Commit `bf64c30c08`

bf64c30c08e9cff055f03670c4100b0dbf6c031f

Verified · cmc

cmc <hello@cleberg.net> · 2026-09-28 06:29 UTC

gitutil: Transport takes a cancel channel and kills its process group

Ref #256

Layout: unified · split

internal/gitutil/gitutil.go +19 −3

		@@ -35,8 +35,10 @@ func InitBare(path, defaultBranch, hooksPath string) error {
35	35	// Transport streams one git transport service (upload-pack, receive-pack,
36	36	// upload-archive). extraEnv entries are appended to the process environment;
37	37	// hooks read the GITBAY_* variables from it. maxPack caps incoming pack
38		// bytes on receive-pack (0 = unlimited).
39		func Transport(service, repoPath string, stdin io.Reader, stdout, errW io.Writer, extraEnv []string, maxPack int64) error {
	38	// bytes on receive-pack (0 = unlimited). Closing cancel kills the service
	39	// and everything it started; a push killed before its pre-receive hook
	40	// answers updates no refs. A nil cancel never fires.
	41	func Transport(service, repoPath string, stdin io.Reader, stdout, errW io.Writer, extraEnv []string, maxPack int64, cancel <-chan struct{}) error {
40	42	var args []string
41	43	switch service {
42	44	case "git-upload-pack", "git-receive-pack", "git-upload-archive":
		@@ -52,7 +54,21 @@ func Transport(service, repoPath string, stdin io.Reader, stdout, errW io.Writer
52	54	cmd.Stdin = stdin
53	55	cmd.Stdout = stdout
54	56	cmd.Stderr = errW
55		return cmd.Run()
	57	ownProcessGroup(cmd)
	58	if err := cmd.Start(); err != nil {
	59	return err
	60	}
	61	finished := make(chan struct{})
	62	go func() {
	63	select {
	64	case <-cancel:
	65	killTree(cmd)
	66	case <-finished:
	67	}
	68	}()
	69	err := cmd.Wait()
	70	close(finished)
	71	return err
56	72	}
57	73
58	74	// IsAncestor reports whether old is an ancestor of new in the repository at

internal/gitutil/proc_other.go added +13

		@@ -0,0 +1,13 @@
	1	//go:build !unix
	2
	3	package gitutil
	4
	5	import "os/exec"
	6
	7	func ownProcessGroup(cmd *exec.Cmd) {}
	8
	9	func killTree(cmd *exec.Cmd) {
	10	if cmd.Process != nil {
	11	cmd.Process.Kill()
	12	}
	13	}

internal/gitutil/proc_unix.go added +26

		@@ -0,0 +1,26 @@
	1	//go:build unix
	2
	3	package gitutil
	4
	5	import (
	6	"os/exec"
	7	"syscall"
	8	)
	9
	10	// ownProcessGroup puts cmd in a process group of its own, so killTree
	11	// ends what it started too: receive-pack runs index-pack and the hooks.
	12	func ownProcessGroup(cmd *exec.Cmd) {
	13	if cmd.SysProcAttr == nil {
	14	cmd.SysProcAttr = &syscall.SysProcAttr{}
	15	}
	16	cmd.SysProcAttr.Setpgid = true
	17	}
	18
	19	func killTree(cmd *exec.Cmd) {
	20	if cmd.Process == nil {
	21	return
	22	}
	23	if err := syscall.Kill(-cmd.Process.Pid, syscall.SIGKILL); err != nil {
	24	cmd.Process.Kill()
	25	}
	26	}

internal/gitutil/transport_test.go added +33

		@@ -0,0 +1,33 @@
	1	package gitutil
	2
	3	import (
	4	"io"
	5	"os/exec"
	6	"strings"
	7	"testing"
	8	"time"
	9	)
	10
	11	// Closing cancel kills the transport; it does not wait for the client
	12	// to hang up. Stdin ends only after the kill, as a cut connection's
	13	// does, so a clean exit here would mean the kill never happened.
	14	func TestTransportCancelKillsGit(t *testing.T) {
	15	dir := t.TempDir()
	16	if out, err := exec.Command("git", "init", "-q", "--bare", dir).CombinedOutput(); err != nil {
	17	t.Fatalf("git init: %v\n%s", err, out)
	18	}
	19	in, w := io.Pipe()
	20	cancel := make(chan struct{})
	21	errc := make(chan error, 1)
	22	go func() { errc <- Transport("git-upload-pack", dir, in, io.Discard, io.Discard, nil, 0, cancel) }()
	23	close(cancel)
	24	time.AfterFunc(500*time.Millisecond, func() { w.Close() })
	25	select {
	26	case err := <-errc:
	27	if err == nil \|\| !strings.Contains(err.Error(), "killed") {
	28	t.Fatalf("Transport returned %v, want the process killed", err)
	29	}
	30	case <-time.After(5 * time.Second):
	31	t.Fatal("Transport did not return after cancel")
	32	}
	33	}

internal/sshd/sshd.go +1 −1

		@@ -461,7 +461,7 @@ func runGit(cfg config.Config, st *store.Store, user store.User, scope string, a
461	461	}
462	462	}
463	463	}
464		if err := gitutil.Transport(service, dir, stdin, stdout, stderr, env, maxPack); err != nil {
	464	if err := gitutil.Transport(service, dir, stdin, stdout, stderr, env, maxPack, nil); err != nil {
465	465	return protocol.ExitFailure
466	466	}
467	467	return protocol.ExitOK

Commit bf64c30c08