1
#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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/* -*- coding: utf-8 -*- */
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* Plymouth - Read a password from Plymouth and output it
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* Copyright © 2010-2022 Teddy Hogeborn
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* Copyright © 2010-2022 Björn Påhlsson
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* This file is part of Mandos.
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* Mandos is free software: you can redistribute it and/or modify it
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* under the terms of the GNU General Public License as published by
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* the Free Software Foundation, either version 3 of the License, or
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* (at your option) any later version.
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* Mandos is distributed in the hope that it will be useful, but
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* WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
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* General Public License for more details.
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* You should have received a copy of the GNU General Public License
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* along with Mandos. If not, see <http://www.gnu.org/licenses/>.
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* Contact the authors at <mandos@recompile.se>.
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#define _GNU_SOURCE /* program_invocation_short_name,
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vasprintf(), asprintf(),
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TEMP_FAILURE_RETRY() */
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#include <sys/types.h> /* sig_atomic_t, pid_t, setuid(),
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geteuid(), setsid() */
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#include <argp.h> /* argp_program_version,
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argp_program_bug_address,
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ARGP_ERR_UNKNOWN, struct argp,
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argp_parse(), ARGP_IN_ORDER */
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#include <stddef.h> /* NULL, size_t */
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#include <stdbool.h> /* bool, false, true */
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#include <stdio.h> /* FILE, fprintf(), vfprintf(),
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vasprintf(), stderr, asprintf(),
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fopen(), fscanf(), fclose(),
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#include <stdarg.h> /* va_list, va_start(), vfprintf() */
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#include <errno.h> /* program_invocation_short_name,
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errno, ENOMEM, EINTR, ENOENT,
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#include <string.h> /* strerror(), strdup(), memcmp() */
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#include <error.h> /* error() */
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#include <stdlib.h> /* free(), getenv(), malloc(),
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reallocarray(), realloc(),
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EXIT_FAILURE, EXIT_SUCCESS */
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#include <unistd.h> /* TEMP_FAILURE_RETRY(), setuid(),
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geteuid(), setsid(), chdir(),
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dup2(), STDERR_FILENO,
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STDOUT_FILENO, fork(), _exit(),
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execv(), ssize_t, readlink(),
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close(), read(), access(), X_OK */
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#include <signal.h> /* kill(), SIGTERM, struct sigaction,
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sigemptyset(), SIGINT, SIGHUP,
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sigaddset(), SIG_IGN */
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#include <sys/wait.h> /* waitpid(), WIFEXITED(),
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WEXITSTATUS(), WIFSIGNALED(),
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#include <iso646.h> /* not, and, or */
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#include <sysexits.h> /* EX_OSERR, EX_USAGE,
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#include <stdint.h> /* SIZE_MAX */
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#include <dirent.h> /* struct dirent, scandir(),
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#include <inttypes.h> /* uintmax_t, strtoumax(), SCNuMAX,
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#include <sys/stat.h> /* struct stat, lstat(), S_ISLNK() */
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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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#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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#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 <argz.h> /* argz_count(), argz_extract() */
