From patchwork Tue Apr 13 17:50:47 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Jeff Layton X-Patchwork-Id: 12201109 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-19.0 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_NONE,URIBL_BLOCKED,USER_AGENT_GIT autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 35E9CC43600 for ; Tue, 13 Apr 2021 17:51:17 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 0F99461244 for ; Tue, 13 Apr 2021 17:51:17 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1347457AbhDMRve (ORCPT ); Tue, 13 Apr 2021 13:51:34 -0400 Received: from mail.kernel.org ([198.145.29.99]:44928 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1347418AbhDMRvX (ORCPT ); Tue, 13 Apr 2021 13:51:23 -0400 Received: by mail.kernel.org (Postfix) with ESMTPSA id 7B8A961176; Tue, 13 Apr 2021 17:51:03 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1618336263; bh=9ePaL4ydgwOOCxoRZDZ5GRS8iw/4x4RIaGn8mzERagQ=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=bYzSvwQ7hgezSxne3uUn9/0fj5PqW3wW3hSjn1v8kr6YQkG4DLSsS7A+l59pKkVXY KDSo5KWgHuqwDquhuOWzM5d2r7rtKOCa8k7JynJM4/ukFQvUKb9ljBlf9mmSZzsdZt PX2QfkHF7RTWrnH/JvmnsLBO2kk9IF6jMkvkY0o5W6IqDkb1AtuwRSn5D4S5p8Awtc hWv102pR6GDx7cMd3gX1dr6YnVvmrP65HriCQ4QzgBVkhorKluOcm3PE25iuvGLUt5 GFz7wsmqTPylvBY44bMWTs3jStx851O3DQNCaXIqjAvpWNWSF0UAYIUZAD0w8D2hgq ReymfrCbwKSog== From: Jeff Layton To: ceph-devel@vger.kernel.org Cc: linux-fsdevel@vger.kernel.org, linux-fscrypt@vger.kernel.org, lhenriques@suse.de Subject: [RFC PATCH v6 15/20] ceph: add helpers for converting names for userland presentation Date: Tue, 13 Apr 2021 13:50:47 -0400 Message-Id: <20210413175052.163865-16-jlayton@kernel.org> X-Mailer: git-send-email 2.30.2 In-Reply-To: <20210413175052.163865-1-jlayton@kernel.org> References: <20210413175052.163865-1-jlayton@kernel.org> MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: linux-fscrypt@vger.kernel.org Signed-off-by: Jeff Layton --- fs/ceph/crypto.c | 76 ++++++++++++++++++++++++++++++++++++++++++++++++ fs/ceph/crypto.h | 41 ++++++++++++++++++++++++++ 2 files changed, 117 insertions(+) diff --git a/fs/ceph/crypto.c b/fs/ceph/crypto.c index f037a4939026..9fed68f37629 100644 --- a/fs/ceph/crypto.c +++ b/fs/ceph/crypto.c @@ -107,3 +107,79 @@ int ceph_fscrypt_prepare_context(struct inode *dir, struct inode *inode, ceph_pagelist_release(pagelist); return ret; } + +/** + * ceph_fname_to_usr - convert a filename for userland presentation + * @fname: ceph_fname to be converted + * @tname: temporary name buffer to use for conversion (may be NULL) + * @oname: where converted name should be placed + * @is_nokey: set to true if key wasn't available during conversion (may be NULL) + * + * Given a filename (usually from the MDS), format it for presentation to + * userland. If @parent is not encrypted, just pass it back as-is. + * + * Otherwise, base64 decode the string, and then ask fscrypt to format it + * for userland presentation. + * + * Returns 0 on success or negative error code on error. + */ +int ceph_fname_to_usr(const struct ceph_fname *fname, struct fscrypt_str *tname, + struct fscrypt_str *oname, bool *is_nokey) +{ + int ret; + struct fscrypt_str _tname = FSTR_INIT(NULL, 0); + struct fscrypt_str iname; + + if (!IS_ENCRYPTED(fname->dir)) { + oname->name = fname->name; + oname->len = fname->name_len; + return 0; + } + + /* Sanity check that the resulting name will fit in the buffer */ + if (fname->name_len > FSCRYPT_BASE64_CHARS(NAME_MAX)) + return -EIO; + + ret = __fscrypt_prepare_readdir(fname->dir); + if (ret) + return ret; + + /* + * Use the raw dentry name as sent by the MDS instead of + * generating a nokey name via fscrypt. + */ + if (!fscrypt_has_encryption_key(fname->dir)) { + memcpy(oname->name, fname->name, fname->name_len); + oname->len = fname->name_len; + if (is_nokey) + *is_nokey = true; + return 0; + } + + if (fname->ctext_len == 0) { + int declen; + + if (!tname) { + ret = fscrypt_fname_alloc_buffer(NAME_MAX, &_tname); + if (ret) + return ret; + tname = &_tname; + } + + declen = fscrypt_base64_decode(fname->name, fname->name_len, tname->name); + if (declen <= 0) { + ret = -EIO; + goto out; + } + iname.name = tname->name; + iname.len = declen; + } else { + iname.name = fname->ctext; + iname.len = fname->ctext_len; + } + + ret = fscrypt_fname_disk_to_usr(fname->dir, 0, 0, &iname, oname); +out: + fscrypt_fname_free_buffer(&_tname); + return ret; +} diff --git a/fs/ceph/crypto.h b/fs/ceph/crypto.h index 331b9c8da7fb..5a3fb68eb814 100644 --- a/fs/ceph/crypto.h +++ b/fs/ceph/crypto.h @@ -11,6 +11,14 @@ #define CEPH_XATTR_NAME_ENCRYPTION_CONTEXT "encryption.ctx" +struct ceph_fname { + struct inode *dir; + char *name; // b64 encoded, possibly hashed + unsigned char *ctext; // binary crypttext (if any) + u32 name_len; // length of name buffer + u32 ctext_len; // length of crypttext +}; + #ifdef CONFIG_FS_ENCRYPTION /* @@ -37,6 +45,22 @@ static inline void ceph_fscrypt_free_dummy_policy(struct ceph_fs_client *fsc) int ceph_fscrypt_prepare_context(struct inode *dir, struct inode *inode, struct ceph_acl_sec_ctx *as); +static inline int ceph_fname_alloc_buffer(struct inode *parent, struct fscrypt_str *fname) +{ + if (!IS_ENCRYPTED(parent)) + return 0; + return fscrypt_fname_alloc_buffer(NAME_MAX, fname); +} + +static inline void ceph_fname_free_buffer(struct inode *parent, struct fscrypt_str *fname) +{ + if (IS_ENCRYPTED(parent)) + fscrypt_fname_free_buffer(fname); +} + +int ceph_fname_to_usr(const struct ceph_fname *fname, struct fscrypt_str *tname, + struct fscrypt_str *oname, bool *is_nokey); + #else /* CONFIG_FS_ENCRYPTION */ static inline void ceph_fscrypt_set_ops(struct super_block *sb) @@ -55,6 +79,23 @@ static inline int ceph_fscrypt_prepare_context(struct inode *dir, struct inode * return 0; } +static inline int ceph_fname_alloc_buffer(struct inode *parent, struct fscrypt_str *fname) +{ + return 0; +} + +static inline void ceph_fname_free_buffer(struct inode *parent, struct fscrypt_str *fname) +{ +} + +static inline int ceph_fname_to_usr(const struct ceph_fname *fname, struct fscrypt_str *tname, + struct fscrypt_str *oname, bool *is_nokey) +{ + oname->name = fname->name; + oname->len = fname->name_len; + return 0; +} + #endif /* CONFIG_FS_ENCRYPTION */ #endif