Create cmd-nse-vl3-vpp

[edwarnicke]

vl3 nse

Description

Create an NSE for vl3.

In the first pass, simply create an NSE that, given a request, uses networkservicemesh/sdk-vpp#341 to create a cmd-nse-vl3-vpp.

For ipam, start by using point2pointipam (we will become more sophisticated as we go along).

In the table created by networkservicemesh/sdk-vpp#341 program routes (see https://github.com/networkservicemesh/sdk-vpp/tree/main/pkg/networkservice/connectioncontext/ipcontext/routes which may be usable as is, or we may need a more sophisticated approach)for all incoming connections.

[edwarnicke]

Note: this is a starting place, its a very simple single instance vL3. Subsequent issues will specify enhancements to make it more sophisticated.

[denis-tingaikin]

This also can be useful https://docs.google.com/document/d/108QWsficn9adJrCppuHZcDi-AqlV7WFOaKKwYvIs-5k/edit#heading=h.1x2n7hnh1w8m

[denis-tingaikin]

@edwarnicke I think we also need to follow this https://drive.google.com/file/d/1eMIkdlav1WwGaTKRgTnkhQ95Ipqw29bu/view for registration vl3 NSEs on startup.

[denis-tingaikin]

Chain of vl3 use

point2pointipam.NewServer(ipnet),
iptable.NewServer(),
sendfd.NewServer(),
up.NewServer(ctx, vppConn),     
connectioncontext.NewServer(vppConn),  
tag.NewServer(ctx, vppConn),
mechanisms.NewServer(map[string]networkservice.NetworkServiceServer{            
  memif.MECHANISM: memif.NewServer(vppConn),   
  kernel.MECHANISM: ... ,
}, 
loopback.NewServer() // attach fib to the interface, fib table?

[glazychev-art]

So, I see the following changes in the chain elements:

New chain elements:

1. ✔️ [sdk] cidr - it is needed for CIDR allocation for a new vl3-NSE from any Global Prefix (for example 172.16.0.0/16). We store it in ipContext.ExtraPrefixes. It also keeps track of which CIDRs have already been allocated for others vl3-NSE (by Requests)
2. [sdk] vl3ipam - allocates IPs. Has differences from point2pointipam:

• If we receive a request from vl-NSE and it hasn't IP (srcIP) - we allocate it from its CIDR.
• If we don't have our IP address (dstIP) - we allocate it from our CIDR and store in map[NetworkServiceName]ipAddress. In this case we have only one IP for a given NetworkService.
• If we receive a request from a NSC - if works as p2p.

3. [sdk-vpp] enableip6 - needed for IPv6. Look: https://lists.fd.io/g/vpp-dev/topic/ipv6_unnumbered_interface/85649127
4. [sdk-vpp] loopback - needed for loopback interface creation. Only this interface will have IP-address.
5. [sdk-vpp] unnumbered - if we have a loopback interface, we need to use unnumbered for a "main" interface instead of ipaddress chain element.

Updated chain elements:

1. [sdk] ippool - probably we need to add to ippool a new method, that pulls a single IP (needed for vl3ipam. P2P uses PullP2PAddrs)
2. ✔️ [sdk] prefixpool - probably a slight modification is needed for convenience (needed for cidr)
3. ✔️ [sdk] up - we need to add WithLoadSwIfIndex option, because we can use loopback interface instead of "main" interface.
4. ✔️ [sdk-vpp] ipaddress - add WithLoadSwIfIndex option (as for up chain-element). Also, we need to dump ipaddress of interface, instead of loading it from metadata. Because, for example, we could already set it on the client part of vl3-NSE, and we need to know about it on the server part.
5. [sdk-vpp] vrf - creates an vrf-table (if doesn't exist) for a given NetworkService.
6. [sdk-vpp] routes - we also need to get a vrfID for a correct configuration.
7. ✔️ [sdk-vpp] wireguard - currently it works only as P2P. We need to update allowed-ip configuration - use routes, instead of Src/DstIP. Link

In the end, the client chain in vl3-NSE will look like:

...
			metadata.NewClient(),
			cidr.NewClient(config.PrefixLen, utils.GetIpFamily(config.CidrPrefix)),
			up.NewClient(ctx, vppConn, up.WithLoadSwIfIndex(loopback.Load)),
			ipaddress.NewClient(vppConn, ipaddress.WithLoadSwIfIndex(loopback.Load)),
			loopback.NewClient(vppConn, loopOpts...),
			up.NewClient(ctx, vppConn),
			mtu.NewClient(vppConn),
			routes.NewClient(vppConn),
			unnumbered.NewClient(vppConn),
			vrf.NewClient(vppConn, vrfOpts...),
			memif.NewClient(vppConn),
			sendfd.NewClient(),
			recvfd.NewClient(),
...

The server chain:

...
			cidr.NewServer(globalCIDR, ownPrefixes, excludePrefixes),
			vl3ipam.NewServer(ownIp, ipamPrefix),
			up.NewServer(ctx, vppConn, up.WithLoadSwIfIndex(loopback.Load)),
			ipaddress.NewServer(vppConn, ipaddress.WithLoadSwIfIndex(loopback.Load)),
			unnumbered.NewServer(vppConn),
			vrf.NewServer(vppConn, vrfOpts...),
			loopback.NewServer(vppConn, loopOpts...),
			mechanisms.NewServer(map[string]networkservice.NetworkServiceServer{
				memif.MECHANISM: chain.NewNetworkServiceServer(
					sendfd.NewServer(),
					up.NewServer(ctx, vppConn),
					mtu.NewServer(vppConn),
					routes.NewServer(vppConn),
					tag.NewServer(ctx, vppConn),
					memif.NewServer(vppConn),
				),
			}),
...

[denis-tingaikin]

@edwarnicke Could you have a look? ☝️

[edwarnicke]

@glazychev-art What is the status of this?

[glazychev-art]

@edwarnicke There are a couple of PRs:
loopback - networkservicemesh/sdk-vpp#384
vl3ipam - need a cursory review - networkservicemesh/sdk#1192