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76
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 *argp_program_version = "plymouth " VERSION;
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const char *argp_program_bug_address = "<mandos@recompile.se>";
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/* Used by Ubuntu 11.04 (Natty Narwahl) */
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const char plymouth_old_old_pid[] = "/dev/.initramfs/plymouth.pid";
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/* Used by Ubuntu 11.10 (Oneiric Ocelot) */
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const char plymouth_old_pid[] = "/run/initramfs/plymouth.pid";
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/* Used by Debian 9 (stretch) */
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const char plymouth_pid[] = "/run/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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const char *plymouthd_default_argv[] = {"/sbin/plymouthd",
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"--attach-to-session",
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"--pid-file=/dev/.initramfs/plymouth.pid",
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static void termination_handler(__attribute__((unused))int signum){
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if(interrupted_by_signal){
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interrupted_by_signal = 1;
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__attribute__((format (gnu_printf, 2, 3), nonnull))
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int fprintf_plus(FILE *stream, const char *format, ...){
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va_start (ap, format);
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fprintf(stream, "Mandos plugin %s: ", program_invocation_short_name);
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return vfprintf(stream, format, ap);
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/* Function to use when printing errors */
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__attribute__((format (gnu_printf, 3, 4)))
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void error_plus(int status, int errnum, const char *formatstring,
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va_start(ap, formatstring);
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ret = vasprintf(&text, formatstring, ap);
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fprintf(stderr, "Mandos plugin %s: ",
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program_invocation_short_name);
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vfprintf(stderr, formatstring, ap);
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fprintf(stderr, ": ");
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fprintf(stderr, "%s\n", strerror(errnum));
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error(status, errno, "vasprintf while printing error");
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fprintf(stderr, "Mandos plugin ");
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error(status, errnum, "%s", text);
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/* Create prompt string */
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char *makeprompt(void){
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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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const char prompt_start[] = "Unlocking the disk";
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const char prompt_end[] = "Enter passphrase";
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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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ret = asprintf(&prompt, "%s\n%s", prompt_start, prompt_end);
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ret = asprintf(&prompt, "%s (%s): ", prompt_start,
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ret = asprintf(&prompt, "%s (%s)\n%s", prompt_start,
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crypttarget, prompt_end);
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if(crypttarget == NULL){
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ret = asprintf(&prompt, "%s %s: ", prompt_start, cryptsource);
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ret = asprintf(&prompt, "%s %s\n%s", prompt_start, cryptsource,
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ret = asprintf(&prompt, "%s %s (%s): ", prompt_start,
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cryptsource, crypttarget);
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ret = asprintf(&prompt, "%s %s (%s)\n%s", prompt_start,
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cryptsource, crypttarget, prompt_end);
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170
bool become_a_daemon(void){
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int ret = setuid(geteuid());
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error(0, errno, "setuid");
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error_plus(0, errno, "setuid");
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error(0, errno, "chdir");
