forked from scionproto/scion
/
validate.go
78 lines (73 loc) · 2.6 KB
/
validate.go
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// Copyright 2016 ETH Zurich
//
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
// http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.
// This file handles overall validation of packets.
package rpkt
import (
"github.com/scionproto/scion/go/lib/addr"
"github.com/scionproto/scion/go/lib/common"
"github.com/scionproto/scion/go/lib/scmp"
)
const (
errCurrIntfInvalid = "Invalid current interface"
errIntfRevoked = "Interface revoked"
errHookResponse = "Extension hook return value unrecognised"
)
// Validate performs basic validation of a packet, including calling any
// registered validation hooks.
func (rp *RtrPkt) Validate() error {
intf, ok := rp.Ctx.Conf.Net.IFs[*rp.ifCurr]
if !ok {
return common.NewBasicError(errCurrIntfInvalid, nil, "ifid", *rp.ifCurr)
}
// XXX(kormat): the rest of the common header is checked by the parsing phase.
if !addr.HostTypeCheck(rp.CmnHdr.DstType) {
return common.NewBasicError("Unsupported destination address type",
scmp.NewError(scmp.C_CmnHdr, scmp.T_C_BadDstType, nil, nil), "type", rp.CmnHdr.DstType)
}
if !addr.HostTypeCheck(rp.CmnHdr.SrcType) || rp.CmnHdr.SrcType == addr.HostTypeSVC {
// Either the source address type isn't supported, or it is an SVC
// address (which is forbidden).
return common.NewBasicError("Unsupported source address type",
scmp.NewError(scmp.C_CmnHdr, scmp.T_C_BadSrcType, nil, nil), "type", rp.CmnHdr.SrcType)
}
if int(rp.CmnHdr.TotalLen) != len(rp.Raw) {
return common.NewBasicError(
"Total length specified in common header doesn't match bytes received",
scmp.NewError(scmp.C_CmnHdr, scmp.T_C_BadPktLen,
&scmp.InfoPktSize{Size: uint16(len(rp.Raw)), MTU: uint16(intf.MTU)}, nil),
"totalLen", rp.CmnHdr.TotalLen, "actual", len(rp.Raw),
)
}
if err := rp.validatePath(rp.DirFrom); err != nil {
return err
}
if err := rp.validateExtns(); err != nil {
return err
}
for i, f := range rp.hooks.Validate {
ret, err := f()
switch {
case err != nil:
return err
case ret == HookContinue:
continue
case ret == HookFinish:
break
default:
return common.NewBasicError(errHookResponse, nil,
"hook", "Validate", "idx", i, "val", ret)
}
}
return nil
}