Re: [B.A.T.M.A.N.] [PATCH 06/15] batman-adv: Distributed ARP Table - add snooping functions for ARP messages
Hey David, thanks for your answer, On Thu, May 24, 2012 at 01:54:57AM -0400, David Miller wrote: From: Sven Eckelmann s...@narfation.org Date: Thu, 24 May 2012 07:34:12 +0200 _You_ were the person that declined the pull request because _you_ wanted to rewrite the ARP handling. So _you_ are the person that has the insight in _your_ plans. Either _you_ tell us what is _your_ problem with it or _you_ will have to point us to a person that knows _you_. If I say that you must not use ARP nor neighbour layer internals, it doesn't mean that I have to come up with the alternative implementation for you. well, thats pretty much answers it. If we must not use ARP or neighbour internals, even after your rewrite (?), we have to come up with an alternative in any case (write our own backened). We don't expect you to come up with an alternative implementation, but as you are the one accepting the patches (or not) we need to know why you decline something and what the problem is so we ca n work around or improve. Thanks Simon signature.asc Description: Digital signature
Re: [B.A.T.M.A.N.] [PATCH 06/15] batman-adv: Distributed ARP Table - add snooping functions for ARP messages
Hello David, we are a little bit in a pinch here - the DAT feature sent with this patchset was developed for a long time, and we need your decision to move on as more and more patches depend on it: * should we rewrite DAT to use our own ARP table/backend or * can we use the ARP neighbor table in another way, maybe after your changes? We thought that re-using existing infrastructure would be smarter, but if you disagree, please tell us so - we would like to get this feature finally upstream and need your input to make the neccesary changes. Thanks Simon On Thu, May 17, 2012 at 07:53:54PM +0800, Marek Lindner wrote: David, On Tuesday, May 01, 2012 08:59:04 David Miller wrote: From: Antonio Quartulli or...@autistici.org Date: Tue, 1 May 2012 00:22:30 +0200 However this patch also contains a procedure which queries the neigh table in order to understand whether a given host is known or not. Would it be possible to do that in another way (Without manually touching the table)? Instead, in the next patch (patch 06/15) batman-adv manually increase the neigh timeouts. Do you think we should avoid doing that as well? If we are allowed to do that, how can we perform the same operation in a cleaner way? Last question: why can't other modules use exported functions? Are you going to change them as well? I really don't have time to discuss your neigh issues right now as I'm busy speaking at conferences and dealing with the backlog of other patches. You'll need to find someone else to discuss it with you, sorry. I hope now is a good moment to bring the questions back onto the table. We still are not sure how to proceed because we have no clear picture of what is going to come and how the exported functions are supposed to be used. David, if you don't have the time to discuss the ARP handling with us could you name someone who knows your plans and the code equally well ? So far, nobody has stepped up. let me add another piece of information: The distributed ARP table does not really depend on the kernel's ARP table. We can easily write our own backend to be totally independent of the kernel's ARP table. Initially, we thought it might be considered a smart move if the code made use of existing kernel infrastructure instead of writing our own storage / user space API / etc, hence duplicating what is already there. But if you feel this is the better way forward we certainly will make the necessary changes. Regards, Marek signature.asc Description: Digital signature
Re: [B.A.T.M.A.N.] [PATCH 06/15] batman-adv: Distributed ARP Table - add snooping functions for ARP messages
From: Sven Eckelmann s...@narfation.org Date: Thu, 24 May 2012 07:34:12 +0200 _You_ were the person that declined the pull request because _you_ wanted to rewrite the ARP handling. So _you_ are the person that has the insight in _your_ plans. Either _you_ tell us what is _your_ problem with it or _you_ will have to point us to a person that knows _you_. If I say that you must not use ARP nor neighbour layer internals, it doesn't mean that I have to come up with the alternative implementation for you. Now, you can ask others on the netdev list for suggestions, but you can't expect me to be the direct and only responder on things like that.
