Pablo Neira Ayuso
2018-Nov-27 00:20 UTC
[Bridge] [PATCH net-next 1/2] br_netfilter: add struct netns_brnf
Hi, On Wed, Nov 07, 2018 at 02:48:58PM +0100, Christian Brauner wrote: [...]> diff --git a/include/net/netns/netfilter.h b/include/net/netns/netfilter.h > index ca043342c0eb..eedbd1ac940e 100644 > --- a/include/net/netns/netfilter.h > +++ b/include/net/netns/netfilter.h > @@ -35,4 +35,20 @@ struct netns_nf { > bool defrag_ipv6; > #endif > }; > + > +struct netns_brnf { > +#ifdef CONFIG_SYSCTL > + struct ctl_table_header *ctl_hdr; > +#endif > + > + /* default value is 1 */ > + int call_iptables; > + int call_ip6tables; > + int call_arptables; > + > + /* default value is 0 */ > + int filter_vlan_tagged; > + int filter_pppoe_tagged; > + int pass_vlan_indev; > +};I have spun on this several times, wondering if there's a way to avoid scratching these many bytes per netns to expose these sysctl entries that are plain on/off toggles... You said this:>Currently, the /proc/sys/net/bridge folder is only created in the >initial network namespaceI think we can add one single sysctl to expose these as flags from net namespaces. Idea is to keep the existing (legacy) sysctl entries for init_net only, and add a new single new one that exposes these as flags (should be also available for consistency in init_net I'd suggest). Flags could be map in this way, eg. 0x1 call_iptables 0x2 call_ip6tables 0x4 call_arptables 0x8 filter_vlan_tagged ... Also documentation would be good to have for this. Would this idea fly for you? Thanks.
Christian Brauner
2018-Nov-27 02:20 UTC
[Bridge] [PATCH net-next 1/2] br_netfilter: add struct netns_brnf
On Tue, Nov 27, 2018 at 01:20:47AM +0100, Pablo Neira Ayuso wrote:> Hi, > > On Wed, Nov 07, 2018 at 02:48:58PM +0100, Christian Brauner wrote: > [...] > > diff --git a/include/net/netns/netfilter.h b/include/net/netns/netfilter.h > > index ca043342c0eb..eedbd1ac940e 100644 > > --- a/include/net/netns/netfilter.h > > +++ b/include/net/netns/netfilter.h > > @@ -35,4 +35,20 @@ struct netns_nf { > > bool defrag_ipv6; > > #endif > > }; > > + > > +struct netns_brnf { > > +#ifdef CONFIG_SYSCTL > > + struct ctl_table_header *ctl_hdr; > > +#endif > > + > > + /* default value is 1 */ > > + int call_iptables; > > + int call_ip6tables; > > + int call_arptables; > > + > > + /* default value is 0 */ > > + int filter_vlan_tagged; > > + int filter_pppoe_tagged; > > + int pass_vlan_indev; > > +}; > > I have spun on this several times, wondering if there's a way to avoid > scratching these many bytes per netns to expose these sysctl entries > that are plain on/off toggles... You said this: > > >Currently, the /proc/sys/net/bridge folder is only created in the > >initial network namespace > > I think we can add one single sysctl to expose these as flags from net > namespaces. Idea is to keep the existing (legacy) sysctl entries for > init_net only, and add a new single new one that exposes these as flags > (should be also available for consistency in init_net I'd suggest). > Flags could be map in this way, eg. > > 0x1 call_iptables > 0x2 call_ip6tables > 0x4 call_arptables > 0x8 filter_vlan_tagged > ... > > Also documentation would be good to have for this. > > Would this idea fly for you? Thanks.My suggestion is to keep these files per network namespace but have a single flag argument in struct netns_brnf: +struct netns_brnf { +#ifdef CONFIG_SYSCTL + struct ctl_table_header *ctl_hdr; +#endif + + /* default value is 1 */ + unsigned int filter_flags; +}; #define BRNF_CALL_IPTABLES 0x1 #define BRNF_CALL_IP6TABLES 0x2 #define BRNF_CALL_ARPTABLES 0x4 #define BRNF_CALL_VLAN_TAGGED 0x8 a write to the corresponding file would then cause the flag to be set or unset in filter_flags. This way we are a) space-efficient internally not bloating struct net while b) not breaking running tools in non-initial network namespaces that expect the files to be there. b) is really the important bit here. :) Christian