2 * TAP-Win32 -- A kernel driver to provide virtual tap device functionality
3 * on Windows. Originally derived from the CIPE-Win32
4 * project by Damion K. Wilson, with extensive modifications by
7 * All source code which derives from the CIPE-Win32 project is
8 * Copyright (C) Damion K. Wilson, 2003, and is released under the
9 * GPL version 2 (see below).
11 * All other source code is Copyright (C) James Yonan, 2003-2004,
12 * and is released under the GPL version 2 (see below).
14 * This program is free software; you can redistribute it and/or modify
15 * it under the terms of the GNU General Public License as published by
16 * the Free Software Foundation; either version 2 of the License, or
17 * (at your option) any later version.
19 * This program is distributed in the hope that it will be useful,
20 * but WITHOUT ANY WARRANTY; without even the implied warranty of
21 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
22 * GNU General Public License for more details.
24 * You should have received a copy of the GNU General Public License
25 * along with this program (see the file COPYING included with this
26 * distribution); if not, see <http://www.gnu.org/licenses/>.
29 #include "qemu/osdep.h"
32 #include "qemu-common.h"
33 #include "clients.h" /* net_init_tap */
35 #include "net/tap.h" /* tap_has_ufo, ... */
36 #include "sysemu/sysemu.h"
37 #include "qemu/error-report.h"
38 #include "qemu/main-loop.h"
46 #define TAP_CONTROL_CODE(request,method) \
47 CTL_CODE (FILE_DEVICE_UNKNOWN, request, method, FILE_ANY_ACCESS)
49 #define TAP_IOCTL_GET_MAC TAP_CONTROL_CODE (1, METHOD_BUFFERED)
50 #define TAP_IOCTL_GET_VERSION TAP_CONTROL_CODE (2, METHOD_BUFFERED)
51 #define TAP_IOCTL_GET_MTU TAP_CONTROL_CODE (3, METHOD_BUFFERED)
52 #define TAP_IOCTL_GET_INFO TAP_CONTROL_CODE (4, METHOD_BUFFERED)
53 #define TAP_IOCTL_CONFIG_POINT_TO_POINT TAP_CONTROL_CODE (5, METHOD_BUFFERED)
54 #define TAP_IOCTL_SET_MEDIA_STATUS TAP_CONTROL_CODE (6, METHOD_BUFFERED)
55 #define TAP_IOCTL_CONFIG_DHCP_MASQ TAP_CONTROL_CODE (7, METHOD_BUFFERED)
56 #define TAP_IOCTL_GET_LOG_LINE TAP_CONTROL_CODE (8, METHOD_BUFFERED)
57 #define TAP_IOCTL_CONFIG_DHCP_SET_OPT TAP_CONTROL_CODE (9, METHOD_BUFFERED)
63 #define ADAPTER_KEY "SYSTEM\\CurrentControlSet\\Control\\Class\\{4D36E972-E325-11CE-BFC1-08002BE10318}"
65 #define NETWORK_CONNECTIONS_KEY "SYSTEM\\CurrentControlSet\\Control\\Network\\{4D36E972-E325-11CE-BFC1-08002BE10318}"
67 //======================
68 // Filesystem prefixes
69 //======================
71 #define USERMODEDEVICEDIR "\\\\.\\Global\\"
72 #define TAPSUFFIX ".tap"
75 //======================
76 // Compile time configuration
77 //======================
79 //#define DEBUG_TAP_WIN32
81 /* FIXME: The asynch write path appears to be broken at
82 * present. WriteFile() ignores the lpNumberOfBytesWritten parameter
83 * for overlapped writes, with the result we return zero bytes sent,
84 * and after handling a single packet, receive is disabled for this
86 /* #define TUN_ASYNCHRONOUS_WRITES 1 */
88 #define TUN_BUFFER_SIZE 1560
89 #define TUN_MAX_BUFFER_COUNT 32
92 * The data member "buffer" must be the first element in the tun_buffer
93 * structure. See the function, tap_win32_free_buffer.
