linux-user: Add default configs for mips64[el]
[qemu.git] / os-posix.c
1 /*
2 * os-posix.c
3 *
4 * Copyright (c) 2003-2008 Fabrice Bellard
5 * Copyright (c) 2010 Red Hat, Inc.
6 *
7 * Permission is hereby granted, free of charge, to any person obtaining a copy
8 * of this software and associated documentation files (the "Software"), to deal
9 * in the Software without restriction, including without limitation the rights
10 * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
11 * copies of the Software, and to permit persons to whom the Software is
12 * furnished to do so, subject to the following conditions:
13 *
14 * The above copyright notice and this permission notice shall be included in
15 * all copies or substantial portions of the Software.
16 *
17 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
18 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
19 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
20 * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
21 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
22 * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
23 * THE SOFTWARE.
24 */
25
26 #include <unistd.h>
27 #include <fcntl.h>
28 #include <signal.h>
29 #include <sys/types.h>
30 #include <sys/wait.h>
31 /*needed for MAP_POPULATE before including qemu-options.h */
32 #include <sys/mman.h>
33 #include <pwd.h>
34 #include <grp.h>
35 #include <libgen.h>
36
37 /* Needed early for CONFIG_BSD etc. */
38 #include "config-host.h"
39 #include "sysemu.h"
40 #include "net/slirp.h"
41 #include "qemu-options.h"
42
43 #ifdef CONFIG_LINUX
44 #include <sys/prctl.h>
45 #endif
46
47 static struct passwd *user_pwd;
48 static const char *chroot_dir;
49 static int daemonize;
50 static int fds[2];
51
52 void os_setup_early_signal_handling(void)
53 {
54 struct sigaction act;
55 sigfillset(&act.sa_mask);
56 act.sa_flags = 0;
57 act.sa_handler = SIG_IGN;
58 sigaction(SIGPIPE, &act, NULL);
59 }
60
61 static void termsig_handler(int signal, siginfo_t *info, void *c)
62 {
63 qemu_system_killed(info->si_signo, info->si_pid);
64 }
65
66 void os_setup_signal_handling(void)
67 {
68 struct sigaction act;
69
70 memset(&act, 0, sizeof(act));
71 act.sa_sigaction = termsig_handler;
72 act.sa_flags = SA_SIGINFO;
73 sigaction(SIGINT, &act, NULL);
74 sigaction(SIGHUP, &act, NULL);
75 sigaction(SIGTERM, &act, NULL);
76 }
77
78 /* Find a likely location for support files using the location of the binary.
79 For installed binaries this will be "$bindir/../share/qemu". When
80 running from the build tree this will be "$bindir/../pc-bios". */
81 #define SHARE_SUFFIX "/share/qemu"
82 #define BUILD_SUFFIX "/pc-bios"
83 char *os_find_datadir(const char *argv0)
84 {
85 char *dir;
86 char *p = NULL;
87 char *res;
88 char buf[PATH_MAX];
89 size_t max_len;
90
91 #if defined(__linux__)
92 {
93 int len;
94 len = readlink("/proc/self/exe", buf, sizeof(buf) - 1);
95 if (len > 0) {
96 buf[len] = 0;
97 p = buf;
98 }
99 }
100 #elif defined(__FreeBSD__)
101 {
102 static int mib[4] = {CTL_KERN, KERN_PROC, KERN_PROC_PATHNAME, -1};
103 size_t len = sizeof(buf) - 1;
104
105 *buf = '\0';
106 if (!sysctl(mib, ARRAY_SIZE(mib), buf, &len, NULL, 0) &&
107 *buf) {
108 buf[sizeof(buf) - 1] = '\0';
109 p = buf;
110 }
111 }
112 #endif
113 /* If we don't have any way of figuring out the actual executable
114 location then try argv[0]. */
115 if (!p) {
116 p = realpath(argv0, buf);
117 if (!p) {
118 return NULL;
119 }
120 }
121 dir = dirname(p);
122 dir = dirname(dir);
123
124 max_len = strlen(dir) +
125 MAX(strlen(SHARE_SUFFIX), strlen(BUILD_SUFFIX)) + 1;
126 res = g_malloc0(max_len);
127 snprintf(res, max_len, "%s%s", dir, SHARE_SUFFIX);
128 if (access(res, R_OK)) {
129 snprintf(res, max_len, "%s%s", dir, BUILD_SUFFIX);
130 if (access(res, R_OK)) {
131 g_free(res);
132 res = NULL;
133 }
134 }
135
136 return res;
137 }
138 #undef SHARE_SUFFIX
139 #undef BUILD_SUFFIX
140
141 void os_set_proc_name(const char *s)
142 {
143 #if defined(PR_SET_NAME)
144 char name[16];
145 if (!s)
146 return;
147 name[sizeof(name) - 1] = 0;
148 strncpy(name, s, sizeof(name));
149 /* Could rewrite argv[0] too, but that's a bit more complicated.
150 This simple way is enough for `top'. */
151 if (prctl(PR_SET_NAME, name)) {
152 perror("unable to change process name");
153 exit(1);
154 }
155 #else
156 fprintf(stderr, "Change of process name not supported by your OS\n");
157 exit(1);
158 #endif
159 }
160
161 /*
162 * Parse OS specific command line options.
