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- Committer: teddy at bsnet
- Date: 2010-09-08 19:25:13 UTC
- Revision ID: teddy@fukt.bsnet.se-20100908192513-ccso0jpam3qg4yze
* TODO: Clarifications.
added
removed
plugins.d/plymouth.c
1
#define _GNU_SOURCE /* asprintf(), TEMP_FAILURE_RETRY() */
2
#include <signal.h> /* sig_atomic_t, struct sigaction,
3
sigemptyset(), sigaddset(), SIGINT,
4
SIGHUP, SIGTERM, sigaction(),
5
kill(), SIG_IGN */
6
#include <stdbool.h> /* bool, false, true */
7
#include <fcntl.h> /* open(), O_RDONLY */
8
#include <iso646.h> /* and, or, not*/
9
#include <sys/types.h> /* size_t, ssize_t, pid_t, struct dirent,
10
waitpid() */
11
#include <sys/wait.h> /* waitpid() */
12
#include <stddef.h> /* NULL */
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#include <string.h> /* strchr(), memcmp() */
14
#include <stdio.h> /* asprintf(), perror(), fopen(), fscanf() */
15
#include <unistd.h> /* close(), readlink(), read(), fork()
16
setsid(), chdir(), dup2()
17
STDERR_FILENO, execv(), access() */
18
#include <stdlib.h> /* free(), EXIT_FAILURE, realloc(),
19
EXIT_SUCCESS, malloc(), _exit(),
20
getenv() */
21
#include <dirent.h> /* scandir(), alphasort() */
22
#include <inttypes.h> /* intmax_t, strtoumax(), SCNuMAX */
23
#include <sys/stat.h> /* struct stat, lstat() */
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#include <sysexits.h> /* EX_OSERR */
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#include <error.h> /* error() */
26
#include <errno.h> /* TEMP_FAILURE_RETRY */
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#include <argz.h> /* argz_count(), argz_extract() */
28
29
sig_atomic_t interrupted_by_signal = 0;
30
const char plymouth_pid[] = "/dev/.initramfs/plymouth.pid";
31
const char plymouth_path[] = "/bin/plymouth";
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const char plymouthd_path[] = "/sbin/plymouthd";
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const char *plymouthd_default_argv[] = {"/sbin/plymouthd", "--mode=boot",
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"--attach-to-session",
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"--pid-file=/dev/.initramfs/plymouth.pid",
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NULL };
37
38
static void termination_handler(__attribute__((unused))int signum){
39
if(interrupted_by_signal){
40
return;
41
}
42
interrupted_by_signal = 1;
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}
44
45
/* Create prompt string */
46
char *makeprompt(void){
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int ret = 0;
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char *prompt;
49
const char *const cryptsource = getenv("cryptsource");
50
const char *const crypttarget = getenv("crypttarget");
51
const char prompt_start[] = "Enter passphrase to unlock the disk";
52
53
if(cryptsource == NULL){
54
if(crypttarget == NULL){
55
ret = asprintf(&prompt, "%s: ", prompt_start);
56
} else {
57
ret = asprintf(&prompt, "%s (%s): ", prompt_start,
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crypttarget);
59
}
60
} else {
61
if(crypttarget == NULL){
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ret = asprintf(&prompt, "%s %s: ", prompt_start, cryptsource);
63
} else {
64
ret = asprintf(&prompt, "%s %s (%s): ", prompt_start,
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cryptsource, crypttarget);
66
}
67
}
68
if(ret == -1){
69
return NULL;
70
}
71
return prompt;
72
}
73
74
void kill_and_wait(pid_t pid){
75
TEMP_FAILURE_RETRY(kill(pid, SIGTERM));
76
TEMP_FAILURE_RETRY(waitpid(pid, NULL, 0));
77
}
78
79
bool become_a_daemon(void){
80
int ret = setuid(geteuid());
81
if(ret == -1){
82
error(0, errno, "setuid");
83
}
84
85
setsid();
86
ret = chdir("/");
87
if(ret == -1){
88
error(0, errno, "chdir");
89
return false;
90
}
91
ret = dup2(STDERR_FILENO, STDOUT_FILENO); /* replace our stdout */
92
if(ret == -1){
93
error(0, errno, "dup2");
94
return false;
