From mboxrd@z Thu Jan  1 00:00:00 1970
Return-Path: <SRS0=M1fl=TR=vger.kernel.org=linux-kernel-owner@kernel.org>
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=-9.0 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS,
	INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS,
	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 13355C04AB4
	for <linux-kernel@archiver.kernel.org>; Fri, 17 May 2019 17:00:00 +0000 (UTC)
Received: from vger.kernel.org (vger.kernel.org [209.132.180.67])
	by mail.kernel.org (Postfix) with ESMTP id E356D2168B
	for <linux-kernel@archiver.kernel.org>; Fri, 17 May 2019 16:59:59 +0000 (UTC)
Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand
        id S1728028AbfEQQ76 (ORCPT
        <rfc822;linux-kernel@archiver.kernel.org>);
        Fri, 17 May 2019 12:59:58 -0400
Received: from lhrrgout.huawei.com ([185.176.76.210]:32953 "EHLO huawei.com"
        rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP
        id S1726575AbfEQQ76 (ORCPT <rfc822;linux-kernel@vger.kernel.org>);
        Fri, 17 May 2019 12:59:58 -0400
Received: from lhreml707-cah.china.huawei.com (unknown [172.18.7.106])
        by Forcepoint Email with ESMTP id A5B5E1A365CDA136CABA;
        Fri, 17 May 2019 17:59:56 +0100 (IST)
Received: from roberto-HP-EliteDesk-800-G2-DM-65W.huawei.com (10.204.65.154)
 by smtpsuk.huawei.com (10.201.108.48) with Microsoft SMTP Server (TLS) id
 14.3.408.0; Fri, 17 May 2019 17:59:46 +0100
From:   Roberto Sassu <roberto.sassu@huawei.com>
To:     <viro@zeniv.linux.org.uk>
CC:     <linux-security-module@vger.kernel.org>,
        <linux-integrity@vger.kernel.org>, <initramfs@vger.kernel.org>,
        <linux-api@vger.kernel.org>, <linux-fsdevel@vger.kernel.org>,
        <linux-kernel@vger.kernel.org>, <zohar@linux.vnet.ibm.com>,
        <silviu.vlasceanu@huawei.com>, <dmitry.kasatkin@huawei.com>,
        <takondra@cisco.com>, <kamensky@cisco.com>, <hpa@zytor.com>,
        <arnd@arndb.de>, <rob@landley.net>, <james.w.mcmechan@gmail.com>,
        <niveditas98@gmail.com>, Roberto Sassu <roberto.sassu@huawei.com>
Subject: [PATCH v3 2/2] initramfs: introduce do_readxattrs()
Date:   Fri, 17 May 2019 18:55:19 +0200
Message-ID: <20190517165519.11507-3-roberto.sassu@huawei.com>
X-Mailer: git-send-email 2.17.1
In-Reply-To: <20190517165519.11507-1-roberto.sassu@huawei.com>
References: <20190517165519.11507-1-roberto.sassu@huawei.com>
MIME-Version: 1.0
Content-Type: text/plain
X-Originating-IP: [10.204.65.154]
X-CFilter-Loop: Reflected
Sender: linux-kernel-owner@vger.kernel.org
Precedence: bulk
List-ID: <linux-kernel.vger.kernel.org>
X-Mailing-List: linux-kernel@vger.kernel.org

This patch adds support for an alternative method to add xattrs to files in
the rootfs filesystem. Instead of extracting them directly from the ram
disk image, they are extracted from a regular file called .xattr-list, that
can be added by any ram disk generator available today. The file format is:

<file #N data len (ASCII, 10 chars)><file #N path>\0
<xattr #N data len (ASCII, 8 chars)><xattr #N name>\0<xattr #N value>

.xattr-list can be generated by executing:

$ getfattr --absolute-names -d -h -R -e hex -m - \
      <file list> | xattr.awk -b > ${initdir}/.xattr-list

where the content of the xattr.awk script is:

