netmaker/nm-proxy/proxy/proxy.go
2022-12-01 10:39:43 +05:30

266 lines
7.8 KiB
Go

package proxy
import (
"context"
"errors"
"fmt"
"log"
"net"
"runtime"
"github.com/gravitl/netmaker/nm-proxy/common"
"github.com/gravitl/netmaker/nm-proxy/models"
)
// Proxy - WireguardProxy proxies
type Proxy struct {
Ctx context.Context
Cancel context.CancelFunc
Config models.ProxyConfig
RemoteConn *net.UDPAddr
LocalConn net.Conn
}
func (p *Proxy) Start() error {
var err error
p.RemoteConn = p.Config.PeerEndpoint
log.Printf("----> Established Remote Conn with RPeer: %s, ----> RAddr: %s", p.Config.RemoteKey.String(), p.RemoteConn.String())
addr, err := GetFreeIp(models.DefaultCIDR, p.Config.WgInterface.Port)
if err != nil {
log.Println("Failed to get freeIp: ", err)
return err
}
wgListenAddr, err := GetInterfaceListenAddr(p.Config.WgInterface.Port)
if err != nil {
log.Println("failed to get wg listen addr: ", err)
return err
}
if runtime.GOOS == "darwin" {
wgListenAddr.IP = net.ParseIP(addr)
}
p.LocalConn, err = net.DialUDP("udp", &net.UDPAddr{
IP: net.ParseIP(addr),
Port: models.NmProxyPort,
}, wgListenAddr)
if err != nil {
log.Printf("failed dialing to local Wireguard port,Err: %v\n", err)
return err
}
log.Printf("Dialing to local Wireguard port %s --> %s\n", p.LocalConn.LocalAddr().String(), p.LocalConn.RemoteAddr().String())
err = p.updateEndpoint()
if err != nil {
log.Printf("error while updating Wireguard peer endpoint [%s] %v\n", p.Config.RemoteKey, err)
return err
}
localAddr, err := net.ResolveUDPAddr("udp", p.LocalConn.LocalAddr().String())
if err != nil {
log.Println("failed to resolve local addr: ", err)
return err
}
p.Config.LocalConnAddr = localAddr
p.Config.RemoteConnAddr = p.RemoteConn
go p.ProxyPeer()
return nil
}
func (p *Proxy) Close() {
log.Println("------> Closing Proxy for ", p.Config.RemoteKey.String())
p.Cancel()
p.LocalConn.Close()
if runtime.GOOS == "darwin" {
host, _, err := net.SplitHostPort(p.LocalConn.LocalAddr().String())
if err != nil {
log.Println("Failed to split host: ", p.LocalConn.LocalAddr().String(), err)
return
}
if host != "127.0.0.1" {
_, err = common.RunCmd(fmt.Sprintf("ifconfig lo0 -alias %s 255.255.255.255", host), true)
if err != nil {
log.Println("Failed to add alias: ", err)
}
}
}
close(p.Config.RecieverChan)
}
func GetInterfaceListenAddr(port int) (*net.UDPAddr, error) {
locallistenAddr := "127.0.0.1"
udpAddr, err := net.ResolveUDPAddr("udp", fmt.Sprintf("%s:%d", locallistenAddr, port))
if err != nil {
return udpAddr, err
}
if !common.IsHostNetwork {
addrs, err := getBoardCastAddress()
if err != nil {
return udpAddr, err
}
for _, addr := range addrs {
if liAddr := addr.(*net.IPNet).IP; liAddr != nil {
udpAddr.IP = liAddr
break
}
}
}
return udpAddr, nil
}
func getBoardCastAddress() ([]net.Addr, error) {
localnets, err := net.Interfaces()
if err != nil {
return nil, err
}
var (
ief net.Interface
addrs []net.Addr
)
for _, ief = range localnets {
if ief.Flags&net.FlagBroadcast != 0 && ief.Flags&net.FlagUp != 0 {
addrs, err = ief.Addrs()
if err == nil {
return addrs, nil
}
}
}
return nil, errors.New("couldn't obtain the broadcast addr")
}
// func StartSniffer(ctx context.Context, ifaceName, ingGwAddr, extClientAddr string, port int) {
// log.Println("Starting Packet Sniffer for iface: ", ifaceName)
// var (
// snapshotLen int32 = 1024
// promiscuous bool = false
// err error
// timeout time.Duration = 1 * time.Microsecond
// handle *pcap.Handle
// )
// // Open device
// handle, err = pcap.OpenLive(ifaceName, snapshotLen, promiscuous, timeout)
// if err != nil {
// log.Println("failed to start sniffer for iface: ", ifaceName, err)
// return
// }
// // if err := handle.SetBPFFilter(fmt.Sprintf("src %s and port %d", extClientAddr, port)); err != nil {
// // log.Println("failed to set bpf filter: ", err)
// // return
// // }
// defer handle.Close()
// // var tcp layers.TCP
// // var icmp layers.ICMPv4
// // var udp layers.UDP
// // parser := gopacket.NewDecodingLayerParser(layers.LayerTypeIPv4, &udp, &tcp, &icmp)
// packetSource := gopacket.NewPacketSource(handle, handle.LinkType())
// for {
// select {
// case <-ctx.Done():
// log.Println("Stopping packet sniffer for iface: ", ifaceName, " port: ", port)
// return
// default:
// packet, err := packetSource.NextPacket()
// if err == nil {
// //processPkt(ifaceName, packet)
// ipLayer := packet.Layer(layers.LayerTypeIPv4)
// if ipLayer != nil {
// fmt.Println("IPv4 layer detected.")