163 * return 0 if option handled, -1 otherwise
164 */
165 void os_parse_cmd_args(int index, const char *optarg)
166 {
167 switch (index) {
168 #ifdef CONFIG_SLIRP
169 case QEMU_OPTION_smb:
170 if (net_slirp_smb(optarg) < 0)
171 exit(1);
172 break;
173 #endif
174 case QEMU_OPTION_runas:
175 user_pwd = getpwnam(optarg);
176 if (!user_pwd) {
177 fprintf(stderr, "User \"%s\" doesn't exist\n", optarg);
178 exit(1);
179 }
180 break;
181 case QEMU_OPTION_chroot:
182 chroot_dir = optarg;
183 break;
184 case QEMU_OPTION_daemonize:
185 daemonize = 1;
186 break;
187 }
188 return;
189 }
190
191 static void change_process_uid(void)
192 {
193 if (user_pwd) {
194 if (setgid(user_pwd->pw_gid) < 0) {
195 fprintf(stderr, "Failed to setgid(%d)\n", user_pwd->pw_gid);
196 exit(1);
197 }
198 if (initgroups(user_pwd->pw_name, user_pwd->pw_gid) < 0) {
199 fprintf(stderr, "Failed to initgroups(\"%s\", %d)\n",
200 user_pwd->pw_name, user_pwd->pw_gid);
201 exit(1);
202 }
203 if (setuid(user_pwd->pw_uid) < 0) {
204 fprintf(stderr, "Failed to setuid(%d)\n", user_pwd->pw_uid);
205 exit(1);
206 }
207 if (setuid(0) != -1) {
208 fprintf(stderr, "Dropping privileges failed\n");
209 exit(1);
210 }
211 }
212 }
213
214 static void change_root(void)
215 {
216 if (chroot_dir) {
217 if (chroot(chroot_dir) < 0) {
218 fprintf(stderr, "chroot failed\n");
219 exit(1);
220 }
221 if (chdir("/")) {
222 perror("not able to chdir to /");
223 exit(1);
224 }
225 }
226
227 }
228
229 void os_daemonize(void)
230 {
231 if (daemonize) {
232 pid_t pid;
233
234 if (pipe(fds) == -1)
235 exit(1);
236
237 pid = fork();
238 if (pid > 0) {
239 uint8_t status;
240 ssize_t len;
241
242 close(fds[1]);
243
244 again:
245 len = read(fds[0], &status, 1);
246 if (len == -1 && (errno == EINTR))
247 goto again;
248
249 if (len != 1)
250 exit(1);
251 else if (status == 1) {
252 fprintf(stderr, "Could not acquire pidfile: %s\n", strerror(errno));
253 exit(1);
254 } else
255 exit(0);
256 } else if (pid < 0)
257 exit(1);
258
259 close(fds[0]);
260 qemu_set_cloexec(fds[1]);
261
262 setsid();
263
264 pid = fork();
265 if (pid > 0)
266 exit(0);
267 else if (pid < 0)
268 exit(1);
269
270 umask(027);
271
272 signal(SIGTSTP, SIG_IGN);
273 signal(SIGTTOU, SIG_IGN);
274 signal(SIGTTIN, SIG_IGN);
275 }
276 }
277
278 void os_setup_post(void)
279 {
280 int fd = 0;
281
282 if (daemonize) {
283 uint8_t status = 0;
284 ssize_t len;
285
286 again1:
287 len = write(fds[1], &status, 1);
288 if (len == -1 && (errno == EINTR))
289 goto again1;
290
291 if (len != 1)
292 exit(1);
293
294 if (chdir("/")) {
295 perror("not able to chdir to /");
296 exit(1);
297 }
298 TFR(fd = qemu_open("/dev/null", O_RDWR));
299 if (fd == -1)
300 exit(1);
301 }
302
303 change_root();
304 change_process_uid();
305
306 if (daemonize) {
307 dup2(fd, 0);
308 dup2(fd, 1);
309 dup2(fd, 2);
310
311 close(fd);
312 }
313 }
314
315 void os_pidfile_error(void)
316 {
317 if (daemonize) {
318 uint8_t status = 1;
319 if (write(fds[1], &status, 1) != 1) {
320 perror("daemonize. Writing to pipe\n");
321 }
322 } else
323 fprintf(stderr, "Could not acquire pid file: %s\n", strerror(errno));
324 }
325
326 void os_set_line_buffering(void)
327 {
328 setvbuf(stdout, NULL, _IOLBF, 0);
329 }
330
331 int qemu_create_pidfile(const char *filename)
332 {
333 char buffer[128];
334 int len;
335 int fd;
336
337 fd = qemu_open(filename, O_RDWR | O_CREAT, 0600);
338 if (fd == -1) {
339 return -1;
340 }
341 if (lockf(fd, F_TLOCK, 0) == -1) {
342 close(fd);
343 return -1;
344 }
345 len = snprintf(buffer, sizeof(buffer), FMT_pid "\n", getpid());
346 if (write(fd, buffer, len) != len) {
347 close(fd);
348 return -1;
349 }
350
351 close(fd);
352 return 0;
353 }