wifi: Add a WifiMac method to check if TX is blocked on a link

src/wifi/model/wifi-mac.cc

@@ -1620,6 +1620,25 @@ WifiMac::UnblockUnicastTxOnLinks(WifiQueueBlockedReason reason,
     }
 }
 
+bool
+WifiMac::GetTxBlockedOnLink(AcIndex ac,
+                            const WifiContainerQueueId& queueId,
+                            uint8_t linkId,
+                            WifiQueueBlockedReason reason) const
+{
+    auto mask = m_scheduler->GetQueueLinkMask(ac, queueId, linkId);
+
+    if (!mask.has_value())
+    {
+        return true; // the link may have not been setup
+    }
+    if (reason == WifiQueueBlockedReason::REASONS_COUNT)
+    {
+        return mask->any();
+    }
+    return mask->test(static_cast<std::size_t>(reason));
+}
+
 void
 WifiMac::Enqueue(Ptr<Packet> packet, Mac48Address to)
 {

src/wifi/model/wifi-mac.h

@@ -351,6 +351,22 @@ class WifiMac : public Object
                                  const Mac48Address& address,
                                  const std::set<uint8_t>& linkIds);
 
+    /**
+     * Check whether the transmission of the packets in the given container queue of the given
+     * Access Category are blocked on the given link for the given reason (if any).
+     *
+     * \param ac the given Access Category
+     * \param queueId the given container queue
+     * \param linkId the ID of the given link
+     * \param reason the reason to block transmissions (REASONS_COUNT indicate no reason)
+     * \return whether transmission is blocked
+     */
+    bool GetTxBlockedOnLink(
+        AcIndex ac,
+        const WifiContainerQueueId& queueId,
+        uint8_t linkId,
+        WifiQueueBlockedReason reason = WifiQueueBlockedReason::REASONS_COUNT) const;
+
     /**
      * Return true if packets can be forwarded to the given destination,
      * false otherwise.