Rolf Meyer
/
ethspam
etherspam shows how to send an Ethernet packet. It simply sends ARP Who is messages for every IP.
main.cpp
- Committer:
- rolf
- Date:
- 2009-09-04
- Revision:
- 0:852db76de235
File content as of revision 0:852db76de235:
#include "mbed.h" // Importing the mbed classes and tools. #include "Ethernet.h" using namespace mbed; __packed // A __packed struct to have no gaps between the members http://en.wikipedia.org/wiki/Data_structure_alignment struct ethpkt { // Ethernet layer: http://en.wikipedia.org/wiki/Ethernet#Physical_layer unsigned char dest[6]; // Destination MAC unsigned char src[6]; // Source MAC unsigned short type; // Payload type. ARP is 0x0806 // ARP layer: http://en.wikipedia.org/wiki/Address_Resolution_Protocol unsigned short hwtype; // Each data link layer protocol is assigned a number used in this field. Ethernet is 0x0001 unsigned short proto; // Each protocol is assigned a number used in this field. IP is 0x0800. unsigned char hwlen; // Length in bytes of a hardware address. Ethernet addresses are 6 bytes long. unsigned char protolen; // Length in bytes of a logical address. IPv4 address are 4 bytes long. unsigned short opcode; // Specifies the operation the sender is performing: // 1 for request, 2 for reply, 3 for RARP request, and 4 for RARP reply. unsigned char shwaddr[6]; // Hardware address of the sender. unsigned char sipaddr[4]; // Protocol address of the sender. unsigned char dhwaddr[6]; // Hardware address of the intended receiver. This field is ignored in requests. unsigned char dipaddr[4]; // Protocol address of the intended receiver. }; Ethernet eth; // The ethernet device DigitalOut led4(LED4); // A LED for showing activity unsigned short htons(unsigned short n) { // Host short to network shor return ((n & 0xff) << 8) | ((n & 0xff00) >> 8); // Byte swapping } void send(const char *ipaddr) { static char data[0x600]; // Packet buffer const unsigned char arplen = 6; // Hardware address length const unsigned char ethlen = 4; // IP address length char hwaddr[arplen]; // Hardware address buffer struct ethpkt *pkg = (struct ethpkt *) &data[0]; // Force the buffer to an ethpkg unsigned char pos = arplen; // Hardware/IP address position eth.address(hwaddr); // Get own hardware address pkg->type = htons(0x0806); // Set type to ARP (0x0806) pkg->hwtype = htons(0x0001); // Hardware type is Ethernet (0x0001) pkg->proto = htons(0x0800); // Protocol is ARP Request (0x0800) pkg->hwlen = arplen; // Hardware addresses are 6 Bytes long pkg->protolen = ethlen; // And protocol addresses 4 Bytes pkg->opcode = htons(0x0001); // Send: whois XX:XX:XX:XX:XX:XX? while(pos-- > 0) { // Write IP/MAC-Addresses (combined loop for all addresses) pkg->src[pos] = hwaddr[pos]; // Set source MAC address to hwaddr on ethernet layer pkg->dest[pos] = 0xFF; // Set destination MAC address to everybody (FF:FF:FF:FF:FF:FF) on ethernet layer pkg->shwaddr[pos] = hwaddr[pos]; // Set source MAC address on ARP layer pkg->dhwaddr[pos] = 0xFF; // Set destination MAC address on ARP layer if(pos < ethlen) { // Check if we can copy IP addresses too. pkg->sipaddr[pos] = 0xFF; // Set source ip address to 255.255.255.255 pkg->dipaddr[pos] = ipaddr[pos]; // Set destination ip address to ipaddr } } eth.write(data, 60); // Write the package eth.send(); // Send the package } // In this example we would like to make ARP requests to ask for every ip address. int main() { // The programm starts here! unsigned int i = 1; // The integer we use as counter and target IP address. char *c = (char *)&i; // We cast the integer to an array of char c[4] to handle it as IP address. printf("Lowlevel Ethernet Spammer\n\n"); // Print out that the programm has been started. while(1) { // Do forever: send(c); // Assamble and send our request. See eth_send function! i++; // Increment counter. What will increment the IP (c[4]) address as well. led4 = 1; // Show activity, by blinking with led 4: wait(0.02); // led4 = 0; // Put the led on and wait for 0.2 seconds wait(0.02); // Put the led off and wait for 0.2 seconds } }