/git_hooks_handle.go (raw)
// SPDX-License-Identifier: AGPL-3.0-only
// SPDX-FileContributor: Runxi Yu <https://runxiyu.org>
package main
import (
"bytes"
"context"
"encoding/binary"
"errors"
"fmt"
"io"
"net"
"os"
"path/filepath"
"strconv"
"strings"
"syscall"
"github.com/go-git/go-git/v5/plumbing"
"github.com/go-git/go-git/v5/plumbing/object"
"github.com/jackc/pgx/v5"
"go.lindenii.runxiyu.org/lindenii-common/ansiec"
)
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) {
var ctx context.Context
var cancel context.CancelFunc
var ucred *syscall.Ucred
var err error
var cookie []byte
var pack_to_hook pack_to_hook_t
var ssh_stderr io.Writer
var ok bool
var hook_return_value byte
defer conn.Close()
ctx, cancel = context.WithCancel(context.Background())
defer cancel()
// There aren't reasonable cases where someone would run this as
// another user.
if ucred, err = get_ucred(conn); err != nil {
if _, err = conn.Write([]byte{1}); err != nil {
return
}
wf_error(conn, "\nUnable to get peer credentials: %v", err)
return
}
if ucred.Uid != uint32(os.Getuid()) {
if _, err = conn.Write([]byte{1}); err != nil {
return
}
wf_error(conn, "\nUID mismatch")
return
}
cookie = make([]byte, 64)
if _, err = conn.Read(cookie); err != nil {
if _, err = conn.Write([]byte{1}); err != nil {
return
}
wf_error(conn, "\nFailed to read cookie: %v", err)
return
}
pack_to_hook, ok = pack_to_hook_by_cookie.Load(string(cookie))
if !ok {
if _, err = conn.Write([]byte{1}); err != nil {
return
}
wf_error(conn, "\nInvalid handler cookie")
return
}
ssh_stderr = pack_to_hook.session.Stderr()
_, _ = ssh_stderr.Write([]byte{'\n'})
hook_return_value = func() byte {
var argc64 uint64
if err = binary.Read(conn, binary.NativeEndian, &argc64); err != nil {
wf_error(ssh_stderr, "Failed to read argc: %v", err)
return 1
}
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 {
wf_error(ssh_stderr, "Failed to read arg: %v", err)
return 1
}
if b[0] == 0 {
break
}
arg.WriteByte(b[0])
}
args = append(args, arg.String())
}
git_env := make(map[string]string)
for {
var env_line bytes.Buffer
for {
b := make([]byte, 1)
n, err := conn.Read(b)
if err != nil || n != 1 {
wf_error(ssh_stderr, "Failed to read environment variable: %v", err)
return 1
}
if b[0] == 0 {
break
}
env_line.WriteByte(b[0])
}
if env_line.Len() == 0 {
break
}
kv := env_line.String()
parts := strings.SplitN(kv, "=", 2)
if len(parts) < 2 {
wf_error(ssh_stderr, "Invalid environment variable line: %v", kv)
return 1
}
git_env[parts[0]] = parts[1]
}
var stdin bytes.Buffer
if _, err = io.Copy(&stdin, conn); err != nil {
wf_error(conn, "Failed to read to the stdin buffer: %v", err)
}
switch filepath.Base(args[0]) {
case "pre-receive":
if pack_to_hook.direct_access {
return 0
} else {
all_ok := true
for {
var line, old_oid, rest, new_oid, ref_name string
var found bool
var old_hash, new_hash plumbing.Hash
var old_commit, new_commit *object.Commit
var git_push_option_count int
git_push_option_count, err = strconv.Atoi(git_env["GIT_PUSH_OPTION_COUNT"])
if err != nil {
wf_error(ssh_stderr, "Failed to parse GIT_PUSH_OPTION_COUNT: %v", err)
return 1
}
// TODO: Allow existing users (even if they are already federated or registered) to add a federated user ID... though perhaps this should be in the normal SSH interface instead of the git push interface?
