ieee80211: honor requested scan BSSID and SSID filters

src/inet/linklayer/ieee80211/mgmt/Ieee80211MgmtSta.cc

@@ -5,6 +5,8 @@
 //
 
 
+#include <algorithm>
+
 #include "inet/linklayer/ieee80211/mgmt/Ieee80211MgmtSta.h"
 #include "inet/linklayer/ieee80211/mgmt/Ieee80211HtMgmtElements.h"
 
@@ -495,14 +497,20 @@ void Ieee80211MgmtSta::sendScanConfirm()
 {
     EV << "Scanning complete, found " << apList.size() << " APs, sending confirmation to agent\n";
 
-    // copy apList contents into a ScanConfirm primitive and send it back
-    int n = apList.size();
+    // copy matching apList contents into a ScanConfirm primitive and send it back
+    // IEEE Std 802.11-2024, 6.5.3.2.2: BSSID and SSID identify specific or wildcard scan targets.
+    auto matchesScanRequest = [this](const ApInfo& ap) {
+        return (scanning.bssid == MacAddress::BROADCAST_ADDRESS || ap.address == scanning.bssid)
+            && (scanning.ssid.empty() || ap.ssid == scanning.ssid);
+    };
+    int n = std::count_if(apList.begin(), apList.end(), matchesScanRequest);
     Ieee80211Prim_ScanConfirm *confirm = new Ieee80211Prim_ScanConfirm();
     confirm->setBssListArraySize(n);
     auto it = apList.begin();
-    // TODO filter for req'd bssid and ssid
-    for (int i = 0; i < n; i++, it++) {
+    for (int i = 0; it != apList.end(); it++) {
         ApInfo *ap = &(*it);
+        if (!matchesScanRequest(*ap))
+            continue;
         Ieee80211Prim_BssDescription& bss = confirm->getBssListForUpdate(i);
         bss.setChannelNumber(ap->channel);
         bss.setBSSID(ap->address);
@@ -512,6 +520,7 @@ void Ieee80211MgmtSta::sendScanConfirm()
         bss.setExtendedSupportedRates(ap->extendedSupportedRates);
         bss.setBeaconInterval(ap->beaconInterval);
         bss.setRxPower(ap->rxPower);
+        i++;
     }
     sendConfirm(confirm, PRC_SUCCESS);
 }

tests/unit/Ieee80211ScanConfirmFilters_1.test

@@ -0,0 +1,77 @@
+%description:
+Exercise the production scan-confirm construction with discovered BSSs that
+share an SSID, unrelated beacons, exact filters and wildcards. Filtering must
+not destroy the discovery cache used by subsequent management operations.
+
+%includes:
+#include "inet/linklayer/ieee80211/mgmt/Ieee80211MgmtSta.h"
+
+using namespace inet;
+using namespace inet::ieee80211;
+
+%global:
+class ScanConfirmStation : public Ieee80211MgmtSta
+{
+  public:
+    std::vector<MacAddress> results;
+    int confirmations = 0;
+
+    void addBss(const char *address, const char *ssid)
+    {
+        apList.emplace_back();
+        auto& ap = apList.back();
+        ap.address = MacAddress(address);
+        ap.ssid = ssid;
+        ap.channel = 1;
+        ap.supportedRates.numRates = 0;
+        ap.extendedSupportedRates.numRates = 0;
+    }
+
+    void confirm(const MacAddress& bssid, const char *ssid, bool active)
+    {
+        scanning = ScanningInfo();
+        scanning.bssid = bssid;
+        scanning.ssid = ssid;
+        scanning.activeScan = active;
+        results.clear();
+        sendScanConfirm();
+        ASSERT(apList.size() == 3);
+    }
+
+  protected:
+    virtual void sendConfirm(Ieee80211PrimConfirm *message, Ieee80211PrimResultCode code) override
+    {
+        ASSERT(code == PRC_SUCCESS);
+        auto confirm = check_and_cast<Ieee80211Prim_ScanConfirm *>(message);
+        confirmations++;
+        for (size_t i = 0; i < confirm->getBssListArraySize(); i++)
+            results.push_back(confirm->getBssList(i).getBSSID());
+        delete confirm;
+    }
+};
+
+%activity:
+ScanConfirmStation station;
+const MacAddress a("02:00:00:00:00:01"), b("02:00:00:00:00:02"), c("02:00:00:00:00:03");
+station.addBss("02:00:00:00:00:01", "requested");
+station.addBss("02:00:00:00:00:02", "requested");
+station.addBss("02:00:00:00:00:03", "unrelated");
+for (bool active : {false, true}) {
+    station.confirm(MacAddress::BROADCAST_ADDRESS, "", active);
+    ASSERT(station.results == std::vector<MacAddress>({a, b, c}));
+    station.confirm(MacAddress::BROADCAST_ADDRESS, "requested", active);
+    ASSERT(station.results == std::vector<MacAddress>({a, b}));
+    station.confirm(b, "", active);
+    ASSERT(station.results == std::vector<MacAddress>({b}));
+    station.confirm(b, "requested", active);
+    ASSERT(station.results == std::vector<MacAddress>({b}));
+    station.confirm(b, "unrelated", active);
+    ASSERT(station.results.empty());
+    station.confirm(MacAddress::BROADCAST_ADDRESS, "absent", active);
+    ASSERT(station.results.empty());
+}
+ASSERT(station.confirmations == 12);
+EV << "Scan confirms honor both filters and preserve discovery cache.\n";
+
+%contains: stdout
+Scan confirms honor both filters and preserve discovery cache.