├── .gitignore ├── Dockerfile ├── Dockerfile.run ├── LICENSE ├── Makefile ├── README.md ├── build └── .gitkeep ├── cmd └── tcpdam │ └── main.go ├── dam.go ├── dam_test.go ├── docker-compose.yml ├── proxy.go └── socket.go /.gitignore: -------------------------------------------------------------------------------- 1 | build 2 | -------------------------------------------------------------------------------- /Dockerfile: -------------------------------------------------------------------------------- 1 | FROM golang 2 | EXPOSE 9999 3 | 4 | ADD . /go/src/github.com/simkim/tcpdam 5 | RUN go get -v github.com/simkim/tcpdam/... 6 | 7 | USER nobody 8 | ENTRYPOINT [ "tcpdam" ] 9 | -------------------------------------------------------------------------------- /Dockerfile.run: -------------------------------------------------------------------------------- 1 | FROM joeshaw/busybox-nonroot 2 | EXPOSE 9999 3 | 4 | COPY build/tcpdam /bin/tcpdam 5 | 6 | USER nobody 7 | CMD ["tcpdam"] 8 | -------------------------------------------------------------------------------- /LICENSE: -------------------------------------------------------------------------------- 1 | GNU GENERAL PUBLIC LICENSE 2 | Version 3, 29 June 2007 3 | 4 | Copyright (C) 2007 Free Software Foundation, Inc. 5 | Everyone is permitted to copy and distribute verbatim copies 6 | of this license document, but changing it is not allowed. 7 | 8 | Preamble 9 | 10 | The GNU General Public License is a free, copyleft license for 11 | software and other kinds of works. 12 | 13 | The licenses for most software and other practical works are designed 14 | to take away your freedom to share and change the works. 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Interpretation of Sections 15 and 16. 613 | 614 | If the disclaimer of warranty and limitation of liability provided 615 | above cannot be given local legal effect according to their terms, 616 | reviewing courts shall apply local law that most closely approximates 617 | an absolute waiver of all civil liability in connection with the 618 | Program, unless a warranty or assumption of liability accompanies a 619 | copy of the Program in return for a fee. 620 | 621 | END OF TERMS AND CONDITIONS 622 | 623 | How to Apply These Terms to Your New Programs 624 | 625 | If you develop a new program, and you want it to be of the greatest 626 | possible use to the public, the best way to achieve this is to make it 627 | free software which everyone can redistribute and change under these terms. 628 | 629 | To do so, attach the following notices to the program. It is safest 630 | to attach them to the start of each source file to most effectively 631 | state the exclusion of warranty; and each file should have at least 632 | the "copyright" line and a pointer to where the full notice is found. 633 | 634 | 635 | Copyright (C) 636 | 637 | This program is free software: you can redistribute it and/or modify 638 | it under the terms of the GNU General Public License as published by 639 | the Free Software Foundation, either version 3 of the License, or 640 | (at your option) any later version. 641 | 642 | This program is distributed in the hope that it will be useful, 643 | but WITHOUT ANY WARRANTY; without even the implied warranty of 644 | MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the 645 | GNU General Public License for more details. 646 | 647 | You should have received a copy of the GNU General Public License 648 | along with this program. If not, see . 649 | 650 | Also add information on how to contact you by electronic and paper mail. 651 | 652 | If the program does terminal interaction, make it output a short 653 | notice like this when it starts in an interactive mode: 654 | 655 | Copyright (C) 656 | This program comes with ABSOLUTELY NO WARRANTY; for details type `show w'. 