Porting OpenBSD MPLS to FreeBSD
Hi freebsd-net@, Long time no see. I've gotten a (Ports) commit bit since then. I haven't been very active in TCP/IP hacking as of late, as more recently I've been more focused on GNOME packages and some GPU drivers. Going back, I'm thinking about porting OpenBSD's MPLS to FreeBSD. I have a two questions: * Is porting OpenBSD MPLS to FreeBSD feasible, or are we better off doing a from-scratch implementation based on netgraph? * Would some of the other committers here be willing to mentor/help me if needed? Unlike my old IPFW patches which got nowhere (plus I no longer use IPFW), I feel this is more something that could be useful when running FreeBSD as a router, but hasn't really been done. -Neel (nc@)
Re: Porting OpenBSD MPLS to FreeBSD
On Fri, Nov 19, 2021 at 11:17:42AM -0800, Neel Chauhan wrote: > * Is porting OpenBSD MPLS to FreeBSD feasible, or are we better off doing > a from-scratch implementation based on netgraph? I'd prefer a netgraph approach, if possible. It helps to concentrate on the important things. > * Would some of the other committers here be willing to mentor/help me if > needed? For the netgraph part ...
Re: Porting OpenBSD MPLS to FreeBSD
> Hi freebsd-net@, > > Long time no see. I've gotten a (Ports) commit bit since then. > > I haven't been very active in TCP/IP hacking as of late, as more > recently I've been more focused on GNOME packages and some GPU drivers. > > Going back, I'm thinking about porting OpenBSD's MPLS to FreeBSD. I have had similiar thoughts on and off over the years, and one pretty solid "want" for this. > > I have a two questions: > > * Is porting OpenBSD MPLS to FreeBSD feasible, or are we better off > doing a from-scratch implementation based on netgraph? Feasible, yes, as to the better off part that probably depends on who you ask. MPLS is not that complicated to implement, so doing it either way all depends on weither you want to deal with netgraph, or the kernel network interface code. Its also probably fairly trivial to do both with a great deal of shared code. > > * Would some of the other committers here be willing to mentor/help me > if needed? Yes. > > Unlike my old IPFW patches which got nowhere (plus I no longer use > IPFW), I feel this is more something that could be useful when running > FreeBSD as a router, but hasn't really been done. I can probably arrange a telco size beta tester too... unless there interested has gone away, which I doubt. > -Neel (nc@) -- Rod Grimes rgri...@freebsd.org
Re: Porting OpenBSD MPLS to FreeBSD
> On 19 Nov 2021, at 19:17, Neel Chauhan wrote: > > Hi freebsd-net@, > > Long time no see. I've gotten a (Ports) commit bit since then. > > I haven't been very active in TCP/IP hacking as of late, as more recently > I've been more focused on GNOME packages and some GPU drivers. > > Going back, I'm thinking about porting OpenBSD's MPLS to FreeBSD. > > I have a two questions: > > * Is porting OpenBSD MPLS to FreeBSD feasible, or are we better off doing a > from-scratch implementation based on netgraph? It depends. MPLS implementaiton can be splitted into multiple logical parts - dataplane (input, control, output, forward) and control plane (programming ip routes+mpls and mpls-only fowarding state). Some parts of the former can indeed be imported from OpenBSD. However, most of the control plane part have to be written from scratch. Finally, it may be desired to maintain an programming interface close to the one already implemented in major routing SW (frr, bird) - I guess that would be simpler to achieve with native, non-netgraph implementation. > > * Would some of the other committers here be willing to mentor/help me if > needed? I’d love to. Most of my the routing-related stack changes (modular lookup framework, nexthops, rtsock cleanups) were done to enable efficient kernel-based MPLS implementation. > > Unlike my old IPFW patches which got nowhere (plus I no longer use IPFW), I > feel this is more something that could be useful when running FreeBSD as a > router, but hasn't really been done. > > -Neel (nc@) >
Re: Porting OpenBSD MPLS to FreeBSD
Hi Alexander, On 2021-12-04 10:42, Alexander V. Chernikov wrote: * Is porting OpenBSD MPLS to FreeBSD feasible, or are we better off doing a from-scratch implementation based on netgraph? It depends. MPLS implementaiton can be splitted into multiple logical parts - dataplane (input, control, output, forward) and control plane (programming ip routes+mpls and mpls-only fowarding state). Some parts of the former can indeed be imported from OpenBSD. However, most of the control plane part have to be written from scratch. Finally, it may be desired to maintain an programming interface close to the one already implemented in major routing SW (frr, bird) - I guess that would be simpler to achieve with native, non-netgraph implementation. Thanks for your description. I haven't started work yet, but I'd probably import the dataplane from OpenBSD where I can and do a new control plane, maybe that with a FRR/Bird-compatible API. I wasn't too keen on using netgraph anyways, I felt it was unnecessary complexity. If I were to work on this, would I be better off starting with the dataplane or control plane? * Would some of the other committers here be willing to mentor/help me if needed? I’d love to. Most of my the routing-related stack changes (modular lookup framework, nexthops, rtsock cleanups) were done to enable efficient kernel-based MPLS implementation. Thanks! -Neel (nc@)
