Session IDs are now 2 bytes, Request IDs are now 2 bytes, Each ICMP e…

…rror response now has an associated error class, Call request callbacks with an error when there are no free request IDs, Update version package.json to 1.1.6, Update README.md for 1.1.6

README.md

@@ -40,10 +40,10 @@ A request can complete in a number of ways, for example the request timed out,
 a response was received from a host other than the targeted host (i.e. a
 gateway) or an error occurred when sending the request.
 
-All errors excluding a timed out error are passed to the callback function as
-an instance of the `Error` object.  For timed out errors the error passed to
-the callback function will be an instance of the `ping.RequestTimedOutError`
-object, with the exposed `message` attribute set to `Request timed out`.
+All errors are sub-classes of the `Error` class.  For timed out errors the
+error passed to the callback function will be an instance of the
+`ping.RequestTimedOutError` class, with the exposed `message` attribute set
+to `Request timed out`.
 
 This makes it easy to determine if a host responded or whether an error
 occurred:
@@ -58,16 +58,29 @@ occurred:
             console.log (target + ": Alive");
     });
 
-If a host other than the target reports an error its address will be included
-in the error, i.e.:
+In addition to the the `ping.RequestTimedOutError` class, the following errors
+are also exported by this module to wrap ICMP error responses:
+
+ * `DestinationUnreachableError`
+ * `PacketTooBigError`
+ * `ParameterProblemError`
+ * `RedirectReceivedError`
+ * `SourceQuenchError`
+ * `TimeExceededError`
+
+These errors are typically reported by hosts other than the intended target.
+In all cases class exposes a `source` attribute which will specify the
+host who reported the error (which could be the intended target).  This will
+also be included in the errors `message` attribute, i.e.:
 
     $ sudo node example/ping-ttl.js 1 192.168.2.10 192.168.2.20 192.168.2.30
     192.168.2.10: Alive
-    192.168.2.20: Error: Time exceeded (source=192.168.1.1)
+    192.168.2.20: TimeExceededError: Time exceeded (source=192.168.1.1)
     192.168.2.30: Not alive
 
 The `Session` class will emit an `error` event for any other error not
-directly associated with a request.
+directly associated with a request.  This is typically an instance of the
+`Error` class with the errors `message` attribute specifying the reason.
 
 # Packet Size
 
@@ -131,7 +144,7 @@ items:
    packets)
  * `retries` - Number of times to re-send a ping requests, defaults to `1`
  * `sessionId` - A unique ID used to identify request and response packets sent
-   by this instance of the `Session` class, valid numbers of in the range of
+   by this instance of the `Session` class, valid numbers are in the range of
    `1` to `65535`, defaults to the value of `process.pid % 65535`
  * `timeout` - Number of milliseconds to wait for a response before re-trying
    or failing, defaults to `2000`
@@ -279,7 +292,7 @@ Bug reports should be sent to <stephen.vickers.sv@gmail.com>.
  * Add the `packetSize` option to the `createSession()` method to specify how
    many bytes each ICMP echo request packet should be
 
-## Version 1.1.5 - ?
+## Version 1.1.5 - 17/05/2013
 
  * Incorrectly parsing ICMP error responses resulting in responses matching
    the wrong request
@@ -290,6 +303,15 @@ Bug reports should be sent to <stephen.vickers.sv@gmail.com>.
  * Added example programs `ping-ttl.js` and `ping6-ttl.js`
  * Use MIT license instead of GPL
 
+## Version 1.1.6 - 17/05/2013
+
+ * Session IDs are now 2 bytes (previously 1 byte), and request IDs are also
+   now 2 bytes long (previously 3 bytes)
+ * Each ICMP error response now has an associated error class (i.e. the
+   `Time exceeded` response maps onto the `ping.TimeExceededError` class)
+ * Call request callbacks with an error when there are no free request IDs
+   because of too many outstanding requests
+
 # Roadmap
 
 In no particular order:

index.js

@@ -19,12 +19,54 @@ var NetworkProtocol = {
 
 _expandConstantObject (NetworkProtocol);
 
-function RequestTimedOutError (message) {
+function DestinationUnreachableError (source) {
+	this.name = "DestinationUnreachableError";
+	this.message = "Destination unreachable (source=" + source + ")";
+	this.source = source;
+}
+util.inherits (DestinationUnreachableError, Error);
+
+function PacketTooBigError (source) {
+	this.name = "PacketTooBigError";
+	this.message = "Packet too big (source=" + source + ")";
+	this.source = source;
+}
+util.inherits (PacketTooBigError, Error);
+
+function ParameterProblemError (source) {
+	this.name = "ParameterProblemError";
+	this.message = "Parameter problem (source=" + source + ")";
+	this.source = source;
+}
+util.inherits (ParameterProblemError, Error);
+
+function RedirectReceivedError (source) {
+	this.name = "RedirectReceivedError";
+	this.message = "Redireect received (source=" + source + ")";
+	this.source = source;
+}
+util.inherits (RedirectReceivedError, Error);
+
+function RequestTimedOutError () {
 	this.name = "RequestTimedOutError";
-	this.message = message;
+	this.message = "Request timed out";
 }
 util.inherits (RequestTimedOutError, Error);
 
