Releasing 1.0.20.
[tinc] / src / cygwin / device.c
1 /*
2     device.c -- Interaction with Windows tap driver in a Cygwin 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 <w32api/windows.h>
24 #include <w32api/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 static pid_t reader_pid;
46 static int sp[2];
47
48 static bool setup_device(void) {
49         HKEY key, key2;
50         int i, err;
51
52         char regpath[1024];
53         char adapterid[1024];
54         char adaptername[1024];
55         char tapname[1024];
56         char gelukt = 0;
57         long len;
58
59         bool found = false;
60
61         get_config_string(lookup_config(config_tree, "Device"), &device);
62         get_config_string(lookup_config(config_tree, "Interface"), &iface);
63
64         /* Open registry and look for network adapters */
65
66         if(RegOpenKeyEx(HKEY_LOCAL_MACHINE, NETWORK_CONNECTIONS_KEY, 0, KEY_READ, &key)) {
67                 logger(LOG_ERR, "Unable to read registry: %s", winerror(GetLastError()));
68                 return false;
69         }
70
71         for (i = 0; ; i++) {
72                 len = sizeof(adapterid);
73                 if(RegEnumKeyEx(key, i, adapterid, &len, 0, 0, 0, NULL))
74                         break;
75
76                 /* Find out more about this adapter */
77
78                 snprintf(regpath, sizeof(regpath), "%s\\%s\\Connection", NETWORK_CONNECTIONS_KEY, adapterid);
79
80                 if(RegOpenKeyEx(HKEY_LOCAL_MACHINE, regpath, 0, KEY_READ, &key2))
81                         continue;
82
83                 len = sizeof(adaptername);
84                 err = RegQueryValueEx(key2, "Name", 0, 0, adaptername, &len);
85
86                 RegCloseKey(key2);
87
88                 if(err)
89                         continue;
90
91                 if(device) {
92                         if(!strcmp(device, adapterid)) {
93                                 found = true;
94                                 break;
95                         } else
96                                 continue;
97                 }
98
99                 if(iface) {
100                         if(!strcmp(iface, adaptername)) {
101                                 found = true;
102                                 break;
103                         } else
104                                 continue;
105                 }
106
107                 snprintf(tapname, sizeof(tapname), USERMODEDEVICEDIR "%s" TAPSUFFIX, adapterid);
108                 device_handle = CreateFile(tapname, GENERIC_WRITE | GENERIC_READ, 0, 0, OPEN_EXISTING, FILE_ATTRIBUTE_SYSTEM, 0);
109                 if(device_handle != INVALID_HANDLE_VALUE) {
110                         CloseHandle(device_handle);
111                         found = true;
112                         break;
113                 }
114         }
115
116         RegCloseKey(key);
117
118         if(!found) {
119                 logger(LOG_ERR, "No Windows tap device found!");
120                 return false;
121         }
122
123         if(!device)
124                 device = xstrdup(adapterid);
125
126         if(!iface)
127                 iface = xstrdup(adaptername);
128
129         snprintf(tapname, sizeof(tapname), USERMODEDEVICEDIR "%s" TAPSUFFIX, device);
130         
131         /* Now we are going to open this device twice: once for reading and once for writing.
132            We do this because apparently it isn't possible to check for activity in the select() loop.
133            Furthermore I don't really know how to do it the "Windows" way. */
134
135         if(socketpair(AF_UNIX, SOCK_DGRAM, PF_UNIX, sp)) {
136                 logger(LOG_DEBUG, "System call `%s' failed: %s", "socketpair", strerror(errno));
137                 return false;
138         }
139
140         /* The parent opens the tap device for writing. */
141         
142         device_handle = CreateFile(tapname, GENERIC_WRITE,  FILE_SHARE_READ,  0,  OPEN_EXISTING, FILE_ATTRIBUTE_SYSTEM , 0);
143         
144         if(device_handle == INVALID_HANDLE_VALUE) {
145                 logger(LOG_ERR, "Could not open Windows tap device %s (%s) for writing: %s", device, iface, winerror(GetLastError()));
146                 return false;
147         }
148
149         device_fd = sp[0];
150
151         /* Get MAC address from tap device */
152
153         if(!DeviceIoControl(device_handle, TAP_IOCTL_GET_MAC, mymac.x, sizeof(mymac.x), mymac.x, sizeof(mymac.x), &len, 0)) {
154                 logger(LOG_ERR, "Could not get MAC address from Windows tap device %s (%s): %s", device, iface, winerror(GetLastError()));
155                 return false;
156         }
157
158         if(routing_mode == RMODE_ROUTER) {
159                 overwrite_mac = 1;
160         }
161
162         /* Now we start the child */
163
164         reader_pid = fork();
165
166         if(reader_pid == -1) {
167                 logger(LOG_DEBUG, "System call `%s' failed: %s", "fork", strerror(errno));
168                 return false;
169         }
170
171         if(!reader_pid) {
172                 /* The child opens the tap device for reading, blocking.
