0642725fa5247b9440967ac788e68fd45d5ba407
[tinc] / src / mingw / device.c
1 /*
2     device.c -- Interaction with Windows tap driver in a MinGW environment
3     Copyright (C) 2002-2005 Ivo Timmermans,
4                   2002-2013 Guus Sliepen <guus@tinc-vpn.org>
5
6     This program is free software; you can redistribute it and/or modify
7     it under the terms of the GNU General Public License as published by
8     the Free Software Foundation; either version 2 of the License, or
9     (at your option) any later version.
10
11     This program is distributed in the hope that it will be useful,
12     but WITHOUT ANY WARRANTY; without even the implied warranty of
13     MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
14     GNU General Public License for more details.
15
16     You should have received a copy of the GNU General Public License along
17     with this program; if not, write to the Free Software Foundation, Inc.,
18     51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
19 */
20
21 #include "../system.h"
22
23 #include <windows.h>
24 #include <winioctl.h>
25
26 #include "../conf.h"
27 #include "../device.h"
28 #include "../logger.h"
29 #include "../names.h"
30 #include "../net.h"
31 #include "../route.h"
32 #include "../utils.h"
33 #include "../xalloc.h"
34
35 #include "common.h"
36
37 int device_fd = -1;
38 static HANDLE device_handle = INVALID_HANDLE_VALUE;
39 char *device = NULL;
40 char *iface = NULL;
41 static char *device_info = NULL;
42
43 static uint64_t device_total_in = 0;
44 static uint64_t device_total_out = 0;
45
46 extern char *myport;
47
48 static DWORD WINAPI tapreader(void *bla) {
49         int status;
50         DWORD len;
51         OVERLAPPED overlapped;
52         vpn_packet_t packet;
53
54         logger(DEBUG_ALWAYS, LOG_DEBUG, "Tap reader running");
55
56         /* Read from tap device and send to parent */
57
58         overlapped.hEvent = CreateEvent(NULL, TRUE, FALSE, NULL);
59
60         for(;;) {
61                 overlapped.Offset = 0;
62                 overlapped.OffsetHigh = 0;
63                 ResetEvent(overlapped.hEvent);
64
65                 status = ReadFile(device_handle, (void *)packet.data, MTU, &len, &overlapped);
66
67                 if(!status) {
68                         if(GetLastError() == ERROR_IO_PENDING) {
69                                 WaitForSingleObject(overlapped.hEvent, INFINITE);
70                                 if(!GetOverlappedResult(device_handle, &overlapped, &len, FALSE))
71                                         continue;
72                         } else {
73                                 logger(DEBUG_ALWAYS, LOG_ERR, "Error while reading from %s %s: %s", device_info,
74                                            device, strerror(errno));
75                                 return -1;
76                         }
77                 }
78
79                 EnterCriticalSection(&mutex);
80                 packet.len = len;
81                 packet.priority = 0;
82                 route(myself, &packet);
83                 event_flush_output();
84                 LeaveCriticalSection(&mutex);
85         }
86 }
87
88 static bool setup_device(void) {
89         HKEY key, key2;
90         int i;
91
92         char regpath[1024];
93         char adapterid[1024];
94         char adaptername[1024];
95         char tapname[1024];
96         DWORD len;
97         unsigned long status;
98
99         bool found = false;
100
101         int err;
102         HANDLE thread;
103
104         get_config_string(lookup_config(config_tree, "Device"), &device);
105         get_config_string(lookup_config(config_tree, "Interface"), &iface);
106
107         /* Open registry and look for network adapters */
108
109         if(RegOpenKeyEx(HKEY_LOCAL_MACHINE, NETWORK_CONNECTIONS_KEY, 0, KEY_READ, &key)) {
110                 logger(DEBUG_ALWAYS, LOG_ERR, "Unable to read registry: %s", winerror(GetLastError()));
111                 return false;
112         }
113
114         for (i = 0; ; i++) {
115                 len = sizeof adapterid;
116                 if(RegEnumKeyEx(key, i, adapterid, &len, 0, 0, 0, NULL))
117                         break;
118
119                 /* Find out more about this adapter */
120
121                 snprintf(regpath, sizeof regpath, "%s\\%s\\Connection", NETWORK_CONNECTIONS_KEY, adapterid);
122
123                 if(RegOpenKeyEx(HKEY_LOCAL_MACHINE, regpath, 0, KEY_READ, &key2))
124                         continue;
125
