void makeTrie(void) {
map<int, hostConf>::iterator j;
string::iterator stringit;
char* temp = new char[16];
string prestring;
char* size = new char[2];
struct cidrprefix tempFix;
for(j = routerEnd.begin(); j != routerEnd.end(); j++) {
prestring = (j->second).overlayPrefix;
for(stringit = prestring.begin(); stringit != prestring.end(); stringit++) {
if(*stringit == '/') {
strcpy(temp, prestring.substr(0, distance(prestring.begin(),stringit)).c_str());
cout << "Temp: " << temp << endl;
inet_pton(AF_INET, temp, (void *)&tempFix.prefix);
stringit++;
size[0] = *stringit;
stringit++;
size[1] = *stringit;
break;
}
}
tempFix.size = (char)atoi(size);
#ifdef DEBUG
cout << "Prefix: " << tempFix.prefix << "/" << (int)tempFix.size << " for router: " << routerIPs[j->first] << endl;
#endif
hosts.insert(tempFix, routerIPs[j->first]);
#ifdef DEBUG
cout << "Testing trie." << endl;
int testaddr;
inet_pton(AF_INET, "1.2.3.1", (void *)&testaddr);
cout << testaddr << hosts.search(testaddr) << endl;
#endif
}
}
int main(int argc, char** argv) {
#ifdef SANDWICH
printf("I'm a sandwich!\n");
#endif
int o;
string configPath;
char isRouter = IP_NOT_FOUND;
while((o = getopt(argc, argv, "rh")) != -1) {
switch(o) {
case 'r':
//enter router mode
isRouter = TRUE;
break;
case 'h':
//enter host mode
isRouter = FALSE;
break;
case '?':
fprintf(stderr, "Unknown option -%c.\n", optopt);
cout << "Specify host with -h or router with -r" << endl;
exit(0);
break;
}
}
configPath = (string)argv[optind];
if(configPath.empty()) {
printf("Please, you must provide a filename.\n");
printf("Usage: overlay [-r -h] config.conf\n");
exit(1);
}
readConfig(configPath);
makeTrie();
struct ifaddrs *demAddrs;
if(getifaddrs(&demAddrs)) {
fprintf(stderr, "Couldn't get real IP address. Aborting.\n");
exit(1);
}
struct in_addr *myAddr;
char* addrBuf = new char[INET_ADDRSTRLEN];
struct sockaddr *mysockaddr = (demAddrs->ifa_addr);
while((strcmp(demAddrs->ifa_name, "eth0") && strcmp(demAddrs->ifa_name, "eth1") && strcmp(demAddrs->ifa_name, "eth2") && strcmp(demAddrs->ifa_name, "eth3") && strcmp(demAddrs->ifa_name, "wlan0"))||(mysockaddr->sa_family!=AF_INET)) {
#ifdef DEBUG
cout << "Interface: " << demAddrs->ifa_name << ". NOPE!" << endl;
#endif
demAddrs = demAddrs->ifa_next;
if(demAddrs==NULL) {
fprintf(stderr, "Couldn't find the specified interface. Aborting. Sorry! Make sure your computer is set up properly.\n");
exit(1);
}
mysockaddr = (demAddrs->ifa_addr);
}
#ifdef DEBUG
cout << "Interface: " << demAddrs->ifa_name << endl;
#endif
myAddr = &(((struct sockaddr_in*)mysockaddr)->sin_addr);
inet_ntop(AF_INET, (void *)myAddr, addrBuf, INET_ADDRSTRLEN);
#ifdef DEBUG
printf("My real IP address is: %s\n", addrBuf);
#endif
map<int, string>::iterator routeit;;
for(routeit = routerIPs.begin(); routeit != routerIPs.end(); routeit++) {
#ifdef DEBUG
cout << "Testing: " << (*routeit).second << endl;
#endif
if(!(*routeit).second.compare((string)addrBuf)) {
isRouter = TRUE;
hostID = (*routeit).first;
break;
}
}
if(isRouter == IP_NOT_FOUND) {
map<int, hostIP>::iterator endit;
for(endit = endIPs.begin(); endit != endIPs.end(); endit++) {
#ifdef DEBUG
cout << "Testing: " << (*endit).second.real << endl;
#endif
if(!(*endit).second.real.compare((string)addrBuf)) {
isRouter = FALSE;
hostID = (*endit).first;
break;
}
}
}
if(isRouter == IP_NOT_FOUND) {
fprintf(stderr, "I couldn't find your IP address in my memory banks. Please check to make sure your configuration file is correct.");
exit(1);
}
if(isRouter) router();
else {
uint32_t myIP = 0;
inet_pton(AF_INET, endIPs[hostID].overlay.c_str(), (void *)&myIP);
string myRouter = hosts.search(myIP);
#ifdef DEBUG
cout << "My router is: " << myRouter << endl;
#endif
unsigned long myRouterInt;
inet_pton(AF_INET, myRouter.c_str(), (void *)&myRouterInt);
host(myRouterInt);
}
return 0;
}
void router(void) {
#ifdef DEBUG
cout << "I am router #" << hostID << "!" << endl;
#endif
//bind socket
int sockfd = create_cs3516_socket();
//initialize for select() call
fd_set readfds;
FD_ZERO(&readfds);
FD_SET(sockfd, &readfds);
//We want a truly nonblocking call so...
