On Tue, 2006-08-01 at 11:29 -0700, Stephen Hemminger wrote: > On Tue, 01 Aug 2006 19:10:09 +0200 > Balazs Scheidler <[EMAIL PROTECTED]> wrote: > > > Hi, > > > > I would like to easily match a set of dynamically created interfaces > > from my packet filter rules. The attached patch forms the basis of my > > implementation and I would like to know whether something like this is > > mergeable to mainline. > > > > The use-case is as follows: > > > > * I have two different subsystems creating interfaces dynamically (for > > example pptpd and serial pppd lines, each creating dynamic pppX > > interfaces), > > * I would like to assign a different set of iptables rules for these > > clients, > > * I would like to react to a new interface being added to a specific set > > in a userspace application, > > > > The reasons I see this needs new kernel functionality: > > > > * iptables supports wildcard interface matching (for example "iptables > > -i ppp+"), but as the names of the interfaces used by PPTPD and PPPD > > cannot be distinguished this way, this is not enough, > > * Reloading the iptables ruleset everytime a new interface comes up is > > not really feasible, as it abrupts packet processing, and validating the > > ruleset in the kernel can take significant amount of time, > > * the kernel change is very simple, adapting userspace to this change is > > also very simple, and in userspace various software packages can easily > > interoperate with each-other once this is merged. > > > > The implementation: > > > > Each interface can belong to a single "group" at a time, an interface > > comes up without being a member in any of the groups. > > > > Userspace can assign interfaces to groups after being created, this > > would typically be performed in /etc/ppp/ip-up.d (and similar) scripts. > > > > In spirit "interface group" is somewhat similar to the "routing > > protocol" field for routing entries, which contains information on which > > routing daemon was responsible for adding the given route entry. > > > > [snip]
> I like the concept, but it probably needs more review. > > There is a bigger issue, which is how should the network device namespace > exist? There are virtualization efforts, that want to virtualize it, > and network device names have always lived in a parallel universe. > I don't expect your patch to solve this... I have read the OLS paper on virtualization, it states that the current state of affairs is that struct net_device will be assigned to one specific namespace. As my change changes struct net_device itself, I expect to work without problems when virtualization comes, the interface group can be interpreted on a per-namespace basis. There probably will be several iptables rulesets when the time comes, one for each namespace, but again, struct net_device will be assigned to a namespace, and the proper iptables tables will be iterated based on the net_device assignment. Am I missing something? -- Bazsi - To unsubscribe from this list: send the line "unsubscribe netdev" in the body of a message to [EMAIL PROTECTED] More majordomo info at http://vger.kernel.org/majordomo-info.html
