/mandos/release

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bzr branch http://bzr.recompile.se/loggerhead/mandos/release
24.1.157 by Björn Påhlsson
added the actually plugin file for plymouth
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#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 */
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#include <stdbool.h>		/* bool, false, true */
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#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 dirent,
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				   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(), fscanf() */
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#include <unistd.h>		/* close(), readlink(), read(), fork()
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				   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 */
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#include <error.h>		/* error() */
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#include <errno.h>		/* TEMP_FAILURE_RETRY */
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#include <stdarg.h>
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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", "--mode=boot",
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					"--attach-to-session",
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					"--pid-file=/dev/.initramfs/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());
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  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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  }
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  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;
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  int ret;
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  pid_t pid;
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  pid = fork();
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  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){
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    /* Child */
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    if(daemonize){
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      if(not become_a_daemon()){
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	_exit(EX_OSERR);
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      }
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    }
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    char **new_argv = NULL;
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    char *tmp;
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    int i = 0;
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    for (; argv[i]!=(char *)NULL; i++){
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      tmp = realloc(new_argv, sizeof(const char *) * ((size_t)i + 1));
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      if (tmp == NULL){
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	error(0, errno, "realloc");
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	free(new_argv);
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	_exit(EXIT_FAILURE);
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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;
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    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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  }
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  do {
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    ret = waitpid(pid, &status, 0);
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  } while(ret == -1 and errno == EINTR
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	  and ((not interrupted_by_signal)
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	       or (not interruptable)));
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  if(interrupted_by_signal and interruptable){
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    return false;
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  }
148
  if(ret == -1){
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    error(0, errno, "waitpid");
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    return false;
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  }
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  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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int is_plymouth(const struct dirent *proc_entry){
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  int ret;
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  {
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    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);
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    if(errno != 0 or *tmp != '\0' or maxvalue != (uintmax_t)((pid_t)maxvalue)){
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      return 0;
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    }
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  }
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  char exe_target[sizeof(plymouth_path)];
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  char *exe_link;
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  ret = asprintf(&exe_link, "/proc/%s/exe", proc_entry->d_name);
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  if(ret == -1){
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    error(0, errno, "asprintf");
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    return 0;
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  }
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  struct stat exe_stat;
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  ret = lstat(exe_link, &exe_stat);
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  if(ret == -1){
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    free(exe_link);
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    if(errno != ENOENT){
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      error(0, errno, "lstat");
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    }
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    return 0;
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  }
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  if(not S_ISLNK(exe_stat.st_mode)
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     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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  }
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  pid_t pid;
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  pid = (pid_t)maxvalue;
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  if((uintmax_t)pid == maxvalue){
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    return pid;
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  }
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  return 0;
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}
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const char **getargv(pid_t pid){
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  int cl_fd;
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  char *cmdline_filename;
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  ssize_t sret;
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  int ret;
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  ret = asprintf(&cmdline_filename, "/proc/%" PRIuMAX "/cmdline",
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		 (uintmax_t)pid);
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  if(ret == -1){
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    error(0, errno, "asprintf");
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    return NULL;
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  }
242
  
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  /* Open /proc/<pid>/cmdline  */
244
  cl_fd = open(cmdline_filename, O_RDONLY);
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  free(cmdline_filename);
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  if(cl_fd == -1){
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    error(0, errno, "open");
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    return NULL;
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  }
250
  
251
  size_t cmdline_allocated = 0;
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  size_t cmdline_len = 0;
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  char *cmdline = NULL;
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  char *tmp;
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  const size_t blocksize = 1024;
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  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);
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	close(cl_fd);
264
	return NULL;
265
      }
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      cmdline = tmp;
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      cmdline_allocated += blocksize;
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    }
269
    