Re: Porting OpenBSD MPLS to FreeBSD
> On 5 Dec 2021, at 03:49, Neel Chauhan wrote: > > Hi Alexander, > > On 2021-12-04 10:42, Alexander V. Chernikov wrote: >>> * Is porting OpenBSD MPLS to FreeBSD feasible, or are we better off doing a >>> from-scratch implementation based on netgraph? >> It depends. MPLS implementaiton can be splitted into multiple logical >> parts - dataplane (input, control, output, forward) and control plane >> (programming ip routes+mpls and mpls-only fowarding state). Some parts >> of the former can indeed be imported from OpenBSD. However, most of >> the control plane part have to be written from scratch. Finally, it >> may be desired to maintain an programming interface close to the one >> already implemented in major routing SW (frr, bird) - I guess that >> would be simpler to achieve with native, non-netgraph implementation. > > Thanks for your description. I haven't started work yet, but I'd probably > import the dataplane from OpenBSD where I can and do a new control plane, > maybe that with a FRR/Bird-compatible API. > > I wasn't too keen on using netgraph anyways, I felt it was unnecessary > complexity. > > If I were to work on this, would I be better off starting with the dataplane > or control plane? I’d start with dataplane first - it’ll allow to get something simple actually working and establish the basic datastructures. With these in place it’ll be easier to do iterate w/ control plane implementation. > >>> * Would some of the other committers here be willing to mentor/help me if >>> needed? >> I’d love to. Most of my the routing-related stack changes (modular >> lookup framework, nexthops, rtsock cleanups) were done to enable >> efficient kernel-based MPLS implementation. > > Thanks! > > -Neel (nc@)
Re: Porting OpenBSD MPLS to FreeBSD
Hi Alexander, On Sun, 2021-12-05 at 22:19 +, Alexander V. Chernikov wrote: > > If I were to work on this, would I be better off starting with the > > dataplane or control plane? > I’d start with dataplane first - it’ll allow to get something simple > actually working and establish the basic datastructures. With these > in place it’ll be easier to do iterate w/ control plane > implementation. > Thanks for your response! I may start with copying over some of the dataplane from OpenBSD, porting it, and then writing a new control plane. -Neel (nc@)
Re: Porting OpenBSD MPLS to FreeBSD
[ Charset UTF-8 unsupported, converting... ] > Hi Alexander, > > On 2021-12-04 10:42, Alexander V. Chernikov wrote: > >> * Is porting OpenBSD MPLS to FreeBSD feasible, or are we better off > >> doing a from-scratch implementation based on netgraph? > > It depends. MPLS implementaiton can be splitted into multiple logical > > parts - dataplane (input, control, output, forward) and control plane > > (programming ip routes+mpls and mpls-only fowarding state). Some parts > > of the former can indeed be imported from OpenBSD. However, most of > > the control plane part have to be written from scratch. Finally, it > > may be desired to maintain an programming interface close to the one > > already implemented in major routing SW (frr, bird) - I guess that > > would be simpler to achieve with native, non-netgraph implementation. > > Thanks for your description. I haven't started work yet, but I'd > probably import the dataplane from OpenBSD where I can and do a new > control plane, maybe that with a FRR/Bird-compatible API. When you get to working with FRR let me know, I am a member of the CI infustructure team there and can hook you up directly with very knowledgeable FRR developers. > > I wasn't too keen on using netgraph anyways, I felt it was unnecessary > complexity. True, but with that complexity comes an ulmost unlimited flexiablity. > If I were to work on this, would I be better off starting with the > dataplane or control plane? I concur with Alexander on this, dataplace first, with an eye on how FRR/Bird interact with the dataplane. > > >> * Would some of the other committers here be willing to mentor/help me > >> if needed? > > I?d love to. Most of my the routing-related stack changes (modular > > lookup framework, nexthops, rtsock cleanups) were done to enable > > efficient kernel-based MPLS implementation. > > Thanks! > > -Neel (nc@) > > -- Rod Grimes rgri...@freebsd.org
Re: Porting OpenBSD MPLS to FreeBSD
On 19.11.2021 23:16, Lutz Donnerhacke wrote: * Is porting OpenBSD MPLS to FreeBSD feasible, or are we better off doing a from-scratch implementation based on netgraph? I'd prefer a netgraph approach, if possible. It helps to concentrate on the important things. Isn't netgraph is very PPS-limited due to excessive logging? I thought, MPLS is carrier-grade stuff, and netgraph is very limited now. -- // Lev Serebryakov
Re: Porting OpenBSD MPLS to FreeBSD
On Mon, Dec 06, 2021 at 11:41:27PM +0300, Lev Serebryakov wrote: > On 19.11.2021 23:16, Lutz Donnerhacke wrote: >>> * Is porting OpenBSD MPLS to FreeBSD feasible, or are we better off doing >>> a from-scratch implementation based on netgraph? >> >> I'd prefer a netgraph approach, if possible. >> It helps to concentrate on the important things. > > Isn't netgraph is very PPS-limited due to excessive logging? No. > I thought, MPLS is carrier-grade stuff, and netgraph is very limited now. I do use netgraph for carrier-grade stuff. Yes, ng_bridge was limited, but this is fixed.
