mirror of
https://github.com/fatedier/frp.git
synced 2025-04-28 19:51:27 +00:00
132 lines
3.0 KiB
Go
132 lines
3.0 KiB
Go
// Copyright 2025 The frp Authors
|
|
//
|
|
// Licensed under the Apache License, Version 2.0 (the "License");
|
|
// you may not use this file except in compliance with the License.
|
|
// You may obtain a copy of the License at
|
|
//
|
|
// http://www.apache.org/licenses/LICENSE-2.0
|
|
//
|
|
// Unless required by applicable law or agreed to in writing, software
|
|
// distributed under the License is distributed on an "AS IS" BASIS,
|
|
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
|
|
// See the License for the specific language governing permissions and
|
|
// limitations under the License.
|
|
|
|
package vnet
|
|
|
|
import (
|
|
"context"
|
|
"crypto/sha256"
|
|
"encoding/hex"
|
|
"fmt"
|
|
"net"
|
|
"strconv"
|
|
"strings"
|
|
|
|
"github.com/vishvananda/netlink"
|
|
"golang.zx2c4.com/wireguard/tun"
|
|
)
|
|
|
|
const (
|
|
baseTunName = "utun"
|
|
defaultMTU = 1420
|
|
)
|
|
|
|
func openTun(_ context.Context, addr string) (tun.Device, error) {
|
|
name, err := findNextTunName(baseTunName)
|
|
if err != nil {
|
|
name = getFallbackTunName(baseTunName, addr)
|
|
}
|
|
|
|
tunDevice, err := tun.CreateTUN(name, defaultMTU)
|
|
if err != nil {
|
|
return nil, fmt.Errorf("failed to create TUN device '%s': %w", name, err)
|
|
}
|
|
|
|
actualName, err := tunDevice.Name()
|
|
if err != nil {
|
|
return nil, err
|
|
}
|
|
|
|
ifn, err := net.InterfaceByName(actualName)
|
|
if err != nil {
|
|
return nil, err
|
|
}
|
|
|
|
link, err := netlink.LinkByName(actualName)
|
|
if err != nil {
|
|
return nil, err
|
|
}
|
|
|
|
ip, cidr, err := net.ParseCIDR(addr)
|
|
if err != nil {
|
|
return nil, err
|
|
}
|
|
if err := netlink.AddrAdd(link, &netlink.Addr{
|
|
IPNet: &net.IPNet{
|
|
IP: ip,
|
|
Mask: cidr.Mask,
|
|
},
|
|
}); err != nil {
|
|
return nil, err
|
|
}
|
|
|
|
if err := netlink.LinkSetUp(link); err != nil {
|
|
return nil, err
|
|
}
|
|
|
|
if err = addRoutes(ifn, cidr); err != nil {
|
|
return nil, err
|
|
}
|
|
return tunDevice, nil
|
|
}
|
|
|
|
func findNextTunName(basename string) (string, error) {
|
|
interfaces, err := net.Interfaces()
|
|
if err != nil {
|
|
return "", fmt.Errorf("failed to get network interfaces: %w", err)
|
|
}
|
|
maxSuffix := -1
|
|
|
|
for _, iface := range interfaces {
|
|
name := iface.Name
|
|
if strings.HasPrefix(name, basename) {
|
|
suffix := name[len(basename):]
|
|
if suffix == "" {
|
|
continue
|
|
}
|
|
|
|
numSuffix, err := strconv.Atoi(suffix)
|
|
if err == nil && numSuffix > maxSuffix {
|
|
maxSuffix = numSuffix
|
|
}
|
|
}
|
|
}
|
|
|
|
nextSuffix := maxSuffix + 1
|
|
name := fmt.Sprintf("%s%d", basename, nextSuffix)
|
|
return name, nil
|
|
}
|
|
|
|
func addRoutes(ifn *net.Interface, cidr *net.IPNet) error {
|
|
r := netlink.Route{
|
|
Dst: cidr,
|
|
LinkIndex: ifn.Index,
|
|
}
|
|
if err := netlink.RouteReplace(&r); err != nil {
|
|
return fmt.Errorf("add route to %v error: %v", r.Dst, err)
|
|
}
|
|
return nil
|
|
}
|
|
|
|
// getFallbackTunName generates a deterministic fallback TUN device name
|
|
// based on the base name and the provided address string using a hash.
|
|
func getFallbackTunName(baseName, addr string) string {
|
|
hasher := sha256.New()
|
|
hasher.Write([]byte(addr))
|
|
hashBytes := hasher.Sum(nil)
|
|
// Use first 4 bytes -> 8 hex chars for brevity, respecting IFNAMSIZ limit.
|
|
shortHash := hex.EncodeToString(hashBytes[:4])
|
|
return fmt.Sprintf("%s%s", baseName, shortHash)
|
|
}
|