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error_plus(0, errno, "chdir");
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ret = dup2(STDERR_FILENO, STDOUT_FILENO); /* replace our stdout */
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error(0, errno, "dup2");
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error_plus(0, errno, "dup2");
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__attribute__((nonnull (2, 3)))
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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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const char * const * const argv, bool interruptable,
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for(const char * const *arg = argv; *arg != NULL; arg++){
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fprintf_plus(stderr, "exec_and_wait arg: %s\n", *arg);
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fprintf_plus(stderr, "exec_and_wait end of args\n");
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error(0, errno, "fork");
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error_plus(0, errno, "fork");
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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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fprintf_plus(stderr, "Interrupted by signal\n");
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error(0, errno, "waitpid");
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error_plus(0, errno, "waitpid");
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if(WIFEXITED(status) and WEXITSTATUS(status) == 0){
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if(WIFEXITED(status)){
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fprintf_plus(stderr, "exec_and_wait exited: %d\n",
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WEXITSTATUS(status));
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} else if(WIFSIGNALED(status)) {
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fprintf_plus(stderr, "exec_and_wait signaled: %d\n",
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if(WIFEXITED(status) and (WEXITSTATUS(status) == 0)){
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__attribute__((nonnull))
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int is_plymouth(const struct dirent *proc_entry){
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maxvalue = strtoumax(proc_entry->d_name, &tmp, 10);
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proc_id = 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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if(errno != 0 or *tmp != '\0'
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or proc_id != (uintmax_t)((pid_t)proc_id)){
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char exe_target[sizeof(plymouth_path)];
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char exe_target[sizeof(plymouthd_path)];
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ret = asprintf(&exe_link, "/proc/%s/exe", proc_entry->d_name);
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error(0, errno, "asprintf");
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error_plus(0, errno, "asprintf");
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306
struct stat exe_stat;
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ret = lstat(exe_link, &exe_stat);
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if(errno != ENOENT){
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error(0, errno, "lstat");
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error_plus(0, errno, "lstat");
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pid_t get_pid(void){
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uintmax_t proc_id = 0;
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FILE *pidfile = fopen(plymouth_pid, "r");
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uintmax_t maxvalue = 0;
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/* Try the new pid file location */
209
338
if(pidfile != NULL){
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ret = fscanf(pidfile, "%" SCNuMAX, &maxvalue);
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ret = fscanf(pidfile, "%" SCNuMAX, &proc_id);
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struct dirent **direntries;
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/* Try the old pid file location */
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pidfile = fopen(plymouth_old_pid, "r");
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ret = fscanf(pidfile, "%" SCNuMAX, &proc_id);
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/* Try the old old pid file location */
358
pidfile = fopen(plymouth_old_old_pid, "r");
360
ret = fscanf(pidfile, "%" SCNuMAX, &proc_id);
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/* Look for a plymouth process */
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struct dirent **direntries = NULL;
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370
ret = scandir("/proc", &direntries, is_plymouth, alphasort);
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sscanf(direntries[0]->d_name, "%" SCNuMAX, &maxvalue);
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error_plus(0, errno, "scandir");
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for(int i = ret-1; i >= 0; i--){
