sing-box/service/resolved/resolve1.go
2025-03-31 23:21:57 +08:00

625 lines
16 KiB
Go

package resolved
import (
"context"
"errors"
"fmt"
"net/netip"
"os"
"os/user"
"path/filepath"
"strconv"
"strings"
"syscall"
"github.com/sagernet/sing-box/adapter"
"github.com/sagernet/sing-box/common/process"
C "github.com/sagernet/sing-box/constant"
"github.com/sagernet/sing-box/dns"
"github.com/sagernet/sing-box/log"
"github.com/sagernet/sing/common"
E "github.com/sagernet/sing/common/exceptions"
F "github.com/sagernet/sing/common/format"
M "github.com/sagernet/sing/common/metadata"
"github.com/godbus/dbus/v5"
mDNS "github.com/miekg/dns"
)
type resolve1Manager Service
type Address struct {
IfIndex int32
Family int32
Address []byte
}
type Name struct {
IfIndex int32
Hostname string
}
type ResourceRecord struct {
IfIndex int32
Type uint16
Class uint16
Data []byte
}
type SRVRecord struct {
Priority uint16
Weight uint16
Port uint16
Hostname string
Addresses []Address
CNAME string
}
type TXTRecord []byte
type LinkDNS struct {
Family int32
Address []byte
}
type LinkDNSEx struct {
Family int32
Address []byte
Port uint16
Name string
}
type LinkDomain struct {
Domain string
RoutingOnly bool
}
func (t *resolve1Manager) getLink(ifIndex int32) (*TransportLink, *dbus.Error) {
link, loaded := t.links[ifIndex]
if !loaded {
link = &TransportLink{}
t.links[ifIndex] = link
iif, err := t.network.InterfaceFinder().ByIndex(int(ifIndex))
if err != nil {
return nil, wrapError(err)
}
link.iif = iif
}
return link, nil
}
func (t *resolve1Manager) getSenderProcess(sender dbus.Sender) (int32, error) {
var senderPid int32
dbusObject := t.systemBus.Object("org.freedesktop.DBus", "/org/freedesktop/DBus")
if dbusObject == nil {
return 0, E.New("missing dbus object")
}
err := dbusObject.Call("org.freedesktop.DBus.GetConnectionUnixProcessID", 0, string(sender)).Store(&senderPid)
if err != nil {
return 0, E.Cause(err, "GetConnectionUnixProcessID")
}
return senderPid, nil
}
func (t *resolve1Manager) createMetadata(sender dbus.Sender) adapter.InboundContext {
var metadata adapter.InboundContext
metadata.Inbound = t.Tag()
metadata.InboundType = C.TypeResolved
senderPid, err := t.getSenderProcess(sender)
if err != nil {
return metadata
}
var processInfo process.Info
metadata.ProcessInfo = &processInfo
processInfo.ProcessID = uint32(senderPid)
processPath, err := os.Readlink(F.ToString("/proc/", senderPid, "/exe"))
if err == nil {
processInfo.ProcessPath = processPath
} else {
processPath, err = os.Readlink(F.ToString("/proc/", senderPid, "/comm"))
if err == nil {
processInfo.ProcessPath = processPath
}
}
var uidFound bool
statusContent, err := os.ReadFile(F.ToString("/proc/", senderPid, "/status"))
if err == nil {
for _, line := range strings.Split(string(statusContent), "\n") {
line = strings.TrimSpace(line)
if strings.HasPrefix(line, "Uid:") {
fields := strings.Fields(line)
if len(fields) >= 2 {
uid, parseErr := strconv.ParseUint(fields[1], 10, 32)
if parseErr != nil {
break
}
processInfo.UserId = int32(uid)
uidFound = true
if osUser, _ := user.LookupId(F.ToString(uid)); osUser != nil {
processInfo.User = osUser.Username
}
break
}
}
}
}
if !uidFound {
metadata.ProcessInfo.UserId = -1
}
return metadata
}
func (t *resolve1Manager) logRequest(sender dbus.Sender, message ...any) context.Context {
ctx := log.ContextWithNewID(t.ctx)
metadata := t.createMetadata(sender)
if metadata.ProcessInfo != nil {
var prefix string
if metadata.ProcessInfo.ProcessPath != "" {
prefix = filepath.Base(metadata.ProcessInfo.ProcessPath)
} else if metadata.ProcessInfo.User != "" {
prefix = F.ToString("user:", metadata.ProcessInfo.User)
} else if metadata.ProcessInfo.UserId != 0 {
prefix = F.ToString("uid:", metadata.ProcessInfo.UserId)
}
t.logger.InfoContext(ctx, "(", prefix, ") ", F.ToString(message...))
