From d7cdc5febf9f2664755002c3a2f84bd348389fe9 Mon Sep 17 00:00:00 2001 From: Michael Halcrow Date: Tue, 16 Oct 2007 01:28:10 -0700 Subject: [PATCH] eCryptfs: update metadata read/write functions Update the metadata read/write functions and grow_file() to use the read_write.c routines. Do not open another lower file; use the persistent lower file instead. Provide a separate function for crypto.c::ecryptfs_read_xattr_region() to get to the lower xattr without having to go through the eCryptfs getxattr. Signed-off-by: Michael Halcrow Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- fs/ecryptfs/crypto.c | 127 ++++++++++++++++------------------ fs/ecryptfs/ecryptfs_kernel.h | 15 ++-- fs/ecryptfs/file.c | 2 +- fs/ecryptfs/inode.c | 101 ++++++++++++--------------- fs/ecryptfs/mmap.c | 2 +- 5 files changed, 114 insertions(+), 133 deletions(-) diff --git a/fs/ecryptfs/crypto.c b/fs/ecryptfs/crypto.c index 7f788ea5da..55110ffe9e 100644 --- a/fs/ecryptfs/crypto.c +++ b/fs/ecryptfs/crypto.c @@ -1342,21 +1342,28 @@ out: return rc; } -int ecryptfs_read_and_validate_header_region(char *data, struct dentry *dentry, - struct vfsmount *mnt) +int ecryptfs_read_and_validate_header_region(char *data, + struct inode *ecryptfs_inode) { + struct ecryptfs_crypt_stat *crypt_stat = + &(ecryptfs_inode_to_private(ecryptfs_inode)->crypt_stat); int rc; - rc = ecryptfs_read_header_region(data, dentry, mnt); - if (rc) + rc = ecryptfs_read_lower(data, 0, crypt_stat->extent_size, + ecryptfs_inode); + if (rc) { + printk(KERN_ERR "%s: Error reading header region; rc = [%d]\n", + __FUNCTION__, rc); goto out; - if (!contains_ecryptfs_marker(data + ECRYPTFS_FILE_SIZE_BYTES)) + } + if (!contains_ecryptfs_marker(data + ECRYPTFS_FILE_SIZE_BYTES)) { rc = -EINVAL; + ecryptfs_printk(KERN_DEBUG, "Valid marker not found\n"); + } out: return rc; } - void ecryptfs_write_header_metadata(char *virt, struct ecryptfs_crypt_stat *crypt_stat, @@ -1441,24 +1448,19 @@ static int ecryptfs_write_headers_virt(char *page_virt, size_t *size, static int ecryptfs_write_metadata_to_contents(struct ecryptfs_crypt_stat *crypt_stat, - struct file *lower_file, char *page_virt) + struct dentry *ecryptfs_dentry, + char *page_virt) { - mm_segment_t oldfs; int current_header_page; int header_pages; - ssize_t size; - int rc = 0; + int rc; - lower_file->f_pos = 0; - oldfs = get_fs(); - set_fs(get_ds()); - size = vfs_write(lower_file, (char __user *)page_virt, PAGE_CACHE_SIZE, - &lower_file->f_pos); - if (size < 0) { - rc = (int)size; - printk(KERN_ERR "Error attempting to write lower page; " - "rc = [%d]\n", rc); - set_fs(oldfs); + rc = ecryptfs_write_lower(ecryptfs_dentry->d_inode, page_virt, + 0, PAGE_CACHE_SIZE); + if (rc) { + printk(KERN_ERR "%s: Error attempting to write header " + "information to lower file; rc = [%d]\n", __FUNCTION__, + rc); goto out; } header_pages = ((crypt_stat->extent_size @@ -1467,18 +1469,19 @@ ecryptfs_write_metadata_to_contents(struct ecryptfs_crypt_stat *crypt_stat, memset(page_virt, 0, PAGE_CACHE_SIZE); current_header_page = 1; while (current_header_page < header_pages) { - size = vfs_write(lower_file, (char __user *)page_virt, - PAGE_CACHE_SIZE, &lower_file->f_pos); - if (size < 0) { - rc = (int)size; - printk(KERN_ERR "Error attempting to write lower page; " - "rc = [%d]\n", rc); - set_fs(oldfs); + loff_t offset; + + offset = (current_header_page << PAGE_CACHE_SHIFT); + if ((rc = ecryptfs_write_lower(ecryptfs_dentry->d_inode, + page_virt, offset, + PAGE_CACHE_SIZE))) { + printk(KERN_ERR "%s: Error attempting to write header " + "information to lower file; rc = [%d]\n", + __FUNCTION__, rc); goto out; } current_header_page++; } - set_fs(oldfs); out: return rc; } @@ -1498,7 +1501,6 @@ ecryptfs_write_metadata_to_xattr(struct dentry *ecryptfs_dentry, /** * ecryptfs_write_metadata * @ecryptfs_dentry: The eCryptfs dentry - * @lower_file: The lower file struct, which was returned from dentry_open * * Write the file headers out. This will likely involve a userspace * callout, in which the session key is encrypted with one or more @@ -1506,22 +1508,21 @@ ecryptfs_write_metadata_to_xattr(struct dentry *ecryptfs_dentry, * retrieved via a prompt. Exactly what happens at this point should * be policy-dependent. * + * TODO: Support header information spanning multiple pages + * * Returns zero on success; non-zero on error */ -int ecryptfs_write_metadata(struct dentry *ecryptfs_dentry, - struct file *lower_file) +int ecryptfs_write_metadata(struct dentry *ecryptfs_dentry) { - struct ecryptfs_crypt_stat *crypt_stat; + struct ecryptfs_crypt_stat *crypt_stat = + &ecryptfs_inode_to_private(ecryptfs_dentry->d_inode)->crypt_stat; char *page_virt; - size_t size; + size_t size = 0; int rc = 0; - crypt_stat = &ecryptfs_inode_to_private( - ecryptfs_dentry->d_inode)->crypt_stat; if (likely(crypt_stat->flags & ECRYPTFS_ENCRYPTED)) { if (!(crypt_stat->flags & ECRYPTFS_KEY_VALID)) { - ecryptfs_printk(KERN_DEBUG, "Key is " - "invalid; bailing out\n"); + printk(KERN_ERR "Key is invalid; bailing out\n"); rc = -EINVAL; goto out; } @@ -1550,7 +1551,8 @@ int ecryptfs_write_metadata(struct dentry *ecryptfs_dentry, crypt_stat, page_virt, size); else - rc = ecryptfs_write_metadata_to_contents(crypt_stat, lower_file, + rc = ecryptfs_write_metadata_to_contents(crypt_stat, + ecryptfs_dentry, page_virt); if (rc) { printk(KERN_ERR "Error writing metadata out to lower file; " @@ -1678,15 +1680,17 @@ out: * * Returns zero on success; non-zero on error */ -int ecryptfs_read_xattr_region(char *page_virt, struct dentry *ecryptfs_dentry) +int ecryptfs_read_xattr_region(char *page_virt, struct inode *ecryptfs_inode) { + struct dentry *lower_dentry = + ecryptfs_inode_to_private(ecryptfs_inode)->lower_file->f_dentry; ssize_t size; int rc = 0; - size = ecryptfs_getxattr(ecryptfs_dentry, ECRYPTFS_XATTR_NAME, - page_virt, ECRYPTFS_DEFAULT_EXTENT_SIZE); + size = ecryptfs_getxattr_lower(lower_dentry, ECRYPTFS_XATTR_NAME, + page_virt, ECRYPTFS_DEFAULT_EXTENT_SIZE); if (size < 0) { - printk(KERN_DEBUG "Error attempting to read the [%s] " + printk(KERN_ERR "Error attempting to read the [%s] " "xattr from the lower file; return value = [%zd]\n", ECRYPTFS_XATTR_NAME, size); rc = -EINVAL; @@ -1701,7 +1705,7 @@ int ecryptfs_read_and_validate_xattr_region(char *page_virt, { int rc; - rc = ecryptfs_read_xattr_region(page_virt, ecryptfs_dentry); + rc = ecryptfs_read_xattr_region(page_virt, ecryptfs_dentry->d_inode); if (rc) goto out; if (!contains_ecryptfs_marker(page_virt + ECRYPTFS_FILE_SIZE_BYTES)) { @@ -1715,8 +1719,6 @@ out: /** * ecryptfs_read_metadata - * @ecryptfs_dentry: The eCryptfs dentry - * @lower_file: The lower file from which to read the metadata * * Common entry point for reading file metadata. From here, we