Allow setting listen address & read parameter from ENV

proxy/bird.go

@@ -0,0 +1,100 @@
+package main
+
+import (
+    "io"
+    "net"
+    "net/http"
+    "sync"
+)
+
+// BIRDv4 connection & mutex lock
+var bird net.Conn
+var birdMutex = &sync.Mutex{}
+
+// BIRDv6 connection & mutex lock
+var bird6 net.Conn
+var bird6Mutex = &sync.Mutex{}
+
+// Read a line from bird socket, removing preceding status number, output it.
+// Returns if there are more lines.
+func birdReadln(bird io.Reader, w io.Writer) bool {
+    // Read from socket byte by byte, until reaching newline character
+    c := make([]byte, 1024, 1024)
+    pos := 0
+    for {
+        if pos >= 1024 { break }
+        _, err := bird.Read(c[pos:pos+1])
+        if err != nil {
+            panic(err)
+        }
+        if c[pos] == byte('\n') {
+            break
+        }
+        pos++
+    }
+
+    c = c[:pos+1]
+    // print(string(c[:]))
+
+    // Remove preceding status number, different situations
+    if pos < 4 {
+        // Line is too short to have a status number
+        if w != nil {
+            pos = 0
+            for c[pos] == byte(' ') { pos++ }
+            w.Write(c[pos:])
+        }
+        return true
+    } else if isNumeric(c[0]) && isNumeric(c[1]) && isNumeric(c[2]) && isNumeric(c[3]) {
+        // There is a status number at beginning, remove first 5 bytes
+        if w != nil && pos > 6 {
+            pos = 5
+            for c[pos] == byte(' ') { pos++ }
+            w.Write(c[pos:])
+        }
+        return c[0] != byte('0') && c[0] != byte('8') && c[0] != byte('9')
+    } else {
+        // There is no status number, only remove preceding spaces
+        if w != nil {
+            pos = 0
+            for c[pos] == byte(' ') { pos++ }
+            w.Write(c[pos:])
+        }
+        return true
+    }
+}
+
+// Write a command to a bird socket
+func birdWriteln(bird io.Writer, s string) {
+    bird.Write([]byte(s + "\n"))
+}
+
+// Handles BIRDv4 queries
+func birdHandler(httpW http.ResponseWriter, httpR *http.Request) {
+    query := string(httpR.URL.Query().Get("q"))
+    if query == "" {
+        invalidHandler(httpW, httpR)
+    } else {
+        birdMutex.Lock()
+        defer birdMutex.Unlock()
+
+        println(query)
+        birdWriteln(bird, query)
+        for birdReadln(bird, httpW) {}
+    }
+}
+
+// Handles BIRDv6 queries
+func bird6Handler(httpW http.ResponseWriter, httpR *http.Request) {
+    query := string(httpR.URL.Query().Get("q"))
+    if query == "" {
+        invalidHandler(httpW, httpR)
+    } else {
+        bird6Mutex.Lock()
+        defer bird6Mutex.Unlock()
+
+        println(query)
+        birdWriteln(bird6, query)
+        for birdReadln(bird6, httpW) {}
+    }
+}

proxy/main.go

@@ -1,187 +1,50 @@
 package main
 
 import (
-    "io"
     "net"
     "net/http"
-    "sync"
-    "runtime"
-    "os/exec"
     "flag"
+    "os"
 )
 
-// BIRDv4 connection & mutex lock
-var bird net.Conn
-var birdMutex = &sync.Mutex{}
-
-// BIRDv6 connection & mutex lock
-var bird6 net.Conn
-var bird6Mutex = &sync.Mutex{}
-
 // Check if a byte is character for number
 func isNumeric(b byte) bool {
     return b >= byte('0') && b <= byte('9')
 }
 
-// Read a line from bird socket, removing preceding status number, output it.
-// Returns if there are more lines.
-func birdReadln(bird io.Reader, w io.Writer) bool {
-    // Read from socket byte by byte, until reaching newline character
-    c := make([]byte, 1024, 1024)
-    pos := 0
-    for {
-        if pos >= 1024 { break }
-        _, err := bird.Read(c[pos:pos+1])
-        if err != nil {
-            panic(err)
-        }
-        if c[pos] == byte('\n') {
-            break
-        }
-        pos++
-    }
-
-    c = c[:pos+1]
-    // print(string(c[:]))
-
-    // Remove preceding status number, different situations
-    if pos < 4 {
-        // Line is too short to have a status number
-        if w != nil {
-            pos = 0
-            for c[pos] == byte(' ') { pos++ }
-            w.Write(c[pos:])
-        }
-        return true
-    } else if isNumeric(c[0]) && isNumeric(c[1]) && isNumeric(c[2]) && isNumeric(c[3]) {
-        // There is a status number at beginning, remove first 5 bytes
-        if w != nil && pos > 6 {
-            pos = 5
-            for c[pos] == byte(' ') { pos++ }
-            w.Write(c[pos:])
-        }
-        return c[0] != byte('0') && c[0] != byte('8') && c[0] != byte('9')
-    } else {
-        // There is no status number, only remove preceding spaces
-        if w != nil {
-            pos = 0
-            for c[pos] == byte(' ') { pos++ }
-            w.Write(c[pos:])
-        }
-        return true
-    }
-}
-
-// Write a command to a bird socket
-func birdWriteln(bird io.Writer, s string) {
-    bird.Write([]byte(s + "\n"))
-}
-
 // Default handler, returns 500 Internal Server Error
 func invalidHandler(httpW http.ResponseWriter, httpR *http.Request) {
     httpW.WriteHeader(http.StatusInternalServerError)
     httpW.Write([]byte("Invalid Request\n"))
 }
 