} else {
t.logger.InfoContext(ctx, F.ToString(message...))
}
return adapter.WithContext(ctx, &metadata)
}
func familyToString(family int32) string {
switch family {
case syscall.AF_UNSPEC:
return "AF_UNSPEC"
case syscall.AF_INET:
return "AF_INET"
case syscall.AF_INET6:
return "AF_INET6"
default:
return F.ToString(family)
}
}
func (t *resolve1Manager) ResolveHostname(sender dbus.Sender, ifIndex int32, hostname string, family int32, flags uint64) (addresses []Address, canonical string, outflags uint64, err *dbus.Error) {
t.linkAccess.Lock()
link, err := t.getLink(ifIndex)
if err != nil {
return
}
t.linkAccess.Unlock()
var strategy C.DomainStrategy
switch family {
case syscall.AF_UNSPEC:
strategy = C.DomainStrategyAsIS
case syscall.AF_INET:
strategy = C.DomainStrategyIPv4Only
case syscall.AF_INET6:
strategy = C.DomainStrategyIPv6Only
}
ctx := t.logRequest(sender, "ResolveHostname ", link.iif.Name, " ", hostname, " ", familyToString(family), " ", flags)
responseAddresses, lookupErr := t.dnsRouter.Lookup(ctx, hostname, adapter.DNSQueryOptions{
LookupStrategy: strategy,
})
if lookupErr != nil {
err = wrapError(err)
return
}
addresses = common.Map(responseAddresses, func(it netip.Addr) Address {
var addrFamily int32
if it.Is4() {
addrFamily = syscall.AF_INET
} else {
addrFamily = syscall.AF_INET6
}
return Address{
IfIndex: ifIndex,
Family: addrFamily,
Address: it.AsSlice(),
}
})
canonical = mDNS.CanonicalName(hostname)
return
}
func (t *resolve1Manager) ResolveAddress(sender dbus.Sender, ifIndex int32, family int32, address []byte, flags uint64) (names []Name, outflags uint64, err *dbus.Error) {
t.linkAccess.Lock()
link, err := t.getLink(ifIndex)
if err != nil {
return
}
t.linkAccess.Unlock()
addr, ok := netip.AddrFromSlice(address)
if !ok {
err = wrapError(E.New("invalid address"))
return
}
var nibbles []string
for i := len(address) - 1; i >= 0; i-- {
b := address[i]
nibbles = append(nibbles, fmt.Sprintf("%x", b&0x0F))
nibbles = append(nibbles, fmt.Sprintf("%x", b>>4))
}
var ptrDomain string
if addr.Is4() {
ptrDomain = strings.Join(nibbles, ".") + ".in-addr.arpa."
} else {
ptrDomain = strings.Join(nibbles, ".") + ".ip6.arpa."
