[PATCH 2/2] Implemented parser for NS_* ioctl commands.

Nikolay Marchuk marchuk.nikolay.a at gmail.com
Wed Mar 22 11:08:01 UTC 2017


Test was rewritten, now it is based on example from https://lists.gt.net/linux/kernel/2606267. New test passed on 4.11-rc2 kernel.
---
 Makefile.am           |   1 +
 configure.ac          |   1 +
 defs.h                |   1 +
 ioctl.c               |   2 +
 nsfs.c                |  94 +++++++++++++++++++++++++++++
 tests/.gitignore      |   1 +
 tests/Makefile.am     |   2 +
 tests/ioctl_nsfs.c    | 160 ++++++++++++++++++++++++++++++++++++++++++++++++++
 tests/ioctl_nsfs.test |  13 ++++
 9 files changed, 275 insertions(+)
 create mode 100644 nsfs.c
 create mode 100644 tests/ioctl_nsfs.c
 create mode 100755 tests/ioctl_nsfs.test

diff --git a/Makefile.am b/Makefile.am
index 8af709b..5a2ce4a 100644
--- a/Makefile.am
+++ b/Makefile.am
@@ -172,6 +172,7 @@ strace_SOURCES =	\
 	net.c		\
 	netlink.c       \
 	nsig.h		\
+	nsfs.c		\
 	numa.c		\
 	oldstat.c	\
 	open.c		\
diff --git a/configure.ac b/configure.ac
index 9e5087b..dc49fdc 100644
--- a/configure.ac
+++ b/configure.ac
@@ -366,6 +366,7 @@ AC_CHECK_HEADERS(m4_normalize([
 	linux/ipc.h
 	linux/mmtimer.h
 	linux/msg.h
+	linux/nsfs.h
 	linux/perf_event.h
 	linux/quota.h
 	linux/seccomp.h
diff --git a/defs.h b/defs.h
index 793971e..0f3ec14 100644
--- a/defs.h
+++ b/defs.h
@@ -640,6 +640,7 @@ name ## _ioctl(struct tcb *, unsigned int request, kernel_ulong_t arg)
 DECL_IOCTL(dm);
 DECL_IOCTL(file);
 DECL_IOCTL(fs_x);
+DECL_IOCTL(nsfs);
 DECL_IOCTL(ptp);
 DECL_IOCTL(scsi);
 DECL_IOCTL(term);
diff --git a/ioctl.c b/ioctl.c
index aa1880f..4511e0b 100644
--- a/ioctl.c
+++ b/ioctl.c
@@ -280,6 +280,8 @@ ioctl_decode(struct tcb *tcp)
 	case 0x94:
 		return btrfs_ioctl(tcp, code, arg);
 #endif
+	case 0xb7:
+		return nsfs_ioctl(tcp, code, arg);
 #ifdef HAVE_LINUX_DM_IOCTL_H
 	case 0xfd:
 		return dm_ioctl(tcp, code, arg);
diff --git a/nsfs.c b/nsfs.c
new file mode 100644
index 0000000..bf12248
--- /dev/null
+++ b/nsfs.c
@@ -0,0 +1,94 @@
+/*
+ * Support for decoding of NS_* ioctl commands.
+ *
+ * Copyright (c) 2017 Nikolay Marchuk <marchuk.nikolay.a at gmail.com>
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in the
+ *    documentation and/or other materials provided with the distribution.
