tweak to allow use of CIDR network masks for proxy

.drone.yml

@@ -23,21 +23,14 @@ steps:
     - go vet
     - go build
 
- - name: stage
-   image: alpine
-   commands:
-    - mkdir artifacts
-    - mv frontend/frontend artifacts/
-    - mv proxy/proxy artifacts/
-    - tar -cvzf bird-lg-go.bdn42.tar.gz -C artifacts .
-
  - name: upload artifacts
    image: git.burble.dn42/burble.dn42/drone-gitea-pkg-plugin:latest
    settings:
      token:
        from_secret: TOKEN
      version: RELEASE
-     artifact: bird-lg-go.bdn42.tar.gz
+     artifact: proxy
+     filename: proxy/proxy
      package: bird-lg-go
      owner: burble.dn42
 

README.md

@@ -127,7 +127,7 @@ Configuration is handled by [viper](https://github.com/spf13/viper), any config
 
 | Config Key | Parameter | Environment Variable | Description |
 | ---------- | --------- | -------------------- | ----------- |
-| allowed_ips | --allowed | ALLOWED_IPS | IPs allowed to access this proxy, separated by commas. Don't set to allow all IPs. (default "") |
+| allowed_ips | --allowed | ALLOWED_IPS | IPs or networks allowed to access this proxy, separated by commas. Don't set to allow all IPs. (default "") |
 | bird_socket | --bird | BIRD_SOCKET | socket file for bird, set either in parameter or environment variable BIRD_SOCKET (default "/var/run/bird/bird.ctl") |
 | listen | --listen | BIRDLG_PROXY_PORT | listen address, set either in parameter or environment variable  BIRDLG_PROXY_PORT(default "8000") |
 | traceroute_bin | --traceroute_bin | BIRDLG_TRACEROUTE_BIN | traceroute binary file, set either in parameter or environment variable  BIRDLG_TRACEROUTE_BIN |

proxy/main.go

@@ -22,8 +22,8 @@ func invalidHandler(httpW http.ResponseWriter, httpR *http.Request) {
 }
 
 func hasAccess(remoteAddr string) bool {
-	// setting.allowedIPs will always have at least one element because of how it's defined
+	// setting.allowedNets will always have at least one element because of how it's defined
-	if len(setting.allowedIPs) == 0 {
+	if len(setting.allowedNets) == 0 {
 		return true
 	}
 
@@ -40,8 +40,8 @@ func hasAccess(remoteAddr string) bool {
 		return false
 	}
 
-	for _, allowedIP := range setting.allowedIPs {
+	for _, net := range setting.allowedNets {
-		if ipObject.Equal(allowedIP) {
+		if net.Contains(ipObject) {
 			return true
 		}
 	}
@@ -49,7 +49,7 @@ func hasAccess(remoteAddr string) bool {
 	return false
 }
 
-// Access handler, check to see if client IP in allowed IPs, continue if it is, send to invalidHandler if not
+// Access handler, check to see if client IP in allowed nets, continue if it is, send to invalidHandler if not
 func accessHandler(next http.Handler) http.Handler {
 	return http.HandlerFunc(func(httpW http.ResponseWriter, httpR *http.Request) {
 		if hasAccess(httpR.RemoteAddr) {
@@ -61,12 +61,12 @@ func accessHandler(next http.Handler) http.Handler {
 }
 
 type settingType struct {
-	birdSocket string
+	birdSocket  string
-	listen     string
+	listen      string
-	allowedIPs []net.IP
+	allowedNets []*net.IPNet
-	tr_bin     string
+	tr_bin      string
-	tr_flags   []string
+	tr_flags    []string
-	tr_raw     bool
+	tr_raw      bool
 }
 
 var setting settingType

proxy/main_test.go

@@ -10,42 +10,61 @@ import (
 )
 
 func TestHasAccessNotConfigured(t *testing.T) {
-	setting.allowedIPs = []net.IP{}
+	setting.allowedNets = []*net.IPNet{}
 	assert.Equal(t, hasAccess("whatever"), true)
 }
 
 func TestHasAccessAllowIPv4(t *testing.T) {
-	setting.allowedIPs = []net.IP{net.ParseIP("1.2.3.4")}
+	_, netip, _ := net.ParseCIDR("1.2.3.4/32")
+	setting.allowedNets = []*net.IPNet{netip}
+	assert.Equal(t, hasAccess("1.2.3.4:4321"), true)
+}
+
+func TestHasAccessAllowIPv4Net(t *testing.T) {
+	_, netip, _ := net.ParseCIDR("1.2.3.0/24")
+	setting.allowedNets = []*net.IPNet{netip}
 	assert.Equal(t, hasAccess("1.2.3.4:4321"), true)
 }
 
 func TestHasAccessDenyIPv4(t *testing.T) {
-	setting.allowedIPs = []net.IP{net.ParseIP("4.3.2.1")}
+	_, netip, _ := net.ParseCIDR("4.3.2.1/32")
+	setting.allowedNets = []*net.IPNet{netip}
 	assert.Equal(t, hasAccess("1.2.3.4:4321"), false)
 }
 
 func TestHasAccessAllowIPv6(t *testing.T) {
-	setting.allowedIPs = []net.IP{net.ParseIP("2001:db8::1")}
+	_, netip, _ := net.ParseCIDR("2001:db8::1/128")
+	setting.allowedNets = []*net.IPNet{netip}
+	assert.Equal(t, hasAccess("[2001:db8::1]:4321"), true)
+}
+
+func TestHasAccessAllowIPv6Net(t *testing.T) {
+	_, netip, _ := net.ParseCIDR("2001:db8::/64")
+	setting.allowedNets = []*net.IPNet{netip}
 	assert.Equal(t, hasAccess("[2001:db8::1]:4321"), true)
 }
 
