From a9a345ebd153d6c5a3f7634b2a839426524c1910 Mon Sep 17 00:00:00 2001 From: Lev Stipakov Date: Tue, 27 Aug 2024 10:58:58 +0300 Subject: [PATCH] timer: refactor timers implementation The current implementation uses "relative" WDF timers which are "not ticked" at low power states and on resume they continue to where they were left of. This makes keepalive timeout detection sub-optimal, since in worst case a client has to wait for "ping-restart" seconds to reconnect, which could be several minutes. Refactor timers in a way that we only have single timer ticking every second. At that tick we compare "last" and "now" timestamps and do actions, similar to what openvpn2 is doing. Fixes #64 Backported from b750b2c ("timer: refactor timers implementation") and ed455c4 ("Fix bug check in timer management routines") Signed-off-by: Lev Stipakov --- PropertySheet.props | 2 +- peer.cpp | 27 +++--------- peer.h | 7 +-- socket.cpp | 2 +- timer.cpp | 102 ++++++++++++++++++++++++++++++-------------- timer.h | 15 ++++--- txqueue.cpp | 2 +- 7 files changed, 91 insertions(+), 66 deletions(-) diff --git a/PropertySheet.props b/PropertySheet.props index f63952e..6bcce73 100644 --- a/PropertySheet.props +++ b/PropertySheet.props @@ -3,7 +3,7 @@ 2 - 0 + 2 1 diff --git a/peer.cpp b/peer.cpp index a7cdd07..3314fee 100644 --- a/peer.cpp +++ b/peer.cpp @@ -43,8 +43,7 @@ VOID OvpnPeerCtxFree(OvpnPeerContext* peer) { OvpnCryptoUninit(&peer->CryptoContext); - OvpnTimerDestroy(&peer->KeepaliveXmitTimer); - OvpnTimerDestroy(&peer->KeepaliveRecvTimer); + OvpnTimerDestroy(&peer->Timer); ExFreePoolWithTag(peer, 'ovpn'); } @@ -147,6 +146,8 @@ OvpnPeerNew(POVPN_DEVICE device, WDFREQUEST request) OvpnPeerZeroStats(&device->Stats); + GOTO_IF_NOT_NT_SUCCESS(done, status, OvpnTimerCreate(device->WdfDevice, peerCtx, &peerCtx->Timer)); + if (proto_tcp) { LOG_IF_NOT_NT_SUCCESS(status = WdfRequestForwardToIoQueue(request, device->PendingNewPeerQueue)); // start async connect @@ -229,29 +230,15 @@ NTSTATUS OvpnPeerSet(POVPN_DEVICE device, WDFREQUEST request) if (set_peer->KeepaliveInterval != -1) { peer->KeepaliveInterval = set_peer->KeepaliveInterval; - if (peer->KeepaliveInterval > 0) { - // keepalive xmit timer, sends ping packets - GOTO_IF_NOT_NT_SUCCESS(done, status, OvpnTimerXmitCreate(device->WdfDevice, peer, peer->KeepaliveInterval, &peer->KeepaliveXmitTimer)); - OvpnTimerReset(peer->KeepaliveXmitTimer, peer->KeepaliveInterval); - } - else { - LOG_INFO("Destroy xmit timer"); - OvpnTimerDestroy(&peer->KeepaliveXmitTimer); - } + // keepalive xmit timer, sends ping packets + OvpnTimerSetXmitInterval(peer->Timer, peer->KeepaliveInterval); } if (peer->KeepaliveTimeout != -1) { peer->KeepaliveTimeout = set_peer->KeepaliveTimeout; - if (peer->KeepaliveTimeout > 0) { - // keepalive recv timer, detects keepalive timeout - GOTO_IF_NOT_NT_SUCCESS(done, status, OvpnTimerRecvCreate(device->WdfDevice, peer, &peer->KeepaliveRecvTimer)); - OvpnTimerReset(peer->KeepaliveRecvTimer, peer->KeepaliveTimeout); - } - else { - LOG_INFO("Destroy recv timer"); - OvpnTimerDestroy(&peer->KeepaliveRecvTimer); - } + // keepalive recv timer, detects keepalive timeout + OvpnTimerSetRecvTimeout(peer->Timer, peer->KeepaliveTimeout); } done: diff --git a/peer.h b/peer.h index 4495171..e1eb5d4 100644 --- a/peer.h +++ b/peer.h @@ -39,11 +39,8 @@ struct OvpnPeerContext // keepalive timeout in seconds LONG KeepaliveTimeout; - // timer used to send periodic ping messages to the server if no data has been sent within the past KeepaliveInterval seconds - WDFTIMER KeepaliveXmitTimer; - - // timer used to report keepalive