From patchwork Fri Jun 25 13:58:29 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Jeff Layton X-Patchwork-Id: 466881 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=-19.4 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_PASS,USER_AGENT_GIT autolearn=unavailable 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 C0251C48BC2 for ; Fri, 25 Jun 2021 13:59:17 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id AF29761973 for ; Fri, 25 Jun 2021 13:59:17 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S232222AbhFYOBh (ORCPT ); Fri, 25 Jun 2021 10:01:37 -0400 Received: from mail.kernel.org ([198.145.29.99]:34400 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S231936AbhFYOBL (ORCPT ); Fri, 25 Jun 2021 10:01:11 -0400 Received: by mail.kernel.org (Postfix) with ESMTPSA id 2069D6135A; Fri, 25 Jun 2021 13:58:50 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1624629530; bh=BPAlxU//3NdlDb/qT9mY4xu+ESoorpTIszsalhs71eM=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=h7+UskuT1CfiCXZ4a0405rWlrzoi9synljzqJx46bObBT/HyG3hjL2zZyeX4qoW0a iZ/zf/9iR4KCJa/2AKwQT5C8pa/P7MqWFRKFrQVDcVEIP9Eat5mSmidHZofUjYHzYQ +V/0HPHs90CkybymTH20927d2GkNf9hijWx+Ezoq3VyKX1PXQcgUVoc27NcXSZa5XA bKPDHKRGkAjsiJWoNuvUyTo9sxp7MO1qQdsxDFEOt5ltSVS2Uvo299GY+aEl/NN4UD vv84/xzgZW53l7S17McXnv30myXBf7C+3noUYbXQvW8t5DUGzrY04Vm4ei1av8xMYq NNZB8DWqj7obw== From: Jeff Layton To: ceph-devel@vger.kernel.org Cc: lhenriques@suse.de, xiubli@redhat.com, linux-fsdevel@vger.kernel.org, linux-fscrypt@vger.kernel.org, dhowells@redhat.com Subject: [RFC PATCH v7 19/24] ceph: add helpers for converting names for userland presentation Date: Fri, 25 Jun 2021 09:58:29 -0400 Message-Id: <20210625135834.12934-20-jlayton@kernel.org> X-Mailer: git-send-email 2.31.1 In-Reply-To: <20210625135834.12934-1-jlayton@kernel.org> References: <20210625135834.12934-1-jlayton@kernel.org> MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: ceph-devel@vger.kernel.org Signed-off-by: Jeff Layton --- fs/ceph/crypto.c | 76 ++++++++++++++++++++++++++++++++++++++++++++++++ fs/ceph/crypto.h | 42 ++++++++++++++++++++++++++ 2 files changed, 118 insertions(+) diff --git a/fs/ceph/crypto.c b/fs/ceph/crypto.c index 675d41fd2eb0..55c7f45c062b 100644 --- a/fs/ceph/crypto.c +++ b/fs/ceph/crypto.c @@ -128,3 +128,79 @@ void ceph_fscrypt_as_ctx_to_req(struct ceph_mds_request *req, struct ceph_acl_se { swap(req->r_fscrypt_auth, as->fscrypt_auth); } + +/** + * 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 60cc92f25fed..879f95972e41 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 struct ceph_fs_client; struct ceph_acl_sec_ctx; @@ -50,6 +58,22 @@ int ceph_fscrypt_prepare_context(struct inode *dir, struct inode *inode, struct ceph_acl_sec_ctx *as); void ceph_fscrypt_as_ctx_to_req(struct ceph_mds_request *req, 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) @@ -72,6 +96,24 @@ static inline void ceph_fscrypt_as_ctx_to_req(struct ceph_mds_request *req, struct ceph_acl_sec_ctx *as_ctx) { } + +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