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=-16.8 required=3.0 tests=BAYES_00,DKIM_INVALID, DKIM_SIGNED,INCLUDES_CR_TRAILER,INCLUDES_PATCH,MAILING_LIST_MULTI, SPF_HELO_NONE,SPF_PASS,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 66AA1C433E0 for ; Fri, 15 Jan 2021 18:19:50 +0000 (UTC) Received: from lists.sourceforge.net (lists.sourceforge.net [216.105.38.7]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id 186BA23A7C; Fri, 15 Jan 2021 18:19:49 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 186BA23A7C Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=kernel.org Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=linux-f2fs-devel-bounces@lists.sourceforge.net Received: from [127.0.0.1] (helo=sfs-ml-4.v29.lw.sourceforge.com) by sfs-ml-4.v29.lw.sourceforge.com with esmtp (Exim 4.90_1) (envelope-from ) id 1l0ThN-0004vI-2d; Fri, 15 Jan 2021 18:19:49 +0000 Received: from [172.30.20.202] (helo=mx.sourceforge.net) by sfs-ml-4.v29.lw.sourceforge.com with esmtps (TLSv1.2:ECDHE-RSA-AES256-GCM-SHA384:256) (Exim 4.90_1) (envelope-from ) id 1l0ThL-0004vB-CH for linux-f2fs-devel@lists.sourceforge.net; Fri, 15 Jan 2021 18:19:47 +0000 DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=sourceforge.net; s=x; h=Content-Transfer-Encoding:MIME-Version:References: In-Reply-To:Message-Id:Date:Subject:Cc:To:From:Sender:Reply-To:Content-Type: Content-ID:Content-Description:Resent-Date:Resent-From:Resent-Sender: Resent-To:Resent-Cc:Resent-Message-ID:List-Id:List-Help:List-Unsubscribe: List-Subscribe:List-Post:List-Owner:List-Archive; bh=a3xetPG2Ch80XToOkQwrjb9u1w9gk7g/viw8i3bX9LA=; b=MEnMbLErwTiZNNooauhUZfsD7E iKtk5zC62sSbFB1BqQq9XGyfB7ztTln/VV4EY3naUvM3xvNLl8FaOaWU7/9t/uPC3WX3EDi0IMm5C 3uBYHrA/lSEe5h2AEggRtRvnuQZ/5nDjN0XqL9RqvQQMye2Uk+g0nbm1Zi2R8f06fJ3Y=; DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=sf.net; s=x ; h=Content-Transfer-Encoding:MIME-Version:References:In-Reply-To:Message-Id: Date:Subject:Cc:To:From:Sender:Reply-To:Content-Type:Content-ID: Content-Description:Resent-Date:Resent-From:Resent-Sender:Resent-To:Resent-Cc :Resent-Message-ID:List-Id:List-Help:List-Unsubscribe:List-Subscribe: List-Post:List-Owner:List-Archive; bh=a3xetPG2Ch80XToOkQwrjb9u1w9gk7g/viw8i3bX9LA=; b=b9cP+zGg4mg0zWeCA/Eb0I89tv VUezzBL5AUnGPyTrlvh7ruWcc8PIeDrYWaMPtwgkYbKV2VooUNMCWYi4Geg/QU+GoSOuhgsJKQFWT YivrTrzp/Dpcx/Mq5kmvDibZc/V+0T0/lNc7WmyPe3ChFycb+mscKkUu9fYX4uJj5Nws=; Received: from mail.kernel.org ([198.145.29.99]) by sfi-mx-1.v28.lw.sourceforge.com with esmtps (TLSv1.2:ECDHE-RSA-AES256-GCM-SHA384:256) (Exim 4.92.2) id 1l0ThD-00GNJq-CO for linux-f2fs-devel@lists.sourceforge.net; Fri, 15 Jan 2021 18:19:47 +0000 Received: by mail.kernel.org (Postfix) with ESMTPSA id BC9D823B03; Fri, 15 Jan 2021 18:19:33 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1610734774; bh=gsd3qneQDJcEAWvK+26tVqknLPQ+kerh+7FxEp9mAvE=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=ChoMe9ho9PcGemgjTm2q12Bj6EiXXCXdgfNIY+rHRqA2eBl8pv5YGPzLH11U8uEPJ OVkenwHQw+fuoDIPVVZNU+2lQrYyiNpBkW7rLCxqwVzIHOoYoFRCVHL8aNS4+z1CB5 znTDLZehtUNRd6hUeqedT7eTp+XFuTC2m2VXmxUUBSruXBOzN8evT9crnLa2WhWbBd 481fhP5zXOwBby4Zs1ap2AsJDJJ3DB3SffV+wBcIssdTGz1LJ7aEyu2vjOMbFhxlkt tRt5FlgHNmQASBoSX82i8xkbTOzc0ndw/uIQp6f9p85nnPd74rc2Fp/6WOkHjWmbuE OratH61jn8whg== From: Eric Biggers To: linux-fscrypt@vger.kernel.org Date: Fri, 15 Jan 2021 10:18:17 -0800 Message-Id: <20210115181819.34732-5-ebiggers@kernel.org> X-Mailer: git-send-email 2.30.0 In-Reply-To: <20210115181819.34732-1-ebiggers@kernel.org> References: <20210115181819.34732-1-ebiggers@kernel.org> MIME-Version: 1.0 X-Headers-End: 1l0ThD-00GNJq-CO Subject: [f2fs-dev] [PATCH 4/6] fs-verity: support reading Merkle tree with ioctl X-BeenThere: linux-f2fs-devel@lists.sourceforge.net X-Mailman-Version: 2.1.21 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: Theodore Ts'o , linux-api@vger.kernel.org, linux-f2fs-devel@lists.sourceforge.net, linux-fsdevel@vger.kernel.org, Jaegeuk Kim , linux-ext4@vger.kernel.org, Victor Hsieh Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Errors-To: linux-f2fs-devel-bounces@lists.sourceforge.net From: Eric Biggers Add support for FS_VERITY_METADATA_TYPE_MERKLE_TREE to FS_IOC_READ_VERITY_METADATA. This allows a userspace server program to retrieve the Merkle tree of a verity file for serving to a client which implements fs-verity compatible verification. See the patch which introduced FS_IOC_READ_VERITY_METADATA for