/* down_to_network() RECEIVES NEW MESSAGES FROM THE APPLICATION LAYER AND
PREPARES THEM FOR TRANSMISSION TO OTHER NODES.
*/
static EVENT_HANDLER( down_to_network) {
NL_PACKET p;
p.length = sizeof(p.msg);
CHECK(CNET_read_application(&p.dest, p.msg, &p.length));
CNET_disable_application(p.dest);
p.src = nodeinfo.address;
p.kind = NL_DATA;
p.seqno = NL_nextpackettosend(p.dest);
p.hopcount = 0;
p.pieceNumber = 0;
p.pieceEnd = 0;
p.src_packet_length = (int) p.length;
p.checksum = CNET_ccitt((unsigned char *) (p.msg), p.src_packet_length);
p.trans_time = 0;
p.is_resent = 0;
//lastPacket = &p;
printf(
"packet generated, src = %d, des = %d, seqno = %d, send_length = %d, checksum = %d\n\n",
nodeinfo.address, p.dest, p.seqno, p.length, p.checksum);
flood((char *) &p, PACKET_SIZE(p), 0, 0);
update_last_packet(&p);
}
static EVENT_HANDLER(ready_app)
{
CnetAddr dest;
int num_unack = next_frame - last_ack_recv;
if(num_unack==(MAXSEQ+1)/2){
timer_wait = CNET_start_timer(EV_TIMER1, TIMEOUT, 0);
CNET_disable_application(ALLNODES);
return;
}
if(num_unack<0){
num_unack=MAXSEQ;
}
// if(trans_frame_state[next_frame%((MAXSEQ+1)/2)] == ACK_WAIT)
// {
// timer_wait = CNET_start_timer(EV_TIMER1, TIMEOUT, 0);
// CNET_disable_application(ALLNODES);
// return;
// }
trans_frame_state[next_frame] = ACK_WAIT;
size_t length = MAX_MESSAGE_SIZE;
CHECK(CNET_read_application(&dest, (char*) last_msg, &length));
frame_send(last_msg, length, next_frame);
next_frame = (next_frame + 1) % (MAXSEQ + 1);
}
/* down_to_network() RECEIVES NEW MESSAGES FROM THE APPLICATION LAYER AND
PREPARES THEM FOR TRANSMISSION TO OTHER NODES.
*/
static EVENT_HANDLER(down_to_network) {
//printf("down_to_network\n");
NL_PACKET p;
p.length = sizeof(p.msg);
//printf("p.length = %d, MAX_MESSAGE_SIZE = %d", p.length, MAX_MESSAGE_SIZE);
CHECK(CNET_read_application(&p.dest, p.msg, &p.length));
CNET_disable_application(p.dest);
p.src = nodeinfo.address;
p.kind = NL_DATA;
//p.hopcount = 0;
memset(p.traveled_hops, -1, MAXHOPS*sizeof(int));
p.traveled_hops[0] = nodeinfo.nodenumber;
p.traveled_hops_count = 1;
p.trans_time = 0;
p.seqno = NL_nextpackettosend(p.dest);
p.pieceNumber = 0;
p.pieceEnd = 0;
p.checksum = CNET_ccitt((unsigned char *) (p.msg), p.length);
lastPacket = &p;
update_last_packet(&p);
printf("Packet generated at host %d, des %d\n\n", nodeinfo.address, p.dest);
flood3((char *) &p, PACKET_SIZE(p), 0, 0);
}
static void down_to_transport(CnetEvent ev, CnetTimer timer, CnetData data) {
/* our packet */
TR_PACKET p;
/* destination address to pass to network layer */
CnetAddr temp;
p.length = sizeof(p.msg);
CHECK(CNET_read_application(&temp, p.msg, &p.length));
CNET_disable_application(temp);
/* establish sequence number */
unsigned long seq = getSequence(temp);
if( seq == -1) {
addAddress(temp,0);
p.sequence_number = 0;
}
else {
unsigned long newseq = seq + p.length;
