316,55 @@ static int ecryptfs_readpage(struct file *file, struct page *page) "[%d]\n", rc); goto out; } + } else if (crypt_stat->flags & ECRYPTFS_VIEW_AS_ENCRYPTED) { + if (crypt_stat->flags & ECRYPTFS_METADATA_IN_XATTR) { + int num_pages_in_header_region = + (crypt_stat->header_extent_size + / PAGE_CACHE_SIZE); + + if (page->index < num_pages_in_header_region) { + char *page_virt; + + page_virt = (char *)kmap(page); + if (!page_virt) { + rc = -ENOMEM; + printk(KERN_ERR "Error mapping page\n"); + goto out; + } + memset(page_virt, 0, PAGE_CACHE_SIZE); + if (page->index == 0) { + rc = ecryptfs_read_xattr_region( + page_virt, file->f_path.dentry); + set_header_info(page_virt, crypt_stat); + } + kunmap(page); + if (rc) { + printk(KERN_ERR "Error reading xattr " + "region\n"); + goto out; + } + } else { + rc = ecryptfs_do_readpage( + file, page, + (page->index + - num_pages_in_header_region)); + if (rc) { + printk(KERN_ERR "Error reading page; " + "rc = [%d]\n", rc); + goto out; + } + } + } else { + rc = ecryptfs_do_readpage(file, page, page->index); + if (rc) { + printk(KERN_ERR "Error reading page; rc = " + "[%d]\n", rc); + goto out; + } + } } else { rc = ecryptfs_decrypt_page(file, page); if (rc) { - ecryptfs_printk(KERN_ERR, "Error decrypting page; " "rc = [%d]\n", rc); goto out; |