657 | This is free software, and you are welcome to redistribute it 658 | under certain conditions; type `show c' for details. 659 | 660 | The hypothetical commands `show w' and `show c' should show the appropriate 661 | parts of the General Public License. Of course, your program's commands 662 | might be different; for a GUI interface, you would use an "about box". 663 | 664 | You should also get your employer (if you work as a programmer) or school, 665 | if any, to sign a "copyright disclaimer" for the program, if necessary. 666 | For more information on this, and how to apply and follow the GNU GPL, see 667 | . 668 | 669 | The GNU General Public License does not permit incorporating your program 670 | into proprietary programs. If your program is a subroutine library, you 671 | may consider it more useful to permit linking proprietary applications with 672 | the library. If this is what you want to do, use the GNU Lesser General 673 | Public License instead of this License. But first, please read 674 | . 675 | -------------------------------------------------------------------------------- /Makefile: -------------------------------------------------------------------------------- 1 | install: deps 2 | go install github.com/simkim/tcpdam 3 | go install github.com/simkim/tcpdam/cmd/tcpdam 4 | 5 | deps: 6 | go get -d github.com/simkim/tcpdam 7 | go get -d github.com/simkim/tcpdam/cmd/tcpdam 8 | 9 | build-bin: 10 | docker run -v `pwd`/build:/go/bin -v `pwd`:/go/src/github.com/simkim/tcpdam --rm golang go get github.com/simkim/tcpdam/... 11 | 12 | build-image: build-bin 13 | docker build -t tcpdam . 14 | 15 | dockerhub: build-image 16 | docker tag tcpdam simkim/tcpdam:latest 17 | docker push simkim/tcpdam:latest 18 | -------------------------------------------------------------------------------- /README.md: -------------------------------------------------------------------------------- 1 | # tcpdam 2 | 3 | ## Overview 4 | 5 | **tcpdam** is a parking proxy for your tcp connection. When your upstream server is ready, send SIGUSR1 to flush connection to the server. 6 | 7 | ## Compilation 8 | 9 | make 10 | 11 | ## Usage 12 | 13 | tcpdam -l LISTEN-HOST:LISTEN-PORT -r REMOTE-HOST:REMOTE-PORT 14 | 15 | will setup a listening tcp server, when something connect it is parked in a waiting list 16 | 17 | killall -USR1 tcpdam 18 | 19 | will lookup REMOTE-HOST once, and open the dam : the parked and new connections are proxified to REMOTE-HOST. 20 | 21 | killall -USR2 tcpdam 22 | 23 | will re-close the dam and start to park new connections, 24 | 25 | ## Configuration 26 | | Env | Command line | Description | 27 | | --- | ------------ | ----------- | 28 | | TCPDAM_LISTEN_ADDRESS | -l | Listen address for incoming connections | 29 | | TCPDAM_REMOTE_ADDRESS | -h | Remote address where the connections will be flushed | 30 | | TCPDAM_DEBUG | -d | Show all information | 31 | | TCPDAM_VERBOSE | -v | Show some information 32 | | TCPDAM_PIDFILE | -p | File which will contain the pid of the dam | 33 | | TCPDAM_CTRLSOCKET | -ctrl-socket | Unix socket to control the dam | 34 | | TCPDAM_MAX_FLUSHING | -max-flushing | Max number of open remote connections | 35 | | TCPDAM_MAX_PARKED | -max-parked | Max number of connections in the queue | 36 | | TCPDAM_OPEN | -open | Start the dam open | 37 | |  | -c | command to send to a running dam | 38 | 39 | ### Remote Commands 40 | 41 | | Command | Description | 42 | | ------- | ----------- | 43 | | open | open the dam unless already open | 44 | | close | close the dam unless already closed | 45 | | set-remote HOST:PORT | switch the remote address, will be used at the