+ * 3. The name of the author may not be used to endorse or promote products
+ *    derived from this software without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
+ * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
+ * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
+ * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
+ * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
+ * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+ * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+ * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+ * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
+ * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ */
+
+#include "defs.h"
+
+#include <linux/ioctl.h>
+
+/* Definitions for commands */
+#ifdef HAVE_LINUX_NSFS_H
+# include <linux/nsfs.h>
+#else
+# ifndef NSIO
+#  define NSIO		0xb7
+# endif
+# ifndef NS_GET_USERNS
+#  define NS_GET_USERNS		_IO(NSIO, 0x1)
+# endif
+# ifndef NS_GET_PARENT
+#  define NS_GET_PARENT		_IO(NSIO, 0x2)
+# endif
+#endif
+
+#ifndef NS_GET_NSTYPE
+# define NS_GET_NSTYPE		_IO(NSIO, 0x3)
+#endif
+#ifndef NS_GET_OWNER_UID
+# define NS_GET_OWNER_UID	_IO(NSIO, 0x4)
+#endif
+
+#include <sys/types.h>
+#include "xlat/setns_types.h"
+
+int
+nsfs_ioctl(struct tcb *tcp, unsigned int code, kernel_ulong_t arg)
+{
+	const char *outstr;
+	uid_t uid;
+	if (entering(tcp)) {
+		switch (code) {
+		case NS_GET_USERNS:
+		case NS_GET_PARENT:
+			return RVAL_DECODED | (1 + RVAL_FD);
+		default:
+			return 0;
+		}
+	} else {
+		switch (code) {
+		case NS_GET_NSTYPE:
+			if (!syserror(tcp)) {
+				outstr = xlookup(setns_types, tcp->u_rval);
+				if (outstr) {
+					tcp->auxstr = outstr;
+					return 1 + RVAL_STR;
+				}
+			}
+			return 1 + RVAL_DECIMAL;
+		case NS_GET_OWNER_UID:
+			tprints(", ");
+			if (!umove_or_printaddr(tcp, arg, &uid)) {
+				printuid("[", uid);
+				tprints("]");
+			}
+			return 1 + RVAL_DECIMAL;
+		default:
+			return 0;
+		}
+	}
+}
diff --git a/tests/.gitignore b/tests/.gitignore
index 477529d..1998097 100644
--- a/tests/.gitignore
+++ b/tests/.gitignore
@@ -122,6 +122,7 @@ ioctl_loop
 ioctl_loop-nv
 ioctl_loop-v
 ioctl_mtd
+ioctl_nsfs
 ioctl_rtc
 ioctl_rtc-v
 ioctl_scsi
diff --git a/tests/Makefile.am b/tests/Makefile.am
index c6c28cc..44b0463 100644
--- a/tests/Makefile.am
+++ b/tests/Makefile.am
@@ -185,6 +185,7 @@ check_PROGRAMS = \
 	ioctl_loop-nv \
 	ioctl_loop-v \
 	ioctl_mtd \
+	ioctl_nsfs \
 	ioctl_rtc \
 	ioctl_rtc-v \
 	ioctl_scsi \
@@ -595,6 +596,7 @@ DECODER_TESTS = \
 	ioctl_loop-v.test \
 	ioctl_loop.test \
 	ioctl_mtd.test \
+	ioctl_nsfs.test \
 	ioctl_rtc-v.test \
 	ioctl_rtc.test \
 	ioctl_scsi.test \
diff --git a/tests/ioctl_nsfs.c b/tests/ioctl_nsfs.c
new file mode 100644
index 0000000..f564962
--- /dev/null
+++ b/tests/ioctl_nsfs.c
@@ -0,0 +1,160 @@
+/*
+ * Check decoding of NS_* commands of ioctl syscall.
+ *
+ * Copyright (c) 2017 Nikolay Marchuk <marchuk.nikolay.a at gmail.com>
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in the
+ *    documentation and/or other materials provided with the distribution.
