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[tinc] / src / uml_socket / device.c
1 /*
2     device.c -- UML network socket
3     Copyright (C) 2002-2005 Ivo Timmermans,
4                   2002-2009 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 <sys/un.h>
24
25 #include "conf.h"
26 #include "net.h"
27 #include "logger.h"
28 #include "utils.h"
29 #include "route.h"
30
31 int device_fd = -1;
32 static int listen_fd = -1;
33 static int request_fd = -1;
34 static int data_fd = -1;
35 static int write_fd = -1;
36 static int state = 0;
37 char *device = NULL;
38 char *iface = NULL;
39 static char *device_info;
40
41 extern char *identname;
42 extern bool running;
43
44 static int device_total_in = 0;
45 static int device_total_out = 0;
46
47 enum request_type { REQ_NEW_CONTROL };
48
49 static struct request {
50   uint32_t magic;
51   uint32_t version;
52   enum request_type type;
53   struct sockaddr_un sock;
54 } request;
55
56 static struct sockaddr_un data_sun;
57
58 bool setup_device(void) {
59         struct sockaddr_un listen_sun;
60         static const int one = 1;
61         struct {
62                 char zero;
63                 int pid;
64                 int usecs;
65         } name;
66         struct timeval tv;
67
68         if(!get_config_string(lookup_config(config_tree, "Device"), &device))
69                 xasprintf(&device, LOCALSTATEDIR "/run/%s.umlsocket", identname);
70
71         get_config_string(lookup_config(config_tree, "Interface"), &iface);
72
73         device_info = "UML network socket";
74
75         if((write_fd = socket(PF_UNIX, SOCK_DGRAM, 0)) < 0) {
76                 logger(LOG_ERR, "Could not open write %s: %s", device_info, strerror(errno));
77                 running = false;
78                 return false;
79         }
80
81         setsockopt(write_fd, SOL_SOCKET, SO_REUSEADDR, &one, sizeof one);
82
83         if(fcntl(write_fd, F_SETFL, O_NONBLOCK) < 0) {
84                 logger(LOG_ERR, "System call `%s' failed: %s", "fcntl", strerror(errno));
85                 running = false;
86                 return false;
87         }
88
89         if((data_fd = socket(PF_UNIX, SOCK_DGRAM, 0)) < 0) {
90                 logger(LOG_ERR, "Could not open data %s: %s", device_info, strerror(errno));
91                 running = false;
92                 return false;
93         }
94
95         setsockopt(data_fd, SOL_SOCKET, SO_REUSEADDR, &one, sizeof one);
96
97         if(fcntl(data_fd, F_SETFL, O_NONBLOCK) < 0) {
98                 logger(LOG_ERR, "System call `%s' failed: %s", "fcntl", strerror(errno));
99                 running = false;
100                 return false;
101         }
102
103         name.zero = 0;
104         name.pid = getpid();
105         gettimeofday(&tv, NULL);
106         name.usecs = tv.tv_usec;
107         data_sun.sun_family = AF_UNIX;
108         memcpy(&data_sun.sun_path, &name, sizeof name);
109         
110         if(bind(data_fd, (struct sockaddr *)&data_sun, sizeof data_sun) < 0) {
111                 logger(LOG_ERR, "Could not bind data %s: %s", device_info, strerror(errno));
112                 running = false;
113                 return false;
114         }
115
116         if((listen_fd = socket(PF_UNIX, SOCK_STREAM, 0)) < 0) {
117                 logger(LOG_ERR, "Could not open %s: %s", device_info,
118                            strerror(errno));
119                 return false;
120         }
121
122         setsockopt(listen_fd, SOL_SOCKET, SO_REUSEADDR, &one, sizeof one);
123
124         if(fcntl(listen_fd, F_SETFL, O_NONBLOCK) < 0) {
125                 logger(LOG_ERR, "System call `%s' failed: %s", "fcntl", strerror(errno));
126                 return false;
127         }
128
129         listen_sun.sun_family = AF_UNIX;
130         strncpy(listen_sun.sun_path, device, sizeof listen_sun.sun_path);
131         if(bind(listen_fd, (struct sockaddr *)&listen_sun, sizeof listen_sun) < 0) {
132                 logger(LOG_ERR, "Could not bind %s to %s: %s", device_info, device, strerror(errno));
133                 return false;
134         }
135
136         if(listen(listen_fd, 1) < 0) {
137                 logger(LOG_ERR, "Could not listen on %s %s: %s", device_info, device, strerror(errno));
138                 return false;
139         }
140
141         device_fd = listen_fd;
142         state = 0;
143
144         logger(LOG_INFO, "%s is a %s", device, device_info);
145
146         if(routing_mode == RMODE_ROUTER)
147                 overwrite_mac = true;
148
149         return true;
150 }
151
152 void close_device(void) {
153         if(listen_fd >= 0)
154                 close(listen_fd);
