Files
ctrld/config.go
2023-05-13 12:04:58 +07:00

383 lines
12 KiB
Go

package ctrld
import (
"context"
"crypto/tls"
"crypto/x509"
"net"
"net/http"
"net/url"
"os"
"strings"
"sync/atomic"
"time"
"github.com/go-playground/validator/v10"
"github.com/miekg/dns"
"github.com/spf13/viper"
"golang.org/x/sync/singleflight"
"github.com/Control-D-Inc/ctrld/internal/dnsrcode"
ctrldnet "github.com/Control-D-Inc/ctrld/internal/net"
)
// SetConfigName set the config name that ctrld will look for.
// DEPRECATED: use SetConfigNameWithPath instead.
func SetConfigName(v *viper.Viper, name string) {
configPath := "$HOME"
// viper has its own way to get user home directory: https://github.com/spf13/viper/blob/v1.14.0/util.go#L134
// To be consistent, we prefer os.UserHomeDir instead.
if homeDir, err := os.UserHomeDir(); err == nil {
configPath = homeDir
}
SetConfigNameWithPath(v, name, configPath)
}
// SetConfigNameWithPath set the config path and name that ctrld will look for.
func SetConfigNameWithPath(v *viper.Viper, name, configPath string) {
v.SetConfigName(name)
v.AddConfigPath(configPath)
v.AddConfigPath(".")
}
// InitConfig initializes default config values for given *viper.Viper instance.
func InitConfig(v *viper.Viper, name string) {
v.SetDefault("listener", map[string]*ListenerConfig{
"0": {
IP: "127.0.0.1",
Port: 53,
},
})
v.SetDefault("network", map[string]*NetworkConfig{
"0": {
Name: "Network 0",
Cidrs: []string{"0.0.0.0/0"},
},
})
v.SetDefault("upstream", map[string]*UpstreamConfig{
"0": {
BootstrapIP: "76.76.2.11",
Name: "Control D - Anti-Malware",
Type: ResolverTypeDOH,
Endpoint: "https://freedns.controld.com/p1",
Timeout: 5000,
},
"1": {
BootstrapIP: "76.76.2.11",
Name: "Control D - No Ads",
Type: ResolverTypeDOQ,
Endpoint: "p2.freedns.controld.com",
Timeout: 3000,
},
})
}
// Config represents ctrld supported configuration.
type Config struct {
Service ServiceConfig `mapstructure:"service" toml:"service,omitempty"`
Listener map[string]*ListenerConfig `mapstructure:"listener" toml:"listener" validate:"min=1,dive"`
Network map[string]*NetworkConfig `mapstructure:"network" toml:"network" validate:"min=1,dive"`
Upstream map[string]*UpstreamConfig `mapstructure:"upstream" toml:"upstream" validate:"min=1,dive"`
}
// HasUpstreamSendClientInfo reports whether the config has any upstream
// is configured to send client info to Control D DNS server.
func (c *Config) HasUpstreamSendClientInfo() bool {
for _, uc := range c.Upstream {
if uc.UpstreamSendClientInfo() {
return true
}
}
return false
}
// ServiceConfig specifies the general ctrld config.
type ServiceConfig struct {
LogLevel string `mapstructure:"log_level" toml:"log_level,omitempty"`
LogPath string `mapstructure:"log_path" toml:"log_path,omitempty"`
CacheEnable bool `mapstructure:"cache_enable" toml:"cache_enable,omitempty"`
CacheSize int `mapstructure:"cache_size" toml:"cache_size,omitempty"`
CacheTTLOverride int `mapstructure:"cache_ttl_override" toml:"cache_ttl_override,omitempty"`
CacheServeStale bool `mapstructure:"cache_serve_stale" toml:"cache_serve_stale,omitempty"`
Daemon bool `mapstructure:"-" toml:"-"`
AllocateIP bool `mapstructure:"-" toml:"-"`
}
// NetworkConfig specifies configuration for networks where ctrld will handle requests.
type NetworkConfig struct {
Name string `mapstructure:"name" toml:"name,omitempty"`
Cidrs []string `mapstructure:"cidrs" toml:"cidrs,omitempty" validate:"dive,cidr"`
IPNets []*net.IPNet `mapstructure:"-" toml:"-"`
}
// UpstreamConfig specifies configuration for upstreams that ctrld will forward requests to.
type UpstreamConfig struct {
Name string `mapstructure:"name" toml:"name,omitempty"`
Type string `mapstructure:"type" toml:"type,omitempty" validate:"oneof=doh doh3 dot doq os legacy"`
Endpoint string `mapstructure:"endpoint" toml:"endpoint,omitempty" validate:"required_unless=Type os"`
BootstrapIP string `mapstructure:"bootstrap_ip" toml:"bootstrap_ip,omitempty"`
Domain string `mapstructure:"-" toml:"-"`
Timeout int `mapstructure:"timeout" toml:"timeout,omitempty" validate:"gte=0"`
// The caller should not access this field directly.
