/* Ethernet packet generator    */
/* Written by Vladimir Zapolsky */
/* mail to avz101c@motolola.com */
/* July 28, 2007                */

#define ETH_FRAME_LEN 1514
#define ETH_HEADER_LEN (2 * ETH_ALEN)

#include <stdlib.h>
#include <string.h>
#include <stdio.h>

#include <netinet/in.h>
#include <linux/if_packet.h>
#include <linux/if_ether.h>
#include <linux/if_arp.h>

#include <sys/ioctl.h>
#include <getopt.h>
#include <unistd.h>
#include <fcntl.h>

typedef struct _Packets
{
    unsigned int dst[ETH_ALEN];
    unsigned int src[ETH_ALEN];
    unsigned char hdr[ETH_HEADER_LEN];
    unsigned char payload;
    char ifname[5];
    int fll;
    int cnt;
    int rnd;
    int len;
} Packets;

Packets packets;
const char* program;

void dump_packets()
{
    printf("Interface name: %s\n", packets.ifname);
    if (packets.fll)
    {
			printf("Fillall\n");
    }
    else
    {
			printf("Source MAC: %02X:%02X:%02X:%02X:%02X:%02X\n", packets.src[0], packets.src[1], packets.src[2], packets.src[3], packets.src[4], packets.src[5]);
			printf("Destination MAC: %02X:%02X:%02X:%02X:%02X:%02X\n", packets.dst[0], packets.dst[1], packets.dst[2], packets.dst[3], packets.dst[4], packets.dst[5]);
		}
    printf("Count: %d\n", packets.cnt);
    printf("Length: %d\n", packets.len);
    if (packets.rnd)
    {
			printf("Payload: random\n");
    }
    else
    {
			printf("Payload: %02X\n", packets.payload);
    }
}

void src_mac(const int sd, int* index)
{
    struct ifreq ifr;
    int i;
    
    strcpy(ifr.ifr_name, packets.ifname);

    if (ioctl(sd, SIOCGIFINDEX, &ifr) == -1)
    {
			perror("Cannot get ifindex of the interface");
			exit(1);
    }
    
    *index = ifr.ifr_ifindex;
    
    if (ioctl(sd, SIOCGIFHWADDR, &ifr) == -1 )
    {
			perror("Cannot get source MAC ");
			exit(1);
    }				
    
    for (i = 0; i < 6; i++)
    {
			packets.src[i] = ifr.ifr_hwaddr.sa_data[i];
    }
    
}

void print_usage()
{
    printf("Usage: %s [options]\n", program);
    printf("  -h  --help                         Display the usage information.\n");
    printf("  -p  --payload   (0x[0-9A-F]{2}|rand) Set payload.\n");
    printf("  -i  --interface eth[0-9]           Set interface.\n");
    printf("  -c  --count     num                Set number of packets to send.\n");
    printf("  -f  --fillall                      Set packet header similar to payload.\n");
    printf("  -d  --dest      XX:XX:XX:XX:XX     Set destination MAC address.\n");
    printf("  -l  --length    num                Set whole length of a packet ( min 60, max 1514 )\n");
    printf("  Default payload is 0x00, interface is eth0, count of packets is 1, length is 1514.\n");
    printf("  Default destination MAC address is 00:00:00:00:00:00.\n");
    exit(1);
}

void print_error(char* str)
{
    printf("%s\n", str);
    exit(1);					    
}

int main (int argc, char* argv[])
{
    int sd = 0;
    int rd = 0;
    
    program = argv[0];
    
    int opt;

    unsigned char buffer[ETH_FRAME_LEN];
    
    int i;
    
    struct sockaddr_ll saddr;    
/*    int status;*/
    
    const char* const short_opt = "hp:i:c:fd:l:";
    const struct option long_opt[] =
    {
			{ "help",      0, NULL, 'h' },
			{ "payload",   1, NULL, 'p' },
			{ "interface", 1, NULL, 'i' },
			{ "count",     1, NULL, 'c' },
			{ "fillall",   0, NULL, 'f' },
			{ "dest",      1, NULL, 'd' },
			{ "length",    1, NULL, 'l' }
    };

    for (i = 0; i < ETH_ALEN; i++)
    {
			packets.dst[i] = 0x00;
			packets.src[i] = 0x00;
    }
    
