Re: [LTP] [PATCH V3] containers: new testcase userns03

[Yuan Sun <sunyuan3@huawei.com>]

Hi Jan,
     I didn't find the synchronization error. The comment added by you 
is great.
You are very careful and professional. Thank you very much.
     Could you please merge the patch into master? Or I will send a V4 
patch
according to your modification.
     Regards.
         Yuan


On 2015/6/19 21:38, Jan Stancek wrote:
> On 06/16/2015 11:28 PM, Yuan Sun wrote:
>>    ID-outside-ns is interpreted according to which process is opening
>> the file. If the process opening the file is in the same user namespace
>> as the process PID, then ID-outside-ns is defined with respect to the
>> parent user namespace. If the process opening the file is in a different
>> user namespace, then ID-outside-ns is defined with respect to the user
>> namespace of the process opening the file.
>>    If kernel version >= 3.19.0, the case will ignore the git check.
>>
>> Signed-off-by: Yuan Sun <sunyuan3@huawei.com>
> Hi,
>
> there is one problem in v3 with synchronization.
> Problem is that child2 can start checking it's uid/gid sooner than
> main sets the mapping.
>
> I have attached my idea for possible fix, comments about changes I made are below.
>
>> ---
>>   runtest/containers                            |   1 +
>>   testcases/kernel/containers/.gitignore        |   1 +
>>   testcases/kernel/containers/userns/userns03.c | 254 ++++++++++++++++++++++++++
>>   3 files changed, 256 insertions(+)
>>   create mode 100644 testcases/kernel/containers/userns/userns03.c
>>
>> diff --git a/runtest/containers b/runtest/containers
>> index bb1beb6..720d0f2 100644
>> --- a/runtest/containers
>> +++ b/runtest/containers
>> @@ -70,3 +70,4 @@ mountns04 mountns04
>>   
>>   userns01 userns01
>>   userns02 userns02
>> +userns03 userns03
>> diff --git a/testcases/kernel/containers/.gitignore b/testcases/kernel/containers/.gitignore
>> index e3c92c9..bd3cb9d 100644
>> --- a/testcases/kernel/containers/.gitignore
>> +++ b/testcases/kernel/containers/.gitignore
>> @@ -5,3 +5,4 @@ mountns/mountns03
>>   mountns/mountns04
>>   userns/userns01
>>   userns/userns02
>> +userns/userns03
>> diff --git a/testcases/kernel/containers/userns/userns03.c b/testcases/kernel/containers/userns/userns03.c
>> new file mode 100644
>> index 0000000..b5596fc
>> --- /dev/null
>> +++ b/testcases/kernel/containers/userns/userns03.c
>> @@ -0,0 +1,254 @@
>> +/*
>> +* Copyright (c) Huawei Technologies Co., Ltd., 2015
>> +* This program is free software; you can redistribute it and/or modify it
>> +* under the terms of the GNU General Public License as published by the Free
>> +* Software Foundation; either version 2 of the License, or (at your option)
>> +* any later version. This program is distributed in the hope that it will be
>> +* useful, but WITHOUT ANY WARRANTY; without even the implied warranty of
>> +* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General
>> +* Public License for more details. You should have received a copy of the GNU
>> +* General Public License along with this program.
>> +*/
>> +
>> +/*
>> +* Verify that:
>> +* /proc/PID/uid_map and /proc/PID/gid_map contains three values separated by
>> +* white space:
>> +* ID-inside-ns   ID-outside-ns   length
>> +*
>> +*  ID-outside-ns is interpreted according to which process is opening the file.
>> +* If the process opening the file is in the same user namespace as the process
>> +* PID, then ID-outside-ns is defined with respect to the parent user namespace.
>> +* If the process opening the file is in a different user namespace, then
>> +* ID-outside-ns is defined with respect to the user namespace of the process
>> +* opening the file.
>> +*/
> I added comment here about when we set/test gid map.
