1 files changed, 340 insertions, 0 deletions
diff --git a/sendmail/libsm/signal.c b/sendmail/libsm/signal.c
new file mode 100644
index 0000000..ce2e242
--- /dev/null
+++ b/sendmail/libsm/signal.c
@@ -0,0 +1,340 @@
+/*
+ * Copyright (c) 2000-2001 Sendmail, Inc. and its suppliers.
+ *      All rights reserved.
+ *
+ * By using this file, you agree to the terms and conditions set
+ * forth in the LICENSE file which can be found at the top level of
+ * the sendmail distribution.
+ */
+
+#include <sm/gen.h>
+SM_RCSID("@(#)$Id: signal.c,v 1.17 2005/06/14 23:07:20 ca Exp $")
+
+#if SM_CONF_SETITIMER
+# include <sm/time.h>
+#endif /* SM_CONF_SETITIMER */
+#include <errno.h>
+#include <stdlib.h>
+#include <time.h>
+#include <unistd.h>
+#include <sm/clock.h>
+#include <sm/signal.h>
+#include <signal.h>
+#include <sm/string.h>
+
+unsigned int	volatile InCriticalSection; /* >0 if inside critical section */
+int		volatile PendingSignal;	/* pending signal to resend */
+
+/*
+**  SM_SIGNAL -- set a signal handler
+**
+**	This is essentially old BSD "signal(3)".
+**
+**	NOTE:	THIS CAN BE CALLED FROM A SIGNAL HANDLER.  DO NOT ADD
+**		ANYTHING TO THIS ROUTINE UNLESS YOU KNOW WHAT YOU ARE
+**		DOING.
+*/
+
+sigfunc_t
+sm_signal(sig, handler)
+	int sig;
+	sigfunc_t handler;
+{
+# if defined(SA_RESTART) || (!defined(SYS5SIGNALS) && !defined(BSD4_3))
+	struct sigaction n, o;
+# endif /* defined(SA_RESTART) || (!defined(SYS5SIGNALS) && !defined(BSD4_3)) */
+
+	/*
+	**  First, try for modern signal calls
+	**  and restartable syscalls
+	*/
+
+# ifdef SA_RESTART
+	(void) memset(&n, '\0', sizeof n);
+#  if USE_SA_SIGACTION
+	n.sa_sigaction = (void(*)(int, siginfo_t *, void *)) handler;
+	n.sa_flags = SA_RESTART|SA_SIGINFO;
+#  else /* USE_SA_SIGACTION */
+	n.sa_handler = handler;
+	n.sa_flags = SA_RESTART;
+#  endif /* USE_SA_SIGACTION */
+	if (sigaction(sig, &n, &o) < 0)
+		return SIG_ERR;
+	return o.sa_handler;
+# else /* SA_RESTART */
+
+	/*
+	**  Else check for SYS5SIGNALS or
+	**  BSD4_3 signals
+	*/
+
+#  if defined(SYS5SIGNALS) || defined(BSD4_3)
+#   ifdef BSD4_3
+	return signal(sig, handler);
+#   else /* BSD4_3 */
+	return sigset(sig, handler);
+#   endif /* BSD4_3 */
+#  else /* defined(SYS5SIGNALS) || defined(BSD4_3) */
+
+	/*
+	**  Finally, if nothing else is available,
+	**  go for a default
+	*/
+
+	(void) memset(&n, '\0', sizeof n);
+	n.sa_handler = handler;
+	if (sigaction(sig, &n, &o) < 0)
+		return SIG_ERR;
+	return o.sa_handler;
+#  endif /* defined(SYS5SIGNALS) || defined(BSD4_3) */
+# endif /* SA_RESTART */
+}
+/*
+**  SM_BLOCKSIGNAL -- hold a signal to prevent delivery
+**
+**	Parameters:
+**		sig -- the signal to block.
