Merge remote-tracking branch 'pali/win32-sysdbg'

7 files changed, 326 insertions, 2 deletions

diff --git a/lib/Makefile b/lib/Makefile
index b29a48f..400c32d 100644
--- a/lib/Makefile
+++ b/lib/Makefile
@@ -59,6 +59,10 @@ OBJS += emulated
 OBJS += win32-cfgmgr32
 endif
 
+ifdef PCI_HAVE_PM_WIN32_SYSDBG
+OBJS += win32-sysdbg
+endif
+
 all: $(PCILIB) $(PCILIBPC)
 
 ifeq ($(SHARED),no)
@@ -108,6 +112,7 @@ filter.o: filter.c $(INCL)
 nbsd-libpci.o: nbsd-libpci.c $(INCL)
 hurd.o: hurd.c $(INCL)
 win32-cfgmgr32.o: win32-cfgmgr32.c $(INCL)
+win32-sysdbg.o: win32-sysdbg.c $(INCL)
 
 # MinGW32 toolchain has some required Win32 header files in /ddk subdirectory.
 # But these header files include another header files from /ddk subdirectory
diff --git a/lib/configure b/lib/configure
index 45a416a..2c74d9d 100755
--- a/lib/configure
+++ b/lib/configure
@@ -145,9 +145,10 @@ case $sys in
 		EXEEXT=.exe
 		;;
 	cygwin|windows)
-		echo_n " win32-cfgmgr32"
+		echo_n " win32-cfgmgr32 win32-sysdbg"
 		echo >>$c '#define PCI_HAVE_64BIT_ADDRESS'
 		echo >>$c '#define PCI_HAVE_PM_WIN32_CFGMGR32'
+		echo >>$c '#define PCI_HAVE_PM_WIN32_SYSDBG'
 		# Warning: MinGW-w64 (incorrectly) provides cfgmgr32 functions
 		# also in other import libraries, not only in libcfgmgr32.a.
 		# So always set -lcfgmgr32 as a first library parameter which
diff --git a/lib/init.c b/lib/init.c
index f997b2b..de7d6f2 100644
--- a/lib/init.c
+++ b/lib/init.c
@@ -81,6 +81,11 @@ static struct pci_methods *pci_methods[PCI_ACCESS_MAX] = {
 #else
   NULL,
 #endif
+#ifdef PCI_HAVE_PM_WIN32_SYSDBG
+  &pm_win32_sysdbg,
+#else
+  NULL,
+#endif
 };
 
 // If PCI_ACCESS_AUTO is selected, we probe the access methods in this order
@@ -96,6 +101,7 @@ static int probe_sequence[] = {
   PCI_ACCESS_SYLIXOS_DEVICE,
   PCI_ACCESS_HURD,
   PCI_ACCESS_WIN32_CFGMGR32,
+  PCI_ACCESS_WIN32_SYSDBG,
   // Low-level methods poking the hardware directly
   PCI_ACCESS_I386_TYPE1,
   PCI_ACCESS_I386_TYPE2,
diff --git a/lib/internal.h b/lib/internal.h
index e0185dd..0a5dce4 100644
--- a/lib/internal.h
+++ b/lib/internal.h
@@ -116,4 +116,4 @@ void pci_free_caps(struct pci_dev *);
 extern struct pci_methods pm_intel_conf1, pm_intel_conf2, pm_linux_proc,
 	pm_fbsd_device, pm_aix_device, pm_nbsd_libpci, pm_obsd_device,
 	pm_dump, pm_linux_sysfs, pm_darwin, pm_sylixos_device, pm_hurd,
-	pm_win32_cfgmgr32;
+	pm_win32_cfgmgr32, pm_win32_sysdbg;
diff --git a/lib/pci.h b/lib/pci.h
index eeb4a55..41a162b 100644
--- a/lib/pci.h
+++ b/lib/pci.h
@@ -44,6 +44,7 @@ enum pci_access_type {
   PCI_ACCESS_SYLIXOS_DEVICE,		/* SylixOS pci */
   PCI_ACCESS_HURD,			/* GNU/Hurd */
   PCI_ACCESS_WIN32_CFGMGR32,		/* Win32 cfgmgr32.dll */
+  PCI_ACCESS_WIN32_SYSDBG,		/* Win32 NT SysDbg */
   PCI_ACCESS_MAX
 };
 