Re: [B.A.T.M.A.N.] [PATCH 06/15] batman-adv: Distributed ARP Table - add snooping functions for ARP messages
David, On Tuesday, May 01, 2012 08:59:04 David Miller wrote: From: Antonio Quartulli or...@autistici.org Date: Tue, 1 May 2012 00:22:30 +0200 However this patch also contains a procedure which queries the neigh table in order to understand whether a given host is known or not. Would it be possible to do that in another way (Without manually touching the table)? Instead, in the next patch (patch 06/15) batman-adv manually increase the neigh timeouts. Do you think we should avoid doing that as well? If we are allowed to do that, how can we perform the same operation in a cleaner way? Last question: why can't other modules use exported functions? Are you going to change them as well? I really don't have time to discuss your neigh issues right now as I'm busy speaking at conferences and dealing with the backlog of other patches. You'll need to find someone else to discuss it with you, sorry. I hope now is a good moment to bring the questions back onto the table. We still are not sure how to proceed because we have no clear picture of what is going to come and how the exported functions are supposed to be used. David, if you don't have the time to discuss the ARP handling with us could you name someone who knows your plans and the code equally well ? So far, nobody has stepped up. let me add another piece of information: The distributed ARP table does not really depend on the kernel's ARP table. We can easily write our own backend to be totally independent of the kernel's ARP table. Initially, we thought it might be considered a smart move if the code made use of existing kernel infrastructure instead of writing our own storage / user space API / etc, hence duplicating what is already there. But if you feel this is the better way forward we certainly will make the necessary changes. Regards, Marek
Re: [B.A.T.M.A.N.] [PATCH 06/15] batman-adv: Distributed ARP Table - add snooping functions for ARP messages
David, On Tuesday, May 01, 2012 08:59:04 David Miller wrote: From: Antonio Quartulli or...@autistici.org Date: Tue, 1 May 2012 00:22:30 +0200 However this patch also contains a procedure which queries the neigh table in order to understand whether a given host is known or not. Would it be possible to do that in another way (Without manually touching the table)? Instead, in the next patch (patch 06/15) batman-adv manually increase the neigh timeouts. Do you think we should avoid doing that as well? If we are allowed to do that, how can we perform the same operation in a cleaner way? Last question: why can't other modules use exported functions? Are you going to change them as well? I really don't have time to discuss your neigh issues right now as I'm busy speaking at conferences and dealing with the backlog of other patches. You'll need to find someone else to discuss it with you, sorry. I hope now is a good moment to bring the questions back onto the table. We still are not sure how to proceed because we have no clear picture of what is going to come and how the exported functions are supposed to be used. David, if you don't have the time to discuss the ARP handling with us could you name someone who knows your plans and the code equally well ? So far, nobody has stepped up. Thanks, Marek
Re: [B.A.T.M.A.N.] [PATCH 06/15] batman-adv: Distributed ARP Table - add snooping functions for ARP messages
From: Antonio Quartulli or...@autistici.org Date: Sun, 29 Apr 2012 10:57:38 +0200 In case of an ARP message going in or out the soft_iface, it is intercepted and a special action is performed. In particular the DHT helper functions previously implemented are used to store all the ARP entries belonging to the network in order to provide a fast and unicast lookup instead of the classic broadcast flooding mechanism. Each node stores the entries it is responsible for (following the DHT rules) in its soft_iface ARP table. This makes it possible to reuse the kernel data structures and functions for ARP management. Signed-off-by: Antonio Quartulli or...@autistici.org Sorry, I'm not letting subsystems outside of net/ipv4/arp.c and related code make changes to the ARP table. I plan to make major surgery to the way neighbour table entries are handled and therefore the less people who get their grubby paws directly in there, the better. Find a way to propagate the ARP packet into the properl ARP receive path to cause the state update to occur, I'm not letting you trigger it by hand in the batman-adv code. Sorry.
Re: [B.A.T.M.A.N.] [PATCH 06/15] batman-adv: Distributed ARP Table - add snooping functions for ARP messages
On Mon, Apr 30, 2012 at 01:05:55 -0400, David Miller wrote: From: Antonio Quartulli or...@autistici.org Date: Sun, 29 Apr 2012 10:57:38 +0200 In case of an ARP message going in or out the soft_iface, it is intercepted and a special action is performed. In particular the DHT helper functions previously implemented are used to store all the ARP entries belonging to the network in order to provide a fast and unicast lookup instead of the classic broadcast flooding mechanism. Each node stores the entries it is responsible for (following the DHT rules) in its soft_iface ARP table. This makes it possible to reuse the kernel data structures and functions for ARP management. Signed-off-by: Antonio Quartulli or...@autistici.org Sorry, I'm not letting subsystems outside of net/ipv4/arp.c and related code make changes to the ARP table. I plan to make major surgery to the way neighbour table entries are handled and therefore the less people who get their grubby paws directly in there, the better. Find a way to propagate the ARP packet into the properl ARP receive path to cause the state update to occur, I'm not letting you trigger it by hand in the batman-adv code. Sorry. Hello David, I perfectly understand. We did it that way because we thought that we could use the exported API. At this point, in my honest opinion, it is better to postpone this new feature for a later pull request. However this patch also contains a procedure which queries the neigh table in order to understand whether a given host is known or not. Would it be possible to do that in another way (Without manually touching the table)? Instead, in the next patch (patch 06/15) batman-adv manually increase the neigh timeouts. Do you think we should avoid doing that as well? If we are allowed to do that, how can we perform the same operation in a cleaner way? Last question: why can't other modules use exported functions? Are you going to change them as well? Thank you very much, -- Antonio Quartulli ..each of us alone is worth nothing.. Ernesto Che Guevara pgpx6CUtZVcO1.pgp Description: PGP signature
Re: [B.A.T.M.A.N.] [PATCH 06/15] batman-adv: Distributed ARP Table - add snooping functions for ARP messages
From: Antonio Quartulli or...@autistici.org Date: Tue, 1 May 2012 00:22:30 +0200 However this patch also contains a procedure which queries the neigh table in order to understand whether a given host is known or not. Would it be possible to do that in another way (Without manually touching the table)? Instead, in the next patch (patch 06/15) batman-adv manually increase the neigh timeouts. Do you think we should avoid doing that as well? If we are allowed to do that, how can we perform the same operation in a cleaner way? Last question: why can't other modules use exported functions? Are you going to change them as well? I really don't have time to discuss your neigh issues right now as I'm busy speaking at conferences and dealing with the backlog of other patches. You'll need to find someone else to discuss it with you, sorry.
