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gitea/cmd/hook.go
wxiaoguang f4538791f5
Refactor internal API for git commands, use meaningful messages instead of "Internal Server Error" (#23687)
# Why this PR comes

At first, I'd like to help users like #23636 (there are a lot)

The unclear "Internal Server Error" is quite anonying, scare users,
frustrate contributors, nobody knows what happens.

So, it's always good to provide meaningful messages to end users (of
course, do not leak sensitive information).

When I started working on the "response message to end users", I found
that the related code has a lot of technical debt. A lot of copy&paste
code, unclear fields and usages.

So I think it's good to make everything clear.

# Tech Backgrounds

Gitea has many sub-commands, some are used by admins, some are used by
SSH servers or Git Hooks. Many sub-commands use "internal API" to
communicate with Gitea web server.

Before, Gitea server always use `StatusCode + Json "err" field` to
return messages.

* The CLI sub-commands: they expect to show all error related messages
to site admin
* The Serv/Hook sub-commands (for git clients): they could only show
safe messages to end users, the error log could only be recorded by
"SSHLog" to Gitea web server.

In the old design, it assumes that:

* If the StatusCode is 500 (in some functions), then the "err" field is
error log, shouldn't be exposed to git client.
* If the StatusCode is 40x, then the "err" field could be exposed. And
some functions always read the "err" no matter what the StatusCode is.

The old code is not strict, and it's difficult to distinguish the
messages clearly and then output them correctly.

# This PR

To help to remove duplicate code and make everything clear, this PR
introduces `ResponseExtra` and `requestJSONResp`.

* `ResponseExtra` is a struct which contains "extra" information of a
internal API response, including StatusCode, UserMsg, Error
* `requestJSONResp` is a generic function which can be used for all
cases to help to simplify the calls.
* Remove all `map["err"]`, always use `private.Response{Err}` to
construct error messages.
* User messages and error messages are separated clearly, the `fail` and
`handleCliResponseExtra` will output correct messages.
* Replace all `Internal Server Error` messages with meaningful (still
safe) messages.

This PR saves more than 300 lines, while makes the git client messages
more clear.

Many gitea-serv/git-hook related essential functions are covered by
tests.

