github.com/SagerNet/gvisor@v0.0.0-20210707092255-7731c139d75c/pkg/tcpip/testutil/testutil.go (about)

     1  // Copyright 2021 The gVisor Authors.
     2  //
     3  // Licensed under the Apache License, Version 2.0 (the "License");
     4  // you may not use this file except in compliance with the License.
     5  // You may obtain a copy of the License at
     6  //
     7  //     http://www.apache.org/licenses/LICENSE-2.0
     8  //
     9  // Unless required by applicable law or agreed to in writing, software
    10  // distributed under the License is distributed on an "AS IS" BASIS,
    11  // WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
    12  // See the License for the specific language governing permissions and
    13  // limitations under the License.
    14  
    15  // Package testutil provides helper functions for netstack unit tests.
    16  package testutil
    17  
    18  import (
    19  	"fmt"
    20  	"net"
    21  	"reflect"
    22  	"strings"
    23  
    24  	"github.com/SagerNet/gvisor/pkg/tcpip"
    25  )
    26  
    27  // MustParse4 parses an IPv4 string (e.g. "192.168.1.1") into a tcpip.Address.
    28  // Passing an IPv4-mapped IPv6 address will yield only the 4 IPv4 bytes.
    29  func MustParse4(addr string) tcpip.Address {
    30  	ip := net.ParseIP(addr).To4()
    31  	if ip == nil {
    32  		panic(fmt.Sprintf("Parse4 expects IPv4 addresses, but was passed %q", addr))
    33  	}
    34  	return tcpip.Address(ip)
    35  }
    36  
    37  // MustParse6 parses an IPv6 string (e.g. "fe80::1") into a tcpip.Address. Passing
    38  // an IPv4 address will yield an IPv4-mapped IPv6 address.
    39  func MustParse6(addr string) tcpip.Address {
    40  	ip := net.ParseIP(addr).To16()
    41  	if ip == nil {
    42  		panic(fmt.Sprintf("Parse6 was passed malformed address %q", addr))
    43  	}
    44  	return tcpip.Address(ip)
    45  }
    46  
    47  func checkFieldCounts(ref, multi reflect.Value) error {
    48  	refTypeName := ref.Type().Name()
    49  	multiTypeName := multi.Type().Name()
    50  	refNumField := ref.NumField()
    51  	multiNumField := multi.NumField()
    52  
    53  	if refNumField != multiNumField {
    54  		return fmt.Errorf("type %s has an incorrect number of fields: got = %d, want = %d (same as type %s)", multiTypeName, multiNumField, refNumField, refTypeName)
    55  	}
    56  
    57  	return nil
    58  }
    59  
    60  func validateField(ref reflect.Value, refName string, m tcpip.MultiCounterStat, multiName string) error {
    61  	s, ok := ref.Addr().Interface().(**tcpip.StatCounter)
    62  	if !ok {
    63  		return fmt.Errorf("expected ref type's to be *StatCounter, but its type is %s", ref.Type().Elem().Name())
    64  	}
    65  
    66  	// The field names are expected to match (case insensitive).
    67  	if !strings.EqualFold(refName, multiName) {
    68  		return fmt.Errorf("wrong field name: got = %s, want = %s", multiName, refName)
    69  	}
    70  
    71  	base := (*s).Value()
    72  	m.Increment()
    73  	if (*s).Value() != base+1 {
    74  		return fmt.Errorf("updates to the '%s MultiCounterStat' counters are not reflected in the '%s CounterStat'", multiName, refName)
    75  	}
    76  
    77  	return nil
    78  }
    79  
    80  // ValidateMultiCounterStats verifies that every counter stored in multi is
    81  // correctly tracking its counterpart in the given counters.
    82  func ValidateMultiCounterStats(multi reflect.Value, counters []reflect.Value) error {
    83  	for _, c := range counters {
    84  		if err := checkFieldCounts(c, multi); err != nil {
    85  			return err
    86  		}
    87  	}
    88  
    89  	for i := 0; i < multi.NumField(); i++ {
    90  		multiName := multi.Type().Field(i).Name
    91  		multiUnsafe := unsafeExposeUnexportedFields(multi.Field(i))
    92  
    93  		if m, ok := multiUnsafe.Addr().Interface().(*tcpip.MultiCounterStat); ok {
    94  			for _, c := range counters {
    95  				if err := validateField(unsafeExposeUnexportedFields(c.Field(i)), c.Type().Field(i).Name, *m, multiName); err != nil {
    96  					return err
    97  				}
    98  			}
    99  		} else {
   100  			var countersNextField []reflect.Value
   101  			for _, c := range counters {
   102  				countersNextField = append(countersNextField, c.Field(i))
   103  			}
   104  			if err := ValidateMultiCounterStats(multi.Field(i), countersNextField); err != nil {
   105  				return err
   106  			}
   107  		}
   108  	}
   109  
   110  	return nil
   111  }
   112  
   113  // MustParseLink parses a Link string into a tcpip.LinkAddress, panicking on
   114  // error.
   115  //
   116  // The string must be in the format aa:bb:cc:dd:ee:ff or aa-bb-cc-dd-ee-ff.
   117  func MustParseLink(addr string) tcpip.LinkAddress {
   118  	parsed, err := tcpip.ParseMACAddress(addr)
   119  	if err != nil {
   120  		panic(fmt.Sprintf("tcpip.ParseMACAddress(%s): %s", addr, err))
   121  	}
   122  	return parsed
   123  }