more details. This has been tested using a new xfstest which calls this ioctl via a new subcommand for the 'fsverity' program from fsverity-utils. Signed-off-by: Eric Biggers --- Documentation/filesystems/fsverity.rst | 10 +++- fs/verity/read_metadata.c | 70 ++++++++++++++++++++++++++ include/uapi/linux/fsverity.h | 2 + 3 files changed, 81 insertions(+), 1 deletion(-) diff --git a/Documentation/filesystems/fsverity.rst b/Documentation/filesystems/fsverity.rst index 9ef7a7de60085..50b47a6d9ea11 100644 --- a/Documentation/filesystems/fsverity.rst +++ b/Documentation/filesystems/fsverity.rst @@ -234,6 +234,8 @@ need this ioctl. This ioctl takes in a pointer to the following structure:: + #define FS_VERITY_METADATA_TYPE_MERKLE_TREE 1 + struct fsverity_read_metadata_arg { __u64 metadata_type; __u64 offset; @@ -242,7 +244,13 @@ This ioctl takes in a pointer to the following structure:: __u64 __reserved; }; -``metadata_type`` specifies the type of metadata to read. +``metadata_type`` specifies the type of metadata to read: + +- ``FS_VERITY_METADATA_TYPE_MERKLE_TREE`` reads the blocks of the + Merkle tree. The blocks are returned in order from the root level + to the leaf level. Within each level, the blocks are returned in + the same order that their hashes are themselves hashed. + See `Merkle tree`_ for more information. The semantics are similar to those of ``pread()``. ``offset`` specifies the offset in bytes into the metadata item to read from, and diff --git a/fs/verity/read_metadata.c b/fs/verity/read_metadata.c index 43be990fd53e4..0f8ad2991cf90 100644 --- a/fs/verity/read_metadata.c +++ b/fs/verity/read_metadata.c @@ -7,8 +7,75 @@ #include "fsverity_private.h" +#include +#include +#include #include +static int fsverity_read_merkle_tree(struct inode *inode, + const struct fsverity_info *vi, + void __user *buf, u64 offset, int length) +{ + const struct fsverity_operations *vops = inode->i_sb->s_vop; + u64 end_offset; + unsigned int offs_in_page; + pgoff_t index, last_index; + int retval = 0; + int err = 0; + + end_offset = min(offset + length, vi->tree_params.tree_size); + if (offset >= end_offset) + return 0; + offs_in_page = offset_in_page(offset); + last_index = (end_offset - 1) >> PAGE_SHIFT; + + /* + * Iterate through each Merkle tree page in the requested range and copy + * the requested portion to userspace. Note that the Merkle tree block + * size isn't important here, as we are returning a byte stream; i.e., + * we can just work with pages even if the tree block size != PAGE_SIZE. + */ + for (index = offset >> PAGE_SHIFT; index <= last_index; index++) { + unsigned long num_ra_pages = + min_t(unsigned long, last_index - index + 1, + inode->i_sb->s_bdi->io_pages); + unsigned int bytes_to_copy = min_t(u64, end_offset - offset, + PAGE_SIZE - offs_in_page); + struct page *page; + const void *virt; + + page = vops->read_merkle_tree_page(inode, index, num_ra_pages); + if (IS_ERR(page)) { + err = PTR_ERR(page); + fsverity_err(inode, + "Error %d reading Merkle tree page %lu", + err, index); + break; + } + + virt = kmap(page); + if (copy_to_user(buf, virt + offs_in_page, bytes_to_copy)) { + kunmap(page); + put_page(page); + err = -EFAULT; + break; + } + kunmap(page); + put_page(page); + + retval += bytes_to_copy; + buf += bytes_to_copy; + offset += bytes_to_copy; + + if (fatal_signal_pending(current)) { + err = -EINTR; + break; + } + cond_resched(); + offs_in_page = 0; + } + return retval ? retval : err; +} /** * fsverity_ioctl_read_metadata() - read verity metadata from a file * @filp: file to read the metadata from @@ -48,6 +115,9 @@ int fsverity_ioctl_read_metadata(struct file *filp, const void __user *uarg) buf = u64_to_user_ptr(arg.buf_ptr); switch (arg.metadata_type) { + case FS_VERITY_METADATA_TYPE_MERKLE_TREE: + return fsverity_read_merkle_tree(inode, vi, buf, arg.offset, + length); default: return -EINVAL; } diff --git a/include/uapi/linux/fsverity.h b/include/uapi/linux/fsverity.h index e062751294d01..94003b153cb3d 100644 --- a/include/uapi/linux/fsverity.h +++ b/include/uapi/linux/fsverity.h @@ -83,6 +83,8 @@ struct fsverity_formatted_digest { __u8 digest[]; }; +#define FS_VERITY_METADATA_TYPE_MERKLE_TREE 1 + struct fsverity_read_metadata_arg { __u64 metadata_type; __u64 offset; -- 2.30.0 _______________________________________________ Linux-f2fs-devel mailing list Linux-f2fs-devel@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/linux-f2fs-devel