Fix various leaks detected by valgrind.

Mostly config options that strdup() their value, causing leaks if
there are multiple config lines or after restarting with SIGHUP.

The last was the fd_set for incoming connections wouldn't be freed
on restart. Also optimize the allocation of fdset and re-use if possible.

src/nrpe.c

@@ -948,10 +948,11 @@ int read_config_file(char *filename)
 				return ERROR;
 			}
 
-		} else if (!strcmp(varname, "command_prefix"))
+		} else if (!strcmp(varname, "command_prefix")) {
+			free(command_prefix);
 			command_prefix = strdup(varvalue);
 
-		else if (!strcmp(varname, "server_address")) {
+		} else if (!strcmp(varname, "server_address")) {
 			strncpy(server_address, varvalue, sizeof(server_address) - 1);
 			server_address[sizeof(server_address) - 1] = '\0';
 
@@ -979,13 +980,15 @@ int read_config_file(char *filename)
 			else
 				debug = FALSE;
 
-		} else if (!strcmp(varname, "nrpe_user"))
+		} else if (!strcmp(varname, "nrpe_user")) {
+			free(nrpe_user);
 			nrpe_user = strdup(varvalue);
 
-		else if (!strcmp(varname, "nrpe_group"))
+		} else if (!strcmp(varname, "nrpe_group")) {
+			free(nrpe_group);
 			nrpe_group = strdup(varvalue);
 
-		else if (!strcmp(varname, "dont_blame_nrpe"))
+		} else if (!strcmp(varname, "dont_blame_nrpe"))
 			allow_arguments = (atoi(varvalue) == 1) ? TRUE : FALSE;
 
 		else if (!strcmp(varname, "disable_syslog"))
@@ -1023,10 +1026,11 @@ int read_config_file(char *filename)
 		} else if (!strcmp(varname, "allow_weak_random_seed"))
 			allow_weak_random_seed = (atoi(varvalue) == 1) ? TRUE : FALSE;
 
-		else if (!strcmp(varname, "pid_file"))
+		else if (!strcmp(varname, "pid_file")) {
+			free(pid_file);
 			pid_file = strdup(varvalue);
 
-		else if (!strcmp(varname, "listen_queue_size")) {
+		} else if (!strcmp(varname, "listen_queue_size")) {
 			listen_queue_size = atoi(varvalue);
 			if (listen_queue_size == 0) {
 				logit(LOG_ERR,
@@ -1084,16 +1088,19 @@ int read_config_file(char *filename)
 			strncpy(sslprm.cipher_list, varvalue, sizeof(sslprm.cipher_list) - 1);
 			sslprm.cipher_list[sizeof(sslprm.cipher_list) - 1] = '\0';
 
-		} else if (!strcmp(varname, "ssl_cert_file"))
+		} else if (!strcmp(varname, "ssl_cert_file")) {
+			free(sslprm.cert_file);
 			sslprm.cert_file = strdup(varvalue);
 
-		else if (!strcmp(varname, "ssl_cacert_file"))
+		} else if (!strcmp(varname, "ssl_cacert_file")) {
+			free(sslprm.cacert_file);
 			sslprm.cacert_file = strdup(varvalue);
 
-		else if (!strcmp(varname, "ssl_privatekey_file"))
+		} else if (!strcmp(varname, "ssl_privatekey_file")) {
+			free(sslprm.privatekey_file);
 			sslprm.privatekey_file = strdup(varvalue);
 
-		else if (!strcmp(varname, "ssl_client_certs")) {
+		} else if (!strcmp(varname, "ssl_client_certs")) {
 			sslprm.client_certs = atoi(varvalue);
 			if ((int)sslprm.client_certs < 0 || sslprm.client_certs > Require_Cert) {
 				logit(LOG_ERR,
@@ -1115,13 +1122,15 @@ int read_config_file(char *filename)
 					   "Invalid log_facility specified in config file '%s' - Line %d\n",
 					   filename, line);
 
-		} else if (!strcmp(varname, "keep_env_vars"))
+		} else if (!strcmp(varname, "keep_env_vars")) {
+			free(keep_env_vars);
 			keep_env_vars = strdup(varvalue);
 
-		else if (!strcmp(varname, "nasty_metachars"))
+		} else if (!strcmp(varname, "nasty_metachars"))
 			nasty_metachars = process_metachars(varvalue);
 
 		else if (!strcmp(varname, "log_file")) {
+			free(log_file);
 			log_file = strdup(varvalue);
 			open_log_file();
 
@@ -1405,11 +1414,13 @@ void wait_for_connections(void)
 	socklen_t fromlen;
 	fd_set   *fdset = NULL;
 	int       maxfd = 0, new_sd = 0, i, rc, retval;
-
+	int       count_fdset = 0;
 	setup_wait_conn();
 
 	/* listen for connection requests - fork() if we get one */
 	while (1) {
+		int need_fdset;
+
 		/* bail out if necessary */
 		if (sigrestart == TRUE || sigshutdown == TRUE)
 			break;
@@ -1419,9 +1430,14 @@ void wait_for_connections(void)
 				maxfd = listen_socks[i];
 		}
 
-		if (fdset != NULL)
+		need_fdset = how_many(maxfd + 1, NFDBITS);
+		if (need_fdset > count_fdset) {
 			free(fdset);
-		fdset = (fd_set *) calloc(how_many(maxfd + 1, NFDBITS), sizeof(fd_mask));
+			fdset = (fd_set *) calloc(need_fdset, sizeof(fd_mask));
+			need_fdset = count_fdset;
+		} else {
+			memset(fdset, 0, count_fdset * sizeof(fd_mask));
+		}
 
 		for (i = 0; i < num_listen_socks; i++)
 			FD_SET(listen_socks[i], fdset);
@@ -1488,6 +1504,7 @@ void wait_for_connections(void)
 	close_listen_socks();
 	freeaddrinfo(listen_addrs);
 	listen_addrs = NULL;
+	free(fdset);
 
 	return;
 }