[LTP] [RFC PATCH v2 1/1] netns_netlink: Rewrite into new API
Cyril Hrubis
chrubis@suse.cz
Tue May 11 10:52:54 CEST 2021
Hi!
> Remove check for iproute 100519 (v2.6.34 => old enough to drop this check).
I guess that this is fine, it seems to be more than 10 years old now.
> Remove check for unshare() CLONE_NEWNET support (since 2.6.24, old enough).
Actually there are CONFIG_FOO_NS variables in kernel .config and
individual namespaces can be turned on/off. So we have to check if
network namespaces have been compiled into kernel or not. I guess that
simplest solution here would be adding .needs_kconfig field with
"CONFIG_NET_NS=y".
> .../kernel/containers/netns/netns_helper.h | 80 -----------
> .../kernel/containers/netns/netns_netlink.c | 127 +++++++-----------
> 2 files changed, 46 insertions(+), 161 deletions(-)
> delete mode 100644 testcases/kernel/containers/netns/netns_helper.h
>
> diff --git a/testcases/kernel/containers/netns/netns_helper.h b/testcases/kernel/containers/netns/netns_helper.h
> deleted file mode 100644
> index 8b876454f..000000000
> --- a/testcases/kernel/containers/netns/netns_helper.h
> +++ /dev/null
> @@ -1,80 +0,0 @@
> -/*
> - * Copyright (c) International Business Machines Corp., 2008
> - * 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. If not, see <http://www.gnu.org/licenses/>.
> - *
> - * Author: Veerendra C <vechandr@in.ibm.com>
> - *
> - * Net namespaces were introduced around 2.6.25. Kernels before that,
> - * assume they are not enabled. Kernels after that, check for -EINVAL
> - * when trying to use CLONE_NEWNET and CLONE_NEWNS.
> - ***************************************************************************/
> -
> -#define _GNU_SOURCE
> -#include <sched.h>
> -#include "config.h"
> -#include "libclone.h"
> -#include "lapi/syscalls.h"
> -#include "test.h"
> -#include "safe_macros.h"
> -
> -#ifndef CLONE_NEWNS
> -#define CLONE_NEWNS -1
> -#endif
> -
> -static void check_iproute(unsigned int spe_ipver)
> -{
> - FILE *ipf;
> - int n;
> - unsigned int ipver = 0;
> -
> - ipf = popen("ip -V", "r");
> - if (ipf == NULL)
> - tst_brkm(TCONF, NULL,
> - "Failed while opening pipe for iproute check");
> -
> - n = fscanf(ipf, "ip utility, iproute2-ss%u", &ipver);
> - if (n < 1) {
> - tst_brkm(TCONF, NULL,
> - "Failed while obtaining version for iproute check");
> - }
> - if (ipver < spe_ipver) {
> - tst_brkm(TCONF, NULL, "The commands in iproute tools do "
> - "not support required objects");
> - }
> -
> - pclose(ipf);
> -}
> -
> -static int dummy(void *arg)
> -{
> - (void) arg;
> - return 0;
> -}
> -
> -static void check_netns(void)
> -{
> - int pid, status;
> - /* Checking if the kernel supports unshare with netns capabilities. */
> - if (CLONE_NEWNS == -1)
> - tst_brkm(TCONF | TERRNO, NULL, "CLONE_NEWNS (%d) not supported",
> - CLONE_NEWNS);
> -
> - pid = do_clone_unshare_test(T_UNSHARE, CLONE_NEWNET | CLONE_NEWNS,
> - dummy, NULL);
> - if (pid == -1)
> - tst_brkm(TCONF | TERRNO, NULL,
> - "unshare syscall smoke test failed");
> -
> - SAFE_WAIT(NULL, &status);
> -}
> diff --git a/testcases/kernel/containers/netns/netns_netlink.c b/testcases/kernel/containers/netns/netns_netlink.c
> index 47e8235d6..8ed285eb4 100644
> --- a/testcases/kernel/containers/netns/netns_netlink.c
> +++ b/testcases/kernel/containers/netns/netns_netlink.c
> @@ -1,34 +1,27 @@
> -/* Copyright (c) 2014 Red Hat, Inc.
> - *
> - * This program is free software: you can redistribute it and/or modify
> - * it under the terms of version 2 the GNU General Public License as
> - * published by the Free Software Foundation.
> - *
> - * 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. If not, see <http://www.gnu.org/licenses/>.
> - ***********************************************************************
> - * File: netns_netlink.c
> +// SPDX-License-Identifier: GPL-2.0
> +/*
> + * Copyright (c) 2014 Red Hat, Inc.
> + * Copyright (c) 2021 Petr Vorel <pvorel@suse.cz>
> + */
> +
> +/*\
> + * [DESCRIPTION]
> *
> * Tests a netlink interface inside a new network namespace.
> - * Description:
> - * 1. Unshares a network namespace (so network related actions
> - * have no effect on a real system)
> - * 2. Forks a child which creates a NETLINK_ROUTE netlink socket
> - * and listens to RTMGRP_LINK (network interface create/delete/up/down)
> - * multicast group.
> - * 4. Child then waits for parent approval to receive data from socket
> - * 3. Parent creates a new TAP interface (dummy0) and immediately
> - * removes it (which should generate some data in child's netlink socket).
> - * Then it allows child to continue.
> - * 4. As the child was listening to RTMGRP_LINK multicast group, it should
> - * detect the new interface creation/deletion (by reading data from netlink
> - * socket), if so, the test passes, otherwise it fails.
> - */
> + *
> + * - Unshares a network namespace (so network related actions
> + * have no effect on a real system).