-// Handles BIRDv4 queries
+// Wrapper of tracer
-func birdHandler(httpW http.ResponseWriter, httpR *http.Request) {
-    query := string(httpR.URL.Query().Get("q"))
-    if query == "" {
-        invalidHandler(httpW, httpR)
-    } else {
-        birdMutex.Lock()
-        defer birdMutex.Unlock()
-
-        println(query)
-        birdWriteln(bird, query)
-        for birdReadln(bird, httpW) {}
-    }
-}
-
-// Handles BIRDv6 queries
-func bird6Handler(httpW http.ResponseWriter, httpR *http.Request) {
-    query := string(httpR.URL.Query().Get("q"))
-    if query == "" {
-        invalidHandler(httpW, httpR)
-    } else {
-        bird6Mutex.Lock()
-        defer bird6Mutex.Unlock()
-
-        println(query)
-        birdWriteln(bird6, query)
-        for birdReadln(bird6, httpW) {}
-    }
-}
-
-// Wrapper of traceroute, IPv4
-func tracerouteIPv4Wrapper(httpW http.ResponseWriter, httpR *http.Request) {
-    tracerouteRealHandler(false, httpW, httpR)
-}
-
-// Wrapper of traceroute, IPv6
-func tracerouteIPv6Wrapper(httpW http.ResponseWriter, httpR *http.Request) {
-    tracerouteRealHandler(true, httpW, httpR)
-}
-
-// Real handler of traceroute requests
-func tracerouteRealHandler(useIPv6 bool, httpW http.ResponseWriter, httpR *http.Request) {
-    query := string(httpR.URL.Query().Get("q"))
-    if query == "" {
-        invalidHandler(httpW, httpR)
-    } else {
-        var cmd string
-        var args []string
-        if runtime.GOOS == "freebsd" || runtime.GOOS == "netbsd" {
-            if useIPv6 { cmd = "traceroute6" } else { cmd = "traceroute" }
-            args = []string{"-a", "-q1", "-w1", "-m15", query}
-        } else if runtime.GOOS == "openbsd" {
-            if useIPv6 { cmd = "traceroute6" } else { cmd = "traceroute" }
-            args = []string{"-A", "-q1", "-w1", "-m15", query}
-        } else if runtime.GOOS == "linux" {
-            cmd = "traceroute"
-            if useIPv6 {
-                args = []string{"-6", "-A", "-q1", "-N32", "-w1", "-m15", query}
-            } else {
-                args = []string{"-4", "-A", "-q1", "-N32", "-w1", "-m15", query}
-            }
-        } else {
-            httpW.WriteHeader(http.StatusInternalServerError)
-            httpW.Write([]byte("Traceroute Not Supported\n"))
-            return
-        }
-        instance := exec.Command(cmd, args...)
-        output, err := instance.Output()
-        if err != nil && runtime.GOOS == "linux" {
-            // Standard traceroute utility failed, maybe system using busybox
-            // Run with less parameters
-            cmd = "traceroute"
-            if useIPv6 {
-                args = []string{"-6", "-q1", "-w1", "-m15", query}
-            } else {
-                args = []string{"-4", "-q1", "-w1", "-m15", query}
-            }
-            instance = exec.Command(cmd, args...)
-            output, err = instance.Output()
-        }
-        if err != nil {
-            httpW.WriteHeader(http.StatusInternalServerError)
-            httpW.Write([]byte("Traceroute Execution Error: "))
-            httpW.Write([]byte(err.Error() + "\n"))
-            return
-        }
-        httpW.Write(output)
-    }
-}
-
 func main() {
     var err error
 