95 typedef struct tun_buffer_s {
96 unsigned char buffer [TUN_BUFFER_SIZE];
97 unsigned long read_size;
98 struct tun_buffer_s* next;
101 typedef struct tap_win32_overlapped {
105 HANDLE output_queue_semaphore;
106 HANDLE free_list_semaphore;
107 HANDLE tap_semaphore;
108 CRITICAL_SECTION output_queue_cs;
109 CRITICAL_SECTION free_list_cs;
110 OVERLAPPED read_overlapped;
111 OVERLAPPED write_overlapped;
112 tun_buffer_t buffers[TUN_MAX_BUFFER_COUNT];
113 tun_buffer_t* free_list;
114 tun_buffer_t* output_queue_front;
115 tun_buffer_t* output_queue_back;
116 } tap_win32_overlapped_t;
118 static tap_win32_overlapped_t tap_overlapped;
120 static tun_buffer_t* get_buffer_from_free_list(tap_win32_overlapped_t* const overlapped)
122 tun_buffer_t* buffer = NULL;
123 WaitForSingleObject(overlapped->free_list_semaphore, INFINITE);
124 EnterCriticalSection(&overlapped->free_list_cs);
125 buffer = overlapped->free_list;
126 // assert(buffer != NULL);
127 overlapped->free_list = buffer->next;
128 LeaveCriticalSection(&overlapped->free_list_cs);
133 static void put_buffer_on_free_list(tap_win32_overlapped_t* const overlapped, tun_buffer_t* const buffer)
135 EnterCriticalSection(&overlapped->free_list_cs);
136 buffer->next = overlapped->free_list;
137 overlapped->free_list = buffer;
138 LeaveCriticalSection(&overlapped->free_list_cs);
139 ReleaseSemaphore(overlapped->free_list_semaphore, 1, NULL);
142 static tun_buffer_t* get_buffer_from_output_queue(tap_win32_overlapped_t* const overlapped, const int block)
144 tun_buffer_t* buffer = NULL;
145 DWORD result, timeout = block ? INFINITE : 0L;
148 result = WaitForSingleObject(overlapped->output_queue_semaphore, timeout);
152 // The semaphore object was signaled.
154 EnterCriticalSection(&overlapped->output_queue_cs);
156 buffer = overlapped->output_queue_front;
157 overlapped->output_queue_front = buffer->next;
159 if(overlapped->output_queue_front == NULL) {
160 overlapped->output_queue_back = NULL;
163 LeaveCriticalSection(&overlapped->output_queue_cs);
166 // Semaphore was nonsignaled, so a time-out occurred.
168 // Cannot open another window.
175 static tun_buffer_t* get_buffer_from_output_queue_immediate (tap_win32_overlapped_t* const overlapped)
177 return get_buffer_from_output_queue(overlapped, 0);
180 static void put_buffer_on_output_queue(tap_win32_overlapped_t* const overlapped, tun_buffer_t* const buffer)
182 EnterCriticalSection(&overlapped->output_queue_cs);
184 if(overlapped->output_queue_front == NULL && overlapped->output_queue_back == NULL) {
185 overlapped->output_queue_front = overlapped->output_queue_back = buffer;
188 overlapped->output_queue_back->next = buffer;
189 overlapped->output_queue_back = buffer;
192 LeaveCriticalSection(&overlapped->output_queue_cs);
194 ReleaseSemaphore(overlapped->output_queue_semaphore, 1, NULL);
198 static int is_tap_win32_dev(const char *guid)
205 status = RegOpenKeyEx(
212 if (status != ERROR_SUCCESS) {
218 char unit_string[256];
220 char component_id_string[] = "ComponentId";
221 char component_id[256];
222 char net_cfg_instance_id_string[] = "NetCfgInstanceId";
223 char net_cfg_instance_id[256];
226 len = sizeof (enum_name);
227 status = RegEnumKeyEx(
237 if (status == ERROR_NO_MORE_ITEMS)
239 else if (status != ERROR_SUCCESS) {
243 snprintf (unit_string, sizeof(unit_string), "%s\\%s",
244 ADAPTER_KEY, enum_name);
246 status = RegOpenKeyEx(
253 if (status != ERROR_SUCCESS) {
256 len = sizeof (component_id);
257 status = RegQueryValueEx(
262 (LPBYTE)component_id,
265 if (!(status != ERROR_SUCCESS || data_type != REG_SZ)) {
266 len = sizeof (net_cfg_instance_id);
267 status = RegQueryValueEx(
269 net_cfg_instance_id_string,
272 (LPBYTE)net_cfg_instance_id,
275 if (status == ERROR_SUCCESS && data_type == REG_SZ) {
276 if (/* !strcmp (component_id, TAP_COMPONENT_ID) &&*/
277 !strcmp (net_cfg_instance_id, guid)) {
278 RegCloseKey (unit_key);
279 RegCloseKey (netcard_key);
284 RegCloseKey (unit_key);
289 RegCloseKey (netcard_key);
293 static int get_device_guid(