 func TestHasAccessAllowIPv6DifferentForm(t *testing.T) {
-	setting.allowedIPs = []net.IP{net.ParseIP("2001:0db8::1")}
+	_, netip, _ := net.ParseCIDR("2001:db8::1/128")
+	setting.allowedNets = []*net.IPNet{netip}
 	assert.Equal(t, hasAccess("[2001:db8::1]:4321"), true)
 }
 
 func TestHasAccessDenyIPv6(t *testing.T) {
-	setting.allowedIPs = []net.IP{net.ParseIP("2001:db8::2")}
+	_, netip, _ := net.ParseCIDR("2001:db8::2/128")
+	setting.allowedNets = []*net.IPNet{netip}
 	assert.Equal(t, hasAccess("[2001:db8::1]:4321"), false)
 }
 
 func TestHasAccessBadClientIP(t *testing.T) {
-	setting.allowedIPs = []net.IP{net.ParseIP("1.2.3.4")}
+	_, netip, _ := net.ParseCIDR("1.2.3.4/32")
+	setting.allowedNets = []*net.IPNet{netip}
 	assert.Equal(t, hasAccess("not an IP"), false)
 }
 
 func TestHasAccessBadClientIPPort(t *testing.T) {
-	setting.allowedIPs = []net.IP{net.ParseIP("1.2.3.4")}
+	_, netip, _ := net.ParseCIDR("1.2.3.4/32")
+	setting.allowedNets = []*net.IPNet{netip}
 	assert.Equal(t, hasAccess("not an IP:not a port"), false)
 }
 
@@ -57,7 +76,8 @@ func TestAccessHandlerAllow(t *testing.T) {
 	r.RemoteAddr = "1.2.3.4:4321"
 	w := httptest.NewRecorder()
 
-	setting.allowedIPs = []net.IP{net.ParseIP("1.2.3.4")}
+	_, netip, _ := net.ParseCIDR("1.2.3.4/32")
+	setting.allowedNets = []*net.IPNet{netip}
 
 	wrappedHandler.ServeHTTP(w, r)
 	assert.Equal(t, w.Code, http.StatusNotFound)
@@ -71,7 +91,8 @@ func TestAccessHandlerDeny(t *testing.T) {
 	r.RemoteAddr = "1.2.3.4:4321"
 	w := httptest.NewRecorder()
 
-	setting.allowedIPs = []net.IP{net.ParseIP("4.3.2.1")}
+	_, netip, _ := net.ParseCIDR("4.3.2.1/32")
+	setting.allowedNets = []*net.IPNet{netip}
 
 	wrappedHandler.ServeHTTP(w, r)
 	assert.Equal(t, w.Code, http.StatusInternalServerError)

proxy/settings.go

@@ -13,7 +13,7 @@ import (
 type viperSettingType struct {
 	BirdSocket      string `mapstructure:"bird_socket"`
 	Listen          string `mapstructure:"listen"`
-	AllowedIPs      string `mapstructure:"allowed_ips"`
+	AllowedNets     string `mapstructure:"allowed_ips"`
 	TracerouteBin   string `mapstructure:"traceroute_bin"`
 	TracerouteFlags string `mapstructure:"traceroute_flags"`
 	TracerouteRaw   bool   `mapstructure:"traceroute_raw"`
@@ -40,7 +40,7 @@ func parseSettings() {
 	pflag.String("listen", "8000", "listen address, set either in parameter or environment variable BIRDLG_PROXY_PORT")
 	viper.BindPFlag("listen", pflag.Lookup("listen"))
 
-	pflag.String("allowed", "", "IPs allowed to access this proxy, separated by commas. Don't set to allow all IPs.")
+	pflag.String("allowed", "", "IPs or networks allowed to access this proxy, separated by commas. Don't set to allow all IPs.")
 	viper.BindPFlag("allowed_ips", pflag.Lookup("allowed"))
 
 	pflag.String("traceroute_bin", "", "traceroute binary file, set either in parameter or environment variable BIRDLG_TRACEROUTE_BIN")
@@ -66,18 +66,31 @@ func parseSettings() {
 	setting.birdSocket = viperSettings.BirdSocket
 	setting.listen = viperSettings.Listen
 
-	if viperSettings.AllowedIPs != "" {
+	if viperSettings.AllowedNets != "" {
-		for _, ip := range strings.Split(viperSettings.AllowedIPs, ",") {
+		for _, arg := range strings.Split(viperSettings.AllowedNets, ",") {
-			ipObject := net.ParseIP(ip)
+
-			if ipObject == nil {
+			// if argument is an IP address, convert to CIDR by adding a suitable mask
-				fmt.Printf("Parse IP %s failed\n", ip)
+			if !strings.Contains(arg, "/") {
-				continue
+				if strings.Contains(arg, ":") {
+					// IPv6 address with /128 mask
+					arg += "/128"
+				} else {
+					// IPv4 address with /32 mask
+					arg += "/32"
+				}
 			}
 
-			setting.allowedIPs = append(setting.allowedIPs, ipObject)
+			// parse the network
+			_, netip, err := net.ParseCIDR(arg)
+			if err != nil {
+				fmt.Printf("Failed to parse CIDR %s: %s\n", arg, err.Error())
+				continue
+			}
+			setting.allowedNets = append(setting.allowedNets, netip)
+
 		}
 	} else {
-		setting.allowedIPs = []net.IP{}
+		setting.allowedNets = []*net.IPNet{}
 	}
 
 	var err error