---------

Co-authored-by: delvh <dev.lh@web.de>
2023-03-29 14:32:26 +08:00

791 lines
20 KiB
Go

// Copyright 2017 The Gitea Authors. All rights reserved.
// SPDX-License-Identifier: MIT
package cmd
import (
"bufio"
"bytes"
"context"
"fmt"
"io"
"os"
"strconv"
"strings"
"time"
"code.gitea.io/gitea/modules/git"
"code.gitea.io/gitea/modules/private"
repo_module "code.gitea.io/gitea/modules/repository"
"code.gitea.io/gitea/modules/setting"
"code.gitea.io/gitea/modules/util"
"github.com/urfave/cli"
)
const (
hookBatchSize = 30
)
var (
// CmdHook represents the available hooks sub-command.
CmdHook = cli.Command{
Name: "hook",
Usage: "Delegate commands to corresponding Git hooks",
Description: "This should only be called by Git",
Subcommands: []cli.Command{
subcmdHookPreReceive,
subcmdHookUpdate,
subcmdHookPostReceive,
subcmdHookProcReceive,
},
}
subcmdHookPreReceive = cli.Command{
Name: "pre-receive",
Usage: "Delegate pre-receive Git hook",
Description: "This command should only be called by Git",
Action: runHookPreReceive,
Flags: []cli.Flag{
cli.BoolFlag{
Name: "debug",
},
},
}
subcmdHookUpdate = cli.Command{
Name: "update",
Usage: "Delegate update Git hook",
Description: "This command should only be called by Git",
Action: runHookUpdate,
Flags: []cli.Flag{
cli.BoolFlag{
Name: "debug",
},
},
}
subcmdHookPostReceive = cli.Command{
Name: "post-receive",
Usage: "Delegate post-receive Git hook",
Description: "This command should only be called by Git",
Action: runHookPostReceive,
Flags: []cli.Flag{
cli.BoolFlag{
Name: "debug",
},
},
}
// Note: new hook since git 2.29
subcmdHookProcReceive = cli.Command{
Name: "proc-receive",
Usage: "Delegate proc-receive Git hook",
Description: "This command should only be called by Git",
Action: runHookProcReceive,
Flags: []cli.Flag{
cli.BoolFlag{
Name: "debug",
},
},
}
)
type delayWriter struct {
internal io.Writer
buf *bytes.Buffer
timer *time.Timer
}
func newDelayWriter(internal io.Writer, delay time.Duration) *delayWriter {
timer := time.NewTimer(delay)
return &delayWriter{
internal: internal,
buf: &bytes.Buffer{},
timer: timer,
}
}
func (d *delayWriter) Write(p []byte) (n int, err error) {
if d.buf != nil {
select {
case <-d.timer.C:
_, err := d.internal.Write(d.buf.Bytes())
if err != nil {
return 0, err
}
d.buf = nil
return d.internal.Write(p)
default:
return d.buf.Write(p)
}
}
return d.internal.Write(p)
}
func (d *delayWriter) WriteString(s string) (n int, err error) {
if d.buf != nil {
select {
case <-d.timer.C:
_, err := d.internal.Write(d.buf.Bytes())
if err != nil {
return 0, err
}
d.buf = nil
return d.internal.Write([]byte(s))
default:
return d.buf.WriteString(s)
}
}
return d.internal.Write([]byte(s))
}
func (d *delayWriter) Close() error {
if d == nil {
return nil
}
stopped := util.StopTimer(d.timer)
if stopped || d.buf == nil {
return nil
}
_, err := d.internal.Write(d.buf.Bytes())
d.buf = nil
return err
}
type nilWriter struct{}
func (n *nilWriter) Write(p []byte) (int, error) {
return len(p), nil
}
func (n *nilWriter) WriteString(s string) (int, error) {
return len(s), nil
}
func runHookPreReceive(c *cli.Context) error {
if isInternal, _ := strconv.ParseBool(os.Getenv(repo_module.EnvIsInternal)); isInternal {
return nil
}
ctx, cancel := installSignals()
defer cancel()
setup(ctx, c.Bool("debug"))
if len(os.Getenv("SSH_ORIGINAL_COMMAND")) == 0 {
if setting.OnlyAllowPushIfGiteaEnvironmentSet {
return fail(ctx, `Rejecting changes as Gitea environment not set.
If you are pushing over SSH you must push with a key managed by
Gitea or set your environment appropriately.`, "")
}
return nil
}
// the environment is set by serv command
isWiki, _ := strconv.ParseBool(os.Getenv(repo_module.EnvRepoIsWiki))
username := os.Getenv(repo_module.EnvRepoUsername)
reponame := os.Getenv(repo_module.EnvRepoName)
userID, _ := strconv.ParseInt(os.Getenv(repo_module.EnvPusherID), 10, 64)
