[medium] discover endpoint IP addresses, both local and public (via stun)

Makefile

@@ -100,6 +100,7 @@ go_get_deps:
 	$(GOGETTER) camlistore.org/pkg/misc/gpgagent
 	$(GOGETTER) camlistore.org/pkg/misc/pinentry
 	$(GOGETTER) github.com/bobappleyard/readline
+	$(GOGETTER) github.com/ccding/go-stun/stun
 ifeq ($(OS),windows)
 	$(GOGETTER) code.google.com/p/winsvc/eventlog
 endif

conf/mig-agent-conf.go.inc

@@ -16,6 +16,9 @@ var ISIMMORTAL bool = true
 // request installing of a service to start the agent at boot
 var MUSTINSTALLSERVICE bool = true
 
+// attempt to discover the public IP of the endpoint by querying a STUN server
+var DISCOVERPUBLICIP = false
+
 var LOGGINGCONF = mig.Logging{
 	Mode:	"stdout",	// stdout | file | syslog
 	Level:	"debug",	// debug | info | ...

conf/mig-agent.cfg.inc

@@ -1,12 +1,13 @@
 ; Sample MIG Agent configuration file
 
 [agent]
-    isimmortal      = on
-    installservice  = on
-    relay           = "amqp://guest:guest@localhost:5672/"
-    socket          = "127.0.0.1:51664"
-    heartbeatfreq   = "300s"
-    moduletimeout   = "300s"
+    isimmortal       = on
+    installservice   = on
+    discoverpublicip = off
+    relay            = "amqp://guest:guest@localhost:5672/"
+    socket           = "127.0.0.1:51664"
+    heartbeatfreq    = "300s"
+    moduletimeout    = "300s"
 
 [certs]
     ca  = "/path/to/ca/cert"

src/mig/agent.go

@@ -23,11 +23,20 @@ type Agent struct {
 }
 
 type AgentEnv struct {
-	Init      string `json:"init,omitempty"`
-	Ident     string `json:"ident,omitempty"`
-	Arch      string `json:"arch,omitempty"`
-	IsProxied bool   `json:"isproxied"`
-	Proxy     string `json:"proxy,omitempty"`
+	Init      string   `json:"init,omitempty"`
+	Ident     string   `json:"ident,omitempty"`
+	Arch      string   `json:"arch,omitempty"`
+	IsProxied bool     `json:"isproxied"`
+	Proxy     string   `json:"proxy,omitempty"`
+	Addresses []string `json:"addresses,omitempty"`
+	NAT       NAT      `json:"nat,omitempty"`
+}
+
+// NAT stores Network Address Translation information of an endpoint
+type NAT struct {
+	IP         string `json:"ip,omitempty"`
+	Result     string `json:"result,omitempty"`
+	StunServer string `json:"stunserver,omitempty"`
 }
 
 // findHostname retrieves the hostname of the node

src/mig/agent/context.go

@@ -136,6 +136,18 @@ func Init(foreground, upgrade bool) (ctx Context, err error) {
 	if err != nil {
 		panic(err)
 	}
+	ctx, err = findLocalIPs(ctx)
+	if err != nil {
+		panic(err)
+	}
+
+	// Attempt to discover the public IP by querying a STUN server
+	if DISCOVERPUBLICIP {
+		ctx, err = findNATviaStun(ctx)
+		if err != nil {
+			panic(err)
+		}
+	}
 
 	// find the run directory
 	ctx.Agent.RunDir = getRunDir()

