syslogd/sysklogd-1.4.1-reload.dif

---
 syslogd.c |   68 ++++++++++++++++++++++++++++++++++++++------------------------
 1 file changed, 42 insertions(+), 26 deletions(-)

--- syslogd.c
+++ syslogd.c	2022-10-19 09:49:43.134694341 +0000
@@ -544,6 +544,10 @@ static char sccsid[]  __attribute__ ((un
 #include <sys/time.h>
 #include <sys/resource.h>
 #include <signal.h>
+#ifndef _GNU_SOURCE
+typedef void (*sighandler_t)(int);
+#endif
+static sighandler_t resignal(int signum, sighandler_t handler);
 
 #include <netinet/in.h>
 #include <netdb.h>
@@ -618,7 +622,7 @@ char	**parts;
 int inetm = 0;
 static int debugging_on = 0;
 static int nlogs = -1;
-static int restart = 0;
+static volatile sig_atomic_t restart;
 
 #define MAXFUNIX	20
 
@@ -1134,13 +1138,13 @@ int main(argc, argv)
 
 	leave = 0;
 
-	(void) signal(SIGTERM, die);
+	(void) resignal(SIGTERM, die);		/* Make recvfrom() be able to receive EINTR */
 	(void) signal(SIGINT, Debug ? die : SIG_IGN);
 	(void) signal(SIGQUIT, Debug ? die : SIG_IGN);
-	(void) signal(SIGCHLD, reapchild);
-	(void) signal(SIGALRM, domark);
-	(void) signal(SIGUSR1, Debug ? debug_switch : SIG_IGN);
+	(void) resignal(SIGCHLD, reapchild);
+	(void) resignal(SIGUSR1, Debug ? debug_switch : SIG_IGN);
 	(void) signal(SIGXFSZ, SIG_IGN);
+	(void) resignal(SIGALRM, domark);	/* Make recvfrom() be able to receive EINTR */
 	(void) alarm(TIMERINTVL);
 
 	/* Create a partial message table for all file descriptors. */
@@ -1161,6 +1165,7 @@ int main(argc, argv)
 
 	dprintf("Starting.\n");
 	init();
+	(void) resignal(SIGHUP, sighup_handler);
 #ifndef TESTING
 	if ( Debug )
 	{
@@ -1232,9 +1237,14 @@ int main(argc, argv)
 				  (fd_set *) NULL, (struct timeval *) NULL);
 		if ( restart )
 		{
+			sigset_t blockhup;
+			sigemptyset(&blockhup);
+			sigaddset  (&blockhup, SIGHUP);
+			(void) sigprocmask(SIG_BLOCK, &blockhup, NULL);
 			restart = 0;
 			dprintf("\nReceived SIGHUP, reloading syslogd.\n");
 			init();
+			(void) sigprocmask (SIG_UNBLOCK, &blockhup, NULL);
 			continue;
 		}
 		if (nfds == 0) {
@@ -1756,7 +1766,8 @@ void logmsg(pri, msg, from, flags)
 	int msglen;
 	char *timestamp;
 #ifdef __gnu_linux__
-	sigset_t mask;
+	sigset_t mask, omask;
+	int lognum;
 #else
 #ifndef SYSV
 	sigset_t omask;
@@ -1771,7 +1782,7 @@ void logmsg(pri, msg, from, flags)
 	sigemptyset(&mask);
 	sigaddset(&mask, SIGHUP);
 	sigaddset(&mask, SIGALRM);
-	sigprocmask(SIG_BLOCK, &mask, NULL);
+	sigprocmask(SIG_BLOCK, &mask, &omask);
 #else
 #ifndef SYSV
 	omask = sigblock(sigmask(SIGHUP)|sigmask(SIGALRM));
@@ -1815,7 +1826,7 @@ void logmsg(pri, msg, from, flags)
 			f->f_file = -1;
 		}
 #ifdef __gnu_linux__
-		sigprocmask(SIG_UNBLOCK, &mask, NULL);
+		sigprocmask(SIG_SETMASK, &omask, NULL);
 #else
 #ifndef SYSV
 		(void) sigsetmask(omask);
@@ -1884,7 +1895,7 @@ void logmsg(pri, msg, from, flags)
 		}
 	}
 #ifdef __gnu_linux__
-	sigprocmask(SIG_UNBLOCK, &mask, NULL);
+	sigprocmask(SIG_SETMASK, &omask, NULL);
 #else
 #ifndef SYSV
 	(void) sigsetmask(omask);
@@ -2213,10 +2224,6 @@ void wallmsg(f, iov)
 	if (fork() == 0) {
 		(void) signal(SIGTERM, SIG_DFL);
 		(void) alarm(0);
-#ifndef SYSV
-		(void) signal(SIGTTOU, SIG_IGN);
-		(void) sigsetmask(0);
-#endif
 		(void) snprintf(greetings, sizeof(greetings),
 		    "\r\n\7Message from syslogd@%s at %.24s ...\r\n",
 			(char *) iov[2].iov_base, ctime(&now));
@@ -2281,19 +2288,32 @@ void wallmsg(f, iov)
 	reenter = 0;
 }
 
+static sighandler_t resignal(int signum, sighandler_t handler)
+{
+	struct sigaction nact, oact;
+	sigset_t sigset;
+
+	nact.sa_handler = handler;
+	sigemptyset (&nact.sa_mask);
+
+	do {
+		if (sigaction(signum, &nact, &oact) == 0)
+			break;
+	} while (errno == EINTR);
+
+	sigemptyset(&sigset);
+	sigaddset(&sigset, signum);
+
+	sigprocmask(SIG_UNBLOCK, &sigset, NULL);
+
+	return oact.sa_handler;
+}
+
 void reapchild()
 {
 	int saved_errno = errno;
-#if defined(SYSV) && !defined(linux)
-	(void) signal(SIGCHLD, reapchild);	/* reset signal handler -ASP */
-	wait ((int *)0);
-#else
 	while (waitpid(-1, (int*)0, WNOHANG|WUNTRACED) > 0)
 		;
-#endif
-#ifdef linux
-	(void) signal(SIGCHLD, reapchild);	/* reset signal handler -ASP */
-#endif
 	errno = saved_errno;
 }
 
@@ -2403,6 +2423,7 @@ void domark()
 #ifdef SYSV
 	for (lognum = 0; lognum <= nlogs; lognum++) {
 		f = &Files[lognum];
+	}
 #else
 	for (f = Files; f; f = f->f_next) {
 #endif
@@ -2414,8 +2435,6 @@ void domark()
 			BACKOFF(f);
 		}
 	}
-	}
-	(void) signal(SIGALRM, domark);
 	(void) alarm(TIMERINTVL);
 }
 
@@ -2424,7 +2443,6 @@ void debug_switch()
 {
 	dprintf("Switching debugging_on to %s\n", (debugging_on == 0) ? "true" : "false");
 	debugging_on = (debugging_on == 0) ? 1 : 0;
-	signal(SIGUSR1, debug_switch);
 }
 
 
@@ -2774,7 +2792,6 @@ void init()
 		logmsg(LOG_SYSLOG|LOG_INFO, "syslogd " VERSION "." PATCHLEVEL \
 		       ": restart." , LocalHostName, ADDDATE);
 #endif
-	(void) signal(SIGHUP, sighup_handler);
 	dprintf("syslogd: restarted.\n");
 }
 #if FALSE
@@ -3175,7 +3192,6 @@ static void allocate_log(void)
 void sighup_handler(int sig)
 {
 	restart = 1;
-	signal(SIGHUP, sighup_handler);
 	return;
 }