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* along with this program. If not, see
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* <http://www.gnu.org/licenses/>.
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* Contact the authors at <https://www.fukt.bsnet.se/~belorn/> and
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* <https://www.fukt.bsnet.se/~teddy/>.
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* Contact the authors at <mandos@recompile.se>.
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#define _GNU_SOURCE /* getline() */
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#define _GNU_SOURCE /* getline(), asprintf() */
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#include <termios.h> /* struct termios, tcsetattr(),
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#include <termios.h> /* struct termios, tcsetattr(),
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TCSAFLUSH, tcgetattr(), ECHO */
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#include <unistd.h> /* struct termios, tcsetattr(),
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STDIN_FILENO, TCSAFLUSH,
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tcgetattr(), ECHO, readlink() */
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#include <signal.h> /* sig_atomic_t, raise(), struct
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sigaction, sigemptyset(),
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sigaction(), sigaddset(), SIGINT,
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SIGQUIT, SIGHUP, SIGTERM */
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#include <stddef.h> /* NULL, size_t */
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#include <sys/types.h> /* ssize_t */
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SIGQUIT, SIGHUP, SIGTERM,
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#include <stddef.h> /* NULL, size_t, ssize_t */
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#include <sys/types.h> /* ssize_t, struct dirent, pid_t,
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#include <stdlib.h> /* EXIT_SUCCESS, EXIT_FAILURE,
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#include <dirent.h> /* scandir(), alphasort() */
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#include <stdio.h> /* fprintf(), stderr, getline(),
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stdin, feof(), perror(), fputc(),
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stdout, getopt_long */
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#include <errno.h> /* errno, EINVAL */
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stdin, feof(), fputc(), vfprintf(),
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#include <errno.h> /* errno, EBADF, ENOTTY, EINVAL,
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EFAULT, EFBIG, EIO, ENOSPC, EINTR
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#include <error.h> /* error() */
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#include <iso646.h> /* or, not */
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#include <stdbool.h> /* bool, false, true */
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#include <string.h> /* strlen, rindex, strncmp, strcmp */
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#include <getopt.h> /* getopt_long */
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#include <inttypes.h> /* strtoumax() */
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#include <sys/stat.h> /* struct stat, lstat(), open() */
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#include <string.h> /* strlen, rindex, memcmp, strerror()
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#include <argp.h> /* struct argp_option, struct
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argp_state, struct argp,
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argp_parse(), error_t,
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ARGP_KEY_ARG, ARGP_KEY_END,
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#include <sysexits.h> /* EX_SOFTWARE, EX_OSERR,
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EX_UNAVAILABLE, EX_IOERR, EX_OK */
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#include <fcntl.h> /* open() */
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#include <stdarg.h> /* va_list, va_start(), ... */
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volatile bool quit_now = false;
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volatile sig_atomic_t quit_now = 0;
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bool debug = false;
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void termination_handler(__attribute__((unused))int signum){
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const char *argp_program_version = "password-prompt " VERSION;
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const char *argp_program_bug_address = "<mandos@recompile.se>";
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/* Needed for conflict resolution */
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const char plymouth_name[] = "plymouthd";
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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, ": %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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static void termination_handler(int signum){
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signal_received = signum;
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bool conflict_detection(void){
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/* plymouth conflicts with password-prompt since both want to read
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from the terminal. Password-prompt will exit if it detects
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plymouth since plymouth performs the same functionality.