// ip, _ := ipLayer.(*layers.IPv4)
// // IP layer variables:
// // Version (Either 4 or 6)
// // IHL (IP Header Length in 32-bit words)
// // TOS, Length, Id, Flags, FragOffset, TTL, Protocol (TCP?),
// // Checksum, SrcIP, DstIP
// fmt.Println("#########################")
// fmt.Printf("From %s to %s\n", ip.SrcIP, ip.DstIP)
// fmt.Println("Protocol: ", ip.Protocol.String())
// if (ip.SrcIP.String() == extClientAddr && ip.DstIP.String() != ingGwAddr) ||
// (ip.DstIP.String() == extClientAddr && ip.SrcIP.String() != ingGwAddr) {
// log.Println("-----> Fowarding PKT From: ", ip.SrcIP, " to: ", ip.DstIP)
// c, err := net.Dial("ip", ip.DstIP.String())
// if err == nil {
// c.Write(ip.Payload)
// c.Close()
// } else {
// log.Println("------> Failed to forward packet from sniffer: ", err)
// }
// }
// fmt.Println("#########################")
// }
// }
// }
// }
// }
// func processPkt(iface string, packet gopacket.Packet) {
// // Let's see if the packet is an ethernet packet
// // ethernetLayer := packet.Layer(layers.LayerTypeEthernet)
// // if ethernetLayer != nil {
// // fmt.Println("Ethernet layer detected.")
// // ethernetPacket, _ := ethernetLayer.(*layers.Ethernet)
// // fmt.Println("Source MAC: ", ethernetPacket.SrcMAC)
// // fmt.Println("Destination MAC: ", ethernetPacket.DstMAC)
// // // Ethernet type is typically IPv4 but could be ARP or other
// // fmt.Println("Ethernet type: ", ethernetPacket.EthernetType)
// // fmt.Println()
// // }
// // Let's see if the packet is IP (even though the ether type told us)
// ipLayer := packet.Layer(layers.LayerTypeIPv4)
// if ipLayer != nil {
// fmt.Println("IPv4 layer detected.")
// ip, _ := ipLayer.(*layers.IPv4)
// // IP layer variables:
// // Version (Either 4 or 6)
// // IHL (IP Header Length in 32-bit words)
// // TOS, Length, Id, Flags, FragOffset, TTL, Protocol (TCP?),
// // Checksum, SrcIP, DstIP
// fmt.Printf("From %s to %s\n", ip.SrcIP, ip.DstIP)
// fmt.Println("Protocol: ", ip.Protocol)
// fmt.Println()
// }
// // udpLayer := packet.Layer(layers.LayerTypeUDP)
// // if udpLayer != nil {
// // udp, _ := udpLayer.(*layers.UDP)
// // fmt.Printf("UDP: From port %d to %d\n", udp.SrcPort, udp.DstPort)
// // fmt.Println()
// // }
// // // Iterate over all layers, printing out each layer type
// // fmt.Println("All packet layers:")
// // for _, layer := range packet.Layers() {
// // fmt.Println("- ", layer.LayerType())
// // }
// // When iterating through packet.Layers() above,
// // if it lists Payload layer then that is the same as
// // this applicationLayer. applicationLayer contains the payload
// // applicationLayer := packet.ApplicationLayer()
// // if applicationLayer != nil {
// // fmt.Println("Application layer/Payload found.")
// // fmt.Printf("%s\n", applicationLayer.Payload())
// // // Search for a string inside the payload
// // if strings.Contains(string(applicationLayer.Payload()), "HTTP") {
// // fmt.Println("HTTP found!")
// // }
// // }
// // Check for errors
// if err := packet.ErrorLayer(); err != nil {
// fmt.Println("Error decoding some part of the packet:", err)
// }
// }