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server

Lindenii Forge’s main backend daemon
Commit info
ID
a29e3bb4c959337796fd743b2853a3ed66c35cce
Author
Runxi Yu <me@runxiyu.org>
Author date
Sat, 05 Apr 2025 21:53:19 +0800
Committer
Runxi Yu <me@runxiyu.org>
Committer date
Sat, 05 Apr 2025 21:53:19 +0800
Actions
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// SPDX-License-Identifier: AGPL-3.0-only
// SPDX-FileCopyrightText: Copyright (c) 2025 Runxi Yu <https://runxiyu.org>

package forge

import (
	"errors"
	"io/fs"
	"log"
	"log/slog"
	"net"
	"net/http"
	"os"
	"os/exec"
	"syscall"
	"time"

	"github.com/jackc/pgx/v5/pgxpool"
	"go.lindenii.runxiyu.org/lindenii-common/cmap"
	goSSH "golang.org/x/crypto/ssh"
)

type Server struct {
	config Config

	// database serves as the primary database handle for this entire application.
	// Transactions or single reads may be used from it. A [pgxpool.Pool] is
	// necessary to safely use pgx concurrently; pgx.Conn, etc. are insufficient.
	database *pgxpool.Pool

	sourceHandler http.Handler
	staticHandler http.Handler

	ircSendBuffered   chan string
	ircSendDirectChan chan errorBack[string]

	// globalData is passed as "global" when rendering HTML templates.
	globalData map[string]any

	serverPubkeyString string
	serverPubkeyFP     string
	serverPubkey       goSSH.PublicKey

	// packPasses contains hook cookies mapped to their packPass.
	packPasses cmap.Map[string, packPass]
}

func (s *Server) Setup() {
	s.sourceHandler = http.StripPrefix(
		"/-/source/",
		http.FileServer(http.FS(embeddedSourceFS)),
	)
	staticFS, err := fs.Sub(embeddedResourcesFS, "static")
	if err != nil {
		panic(err)
	}
	s.staticHandler = http.StripPrefix("/-/static/", http.FileServer(http.FS(staticFS)))
	s.globalData = map[string]any{
		"server_public_key_string":      &s.serverPubkeyString,
		"server_public_key_fingerprint": &s.serverPubkeyFP,
		"forge_version":                 VERSION,
		"forge_version":                 version,
		// Some other ones are populated after config parsing
	}
}

func (s *Server) Run() {
	if err := s.deployHooks(); err != nil {
		slog.Error("deploying hooks", "error", err)
		os.Exit(1)
	}
	if err := loadTemplates(); err != nil {
		slog.Error("loading templates", "error", err)
		os.Exit(1)
	}
	if err := s.deployGit2D(); err != nil {
		slog.Error("deploying git2d", "error", err)
		os.Exit(1)
	}

	// Launch Git2D
	go func() {
		cmd := exec.Command(s.config.Git.DaemonPath, s.config.Git.Socket) //#nosec G204
		cmd.Stderr = log.Writer()
		cmd.Stdout = log.Writer()
		if err := cmd.Run(); err != nil {
			panic(err)
		}
	}()

	// UNIX socket listener for hooks
	{
		hooksListener, err := net.Listen("unix", s.config.Hooks.Socket)
		if errors.Is(err, syscall.EADDRINUSE) {
			slog.Warn("removing existing socket", "path", s.config.Hooks.Socket)
			if err = syscall.Unlink(s.config.Hooks.Socket); err != nil {
				slog.Error("removing existing socket", "path", s.config.Hooks.Socket, "error", err)
				os.Exit(1)
			}
			if hooksListener, err = net.Listen("unix", s.config.Hooks.Socket); err != nil {
				slog.Error("listening hooks", "error", err)
				os.Exit(1)
			}
		} else if err != nil {
			slog.Error("listening hooks", "error", err)
			os.Exit(1)
		}
		slog.Info("listening hooks on unix", "path", s.config.Hooks.Socket)
		go func() {
			if err = s.serveGitHooks(hooksListener); err != nil {
				slog.Error("serving hooks", "error", err)
				os.Exit(1)
			}
		}()
	}