+**
+**	Returns:
+**		1 signal was previously blocked
+**		0 signal was not previously blocked
+**		-1 on failure.
+*/
+
+int
+sm_blocksignal(sig)
+	int sig;
+{
+# ifdef BSD4_3
+#  ifndef sigmask
+#   define sigmask(s)	(1 << ((s) - 1))
+#  endif /* ! sigmask */
+	return (sigblock(sigmask(sig)) & sigmask(sig)) != 0;
+# else /* BSD4_3 */
+#  ifdef ALTOS_SYSTEM_V
+	sigfunc_t handler;
+
+	handler = sigset(sig, SIG_HOLD);
+	if (handler == SIG_ERR)
+		return -1;
+	else
+		return handler == SIG_HOLD;
+#  else /* ALTOS_SYSTEM_V */
+	sigset_t sset, oset;
+
+	(void) sigemptyset(&sset);
+	(void) sigaddset(&sset, sig);
+	if (sigprocmask(SIG_BLOCK, &sset, &oset) < 0)
+		return -1;
+	else
+		return sigismember(&oset, sig);
+#  endif /* ALTOS_SYSTEM_V */
+# endif /* BSD4_3 */
+}
+/*
+**  SM_RELEASESIGNAL -- release a held signal
+**
+**	Parameters:
+**		sig -- the signal to release.
+**
+**	Returns:
+**		1 signal was previously blocked
+**		0 signal was not previously blocked
+**		-1 on failure.
+*/
+
+int
+sm_releasesignal(sig)
+	int sig;
+{
+# ifdef BSD4_3
+	return (sigsetmask(sigblock(0) & ~sigmask(sig)) & sigmask(sig)) != 0;
+# else /* BSD4_3 */
+#  ifdef ALTOS_SYSTEM_V
+	sigfunc_t handler;
+
+	handler = sigset(sig, SIG_HOLD);
+	if (sigrelse(sig) < 0)
+		return -1;
+	else
+		return handler == SIG_HOLD;
+#  else /* ALTOS_SYSTEM_V */
+	sigset_t sset, oset;
+
+	(void) sigemptyset(&sset);
+	(void) sigaddset(&sset, sig);
+	if (sigprocmask(SIG_UNBLOCK, &sset, &oset) < 0)
+		return -1;
+	else
+		return sigismember(&oset, sig);
+#  endif /* ALTOS_SYSTEM_V */
+# endif /* BSD4_3 */
+}
+/*
+**  PEND_SIGNAL -- Add a signal to the pending signal list
+**
+**	Parameters:
+**		sig -- signal to add
+**
+**	Returns:
+**		none.
+**
+**	NOTE:	THIS CAN BE CALLED FROM A SIGNAL HANDLER.  DO NOT ADD
+**		ANYTHING TO THIS ROUTINE UNLESS YOU KNOW WHAT YOU ARE
+**		DOING.
+*/
+
+void
+pend_signal(sig)
+	int sig;
+{
+	int sigbit;
+	int save_errno = errno;
+#if SM_CONF_SETITIMER
+	struct itimerval clr;
+#endif /* SM_CONF_SETITIMER */
+
+	/*
+	**  Don't want to interrupt something critical, hence delay
+	**  the alarm for one second.  Hopefully, by then we
+	**  will be out of the critical section.  If not, then
+	**  we will just delay again.  The events to be run will
+	**  still all be run, maybe just a little bit late.
