golang.zx2c4.com/wireguard/windows@v0.5.4-0.20230123132234-dcc0eb72a04b/conf/name.go (about)

     1  /* SPDX-License-Identifier: MIT
     2   *
     3   * Copyright (C) 2019-2022 WireGuard LLC. All Rights Reserved.
     4   */
     5  
     6  package conf
     7  
     8  import (
     9  	"errors"
    10  	"regexp"
    11  	"strconv"
    12  	"strings"
    13  )
    14  
    15  var reservedNames = []string{
    16  	"CON", "PRN", "AUX", "NUL",
    17  	"COM1", "COM2", "COM3", "COM4", "COM5", "COM6", "COM7", "COM8", "COM9",
    18  	"LPT1", "LPT2", "LPT3", "LPT4", "LPT5", "LPT6", "LPT7", "LPT8", "LPT9",
    19  }
    20  
    21  const (
    22  	serviceNameForbidden = "$"
    23  	netshellDllForbidden = "\\/:*?\"<>|\t"
    24  	specialChars         = "/\\<>:\"|?*\x01\x02\x03\x04\x05\x06\x07\x08\x09\x0a\x0b\x0c\x0d\x0e\x0f\x10\x11\x12\x13\x14\x15\x16\x17\x18\x19\x1a\x1b\x1c\x1d\x1e\x1f\x00"
    25  )
    26  
    27  var allowedNameFormat = regexp.MustCompile("^[a-zA-Z0-9_=+.-]{1,32}$")
    28  
    29  func isReserved(name string) bool {
    30  	if len(name) == 0 {
    31  		return false
    32  	}
    33  	for _, reserved := range reservedNames {
    34  		if strings.EqualFold(name, reserved) {
    35  			return true
    36  		}
    37  		for i := len(name) - 1; i >= 0; i-- {
    38  			if name[i] == '.' {
    39  				if strings.EqualFold(name[:i], reserved) {
    40  					return true
    41  				}
    42  				break
    43  			}
    44  		}
    45  	}
    46  	return false
    47  }
    48  
    49  func hasSpecialChars(name string) bool {
    50  	return strings.ContainsAny(name, specialChars) || strings.ContainsAny(name, netshellDllForbidden) || strings.ContainsAny(name, serviceNameForbidden)
    51  }
    52  
    53  func TunnelNameIsValid(name string) bool {
    54  	// Aside from our own restrictions, let's impose the Windows restrictions first
    55  	if isReserved(name) || hasSpecialChars(name) {
    56  		return false
    57  	}
    58  	return allowedNameFormat.MatchString(name)
    59  }
    60  
    61  type naturalSortToken struct {
    62  	maybeString string
    63  	maybeNumber int
    64  }
    65  
    66  type naturalSortString struct {
    67  	originalString string
    68  	tokens         []naturalSortToken
    69  }
    70  
    71  var naturalSortDigitFinder = regexp.MustCompile(`\d+|\D+`)
    72  
    73  func newNaturalSortString(s string) (t naturalSortString) {
    74  	t.originalString = s
    75  	s = strings.ToLower(strings.Join(strings.Fields(s), " "))
    76  	x := naturalSortDigitFinder.FindAllString(s, -1)
    77  	t.tokens = make([]naturalSortToken, len(x))
    78  	for i, s := range x {
    79  		if n, err := strconv.Atoi(s); err == nil {
    80  			t.tokens[i].maybeNumber = n
    81  		} else {
    82  			t.tokens[i].maybeString = s
    83  		}
    84  	}
    85  	return
    86  }
    87  
    88  func (f1 naturalSortToken) Cmp(f2 naturalSortToken) int {
    89  	if len(f1.maybeString) == 0 {
    90  		if len(f2.maybeString) > 0 || f1.maybeNumber < f2.maybeNumber {
    91  			return -1
    92  		} else if f1.maybeNumber > f2.maybeNumber {
    93  			return 1
    94  		}
    95  	} else if len(f2.maybeString) == 0 || f1.maybeString > f2.maybeString {
    96  		return 1
    97  	} else if f1.maybeString < f2.maybeString {
    98  		return -1
    99  	}
   100  	return 0
   101  }
   102  
   103  func TunnelNameIsLess(a, b string) bool {
   104  	if a == b {
   105  		return false
   106  	}
   107  	na, nb := newNaturalSortString(a), newNaturalSortString(b)
   108  	for i, t := range nb.tokens {
   109  		if i == len(na.tokens) {
   110  			return true
   111  		}
   112  		switch na.tokens[i].Cmp(t) {
   113  		case -1:
   114  			return true
   115  		case 1:
   116  			return false
   117  		}
   118  	}
   119  	return false
   120  }
   121  
   122  func ServiceNameOfTunnel(tunnelName string) (string, error) {
   123  	if !TunnelNameIsValid(tunnelName) {
   124  		return "", errors.New("Tunnel name is not valid")
   125  	}
   126  	return "WireGuardTunnel$" + tunnelName, nil
   127  }