	// UNIX socket listener for LMTP
	{
		lmtpListener, err := net.Listen("unix", s.config.LMTP.Socket)
		if errors.Is(err, syscall.EADDRINUSE) {
			slog.Warn("removing existing socket", "path", s.config.LMTP.Socket)
			if err = syscall.Unlink(s.config.LMTP.Socket); err != nil {
				slog.Error("removing existing socket", "path", s.config.LMTP.Socket, "error", err)
				os.Exit(1)
			}
			if lmtpListener, err = net.Listen("unix", s.config.LMTP.Socket); err != nil {
				slog.Error("listening LMTP", "error", err)
				os.Exit(1)
			}
		} else if err != nil {
			slog.Error("listening LMTP", "error", err)
			os.Exit(1)
		}
		slog.Info("listening LMTP on unix", "path", s.config.LMTP.Socket)
		go func() {
			if err = s.serveLMTP(lmtpListener); err != nil {
				slog.Error("serving LMTP", "error", err)
				os.Exit(1)
			}
		}()
	}

	// SSH listener
	{
		sshListener, err := net.Listen(s.config.SSH.Net, s.config.SSH.Addr)
		if errors.Is(err, syscall.EADDRINUSE) && s.config.SSH.Net == "unix" {
			slog.Warn("removing existing socket", "path", s.config.SSH.Addr)
			if err = syscall.Unlink(s.config.SSH.Addr); err != nil {
				slog.Error("removing existing socket", "path", s.config.SSH.Addr, "error", err)
				os.Exit(1)
			}
			if sshListener, err = net.Listen(s.config.SSH.Net, s.config.SSH.Addr); err != nil {
				slog.Error("listening SSH", "error", err)
				os.Exit(1)
			}
		} else if err != nil {
			slog.Error("listening SSH", "error", err)
			os.Exit(1)
		}
		slog.Info("listening SSH on", "net", s.config.SSH.Net, "addr", s.config.SSH.Addr)
		go func() {
			if err = s.serveSSH(sshListener); err != nil {
				slog.Error("serving SSH", "error", err)
				os.Exit(1)
			}
		}()
	}

	// HTTP listener
	{
		httpListener, err := net.Listen(s.config.HTTP.Net, s.config.HTTP.Addr)
		if errors.Is(err, syscall.EADDRINUSE) && s.config.HTTP.Net == "unix" {
			slog.Warn("removing existing socket", "path", s.config.HTTP.Addr)
			if err = syscall.Unlink(s.config.HTTP.Addr); err != nil {
				slog.Error("removing existing socket", "path", s.config.HTTP.Addr, "error", err)
				os.Exit(1)
			}
			if httpListener, err = net.Listen(s.config.HTTP.Net, s.config.HTTP.Addr); err != nil {
				slog.Error("listening HTTP", "error", err)
				os.Exit(1)
			}
		} else if err != nil {
			slog.Error("listening HTTP", "error", err)
			os.Exit(1)
		}
		server := http.Server{
			Handler:      s,
			ReadTimeout:  time.Duration(s.config.HTTP.ReadTimeout) * time.Second,
			WriteTimeout: time.Duration(s.config.HTTP.ReadTimeout) * time.Second,
			IdleTimeout:  time.Duration(s.config.HTTP.ReadTimeout) * time.Second,
		} //exhaustruct:ignore
		slog.Info("listening HTTP on", "net", s.config.HTTP.Net, "addr", s.config.HTTP.Addr)
		go func() {
			if err = server.Serve(httpListener); err != nil && !errors.Is(err, http.ErrServerClosed) {
				slog.Error("serving HTTP", "error", err)
				os.Exit(1)
			}
		}()
	}

