cleanup: purge go/lib/{hpkt,spkt,scmp} (#3898)

Also cleanup a lot of other legacy code and remove the option to switch between header formats.

Co-authored-by: Lukas Vogel <vogel@anapaya.net>

go.mod

@@ -44,7 +44,6 @@ require (
 	google.golang.org/genproto v0.0.0-20191002211648-c459b9ce5143 // indirect
 	google.golang.org/grpc v1.29.1
 	google.golang.org/protobuf v1.23.0
-	gopkg.in/restruct.v1 v1.0.0-20151213023948-80ede2e57cc2
 	gopkg.in/yaml.v2 v2.3.0
 	zombiezen.com/go/capnproto2 v0.0.0-20190813022230-ddfb9bb855fa
 )

go.sum

@@ -649,8 +649,6 @@ gopkg.in/fsnotify.v1 v1.4.7 h1:xOHLXZwVvI9hhs+cLKq5+I5onOuwQLhQwiu63xxlHs4=
 gopkg.in/fsnotify.v1 v1.4.7/go.mod h1:Tz8NjZHkW78fSQdbUxIjBTcgA1z1m8ZHf0WmKUhAMys=
 gopkg.in/gcfg.v1 v1.2.3/go.mod h1:yesOnuUOFQAhST5vPY4nbZsb/huCgGGXlipJsBn0b3o=
 gopkg.in/inf.v0 v0.9.1/go.mod h1:cWUDdTG/fYaXco+Dcufb5Vnc6Gp2YChqWtbxRZE0mXw=
-gopkg.in/restruct.v1 v1.0.0-20151213023948-80ede2e57cc2 h1:pqzOumCQ6icMR4sIIYRe2w7xCERvcPOFx22W9jSRsWg=
-gopkg.in/restruct.v1 v1.0.0-20151213023948-80ede2e57cc2/go.mod h1:WJaLhyHHEQFOgwIxu/SJxvUHJA18glYsMETBTMIySTY=
 gopkg.in/resty.v1 v1.12.0/go.mod h1:mDo4pnntr5jdWRML875a/NmxYqAlA73dVijT2AXvQQo=
 gopkg.in/tomb.v1 v1.0.0-20141024135613-dd632973f1e7 h1:uRGJdciOHaEIrze2W8Q3AKkepLTh2hOroT7a+7czfdQ=
 gopkg.in/tomb.v1 v1.0.0-20141024135613-dd632973f1e7/go.mod h1:dt/ZhP58zS4L8KSrWDmTeBkI65Dw0HsyUHuEVlX15mw=

go/cs/cs.go

@@ -400,7 +400,6 @@ func run(file string) error {
 		&onehop.OHPPacketDispatcherService{
 			PacketDispatcherService: &snet.DefaultPacketDispatcherService{
 				Dispatcher: reliable.NewDispatcher(""),
-				Version2:   true,
 			},
 		},
 	)

go/cs/onehop/network.go

@@ -47,18 +47,14 @@ type ohpPacketConn struct {
 }
 
 func (c *ohpPacketConn) WriteTo(pkt *snet.Packet, ov *net.UDPAddr) error {
-	extensions := pkt.Extensions
 	return c.PacketConn.WriteTo(
 		&snet.Packet{
 			Bytes: pkt.Bytes,
 			PacketInfo: snet.PacketInfo{
 				Destination: pkt.Destination,
 				Source:      pkt.Source,
 				Path:        pkt.Path,
-				Extensions:  extensions,
-				L4Header:    pkt.L4Header,
 				Payload:     pkt.Payload,
-				PayloadV2:   pkt.PayloadV2,
 			},
 		},
 		ov,

go/cs/onehop/sender.go

@@ -84,7 +84,7 @@ func (s *Sender) CreatePkt(msg *Msg) (*snet.Packet, error) {
 				Host: addr.HostFromIP(s.Addr.IP),
 			},
 			Path: (*spath.Path)(path),
-			PayloadV2: snet.UDPPayload{
+			Payload: snet.UDPPayload{
 				SrcPort: uint16(s.Addr.Port),
 				Payload: msg.Pld,
 			},

go/cs/onehop/sender_test.go

@@ -122,8 +122,8 @@ func checkTestPkt(t *testing.T, s *Sender, msg *Msg, pkt *snet.Packet) {
 		Host: addr.HostFromIPStr("127.0.0.1"),
 	}, pkt.Source)
 	assert.True(t, pkt.Path.IsOHP())
-	assert.Equal(t, uint16(4242), pkt.PayloadV2.(snet.UDPPayload).SrcPort)
-	assert.Equal(t, msg.Pld, pkt.PayloadV2.(snet.UDPPayload).Payload)
+	assert.Equal(t, uint16(4242), pkt.Payload.(snet.UDPPayload).SrcPort)
+	assert.Equal(t, msg.Pld, pkt.Payload.(snet.UDPPayload).Payload)
 }
 
 // testConn is a packet conn that returns an empty underlay address.

