multipeer: delete expired peer

On keepalive timeout, delete peer context from all tables, unititialize crypto/timer and and free the peer context memory. Github: #88 Signed-off-by: Lev Stipakov <[email protected]>
OpenVPN · Oct 22, 2024 · c0a1dcc · c0a1dcc
1 parent 3b74322
commit c0a1dcc
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Showing 3 changed files with 55 additions and 4 deletions.
diff --git a/Driver.cpp b/Driver.cpp
@@ -897,3 +897,49 @@ OvpnFindPeerVPN6(POVPN_DEVICE device, IN6_ADDR addr)
     OvpnPeerContext** ptr = (OvpnPeerContext**)RtlLookupElementGenericTable(&device->PeersByVpn6, &pp);
     return ptr ? (OvpnPeerContext*)*ptr : NULL;
 }
+
+VOID
+OvpnDeletePeerFromTable(RTL_GENERIC_TABLE *table, OvpnPeerContext *peer, char* tableName)
+{
+    auto peerId = peer->PeerId;
+    auto pp = &peer;
+
+    if (RtlDeleteElementGenericTable(table, pp)) {
+        LOG_INFO("Peer deleted", TraceLoggingValue(tableName, "table"), TraceLoggingValue(peerId, "peer-id"));
+
+        if (InterlockedDecrement(&peer->RefCounter) == 0) {
+            OvpnPeerCtxFree(peer);
+            LOG_INFO("Peer freed", TraceLoggingValue(peerId, "peer-id"));
+        }
+    }
+    else {
+        LOG_INFO("Peer not found", TraceLoggingValue(tableName, "table"), TraceLoggingValue(peerId, "peer-id"));
+    }
+}
+
+NTSTATUS
+OvpnDeletePeer(POVPN_DEVICE device, INT32 peerId)
+{
+    NTSTATUS status = STATUS_SUCCESS;
+
+    KIRQL kirql = ExAcquireSpinLockExclusive(&device->SpinLock);
+
+    LOG_INFO("Deleting peer", TraceLoggingValue(peerId, "peer-id"));
+
+    // get peer from main table
+    OvpnPeerContext* peerCtx = OvpnFindPeer(device, peerId);
+    if (peerCtx == NULL) {
+        status = STATUS_NOT_FOUND;
+        LOG_WARN("Peer not found", TraceLoggingValue(peerId, "peer-id"));
+    }
+    else {
+        OvpnDeletePeerFromTable(&device->PeersByVpn4, peerCtx, "vpn4");
+        OvpnDeletePeerFromTable(&device->PeersByVpn6, peerCtx, "vpn6");
+
+        OvpnDeletePeerFromTable(&device->Peers, peerCtx, "peers");
+    }
+
+    ExReleaseSpinLockExclusive(&device->SpinLock, kirql);
+
+    return status;
+}
diff --git a/Driver.h b/Driver.h
@@ -150,3 +150,7 @@ OvpnFindPeerVPN4(_In_ POVPN_DEVICE device, _In_ IN_ADDR addr);
 _Must_inspect_result_
 OvpnPeerContext*
 OvpnFindPeerVPN6(_In_ POVPN_DEVICE device, _In_ IN6_ADDR addr);
+
+_Must_inspect_result_
+NTSTATUS
+OvpnDeletePeer(_In_ POVPN_DEVICE device, INT32 peerId);
diff --git a/timer.cpp b/timer.cpp
@@ -117,20 +117,23 @@ static BOOLEAN OvpnTimerRecv(WDFTIMER timer)
     if (device->Mode == OVPN_MODE_P2P) {
         status = WdfIoQueueRetrieveNextRequest(device->PendingReadsQueue, &request);
         if (!NT_SUCCESS(status)) {
-            LOG_WARN("No pending request for keepalive timeout notification");
+            LOG_INFO("No pending request for keepalive timeout notification");
             return FALSE;
         }
 
         ULONG_PTR bytesSent = 0;
         WdfRequestCompleteWithInformation(request, STATUS_CONNECTION_DISCONNECTED, bytesSent);
     }
     else {
+        (VOID)OvpnDeletePeer(device, peerId);
+
         status = WdfIoQueueRetrieveNextRequest(device->PendingNotificationRequestsQueue, &request);
         if (!NT_SUCCESS(status)) {
-            LOG_WARN("Adding keepalive timeout notification to the queue");
+            LOG_INFO("Adding keepalive timeout notification to the queue");
             return NT_SUCCESS(device->PendingNotificationsQueue.AddEvent(OVPN_NOTIFY_DEL_PEER, peerId, OVPN_DEL_PEER_REASON_EXPIRED));
         }
         else {
+            LOG_INFO("Notify userspace about expired peer");
             OVPN_NOTIFY_EVENT *evt;
             ULONG_PTR bytesSent = 0;
             LOG_IF_NOT_NT_SUCCESS(status = WdfRequestRetrieveOutputBuffer(request, sizeof(OVPN_NOTIFY_EVENT), (PVOID*)&evt, nullptr));
@@ -141,8 +144,6 @@ static BOOLEAN OvpnTimerRecv(WDFTIMER timer)
                 bytesSent = sizeof(OVPN_NOTIFY_EVENT);
             }
             WdfRequestCompleteWithInformation(request, status, bytesSent);
-
-            // TODO: remove peer
         }
     }