Allow msg to set parameters for snmp nodes. (#299)

* I've modified the snmp libraries so that the server and the community can be defined by the msg.
Error will be thrown if you try to override what was defined in the node.
Verified that the contents of msg is no longer clobbered.

Signed-off-by: Bryan Malyn <bimalyn@us.ibm.com>

* Replaced tabs with 4 spaces.
Signed-off-by: Bryan Malyn <bimalyn@us.ibm.com>

io/snmp/snmp.html

@@ -37,7 +37,7 @@
         category: 'network-input',
         color:"YellowGreen",
         defaults: {
-            host: {value:"",required:true},
+            host: {value:""},
             community: {value:"public",required:true},
             version: {value:"1",required:true},
             oids: {value:""},
@@ -94,7 +94,7 @@
         category: 'network-input',
         color:"YellowGreen",
         defaults: {
-            host: {value:"",required:true},
+            host: {value:""},
             community: {value:"public",required:true},
             version: {value:"1",required:true},
             oids: {value:""},
@@ -150,7 +150,7 @@
         category: 'network-input',
         color:"YellowGreen",
         defaults: {
-            host: {value:"",required:true},
+            host: {value:""},
             community: {value:"public",required:true},
             version: {value:"1",required:true},
             oids: {value:""},
@@ -208,7 +208,7 @@
         category: 'network-input',
         color:"YellowGreen",
         defaults: {
-            host: {value:"",required:true},
+            host: {value:""},
             community: {value:"public",required:true},
             version: {value:"1",required:true},
             oids: {value:""},

io/snmp/snmp.js

@@ -5,16 +5,21 @@ module.exports = function(RED) {
 
     function SnmpNode(n) {
         RED.nodes.createNode(this,n);
-        this.community = n.community || "public";
+        this.community = n.community;
-        this.host = n.host || "127.0.0.1";
+        this.host = n.host;
         this.version = (n.version === "2c") ? snmp.Version2c : snmp.Version1;
         this.oids = n.oids.replace(/\s/g,"");
-        this.session = snmp.createSession(this.host, this.community, {version: this.version});
         var node = this;
 
         this.on("input",function(msg) {
             var oids = node.oids || msg.oid;
             if (oids) {
+                if (msg.host && node.host || msg.community && node.community) {
+                    node.warn(RED._("common.errors.nooverride"));
+                }
+                var host = node.host || msg.host;
+                var community = node.community || msg.community;
+                node.session = snmp.createSession(host, community, {version: node.version});
                 node.session.get(oids.split(","), function(error, varbinds) {
                     if (error) {
                         node.error(error.toString(),msg);
@@ -40,18 +45,22 @@ module.exports = function(RED) {
                 node.warn("No oid(s) to search for");
             }
         });
+        
+        this.on("close", function(){
+            if (node.session){
+                node.session.close();
+            }
+        });
     }
     RED.nodes.registerType("snmp",SnmpNode);
 
     function SnmpTNode(n) {
         RED.nodes.createNode(this,n);
-        this.community = n.community || "public";
+        this.community = n.community;
-        this.host = n.host || "127.0.0.1";
+        this.host = n.host;
         this.version = (n.version === "2c") ? snmp.Version2c : snmp.Version1;
         this.oids = n.oids.replace(/\s/g,"");
-        this.session = snmp.createSession(this.host, this.community, {version: this.version});
         var node = this;
-        var msg;
         var maxRepetitions = 20;
 
         function sortInt(a, b) {
@@ -60,73 +69,69 @@ module.exports = function(RED) {
             else { return 0; }
         }
 
-        function responseCb(error, table) {
+        this.on("input",function(msg) {
-            if (error) {
-                console.error(error.toString());
-            }
-            else {
-                var indexes = [];
-                for (var index in table) {
-                    if (table.hasOwnProperty(index)) {
-                        indexes.push(parseInt(index));
-                    }
-                }
-                indexes.sort(sortInt);
-                for (var i = 0; i < indexes.length; i++) {
-                    var columns = [];
-                    for (var column in table[indexes[i]]) {
-                        if (table[indexes[i]].hasOwnProperty(column)) {
-                            columns.push(parseInt(column));
-                        }
-                    }
-                    columns.sort(sortInt);
-                    // console.log("row index = " + indexes[i]);
-                    // for (var j = 0; j < columns.length; j++) {
-                    //     console.log("  column " + columns[j] + " = " + table[indexes[i]][columns[j]]);
-                    // }
-                }
-                msg.payload = table;
-                node.send(msg);
-            }
-        }
-
-        this.on("input",function(m) {
-            msg = m;
             var oids = node.oids || msg.oid;
             if (oids) {
                 msg.oid = oids;
-                node.session.table(oids, maxRepetitions, responseCb);
+                if (msg.host && node.host || msg.community && node.community) {
+                    node.warn(RED._("common.errors.nooverride"));
+                }
+                var host = node.host || msg.host;
+                var community = node.community || msg.community;
+                node.session = snmp.createSession(host, community, {version: node.version});
+                node.session.table(oids, maxRepetitions, function(error, table) {
+                    if (error) {
+                        node.error(error.toString());
+                    }
+                    else {
+                        var indexes = [];
+                        for (var index in table) {
+                            if (table.hasOwnProperty(index)) {
+                                indexes.push(parseInt(index));
+                            }
+                        }
+                        indexes.sort(sortInt);
+                        for (var i = 0; i < indexes.length; i++) {
+                            var columns = [];
+                            for (var column in table[indexes[i]]) {
+                                if (table[indexes[i]].hasOwnProperty(column)) {
+                                    columns.push(parseInt(column));
+                                }
+                            }
+                            columns.sort(sortInt);
+                            // console.log("row index = " + indexes[i]);
+                            // for (var j = 0; j < columns.length; j++) {
+                            //     console.log("  column " + columns[j] + " = " + table[indexes[i]][columns[j]]);
+                            // }
+                        }
+                        msg.payload = table;
+                        node.send(msg);
+                    }
+                });
             }
             else {
                 node.warn("No oid to search for");
             }
         });
+        
+        this.on("close", function(){
+            if (node.session){
+                node.session.close();
+            }
+        });
     }
     RED.nodes.registerType("snmp table",SnmpTNode);
 
