feature: flags -F, --max_retries and --ttl (wip)

include/parsing.h

@@ -1,18 +1,22 @@
 #pragma once
 
+#include <stdbool.h>
 #include <stdint.h>
 
 #include "scan.h"
 
-#define NB_OPTIONS 6
-
 typedef enum {
+	// long options
 	FL_HELP,
 	FL_PORTS,
 	FL_IP,
 	FL_FILE,
 	FL_SPEEDUP,
 	FL_SCAN,
+	FL_MAXRETRIES,
+	FL_TTL,
+	// short options
+	FL_FAST,
 } e_flag;
 
 struct option_lst {
@@ -22,6 +26,7 @@ struct option_lst {
 };
 
 struct option_lst *parse_options(int ac, char *const *av);
+bool option_isset(const struct option_lst *options, e_flag flag);
 char *get_option_arg(const struct option_lst *options, e_flag flag);
 int parse_ports(const char *arg, uint16_t *start, uint16_t *end);
 e_scantype parse_type(const char *arg);

include/scan.h

@@ -20,6 +20,8 @@ struct scan {
 	uint16_t port_start;
 	uint16_t port;
 	e_scantype type;
+	uint8_t ttl;
+	uint8_t max_retries;
 	struct response *response;
 };
 

include/thread.h

@@ -12,6 +12,8 @@ struct thread {
 	uint16_t port_end;
 	char *dest_addr;
 	e_scantype type;
+	uint8_t max_retries;
+	uint8_t ttl;
 	struct host host;
 	struct response *responses;
 };

src/parsing.c

@@ -1,5 +1,6 @@
 #include <ctype.h>
 #include <getopt.h>
+#include <stdbool.h>
 #include <stddef.h>
 #include <stdint.h>
 #include <stdio.h>
@@ -18,6 +19,16 @@ void free_options(struct option_lst *options)
 	}
 }
 
+bool option_isset(const struct option_lst *options, e_flag flag)
+{
+	if (!options)
+		return false;
+	for (const struct option_lst *it = options; it; it = it->next)
+		if (it->flag == flag)
+			return true;
+	return false;
+}
+
 char *get_option_arg(const struct option_lst *options, e_flag flag)
 {
 	if (!options)
@@ -45,16 +56,16 @@ e_scantype parse_type(const char *arg)
 int parse_ports(const char *arg, uint16_t *p_start, uint16_t *p_end)
 {
 	size_t i = 0;
-	if (!arg) {
+	if (!arg)
-		*p_start = 1;
+		return -1;
-		*p_end = 1024;
-		return 0;
-	}
 	for (; isdigit(arg[i]); i++)
 		;
 	int start = atoi(arg);
-	if (arg[i] == '\0')
+	if (arg[i] == '\0') {
+		*p_start = start;
+		*p_end = start;
 		return 0;
+	}
 	if (arg[i++] != '-')
 		goto error;
 	int end = atoi(arg + i);
@@ -82,7 +93,7 @@ error:
 static int check_arg(e_flag flag, const char *arg)
 {
 	switch (flag) {
-	case FL_SPEEDUP:
+	case FL_SPEEDUP: {
 		for (size_t i = 0; arg[i]; i++)
 			if (!isdigit(arg[i]))
 				return -1;
@@ -96,6 +107,7 @@ static int check_arg(e_flag flag, const char *arg)
 			return -1;
 		}
 		break;
+	}
 	case FL_SCAN:
 		if (!strcmp(arg, "SYN"))
 			break;
@@ -110,6 +122,37 @@ static int check_arg(e_flag flag, const char *arg)
 		if (!strcmp(arg, "UDP"))
 			break;
 		return -1;
+	case FL_TTL: {
+		int nb = atoi(arg);
+		if (nb == 0) {
+			dprintf(2, "ft_nmap: cannot set unicast time-to-live: "
+			           "Invalid argument\n");
+			return -1;
+		} else if (nb < 0 || nb > 255) {
+			dprintf(
+			    2,
+			    "ft_nmap: invalid argument: '%s': out of range: 0 "
+			    "<= value <= 255\n",
+			    arg);
+			return -1;
+		}
+		break;
+	}
+	case FL_MAXRETRIES: {
+		int nb = atoi(arg);
+		if (nb == 0) {
+			dprintf(2, "ft_nmap: cannot set max_retries to 0\n");
+			return -1;
+		} else if (nb < 0 || nb > 255) {
+			dprintf(
+			    2,
+			    "ft_nmap: invalid argument: '%s': out of range: 0 "
+			    "<= value <= 255\n",
+			    arg);
+			return -1;
+		}
+		break;
+	}
 	default:
 		break;
 	}
@@ -149,23 +192,32 @@ static int add_option(struct option_lst **head, e_flag flag, char *arg)
 struct option_lst *parse_options(int ac, char *const *av)
 {
 	struct option_lst *head = NULL;
-	const struct option options[NB_OPTIONS] = {
+	const struct option options[] = {
 	    {"help", no_argument, 0, 0},
 	    {"ports", required_argument, 0, 0},
 	    {"ip", required_argument, 0, 0},
 	    {"file", required_argument, 0, 0},
 	    {"speedup", required_argument, 0, 0},
 	    {"scan", required_argument, 0, 0},
+	    {"max_retries", required_argument, 0, 0},
+	    {"ttl", required_argument, 0, 0},
 	};
 
 	int c;
 	while (1) {
 		int option_index = 0;
-		c = getopt_long(ac, av, "", options, &option_index);
+		c = getopt_long(ac, av, "F", options, &option_index);
 		if (c == -1)
 			break;
-		else if (c)
+		switch (c) {
+		case 'F':
+			add_option(&head, FL_FAST, optarg);
+			break;
+		case '?':
 			return NULL;
+		default:
+			break;
+		}
 		if (check_arg(option_index, optarg) < 0)
 			return NULL;
 		if (add_option(&head, option_index, optarg) < 0)

src/scan.c

@@ -39,8 +39,7 @@ static void dispatch_callback(u_char *user, const struct pcap_pkthdr *h,
 	}
 }
 