diff --git a/lib/win32-sysdbg.c b/lib/win32-sysdbg.c
new file mode 100644
index 0000000..5d0c07a
--- /dev/null
+++ b/lib/win32-sysdbg.c
@@ -0,0 +1,304 @@
+/*
+ *      The PCI Library -- PCI config space access using NT SysDbg interface
+ *
+ *      Copyright (c) 2022 Pali Rohár <pali@kernel.org>
+ *
+ *      Can be freely distributed and used under the terms of the GNU GPL.
+ */
+
+#include <windows.h>
+
+#include "internal.h"
+#include "i386-io-windows.h"
+
+#ifndef NTSTATUS
+#define NTSTATUS LONG
+#endif
+#ifndef STATUS_UNSUCCESSFUL
+#define STATUS_UNSUCCESSFUL (NTSTATUS)0xC0000001
+#endif
+#ifndef STATUS_NOT_IMPLEMENTED
+#define STATUS_NOT_IMPLEMENTED (NTSTATUS)0xC0000002
+#endif
+#ifndef STATUS_INVALID_INFO_CLASS
+#define STATUS_INVALID_INFO_CLASS (NTSTATUS)0xC0000003
+#endif
+#ifndef STATUS_ACCESS_DENIED
+#define STATUS_ACCESS_DENIED (NTSTATUS)0xC0000022
+#endif
+#ifndef STATUS_DEBUGGER_INACTIVE
+#define STATUS_DEBUGGER_INACTIVE (NTSTATUS)0xC0000354
+#endif
+
+#ifndef BUS_DATA_TYPE
+#define BUS_DATA_TYPE LONG
+#endif
+#ifndef PCIConfiguration
+#define PCIConfiguration (BUS_DATA_TYPE)4
+#endif
+
+#ifndef SYSDBG_COMMAND
+#define SYSDBG_COMMAND ULONG
+#endif
+#ifndef SysDbgReadBusData
+#define SysDbgReadBusData (SYSDBG_COMMAND)18
+#endif
+#ifndef SysDbgWriteBusData
+#define SysDbgWriteBusData (SYSDBG_COMMAND)19
+#endif
+
+#ifndef SYSDBG_BUS_DATA
+typedef struct _SYSDBG_BUS_DATA {
+  ULONG Address;
+  PVOID Buffer;
+  ULONG Request;
+  BUS_DATA_TYPE BusDataType;
+  ULONG BusNumber;
+  ULONG SlotNumber;
+} SYSDBG_BUS_DATA, *PSYSDBG_BUS_DATA;
+#define SYSDBG_BUS_DATA SYSDBG_BUS_DATA
+#endif
+
+#ifndef PCI_SLOT_NUMBER
+typedef struct _PCI_SLOT_NUMBER {
+  union {
+    struct {
+      ULONG DeviceNumber:5;
+      ULONG FunctionNumber:3;
+      ULONG Reserved:24;
+    } bits;
+    ULONG AsULONG;
+  } u;
+} PCI_SLOT_NUMBER, *PPCI_SLOT_NUMBER;
+#define PCI_SLOT_NUMBER PCI_SLOT_NUMBER
+#endif
+
+#ifdef NtSystemDebugControl
+#undef NtSystemDebugControl
+#endif
+static NTSTATUS (NTAPI *MyNtSystemDebugControl)(SYSDBG_COMMAND Command, PVOID InputBuffer, ULONG InputBufferLength, PVOID OutputBuffer, ULONG OutputBufferLength, PULONG ReturnLength);
+#define NtSystemDebugControl MyNtSystemDebugControl
+
+static BOOL debug_privilege_enabled;
+static LUID luid_debug_privilege;
+static BOOL revert_only_privilege;
+static HANDLE revert_token;
+static HMODULE ntdll;
+
+static int win32_sysdbg_initialized;
+
+static NTSTATUS
+win32_sysdbg_pci_bus_data(BOOL WriteBusData, BYTE BusNumber, BYTE DeviceNumber, BYTE FunctionNumber, BYTE Address, PVOID Buffer, BYTE BufferSize, PULONG Length)
+{
+  SYSDBG_BUS_DATA sysdbg_cmd;
+  PCI_SLOT_NUMBER pci_slot;
+
+  if (!NtSystemDebugControl)
+    return STATUS_NOT_IMPLEMENTED;
+
+  memset(&pci_slot, 0, sizeof(pci_slot));
+  memset(&sysdbg_cmd, 0, sizeof(sysdbg_cmd));
+
+  sysdbg_cmd.Address = Address;
+  sysdbg_cmd.Buffer = Buffer;
+  sysdbg_cmd.Request = BufferSize;
+  sysdbg_cmd.BusDataType = PCIConfiguration;
+  sysdbg_cmd.BusNumber = BusNumber;
+  pci_slot.u.bits.DeviceNumber = DeviceNumber;