setSequence(temp,newseq);
p.sequence_number = newseq;
}
p.checksum = checksum_crc32( ((char*)&p)+sizeof(unsigned int)
, TR_PACKET_SIZE(p) - sizeof(unsigned int));
down_to_network( (char*)&p , TR_PACKET_SIZE(p) , temp);
/* enqueuePacket((char*)&p, TR_PACKET_SIZE(p), temp); */
CNET_start_timer(EV_TIMER1, 1000, (CnetData)1);
}
static void push_message(MSG msg, size_t msgLength){
if(queue_nitems(msg_queue) < MAX_MSG_QUEUE_SIZE){
//printf("Pushing a message for %d with length %d\n", msg.dest, msgLength);
queue_add(msg_queue, &msg, msgLength);
}
if(queue_nitems(msg_queue) == MAX_MSG_QUEUE_SIZE){
CNET_disable_application(nodeinfo.address);
}
network_send();
}
static EVENT_HANDLER(application_ready){
MSG msg;
size_t len = sizeof(MSG);
CHECK(CNET_read_application(&msg.dest, &msg.data, &len));
queue_add(msg_queue, &msg, len + MESSAGE_HEADER_SIZE);
if(queue_nitems(msg_queue) == MAX_MSG_QUEUE_SIZE){
CHECK(CNET_disable_application(ALLNODES));
app_enabled = false;
}
}
static EVENT_HANDLER(application_ready)
{
CnetAddr destaddr;
lastlength = sizeof(MSG);
CHECK(CNET_read_application(&destaddr, (char *)lastmsg, &lastlength));
CNET_disable_application(ALLNODES);
transmit_frame(lastmsg, DATA, lastlength, nextframetosend);
nextframetosend = 1-nextframetosend;
}
/* down_to_network() RECEIVES NEW MESSAGES FROM THE APPLICATION LAYER AND
PREPARES THEM FOR TRANSMISSION TO OTHER NODES.
*/
static EVENT_HANDLER( down_to_network) {
NL_PACKET p;
NL_PACKET test;
p.length = sizeof(p.msg);
CHECK(CNET_read_application(&p.dest, p.msg, &p.length));
CNET_disable_application(p.dest);
p.src = nodeinfo.address;
p.kind = NL_DATA;
p.seqno = NL_nextpackettosend(p.dest);
p.hopcount = 0;
p.pieceStartPosition = 0;
p.pieceEnd = 0;
p.src_packet_length = (int) p.length;
p.checksum = CNET_crc32((unsigned char *) (p.msg), p.src_packet_length);
p.piece_checksum = CNET_crc32((unsigned char *) (p.msg),
p.src_packet_length);
p.trans_time = 0;
p.is_resent = 0;
test.src = nodeinfo.address;
test.dest = p.dest;
test.kind = NL_TEST;
test.hopcount = 0;
test.seqno = 0;
test.min_mtu = INT_MAX;
test.length = 0;
test.pieceStartPosition = 0;
test.src_packet_length = PACKET_HEADER_SIZE;
test.checksum = 0;
test.piece_checksum = 0;
test.trans_time = 0;
test.is_resent = 0;
NL_updatelastsendtest(&test);
update_last_packet(&p);
flood_test((char *) &test, PACKET_HEADER_SIZE, 0, 0);
//TODO: please inform the mtu from src to dest by using pathfinder packet
//size_t mtu_from_src_to_dest = 96;
//piece_to_flood((char *) &p, mtu_from_src_to_dest);
}
///Worker Method
///Called to send a nl_packet to an associated access point.
///If this device is not associated, we abort and manage association instead
///as there is nowhere to transmit the packet to.
static int transmit(struct nl_packet *packet)
{
fprintf(stdout, "\tTransmitting.\n");
// Create a broadcast address.
