Subject: Re: [PATCH v3 bpf-next 3/3] selftests/bpf: Ensure cgroup/connect{4,6} programs can bind unpriv ICMP ping

From: Martin KaFai Lau <[email-masked]>
Date: Thu, 8 Sep 2022 16:32:39 -0700

On 9/8/22 4:16 PM, YiFei Zhu wrote:
> +void test_connect_ping(void)
> +{
> +	struct connect_ping *skel;
> +	int cgroup_fd;
> +
> +	if (!ASSERT_OK(unshare(CLONE_NEWNET | CLONE_NEWNS), "unshare"))
> +		return;
> +
> +	/* overmount sysfs, and making original sysfs private so overmount
> +	 * does not propagate to other mntns.
> +	 */
> +	if (!ASSERT_OK(mount("none", "/sys", NULL, MS_PRIVATE, NULL),
> +		       "remount-private-sys"))
> +		return;
> +	if (!ASSERT_OK(mount("sysfs", "/sys", "sysfs", 0, NULL),
> +		       "mount-sys"))
> +		return;
> +	if (!ASSERT_OK(mount("bpffs", "/sys/fs/bpf", "bpf", 0, NULL),
> +		       "mount-bpf"))
> +		goto clean_mount;
> +
> +	if (!ASSERT_OK(system("ip link set dev lo up"), "lo-up"))
> +		goto clean_mount;
> +	if (!ASSERT_OK(system("ip addr add 1.1.1.1 dev lo"), "lo-addr-v4"))
> +		goto clean_mount;
> +	if (!ASSERT_OK(system("ip -6 addr add 2001:db8::1 dev lo"), "lo-addr-v6"))
> +		goto clean_mount;
> +	if (write_sysctl("/proc/sys/net/ipv4/ping_group_range", "0 0"))
> +		goto clean_mount;
> +
> +	cgroup_fd = test__join_cgroup("/connect_ping");
> +	if (!ASSERT_GE(cgroup_fd, 0, "cg-create"))
> +		goto clean_mount;
> +
> +	skel = connect_ping__open_and_load();
> +	if (!ASSERT_OK_PTR(skel, "skel-load"))
> +		goto close_cgroup;
> +	skel->links.connect_v4_prog =
> +		bpf_program__attach_cgroup(skel->progs.connect_v4_prog, cgroup_fd);
> +	if (!ASSERT_OK_PTR(skel->links.connect_v4_prog, "cg-attach-v4"))
> +		goto close_cgroup;

connect_ping__destroy() is also needed in this error path.

I had already mentioned that in v2.  I went back to v2 and noticed my 
editor some how merged my reply with the previous quoted line ">".  A 
similar thing happened in my recent replies also.  I hope it appears 
fine this time.

> +	skel->links.connect_v6_prog =
> +		bpf_program__attach_cgroup(skel->progs.connect_v6_prog, cgroup_fd);
> +	if (!ASSERT_OK_PTR(skel->links.connect_v6_prog, "cg-attach-v6"))
> +		goto close_cgroup;

Same here.