wgconf/conf/parser.go
Vincent Batts 77158f3dde
conf: add from wireguard-windows/conf/@b73dcdb
Signed-off-by: Vincent Batts <vbatts@hashbangbash.com>
2021-04-21 07:03:18 -04:00

506 lines
12 KiB
Go

/* SPDX-License-Identifier: MIT
*
* Copyright (C) 2019-2021 WireGuard LLC. All Rights Reserved.
*/
package conf
import (
"bufio"
"encoding/base64"
"encoding/hex"
"io"
"net"
"strconv"
"strings"
"time"
"golang.org/x/text/encoding/unicode"
"golang.zx2c4.com/wireguard/windows/l18n"
)
type ParseError struct {
why string
offender string
}
func (e *ParseError) Error() string {
return l18n.Sprintf("%s: %q", e.why, e.offender)
}
func parseIPCidr(s string) (ipcidr *IPCidr, err error) {
var addrStr, cidrStr string
var cidr int
i := strings.IndexByte(s, '/')
if i < 0 {
addrStr = s
} else {
addrStr, cidrStr = s[:i], s[i+1:]
}
err = &ParseError{l18n.Sprintf("Invalid IP address"), s}
addr := net.ParseIP(addrStr)
if addr == nil {
return
}
maybeV4 := addr.To4()
if maybeV4 != nil {
addr = maybeV4
}
if len(cidrStr) > 0 {
err = &ParseError{l18n.Sprintf("Invalid network prefix length"), s}
cidr, err = strconv.Atoi(cidrStr)
if err != nil || cidr < 0 || cidr > 128 {
return
}
if cidr > 32 && maybeV4 != nil {
return
}
} else {
if maybeV4 != nil {
cidr = 32
} else {
cidr = 128
}
}
return &IPCidr{addr, uint8(cidr)}, nil
}
func parseEndpoint(s string) (*Endpoint, error) {
i := strings.LastIndexByte(s, ':')
if i < 0 {
return nil, &ParseError{l18n.Sprintf("Missing port from endpoint"), s}
}
host, portStr := s[:i], s[i+1:]
if len(host) < 1 {
return nil, &ParseError{l18n.Sprintf("Invalid endpoint host"), host}
}
port, err := parsePort(portStr)
if err != nil {
return nil, err
}
hostColon := strings.IndexByte(host, ':')
if host[0] == '[' || host[len(host)-1] == ']' || hostColon > 0 {
err := &ParseError{l18n.Sprintf("Brackets must contain an IPv6 address"), host}
if len(host) > 3 && host[0] == '[' && host[len(host)-1] == ']' && hostColon > 0 {
end := len(host) - 1
if i := strings.LastIndexByte(host, '%'); i > 1 {
end = i
}
maybeV6 := net.ParseIP(host[1:end])
if maybeV6 == nil || len(maybeV6) != net.IPv6len {
return nil, err
}
} else {
return nil, err
}
host = host[1 : len(host)-1]
}
return &Endpoint{host, uint16(port)}, nil
}
func parseMTU(s string) (uint16, error) {
m, err := strconv.Atoi(s)
if err != nil {
return 0, err
}
if m < 576 || m > 65535 {
return 0, &ParseError{l18n.Sprintf("Invalid MTU"), s}
}
return uint16(m), nil
}
func parsePort(s string) (uint16, error) {
m, err := strconv.Atoi(s)
if err != nil {
return 0, err
}
if m < 0 || m > 65535 {
return 0, &ParseError{l18n.Sprintf("Invalid port"), s}
}
return uint16(m), nil
}
func parsePersistentKeepalive(s string) (uint16, error) {
if s == "off" {
return 0, nil
}
m, err := strconv.Atoi(s)
if err != nil {
return 0, err
}
if m < 0 || m > 65535 {
return 0, &ParseError{l18n.Sprintf("Invalid persistent keepalive"), s}
}
return uint16(m), nil
}
func parseKeyBase64(s string) (*Key, error) {
k, err := base64.StdEncoding.DecodeString(s)
if err != nil {
return nil, &ParseError{l18n.Sprintf("Invalid key: %v", err), s}
}
if len(k) != KeyLength {
return nil, &ParseError{l18n.Sprintf("Keys must decode to exactly 32 bytes"), s}
}
var key Key
copy(key[:], k)
return &key, nil
}
func parseKeyHex(s string) (*Key, error) {
k, err := hex.DecodeString(s)
if err != nil {
return nil, &ParseError{l18n.Sprintf("Invalid key: %v", err), s}
}
if len(k) != KeyLength {
return nil, &ParseError{l18n.Sprintf("Keys must decode to exactly 32 bytes"), s}
}
var key Key
copy(key[:], k)
return &key, nil
}
func parseBytesOrStamp(s string) (uint64, error) {
b, err := strconv.ParseUint(s, 10, 64)
if err != nil {
return 0, &ParseError{l18n.Sprintf("Number must be a number between 0 and 2^64-1: %v", err), s}