prID, _ := strconv.ParseInt(os.Getenv(repo_module.EnvPRID), 10, 64)
deployKeyID, _ := strconv.ParseInt(os.Getenv(repo_module.EnvDeployKeyID), 10, 64)
actionPerm, _ := strconv.ParseInt(os.Getenv(repo_module.EnvActionPerm), 10, 64)
hookOptions := private.HookOptions{
UserID: userID,
GitAlternativeObjectDirectories: os.Getenv(private.GitAlternativeObjectDirectories),
GitObjectDirectory: os.Getenv(private.GitObjectDirectory),
GitQuarantinePath: os.Getenv(private.GitQuarantinePath),
GitPushOptions: pushOptions(),
PullRequestID: prID,
DeployKeyID: deployKeyID,
ActionPerm: int(actionPerm),
}
scanner := bufio.NewScanner(os.Stdin)
oldCommitIDs := make([]string, hookBatchSize)
newCommitIDs := make([]string, hookBatchSize)
refFullNames := make([]string, hookBatchSize)
count := 0
total := 0
lastline := 0
var out io.Writer
out = &nilWriter{}
if setting.Git.VerbosePush {
if setting.Git.VerbosePushDelay > 0 {
dWriter := newDelayWriter(os.Stdout, setting.Git.VerbosePushDelay)
defer dWriter.Close()
out = dWriter
} else {
out = os.Stdout
}
}
supportProcReceive := false
if git.CheckGitVersionAtLeast("2.29") == nil {
supportProcReceive = true
}
for scanner.Scan() {
// TODO: support news feeds for wiki
if isWiki {
continue
}
fields := bytes.Fields(scanner.Bytes())
if len(fields) != 3 {
continue
}
oldCommitID := string(fields[0])
newCommitID := string(fields[1])
refFullName := string(fields[2])
total++
lastline++
// If the ref is a branch or tag, check if it's protected
// if supportProcReceive all ref should be checked because
// permission check was delayed
if supportProcReceive || strings.HasPrefix(refFullName, git.BranchPrefix) || strings.HasPrefix(refFullName, git.TagPrefix) {
oldCommitIDs[count] = oldCommitID
newCommitIDs[count] = newCommitID
refFullNames[count] = refFullName
count++
fmt.Fprintf(out, "*")
if count >= hookBatchSize {
fmt.Fprintf(out, " Checking %d references\n", count)
hookOptions.OldCommitIDs = oldCommitIDs
hookOptions.NewCommitIDs = newCommitIDs
hookOptions.RefFullNames = refFullNames
extra := private.HookPreReceive(ctx, username, reponame, hookOptions)
if extra.HasError() {
return fail(ctx, extra.UserMsg, "HookPreReceive(batch) failed: %v", extra.Error)
}
count = 0
lastline = 0
}
} else {
fmt.Fprintf(out, ".")
}
if lastline >= hookBatchSize {
fmt.Fprintf(out, "\n")
lastline = 0
}
}
if count > 0 {
hookOptions.OldCommitIDs = oldCommitIDs[:count]
hookOptions.NewCommitIDs = newCommitIDs[:count]
hookOptions.RefFullNames = refFullNames[:count]
fmt.Fprintf(out, " Checking %d references\n", count)
extra := private.HookPreReceive(ctx, username, reponame, hookOptions)
if extra.HasError() {
return fail(ctx, extra.UserMsg, "HookPreReceive(last) failed: %v", extra.Error)
}
} else if lastline > 0 {
fmt.Fprintf(out, "\n")
}
fmt.Fprintf(out, "Checked %d references in total\n", total)
return nil
}
func runHookUpdate(c *cli.Context) error {
// Update is empty and is kept only for backwards compatibility
return nil
}
func runHookPostReceive(c *cli.Context) error {
ctx, cancel := installSignals()
defer cancel()
setup(ctx, c.Bool("debug"))
// First of all run update-server-info no matter what
if _, _, err := git.NewCommand(ctx, "update-server-info").RunStdString(nil); err != nil {
return fmt.Errorf("Failed to call 'git update-server-info': %w", err)
}
// Now if we're an internal don't do anything else
if isInternal, _ := strconv.ParseBool(os.Getenv(repo_module.EnvIsInternal)); isInternal {
return nil
}
if len(os.Getenv("SSH_ORIGINAL_COMMAND")) == 0 {
if setting.OnlyAllowPushIfGiteaEnvironmentSet {
return fail(ctx, `Rejecting changes as Gitea environment not set.
If you are pushing over SSH you must push with a key managed by
Gitea or set your environment appropriately.`, "")
}
return nil
}
var out io.Writer
var dWriter *delayWriter
out = &nilWriter{}
if setting.Git.VerbosePush {
if setting.Git.VerbosePushDelay > 0 {
