add

src/checksum.c

@@ -0,0 +1,19 @@
+#include <stdint.h>
+
+uint16_t checksum(const uint16_t *data, int len)
+{
+	uint32_t sum = 0;
+	int i = 0;
+
+	while (len > 1)
+	{
+		sum += data[i++];
+		len -= 2;
+	}
+	if (len == 1)
+		sum += ((uint8_t *)data)[i];
+
+	while (sum >> 16)
+		sum = (sum & 0xFFFF) + (sum >> 16);
+	return (~sum);
+}

src/checksum.h

@@ -0,0 +1,5 @@
+#pragma once
+
+#include <stdint.h>
+
+uint16_t checksum(const uint16_t *data, int len);

src/config.c

@@ -4,6 +4,7 @@
 
 void set_default_config(struct config *conf)
 {
+    conf->data_size = 56;
     conf->count = 5;
     conf->flood = false;
     conf->interval = 1;

src/config.h

@@ -11,6 +11,7 @@ struct config {
     uint64_t count;
     uint64_t interval;
     uint64_t time_to_live;
+    uint64_t data_size;
     bool verbose;
 };
 

src/data.c

@@ -0,0 +1,22 @@
+#include <stdint.h>
+#include <stdlib.h>
+#include <fcntl.h>
+#include <unistd.h>
+
+int get_data(char *payload, uint64_t payload_size)
+{
+    int fd;
+    int red;
+
+    fd = open("/dev/random", O_RDONLY);
+    if (fd == -1)
+        return 1;
+
+    red = read(fd, payload, payload_size);
+    if (red >= 0 && (uint64_t) red == payload_size)
+    {
+        close(fd);
+        return 1;
+    }
+    return 0;
+}

src/data.h

@@ -0,0 +1,5 @@
+#pragma once
+
+#include <stdint.h>
+
+int get_data(char *payload, uint64_t payload_size);

src/dns.c

@@ -0,0 +1,41 @@
+#include <arpa/inet.h>
+#include <netdb.h>
+#include <netinet/in.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <sys/socket.h>
+
+int dns_lookup(char *ip_addr, const char *hostname,
+               struct sockaddr_in *addr_con)
+{
+	struct hostent *host = gethostbyname2(hostname, AF_INET);
+	if (!host) {
+		dprintf(2,
+		        "Hostname '%s' doesn't exist or has invalid format.\n",
+		        hostname);
+		return -1;
+	}
+	strcpy(ip_addr, inet_ntoa(*(struct in_addr *)host->h_addr));
+	(*addr_con).sin_family = host->h_addrtype;
+	(*addr_con).sin_port = htons(0);
+	(*addr_con).sin_addr.s_addr = *(long *)host->h_addr;
+
+	return 0;
+}
+
+int reverse_dns_lookup(char *ip_addr, char *host)
+{
+	struct sockaddr_in tmp_addr;
+
+	tmp_addr.sin_family = AF_INET;
+	tmp_addr.sin_addr.s_addr = inet_addr(ip_addr);
+	if (getnameinfo((struct sockaddr *)&tmp_addr,
+	                sizeof(struct sockaddr_in), host, NI_MAXHOST, NULL, 0,
+	                NI_NAMEREQD)) {
+		dprintf(2, "Could not resolve reverse lookup of %s\n", ip_addr);
+		return -1;
+	}
+
+	return 0;
+}

src/dns.h

@@ -0,0 +1,5 @@
+#pragma once
+
+#include <netinet/in.h>
+
+int dns_lookup(const char *host, struct sockaddr_in *addr);

src/main.c

@@ -1,16 +1,20 @@
 #include "config.h"
+#include "dns.h"
 #include "parsing.h"
 #include <arpa/inet.h>
+#include <netinet/ip.h>
 #include <netinet/ip_icmp.h>
 #include <signal.h>
 #include <netinet/in.h>
 #include <stdbool.h>
 #include <stdint.h>
 #include <stdio.h>
+#include <stdlib.h>
 #include <string.h>
 #include <sys/socket.h>
 #include <unistd.h>
 
+
 bool loop = true;
 
 static void signal_handler(int code)
@@ -51,38 +55,17 @@ int init_socket(const struct config *conf)
     return sock_fd;
 }
 
-uint16_t checksum(const uint16_t *data, int len)
-{
-	uint32_t sum = 0;
-	int i = 0;
 
-	while (len > 1)
-	{
-		sum += data[i++];
-		len -= 2;
-	}
-	if (len == 1)
-		sum += ((uint8_t *)data)[i];
 
