lint: netstack/icmp rmv unused vars and funcs

Author: ignoramous

intra/netstack/icmp.go

@@ -7,8 +7,6 @@
 package netstack
 
 import (
-	"math"
-
 	"github.com/celzero/firestack/intra/core"
 	"github.com/celzero/firestack/intra/log"
 	"gvisor.dev/gvisor/pkg/buffer"
@@ -482,157 +480,6 @@ func (f *icmpForwarder) icmpErr6(id stack.TransportEndpointID, pkt *stack.Packet
 	return werr
 }
 
-// github.com/google/gvisor/blob/738e1d995f/pkg/tcpip/network/ipv4/ipv4.go#L2007
-// optionAction describes possible actions that may be taken on an option
-// while processing it.
-type optionAction uint8
-
-const (
-	// optionRemove says that the option should not be in the output option set.
-	optionRemove optionAction = iota
-
-	// optionProcess says that the option should be fully processed.
-	optionProcess
-
-	// optionVerify says the option should be checked and passed unchanged.
-	optionVerify
-
-	// optionPass says to pass the output set without checking.
-	optionPass
-)
-
-// github.com/google/gvisor/blob/738e1d995f6/pkg/tcpip/network/ipv4/ipv4.go#L2026
-// optionActions list what to do for each option in a given scenario.
-type optionActions struct {
-	// timestamp controls what to do with a Timestamp option.
-	timestamp optionAction
-
-	// recordRoute controls what to do with a Record Route option.
-	recordRoute optionAction
-
-	// routerAlert controls what to do with a Router Alert option.
-	routerAlert optionAction
-
-	// unknown controls what to do with an unknown option.
-	unknown optionAction
-}
-
-func (f *icmpForwarder) ipOpts(pkt *stack.PacketBuffer, iph header.IPv4) (o header.IPv4Options) {
-	if opts := iph.Options(); len(opts) != 0 {
-		// RFC 1122 section 3.2.2.6 (page 43) (and similar for other round trip
-		// type ICMP packets):
-		//    If a Record Route and/or Time Stamp option is received in an
-		//    ICMP Echo Request, this option (these options) SHOULD be
-		//    updated to include the current host and included in the IP
-		//    header of the Echo Reply message, without "truncation".
-		//    Thus, the recorded route will be for the entire round trip.
-		//
-		// So we need to let the option processor know how it should handle them.
-		echoOps := optionActions{
-			timestamp:   optionProcess,
-			recordRoute: optionProcess,
-			routerAlert: optionVerify,
-			unknown:     optionRemove,
-		}
-		var ierr *header.IPv4OptParameterProblem
-		o, ierr = f.processIPOptions(pkt, opts, echoOps)
-		if ierr != nil { // always nil for now
-			log.E("icmp: v4: %s: ipOpts: %v", f.o, ierr)
-		}
-		copied := copy(opts, o)
-		for i := copied; i < len(opts); i++ {
-			// Pad with 0 (EOL). RFC 791 page 23 says "The padding is zero".
-			opts[i] = byte(header.IPv4OptionListEndType)
-		}
-	}
-	return
-}
-
-// from: github.com/google/gvisor/blob/738e1d995f/pkg/tcpip/network/ipv4/ipv4.go#L2318
-// processIPOptions parses the IPv4 options and produces a new set of options
-// suitable for use in the next step of packet processing as informed by usage.
-// The original will not be touched.
-//
-// If there were no errors during parsing, the new set of options is returned as
-// a new buffer.
-func (f *icmpForwarder) processIPOptions(pkt *stack.PacketBuffer, opts header.IPv4Options, usage optionActions) (header.IPv4Options, *header.IPv4OptParameterProblem) {
-	optIter := opts.MakeIterator()
-
-	// Except NOP, each option must only appear at most once (RFC 791 section 3.1,
-	// at the definition of every type).
-	// Keep track of each option we find to enable duplicate option detection.
-	var seenOptions [math.MaxUint8 + 1]bool
-
-	for {
-		option, done, optProblem := optIter.Next()
-		if done || optProblem != nil {
-			return optIter.Finalize(), optProblem
-		}
-		if option == nil { // nilaway
-			return nil, &header.IPv4OptParameterProblem{
-				Pointer:  optIter.ErrCursor,
-				NeedICMP: true,
-			}
-		}
-		optType := option.Type()
-		if optType == header.IPv4OptionNOPType {
-			optIter.PushNOPOrEnd(optType)
-			continue
-		}
-		if optType == header.IPv4OptionListEndType {
-			optIter.PushNOPOrEnd(optType)
-			return optIter.Finalize(), nil
-		}
-
-		// check for repeating options (multiple NOPs are OK)
-		if seenOptions[optType] {
-			return nil, &header.IPv4OptParameterProblem{
-				Pointer:  optIter.ErrCursor,
-				NeedICMP: true,
-			}
-		}
-		seenOptions[optType] = true
-
-		optLen, optProblem := func() (int, *header.IPv4OptParameterProblem) {
-			switch option := option.(type) {
-			case *header.IPv4OptionTimestamp:
-				if usage.timestamp != optionRemove {
-					// clock := f.s.Clock()
-					newBuffer := optIter.InitReplacement(option)
-					// todo: optProblem := handleTimestamp(header.IPv4OptionTimestamp(newBuffer), localAddress, clock, usage)
-					return len(newBuffer), nil
-				}
-
-			case *header.IPv4OptionRecordRoute:
-				if usage.recordRoute != optionRemove {
-					newBuffer := optIter.InitReplacement(option)
-					// todo: optProblem := handleRecordRoute(header.IPv4OptionRecordRoute(newBuffer), localAddress, usage)
-					return len(newBuffer), nil
-				}
-
-			case *header.IPv4OptionRouterAlert:
-				if usage.routerAlert != optionRemove {
-					newBuffer := optIter.InitReplacement(option)
-					// todo: optProblem := handleRouterAlert(header.IPv4OptionRouterAlert(newBuffer))
-					return len(newBuffer), nil
-				}
-
-			default:
-				if usage.unknown == optionPass {
-					return len(optIter.InitReplacement(option)), nil
-				}
-			}
-			return 0, nil
-		}()
-
-		if optProblem != nil {
-			optProblem.Pointer += optIter.ErrCursor
-			return nil, optProblem
-		}
-		optIter.ConsumeBuffer(optLen)
-	}
-}
-
 func loge(err tcpip.Error) (f log.LogFn) {
 	f = log.E
 	if err == nil {