X-Git-Url: https://tinc-vpn.org/git/browse?p=tinc;a=blobdiff_plain;f=src%2Fmingw%2Fdevice.c;h=bf8ae13779cc3375bc1d936a14eecbfadf6c4f6e;hp=6d916ba573c27841a01bf6ab7f7d99b0b56fd6bd;hb=d6b45d005530496e48325a6174ecdd889a17bfc1;hpb=a1e72f84d08b76784c11ff723666ceeaef2756eb

diff --git a/src/mingw/device.c b/src/mingw/device.c
index 6d916ba5..bf8ae137 100644
--- a/src/mingw/device.c
+++ b/src/mingw/device.c
@@ -1,7 +1,7 @@
 /*
     device.c -- Interaction with Windows tap driver in a MinGW environment
     Copyright (C) 2002-2005 Ivo Timmermans,
-                  2002-2007 Guus Sliepen <guus@tinc-vpn.org>
+                  2002-2018 Guus Sliepen <guus@tinc-vpn.org>
 
     This program is free software; you can redistribute it and/or modify
     it under the terms of the GNU General Public License as published by
@@ -13,116 +13,88 @@
     MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
     GNU General Public License for more details.
 
-    You should have received a copy of the GNU General Public License
-    along with this program; if not, write to the Free Software
-    Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
-
-    $Id$
+    You should have received a copy of the GNU General Public License along
+    with this program; if not, write to the Free Software Foundation, Inc.,
+    51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
 */
 
-#include "system.h"
+#include "../system.h"
 
 #include <windows.h>
 #include <winioctl.h>
 
-#include "conf.h"
-#include "logger.h"
-#include "net.h"
-#include "route.h"
-#include "utils.h"
-#include "xalloc.h"
+#include "../conf.h"
+#include "../device.h"
+#include "../logger.h"
+#include "../names.h"
+#include "../net.h"
+#include "../route.h"
+#include "../utils.h"
+#include "../xalloc.h"
 
-#include "mingw/common.h"
+#include "common.h"
 
-int device_fd = 0;
+int device_fd = -1;
 static HANDLE device_handle = INVALID_HANDLE_VALUE;
+static io_t device_read_io;
+static OVERLAPPED device_read_overlapped;
+static OVERLAPPED device_write_overlapped;
+static vpn_packet_t device_read_packet;
+static vpn_packet_t device_write_packet;
 char *device = NULL;
 char *iface = NULL;
-char *device_info = NULL;
-
-static int device_total_in = 0;
-static int device_total_out = 0;
+static const char *device_info = "Windows tap device";
 
 extern char *myport;
 
-static struct packetbuf {
-	uint8_t data[MTU];
-	length_t len;
-} *bufs;
-
-static int nbufs = 64;
-
-DWORD WINAPI tapreader(void *bla) {
-	int sock, err, status;
-	struct addrinfo *ai;
-	struct addrinfo hint = {
-		.ai_family = AF_UNSPEC,
-		.ai_socktype = SOCK_STREAM,
-		.ai_protocol = IPPROTO_TCP,
-		.ai_flags = 0,
-	};
-	unsigned char bufno = 0;
-	long len;
-	OVERLAPPED overlapped;
-
-	/* Open a socket to the parent process */
-
-	err = getaddrinfo(NULL, myport, &hint, &ai);
-
-	if(err || !ai) {
-		logger(LOG_ERR, _("System call `%s' failed: %s"), "getaddrinfo", gai_strerror(errno));
-		return -1;
-	}
+static void device_issue_read() {
+	int status;
 
-	sock = socket(ai->ai_family, SOCK_STREAM, IPPROTO_TCP);
+	for(;;) {
+		ResetEvent(device_read_overlapped.hEvent);
 
-	freeaddrinfo(ai);
+		DWORD len;
+		status = ReadFile(device_handle, (void *)device_read_packet.data, MTU, &len, &device_read_overlapped);
 
-	if(sock < 0) {
-		logger(LOG_ERR, _("System call `%s' failed: %s"), "socket", strerror(errno));
-		return -1;
-	}
+		if(!status) {
+			if(GetLastError() != ERROR_IO_PENDING)
+				logger(DEBUG_ALWAYS, LOG_ERR, "Error while reading from %s %s: %s", device_info,
+				       device, strerror(errno));
 
-	if(connect(sock, ai->ai_addr, ai->ai_addrlen)) {
-		logger(LOG_ERR, _("System call `%s' failed: %s"), "connect", strerror(errno));
-		return -1;
-	}
+			break;
+		}
 