// Use UpstreamSendClientInfo instead.
SendClientInfo *bool `mapstructure:"send_client_info" toml:"send_client_info,omitempty"`
transport *http.Transport `mapstructure:"-" toml:"-"`
http3RoundTripper http.RoundTripper `mapstructure:"-" toml:"-"`
certPool *x509.CertPool `mapstructure:"-" toml:"-"`
u *url.URL `mapstructure:"-" toml:"-"`
g singleflight.Group
bootstrapIPs []string
nextBootstrapIP atomic.Uint32
}
// ListenerConfig specifies the networks configuration that ctrld will run on.
type ListenerConfig struct {
IP string `mapstructure:"ip" toml:"ip,omitempty" validate:"iporempty"`
Port int `mapstructure:"port" toml:"port,omitempty" validate:"gte=0"`
Restricted bool `mapstructure:"restricted" toml:"restricted,omitempty"`
Policy *ListenerPolicyConfig `mapstructure:"policy" toml:"policy,omitempty"`
}
// ListenerPolicyConfig specifies the policy rules for ctrld to filter incoming requests.
type ListenerPolicyConfig struct {
Name string `mapstructure:"name" toml:"name,omitempty"`
Networks []Rule `mapstructure:"networks" toml:"networks,omitempty,inline,multiline" validate:"dive,len=1"`
Rules []Rule `mapstructure:"rules" toml:"rules,omitempty,inline,multiline" validate:"dive,len=1"`
FailoverRcodes []string `mapstructure:"failover_rcodes" toml:"failover_rcodes,omitempty" validate:"dive,dnsrcode"`
FailoverRcodeNumbers []int `mapstructure:"-" toml:"-"`
}
// Rule is a map from source to list of upstreams.
// ctrld uses rule to perform requests matching and forward
// the request to corresponding upstreams if it's matched.
type Rule map[string][]string
// Init initialized necessary values for an UpstreamConfig.
func (uc *UpstreamConfig) Init() {
if u, err := url.Parse(uc.Endpoint); err == nil {
uc.Domain = u.Host
switch uc.Type {
case ResolverTypeDOH, ResolverTypeDOH3:
uc.u = u
}
}
if uc.Domain != "" {
return
}
if !strings.Contains(uc.Endpoint, ":") {
uc.Domain = uc.Endpoint
uc.Endpoint = net.JoinHostPort(uc.Endpoint, defaultPortFor(uc.Type))
}
host, _, _ := net.SplitHostPort(uc.Endpoint)
uc.Domain = host
if net.ParseIP(uc.Domain) != nil {
uc.BootstrapIP = uc.Domain
}
}
// UpstreamSendClientInfo reports whether the upstream is
// configured to send client info to Control D DNS server.
//
// Client info includes:
// - MAC
// - Lan IP
// - Hostname
func (uc *UpstreamConfig) UpstreamSendClientInfo() bool {
if uc.SendClientInfo != nil && !(*uc.SendClientInfo) {
return false
}
if uc.SendClientInfo == nil {
return true
}
switch uc.Type {
case ResolverTypeDOH, ResolverTypeDOH3:
if u, err := url.Parse(uc.Endpoint); err == nil {
domain := u.Hostname()
for _, parent := range []string{"controld.com", "controld.net"} {
if dns.IsSubDomain(parent, domain) {
return true
}
}
}
}
return false
}
func (uc *UpstreamConfig) BootstrapIPs() []string {
return uc.bootstrapIPs
}
// SetCertPool sets the system cert pool used for TLS connections.
func (uc *UpstreamConfig) SetCertPool(cp *x509.CertPool) {
uc.certPool = cp
}
// SetupBootstrapIP manually find all available IPs of the upstream.
// The first usable IP will be used as bootstrap IP of the upstream.
func (uc *UpstreamConfig) SetupBootstrapIP() {
uc.setupBootstrapIP(true)
}
// SetupBootstrapIP manually find all available IPs of the upstream.
// The first usable IP will be used as bootstrap IP of the upstream.
func (uc *UpstreamConfig) setupBootstrapIP(withBootstrapDNS bool) {
uc.bootstrapIPs = lookupIP(uc.Domain, uc.Timeout, withBootstrapDNS)
ProxyLog.Debug().Msgf("Bootstrap IPs: %v", uc.bootstrapIPs)
}
// ReBootstrap re-setup the bootstrap IP and the transport.
func (uc *UpstreamConfig) ReBootstrap() {
switch uc.Type {
case ResolverTypeDOH, ResolverTypeDOH3:
default:
return
}
_, _, _ = uc.g.Do("ReBootstrap", func() (any, error) {
ProxyLog.Debug().Msg("re-bootstrapping upstream ip")
uc.BootstrapIP = ""
uc.setupTransportWithoutPingUpstream()
return true, nil
})
}
func (uc *UpstreamConfig) setupTransportWithoutPingUpstream() {
switch uc.Type {
case ResolverTypeDOH:
uc.setupDOHTransportWithoutPingUpstream()
case ResolverTypeDOH3:
uc.setupDOH3TransportWithoutPingUpstream()
}
}
// SetupTransport initializes the network transport used to connect to upstream server.
