1 files changed, 79 insertions, 0 deletions
diff --git a/relay/relay.go b/relay/relay.go
new file mode 100644
index 0000000..b52a923
--- /dev/null
+++ b/relay/relay.go
@@ -0,0 +1,79 @@
+package relay
+
+import (
+	"context"
+	"fmt"
+	"sync"
+
+	pb "github.com/boozec/rahanna/relay/proto"
+)
+
+type Server struct {
+	pb.UnimplementedRelayServer
+}
+
+type name string
+
+// TODO: use pair of ips and ports
+type ips struct {
+	ip0 string
+	ip1 string
+}
+
+var mu sync.Mutex
+
+// Map each name to a pair of IPs
+var table = make(map[name]ips)
+
+func (s *Server) RegisterName(ctx context.Context, in *pb.RelayRequest) (*pb.RelayResponse, error) {
+	mu.Lock()
+	defer mu.Unlock()
+
+	if in.Ip == "" {
+		return nil, fmt.Errorf("IP address cannot be empty")
+	}
+
+	sessionName := newSession()
+	for {
+		if _, ok := table[name(sessionName)]; !ok {
+			break
+		}
+		sessionName = newSession()
+	}
+
+	table[name(sessionName)] = ips{ip0: in.Ip, ip1: ""}
+	return &pb.RelayResponse{Name: sessionName, Ip: in.Ip}, nil
+}
+
+func (s *Server) Lookup(ctx context.Context, in *pb.LookupRequest) (*pb.RelayResponse, error) {
+	mu.Lock()
+	defer mu.Unlock()
+
+	if in.Name == "" {
+		return nil, fmt.Errorf("name cannot be empty")
+	}
+
+	entry, ok := table[name(in.Name)]
+	if !ok {
+		return nil, fmt.Errorf("name not found")
+	}
+
+	return &pb.RelayResponse{Name: in.Name, Ip: entry.ip0}, nil
+}
+
+func (s *Server) CloseName(ctx context.Context, in *pb.LookupRequest) (*pb.CloseResponse, error) {
+	mu.Lock()
+	defer mu.Unlock()
+
+	if in.Name == "" {
+		return nil, fmt.Errorf("name cannot be empty")
+	}
+
+	_, ok := table[name(in.Name)]
+	if !ok {
+		return &pb.CloseResponse{Status: false}, fmt.Errorf("name not found")
+	}
+
+	delete(table, name(in.Name))
+	return &pb.CloseResponse{Status: true}, nil
+}