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 */
36 #include "net/tap.h" /* tap_has_ufo, ... */
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
;
689 uint8_t *buf
, *orig_buf
;
692 uint8_t min_pkt
[ETH_ZLEN
];
693 size_t min_pktsz
= sizeof(min_pkt
);
695 size
= tap_win32_read(s
->handle
, &buf
, max_size
);
699 if (net_peer_needs_padding(&s
->nc
)) {
700 if (eth_pad_short_frame(min_pkt
, &min_pktsz
, buf
, size
)) {
706 qemu_send_packet(&s
->nc
, buf
, size
);
707 tap_win32_free_buffer(s
->handle
, orig_buf
);
711 static bool tap_has_ufo(NetClientState
*nc
)
716 static bool tap_has_vnet_hdr(NetClientState
*nc
)
721 int tap_probe_vnet_hdr_len(int fd
, int len
)
726 void tap_fd_set_vnet_hdr_len(int fd
, int len
)
730 int tap_fd_set_vnet_le(int fd
, int is_le
)
735 int tap_fd_set_vnet_be(int fd
, int is_be
)
740 static void tap_using_vnet_hdr(NetClientState
*nc
, bool using_vnet_hdr
)
744 static void tap_set_offload(NetClientState
*nc
, int csum
, int tso4
,
745 int tso6
, int ecn
, int ufo
)
749 struct vhost_net
*tap_get_vhost_net(NetClientState
*nc
)
754 static bool tap_has_vnet_hdr_len(NetClientState
*nc
, int len
)
759 static void tap_set_vnet_hdr_len(NetClientState
*nc
, int len
)
764 static NetClientInfo net_tap_win32_info
= {
765 .type
= NET_CLIENT_DRIVER_TAP
,
766 .size
= sizeof(TAPState
),
767 .receive
= tap_receive
,
768 .cleanup
= tap_cleanup
,
769 .has_ufo
= tap_has_ufo
,
770 .has_vnet_hdr
= tap_has_vnet_hdr
,
771 .has_vnet_hdr_len
= tap_has_vnet_hdr_len
,
772 .using_vnet_hdr
= tap_using_vnet_hdr
,
773 .set_offload
= tap_set_offload
,
774 .set_vnet_hdr_len
= tap_set_vnet_hdr_len
,
777 static int tap_win32_init(NetClientState
*peer
, const char *model
,
778 const char *name
, const char *ifname
)
782 tap_win32_overlapped_t
*handle
;
784 if (tap_win32_open(&handle
, ifname
) < 0) {
785 printf("tap: Could not open '%s'\n", ifname
);
789 nc
= qemu_new_net_client(&net_tap_win32_info
, peer
, model
, name
);
791 s
= DO_UPCAST(TAPState
, nc
, nc
);
793 snprintf(s
->nc
.info_str
, sizeof(s
->nc
.info_str
),
794 "tap: ifname=%s", ifname
);
798 qemu_add_wait_object(s
->handle
->tap_semaphore
, tap_win32_send
, s
);
803 int net_init_tap(const Netdev
*netdev
, const char *name
,
804 NetClientState
*peer
, Error
**errp
)
806 /* FIXME error_setg(errp, ...) on failure */
807 const NetdevTapOptions
*tap
;
809 assert(netdev
->type
== NET_CLIENT_DRIVER_TAP
);
810 tap
= &netdev
->u
.tap
;
812 if (!tap
->has_ifname
) {
813 error_report("tap: no interface name");
817 if (tap_win32_init(peer
, "tap", name
, tap
->ifname
) == -1) {
824 int tap_enable(NetClientState
*nc
)
829 int tap_disable(NetClientState
*nc
)