}
return b, nil
}
func splitList(s string) ([]string, error) {
var out []string
for _, split := range strings.Split(s, ",") {
trim := strings.TrimSpace(split)
if len(trim) == 0 {
return nil, &ParseError{l18n.Sprintf("Two commas in a row"), s}
}
out = append(out, trim)
}
return out, nil
}
type parserState int
const (
inInterfaceSection parserState = iota
inPeerSection
notInASection
)
func (c *Config) maybeAddPeer(p *Peer) {
if p != nil {
c.Peers = append(c.Peers, *p)
}
}
func FromWgQuick(s string, name string) (*Config, error) {
if !TunnelNameIsValid(name) {
return nil, &ParseError{l18n.Sprintf("Tunnel name is not valid"), name}
}
lines := strings.Split(s, "\n")
parserState := notInASection
conf := Config{Name: name}
sawPrivateKey := false
var peer *Peer
for _, line := range lines {
pound := strings.IndexByte(line, '#')
if pound >= 0 {
line = line[:pound]
}
line = strings.TrimSpace(line)
lineLower := strings.ToLower(line)
if len(line) == 0 {
continue
}
if lineLower == "[interface]" {
conf.maybeAddPeer(peer)
parserState = inInterfaceSection
continue
}
if lineLower == "[peer]" {
conf.maybeAddPeer(peer)
peer = &Peer{}
parserState = inPeerSection
continue
}
if parserState == notInASection {
return nil, &ParseError{l18n.Sprintf("Line must occur in a section"), line}
}
equals := strings.IndexByte(line, '=')
if equals < 0 {
return nil, &ParseError{l18n.Sprintf("Config key is missing an equals separator"), line}
}
key, val := strings.TrimSpace(lineLower[:equals]), strings.TrimSpace(line[equals+1:])
if len(val) == 0 {
return nil, &ParseError{l18n.Sprintf("Key must have a value"), line}
}
if parserState == inInterfaceSection {
switch key {
case "privatekey":
k, err := parseKeyBase64(val)
if err != nil {
return nil, err
}
conf.Interface.PrivateKey = *k
sawPrivateKey = true
case "listenport":
p, err := parsePort(val)
if err != nil {
return nil, err
}
conf.Interface.ListenPort = p
case "mtu":
m, err := parseMTU(val)
if err != nil {
return nil, err
}
conf.Interface.MTU = m
case "address":
addresses, err := splitList(val)
if err != nil {
return nil, err
}
for _, address := range addresses {
a, err := parseIPCidr(address)
if err != nil {
return nil, err
}
conf.Interface.Addresses = append(conf.Interface.Addresses, *a)
}
case "dns":
addresses, err := splitList(val)
if err != nil {
return nil, err
}
for _, address := range addresses {
a := net.ParseIP(address)
if a == nil {
conf.Interface.DNSSearch = append(conf.Interface.DNSSearch, address)
} else {
conf.Interface.DNS = append(conf.Interface.DNS, a)
}
}
case "preup":
conf.Interface.PreUp = val
case "postup":
conf.Interface.PostUp = val
case "predown":
conf.Interface.PreDown = val
case "postdown":
conf.Interface.PostDown = val
default:
return nil, &ParseError{l18n.Sprintf("Invalid key for [Interface] section"), key}
}
} else if parserState == inPeerSection {
switch key {
case "publickey":
k, err := parseKeyBase64(val)
if err != nil {
return nil, err
}
peer.PublicKey = *k
case "presharedkey":
k, err := parseKeyBase64(val)
if err != nil {
return nil, err
}
peer.PresharedKey = *k
case "allowedips":
addresses, err := splitList(val)
if err != nil {
return nil, err
}
for _, address := range addresses {
a, err := parseIPCidr(address)
if err != nil {
return nil, err
}
peer.AllowedIPs = append(peer.AllowedIPs, *a)
}
case "persistentkeepalive":
p, err := parsePersistentKeepalive(val)
if err != nil {
return nil, err
}
peer.PersistentKeepalive = p
case "endpoint":
e, err := parseEndpoint(val)
if err != nil {
return nil, err
}
peer.Endpoint = *e
default:
return nil, &ParseError{l18n.Sprintf("Invalid key for [Peer] section"), key}
}
}
}
conf.maybeAddPeer(peer)
if !sawPrivateKey {