dWriter = newDelayWriter(os.Stdout, setting.Git.VerbosePushDelay)
defer dWriter.Close()
out = dWriter
} else {
out = os.Stdout
}
}
// the environment is set by serv command
repoUser := os.Getenv(repo_module.EnvRepoUsername)
isWiki, _ := strconv.ParseBool(os.Getenv(repo_module.EnvRepoIsWiki))
repoName := os.Getenv(repo_module.EnvRepoName)
pusherID, _ := strconv.ParseInt(os.Getenv(repo_module.EnvPusherID), 10, 64)
pusherName := os.Getenv(repo_module.EnvPusherName)
hookOptions := private.HookOptions{
UserName: pusherName,
UserID: pusherID,
GitAlternativeObjectDirectories: os.Getenv(private.GitAlternativeObjectDirectories),
GitObjectDirectory: os.Getenv(private.GitObjectDirectory),
GitQuarantinePath: os.Getenv(private.GitQuarantinePath),
GitPushOptions: pushOptions(),
}
oldCommitIDs := make([]string, hookBatchSize)
newCommitIDs := make([]string, hookBatchSize)
refFullNames := make([]string, hookBatchSize)
count := 0
total := 0
wasEmpty := false
masterPushed := false
results := make([]private.HookPostReceiveBranchResult, 0)
scanner := bufio.NewScanner(os.Stdin)
for scanner.Scan() {
// TODO: support news feeds for wiki
if isWiki {
continue
}
fields := bytes.Fields(scanner.Bytes())
if len(fields) != 3 {
continue
}
fmt.Fprintf(out, ".")
oldCommitIDs[count] = string(fields[0])
newCommitIDs[count] = string(fields[1])
refFullNames[count] = string(fields[2])
if refFullNames[count] == git.BranchPrefix+"master" && newCommitIDs[count] != git.EmptySHA && count == total {
masterPushed = true
}
count++
total++
if count >= hookBatchSize {
fmt.Fprintf(out, " Processing %d references\n", count)
hookOptions.OldCommitIDs = oldCommitIDs
hookOptions.NewCommitIDs = newCommitIDs
hookOptions.RefFullNames = refFullNames
resp, extra := private.HookPostReceive(ctx, repoUser, repoName, hookOptions)
if extra.HasError() {
_ = dWriter.Close()
hookPrintResults(results)
return fail(ctx, extra.UserMsg, "HookPostReceive failed: %v", extra.Error)
}
wasEmpty = wasEmpty || resp.RepoWasEmpty
results = append(results, resp.Results...)
count = 0
}
}
if count == 0 {
if wasEmpty && masterPushed {
// We need to tell the repo to reset the default branch to master
extra := private.SetDefaultBranch(ctx, repoUser, repoName, "master")
if extra.HasError() {
return fail(ctx, extra.UserMsg, "SetDefaultBranch failed: %v", extra.Error)
}
}
fmt.Fprintf(out, "Processed %d references in total\n", total)
_ = dWriter.Close()
hookPrintResults(results)
return nil
}
hookOptions.OldCommitIDs = oldCommitIDs[:count]
hookOptions.NewCommitIDs = newCommitIDs[:count]
hookOptions.RefFullNames = refFullNames[:count]
fmt.Fprintf(out, " Processing %d references\n", count)
resp, extra := private.HookPostReceive(ctx, repoUser, repoName, hookOptions)
if resp == nil {
_ = dWriter.Close()
hookPrintResults(results)
return fail(ctx, extra.UserMsg, "HookPostReceive failed: %v", extra.Error)
}
wasEmpty = wasEmpty || resp.RepoWasEmpty
results = append(results, resp.Results...)
fmt.Fprintf(out, "Processed %d references in total\n", total)
if wasEmpty && masterPushed {
// We need to tell the repo to reset the default branch to master
extra := private.SetDefaultBranch(ctx, repoUser, repoName, "master")
if extra.HasError() {
return fail(ctx, extra.UserMsg, "SetDefaultBranch failed: %v", extra.Error)
}
}
_ = dWriter.Close()
hookPrintResults(results)
return nil
}
func hookPrintResults(results []private.HookPostReceiveBranchResult) {
for _, res := range results {
if !res.Message {
continue
}
fmt.Fprintln(os.Stderr, "")
if res.Create {
fmt.Fprintf(os.Stderr, "Create a new pull request for '%s':\n", res.Branch)
fmt.Fprintf(os.Stderr, " %s\n", res.URL)
} else {
fmt.Fprint(os.Stderr, "Visit the existing pull request:\n")
fmt.Fprintf(os.Stderr, " %s\n", res.URL)
}
fmt.Fprintln(os.Stderr, "")
os.Stderr.Sync()
}
}
func pushOptions() map[string]string {
opts := make(map[string]string)
if pushCount, err := strconv.Atoi(os.Getenv(private.GitPushOptionCount)); err == nil {
