snet: replace PathInterface interface with a struct (#3879)

Use a simple struct directly instead of an interface.
Contrary to what was implied by code comments, this does not appear to
introduce any problematic dependencies.

go/cs/segutil/filter.go

@@ -18,7 +18,6 @@ import (
 	"fmt"
 	"strings"
 
-	"github.com/scionproto/scion/go/lib/addr"
 	"github.com/scionproto/scion/go/lib/common"
 	"github.com/scionproto/scion/go/lib/ctrl/seg"
 	"github.com/scionproto/scion/go/lib/pathpol"
@@ -58,7 +57,7 @@ func segsToPs(segs seg.Segments, dir Direction) pathpol.PathSet {
 	ps := make(pathpol.PathSet, len(segs))
 	for _, seg := range segs {
 		sw := wrap(seg, dir)
-		ps[sw.Fingerprint()] = sw
+		ps[sw.key] = sw
 	}
 	return ps
 }
@@ -92,9 +91,9 @@ func wrap(seg *seg.PathSegment, dir Direction) segWrap {
 
 		for _, ifid := range interfaces {
 			if ifid != 0 {
-				intfs = append(intfs, pathInterface{
-					ia:   asEntry.Local,
-					ifid: common.IFIDType(ifid),
+				intfs = append(intfs, snet.PathInterface{
+					IA: asEntry.Local,
+					ID: common.IFIDType(ifid),
 				})
 				keyParts = append(keyParts, fmt.Sprintf("%s#%d", asEntry.Local, ifid))
 			}
@@ -113,13 +112,4 @@ func wrap(seg *seg.PathSegment, dir Direction) segWrap {
 	}
 }
 
-func (s segWrap) Interfaces() []snet.PathInterface  { return s.intfs }
-func (s segWrap) Fingerprint() snet.PathFingerprint { return s.key }
-
-type pathInterface struct {
-	ia   addr.IA
-	ifid common.IFIDType
-}
-
-func (i pathInterface) IA() addr.IA         { return i.ia }
-func (i pathInterface) ID() common.IFIDType { return i.ifid }
+func (s segWrap) Interfaces() []snet.PathInterface { return s.intfs }

go/cs/segutil/router.go

@@ -84,28 +84,26 @@ func (r *Router) translate(comb *combinator.Path, dst addr.IA) (path, error) {
 	} else {
 		sp = spath.NewV2(buf.Bytes(), false)
 	}
-	nextHop, ok := r.Pather.TopoProvider.Get().UnderlayNextHop(comb.Interfaces[0].IfID)
+	nextHop, ok := r.Pather.TopoProvider.Get().UnderlayNextHop(comb.Interfaces[0].ID)
 	if !ok {
 		return path{}, serrors.New("Unable to find first-hop BR for path",
-			"ifid", comb.Interfaces[0].IfID)
+			"ifid", comb.Interfaces[0].ID)
 	}
 	p := path{
-		interfaces: make([]pathInterface, 0, len(comb.Interfaces)),
+		interfaces: make([]snet.PathInterface, len(comb.Interfaces)),
 		underlay:   nextHop,
 		spath:      sp,
 		metadata: pathMetadata{
 			mtu:    comb.Mtu,
 			expiry: comb.ComputeExpTime(),
 		},
 	}
-	for _, intf := range comb.Interfaces {
-		p.interfaces = append(p.interfaces, pathInterface{ia: intf.IA(), ifid: intf.ID()})
-	}
+	copy(p.interfaces, comb.Interfaces)
 	return p, nil
 }
 
 type path struct {
-	interfaces []pathInterface
+	interfaces []snet.PathInterface
 	underlay   *net.UDPAddr
 	spath      *spath.Path
 	dst        addr.IA
@@ -150,7 +148,7 @@ func (p path) Destination() addr.IA {
 	if len(p.interfaces) == 0 {
 		return p.dst
 	}
-	return p.interfaces[len(p.interfaces)-1].IA()
+	return p.interfaces[len(p.interfaces)-1].IA
 }
 
