forgejo/cmd/serv.go
zeripath 302e8b6d02
Prevent zombie processes (#16314)
Unfortunately go doesn't always ensure that execd processes are completely
waited for. On linux this means that zombie processes can occur.

This PR ensures that these are waited for by using signal notifier in serv and
passing a context elsewhere.

Signed-off-by: Andrew Thornton <art27@cantab.net>
2021-06-30 22:07:23 +02:00

323 lines
9 KiB
Go

// Copyright 2014 The Gogs Authors. All rights reserved.
// Copyright 2016 The Gitea Authors. All rights reserved.
// Use of this source code is governed by a MIT-style
// license that can be found in the LICENSE file.
package cmd
import (
"context"
"fmt"
"net/http"
"net/url"
"os"
"os/exec"
"os/signal"
"regexp"
"strconv"
"strings"
"syscall"
"time"
"code.gitea.io/gitea/models"
"code.gitea.io/gitea/modules/log"
"code.gitea.io/gitea/modules/pprof"
"code.gitea.io/gitea/modules/private"
"code.gitea.io/gitea/modules/setting"
"code.gitea.io/gitea/services/lfs"
"github.com/dgrijalva/jwt-go"
jsoniter "github.com/json-iterator/go"
"github.com/kballard/go-shellquote"
"github.com/urfave/cli"
)
const (
lfsAuthenticateVerb = "git-lfs-authenticate"
)
// CmdServ represents the available serv sub-command.
var CmdServ = cli.Command{
Name: "serv",
Usage: "This command should only be called by SSH shell",
Description: `Serv provide access auth for repositories`,
Action: runServ,
Flags: []cli.Flag{
cli.BoolFlag{
Name: "enable-pprof",
},
cli.BoolFlag{
Name: "debug",
},
},
}
func setup(logPath string, debug bool) {
_ = log.DelLogger("console")
if debug {
_ = log.NewLogger(1000, "console", "console", `{"level":"trace","stacktracelevel":"NONE","stderr":true}`)
} else {
_ = log.NewLogger(1000, "console", "console", `{"level":"fatal","stacktracelevel":"NONE","stderr":true}`)
}
setting.NewContext()
if debug {
setting.RunMode = "dev"
}
}
var (
allowedCommands = map[string]models.AccessMode{
"git-upload-pack": models.AccessModeRead,
"git-upload-archive": models.AccessModeRead,
"git-receive-pack": models.AccessModeWrite,
lfsAuthenticateVerb: models.AccessModeNone,
}
alphaDashDotPattern = regexp.MustCompile(`[^\w-\.]`)
)
func fail(userMessage, logMessage string, args ...interface{}) {
fmt.Fprintln(os.Stderr, "Gitea:", userMessage)
if len(logMessage) > 0 {
if !setting.IsProd() {
fmt.Fprintf(os.Stderr, logMessage+"\n", args...)
}
}
if len(logMessage) > 0 {
_ = private.SSHLog(true, fmt.Sprintf(logMessage+": ", args...))
}
os.Exit(1)
}
func runServ(c *cli.Context) error {
// FIXME: This needs to internationalised
setup("serv.log", c.Bool("debug"))
if setting.SSH.Disabled {
println("Gitea: SSH has been disabled")
return nil
}
if len(c.Args()) < 1 {
if err := cli.ShowSubcommandHelp(c); err != nil {
fmt.Printf("error showing subcommand help: %v\n", err)
}
return nil
}
keys := strings.Split(c.Args()[0], "-")
if len(keys) != 2 || keys[0] != "key" {
fail("Key ID format error", "Invalid key argument: %s", c.Args()[0])
}
keyID, err := strconv.ParseInt(keys[1], 10, 64)
if err != nil {
fail("Key ID format error", "Invalid key argument: %s", c.Args()[1])
}
cmd := os.Getenv("SSH_ORIGINAL_COMMAND")
if len(cmd) == 0 {
key, user, err := private.ServNoCommand(keyID)
if err != nil {
fail("Internal error", "Failed to check provided key: %v", err)
}
switch key.Type {
case models.KeyTypeDeploy:
println("Hi there! You've successfully authenticated with the deploy key named " + key.Name + ", but Gitea does not provide shell access.")
case models.KeyTypePrincipal:
println("Hi there! You've successfully authenticated with the principal " + key.Content + ", but Gitea does not provide shell access.")
default:
println("Hi there, " + user.Name + "! You've successfully authenticated with the key named " + key.Name + ", but Gitea does not provide shell access.")
}
println("If this is unexpected, please log in with password and setup Gitea under another user.")
return nil
} else if c.Bool("debug") {
log.Debug("SSH_ORIGINAL_COMMAND: %s", os.Getenv("SSH_ORIGINAL_COMMAND"))
}
words, err := shellquote.Split(cmd)
if err != nil {
fail("Error parsing arguments", "Failed to parse arguments: %v", err)
}
if len(words) < 2 {
fail("Too few arguments", "Too few arguments in cmd: %s", cmd)
}
verb := words[0]
repoPath := words[1]
if repoPath[0] == '/' {
repoPath = repoPath[1:]
}
var lfsVerb string
if verb == lfsAuthenticateVerb {
if !setting.LFS.StartServer {
fail("Unknown git command", "LFS authentication request over SSH denied, LFS support is disabled")
}
if len(words) > 2 {
lfsVerb = words[2]
}
}
// LowerCase and trim the repoPath as that's how they are stored.
