Allow listening on a Unix Domain Socket

config.go

@@ -20,6 +20,7 @@ import (
 
 type Config struct {
  Addr []string // TCP addresses to listen on. e.g. ":1234", "1.2.3.4:1234" or "[::1]:1234"
+ Uds string // Unix Domain Socket to listen on
  MaxForks int // Number of allowable concurrent forks
  LogLevel libwebsocketd.LogLevel
  RedirPort int
@@ -65,6 +66,7 @@ func parseCommandLine() *Config {
 
  // server config options
  portFlag := flag.Int("port", 0, "HTTP port to listen on")
+ udsFlag := flag.String("uds", "", "Path of the Unix Domain Socket to listen on")
  versionFlag := flag.Bool("version", false, "Print version and exit")
  licenseFlag := flag.Bool("license", false, "Print license and exit")
  logLevelFlag := flag.String("loglevel", "access", "Log level, one of: debug, trace, access, info, error, fatal")
@@ -104,23 +106,27 @@ func parseCommandLine() *Config {
  }
  }
 
+ ipSocknum := len(addrlist)
  port := *portFlag
- if port == 0 {
+ udsOnly := *udsFlag != "" && ipSocknum == 0 && port == 0 && *redirPortFlag == 0
+
+ if port == 0 && !udsOnly {
  if *sslFlag {
  port = 443
  } else {
  port = 80
  }
  }
 
- if socknum := len(addrlist); socknum != 0 {
- mainConfig.Addr = make([]string, socknum)
+ if ipSocknum != 0 {
+ mainConfig.Addr = make([]string, ipSocknum)
  for i, addrSingle := range addrlist {
  mainConfig.Addr[i] = fmt.Sprintf("%s:%d", addrSingle, port)
  }
- } else {
+ } else if !udsOnly {
  mainConfig.Addr = []string{fmt.Sprintf(":%d", port)}
  }
+ mainConfig.Uds = *udsFlag
  mainConfig.MaxForks = *maxForksFlag
  mainConfig.RedirPort = *redirPortFlag
  mainConfig.LogLevel = libwebsocketd.LevelFromString(*logLevelFlag)

help.go

@@ -36,6 +36,11 @@ Options:
  Use square brackets to specify IPv6 address.
  Default: "" (all)
 
+ --uds=PATH Path to create a Unix Domain Socket to listen
+ on. If this is specified and no IP-specific
+ flags are specified, do not listen on IP.
+ Default: "" (do not serve on UDS)
+
  --sameorigin={true,false} Restrict (HTTP 403) protocol upgrades if the
  Origin header does not match to requested HTTP
  Host. Default: false.

libwebsocketd/handler.go

@@ -35,8 +35,9 @@ func NewWebsocketdHandler(s *WebsocketdServer, req *http.Request, log *LogScope)
 
  wsh.RemoteInfo, err = GetRemoteInfo(req.RemoteAddr, s.Config.ReverseLookup)
  if err != nil {
+ // This occurs when serving over Unix Domain Sockets.
  log.Error("session", "Could not understand remote address '%s': %s", req.RemoteAddr, err)
- return nil, err
+ wsh.RemoteInfo = &RemoteInfo{Addr: "unknown_host", Host: "unknown_host", Port: ""}
  }
  log.Associate("remote", wsh.RemoteInfo.Host)
 

main.go

@@ -7,6 +7,7 @@ package main
 
 import (
  "fmt"
+ "net"
  "net/http"
  "os"
  "runtime"
@@ -70,24 +71,28 @@ func main() {
  }
 
  rejects := make(chan error, 1)
+
+ // Serve and ServeTLS, called by the serve function below, do not return
+ // except on error. Let's run serve in a go routine, reporting result to
+ // control channel. This allows us to have multiple serve addresses.
+ serve := func(network, address string) {
+ if listener, err := net.Listen(network, address); err != nil {
+ rejects <- err
+ } else if config.Ssl {
+ rejects <- http.ServeTLS(listener, nil, config.CertFile, config.KeyFile)
+ } else {
+ rejects <- http.Serve(listener, nil)
+ }
+ }
+
  for _, addrSingle := range config.Addr {
  log.Info("server", "Starting WebSocket server : %s", handler.TellURL("ws", addrSingle, "/"))
  if config.DevConsole {
  log.Info("server", "Developer console enabled : %s", handler.TellURL("http", addrSingle, "/"))
  } else if config.StaticDir != "" || config.CgiDir != "" {
  log.Info("server", "Serving CGI or static files : %s", handler.TellURL("http", addrSingle, "/"))
  }
- // ListenAndServe is blocking function. Let's run it in
- // go routine, reporting result to control channel.
- // Since it's blocking it'll never return non-error.
-
- go func(addr string) {
- if config.Ssl {
- rejects <- http.ListenAndServeTLS(addr, config.CertFile, config.KeyFile, nil)
- } else {
- rejects <- http.ListenAndServe(addr, nil)
- }
- }(addrSingle)
+ go serve("tcp", addrSingle)
 
  if config.RedirPort != 0 {
  go func(addr string) {
@@ -112,6 +117,10 @@ func main() {
  }(addrSingle)
  }
  }
+ if config.Uds != "" {
+ log.Info("server", "Starting WebSocket server on Unix Domain Socket: %s", config.Uds)
+ go serve("unix", config.Uds)
+ }
  err := <-rejects
  if err != nil {
  log.Fatal("server", "Can't start server: %s", err)