Files
netbird/client/iface/wgproxy/rawsocket/rawsocket.go
Zoltan Papp 05af39a69b [client] Add IPv6 support to UDP WireGuard proxy (#5169)
* Add IPv6 support to UDP WireGuard proxy

Add IPv6 packet header support in UDP raw socket proxy
to handle both IPv4 and IPv6 source addresses.
Refactor error handling in proxy bind implementations
to validate endpoints before acquiring locks.
2026-01-26 14:03:32 +01:00

95 lines
3.0 KiB
Go

//go:build linux && !android
package rawsocket
import (
"fmt"
"net"
"os"
"syscall"
log "github.com/sirupsen/logrus"
"golang.org/x/sys/unix"
nbnet "github.com/netbirdio/netbird/client/net"
)
// PrepareSenderRawSocketIPv4 creates and configures a raw socket for sending IPv4 packets
func PrepareSenderRawSocketIPv4() (net.PacketConn, error) {
return prepareSenderRawSocket(syscall.AF_INET, true)
}
// PrepareSenderRawSocketIPv6 creates and configures a raw socket for sending IPv6 packets
func PrepareSenderRawSocketIPv6() (net.PacketConn, error) {
return prepareSenderRawSocket(syscall.AF_INET6, false)
}
func prepareSenderRawSocket(family int, isIPv4 bool) (net.PacketConn, error) {
// Create a raw socket.
fd, err := syscall.Socket(family, syscall.SOCK_RAW, syscall.IPPROTO_RAW)
if err != nil {
return nil, fmt.Errorf("creating raw socket failed: %w", err)
}
// Set the header include option on the socket to tell the kernel that headers are included in the packet.
// For IPv4, we need to set IP_HDRINCL. For IPv6, we need to set IPV6_HDRINCL to accept application-provided IPv6 headers.
if isIPv4 {
err = syscall.SetsockoptInt(fd, syscall.IPPROTO_IP, unix.IP_HDRINCL, 1)
if err != nil {
if closeErr := syscall.Close(fd); closeErr != nil {
log.Warnf("failed to close raw socket fd: %v", closeErr)
}
return nil, fmt.Errorf("setting IP_HDRINCL failed: %w", err)
}
} else {
err = syscall.SetsockoptInt(fd, syscall.IPPROTO_IPV6, unix.IPV6_HDRINCL, 1)
if err != nil {
if closeErr := syscall.Close(fd); closeErr != nil {
log.Warnf("failed to close raw socket fd: %v", closeErr)
}
return nil, fmt.Errorf("setting IPV6_HDRINCL failed: %w", err)
}
}
// Bind the socket to the "lo" interface.
err = syscall.SetsockoptString(fd, syscall.SOL_SOCKET, syscall.SO_BINDTODEVICE, "lo")
if err != nil {
if closeErr := syscall.Close(fd); closeErr != nil {
log.Warnf("failed to close raw socket fd: %v", closeErr)
}
return nil, fmt.Errorf("binding to lo interface failed: %w", err)
}
// Set the fwmark on the socket.
err = nbnet.SetSocketOpt(fd)
if err != nil {
if closeErr := syscall.Close(fd); closeErr != nil {
log.Warnf("failed to close raw socket fd: %v", closeErr)
}
return nil, fmt.Errorf("setting fwmark failed: %w", err)
}
// Convert the file descriptor to a PacketConn.
file := os.NewFile(uintptr(fd), fmt.Sprintf("fd %d", fd))
if file == nil {
if closeErr := syscall.Close(fd); closeErr != nil {
log.Warnf("failed to close raw socket fd: %v", closeErr)
}
return nil, fmt.Errorf("converting fd to file failed")
}
packetConn, err := net.FilePacketConn(file)
if err != nil {
if closeErr := file.Close(); closeErr != nil {
log.Warnf("failed to close file: %v", closeErr)
}
return nil, fmt.Errorf("converting file to packet conn failed: %w", err)
}
// Close the original file to release the FD (net.FilePacketConn duplicates it)
if closeErr := file.Close(); closeErr != nil {
log.Warnf("failed to close file after creating packet conn: %v", closeErr)
}
return packetConn, nil
}