repoPath = strings.ToLower(strings.TrimSpace(repoPath))
rr := strings.SplitN(repoPath, "/", 2)
if len(rr) != 2 {
fail("Invalid repository path", "Invalid repository path: %v", repoPath)
}
username := strings.ToLower(rr[0])
reponame := strings.ToLower(strings.TrimSuffix(rr[1], ".git"))
if alphaDashDotPattern.MatchString(reponame) {
fail("Invalid repo name", "Invalid repo name: %s", reponame)
}
if setting.EnablePprof || c.Bool("enable-pprof") {
if err := os.MkdirAll(setting.PprofDataPath, os.ModePerm); err != nil {
fail("Error while trying to create PPROF_DATA_PATH", "Error while trying to create PPROF_DATA_PATH: %v", err)
}
stopCPUProfiler, err := pprof.DumpCPUProfileForUsername(setting.PprofDataPath, username)
if err != nil {
fail("Internal Server Error", "Unable to start CPU profile: %v", err)
}
defer func() {
stopCPUProfiler()
err := pprof.DumpMemProfileForUsername(setting.PprofDataPath, username)
if err != nil {
fail("Internal Server Error", "Unable to dump Mem Profile: %v", err)
}
}()
}
requestedMode, has := allowedCommands[verb]
if !has {
fail("Unknown git command", "Unknown git command %s", verb)
}
if verb == lfsAuthenticateVerb {
if lfsVerb == "upload" {
requestedMode = models.AccessModeWrite
} else if lfsVerb == "download" {
requestedMode = models.AccessModeRead
} else {
fail("Unknown LFS verb", "Unknown lfs verb %s", lfsVerb)
}
}
results, err := private.ServCommand(keyID, username, reponame, requestedMode, verb, lfsVerb)
if err != nil {
if private.IsErrServCommand(err) {
errServCommand := err.(private.ErrServCommand)
if errServCommand.StatusCode != http.StatusInternalServerError {
fail("Unauthorized", "%s", errServCommand.Error())
} else {
fail("Internal Server Error", "%s", errServCommand.Error())
}
}
fail("Internal Server Error", "%s", err.Error())
}
os.Setenv(models.EnvRepoIsWiki, strconv.FormatBool(results.IsWiki))
os.Setenv(models.EnvRepoName, results.RepoName)
os.Setenv(models.EnvRepoUsername, results.OwnerName)
os.Setenv(models.EnvPusherName, results.UserName)
os.Setenv(models.EnvPusherEmail, results.UserEmail)
os.Setenv(models.EnvPusherID, strconv.FormatInt(results.UserID, 10))
os.Setenv(models.EnvRepoID, strconv.FormatInt(results.RepoID, 10))
os.Setenv(models.EnvPRID, fmt.Sprintf("%d", 0))
os.Setenv(models.EnvIsDeployKey, fmt.Sprintf("%t", results.IsDeployKey))
os.Setenv(models.EnvKeyID, fmt.Sprintf("%d", results.KeyID))
os.Setenv(models.EnvAppURL, setting.AppURL)
//LFS token authentication
if verb == lfsAuthenticateVerb {
url := fmt.Sprintf("%s%s/%s.git/info/lfs", setting.AppURL, url.PathEscape(results.OwnerName), url.PathEscape(results.RepoName))
now := time.Now()
claims := lfs.Claims{
StandardClaims: jwt.StandardClaims{
ExpiresAt: now.Add(setting.LFS.HTTPAuthExpiry).Unix(),
NotBefore: now.Unix(),
},
RepoID: results.RepoID,
Op: lfsVerb,
UserID: results.UserID,
}
token := jwt.NewWithClaims(jwt.SigningMethodHS256, claims)
// Sign and get the complete encoded token as a string using the secret
tokenString, err := token.SignedString(setting.LFS.JWTSecretBytes)
if err != nil {
fail("Internal error", "Failed to sign JWT token: %v", err)
}
tokenAuthentication := &models.LFSTokenResponse{
Header: make(map[string]string),
Href: url,
}
tokenAuthentication.Header["Authorization"] = fmt.Sprintf("Bearer %s", tokenString)
json := jsoniter.ConfigCompatibleWithStandardLibrary
enc := json.NewEncoder(os.Stdout)
err = enc.Encode(tokenAuthentication)
if err != nil {
fail("Internal error", "Failed to encode LFS json response: %v", err)
}
return nil
}
// Special handle for Windows.
if setting.IsWindows {
verb = strings.Replace(verb, "-", " ", 1)
}
ctx, cancel := context.WithCancel(context.Background())
defer cancel()
go func() {
// install notify
signalChannel := make(chan os.Signal, 1)
signal.Notify(
signalChannel,
syscall.SIGINT,
syscall.SIGTERM,
)
select {
case <-signalChannel:
case <-ctx.Done():
}
cancel()
signal.Reset()
}()
var gitcmd *exec.Cmd
verbs := strings.Split(verb, " ")
if len(verbs) == 2 {
gitcmd = exec.CommandContext(ctx, verbs[0], verbs[1], repoPath)
} else {
gitcmd = exec.CommandContext(ctx, verb, repoPath)
}
gitcmd.Dir = setting.RepoRootPath
gitcmd.Stdout = os.Stdout
gitcmd.Stdin = os.Stdin
gitcmd.Stderr = os.Stderr
if err = gitcmd.Run(); err != nil {
fail("Internal error", "Failed to execute git command: %v", err)
}
// Update user key activity.
if results.KeyID > 0 {
if err = private.UpdatePublicKeyInRepo(results.KeyID, results.RepoID); err != nil {
fail("Internal error", "UpdatePublicKeyInRepo: %v", err)
}
}
return nil
}