}
request := &mDNS.Msg{
MsgHdr: mDNS.MsgHdr{
RecursionDesired: true,
},
Question: []mDNS.Question{
{
Name: mDNS.Fqdn(ptrDomain),
Qtype: mDNS.TypePTR,
Qclass: mDNS.ClassINET,
},
},
}
ctx := t.logRequest(sender, "ResolveAddress ", link.iif.Name, familyToString(family), addr, flags)
response, lookupErr := t.dnsRouter.Exchange(ctx, request, adapter.DNSQueryOptions{})
if lookupErr != nil {
err = wrapError(err)
return
}
if response.Rcode != mDNS.RcodeSuccess {
err = rcodeError(response.Rcode)
return
}
for _, rawRR := range response.Answer {
switch rr := rawRR.(type) {
case *mDNS.PTR:
names = append(names, Name{
IfIndex: ifIndex,
Hostname: rr.Ptr,
})
}
}
return
}
func (t *resolve1Manager) ResolveRecord(sender dbus.Sender, ifIndex int32, family int32, hostname string, qClass uint16, qType uint16, flags uint64) (records []ResourceRecord, outflags uint64, err *dbus.Error) {
t.linkAccess.Lock()
link, err := t.getLink(ifIndex)
if err != nil {
return
}
t.linkAccess.Unlock()
request := &mDNS.Msg{
MsgHdr: mDNS.MsgHdr{
RecursionDesired: true,
},
Question: []mDNS.Question{
{
Name: mDNS.Fqdn(hostname),
Qtype: qType,
Qclass: qClass,
},
},
}
ctx := t.logRequest(sender, "ResolveRecord ", link.iif.Name, familyToString(family), hostname, mDNS.Class(qClass), mDNS.Type(qType), flags)
response, exchangeErr := t.dnsRouter.Exchange(ctx, request, adapter.DNSQueryOptions{})
if exchangeErr != nil {
err = wrapError(exchangeErr)
return
}
if response.Rcode != mDNS.RcodeSuccess {
err = rcodeError(response.Rcode)
return
}
for _, rr := range response.Answer {
var record ResourceRecord
record.IfIndex = ifIndex
record.Type = rr.Header().Rrtype
record.Class = rr.Header().Class
data := make([]byte, mDNS.Len(rr))
_, unpackErr := mDNS.PackRR(rr, data, 0, nil, false)
if unpackErr != nil {
err = wrapError(unpackErr)
}
record.Data = data
}
return
}
func (t *resolve1Manager) ResolveService(sender dbus.Sender, ifIndex int32, hostname string, sType string, domain string, family int32, flags uint64) (srvData []SRVRecord, txtData []TXTRecord, canonicalName string, canonicalType string, canonicalDomain string, outflags uint64, err *dbus.Error) {
t.linkAccess.Lock()
link, err := t.getLink(ifIndex)
if err != nil {
return
}
t.linkAccess.Unlock()
serviceName := hostname
if hostname != "" && !strings.HasSuffix(hostname, ".") {
serviceName += "."
}
serviceName += sType
if !strings.HasSuffix(serviceName, ".") {
serviceName += "."
}
serviceName += domain
if !strings.HasSuffix(serviceName, ".") {
serviceName += "."
}
ctx := t.logRequest(sender, "ResolveService ", link.iif.Name, " ", hostname, " ", sType, " ", domain, " ", familyToString(family), " ", flags)
srvRequest := &mDNS.Msg{
MsgHdr: mDNS.MsgHdr{
RecursionDesired: true,
},
Question: []mDNS.Question{
{
Name: serviceName,
Qtype: mDNS.TypeSRV,
Qclass: mDNS.ClassINET,
},
},
}
srvResponse, exchangeErr := t.dnsRouter.Exchange(ctx, srvRequest, adapter.DNSQueryOptions{})
if exchangeErr != nil {
err = wrapError(exchangeErr)
return
}
if srvResponse.Rcode != mDNS.RcodeSuccess {
err = rcodeError(srvResponse.Rcode)
return
}
txtRequest := &mDNS.Msg{
MsgHdr: mDNS.MsgHdr{
RecursionDesired: true,
},
Question: []mDNS.Question{
{
Name: serviceName,