-	while (sum >> 16)
-		sum = (sum & 0xFFFF) + (sum >> 16);
-	return (~sum);
-}
-
-int send_packet(int sock_fd, const char* host, uint64_t seq, const struct config *conf)
+int send_packet(int sock_fd, struct in_addr *dest, void *packet, uint64_t packet_size)
 {
-    (void) conf;
     struct sockaddr_in addr;
-    inet_aton(host, &addr.sin_addr);
 
-    struct icmphdr icmp_hdr;
-    memset(&icmp_hdr, 0, sizeof(icmp_hdr));
-    icmp_hdr.type = ICMP_ECHO;
-    icmp_hdr.un.echo.id = getpid();
-    icmp_hdr.un.echo.sequence = seq;
-    icmp_hdr.checksum = checksum((uint16_t*)&icmp_hdr, sizeof(icmp_hdr));
+    memset(&addr, 0, sizeof(struct sockaddr_in));
+    addr.sin_family = AF_INET;
+    addr.sin_addr = *dest;
 
-    if (sendto(sock_fd, &icmp_hdr, sizeof(icmp_hdr), 0, (struct sockaddr*)&addr, sizeof(addr)) == -1)
+    if (sendto(sock_fd, packet, packet_size, 0, (struct sockaddr*)&addr, sizeof(addr)) == -1)
     {
         dprintf(2, "ft_printf: failed to send packet\n");
         return 1;
@@ -109,34 +92,43 @@ int recv_packet(int sock_fd, const char *host, uint64_t seq, const struct config
 
 int main(int ac, char **av)
 {
+    struct config conf;
+    struct sockaddr_in addr;
+
     (void)ac;
 
     signal(SIGINT, signal_handler);
 
-    struct config conf;
     set_default_config(&conf);
     const char *host = parsing((const char * const *) av, &conf);
     if (host == NULL)
         return 1;
 
+    if (dns_lookup(host, &addr))
+        return 1;
+
     const int sock_fd = init_socket(&conf);
     if (sock_fd == -1)
         return 2;
     
-    static uint64_t seq = 1;
+    char ipstr[INET6_ADDRSTRLEN];
+    inet_ntop(AF_INET, &addr, ipstr, sizeof ipstr);
+    printf("IP: %s\n", ipstr);
+
+    return 1;
+
     while (loop)
     {
-        if (send_packet(sock_fd, host, seq, &conf))
+        if (send_packet(sock_fd,  NULL, NULL, 0))
         {
             close(sock_fd);
             return 1;
         };
-        if (recv_packet(sock_fd, host, seq, &conf))
+        if (recv_packet(sock_fd, host, 0, &conf))
         {
             close(sock_fd);
             return 1;
         }
-        seq++;
         sleep(conf.interval);
     }
 

src/packet.c

@@ -0,0 +1,47 @@
+#include "packet.h"
+#include "checksum.h"
+#include "config.h"
+#include "data.h"
+#include "data.h"
+#include <netinet/ip.h>
+#include <netinet/ip_icmp.h>
+#include <stdint.h>
+#include <stdlib.h>
+#include <string.h>
+#include <unistd.h>
+
+uint64_t get_packet_size(uint64_t data_size)
+{
+    return  + sizeof(struct icmphdr) + data_size;
+}
+
+void *create_packet(uint64_t data_size)
+{
+    static uint32_t seq = 1;
+    struct icmphdr *icmp_hdr;
+    char *data;
+    byte *packet;
+
+    packet = malloc(get_packet_size(data_size));
+    if (packet == NULL)
+        return NULL;
+
+    memset(packet, 0, get_packet_size(data_size));
+    icmp_hdr = (void *) packet;
+    data = (char*) packet +  sizeof(struct icmphdr);
+    
+    if (get_data(data, data_size))
+    {
+        free(packet);
+        return NULL;
+    }
+    
+    icmp_hdr->type = ICMP_ECHO;
+    icmp_hdr->un.echo.id = getpid();
+    icmp_hdr->un.echo.sequence = seq;
+    icmp_hdr->checksum = checksum((uint16_t*)icmp_hdr, get_packet_size(data_size));
+
+    seq++;
+
+    return packet;
+}

src/packet.h

@@ -0,0 +1,7 @@
+#pragma once
+
+#include <stdint.h>
+
+typedef uint8_t byte;
+
+uint64_t get_packet_size(uint64_t payload_size);