From mboxrd@z Thu Jan 1 00:00:00 1970 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=-18.2 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,URIBL_BLOCKED,USER_AGENT_SANE_2 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 E8E5BC43216 for ; Wed, 28 Jul 2021 11:38:43 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id C511B60E9B for ; Wed, 28 Jul 2021 11:38:43 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S234651AbhG1Lin (ORCPT ); Wed, 28 Jul 2021 07:38:43 -0400 Received: from mail.kernel.org ([198.145.29.99]:39070 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S232530AbhG1Lim (ORCPT ); Wed, 28 Jul 2021 07:38:42 -0400 Received: by mail.kernel.org (Postfix) with ESMTPSA id 6960160F0F; Wed, 28 Jul 2021 11:38:38 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1627472320; bh=Ed2M1byFas5CO43HSA9Lq5GBOUwZSeoYtuJfi8LoAV4=; h=Date:From:To:Cc:Subject:In-Reply-To:References:From; b=KDURb2ySdRAfjvo5j+UgIFVDMo8Jf/RpF6G2uDWbhGYHKOiaPzSfoiEh0yaplfv0g kEAG1j/cpuKFNqw77gKIo9+BVgANKIN5GTqO3CMqxeCraVRgK7/1dgN3QWZPxlTtmx 3o2qz7sOYjDQLfZdA5F4fbGw3/jh3X05P/59fLuxh/YDRW8FDWyQqW9vny+B6V8n4i kzeLN83EfE39JDVQGiPotb7KnIHjTAt2SG9S/eBmWmfdleRDuPQnHI4G14CEBs/SYC xi7nJ/usEEG1N4rzkWnq0L4oUoTBMUz1Fkp7xjA8VUpzVaRPmKlme36grvz2SqELAT l10Ls+6ecP5ZQ== Date: Wed, 28 Jul 2021 13:38:35 +0200 From: Mauro Carvalho Chehab To: Roberto Sassu Cc: , , , , , , Subject: Re: [RFC][PATCH v2 03/12] diglim: Objects Message-ID: <20210728133835.2e55e0eb@coco.lan> In-Reply-To: <20210726163700.2092768-4-roberto.sassu@huawei.com> References: <20210726163700.2092768-1-roberto.sassu@huawei.com> <20210726163700.2092768-4-roberto.sassu@huawei.com> X-Mailer: Claws Mail 4.0.0 (GTK+ 3.24.30; x86_64-redhat-linux-gnu) MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Em Mon, 26 Jul 2021 18:36:51 +0200 Roberto Sassu escreveu: > Define the objects to manage digest lists: > > - digest_list_item: a digest list loaded into the kernel; > - digest_list_item_ref: a reference to a digest list; > - digest_item: a digest of a digest list. > > Also define some helpers for the objects. More information can be found in > Documentation/security/diglim/implementation.rst. > > Signed-off-by: Roberto Sassu > --- > .../security/diglim/implementation.rst | 105 ++++++++++++++ > MAINTAINERS | 1 + > security/integrity/diglim/diglim.h | 134 ++++++++++++++++++ > 3 files changed, 240 insertions(+) > create mode 100644 security/integrity/diglim/diglim.h > > diff --git a/Documentation/security/diglim/implementation.rst b/Documentation/security/diglim/implementation.rst > index 59a180b3bb3f..6002049612a1 100644 > --- a/Documentation/security/diglim/implementation.rst > +++ b/Documentation/security/diglim/implementation.rst > @@ -95,3 +95,108 @@ with digest lists: > > - ``DIGEST_LIST_ADD``: the digest list is being added; > - ``DIGEST_LIST_DEL``: the digest list is being deleted. > + > + > +Objects > +------- > + > +This section defines the objects to manage digest lists. > + > +.. kernel-doc:: security/integrity/diglim/diglim.h > + > +They are represented in the following class diagram: > + > +:: > + > + digest_offset, > + hdr_offset---------------+ > + | > + | > + +------------------+ | +----------------------+ > + | digest_list_item |--- N:1 ---| digest_list_item_ref | > + +------------------+ +----------------------+ > + | > + 1:N > + | > + +-------------+ > + | digest_item | > + +-------------+ > + > +A ``digest_list_item`` is associated to one or multiple > +``digest_list_item_ref``, one for each digest it contains. However, > +a ``digest_list_item_ref`` is associated to only one ``digest_list_item``, > +as it represents a single location