chore: add derpserver to wsproxy, add proxies to derpmap (#7311)

tailnet/derpmap.go

@@ -97,3 +97,115 @@ func NewDERPMap(ctx context.Context, region *tailcfg.DERPRegion, stunAddrs []str
 
 	return derpMap, nil
 }
+
+// CompareDERPMaps returns true if the given DERPMaps are equivalent. Ordering
+// of slices is ignored.
+//
+// If the first map is nil, the second map must also be nil for them to be
+// considered equivalent. If the second map is nil, the first map can be any
+// value and the function will return true.
+func CompareDERPMaps(a *tailcfg.DERPMap, b *tailcfg.DERPMap) bool {
+	if a == nil {
+		return b == nil
+	}
+	if b == nil {
+		return true
+	}
+	if len(a.Regions) != len(b.Regions) {
+		return false
+	}
+	if a.OmitDefaultRegions != b.OmitDefaultRegions {
+		return false
+	}
+
+	for id, region := range a.Regions {
+		other, ok := b.Regions[id]
+		if !ok {
+			return false
+		}
+		if !compareDERPRegions(region, other) {
+			return false
+		}
+	}
+	return true
+}
+
+func compareDERPRegions(a *tailcfg.DERPRegion, b *tailcfg.DERPRegion) bool {
+	if a == nil || b == nil {
+		return false
+	}
+	if a.EmbeddedRelay != b.EmbeddedRelay {
+		return false
+	}
+	if a.RegionID != b.RegionID {
+		return false
+	}
+	if a.RegionCode != b.RegionCode {
+		return false
+	}
+	if a.RegionName != b.RegionName {
+		return false
+	}
+	if a.Avoid != b.Avoid {
+		return false
+	}
+	if len(a.Nodes) != len(b.Nodes) {
+		return false
+	}
+
+	// Convert both slices to maps so ordering can be ignored easier.
+	aNodes := map[string]*tailcfg.DERPNode{}
+	for _, node := range a.Nodes {
+		aNodes[node.Name] = node
+	}
+	bNodes := map[string]*tailcfg.DERPNode{}
+	for _, node := range b.Nodes {
+		bNodes[node.Name] = node
+	}
+
+	for name, aNode := range aNodes {
+		bNode, ok := bNodes[name]
+		if !ok {
+			return false
+		}
+
+		if aNode.Name != bNode.Name {
+			return false
+		}
+		if aNode.RegionID != bNode.RegionID {
+			return false
+		}
+		if aNode.HostName != bNode.HostName {
+			return false
+		}
+		if aNode.CertName != bNode.CertName {
+			return false
+		}
+		if aNode.IPv4 != bNode.IPv4 {
+			return false
+		}
+		if aNode.IPv6 != bNode.IPv6 {
+			return false
+		}
+		if aNode.STUNPort != bNode.STUNPort {
+			return false
+		}
+		if aNode.STUNOnly != bNode.STUNOnly {
+			return false
+		}
+		if aNode.DERPPort != bNode.DERPPort {
+			return false
+		}
+		if aNode.InsecureForTests != bNode.InsecureForTests {
+			return false
+		}
+		if aNode.ForceHTTP != bNode.ForceHTTP {
+			return false
+		}
+		if aNode.STUNTestIP != bNode.STUNTestIP {
+			return false
+		}
+	}
+
+	return true
+}