Adding upstream version 9.0.3.

Signed-off-by: Daniel Baumann <daniel@debian.org>

1 files changed, 321 insertions, 0 deletions

diff --git a/modules/graceful/net_unix.go b/modules/graceful/net_unix.go
new file mode 100644
index 0000000..796e005
--- /dev/null
+++ b/modules/graceful/net_unix.go
@@ -0,0 +1,321 @@
+// Copyright 2019 The Gitea Authors. All rights reserved.
+// SPDX-License-Identifier: MIT
+
+// This code is heavily inspired by the archived gofacebook/gracenet/net.go handler
+
+//go:build !windows
+
+package graceful
+
+import (
+	"fmt"
+	"net"
+	"os"
+	"strconv"
+	"strings"
+	"sync"
+	"time"
+
+	"code.gitea.io/gitea/modules/log"
+	"code.gitea.io/gitea/modules/setting"
+	"code.gitea.io/gitea/modules/util"
+)
+
+const (
+	listenFDsEnv = "LISTEN_FDS"
+	startFD      = 3
+	unlinkFDsEnv = "GITEA_UNLINK_FDS"
+
+	notifySocketEnv    = "NOTIFY_SOCKET"
+	watchdogTimeoutEnv = "WATCHDOG_USEC"
+)
+
+// In order to keep the working directory the same as when we started we record
+// it at startup.
+var originalWD, _ = os.Getwd()
+
+var (
+	once  = sync.Once{}
+	mutex = sync.Mutex{}
+
+	providedListenersToUnlink = []bool{}
+	activeListenersToUnlink   = []bool{}
+	providedListeners         = []net.Listener{}
+	activeListeners           = []net.Listener{}
+
+	notifySocketAddr string
+	watchdogTimeout  time.Duration
+)
+
+func getProvidedFDs() (savedErr error) {
+	// Only inherit the provided FDS once but we will save the error so that repeated calls to this function will return the same error
+	once.Do(func() {
+		mutex.Lock()
+		defer mutex.Unlock()
+		// now handle some additional systemd provided things
+		notifySocketAddr = os.Getenv(notifySocketEnv)
+		if notifySocketAddr != "" {
+			log.Debug("Systemd Notify Socket provided: %s", notifySocketAddr)
+			savedErr = os.Unsetenv(notifySocketEnv)
+			if savedErr != nil {
+				log.Warn("Unable to Unset the NOTIFY_SOCKET environment variable: %v", savedErr)
+				return
+			}
+			// FIXME: We don't handle WATCHDOG_PID
+			timeoutStr := os.Getenv(watchdogTimeoutEnv)
+			if timeoutStr != "" {
+				savedErr = os.Unsetenv(watchdogTimeoutEnv)
+				if savedErr != nil {
+					log.Warn("Unable to Unset the WATCHDOG_USEC environment variable: %v", savedErr)
+					return
+				}
+
+				s, err := strconv.ParseInt(timeoutStr, 10, 64)
+				if err != nil {
+					log.Error("Unable to parse the provided WATCHDOG_USEC: %v", err)
+					savedErr = fmt.Errorf("unable to parse the provided WATCHDOG_USEC: %w", err)
+					return
+				}
+				if s <= 0 {
+					log.Error("Unable to parse the provided WATCHDOG_USEC: %s should be a positive number", timeoutStr)
+					savedErr = fmt.Errorf("unable to parse the provided WATCHDOG_USEC: %s should be a positive number", timeoutStr)
+					return
+				}
+				watchdogTimeout = time.Duration(s) * time.Microsecond
+			}
+		} else {
+			log.Trace("No Systemd Notify Socket provided")
+		}
+
+		numFDs := os.Getenv(listenFDsEnv)
+		if numFDs == "" {
+			return
+		}
+		n, err := strconv.Atoi(numFDs)
+		if err != nil {
+			savedErr = fmt.Errorf("%s is not a number: %s. Err: %w", listenFDsEnv, numFDs, err)
+			return
+		}
+
+		fdsToUnlinkStr := strings.Split(os.Getenv(unlinkFDsEnv), ",")
+		providedListenersToUnlink = make([]bool, n)
+		for _, fdStr := range fdsToUnlinkStr {
+			i, err := strconv.Atoi(fdStr)
+			if err != nil || i < 0 || i >= n {
+				continue
+			}
+			providedListenersToUnlink[i] = true
+		}
+
+		for i := startFD; i < n+startFD; i++ {
+			file := os.NewFile(uintptr(i), fmt.Sprintf("listener_FD%d", i))
+
+			l, err := net.FileListener(file)
+			if err == nil {
+				// Close the inherited file if it's a listener
+				if err = file.Close(); err != nil {
+					savedErr = fmt.Errorf("error closing provided socket fd %d: %w", i, err)
+					return
+				}
+				providedListeners = append(providedListeners, l)
+				continue
+			}
+
+			// If needed we can handle packetconns here.
