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package main
import (
"bytes"
"encoding/binary"
"errors"
"fmt"
"io"
"net"
"os"
"path/filepath"
"strings"
"syscall"
)
var (
err_get_fd = errors.New("unable to get file descriptor")
err_get_ucred = errors.New("failed getsockopt")
)
// hooks_handle_connection handles a connection from git_hooks_client via the
// unix socket.
func hooks_handle_connection(conn net.Conn) {
defer conn.Close()
// There aren't reasonable cases where someone would run this as
// another user.
ucred, err := get_ucred(conn)
if err != nil {
if _, err := conn.Write([]byte{1}); err != nil {
return
}
fmt.Fprintln(conn, "Unable to get peer credentials:", err.Error())
return
}
if ucred.Uid != uint32(os.Getuid()) {
if _, err := conn.Write([]byte{1}); err != nil {
return
}
fmt.Fprintln(conn, "UID mismatch")
return
}
cookie := make([]byte, 64)
_, err = conn.Read(cookie)
if err != nil {
if _, err := conn.Write([]byte{1}); err != nil {
return
}
fmt.Fprintln(conn, "Failed to read cookie:", err.Error())
return
}
pack_to_hook, ok := pack_to_hook_by_cookie.Load(string(cookie))
if !ok {
if _, err := conn.Write([]byte{1}); err != nil {
return
}
fmt.Fprintln(conn, "Invalid handler cookie")
return
}
var argc64 uint64
err = binary.Read(conn, binary.NativeEndian, &argc64)
if err != nil {
if _, err := conn.Write([]byte{1}); err != nil {
return
}
fmt.Fprintln(conn, "Failed to read argc:", err.Error())
return
}
var args []string
for i := uint64(0); i < argc64; i++ {
var arg bytes.Buffer
for {
b := make([]byte, 1)
n, err := conn.Read(b)
if err != nil || n != 1 {
if _, err := conn.Write([]byte{1}); err != nil {
return
}
fmt.Fprintln(conn, "Failed to read arg:", err.Error())
return
}
if b[0] == 0 {
break
}
arg.WriteByte(b[0])
}
args = append(args, arg.String())
}
var stdin bytes.Buffer
_, err = io.Copy(&stdin, conn)
if err != nil {
fmt.Fprintln(conn, "Failed to read to the stdin buffer:", err.Error())
}
switch filepath.Base(args[0]) {
case "pre-receive":
if pack_to_hook.direct_access {
if _, err := conn.Write([]byte{0}); err != nil {
return
}
} else {
ref_ok := make(map[string]uint8)
// 0 for ok
// 1 for rejection due to not a contrib branch
// 2 for rejection due to not being a new branch
for {
line, err := stdin.ReadString('\n')
if errors.Is(err, io.EOF) {
break
}
line = line[:len(line)-1]
old_oid, rest, found := strings.Cut(line, " ")
if !found {
if _, err := conn.Write([]byte{1}); err != nil {
return
}
fmt.Fprintln(conn, "Invalid pre-receive line:", line)
break
}
new_oid, ref_name, found := strings.Cut(rest, " ")
if !found {
if _, err := conn.Write([]byte{1}); err != nil {
return
}
fmt.Fprintln(conn, "Invalid pre-receive line:", line)
break
}
_ = new_oid
if strings.HasPrefix(ref_name, "refs/heads/contrib/") {
if all_zero_num_string(old_oid) {
ref_ok[ref_name] = 0
// TODO: Create a merge request. If that fails,
// we should just reject this entire push
// immediately.
} else {
ref_ok[ref_name] = 2
// TODO: Check if the current user is authorized
// to push to this contrib branch.
// Then, check if this push is a fast-forward.
// If not, we create a MR history archive ref
// that points to the old object name.
}
} else {
ref_ok[ref_name] = 1
}
}
if or_all_in_map(ref_ok) == 0 {
if _, err := conn.Write([]byte{0}); err != nil {
return
}
fmt.Fprintln(conn, "Stuff")
} else {
if _, err := conn.Write([]byte{1}); err != nil {
return
}
for ref, status := range ref_ok {
switch status {
case 0:
fmt.Fprintln(conn, "Acceptable", ref)
case 1:
fmt.Fprintln(conn, "Not in the contrib/ namespace", ref)
case 2:
fmt.Fprintln(conn, "Branch already exists", ref)
default:
panic("Invalid branch status")
}
}
}
}
default:
if _, err := conn.Write([]byte{1}); err != nil {
return
}
fmt.Fprintln(conn, "Invalid hook:", args[0])
}
}
func serve_git_hooks(listener net.Listener) error {
for {
conn, err := listener.Accept()
if err != nil {
return err
}
go hooks_handle_connection(conn)
}
}
func get_ucred(conn net.Conn) (*syscall.Ucred, error) {
unix_conn := conn.(*net.UnixConn)
fd, err := unix_conn.File()
if err != nil {
return nil, err_get_fd
}
defer fd.Close()
ucred, err := syscall.GetsockoptUcred(int(fd.Fd()), syscall.SOL_SOCKET, syscall.SO_PEERCRED)
if err != nil {
return nil, err_get_ucred
}
return ucred, nil
}
func all_zero_num_string(s string) bool {
for _, r := range s {
if r != '0' {
return false
}
}
return true
}
func or_all_in_map[K comparable, V uint8 | uint16 | uint32 | uint64](m map[K]V) (result V) {
for _, value := range m {
result |= value
}
return
}
|
