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/* SPDX-License-Identifier: GPL-2.0
*
* Copyright (C) 2015-2021 Jason A. Donenfeld <Jason@zx2c4.com>. All Rights Reserved.
*/
#include "logging.h"
#include "ioctl.h"
#include "device.h"
#include <ntstrsafe.h>
_Use_decl_annotations_
VOID
LogRingInit(LOG_RING *Log)
{
Log->CurrentWriters = Log->FirstAndLength = 0;
KeInitializeEvent(&Log->NewEntry, SynchronizationEvent, FALSE);
}
typedef struct _FIRST_AND_LENGTH
{
USHORT First, Length;
} FIRST_AND_LENGTH;
static_assert(sizeof(FIRST_AND_LENGTH) == sizeof(((LOG_RING *)0)->FirstAndLength), "First and length size mismatch");
_Use_decl_annotations_
VOID
LogRingWrite(LOG_RING *Log, PCSTR Format, ...)
{
LARGE_INTEGER Timestamp;
KeQuerySystemTime(&Timestamp);
if (InterlockedIncrement(&Log->CurrentWriters) >= BUFFERED_LOG_ENTRIES - 1)
goto out; /* Drop log entries if there's contention, rather than block. */
USHORT Index;
for (LONG OldFal = ReadNoFence(&Log->FirstAndLength);;)
{
LONG NewFal = OldFal;
FIRST_AND_LENGTH *Fal = (FIRST_AND_LENGTH *)&NewFal;
if (Fal->Length == BUFFERED_LOG_ENTRIES)
Fal->First = (Fal->First + 1) & BUFFERED_LOG_ENTRIES_MASK;
else
++Fal->Length;
Index = (Fal->First + Fal->Length - 1) & BUFFERED_LOG_ENTRIES_MASK;
LONG CurFal = InterlockedCompareExchange(&Log->FirstAndLength, NewFal, OldFal);
if (CurFal == OldFal)
break;
OldFal = CurFal;
}
Log->Entries[Index].Timestamp = Timestamp.QuadPart;
va_list Args;
va_start(Args, Format);
RtlStringCbVPrintfA(Log->Entries[Index].Msg, sizeof(Log->Entries[Index].Msg), Format, Args);
va_end(Args);
KeSetEvent(&Log->NewEntry, IO_NO_INCREMENT, FALSE);
out:
InterlockedDecrement(&Log->CurrentWriters);
}
_Use_decl_annotations_
NTSTATUS
LogRingRead(LOG_RING *Log, WG_IOCTL_LOG_ENTRY *Entry, BOOLEAN *WhileFalse)
{
NTSTATUS Status;
while (!ReadBooleanNoFence(WhileFalse))
{
USHORT Index;
for (LONG OldFal = ReadNoFence(&Log->FirstAndLength);;)
{
LONG NewFal = OldFal;
FIRST_AND_LENGTH *Fal = (FIRST_AND_LENGTH *)&NewFal;
if (!Fal->Length)
goto wait;
Index = Fal->First & BUFFERED_LOG_ENTRIES_MASK;
Fal->First = (Fal->First + 1) & BUFFERED_LOG_ENTRIES_MASK;
--Fal->Length;
LONG CurFal = InterlockedCompareExchange(&Log->FirstAndLength, NewFal, OldFal);
if (CurFal == OldFal)
break;
OldFal = CurFal;
}
RtlCopyMemory(Entry, &Log->Entries[Index], sizeof(*Entry));
return STATUS_SUCCESS;
wait:
Status = KeWaitForSingleObject(&Log->NewEntry, UserRequest, UserMode, TRUE, NULL);
if (Status != STATUS_SUCCESS) /* Intentionally not using NT_SUCCESS */