+	*/
+
+	switch (sig)
+	{
+	  case SIGHUP:
+		sigbit = PEND_SIGHUP;
+		break;
+
+	  case SIGINT:
+		sigbit = PEND_SIGINT;
+		break;
+
+	  case SIGTERM:
+		sigbit = PEND_SIGTERM;
+		break;
+
+	  case SIGUSR1:
+		sigbit = PEND_SIGUSR1;
+		break;
+
+	  case SIGALRM:
+		/* don't have to pend these */
+		sigbit = 0;
+		break;
+
+	  default:
+		/* If we get here, we are in trouble */
+		abort();
+
+		/* NOTREACHED */
+		/* shut up stupid compiler warning on HP-UX 11 */
+		sigbit = 0;
+		break;
+	}
+
+	if (sigbit != 0)
+		PendingSignal |= sigbit;
+	(void) sm_signal(SIGALRM, sm_tick);
+#if SM_CONF_SETITIMER
+	clr.it_interval.tv_sec = 0;
+	clr.it_interval.tv_usec = 0;
+	clr.it_value.tv_sec = 1;
+	clr.it_value.tv_usec = 0;
+	(void) setitimer(ITIMER_REAL, &clr, NULL);
+#else /* SM_CONF_SETITIMER */
+	(void) alarm(1);
+#endif /* SM_CONF_SETITIMER */
+	errno = save_errno;
+}
+/*
+**  SM_ALLSIGNALS -- act on all signals
+**
+**	Parameters:
+**		block -- whether to block or release all signals.
+**
+**	Returns:
+**		none.
+*/
+
+void
+sm_allsignals(block)
+	bool block;
+{
+# ifdef BSD4_3
+#  ifndef sigmask
+#   define sigmask(s)	(1 << ((s) - 1))
+#  endif /* ! sigmask */
+	if (block)
+	{
+		int mask = 0;
+
+		mask |= sigmask(SIGALRM);
+		mask |= sigmask(SIGCHLD);
+		mask |= sigmask(SIGHUP);
+		mask |= sigmask(SIGINT);
+		mask |= sigmask(SIGTERM);
+		mask |= sigmask(SIGUSR1);
+
+		(void) sigblock(mask);
+	}
+	else
+		sigsetmask(0);
+# else /* BSD4_3 */
+#  ifdef ALTOS_SYSTEM_V
+	if (block)
+	{
+		(void) sigset(SIGALRM, SIG_HOLD);
+		(void) sigset(SIGCHLD, SIG_HOLD);
+		(void) sigset(SIGHUP, SIG_HOLD);
+		(void) sigset(SIGINT, SIG_HOLD);
+		(void) sigset(SIGTERM, SIG_HOLD);
+		(void) sigset(SIGUSR1, SIG_HOLD);
+	}
+	else
+	{
+		(void) sigset(SIGALRM, SIG_DFL);
+		(void) sigset(SIGCHLD, SIG_DFL);
+		(void) sigset(SIGHUP, SIG_DFL);
+		(void) sigset(SIGINT, SIG_DFL);
+		(void) sigset(SIGTERM, SIG_DFL);
+		(void) sigset(SIGUSR1, SIG_DFL);
+	}
+#  else /* ALTOS_SYSTEM_V */
+	sigset_t sset;
+
+	(void) sigemptyset(&sset);
+	(void) sigaddset(&sset, SIGALRM);
+	(void) sigaddset(&sset, SIGCHLD);
+	(void) sigaddset(&sset, SIGHUP);
+	(void) sigaddset(&sset, SIGINT);
+	(void) sigaddset(&sset, SIGTERM);
+	(void) sigaddset(&sset, SIGUSR1);
+	(void) sigprocmask(block ? SIG_BLOCK : SIG_UNBLOCK, &sset, NULL);
+#  endif /* ALTOS_SYSTEM_V */
+# endif /* BSD4_3 */
+}
+/*
+**  SM_SIGNAL_NOOP -- A signal no-op function
+**
+**	Parameters:
+**		sig -- signal received
+**
+**	Returns:
+**		SIGFUNC_RETURN
+*/
+
+/* ARGSUSED */
+SIGFUNC_DECL
+sm_signal_noop(sig)
+	int sig;
+{
+	int save_errno = errno;
+
+	FIX_SYSV_SIGNAL(sig, sm_signal_noop);
+	errno = save_errno;
+	return SIGFUNC_RETURN;
+}
+