// Also it'd be nice to be able to combine users or whatever
if pack_to_hook.contrib_requirements == "federated" && pack_to_hook.user_type != "federated" && pack_to_hook.user_type != "registered" {
if git_push_option_count == 0 {
wf_error(ssh_stderr, "This repo requires contributors to be either federated or registered users. You must supply your federated user ID as a push option. For example, git push -o fedid=sr.ht:runxiyu")
return 1
}
for i := 0; i < git_push_option_count; i++ {
push_option, ok := git_env[fmt.Sprintf("GIT_PUSH_OPTION_%d", i)]
if !ok {
wf_error(ssh_stderr, "Failed to get push option %d", i)
return 1
}
if strings.HasPrefix(push_option, "fedid=") {
federated_user_identifier := strings.TrimPrefix(push_option, "fedid=")
service, username, found := strings.Cut(federated_user_identifier, ":")
if !found {
wf_error(ssh_stderr, "Invalid federated user identifier %#v does not contain a colon", federated_user_identifier)
return 1
}
ok, err := check_and_update_federated_user_status(ctx, pack_to_hook.user_id, service, username, pack_to_hook.pubkey)
if err != nil {
wf_error(ssh_stderr, "Failed to verify federated user identifier %#v: %v", federated_user_identifier, err)
return 1
}
if !ok {
wf_error(ssh_stderr, "Failed to verify federated user identifier %#v: you don't seem to be on the list", federated_user_identifier)
return 1
}
break
}
if i == git_push_option_count-1 {
wf_error(ssh_stderr, "This repo requires contributors to be either federated or registered users. You must supply your federated user ID as a push option. For example, git push -o fedid=sr.ht:runxiyu")
return 1
}
}
}
line, err = stdin.ReadString('\n')
if errors.Is(err, io.EOF) {
break
} else if err != nil {
wf_error(ssh_stderr, "Failed to read pre-receive line: %v", err)
return 1
}
line = line[:len(line)-1]
old_oid, rest, found = strings.Cut(line, " ")
if !found {
wf_error(ssh_stderr, "Invalid pre-receive line: %v", line)
return 1
}
new_oid, ref_name, found = strings.Cut(rest, " ")
if !found {
wf_error(ssh_stderr, "Invalid pre-receive line: %v", line)
return 1
}
if strings.HasPrefix(ref_name, "refs/heads/contrib/") {
if all_zero_num_string(old_oid) { // New branch
fmt.Fprintln(ssh_stderr, ansiec.Blue+"POK"+ansiec.Reset, ref_name)
var new_mr_id int
err = database.QueryRow(ctx,
"INSERT INTO merge_requests (repo_id, creator, source_ref, status) VALUES ($1, $2, $3, 'open') RETURNING id",
pack_to_hook.repo_id, pack_to_hook.user_id, strings.TrimPrefix(ref_name, "refs/heads/"),
).Scan(&new_mr_id)
if err != nil {
wf_error(ssh_stderr, "Error creating merge request: %v", err)
return 1
}
fmt.Fprintln(ssh_stderr, ansiec.Blue+"Created merge request at", generate_http_remote_url(pack_to_hook.group_path, pack_to_hook.repo_name)+"/contrib/"+strconv.FormatUint(uint64(new_mr_id), 10)+"/"+ansiec.Reset)
} else { // Existing contrib branch
var existing_merge_request_user_id int
var is_ancestor bool
err = database.QueryRow(ctx,
"SELECT COALESCE(creator, 0) FROM merge_requests WHERE source_ref = $1 AND repo_id = $2",
strings.TrimPrefix(ref_name, "refs/heads/"), pack_to_hook.repo_id,
).Scan(&existing_merge_request_user_id)
if err != nil {
if errors.Is(err, pgx.ErrNoRows) {
wf_error(ssh_stderr, "No existing merge request for existing contrib branch: %v", err)
} else {
wf_error(ssh_stderr, "Error querying for existing merge request: %v", err)
}
return 1
}
if existing_merge_request_user_id == 0 {
all_ok = false
fmt.Fprintln(ssh_stderr, ansiec.Red+"NAK"+ansiec.Reset, ref_name, "(branch belongs to unowned MR)")
continue
}
if existing_merge_request_user_id != pack_to_hook.user_id {
all_ok = false
fmt.Fprintln(ssh_stderr, ansiec.Red+"NAK"+ansiec.Reset, ref_name, "(branch belongs another user's MR)")
continue
}
old_hash = plumbing.NewHash(old_oid)
if old_commit, err = pack_to_hook.repo.CommitObject(old_hash); err != nil {
wf_error(ssh_stderr, "Daemon failed to get old commit: %v", err)
return 1
}
// Potential BUG: I'm not sure if new_commit is guaranteed to be
// detectable as they haven't been merged into the main repo's
// objects yet. But it seems to work, and I don't think there's
// any reason for this to only work intermitently.
new_hash = plumbing.NewHash(new_oid)
if new_commit, err = pack_to_hook.repo.CommitObject(new_hash); err != nil {
wf_error(ssh_stderr, "Daemon failed to get new commit: %v", err)
return 1
}
if is_ancestor, err = old_commit.IsAncestor(new_commit); err != nil {
wf_error(ssh_stderr, "Daemon failed to check if old commit is ancestor: %v", err)
return 1
}
if !is_ancestor {
// TODO: Create MR snapshot ref instead
all_ok = false
fmt.Fprintln(ssh_stderr, ansiec.Red+"NAK"+ansiec.Reset, ref_name, "(force pushes are not supported yet)")
continue
}
fmt.Fprintln(ssh_stderr, ansiec.Blue+"POK"+ansiec.Reset, ref_name)
}
} else { // Non-contrib branch
all_ok = false
fmt.Fprintln(ssh_stderr, ansiec.Red+"NAK"+ansiec.Reset, ref_name, "(you cannot push to branches outside of contrib/*)")
}
}
fmt.Fprintln(ssh_stderr)
if all_ok {
fmt.Fprintln(ssh_stderr, "Overall "+ansiec.Green+"ACK"+ansiec.Reset+" (all checks passed)")
return 0
} else {
fmt.Fprintln(ssh_stderr, "Overall "+ansiec.Red+"NAK"+ansiec.Reset+" (one or more branches failed checks)")
return 1
}
}
default:
fmt.Fprintln(ssh_stderr, ansiec.Red+"Invalid hook:", args[0]+ansiec.Reset)
return 1
}
}()
fmt.Fprintln(ssh_stderr)
_, _ = conn.Write([]byte{hook_return_value})
}
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) (ucred *syscall.Ucred, err error) {
var unix_conn *net.UnixConn = conn.(*net.UnixConn)
var fd *os.File
if fd, err = unix_conn.File(); err != nil {
return nil, err_get_fd
}
defer fd.Close()
if ucred, err = syscall.GetsockoptUcred(int(fd.Fd()), syscall.SOL_SOCKET, syscall.SO_PEERCRED); 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
}