#! /usr/bin/awk -f
{
  if (!length($0)) {
    printf("%.10x%s\0", len, file);
    for (x in xattr) {
      printf("%.8x%s\0", xattr_len[x], x);
      for (i = 0; i < length(xattr[x]) / 2; i++) {
        printf("%c", strtonum("0x"substr(xattr[x], i * 2 + 1, 2)));
      }
    }
    i = 0;
    delete xattr;
    delete xattr_len;
    next;
  };
  if (i == 0) {
    file=$3;
    len=length(file) + 8 + 1;
  }
  if (i > 0) {
    split($0, a, "=");
    xattr[a[1]]=substr(a[2], 3);
    xattr_len[a[1]]=length(a[1]) + 1 + 8 + length(xattr[a[1]]) / 2;
    len+=xattr_len[a[1]];
  };
  i++;
}

Signed-off-by: Roberto Sassu <roberto.sassu@huawei.com>
---
 init/initramfs.c | 99 ++++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 99 insertions(+)

diff --git a/init/initramfs.c b/init/initramfs.c
index 0c6dd1d5d3f6..6ec018c6279a 100644
--- a/init/initramfs.c
+++ b/init/initramfs.c
@@ -13,6 +13,8 @@
 #include <linux/namei.h>
 #include <linux/xattr.h>
 
+#define XATTR_LIST_FILENAME ".xattr-list"
+
 static ssize_t __init xwrite(int fd, const char *p, size_t count)
 {
 	ssize_t out = 0;
@@ -382,6 +384,97 @@ static int __init __maybe_unused do_setxattrs(char *pathname)
 	return 0;
 }
 
+struct path_hdr {
+	char p_size[10]; /* total size including p_size field */
+	char p_data[];   /* <path>\0<xattrs> */
+};
+
+static int __init do_readxattrs(void)
+{
+	struct path_hdr hdr;
+	char *path = NULL;
+	char str[sizeof(hdr.p_size) + 1];
+	unsigned long file_entry_size;
+	size_t size, path_size, total_size;
+	struct kstat st;
+	struct file *file;
+	loff_t pos;
+	int ret;
+
+	ret = vfs_lstat(XATTR_LIST_FILENAME, &st);
+	if (ret < 0)
+		return ret;
+
+	total_size = st.size;
+
+	file = filp_open(XATTR_LIST_FILENAME, O_RDONLY, 0);
+	if (IS_ERR(file))
+		return PTR_ERR(file);
+
+	pos = file->f_pos;
+
+	while (total_size) {
+		size = kernel_read(file, (char *)&hdr, sizeof(hdr), &pos);
+		if (size != sizeof(hdr)) {
+			ret = -EIO;
+			goto out;
+		}
+
+		total_size -= size;
+
+		str[sizeof(hdr.p_size)] = 0;
+		memcpy(str, hdr.p_size, sizeof(hdr.p_size));
+		ret = kstrtoul(str, 16, &file_entry_size);
+		if (ret < 0)
+			goto out;
+
+		file_entry_size -= sizeof(sizeof(hdr.p_size));
+		if (file_entry_size > total_size) {
+			ret = -EINVAL;
+			goto out;
+		}
+
+		path = vmalloc(file_entry_size);
+		if (!path) {
+			ret = -ENOMEM;
+			goto out;
+		}
+
+		size = kernel_read(file, path, file_entry_size, &pos);
+		if (size != file_entry_size) {
+			ret = -EIO;
+			goto out_free;
+		}
+
+		total_size -= size;
+
+		path_size = strnlen(path, file_entry_size);
+		if (path_size == file_entry_size) {
+			ret = -EINVAL;
+			goto out_free;
+		}
+
+		xattr_buf = path + path_size + 1;
+		xattr_len = file_entry_size - path_size - 1;
+
+		ret = do_setxattrs(path);
+		vfree(path);
+		path = NULL;
+
+		if (ret < 0)
+			break;
+	}
+out_free:
+	vfree(path);
+out:
+	fput(file);
+
+	if (ret < 0)
+		error("Unable to parse xattrs");
+
+	return ret;
+}
+
 static __initdata int wfd;
 
