Hacktoberfest 2026: the issues maintainers tagged for October, open and beginner-friendly. Browse Hacktoberfest issues

Crash if using import "C" in main file

Open
  • Is something wrong?
#47 1 comment 0 reactions 0 assignees View on GitHub

Nobody has claimed this yet.

Assessment

Difficulty
4/5
Estimated time
3-5 days
Newbie friendliness
25/100
Issue type
Bug
Clarity
Needs clarification
Activity status
Stale
Tech stack
go
Domain
networking

Research direction

Reproduce the crash on Windows arm64 using the reported configuration and wrapper package, focusing on the import "C" change in the main file and the New and Run entry points. Compare execution with and without cgo and capture the runtime failure; done means identifying the cause and adding a regression test or documented fix for the crashing setup.

Written by the indexing model from the issue text.

Description

i'm trying to use your library in my project, and want to wrap it for my project with go layer that exports dll file, and in this case im getting null pointer in runtime

step to reproduce:

  1. use Windows arm64
  2. import "C" in main file
  3. start sing-box instance
  4. runtime crashes with no error

sing-box config: { "log": { "level": "warning", "timestamp": true }, "dns": { "servers": [ { "tag": "remote", "address": "8.8.8.8", "detour": "proxy" } ], "final": "remote" }, "inbounds": [ { "type": "tun", "tag": "tun-in", "interface_name": "singbox_tun", "address": [ "172.19.0.1/30" ], "mtu": 9000, "auto_route": true, "strict_route": false, "stack": "gvisor", "sniff": true } ], "outbounds": [ { "type": "socks", "tag": "proxy", "server": "127.0.0.1", "server_port": 10808, "version": "5" }, { "type": "direct", "tag": "direct" }, { "type": "dns", "tag": "dns_out" } ], "route": { "auto_detect_interface": true, "rules": [ { "outbound": "direct", "ip_is_private": true }, { "outbound": "dns_out", "port": [ 53 ], "process_name": [ "xray.exe", "cracker.exe" ] }, { "outbound": "direct", "process_name": [ "xray.exe", "cracker.exe" ] }, { "outbound": "proxy", "network": "tcp,udp" } ] } }

Wrapper package that calls from main


import (
	"context"
	"fmt"
	"os"
	"os/user"
	"strconv"

	"github.com/sagernet/sing-box/experimental/deprecated"
	"github.com/sagernet/sing-box/include"
	"github.com/sagernet/sing-box/log"
	"github.com/sagernet/sing-box/option"
	"github.com/sagernet/sing/common/json"
	"github.com/sagernet/sing/service"
	"github.com/sagernet/sing/service/filemanager"

	box "github.com/sagernet/sing-box"
)

var (
	globalCtx context.Context
)

type SingBox struct {
	tun *box.Box
}

func New(configJson string) (*SingBox, error) {
	configBytes := []byte(configJson)
	options, err := json.UnmarshalExtendedContext[option.Options](globalCtx, configBytes)
	if err != nil {
		return nil, fmt.Errorf("Error while parse options from config json : ", err.Error())
	}
	ctx, cancel := context.WithCancel(globalCtx)
	instance, err := box.New(box.Options{
		Context: ctx,
		Options: options,
	})
	if err != nil {
		cancel()
		return nil, fmt.Errorf("Error while creating sing box instance : ", err.Error())
	}
	return &SingBox{
		tun: instance,
	}, nil
}

func (s *SingBox) Run() error {
	err := s.tun.Start()
	if err != nil {
		return fmt.Errorf("Error while starting sing box : ", err)
	}
	return nil
}

func (s *SingBox) Stop() error {
	err := s.tun.Close()
	if err != nil {
		return fmt.Errorf("Error while stoping sing box : ", err)
	}
	return nil
}

func init() {
	globalCtx = context.Background()
	sudoUser := os.Getenv("SUDO_USER")
	sudoUID, _ := strconv.Atoi(os.Getenv("SUDO_UID"))
	sudoGID, _ := strconv.Atoi(os.Getenv("SUDO_GID"))
	if sudoUID == 0 && sudoGID == 0 && sudoUser != "" {
		sudoUserObject, _ := user.Lookup(sudoUser)
		if sudoUserObject != nil {
			sudoUID, _ = strconv.Atoi(sudoUserObject.Uid)
			sudoGID, _ = strconv.Atoi(sudoUserObject.Gid)
		}
	}
	if sudoUID > 0 && sudoGID > 0 {
		globalCtx = filemanager.WithDefault(globalCtx, "", "", sudoUID, sudoGID)
	}

	globalCtx = service.ContextWith(globalCtx, deprecated.NewStderrManager(log.StdLogger()))
	globalCtx = box.Context(globalCtx, include.InboundRegistry(), include.OutboundRegistry(), include.EndpointRegistry())
}```

i need to use it as library for KMM project, i'm not expirenced in go and cgo. thanks for answer in advance
Dominant language
Go
Stars
241
Forks
243
No merged PRs in 30d

Getting set up

This project ships no dev container, Dockerfile or contributing guide, so setting up is up to you: start from its README, and see our first-contribution guide for the general steps.

First steps

  1. Read the whole issue, then the project's contributing guide.
  2. Comment on the issue to say you are picking it up — it saves two people doing the same work.
  3. Fork the repository and make your change on a branch.
  4. Open a pull request that references the issue number.

More from SagerNet/sing-tun

All issues in SagerNet/sing-tun

Similar issues

More Go issues

Get new issues in your inbox

A short digest of beginner-friendly GitHub issues.