some stability improvements
[strongswan.git] / src / dumm / mconsole.c
1 /*
2 * Copyright (C) 2007 Martin Willi
3 * Hochschule fuer Technik Rapperswil
4 * Copyright (C) 2001-2004 Jeff Dike
5 *
6 * Based on the "uml_mconsole" utility from Jeff Dike.
7 *
8 * This program is free software; you can redistribute it and/or modify it
9 * under the terms of the GNU General Public License as published by the
10 * Free Software Foundation; either version 2 of the License, or (at your
11 * option) any later version. See <http://www.fsf.org/copyleft/gpl.txt>.
12 *
13 * This program is distributed in the hope that it will be useful, but
14 * WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
15 * or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
16 * for more details.
17 */
18
19 #define _GNU_SOURCE
20
21 #include <sys/types.h>
22 #include <unistd.h>
23 #include <stdio.h>
24 #include <sys/socket.h>
25 #include <errno.h>
26 #include <sys/un.h>
27
28 #include <debug.h>
29
30 #include "mconsole.h"
31
32 #define MCONSOLE_MAGIC 0xcafebabe
33 #define MCONSOLE_VERSION 2
34 #define MCONSOLE_MAX_DATA 512
35
36 typedef struct private_mconsole_t private_mconsole_t;
37
38 struct private_mconsole_t {
39 /** public interface */
40 mconsole_t public;
41 /** mconsole socket */
42 int console;
43 /** notify socket */
44 int notify;
45 /** address of uml socket */
46 struct sockaddr_un uml;
47 /** idle function */
48 void (*idle)(void);
49 };
50
51 /**
52 * mconsole message format from "arch/um/include/mconsole.h"
53 */
54 typedef struct mconsole_request mconsole_request;
55 /** mconsole request message */
56 struct mconsole_request {
57 u_int32_t magic;
58 u_int32_t version;
59 u_int32_t len;
60 char data[MCONSOLE_MAX_DATA];
61 };
62
63
64 typedef struct mconsole_reply mconsole_reply;
65 /** mconsole reply message */
66 struct mconsole_reply {
67 u_int32_t err;
68 u_int32_t more;
69 u_int32_t len;
70 char data[MCONSOLE_MAX_DATA];
71 };
72
73 typedef struct mconsole_notify mconsole_notify;
74 /** mconsole notify message */
75 struct mconsole_notify {
76 u_int32_t magic;
77 u_int32_t version;
78 enum {
79 MCONSOLE_SOCKET,
80 MCONSOLE_PANIC,
81 MCONSOLE_HANG,
82 MCONSOLE_USER_NOTIFY,
83 } type;
84 u_int32_t len;
85 char data[MCONSOLE_MAX_DATA];
86 };
87
88 /**
89 * send a request to UML using mconsole
90 */
91 static int request(private_mconsole_t *this, char *command,
92 char buf[], size_t *size)
93 {
94 mconsole_request request;
95 mconsole_reply reply;
96 int len, total = 0, flags = 0;
97
98 memset(&request, 0, sizeof(request));
99 request.magic = MCONSOLE_MAGIC;
100 request.version = MCONSOLE_VERSION;
101 request.len = min(strlen(command), sizeof(reply.data) - 1);
102 strncpy(request.data, command, request.len);
103 *buf = '\0';
104 (*size)--;
105
106 if (this->idle)
107 {
108 flags = MSG_DONTWAIT;
109 }
110 do
111 {
112 if (this->idle)
113 {
114 this->idle();
115 }
116 len = sendto(this->console, &request, sizeof(request), flags,
117 (struct sockaddr*)&this->uml, sizeof(this->uml));
118 }
119 while (len < 0 && (errno == EINTR || errno == EAGAIN));
120
121 if (len < 0)
122 {
123 snprintf(buf, *size, "sending mconsole command to UML failed: %m");
124 return -1;
125 }
126 do
127 {
128 len = recv(this->console, &reply, sizeof(reply), flags);
129 if (len < 0 && (errno == EINTR || errno == EAGAIN))
130 {
131 if (this->idle)
132 {
133 this->idle();
134 }
135 continue;
136 }
137 if (len < 0)
138 {
139 snprintf(buf, *size, "receiving from mconsole failed: %m");
140 return -1;
141 }
142 if (len > 0)
143 {
144 strncat(buf, reply.data, min(reply.len, *size - total));
145 total += reply.len;
146 }
147 }
148 while (reply.more);
149
150 *size = total;
151 return reply.err;
152 }
153
154 /**
155 * Implementation of mconsole_t.add_iface.
156 */
157 static bool add_iface(private_mconsole_t *this, char *guest, char *host)
158 {
159 char in[128], out[128];
160 int len, tries = 0;
161
162 len = snprintf(in, sizeof(in), "config %s=tuntap,%s", guest, host);
163 if (len < 0 || len >= sizeof(in))
164 {
165 return FALSE;
166 }
167 while (tries++ < 10)
168 {
169 len = sizeof(in);
170 if (request(this, in, out, &len) == 0)
171 {
172 return TRUE;
173 }
174 usleep(10000 * tries);
175 }
176 DBG1("adding interface failed: %.*s", len, out);
177 return FALSE;
178 }
179
180 /**
181 * Implementation of mconsole_t.del_iface.