Re: Porting OpenBSD MPLS to FreeBSD
Hi Neel, it is exciting to see the topic coming alive again. Once you think is good/ready for testing, or when you require it, i can avail hardware , routers and traffic generator to take the stack for a ride. Count me in for testing, reporting, etc. Best regards. Santi On 12/6/21 18:40, Rodney W. Grimes wrote: [ Charset UTF-8 unsupported, converting... ] Hi Alexander, On 2021-12-04 10:42, Alexander V. Chernikov wrote: * Is porting OpenBSD MPLS to FreeBSD feasible, or are we better off doing a from-scratch implementation based on netgraph? It depends. MPLS implementaiton can be splitted into multiple logical parts - dataplane (input, control, output, forward) and control plane (programming ip routes+mpls and mpls-only fowarding state). Some parts of the former can indeed be imported from OpenBSD. However, most of the control plane part have to be written from scratch. Finally, it may be desired to maintain an programming interface close to the one already implemented in major routing SW (frr, bird) - I guess that would be simpler to achieve with native, non-netgraph implementation. Thanks for your description. I haven't started work yet, but I'd probably import the dataplane from OpenBSD where I can and do a new control plane, maybe that with a FRR/Bird-compatible API. When you get to working with FRR let me know, I am a member of the CI infustructure team there and can hook you up directly with very knowledgeable FRR developers. I wasn't too keen on using netgraph anyways, I felt it was unnecessary complexity. True, but with that complexity comes an ulmost unlimited flexiablity. If I were to work on this, would I be better off starting with the dataplane or control plane? I concur with Alexander on this, dataplace first, with an eye on how FRR/Bird interact with the dataplane. * Would some of the other committers here be willing to mentor/help me if needed? I?d love to. Most of my the routing-related stack changes (modular lookup framework, nexthops, rtsock cleanups) were done to enable efficient kernel-based MPLS implementation. Thanks! -Neel (nc@)
Re: Porting OpenBSD MPLS to FreeBSD
I would also like to be on the list of possible beta testers. On Tue, Dec 7, 2021 at 11:27 AM Santiago Martinez wrote: > Hi Neel, it is exciting to see the topic coming alive again. > > Once you think is good/ready for testing, or when you require it, i can > avail hardware , routers and traffic generator to take the stack for a > ride. > > Count me in for testing, reporting, etc. > > Best regards. > > Santi > > On 12/6/21 18:40, Rodney W. Grimes wrote: > > [ Charset UTF-8 unsupported, converting... ] > >> Hi Alexander, > >> > >> On 2021-12-04 10:42, Alexander V. Chernikov wrote: > >>>> * Is porting OpenBSD MPLS to FreeBSD feasible, or are we better off > >>>> doing a from-scratch implementation based on netgraph? > >>> It depends. MPLS implementaiton can be splitted into multiple logical > >>> parts - dataplane (input, control, output, forward) and control plane > >>> (programming ip routes+mpls and mpls-only fowarding state). Some parts > >>> of the former can indeed be imported from OpenBSD. However, most of > >>> the control plane part have to be written from scratch. Finally, it > >>> may be desired to maintain an programming interface close to the one > >>> already implemented in major routing SW (frr, bird) - I guess that > >>> would be simpler to achieve with native, non-netgraph implementation. > >> Thanks for your description. I haven't started work yet, but I'd > >> probably import the dataplane from OpenBSD where I can and do a new > >> control plane, maybe that with a FRR/Bird-compatible API. > > When you get to working with FRR let me know, I am a member of > > the CI infustructure team there and can hook you up directly > > with very knowledgeable FRR developers. > > > >> I wasn't too keen on using netgraph anyways, I felt it was unnecessary > >> complexity. > > True, but with that complexity comes an ulmost unlimited flexiablity. > > > >> If I were to work on this, would I be better off starting with the > >> dataplane or control plane? > > I concur with Alexander on this, dataplace first, with an eye on how > > FRR/Bird interact with the dataplane. > > > >>>> * Would some of the other committers here be willing to mentor/help me > >>>> if needed? > >>> I?d love to. Most of my the routing-related stack changes (modular > >>> lookup framework, nexthops, rtsock cleanups) were done to enable > >>> efficient kernel-based MPLS implementation. > >> Thanks! > >> > >> -Neel (nc@) > >> > >> > >