+ * 3. The name of the author may not be used to endorse or promote products
+ *    derived from this software without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
+ * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
+ * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
+ * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
+ * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
+ * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+ * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+ * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+ * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
+ * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ */
+
+#include "tests.h"
+
+#include <fcntl.h>
+#include <limits.h>
+#include <linux/ioctl.h>
+
+/* Definitions for commands */
+#ifdef HAVE_LINUX_NSFS_H
+# include <linux/nsfs.h>
+#else
+# ifndef NSIO
+#  define NSIO		0xb7
+# endif
+# ifndef NS_GET_USERNS
+#  define NS_GET_USERNS		_IO(NSIO, 0x1)
+# endif
+# ifndef NS_GET_PARENT
+#  define NS_GET_PARENT		_IO(NSIO, 0x2)
+# endif
+#endif
+
+#ifndef NS_GET_NSTYPE
+# define NS_GET_NSTYPE		_IO(NSIO, 0x3)
+#endif
+#ifndef NS_GET_OWNER_UID
+# define NS_GET_OWNER_UID	_IO(NSIO, 0x4)
+#endif
+
+#include <signal.h>
+#include <sched.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <sys/ioctl.h>
+#include <sys/types.h>
+#include <sys/wait.h>
+#include <unistd.h>
+
+static void
+test_no_namespace(void)
+{
+	ioctl(-1, NS_GET_USERNS);
+	printf("ioctl(-1, NS_GET_USERNS) = -1 EBADF (%m)\n");
+	ioctl(-1, NS_GET_PARENT);
+	printf("ioctl(-1, NS_GET_PARENT) = -1 EBADF (%m)\n");
+	ioctl(-1, NS_GET_NSTYPE);
+	printf("ioctl(-1, NS_GET_NSTYPE) = -1 EBADF (%m)\n");
+	ioctl(-1, NS_GET_OWNER_UID, NULL);
+	printf("ioctl(-1, NS_GET_OWNER_UID, NULL) = -1 EBADF (%m)\n");
+}
+
+static void
+test_clone(pid_t pid)
+{
+	int ns_fd, userns_fd, parent_ns_fd, nstype, rc;
+	const char *errstr;
+	char path[PATH_MAX];
+	uid_t uid;
+
+	snprintf(path, sizeof(path), "/proc/%d/ns/user", pid);
+	ns_fd = open(path, O_RDONLY);
+	if (ns_fd == -1)
+		perror_msg_and_skip("Open user namespace file error");
+
+	userns_fd = ioctl(ns_fd, NS_GET_USERNS);
+	errstr = sprintrc(userns_fd);
+	printf("ioctl(%d, NS_GET_USERNS) = %s\n", ns_fd, errstr);
+
+	parent_ns_fd = ioctl(userns_fd, NS_GET_PARENT);
+	errstr = sprintrc(parent_ns_fd);
+	printf("ioctl(%d, NS_GET_PARENT) = %s\n", userns_fd, errstr);
+
+	nstype = ioctl(userns_fd, NS_GET_NSTYPE);
+	errstr = sprintrc(nstype);
+	if (nstype == CLONE_NEWUSER) {
+		printf("ioctl(%d, NS_GET_NSTYPE) = %d (CLONE_NEWUSER)\n", userns_fd,
+			   nstype);
+	} else {
+		printf("ioctl(%d, NS_GET_NSTYPE) = %s\n", userns_fd, errstr);
+	}
+
+	rc = ioctl(userns_fd, NS_GET_OWNER_UID, &uid);
+	errstr = sprintrc(rc);
+	if (rc == -1) {
+		printf("ioctl(%d, NS_GET_OWNER_UID, %p) = %s\n", userns_fd, &uid,
+			   errstr);
+	} else {
+		printf("ioctl(%d, NS_GET_OWNER_UID, [", userns_fd);
+		if ((uid_t) -1U == (uid_t) uid)
+			printf("-1]) = %s\n", errstr);
+		else
+			printf("%u]) = %s\n", uid, errstr);
+	}
+}
+
+static int
+childFunc(void *arg)
+{
+		sleep(5);
+		return 0;
+}
+
+#define STACK_SIZE (1024 * 1024)
+
+static void
+test_user_namespace(void)
+{
+	char *stack;
+	pid_t pid;
+
+	stack = malloc(STACK_SIZE);
+	if (stack == NULL) {
+		perror_msg_and_skip("Malloc error");
+	}
+
+	pid = clone(childFunc, stack + STACK_SIZE, CLONE_NEWUSER | CLONE_UNTRACED,
+				NULL);
+	if (pid == -1)
+		perror_msg_and_skip("Clone error");
+
+	test_clone(pid);
+	kill(pid, SIGKILL);
+}
+
+int
+main(void)
+{
+	test_no_namespace();
+	test_user_namespace();
+	puts("+++ exited with 0 +++");
+	return 0;
+}
diff --git a/tests/ioctl_nsfs.test b/tests/ioctl_nsfs.test
new file mode 100755
index 0000000..8fe8da5
--- /dev/null
+++ b/tests/ioctl_nsfs.test
@@ -0,0 +1,13 @@
+#!/bin/sh
+
+# Check decoding of NS_* ioctls.
+
+. "${srcdir=.}/init.sh"
+
+run_prog > /dev/null
+run_strace -a16 -eioctl $args > "$EXP"
+check_prog grep
+grep -v '^ioctl([012],' < "$LOG" > "$OUT"
+match_diff "$OUT" "$EXP"
+
+rm -f "$EXP" "$OUT"
-- 
2.1.4





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