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- Committer: Björn Påhlsson
- Date: 2009-11-16 14:41:32 UTC
- mto: (24.1.154 mandos) (237.4.3 mandos-release)
- mto: This revision was merged to the branch mainline in revision 415.
- Revision ID: belorn@braxen-20091116144132-89ake84mbhgkhcah
todo
- files removed:
- DBUS-API
- files modified:
- .bzrignore
added
removed
plugins.d/plymouth.c
1
/* -*- coding: utf-8 -*- */
2
/*
3
* Usplash - Read a password from usplash and output it
4
*
5
* Copyright © 2010 Teddy Hogeborn
6
* Copyright © 2010 Björn Påhlsson
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*
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* This program is free software: you can redistribute it and/or
9
* modify it under the terms of the GNU General Public License as
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* published by the Free Software Foundation, either version 3 of the
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* License, or (at your option) any later version.
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*
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* This program is distributed in the hope that it will be useful, but
14
* WITHOUT ANY WARRANTY; without even the implied warranty of
15
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
16
* General Public License for more details.
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*
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* You should have received a copy of the GNU General Public License
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* along with this program. If not, see
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* <http://www.gnu.org/licenses/>.
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*
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* Contact the authors at <mandos@fukt.bsnet.se>.
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*/
24
25
#define _GNU_SOURCE /* asprintf(), TEMP_FAILURE_RETRY() */
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#include <signal.h> /* sig_atomic_t, struct sigaction,
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sigemptyset(), sigaddset(), SIGINT,
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SIGHUP, SIGTERM, sigaction(),
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kill(), SIG_IGN */
30
#include <stdbool.h> /* bool, false, true */
31
#include <fcntl.h> /* open(), O_RDONLY */
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#include <iso646.h> /* and, or, not*/
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#include <sys/types.h> /* size_t, ssize_t, pid_t, struct
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dirent, waitpid() */
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#include <sys/wait.h> /* waitpid() */
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#include <stddef.h> /* NULL */
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#include <string.h> /* strchr(), memcmp() */
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#include <stdio.h> /* asprintf(), perror(), fopen(),
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fscanf() */
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#include <unistd.h> /* close(), readlink(), read(),
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fork(), setsid(), chdir(), dup2(),
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STDERR_FILENO, execv(), access() */
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#include <stdlib.h> /* free(), EXIT_FAILURE, realloc(),
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EXIT_SUCCESS, malloc(), _exit(),
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getenv() */
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#include <dirent.h> /* scandir(), alphasort() */
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#include <inttypes.h> /* intmax_t, strtoumax(), SCNuMAX */
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#include <sys/stat.h> /* struct stat, lstat() */
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#include <sysexits.h> /* EX_OSERR, EX_UNAVAILABLE */
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#include <error.h> /* error() */
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#include <errno.h> /* TEMP_FAILURE_RETRY */
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#include <argz.h> /* argz_count(), argz_extract() */
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sig_atomic_t interrupted_by_signal = 0;
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const char plymouth_pid[] = "/dev/.initramfs/plymouth.pid";
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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",
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"--mode=boot",
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"--attach-to-session",
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"--pid-file="
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"/dev/.initramfs/"
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"plymouth.pid",
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NULL };
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static void termination_handler(__attribute__((unused))int signum){
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if(interrupted_by_signal){
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return;
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}
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interrupted_by_signal = 1;
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}
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/* Create prompt string */
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char *makeprompt(void){
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int ret = 0;
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char *prompt;
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const char *const cryptsource = getenv("cryptsource");
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const char *const crypttarget = getenv("crypttarget");
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const char prompt_start[] = "Enter passphrase to unlock the disk";
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if(cryptsource == NULL){
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if(crypttarget == NULL){
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ret = asprintf(&prompt, "%s: ", prompt_start);
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} else {
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ret = asprintf(&prompt, "%s (%s): ", prompt_start,
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crypttarget);
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}
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} else {
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if(crypttarget == NULL){