126                 len = sizeof adaptername;
127                 err = RegQueryValueEx(key2, "Name", 0, 0, (LPBYTE)adaptername, &len);
128
129                 RegCloseKey(key2);
130
131                 if(err)
132                         continue;
133
134                 if(device) {
135                         if(!strcmp(device, adapterid)) {
136                                 found = true;
137                                 break;
138                         } else
139                                 continue;
140                 }
141
142                 if(iface) {
143                         if(!strcmp(iface, adaptername)) {
144                                 found = true;
145                                 break;
146                         } else
147                                 continue;
148                 }
149
150                 snprintf(tapname, sizeof tapname, USERMODEDEVICEDIR "%s" TAPSUFFIX, adapterid);
151                 device_handle = CreateFile(tapname, GENERIC_WRITE | GENERIC_READ, 0, 0, OPEN_EXISTING, FILE_ATTRIBUTE_SYSTEM | FILE_FLAG_OVERLAPPED, 0);
152                 if(device_handle != INVALID_HANDLE_VALUE) {
153                         found = true;
154                         break;
155                 }
156         }
157
158         RegCloseKey(key);
159
160         if(!found) {
161                 logger(DEBUG_ALWAYS, LOG_ERR, "No Windows tap device found!");
162                 return false;
163         }
164
165         if(!device)
166                 device = xstrdup(adapterid);
167
168         if(!iface)
169                 iface = xstrdup(adaptername);
170
171         /* Try to open the corresponding tap device */
172
173         if(device_handle == INVALID_HANDLE_VALUE) {
174                 snprintf(tapname, sizeof tapname, USERMODEDEVICEDIR "%s" TAPSUFFIX, device);
175                 device_handle = CreateFile(tapname, GENERIC_WRITE | GENERIC_READ, 0, 0, OPEN_EXISTING, FILE_ATTRIBUTE_SYSTEM | FILE_FLAG_OVERLAPPED, 0);
176         }
177
178         if(device_handle == INVALID_HANDLE_VALUE) {
179                 logger(DEBUG_ALWAYS, LOG_ERR, "%s (%s) is not a usable Windows tap device: %s", device, iface, winerror(GetLastError()));
180                 return false;
181         }
182
183         /* Get MAC address from tap device */
184
185         if(!DeviceIoControl(device_handle, TAP_IOCTL_GET_MAC, mymac.x, sizeof mymac.x, mymac.x, sizeof mymac.x, &len, 0)) {
186                 logger(DEBUG_ALWAYS, LOG_ERR, "Could not get MAC address from Windows tap device %s (%s): %s", device, iface, winerror(GetLastError()));
187                 return false;
188         }
189
190         if(routing_mode == RMODE_ROUTER) {
191                 overwrite_mac = 1;
192         }
193
194         /* Start the tap reader */
195
196         thread = CreateThread(NULL, 0, tapreader, NULL, 0, NULL);
197
198         if(!thread) {
199                 logger(DEBUG_ALWAYS, LOG_ERR, "System call `%s' failed: %s", "CreateThread", winerror(GetLastError()));
200                 return false;
201         }
202
203         /* Set media status for newer TAP-Win32 devices */
204
205         status = true;
206         DeviceIoControl(device_handle, TAP_IOCTL_SET_MEDIA_STATUS, &status, sizeof status, &status, sizeof status, &len, NULL);
207
208         device_info = "Windows tap device";
209
210         logger(DEBUG_ALWAYS, LOG_INFO, "%s (%s) is a %s", device, iface, device_info);
211
212         return true;
213 }
214
215 static void close_device(void) {
216         CloseHandle(device_handle);
217
218         free(device);
219         free(iface);
220 }
221
222 static bool read_packet(vpn_packet_t *packet) {
223         return false;
224 }
225
226 static bool write_packet(vpn_packet_t *packet) {
227         DWORD outlen;
228         OVERLAPPED overlapped = {0};
229
230         logger(DEBUG_TRAFFIC, LOG_DEBUG, "Writing packet of %d bytes to %s",
231                            packet->len, device_info);
232
233         if(!WriteFile(device_handle, packet->data, packet->len, &outlen, &overlapped)) {
234                 logger(DEBUG_ALWAYS, LOG_ERR, "Error while writing to %s %s: %s", device_info, device, winerror(GetLastError()));
235                 return false;
236         }
237
238         device_total_out += packet->len;
239
240         return true;
241 }
242
243 const devops_t os_devops = {
244         .setup = setup_device,
245         .close = close_device,
246         .read = read_packet,
247         .write = write_packet,
248 };