    packets.len = ETH_FRAME_LEN;
    packets.rnd = 0;
    packets.cnt = 1;
    packets.payload = 0x00;
    packets.fll = 0;
    strcpy(packets.ifname, "eth0");
    
    do
    {
	opt = getopt_long(argc, argv, short_opt, long_opt, NULL);
	switch (opt)
	{
	    case 'h':
		print_usage();
	    case 'p':
		if (strlen(optarg) != 4)
		{
		    print_error("Invalid payload");
		}
		else if (!strcmp("rand", optarg))
		{
		    packets.rnd = 1;
		}
		else if (!strncmp("0x", optarg, 2))
		{
		    packets.payload = strtol(optarg, (char**)NULL, 16);
		}
		else
		{
		    print_error("Invalid payload");
		}
		break;
	    case 'i':
		if (strlen(optarg) > 4 || strncmp("eth", optarg, 3))
		{
		    print_error("Invalid interface name");
		}
		strcpy(packets.ifname, optarg);
		break;
	    case 'c':
		packets.cnt = strtol(optarg, (char**)NULL, 10);
		if (packets.cnt <= 0)
		{
		    print_error("Invalid count");
		}
		break;
	    case 'f':
		packets.fll = 1;
		break;
	    case 'd':
		if (strlen(optarg) != 17)
		{
		    print_error("Invalid destination MAC address");
		}
		else
		{
		    for (i = 0; i < 5; i++)
		    {
			if (optarg[3*i+2] != ':')
			{
			    print_error("Invalid destination MAC address");
			}
		    }

		    if (sscanf(optarg, "%x:%x:%x:%x:%x:%x", &packets.dst[0], &packets.dst[1], &packets.dst[2], &packets.dst[3], &packets.dst[4], &packets.dst[5]) != ETH_ALEN)
		    {
			print_error("Invalid destination MAC address");
		    }
		}
		break;
	    case 'l':
		packets.len = strtol(optarg, (char**)NULL, 10);
		if (packets.len > ETH_FRAME_LEN || packets.len < 60)
		{
		    print_error("Invalid length");
		}
		break;
	    default:
		break;
	}
    }
    while (opt != -1);

    /* Body */

    if (packets.rnd)
    {
	rd = open("/dev/urandom", O_RDONLY);
	if (rd == -1)
	{
	    printf("Cannot open /dev/urandom, packets are filled with zeroes\n");
	    packets.rnd = 0;
	}
    }
    
    sd = socket(PF_PACKET, SOCK_RAW, htons(ETH_P_ALL));
    if (sd == -1)
    {
	perror("Cannot open socket ");
	exit(1);
    }
    
    saddr.sll_family   = PF_PACKET;
    saddr.sll_protocol = htons(ETH_P_IP);
    src_mac(sd, &saddr.sll_ifindex);
    saddr.sll_hatype   = ARPHRD_ETHER;
    saddr.sll_pkttype  = PACKET_OTHERHOST;
    saddr.sll_halen    = ETH_ALEN;
    
/*    saddr.sll_addr[i] = packets.dst[i];*/
    
    dump_packets();
    
    /* Generate payload */

    for (i = 0; i < ETH_ALEN; i++)
    {
			packets.hdr[i] = (unsigned char)packets.dst[i];
			packets.hdr[i + ETH_ALEN] = (unsigned char)packets.src[i];
    }
    
    if (!packets.rnd)
    {
			memset((void*)buffer, packets.payload, packets.len);
    }

    if (!packets.fll)
    {
        memcpy((void*)buffer, (void*)packets.hdr, ETH_HEADER_LEN);
    }
    
    while(packets.cnt > 0)
    {
        if (packets.rnd)
	{
	    if (packets.fll)
	    {
				read(rd, buffer, packets.len);
	    }
	    else
	    {
				read(rd, &buffer[ETH_HEADER_LEN], packets.len - ETH_HEADER_LEN);
	    }
        }
        
		if (sendto(sd, buffer, packets.len, 0, (struct sockaddr*)&saddr, sizeof(saddr)) != packets.len)	
		{
		    print_error("Cannot send a packet");
		    perror("");
		}	
	
	packets.cnt--;
    }

    printf("Done.\n");
    
    if (rd > 0)
    {
	close(rd);
    }
    
    close(sd);
    
    return(0);
}