could * retrieve the header information from the header region of the file, @@ -1727,15 +1729,13 @@ out: * * Returns zero if valid headers found and parsed; non-zero otherwise */ -int ecryptfs_read_metadata(struct dentry *ecryptfs_dentry, - struct file *lower_file) +int ecryptfs_read_metadata(struct dentry *ecryptfs_dentry) { int rc = 0; char *page_virt = NULL; - mm_segment_t oldfs; - ssize_t bytes_read; + struct inode *ecryptfs_inode = ecryptfs_dentry->d_inode; struct ecryptfs_crypt_stat *crypt_stat = - &ecryptfs_inode_to_private(ecryptfs_dentry->d_inode)->crypt_stat; + &ecryptfs_inode_to_private(ecryptfs_inode)->crypt_stat; struct ecryptfs_mount_crypt_stat *mount_crypt_stat = &ecryptfs_superblock_to_private( ecryptfs_dentry->d_sb)->mount_crypt_stat; @@ -1746,27 +1746,18 @@ int ecryptfs_read_metadata(struct dentry *ecryptfs_dentry, page_virt = kmem_cache_alloc(ecryptfs_header_cache_1, GFP_USER); if (!page_virt) { rc = -ENOMEM; - ecryptfs_printk(KERN_ERR, "Unable to allocate page_virt\n"); + printk(KERN_ERR "%s: Unable to allocate page_virt\n", + __FUNCTION__); goto out; } - lower_file->f_pos = 0; - oldfs = get_fs(); - set_fs(get_ds()); - bytes_read = lower_file->f_op->read(lower_file, - (char __user *)page_virt, - ECRYPTFS_DEFAULT_EXTENT_SIZE, - &lower_file->f_pos); - set_fs(oldfs); - if (bytes_read != ECRYPTFS_DEFAULT_EXTENT_SIZE) { - rc = -EINVAL; - goto out; - } - rc = ecryptfs_read_headers_virt(page_virt, crypt_stat, - ecryptfs_dentry, - ECRYPTFS_VALIDATE_HEADER_SIZE); + rc = ecryptfs_read_lower(page_virt, 0, crypt_stat->extent_size, + ecryptfs_inode); + if (!rc) + rc = ecryptfs_read_headers_virt(page_virt, crypt_stat, + ecryptfs_dentry, + ECRYPTFS_VALIDATE_HEADER_SIZE); if (rc) { - rc = ecryptfs_read_xattr_region(page_virt, - ecryptfs_dentry); + rc = ecryptfs_read_xattr_region(page_virt, ecryptfs_inode); if (rc) { printk(KERN_DEBUG "Valid eCryptfs headers not found in " "file header region or xattr region\n"); diff --git a/fs/ecryptfs/ecryptfs_kernel.h b/fs/ecryptfs/ecryptfs_kernel.h index 65f7ddfd4d..3e52b42fba 100644 --- a/fs/ecryptfs/ecryptfs_kernel.h +++ b/fs/ecryptfs/ecryptfs_kernel.h @@ -570,13 +570,11 @@ int ecryptfs_writepage_and_release_lower_page(struct page *lower_page, struct writeback_control *wbc); int ecryptfs_encrypt_page(struct page *page); int ecryptfs_decrypt_page(struct page *page); -int ecryptfs_write_metadata(struct dentry *ecryptfs_dentry, - struct file *lower_file); -int ecryptfs_read_metadata(struct dentry *ecryptfs_dentry, - struct file *lower_file); +int ecryptfs_write_metadata(struct dentry *ecryptfs_dentry); +int ecryptfs_read_metadata(struct dentry *ecryptfs_dentry); int ecryptfs_new_file_context(struct dentry *ecryptfs_dentry); -int ecryptfs_read_and_validate_header_region(char *data, struct dentry *dentry, - struct vfsmount *mnt); +int ecryptfs_read_and_validate_header_region(char *data, + struct inode *ecryptfs_inode); int ecryptfs_read_and_validate_xattr_region(char *page_virt, struct dentry *ecryptfs_dentry); u16 ecryptfs_code_for_cipher_string(struct ecryptfs_crypt_stat *crypt_stat); @@ -599,10 +597,13 @@ int ecryptfs_open_lower_file(struct file **lower_file, int ecryptfs_close_lower_file(struct file *lower_file); ssize_t ecryptfs_getxattr(struct dentry *dentry, const char *name, void *value, size_t size); +ssize_t +ecryptfs_getxattr_lower(struct dentry *lower_dentry, const