+  pci_slot.u.bits.FunctionNumber = FunctionNumber;
+  sysdbg_cmd.SlotNumber = pci_slot.u.AsULONG;
+
+  *Length = 0;
+  return NtSystemDebugControl(WriteBusData ? SysDbgWriteBusData : SysDbgReadBusData, &sysdbg_cmd, sizeof(sysdbg_cmd), NULL, 0, Length);
+}
+
+static int
+win32_sysdbg_setup(struct pci_access *a)
+{
+  UINT prev_error_mode;
+  NTSTATUS status;
+  ULONG ret_len;
+  DWORD id;
+
+  if (win32_sysdbg_initialized)
+    return 1;
+
+  prev_error_mode = change_error_mode(SEM_FAILCRITICALERRORS);
+  ntdll = LoadLibrary(TEXT("ntdll.dll"));
+  change_error_mode(prev_error_mode);
+  if (!ntdll)
+    {
+      a->debug("Cannot open ntdll.dll library.");
+      return 0;
+    }
+
+  NtSystemDebugControl = (LPVOID)GetProcAddress(ntdll, "NtSystemDebugControl");
+  if (!NtSystemDebugControl)
+    {
+      a->debug("Function NtSystemDebugControl() is not supported.");
+      FreeLibrary(ntdll);
+      ntdll = NULL;
+      return 0;
+    }
+
+  /*
+   * Try to read PCI id register from PCI device 00:00.0.
+   * If this device does not exist and NT SysDbg API is working then
+   * NT SysDbg returns STATUS_UNSUCCESSFUL.
+   */
+  status = win32_sysdbg_pci_bus_data(FALSE, 0, 0, 0, 0, &id, sizeof(id), &ret_len);
+  if ((status >= 0 && ret_len == sizeof(id)) || status == STATUS_UNSUCCESSFUL)
+    {
+      win32_sysdbg_initialized = 1;
+      return 1;
+    }
+  else if (status != STATUS_ACCESS_DENIED)
+    {
+      if (status == STATUS_NOT_IMPLEMENTED || status == STATUS_INVALID_INFO_CLASS)
+        a->debug("NT SysDbg is not supported.");
+      else if (status == STATUS_DEBUGGER_INACTIVE)
+        a->debug("NT SysDbg is disabled.");
+      else
+        a->debug("NT SysDbg returned error 0x%lx.", status);
+      FreeLibrary(ntdll);
+      ntdll = NULL;
+      NtSystemDebugControl = NULL;
+      return 0;
+    }
+
+  a->debug("NT SysDbg returned Access Denied, trying again with Debug privilege...");
+
+  if (!LookupPrivilegeValue(NULL, SE_DEBUG_NAME, &luid_debug_privilege))
+    {
+      a->debug("Debug privilege is not supported.");
+      FreeLibrary(ntdll);
+      ntdll = NULL;
+      NtSystemDebugControl = NULL;
+      return 0;
+    }
+
+  if (!enable_privilege(luid_debug_privilege, &revert_token, &revert_only_privilege))
+    {
+      a->debug("Cannot enable Debug privilege.");
+      FreeLibrary(ntdll);
+      ntdll = NULL;
+      NtSystemDebugControl = NULL;
+      return 0;
+    }
+
+  status = win32_sysdbg_pci_bus_data(FALSE, 0, 0, 0, 0, &id, sizeof(id), &ret_len);
+  if ((status >= 0 && ret_len == sizeof(id)) || status == STATUS_UNSUCCESSFUL)
+    {
+      a->debug("Succeeded.");
+      debug_privilege_enabled = TRUE;
+      win32_sysdbg_initialized = 1;
+      return 1;
+    }
+
+  revert_privilege(luid_debug_privilege, revert_token, revert_only_privilege);
+  revert_token = NULL;
+  revert_only_privilege = FALSE;
+
+  FreeLibrary(ntdll);
+  ntdll = NULL;
+  NtSystemDebugControl = NULL;
+
+  if (status == STATUS_NOT_IMPLEMENTED || status == STATUS_INVALID_INFO_CLASS)
+    a->debug("NT SysDbg is not supported.");
+  else if (status == STATUS_DEBUGGER_INACTIVE)