297 int actual_name_size)
300 HKEY control_net_key;
305 status = RegOpenKeyEx(
307 NETWORK_CONNECTIONS_KEY,
312 if (status != ERROR_SUCCESS) {
319 char connection_string[256];
323 const char name_string[] = "Name";
325 len = sizeof (enum_name);
326 status = RegEnumKeyEx(
336 if (status == ERROR_NO_MORE_ITEMS)
338 else if (status != ERROR_SUCCESS) {
342 snprintf(connection_string,
343 sizeof(connection_string),
344 "%s\\%s\\Connection",
345 NETWORK_CONNECTIONS_KEY, enum_name);
347 status = RegOpenKeyEx(
354 if (status == ERROR_SUCCESS) {
355 len = sizeof (name_data);
356 status = RegQueryValueEx(
364 if (status != ERROR_SUCCESS || name_type != REG_SZ) {
369 if (is_tap_win32_dev(enum_name)) {
370 snprintf(name, name_size, "%s", enum_name);
372 if (strcmp(actual_name, "") != 0) {
373 if (strcmp(name_data, actual_name) != 0) {
374 RegCloseKey (connection_key);
380 snprintf(actual_name, actual_name_size, "%s", name_data);
387 RegCloseKey (connection_key);
392 RegCloseKey (control_net_key);
400 static int tap_win32_set_status(HANDLE handle, int status)
402 unsigned long len = 0;
404 return DeviceIoControl(handle, TAP_IOCTL_SET_MEDIA_STATUS,
405 &status, sizeof (status),
406 &status, sizeof (status), &len, NULL);
409 static void tap_win32_overlapped_init(tap_win32_overlapped_t* const overlapped, const HANDLE handle)
411 overlapped->handle = handle;
413 overlapped->read_event = CreateEvent(NULL, FALSE, FALSE, NULL);
414 overlapped->write_event = CreateEvent(NULL, FALSE, FALSE, NULL);
416 overlapped->read_overlapped.Offset = 0;
417 overlapped->read_overlapped.OffsetHigh = 0;
418 overlapped->read_overlapped.hEvent = overlapped->read_event;
420 overlapped->write_overlapped.Offset = 0;
421 overlapped->write_overlapped.OffsetHigh = 0;
422 overlapped->write_overlapped.hEvent = overlapped->write_event;
424 InitializeCriticalSection(&overlapped->output_queue_cs);
425 InitializeCriticalSection(&overlapped->free_list_cs);
427 overlapped->output_queue_semaphore = CreateSemaphore(
428 NULL, // default security attributes
430 TUN_MAX_BUFFER_COUNT, // maximum count
431 NULL); // unnamed semaphore
433 if(!overlapped->output_queue_semaphore) {
434 fprintf(stderr, "error creating output queue semaphore!\n");
437 overlapped->free_list_semaphore = CreateSemaphore(
438 NULL, // default security attributes
439 TUN_MAX_BUFFER_COUNT, // initial count
440 TUN_MAX_BUFFER_COUNT, // maximum count
441 NULL); // unnamed semaphore
443 if(!overlapped->free_list_semaphore) {
444 fprintf(stderr, "error creating free list semaphore!\n");
447 overlapped->free_list = overlapped->output_queue_front = overlapped->output_queue_back = NULL;
451 for(index = 0; index < TUN_MAX_BUFFER_COUNT; index++) {
452 tun_buffer_t* element = &overlapped->buffers[index];
453 element->next = overlapped->free_list;
454 overlapped->free_list = element;
457 /* To count buffers, initially no-signal. */
458 overlapped->tap_semaphore = CreateSemaphore(NULL, 0, TUN_MAX_BUFFER_COUNT, NULL);
459 if(!overlapped->tap_semaphore)
460 fprintf(stderr, "error creating tap_semaphore.\n");
463 static int tap_win32_write(tap_win32_overlapped_t *overlapped,
464 const void *buffer, unsigned long size)
466 unsigned long write_size;
470 #ifdef TUN_ASYNCHRONOUS_WRITES
471 result = GetOverlappedResult( overlapped->handle, &overlapped->write_overlapped,
474 if (!result && GetLastError() == ERROR_IO_INCOMPLETE)
475 WaitForSingleObject(overlapped->write_event, INFINITE);
478 result = WriteFile(overlapped->handle, buffer, size,
479 &write_size, &overlapped->write_overlapped);
481 #ifdef TUN_ASYNCHRONOUS_WRITES
482 /* FIXME: we can't sensibly set write_size here, without waiting
483 * for the IO to complete! Moreover, we can't return zero,
484 * because that will disable receive on this interface, and we
485 * also can't assume it will succeed and return the full size,
486 * because that will result in the buffer being reclaimed while
487 * the IO is in progress. */
488 #error Async writes are broken. Please disable TUN_ASYNCHRONOUS_WRITES.
