fix: pcap_dispatch is non blocking

feature: no response handle

include/response.h

@@ -7,14 +7,20 @@
 
 #include "scan.h"
 
+#define TIMEOUT 1
+
 typedef enum {
-	OPEN = 1,
+	OPENED,
-	CLOSE,
+	CLOSED,
 	FILTERED,
 	UNFILTERED,
 	OPENFILTERED,
 } e_state;
 
+[[__maybe_unused__]] static const char *states_str[] = {
+    "OPENED", "CLOSED", "FILTERED", "UNFILTERED", "OPENFILTERED",
+};
+
 struct response {
 	uint16_t port;
 	e_state states[SCAN_ALL];
@@ -24,3 +30,4 @@ struct response {
 void tcp_response(const struct tcphdr *tcphdr, const struct scan *data);
 void udp_response(const struct udphdr *udphdr, const struct scan *data);
 void icmp_response(const struct icmphdr *icmphdr, const struct scan *data);
+void no_response(const struct scan *data);

src/main.c

@@ -28,6 +28,17 @@ static int scan_host(char *host, const struct option_lst *options)
 	struct response responses[1024] = {0};
 	if (create_threads(options, ip_addr, responses) < 0)
 		return 1;
+	static const char *types_str[] = {
+	    "NULL", "SYN", "ACK", "FIN", "XMAS", "UDP",
+	};
+	for (uint16_t i = 0; i < 50; i++) {
+		printf("%d: ", i + 1);
+		for (e_scantype type = SCAN_NULL; type < SCAN_ALL; type++) {
+			printf("%s(%s) ", types_str[type],
+			       states_str[responses[i].states[type]]);
+		}
+		printf("\n");
+	}
 	return 0;
 }
 

src/parsing.c

@@ -31,7 +31,7 @@ char *get_option_arg(const struct option_lst *options, e_flag flag)
 e_scantype parse_type(const char *arg)
 {
 	const char *types[] = {
-	    "SYN", "NULL", "ACK", "FIN", "XMAS", "UDP",
+	    "NULL", "SYN", "ACK", "FIN", "XMAS", "UDP",
 	};
 
 	if (!arg)
@@ -53,15 +53,17 @@ int parse_ports(const char *arg, uint16_t *p_start, uint16_t *p_end)
 	for (; isdigit(arg[i]); i++)
 		;
 	int start = atoi(arg);
+	if (arg[i] == '\0')
+		return 0;
 	if (arg[i++] != '-')
-		return -1;
+		goto error;
 	int end = atoi(arg + i);
 	for (; isdigit(arg[i]); i++)
 		;
 	if (arg[i])
-		return -1;
+		goto error;
 	if (start >= end)
-		return -1;
+		goto error;
 	if (end > UINT16_MAX) {
 		dprintf(2,
 		        "ft_nmap: invalid argument: '%s': out of range: 0 "
@@ -72,6 +74,9 @@ int parse_ports(const char *arg, uint16_t *p_start, uint16_t *p_end)
 	*p_start = start;
 	*p_end = end;
 	return 0;
+error:
+	dprintf(2, "ft_nmap: invalid argument: '%s'\n", arg);
+	return -1;
 }
 
 static int check_arg(e_flag flag, const char *arg)

src/response.c

@@ -15,17 +15,17 @@ void tcp_response(const struct tcphdr *tcphdr, const struct scan *data)
 	}
 	if (type == SCAN_SYN) {
 		if (tcphdr->ack == 1 && tcphdr->syn == 1)
-			data->response->states[type] = OPEN;
+			data->response->states[type] = OPENED;
 		else if (tcphdr->ack == 1 && tcphdr->rst == 1)
-			data->response->states[type] = CLOSE;
+			data->response->states[type] = CLOSED;
 	} else if (type == SCAN_ACK && tcphdr->rst == 1)
 		data->response->states[type] = UNFILTERED;
 	else if (type == SCAN_NULL && tcphdr->rst == 1)
-		data->response->states[type] = CLOSE;
+		data->response->states[type] = CLOSED;
 	else if (type == SCAN_FIN && tcphdr->rst == 1)
-		data->response->states[type] = CLOSE;
+		data->response->states[type] = CLOSED;
 	else if (type == SCAN_XMAS && tcphdr->rst == 1)
-		data->response->states[type] = CLOSE;
+		data->response->states[type] = CLOSED;
 }
 