return nil, &ParseError{l18n.Sprintf("An interface must have a private key"), l18n.Sprintf("[none specified]")}
}
for _, p := range conf.Peers {
if p.PublicKey.IsZero() {
return nil, &ParseError{l18n.Sprintf("All peers must have public keys"), l18n.Sprintf("[none specified]")}
}
}
return &conf, nil
}
func FromWgQuickWithUnknownEncoding(s string, name string) (*Config, error) {
c, firstErr := FromWgQuick(s, name)
if firstErr == nil {
return c, nil
}
for _, encoding := range unicode.All {
decoded, err := encoding.NewDecoder().String(s)
if err == nil {
c, err := FromWgQuick(decoded, name)
if err == nil {
return c, nil
}
}
}
return nil, firstErr
}
func FromUAPI(reader io.Reader, existingConfig *Config) (*Config, error) {
parserState := inInterfaceSection
conf := Config{
Name: existingConfig.Name,
Interface: Interface{
Addresses: existingConfig.Interface.Addresses,
DNS: existingConfig.Interface.DNS,
DNSSearch: existingConfig.Interface.DNSSearch,
MTU: existingConfig.Interface.MTU,
PreUp: existingConfig.Interface.PreUp,
PostUp: existingConfig.Interface.PostUp,
PreDown: existingConfig.Interface.PreDown,
PostDown: existingConfig.Interface.PostDown,
},
}
var peer *Peer
lineReader := bufio.NewReader(reader)
for {
line, err := lineReader.ReadString('\n')
if err != nil {
return nil, err
}
line = line[:len(line)-1]
if len(line) == 0 {
break
}
equals := strings.IndexByte(line, '=')
if equals < 0 {
return nil, &ParseError{l18n.Sprintf("Config key is missing an equals separator"), line}
}
key, val := line[:equals], line[equals+1:]
if len(val) == 0 {
return nil, &ParseError{l18n.Sprintf("Key must have a value"), line}
}
switch key {
case "public_key":
conf.maybeAddPeer(peer)
peer = &Peer{}
parserState = inPeerSection
case "errno":
if val == "0" {
continue
} else {
return nil, &ParseError{l18n.Sprintf("Error in getting configuration"), val}
}
}
if parserState == inInterfaceSection {
switch key {
case "private_key":
k, err := parseKeyHex(val)
if err != nil {
return nil, err
}
conf.Interface.PrivateKey = *k
case "listen_port":
p, err := parsePort(val)
if err != nil {
return nil, err
}
conf.Interface.ListenPort = p
case "fwmark":
// Ignored for now.
default:
return nil, &ParseError{l18n.Sprintf("Invalid key for interface section"), key}
}
} else if parserState == inPeerSection {
switch key {
case "public_key":
k, err := parseKeyHex(val)
if err != nil {
return nil, err
}
peer.PublicKey = *k
case "preshared_key":
k, err := parseKeyHex(val)
if err != nil {
return nil, err
}
peer.PresharedKey = *k
case "protocol_version":
if val != "1" {
return nil, &ParseError{l18n.Sprintf("Protocol version must be 1"), val}
}
case "allowed_ip":
a, err := parseIPCidr(val)
if err != nil {
return nil, err
}
peer.AllowedIPs = append(peer.AllowedIPs, *a)
case "persistent_keepalive_interval":
p, err := parsePersistentKeepalive(val)
if err != nil {
return nil, err
}
peer.PersistentKeepalive = p
case "endpoint":
e, err := parseEndpoint(val)
if err != nil {
return nil, err
}
peer.Endpoint = *e
case "tx_bytes":
b, err := parseBytesOrStamp(val)
if err != nil {
return nil, err
}
peer.TxBytes = Bytes(b)
case "rx_bytes":
b, err := parseBytesOrStamp(val)
if err != nil {
return nil, err
}
peer.RxBytes = Bytes(b)
case "last_handshake_time_sec":
t, err := parseBytesOrStamp(val)
if err != nil {
return nil, err
}
peer.LastHandshakeTime += HandshakeTime(time.Duration(t) * time.Second)
case "last_handshake_time_nsec":
t, err := parseBytesOrStamp(val)
if err != nil {
return nil, err
}
peer.LastHandshakeTime += HandshakeTime(time.Duration(t) * time.Nanosecond)
default:
return nil, &ParseError{l18n.Sprintf("Invalid key for peer section"), key}
}
}
}
conf.maybeAddPeer(peer)
return &conf, nil
}