Re: Porting OpenBSD MPLS to FreeBSD
On 07.12.2021 17:28, Lutz Donnerhacke wrote: I'd prefer a netgraph approach, if possible. It helps to concentrate on the important things. Isn't netgraph is very PPS-limited due to excessive logging? No. s/logging/locking/, I don't understand, what I've been thinking about to make such stupid mistake. I thought, MPLS is carrier-grade stuff, and netgraph is very limited now. I do use netgraph for carrier-grade stuff. Yes, ng_bridge was limited, but this is fixed. Doesn't it take separate lock for each packet passed though hook? I'm sure, it was true some time ago... -- // Lev Serebryakov
Re: Porting OpenBSD MPLS to FreeBSD
On Wed, Dec 08, 2021 at 11:08:38AM +0300, Lev Serebryakov wrote: > On 07.12.2021 17:28, Lutz Donnerhacke wrote: >> I do use netgraph for carrier-grade stuff. >> Yes, ng_bridge was limited, but this is fixed. > Doesn't it take separate lock for each packet passed though hook? I'm sure, > it was true some time ago... It's a read lock for each packet on each, which can be shared by CPUs. I'm not aware that there are a major perfomace penalty, so I'd assume the lock is lightweight.
Re: Porting OpenBSD MPLS to FreeBSD
08.12.2021 21:01, Lutz Donnerhacke пишет: On Wed, Dec 08, 2021 at 11:08:38AM +0300, Lev Serebryakov wrote: On 07.12.2021 17:28, Lutz Donnerhacke wrote: I do use netgraph for carrier-grade stuff. Yes, ng_bridge was limited, but this is fixed. Doesn't it take separate lock for each packet passed though hook? I'm sure, it was true some time ago... It's a read lock for each packet on each, which can be shared by CPUs. I'm not aware that there are a major perfomace penalty, so I'd assume the lock is lightweight. Hi, from the previous experience, when we had rwlock on fast path in the network stack - it was limited from 500Kpps to 2-4Mpps rate. It depends on number of CPU cores and NIC queues. Using rwlock on high pps rate leads to high lock contention. So, this is just personal perception and experience what we call carrier-grade stuff. I also think it is better to make MPLS implementation independent from netgraph. At least until it become lockless. -- WBR, Andrey V. Elsukov OpenPGP_signature Description: OpenPGP digital signature
Re: Porting OpenBSD MPLS to FreeBSD
> > Hi freebsd-net@, > > > > Long time no see. I've gotten a (Ports) commit bit since then. > > > > I haven't been very active in TCP/IP hacking as of late, as more > > recently I've been more focused on GNOME packages and some GPU drivers. > > > > Going back, I'm thinking about porting OpenBSD's MPLS to FreeBSD. > > I have had similiar thoughts on and off over the years, > and one pretty solid "want" for this. > > > > > I have a two questions: > > > > * Is porting OpenBSD MPLS to FreeBSD feasible, or are we better off > > doing a from-scratch implementation based on netgraph? > > Feasible, yes, as to the better off part that probably depends on > who you ask. MPLS is not that complicated to implement, so doing > it either way all depends on weither you want to deal with netgraph, > or the kernel network interface code. Its also probably fairly trivial > to do both with a great deal of shared code. > > > > > * Would some of the other committers here be willing to mentor/help me > > if needed? > > Yes. > > > > > Unlike my old IPFW patches which got nowhere (plus I no longer use > > IPFW), I feel this is more something that could be useful when running > > FreeBSD as a router, but hasn't really been done. > > I can probably arrange a telco size beta tester too... unless > there interested has gone away, which I doubt. > > > -Neel (nc@) Just to follow up, I had a discussion in the weekly Open Source Routing meeting, and have identified the FRR MPLS expert and have help avaliable from that resource for this work. The first order answer on making things FRR compatible is that if you use the OpenBSD API it would be pretty much a drop in function. I have also been asked if there would be a willingness to work with the OSR/FRR folks (netdef.org) in getting the MPLS CI framework working on FreeBSD. They already do CI testing of FRR on FreeBSD, but since there is no MPLS that feature is not tested. I am working out the details on a cross introduction of the FRR MPLS developer and yourself Neel, if you want to travel down that road. This person works cross platform on FRR, iirc mainly BGP, MPLS, and SR on Linux and BSD. -- Rod Grimes rgri...@freebsd.org