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}
96
return true;
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}
98
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bool exec_and_wait(pid_t *pid_return, const char *path,
100
const char **argv, bool interruptable,
101
bool daemonize){
102
int status;
103
int ret;
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pid_t pid;
105
pid = fork();
106
if(pid == -1){
107
error(0, errno, "fork");
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return false;
109
}
110
if(pid == 0){
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/* Child */
112
if(daemonize){
113
if(not become_a_daemon()){
114
_exit(EX_OSERR);
115
}
116
}
117
118
char **new_argv = NULL;
119
char *tmp;
120
int i = 0;
121
for (; argv[i]!=(char *)NULL; i++){
122
tmp = realloc(new_argv, sizeof(const char *) * ((size_t)i + 1));
123
if (tmp == NULL){
124
error(0, errno, "realloc");
125
free(new_argv);
126
_exit(EXIT_FAILURE);
127
}
128
new_argv = (char **)tmp;
129
new_argv[i] = strdup(argv[i]);
130
}
131
new_argv[i] = (char *) NULL;
132
133
execv(path, (char *const *)new_argv);
134
error(0, errno, "execv");
135
_exit(EXIT_FAILURE);
136
}
137
if(pid_return != NULL){
138
*pid_return = pid;
139
}
140
do {
141
ret = waitpid(pid, &status, 0);
142
} while(ret == -1 and errno == EINTR
143
and ((not interrupted_by_signal)
144
or (not interruptable)));
145
if(interrupted_by_signal and interruptable){
146
return false;
147
}
148
if(ret == -1){
149
error(0, errno, "waitpid");
150
return false;
151
}
152
if(WIFEXITED(status) and WEXITSTATUS(status) == 0){
153
return true;
154
}
155
return false;
156
}
157
158
int is_plymouth(const struct dirent *proc_entry){
159
int ret;
160
{
161
uintmax_t maxvalue;
162
char *tmp;
163
errno = 0;
164
maxvalue = strtoumax(proc_entry->d_name, &tmp, 10);
165
166
if(errno != 0 or *tmp != '\0' or maxvalue != (uintmax_t)((pid_t)maxvalue)){
167
return 0;
168
}
169
}
170
char exe_target[sizeof(plymouth_path)];
171
char *exe_link;
172
ret = asprintf(&exe_link, "/proc/%s/exe", proc_entry->d_name);
173
if(ret == -1){
174
error(0, errno, "asprintf");
175
return 0;
176
}
177
178
struct stat exe_stat;
179
ret = lstat(exe_link, &exe_stat);
180
if(ret == -1){
181
free(exe_link);
182
if(errno != ENOENT){
183
error(0, errno, "lstat");
184
}
185
return 0;
186
}
187
188
if(not S_ISLNK(exe_stat.st_mode)
189
or exe_stat.st_uid != 0
190
or exe_stat.st_gid != 0){
191
free(exe_link);
192
return 0;
193
}
194
195
ssize_t sret = readlink(exe_link, exe_target, sizeof(exe_target));
196
free(exe_link);
197
if((sret != (ssize_t)sizeof(plymouth_path)-1) or
198
(memcmp(plymouth_path, exe_target,
199
sizeof(plymouth_path)-1) != 0)){
200
return 0;
201
}
202
return 1;
203
}
204
205
pid_t get_pid(void){
206
int ret;
207
FILE *pidfile = fopen(plymouth_pid, "r");
208
uintmax_t maxvalue = 0;
209
if(pidfile != NULL){
210
ret = fscanf(pidfile, "%" SCNuMAX, &maxvalue);
211
if(ret != 1){
212
maxvalue = 0;
213
}
214
fclose(pidfile);
215
}
216
if(maxvalue == 0){
217
struct dirent **direntries;
218
ret = scandir("/proc", &direntries, is_plymouth, alphasort);
219
sscanf(direntries[0]->d_name, "%" SCNuMAX, &maxvalue);
220
}
221
pid_t pid;
222
pid = (pid_t)maxvalue;
223
if((uintmax_t)pid == maxvalue){
224
return pid;
225
}
226
227
return 0;
228
}
229
230
const char **getargv(pid_t pid){
231
int cl_fd;
232
char *cmdline_filename;
233
ssize_t sret;
234
int ret;
235
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ret = asprintf(&cmdline_filename, "/proc/%" PRIuMAX "/cmdline",
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(uintmax_t)pid);
238
if(ret == -1){
239
error(0, errno, "asprintf");
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return NULL;
241
}
242
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/* Open /proc/<pid>/cmdline */
244
cl_fd = open(cmdline_filename, O_RDONLY);
245
free(cmdline_filename);
246
if(cl_fd == -1){
247
error(0, errno, "open");
248
return NULL;