next open | 46 | 47 | ## Limits 48 | 49 | ### Open file descriptors 50 | 51 | You need to configure your maximum number of file descriptor to allow a high number of parked connections 52 | 53 | * debian : configure /etc/security/limits.conf 54 | * docker : docker run --ulimit nofile=100000:100000 55 | * compose : see docker-compose.yml 56 | 57 | ### netfilter conntrack size 58 | 59 | TODO 60 | 61 | ### tcp TIME_WAIT 62 | 63 | TODO 64 | 65 | ## Docker 66 | 67 | ### From the hub 68 | 69 | To run the dam 70 | 71 | docker run -p 9999:9999 --rm -ti --name tcpdam_test simkim/tcpdam tcpdam -r google.com:80 72 | 73 | To open the dam 74 | 75 | docker exec tcpdam_test killall -USR1 tcpdam 76 | 77 | To open the dam, wait for connections to terminate and quit 78 | 79 | docker stop tcpdam_test 80 | 81 | ### From local build 82 | 83 | Edit docker-compose.yml 84 | 85 | docker run -v `pwd`/build:/go/bin -v `pwd`:/go/src/github.com/simkim/tcpdam --rm golang go get github.com/simkim/tcpdam/... 86 | docker-compose build 87 | docker-compose up 88 | -------------------------------------------------------------------------------- /build/.gitkeep: -------------------------------------------------------------------------------- https://raw.githubusercontent.com/simkim/tcpdam/6d55809b18ee7bc2845c6f6f873d2d898ddd8484/build/.gitkeep -------------------------------------------------------------------------------- /cmd/tcpdam/main.go: -------------------------------------------------------------------------------- 1 | package main 2 | 3 | import ( 4 | "flag" 5 | "os" 6 | "strconv" 7 | 8 | "github.com/op/go-logging" 9 | "github.com/simkim/tcpdam" 10 | ) 11 | 12 | func configFromEnv(key string, _default string) string { 13 | if os.Getenv(key) != "" { 14 | return os.Getenv(key) 15 | } 16 | return _default 17 | } 18 | 19 | func configFromEnvInt(key string, _default int) int { 20 | if os.Getenv(key) != "" { 21 | rc, err := strconv.Atoi(os.Getenv(key)) 22 | if err != nil { 23 | log.Warning("Invalid value %s in env var %s", os.Getenv(key), key) 24 | return _default 25 | } 26 | return rc 27 | } 28 | return _default 29 | } 30 | 31 | func configFromEnvBool(key string, _default bool) bool { 32 | if os.Getenv(key) != "" { 33 | rc, err := strconv.ParseBool(os.Getenv(key)) 34 | if err != nil { 35 | log.Warning("Invalid value %s in env var %s", os.Getenv(key), key) 36 | return _default 37 | } 38 | return rc 39 | } 40 | return _default 41 | } 42 | 43 | var ( 44 | listenAddr = flag.String("l", configFromEnv("TCPDAM_LISTEN_ADDRESS", ":9999"), "listen address (TCPDAM_LISTEN_ADDRESS)") 45 | remoteAddr = flag.String("r", configFromEnv("TCPDAM_REMOTE_ADDRESS", "127.0.0.1:80"), "remote address (TCPDAM_REMOTE_ADDRESS)") 46 | maxParkedProxies = flag.Int("max-parked", configFromEnvInt("TCPDAM_MAX_PARKED", 100000), "maximum parked connections") 47 | maxFlushingProxies = flag.Int("max-flushing", configFromEnvInt("TCPDAM_MAX_FLUSHING", 10), "maximum flushing connections") 48 | verbose = flag.Bool("v", configFromEnvBool("TCPDAM_VERBOSE", false), "show major events like open/close (TCPDAM_VERBOSE)") 49 | debug = flag.Bool("d", configFromEnvBool("TCPDAM_DEBUG", false), "show all debug events (TCPDAM_DEBUG)") 50 | pidFile = flag.String("p", configFromEnv("TCPDAM_PIDFILE", ""), "pid file (TCPDAM_PIDFILE)") 51 | ctrlSocket = flag.String("ctrl-socket", configFromEnv("TCPDAM_CTRLSOCKET", "tcpdam.sock"), "control socket (TCPDAM_CTRLSOCKET)") 52 | open = flag.Bool("open", configFromEnvBool("TCPDAM_OPEN", false), "start already open (TCPDAM_OPEN)") 53 | command = flag.String("c", "", "command to send to running instance") 54 | ) 55 | 56 | func setupLogging() { 57 | backend := logging.NewLogBackend(os.Stderr, "", 0) 58 | var format = logging.MustStringFormatter( 59 | `%{color}%{time:15:04:05.000} %{shortfunc} ▶ %{level:.4s} %{id:03x}%{color:reset} %{message}`, 60 | ) 61 | backendFormatter := logging.NewBackendFormatter(backend, format) 62 | if !