Try to recover from some bad CAP replies, docs

[quassel.git] / src / core / coresessioneventprocessor.cpp

diff --git a/src/core/coresessioneventprocessor.cpp b/src/core/coresessioneventprocessor.cpp
index fa5fc36..5b639b7 100644 (file)
--- a/src/core/coresessioneventprocessor.cpp
+++ b/src/core/coresessioneventprocessor.cpp
@@ -155,7 +155,12 @@ void CoreSessionEventProcessor::processIrcEventCap(IrcEvent *e)
     // Handle capability negotiation
     // See: http://ircv3.net/specs/core/capability-negotiation-3.2.html
     // And: http://ircv3.net/specs/core/capability-negotiation-3.1.html
-    if (e->params().count() >= 3) {
+
+    // All commands require at least 2 parameters
+    if (!checkParamCount(e, 2))
+        return;
+
+    if (e->params().count() >= 2) {
         CoreNetwork *coreNet = coreNetwork(e);
         QString capCommand = e->params().at(1).trimmed().toUpper();
         if (capCommand == "LS" || capCommand == "NEW") {
@@ -172,8 +177,18 @@ void CoreSessionEventProcessor::processIrcEventCap(IrcEvent *e)
             } else {
                 // Single line reply
                 capListFinished = true;
-                availableCaps = e->params().at(2).split(' ');
+                if (e->params().count() >= 3) {
+                    // Some capabilities are specified, add them
+                    availableCaps = e->params().at(2).split(' ');
+                } else {
+                    // No capabilities available, add an empty list
+                    availableCaps = QStringList();
+                }
             }
+            // Sort capabilities before requesting for consistency among networks.  This may avoid
+            // unexpected cases when some networks offer capabilities in a different order than
+            // others.  It also looks nicer in logs.  Not required.
+            availableCaps.sort();
             // Store what capabilities are available
             QString availableCapName, availableCapValue;
             for (int i = 0; i < availableCaps.count(); ++i) {
@@ -196,6 +211,13 @@ void CoreSessionEventProcessor::processIrcEventCap(IrcEvent *e)
             if (capListFinished)
                 coreNet->beginCapNegotiation();
         } else if (capCommand == "ACK") {
+            // CAP ACK requires at least 3 parameters (no empty response allowed)
+            if (!checkParamCount(e, 3)) {
+                // If an invalid reply is sent, try to continue rather than getting stuck.
+                coreNet->sendNextCap();
+                return;
+            }
+
             // Server: CAP * ACK :multi-prefix sasl
             // Got the capability we want, handle as needed.
             // As only one capability is requested at a time, no need to split
@@ -211,6 +233,16 @@ void CoreSessionEventProcessor::processIrcEventCap(IrcEvent *e)
                 coreNet->sendNextCap();
             }
         } else if (capCommand == "NAK" || capCommand == "DEL") {
+            // CAP NAK/DEL require at least 3 parameters (no empty response allowed)
+            if (!checkParamCount(e, 3)) {
+                if (capCommand == "NAK") {
+                    // If an invalid reply is sent, try to continue rather than getting stuck.  This
+                    // only matters for denied caps, not removed caps.
+                    coreNet->sendNextCap();
+                }
+                return;
+            }
+
             // Either something went wrong with this capability, or it is no longer supported
             // > For CAP NAK
             // Server: CAP * NAK :multi-prefix sasl
@@ -230,8 +262,8 @@ void CoreSessionEventProcessor::processIrcEventCap(IrcEvent *e)
             }
 
             if (capCommand == "NAK") {
-                // Continue negotiation when capability listing complete only if this is the result
-                // of a denied cap, not a removed cap
+                // Continue negotiation only if this is the result of a denied cap, not a removed
+                // cap
                 coreNet->sendNextCap();
             }
         }