Merge pull request #268 from djs55/iptables-for-master

Add the piñata-ga iptables wrapper

alpine/Dockerfile

@@ -75,6 +75,7 @@ COPY packages/9pmount-vsock/9pmount-vsock /sbin
 COPY packages/test/etc /etc
 COPY packages/test/mobytest /usr/bin
 COPY packages/sysctl/etc /etc
+COPY packages/iptables/iptables /usr/local/sbin/iptables
 
 RUN \
   rc-update add swap boot && \

alpine/packages/Makefile

@@ -10,6 +10,7 @@ all:
 	$(MAKE) -C llmnrd OS=linux
 	$(MAKE) -C gummiboot OS=linux
 	$(MAKE) -C 9pmount-vsock OS=linux
+	$(MAKE) -C iptables OS=linux
 
 arm:
 	$(MAKE) -C transfused OS=linux ARCH=arm
@@ -33,3 +34,4 @@ clean:
 	$(MAKE) -C llmnrd clean
 	$(MAKE) -C gummiboot clean
 	$(MAKE) -C 9pmount-vsock clean
+	$(MAKE) -C iptables clean

alpine/packages/docker/etc/init.d/docker

@@ -60,6 +60,9 @@ start()
 
 	DOCKER_LOGFILE="/var/log/docker.log"
 
+	# Allow iptables to be overriden
+	export PATH=/usr/local/sbin:$PATH
+
 	start-stop-daemon --start --quiet \
 		--background \
 		--exec ${command} \

alpine/packages/iptables/.gitignore

@@ -0,0 +1 @@
+iptables

alpine/packages/iptables/Dockerfile

@@ -0,0 +1,7 @@
+FROM ocaml/opam:alpine
+RUN sudo apk add m4
+RUN opam install ocamlfind astring -y
+WORKDIR /app
+ADD . /app
+RUN sudo chown -R opam /app
+RUN opam config exec -- ocamlfind ocamlopt -package unix,astring -linkpkg -o iptables main.ml

alpine/packages/iptables/Makefile

@@ -0,0 +1,9 @@
+all: iptables
+
+iptables: Dockerfile main.ml
+	docker build -t iptables:build .
+	docker run --rm iptables:build cat /app/iptables > iptables
+	chmod 755 iptables
+
+clean:
+	docker images -q iptables:build | xargs docker rmi -f || true

alpine/packages/iptables/main.ml

@@ -0,0 +1,100 @@
+(* ocamlfind ocamlopt -package unix,astring -linkpkg -o iptables iptables.ml *)
+
+(*
+--wait -t nat -I DOCKER-INGRESS -p tcp --dport 80 -j DNAT --to-destination 172.18.0.2:80
+--wait -t nat -D DOCKER-INGRESS -p tcp --dport 80 -j DNAT --to-destination 172.18.0.2:80
+*)
+
+let _iptables = "/sbin/iptables"
+let _proxy = "/usr/bin/docker-proxy"
+let _pid_dir = "/var/run/service-port-opener"
+
+type port = {
+  proto: string;
+  dport: string; (* host port *)
+  ip:    string; (* container ip *)
+  port:  string; (* container port *)
+}
+
+let log_fd = Unix.openfile "/var/log/service-port-opener.log" [ Unix.O_WRONLY; Unix.O_APPEND; Unix.O_CREAT ] 0o0644
+
+let logf fmt =
+  Printf.ksprintf (fun s ->
+    let s = s ^ "\n" in
+    let rec loop ofs remaining =
+      if remaining > 0 then begin
+        let n = Unix.write log_fd s ofs remaining in
+        loop (ofs + n) (remaining - n)
+      end in
+    loop 0 (String.length s)
+  ) fmt
+
+let pid_filename { proto; dport; ip; port } =
+  Printf.sprintf "%s/%s.%s.%s.%s.pid" _pid_dir proto dport ip port
+
+let insert ({ proto; dport; ip; port } as p) =
+  let filename = pid_filename p in
+  logf "insert: creating a proxy for %s" filename;
+  let args = [ _proxy; "-proto"; proto; "-container-ip"; ip; "-container-port"; port; "-host-ip"; "0.0.0.0"; "-host-port"; dport; "-i"; "-no-local-ip" ] in
+  let pid = Unix.fork () in
+  if pid == 0 then begin
+    logf "binary = %s args = %s" _proxy (String.concat "; " args);
+    (* Close the vast number of fds I've inherited from docker *)
+    (* TODO(djs55): revisit, possibly by filing a docker/docker issue *)
+    for i = 0 to 1023 do
+      let fd : Unix.file_descr = Obj.magic i in
+      try Unix.close fd with Unix.Unix_error(Unix.EBADF, _, _) -> ()
+    done;
+    let null = Unix.openfile "/dev/null" [ Unix.O_RDWR ] 0 in
+    Unix.dup2 null Unix.stdin;
+    Unix.dup2 null Unix.stdout;
+    Unix.dup2 null Unix.stderr;
+    (try Unix.execv _proxy (Array.of_list args) with e -> logf "Failed with %s" (Printexc.to_string e));
+    exit 1
+  end else begin
+    (* write pid to a file (not atomically) *)
+    let oc = open_out filename in
+    output_string oc (string_of_int pid);
+    close_out oc
+  end
+
+let delete ({ proto; dport; ip; port } as p) =
+  let filename = pid_filename p in
+  logf "delete: removing a proxy for %s" filename;
+  (* read the pid from a file *)
+  try
+    let ic = open_in filename in
+    let pid = int_of_string (input_line ic) in
+    logf "Sending SIGTERM to %d" pid;
+    Unix.kill pid Sys.sigterm;
+    Unix.unlink filename
+  with e ->
+    logf "delete: failed to remove proxy for %s: %s" filename (Printexc.to_string e);
+    ()
+
+let parse_ip_port ip_port = match Astring.String.cut ~sep:":" ip_port with
+  | None ->
+    failwith ("Failed to parse <ip:port>:" ^ ip_port)
+  | Some (ip, port) ->
+    ip, port
+
+let _ =
+  ( try Unix.mkdir _pid_dir 0o0755 with Unix.Unix_error(Unix.EEXIST, _, _) -> () );
+  let port_forwarding =
+    try
+      let ic = open_in "/Database/branch/master/ro/com.docker.driver.amd64-linux/native/port-forwarding" in
+      bool_of_string (String.trim (input_line ic))
+    with _ -> false in
+  logf "port_forwarding=%b intercepted arguments [%s]" port_forwarding (String.concat "; " (Array.to_list Sys.argv));
+  if port_forwarding then begin
+    match Array.to_list Sys.argv with
+    | [ _; "--wait"; "-t"; "nat"; "-I"; "DOCKER-INGRESS"; "-p"; proto; "--dport"; dport; "-j"; "DNAT"; "--to-destination"; ip_port ] ->
+      let ip, port = parse_ip_port ip_port in
+      insert { proto; dport; ip; port }
+    | [ _; "--wait"; "-t"; "nat"; "-D"; "DOCKER-INGRESS"; "-p"; proto; "--dport"; dport; "-j"; "DNAT"; "--to-destination"; ip_port ] ->
+      let ip, port = parse_ip_port ip_port in
+      delete { proto; dport; ip; port }
+    | _ ->
+      ()
+  end;
+  Unix.execv _iptables Sys.argv