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__attribute__((nonnull))
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int is_plymouth(const struct dirent *proc_entry){
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proc_id = strtoumax(proc_entry->d_name, &tmp, 10);
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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 *cmdline_filename;
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ret = asprintf(&cmdline_filename, "/proc/%s/cmdline",
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error_plus(0, errno, "asprintf");
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/* Open /proc/<pid>/cmdline */
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cl_fd = open(cmdline_filename, O_RDONLY);
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free(cmdline_filename);
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error_plus(0, errno, "open");
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char *cmdline = NULL;
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size_t cmdline_len = 0;
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size_t cmdline_allocated = 0;
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const size_t blocksize = 1024;
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/* Allocate more space? */
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if(cmdline_len + blocksize + 1 > cmdline_allocated){
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tmp = realloc(cmdline, cmdline_allocated + blocksize + 1);
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error_plus(0, errno, "realloc");
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cmdline_allocated += blocksize;
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sret = read(cl_fd, cmdline + cmdline_len,
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cmdline_allocated - cmdline_len);
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error_plus(0, errno, "read");
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cmdline_len += (size_t)sret;
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error_plus(0, errno, "close");
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cmdline[cmdline_len] = '\0'; /* Make sure it is terminated */
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/* we now have cmdline */
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char *cmdline_base = strrchr(cmdline, '/');
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if(cmdline_base != NULL){
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cmdline_base += 1; /* skip the slash */
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cmdline_base = cmdline;
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if(strcmp(cmdline_base, plymouth_name) != 0){
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fprintf(stderr, "\"%s\" is not \"%s\"\n", cmdline_base,
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fprintf(stderr, "\"%s\" equals \"%s\"\n", cmdline_base,
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struct dirent **direntries = NULL;
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ret = scandir("/proc", &direntries, is_plymouth, alphasort);
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error_plus(1, errno, "scandir");
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int main(int argc, char **argv){
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struct termios t_new, t_old;
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char *buffer = NULL;
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struct sigaction old_action,
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new_action = { .sa_handler = termination_handler,
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static struct option long_options[] = {
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{"debug", no_argument, (int *)&debug, 1},
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{"prefix", required_argument, 0, 'p'},
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ret = getopt_long (argc, argv, "p:", long_options, &option_index);
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struct argp_option options[] = {
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{ .name = "prefix", .key = 'p',
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.arg = "PREFIX", .flags = 0,
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.doc = "Prefix shown before the prompt", .group = 2 },
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{ .name = "debug", .key = 128,
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.doc = "Debug mode", .group = 3 },
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* These reproduce what we would get without ARGP_NO_HELP
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{ .name = "help", .key = '?',
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.doc = "Give this help list", .group = -1 },
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{ .name = "usage", .key = -3,
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.doc = "Give a short usage message", .group = -1 },
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{ .name = "version", .key = 'V',
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.doc = "Print program version", .group = -1 },
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__attribute__((nonnull(3)))
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error_t parse_opt (int key, char *arg, struct argp_state *state){
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* These reproduce what we would get without ARGP_NO_HELP
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case '?': /* --help */
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argp_state_help(state, state->out_stream,
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(ARGP_HELP_STD_HELP | ARGP_HELP_EXIT_ERR)
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& ~(unsigned int)ARGP_HELP_EXIT_OK);
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case -3: /* --usage */
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argp_state_help(state, state->out_stream,
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ARGP_HELP_USAGE | ARGP_HELP_EXIT_ERR);
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case 'V': /* --version */
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fprintf(state->out_stream, "%s\n", argp_program_version);
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exit(argp_err_exit_status);
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return ARGP_ERR_UNKNOWN;
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struct argp argp = { .options = options, .parser = parse_opt,
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.doc = "Mandos password-prompt -- Read and"
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" output a password" };
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ret = argp_parse(&argp, argc, argv,
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ARGP_IN_ORDER | ARGP_NO_HELP, NULL, NULL);