timeout error to userspace when no data has been received for KeepaliveTimeout seconds - WDFTIMER KeepaliveRecvTimer; + // 1-sec timer which handles ping intervals and keepalive timeouts + WDFTIMER Timer; }; _Must_inspect_result_ diff --git a/socket.cpp b/socket.cpp index ef57e37..1b3ca42 100644 --- a/socket.cpp +++ b/socket.cpp @@ -203,7 +203,7 @@ VOID OvpnSocketDataPacketReceived(_In_ POVPN_DEVICE device, UCHAR op, _In_reads_ return; } - OvpnTimerReset(peer->KeepaliveRecvTimer, peer->KeepaliveTimeout); + OvpnTimerResetRecv(peer->Timer); // points to the beginning of plaintext UCHAR* buf = buffer->Data + device->CryptoOverhead; diff --git a/timer.cpp b/timer.cpp index bac0e9b..2aa9fbb 100644 --- a/timer.cpp +++ b/timer.cpp @@ -37,6 +37,13 @@ static const UCHAR OvpnKeepaliveMessage[] = { // Context added to a timer's attributes typedef struct _OVPN_PEER_TIMER_CONTEXT { OvpnPeerContext* Peer; + + LARGE_INTEGER lastXmit; + LARGE_INTEGER lastRecv; + + // 0 means "not set" + LONG recvTimeout; + LONG xmitInterval; } OVPN_PEER_TIMER_CONTEXT, * POVPN_PEER_TIMER_CONTEXT; WDF_DECLARE_CONTEXT_TYPE_WITH_NAME(OVPN_PEER_TIMER_CONTEXT, OvpnGetPeerTimerContext); @@ -47,11 +54,8 @@ BOOLEAN OvpnTimerIsKeepaliveMessage(const PUCHAR buf, SIZE_T len) return RtlCompareMemory(buf, OvpnKeepaliveMessage, len) == sizeof(OvpnKeepaliveMessage); } -_Function_class_(EVT_WDF_TIMER) static VOID OvpnTimerXmit(WDFTIMER timer) { - LOG_ENTER(); - POVPN_DEVICE device = OvpnGetDeviceContext(WdfTimerGetParentObject(timer)); POVPN_PEER_TIMER_CONTEXT timerCtx = OvpnGetPeerTimerContext(timer); OVPN_TX_BUFFER* buffer; @@ -92,30 +96,24 @@ static VOID OvpnTimerXmit(WDFTIMER timer) OvpnTxBufferPoolPut(buffer); } ExReleaseSpinLockShared(&device->SpinLock, kiqrl); - - LOG_EXIT(); } -_Function_class_(EVT_WDF_TIMER) -static VOID OvpnTimerRecv(WDFTIMER timer) +static BOOLEAN OvpnTimerRecv(WDFTIMER timer) { - LOG_ENTER(); - - LOG_WARN("Keepalive timeout"); - POVPN_DEVICE device = OvpnGetDeviceContext(WdfTimerGetParentObject(timer)); WDFREQUEST request; NTSTATUS status = WdfIoQueueRetrieveNextRequest(device->PendingReadsQueue, &request); if (!NT_SUCCESS(status)) { LOG_WARN("No pending request for keepalive timeout notification"); + return FALSE; } else { + LOG_INFO("Notify userspace about keepalive timeout"); ULONG_PTR bytesSent = 0; WdfRequestCompleteWithInformation(request, STATUS_CONNECTION_DISCONNECTED, bytesSent); + return TRUE; } - - LOG_EXIT(); } _Use_decl_annotations_ @@ -129,7 +127,31 @@ VOID OvpnTimerDestroy(WDFTIMER* timer) } } -static NTSTATUS OvpnTimerCreate(WDFOBJECT parent, OvpnPeerContext* peer, ULONG period, PFN_WDF_TIMER func, _Inout_ WDFTIMER* timer) +_Function_class_(EVT_WDF_TIMER) +static VOID OvpnTimerTick(WDFTIMER timer) +{ + LARGE_INTEGER now; + KeQuerySystemTime(&now); + + POVPN_PEER_TIMER_CONTEXT timerCtx = OvpnGetPeerTimerContext(timer); + if ((timerCtx->xmitInterval > 0) && (((now.QuadPart - timerCtx->lastXmit.QuadPart) / WDF_TIMEOUT_TO_SEC) > timerCtx->xmitInterval)) + { + OvpnTimerXmit(timer); + timerCtx->lastXmit = now; + } + + if ((timerCtx->recvTimeout > 0) && (((now.QuadPart - timerCtx->lastRecv.QuadPart) / WDF_TIMEOUT_TO_SEC) > timerCtx->recvTimeout)) + { + // have we have completed pending read request? + if (OvpnTimerRecv(timer)) + { + timerCtx->recvTimeout = 0; // one-off timer + } + } +} + +_Use_decl_annotations_ +NTSTATUS OvpnTimerCreate(WDFOBJECT parent, OvpnPeerContext* peer, _Inout_ WDFTIMER* timer) { LOG_ENTER(); @@ -141,8 +163,9 @@ static NTSTATUS OvpnTimerCreate(WDFOBJECT parent, OvpnPeerContext* peer, ULONG p } WDF_TIMER_CONFIG