 func (p path) Metadata() snet.PathMetadata {
@@ -178,14 +176,14 @@ func (p path) fmtInterfaces() []string {
 		return hops
 	}
 	intf := p.interfaces[0]
-	hops = append(hops, fmt.Sprintf("%s %d", intf.IA(), intf.ID()))
+	hops = append(hops, fmt.Sprintf("%s %d", intf.IA, intf.ID))
 	for i := 1; i < len(p.interfaces)-1; i += 2 {
 		inIntf := p.interfaces[i]
 		outIntf := p.interfaces[i+1]
-		hops = append(hops, fmt.Sprintf("%d %s %d", inIntf.ID(), inIntf.IA(), outIntf.ID()))
+		hops = append(hops, fmt.Sprintf("%d %s %d", inIntf.ID, inIntf.IA, outIntf.ID))
 	}
 	intf = p.interfaces[len(p.interfaces)-1]
-	hops = append(hops, fmt.Sprintf("%d %s", intf.ID(), intf.IA()))
+	hops = append(hops, fmt.Sprintf("%d %s", intf.ID, intf.IA))
 	return hops
 }
 

go/lib/infra/modules/combinator/BUILD.bazel

@@ -13,10 +13,10 @@ go_library(
         "//go/lib/addr:go_default_library",
         "//go/lib/common:go_default_library",
         "//go/lib/ctrl/seg:go_default_library",
-        "//go/lib/sciond:go_default_library",
         "//go/lib/serrors:go_default_library",
         "//go/lib/slayers/path:go_default_library",
         "//go/lib/slayers/path/scion:go_default_library",
+        "//go/lib/snet:go_default_library",
         "//go/lib/spath:go_default_library",
         "//go/lib/util:go_default_library",
         "//go/proto:go_default_library",

go/lib/infra/modules/combinator/combinator.go

@@ -32,10 +32,10 @@ import (
 	"github.com/scionproto/scion/go/lib/addr"
 	"github.com/scionproto/scion/go/lib/common"
 	"github.com/scionproto/scion/go/lib/ctrl/seg"
-	"github.com/scionproto/scion/go/lib/sciond"
 	"github.com/scionproto/scion/go/lib/serrors"
 	"github.com/scionproto/scion/go/lib/slayers/path"
 	"github.com/scionproto/scion/go/lib/slayers/path/scion"
+	"github.com/scionproto/scion/go/lib/snet"
 	"github.com/scionproto/scion/go/lib/spath"
 	"github.com/scionproto/scion/go/lib/util"
 	"github.com/scionproto/scion/go/proto"
@@ -95,7 +95,7 @@ type Path struct {
 	Segments   []*Segment
 	Weight     int
 	Mtu        uint16
-	Interfaces []sciond.PathInterface
+	Interfaces []snet.PathInterface
 	StaticInfo *PathMetadata
 
 	HeaderV2 bool
@@ -124,7 +124,7 @@ func (p *Path) reverseDownSegment() {
 }
 
 func (p *Path) aggregateInterfaces() {
-	p.Interfaces = []sciond.PathInterface{}
+	p.Interfaces = []snet.PathInterface{}
 	for _, segment := range p.Segments {
 		p.Interfaces = append(p.Interfaces, segment.Interfaces...)
 	}
@@ -228,7 +228,7 @@ type Segment struct {
 	InfoField  *InfoField
 	HopFields  []*HopField
 	Type       proto.PathSegType
-	Interfaces []sciond.PathInterface
+	Interfaces []snet.PathInterface
 }
 
