Adding support for pid file

--- smtptrapd.c.orig	2008-01-05 21:39:36 +0300

+++ smtptrapd.c	2008-01-05 21:39:57 +0300

@@ -76,6 +76,7 @@

 	char *chroot_dir;

 	char *banner;

 	char *username;

+	char *pidfile;

 	struct in_addr local_ip;

 	short bind_local;

 	int port;

@@ -121,6 +122,7 @@

 int drop_priv(void) {

 	struct passwd *p;

+	FILE *pidfile;

 	p = getpwnam((config.username == NULL) ?  

 	               UNPRIV_USER : config.username);

@@ -131,6 +133,23 @@

 		return -1;

 	}

+        if (config.pidfile) {

+                /* write to pid file */

+                if ((pidfile=fopen(config.pidfile, "w")) == NULL) {

+                        syslog(LOG_CRIT, "error: could not open pid file %s: %s", 

+			                 config.pidfile, strerror(errno));

+                        return -1;

+                }

+                fprintf(pidfile, "%d\n", (unsigned int)getpid());

+

+                /* we're done, clean up */

+                if (fclose(pidfile) != 0) {

+                        syslog(LOG_CRIT, "error: could not close pid file %s: %s", 

+			                 config.pidfile, strerror(errno));

+                        return -1;

+		}

+        }

+

 	if (config.chroot_dir != NULL) {

 		if (chdir(config.chroot_dir) != 0)

@@ -181,7 +200,7 @@

 			char buf[BUFSIZ];

 			struct sockaddr_in addr;

-			int addrlen = sizeof(addr);

+			unsigned int addrlen = sizeof(addr);

 			pthread_mutex_unlock(&queue.mutex);

@@ -270,7 +289,7 @@

 	int state = SMTP_STATE_NONE;

 	char buf[BUFSIZ], from[LOG_SIZ], rcpt[LOG_SIZ];

 	struct sockaddr_in addr;

-	int addrlen = sizeof(addr);

+	unsigned int addrlen = sizeof(addr);

 	int i = 0, etime = 0, itime = time(NULL);

 	/* some nice initialisation of strings */

@@ -452,11 +471,12 @@

 	config.chroot_dir = NULL;

 	config.username = NULL;

 	config.banner = NULL;

+	config.pidfile = NULL;

 	config.port = LISTEN_PORT;

 	config.threads = NUM_CONSUMER;

 	config.max_queue_len = MAX_QUEUE_LEN;

-	while ((c = getopt(argc, argv, "hc:l:p:b:u:m:t:")) != -1) {

+	while ((c = getopt(argc, argv, "hc:l:p:b:u:m:t:f:")) != -1) {

 		switch (c) {

 			case 'h':

@@ -467,7 +487,8 @@

 				       "-u [username] "

 				       "-t [number of threads] "

 				       "-p [listen port] "

-				       "-m [max accept queue length]");

+				       "-m [max accept queue length] "

+				       "-f [pid file path]" );

 				exit(EX_USAGE);

@@ -486,6 +507,10 @@

 				config.chroot_dir = strdup(optarg);

 			break;

+			case 'f':

+				config.pidfile = strdup(optarg);

+			break;

+

 			case 'b':

 				config.banner = strdup(optarg);

 			break;