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fprintf(stderr, "bad arguments\n");
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error_plus(0, errno, "argp_parse");
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fprintf(stderr, "Starting %s\n", argv[0]);
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if(conflict_detection()){
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fprintf(stderr, "Stopping %s because of conflict\n", argv[0]);
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fprintf(stderr, "Storing current terminal attributes\n");
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if (tcgetattr(STDIN_FILENO, &t_old) != 0){
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if(tcgetattr(STDIN_FILENO, &t_old) != 0){
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error_plus(0, errno, "tcgetattr");
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return EX_UNAVAILABLE;
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335
sigemptyset(&new_action.sa_mask);
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sigaddset(&new_action.sa_mask, SIGINT);
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sigaddset(&new_action.sa_mask, SIGHUP);
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sigaddset(&new_action.sa_mask, SIGTERM);
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sigaction(SIGINT, NULL, &old_action);
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if (old_action.sa_handler != SIG_IGN)
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sigaction(SIGINT, &new_action, NULL);
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sigaction(SIGHUP, NULL, &old_action);
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if (old_action.sa_handler != SIG_IGN)
112
sigaction(SIGHUP, &new_action, NULL);
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sigaction(SIGTERM, NULL, &old_action);
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if (old_action.sa_handler != SIG_IGN)
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sigaction(SIGTERM, &new_action, NULL);
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ret = sigaddset(&new_action.sa_mask, SIGINT);
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error_plus(0, errno, "sigaddset");
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ret = sigaddset(&new_action.sa_mask, SIGHUP);
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error_plus(0, errno, "sigaddset");
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ret = sigaddset(&new_action.sa_mask, SIGTERM);
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error_plus(0, errno, "sigaddset");
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/* Need to check if the handler is SIG_IGN before handling:
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| [[info:libc:Initial Signal Actions]] |
353
| [[info:libc:Basic Signal Handling]] |
355
ret = sigaction(SIGINT, NULL, &old_action);
357
error_plus(0, errno, "sigaction");
360
if(old_action.sa_handler != SIG_IGN){
361
ret = sigaction(SIGINT, &new_action, NULL);
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error_plus(0, errno, "sigaction");
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ret = sigaction(SIGHUP, NULL, &old_action);
369
error_plus(0, errno, "sigaction");
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if(old_action.sa_handler != SIG_IGN){
373
ret = sigaction(SIGHUP, &new_action, NULL);
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error_plus(0, errno, "sigaction");
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ret = sigaction(SIGTERM, NULL, &old_action);
381
error_plus(0, errno, "sigaction");
384
if(old_action.sa_handler != SIG_IGN){
385
ret = sigaction(SIGTERM, &new_action, NULL);
387
error_plus(0, errno, "sigaction");
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394
fprintf(stderr, "Removing echo flag from terminal attributes\n");
123
t_new.c_lflag &= ~ECHO;
124
if (tcsetattr(STDIN_FILENO, TCSAFLUSH, &t_new) != 0){
125
perror("tcsetattr-echo");
398
t_new.c_lflag &= ~(tcflag_t)ECHO;
399
if(tcsetattr(STDIN_FILENO, TCSAFLUSH, &t_new) != 0){
401
error_plus(0, errno, "tcsetattr-echo");
405
return EX_UNAVAILABLE;
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413
fprintf(stderr, "Waiting for input from stdin \n");
418
fprintf(stderr, "Interrupted by signal, exiting.\n");
134
420
status = EXIT_FAILURE;
139
fprintf(stderr, "%s Password: ", prefix);
141
fprintf(stderr, "Password: ");
143
ret = getline(&buffer, &n, stdin);
145
fprintf(stdout, "%s", buffer);
425
fprintf(stderr, "%s ", prefix);
428
const char *cryptsource = getenv("CRYPTTAB_SOURCE");
429
const char *crypttarget = getenv("CRYPTTAB_NAME");
430
/* Before cryptsetup 1.1.0~rc2 */
431
if(cryptsource == NULL){
432
cryptsource = getenv("cryptsource");
434
if(crypttarget == NULL){
435
crypttarget = getenv("crypttarget");
437
const char *const prompt1 = "Unlocking the disk";
438
const char *const prompt2 = "Enter passphrase";
439
if(cryptsource == NULL){
440
if(crypttarget == NULL){
441
fprintf(stderr, "%s to unlock the disk: ", prompt2);
443
fprintf(stderr, "%s (%s)\n%s: ", prompt1, crypttarget,
447
if(crypttarget == NULL){
448
fprintf(stderr, "%s %s\n%s: ", prompt1, cryptsource,
451
fprintf(stderr, "%s %s (%s)\n%s: ", prompt1, cryptsource,
452
crypttarget, prompt2);
456
sret = getline(&buffer, &n, stdin);
146
458
status = EXIT_SUCCESS;
459
/* Make n = data size instead of allocated buffer size */
461
/* Strip final newline */
462
if(n > 0 and buffer[n-1] == '\n'){
463
buffer[n-1] = '\0'; /* not strictly necessary */
468
sret = write(STDOUT_FILENO, buffer + written, n - written);
471
error_plus(0, errno, "write");
483
status = EXIT_FAILURE;
488
written += (size_t)sret;
490
sret = close(STDOUT_FILENO);
493
error_plus(0, errno, "close");
149
// ret == 0 makes no other sence than to retry to read from stdin
151
if (errno != EINTR and not feof(stdin)){
153
status = EXIT_FAILURE;
508
if(errno != EINTR and not feof(stdin)){
509
error_plus(0, errno, "getline");
512
status = EX_UNAVAILABLE;
523
/* if(sret == 0), then the only sensible thing to do is to retry
524
to read from stdin */
157
525
fputc('\n', stderr);
526
if(debug and not quit_now){
527
/* If quit_now is nonzero, we were interrupted by a signal, and
528
will print that later, so no need to show this too. */
529
fprintf(stderr, "getline() returned 0, retrying.\n");
161
536
fprintf(stderr, "Restoring terminal attributes\n");
163
if (tcsetattr(STDIN_FILENO, TCSAFLUSH, &t_old) != 0){
164
perror("tcsetattr+echo");
168
fprintf(stderr, "%s is exiting\n", argv[0]);
538
if(tcsetattr(STDIN_FILENO, TCSAFLUSH, &t_old) != 0){
539
error_plus(0, errno, "tcsetattr+echo");
543
sigemptyset(&old_action.sa_mask);
544
old_action.sa_handler = SIG_DFL;
545
ret = sigaction(signal_received, &old_action, NULL);
547
error_plus(0, errno, "sigaction");
549
raise(signal_received);
553
fprintf(stderr, "%s is exiting with status %d\n", argv[0],
556
if(status == EXIT_SUCCESS or status == EX_OK){