 // initInfoFieldFrom copies the info field in pathSegment, and sets it as the
@@ -336,8 +336,8 @@ func FilterLongPaths(paths []*Path) []*Path {
 		long := false
 		iaCounts := make(map[addr.IA]int)
 		for _, iface := range path.Interfaces {
-			iaCounts[iface.IA()]++
-			if iaCounts[iface.IA()] > 2 {
+			iaCounts[iface.IA]++
+			if iaCounts[iface.IA] > 2 {
 				long = true
 				break
 			}

go/lib/infra/modules/combinator/graph.go

@@ -23,7 +23,7 @@ import (
 	"github.com/scionproto/scion/go/lib/addr"
 	"github.com/scionproto/scion/go/lib/common"
 	"github.com/scionproto/scion/go/lib/ctrl/seg"
-	"github.com/scionproto/scion/go/lib/sciond"
+	"github.com/scionproto/scion/go/lib/snet"
 	"github.com/scionproto/scion/go/proto"
 )
 
@@ -288,7 +288,7 @@ func (solution *PathSolution) getFwdPathMetadata() *Path {
 	}
 	for _, solEdge := range solution.edges {
 		var hops []*HopField
-		var intfs []sciond.PathInterface
+		var intfs []snet.PathInterface
 
 		// Go through each ASEntry, starting from the last one, until we
 		// find a shortcut (which can be 0, meaning the end of the segment).
@@ -327,16 +327,16 @@ func (solution *PathSolution) getFwdPathMetadata() *Path {
 			// Segment is traversed in reverse construction direction.
 			// Only include non-zero interfaces.
 			if hopField.ConsEgress != 0 {
-				intfs = append(intfs, sciond.PathInterface{
-					RawIsdas: asEntry.Local.IAInt(),
-					IfID:     common.IFIDType(hopField.ConsEgress),
+				intfs = append(intfs, snet.PathInterface{
+					IA: asEntry.Local,
+					ID: common.IFIDType(hopField.ConsEgress),
 				})
 			}
 			// In a non-peer shortcut the AS is not traversed completely.
 			if hopField.ConsIngress != 0 && (!isShortcut || isPeer) {
-				intfs = append(intfs, sciond.PathInterface{
-					RawIsdas: asEntry.Local.IAInt(),
-					IfID:     common.IFIDType(hopField.ConsIngress),
+				intfs = append(intfs, snet.PathInterface{
+					IA: asEntry.Local,
+					ID: common.IFIDType(hopField.ConsIngress),
 				})
 			}
 			hops = append(hops, hopField)
@@ -549,15 +549,15 @@ func minUint16(x, y uint16) uint16 {
 	return y
 }
 
-func getPathInterfaces(ia addr.IA, inIFID, outIFID common.IFIDType) []sciond.PathInterface {
-	var result []sciond.PathInterface
+func getPathInterfaces(ia addr.IA, inIFID, outIFID common.IFIDType) []snet.PathInterface {
+	var result []snet.PathInterface
 	if inIFID != 0 {
 		result = append(result,
-			sciond.PathInterface{RawIsdas: ia.IAInt(), IfID: inIFID})
+			snet.PathInterface{IA: ia, ID: inIFID})
 	}
 	if outIFID != 0 {
 		result = append(result,
-			sciond.PathInterface{RawIsdas: ia.IAInt(), IfID: outIFID})
+			snet.PathInterface{IA: ia, ID: outIFID})
 	}
 	return result
 }

go/lib/infra/modules/segfetcher/pather.go

@@ -126,7 +126,7 @@ func (p *Pather) filterRevoked(ctx context.Context,
 		for _, iface := range path.Interfaces {
 			// cache automatically expires outdated revocations every second,
 			// so a cache hit implies revocation is still active.
-			revs, err := p.RevCache.Get(ctx, revcache.SingleKey(iface.IA(), iface.IfID))
+			revs, err := p.RevCache.Get(ctx, revcache.SingleKey(iface.IA, iface.ID))
 			if err != nil {
 				logger.Error("[segfetcher.Pather] Failed to get revocation", "err", err)
 				// continue, the client might still get some usable paths like this.