182 */
183 static bool del_iface(private_mconsole_t *this, char *guest)
184 {
185 char buf[128];
186 int len;
187
188 len = snprintf(buf, sizeof(buf), "remove %s", guest);
189 if (len < 0 || len >= sizeof(buf))
190 {
191 return FALSE;
192 }
193 if (request(this, buf, buf, &len) != 0)
194 {
195 return FALSE;
196 }
197 return TRUE;
198 }
199
200 /**
201 * Poll until guest is ready
202 */
203 static bool wait_bootup(private_mconsole_t *this)
204 {
205 char buf[128];
206 int len, res;
207
208 while (TRUE)
209 {
210 len = sizeof(buf);
211 res = request(this, "config eth9=mcast", buf, &len);
212 if (res < 0)
213 {
214 return FALSE;
215 }
216 if (res == 0)
217 {
218 while (request(this, "remove eth9", buf, &len) != 0)
219 {
220 usleep(50000);
221 }
222 return TRUE;
223 }
224 if (this->idle)
225 {
226 this->idle();
227 }
228 else
229 {
230 usleep(50000);
231 }
232 }
233 }
234
235 /**
236 * Implementation of mconsole_t.destroy.
237 */
238 static void destroy(private_mconsole_t *this)
239 {
240 close(this->console);
241 close(this->notify);
242 free(this);
243 }
244
245 /**
246 * setup the mconsole notify connection and wait for its readyness
247 */
248 static bool wait_for_notify(private_mconsole_t *this, char *nsock)
249 {
250 struct sockaddr_un addr;
251 mconsole_notify notify;
252 int len, flags = 0;
253
254 this->notify = socket(AF_UNIX, SOCK_DGRAM, 0);
255 if (this->notify < 0)
256 {
257 DBG1("opening mconsole notify socket failed: %m");
258 return FALSE;
259 }
260 memset(&addr, 0, sizeof(addr));
261 addr.sun_family = AF_UNIX;
262 strncpy(addr.sun_path, nsock, sizeof(addr));
263 if (bind(this->notify, (struct sockaddr*)&addr, sizeof(addr)) < 0)
264 {
265 DBG1("binding mconsole notify socket to '%s' failed: %m", nsock);
266 close(this->notify);
267 return FALSE;
268 }
269 if (this->idle)
270 {
271 flags = MSG_DONTWAIT;
272 }
273 do
274 {
275 if (this->idle)
276 {
277 this->idle();
278 }
279 len = recvfrom(this->notify, &notify, sizeof(notify), flags, NULL, 0);
280 }
281 while (len < 0 && (errno == EINTR || errno == EAGAIN));
282
283 if (len < 0 || len >= sizeof(notify))
284 {
285 DBG1("reading from mconsole notify socket failed: %m");
286 close(this->notify);
287 unlink(nsock);
288 return FALSE;
289 }
290 if (notify.magic != MCONSOLE_MAGIC ||
291 notify.version != MCONSOLE_VERSION ||
292 notify.type != MCONSOLE_SOCKET)
293 {
294 DBG1("received unexpected message from mconsole notify socket: %b",
295 &notify, sizeof(notify));
296 close(this->notify);
297 unlink(nsock);
298 return FALSE;
299 }
300 memset(&this->uml, 0, sizeof(this->uml));
301 this->uml.sun_family = AF_UNIX;
302 strncpy(this->uml.sun_path, (char*)&notify.data, sizeof(this->uml.sun_path));
303 return TRUE;
304 }
305
306 /**
307 * setup the mconsole console connection
308 */
309 static bool setup_console(private_mconsole_t *this)
310 {
311 struct sockaddr_un addr;
312
313 this->console = socket(AF_UNIX, SOCK_DGRAM, 0);
314 if (this->console < 0)
315 {
316 DBG1("opening mconsole socket failed: %m");
317 return FALSE;
318 }
319 memset(&addr, 0, sizeof(addr));
320 addr.sun_family = AF_UNIX;
321 snprintf(&addr.sun_path[1], sizeof(addr.sun_path), "%5d-%d",
322 getpid(), this->console);
323 if (bind(this->console, (struct sockaddr*)&addr, sizeof(addr)) < 0)
324 {
325 DBG1("binding mconsole socket to '%s' failed: %m", &addr.sun_path[1]);
326 close(this->console);
327 return FALSE;
328 }
329 return TRUE;
330 }
331
332 /**
333 * create the mconsole instance
334 */
335 mconsole_t *mconsole_create(char *notify, void(*idle)(void))
336 {
337 private_mconsole_t *this = malloc_thing(private_mconsole_t);
338
339 this->public.add_iface = (bool(*)(mconsole_t*, char *guest, char *host))add_iface;
340 this->public.del_iface = (bool(*)(mconsole_t*, char *guest))del_iface;
341 this->public.destroy = (void*)destroy;
342
343 this->idle = idle;
344
345 if (!wait_for_notify(this, notify))
346 {
347 free(this);
348 return NULL;
349 }
350
351 if (!setup_console(this))
352 {
353 close(this->notify);
354 unlink(notify);
355 free(this);
356 return NULL;
357 }
358 unlink(notify);
359
360 if (!wait_bootup(this))
361 {
362 destroy(this);
363 return NULL;
364 }
365
366 return &this->public;
367 }
368