struct timeval timeoutval;
timeoutval.tv_sec = 10;
timeoutval.tv_usec = 0;
map<string, deque<struct message *> > outputbuffers;
map<int, hostIP>::iterator it;
struct cidrprefix tempFix;
for(it = endIPs.begin(); it != endIPs.end(); it++) {
inet_pton(AF_INET, (*it).second.overlay.c_str(), (void *)&tempFix.prefix);
tempFix.size = 32;
hosts.insert(tempFix, (*it).second.real);
outputbuffers[(*it).second.real] = *(new deque<struct message *>); //Try to access the output buffer for this IP, but since it won't exist, create one.
#ifdef DEBUG
cout << "I just inserted " << hosts.search(tempFix.prefix) << endl;
#endif
}
while(TRUE){
//check if we have anything to read
FD_ZERO(&readfds);
FD_SET(sockfd, &readfds);
select(sockfd+1, &readfds, NULL, NULL, &timeoutval);
//while we have a packet to receive, handle it
if(FD_ISSET(sockfd, &readfds)){
#ifdef DEBUG
cout << "Received a packet!" << endl;
#endif
struct message *receivemessage = new struct message();
receivemessage->buffer = (char*)malloc(MAX_PACKET_SIZE);
cs3516_recv(sockfd, receivemessage->buffer, MAX_PACKET_SIZE);
time(&(receivemessage->recvtime));
iphdr *ip = (iphdr*)(receivemessage->buffer);
//get the real ip address of the destination
string interface = hosts.search((uint32_t)(ip->daddr));
cout << "Going to router: " << interface << endl;
deque<struct message *> outputqueue;
//Get some info from the packet for logging purposes
char srcstr[INET_ADDRSTRLEN], dststr[INET_ADDRSTRLEN];
inet_ntop(AF_INET, &(ip->saddr), srcstr, INET_ADDRSTRLEN);
inet_ntop(AF_INET, &(ip->daddr), dststr, INET_ADDRSTRLEN);
cout << "This fella is going to " << dststr << endl;
short id = ntohs(ip->id);
//get the output queue
cout << "Interface: " << interface << endl;
if(outputbuffers.find(interface)!=outputbuffers.end()){
outputqueue = outputbuffers.find(interface)->second;
} else {
//we don't know who this is! Log it and drop that packet like it's hot
writetolog(srcstr, dststr, id, "NO_ROUTE_TO_HOST", "");
continue;
}
//decrement the ttl value
(ip->ttl)--;
if((ip->ttl)>0){
if(outputqueue.size()<=configuration.queueLength){
outputbuffers[interface].push_back(receivemessage);
writetolog(srcstr, dststr, id, "SENT_OK", interface);
} else {
//drop the packet and log
writetolog(srcstr, dststr, id, "MAX_SENDQ_EXCEEDED", "");
}
} else {
//drop the packet and log
writetolog(srcstr, dststr, id, "TTL_EXPIRED", "");
}
}
//look at queues to see if any send delays have elapsed
//TODO per-queue send delay as specified by the assignment
for(map<string, deque<struct message *> >::iterator i = outputbuffers.begin(); i != outputbuffers.end(); i++) {
string interface = (*i).first;
double delay = 0;
bool isRouter = false;
int hostToSend = lookupHost(interface, &isRouter);
if(isRouter)
delay = routerRouter[hostToSend].sendDelay;
else
delay = routerEnd[hostToSend].sendDelay;
deque<struct message *> buffer = (*i).second;
if(buffer.size()>0){
struct message* currentmsg = buffer.front();
time_t currenttime;
time(¤ttime);
double waited = difftime(currenttime, currentmsg->recvtime);
if(waited>(delay/1000)){
unsigned int interfacebytes;
//convert address to bytes
inet_pton(AF_INET, (char*)interface.c_str(), (void *)&interfacebytes);
#ifdef DEBUG
cout << "Down to the nitty-gritty: sending the packet." << endl;
#endif
int status = cs3516_send(sockfd, currentmsg->buffer, MAX_PACKET_SIZE, interfacebytes);
//if(status) sent = TRUE;
if(!status) fprintf(stderr, "There was an error sending the file. No bytes were sent.");
//free(currentmsg->buffer);
delete currentmsg;
outputbuffers[interface].pop_front();
}
}
}
}
}