489 #else /* !TUN_ASYNCHRONOUS_WRITES */
491 error = GetLastError();
492 if (error == ERROR_IO_PENDING) {
493 result = GetOverlappedResult(overlapped->handle,
494 &overlapped->write_overlapped,
501 #ifdef DEBUG_TAP_WIN32
503 error = GetLastError();
504 FormatMessage(FORMAT_MESSAGE_ALLOCATE_BUFFER|FORMAT_MESSAGE_FROM_SYSTEM,
505 NULL, error, MAKELANGID(LANG_NEUTRAL, SUBLANG_DEFAULT),
507 fprintf(stderr, "Tap-Win32: Error WriteFile %d - %s\n", error, msgbuf);
516 static DWORD WINAPI tap_win32_thread_entry(LPVOID param)
518 tap_win32_overlapped_t *overlapped = (tap_win32_overlapped_t*)param;
519 unsigned long read_size;
522 tun_buffer_t* buffer = get_buffer_from_free_list(overlapped);
526 result = ReadFile(overlapped->handle,
528 sizeof(buffer->buffer),
530 &overlapped->read_overlapped);
532 dwError = GetLastError();
533 if (dwError == ERROR_IO_PENDING) {
534 WaitForSingleObject(overlapped->read_event, INFINITE);
535 result = GetOverlappedResult( overlapped->handle, &overlapped->read_overlapped,
538 #ifdef DEBUG_TAP_WIN32
540 dwError = GetLastError();
541 FormatMessage( FORMAT_MESSAGE_ALLOCATE_BUFFER | FORMAT_MESSAGE_FROM_SYSTEM,
542 NULL, dwError, MAKELANGID(LANG_NEUTRAL, SUBLANG_DEFAULT),
543 (LPTSTR) & lpBuffer, 0, NULL );
544 fprintf(stderr, "Tap-Win32: Error GetOverlappedResult %d - %s\n", dwError, lpBuffer);
545 LocalFree( lpBuffer );
549 #ifdef DEBUG_TAP_WIN32
551 FormatMessage( FORMAT_MESSAGE_ALLOCATE_BUFFER | FORMAT_MESSAGE_FROM_SYSTEM,
552 NULL, dwError, MAKELANGID(LANG_NEUTRAL, SUBLANG_DEFAULT),
553 (LPTSTR) & lpBuffer, 0, NULL );
554 fprintf(stderr, "Tap-Win32: Error ReadFile %d - %s\n", dwError, lpBuffer);
555 LocalFree( lpBuffer );
561 buffer->read_size = read_size;
562 put_buffer_on_output_queue(overlapped, buffer);
563 ReleaseSemaphore(overlapped->tap_semaphore, 1, NULL);
564 buffer = get_buffer_from_free_list(overlapped);
571 static int tap_win32_read(tap_win32_overlapped_t *overlapped,
572 uint8_t **pbuf, int max_size)
576 tun_buffer_t* buffer = get_buffer_from_output_queue_immediate(overlapped);
579 *pbuf = buffer->buffer;
580 size = (int)buffer->read_size;
581 if(size > max_size) {
589 static void tap_win32_free_buffer(tap_win32_overlapped_t *overlapped,
592 tun_buffer_t* buffer = (tun_buffer_t*)pbuf;
593 put_buffer_on_free_list(overlapped, buffer);
596 static int tap_win32_open(tap_win32_overlapped_t **phandle,
597 const char *preferred_name)
599 char device_path[256];
600 char device_guid[0x100];
604 char name_buffer[0x100] = {0, };
613 if (preferred_name != NULL) {
614 snprintf(name_buffer, sizeof(name_buffer), "%s", preferred_name);
617 rc = get_device_guid(device_guid, sizeof(device_guid), name_buffer, sizeof(name_buffer));
621 snprintf (device_path, sizeof(device_path), "%s%s%s",
626 handle = CreateFile (
628 GENERIC_READ | GENERIC_WRITE,
632 FILE_ATTRIBUTE_SYSTEM | FILE_FLAG_OVERLAPPED,
635 if (handle == INVALID_HANDLE_VALUE) {
639 bret = DeviceIoControl(handle, TAP_IOCTL_GET_VERSION,
640 &version, sizeof (version),
641 &version, sizeof (version), &version_len, NULL);