-	logger(LOG_DEBUG, _("Tap reader running"));
+		device_read_packet.len = len;
+		device_read_packet.priority = 0;
+		route(myself, &device_read_packet);
+	}
+}
 
-	/* Read from tap device and send to parent */
+static void device_handle_read(void *data, int flags) {
+	(void)data;
+	(void)flags;
 
-	overlapped.hEvent = CreateEvent(NULL, TRUE, FALSE, NULL);
-	
-	for(;;) {
-		overlapped.Offset = 0;
-		overlapped.OffsetHigh = 0;
-		ResetEvent(overlapped.hEvent);
+	DWORD len;
 
-		status = ReadFile(device_handle, bufs[bufno].data, MTU, &len, &overlapped);
+	if(!GetOverlappedResult(device_handle, &device_read_overlapped, &len, FALSE)) {
+		logger(DEBUG_ALWAYS, LOG_ERR, "Error getting read result from %s %s: %s", device_info,
+		       device, strerror(errno));
 
-		if(!status) {
-			if(GetLastError() == ERROR_IO_PENDING) {
-				WaitForSingleObject(overlapped.hEvent, INFINITE);
-				if(!GetOverlappedResult(device_handle, &overlapped, &len, FALSE))
-					continue;
-			} else {
-				logger(LOG_ERR, _("Error while reading from %s %s: %s"), device_info,
-					   device, strerror(errno));
-				return -1;
-			}
+		if(GetLastError() != ERROR_IO_INCOMPLETE) {
+			/* Must reset event or it will keep firing. */
+			ResetEvent(device_read_overlapped.hEvent);
 		}
 
-		bufs[bufno].len = len;
-		if(send(sock, &bufno, 1, 0) <= 0)
-			return -1;
-		if(++bufno >= nbufs)
-			bufno = 0;
+		return;
 	}
+
+	device_read_packet.len = len;
+	device_read_packet.priority = 0;
+	route(myself, &device_read_packet);
+	device_issue_read();
 }
 
-bool setup_device(void)
-{
+static bool setup_device(void) {
 	HKEY key, key2;
 	int i;
 
@@ -130,72 +102,71 @@ bool setup_device(void)
 	char adapterid[1024];
 	char adaptername[1024];
 	char tapname[1024];
-	long len;
-	unsigned long status;
+	DWORD len;
 
 	bool found = false;
 
-	int sock, err;
-	HANDLE thread;
-
-	struct addrinfo *ai;
-	struct addrinfo hint = {
-		.ai_family = AF_UNSPEC,
-		.ai_socktype = SOCK_STREAM,
-		.ai_protocol = IPPROTO_TCP,
-		.ai_flags = 0,
-	};
-
-	cp();
+	int err;
 
 	get_config_string(lookup_config(config_tree, "Device"), &device);
 	get_config_string(lookup_config(config_tree, "Interface"), &iface);
 
+	if(device && iface) {
+		logger(DEBUG_ALWAYS, LOG_WARNING, "Warning: both Device and Interface specified, results may not be as expected");
+	}
+
 	/* Open registry and look for network adapters */
 
 	if(RegOpenKeyEx(HKEY_LOCAL_MACHINE, NETWORK_CONNECTIONS_KEY, 0, KEY_READ, &key)) {
-		logger(LOG_ERR, _("Unable to read registry: %s"), winerror(GetLastError()));
+		logger(DEBUG_ALWAYS, LOG_ERR, "Unable to read registry: %s", winerror(GetLastError()));
 		return false;
 	}
 
-	for (i = 0; ; i++) {
+	for(i = 0; ; i++) {
 		len = sizeof(adapterid);
-		if(RegEnumKeyEx(key, i, adapterid, &len, 0, 0, 0, NULL))
+
+		if(RegEnumKeyEx(key, i, adapterid, &len, 0, 0, 0, NULL)) {
 			break;
+		}
 
 		/* Find out more about this adapter */
 
 		snprintf(regpath, sizeof(regpath), "%s\\%s\\Connection", NETWORK_CONNECTIONS_KEY, adapterid);
 
-                if(RegOpenKeyEx(HKEY_LOCAL_MACHINE, regpath, 0, KEY_READ, &key2))
+		if(RegOpenKeyEx(HKEY_LOCAL_MACHINE, regpath, 0, KEY_READ, &key2)) {
 			continue;
+		}
 
 		len = sizeof(adaptername);
-		err = RegQueryValueEx(key2, "Name", 0, 0, adaptername, &len);
+		err = RegQueryValueEx(key2, "Name", 0, 0, (LPBYTE)adaptername, &len);
 