249
}
250
251
size_t cmdline_allocated = 0;
252
size_t cmdline_len = 0;
253
char *cmdline = NULL;
254
char *tmp;
255
const size_t blocksize = 1024;
256
do {
257
/* Allocate more space? */
258
if(cmdline_len + blocksize > cmdline_allocated){
259
tmp = realloc(cmdline, cmdline_allocated + blocksize);
260
if(tmp == NULL){
261
error(0, errno, "realloc");
262
free(cmdline);
263
close(cl_fd);
264
return NULL;
265
}
266
cmdline = tmp;
267
cmdline_allocated += blocksize;
268
}
269
270
/* Read data */
271
sret = read(cl_fd, cmdline + cmdline_len,
272
cmdline_allocated - cmdline_len);
273
if(sret == -1){
274
error(0, errno, "read");
275
free(cmdline);
276
close(cl_fd);
277
return NULL;
278
}
279
cmdline_len += (size_t)sret;
280
} while(sret != 0);
281
ret = close(cl_fd);
282
if(ret == -1){
283
error(0, errno, "close");
284
free(cmdline);
285
return NULL;
286
}
287
288
/* we got cmdline and cmdline_len, ignore rest... */
289
char **argv = malloc((argz_count(cmdline, cmdline_len) + 1)
290
* sizeof(char *)); /* Get number of args */
291
if(argv == NULL){
292
error(0, errno, "argv = malloc()");
293
free(cmdline);
294
return NULL;
295
}
296
argz_extract(cmdline, cmdline_len, argv); /* Create argv */
297
return (const char **)argv;
298
}
299
300
int main(__attribute__((unused))int argc,
301
__attribute__((unused))char **argv){
302
char *prompt;
303
char *prompt_arg;
304
pid_t plymouth_command_pid;
305
int ret;
306
bool bret;
307
308
/* test -x /bin/plymouth */
309
ret = access(plymouth_path, X_OK);
310
if(ret == -1){
311
exit(EXIT_FAILURE);
312
}
313
314
{ /* Add signal handlers */
315
struct sigaction old_action,
316
new_action = { .sa_handler = termination_handler,
317
.sa_flags = 0 };
318
sigemptyset(&new_action.sa_mask);
319
for(int *sig = (int[]){ SIGINT, SIGHUP, SIGTERM, 0 }; *sig != 0; sig++){
320
ret = sigaddset(&new_action.sa_mask, *sig);
321
if(ret == -1){
322
error(0, errno, "sigaddset");
323
exit(EX_OSERR);
324
}
325
ret = sigaction(*sig, NULL, &old_action);
326
if(ret == -1){
327
error(0, errno, "sigaction");
328
exit(EX_OSERR);
329
}
330
if(old_action.sa_handler != SIG_IGN){
331
ret = sigaction(*sig, &new_action, NULL);
332
if(ret == -1){
333
error(0, errno, "sigaction");
334
exit(EX_OSERR);
335
}
336
}
337
}
338
}
339
340
/* plymouth --ping */
341
bret = exec_and_wait(&plymouth_command_pid, plymouth_path,
342
(const char *[]){ (const char *)plymouth_path, (const char *)"--ping", (const char *)NULL},
343
true, false);
344
if(not bret){
345
if(interrupted_by_signal){
346
kill_and_wait(plymouth_command_pid);
347
}
348
exit(EXIT_FAILURE);
349
}
350
351
prompt = makeprompt();
352
ret = asprintf(&prompt_arg, "--prompt=%s", prompt);
353
free(prompt);
354
if(ret == -1){
355
error(0, errno, "asprintf");
356
exit(EXIT_FAILURE);
357
}
358
359
/* plymouth ask-for-password --prompt="$prompt" */
360
bret = exec_and_wait(&plymouth_command_pid, plymouth_path,
361
(const char *[]){plymouth_path, "ask-for-password", prompt_arg, NULL},
362
true, false);
363
free(prompt_arg);
364
if(not bret){
365
if(interrupted_by_signal){
366
kill_and_wait(plymouth_command_pid);
367
} else {
368
exit(EXIT_FAILURE);
369
}
370
}
371
372
if(bret){
373
exit(EXIT_SUCCESS);
374
}
375
376
const char **plymouthd_argv = NULL;
377
pid_t pid = get_pid();
378
if(pid == 0){
379
error(0, 0, "plymouthd pid not found");
380
} else {
381
plymouthd_argv = getargv(pid);
382
}
383
if(plymouthd_argv == NULL){
384
plymouthd_argv = plymouthd_default_argv;
385
}
386
387
bret = exec_and_wait(NULL, plymouth_path,
388
(const char *[]){plymouth_path, "quit", NULL}, false, false);
389
if(not bret){
390
exit(EXIT_FAILURE);
391
}
392
bret = exec_and_wait(NULL, plymouthd_path, plymouthd_argv, false, true);
393
if(not bret){
394
exit(EXIT_FAILURE);
395
}
396
exec_and_wait(NULL, plymouth_path,
397
(const char *[]){ plymouth_path, "show-splash", NULL }, false, false);
398
exit(EXIT_FAILURE);
399
}
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