648 if (!tap_win32_set_status(handle, TRUE)) {
652 tap_win32_overlapped_init(&tap_overlapped, handle);
654 *phandle = &tap_overlapped;
656 CreateThread(NULL, 0, tap_win32_thread_entry,
657 (LPVOID)&tap_overlapped, 0, &idThread);
661 /********************************************/
663 typedef struct TAPState {
665 tap_win32_overlapped_t *handle;
668 static void tap_cleanup(NetClientState *nc)
670 TAPState *s = DO_UPCAST(TAPState, nc, nc);
672 qemu_del_wait_object(s->handle->tap_semaphore, NULL, NULL);
674 /* FIXME: need to kill thread and close file handle:
679 static ssize_t tap_receive(NetClientState *nc, const uint8_t *buf, size_t size)
681 TAPState *s = DO_UPCAST(TAPState, nc, nc);
683 return tap_win32_write(s->handle, buf, size);
686 static void tap_win32_send(void *opaque)
688 TAPState *s = opaque;
693 size = tap_win32_read(s->handle, &buf, max_size);
695 qemu_send_packet(&s->nc, buf, size);
696 tap_win32_free_buffer(s->handle, buf);
700 static bool tap_has_ufo(NetClientState *nc)
705 static bool tap_has_vnet_hdr(NetClientState *nc)
710 int tap_probe_vnet_hdr_len(int fd, int len)
715 void tap_fd_set_vnet_hdr_len(int fd, int len)
719 int tap_fd_set_vnet_le(int fd, int is_le)
724 int tap_fd_set_vnet_be(int fd, int is_be)
729 static void tap_using_vnet_hdr(NetClientState *nc, bool using_vnet_hdr)
733 static void tap_set_offload(NetClientState *nc, int csum, int tso4,
734 int tso6, int ecn, int ufo)
738 struct vhost_net *tap_get_vhost_net(NetClientState *nc)
743 static bool tap_has_vnet_hdr_len(NetClientState *nc, int len)
748 static void tap_set_vnet_hdr_len(NetClientState *nc, int len)
753 static NetClientInfo net_tap_win32_info = {
754 .type = NET_CLIENT_DRIVER_TAP,
755 .size = sizeof(TAPState),
756 .receive = tap_receive,
757 .cleanup = tap_cleanup,
758 .has_ufo = tap_has_ufo,
759 .has_vnet_hdr = tap_has_vnet_hdr,
760 .has_vnet_hdr_len = tap_has_vnet_hdr_len,
761 .using_vnet_hdr = tap_using_vnet_hdr,
762 .set_offload = tap_set_offload,
763 .set_vnet_hdr_len = tap_set_vnet_hdr_len,
766 static int tap_win32_init(NetClientState *peer, const char *model,
767 const char *name, const char *ifname)
771 tap_win32_overlapped_t *handle;
773 if (tap_win32_open(&handle, ifname) < 0) {
774 printf("tap: Could not open '%s'\n", ifname);
778 nc = qemu_new_net_client(&net_tap_win32_info, peer, model, name);
780 s = DO_UPCAST(TAPState, nc, nc);
782 snprintf(s->nc.info_str, sizeof(s->nc.info_str),
783 "tap: ifname=%s", ifname);
787 qemu_add_wait_object(s->handle->tap_semaphore, tap_win32_send, s);
792 int net_init_tap(const Netdev *netdev, const char *name,
793 NetClientState *peer, Error **errp)
795 /* FIXME error_setg(errp, ...) on failure */
796 const NetdevTapOptions *tap;
798 assert(netdev->type == NET_CLIENT_DRIVER_TAP);
799 tap = &netdev->u.tap;
801 if (!tap->has_ifname) {
802 error_report("tap: no interface name");
806 if (tap_win32_init(peer, "tap", name, tap->ifname) == -1) {
813 int tap_enable(NetClientState *nc)
818 int tap_disable(NetClientState *nc)