From patchwork Wed Apr 12 11:09:22 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Patchwork-Submitter: Xiubo Li X-Patchwork-Id: 13208853 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 056FEC77B6E for ; Wed, 12 Apr 2023 11:17:21 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S230162AbjDLLRT (ORCPT ); Wed, 12 Apr 2023 07:17:19 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:40460 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S230157AbjDLLRK (ORCPT ); Wed, 12 Apr 2023 07:17:10 -0400 Received: from us-smtp-delivery-124.mimecast.com (us-smtp-delivery-124.mimecast.com [170.10.129.124]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id A835C7ABB for ; Wed, 12 Apr 2023 04:16:00 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1681298097; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=3BAbATd1xJgJPUynNeS30f3WMP5FoE3ulAIRL1cQX/8=; b=Gr4s/2xCS9aLxxUVxG5y8oafpNZ/69aBkEPiI8hS6++TDy4KA1eMadfpAACi2TXTS2gKh9 veVNgkF5Gl86wDZOqm0H8fP3RICZxqedYPPMvTVrO3Q2lk6jfGFSb7SrnX/8zGQTHsB/cg As6yz9MnPqeCimc9gYhpjU2lhTyIH0U= Received: from mimecast-mx02.redhat.com (mx3-rdu2.redhat.com [66.187.233.73]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id us-mta-81-96UOSXVNM8m0lpuE5sY8Yw-1; Wed, 12 Apr 2023 07:14:54 -0400 X-MC-Unique: 96UOSXVNM8m0lpuE5sY8Yw-1 Received: from smtp.corp.redhat.com (int-mx08.intmail.prod.int.rdu2.redhat.com [10.11.54.8]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx02.redhat.com (Postfix) with ESMTPS id A88C93813F3E; Wed, 12 Apr 2023 11:14:53 +0000 (UTC) Received: from li-a71a4dcc-35d1-11b2-a85c-951838863c8d.ibm.com.com (ovpn-12-131.pek2.redhat.com [10.72.12.131]) by smtp.corp.redhat.com (Postfix) with ESMTP id EFF4BC15BB8; Wed, 12 Apr 2023 11:14:49 +0000 (UTC) From: xiubli@redhat.com To: idryomov@gmail.com, ceph-devel@vger.kernel.org Cc: jlayton@kernel.org, vshankar@redhat.com, mchangir@redhat.com, lhenriques@suse.de, Xiubo Li Subject: [PATCH v18 63/71] ceph: add support for handling encrypted snapshot names Date: Wed, 12 Apr 2023 19:09:22 +0800 Message-Id: <20230412110930.176835-64-xiubli@redhat.com> In-Reply-To: <20230412110930.176835-1-xiubli@redhat.com> References: <20230412110930.176835-1-xiubli@redhat.com> MIME-Version: 1.0 X-Scanned-By: MIMEDefang 3.1 on 10.11.54.8 Precedence: bulk List-ID: X-Mailing-List: ceph-devel@vger.kernel.org From: Luís Henriques When creating a snapshot, the .snap directories for every subdirectory will show the snapshot name in the "long format": # mkdir .snap/my-snap # ls my-dir/.snap/ _my-snap_1099511627782 Encrypted snapshots will need to be able to handle these snapshot names by encrypting/decrypting only the snapshot part of the string ('my-snap'). Also, since the MDS prevents snapshot names to be bigger than 240 characters it is necessary to adapt CEPH_NOHASH_NAME_MAX to accommodate this extra limitation. Tested-by: Luís Henriques Tested-by: Venky Shankar Signed-off-by: Luís Henriques Reviewed-by: Xiubo Li Signed-off-by: Jeff Layton --- fs/ceph/crypto.c | 192 ++++++++++++++++++++++++++++++++++++++++------- fs/ceph/crypto.h | 4 +- 2 files changed, 166 insertions(+), 30 deletions(-) diff --git a/fs/ceph/crypto.c b/fs/ceph/crypto.c index 35e292045e9d..5bdd779217d8 100644 --- a/fs/ceph/crypto.c +++ b/fs/ceph/crypto.c @@ -189,16 +189,100 @@ void ceph_fscrypt_as_ctx_to_req(struct ceph_mds_request *req, struct ceph_acl_se swap(req->r_fscrypt_auth, as->fscrypt_auth); } -int ceph_encode_encrypted_dname(const struct inode *parent, struct qstr *d_name, char *buf) +/* + * User-created snapshots can't start with '_'. Snapshots that start with this + * character are special (hint: there aren't real snapshots) and use the + * following format: + * + * __ + * + * where: + * - - the real snapshot name that may need to be decrypted, + * - - the inode number (in decimal) for the actual snapshot + * + * This function parses these snapshot names and returns the inode + * . 