173                    It passes everything it reads to the socket. */
174         
175                 char buf[MTU];
176                 long lenin;
177
178                 CloseHandle(device_handle);
179
180                 device_handle = CreateFile(tapname, GENERIC_READ, FILE_SHARE_WRITE, 0,  OPEN_EXISTING, FILE_ATTRIBUTE_SYSTEM, 0);
181
182                 if(device_handle == INVALID_HANDLE_VALUE) {
183                         logger(LOG_ERR, "Could not open Windows tap device %s (%s) for reading: %s", device, iface, winerror(GetLastError()));
184                         buf[0] = 0;
185                         write(sp[1], buf, 1);
186                         exit(1);
187                 }
188
189                 logger(LOG_DEBUG, "Tap reader forked and running.");
190
191                 /* Notify success */
192
193                 buf[0] = 1;
194                 write(sp[1], buf, 1);
195
196                 /* Pass packets */
197
198                 for(;;) {
199                         ReadFile(device_handle, buf, MTU, &lenin, NULL);
200                         write(sp[1], buf, lenin);
201                 }
202         }
203
204         read(device_fd, &gelukt, 1);
205         if(gelukt != 1) {
206                 logger(LOG_DEBUG, "Tap reader failed!");
207                 return false;
208         }
209
210         device_info = "Windows tap device";
211
212         logger(LOG_INFO, "%s (%s) is a %s", device, iface, device_info);
213
214         return true;
215 }
216
217 static void close_device(void) {
218         close(sp[0]);
219         close(sp[1]);
220         CloseHandle(device_handle);
221
222         kill(reader_pid, SIGKILL);
223
224         free(device);
225         free(iface);
226 }
227
228 static bool read_packet(vpn_packet_t *packet) {
229         int lenin;
230
231         if((lenin = read(sp[0], packet->data, MTU)) <= 0) {
232                 logger(LOG_ERR, "Error while reading from %s %s: %s", device_info,
233                            device, strerror(errno));
234                 return false;
235         }
236         
237         packet->len = lenin;
238
239         device_total_in += packet->len;
240
241         ifdebug(TRAFFIC) logger(LOG_DEBUG, "Read packet of %d bytes from %s", packet->len,
242                            device_info);
243
244         return true;
245 }
246
247 static bool write_packet(vpn_packet_t *packet) {
248         long lenout;
249
250         ifdebug(TRAFFIC) logger(LOG_DEBUG, "Writing packet of %d bytes to %s",
251                            packet->len, device_info);
252
253         if(!WriteFile (device_handle, packet->data, packet->len, &lenout, NULL)) {
254                 logger(LOG_ERR, "Error while writing to %s %s: %s", device_info, device, winerror(GetLastError()));
255                 return false;
256         }
257
258         device_total_out += packet->len;
259
260         return true;
261 }
262
263 static void dump_device_stats(void) {
264         logger(LOG_DEBUG, "Statistics for %s %s:", device_info, device);
265         logger(LOG_DEBUG, " total bytes in:  %10"PRIu64, device_total_in);
266         logger(LOG_DEBUG, " total bytes out: %10"PRIu64, device_total_out);
267 }
268
269 const devops_t os_devops = {
270         .setup = setup_device,
271         .close = close_device,
272         .read = read_packet,
273         .write = write_packet,
274         .dump_stats = dump_device_stats,
275 };