]> git.meshlink.io Git - meshlink/blob - src/mingw/device.c
Fix sparse warnings and add an extra sprinkling of const.
[meshlink] / 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                   2002-2011 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 "net.h"
30 #include "route.h"
31 #include "utils.h"
32 #include "xalloc.h"
33
34 #include "mingw/common.h"
35
36 int device_fd = -1;
37 static HANDLE device_handle = INVALID_HANDLE_VALUE;
38 char *device = NULL;
39 char *iface = NULL;
40 static char *device_info = NULL;
41
42 static uint64_t device_total_in = 0;
43 static uint64_t device_total_out = 0;
44
45 extern char *myport;
46
47 static DWORD WINAPI tapreader(void *bla) {
48         int status;
49         long len;
50         OVERLAPPED overlapped;
51         vpn_packet_t packet;
52
53         logger(LOG_DEBUG, "Tap reader running");
54
55         /* Read from tap device and send to parent */
56
57         overlapped.hEvent = CreateEvent(NULL, TRUE, FALSE, NULL);
58
59         for(;;) {
60                 overlapped.Offset = 0;
61                 overlapped.OffsetHigh = 0;
62                 ResetEvent(overlapped.hEvent);
63
64                 status = ReadFile(device_handle, packet.data, MTU, &len, &overlapped);
65
66                 if(!status) {
67                         if(GetLastError() == ERROR_IO_PENDING) {
68                                 WaitForSingleObject(overlapped.hEvent, INFINITE);
69                                 if(!GetOverlappedResult(device_handle, &overlapped, &len, FALSE))
70                                         continue;
71                         } else {
72                                 logger(LOG_ERR, "Error while reading from %s %s: %s", device_info,
73                                            device, strerror(errno));
74                                 return -1;
75                         }
76                 }
77
78                 EnterCriticalSection(&mutex);
79                 packet.len = len;
80                 packet.priority = 0;
81                 route(myself, &packet);
82                 LeaveCriticalSection(&mutex);
83         }
84 }
85
86 bool setup_device(void) {
87         HKEY key, key2;
88         int i;
89
90         char regpath[1024];
91         char adapterid[1024];
92         char adaptername[1024];
93         char tapname[1024];
94         long len;
95         unsigned long status;
96
97         bool found = false;
98
99         int err;
100         HANDLE thread;
101
102         get_config_string(lookup_config(config_tree, "Device"), &device);
103         get_config_string(lookup_config(config_tree, "Interface"), &iface);
104
105         /* Open registry and look for network adapters */
106
107         if(RegOpenKeyEx(HKEY_LOCAL_MACHINE, NETWORK_CONNECTIONS_KEY, 0, KEY_READ, &key)) {
108                 logger(LOG_ERR, "Unable to read registry: %s", winerror(GetLastError()));
109                 return false;
110         }
111
112         for (i = 0; ; i++) {
113                 len = sizeof(adapterid);
114                 if(RegEnumKeyEx(key, i, adapterid, &len, 0, 0, 0, NULL))
115                         break;
116
117                 /* Find out more about this adapter */
118
119                 snprintf(regpath, sizeof(regpath), "%s\\%s\\Connection", NETWORK_CONNECTIONS_KEY, adapterid);
120
121                 if(RegOpenKeyEx(HKEY_LOCAL_MACHINE, regpath, 0, KEY_READ, &key2))
122                         continue;
123
124                 len = sizeof(adaptername);
125                 err = RegQueryValueEx(key2, "Name", 0, 0, adaptername, &len);
126
127                 RegCloseKey(key2);
128
129                 if(err)
130                         continue;
131
132                 if(device) {
133                         if(!strcmp(device, adapterid)) {
134                                 found = true;
135                                 break;
136                         } else
137                                 continue;
138                 }