'name_len' will also bet set with the + * length. + */ +static struct inode *parse_longname(const struct inode *parent, const char *name, + int *name_len) +{ + struct inode *dir = NULL; + struct ceph_vino vino = { .snap = CEPH_NOSNAP }; + char *inode_number; + char *name_end; + int orig_len = *name_len; + int ret = -EIO; + + /* Skip initial '_' */ + name++; + name_end = strrchr(name, '_'); + if (!name_end) { + dout("Failed to parse long snapshot name: %s\n", name); + return ERR_PTR(-EIO); + } + *name_len = (name_end - name); + if (*name_len <= 0) { + pr_err("Failed to parse long snapshot name\n"); + return ERR_PTR(-EIO); + } + + /* Get the inode number */ + inode_number = kmemdup_nul(name_end + 1, + orig_len - *name_len - 2, + GFP_KERNEL); + if (!inode_number) + return ERR_PTR(-ENOMEM); + ret = kstrtou64(inode_number, 10, &vino.ino); + if (ret) { + dout("Failed to parse inode number: %s\n", name); + dir = ERR_PTR(ret); + goto out; + } + + /* And finally the inode */ + dir = ceph_find_inode(parent->i_sb, vino); + if (!dir) { + /* This can happen if we're not mounting cephfs on the root */ + dir = ceph_get_inode(parent->i_sb, vino, NULL); + if (!dir) + dir = ERR_PTR(-ENOENT); + } + if (IS_ERR(dir)) + dout("Can't find inode %s (%s)\n", inode_number, name); + +out: + kfree(inode_number); + return dir; +} + +int ceph_encode_encrypted_dname(struct inode *parent, struct qstr *d_name, char *buf) { + struct inode *dir = parent; + struct qstr iname; u32 len; + int name_len; int elen; int ret; - u8 *cryptbuf; + u8 *cryptbuf = NULL; + + iname.name = d_name->name; + name_len = d_name->len; + + /* Handle the special case of snapshot names that start with '_' */ + if ((ceph_snap(dir) == CEPH_SNAPDIR) && (name_len > 0) && + (iname.name[0] == '_')) { + dir = parse_longname(parent, iname.name, &name_len); + if (IS_ERR(dir)) + return PTR_ERR(dir); + iname.name++; /* skip initial '_' */ + } + iname.len = name_len; - if (!fscrypt_has_encryption_key(parent)) { + if (!fscrypt_has_encryption_key(dir)) { memcpy(buf, d_name->name, d_name->len); - return d_name->len; + elen = d_name->len; + goto out; } /* @@ -207,18 +291,22 @@ int ceph_encode_encrypted_dname(const struct inode *parent, struct qstr *d_name, * * See: fscrypt_setup_filename */ - if (!fscrypt_fname_encrypted_size(parent, d_name->len, NAME_MAX, &len)) - return -ENAMETOOLONG; + if (!fscrypt_fname_encrypted_size(dir, iname.len, NAME_MAX, &len)) { + elen = -ENAMETOOLONG; + goto out; + } /* Allocate a buffer appropriate to hold the result */ cryptbuf = kmalloc(len > CEPH_NOHASH_NAME_MAX ? NAME_MAX : len, GFP_KERNEL); - if (!cryptbuf) - return -ENOMEM; + if (!cryptbuf) { + elen = -ENOMEM; + goto out; + } - ret = fscrypt_fname_encrypt(parent, d_name, cryptbuf, len); + ret = fscrypt_fname_encrypt(dir, &iname, cryptbuf, len); if (ret) { - kfree(cryptbuf); - return ret; + elen = ret; + goto out; } /* hash the end if the name is long enough */ @@ -234,12 +322,30 @@ int ceph_encode_encrypted_dname(const struct inode *parent, struct qstr *d_name, /* base64 encode the encrypted name */ elen = ceph_base64_encode(cryptbuf, len, buf); - kfree(cryptbuf); dout("base64-encoded ciphertext name = %.*s\n", elen, buf); + + /* To understand the 240 limit, see CEPH_NOHASH_NAME_MAX comments */ + WARN_ON(elen > 240); + if ((elen > 0) && (dir != parent)) { + char tmp_buf[NAME_MAX]; + + elen = snprintf(tmp_buf, sizeof(tmp_buf), "_%.