src/signals.c

   1 #define _GNU_SOURCE
   2 #include <stdio.h>
   3
   4 #include <signal.h>
   5
   6 #include <string.h>
   7
   8 #include "signals.h"
   9 #include "util.h"
  10
  11 static const char *termination_blurb =
  12   "\n"
  13   "*******************************************************************************\n"
  14   "*** vlock caught a fatal signal and will now terminate.  The reason for     ***\n"
  15   "*** this is very likely an error in the program.  Please notify the author  ***\n"
  16   "*** about this problem by sending an email to the address below.  Include   ***\n"
  17   "*** all messages leading up to this one and as much information as possible ***\n"
  18   "*** about your system and configuration.                                    ***\n"
  19   "*** Please include the word \"vlock\" in the subject of your email.  Sorry    ***\n"
  20   "*** for any inconvenience.                                                  ***\n"
  21   "***                                                                         ***\n"
  22   "*** Frank Benkstein <frank-vlock@benkstein.net>                             ***\n"
  23   "*******************************************************************************\n"
  24   "\n"
  25 ;
  26
  27 static void terminate(int signum)
  28 {
  29   vlock_invoke_atexit();
  30
  31   fprintf(stderr, "vlock: Killed by signal %d (%s)!\n", signum,
  32           strsignal(signum));
  33
  34   if (signum != SIGTERM)
  35     fputs(termination_blurb, stderr);
  36
  37   raise(signum);
  38 }
  39
  40 void install_signal_handlers(void)
  41 {
  42   struct sigaction sa;
  43
  44   /* Ignore some signals. */
  45   (void) sigemptyset(&(sa.sa_mask));
  46   sa.sa_flags = SA_RESTART;
  47   sa.sa_handler = SIG_IGN;
  48   (void) sigaction(SIGTSTP, &sa, NULL);
  49
  50   /* Handle termination signals.  None of these should be delivered in a normal
  51    * run of the program because terminal signals (INT, QUIT) are disabled
  52    * below. */
  53   sa.sa_flags = SA_RESETHAND;
  54   sa.sa_handler = terminate;
  55   (void) sigaction(SIGINT, &sa, NULL);
  56   (void) sigaction(SIGQUIT, &sa, NULL);
  57   (void) sigaction(SIGTERM, &sa, NULL);
  58   (void) sigaction(SIGHUP, &sa, NULL);
  59   (void) sigaction(SIGABRT, &sa, NULL);
  60   (void) sigaction(SIGSEGV, &sa, NULL);
  61 }
  62