139
140                 if(iface) {
141                         if(!strcmp(iface, adaptername)) {
142                                 found = true;
143                                 break;
144                         } else
145                                 continue;
146                 }
147
148                 snprintf(tapname, sizeof(tapname), USERMODEDEVICEDIR "%s" TAPSUFFIX, adapterid);
149                 device_handle = CreateFile(tapname, GENERIC_WRITE | GENERIC_READ, 0, 0, OPEN_EXISTING, FILE_ATTRIBUTE_SYSTEM | FILE_FLAG_OVERLAPPED, 0);
150                 if(device_handle != INVALID_HANDLE_VALUE) {
151                         found = true;
152                         break;
153                 }
154         }
155
156         RegCloseKey(key);
157
158         if(!found) {
159                 logger(LOG_ERR, "No Windows tap device found!");
160                 return false;
161         }
162
163         if(!device)
164                 device = xstrdup(adapterid);
165
166         if(!iface)
167                 iface = xstrdup(adaptername);
168
169         /* Try to open the corresponding tap device */
170
171         if(device_handle == INVALID_HANDLE_VALUE) {
172                 snprintf(tapname, sizeof(tapname), USERMODEDEVICEDIR "%s" TAPSUFFIX, device);
173                 device_handle = CreateFile(tapname, GENERIC_WRITE | GENERIC_READ, 0, 0, OPEN_EXISTING, FILE_ATTRIBUTE_SYSTEM | FILE_FLAG_OVERLAPPED, 0);
174         }
175         
176         if(device_handle == INVALID_HANDLE_VALUE) {
177                 logger(LOG_ERR, "%s (%s) is not a usable Windows tap device: %s", device, iface, winerror(GetLastError()));
178                 return false;
179         }
180
181         /* Get MAC address from tap device */
182
183         if(!DeviceIoControl(device_handle, TAP_IOCTL_GET_MAC, mymac.x, sizeof(mymac.x), mymac.x, sizeof(mymac.x), &len, 0)) {
184                 logger(LOG_ERR, "Could not get MAC address from Windows tap device %s (%s): %s", device, iface, winerror(GetLastError()));
185                 return false;
186         }
187
188         if(routing_mode == RMODE_ROUTER) {
189                 overwrite_mac = 1;
190         }
191
192         /* Start the tap reader */
193
194         thread = CreateThread(NULL, 0, tapreader, NULL, 0, NULL);
195
196         if(!thread) {
197                 logger(LOG_ERR, "System call `%s' failed: %s", "CreateThread", winerror(GetLastError()));
198                 return false;
199         }
200
201         /* Set media status for newer TAP-Win32 devices */
202
203         status = true;
204         DeviceIoControl(device_handle, TAP_IOCTL_SET_MEDIA_STATUS, &status, sizeof(status), &status, sizeof(status), &len, NULL);
205
206         device_info = "Windows tap device";
207
208         logger(LOG_INFO, "%s (%s) is a %s", device, iface, device_info);
209
210         return true;
211 }
212
213 void close_device(void) {
214         CloseHandle(device_handle);
215
216         free(device);
217         free(iface);
218 }
219
220 bool read_packet(vpn_packet_t *packet) {
221         return false;
222 }
223
224 bool write_packet(vpn_packet_t *packet) {
225         long lenout;
226         OVERLAPPED overlapped = {0};
227
228         ifdebug(TRAFFIC) logger(LOG_DEBUG, "Writing packet of %d bytes to %s",
229                            packet->len, device_info);
230
231         if(!WriteFile(device_handle, packet->data, packet->len, &lenout, &overlapped)) {
232                 logger(LOG_ERR, "Error while writing to %s %s: %s", device_info, device, winerror(GetLastError()));
233                 return false;
234         }
235
236         device_total_out += packet->len;
237
238         return true;
239 }
240
241 void dump_device_stats(void) {
242         logger(LOG_DEBUG, "Statistics for %s %s:", device_info, device);
243         logger(LOG_DEBUG, " total bytes in:  %10"PRIu64, device_total_in);
244         logger(LOG_DEBUG, " total bytes out: %10"PRIu64, device_total_out);
245 }