+			savedErr = fmt.Errorf("Error getting provided socket fd %d: %w", i, err)
+			return
+		}
+	})
+	return savedErr
+}
+
+// closeProvidedListeners closes all unused provided listeners.
+func closeProvidedListeners() {
+	mutex.Lock()
+	defer mutex.Unlock()
+	for _, l := range providedListeners {
+		err := l.Close()
+		if err != nil {
+			log.Error("Error in closing unused provided listener: %v", err)
+		}
+	}
+	providedListeners = []net.Listener{}
+}
+
+// DefaultGetListener obtains a listener for the stream-oriented local network address:
+// "tcp", "tcp4", "tcp6", "unix" or "unixpacket".
+func DefaultGetListener(network, address string) (net.Listener, error) {
+	// Add a deferral to say that we've tried to grab a listener
+	defer GetManager().InformCleanup()
+	switch network {
+	case "tcp", "tcp4", "tcp6":
+		tcpAddr, err := net.ResolveTCPAddr(network, address)
+		if err != nil {
+			return nil, err
+		}
+		return GetListenerTCP(network, tcpAddr)
+	case "unix", "unixpacket":
+		unixAddr, err := net.ResolveUnixAddr(network, address)
+		if err != nil {
+			return nil, err
+		}
+		return GetListenerUnix(network, unixAddr)
+	default:
+		return nil, net.UnknownNetworkError(network)
+	}
+}
+
+// GetListenerTCP announces on the local network address. The network must be:
+// "tcp", "tcp4" or "tcp6". It returns a provided net.Listener for the
+// matching network and address, or creates a new one using net.ListenTCP.
+func GetListenerTCP(network string, address *net.TCPAddr) (*net.TCPListener, error) {
+	if err := getProvidedFDs(); err != nil {
+		return nil, err
+	}
+
+	mutex.Lock()
+	defer mutex.Unlock()
+
+	// look for a provided listener
+	for i, l := range providedListeners {
+		if isSameAddr(l.Addr(), address) {
+			providedListeners = append(providedListeners[:i], providedListeners[i+1:]...)
+			needsUnlink := providedListenersToUnlink[i]
+			providedListenersToUnlink = append(providedListenersToUnlink[:i], providedListenersToUnlink[i+1:]...)
+
+			activeListeners = append(activeListeners, l)
+			activeListenersToUnlink = append(activeListenersToUnlink, needsUnlink)
+			return l.(*net.TCPListener), nil
+		}
+	}
+
+	// no provided listener for this address -> make a fresh listener
+	l, err := net.ListenTCP(network, address)
+	if err != nil {
+		return nil, err
+	}
+	activeListeners = append(activeListeners, l)
+	activeListenersToUnlink = append(activeListenersToUnlink, false)
+	return l, nil
+}
+
+// GetListenerUnix announces on the local network address. The network must be:
+// "unix" or "unixpacket". It returns a provided net.Listener for the
+// matching network and address, or creates a new one using net.ListenUnix.