within a specific digest list. > + > +Given that a ``digest_list_item_ref`` represents a single location, it is > +associated to only one ``digest_item``. However, a ``digest_item`` can have > +multiple references (as it might appears multiple times within the same > +digest list or in different digest lists, if it is duplicated). > + > +All digest list references are stored for a given digest, so that a query > +result can include the OR of the modifiers and actions of each referenced > +digest list. > + > +The relationship between the described objects can be graphically > +represented as: > + > +:: Just merge "::" at the previous line (everywhere). > + > + Hash table +-------------+ +-------------+ > + PARSER +-----+ | digest_item | | digest_item | > + FILE | key |-->| |-->...-->| | > + METADATA +-----+ |ref0|...|refN| |ref0|...|refN| > + +-------------+ +-------------+ > + ref0: | | refN: > + digest_offset | +-----------------------------+ digest_offset > + hdr_offset | | hdr_offset > + | | > + V V > + +--------------------+ > + | digest_list_item | > + | | > + | size, buf, actions | > + +--------------------+ > + ^ > + | > + Hash table +-------------+ +-------------+ > + DIGEST_LIST +-----+ |ref0 | |ref0 | > + | key |-->| |-->...-->| | > + +-----+ | digest_item | | digest_item | > + +-------------+ +-------------+ > + > +The reference for the digest of the digest list differs from the references > +for the other digest types. ``digest_offset`` and ``hdr_offset`` are set to > +zero, so that the digest of the digest list is retrieved from the > +``digest_list_item`` structure directly (see ``get_digest()`` below). > + > +Finally, this section defines useful helpers to access a digest or the > +header the digest belongs to. For example: > + > +:: > + > + static inline struct compact_list_hdr *get_hdr( > + struct digest_list_item *digest_list, > + loff_t hdr_offset) I would write this to avoid ending a line with an open parenthesis. You could, for instance, write it as: static inline struct compact_list_hdr * get_hdr(struct digest_list_item *digest_list, off_t hdr_offset) if you also want to avoid to have a line bigger than 80 columns. > + { > + return (struct compact_list_hdr *)(digest_list->buf + hdr_offset); > + } > + > +the header can be obtained by summing the address of the digest list buffer > +in the ``digest_list_item`` structure with ``hdr_offset``. > + > +Similarly: > + > +:: > + > + static inline u8 *get_digest(struct digest_list_item *digest_list, > + loff_t digest_offset, loff_t hdr_offset) > + { > + /* Digest list digest is stored in a different place. */ > + if (!digest_offset) > + return digest_list->digest; > + return digest_list->buf + digest_offset; > + } > + > +the digest can be obtained by summing the address of the digest list buffer > +with ``digest_offset`` (except for the digest lists, where the digest is > +stored in the ``digest`` field of the ``digest_list_item`` structure). > diff --git a/MAINTAINERS b/MAINTAINERS > index f61f5239468a..f7592d41367d 100644 > --- a/MAINTAINERS > +++ b/MAINTAINERS > @@ -5462,6 +5462,7 @@ F: Documentation/security/diglim/implementation.rst > F: Documentation/security/diglim/index.rst > F: Documentation/security/diglim/introduction.rst > F: include/uapi/linux/diglim.h > +F: security/integrity/diglim/diglim.h > > DIOLAN U2C-12 I2C DRIVER > M: Guenter Roeck > diff --git a/security/integrity/diglim/diglim.h b/security/integrity/diglim/diglim.h > new file mode 100644 > index 000000000000..578253d7e1d1 > --- /dev/null > +++ b/security/integrity/diglim/diglim.h > @@ -0,0 +1,134 @@ > +/* SPDX-License-Identifier: GPL-2.0 */ > +/* > + * Copyright (C) 2005,2006,2007,2008 IBM Corporation > + * Copyright (C) 2017-2021 Huawei Technologies Duesseldorf GmbH > + * > + * Author: Roberto Sassu > + * > + * Definitions only used inside DIGLIM. > + */ > + > +#ifndef __DIGLIM_INTERNAL_H > +#define __DIGLIM_INTERNAL_H > + > +#include > +#include > +#include > +#include > +#include > +#include > +#include > +#include > +#include > +#include > + > +#define MAX_DIGEST_SIZE 64 > +#define HASH_BITS 10 > +#define DIGLIM_HTABLE_SIZE (1 << HASH_BITS) > + > +/** > + * struct digest_list_item - a digest list loaded into the kernel > + * > + * @size: size of the digest list buffer > + * @buf: digest list buffer > + * @digest: digest of the digest list > + * @label: label used to identify the digest list (e.g. file name) > + * @actions: actions performed on the digest list > + * @algo: digest algorithm > + */ > +struct digest_list_item { > + loff_t size; > + u8 *buf; > + u8 digest[64]; > + const char *label; > + u8 actions; > + enum hash_algo algo; > +}; > + > +/** > + * struct digest_list_item_ref - a reference to a digest list > + * > + * @list: linked list pointers > + * @digest_list: pointer to struct digest_list_item > + * @digest_offset: offset of the digest in the referenced digest list > + * @hdr_offset: offset of the header the digest refers to in the digest list > + */ > +struct digest_list_item_ref { > + struct list_head list; > + struct digest_list_item *digest_list; > + u32 digest_offset; > + u32 hdr_offset; > +}; > + > +/** > + * struct digest_item - a digest of a digest list > + * > + * @hnext: pointers of the hash table > + * @refs: linked list of struct digest_list_item_ref > + */ > +struct digest_item { > + struct hlist_node hnext; > + struct list_head refs; > +}; > + > +struct h_table { > + unsigned long len; > + struct hlist_head queue[DIGLIM_HTABLE_SIZE]; > +}; > + > +static inline unsigned int hash_key(u8 *digest) > +{ > + return (digest[0] | digest[1] << 8) % DIGLIM_HTABLE_SIZE; > +} > + > +static inline struct compact_list_hdr *get_hdr( > + struct digest_list_item *digest_list, > + loff_t hdr_offset) Same here with regards to open parenthesis. > +{ > + return (struct compact_list_hdr *)(digest_list->buf + hdr_offset); > +} > + > +static inline enum hash_algo get_algo(struct digest_list_item *digest_list, > + loff_t digest_offset, loff_t hdr_offset) > +{ > + /* Digest list digest algorithm is stored in a different place. */ > + if (!digest_offset) > + return digest_list->algo; > + > + return get_hdr(digest_list, hdr_offset)->algo; > +} > + > +static inline u8 *get_digest(struct digest_list_item *digest_list, > + loff_t digest_offset, loff_t hdr_offset) > +{ > + /* Digest list digest is stored in a different place. */ > + if (!digest_offset) > + return digest_list->digest; > + > + return digest_list->buf + digest_offset; > +} > + > +static inline struct compact_list_hdr *get_hdr_ref( > + struct digest_list_item_ref *ref) > +{ > + return get_hdr(ref->digest_list, ref->hdr_offset); > +} > + > +static inline enum hash_algo get_algo_ref(struct digest_list_item_ref *ref) > +{ > + /* Digest list digest algorithm is stored in a different place. */ > + if (!ref->digest_offset) > + return ref->digest_list->algo; > + > + return get_hdr_ref(ref)->algo; > +} > + > +static inline u8 *get_digest_ref(struct digest_list_item_ref *ref) > +{ > + /* Digest list digest is stored in a different place. */ > + if (!ref->digest_offset) > + return ref->digest_list->digest; > + > + return ref->digest_list->buf + ref->digest_offset; > +} I would also document the above static inline functions and struct h_table. > +#endif /*__DIGLIM_INTERNAL_H*/ Thanks, Mauro