 static int __init do_name(void)
@@ -391,6 +484,11 @@ static int __init do_name(void)
 	if (strcmp(collected, "TRAILER!!!") == 0) {
 		free_hash();
 		return 0;
+	} else if (strcmp(collected, XATTR_LIST_FILENAME) == 0) {
+		struct kstat st;
+
+		if (!vfs_lstat(collected, &st))
+			do_readxattrs();
 	}
 	clean_path(collected, mode);
 	if (S_ISREG(mode)) {
@@ -562,6 +660,7 @@ static char * __init unpack_to_rootfs(char *buf, unsigned long len)
 		buf += my_inptr;
 		len -= my_inptr;
 	}
+	do_readxattrs();
 	dir_utime();
 	kfree(name_buf);
 	kfree(symlink_buf);
-- 
2.17.1


From mboxrd@z Thu Jan  1 00:00:00 1970
From: Roberto Sassu <roberto.sassu@huawei.com>
Subject: [PATCH v3 2/2] initramfs: introduce do_readxattrs()
Date: Fri, 17 May 2019 18:55:19 +0200
Message-ID: <20190517165519.11507-3-roberto.sassu@huawei.com>
References: <20190517165519.11507-1-roberto.sassu@huawei.com>
Mime-Version: 1.0
Content-Type: text/plain
Return-path: <linux-kernel-owner@vger.kernel.org>
In-Reply-To: <20190517165519.11507-1-roberto.sassu@huawei.com>
Sender: linux-kernel-owner@vger.kernel.org
To: viro@zeniv.linux.org.uk
Cc: linux-security-module@vger.kernel.org, linux-integrity@vger.kernel.org, initramfs@vger.kernel.org, linux-api@vger.kernel.org, linux-fsdevel@vger.kernel.org, linux-kernel@vger.kernel.org, zohar@linux.vnet.ibm.com, silviu.vlasceanu@huawei.com, dmitry.kasatkin@huawei.com, takondra@cisco.com, kamensky@cisco.com, hpa@zytor.com, arnd@arndb.de, rob@landley.net, james.w.mcmechan@gmail.com, niveditas98@gmail.com, Roberto Sassu <roberto.sassu@huawei.com>
List-Id: linux-api@vger.kernel.org

This patch adds support for an alternative method to add xattrs to files in
the rootfs filesystem. Instead of extracting them directly from the ram
disk image, they are extracted from a regular file called .xattr-list, that
can be added by any ram disk generator available today. The file format is:

<file #N data len (ASCII, 10 chars)><file #N path>\0
<xattr #N data len (ASCII, 8 chars)><xattr #N name>\0<xattr #N value>

.xattr-list can be generated by executing:

$ getfattr --absolute-names -d -h -R -e hex -m - \
      <file list> | xattr.awk -b > ${initdir}/.xattr-list

where the content of the xattr.awk script is:

#! /usr/bin/awk -f
{
  if (!length($0)) {
    printf("%.10x%s\0", len, file);
    for (x in xattr) {
      printf("%.8x%s\0", xattr_len[x], x);
      for (i = 0; i < length(xattr[x]) / 2; i++) {
        printf("%c", strtonum("0x"substr(xattr[x], i * 2 + 1, 2)));
      }
    }
    i = 0;
    delete xattr;
    delete xattr_len;
    next;
  };
  if (i == 0) {
    file=$3;
    len=length(file) + 8 + 1;
  }
  if (i > 0) {
    split($0, a, "=");
    xattr[a[1]]=substr(a[2], 3);
    xattr_len[a[1]]=length(a[1]) + 1 + 8 + length(xattr[a[1]]) / 2;
    len+=xattr_len[a[1]];
  };
  i++;
}