+function SourceQuenchError (source) {
+	this.name = "SourceQuenchError";
+	this.message = "Source quench (source=" + source + ")";
+	this.source = source;
+}
+util.inherits (SourceQuenchError, Error);
+
+function TimeExceededError (source) {
+	this.name = "TimeExceededError";
+	this.message = "Time exceeded (source=" + source + ")";
+	this.source = source;
+}
+util.inherits (TimeExceededError, Error);
+
 function Session (options) {
 	this.retries = (options && options.retries) ? options.retries : 1;
 	this.timeout = (options && options.timeout) ? options.timeout : 2000;
@@ -45,7 +87,7 @@ function Session (options) {
 			? options.sessionId
 			: process.pid;
 
-	this.sessionId = this.sessionId % 255;
+	this.sessionId = this.sessionId % 65535;
 
 	this.nextId = 1;
 
@@ -176,12 +218,12 @@ Session.prototype.fromBuffer = function (buffer) {
 	}
 
 	// Response is not for a request we generated
-	if (buffer.readUInt8 (offset + 4) != this.sessionId)
+	if (buffer.readUInt16BE (offset + 4) != this.sessionId)
 		return;
 
 	buffer[offset + 4] = 0;
 
-	var id = buffer.readUInt32BE (offset + 4);
+	var id = buffer.readUInt16BE (offset + 6);
 	var req = this.reqs[id];
 
 	if (req) {
@@ -211,17 +253,13 @@ Session.prototype.onSocketMessage = function (buffer, source) {
 		this.reqRemove (req.id);
 		if (this.addressFamily == raw.AddressFamily.IPv6) {
 			if (req.type == 1) {
-				req.callback (new Error ("Destination unreachable (source="
-						+ source + ")"), req.target);
+				req.callback (new DestinationUnreachableError (source), req.target);
 			} else if (req.type == 2) {
-				req.callback (new Error ("Packet too big (source=" + source + ")"),
-						req.target);
+				req.callback (new PacketTooBigError (source), req.target);
 			} else if (req.type == 3) {
-				req.callback (new Error ("Time exceeded (source=" + source + ")"),
-						req.target);
+				req.callback (new TimeExceededError (source), req.target);
 			} else if (req.type == 4) {
-				req.callback (new Error ("Parameter problem (source=" + source
-						+ ")"), req.target);
+				req.callback (new ParameterProblemError (source), req.target);
 			} else if (req.type == 129) {
 				req.callback (null, req.target);
 			} else {
@@ -232,17 +270,13 @@ Session.prototype.onSocketMessage = function (buffer, source) {
 			if (req.type == 0) {
 				req.callback (null, req.target);
 			} else if (req.type == 3) {
-				req.callback (new Error ("Destination unreachable (source="
-						+ source + ")"), req.target);
+				req.callback (new DestinationUnreachableError (source), req.target);
 			} else if (req.type == 4) {
-				req.callback (new Error ("Source quench (source=" + source + ")"),
-						req.target);
+				req.callback (new SourceQuenchError (source), req.target);
 			} else if (req.type == 5) {
-				req.callback (new Error ("Redirect received (source=" + source
-						+ ")"), req.target);
+				req.callback (new RedirectReceivedError (source), req.target);
 			} else if (req.type == 11) {
-				req.callback (new Error ("Time exceeded (source=" + source + ")"),
-						req.target);
+				req.callback (new TimeExceededError (source), req.target);
 			} else {
 				req.callback (new Error ("Unknown response type '" + req.type
 						+ "' (source=" + source + ")"), req.target);
@@ -274,19 +308,28 @@ Session.prototype.onTimeout = function (req) {
 
 // Keep searching for an ID which is not in use
 Session.prototype._generateId = function () {
+	var startId = this.nextId;
 	while (1) {
-		if (this.nextId > 16777215)
+		if (this.nextId > 65535)
 			this.nextId = 1;
 		if (this.reqs[this.nextId]) {
 			this.nextId++
-			continue;
 		} else {
 			return this.nextId;
 		}
+		// No free request IDs
+		if (this.nextId == startId)
+			return;
 	}
 }
 
 Session.prototype.pingHost = function (target, callback) {
+	var id = this._generateId ();
+	if (! id) {
+		callback (new Error ("Too many requests outstanding"), target);
+		return this;
+	}
+
 	var req = {
 		id: this._generateId (),
 		retries: this.retries,
@@ -345,9 +388,8 @@ Session.prototype.toBuffer = function (req) {
 	buffer.writeUInt8 (type, 0);
 	buffer.writeUInt8 (0, 1);
 	buffer.writeUInt16BE (0, 2);
-	buffer.writeUInt32BE (req.id, 4);
-
-	buffer[4] = this.sessionId;
+	buffer.writeUInt16BE (this.sessionId, 4);
+	buffer.writeUInt16BE (req.id, 6);
 
 	// Checksums are be generated by our raw.Socket instance
 
@@ -362,4 +404,10 @@ exports.NetworkProtocol = NetworkProtocol;
 
 exports.Session = Session;
 
+exports.DestinationUnreachableError = DestinationUnreachableError;
+exports.PacketTooBigError = PacketTooBigError;
+exports.ParameterProblemError = ParameterProblemError;
+exports.RedirectReceivedError = RedirectReceivedError;
 exports.RequestTimedOutError = RequestTimedOutError;
+exports.SourceQuenchError = SourceQuenchError;
+exports.TimeExceededError = TimeExceededError;

package.json

@@ -1,6 +1,6 @@
 {
   "name": "net-ping",
-  "version": "1.1.5",
+  "version": "1.1.6",
   "description": "Ping many hosts at once.",
   "main": "index.js",
   "directories": {