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    /* Read data */
271
    sret = read(cl_fd, cmdline + cmdline_len,
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		cmdline_allocated - cmdline_len);
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    if(sret == -1){
274
      error(0, errno, "read");
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      free(cmdline);
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      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
  const char **argv = NULL;
290
  size_t argv_size = 0;
291
  for(char *arg = cmdline; arg-cmdline < (ssize_t)cmdline_len;
292
      arg = strchr(arg, '\0')+1){
293
    tmp = realloc(argv, ((++argv_size)+1)*sizeof(char *));
294
    if(tmp == NULL){
295
      error(0, errno, "realloc");
296
      free(argv);
297
      return NULL;
298
    }
299
    argv = (const char **)tmp;
300
    argv[argv_size-1] = arg;
301
  }
302
  argv[argv_size] = NULL;
303
  return argv;
304
}
305
306
int main(__attribute__((unused))int argc,
307
	 __attribute__((unused))char **argv){
308
  char *prompt;
309
  char *prompt_arg;
310
  pid_t plymouth_command_pid;
311
  int ret;
312
  bool bret;
313
314
  /* test -x /bin/plymouth */
315
  ret = access(plymouth_path, X_OK);
316
  if(ret == -1){
317
    exit(EXIT_FAILURE);
318
  }
319
320
  { /* Add signal handlers */
321
    struct sigaction old_action,
322
      new_action = { .sa_handler = termination_handler,
323
		     .sa_flags = 0 };
324
    sigemptyset(&new_action.sa_mask);
325
    for(int *sig = (int[]){ SIGINT, SIGHUP, SIGTERM, 0 }; *sig != 0; sig++){
326
      ret = sigaddset(&new_action.sa_mask, *sig);
327
      if(ret == -1){
328
	error(0, errno, "sigaddset");
329
	exit(EX_OSERR);
330
      }
331
      ret = sigaction(*sig, NULL, &old_action);
332
      if(ret == -1){
333
	error(0, errno, "sigaction");
334
	exit(EX_OSERR);
335
      }
336
      if(old_action.sa_handler != SIG_IGN){
337
	ret = sigaction(*sig, &new_action, NULL);
338
	if(ret == -1){
339
	  error(0, errno, "sigaction");
340
	  exit(EX_OSERR);
341
	}
342
      }
343
    }
344
  }
345
    
346
  /* plymouth --ping */
347
  bret = exec_and_wait(&plymouth_command_pid, plymouth_path,
348
		       (const char *[]){ (const char *)plymouth_path, (const char *)"--ping", (const char *)NULL},
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		       true, false);
350
  if(not bret){
351
    if(interrupted_by_signal){
352
      kill_and_wait(plymouth_command_pid);
353
    }
354
    exit(EXIT_FAILURE);
355
  }
356
  
357
  prompt = makeprompt();
358
  ret = asprintf(&prompt_arg, "--prompt=%s", prompt);
359
  free(prompt);
360
  if(ret == -1){
361
    error(0, errno, "asprintf");
362
    exit(EXIT_FAILURE);
363
  }
364
  
365
  /* plymouth ask-for-password --prompt="$prompt" */
366
  bret = exec_and_wait(&plymouth_command_pid, plymouth_path,
367
		       (const char *[]){plymouth_path, "ask-for-password", prompt_arg, NULL},
368
		       true, false);
369
  free(prompt_arg);
370
  if(not bret){
371
    if(interrupted_by_signal){
372
      kill_and_wait(plymouth_command_pid);
373
    } else {
374
      exit(EXIT_FAILURE);
375
    }
376
  }
377
  
378
  if(bret){
379
    exit(EXIT_SUCCESS);
380
  }
381
  
382
  const char **plymouthd_argv = NULL;
383
  pid_t pid = get_pid();
384
  if(pid == 0){
385
    error(0, 0, "plymouthd pid not found");
386
  } else {
387
    plymouthd_argv = getargv(pid);
388
  }
389
  if(plymouthd_argv == NULL){
390
    plymouthd_argv = plymouthd_default_argv;
391
  }
392
  
393
  bret = exec_and_wait(NULL, plymouth_path,
394
  		       (const char *[]){plymouth_path, "quit", NULL}, false, false);
395
  if(not bret){
396
    exit(EXIT_FAILURE);
397
  }
398
  bret = exec_and_wait(NULL, plymouthd_path, plymouthd_argv, false, true);
399
  if(not bret){
400
    exit(EXIT_FAILURE);
401
  }
402
  exec_and_wait(NULL, plymouth_path,
403
  		(const char *[]){ plymouth_path, "show-splash", NULL }, false, false);
404
  exit(EXIT_FAILURE);
405
}