CnetNICaddr wifi_dest;
CHECK(CNET_parse_nicaddr(wifi_dest, "ff:ff:ff:ff:ff:ff"));
//uint16_t packet_length = NL_PACKET_LENGTH(packet);
uint16_t packet_length = sizeof(*packet);
if(packet->type == NULL_FRAME)
{
fprintf(stderr, "\t%s is attempting to send a null packet!\n",nodeinfo.nodename);
exit(0);
}
if(isAss == false)
{
fprintf(stdout, "\tWhoops! %s is not associated!\n\t Starting Probe\n", nodeinfo.nodename);
// CHECK(CNET_disable_application(ALLNODES));
probe_timer = CNET_start_timer(EV_TIMER1, 100, 0);
return 0;
}
else
{
fprintf(stdout, "\tAssociation is true, sending frame.\n");
fprintf(stdout, "\n packet src:%i dest:%i\n",packet->src, packet->dest);
if(packet->dest > 133) exit(0);
dll_wifi_write(dll_states[1], wifi_dest, (char *)packet, packet_length);
if(packet->type == NL_DATA )
{
CHECK(CNET_disable_application(ALLNODES));
printf(" DATA transmitted, seq=%d\n", packet->seq);
data_timeout = CNET_start_timer(EV_TIMER2, CNET_rand() * 50000 + 500000, 0); /// one second wait time
}
return 1;
}
}
static void datalink_down(FRAME frame, int inLink, int outLink)
{
// FRAME IS BEING FORWARDED
if ( outLink != 0 )
{
// MORE ROOM TO SEND SO TRANSMIT FRAME
if (numInWindow[outLink - 1] < MAX_SEQ)
{
transmit_ack(inLink, frame.seq);
inc(&frameExpected[inLink - 1]);
frame.seq = nextFrameToSend[outLink - 1];
// STORE FRAME IN THE OUTGOING WINDOW
window[outLink - 1][nextFrameToSend[outLink - 1]] = frame;
numInWindow[outLink - 1] += 1;
// TRANSMIT THE FRAME OUT
frame.link = outLink;
transmit_frame(frame);
inc(&nextFrameToSend[outLink - 1]);
}
// NOT ENOUGH ROOM IN WINDOW TO SEND
else
{
if (numInBuffer[outLink - 1] < MAX_SEQ + 1)
{
transmit_ack(inLink, frame.seq);
inc(&frameExpected[inLink - 1]);
// STORE FRAME IN THE BUFFER
buffer[outLink - 1][bufferBounds[outLink - 1][1]] = frame;
numInBuffer[outLink - 1] += 1;
inc(&bufferBounds[outLink - 1][1]);
printf("\t\t\t\t\tADDED TO BUFFER\n");
}
else
{
// IF WINDOW AND BUFFER BOTH FULL, CAN'T DO ANYTHING. DROP
printf("\t\t\t\t\tBUFFER FULL, FRAME DROPPED\n");
}
}
// IF THE WINDOW IS CURRENTLY FULL
if (numInWindow[outLink - 1] >= MAX_SEQ)
{
// DISABLE GENERATION OF NEW MESSAGES WHILE WINDOW IS FULL
for ( int ii = 0; ii < NUM_NODES; ii++ )
{
// ONLY DISABLE MESSAGES FOR DESTINATION ROUTED THROUGH outLink
if ( routingTable[nodeinfo.nodenumber][ii] == outLink )
{
CNET_disable_application( ii );
printf("\t\t\t\t\tDISABLED APPLICATION\n");
CNET_set_LED( outLink-1, "red" );
}
}
}
}
else
{
// MORE ROOM TO SEND SO TRANSMIT FRAME
if (numInWindow[inLink - 1] < MAX_SEQ)
{
// GET SEQUENCE NUMBER, STORE FRAME IN WINDOW, INC WINDOW NUMBER
frame.seq = nextFrameToSend[inLink - 1];
window[inLink - 1][nextFrameToSend[inLink - 1]] = frame;
numInWindow[inLink - 1] += 1;
// CALL DLL TO TRANSMIT FRAME
frame.link = inLink;
transmit_frame(frame);
inc(&nextFrameToSend[inLink - 1]);
}
// NOT ENOUGH ROOM IN WINDOW TO SEND
else
{
// ADD FRAME TO THE BUFFER WAITING TO SEND OUT
buffer[inLink - 1][bufferBounds[inLink - 1][1]] = frame;
numInBuffer[inLink - 1] += 1;
inc(&bufferBounds[inLink - 1][1]);
// PRINT DESTINATION OF MESSAGE, LINK, INDEX IN BUFFER
printf("\nADDED TO BUFFER\n");
printf("DEST:\t%s\n", nodenames[frame.destNode]);
printf("LINK:\t%d\n", inLink);
printf("INDEX:\t%d\n", bufferBounds[inLink - 1][1] - 1);
}
// IF THE WINDOW IS CURRENTLY FULL
if (numInWindow[inLink - 1] >= MAX_SEQ)
{
// ONLY DISABLE MESSAGES FOR DESTINATION ROUTED THROUGH outLink
for ( int ii = 0; ii < NUM_NODES; ii++ )
{
if ( routingTable[nodeinfo.nodenumber][ii] == inLink )
{
CNET_disable_application( ii );
printf("DISABLE APPLICATION FOR %s\n", nodenames[ii] );
CNET_set_LED( inLink-1 , "red" );
}
}
}
}
}
///Worker Method
///Called when we receive data from one of our data link layers.