-static void send_recv_packet(const struct scan *data, int sockfd,
+static int send_recv_packet(const struct scan *data, int sockfd, pcap_t *handle)
-                             pcap_t *handle)
 {
 	send_packet(data, sockfd);
 	uint8_t timer = 0;
@@ -49,9 +48,12 @@ static void send_recv_packet(const struct scan *data, int sockfd,
 			break;
 		usleep(100000);
 	}
-	if (timer == TIMEOUT * 100)
-		no_response(data);
 	pcap_breakloop(handle);
+	if (timer == TIMEOUT * 100) {
+		no_response(data);
+		return 0;
+	}
+	return 1;
 }
 
 int scan(struct scan *data)
@@ -102,11 +104,17 @@ int scan(struct scan *data)
 	if (data->type == SCAN_ALL) {
 		for (e_scantype type = SCAN_NULL; type < SCAN_ALL; type++) {
 			data->type = type;
-			send_recv_packet(data, sockfd, handle);
+			for (uint8_t retries = 0; retries < data->max_retries;
+			     retries++)
+				if (send_recv_packet(data, sockfd, handle))
+					break;
 		}
 		data->type = SCAN_ALL;
 	} else {
-		send_recv_packet(data, sockfd, handle);
+		for (uint8_t retries = 0; retries < data->max_retries;
+		     retries++)
+			if (send_recv_packet(data, sockfd, handle))
+				break;
 	}
 
 	pcap_close(handle);

src/thread.c

@@ -33,6 +33,8 @@ void *routine(void *p_data)
 	    .host = &thread_data->host,
 	    .port_start = thread_data->port_start,
 	    .type = thread_data->type,
+	    .max_retries = thread_data->max_retries,
+	    .ttl = thread_data->ttl,
 	};
 
 	for (uint16_t port = thread_data->port_start;
@@ -60,15 +62,26 @@ static struct thread *init_threads_data(const struct option_lst *options,
 	}
 	for (uint8_t i = 0; i < nb_threads; i++) {
 		memcpy(&threads[i].host, host, sizeof(struct host));
+		threads[i].port_start = 1;
+		threads[i].port_end = 1024;
+		if (option_isset(options, FL_FAST))
+			threads[i].port_end = 128;
 		const char *ports = get_option_arg(options, FL_PORTS);
 		if (parse_ports(ports, &threads[i].port_start,
-		                &threads[i].port_end) < 0)
+		                &threads[i].port_end) < 0) {
+			if (!option_isset(options, FL_FAST))
 				goto error;
+			threads[i].port_end = 128;
+		}
 		threads[i].type = parse_type(get_option_arg(options, FL_SCAN));
 		if (threads[i].type < 0)
 			goto error;
 		threads[i].dest_addr = ip_addr;
 		threads[i].responses = responses;
+		char *max_retries = get_option_arg(options, FL_MAXRETRIES);
+		threads[i].max_retries = max_retries ? atoi(max_retries) : 1;
+		char *ttl = get_option_arg(options, FL_TTL);
+		threads[i].ttl = ttl ? atoi(ttl) : 48;
 	}
 
 	return threads;
@@ -80,29 +93,36 @@ error:
 int create_threads(const struct option_lst *options, char *ip_addr,
                    struct response *responses)
 {
-	uint16_t port_start = 0, port_end = 0;
-	const char *ports = get_option_arg(options, FL_PORTS);
-	if (parse_ports(ports, &port_start, &port_end) < 0)
-		return -1;
 	struct host host;
 	if (get_interface_name(&host) < 0)
 		return -1;
 
-	const char *arg = get_option_arg(options, FL_SPEEDUP);
+	uint16_t port_start = 1;
-	// Launche single thread routine if it's a 1 port scan or if no speedup
+	uint16_t port_end = 1024;
-	// option was passed
+	const char *ports = get_option_arg(options, FL_PORTS);
-	if (!arg || !port_end) {
+	if (parse_ports(ports, &port_start, &port_end) < 0) {
+		if (!option_isset(options, FL_FAST))
+			return -1;
+		port_end = 128;
+	}
+
+	const char *nb_threads_str = get_option_arg(options, FL_SPEEDUP);
+	if (!nb_threads_str) {
 		struct thread *thread_data =
 		    init_threads_data(options, ip_addr, &host, responses, 1);
-		thread_data->port_start = port_start;
-		thread_data->port_end = port_end;
 		g_start = true;
 		routine(thread_data);
 		free(thread_data);
 		return 0;
 	}
 
-	uint8_t nb_threads = atoi(arg);
+	uint8_t nb_threads = atoi(nb_threads_str);
+	if (port_end - port_start < nb_threads) {
+		dprintf(2, "ft_nmap: number of threads to use must be superior "
+		           "or equals to the ports range\n");
+		return -1;
+	}
+
 	struct thread *threads_data =
 	    init_threads_data(options, ip_addr, &host, responses, nb_threads);
 	if (!threads_data)