for idx := 0; idx < pushCount; idx++ {
opt := os.Getenv(fmt.Sprintf("GIT_PUSH_OPTION_%d", idx))
kv := strings.SplitN(opt, "=", 2)
if len(kv) == 2 {
opts[kv[0]] = kv[1]
}
}
}
return opts
}
func runHookProcReceive(c *cli.Context) error {
ctx, cancel := installSignals()
defer cancel()
setup(ctx, c.Bool("debug"))
if len(os.Getenv("SSH_ORIGINAL_COMMAND")) == 0 {
if setting.OnlyAllowPushIfGiteaEnvironmentSet {
return fail(ctx, `Rejecting changes as Gitea environment not set.
If you are pushing over SSH you must push with a key managed by
Gitea or set your environment appropriately.`, "")
}
return nil
}
if git.CheckGitVersionAtLeast("2.29") != nil {
return fail(ctx, "No proc-receive support", "current git version doesn't support proc-receive.")
}
reader := bufio.NewReader(os.Stdin)
repoUser := os.Getenv(repo_module.EnvRepoUsername)
repoName := os.Getenv(repo_module.EnvRepoName)
pusherID, _ := strconv.ParseInt(os.Getenv(repo_module.EnvPusherID), 10, 64)
pusherName := os.Getenv(repo_module.EnvPusherName)
// 1. Version and features negotiation.
// S: PKT-LINE(version=1\0push-options atomic...) / PKT-LINE(version=1\n)
// S: flush-pkt
// H: PKT-LINE(version=1\0push-options...)
// H: flush-pkt
rs, err := readPktLine(ctx, reader, pktLineTypeData)
if err != nil {
return err
}
const VersionHead string = "version=1"
var (
hasPushOptions bool
response = []byte(VersionHead)
requestOptions []string
)
index := bytes.IndexByte(rs.Data, byte(0))
if index >= len(rs.Data) {
return fail(ctx, "Protocol: format error", "pkt-line: format error "+fmt.Sprint(rs.Data))
}
if index < 0 {
if len(rs.Data) == 10 && rs.Data[9] == '\n' {
index = 9
} else {
return fail(ctx, "Protocol: format error", "pkt-line: format error "+fmt.Sprint(rs.Data))
}
}
if string(rs.Data[0:index]) != VersionHead {
return fail(ctx, "Protocol: version error", "Received unsupported version: %s", string(rs.Data[0:index]))
}
requestOptions = strings.Split(string(rs.Data[index+1:]), " ")
for _, option := range requestOptions {
if strings.HasPrefix(option, "push-options") {
response = append(response, byte(0))
response = append(response, []byte("push-options")...)
hasPushOptions = true
}
}
response = append(response, '\n')
_, err = readPktLine(ctx, reader, pktLineTypeFlush)
if err != nil {
return err
}
err = writeDataPktLine(ctx, os.Stdout, response)
if err != nil {
return err
}
err = writeFlushPktLine(ctx, os.Stdout)
if err != nil {
return err
}
// 2. receive commands from server.
// S: PKT-LINE(<old-oid> <new-oid> <ref>)
// S: ... ...
// S: flush-pkt
// # [receive push-options]
// S: PKT-LINE(push-option)
// S: ... ...
// S: flush-pkt
hookOptions := private.HookOptions{
UserName: pusherName,
UserID: pusherID,
}
hookOptions.OldCommitIDs = make([]string, 0, hookBatchSize)
hookOptions.NewCommitIDs = make([]string, 0, hookBatchSize)
hookOptions.RefFullNames = make([]string, 0, hookBatchSize)
for {
// note: pktLineTypeUnknow means pktLineTypeFlush and pktLineTypeData all allowed
rs, err = readPktLine(ctx, reader, pktLineTypeUnknow)
if err != nil {
return err
}
if rs.Type == pktLineTypeFlush {
break
}
t := strings.SplitN(string(rs.Data), " ", 3)
if len(t) != 3 {
continue
}
hookOptions.OldCommitIDs = append(hookOptions.OldCommitIDs, t[0])
hookOptions.NewCommitIDs = append(hookOptions.NewCommitIDs, t[1])
hookOptions.RefFullNames = append(hookOptions.RefFullNames, t[2])
}
hookOptions.GitPushOptions = make(map[string]string)
if hasPushOptions {
for {
rs, err = readPktLine(ctx, reader, pktLineTypeUnknow)
if err != nil {
return err
}
if rs.Type == pktLineTypeFlush {
break
}
kv := strings.SplitN(string(rs.Data), "=", 2)
if len(kv) == 2 {
hookOptions.GitPushOptions[kv[0]] = kv[1]
}
}
}
// 3. run hook
resp, extra := private.HookProcReceive(ctx, repoUser, repoName, hookOptions)
if extra.HasError() {
return fail(ctx, extra.UserMsg, "HookProcReceive failed: %v", extra.Error)