go/lib/pathmgr/pathmgr.go

@@ -225,8 +225,7 @@ func (r *resolver) Revoke(ctx context.Context, sRevInfo *path_mgmt.SignedRevInfo
 	}
 	// Each watcher contains a cache; purge paths matched by the revocation
 	// immediately from each cache.
-	pi := sciond.PathInterface{RawIsdas: revInfo.IA().IAInt(),
-		IfID: common.IFIDType(revInfo.IfID)}
+	pi := snet.PathInterface{IA: revInfo.IA(), ID: revInfo.IfID}
 	f := func(w *WatchRunner) {
 		pathsBeforeRev := w.sp.Load().APS
 		pathsAfterRev := dropRevoked(pathsBeforeRev, pi)
@@ -242,7 +241,7 @@ func (r *resolver) logger(ctx context.Context) log.Logger {
 	return log.FromCtx(ctx).New("lib", "PathResolver")
 }
 
-func dropRevoked(aps spathmeta.AppPathSet, pi sciond.PathInterface) spathmeta.AppPathSet {
+func dropRevoked(aps spathmeta.AppPathSet, pi snet.PathInterface) spathmeta.AppPathSet {
 	other := make(spathmeta.AppPathSet)
 	for key, path := range aps {
 		if !matches(path, pi) {
@@ -252,9 +251,9 @@ func dropRevoked(aps spathmeta.AppPathSet, pi sciond.PathInterface) spathmeta.Ap
 	return other
 }
 
-func matches(path snet.Path, predicatePI sciond.PathInterface) bool {
+func matches(path snet.Path, predicatePI snet.PathInterface) bool {
 	for _, pi := range path.Interfaces() {
-		if pi.IA().Equal(predicatePI.IA()) && pi.ID() == predicatePI.ID() {
+		if pi.IA.Equal(predicatePI.IA) && pi.ID == predicatePI.ID {
 			return true
 		}
 	}

go/lib/pathmgr/pathmgr_test.go

@@ -225,7 +225,7 @@ func TestWatchFilter(t *testing.T) {
 			replySet := make(pathpol.PathSet)
 			for key, v := range ps {
 				for _, intf := range v.Interfaces() {
-					if intf.IA().Equal(src) && intf.ID() == 105 {
+					if intf.IA.Equal(src) && intf.ID == 105 {
 						replySet[key] = v
 						break
 					}

go/lib/pathmgr/util_test.go

@@ -22,7 +22,6 @@ import (
 
 	"github.com/golang/mock/gomock"
 
-	"github.com/scionproto/scion/go/lib/addr"
 	"github.com/scionproto/scion/go/lib/common"
 	"github.com/scionproto/scion/go/lib/snet"
 	"github.com/scionproto/scion/go/lib/snet/mock_snet"
@@ -46,9 +45,9 @@ func createPath(t testing.TB, ctrl *gomock.Controller, desc string) snet.Path {
 		if len(tokens) != 2 {
 			t.Fatalf("Invalid path description: %s", desc)
 		}
-		interfaces = append(interfaces, intf{
-			ia: xtest.MustParseIA(tokens[0]),
-			id: mustIfID(t, tokens[1]),
+		interfaces = append(interfaces, snet.PathInterface{
+			IA: xtest.MustParseIA(tokens[0]),
+			ID: mustIfID(t, tokens[1]),
 		})
 	}
 	path.EXPECT().Interfaces().Return(interfaces).AnyTimes()
@@ -62,11 +61,3 @@ func mustIfID(t testing.TB, s string) common.IFIDType {
 	}
 	return common.IFIDType(ifID)
 }
-
-type intf struct {
-	ia addr.IA
-	id common.IFIDType
-}
-
-func (i intf) IA() addr.IA         { return i.ia }
-func (i intf) ID() common.IFIDType { return i.id }