///Handles association with AP's and propagation of frames to other layers.
static void up_from_dll(int link, const char *data, size_t length)
{
//fprintf(stdout, "\t%s: Received frame from dll on link\n", nodeinfo.nodename);
if (length > sizeof(struct nl_packet)) {
printf("\t%s: %zu is larger than a nl_packet! ignoring.\n",nodeinfo.nodename, length);
return;
}
//Treat this frame as a network layer packet.
struct nl_packet packet;
memset(&packet, 0, sizeof(packet));
memcpy(&packet, data, length);
fprintf(stdout, "\tPacket dest %i: \n\t %s's src: %i\n", packet.dest, nodeinfo.nodename, nodeinfo.address);
fprintf(stdout, "\t%s: Received frame from dll on link %d\n\tfrom node %" PRId32
" for node %" PRId32 ".\n",nodeinfo.nodename, link, packet.src, packet.dest);
uint32_t checksum = packet.checksum;
packet.checksum = 0;
fprintf(stdout,"\t%s has received a nl_packet of type ",nodeinfo.nodename);
printFRAMEKIND(packet.type);
fprintf(stdout,"\n");
if (CNET_crc32((unsigned char *)&packet, sizeof(packet)) != checksum) {
fprintf(stdout, "\tChecksum failed.\n");
//return;
}
if (packet.dest != nodeinfo.address) {
fprintf(stdout, "\tThat's not for me.\n");
fprintf(stdout, "\tPacket dest %i: \n\t %s's src: %i\n", packet.dest, nodeinfo.nodename, nodeinfo.address);
fprintf(stdout, "\tPacket src %i: \n", packet.src);
return;
}
// Check if we've seen this packet rece ntly.
for (size_t i = 0; i < PACKET_MEMORY_LENGTH; ++i) {
if (seen_checksums[i] == checksum) {
fprintf(stdout, "\tI seem to have seen this recently.\n");
return;
}
}
// Remember the checksum of this packet.
seen_checksums[next_seen_checksum++] = checksum;
next_seen_checksum %= PACKET_MEMORY_LENGTH;
fprintf(stdout,"\t%s has received a nl_packet of type ",nodeinfo.nodename);
printFRAMEKIND(packet.type);
fprintf(stdout,"\n");
struct nl_packet assRequest;
switch (packet.type)
{
case NL_DATA :
fprintf(stdout, "\nDATA FRAME FOR %i @ %i, seq=%d \n", packet.dest, nodeinfo.address, packet.seq);
if(packet.seq == frameexpected)
{
fprintf(stdout, "\tDATA Up to the application layer!\n");
size_t payload_length = packet.length;
CHECK(CNET_write_application(packet.data, &payload_length));
frameexpected = 1 - frameexpected;
} else {
fprintf(stdout, "\tignored...\n");
}
struct nl_packet ackPacket = (struct nl_packet){
.src = nodeinfo.address,
.dest = packet.src,
.length = NL_MAXDATA,
.type = NL_ACK
};
memcpy(ackPacket.data,nodeinfo.nodename,sizeof(nodeinfo.nodename));
ackPacket.seq = packet.seq;
ackPacket.checksum = CNET_crc32((unsigned char *)&ackPacket, sizeof(ackPacket));
fprintf(stdout, "\tTransmitting an acknowledgement packet, seq = %i!*********************\n", ackPacket.seq);
fprintf(stdout, "\n ackpacket src:%i dest:%i\n",ackPacket.src, ackPacket.dest);
if(ackPacket.dest > 133) exit(0);
transmit(&ackPacket);
break;
case NL_ACK :
//CANCEL THE TIMEOUT FUNCTION AS WE HAVE RECEIVED THE ACKNOWLEEDGEMENT EXPECTED
//If it has the expected sequence number
if(packet.seq == ackexpected) {
printf("\t\t\t\t**************ACK received, seq=%d\n", packet.seq);
CHECK(CNET_stop_timer(data_timeout));
ackexpected = 1-ackexpected;
CHECK(CNET_enable_application(ALLNODES));
}
break;
case NL_ASSREQ :
if(timeAPset == false)
{
if(isAss == false)
{
fprintf(stdout, "\n%s is now associated with ap link %i\n",
nodeinfo.nodename,packet.src);
CHECK(CNET_stop_timer(probe_timer));
assRequest.type = NL_ASSREQ;
assRequest.dest = packet.src;
assRequest.src = nodeinfo.address;
assRequest.length = NL_MAXDATA;
assRequest.checksum = CNET_crc32((unsigned char *)&assRequest, sizeof(assRequest));
fprintf(stdout, "\ttoSend is of frame type ");
printFRAMEKIND(toSend->type);
fprintf(stdout, "\n");
fprintf(stdout, "\n%s Is ASSOCIATED!**********\n",nodeinfo.nodename);
if(assRequest.dest > 133) exit(0);
//DOING THINGS
timeAPset = true;
isAss = true;
transmit(&assRequest);
CHECK(CNET_enable_application(ALLNODES));
}
else
{
fprintf(stderr, "HOLY CRAP BATMAN! I'M REASSOCIATING!\n");
//exit(EXIT_FAILURE);;
isAss = true;
CHECK(CNET_stop_timer(probe_timer));
}
timeAPset = nodeinfo.time_of_day.sec;
}
break;
default :
fprintf(stdout, "\tFollowing default\n");
exit(0);
// Send this packet to the application layer.