>
>> +
>> +#define _GNU_SOURCE
>> +#include <sys/wait.h>
>> +#include <assert.h>
>> +#include <stdio.h>
>> +#include <stdlib.h>
>> +#include <stdbool.h>
>> +#include <unistd.h>
>> +#include <string.h>
>> +#include <errno.h>
>> +#include "test.h"
>> +#include "libclone.h"
>> +#include "userns_helper.h"
>> +
>> +char *TCID = "user_namespace3";
>> +int TST_TOTAL = 1;
>> +static int cpid1, parentuid, parentgid;
>> +static bool setgroupstag = true;
>> +
>> +#define CHILD1UID 0
>> +#define CHILD1GID 0
>> +#define CHILD2UID 200
>> +#define CHILD2GID 200
>> +#define UID_MAP 0
>> +#define GID_MAP 1
>> +#define UID_MAP 0
>> +#define GID_MAP 1
> UID_MAP, GID_MAP is defined twice, I deleted one.
>
>> +
>> +/*
>> + * child_fn1() - Inside a new user namespace
>> + */
>> +static int child_fn1(void)
>> +{
>> +	TST_SAFE_CHECKPOINT_WAKE_AND_WAIT(NULL, 0);
>> +	return 0;
>> +}
>> +
>> +
>> +/*
>> + * child_fn2() - Inside a new user namespace
>> + */
>> +static int child_fn2(void)
>> +{
>> +	int exit_val;
>> +	int uid, gid;
>> +	char cpid1uidpath[BUFSIZ];
>> +	char cpid1gidpath[BUFSIZ];
>> +	int idinsidens, idoutsidens, length;
>> +
> I added WAIT here, so child doesn't start before main sets the mapping.
>
>> +	uid = geteuid();
>> +	gid = getegid();
>> +
>> +	if (uid == CHILD2UID) {
>> +		printf("Got expected uid.\n");
> I removed this printf.
>
>> +		exit_val = 0;
>> +	} else {
>> +		printf("unexpected uid=%d\n", uid);
>> +		exit_val = 1;
>> +	}
>> +
>> +	if (setgroupstag == false) {
>> +		if (gid == CHILD2GID) {
>> +			printf("Got expected gid.\n");
>> +			exit_val = 0;
>> +		} else {
>> +			printf("unexpected: gid=%d\n", gid);
>> +			exit_val = 1;
>> +		}
>> +	}
>> +	/*Get the uid parameters of the child_fn2 process.*/
>> +	SAFE_FILE_SCANF(NULL, "/proc/self/uid_map", "%d %d %d", &idinsidens,
>> +		&idoutsidens, &length);
>> +
>> +	/* map file format:ID-inside-ns   ID-outside-ns   length
>> +	If the process opening the file is in the same user namespace as
>> +	the process PID, then ID-outside-ns is defined with respect to the
>> +	 parent user namespace.*/
>> +	if (idinsidens != CHILD2UID || idoutsidens != parentuid) {
>> +		printf("child_fn2 checks /proc/cpid2/uid_map:\n");
>> +		printf("unexpected: idinsidens=%d idoutsidens=%d\n",
>> +			idinsidens, idoutsidens);
>> +		exit_val = 1;
>> +	}
>> +
>> +	sprintf(cpid1uidpath, "/proc/%d/uid_map", cpid1);
>> +	SAFE_FILE_SCANF(NULL, cpid1uidpath, "%d %d %d", &idinsidens,
>> +		&idoutsidens, &length);
>> +
>> +	/* If the process opening the file is in a different user namespace,
>> +	then ID-outside-ns is defined with respect to the user namespace
>> +	of the process opening the file.*/
>> +	if (idinsidens != CHILD1UID || idoutsidens != CHILD2UID) {
>> +		printf("child_fn2 checks /proc/cpid1/uid_map:\n");
>> +		printf("unexpected: idinsidens=%d idoutsidens=%d\n",
>> +			idinsidens, idoutsidens);
>> +		exit_val = 1;
>> +	}
>> +
>> +	if (setgroupstag == false) {