go/lib/pathpol/hop_pred.go

@@ -88,10 +88,10 @@ func HopPredicateFromString(str string) (*HopPredicate, error) {
 // pathIFMatch takes a PathInterface and a bool indicating if the ingress
 // interface needs to be matching. It returns true if the HopPredicate matches the PathInterface
 func (hp *HopPredicate) pathIFMatch(pi snet.PathInterface, in bool) bool {
-	if hp.ISD != 0 && pi.IA().I != hp.ISD {
+	if hp.ISD != 0 && pi.IA.I != hp.ISD {
 		return false
 	}
-	if hp.AS != 0 && pi.IA().A != hp.AS {
+	if hp.AS != 0 && pi.IA.A != hp.AS {
 		return false
 	}
 	ifInd := 0
@@ -101,7 +101,7 @@ func (hp *HopPredicate) pathIFMatch(pi snet.PathInterface, in bool) bool {
 	if len(hp.IfIDs) == 2 && !in {
 		ifInd = 1
 	}
-	if hp.IfIDs[ifInd] != 0 && hp.IfIDs[ifInd] != pi.ID() {
+	if hp.IfIDs[ifInd] != 0 && hp.IfIDs[ifInd] != pi.ID {
 		return false
 	}
 	return true

go/lib/pathpol/policy_test.go

@@ -26,7 +26,6 @@ import (
 	"github.com/stretchr/testify/require"
 
 	"github.com/scionproto/scion/go/lib/addr"
-	"github.com/scionproto/scion/go/lib/common"
 	"github.com/scionproto/scion/go/lib/snet"
 	"github.com/scionproto/scion/go/lib/xtest"
 	"github.com/scionproto/scion/go/lib/xtest/graph"
@@ -634,7 +633,7 @@ func (p PathProvider) GetPaths(src, dst addr.IA) PathSet {
 		var key strings.Builder
 		for _, ifid := range ifids {
 			ia := p.g.GetParent(ifid)
-			pathIntfs = append(pathIntfs, testPathIntf{ia: ia, ifid: ifid})
+			pathIntfs = append(pathIntfs, snet.PathInterface{IA: ia, ID: ifid})
 			key.WriteString(fmt.Sprintf("%s-%d", ia, ifid))
 		}
 		result[snet.PathFingerprint(key.String())] = &testPath{
@@ -652,14 +651,6 @@ func (p *testPath) Interfaces() []snet.PathInterface {
 	return p.interfaces
 }
 
-type testPathIntf struct {
-	ia   addr.IA
-	ifid common.IFIDType
-}
-
-func (i testPathIntf) ID() common.IFIDType { return i.ifid }
-func (i testPathIntf) IA() addr.IA         { return i.ia }
-
 func mustHopPredicate(t *testing.T, str string) *HopPredicate {
 	hp, err := HopPredicateFromString(str)
 	xtest.FailOnErr(t, err)

go/lib/pathpol/sequence.go

@@ -91,13 +91,13 @@ func (s *Sequence) Eval(inputSet PathSet) PathSet {
 		// one element in form <IA>#<inbound-interface>,<outbound-interface>,
 		// e.g. 64-ff00:0:112#3,5. For the source AS, the inbound interface will be
 		// zero. For destination AS, outbound interface will be zero.
-		p := fmt.Sprintf("%s#0,%d ", ifaces[0].IA(), ifaces[0].ID())
+		p := fmt.Sprintf("%s#0,%d ", ifaces[0].IA, ifaces[0].ID)
 		for i := 1; i < len(ifaces)-1; i += 2 {
-			p += fmt.Sprintf("%s#%d,%d ", ifaces[i].IA(),
-				ifaces[i].ID(), ifaces[i+1].ID())
+			p += fmt.Sprintf("%s#%d,%d ", ifaces[i].IA,
+				ifaces[i].ID, ifaces[i+1].ID)
 		}
-		p += fmt.Sprintf("%s#%d,0 ", ifaces[len(ifaces)-1].IA(),
-			ifaces[len(ifaces)-1].ID())
+		p += fmt.Sprintf("%s#%d,0 ", ifaces[len(ifaces)-1].IA,
+			ifaces[len(ifaces)-1].ID)
 		// Check whether the string matches the sequence regexp.
 		//fmt.Printf("EVAL: %s\n", p)
 		if s.re.MatchString(p) {