 void udp_response(const struct udphdr *udphdr, const struct scan *data)
@@ -36,7 +36,7 @@ void udp_response(const struct udphdr *udphdr, const struct scan *data)
 		           "scan\n");
 		return;
 	}
-	data->response->states[SCAN_UDP] = OPEN;
+	data->response->states[SCAN_UDP] = OPENED;
 }
 
 void icmp_response(const struct icmphdr *icmphdr, const struct scan *data)
@@ -54,7 +54,25 @@ void icmp_response(const struct icmphdr *icmphdr, const struct scan *data)
 	else if (type == SCAN_XMAS && icmphdr->type == 3)
 		data->response->states[type] = FILTERED;
 	else if (type == SCAN_UDP && icmphdr->type == 3 && icmphdr->code == 3)
-		data->response->states[type] = CLOSE;
+		data->response->states[type] = CLOSED;
 	else if (type == SCAN_UDP && icmphdr->type == 3 && icmphdr->code != 3)
 		data->response->states[type] = FILTERED;
 }
+
+void no_response(const struct scan *data)
+{
+	const e_scantype type = data->type;
+
+	if (type == SCAN_SYN)
+		data->response->states[type] = FILTERED;
+	else if (type == SCAN_ACK)
+		data->response->states[type] = FILTERED;
+	else if (type == SCAN_NULL)
+		data->response->states[type] = OPENFILTERED;
+	else if (type == SCAN_FIN)
+		data->response->states[type] = OPENFILTERED;
+	else if (type == SCAN_XMAS)
+		data->response->states[type] = OPENFILTERED;
+	else if (type == SCAN_UDP)
+		data->response->states[type] = OPENFILTERED;
+}

src/scan.c

@@ -39,6 +39,21 @@ static void dispatch_callback(u_char *user, const struct pcap_pkthdr *h,
 	}
 }
 
+static void send_recv_packet(const struct scan *data, int sockfd,
+                             pcap_t *handle)
+{
+	send_packet(data, sockfd);
+	uint8_t timer = 0;
+	for (; timer < TIMEOUT * 100; timer++) {
+		if (pcap_dispatch(handle, 1, dispatch_callback, (u_char *)data))
+			break;
+		usleep(100000);
+	}
+	if (timer == TIMEOUT * 100)
+		no_response(data);
+	pcap_breakloop(handle);
+}
+
 int scan(struct scan *data)
 {
 	int sockfd = socket(AF_INET, SOCK_RAW,
@@ -82,20 +97,16 @@ int scan(struct scan *data)
 
 	pcap_freecode(&fp);
 
+	pcap_setnonblock(handle, 1, errbuf);
+
 	if (data->type == SCAN_ALL) {
 		for (e_scantype type = SCAN_NULL; type < SCAN_ALL; type++) {
 			data->type = type;
-			send_packet(data, sockfd);
+			send_recv_packet(data, sockfd, handle);
-			if (!pcap_dispatch(handle, 1, dispatch_callback,
-			                   (u_char *)data))
-				printf("timeout\n"); // TODO handle no response
 		}
 		data->type = SCAN_ALL;
 	} else {
-		send_packet(data, sockfd);
+		send_recv_packet(data, sockfd, handle);
-		if (!pcap_dispatch(handle, 1, dispatch_callback,
-		                   (u_char *)data))
-			printf("timeout\n");
 	}
 
 	pcap_close(handle);

src/thread.c

@@ -80,7 +80,7 @@ error:
 int create_threads(const struct option_lst *options, char *ip_addr,
                    struct response *responses)
 {
-	uint16_t port_start, port_end;
+	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;