char *name, + void *value, size_t size); int ecryptfs_setxattr(struct dentry *dentry, const char *name, const void *value, size_t size, int flags); -int ecryptfs_read_xattr_region(char *page_virt, struct dentry *ecryptfs_dentry); +int ecryptfs_read_xattr_region(char *page_virt, struct inode *ecryptfs_inode); int ecryptfs_process_helo(unsigned int transport, uid_t uid, pid_t pid); int ecryptfs_process_quit(uid_t uid, pid_t pid); int ecryptfs_process_response(struct ecryptfs_message *msg, uid_t uid, diff --git a/fs/ecryptfs/file.c b/fs/ecryptfs/file.c index 59c846d29a..df70bfa176 100644 --- a/fs/ecryptfs/file.c +++ b/fs/ecryptfs/file.c @@ -248,7 +248,7 @@ static int ecryptfs_open(struct inode *inode, struct file *file) 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, lower_file); + rc = ecryptfs_read_metadata(ecryptfs_dentry); if (rc) { ecryptfs_printk(KERN_DEBUG, "Valid headers not found\n"); diff --git a/fs/ecryptfs/inode.c b/fs/ecryptfs/inode.c index c746b5d8a3..a29dc31965 100644 --- a/fs/ecryptfs/inode.c +++ b/fs/ecryptfs/inode.c @@ -153,37 +153,30 @@ out: /** * grow_file - * @ecryptfs_dentry: the ecryptfs dentry - * @lower_file: The lower file - * @inode: The ecryptfs inode - * @lower_inode: The lower inode + * @ecryptfs_dentry: the eCryptfs dentry * * This is the code which will grow the file to its correct size. */ -static int grow_file(struct dentry *ecryptfs_dentry, struct file *lower_file, - struct inode *inode, struct inode *lower_inode) +static int grow_file(struct dentry *ecryptfs_dentry) { - int rc = 0; + struct inode *ecryptfs_inode = ecryptfs_dentry->d_inode; struct file fake_file; struct ecryptfs_file_info tmp_file_info; + char zero_virt[] = { 0x00 }; + int rc = 0; memset(&fake_file, 0, sizeof(fake_file)); fake_file.f_path.dentry = ecryptfs_dentry; memset(&tmp_file_info, 0, sizeof(tmp_file_info)); ecryptfs_set_file_private(&fake_file, &tmp_file_info); - ecryptfs_set_file_lower(&fake_file, lower_file); - rc = ecryptfs_fill_zeros(&fake_file, 1); - if (rc) { - ecryptfs_inode_to_private(inode)->crypt_stat.flags |= - ECRYPTFS_SECURITY_WARNING; - ecryptfs_printk(KERN_WARNING, "Error attempting to fill zeros " - "in file; rc = [%d]\n", rc); - goto out; - } - i_size_write(inode, 0); - rc = ecryptfs_write_inode_size_to_metadata(inode); - ecryptfs_inode_to_private(inode)->crypt_stat.flags |= ECRYPTFS_NEW_FILE; -out: + ecryptfs_set_file_lower( + &fake_file, + ecryptfs_inode_to_private(ecryptfs_inode)->lower_file); + rc = ecryptfs_write(&fake_file, zero_virt, 0, 1); + i_size_write(ecryptfs_inode, 0); + rc = ecryptfs_write_inode_size_to_metadata(ecryptfs_inode); + ecryptfs_inode_to_private(ecryptfs_inode)->crypt_stat.flags |= + ECRYPTFS_NEW_FILE; return rc; } @@ -197,53 +190,31 @@ out: */ static int ecryptfs_initialize_file(struct dentry *ecryptfs_dentry) { + struct ecryptfs_crypt_stat *crypt_stat = + &ecryptfs_inode_to_private(ecryptfs_dentry->d_inode)->crypt_stat; int rc = 0; - int lower_flags; - struct ecryptfs_crypt_stat *crypt_stat; - struct dentry *lower_dentry; - struct file *lower_file; - struct inode *inode, *lower_inode; - struct vfsmount *lower_mnt; - lower_dentry = ecryptfs_dentry_to_lower(ecryptfs_dentry); - ecryptfs_printk(KERN_DEBUG, "lower_dentry->d_name.name = [%s]\n", - lower_dentry->d_name.name); - inode = ecryptfs_dentry->d_inode; - crypt_stat = &ecryptfs_inode_to_private(inode)->crypt_stat; - lower_flags = ((O_CREAT | O_TRUNC) & O_ACCMODE) | O_RDWR; - lower_mnt = ecryptfs_dentry_to_lower_mnt(ecryptfs_dentry); - /* Corresponding fput() at end of this function */ - rc = ecryptfs_open_lower_file(&lower_file, lower_dentry, lower_mnt, - lower_flags); - if (rc) { - ecryptfs_printk(KERN_ERR, - "Error opening dentry; rc = [%i]\n", rc); - goto out; - } - lower_inode = lower_dentry->d_inode; if (S_ISDIR(ecryptfs_dentry->d_inode->i_mode)) { ecryptfs_printk(KERN_DEBUG, "This is a directory\n"); crypt_stat->flags &= ~(ECRYPTFS_ENCRYPTED); - goto out_fput; + goto out; } crypt_stat->flags |= ECRYPTFS_NEW_FILE; ecryptfs_printk(KERN_DEBUG, "Initializing crypto context\n"); rc = ecryptfs_new_file_context(ecryptfs_dentry); if (rc) { - ecryptfs_printk(KERN_DEBUG, "Error creating new file " - "context\n"); - goto out_fput; + ecryptfs_printk(KERN_ERR, "Error creating new file " + "context; rc = [%d]\n", rc); + goto out; } - rc = ecryptfs_write_metadata(ecryptfs_dentry, lower_file); + rc = ecryptfs_write_metadata(ecryptfs_dentry); if (rc) { - ecryptfs_printk(KERN_DEBUG, "Error writing headers\n"); - goto out_fput; + printk(KERN_ERR "Error writing headers; rc = [%d]\n", rc); + goto out; } - rc = grow_file(ecryptfs_dentry, lower_file, inode, lower_inode); -out_fput: - rc = ecryptfs_close_lower_file(lower_file); + rc = grow_file(ecryptfs_dentry); if (rc) - printk(KERN_ERR "Error closing lower_file\n"); + printk(KERN_ERR "Error growing file; rc = [%d]\n", rc); out: return rc; } @@ -389,8 +360,8 @@ static struct dentry *ecryptfs_lookup(struct inode *dir, struct dentry *dentry, crypt_stat = &ecryptfs_inode_to_private(dentry->d_inode)->crypt_stat; if (!(crypt_stat->flags & ECRYPTFS_POLICY_APPLIED)) ecryptfs_set_default_sizes(crypt_stat); - rc = ecryptfs_read_and_validate_header_region(page_virt, lower_dentry, - nd->mnt); + rc = ecryptfs_read_and_validate_header_region(page_virt, + dentry->d_inode); if (rc) { rc = ecryptfs_read_and_validate_xattr_region(page_virt, dentry); if (rc) { @@ -941,7 +912,7 @@ static int ecryptfs_setattr(struct dentry *dentry, struct iattr *ia) } mount_crypt_stat = &ecryptfs_superblock_to_private( dentry->d_sb)->mount_crypt_stat; - rc = ecryptfs_read_metadata(dentry, lower_file); + rc = ecryptfs_read_metadata(dentry); if (rc) { if (!(mount_crypt_stat->flags & ECRYPTFS_PLAINTEXT_PASSTHROUGH_ENABLED)) { @@ -1002,6 +973,24 @@ out: return rc; } +ssize_t +ecryptfs_getxattr_lower(struct dentry *lower_dentry, const char *name, + void *value, size_t size) +{ + int rc = 0; + + if (!lower_dentry->d_inode->i_op->getxattr) { + rc = -ENOSYS; + goto out; + } + mutex_lock(&lower_dentry->d_inode->i_mutex); + rc = lower_dentry->d_inode->i_op->getxattr(lower_dentry, name, value, + size); + mutex_unlock(&lower_dentry->d_inode->i_mutex); +out: + return rc; +} + ssize_t ecryptfs_getxattr(struct dentry *dentry, const char *name, void *value, size_t size) diff --git a/fs/ecryptfs/mmap.c b/fs/ecryptfs/mmap.c index 9b621108d5..60e635eddc 100644 --- a/fs/ecryptfs/mmap.c +++ b/fs/ecryptfs/mmap.c @@ -307,7 +307,7 @@ static int ecryptfs_readpage(struct file *file, struct page *page) memset(page_virt, 0, PAGE_CACHE_SIZE); if (page->index == 0) { rc = ecryptfs_read_xattr_region( - page_virt, file->f_path.dentry); + page_virt, page->mapping->host); set_header_info(page_virt, crypt_stat); } kunmap_atomic(page_virt, KM_USER0); -- 2.39.5