go/dispatcher/BUILD.bazel

@@ -32,13 +32,8 @@ go_test(
     embed = [":go_default_library"],
     deps = [
         "//go/lib/addr:go_default_library",
-        "//go/lib/common:go_default_library",
-        "//go/lib/hpkt:go_default_library",
-        "//go/lib/l4:go_default_library",
-        "//go/lib/scmp:go_default_library",
         "//go/lib/snet:go_default_library",
         "//go/lib/sock/reliable:go_default_library",
-        "//go/lib/spkt:go_default_library",
         "//go/lib/xtest:go_default_library",
         "@com_github_stretchr_testify//assert:go_default_library",
         "@com_github_stretchr_testify//require:go_default_library",

go/dispatcher/dispatcher/BUILD.bazel

@@ -4,7 +4,6 @@ go_library(
     name = "go_default_library",
     srcs = [
         "dispatcher.go",
-        "scmp.go",
         "table.go",
         "underlay.go",
     ],
@@ -16,14 +15,10 @@ go_library(
         "//go/dispatcher/internal/respool:go_default_library",
         "//go/lib/addr:go_default_library",
         "//go/lib/common:go_default_library",
-        "//go/lib/hpkt:go_default_library",
-        "//go/lib/l4:go_default_library",
         "//go/lib/log:go_default_library",
         "//go/lib/ringbuf:go_default_library",
-        "//go/lib/scmp:go_default_library",
         "//go/lib/serrors:go_default_library",
         "//go/lib/slayers:go_default_library",
-        "//go/lib/spkt:go_default_library",
         "//go/lib/underlay/conn:go_default_library",
         "@com_github_google_gopacket//:go_default_library",
     ],
@@ -38,12 +33,9 @@ go_test(
         "//go/lib/addr:go_default_library",
         "//go/lib/common:go_default_library",
         "//go/lib/l4:go_default_library",
-        "//go/lib/l4/mock_l4:go_default_library",
-        "//go/lib/scmp:go_default_library",
         "//go/lib/slayers:go_default_library",
         "//go/lib/slayers/path:go_default_library",
         "//go/lib/slayers/path/scion:go_default_library",
-        "//go/lib/spkt:go_default_library",
         "//go/lib/xtest:go_default_library",
         "@com_github_golang_mock//gomock:go_default_library",
         "@com_github_google_gopacket//:go_default_library",

go/dispatcher/dispatcher/dispatcher.go

@@ -13,10 +13,8 @@ import (
 	"github.com/scionproto/scion/go/lib/common"
 	"github.com/scionproto/scion/go/lib/log"
 	"github.com/scionproto/scion/go/lib/ringbuf"
-	"github.com/scionproto/scion/go/lib/scmp"
 	"github.com/scionproto/scion/go/lib/serrors"
 	"github.com/scionproto/scion/go/lib/slayers"
-	"github.com/scionproto/scion/go/lib/spkt"
 	"github.com/scionproto/scion/go/lib/underlay/conn"
 )
 
@@ -33,8 +31,6 @@ type Server struct {
 	routingTable *IATable
 	ipv4Conn     net.PacketConn
 	ipv6Conn     net.PacketConn
-	// HeaderV2 indicates whether the new header format is used.
-	HeaderV2 bool
 }
 
 // NewServer creates new instance of Server. Internally, it opens the dispatcher ports
@@ -75,7 +71,6 @@ func (as *Server) Serve() error {
 		netToRingDataplane := &NetToRingDataplane{
 			UnderlayConn: as.ipv4Conn,
 			RoutingTable: as.routingTable,
-			HeaderV2:     as.HeaderV2,
 		}
 		errChan <- netToRingDataplane.Run()
 	}()
@@ -84,7 +79,6 @@ func (as *Server) Serve() error {
 		netToRingDataplane := &NetToRingDataplane{
 			UnderlayConn: as.ipv6Conn,
 			RoutingTable: as.routingTable,
-			HeaderV2:     as.HeaderV2,
 		}
 		errChan <- netToRingDataplane.Run()
 	}()
@@ -135,8 +129,6 @@ func (ac *Conn) WriteTo(p []byte, addr net.Addr) (int, error) {
 
 // Write is optimized for the use by ConnHandler (avoids reparsing the packet).
 func (ac *Conn) Write(pkt *respool.Packet) (int, error) {
-	// FIXME(roosd): Drop this with header v1.
-	registerIfSCMPRequest(ac.regReference, &pkt.Info)
 	// XXX(roosd): Ignore error since there is nothing we can do about it.
 	// Currently, the ID space is shared between all applications that register
 	// with the dispatcher. Likelihood that they overlap is very small.
@@ -226,27 +218,6 @@ func openConn(network, address string, p SocketMetaHandler) (net.PacketConn, err
 	return &underlayConnWrapper{Conn: c, Handler: p}, nil
 }
 
-// registerIfSCMPRequest registers the ID of the SCMP Request, if it is an
-// SCMP::General::EchoRequest, SCMP::General::TraceRouteRequest or SCMP::General::RecordPathRequest
-// packet. It also increments SCMP-related metrics.
-func registerIfSCMPRequest(ref registration.RegReference, packet *spkt.ScnPkt) error {
-	if scmpHdr, ok := packet.L4.(*scmp.Hdr); ok {
-		metrics.M.SCMPWritePkts(
-			metrics.SCMP{
-				Class: scmpHdr.Class.String(),
-				Type:  scmpHdr.Type.Name(scmpHdr.Class),
-			},
-		).Inc()
-		if !isSCMPGeneralRequest(scmpHdr) {
-			return nil
-		}
-		if id := getSCMPGeneralID(packet); id != 0 {
-			return ref.RegisterID(id)
-		}
-	}
-	return nil
-}
-
 // registerIfSCMPInfo registers the ID of the SCMP request if it is an echo or
 // traceroute message.
 func registerIfSCMPInfo(ref registration.RegReference, pkt *respool.Packet) error {