>> +		sprintf(cpid1gidpath, "/proc/%d/gid_map", cpid1);
>> +		SAFE_FILE_SCANF(NULL, "/proc/self/gid_map", "%d %d %d",
>> +			 &idinsidens, &idoutsidens, &length);
>> +
>> +		if (idinsidens != CHILD2GID || idoutsidens != parentgid) {
>> +			printf("child_fn2 checks /proc/cpid2/gid_map:\n");
>> +			printf("unexpected: idinsidens=%d idoutsidens=%d\n",
>> +				idinsidens, idoutsidens);
>> +			exit_val = 1;
>> +		}
>> +
>> +		SAFE_FILE_SCANF(NULL, cpid1gidpath, "%d %d %d", &idinsidens,
>> +			&idoutsidens, &length);
>> +
>> +		if (idinsidens != CHILD1GID || idoutsidens != CHILD2GID) {
>> +			printf("child_fn1 checks /proc/cpid1/gid_map:\n");
>> +			printf("unexpected: idinsidens=%d idoutsidens=%d\n",
>> +				idinsidens, idoutsidens);
>> +			exit_val = 1;
>> +		}
>> +	}
>> +	TST_SAFE_CHECKPOINT_WAKE_AND_WAIT(NULL, 1);
>> +	return exit_val;
>> +}
>> +
>> +
>> +static void setup(void)
>> +{
>> +	char read_buf[BUFSIZ];
>> +
>> +	check_newuser();
>> +	tst_tmpdir();
>> +	TST_CHECKPOINT_INIT(NULL);
>> +	if (access("/proc/self/setgroups", F_OK) == 0) {
>> +		SAFE_FILE_SCANF(NULL, "/proc/self/setgroups", "%s", read_buf);
> added cleanup
>
>> +		if (strcmp(read_buf, "deny") == 0)
>> +			setgroupstag = false;
>> +	}
>> +}
>> +
>> +static void cleanup(void)
>> +{
>> +	tst_rmdir();
>> +}
>> +
>> +static int updatemap(int cpid, bool type, int idnum, int parentmappid)
>> +{
>> +	char path[BUFSIZ];
>> +	char content[BUFSIZ];
>> +	int fd;
>> +
>> +	if (type == UID_MAP)
>> +		sprintf(path, "/proc/%d/uid_map", cpid);
>> +	else if (type == GID_MAP)
>> +		sprintf(path, "/proc/%d/gid_map", cpid);
>> +	else
>> +		tst_brkm(TFAIL, cleanup, "invalid type parameter");
>> +
>> +	sprintf(content, "%d %d 1", idnum, parentmappid);
>> +	fd = SAFE_OPEN(NULL, path, O_WRONLY, 0644);
>> +	SAFE_WRITE(cleanup, 1, fd, content, strlen(content));
>> +	SAFE_CLOSE(cleanup, fd);
>> +	return 0;
>> +}
>> +
>> +int main(int argc, char *argv[])
>> +{
>> +	pid_t cpid2;
>> +	int cpid1status, cpid2status;
>> +	int lc;
>> +
>> +	tst_parse_opts(argc, argv, NULL, NULL);
>> +	setup();
>> +
>> +	for (lc = 0; TEST_LOOPING(lc); lc++) {
>> +		tst_count = 0;
>> +
>> +		parentuid = geteuid();
>> +		parentgid = getegid();
>> +
>> +		cpid1 = ltp_clone_quick(CLONE_NEWUSER | SIGCHLD,
>> +			(void *)child_fn1, NULL);
>> +		if (cpid1 < 0)
>> +			tst_brkm(TFAIL | TERRNO, cleanup,
>> +				"cpid1 clone failed");
>> +
>> +		cpid2 = ltp_clone_quick(CLONE_NEWUSER | SIGCHLD,
>> +			(void *)child_fn2, NULL);
>> +		if (cpid2 < 0)
>> +			tst_brkm(TFAIL | TERRNO, cleanup,
>> +				"cpid2 clone failed");
>> +
>> +		updatemap(cpid1, 0, CHILD1UID, parentuid);
>> +		updatemap(cpid2, 0, CHILD2UID, parentuid);
>> +
>> +		if (setgroupstag == false) {
>> +			updatemap(cpid1, 1, CHILD1GID, parentuid);
>> +			updatemap(cpid2, 1, CHILD2GID, parentuid);
>> +		}
> calls to updatemap changed to use defines rather than 0/1
>
> Regards,
> Jan
>
>


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