src/mig/agent/env.go

@@ -0,0 +1,95 @@
+// This Source Code Form is subject to the terms of the Mozilla Public
+// License, v. 2.0. If a copy of the MPL was not distributed with this
+// file, You can obtain one at http://mozilla.org/MPL/2.0/.
+//
+// Contributor:
+// - Julien Vehent jvehent@mozilla.com [:ulfr]
+package main
+
+import (
+	"fmt"
+	"mig"
+	"net"
+
+	"github.com/ccding/go-stun/stun"
+)
+
+func findLocalIPs(orig_ctx Context) (ctx Context, err error) {
+	ctx = orig_ctx
+	// grab the local ip addresses
+	addresses, err := net.InterfaceAddrs()
+	if err != nil {
+		panic(err)
+	}
+	for _, addr := range addresses {
+		if addr.String() == "127.0.0.1/8" || addr.String() == "::1/128" {
+			continue
+		}
+		ctx.Agent.Env.Addresses = append(ctx.Agent.Env.Addresses, addr.String())
+		ctx.Channels.Log <- mig.Log{Desc: fmt.Sprintf("Found local address %s", addr.String())}.Debug()
+	}
+	return
+}
+
+var stunHosts = map[string]int{
+	"stun01.sipphone.com": 3478,
+	"stun.ekiga.net":      3478,
+	"stun.fwdnet.net":     3478,
+	"stun.ideasip.com":    3478,
+	"stun.iptel.org":      3478,
+	"stun.rixtelecom.se":  3478,
+	"stun.schlund.de":     3478,
+	"stunserver.org":      3478,
+	"stun.softjoys.com":   3478,
+	"stun.voiparound.com": 3478,
+	"stun.voipbuster.com": 3478,
+	"stun.voipstunt.com":  3478,
+	"stun.voxgratia.org":  3478,
+	"stun.xten.com":       3478,
+}
+var maxStunLookups = 3
+
+func findNATviaStun(orig_ctx Context) (ctx Context, err error) {
+	ctx = orig_ctx
+	ctr := 0
+	for stunSrv, stunPort := range stunHosts {
+		stun.SetServerHost(stunSrv, stunPort)
+		nat, host, err := stun.Discover()
+		if err != nil {
+			ctx.Channels.Log <- mig.Log{Desc: fmt.Sprintf("STUN discovery failed against %s:%d with error '%v'", stunSrv, stunPort, err)}.Debug()
+		}
+		switch nat {
+		case stun.NAT_ERROR:
+			ctx.Agent.Env.NAT.Result = "Test failed"
+		case stun.NAT_UNKNOWN:
+			ctx.Agent.Env.NAT.Result = "Unexpected response from the STUN server"
+		case stun.NAT_BLOCKED:
+			ctx.Agent.Env.NAT.Result = "UDP is blocked"
+		case stun.NAT_FULL:
+			ctx.Agent.Env.NAT.Result = "Full cone NAT"
+		case stun.NAT_SYMETRIC:
+			ctx.Agent.Env.NAT.Result = "Symetric NAT"
+		case stun.NAT_RESTRICTED:
+			ctx.Agent.Env.NAT.Result = "Restricted NAT"
+		case stun.NAT_PORT_RESTRICTED:
+			ctx.Agent.Env.NAT.Result = "Port restricted NAT"
+		case stun.NAT_NONE:
+			ctx.Agent.Env.NAT.Result = "Not behind a NAT"
+		case stun.NAT_SYMETRIC_UDP_FIREWALL:
+			ctx.Agent.Env.NAT.Result = "Symetric UDP firewall"
+		default:
+			ctx.Agent.Env.NAT.Result = "Unknown"
+		}
+		if host != nil {
+			ctx.Agent.Env.NAT.IP = host.Ip()
+			ctx.Agent.Env.NAT.StunServer = fmt.Sprintf("%s:%d", stunSrv, stunPort)
+			break
+		}
+		ctr++
+		if ctr == 3 {
+			ctx.Agent.Env.NAT.Result = "Max lookups reached without results"
+			break
+		}
+	}
+	return
+}

src/mig/agent/env_linux.go

@@ -53,8 +53,10 @@ func findOSInfo(orig_ctx Context) (ctx Context, err error) {
 	}()
 	ctx.Agent.OS = runtime.GOOS
 	ctx.Channels.Log <- mig.Log{Desc: fmt.Sprintf("OS is %s", ctx.Agent.OS)}.Debug()
+
 	ctx.Agent.Env.Arch = runtime.GOARCH
 	ctx.Channels.Log <- mig.Log{Desc: fmt.Sprintf("Arch is %s", ctx.Agent.Env.Arch)}.Debug()
+
 	ctx.Agent.Env.Ident, err = getLSBRelease()
 	if err != nil {
 		ctx.Channels.Log <- mig.Log{Desc: fmt.Sprintf("getLSBRelease() failed: %v", err)}.Info()
@@ -64,11 +66,13 @@ func findOSInfo(orig_ctx Context) (ctx Context, err error) {
 		}
 	}
 	ctx.Channels.Log <- mig.Log{Desc: fmt.Sprintf("Ident is %s", ctx.Agent.Env.Ident)}.Debug()
+
 	ctx.Agent.Env.Init, err = getInit()
 	if err != nil {
 		panic(err)
 	}
 	ctx.Channels.Log <- mig.Log{Desc: fmt.Sprintf("Init is %s", ctx.Agent.Env.Init)}.Debug()
+
 	return
 }