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ret = sscanf(direntries[i]->d_name, "%" SCNuMAX, &proc_id);
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error_plus(0, errno, "sscanf");
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/* scandir might preallocate for this variable (man page unclear).
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even if ret == 0, therefore we need to free it. */
222
pid = (pid_t)maxvalue;
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if((uintmax_t)pid == maxvalue){
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pid = (pid_t)proc_id;
391
if((uintmax_t)pid == proc_id){
230
const char **getargv(pid_t pid){
398
char **getargv(pid_t pid){
232
400
char *cmdline_filename;
289
457
char **argv = malloc((argz_count(cmdline, cmdline_len) + 1)
290
458
* sizeof(char *)); /* Get number of args */
291
459
if(argv == NULL){
292
error(0, errno, "argv = malloc()");
460
error_plus(0, errno, "argv = malloc()");
296
464
argz_extract(cmdline, cmdline_len, argv); /* Create argv */
297
return (const char **)argv;
300
468
int main(__attribute__((unused))int argc,
301
469
__attribute__((unused))char **argv){
303
471
char *prompt_arg;
304
472
pid_t plymouth_command_pid;
477
struct argp_option options[] = {
478
{ .name = "prompt", .key = 128, .arg = "PROMPT",
479
.doc = "The prompt to show" },
480
{ .name = "debug", .key = 129,
481
.doc = "Debug mode" },
485
__attribute__((nonnull(3)))
486
error_t parse_opt (int key, char *arg, __attribute__((unused))
487
struct argp_state *state){
490
case 128: /* --prompt */
493
fprintf_plus(stderr, "Custom prompt \"%s\"\n", prompt);
496
case 129: /* --debug */
500
return ARGP_ERR_UNKNOWN;
505
struct argp argp = { .options = options, .parser = parse_opt,
507
.doc = "Mandos plymouth -- Read and"
508
" output a password" };
509
ret = argp_parse(&argp, argc, argv, ARGP_IN_ORDER, NULL, NULL);
516
error_plus(0, errno, "argp_parse");
519
error_plus(0, errno, "argp_parse");
308
524
/* test -x /bin/plymouth */
309
525
ret = access(plymouth_path, X_OK);
527
/* Plymouth is probably not installed. Don't print an error
528
message, just exit. */
530
fprintf_plus(stderr, "Plymouth (%s) not found\n",
533
exit(EX_UNAVAILABLE);
314
536
{ /* Add signal handlers */
315
537
struct sigaction old_action,
316
538
new_action = { .sa_handler = termination_handler,
318
540
sigemptyset(&new_action.sa_mask);
319
for(int *sig = (int[]){ SIGINT, SIGHUP, SIGTERM, 0 }; *sig != 0; sig++){
541
for(int *sig = (int[]){ SIGINT, SIGHUP, SIGTERM, 0 };
320
543
ret = sigaddset(&new_action.sa_mask, *sig);
322
error(0, errno, "sigaddset");
545
error_plus(EX_OSERR, errno, "sigaddset");
325
547
ret = sigaction(*sig, NULL, &old_action);
327
error(0, errno, "sigaction");
549
error_plus(EX_OSERR, errno, "sigaction");
330
551
if(old_action.sa_handler != SIG_IGN){
331
552
ret = sigaction(*sig, &new_action, NULL);
333
error(0, errno, "sigaction");
554
error_plus(EX_OSERR, errno, "sigaction");
340
560
/* plymouth --ping */
341
561
bret = exec_and_wait(&plymouth_command_pid, plymouth_path,
342
(const char *[]){ (const char *)plymouth_path, (const char *)"--ping", (const char *)NULL},
563
{ plymouth_path, "--ping", NULL },
345
566
if(interrupted_by_signal){
346
567
kill_and_wait(plymouth_command_pid);
570
/* Plymouth is probably not running. Don't print an error
571
message, just exit. */
573
fprintf_plus(stderr, "Plymouth not running\n");
575
exit(EX_UNAVAILABLE);
351
prompt = makeprompt();
352
ret = asprintf(&prompt_arg, "--prompt=%s", prompt);
579
ret = asprintf(&prompt_arg, "--prompt=%s", prompt);
581
char *made_prompt = makeprompt();
582
ret = asprintf(&prompt_arg, "--prompt=%s", made_prompt);
355
error(0, errno, "asprintf");
586
error_plus(EX_OSERR, errno, "asprintf");
359
589
/* 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},
591
fprintf_plus(stderr, "Prompting for password via Plymouth\n");
593
bret = exec_and_wait(&plymouth_command_pid,
594
plymouth_path, (const char *[])
595
{ plymouth_path, "ask-for-password",
363
598
free(prompt_arg);
365
if(interrupted_by_signal){
366
kill_and_wait(plymouth_command_pid);
373
600
exit(EXIT_SUCCESS);
602
if(not interrupted_by_signal){
603
/* exec_and_wait failed for some other reason */
606
kill_and_wait(plymouth_command_pid);
376
const char **plymouthd_argv = NULL;
608
char **plymouthd_argv = NULL;
377
609
pid_t pid = get_pid();
379
error(0, 0, "plymouthd pid not found");
611
error_plus(0, 0, "plymouthd pid not found");
381
613
plymouthd_argv = getargv(pid);
383
if(plymouthd_argv == NULL){
384
plymouthd_argv = plymouthd_default_argv;
387
bret = exec_and_wait(NULL, plymouth_path,
388
(const char *[]){plymouth_path, "quit", NULL}, false, false);
392
bret = exec_and_wait(NULL, plymouthd_path, plymouthd_argv, false, true);
396
exec_and_wait(NULL, plymouth_path,
397
(const char *[]){ plymouth_path, "show-splash", NULL }, false, false);
616
bret = exec_and_wait(NULL, plymouth_path, (const char *[])
617
{ plymouth_path, "quit", NULL },
620
if(plymouthd_argv != NULL){
621
free(*plymouthd_argv);
622
free(plymouthd_argv);
626
bret = exec_and_wait(NULL, plymouthd_path,
627
(plymouthd_argv != NULL)
628
? (const char * const *)plymouthd_argv
629
: plymouthd_default_argv,
631
if(plymouthd_argv != NULL){
632
free(*plymouthd_argv);
633
free(plymouthd_argv);
638
exec_and_wait(NULL, plymouth_path, (const char *[])
639
{ plymouth_path, "show-splash", NULL },
398
641
exit(EXIT_FAILURE);