From: Jack Allnutt <jack@allnutt.eu>
Date: Sun, 15 Sep 2013 12:26:05 +0000 (+0100)
Subject: New maximum buffer size when holding data between calls to parse()
X-Git-Url: https://vcs.fsf.org/?a=commitdiff_plain;h=f429dec110407bef708c120dee9e7abbda141595;p=KiwiIRC.git

New maximum buffer size when holding data between calls to parse()

Also check to see if the chunk has a \n byte in it, fixing #382
---

diff --git a/server/irc/connection.js b/server/irc/connection.js
index 6e67805..7d269b8 100644
--- a/server/irc/connection.js
+++ b/server/irc/connection.js
@@ -638,7 +638,9 @@ var parse = function (data) {
         tag,
         buf_start = 0,
         bufs = [],
-        line = '';
+        line = '',
+        max_buffer_size = 1024; // 1024 bytes is the maximum length of two RFC1459 IRC messages.
+                                // May need tweaking when IRCv3 message tags are more widespread
 
     // Split data chunk into individual lines
     for (i = 0; i < data.length; i++) {
@@ -648,6 +650,24 @@ var parse = function (data) {
         }
     }
 
+    // If this chunk does not contain an \n byte, check to see if buffering it would exceed the max buffer size
+    if (!bufs[0]) {
+        if (((this.held_data) ? this.held_data.length : 0 ) + data.length > max_buffer_size) {
+            // Buffering this data would exeed our max buffer size
+            this.emit('error', 'Message buffer too large');
+            this.socket.destroy();
+            return;
+        } else {
+            if (this.held_data) {
+                this.held_data = Buffer.concat([this.held_data, data], this.held_data.length + data.length);
+            } else {
+                this.held_data = data;
+            }
+            // No complete line so no need to continue parsing this chunk
+            return;
+        }
+    }
+
     // If we have an incomplete line held from the previous chunk of data
     // merge it with the first line from this chunk of data
     if (this.hold_last && this.held_data !== null) {
@@ -659,6 +679,12 @@ var parse = function (data) {
     // If the last line of data in this chunk is not complete, hold it so
     // it can be merged with the first line from the next chunk
     if (buf_start < i) {
+        if ((data.length - buf_start) > max_buffer_size) {
+            // Buffering this data would exeed our max buffer size
+            this.emit('error', 'Message buffer too large');
+            this.socket.destroy();
+            return;
+        }
         this.hold_last = true;
         this.held_data = new Buffer(data.length - buf_start);
         data.copy(this.held_data, 0, buf_start);