Qtype: mDNS.TypeTXT,
Qclass: mDNS.ClassINET,
},
},
}
txtResponse, exchangeErr := t.dnsRouter.Exchange(ctx, txtRequest, adapter.DNSQueryOptions{})
if exchangeErr != nil {
err = wrapError(exchangeErr)
return
}
for _, rawRR := range srvResponse.Answer {
switch rr := rawRR.(type) {
case *mDNS.SRV:
var srvRecord SRVRecord
srvRecord.Priority = rr.Priority
srvRecord.Weight = rr.Weight
srvRecord.Port = rr.Port
srvRecord.Hostname = rr.Target
var strategy C.DomainStrategy
switch family {
case syscall.AF_UNSPEC:
strategy = C.DomainStrategyAsIS
case syscall.AF_INET:
strategy = C.DomainStrategyIPv4Only
case syscall.AF_INET6:
strategy = C.DomainStrategyIPv6Only
}
addrs, lookupErr := t.dnsRouter.Lookup(ctx, rr.Target, adapter.DNSQueryOptions{
LookupStrategy: strategy,
})
if lookupErr == nil {
srvRecord.Addresses = common.Map(addrs, func(it netip.Addr) Address {
var addrFamily int32
if it.Is4() {
addrFamily = syscall.AF_INET
} else {
addrFamily = syscall.AF_INET6
}
return Address{
IfIndex: ifIndex,
Family: addrFamily,
Address: it.AsSlice(),
}
})
}
for _, a := range srvResponse.Answer {
if cname, ok := a.(*mDNS.CNAME); ok && cname.Header().Name == rr.Target {
srvRecord.CNAME = cname.Target
break
}
}
srvData = append(srvData, srvRecord)
}
}
for _, rawRR := range txtResponse.Answer {
switch rr := rawRR.(type) {
case *mDNS.TXT:
data := make([]byte, mDNS.Len(rr))
_, packErr := mDNS.PackRR(rr, data, 0, nil, false)
if packErr == nil {
txtData = append(txtData, data)
}
}
}
canonicalName = mDNS.CanonicalName(hostname)
canonicalType = mDNS.CanonicalName(sType)
canonicalDomain = mDNS.CanonicalName(domain)
return
}
func (t *resolve1Manager) SetLinkDNS(sender dbus.Sender, ifIndex int32, addresses []LinkDNS) *dbus.Error {
t.linkAccess.Lock()
defer t.linkAccess.Unlock()
link, err := t.getLink(ifIndex)
if err != nil {
return wrapError(err)
}
link.address = addresses
if len(addresses) > 0 {
t.logRequest(sender, "SetLinkDNS ", link.iif.Name, " ", strings.Join(common.Map(addresses, func(it LinkDNS) string {
return M.AddrFromIP(it.Address).String()
}), ", "))
} else {
t.logRequest(sender, "SetLinkDNS ", link.iif.Name, " (empty)")
}
return t.postUpdate(link)
}
func (t *resolve1Manager) SetLinkDNSEx(sender dbus.Sender, ifIndex int32, addresses []LinkDNSEx) *dbus.Error {
t.linkAccess.Lock()
defer t.linkAccess.Unlock()
link, err := t.getLink(ifIndex)
if err != nil {
return wrapError(err)
}
link.addressEx = addresses
if len(addresses) > 0 {
t.logRequest(sender, "SetLinkDNSEx ", link.iif.Name, " ", strings.Join(common.Map(addresses, func(it LinkDNSEx) string {
return M.SocksaddrFrom(M.AddrFromIP(it.Address), it.Port).String()
}), ", "))
} else {
t.logRequest(sender, "SetLinkDNSEx ", link.iif.Name, " (empty)")
}
return t.postUpdate(link)
}
func (t *resolve1Manager) SetLinkDomains(sender dbus.Sender, ifIndex int32, domains []LinkDomain) *dbus.Error {
t.linkAccess.Lock()
defer t.linkAccess.Unlock()
link, err := t.getLink(ifIndex)
if err != nil {
return wrapError(err)
}
link.domain = domains
if len(domains) > 0 {
t.logRequest(sender, "SetLinkDomains ", link.iif.Name, " ", strings.Join(common.Map(domains, func(domain LinkDomain) string {
if !domain.RoutingOnly {
return domain.Domain
} else {