timerConfig; - WDF_TIMER_CONFIG_INIT(&timerConfig, func); - timerConfig.Period = period * 1000; + WDF_TIMER_CONFIG_INIT(&timerConfig, OvpnTimerTick); + timerConfig.TolerableDelay = TolerableDelayUnlimited; + timerConfig.Period = 1000; WDF_OBJECT_ATTRIBUTES timerAttributes; WDF_OBJECT_ATTRIBUTES_INIT(&timerAttributes); @@ -155,36 +178,49 @@ static NTSTATUS OvpnTimerCreate(WDFOBJECT parent, OvpnPeerContext* peer, ULONG p if (NT_SUCCESS(status)) { POVPN_PEER_TIMER_CONTEXT pTimerContext = OvpnGetPeerTimerContext(*timer); pTimerContext->Peer = peer; + WdfTimerStart(*timer, WDF_REL_TIMEOUT_IN_SEC(1)); } LOG_EXIT(); return status; } -_Use_decl_annotations_ -NTSTATUS OvpnTimerXmitCreate(WDFOBJECT parent, OvpnPeerContext* peer, ULONG period, WDFTIMER* timer) +#define CHECK_TIMER_HANDLE(timer) \ + do { \ + if ((timer) == WDF_NO_HANDLE) { \ + LOG_ERROR("Timer handle is not initialized"); \ + return; \ + } \ + } while (0) + +VOID OvpnTimerSetXmitInterval(WDFTIMER timer, LONG xmitInterval) { - NTSTATUS status; - LOG_INFO("Create xmit timer", TraceLoggingValue(period, "period")); - LOG_IF_NOT_NT_SUCCESS(status = OvpnTimerCreate(parent, peer, period, OvpnTimerXmit, timer)); + CHECK_TIMER_HANDLE(timer); - return status; + POVPN_PEER_TIMER_CONTEXT timerCtx = OvpnGetPeerTimerContext(timer); + timerCtx->xmitInterval = xmitInterval; + KeQuerySystemTime(&timerCtx->lastXmit); } -_Use_decl_annotations_ -NTSTATUS OvpnTimerRecvCreate(WDFOBJECT parent, OvpnPeerContext* peer, WDFTIMER* timer) +VOID OvpnTimerSetRecvTimeout(WDFTIMER timer, LONG recvTimeout) { - NTSTATUS status; - LOG_INFO("Create recv timer"); - LOG_IF_NOT_NT_SUCCESS(status = OvpnTimerCreate(parent, peer, 0, OvpnTimerRecv, timer)); + CHECK_TIMER_HANDLE(timer); - return status; + POVPN_PEER_TIMER_CONTEXT timerCtx = OvpnGetPeerTimerContext(timer); + timerCtx->recvTimeout = recvTimeout; + KeQuerySystemTime(&timerCtx->lastRecv); } -VOID OvpnTimerReset(WDFTIMER timer, ULONG dueTime) +VOID OvpnTimerResetXmit(WDFTIMER timer) { - if (timer != WDF_NO_HANDLE) { - // if timer has already been created this will reset "due time" value to the new one - WdfTimerStart(timer, WDF_REL_TIMEOUT_IN_SEC(dueTime)); - } + CHECK_TIMER_HANDLE(timer); + + POVPN_PEER_TIMER_CONTEXT timerCtx = OvpnGetPeerTimerContext(timer); + KeQuerySystemTime(&timerCtx->lastXmit); +} + +VOID OvpnTimerResetRecv(WDFTIMER timer) +{ + POVPN_PEER_TIMER_CONTEXT timerCtx = OvpnGetPeerTimerContext(timer); + KeQuerySystemTime(&timerCtx->lastRecv); } diff --git a/timer.h b/timer.h index b9f8bfc..88ee019 100644 --- a/timer.h +++ b/timer.h @@ -26,15 +26,20 @@ #include VOID -OvpnTimerReset(WDFTIMER timer, ULONG dueTime); +OvpnTimerResetXmit(WDFTIMER timer); -_Must_inspect_result_ -NTSTATUS -OvpnTimerXmitCreate(WDFOBJECT parent, OvpnPeerContext* peer, ULONG period, _Inout_ WDFTIMER* timer); +VOID +OvpnTimerResetRecv(WDFTIMER timer); _Must_inspect_result_ NTSTATUS -OvpnTimerRecvCreate(WDFOBJECT parent, OvpnPeerContext* peer, _Inout_ WDFTIMER* timer); +OvpnTimerCreate(WDFOBJECT parent, OvpnPeerContext* peer, _Inout_ WDFTIMER* timer); + +VOID +OvpnTimerSetXmitInterval(WDFTIMER timer, LONG xmitInterval); + +VOID +OvpnTimerSetRecvTimeout(WDFTIMER timer, LONG recvTimeout); VOID OvpnTimerDestroy(_Inout_ WDFTIMER* timer); diff --git a/txqueue.cpp b/txqueue.cpp index a93a470..5325c87 100644 --- a/txqueue.cpp +++ b/txqueue.cpp @@ -128,7 +128,7 @@ OvpnTxProcessPacket(_In_ POVPN_DEVICE device, _In_ POVPN_TXQUEUE queue, _In_ NET *tail = buffer; } - OvpnTimerReset(peer->KeepaliveXmitTimer, peer->KeepaliveInterval); + OvpnTimerResetXmit(peer->Timer); } else { OvpnTxBufferPoolPut(buffer);