Detect base context

README.md

@@ -12,10 +12,9 @@ binding. (It has been tested with eJabberd 2.1.10 and OpenLDAP 2.4.31.)
 Configuration
 -------------
 
-Edit the file `etc/ejabberd-auth.yaml` and configure:
-
- - At a minimum, the base context for your server.
- - Any other settings where the default is inappropriate.
+For OpenLDAP the default settings may suffice, assuming anonymous
+searches are allowed. Edit the file `etc/ejabberd-auth.yaml` to
+review the default configuration and adjust anything necessary.
 
 *Note that installing globally (below) will copy this file to global location.*
 

etc/ejabberd-auth.yaml

@@ -6,9 +6,11 @@
 # The method to use for authentication.
 # (At the moment 'ldap' is the only supported method.)
 # Default: ldap
-#method: ldap
+method: ldap
 
-ldap:
+# Uncomment if any of the following LDAP properties need
+# to be set.
+#ldap:
     # URL to use to connect to the server.
     # Default: ldap://localhost
     #uri: ldap://localhost
@@ -22,8 +24,8 @@ ldap:
     #    password: guessmeifyoucan
 
     # Base for searching.
-    # Default: none
-    base: dc=example,dc=com
+    # Default: autodetect
+    #base: dc=example,dc=com
 
     # Attribute to match against the username.
     # Default: uuid

lib/auth-ldap.js

@@ -5,6 +5,37 @@ var ldap   = require('ldapjs'),
     assert = require('assert'),
     auth   = require('./auth');
 
+function listRoots(client, callback) {
+    client.search("", {
+        filter: '(namingContexts=*)',
+        scope: 'base',
+        attributes: 'namingContexts',
+        attrsOnly: true
+    }, function(err, res) {
+        if (err) {
+            console.warn("Error searching for base contexts: " + err);
+            callback();
+        } else {
+            var roots = [];
+            res.on('searchEntry', function(entry) {
+                roots.push(entry.object.namingContexts)
+            });
+            res.on('error', function(err) {
+                console.warn("Error while searching for base contexts: " + err);
+                callback();
+            });
+            res.on('end', function(result) {
+                if (result.status === ldap.LDAP_SUCCESS) {
+                    callback(roots);
+                } else {
+                    console.error("LDAP error searching for base contexts: " + result.status);
+                    callback();
+                }
+            });
+        }
+    });
+}
+
 function start(options) {
     var base         = options.base,
         admin        = options.admin,
@@ -14,7 +45,7 @@ function start(options) {
         objectFilter = ldap.parseFilter(filter),
         client       = ldap.createClient({ url: url });
 
-    function bindEvents() {
+    function bindChannel(base) {
         function findJabberUser(user, callback) {
             client.search(base, {
                 filter: new ldap.AndFilter({
@@ -103,13 +134,36 @@ function start(options) {
         });
     }
 
+    function bindChannelWithSearchBase(base) {
+        if (base) {
+            bindChannel(base);
+        } else {
+            listRoots(client, function(bases) {
+                switch (bases.length) {
+                    case 0:
+                        console.error("Cannot detect root naming context. Please configure manually.");
+                        break;
+                    case 1:
+                        var base = bases[0];
+                        console.warn("Auto-detected base context: " + base);
+                        bindChannel(base);
+                        break;
+                    case 2:
+                        console.error("Multiple bases detected. Please configure manually.");
+                        break;
+
+                }
+            });
+        }
+    }
+
     if (admin) {
         client.bind(admin.dn, admin.password, function(err) {
             assert.ifError(err);
-            bindEvents();
+            bindChannelWithSearchBase(base);
         });
     } else {
-        bindEvents();
+        bindChannelWithSearchBase(base);
     }
 }