*debug { 63 | backendLeveled := logging.AddModuleLevel(backendFormatter) 64 | if *verbose { 65 | backendLeveled.SetLevel(logging.NOTICE, "") 66 | } else { 67 | backendLeveled.SetLevel(logging.WARNING, "") 68 | } 69 | logging.SetBackend(backendLeveled) 70 | } else { 71 | logging.SetBackend(backendFormatter) 72 | } 73 | } 74 | 75 | func teardownPidfile() error { 76 | err := os.Remove(*pidFile) 77 | if err != nil { 78 | log.Errorf("Can't remove pidfile : %s", err.Error()) 79 | } 80 | return err 81 | } 82 | 83 | func setupPidfile() (bool, error) { 84 | if *pidFile == "" { 85 | return false, nil 86 | } 87 | file, err := os.OpenFile(*pidFile, os.O_CREATE|os.O_EXCL|os.O_WRONLY|os.O_TRUNC, 0777) 88 | if err != nil { 89 | return false, err 90 | } 91 | pid := os.Getpid() 92 | log.Debugf("Write pid %d to pidfile %s\n", pid, *pidFile) 93 | file.Write([]byte(strconv.Itoa(pid))) 94 | file.Close() 95 | return true, nil 96 | } 97 | 98 | var log = logging.MustGetLogger("tcpdam") 99 | 100 | func checkCommand() { 101 | if *command != "" { 102 | if *ctrlSocket == "" { 103 | log.Error("Need a control socket") 104 | os.Exit(1) 105 | } 106 | err := tcpdam.SendControlCommand(*ctrlSocket, *command) 107 | if err != nil { 108 | log.Errorf("Error sending command : %s", err.Error()) 109 | os.Exit(1) 110 | } 111 | os.Exit(0) 112 | } 113 | } 114 | 115 | func main() { 116 | flag.Parse() 117 | setupLogging() 118 | checkCommand() 119 | 120 | hasPid, err := setupPidfile() 121 | if err != nil { 122 | log.Errorf("Can't create pid file : %s\n", err.Error()) 123 | os.Exit(1) 124 | } else { 125 | if hasPid { 126 | defer teardownPidfile() 127 | } 128 | } 129 | log.Noticef("tcpdam started (%s -> %s)", *listenAddr, *remoteAddr) 130 | dam := tcpdam.NewDam(*listenAddr, *remoteAddr, *maxParkedProxies, *maxFlushingProxies) 131 | dam.Logger = log 132 | if *ctrlSocket != "" { 133 | go dam.StartControlSocket(*ctrlSocket) 134 | defer os.Remove(*ctrlSocket) 135 | } 136 | err = dam.Start(*open) 137 | if err != nil { 138 | log.Errorf("An error occured: %s", err.Error()) 139 | } 140 | log.Notice("tcpdam stopped") 141 | } 142 | -------------------------------------------------------------------------------- /dam.go: -------------------------------------------------------------------------------- 1 | package tcpdam 2 | 3 | import ( 4 | "net" 5 | "os" 6 | "os/signal" 7 | "syscall" 8 | "time" 9 | 10 | "github.com/op/go-logging" 11 | ) 12 | 13 | type Dam struct { 14 | open bool 15 | listenAddr string 16 | remoteAddr string 17 | raddr *net.TCPAddr 18 | listener *net.TCPListener 19 | parkedProxies chan *Proxy 20 | flushingProxies chan bool 21 | close chan bool 22 | quit chan bool 23 | sigs chan os.Signal 24 | Logger *logging.Logger 25 | } 26 | 27 | func NewDam(listenAddr string, remoteAddr string, maxParked int, maxFlushing int) *Dam { 28 | return &Dam{ 29 | open: false, 30 | listenAddr: listenAddr, 31 | remoteAddr: remoteAddr, 32 | parkedProxies: make(chan *Proxy, maxParked), 33 | flushingProxies: make(chan bool, maxFlushing), 34 | close: make(chan bool), 35 | Logger: logging.MustGetLogger("dam"), 36 | } 37 | } 38 | 39 | func (dam *Dam) SetRemoteAddr(remoteAddr string) { 40 | if dam.open { 41 | dam.Logger.Warning("Changing remote address on open dam will not be effective until closing and reopening") 42 | } 43 | dam.remoteAddr = remoteAddr 44 | dam.Logger.Infof("Remote address is now %s", remoteAddr) 45 | } 46 | 47 | func (dam *Dam) Dial() (*net.TCPConn, error) { 48 | rconn, err := net.DialTCP("tcp", nil, dam.raddr) 49 | if err != nil { 50 | dam.Logger.Warningf("Can't connect to upstream : %s\n", err.Error()) 51 | } 52 | return rconn, err 53 | } 54 | 55 | func (dam *Dam) Flushed(p *Proxy) { 56 | <-dam.flushingProxies 57 | } 58 | 59 | func (dam *Dam) Push(conn *net.TCPConn) { 60 | p := &Proxy{ 61 | Lconn: conn, 62 | Dam: dam, 63 | Logger: dam.Logger, 64 | } 65 | dam.parkedProxies <- p 66 | } 67 | 68 | func (dam *Dam) Close() { 69 | if !dam.open { 70 | dam.Logger.Debugf("Already closed") 71 | return 72 | } 73 | dam.open = false 74 | dam.close <- true 75 | dam.Logger.Notice("Close dam") 76 | } 77 | 78 | func (dam *Dam) Open() error { 79 | if dam.open { 80 | dam.Logger.Debug("Already opened") 81 | return nil 82 | } 83 | dam.Logger.Debugf("Resolving %s\n", dam.remoteAddr) 84 | var err error 85 | dam.raddr, err = net.ResolveTCPAddr("tcp", dam.remoteAddr) 86 | if err != nil { 87 | dam.Logger.Warningf("Can't resolve remote addr %s\n", err.Error()) 88 | return err 89 | } 90 | 91 | dam.Logger.Noticef("Open dam (%d parked)", len(dam.parkedProxies)) 92 | dam.open = true 93 | go dam.Flush() 94 | return nil 95 | } 96 | 97 | func (dam *Dam) Flush() { 98 | dam.Logger.Debug("Flushing dam requested") 99 | 100 | for { 101 | dam.Logger.Debug("Flushing dam ...") 102 | select { 103 | case <-dam.close: 104 | goto end 105 | case p := <-dam.parkedProxies: 106 | dam.flushingProxies <- true 107 | go p.Flush() 108 | } 109 | } 110 | end: 111 | dam.Logger.Debug("Flushing dam done") 112 | } 113 | 114 | func (dam *Dam) Start(open bool) error { 115 | laddr, err := net.ResolveTCPAddr("tcp", dam.listenAddr) 116 | if err != nil { 117 | dam.Logger.Errorf("Can't resolve listen address: %s", err.Error()) 118 | return err 119 | } 120 | 121 | dam.listener, err = net.ListenTCP("tcp", laddr) 122 | if err != nil { 123 | dam.Logger.Errorf("Can't listen: %s", err.Error()) 124 | return err 125 | } 126 | dam.quit = make(chan bool, 1) 127 | defer dam.StopListeningSignal() 128 | go dam.ListenSignal() 129 | if open { 130 | dam.Open() 131 | } 132 | for { 133 | delay := time.Duration(1) * time.Second 134 | deadline := time.Now().Add(delay) 135 | dam.listener.SetDeadline(deadline) 136 | conn, err := dam.listener.AcceptTCP() 137 | if err != nil { 138 | if err, ok := err.(net.Error); ok && err.Timeout() { 139 | select { 140 | case <-dam.quit: 141 | dam.Logger.Debug("Received quit -> return") 142 | dam.listener.Close() 143 | dam.waitEmpty() 144 | return nil 145 | default: 146 | continue 147 | } 148 | } else { 149 | return err 150 | } 151 | } 152 | dam.Push(conn) 153 | } 154 | } 155 | 156 | func (dam *Dam) Stop() { 157 | dam.Logger.Info("Stop requested") 158 | dam.quit <- true 159 | } 160 | 161 | func (dam *Dam) waitEmpty() { 162 | dam.Logger.Debug("Wait the dam to become empty") 163 | for len(dam.flushingProxies) > 0 { 164 | dam.Logger.Debug("Wait the dam to become empty loop") 165 | time.Sleep(1 * time.Second) 166 | } 167 | dam.Logger.Debug("Wait the dam to become empty loop done") 168 | } 169 | 170 | func (dam *Dam) ListenSignal() { 171 | dam.sigs = make(chan os.Signal, 1) 172 | signal.Notify(dam.sigs, syscall.SIGUSR1, syscall.SIGUSR2, syscall.SIGTERM, syscall.SIGINT) 173 | for { 174 | sig := <-dam.sigs 175 | switch sig { 176 | case syscall.SIGTERM, syscall.SIGINT: 177 | dam.Open() 178 | dam.Stop() 179 | case syscall.SIGUSR1: 180 | dam.Open() 181 | case syscall.SIGUSR2: 182 | dam.Close() 183 | } 184 | } 185 | } 186 | 187 | func (dam *Dam) StopListeningSignal() { 188 | signal.Stop(dam.sigs) 189 | close(dam.sigs) 190 | } 191 | -------------------------------------------------------------------------------- /dam_test.go: -------------------------------------------------------------------------------- 1 | package tcpdam_test 2 | 3 | import "github.com/simkim/tcpdam" 4 | import "testing" 5 | 6 | // disclamer : I don't now how to test code in got yet ... 