Signed-off-by: Roberto Sassu <roberto.sassu@huawei.com>
---
 init/initramfs.c | 99 ++++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 99 insertions(+)

diff --git a/init/initramfs.c b/init/initramfs.c
index 0c6dd1d5d3f6..6ec018c6279a 100644
--- a/init/initramfs.c
+++ b/init/initramfs.c
@@ -13,6 +13,8 @@
 #include <linux/namei.h>
 #include <linux/xattr.h>
 
+#define XATTR_LIST_FILENAME ".xattr-list"
+
 static ssize_t __init xwrite(int fd, const char *p, size_t count)
 {
 	ssize_t out = 0;
@@ -382,6 +384,97 @@ static int __init __maybe_unused do_setxattrs(char *pathname)
 	return 0;
 }
 
+struct path_hdr {
+	char p_size[10]; /* total size including p_size field */
+	char p_data[];   /* <path>\0<xattrs> */
+};
+
+static int __init do_readxattrs(void)
+{
+	struct path_hdr hdr;
+	char *path = NULL;
+	char str[sizeof(hdr.p_size) + 1];
+	unsigned long file_entry_size;
+	size_t size, path_size, total_size;
+	struct kstat st;
+	struct file *file;
+	loff_t pos;
+	int ret;
+
+	ret = vfs_lstat(XATTR_LIST_FILENAME, &st);
+	if (ret < 0)
+		return ret;
+
+	total_size = st.size;
+
+	file = filp_open(XATTR_LIST_FILENAME, O_RDONLY, 0);
+	if (IS_ERR(file))
+		return PTR_ERR(file);
+
+	pos = file->f_pos;
+
+	while (total_size) {
+		size = kernel_read(file, (char *)&hdr, sizeof(hdr), &pos);
+		if (size != sizeof(hdr)) {
+			ret = -EIO;
+			goto out;
+		}
+
+		total_size -= size;
+
+		str[sizeof(hdr.p_size)] = 0;
+		memcpy(str, hdr.p_size, sizeof(hdr.p_size));
+		ret = kstrtoul(str, 16, &file_entry_size);
+		if (ret < 0)
+			goto out;
+
+		file_entry_size -= sizeof(sizeof(hdr.p_size));
+		if (file_entry_size > total_size) {
+			ret = -EINVAL;
+			goto out;
+		}
+
+		path = vmalloc(file_entry_size);
+		if (!path) {
+			ret = -ENOMEM;
+			goto out;
+		}
+
+		size = kernel_read(file, path, file_entry_size, &pos);
+		if (size != file_entry_size) {
+			ret = -EIO;
+			goto out_free;
+		}
+
+		total_size -= size;
+
+		path_size = strnlen(path, file_entry_size);
+		if (path_size == file_entry_size) {
+			ret = -EINVAL;
+			goto out_free;
+		}
+
+		xattr_buf = path + path_size + 1;
+		xattr_len = file_entry_size - path_size - 1;
+
+		ret = do_setxattrs(path);
+		vfree(path);
+		path = NULL;
+
+		if (ret < 0)
+			break;
+	}
+out_free:
+	vfree(path);
+out:
+	fput(file);
+
+	if (ret < 0)
+		error("Unable to parse xattrs");
+
+	return ret;
+}
+
 static __initdata int wfd;
 
 static int __init do_name(void)
@@ -391,6 +484,11 @@ static int __init do_name(void)
 	if (strcmp(collected, "TRAILER!!!") == 0) {
 		free_hash();
 		return 0;
+	} else if (strcmp(collected, XATTR_LIST_FILENAME) == 0) {
+		struct kstat st;
+
+		if (!vfs_lstat(collected, &st))
+			do_readxattrs();
 	}
 	clean_path(collected, mode);
 	if (S_ISREG(mode)) {
@@ -562,6 +660,7 @@ static char * __init unpack_to_rootfs(char *buf, unsigned long len)
 		buf += my_inptr;
 		len -= my_inptr;
 	}
+	do_readxattrs();
 	dir_utime();
 	kfree(name_buf);
 	kfree(symlink_buf);
-- 
2.17.1