alpine/packages/proxy/one.go

@@ -11,22 +11,31 @@ import (
 )
 
 func onePort() {
-	host, _, container := parseHostContainerAddrs()
+	host, _, container, localIP := parseHostContainerAddrs()
 
-	ipP, err := libproxy.NewIPProxy(host, container)
+	var ipP libproxy.Proxy
+	var err error
+
+	if localIP {
+		ipP, err = libproxy.NewIPProxy(host, container)
 		if err != nil {
 			sendError(err)
 		}
+	}
 
 	ctl, err := exposePort(host, container)
 	if err != nil {
 		sendError(err)
 	}
 
-	go handleStopSignals(ipP)
+	go handleStopSignals()
 	// TODO: avoid this line if we are running in a TTY
 	sendOK()
+	if ipP != nil {
 		ipP.Run()
+        } else {
+		select{} // sleep forever
+        }
 	ctl.Close() // ensure ctl remains alive and un-GCed until here
 	os.Exit(0)
 }

alpine/packages/proxy/proxy.go

@@ -8,8 +8,6 @@ import (
 	"os"
 	"os/signal"
 	"syscall"
-
-	"proxy/libproxy"
 )
 
 var interactiveMode bool
@@ -48,7 +46,7 @@ var vSockUDPPortOffset = 0x20000
 
 // parseHostContainerAddrs parses the flags passed on reexec to create the TCP or UDP
 // net.Addrs to map the host and container ports
-func parseHostContainerAddrs() (host net.Addr, port int, container net.Addr) {
+func parseHostContainerAddrs() (host net.Addr, port int, container net.Addr, localIP bool) {
 	var (
 		proto         = flag.String("proto", "tcp", "proxy protocol")
 		hostIP        = flag.String("host-ip", "", "host ip")
@@ -56,6 +54,7 @@ func parseHostContainerAddrs() (host net.Addr, port int, container net.Addr) {
 		containerIP   = flag.String("container-ip", "", "container ip")
 		containerPort = flag.Int("container-port", -1, "container port")
 		interactive   = flag.Bool("i", false, "print success/failure to stdout/stderr")
+		noLocalIP     = flag.Bool("no-local-ip", false, "bind only on the Host, not in the VM")
 	)
 
 	flag.Parse()
@@ -73,17 +72,15 @@ func parseHostContainerAddrs() (host net.Addr, port int, container net.Addr) {
 	default:
 		log.Fatalf("unsupported protocol %s", *proto)
 	}
-
-	return host, port, container
+	localIP = ! *noLocalIP
+	return host, port, container, localIP
 }
 
-func handleStopSignals(p libproxy.Proxy) {
+func handleStopSignals() {
 	s := make(chan os.Signal, 10)
 	signal.Notify(s, os.Interrupt, syscall.SIGTERM, syscall.SIGSTOP)
 
 	for range s {
 		os.Exit(0)
-		// The vsock proxy cannot be shutdown the same way as the TCP one:
-		//p.Close()
 	}
 }