--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/src/syslog2iptables.cpp	Wed Nov 23 19:29:14 2005 -0800
@@ -0,0 +1,254 @@
+/***************************************************************************
+ *	 Copyright (C) 2005 by 510 Software Group							   *
+ *																		   *
+ *																		   *
+ *	 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.,									   *
+ *	 59 Temple Place - Suite 330, Boston, MA  02111-1307, USA.			   *
+ ***************************************************************************/
+
+
+#ifdef HAVE_CONFIG_H
+#include <config.h>
+#endif
+
+#include <iostream>
+#include <cstdlib>
+#include <errno.h>
+#include <sysexits.h>
+#include <unistd.h>
+#include <pthread.h>
+#include <syslog.h>
+#include <sys/types.h>
+#include <sys/stat.h>
+#include <sys/wait.h>	/* header for waitpid() and various macros */
+#include <signal.h> 	/* header for signal functions */
+#include "includes.h"
+
+int  debug_syslog  = 0;
+bool syslog_opened = false;
+bool use_syslog    = true;	// false to printf
+bool loader_run    = true;	// used to stop the config loader thread
+CONFIG	 *config = NULL;	// protected by the config_mutex
+int   generation = 0;		// protected by the config_mutex
+const int maxlen = 1000;	// used for snprintf buffers
+
+pthread_mutex_t  config_mutex;
+pthread_mutex_t  syslog_mutex;
+
+
+////////////////////////////////////////////////
+// syslog a message
+//
+void my_syslog(char *text) {
+	if (use_syslog) {
+		pthread_mutex_lock(&syslog_mutex);
+			if (!syslog_opened) {
+				openlog("syslog2iptables", LOG_PID, LOG_MAIL);
+				syslog_opened = true;
+			}
+			syslog(LOG_NOTICE, "%s", text);
+		pthread_mutex_unlock(&syslog_mutex);
+	}
+	else {
+		printf("%s \n", text);
+	}
+}
+
+////////////////////////////////////////////////
+//	reload the config
+//
+CONFIG* new_conf();
+CONFIG* new_conf() {
+	CONFIG *newc = new CONFIG;
+	pthread_mutex_lock(&config_mutex);
+		newc->generation = generation++;
+	pthread_mutex_unlock(&config_mutex);
+	if (debug_syslog) {
+		char buf[maxlen];
+		snprintf(buf, sizeof(buf), "loading configuration generation %d", newc->generation);
+		my_syslog(buf);
+	}
+	if (load_conf(*newc, "syslog2iptables.conf")) {
+		newc->load_time = time(NULL);
+		return newc;
+	}
+	delete newc;
+	return NULL;
+}
+
+
+////////////////////////////////////////////////
+//	thread to watch the old config files for changes
+//	and reload when needed. we also cleanup old
+//	configs whose reference count has gone to zero.
+//
+void* config_loader(void *arg);
+void* config_loader(void *arg) {
+	typedef set<CONFIG *> configp_set;
+	configp_set old_configs;
+	while (loader_run) {
+		sleep(180);  // look for modifications every 3 minutes
+		if (!loader_run) break;
+		CONFIG &dc = *config;
+		time_t then = dc.load_time;
+		struct stat st;
+		bool reload = false;
+		for (string_set::iterator i=dc.config_files.begin(); i!=dc.config_files.end(); i++) {
+			char *fn = *i;
+			if (stat(fn, &st))			 reload = true; // file disappeared
+			else if (st.st_mtime > then) reload = true; // file modified
+			if (reload) break;
+		}
+		if (reload) {
+			CONFIG *newc = new_conf();
+			if (newc) {
+				// replace the global config pointer
+				pthread_mutex_lock(&config_mutex);
+					CONFIG *old = config;
+					config = newc;
+				pthread_mutex_unlock(&config_mutex);
+				if (old) old_configs.insert(old);
+			}
+			else {
+				// failed to load new config
+				my_syslog("failed to load new configuration");
+				system("echo 'failed to load new /etc/syslog2iptables.conf' | mail -s 'error in /etc/syslog2iptables.conf' root");
+				// update the load time on the current config to prevent complaining every 3 minutes
+				dc.load_time = time(NULL);
+			}
+		}
+		// now look for old configs with zero ref counts
+		for (configp_set::iterator i=old_configs.begin(); i!=old_configs.end(); ) {
+			CONFIG *old = *i;
+			if (!old->reference_count) {
+				if (debug_syslog) {
+					char buf[maxlen];
+					snprintf(buf, sizeof(buf), "freeing memory for old configuration generation %d", old->generation);
+					my_syslog(buf);
+				}
+				delete old; // destructor does all the work
+				old_configs.erase(i++);
+			}
+			else i++;
+		}
+	}
+	return NULL;
+}
+
+
+////////////////////////////////////////////////
+// The signal handler function -- only gets called when a SIGCHLD
+// is received, ie when a child terminates
+//
+void sig_chld(int signo)
+{
+	int status;
+	/* Wait for any child without blocking */
+	while (waitpid(-1, &status, WNOHANG) > 0) {
+		// ignore child exit status, we only do this to cleanup zombies
+	}
+}
+
+
+void usage(char *prog);
+void usage(char *prog)
+{
+}
+
+
+int main(int argc, char *argv[])
+{
+	token_init();
+	bool check	 = true;
+	int c;
+	const char *args = "ch";
+	extern char *optarg;
+
+	// Process command line options
+	while ((c = getopt(argc, argv, args)) != -1) {
+		switch (c) {
+			case 'c':
+				check = true;
+				break;
+
+			case 'h':
+			default:
+				usage(argv[0]);
+				exit(EX_USAGE);
+		}
+	}
+
+	if (check) {
+		use_syslog	 = false;
+		debug_syslog = 10;
+		CONFIG *conf = new_conf();
+		if (conf) {
+			conf->dump();
+			delete conf;
+			return 0;
+		}
+		else {
+			return 1;	// config failed to load
+		}
+	}
+
+	// switch to background mode
+	if (daemon(1,0) < 0) {
+		fprintf(stderr, "daemon() call failed\n");
+		exit(EX_UNAVAILABLE);
+	}
+
+	// write the pid
+	const char *pidpath = "/var/run/syslog2iptables.pid";
+	unlink(pidpath);
+	FILE *f = fopen(pidpath, "w");
+	if (f) {
+#ifdef linux
+		// from a comment in the DCC source code:
+		// Linux threads are broken.  Signals given the
+		// original process are delivered to only the
+		// thread that happens to have that PID.  The
+		// sendmail libmilter thread that needs to hear
+		// SIGINT and other signals does not, and that breaks
+		// scripts that need to stop milters.
+		// However, signaling the process group works.
+		fprintf(f, "-%d\n", (u_int)getpgrp());
+#else
+		fprintf(f, "%d\n", (u_int)getpid());
+#endif
+		fclose(f);
+	}
+
+	// initialize the thread sync objects
+	pthread_mutex_init(&config_mutex, 0);
+	pthread_mutex_init(&syslog_mutex, 0);
+
+	// load the initial config
+	config = new_conf();
+	if (!config) {
+		my_syslog("failed to load initial configuration, quitting");
+		exit(1);
+	}
+
+	// only create threads after the fork() in daemon
+	pthread_t tid;
+	if (pthread_create(&tid, 0, config_loader, 0))
+		my_syslog("failed to create config loader thread");
+	if (pthread_detach(tid))
+		my_syslog("failed to detach config loader thread");
+
+	loader_run = false; 	// eventually the config loader thread will terminate
+	return EXIT_SUCCESS;
+}