Method updateStateFromResponse

control/controlclient/map.go:589–740

updateStateFromResponse updates ms from res. It takes ownership of res.

(resp *tailcfg.MapResponse)

// updateStateFromResponse updates ms from res. It takes ownership of res.
func (ms *mapSession) updateStateFromResponse(resp *tailcfg.MapResponse) {
	ms.updatePeersStateFromResponse(resp)

	if resp.Node != nil {
		ms.lastNode = resp.Node.View()

		capSet := set.Set[tailcfg.NodeCapability]{}
		for _, c := range resp.Node.Capabilities {
			capSet.Add(c)
		}
		for c := range resp.Node.CapMap {
			capSet.Add(c)
		}
		ms.lastCapSet = capSet
	}

	for _, up := range resp.UserProfiles {
		ms.lastUserProfile[up.ID] = up.View()
	}
	// TODO(bradfitz): clean up old user profiles? maybe not worth it.

	if dm := resp.DERPMap; dm != nil {
		ms.vlogf("netmap: new map contains DERP map")

		// Guard against the control server accidentally sending
		// a nil region definition, which at least Headscale was
		// observed to send.
		for rid, r := range dm.Regions {
			if r == nil {
				delete(dm.Regions, rid)
			}
		}

		// In the copy/v86 wasm environment with limited networking, if the
		// control plane didn't pick our DERP home for us, do it ourselves and
		// mark all but the lowest region as NoMeasureNoHome. For prod, this
		// will be Region 1, NYC, a compromise between the US and Europe. But
		// really the control plane should pick this. This is only a fallback.
		if hostinfo.IsInVM86() {
			numCanMeasure := 0
			lowest := 0
			for rid, r := range dm.Regions {
				if !r.NoMeasureNoHome {
					numCanMeasure++
					if lowest == 0 || rid < lowest {
						lowest = rid
					}
				}
			}
			if numCanMeasure > 1 {
				for rid, r := range dm.Regions {
					if rid != lowest {
						r.NoMeasureNoHome = true
					}
				}
			}
		}