Add files via upload

Added PID lock file

ttl_iptables.c

@@ -1,3 +1,8 @@
+/*
+ * 2019-03-14
+ * Copyright (C)  西门吹雪
+ * [email protected]
+ */
 #include <stdio.h>
 #include <stdlib.h>
 #include <ctype.h>
@@ -6,16 +11,18 @@
 #include <signal.h>
 #include <sys/types.h>
 #include <sys/wait.h>
+#include <sys/stat.h>
 #include <hiredis.h>
 #include <fcntl.h>
 #include <time.h>
 #include <arpa/inet.h>
- char *__progname;
-/*
- * 2019-03-14
- * Copyright (C)  西门吹雪 
- * [email protected]
- */
+#include <errno.h>
+#include <limits.h>
+#include <sys/file.h>
+
+char *__progname;
+static volatile sig_atomic_t got_sighup, got_sigchld;
+#define _PATH_TTL_IPTABLES_PID	"/var/run/ttl_iptables.pid"
 
 char *get_progname(char *argv0) {
 	char *p, *q;
@@ -86,7 +93,106 @@ int check_ipaddr(char *str) {
 	return 1;
 }
 
+static void sighup_handler(int x) {
+	got_sighup = 1;
+}
+
+static void sigchld_handler(int x) {
+	got_sigchld = 1;
+}
+
+static void quit(int x) {
+	(void) unlink(_PATH_TTL_IPTABLES_PID);
+	_exit(0);
+}
+
+static void sigchld_reaper(void) {
+	int waiter;
+	pid_t pid;
+
+	do {
+		pid = waitpid(-1, &waiter, WNOHANG);
+		switch (pid) {
+		case -1:
+			if (errno == EINTR)
+				break;
+		case 0:
+			break;
+		default:
+			break;
+		}
+	} while (pid > 0);
+}
+
+static void acquire_daemonlock(int closeflag) {
+	static int fd = -1;
+	char buf[3 * 100];
+	const char *pidfile;
+	char *ep;
+	long otherpid;
+	ssize_t num;
+
+	if (closeflag) {
+		/* close stashed fd for child so we don't leak it. */
+		if (fd != -1) {
+			close(fd);
+			fd = -1;
+		}
+		return;
+	}
+
+	if (fd == -1) {
+		pidfile = _PATH_TTL_IPTABLES_PID;
+		/* Initial mode is 0600 to prevent flock() race/DoS. */
+		if ((fd = open(pidfile, O_RDWR | O_CREAT, 0600)) == -1) {
+			sprintf(buf, "can't open or create %s: %s", pidfile,
+					strerror(errno));
+			fprintf(stderr, "%s\n", buf);
+			exit(1);
+		}
+
+		if (flock(fd, LOCK_EX | LOCK_NB) < 0) {
+			int save_errno = errno;
+
+			bzero(buf, sizeof(buf));
+			if ((num = read(fd, buf, sizeof(buf) - 1)) > 0&&
+			(otherpid = strtol(buf, &ep, 10)) > 0 &&
+			ep != buf && *ep == '\n' && otherpid != LONG_MAX) {
+				sprintf(buf, "can't lock %s, otherpid may be %ld: %s", pidfile,
+						otherpid, strerror(save_errno));
+			} else {
+				sprintf(buf, "can't lock %s, otherpid unknown: %s", pidfile,
+						strerror(save_errno));
+			}
+			sprintf(buf, "can't lock %s, otherpid may be %ld: %s", pidfile,
+					otherpid, strerror(save_errno));
+			fprintf(stderr, "%s\n", buf);
+			exit(1);
+		}
+		(void) fchmod(fd, 0644);
+		(void) fcntl(fd, F_SETFD, 1);
+	}
+
+	sprintf(buf, "%ld\n", (long) getpid());
+	(void) lseek(fd, (off_t) 0, SEEK_SET);
+	num = write(fd, buf, strlen(buf));
+	(void) ftruncate(fd, num);
+}
 int main(int argc, char **argv) {
+	struct sigaction sact;
+	bzero((char * )&sact, sizeof sact);
+	sigemptyset(&sact.sa_mask);
+	sact.sa_flags = 0;
+	sact.sa_flags |= SA_RESTART;
+	sact.sa_handler = sigchld_handler;
+	(void) sigaction(SIGCHLD, &sact, NULL);
+	sact.sa_handler = sighup_handler;
+	(void) sigaction(SIGHUP, &sact, NULL);
+	sact.sa_handler = quit;
+	(void) sigaction(SIGINT, &sact, NULL);
+	(void) sigaction(SIGTERM, &sact, NULL);
+	acquire_daemonlock(0);
+
 	redisContext *c;
 	redisReply *reply;
 	const char *hostname = (argc > 1) ? argv[1] : "127.0.0.1";
@@ -110,6 +216,7 @@ int main(int argc, char **argv) {
 		exit(1);
 	}
 	daemon(0, 0);
+	acquire_daemonlock(0);
 	static char insert_command[256];
 	static char msg[1024];
 	pid_t pid;
@@ -134,8 +241,17 @@ int main(int argc, char **argv) {
 			close(fd);
 		}
 		freeReplyObject(reply);
+		/* Check to see if we received a signal while running jobs. */
+		if (got_sighup) {
+			got_sighup = 0;
+			redisFree(c);
+			close(logfd);
+		}
+		if (got_sigchld) {
+			got_sigchld = 0;
+			sigchld_reaper();
+		}
 	}
-	redisFree(c);
-	close(logfd);
 	return 0;
 }
+