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feature: Adds basic UDP support.

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This commit is contained in:
Tera << 8 2025-02-19 07:58:42 -05:00
parent 15176831e6
commit f8a4fe00a0
Signed by: imterah
GPG key ID: 8FA7DD57BA6CEA37
3 changed files with 183 additions and 7 deletions
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10
backend/commonbackend/unmarshal.go
View file

@ -213,7 +213,7 @@ func Unmarshal(conn io.Reader) (interface{}, error) {
if protocolBytes[0] == TCP {
protocol = "tcp"
} else if protocolBytes[1] == UDP {
} else if protocolBytes[0] == UDP {
protocol = "udp"
} else {
return nil, fmt.Errorf("invalid protocol")
@ -270,7 +270,7 @@ func Unmarshal(conn io.Reader) (interface{}, error) {
if protocolBytes[0] == TCP {
protocol = "tcp"
} else if protocolBytes[1] == UDP {
} else if protocolBytes[0] == UDP {
protocol = "udp"
} else {
return nil, fmt.Errorf("invalid protocol")
@ -364,7 +364,7 @@ func Unmarshal(conn io.Reader) (interface{}, error) {
if protocolBytes[0] == TCP {
protocol = "tcp"
} else if protocolBytes[1] == UDP {
} else if protocolBytes[0] == UDP {
protocol = "udp"
} else {
return nil, fmt.Errorf("invalid protocol")
@ -523,7 +523,7 @@ func Unmarshal(conn io.Reader) (interface{}, error) {
if protocolBytes[0] == TCP {
protocol = "tcp"
} else if protocolBytes[1] == UDP {
} else if protocolBytes[0] == UDP {
protocol = "udp"
} else {
return nil, fmt.Errorf("invalid protocol")
@ -580,7 +580,7 @@ func Unmarshal(conn io.Reader) (interface{}, error) {
if protocolBytes[0] == TCP {
protocol = "tcp"
} else if protocolBytes[1] == UDP {
} else if protocolBytes[0] == UDP {
protocol = "udp"
} else {
return nil, fmt.Errorf("invalid protocol")

68
backend/sshappbackend/local-code/main.go
View file

@ -19,6 +19,7 @@ import (
"git.terah.dev/imterah/hermes/backend/commonbackend"
"git.terah.dev/imterah/hermes/backend/sshappbackend/datacommands"
"git.terah.dev/imterah/hermes/backend/sshappbackend/gaslighter"
"git.terah.dev/imterah/hermes/backend/sshappbackend/local-code/porttranslation"
"github.com/charmbracelet/log"
"github.com/go-playground/validator/v10"
"github.com/pkg/sftp"
@ -32,6 +33,7 @@ type TCPProxy struct {
type UDPProxy struct {
proxyInformation *commonbackend.AddProxy
portTranslation *porttranslation.PortTranslation
}
type SSHAppBackendData struct {
@ -397,7 +399,56 @@ func (backend *SSHAppBackend) StartProxy(command *commonbackend.AddProxy) (bool,
} else if command.Protocol == "udp" {
backend.udpProxies[proxyStatus.ProxyID] = &UDPProxy{
proxyInformation: command,
portTranslation: &porttranslation.PortTranslation{},
}
backend.udpProxies[proxyStatus.ProxyID].portTranslation.UDPAddr = &net.UDPAddr{
IP: net.ParseIP(command.SourceIP),
Port: int(command.SourcePort),
}
udpMessageCommand := &datacommands.UDPProxyData{}
udpMessageCommand.ProxyID = proxyStatus.ProxyID
backend.udpProxies[proxyStatus.ProxyID].portTranslation.WriteFrom = func(ip string, port uint16, data []byte) {
udpMessageCommand.ClientIP = ip
udpMessageCommand.ClientPort = port
udpMessageCommand.DataLength = uint16(len(data))
marshalledCommand, err := datacommands.Marshal(udpMessageCommand)
if err != nil {
log.Warnf("Failed to marshal UDP message header")
return
}
if _, err := backend.currentSock.Write(marshalledCommand); err != nil {
log.Warnf("Failed to write UDP message header")
return
}
if _, err := backend.currentSock.Write(data); err != nil {
log.Warnf("Failed to write UDP message")
return
}
}
go func() {
for {
time.Sleep(3 * time.Minute)
// Checks if the proxy still exists before continuing
_, ok := backend.udpProxies[proxyStatus.ProxyID]
if !ok {
return
}
// Then attempt to run cleanup tasks
log.Debug("Running UDP proxy cleanup tasks (invoking CleanupPorts() on portTranslation)")
backend.udpProxies[proxyStatus.ProxyID].portTranslation.CleanupPorts()
}
}()
}
return true, nil
@ -474,17 +525,20 @@ func (backend *SSHAppBackend) StopProxy(command *commonbackend.RemoveProxy) (boo
return true, fmt.Errorf("failed to stop proxy: still running")
}
// TODO: finish code for UDP
proxy.portTranslation.StopAllPorts()
delete(backend.udpProxies, proxyIndex)
}
}
return false, fmt.Errorf("could not find the proxy")
}
// TODO: implement!
func (backend *SSHAppBackend) GetAllClientConnections() []*commonbackend.ProxyClientConnection {
return []*commonbackend.ProxyClientConnection{}
}
// We don't have any parameter limitations, so we should be good.
func (backend *SSHAppBackend) CheckParametersForConnections(clientParameters *commonbackend.CheckClientParameters) *commonbackend.CheckParametersResponse {
return &commonbackend.CheckParametersResponse{
IsValid: true,
@ -617,7 +671,17 @@ func (backend *SSHAppBackend) HandleTCPMessage(message *datacommands.TCPProxyDat
connection.Write(data)
}
func (backend *SSHAppBackend) HandleUDPMessage(message *datacommands.UDPProxyData, data []byte) {}
func (backend *SSHAppBackend) HandleUDPMessage(message *datacommands.UDPProxyData, data []byte) {
proxy, ok := backend.udpProxies[message.ProxyID]
if !ok {
log.Warn("Could not find UDP proxy")
}
if _, err := proxy.portTranslation.WriteTo(message.ClientIP, message.ClientPort, data); err != nil {
log.Warnf("Failed to write to UDP: %s", err.Error())
}
}
func (backend *SSHAppBackend) SendNonCriticalMessage(iface interface{}) (interface{}, error) {
if backend.currentSock == nil {

