signals.c

#include "afl-fuzz.h"

/* Handle stop signal (Ctrl-C, etc). */

static void handle_stop_sig(int sig) {
  stop_soon = 1;

  if (child_pid > 0) kill(child_pid, SIGKILL);
  if (forksrv_pid > 0) kill(forksrv_pid, SIGKILL);
}

/* Handle skip request (SIGUSR1). */

static void handle_skipreq(int sig) { skip_requested = 1; }

/* Handle timeout (SIGALRM). */

static void handle_timeout(int sig) {
  if (child_pid > 0) {
    child_timed_out = 1;
    kill(child_pid, SIGKILL);

  } else if (child_pid == -1 && forksrv_pid > 0) {
    child_timed_out = 1;
    kill(forksrv_pid, SIGKILL);
  }
}

/* Handle screen resize (SIGWINCH). */

void handle_resize(int sig) { clear_screen = 1; }

/* Set up signal handlers. More complicated that needs to be, because libc on
   Solaris doesn't resume interrupted reads(), sets SA_RESETHAND when you call
   siginterrupt(), and does other unnecessary things. */

void setup_signal_handlers(void) {
  struct sigaction sa;

  sa.sa_handler = NULL;
  sa.sa_flags = SA_RESTART;
  sa.sa_sigaction = NULL;

  sigemptyset(&sa.sa_mask);

  /* Various ways of saying "stop". */

  sa.sa_handler = handle_stop_sig;
  sigaction(SIGHUP, &sa, NULL);
  sigaction(SIGINT, &sa, NULL);
  sigaction(SIGTERM, &sa, NULL);

  /* Exec timeout notifications. */

  sa.sa_handler = handle_timeout;
  sigaction(SIGALRM, &sa, NULL);

  /* Window resize */

  sa.sa_handler = handle_resize;
  sigaction(SIGWINCH, &sa, NULL);

  /* SIGUSR1: skip entry */

  sa.sa_handler = handle_skipreq;
  sigaction(SIGUSR1, &sa, NULL);

  /* Things we don't care about. */

  sa.sa_handler = SIG_IGN;
  sigaction(SIGTSTP, &sa, NULL);
  sigaction(SIGPIPE, &sa, NULL);
}