// For now, only DoH upstream is supported.
func (uc *UpstreamConfig) SetupTransport() {
switch uc.Type {
case ResolverTypeDOH:
uc.setupDOHTransport()
case ResolverTypeDOH3:
uc.setupDOH3Transport()
}
}
func (uc *UpstreamConfig) setupDOHTransport() {
uc.setupDOHTransportWithoutPingUpstream()
uc.pingUpstream()
}
func (uc *UpstreamConfig) setupDOHTransportWithoutPingUpstream() {
uc.transport = http.DefaultTransport.(*http.Transport).Clone()
uc.transport.IdleConnTimeout = 5 * time.Second
uc.transport.TLSClientConfig = &tls.Config{RootCAs: uc.certPool}
dialerTimeoutMs := 2000
if uc.Timeout > 0 && uc.Timeout < dialerTimeoutMs {
dialerTimeoutMs = uc.Timeout
}
dialerTimeout := time.Duration(dialerTimeoutMs) * time.Millisecond
uc.transport.DialContext = func(ctx context.Context, network, addr string) (net.Conn, error) {
_, port, _ := net.SplitHostPort(addr)
if uc.BootstrapIP != "" {
dialer := net.Dialer{Timeout: dialerTimeout, KeepAlive: dialerTimeout}
addr := net.JoinHostPort(uc.BootstrapIP, port)
Log(ctx, ProxyLog.Debug(), "sending doh request to: %s", addr)
return dialer.DialContext(ctx, network, addr)
}
pd := &ctrldnet.ParallelDialer{}
pd.Timeout = dialerTimeout
pd.KeepAlive = dialerTimeout
addrs := make([]string, len(uc.bootstrapIPs))
for i := range uc.bootstrapIPs {
addrs[i] = net.JoinHostPort(uc.bootstrapIPs[i], port)
}
conn, err := pd.DialContext(ctx, network, addrs)
if err != nil {
return nil, err
}
Log(ctx, ProxyLog.Debug(), "sending doh request to: %s", conn.RemoteAddr())
return conn, nil
}
}
func (uc *UpstreamConfig) pingUpstream() {
// Warming up the transport by querying a test packet.
dnsResolver, err := NewResolver(uc)
if err != nil {
ProxyLog.Error().Err(err).Msgf("failed to create resolver for upstream: %s", uc.Name)
return
}
msg := new(dns.Msg)
msg.SetQuestion(".", dns.TypeNS)
msg.MsgHdr.RecursionDesired = true
ctx, cancel := context.WithTimeout(context.Background(), 5*time.Second)
defer cancel()
_, _ = dnsResolver.Resolve(ctx, msg)
}
// Init initialized necessary values for an ListenerConfig.
func (lc *ListenerConfig) Init() {
if lc.Policy != nil {
lc.Policy.FailoverRcodeNumbers = make([]int, len(lc.Policy.FailoverRcodes))
for i, rcode := range lc.Policy.FailoverRcodes {
lc.Policy.FailoverRcodeNumbers[i] = dnsrcode.FromString(rcode)
}
}
}
// ValidateConfig validates the given config.
func ValidateConfig(validate *validator.Validate, cfg *Config) error {
_ = validate.RegisterValidation("dnsrcode", validateDnsRcode)
_ = validate.RegisterValidation("iporempty", validateIpOrEmpty)
return validate.Struct(cfg)
}
func validateDnsRcode(fl validator.FieldLevel) bool {
return dnsrcode.FromString(fl.Field().String()) != -1
}
func validateIpOrEmpty(fl validator.FieldLevel) bool {
val := fl.Field().String()
if val == "" {
return true
}
return net.ParseIP(val) != nil
}
func defaultPortFor(typ string) string {
switch typ {
case ResolverTypeDOH, ResolverTypeDOH3:
return "443"
case ResolverTypeDOQ, ResolverTypeDOT:
return "853"
case ResolverTypeLegacy:
return "53"
}
return "53"
}
// ResolverTypeFromEndpoint tries guessing the resolver type with a given endpoint
// using following rules:
//
// - If endpoint is an IP address -> ResolverTypeLegacy
// - If endpoint starts with "https://" -> ResolverTypeDOH
// - If endpoint starts with "quic://" -> ResolverTypeDOQ
// - For anything else -> ResolverTypeDOT
func ResolverTypeFromEndpoint(endpoint string) string {
switch {
case strings.HasPrefix(endpoint, "https://"):
return ResolverTypeDOH
case strings.HasPrefix(endpoint, "quic://"):
return ResolverTypeDOQ
}
host := endpoint
if strings.Contains(endpoint, ":") {
host, _, _ = net.SplitHostPort(host)
}
if ip := net.ParseIP(host); ip != nil {
return ResolverTypeLegacy
}
return ResolverTypeDOT
}