112
backend/sshappbackend/local-code/porttranslation/translation.go Normal file
View file

@ -0,0 +1,112 @@
package porttranslation
import (
"fmt"
"net"
"sync"
"time"
)
type connectionData struct {
udpConn *net.UDPConn
buf []byte
hasBeenAliveFor time.Time
}
type PortTranslation struct {
UDPAddr *net.UDPAddr
WriteFrom func(ip string, port uint16, data []byte)
newConnectionLock sync.Mutex
connections map[string]map[uint16]*connectionData
}
func (translation *PortTranslation) CleanupPorts() {
if translation.connections == nil {
translation.connections = map[string]map[uint16]*connectionData{}
return
}
for connectionIPIndex, connectionPorts := range translation.connections {
anyAreAlive := false
for connectionPortIndex, connectionData := range connectionPorts {
if time.Now().Before(connectionData.hasBeenAliveFor.Add(3 * time.Minute)) {
anyAreAlive = true
continue
}
connectionData.udpConn.Close()
delete(connectionPorts, connectionPortIndex)
}
if !anyAreAlive {
delete(translation.connections, connectionIPIndex)
}
}
}
func (translation *PortTranslation) StopAllPorts() {
if translation.connections == nil {
return
}
for connectionIPIndex, connectionPorts := range translation.connections {
for connectionPortIndex, connectionData := range connectionPorts {
connectionData.udpConn.Close()
delete(connectionPorts, connectionPortIndex)
}
delete(translation.connections, connectionIPIndex)
}
translation.connections = nil
}
func (translation *PortTranslation) WriteTo(ip string, port uint16, data []byte) (int, error) {
if translation.connections == nil {
translation.connections = map[string]map[uint16]*connectionData{}
}
connectionPortData, ok := translation.connections[ip]
if !ok {
translation.connections[ip] = map[uint16]*connectionData{}
connectionPortData = translation.connections[ip]
}
connectionStruct, ok := connectionPortData[port]
if !ok {
connectionPortData[port] = &connectionData{}
connectionStruct = connectionPortData[port]
udpConn, err := net.DialUDP("udp", nil, translation.UDPAddr)
if err != nil {
return 0, fmt.Errorf("failed to initialize UDP socket: %s", err.Error())
}
connectionStruct.udpConn = udpConn
connectionStruct.buf = make([]byte, 65535)
go func() {
for {
n, err := udpConn.Read(connectionStruct.buf)
if err != nil {
udpConn.Close()
delete(connectionPortData, port)
return
}
connectionStruct.hasBeenAliveFor = time.Now()
translation.WriteFrom(ip, port, connectionStruct.buf[:n])
}
}()
}
connectionStruct.hasBeenAliveFor = time.Now()
return connectionStruct.udpConn.Write(data)
}