Pablo Neira Ayuso
2019-Jun-07 14:28 UTC
[Bridge] [PATCH RESEND net-next 1/2] br_netfilter: add struct netns_brnf
On Fri, Jun 07, 2019 at 03:25:16PM +0200, Christian Brauner wrote:> On Thu, Jun 06, 2019 at 06:30:35PM +0200, Pablo Neira Ayuso wrote: > > On Thu, Jun 06, 2019 at 05:19:39PM +0200, Christian Brauner wrote: > > > On Thu, Jun 06, 2019 at 08:14:40AM -0700, Stephen Hemminger wrote: > > > > On Thu, 6 Jun 2019 13:41:41 +0200 > > > > Christian Brauner <christian at brauner.io> wrote: > > > > > > > > > +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; > > > > > +}; > > > > > > > > Do you really need to waste four bytes for each > > > > flag value. If you use a u8 that would work just as well. > > > > > > I think we had discussed something like this but the problem why we > > > can't do this stems from how the sysctl-table stuff is implemented. > > > I distinctly remember that it couldn't be done with a flag due to that. > > > > Could you define a pernet_operations object? I mean, define the id and size > > fields, then pass it to register_pernet_subsys() for registration. > > Similar to what we do in net/ipv4/netfilter/ipt_CLUSTER.c, see > > clusterip_net_ops and clusterip_pernet() for instance. > > Hm, I don't think that would work. The sysctls for br_netfilter are > located in /proc/sys/net/bridge under /proc/sys/net which is tightly > integrated with the sysctls infrastructure for all of net/ and all the > folder underneath it including "core", "ipv4" and "ipv6". > I don't think creating and managing files manually in /proc/sys/net is > going to fly. It also doesn't seem very wise from a consistency and > complexity pov. I'm also not sure if this would work at all wrt to file > creation and reference counting if there are two different ways of > managing them in the same subfolder... > (clusterip creates files manually underneath /proc/net which probably is > the reason why it gets away with it.)br_netfilter is now a module, and br_netfilter_hooks.c is part of it IIRC, this file registers these sysctl entries from the module __init path. It would be a matter of adding a new .init callback to the existing brnf_net_ops object in br_netfilter_hooks.c. Then, call register_net_sysctl() from this .init callback to register the sysctl entries per netns. There is already a brnf_net area that you can reuse for this purpose, to place these pernetns flags... struct brnf_net { bool enabled; }; which is going to be glad to have more fields (under the #ifdef CONFIG_SYSCTL) there.
Pablo Neira Ayuso
2019-Jun-07 14:43 UTC
[Bridge] [PATCH RESEND net-next 1/2] br_netfilter: add struct netns_brnf
On Fri, Jun 07, 2019 at 04:28:58PM +0200, Pablo Neira Ayuso wrote:> On Fri, Jun 07, 2019 at 03:25:16PM +0200, Christian Brauner wrote: > > On Thu, Jun 06, 2019 at 06:30:35PM +0200, Pablo Neira Ayuso wrote: > > > On Thu, Jun 06, 2019 at 05:19:39PM +0200, Christian Brauner wrote: > > > > On Thu, Jun 06, 2019 at 08:14:40AM -0700, Stephen Hemminger wrote: > > > > > On Thu, 6 Jun 2019 13:41:41 +0200 > > > > > Christian Brauner <christian at brauner.io> wrote: > > > > > > > > > > > +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; > > > > > > +}; > > > > > > > > > > Do you really need to waste four bytes for each > > > > > flag value. If you use a u8 that would work just as well. > > > > > > > > I think we had discussed something like this but the problem why we > > > > can't do this stems from how the sysctl-table stuff is implemented. > > > > I distinctly remember that it couldn't be done with a flag due to that. > > > > > > Could you define a pernet_operations object? I mean, define the id and size > > > fields, then pass it to register_pernet_subsys() for registration. > > > Similar to what we do in net/ipv4/netfilter/ipt_CLUSTER.c, see > > > clusterip_net_ops and clusterip_pernet() for instance. > > > > Hm, I don't think that would work. The sysctls for br_netfilter are > > located in /proc/sys/net/bridge under /proc/sys/net which is tightly > > integrated with the sysctls infrastructure for all of net/ and all the > > folder underneath it including "core", "ipv4" and "ipv6". > > I don't think creating and managing files manually in /proc/sys/net is > > going to fly. It also doesn't seem very wise from a consistency and > > complexity pov. I'm also not sure if this would work at all wrt to file > > creation and reference counting if there are two different ways of > > managing them in the same subfolder... > > (clusterip creates files manually underneath /proc/net which probably is > > the reason why it gets away with it.) > > br_netfilter is now a module, and br_netfilter_hooks.c is part of it > IIRC, this file registers these sysctl entries from the module __init > path. > > It would be a matter of adding a new .init callback to the existing > brnf_net_ops object in br_netfilter_hooks.c. Then, call > register_net_sysctl() from this .init callback to register the sysctl > entries per netns.Actually, this is what you patch is doing...> There is already a brnf_net area that you can reuse for this purpose, > to place these pernetns flags... > > struct brnf_net { > bool enabled; > }; > > which is going to be glad to have more fields (under the #ifdef > CONFIG_SYSCTL) there.... except that struct brnf_net is not used to store the ctl_table. So what I'm propose should be result in a small update to your patch 2/2.