hw/net: fix mcf_fec driver receiver
[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/sysemu.h"
40 #include "net/slirp.h"
41 #include "qemu-options.h"
42 #include "qemu/rcu.h"
43
44 #ifdef CONFIG_LINUX
45 #include <sys/prctl.h>
46 #endif
47
48 static struct passwd *user_pwd;
49 static const char *chroot_dir;
50 static int daemonize;
51 static int daemon_pipe;
52
53 void os_setup_early_signal_handling(void)
54 {
55 struct sigaction act;
56 sigfillset(&act.sa_mask);
57 act.sa_flags = 0;
58 act.sa_handler = SIG_IGN;
59 sigaction(SIGPIPE, &act, NULL);
60 }
61
62 static void termsig_handler(int signal, siginfo_t *info, void *c)
63 {
64 qemu_system_killed(info->si_signo, info->si_pid);
65 }
66
67 void os_setup_signal_handling(void)
68 {
69 struct sigaction act;
70
71 memset(&act, 0, sizeof(act));
72 act.sa_sigaction = termsig_handler;
73 act.sa_flags = SA_SIGINFO;
74 sigaction(SIGINT, &act, NULL);
75 sigaction(SIGHUP, &act, NULL);
76 sigaction(SIGTERM, &act, NULL);
77 }
78
79 /* Find a likely location for support files using the location of the binary.
80 For installed binaries this will be "$bindir/../share/qemu". When
81 running from the build tree this will be "$bindir/../pc-bios". */
82 #define SHARE_SUFFIX "/share/qemu"
83 #define BUILD_SUFFIX "/pc-bios"
84 char *os_find_datadir(void)
85 {
86 char *dir, *exec_dir;
87 char *res;
88 size_t max_len;
89
90 exec_dir = qemu_get_exec_dir();
91 if (exec_dir == NULL) {
92 return NULL;
93 }
94 dir = dirname(exec_dir);
95
96 max_len = strlen(dir) +
97 MAX(strlen(SHARE_SUFFIX), strlen(BUILD_SUFFIX)) + 1;
98 res = g_malloc0(max_len);
99 snprintf(res, max_len, "%s%s", dir, SHARE_SUFFIX);
100 if (access(res, R_OK)) {
101 snprintf(res, max_len, "%s%s", dir, BUILD_SUFFIX);
102 if (access(res, R_OK)) {
103 g_free(res);
104 res = NULL;
105 }
106 }
107
108 g_free(exec_dir);
109 return res;
110 }
111 #undef SHARE_SUFFIX
112 #undef BUILD_SUFFIX
113
114 void os_set_proc_name(const char *s)
115 {
116 #if defined(PR_SET_NAME)
117 char name[16];
118 if (!s)
119 return;
120 pstrcpy(name, sizeof(name), s);
121 /* Could rewrite argv[0] too, but that's a bit more complicated.
122 This simple way is enough for `top'. */
123 if (prctl(PR_SET_NAME, name)) {
124 perror("unable to change process name");
125 exit(1);
126 }
127 #else
128 fprintf(stderr, "Change of process name not supported by your OS\n");
129 exit(1);
130 #endif
131 }
132
133 /*
134 * Parse OS specific command line options.