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ret = asprintf(&prompt, "%s %s: ", prompt_start, cryptsource);
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} else {
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ret = asprintf(&prompt, "%s %s (%s): ", prompt_start,
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cryptsource, crypttarget);
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}
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}
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if(ret == -1){
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return NULL;
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}
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return prompt;
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}
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void kill_and_wait(pid_t pid){
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TEMP_FAILURE_RETRY(kill(pid, SIGTERM));
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TEMP_FAILURE_RETRY(waitpid(pid, NULL, 0));
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}
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bool become_a_daemon(void){
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int ret = setuid(geteuid());
109
if(ret == -1){
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error(0, errno, "setuid");
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}
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setsid();
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ret = chdir("/");
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if(ret == -1){
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error(0, errno, "chdir");
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return false;
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}
119
ret = dup2(STDERR_FILENO, STDOUT_FILENO); /* replace our stdout */
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if(ret == -1){
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error(0, errno, "dup2");
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return false;
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}
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return true;
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}
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bool exec_and_wait(pid_t *pid_return, const char *path,
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const char **argv, bool interruptable,
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bool daemonize){
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int status;
131
int ret;
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pid_t pid;
133
pid = fork();
134
if(pid == -1){
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error(0, errno, "fork");
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return false;
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}
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if(pid == 0){
139
/* Child */
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if(daemonize){
141
if(not become_a_daemon()){
142
_exit(EX_OSERR);
143
}
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}
145
146
char **new_argv = NULL;
147
char *tmp;
148
int i = 0;
149
for (; argv[i]!=(char *)NULL; i++){
150
tmp = realloc(new_argv, sizeof(const char *) * ((size_t)i + 1));
151
if (tmp == NULL){
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error(0, errno, "realloc");
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free(new_argv);
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_exit(EX_OSERR);
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}
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new_argv = (char **)tmp;
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new_argv[i] = strdup(argv[i]);
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}
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new_argv[i] = (char *) NULL;
160
161
execv(path, (char *const *)new_argv);
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error(0, errno, "execv");
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_exit(EXIT_FAILURE);
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}
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if(pid_return != NULL){
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*pid_return = pid;
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}
168
do {
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ret = waitpid(pid, &status, 0);
170
} while(ret == -1 and errno == EINTR
171
and ((not interrupted_by_signal)
172
or (not interruptable)));
173
if(interrupted_by_signal and interruptable){
174
return false;
175
}
176
if(ret == -1){
177
error(0, errno, "waitpid");
178
return false;
179
}
180
if(WIFEXITED(status) and (WEXITSTATUS(status) == 0)){
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return true;
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}
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return false;
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}
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186
int is_plymouth(const struct dirent *proc_entry){
187
int ret;
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{
189
uintmax_t maxvalue;
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char *tmp;
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errno = 0;
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maxvalue = strtoumax(proc_entry->d_name, &tmp, 10);
193
194
if(errno != 0 or *tmp != '\0'
195
or maxvalue != (uintmax_t)((pid_t)maxvalue)){
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return 0;
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}
198
}
199
char exe_target[sizeof(plymouth_path)];
200
char *exe_link;
201
ret = asprintf(&exe_link, "/proc/%s/exe", proc_entry->d_name);
202
if(ret == -1){
203
error(0, errno, "asprintf");
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return 0;
205
}
206
207
struct stat exe_stat;
208
ret = lstat(exe_link, &exe_stat);
209
if(ret == -1){
210
free(exe_link);
211
if(errno != ENOENT){
212
error(0, errno, "lstat");
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}
214
return 0;
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}
216
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if(not S_ISLNK(exe_stat.st_mode)
218
or exe_stat.st_uid != 0
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or exe_stat.st_gid != 0){
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free(exe_link);
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return 0;
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}
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ssize_t sret = readlink(exe_link, exe_target, sizeof(exe_target));
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free(exe_link);
