On Wed, 2017-08-09 at 08:52 +0300, Nikolay Borisov wrote:
> Commit dcd87999d415 ("igmp: net: Move igmp namespace init to correct file")
> moved the igmp sysctls initialization from tcp_sk_init to igmp_net_init. This
> function is only called as part of per-namespace initialization, only if
> CONFIG_IP_MULTICAST is defined, otherwise igmp_mc_init() call in ip_init is
> compiled out, casuing the igmp pernet ops to not be registerd and those sysctl
> being left initialized with 0. However, there are certain functions, such as
> ip_mc_join_group which are always compiled and make use of some of those
> sysctls. Let's do a partial revert of the aforementioned commit and move the
> sysctl initialization back into tcp_sk_init, that way they will always have
> sane values.
>
> Fixes: dcd87999d415 ("igmp: net: Move igmp namespace init to correct file")
> Link: https://bugzilla.kernel.org/show_bug.cgi?id=196595
> Reported-by: Gerardo Exequiel Pozzi <vmlinuz...@gmail.com>
> Tested-by: Gerardo Exequiel Pozzi <vmlinuz...@gmail.com>
> Signed-off-by: Nikolay Borisov <nbori...@suse.com>
> Cc: <sta...@vger.kernel.org> # 4.6
> ---
> net/ipv4/igmp.c | 6 ------
> net/ipv4/tcp_ipv4.c | 6 ++++++
> 2 files changed, 6 insertions(+), 6 deletions(-)
>
> diff --git a/net/ipv4/igmp.c b/net/ipv4/igmp.c
> index 28f14afd0dd3..498706b072fb 100644
> --- a/net/ipv4/igmp.c
> +++ b/net/ipv4/igmp.c
> @@ -2974,12 +2974,6 @@ static int __net_init igmp_net_init(struct net *net)
> goto out_sock;
> }
>
> - /* Sysctl initialization */
> - net->ipv4.sysctl_igmp_max_memberships = 20;
> - net->ipv4.sysctl_igmp_max_msf = 10;
> - /* IGMP reports for link-local multicast groups are enabled by default
> */
> - net->ipv4.sysctl_igmp_llm_reports = 1;
> - net->ipv4.sysctl_igmp_qrv = 2;
> return 0;
>
> out_sock:
> diff --git a/net/ipv4/tcp_ipv4.c b/net/ipv4/tcp_ipv4.c
> index a20e7f03d5f7..64ba2c93d396 100644
> --- a/net/ipv4/tcp_ipv4.c
> +++ b/net/ipv4/tcp_ipv4.c
> @@ -2528,6 +2528,12 @@ static int __net_init tcp_sk_init(struct net *net)
> net->ipv4.sysctl_tcp_window_scaling = 1;
> net->ipv4.sysctl_tcp_timestamps = 1;
>
> + net->ipv4.sysctl_igmp_max_memberships = 20;
> + net->ipv4.sysctl_igmp_max_msf = 10;
> + /* IGMP reports for link-local multicast groups are enabled by default
> */
> + net->ipv4.sysctl_igmp_llm_reports = 1;
> + net->ipv4.sysctl_igmp_qrv = 2;
> +
>
I would rather move this to inet_init_net(), since IGMP does not belong
to TCP.
Thanks !