 		RegCloseKey(key2);
 
-		if(err)
+		if(err) {
 			continue;
+		}
 
 		if(device) {
 			if(!strcmp(device, adapterid)) {
 				found = true;
 				break;
-			} else
+			} else {
 				continue;
+			}
 		}
 
 		if(iface) {
 			if(!strcmp(iface, adaptername)) {
 				found = true;
 				break;
-			} else
+			} else {
 				continue;
+			}
 		}
 
 		snprintf(tapname, sizeof(tapname), USERMODEDEVICEDIR "%s" TAPSUFFIX, adapterid);
 		device_handle = CreateFile(tapname, GENERIC_WRITE | GENERIC_READ, 0, 0, OPEN_EXISTING, FILE_ATTRIBUTE_SYSTEM | FILE_FLAG_OVERLAPPED, 0);
+
 		if(device_handle != INVALID_HANDLE_VALUE) {
 			found = true;
 			break;
@@ -205,15 +176,17 @@ bool setup_device(void)
 	RegCloseKey(key);
 
 	if(!found) {
-		logger(LOG_ERR, _("No Windows tap device found!"));
+		logger(DEBUG_ALWAYS, LOG_ERR, "No Windows tap device found!");
 		return false;
 	}
 
-	if(!device)
+	if(!device) {
 		device = xstrdup(adapterid);
+	}
 
-	if(!iface)
+	if(!iface) {
 		iface = xstrdup(adaptername);
+	}
 
 	/* Try to open the corresponding tap device */
 
@@ -221,16 +194,36 @@ bool setup_device(void)
 		snprintf(tapname, sizeof(tapname), USERMODEDEVICEDIR "%s" TAPSUFFIX, device);
 		device_handle = CreateFile(tapname, GENERIC_WRITE | GENERIC_READ, 0, 0, OPEN_EXISTING, FILE_ATTRIBUTE_SYSTEM | FILE_FLAG_OVERLAPPED, 0);
 	}
-	
+
 	if(device_handle == INVALID_HANDLE_VALUE) {
-		logger(LOG_ERR, _("%s (%s) is not a usable Windows tap device: %s"), device, iface, winerror(GetLastError()));
+		logger(DEBUG_ALWAYS, LOG_ERR, "%s (%s) is not a usable Windows tap device: %s", device, iface, winerror(GetLastError()));
 		return false;
 	}
 
+	/* Get version information from tap device */
+
+	{
+		ULONG info[3] = {0};
+		DWORD len;
+
+		if(!DeviceIoControl(device_handle, TAP_IOCTL_GET_VERSION, &info, sizeof(info), &info, sizeof(info), &len, NULL)) {
+			logger(DEBUG_ALWAYS, LOG_WARNING, "Could not get version information from Windows tap device %s (%s): %s", device, iface, winerror(GetLastError()));
+		} else {
+			logger(DEBUG_ALWAYS, LOG_INFO, "TAP-Windows driver version: %lu.%lu%s", info[0], info[1], info[2] ? " (DEBUG)" : "");
+
+			/* Warn if using >=9.21. This is because starting from 9.21, TAP-Win32 seems to use a different, less efficient write path. */
+			if(info[0] == 9 && info[1] >= 21)
+				logger(DEBUG_ALWAYS, LOG_WARNING,
+				       "You are using the newer (>= 9.0.0.21, NDIS6) series of TAP-Win32 drivers. "
+				       "Using these drivers with tinc is not recommended as it can result in poor performance. "
+				       "You might want to revert back to 9.0.0.9 instead.");
+		}
+	}
+
 	/* Get MAC address from tap device */
 
 	if(!DeviceIoControl(device_handle, TAP_IOCTL_GET_MAC, mymac.x, sizeof(mymac.x), mymac.x, sizeof(mymac.x), &len, 0)) {
-		logger(LOG_ERR, _("Could not get MAC address from Windows tap device %s (%s): %s"), device, iface, winerror(GetLastError()));
+		logger(DEBUG_ALWAYS, LOG_ERR, "Could not get MAC address from Windows tap device %s (%s): %s", device, iface, winerror(GetLastError()));
 		return false;
 	}
 
@@ -238,129 +231,127 @@ bool setup_device(void)
 		overwrite_mac = 1;
 	}
 
-	/* Set up ringbuffer */
+	device_info = "Windows tap device";
 