155
156         if(request_fd >= 0)
157                 close(request_fd);
158
159         if(data_fd >= 0)
160                 close(data_fd);
161
162         if(write_fd >= 0)
163                 close(write_fd);
164
165         unlink(device);
166
167         free(device);
168         if(iface) free(iface);
169 }
170
171 bool read_packet(vpn_packet_t *packet) {
172         int lenin;
173
174         switch(state) {
175                 case 0: {
176                         struct sockaddr sa;
177                         int salen = sizeof sa;
178
179                         request_fd = accept(listen_fd, &sa, &salen);
180                         if(request_fd < 0) {
181                                 logger(LOG_ERR, "Could not accept connection to %s %s: %s", device_info, device, strerror(errno));
182                                 return false;
183                         }
184
185                         if(fcntl(listen_fd, F_SETFL, O_NONBLOCK) < 0) {
186                                 logger(LOG_ERR, "System call `%s' failed: %s", "fcntl", strerror(errno));
187                                 running = false;
188                                 return false;
189                         }
190
191                         close(listen_fd);
192                         listen_fd = -1;
193                         device_fd = request_fd;
194                         state = 1;
195
196                         return false;
197                 }
198
199                 case 1: {
200                         if((lenin = read(request_fd, &request, sizeof request)) != sizeof request) {
201                                 logger(LOG_ERR, "Error while reading request from %s %s: %s", device_info,
202                                            device, strerror(errno));
203                                 running = false;
204                                 return false;
205                         }
206
207                         if(request.magic != 0xfeedface || request.version != 3 || request.type != REQ_NEW_CONTROL) {
208                                 logger(LOG_ERR, "Unknown magic %x, version %d, request type %d from %s %s",
209                                                 request.magic, request.version, request.type, device_info, device);
210                                 running = false;
211                                 return false;
212                         }
213
214                         if(connect(write_fd, &request.sock, sizeof request.sock) < 0) {
215                                 logger(LOG_ERR, "Could not bind write %s: %s", device_info, strerror(errno));
216                                 running = false;
217                                 return false;
218                         }
219
220                         write(request_fd, &data_sun, sizeof data_sun);
221                         device_fd = data_fd;
222
223                         logger(LOG_INFO, "Connection with UML established");
224
225                         state = 2;
226                         return false;
227                 }
228
229                 case 2: {
230                         if((lenin = read(data_fd, packet->data, MTU)) <= 0) {
231                                 logger(LOG_ERR, "Error while reading from %s %s: %s", device_info,
232                                            device, strerror(errno));
233                                 running = false;
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 }
248
249 bool write_packet(vpn_packet_t *packet) {
250         if(state != 2) {
251                 ifdebug(TRAFFIC) logger(LOG_DEBUG, "Dropping packet of %d bytes to %s: not connected to UML yet",
252                                 packet->len, device_info);
253                 return false;
254         }
255
256         ifdebug(TRAFFIC) logger(LOG_DEBUG, "Writing packet of %d bytes to %s",
257                            packet->len, device_info);
258
259         if(write(write_fd, packet->data, packet->len) < 0) {
260                 if(errno != EINTR && errno != EAGAIN) {
261                         logger(LOG_ERR, "Can't write to %s %s: %s", device_info, device, strerror(errno));
262                         running = false;
263                 }
264
265                 return false;
266         }
267
268         device_total_out += packet->len;
269
270         return true;
271 }
272
273 void dump_device_stats(void) {
274         logger(LOG_DEBUG, "Statistics for %s %s:", device_info, device);
275         logger(LOG_DEBUG, " total bytes in:  %10d", device_total_in);
276         logger(LOG_DEBUG, " total bytes out: %10d", device_total_out);
277 }