7 | 8 | var ( 9 | la = ":9999" 10 | ra = "example.com:80" 11 | ) 12 | 13 | func TestCreateDam(t *testing.T) { 14 | dam := tcpdam.NewDam(la, ra, 1, 1) 15 | if dam == nil { 16 | t.Errorf("Dam should not be nil") 17 | } 18 | } 19 | 20 | func TestOpeningDam(t *testing.T) { 21 | dam := tcpdam.NewDam(la, ra, 1, 1) 22 | if dam == nil { 23 | t.Errorf("Dam should not be nil") 24 | } 25 | err := dam.Open() 26 | if err != nil { 27 | t.Errorf("Can't open the dam : %s", err.Error) 28 | } 29 | } 30 | -------------------------------------------------------------------------------- /docker-compose.yml: -------------------------------------------------------------------------------- 1 | app: 2 | build: . 3 | dockerfile: Dockerfile.run 4 | ports: 5 | - "9999:9999" 6 | ulimits: 7 | nofile: 8 | soft: 1048576 9 | hard: 1048576 10 | environment: 11 | TCPDAM_REMOTE_ADDRESS: "httpbin.com:80" 12 | TCPDAM_DEBUG: "1" 13 | TCPDAM_MAX_FLUSHING: "1" 14 | -------------------------------------------------------------------------------- /proxy.go: -------------------------------------------------------------------------------- 1 | package tcpdam 2 | 3 | import ( 4 | "io" 5 | "sync" 6 | 7 | "github.com/op/go-logging" 8 | ) 9 | 10 | type Proxy struct { 11 | Lconn, Rconn io.ReadWriteCloser 12 | Dam *Dam 13 | Logger *logging.Logger 14 | } 15 | 16 | func (p *Proxy) Flush() error { 17 | p.Logger.Debug("Flush connection") 18 | defer p.Lconn.Close() 19 | defer p.Dam.Flushed(p) 20 | Rconn, err := p.Dam.Dial() 21 | if err != nil { 22 | return err 23 | } 24 | p.Rconn = Rconn 25 | 26 | defer p.Rconn.Close() 27 | 28 | var wg sync.WaitGroup 29 | 30 | wg.Add(1) 31 | go func() { 32 | io.Copy(p.Lconn, p.Rconn) 33 | p.Lconn.Close() 34 | wg.Done() 35 | }() 36 | 37 | wg.Add(1) 38 | go func() { 39 | io.Copy(p.Rconn, p.Lconn) 40 | p.Rconn.Close() 41 | wg.Done() 42 | }() 43 | 44 | wg.Wait() 45 | p.Logger.Debug("Flushing connection done") 46 | return nil 47 | } 48 | 49 | func (p *Proxy) Start() { 50 | // Should slowly read and buffer Lconn to not timeout 51 | } 52 | -------------------------------------------------------------------------------- /socket.go: -------------------------------------------------------------------------------- 1 | package tcpdam 2 | 3 | import ( 4 | "net" 5 | "os" 6 | "strings" 7 | ) 8 | 9 | func (dam *Dam) executeCommand(args []string) { 10 | switch args[0] { 11 | case "open": 12 | dam.Open() 13 | case "close": 14 | dam.Close() 15 | case "set-remote": 16 | if len(args) > 1 { 17 | dam.SetRemoteAddr(args[1]) 18 | } else { 19 | dam.Logger.Errorf("Missing argument for %s", args[0]) 20 | } 21 | default: 22 | dam.Logger.Errorf("Command not found: %s", args[0]) 23 | } 24 | } 25 | 26 | func (dam *Dam) StartControlSocket(path string) { 27 | dam.Logger.Debugf("Starting control socket at %s", path) 28 | l, err := net.ListenUnix("unix", &net.UnixAddr{Name: path, Net: "unix"}) 29 | if err != nil { 30 | panic(err) 31 | } 32 | defer os.Remove(path) 33 | 34 | for { 35 | conn, err := l.AcceptUnix() 36 | if err != nil { 37 | panic(err) 38 | } 39 | var buf [1024]byte 40 | n, err := conn.Read(buf[:]) 41 | if err != nil { 42 | panic(err) 43 | } 44 | args := strings.Split(strings.TrimSpace(string(buf[:n])), " ") 45 | dam.executeCommand(args) 46 | conn.Close() 47 | } 48 | } 49 | 50 | func SendControlCommand(path string, command string) error { 51 | conn, err := net.DialUnix("unix", nil, 52 | &net.UnixAddr{Name: path, Net: "unix"}) 53 | if err != nil { 54 | return err 55 | } 56 | defer conn.Close() 57 | 58 | _, err = conn.Write([]byte(command)) 59 | return err 60 | } 61 | --------------------------------------------------------------------------------