Use read_host_config() where appropriate.
[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                   2002-2013 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 <w32api/windows.h>
24 #include <w32api/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 "../mingw/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 static pid_t reader_pid;
47 static int sp[2];
48
49 static bool setup_device(void) {
50         HKEY key, key2;
51         int i, err;
52
53         char regpath[1024];
54         char adapterid[1024];
55         char adaptername[1024];
56         char tapname[1024];
57         char gelukt = 0;
58         long len;
59
60         bool found = false;
61
62         get_config_string(lookup_config(config_tree, "Device"), &device);
63         get_config_string(lookup_config(config_tree, "Interface"), &iface);
64
65         /* Open registry and look for network adapters */
66
67         if(RegOpenKeyEx(HKEY_LOCAL_MACHINE, NETWORK_CONNECTIONS_KEY, 0, KEY_READ, &key)) {
68                 logger(DEBUG_ALWAYS, LOG_ERR, "Unable to read registry: %s", winerror(GetLastError()));
69                 return false;
70         }
71
72         for (i = 0; ; i++) {
73                 len = sizeof adapterid;
74                 if(RegEnumKeyEx(key, i, adapterid, &len, 0, 0, 0, NULL))
75                         break;
76
77                 /* Find out more about this adapter */
78
79                 snprintf(regpath, sizeof regpath, "%s\\%s\\Connection", NETWORK_CONNECTIONS_KEY, adapterid);
80
81                 if(RegOpenKeyEx(HKEY_LOCAL_MACHINE, regpath, 0, KEY_READ, &key2))
82                         continue;
83
84                 len = sizeof adaptername;
85                 err = RegQueryValueEx(key2, "Name", 0, 0, adaptername, &len);
86
87                 RegCloseKey(key2);
88
89                 if(err)
90                         continue;
91
92                 if(device) {
93                         if(!strcmp(device, adapterid)) {
94                                 found = true;
95                                 break;
96                         } else
97                                 continue;
98                 }
99
100                 if(iface) {
101                         if(!strcmp(iface, adaptername)) {
102                                 found = true;
103                                 break;
104                         } else
105                                 continue;
106                 }
107
108                 snprintf(tapname, sizeof tapname, USERMODEDEVICEDIR "%s" TAPSUFFIX, adapterid);
109                 device_handle = CreateFile(tapname, GENERIC_WRITE | GENERIC_READ, 0, 0, OPEN_EXISTING, FILE_ATTRIBUTE_SYSTEM, 0);
110                 if(device_handle != INVALID_HANDLE_VALUE) {
111                         CloseHandle(device_handle);
112                         found = true;
113                         break;
114                 }
115         }
116
117         RegCloseKey(key);
118
119         if(!found) {
120                 logger(DEBUG_ALWAYS, LOG_ERR, "No Windows tap device found!");
121                 return false;
122         }
123
124         if(!device)
125                 device = xstrdup(adapterid);
126
127         if(!iface)
128                 iface = xstrdup(adaptername);
129
130         snprintf(tapname, sizeof tapname, USERMODEDEVICEDIR "%s" TAPSUFFIX, device);
131
132         /* Now we are going to open this device twice: once for reading and once for writing.
133            We do this because apparently it isn't possible to check for activity in the select() loop.
134            Furthermore I don't really know how to do it the "Windows" way. */
135
136         if(socketpair(AF_UNIX, SOCK_DGRAM, PF_UNIX, sp)) {
137                 logger(DEBUG_ALWAYS, LOG_DEBUG, "System call `%s' failed: %s", "socketpair", strerror(errno));
138                 return false;
139         }
140
141         /* The parent opens the tap device for writing. */
142
143         device_handle = CreateFile(tapname, GENERIC_WRITE,  FILE_SHARE_READ,  0,  OPEN_EXISTING, FILE_ATTRIBUTE_SYSTEM , 0);
144
145         if(device_handle == INVALID_HANDLE_VALUE) {
146                 logger(DEBUG_ALWAYS, LOG_ERR, "Could not open Windows tap device %s (%s) for writing: %s", device, iface, winerror(GetLastError()));
147                 return false;
148         }
149
150         device_fd = sp[0];
151
152         /* Get MAC address from tap device */
153
154         if(!DeviceIoControl(device_handle, TAP_IOCTL_GET_MAC, mymac.x, sizeof mymac.x, mymac.x, sizeof mymac.x, &len, 0)) {
155                 logger(DEBUG_ALWAYS, LOG_ERR, "Could not get MAC address from Windows tap device %s (%s): %s", device, iface, winerror(GetLastError()));
156                 return false;
157         }
158
159         if(routing_mode == RMODE_ROUTER) {
160                 overwrite_mac = 1;
161         }
162
163         /* Now we start the child */
164
165         reader_pid = fork();
166
167         if(reader_pid == -1) {
168                 logger(DEBUG_ALWAYS, LOG_DEBUG, "System call `%s' failed: %s", "fork", strerror(errno));
169                 return false;
170         }
171
172         if(!reader_pid) {
173                 /* The child opens the tap device for reading, blocking.