> + * - Forks a child which creates a NETLINK_ROUTE netlink socket
> + * and listens to RTMGRP_LINK (network interface create/delete/up/down)
> + * multicast group.
> + * - Child then waits for parent approval to receive data from socket
> + * - Parent creates a new TAP interface (dummy0) and immediately
> + * removes it (which should generate some data in child's netlink socket).
> + * Then it allows child to continue.
> + * - As the child was listening to RTMGRP_LINK multicast group, it should
> + * detect the new interface creation/deletion (by reading data from netlink
> + * socket), if so, the test passes, otherwise it fails.
> +\*/
>
> #define _GNU_SOURCE
> #include <sys/wait.h>
> @@ -40,29 +33,13 @@
> #include <stdio.h>
> #include <stdlib.h>
> #include <errno.h>
> -#include "netns_helper.h"
> -#include "test.h"
> -#include "safe_macros.h"
> -
> -#define MAX_TRIES 1000
> -#define IP_TUNTAP_MIN_VER 100519
> +#include <sched.h>
>
> -char *TCID = "netns_netlink";
> -int TST_TOTAL = 1;
> -
> -static void cleanup(void)
> -{
> - tst_rmdir();
> -}
> +#include "tst_test.h"
> +#include "tst_safe_macros.h"
> +#include "lapi/namespaces_constants.h"
>
> -static void setup(void)
> -{
> - tst_require_root();
> - check_iproute(IP_TUNTAP_MIN_VER);
> - check_netns();
> - tst_tmpdir();
> - TST_CHECKPOINT_INIT(tst_rmdir);
> -}
> +#define MAX_TRIES 1000
>
> int child_func(void)
static int child_func(void)
> {
> @@ -71,8 +48,7 @@ int child_func(void)
> char buffer[4096];
> struct nlmsghdr *nlh;
>
> - /* child will listen to a network interface create/delete/up/down
> - * events */
> + /* child will listen to a network interface create/delete/up/down events */
> memset(&sa, 0, sizeof(sa));
> sa.nl_family = AF_NETLINK;
> sa.nl_groups = RTMGRP_LINK;
> @@ -89,7 +65,7 @@ int child_func(void)
> }
>
> /* waits for parent to create an interface */
> - TST_SAFE_CHECKPOINT_WAIT(NULL, 0);
> + TST_CHECKPOINT_WAIT(0);
>
> /* To get rid of "resource temporarily unavailable" errors
> * when testing with -i option */
> @@ -121,60 +97,49 @@ int child_func(void)
> return 0;
> }
We can simplify the code here by using SAFE_MACROS() which is allowed in
new library.
> -static void test(void)
> +static void test_netns_netlink(void)
> {
> pid_t pid;
> int status;
>
> /* unshares the network namespace */
> - if (unshare(CLONE_NEWNET) == -1)
> - tst_brkm(TBROK | TERRNO, cleanup, "unshare failed");
> + SAFE_UNSHARE(CLONE_NEWNET);
>
> - pid = tst_fork();
> - if (pid < 0) {
> - tst_brkm(TBROK | TERRNO, cleanup, "fork failed");
> - }
> + pid = SAFE_FORK();
> if (pid == 0) {
> _exit(child_func());
No need for _exit() here, _exit() is to be used from signal handlers.
> }
>
> /* creates TAP network interface dummy0 */
> if (WEXITSTATUS(system("ip tuntap add dev dummy0 mode tap")))
> - tst_brkm(TBROK, cleanup, "system() failed");
> + tst_brk(TBROK, "system() failed");
>
> /* removes previously created dummy0 device */
> if (WEXITSTATUS(system("ip tuntap del mode tap dummy0")))
> - tst_brkm(TBROK, cleanup, "system() failed");
> + tst_brk(TBROK, "system() failed");
>
> /* allow child to continue */
> - TST_SAFE_CHECKPOINT_WAKE(cleanup, 0);
> -
> + TST_CHECKPOINT_WAKE(0);
>
> - SAFE_WAITPID(cleanup, pid, &status, 0);
> + SAFE_WAITPID(pid, &status, 0);
> if (WIFEXITED(status) && WEXITSTATUS(status) != 0) {
> - tst_resm(TFAIL, "netlink interface fail");
> + tst_res(TFAIL, "netlink interface fail");
> return;
> }
We can also get rid of this result propagation as we can:
- use SAFE_MACROS in child
- use tst_res() in child as:
static void child_func(void)
{
...
if (event_found)
tst_res(TPASS, "...");
else
tst_res(TFAIL, "...");
exit(0);
}
And with that all we have to do is a call to tst_reap_children()
> if (WIFSIGNALED(status)) {
> - tst_resm(TFAIL, "child was killed with signal %s",
> + tst_res(TFAIL, "child was killed with signal %s",
> tst_strsig(WTERMSIG(status)));
> return;
> }
>
> - tst_resm(TPASS, "netlink interface pass");
> + tst_res(TPASS, "netlink interface pass");
> }
>
> -int main(int argc, char *argv[])
> -{
> - int lc;
> -
> - tst_parse_opts(argc, argv, NULL, NULL);
> -
> - setup();
>
> - for (lc = 0; TEST_LOOPING(lc); lc++)
> - test();
> -
> - cleanup();
> - tst_exit();
> -}
> +static struct tst_test test = {
> + .test_all = test_netns_netlink,
> + .needs_checkpoints = 1,
> + .needs_tmpdir = 1,
> + .needs_root = 1,
> + .forks_child = 1,
> +};
> --
> 2.30.2
>
--
Cyril Hrubis
chrubis@suse.cz
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