upstream/1.1.0_cvsrelease/1.1.0_cvs

1 files changed, 208 insertions, 0 deletions

diff --git a/gnu/libexec/uucp/libunix/signal.c b/gnu/libexec/uucp/libunix/signal.c
new file mode 100644
index 000000000000..33e24a724574
--- /dev/null
+++ b/gnu/libexec/uucp/libunix/signal.c
@@ -0,0 +1,208 @@
+/* signal.c
+   Signal handling routines.
+
+   Copyright (C) 1992 Ian Lance Taylor
+
+   This file is part of the Taylor UUCP package.
+
+   This program is free software; you can redistribute it and/or
+   modify it under the terms of the GNU General Public License as
+   published by the Free Software Foundation; either version 2 of the
+   License, or (at your option) any later version.
+
+   This program is distributed in the hope that it will be useful, but
+   WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+   General Public License for more details.
+
+   You should have received a copy of the GNU General Public License
+   along with this program; if not, write to the Free Software
+   Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
+
+   The author of the program may be contacted at ian@airs.com or
+   c/o Infinity Development Systems, P.O. Box 520, Waltham, MA 02254.
+   */
+
+#include "uucp.h"
+
+#include "uudefs.h"
+#include "sysdep.h"
+#include "system.h"
+
+#include <errno.h>
+
+/* Signal handling routines.  When we catch a signal, we want to set
+   the appropriate elements of afSignal and afLog_signal to TRUE.  If
+   we are on a system which restarts system calls, we may also want to
+   longjmp out.  On a system which does not restart system calls,
+   these signal handling routines are well-defined by ANSI C.  */
+
+#if HAVE_RESTARTABLE_SYSCALLS
+volatile sig_atomic_t fSjmp;
+volatile jmp_buf sSjmp_buf;
+#endif /* HAVE_RESTARTABLE_SYSCALLS */
+
+/* Some systems, such as SunOS, have a SA_INTERRUPT bit that must be
+   set in the sigaction structure to force system calls to be
+   interrupted.  */
+#ifndef SA_INTERRUPT
+#define SA_INTERRUPT 0
+#endif
+
+/* The SVR3 sigset function can be called just like signal, unless
+   system calls are restarted which is extremely unlikely; we prevent
+   this case in sysh.unx.  */
+#if HAVE_SIGSET && ! HAVE_SIGACTION && ! HAVE_SIGVEC
+#define signal sigset
+#endif
+
+/* The sigvec structure changed from 4.2BSD to 4.3BSD.  These macros
+   make the 4.3 code backward compatible.  */
+#ifndef SV_INTERRUPT
+#define SV_INTERRUPT 0
+#endif
+#if ! HAVE_SIGVEC_SV_FLAGS
+#define sv_flags sv_onstack
+#endif
+
+/* Catch a signal.  Reinstall the signal handler if necessary, set the
+   appropriate variables, and do a longjmp if necessary.  */
+
+RETSIGTYPE
+ussignal (isig)
+     int isig;
+{
+  int iindex;
+
+#if ! HAVE_SIGACTION && ! HAVE_SIGVEC && ! HAVE_SIGSET
+  (void) signal (isig, ussignal);
+#endif
+
+  switch (isig)
+    {
+    default: iindex = INDEXSIG_SIGHUP; break;
+#ifdef SIGINT
+    case SIGINT: iindex = INDEXSIG_SIGINT; break;
+#endif
+#ifdef SIGQUIT
+    case SIGQUIT: iindex = INDEXSIG_SIGQUIT; break;
+#endif
+#ifdef SIGTERM
+    case SIGTERM: iindex = INDEXSIG_SIGTERM; break;
+#endif
+#ifdef SIGPIPE
+    case SIGPIPE: iindex = INDEXSIG_SIGPIPE; break;
+#endif
+    }
+
+  afSignal[iindex] = TRUE;
+  afLog_signal[iindex] = TRUE;
+
+#if HAVE_RESTARTABLE_SYSCALLS
+  if (fSjmp)
+    longjmp (sSjmp_buf, 1);
+#endif /* HAVE_RESTARTABLE_SYSCALLS */
+}
+
+/* Prepare to catch a signal.  This is basically the ANSI C routine
+   signal, but it uses sigaction or sigvec instead if they are
+   available.  If fforce is FALSE, we do not set the signal if it is
+   currently being ignored.  If pfignored is not NULL and fforce is
+   FALSE, then *pfignored will be set to TRUE if the signal was
+   previously being ignored (if fforce is TRUE the value returned in
+   *pfignored is meaningless).  If we can't change the signal handler
+   we give a fatal error.  */
+
+void
+usset_signal (isig, pfn, fforce, pfignored)
+     int isig;
+     RETSIGTYPE (*pfn) P((int));
+     boolean fforce;
+     boolean *pfignored;
+{
+#if HAVE_SIGACTION
+
+  struct sigaction s;
+
+  if (! fforce)
+    {
+      (void) (sigemptyset (&s.sa_mask));
+      if (sigaction (isig, (struct sigaction *) NULL, &s) != 0)
+	ulog (LOG_FATAL, "sigaction (%d): %s", isig, strerror (errno));
+
+      if (s.sa_handler == SIG_IGN)
+	{
+	  if (pfignored != NULL)
+	    *pfignored = TRUE;
+	  return;
+	}
+
+      if (pfignored != NULL)
+	*pfignored = FALSE;
+    }
+
+  s.sa_handler = pfn;
+  (void) (sigemptyset (&s.sa_mask));
+  s.sa_flags = SA_INTERRUPT;
+
+  if (sigaction (isig, &s, (struct sigaction *) NULL) != 0)
+    ulog (LOG_FATAL, "sigaction (%d): %s", isig, strerror (errno));
+
+#else /* ! HAVE_SIGACTION */
+#if HAVE_SIGVEC
+
+  struct sigvec s;
+
+  if (! fforce)
+    {
+      if (sigvec (isig, (struct sigvec *) NULL, &s) != 0)
+	ulog (LOG_FATAL, "sigvec (%d): %s", isig, strerror (errno));
+
+      if (s.sv_handler == SIG_IGN)
+	{
+	  if (pfignored != NULL)
+	    *pfignored = TRUE;
+	  return;
+	}
+
+      if (pfignored != NULL)
+	*pfignored = FALSE;
+    }
+
+  s.sv_handler = pfn;
+  s.sv_mask = 0;
+  s.sv_flags = SV_INTERRUPT;
+
+  if (sigvec (isig, &s, (struct sigvec *) NULL) != 0)
+    ulog (LOG_FATAL, "sigvec (%d): %s", isig, strerror (errno));
+
+#else /* ! HAVE_SIGVEC */
+
+  if (! fforce)
+    {
+      if (signal (isig, SIG_IGN) == SIG_IGN)
+	{
+	  if (pfignored != NULL)
+	    *pfignored = TRUE;
+	  return;
+	}
+
+      if (pfignored != NULL)
+	*pfignored = FALSE;
+    }
+
+  (void) signal (isig, pfn);
+
+#endif /* ! HAVE_SIGVEC */
+#endif /* ! HAVE_SIGACTION */
+}
+
+/* The routine called by the system independent code, which always
+   uses the same signal handler.  */
+
+void
+usysdep_signal (isig)
+     int isig;
+{
+  usset_signal (isig, ussignal, FALSE, (boolean *) NULL);
+}