fix: data races with getservent

feature: time elapsed in the print

src/main.c

@@ -5,6 +5,7 @@
 #include <stdio.h>
 #include <stdlib.h>
 #include <string.h>
+#include <time.h>
 
 #include "dns.h"
 #include "interface.h"
@@ -19,11 +20,19 @@ static int scan_host(struct scan *general, uint8_t nb_threads)
 	if (dns_lookup(general->dest_addr, general->dest_addr, &addr_con)) {
 		return -1;
 	}
+
 	struct response responses[1024] = {0};
+	struct timespec start, end;
+
 	general->responses = responses;
+	printf("Scanning...\n");
+	clock_gettime(CLOCK_MONOTONIC, &start);
 	if (create_threads(general, nb_threads) < 0)
 		return -1;
-	print_host_results(general, 10);
+	clock_gettime(CLOCK_MONOTONIC, &end);
+	double time_elapsed =
+	    (end.tv_sec - start.tv_sec) + (end.tv_nsec - start.tv_nsec) / 1e9;
+	print_host_results(general, time_elapsed);
 	return 0;
 }
 
@@ -37,8 +46,10 @@ int main(int ac, char **av)
 	}
 
 	struct option_lst *options = parse_options(ac, av);
-	if (options == NULL)
+	if (options == NULL) {
+		print_usage();
 		return 1;
+	}
 
 	if (option_isset(options, FL_HELP)) {
 		print_usage();

src/print.c

@@ -68,7 +68,6 @@ static void print_port_state(uint16_t port, e_scantype type,
 
 void print_host_results(const struct scan *general, double scan_time)
 {
-	printf("Scan took %lf secs\n", scan_time);
 	printf("IP address: %s\n", general->dest_addr);
 	printf("Opened ports:\n");
 	for (uint16_t port = general->port_start; port < general->port_end;
@@ -87,4 +86,5 @@ void print_host_results(const struct scan *general, double scan_time)
 		if (!is_port_opened(response->states, general->type))
 			print_port_state(port, general->type, response);
 	}
+	printf("\nScan took %lf secs\n", scan_time);
 }

src/response.c

@@ -12,24 +12,27 @@ extern pthread_mutex_t g_getservent;
 
 static char *get_service_name(int port, char *proto)
 {
+	char *name = NULL;
 	pthread_mutex_lock(&g_getservent);
 	struct servent *servent = getservbyport(htons(port), proto);
+	if (servent)
+		name = strdup(servent->s_name);
 	pthread_mutex_unlock(&g_getservent);
-	if (!servent)
+	return name;
-		return NULL;
-	return strdup(servent->s_name);
 }
 
 void tcp_response(const struct tcphdr *tcphdr, const struct scan *data)
 {
 	const e_scantype type = data->type;
 	if (type == SCAN_UDP) {
-		dprintf(2, "ft_nmap: error: received a TCP responses for an UDP "
+		dprintf(2,
-		           "scan\n");
+		        "ft_nmap: error: received a TCP responses for an UDP "
+		        "scan\n");
 		return;
 	}
 	if (data->responses->service == NULL)
-		data->responses->service = get_service_name(data->port_start, "tcp");
+		data->responses->service =
+		    get_service_name(data->port_start, "tcp");
 	if (type == SCAN_SYN) {
 		if (tcphdr->ack == 1 && tcphdr->syn == 1)
 			data->responses->states[type] = OPENED;
@@ -49,12 +52,14 @@ void udp_response(const struct udphdr *udphdr, const struct scan *data)
 {
 	(void)udphdr;
 	if (data->type != SCAN_UDP) {
-		dprintf(2, "ft_nmap: error: received an UDP responses for a TCP "
+		dprintf(2,
-		           "scan\n");
+		        "ft_nmap: error: received an UDP responses for a TCP "
+		        "scan\n");
 		return;
 	}
 	if (data->responses->service == NULL)
-		data->responses->service = get_service_name(data->port_start, "udp");
+		data->responses->service =
+		    get_service_name(data->port_start, "udp");
 	data->responses->states[SCAN_UDP] = OPENED;
 }
 
@@ -64,7 +69,8 @@ void icmp_response(const struct icmphdr *icmphdr, const struct scan *data)
 
 	data->responses->service = get_service_name(data->port_start, "udp");
 	if (data->responses->service == NULL)
-		data->responses->service = get_service_name(data->port_start, "tcp");
+		data->responses->service =
+		    get_service_name(data->port_start, "tcp");
 	if (type == SCAN_SYN && icmphdr->type == 3)
 		data->responses->states[type] = FILTERED;
 	else if (type == SCAN_ACK && icmphdr->type == 3)
@@ -87,7 +93,8 @@ void no_response(const struct scan *data)
 
 	data->responses->service = get_service_name(data->port_start, "udp");
 	if (data->responses->service == NULL)
-		data->responses->service = get_service_name(data->port_start, "tcp");
+		data->responses->service =
+		    get_service_name(data->port_start, "tcp");
 	if (type == SCAN_SYN)
 		data->responses->states[type] = FILTERED;
 	else if (type == SCAN_ACK)