+func GetListenerUnix(network string, address *net.UnixAddr) (*net.UnixListener, error) {
+	if err := getProvidedFDs(); err != nil {
+		return nil, err
+	}
+
+	mutex.Lock()
+	defer mutex.Unlock()
+
+	// look for a provided listener
+	for i, l := range providedListeners {
+		if isSameAddr(l.Addr(), address) {
+			providedListeners = append(providedListeners[:i], providedListeners[i+1:]...)
+			needsUnlink := providedListenersToUnlink[i]
+			providedListenersToUnlink = append(providedListenersToUnlink[:i], providedListenersToUnlink[i+1:]...)
+
+			activeListenersToUnlink = append(activeListenersToUnlink, needsUnlink)
+			activeListeners = append(activeListeners, l)
+			unixListener := l.(*net.UnixListener)
+			if needsUnlink {
+				unixListener.SetUnlinkOnClose(true)
+			}
+			return unixListener, nil
+		}
+	}
+
+	// make a fresh listener
+	if err := util.Remove(address.Name); err != nil && !os.IsNotExist(err) {
+		return nil, fmt.Errorf("Failed to remove unix socket %s: %w", address.Name, err)
+	}
+
+	l, err := net.ListenUnix(network, address)
+	if err != nil {
+		return nil, err
+	}
+
+	fileMode := os.FileMode(setting.UnixSocketPermission)
+	if err = os.Chmod(address.Name, fileMode); err != nil {
+		return nil, fmt.Errorf("Failed to set permission of unix socket to %s: %w", fileMode.String(), err)
+	}
+
+	activeListeners = append(activeListeners, l)
+	activeListenersToUnlink = append(activeListenersToUnlink, true)
+	return l, nil
+}
+
+func isSameAddr(a1, a2 net.Addr) bool {
+	// If the addresses are not on the same network fail.
+	if a1.Network() != a2.Network() {
+		return false
+	}
+
+	// If the two addresses have the same string representation they're equal
+	a1s := a1.String()
+	a2s := a2.String()
+	if a1s == a2s {
+		return true
+	}
+
+	// This allows for ipv6 vs ipv4 local addresses to compare as equal. This
+	// scenario is common when listening on localhost.
+	const ipv6prefix = "[::]"
+	a1s = strings.TrimPrefix(a1s, ipv6prefix)
+	a2s = strings.TrimPrefix(a2s, ipv6prefix)
+	const ipv4prefix = "0.0.0.0"
+	a1s = strings.TrimPrefix(a1s, ipv4prefix)
+	a2s = strings.TrimPrefix(a2s, ipv4prefix)
+	return a1s == a2s
+}
+
+func getActiveListeners() []net.Listener {
+	mutex.Lock()
+	defer mutex.Unlock()
+	listeners := make([]net.Listener, len(activeListeners))
+	copy(listeners, activeListeners)
+	return listeners
+}
+
+func getActiveListenersToUnlink() []bool {
+	mutex.Lock()
+	defer mutex.Unlock()
+	listenersToUnlink := make([]bool, len(activeListenersToUnlink))
+	copy(listenersToUnlink, activeListenersToUnlink)
+	return listenersToUnlink
+}
+
+func getNotifySocket() (*net.UnixConn, error) {
+	if err := getProvidedFDs(); err != nil {
+		// This error will be logged elsewhere
+		return nil, nil
+	}
+
+	if notifySocketAddr == "" {
+		return nil, nil
+	}
+
+	socketAddr := &net.UnixAddr{
+		Name: notifySocketAddr,
+		Net:  "unixgram",
+	}
+
+	notifySocket, err := net.DialUnix(socketAddr.Net, nil, socketAddr)
+	if err != nil {
+		log.Warn("failed to dial NOTIFY_SOCKET %s: %v", socketAddr, err)
+		return nil, err
+	}
+
+	return notifySocket, nil
+}
+
+func getWatchdogTimeout() time.Duration {
+	if err := getProvidedFDs(); err != nil {
+		// This error will be logged elsewhere
+		return 0
+	}
+
+	return watchdogTimeout
+}