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#define _GNU_SOURCE /* asprintf() */
#include <signal.h> /* sig_atomic_t, struct sigaction,
sigemptyset(), sigaddset(),
sigaction, SIGINT, SIG_IGN, SIGHUP,
SIGTERM, kill(), SIGKILL */
#include <stddef.h> /* NULL */
#include <stdlib.h> /* getenv() */
#include <stdio.h> /* asprintf(), perror() */
#include <stdlib.h> /* EXIT_FAILURE, EXIT_SUCCESS,
strtoul(), free() */
#include <sys/types.h> /* pid_t, DIR, struct dirent,
ssize_t */
#include <dirent.h> /* opendir(), readdir(), closedir() */
#include <unistd.h> /* readlink(), fork(), execl(),
_exit */
#include <string.h> /* memcmp() */
#include <iso646.h> /* and */
#include <errno.h> /* errno */
#include <sys/wait.h> /* waitpid(), WIFEXITED(),
WEXITSTATUS() */
sig_atomic_t interrupted_by_signal = 0;
static void termination_handler(__attribute__((unused))int signum){
interrupted_by_signal = 1;
}
int main(__attribute__((unused))int argc,
__attribute__((unused))char **argv){
int ret = 0;
/* Create prompt string */
char *prompt = NULL;
{
const char *const cryptsource = getenv("cryptsource");
const char *const crypttarget = getenv("crypttarget");
const char *const prompt_start = "getpass "
"Enter passphrase to unlock the disk";
if(cryptsource == NULL){
if(crypttarget == NULL){
ret = asprintf(&prompt, "%s: ", prompt_start);
} else {
ret = asprintf(&prompt, "%s (%s): ", prompt_start,
crypttarget);
}
} else {
if(crypttarget == NULL){
ret = asprintf(&prompt, "%s %s: ", prompt_start, cryptsource);
} else {
ret = asprintf(&prompt, "%s %s (%s): ", prompt_start,
cryptsource, crypttarget);
}
}
if(ret == -1){
return EXIT_FAILURE;
}
}
/* Find splashy process */
pid_t splashy_pid = 0;
{
const char splashy_name[] = "/sbin/splashy";
DIR *proc_dir = opendir("/proc");
if(proc_dir == NULL){
free(prompt);
perror("opendir");
return EXIT_FAILURE;
}
for(struct dirent *proc_ent = readdir(proc_dir);
proc_ent != NULL;
proc_ent = readdir(proc_dir)){
pid_t pid = (pid_t) strtoul(proc_ent->d_name, NULL, 10);
if(pid == 0){
/* Not a process */
continue;
}
/* Find the executable name by doing readlink() on the
/proc/<pid>/exe link */
char exe_target[sizeof(splashy_name)];
ssize_t sret;
{
char *exe_link;
ret = asprintf(&exe_link, "/proc/%s/exe", proc_ent->d_name);
if(ret == -1){
perror("asprintf");
free(prompt);
closedir(proc_dir);
return EXIT_FAILURE;
}
sret = readlink(exe_link, exe_target, sizeof(exe_target));
free(exe_link);
}
if((sret == ((ssize_t)sizeof(exe_target)-1))
and (memcmp(splashy_name, exe_target,
sizeof(exe_target)-1) == 0)){
splashy_pid = pid;
break;
}
}
closedir(proc_dir);
}
if(splashy_pid == 0){
free(prompt);
return EXIT_FAILURE;
}
/* Set up the signal handler */
{
struct sigaction old_action,
new_action = { .sa_handler = termination_handler,
.sa_flags = 0 };
sigemptyset(&new_action.sa_mask);
sigaddset(&new_action.sa_mask, SIGINT);
sigaddset(&new_action.sa_mask, SIGHUP);
sigaddset(&new_action.sa_mask, SIGTERM);
ret = sigaction(SIGINT, NULL, &old_action);
if(ret == -1){
perror("sigaction");
free(prompt);
return EXIT_FAILURE;
}
if (old_action.sa_handler != SIG_IGN){
ret = sigaction(SIGINT, &new_action, NULL);
if(ret == -1){
perror("sigaction");
free(prompt);
return EXIT_FAILURE;
}
}
ret = sigaction(SIGHUP, NULL, &old_action);
if(ret == -1){
perror("sigaction");
free(prompt);
return EXIT_FAILURE;
}
if (old_action.sa_handler != SIG_IGN){
ret = sigaction(SIGHUP, &new_action, NULL);
if(ret == -1){
perror("sigaction");
free(prompt);
return EXIT_FAILURE;
}
}
ret = sigaction(SIGTERM, NULL, &old_action);
if(ret == -1){
perror("sigaction");
free(prompt);
return EXIT_FAILURE;
}
if (old_action.sa_handler != SIG_IGN){
ret = sigaction(SIGTERM, &new_action, NULL);
if(ret == -1){
perror("sigaction");
free(prompt);
return EXIT_FAILURE;
}
}
}
/* Fork off the splashy command to prompt for password */
pid_t splashy_command_pid = 0;
if(not interrupted_by_signal){
splashy_command_pid = fork();
if(splashy_command_pid == -1){
if(not interrupted_by_signal){
perror("fork");
}
return EXIT_FAILURE;
}
/* Child */
if(splashy_command_pid == 0){
const char splashy_command[] = "/sbin/splashy_update";
ret = execl(splashy_command, splashy_command, prompt,
(char *)NULL);
if(not interrupted_by_signal and errno != ENOENT){
/* Don't report "File not found", since splashy might not be
installed. */
perror("execl");
}
free(prompt);
return EXIT_FAILURE;
}
}
/* Parent */
free(prompt);
/* Wait for command to complete */
int status;
while(not interrupted_by_signal){
waitpid(splashy_command_pid, &status, 0);
if(not interrupted_by_signal
and WIFEXITED(status) and WEXITSTATUS(status)==0){
return EXIT_SUCCESS;
}
}
kill(splashy_pid, SIGTERM);
if(interrupted_by_signal){
kill(splashy_command_pid, SIGTERM);
}
pid_t new_splashy_pid = fork();
if(new_splashy_pid == 0){
/* Child; will become new splashy process */
while(kill(splashy_pid, 0)){
sleep(2);
kill(splashy_pid, SIGKILL);
sleep(1);
}
ret = dup2(STDERR_FILENO, STDOUT_FILENO); /* replace our stdout */
if(ret == -1){
perror("dup2");
_exit(EXIT_FAILURE);
}
execl("/sbin/splashy", "/sbin/splashy", "boot", (char *)NULL);
}
return EXIT_FAILURE;
}
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