135 * return 0 if option handled, -1 otherwise
136 */
137 void os_parse_cmd_args(int index, const char *optarg)
138 {
139 switch (index) {
140 #ifdef CONFIG_SLIRP
141 case QEMU_OPTION_smb:
142 if (net_slirp_smb(optarg) < 0)
143 exit(1);
144 break;
145 #endif
146 case QEMU_OPTION_runas:
147 user_pwd = getpwnam(optarg);
148 if (!user_pwd) {
149 fprintf(stderr, "User \"%s\" doesn't exist\n", optarg);
150 exit(1);
151 }
152 break;
153 case QEMU_OPTION_chroot:
154 chroot_dir = optarg;
155 break;
156 case QEMU_OPTION_daemonize:
157 daemonize = 1;
158 break;
159 #if defined(CONFIG_LINUX)
160 case QEMU_OPTION_enablefips:
161 fips_set_state(true);
162 break;
163 #endif
164 }
165 }
166
167 static void change_process_uid(void)
168 {
169 if (user_pwd) {
170 if (setgid(user_pwd->pw_gid) < 0) {
171 fprintf(stderr, "Failed to setgid(%d)\n", user_pwd->pw_gid);
172 exit(1);
173 }
174 if (initgroups(user_pwd->pw_name, user_pwd->pw_gid) < 0) {
175 fprintf(stderr, "Failed to initgroups(\"%s\", %d)\n",
176 user_pwd->pw_name, user_pwd->pw_gid);
177 exit(1);
178 }
179 if (setuid(user_pwd->pw_uid) < 0) {
180 fprintf(stderr, "Failed to setuid(%d)\n", user_pwd->pw_uid);
181 exit(1);
182 }
183 if (setuid(0) != -1) {
184 fprintf(stderr, "Dropping privileges failed\n");
185 exit(1);
186 }
187 }
188 }
189
190 static void change_root(void)
191 {
192 if (chroot_dir) {
193 if (chroot(chroot_dir) < 0) {
194 fprintf(stderr, "chroot failed\n");
195 exit(1);
196 }
197 if (chdir("/")) {
198 perror("not able to chdir to /");
199 exit(1);
200 }
201 }
202
203 }
204
205 void os_daemonize(void)
206 {
207 if (daemonize) {
208 pid_t pid;
209 int fds[2];
210
211 if (pipe(fds) == -1) {
212 exit(1);
213 }
214
215 pid = fork();
216 if (pid > 0) {
217 uint8_t status;
218 ssize_t len;
219
220 close(fds[1]);
221
222 do {
223 len = read(fds[0], &status, 1);
224 } while (len < 0 && errno == EINTR);
225
226 /* only exit successfully if our child actually wrote
227 * a one-byte zero to our pipe, upon successful init */
228 exit(len == 1 && status == 0 ? 0 : 1);
229
230 } else if (pid < 0) {
231 exit(1);
232 }
233
234 close(fds[0]);
235 daemon_pipe = fds[1];
236 qemu_set_cloexec(daemon_pipe);
237
238 setsid();
239
240 pid = fork();
241 if (pid > 0) {
242 exit(0);
243 } else if (pid < 0) {
244 exit(1);
245 }
246 umask(027);
247
248 signal(SIGTSTP, SIG_IGN);
249 signal(SIGTTOU, SIG_IGN);
250 signal(SIGTTIN, SIG_IGN);
251 rcu_after_fork();
252 }
253 }
254
255 void os_setup_post(void)
256 {
257 int fd = 0;
258
259 if (daemonize) {
260 if (chdir("/")) {
261 perror("not able to chdir to /");
262 exit(1);
263 }
264 TFR(fd = qemu_open("/dev/null", O_RDWR));
265 if (fd == -1) {
266 exit(1);
267 }
268 }
269
270 change_root();
271 change_process_uid();
272
273 if (daemonize) {
274 uint8_t status = 0;
275 ssize_t len;
276
277 dup2(fd, 0);
278 dup2(fd, 1);
279 dup2(fd, 2);
280
281 close(fd);
282
283 do {
284 len = write(daemon_pipe, &status, 1);
285 } while (len < 0 && errno == EINTR);
286 if (len != 1) {
287 exit(1);
288 }
289 }
290 }
291
292 void os_set_line_buffering(void)
293 {
294 setvbuf(stdout, NULL, _IOLBF, 0);
295 }
296
297 int qemu_create_pidfile(const char *filename)
298 {
299 char buffer[128];
300 int len;
301 int fd;
302
303 fd = qemu_open(filename, O_RDWR | O_CREAT, 0600);
304 if (fd == -1) {
305 return -1;
306 }
307 if (lockf(fd, F_TLOCK, 0) == -1) {
308 close(fd);
309 return -1;
310 }
311 len = snprintf(buffer, sizeof(buffer), FMT_pid "\n", getpid());
312 if (write(fd, buffer, len) != len) {
313 close(fd);
314 return -1;
315 }
316
317 /* keep pidfile open & locked forever */
318 return 0;
319 }
320
321 bool is_daemonized(void)
322 {
323 return daemonize;
324 }
325
326 int os_mlock(void)
327 {
328 int ret = 0;
329
330 ret = mlockall(MCL_CURRENT | MCL_FUTURE);
331 if (ret < 0) {
332 perror("mlockall");
333 }
334
335 return ret;
336 }