+    a->debug("NT SysDbg is disabled.");
+  else if (status == STATUS_ACCESS_DENIED)
+    a->debug("NT SysDbg returned Access Denied.");
+  else
+    a->debug("NT SysDbg returned error 0x%lx.", status);
+
+  return 0;
+}
+
+static int
+win32_sysdbg_detect(struct pci_access *a)
+{
+  if (!win32_sysdbg_setup(a))
+    return 0;
+
+  return 1;
+}
+
+static void
+win32_sysdbg_init(struct pci_access *a)
+{
+  if (!win32_sysdbg_setup(a))
+    {
+      a->debug("\n");
+      a->error("NT SysDbg PCI Bus Data interface cannot be accessed.");
+    }
+}
+
+static void
+win32_sysdbg_cleanup(struct pci_access *a UNUSED)
+{
+  if (!win32_sysdbg_initialized)
+    return;
+
+  if (debug_privilege_enabled)
+    {
+      revert_privilege(luid_debug_privilege, revert_token, revert_only_privilege);
+      revert_token = NULL;
+      revert_only_privilege = FALSE;
+      debug_privilege_enabled = FALSE;
+    }
+
+  FreeLibrary(ntdll);
+  ntdll = NULL;
+  NtSystemDebugControl = NULL;
+
+  win32_sysdbg_initialized = 0;
+}
+
+static int
+win32_sysdbg_read(struct pci_dev *d, int pos, byte *buf, int len)
+{
+  NTSTATUS status;
+  ULONG ret_len;
+
+  if ((unsigned int)d->domain > 0 || (unsigned int)pos > 255 || (unsigned int)(pos+len) > 256)
+    return 0;
+
+  status = win32_sysdbg_pci_bus_data(FALSE, d->bus, d->dev, d->func, pos, buf, len, &ret_len);
+  if (status < 0 || ret_len != (unsigned int)len)
+    return 0;
+
+  return 1;
+}
+
+static int
+win32_sysdbg_write(struct pci_dev *d, int pos, byte *buf, int len)
+{
+  NTSTATUS status;
+  ULONG ret_len;
+
+  if ((unsigned int)d->domain > 0 || (unsigned int)pos > 255 || (unsigned int)(pos+len) > 256)
+    return 0;
+
+  status = win32_sysdbg_pci_bus_data(TRUE, d->bus, d->dev, d->func, pos, buf, len, &ret_len);
+  if (status < 0 || ret_len != (unsigned int)len)
+    return 0;
+
+  return 1;
+}
+
+struct pci_methods pm_win32_sysdbg = {
+  "win32-sysdbg",
+  "Win32 PCI config space access using NT SysDbg Bus Data interface",
+  NULL,					/* config */
+  win32_sysdbg_detect,
+  win32_sysdbg_init,
+  win32_sysdbg_cleanup,
+  pci_generic_scan,
+  pci_generic_fill_info,
+  win32_sysdbg_read,
+  win32_sysdbg_write,
+  NULL,					/* read_vpd */
+  NULL,					/* init_dev */
+  NULL					/* cleanup_dev */
+};
diff --git a/pcilib.man b/pcilib.man
index 63e58c8..115f1f3 100644
--- a/pcilib.man
+++ b/pcilib.man
@@ -76,6 +76,13 @@ is no access to the PCI configuration space but libpci provides read-only
 virtual emulation based on information from Configuration Manager. Starting
 with Windows 8 (NT 6.2) it is not possible to retrieve resources from 32-bit
 application or library on 64-bit system.
+.TP
+.B win32-sysdbg
+Access to the PCI configuration space via NT SysDbg interface on Windows
+systems. Process needs to have Debug privilege, which local Administrators
+have by default. Not available on 64-bit systems and neither on recent 32-bit
+systems. Only devices from the first domain are accessible and only first
+256 bytes of the PCI configuration space is accessible via this method.
 
 .SH PARAMETERS