174                    It passes everything it reads to the socket. */
175
176                 char buf[MTU];
177                 long inlen;
178
179                 CloseHandle(device_handle);
180
181                 device_handle = CreateFile(tapname, GENERIC_READ, FILE_SHARE_WRITE, 0,  OPEN_EXISTING, FILE_ATTRIBUTE_SYSTEM, 0);
182
183                 if(device_handle == INVALID_HANDLE_VALUE) {
184                         logger(DEBUG_ALWAYS, LOG_ERR, "Could not open Windows tap device %s (%s) for reading: %s", device, iface, winerror(GetLastError()));
185                         buf[0] = 0;
186                         write(sp[1], buf, 1);
187                         exit(1);
188                 }
189
190                 logger(DEBUG_ALWAYS, LOG_DEBUG, "Tap reader forked and running.");
191
192                 /* Notify success */
193
194                 buf[0] = 1;
195                 write(sp[1], buf, 1);
196
197                 /* Pass packets */
198
199                 for(;;) {
200                         ReadFile(device_handle, buf, MTU, &inlen, NULL);
201                         write(sp[1], buf, inlen);
202                 }
203         }
204
205         read(device_fd, &gelukt, 1);
206         if(gelukt != 1) {
207                 logger(DEBUG_ALWAYS, LOG_DEBUG, "Tap reader failed!");
208                 return false;
209         }
210
211         device_info = "Windows tap device";
212
213         logger(DEBUG_ALWAYS, LOG_INFO, "%s (%s) is a %s", device, iface, device_info);
214
215         return true;
216 }
217
218 static void close_device(void) {
219         close(sp[0]);
220         close(sp[1]);
221         CloseHandle(device_handle);
222
223         kill(reader_pid, SIGKILL);
224
225         free(device);
226         free(iface);
227 }
228
229 static bool read_packet(vpn_packet_t *packet) {
230         int inlen;
231
232         if((inlen = read(sp[0], packet->data, MTU)) <= 0) {
233                 logger(DEBUG_ALWAYS, LOG_ERR, "Error while reading from %s %s: %s", device_info,
234                            device, strerror(errno));
235                 return false;
236         }
237
238         packet->len = inlen;
239
240         device_total_in += packet->len;
241
242         logger(DEBUG_TRAFFIC, LOG_DEBUG, "Read packet of %d bytes from %s", packet->len,
243                            device_info);
244
245         return true;
246 }
247
248 static bool write_packet(vpn_packet_t *packet) {
249         long outlen;
250
251         logger(DEBUG_TRAFFIC, LOG_DEBUG, "Writing packet of %d bytes to %s",
252                            packet->len, device_info);
253
254         if(!WriteFile (device_handle, packet->data, packet->len, &outlen, NULL)) {
255                 logger(DEBUG_ALWAYS, LOG_ERR, "Error while writing to %s %s: %s", device_info, device, winerror(GetLastError()));
256                 return false;
257         }
258
259         device_total_out += packet->len;
260
261         return true;
262 }
263
264 static void dump_device_stats(void) {
265         logger(DEBUG_ALWAYS, LOG_DEBUG, "Statistics for %s %s:", device_info, device);
266         logger(DEBUG_ALWAYS, LOG_DEBUG, " total bytes in:  %10"PRIu64, device_total_in);
267         logger(DEBUG_ALWAYS, LOG_DEBUG, " total bytes out: %10"PRIu64, device_total_out);
268 }
269
270 const devops_t os_devops = {
271         .setup = setup_device,
272         .close = close_device,
273         .read = read_packet,
274         .write = write_packet,
275         .dump_stats = dump_device_stats,
276 };