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if((sret != (ssize_t)sizeof(plymouth_path)-1) or
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(memcmp(plymouth_path, exe_target,
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sizeof(plymouth_path)-1) != 0)){
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return 0;
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}
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return 1;
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}
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pid_t get_pid(void){
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int ret;
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FILE *pidfile = fopen(plymouth_pid, "r");
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uintmax_t maxvalue = 0;
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if(pidfile != NULL){
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ret = fscanf(pidfile, "%" SCNuMAX, &maxvalue);
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if(ret != 1){
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maxvalue = 0;
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}
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fclose(pidfile);
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}
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if(maxvalue == 0){
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struct dirent **direntries;
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ret = scandir("/proc", &direntries, is_plymouth, alphasort);
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sscanf(direntries[0]->d_name, "%" SCNuMAX, &maxvalue);
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}
250
pid_t pid;
251
pid = (pid_t)maxvalue;
252
if((uintmax_t)pid == maxvalue){
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return pid;
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}
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256
return 0;
257
}
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const char **getargv(pid_t pid){
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int cl_fd;
261
char *cmdline_filename;
262
ssize_t sret;
263
int ret;
264
265
ret = asprintf(&cmdline_filename, "/proc/%" PRIuMAX "/cmdline",
266
(uintmax_t)pid);
267
if(ret == -1){
268
error(0, errno, "asprintf");
269
return NULL;
270
}
271
272
/* Open /proc/<pid>/cmdline */
273
cl_fd = open(cmdline_filename, O_RDONLY);
274
free(cmdline_filename);
275
if(cl_fd == -1){
276
error(0, errno, "open");
277
return NULL;
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}
279
280
size_t cmdline_allocated = 0;
281
size_t cmdline_len = 0;
282
char *cmdline = NULL;
283
char *tmp;
284
const size_t blocksize = 1024;
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do {
286
/* Allocate more space? */
287
if(cmdline_len + blocksize > cmdline_allocated){
288
tmp = realloc(cmdline, cmdline_allocated + blocksize);
289
if(tmp == NULL){
290
error(0, errno, "realloc");
291
free(cmdline);
292
close(cl_fd);
293
return NULL;
294
}
295
cmdline = tmp;
296
cmdline_allocated += blocksize;
297
}
298
299
/* Read data */
300
sret = read(cl_fd, cmdline + cmdline_len,
301
cmdline_allocated - cmdline_len);
302
if(sret == -1){
303
error(0, errno, "read");
304
free(cmdline);
305
close(cl_fd);
306
return NULL;
307
}
308
cmdline_len += (size_t)sret;
309
} while(sret != 0);
310
ret = close(cl_fd);
311
if(ret == -1){
312
error(0, errno, "close");
313
free(cmdline);
314
return NULL;
315
}
316
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/* we got cmdline and cmdline_len, ignore rest... */
318
char **argv = malloc((argz_count(cmdline, cmdline_len) + 1)
319
* sizeof(char *)); /* Get number of args */
320
if(argv == NULL){
321
error(0, errno, "argv = malloc()");
322
free(cmdline);
323
return NULL;
324
}
325
argz_extract(cmdline, cmdline_len, argv); /* Create argv */
326
return (const char **)argv;
327
}
328
329
int main(__attribute__((unused))int argc,
330
__attribute__((unused))char **argv){
331
char *prompt;
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char *prompt_arg;
333
pid_t plymouth_command_pid;
334
int ret;
335
bool bret;
336
337
/* test -x /bin/plymouth */
338
ret = access(plymouth_path, X_OK);
339
if(ret == -1){
340
/* Plymouth is probably not installed. Don't print an error
341
message, just exit. */
342
exit(EX_UNAVAILABLE);
343
}
344
345
{ /* Add signal handlers */
346
struct sigaction old_action,
347
new_action = { .sa_handler = termination_handler,
348
.sa_flags = 0 };
349
sigemptyset(&new_action.sa_mask);
350
for(int *sig = (int[]){ SIGINT, SIGHUP, SIGTERM, 0 };
351
*sig != 0; sig++){
352
ret = sigaddset(&new_action.sa_mask, *sig);
353
if(ret == -1){
354
error(EX_OSERR, errno, "sigaddset");
355
}
356
ret = sigaction(*sig, NULL, &old_action);
357
if(ret == -1){
358
error(EX_OSERR, errno, "sigaction");
359
}
360
if(old_action.sa_handler != SIG_IGN){
361
ret = sigaction(*sig, &new_action, NULL);
362
if(ret == -1){
363
error(EX_OSERR, errno, "sigaction");
364
}
365
}
366
}
367
}
368
369
/* plymouth --ping */
370
bret = exec_and_wait(&plymouth_command_pid, plymouth_path,
371
(const char *[])
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{ plymouth_path, "--ping", NULL },
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true, false);
374
if(not bret){
375
if(interrupted_by_signal){
376
kill_and_wait(plymouth_command_pid);
377
exit(EXIT_FAILURE);
378
}
379
/* Plymouth is probably not running. Don't print an error
380
message, just exit. */
381
exit(EX_UNAVAILABLE);
382
}
383
384
prompt = makeprompt();
385
ret = asprintf(&prompt_arg, "--prompt=%s", prompt);
386
free(prompt);
387
if(ret == -1){
388
error(EX_OSERR, errno, "asprintf");
389
}
390
391
/* plymouth ask-for-password --prompt="$prompt" */
392
bret = exec_and_wait(&plymouth_command_pid,
393
plymouth_path, (const char *[])
394
{ plymouth_path, "ask-for-password",
395
prompt_arg, NULL },
396
true, false);
397
free(prompt_arg);
398
if(bret){
399
exit(EXIT_SUCCESS);
400
}
401
if(not interrupted_by_signal){
402
/* exec_and_wait failed for some other reason */
403
exit(EXIT_FAILURE);
404
}
405
kill_and_wait(plymouth_command_pid);
406
407
const char **plymouthd_argv;
408
pid_t pid = get_pid();
409
if(pid == 0){
410
error(0, 0, "plymouthd pid not found");
411
plymouthd_argv = plymouthd_default_argv;
412
} else {
413
plymouthd_argv = getargv(pid);
414
}
415
416
bret = exec_and_wait(NULL, plymouth_path, (const char *[])
417
{ plymouth_path, "quit", NULL },
418
false, false);
419
if(not bret){
420
exit(EXIT_FAILURE);
421
}
422
bret = exec_and_wait(NULL, plymouthd_path, plymouthd_argv,
423
false, true);
424
if(not bret){
425
exit(EXIT_FAILURE);
426
}
427
exec_and_wait(NULL, plymouth_path, (const char *[])
428
{ plymouth_path, "show-splash", NULL },
429
false, false);
430
exit(EXIT_FAILURE);
431
}
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