     function SnmpSubtreeNode(n) {
         RED.nodes.createNode(this,n);
-        this.community = n.community || "public";
+        this.community = n.community;
-        this.host = n.host || "127.0.0.1";
+        this.host = n.host;
         this.version = (n.version === "2c") ? snmp.Version2c : snmp.Version1;
         this.oids = n.oids.replace(/\s/g,"");
-        this.session = snmp.createSession(this.host, this.community, {version: this.version});
         var node = this;
         var maxRepetitions = 20;
         var response = [];
 
-        function doneCb(error) {
-            if (error) {
-                console.error(error.toString());
-            }
-            else {
-                var msg = {};
-                msg.payload = response;
-                node.send(msg);
-                response.clear();
-            }
-        }
-
         function feedCb(varbinds) {
             for (var i = 0; i < varbinds.length; i++) {
                 if (snmp.isVarbindError(varbinds[i])) {
@@ -134,7 +139,7 @@ module.exports = function(RED) {
                 }
                 else {
                     //console.log(varbinds[i].oid + "|" + varbinds[i].value);
-                    response.add({oid: varbinds[i].oid, value: varbinds[i].value});
+                    response.push({oid: varbinds[i].oid, value: varbinds[i].value});
                 }
             }
         }
@@ -143,39 +148,47 @@ module.exports = function(RED) {
             var oids = node.oids || msg.oid;
             if (oids) {
                 msg.oid = oids;
-                node.session.subtree(msg.oid, maxRepetitions, feedCb, doneCb);
+                if (msg.host && node.host || msg.community && node.community) {
-                //node.session.subtree(oids, maxRepetitions, responseCb);
+                    node.warn(RED._("common.errors.nooverride"));
+                }
+                var host = node.host || msg.host;
+                var community = node.community || msg.community;
+                node.session = snmp.createSession(host, community, {version: node.version});
+                node.session.subtree(msg.oid, maxRepetitions, feedCb, function(error) {
+                    if (error) {
+                        node.error(error.toString());
+                    }
+                    else {
+                        msg.payload = response;
+                        node.send(msg);
+                        //Clears response
+                        response.length = 0;
+                    }
+                });
             }
             else {
                 node.warn("No oid to search for");
             }
         });
+        
+        this.on("close", function(){
+            if (node.session){
+                node.session.close();
+            }
+        });
     }
     RED.nodes.registerType("snmp subtree",SnmpSubtreeNode);
 
     function SnmpWalkerNode(n) {
         RED.nodes.createNode(this,n);
-        this.community = n.community || "public";
+        this.community = n.community;
-        this.host = n.host || "127.0.0.1";
+        this.host = n.host;
         this.version = (n.version === "2c") ? snmp.Version2c : snmp.Version1;
         this.oids = n.oids.replace(/\s/g,"");
-        this.session = snmp.createSession(this.host, this.community, {version: this.version});
         var node = this;
         var maxRepetitions = 20;
         var response = [];
 
-        function doneCb(error) {
-            if (error) {
-                node.error(error.toString());
-            }
-            else {
-                var msg = {};
-                msg.payload = response;
-                node.send(msg);
-                response.clear();
-            }
-        }
-
         function feedCb(varbinds) {
             for (var i = 0; i < varbinds.length; i++) {
                 if (snmp.isVarbindError(varbinds[i])) {
@@ -183,21 +196,44 @@ module.exports = function(RED) {
                 }
                 else {
                     //console.log(varbinds[i].oid + "|" + varbinds[i].value);
-                    response.add({oid: varbinds[i].oid, value: varbinds[i].value});
+                    response.push({oid: varbinds[i].oid, value: varbinds[i].value});
                 }
             }
         }
 
         this.on("input",function(msg) {
+            node.msg = msg;
             var oids = node.oids || msg.oid;
             if (oids) {
                 msg.oid = oids;
-                node.session.walk(msg.oid, maxRepetitions, feedCb, doneCb);
+                if (msg.host && node.host || msg.community && node.community) {
+                    node.warn(RED._("common.errors.nooverride"));
+                }
+                var host = node.host || msg.host;
+                var community = node.community || msg.community;
+                node.session = snmp.createSession(host, community, {version: node.version});
+                node.session.walk(msg.oid, maxRepetitions, feedCb, function(error) {
+                    if (error) {
+                        node.error(error.toString());
+                    }
+                    else {
+                        msg.payload = response;
+                        node.send(msg);
+                        //Clears response
+                        response.length = 0;
+                    }
+                });
             }
             else {
                 node.warn("No oid to search for");
             }
         });
+        
+        this.on("close", function(){
+            if (node.session){
+                node.session.close();
+            }
+        });
     }
     RED.nodes.registerType("snmp walker",SnmpWalkerNode);
 };