-    birdPtr := flag.String("bird", "/var/run/bird/bird.ctl", "socket file for bird")
+    // Prepare default socket paths, use environment variable if possible
-    bird6Ptr := flag.String("bird6", "/var/run/bird/bird6.ctl", "socket file for bird6")
+    birdSocketDefault := "/var/run/bird/bird.ctl"
+    bird6SocketDefault := "/var/run/bird/bird6.ctl"
+    listenDefault := ":8000"
+
+    if birdSocketEnv := os.Getenv("BIRD_SOCKET"); birdSocketEnv != "" {
+        birdSocketDefault = birdSocketEnv
+    }
+    if bird6SocketEnv := os.Getenv("BIRD6_SOCKET"); bird6SocketEnv != "" {
+        bird6SocketDefault = bird6SocketEnv
+    }
+    if listenEnv := os.Getenv("BIRDLG_LISTEN"); listenEnv != "" {
+        listenDefault = listenEnv
+    }
+
+    // Allow parameters to override environment variables
+    birdParam := flag.String("bird", birdSocketDefault, "socket file for bird, set either in parameter or environment variable BIRD_SOCKET")
+    bird6Param := flag.String("bird6", bird6SocketDefault, "socket file for bird6, set either in parameter or environment variable BIRD6_SOCKET")
+    listenParam := flag.String("listen", listenDefault, "listen address, set either in parameter or environment variable BIRDLG_LISTEN")
     flag.Parse()
 
     // Initialize BIRDv4 socket
-    bird, err = net.Dial("unix", *birdPtr)
+    bird, err = net.Dial("unix", *birdParam)
     if err != nil {
         panic(err)
     }
@@ -192,7 +55,7 @@ func main() {
     birdReadln(bird, nil)
 
     // Initialize BIRDv6 socket
-    bird6, err = net.Dial("unix", *bird6Ptr)
+    bird6, err = net.Dial("unix", *bird6Param)
     if err != nil {
         panic(err)
     }
@@ -208,5 +71,5 @@ func main() {
     http.HandleFunc("/bird6", bird6Handler)
     http.HandleFunc("/traceroute", tracerouteIPv4Wrapper)
     http.HandleFunc("/traceroute6", tracerouteIPv6Wrapper)
-    http.ListenAndServe(":8000", nil)
+    http.ListenAndServe(*listenParam, nil)
 }

proxy/traceroute.go

@@ -0,0 +1,67 @@
+package main
+
+import (
+    "net/http"
+    "runtime"
+    "os/exec"
+)
+
+// Wrapper of traceroute, IPv4
+func tracerouteIPv4Wrapper(httpW http.ResponseWriter, httpR *http.Request) {
+    tracerouteRealHandler(false, httpW, httpR)
+}
+
+// Wrapper of traceroute, IPv6
+func tracerouteIPv6Wrapper(httpW http.ResponseWriter, httpR *http.Request) {
+    tracerouteRealHandler(true, httpW, httpR)
+}
+
+// Real handler of traceroute requests
+func tracerouteRealHandler(useIPv6 bool, httpW http.ResponseWriter, httpR *http.Request) {
+    query := string(httpR.URL.Query().Get("q"))
+    if query == "" {
+        invalidHandler(httpW, httpR)
+    } else {
+        var cmd string
+        var args []string
+        if runtime.GOOS == "freebsd" || runtime.GOOS == "netbsd" {
+            if useIPv6 { cmd = "traceroute6" } else { cmd = "traceroute" }
+            args = []string{"-a", "-q1", "-w1", "-m15", query}
+        } else if runtime.GOOS == "openbsd" {
+            if useIPv6 { cmd = "traceroute6" } else { cmd = "traceroute" }
+            args = []string{"-A", "-q1", "-w1", "-m15", query}
+        } else if runtime.GOOS == "linux" {
+            cmd = "traceroute"
+            if useIPv6 {
+                args = []string{"-6", "-A", "-q1", "-N32", "-w1", "-m15", query}
+            } else {
+                args = []string{"-4", "-A", "-q1", "-N32", "-w1", "-m15", query}
+            }
+        } else {
+            httpW.WriteHeader(http.StatusInternalServerError)
+            httpW.Write([]byte("Traceroute Not Supported\n"))
+            return
+        }
+        instance := exec.Command(cmd, args...)
+        output, err := instance.Output()
+        if err != nil && runtime.GOOS == "linux" {
+            // Standard traceroute utility failed, maybe system using busybox
+            // Run with less parameters
+            cmd = "traceroute"
+            if useIPv6 {
+                args = []string{"-6", "-q1", "-w1", "-m15", query}
+            } else {
+                args = []string{"-4", "-q1", "-w1", "-m15", query}
+            }
+            instance = exec.Command(cmd, args...)
+            output, err = instance.Output()
+        }
+        if err != nil {
+            httpW.WriteHeader(http.StatusInternalServerError)
+            httpW.Write([]byte("Traceroute Execution Error: "))
+            httpW.Write([]byte(err.Error() + "\n"))
+            return
+        }
+        httpW.Write(output)
+    }
+}