break;
}
return STATUS_CANCELLED;
}
enum
{
RATELIMIT_INTERVAL = 5 * SYS_TIME_UNITS_PER_SEC,
RATELIMIT_BURST = 10,
};
_Use_decl_annotations_
BOOLEAN
LogRingIsRatelimited(_Inout_ LOG_RING *Log)
{
BOOLEAN Ret = TRUE;
if (InterlockedCompareExchange(&Log->RatelimitChecking, 1, 0) != 0)
return Ret;
ULONG64 Now = KeQueryInterruptTime();
if (!Log->RatelimitStart)
Log->RatelimitStart = Now;
if ((LONG64)(Log->RatelimitStart + RATELIMIT_INTERVAL) - (LONG64)Now < 0)
{
if (Log->RatelimitMissed)
{
LogWarn(
CONTAINING_RECORD(Log, WG_DEVICE, Log),
"%u log lines swallowed by rate limiting",
Log->RatelimitMissed);
Log->RatelimitMissed = 0;
}
Log->RatelimitStart = Now;
Log->RatelimitPrinted = 0;
}
if (Log->RatelimitPrinted <= RATELIMIT_BURST)
{
++Log->RatelimitPrinted;
Ret = FALSE;
}
else
++Log->RatelimitMissed;
WriteNoFence(&Log->RatelimitChecking, 0);
return Ret;
}
_Use_decl_annotations_
VOID
SockaddrToString(PSTR Buffer, CONST SOCKADDR_INET *Addr)
{
if (Addr->si_family == AF_INET)
{
ULONG Length = SOCKADDR_STR_MAX_LEN;
if (NT_SUCCESS(RtlIpv4AddressToStringExA(&Addr->Ipv4.sin_addr, Addr->Ipv4.sin_port, Buffer, &Length)))
return;
}
else if (Addr->si_family == AF_INET6)
{
ULONG Length = SOCKADDR_STR_MAX_LEN;
if (NT_SUCCESS(RtlIpv6AddressToStringExA(
&Addr->Ipv6.sin6_addr, Addr->Ipv6.sin6_scope_id, Addr->Ipv6.sin6_port, Buffer, &Length)))
return;
}
RtlStringCbCopyA(Buffer, SOCKADDR_STR_MAX_LEN, "no address");
}
#if DBG
_Use_decl_annotations_
VOID
DumpNetBuffer(NET_BUFFER *Nb, CHAR *Prefix)
{
ULONG Len = NET_BUFFER_DATA_LENGTH(Nb);
CHAR Format[128];
DbgPrintEx(DPFLTR_IHVNETWORK_ID, 1, LOG_DRIVER_PREFIX "%s (%u):\n", Prefix, Len);
ULONG MdlOffset = NET_BUFFER_CURRENT_MDL_OFFSET(Nb), i = 0, k = 0;
for (MDL *Mdl = NET_BUFFER_CURRENT_MDL(Nb); Mdl; Mdl = Mdl->Next)
{
if (!Len)
break;
ULONG MdlLen = min(MmGetMdlByteCount(Mdl) - MdlOffset, Len);
UCHAR *Data = MmGetSystemAddressForMdlSafe(Mdl, NormalPagePriority | MdlMappingNoExecute | MdlMappingNoWrite);
for (ULONG j = 0; j < MdlLen; ++j, ++k)
{
i += Data ? _snprintf_s(
Format + i,
sizeof(Format) - i,
_TRUNCATE,
"%02x%c",
Data[j + MdlOffset],
(k % 16 == 15) ? '\n' : ' ')
: _snprintf_s(Format + i, sizeof(Format) - i, _TRUNCATE, "..%c", (k % 16 == 15) ? '\n' : ' ');
if (k % 16 == 15)
{
DbgPrintEx(DPFLTR_IHVNETWORK_ID, 1, "%s", Format);
i = 0;
Format[0] = 0;
}
}
Len -= MdlLen;
MdlOffset = 0;
}
if (i)
DbgPrintEx(DPFLTR_IHVNETWORK_ID, 1, "%s\n", Format);
}
#endif
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