return "~" + domain.Domain
}
}), ", "))
} else {
t.logRequest(sender, "SetLinkDomains ", link.iif.Name, " (empty)")
}
return t.postUpdate(link)
}
func (t *resolve1Manager) SetLinkDefaultRoute(sender dbus.Sender, ifIndex int32, defaultRoute bool) *dbus.Error {
t.linkAccess.Lock()
defer t.linkAccess.Unlock()
link, err := t.getLink(ifIndex)
if err != nil {
return err
}
link.defaultRoute = defaultRoute
t.defaultRouteSequence = append(t.defaultRouteSequence, ifIndex)
var defaultRouteString string
if defaultRoute {
defaultRouteString = "yes"
} else {
defaultRouteString = "no"
}
t.logRequest(sender, "SetLinkDefaultRoute ", link.iif.Name, " ", defaultRouteString)
return t.postUpdate(link)
}
func (t *resolve1Manager) SetLinkLLMNR(ifIndex int32, llmnrMode string) *dbus.Error {
return nil
}
func (t *resolve1Manager) SetLinkMulticastDNS(ifIndex int32, mdnsMode string) *dbus.Error {
return nil
}
func (t *resolve1Manager) SetLinkDNSOverTLS(sender dbus.Sender, ifIndex int32, dotMode string) *dbus.Error {
t.linkAccess.Lock()
defer t.linkAccess.Unlock()
link, err := t.getLink(ifIndex)
if err != nil {
return wrapError(err)
}
switch dotMode {
case "yes":
link.dnsOverTLS = true
case "":
dotMode = "no"
fallthrough
case "opportunistic", "no":
link.dnsOverTLS = false
}
t.logRequest(sender, "SetLinkDNSOverTLS ", link.iif.Name, " ", dotMode)
return t.postUpdate(link)
}
func (t *resolve1Manager) SetLinkDNSSEC(ifIndex int32, dnssecMode string) *dbus.Error {
return nil
}
func (t *resolve1Manager) SetLinkDNSSECNegativeTrustAnchors(ifIndex int32, domains []string) *dbus.Error {
return nil
}
func (t *resolve1Manager) RevertLink(sender dbus.Sender, ifIndex int32) *dbus.Error {
t.linkAccess.Lock()
defer t.linkAccess.Unlock()
link, err := t.getLink(ifIndex)
if err != nil {
return wrapError(err)
}
delete(t.links, ifIndex)
t.logRequest(sender, "RevertLink ", link.iif.Name)
return t.postUpdate(link)
}
// TODO: implement RegisterService, UnregisterService
func (t *resolve1Manager) RegisterService(sender dbus.Sender, identifier string, nameTemplate string, serviceType string, port uint16, priority uint16, weight uint16, txtRecords []TXTRecord) (objectPath dbus.ObjectPath, dbusErr *dbus.Error) {
return "", wrapError(E.New("not implemented"))
}
func (t *resolve1Manager) UnregisterService(sender dbus.Sender, servicePath dbus.ObjectPath) error {
return wrapError(E.New("not implemented"))
}
func (t *resolve1Manager) ResetStatistics() *dbus.Error {
return nil
}
func (t *resolve1Manager) FlushCaches(sender dbus.Sender) *dbus.Error {
t.dnsRouter.ClearCache()
t.logRequest(sender, "FlushCaches")
return nil
}
func (t *resolve1Manager) ResetServerFeatures() *dbus.Error {
return nil
}
func (t *resolve1Manager) postUpdate(link *TransportLink) *dbus.Error {
if t.updateCallback != nil {
return wrapError(t.updateCallback(link))
}
return nil
}
func rcodeError(rcode int) *dbus.Error {
return dbus.NewError("org.freedesktop.resolve1.DnsError."+mDNS.RcodeToString[rcode], []any{mDNS.RcodeToString[rcode]})
}
func wrapError(err error) *dbus.Error {
if err == nil {
return nil
}
var rcode dns.RcodeError
if errors.As(err, &rcode) {
return rcodeError(int(rcode))
}
return dbus.MakeFailedError(err)
}