	// IRC bot
	go s.ircBotLoop()

	select {}
}
// SPDX-License-Identifier: AGPL-3.0-only
// SPDX-FileCopyrightText: Copyright (c) 2025 Runxi Yu <https://runxiyu.org>

package forge

import (
	"fmt"
	"log/slog"
	"net"
	"os"
	"strings"

	gliderSSH "github.com/gliderlabs/ssh"
	"go.lindenii.runxiyu.org/forge/internal/ansiec"
	"go.lindenii.runxiyu.org/forge/internal/misc"
	goSSH "golang.org/x/crypto/ssh"
)

// serveSSH serves SSH on a [net.Listener]. The listener should generally be a
// TCP listener, although AF_UNIX SOCK_STREAM listeners may be appropriate in
// rare cases.
func (s *Server) serveSSH(listener net.Listener) error {
	var hostKeyBytes []byte
	var hostKey goSSH.Signer
	var err error
	var server *gliderSSH.Server

	if hostKeyBytes, err = os.ReadFile(s.config.SSH.Key); err != nil {
		return err
	}

	if hostKey, err = goSSH.ParsePrivateKey(hostKeyBytes); err != nil {
		return err
	}

	s.serverPubkey = hostKey.PublicKey()
	s.serverPubkeyString = misc.BytesToString(goSSH.MarshalAuthorizedKey(s.serverPubkey))
	s.serverPubkeyFP = goSSH.FingerprintSHA256(s.serverPubkey)

	server = &gliderSSH.Server{
		Handler: func(session gliderSSH.Session) {
			clientPubkey := session.PublicKey()
			var clientPubkeyStr string
			if clientPubkey != nil {
				clientPubkeyStr = strings.TrimSuffix(misc.BytesToString(goSSH.MarshalAuthorizedKey(clientPubkey)), "\n")
			}

			slog.Info("incoming ssh", "addr", session.RemoteAddr().String(), "key", clientPubkeyStr, "command", session.RawCommand())
			fmt.Fprintln(session.Stderr(), ansiec.Blue+"Lindenii Forge "+VERSION+", source at "+strings.TrimSuffix(s.config.HTTP.Root, "/")+"/-/source/"+ansiec.Reset+"\r")
			fmt.Fprintln(session.Stderr(), ansiec.Blue+"Lindenii Forge "+version+", source at "+strings.TrimSuffix(s.config.HTTP.Root, "/")+"/-/source/"+ansiec.Reset+"\r")

			cmd := session.Command()

			if len(cmd) < 2 {
				fmt.Fprintln(session.Stderr(), "Insufficient arguments\r")
				return
			}

			switch cmd[0] {
			case "git-upload-pack":
				if len(cmd) > 2 {
					fmt.Fprintln(session.Stderr(), "Too many arguments\r")
					return
				}
				err = s.sshHandleUploadPack(session, clientPubkeyStr, cmd[1])
			case "git-receive-pack":
				if len(cmd) > 2 {
					fmt.Fprintln(session.Stderr(), "Too many arguments\r")
					return
				}
				err = s.sshHandleRecvPack(session, clientPubkeyStr, cmd[1])
			default:
				fmt.Fprintln(session.Stderr(), "Unsupported command: "+cmd[0]+"\r")
				return
			}
			if err != nil {
				fmt.Fprintln(session.Stderr(), err.Error())
				return
			}
		},
		PublicKeyHandler:           func(_ gliderSSH.Context, _ gliderSSH.PublicKey) bool { return true },
		KeyboardInteractiveHandler: func(_ gliderSSH.Context, _ goSSH.KeyboardInteractiveChallenge) bool { return true },
		// It is intentional that we do not check any credentials and accept all connections.
		// This allows all users to connect and clone repositories. However, the public key
		// is passed to handlers, so e.g. the push handler could check the key and reject the
		// push if it needs to.
	} //exhaustruct:ignore

	server.AddHostKey(hostKey)

	if err = server.Serve(listener); err != nil {
		slog.Error("error serving SSH", "error", err.Error())
		os.Exit(1)
	}

	return nil
}
package forge

var VERSION = "unknown" //nolint:gochecknoglobals
var version = "unknown" //nolint:gochecknoglobals