-	get_config_int(lookup_config(config_tree, "RingBufferSize"), &nbufs);
-	if(nbufs <= 1)
-		nbufs = 1;
-	else if(nbufs > 256)
-		nbufs = 256;
-	
-	bufs = xmalloc_and_zero(nbufs * sizeof *bufs);
+	logger(DEBUG_ALWAYS, LOG_INFO, "%s (%s) is a %s", device, iface, device_info);
 
-	/* Create a listening socket */
+	device_read_overlapped.hEvent = CreateEvent(NULL, TRUE, FALSE, NULL);
+	device_write_overlapped.hEvent = CreateEvent(NULL, TRUE, FALSE, NULL);
 
-	err = getaddrinfo(NULL, myport, &hint, &ai);
+	return true;
+}
 
-	if(err || !ai) {
-		logger(LOG_ERR, _("System call `%s' failed: %s"), "getaddrinfo", gai_strerror(errno));
-		return false;
-	}
+static void enable_device(void) {
+	logger(DEBUG_ALWAYS, LOG_INFO, "Enabling %s", device_info);
 
-	sock = socket(ai->ai_family, SOCK_STREAM, IPPROTO_TCP);
+	ULONG status = 1;
+	DWORD len;
+	DeviceIoControl(device_handle, TAP_IOCTL_SET_MEDIA_STATUS, &status, sizeof(status), &status, sizeof(status), &len, NULL);
 
-	if(sock < 0) {
-		logger(LOG_ERR, _("System call `%s' failed: %s"), "socket", strerror(errno));
-		return false;
-	}
+	/* We don't use the write event directly, but GetOverlappedResult() does, internally. */
 
-	if(bind(sock, ai->ai_addr, ai->ai_addrlen)) {
-		logger(LOG_ERR, _("System call `%s' failed: %s"), "bind", strerror(errno));
-		return false;
-	}
+	io_add_event(&device_read_io, device_handle_read, NULL, device_read_overlapped.hEvent);
+	device_issue_read();
+}
 
-	freeaddrinfo(ai);
+static void disable_device(void) {
+	logger(DEBUG_ALWAYS, LOG_INFO, "Disabling %s", device_info);
 
-	if(listen(sock, 1)) {
-		logger(LOG_ERR, _("System call `%s' failed: %s"), "listen", strerror(errno));
-		return false;
-	}
+	io_del(&device_read_io);
 
-	/* Start the tap reader */
+	ULONG status = 0;
+	DWORD len;
+	DeviceIoControl(device_handle, TAP_IOCTL_SET_MEDIA_STATUS, &status, sizeof(status), &status, sizeof(status), &len, NULL);
 
-	thread = CreateThread(NULL, 0, tapreader, NULL, 0, NULL);
+	/* Note that we don't try to cancel ongoing I/O here - we just stop listening.
+	   This is because some TAP-Win32 drivers don't seem to handle cancellation very well,
+	   especially when combined with other events such as the computer going to sleep - cases
+	   were observed where the GetOverlappedResult() would just block indefinitely and never
+	   return in that case. */
+}
 
-	if(!thread) {
-		logger(LOG_ERR, _("System call `%s' failed: %s"), "CreateThread", winerror(GetLastError()));
-		return false;
-	}
+static void close_device(void) {
+	CancelIo(device_handle);
 
-	/* Wait for the tap reader to connect back to us */
+	/* According to MSDN, CancelIo() does not necessarily wait for the operation to complete.
+	   To prevent race conditions, make sure the operation is complete
+	   before we close the event it's referencing. */
 
-	if((device_fd = accept(sock, NULL, 0)) == -1) {
-		logger(LOG_ERR, _("System call `%s' failed: %s"), "accept", strerror(errno));
-		return false;
-	}
+	DWORD len;
 
-	closesocket(sock);
+	if(!GetOverlappedResult(device_handle, &device_read_overlapped, &len, TRUE) && GetLastError() != ERROR_OPERATION_ABORTED) {
+		logger(DEBUG_ALWAYS, LOG_ERR, "Could not wait for %s %s read to cancel: %s", device_info, device, winerror(GetLastError()));
+	}
 
-	/* Set media status for newer TAP-Win32 devices */
+	if(device_write_packet.len > 0 && !GetOverlappedResult(device_handle, &device_write_overlapped, &len, TRUE) && GetLastError() != ERROR_OPERATION_ABORTED) {
+		logger(DEBUG_ALWAYS, LOG_ERR, "Could not wait for %s %s write to cancel: %s", device_info, device, winerror(GetLastError()));
+	}
 