fprintf(stdout, "\tUp to the application layer!\n");
size_t payload_length = packet.length;
CHECK(CNET_write_application(packet.data, &payload_length));
break;
}
}
///Event Handler
///Called when this mobile node's application layer has generated a new message.
///Proceeds to transmit the generated message.
static EVENT_HANDLER(application_ready)
{
fprintf(stdout, "\t%s's application later ready, creating new message.\n\t Max data: %i, Type: %" PRId32".\n",nodeinfo.nodename, NL_MAXDATA, NL_DATA);
toSend->src = nodeinfo.address;
toSend->length = NL_MAXDATA;
toSend->type = NL_DATA;
toSend->seq = nextframetosend;
printf( " THE NEXT FRAME TO SEND IS %i\n", nextframetosend);
struct nl_packet temp = (struct nl_packet){
.src = nodeinfo.address,
.length = NL_MAXDATA,
};
//update toSend
CHECK(CNET_read_application(&temp.dest, temp.data, &temp.length));
memcpy(&(toSend->dest),&temp.dest,sizeof(temp.dest));
memcpy(&(toSend->data), &temp.data, temp.length);
toSend->length = temp.length;
fprintf(stdout, "\ntoSend dest:%i\n", toSend->dest);
fprintf(stdout, "\tAppready: toSend is of frame type ");
printFRAMEKIND(toSend->type);
fprintf(stdout, "\n");
toSend->checksum = CNET_crc32((unsigned char *)&toSend, sizeof(toSend));
fprintf(stdout, "\t%s: Generated message for % " PRId32
",\n\t attempting to transmit\n",nodeinfo.nodename,
toSend->dest);
CHECK(CNET_disable_application(ALLNODES));
transmit(toSend);
if(toSend->type != NL_DATA)
{
fprintf(stderr, "\t%s toSend is not DATA!\n",nodeinfo.nodename);
exit(0);
}
// CNET_start_timer(EV_TIMER2, 1, 0);
nextframetosend = 1-nextframetosend;
fprintf(stdout, "\tPacket transmitted successfully.\n");
}
///Event Handler
///Creates a new probe packet and sends it to transmit for propagation.
///This packet is used to discover access points and find an appropriate one
///for association.
///It then starts a timer to ensure that if there is no response, an additional
///probe is sent after a period of time.
///The timer is stopped once an acknowledgement is received and the mobile device
///is considered 'associated' with an access point.
static EVENT_HANDLER(probe)
{
probe_timer = CNET_start_timer(EV_TIMER3, 5000000, 0);
fprintf(stdout, "\n%s Probing...\n", nodeinfo.nodename);
struct nl_packet packet = (struct nl_packet){
.src = nodeinfo.address,
.length = NL_MAXDATA,
};
memcpy(packet.data,nodeinfo.nodename,sizeof(nodeinfo.nodename));
packet.type = NL_PROBE;
packet.checksum = CNET_crc32((unsigned char *)&packet, sizeof(packet));
//create broadcast address
CnetNICaddr wifi_dest;
CHECK(CNET_parse_nicaddr(wifi_dest, "ff:ff:ff:ff:ff:ff"));
uint16_t packet_length = NL_PACKET_LENGTH(packet);
CHECK(CNET_disable_application(ALLNODES));
dll_wifi_write(dll_states[1], wifi_dest, (char *)&packet, packet_length);
}
static EVENT_HANDLER(timeouts)
{
printf("timeout, seq=%d\n", ackexpected);
transmit(toSend);
}