*s_%ld", + elen, buf, dir->i_ino); + memcpy(buf, tmp_buf, elen); + } + +out: + kfree(cryptbuf); + if (dir != parent) { + if ((dir->i_state & I_NEW)) + discard_new_inode(dir); + else + iput(dir); + } return elen; } -int ceph_encode_encrypted_fname(const struct inode *parent, struct dentry *dentry, char *buf) +int ceph_encode_encrypted_fname(struct inode *parent, struct dentry *dentry, char *buf) { WARN_ON_ONCE(!fscrypt_has_encryption_key(parent)); @@ -264,29 +370,42 @@ int ceph_encode_encrypted_fname(const struct inode *parent, struct dentry *dentr int ceph_fname_to_usr(const struct ceph_fname *fname, struct fscrypt_str *tname, struct fscrypt_str *oname, bool *is_nokey) { - int ret; + struct inode *dir = fname->dir; 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; - } + char *name = fname->name; + int name_len = fname->name_len; + int ret; /* Sanity check that the resulting name will fit in the buffer */ if (fname->name_len > NAME_MAX || fname->ctext_len > NAME_MAX) return -EIO; - ret = ceph_fscrypt_prepare_readdir(fname->dir); - if (ret < 0) - return ret; + /* Handle the special case of snapshot names that start with '_' */ + if ((ceph_snap(dir) == CEPH_SNAPDIR) && (name_len > 0) && + (name[0] == '_')) { + dir = parse_longname(dir, name, &name_len); + if (IS_ERR(dir)) + return PTR_ERR(dir); + name++; /* skip initial '_' */ + } + + if (!IS_ENCRYPTED(dir)) { + oname->name = fname->name; + oname->len = fname->name_len; + ret = 0; + goto out_inode; + } + + ret = ceph_fscrypt_prepare_readdir(dir); + if (ret) + goto out_inode; /* * 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)) { + if (!fscrypt_has_encryption_key(dir)) { if (fname->no_copy) oname->name = fname->name; else @@ -294,7 +413,8 @@ int ceph_fname_to_usr(const struct ceph_fname *fname, struct fscrypt_str *tname, oname->len = fname->name_len; if (is_nokey) *is_nokey = true; - return 0; + ret = 0; + goto out_inode; } if (fname->ctext_len == 0) { @@ -303,11 +423,11 @@ int ceph_fname_to_usr(const struct ceph_fname *fname, struct fscrypt_str *tname, if (!tname) { ret = fscrypt_fname_alloc_buffer(NAME_MAX, &_tname); if (ret) - return ret; + goto out_inode; tname = &_tname; } - declen = ceph_base64_decode(fname->name, fname->name_len, tname->name); + declen = ceph_base64_decode(name, name_len, tname->name); if (declen <= 0) { ret = -EIO; goto out; @@ -319,9 +439,25 @@ int ceph_fname_to_usr(const struct ceph_fname *fname, struct fscrypt_str *tname, iname.len = fname->ctext_len; } - ret = fscrypt_fname_disk_to_usr(fname->dir, 0, 0, &iname, oname); + ret = fscrypt_fname_disk_to_usr(dir, 0, 0, &iname, oname); + if (!ret && (dir != fname->dir)) { + char tmp_buf[CEPH_BASE64_CHARS(NAME_MAX)]; + + name_len = snprintf(tmp_buf, sizeof(tmp_buf), "_%.*s_%ld", + oname->len, oname->name, dir->i_ino); + memcpy(oname->name, tmp_buf, name_len); + oname->len = name_len; + } + out: fscrypt_fname_free_buffer(&_tname); +out_inode: + if ((dir != fname->dir) && !IS_ERR(dir)) { + if ((dir->i_state & I_NEW)) + discard_new_inode(dir); + else + iput(dir); + } return ret; } diff --git a/fs/ceph/crypto.h b/fs/ceph/crypto.h index 0d0343906d29..d0e88f6d254d 100644 --- a/fs/ceph/crypto.h +++ b/fs/ceph/crypto.h @@ -101,8 +101,8 @@ 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); void ceph_fscrypt_as_ctx_to_req(struct ceph_mds_request *req, struct ceph_acl_sec_ctx *as); -int ceph_encode_encrypted_dname(const struct inode *parent, struct qstr *d_name, char *buf); -int ceph_encode_encrypted_fname(const struct inode *parent, struct dentry *dentry, char *buf); +int ceph_encode_encrypted_dname(struct inode *parent, struct qstr *d_name, char *buf); +int ceph_encode_encrypted_fname(struct inode *parent, struct dentry *dentry, char *buf); static inline int ceph_fname_alloc_buffer(struct inode *parent, struct fscrypt_str *fname) {