-	status = true;
-	DeviceIoControl(device_handle, TAP_IOCTL_SET_MEDIA_STATUS, &status, sizeof(status), &status, sizeof(status), &len, NULL);
+	device_write_packet.len = 0;
 
-	device_info = _("Windows tap device");
+	CloseHandle(device_read_overlapped.hEvent);
+	CloseHandle(device_write_overlapped.hEvent);
 
-	logger(LOG_INFO, _("%s (%s) is a %s"), device, iface, device_info);
+	CloseHandle(device_handle);
+	device_handle = INVALID_HANDLE_VALUE;
 
-	return true;
+	free(device);
+	device = NULL;
+	free(iface);
+	iface = NULL;
+	device_info = NULL;
 }
 
-void close_device(void)
-{
-	cp();
-
-	CloseHandle(device_handle);
+static bool read_packet(vpn_packet_t *packet) {
+	(void)packet;
+	return false;
 }
 
-bool read_packet(vpn_packet_t *packet)
-{
-	unsigned char bufno;
-
-	cp();
-
-	if((recv(device_fd, &bufno, 1, 0)) <= 0) {
-		logger(LOG_ERR, _("Error while reading from %s %s: %s"), device_info,
-			   device, strerror(errno));
-		return false;
-	}
-	
-	packet->len = bufs[bufno].len;
-	memcpy(packet->data, bufs[bufno].data, bufs[bufno].len);
+static bool write_packet(vpn_packet_t *packet) {
+	DWORD outlen;
 
-	device_total_in += packet->len;
+	logger(DEBUG_TRAFFIC, LOG_DEBUG, "Writing packet of %d bytes to %s",
+	       packet->len, device_info);
 
-	ifdebug(TRAFFIC) logger(LOG_DEBUG, _("Read packet of %d bytes from %s"), packet->len,
-			   device_info);
+	if(device_write_packet.len > 0) {
+		/* Make sure the previous write operation is finished before we start the next one;
+		   otherwise we end up with multiple write ops referencing the same OVERLAPPED structure,
+		   which according to MSDN is a no-no. */
 
-	return true;
-}
+		if(!GetOverlappedResult(device_handle, &device_write_overlapped, &outlen, FALSE)) {
+			if(GetLastError() != ERROR_IO_INCOMPLETE) {
+				logger(DEBUG_ALWAYS, LOG_ERR, "Error completing previously queued write to %s %s: %s", device_info, device, winerror(GetLastError()));
+			} else {
+				logger(DEBUG_TRAFFIC, LOG_ERR, "Previous overlapped write to %s %s still in progress", device_info, device);
+				// drop this packet
+				return true;
+			}
+		}
+	}
 
-bool write_packet(vpn_packet_t *packet)
-{
-	long lenout;
-	OVERLAPPED overlapped = {0};
+	/* Copy the packet, since the write operation might still be ongoing after we return. */
 
-	cp();
+	memcpy(&device_write_packet, packet, sizeof(*packet));
 
-	ifdebug(TRAFFIC) logger(LOG_DEBUG, _("Writing packet of %d bytes to %s"),
-			   packet->len, device_info);
+	ResetEvent(device_write_overlapped.hEvent);
 
-	if(!WriteFile(device_handle, packet->data, packet->len, &lenout, &overlapped)) {
-		logger(LOG_ERR, _("Error while writing to %s %s: %s"), device_info, device, winerror(GetLastError()));
+	if(WriteFile(device_handle, DATA(&device_write_packet), device_write_packet.len, &outlen, &device_write_overlapped)) {
+		// Write was completed immediately.
+		device_write_packet.len = 0;
+	} else if(GetLastError() != ERROR_IO_PENDING) {
+		logger(DEBUG_ALWAYS, LOG_ERR, "Error while writing to %s %s: %s", device_info, device, winerror(GetLastError()));
+		device_write_packet.len = 0;
 		return false;
 	}
 
-	device_total_out += packet->len;
-
 	return true;
 }
 
-void dump_device_stats(void)
-{
-	cp();
-
-	logger(LOG_DEBUG, _("Statistics for %s %s:"), device_info, device);
-	logger(LOG_DEBUG, _(" total bytes in:  %10d"), device_total_in);
-	logger(LOG_DEBUG, _(" total bytes out: %10d"), device_total_out);
-}
+const devops_t os_devops = {
+	.setup = setup_device,
+	.close = close_device,
+	.read = read_packet,
+	.write = write_packet,
+	.enable = enable_device,
+	.disable = disable_device,
+};