}
// 4. response result to service
// # a. OK, but has an alternate reference. The alternate reference name
// # and other status can be given in option directives.
// H: PKT-LINE(ok <ref>)
// H: PKT-LINE(option refname <refname>)
// H: PKT-LINE(option old-oid <old-oid>)
// H: PKT-LINE(option new-oid <new-oid>)
// H: PKT-LINE(option forced-update)
// H: ... ...
// H: flush-pkt
// # b. NO, I reject it.
// H: PKT-LINE(ng <ref> <reason>)
// # c. Fall through, let 'receive-pack' to execute it.
// H: PKT-LINE(ok <ref>)
// H: PKT-LINE(option fall-through)
for _, rs := range resp.Results {
if len(rs.Err) > 0 {
err = writeDataPktLine(ctx, os.Stdout, []byte("ng "+rs.OriginalRef+" "+rs.Err))
if err != nil {
return err
}
continue
}
if rs.IsNotMatched {
err = writeDataPktLine(ctx, os.Stdout, []byte("ok "+rs.OriginalRef))
if err != nil {
return err
}
err = writeDataPktLine(ctx, os.Stdout, []byte("option fall-through"))
if err != nil {
return err
}
continue
}
err = writeDataPktLine(ctx, os.Stdout, []byte("ok "+rs.OriginalRef))
if err != nil {
return err
}
err = writeDataPktLine(ctx, os.Stdout, []byte("option refname "+rs.Ref))
if err != nil {
return err
}
if rs.OldOID != git.EmptySHA {
err = writeDataPktLine(ctx, os.Stdout, []byte("option old-oid "+rs.OldOID))
if err != nil {
return err
}
}
err = writeDataPktLine(ctx, os.Stdout, []byte("option new-oid "+rs.NewOID))
if err != nil {
return err
}
if rs.IsForcePush {
err = writeDataPktLine(ctx, os.Stdout, []byte("option forced-update"))
if err != nil {
return err
}
}
}
err = writeFlushPktLine(ctx, os.Stdout)
return err
}
// git PKT-Line api
// pktLineType message type of pkt-line
type pktLineType int64
const (
// UnKnow type
pktLineTypeUnknow pktLineType = 0
// flush-pkt "0000"
pktLineTypeFlush pktLineType = iota
// data line
pktLineTypeData
)
// gitPktLine pkt-line api
type gitPktLine struct {
Type pktLineType
Length uint64
Data []byte
}
func readPktLine(ctx context.Context, in *bufio.Reader, requestType pktLineType) (*gitPktLine, error) {
var (
err error
r *gitPktLine
)
// read prefix
lengthBytes := make([]byte, 4)
for i := 0; i < 4; i++ {
lengthBytes[i], err = in.ReadByte()
if err != nil {
return nil, fail(ctx, "Protocol: stdin error", "Pkt-Line: read stdin failed : %v", err)
}
}
r = new(gitPktLine)
r.Length, err = strconv.ParseUint(string(lengthBytes), 16, 32)
if err != nil {
return nil, fail(ctx, "Protocol: format parse error", "Pkt-Line format is wrong :%v", err)
}
if r.Length == 0 {
if requestType == pktLineTypeData {
return nil, fail(ctx, "Protocol: format data error", "Pkt-Line format is wrong")
}
r.Type = pktLineTypeFlush
return r, nil
}
if r.Length <= 4 || r.Length > 65520 || requestType == pktLineTypeFlush {
return nil, fail(ctx, "Protocol: format length error", "Pkt-Line format is wrong")
}
r.Data = make([]byte, r.Length-4)
for i := range r.Data {
r.Data[i], err = in.ReadByte()
if err != nil {
return nil, fail(ctx, "Protocol: data error", "Pkt-Line: read stdin failed : %v", err)
}
}
r.Type = pktLineTypeData
return r, nil
}
func writeFlushPktLine(ctx context.Context, out io.Writer) error {
l, err := out.Write([]byte("0000"))
if err != nil || l != 4 {
return fail(ctx, "Protocol: write error", "Pkt-Line response failed: %v", err)
}
return nil
}
func writeDataPktLine(ctx context.Context, out io.Writer, data []byte) error {
hexchar := []byte("0123456789abcdef")
hex := func(n uint64) byte {
return hexchar[(n)&15]
}
length := uint64(len(data) + 4)
tmp := make([]byte, 4)
tmp[0] = hex(length >> 12)
tmp[1] = hex(length >> 8)
tmp[2] = hex(length >> 4)
tmp[3] = hex(length)
lr, err := out.Write(tmp)
if err != nil || lr != 4 {
return fail(ctx, "Protocol: write error", "Pkt-Line response failed: %v", err)
}
lr, err = out.Write(data)
if err != nil || int(length-4) != lr {
return fail(ctx, "Protocol: write error", "Pkt-Line response failed: %v", err)
}
return nil
}