#include "CS.h"

CSP csP;

void sighandle(int sig) { return; }
void abend(DebugP deP) {
   int pid;
   //LOG(0, "ABORT, netstat:");
   //if(!(pid = fork())) {
   //   execl("/bin/bash", "/bin/bash", "-c", "netstat -n --inet -a | grep 1[123][0-9][0-9][0-9] >net_stat", (char *) NULL);
   //   exit(EXIT_SUCCESS);
   //}
   waitpid(pid, NULL, 0);
   LOG(0, "ABORT, backtrace:");
   deP->back_trace();
   kill(0, SIGTERM);
   exit(EXIT_FAILURE);
}
char *gpa(struct sockaddr *ai_addr) {							// returns string with IP4 address & port assigned to the socket
   char *s = (char*) malloc(64);
   unsigned short port = *(unsigned short*) ai_addr->sa_data;
   char *a = ai_addr->sa_data + 2;
   sprintf(s, "%hhu.%hhu.%hhu.%hhu %hu", a[0], a[1], a[2], a[3], ntohs(port));
   return s;
}
void gai(int level, struct addrinfo *ai, DebugP deP) {			// logs assigned IP4 addresses from addrinfo chain
   struct addrinfo *sa = ai;
   if (deP->debug >= level) do {
      char *s = gpa(sa->ai_addr);
      strcpy(deP->s, s); free(s);
      deP->deb(level);
   } while ((sa = sa->ai_next));
   fflush(stderr);
}
void ssl_err(char *s, DebugP deP) {
   long e = ERR_get_error();
   while(e) {
      LOG(0, "%s: %s", s, ERR_error_string(e, NULL));
      e = ERR_get_error();
   }
}
static int getArg(const char *a) {
	return (getenv(a) != NULL) ? atoi(getenv(a)) : 0; }
HeaderS::HeaderS() {
	this->ttl = 0; }
HeaderS::HeaderS(int ttl) {
	this->ttl = ttl; }
int HeaderS::len() {
	return sizeof(HeaderS); }
PayloadS::PayloadS() {
	strcpy(&text, "EMPTY"); }
PayloadS::PayloadS(const char *text) {
	ts = time(NULL);
	strcpy(&(this->text), text); }
int PayloadS::check(PayloadP p) {
   return (int)(strcmp(&text, &p->text) == 0); }
char *PayloadS::deliver() {
   return &text; }
string PayloadS::digest() {
	string payl_s = string(&text);
	if(payl_s.size() < 24) return payl_s;
	else return payl_s.substr(0, 8) + string("--------") + payl_s.substr(payl_s.size() - 8, 8); }
void PayloadS::sabotage() {
	text = '?'; }
int PayloadS::len() {
	return sizeof(PayloadS) + strlen(&text); }
int ContainerS::len() {
	return hdr.len() + payl.len(); }
DataC::DataC() {}
DataC::DataC(DebugP callerDeP) {
   deP = new DebugC();
   DEBID("%s DATA", callerDeP->debid);
   dataLen = sizeof(HeaderS) + sizeof(PayloadS) + csP->text.size();
   contP = static_cast<ContainerP>(operator new(dataLen));
   new(&contP->hdr) HeaderS();
   new(&contP->payl) PayloadS();
   LOG(5, "Empty Data instance established");
}
void DataC::load(int ttl, const char *text) {
   new(&contP->hdr) HeaderS(ttl);
   new(&contP->payl) PayloadS(text);
   LOG(5, "Data instance loaded with payload");
   return;
}
string DataC::unld() {
	return string(&(contP->payl.text)); }
string DataC::digest() {
	return contP->payl.digest(); }
int DataC::dttl() {
   return --contP->hdr.ttl; }
int DataC::ttl() {
	return contP->hdr.ttl; }
bool DataC::dataOk() {
   return csP->text == string(&(contP->payl.text)); }
int DataC::ts() {
   return contP->hdr.ts; }
int DataC::remPort(int remPort) {
   return (contP->hdr.remPort = remPort); }
int DataC::remPort() {
   return contP->hdr.remPort; }
NodeC::NodeC(ConstellationP co, int port) {
   deP = new DebugC();
   DEBID("%sSSL %s node %d", co->ssl ? "" : "non", co->topo==mash ? "MASH" : "RING", port);
   LOG(4, "intializing ...");
   data = DataC(deP);
   topo = co->topo;
   locPort = port;
   first = co->first;
   nodes = co->nodes;
   last = first + nodes - 1;
   cliSides = new SocketS[nodes];
   srvSides = new SocketS[nodes];
   for(int k=0; k<nodes; k++) 	cliSides[k].sc = srvSides[k].sc = -1;
   kicker = (locPort == first);
   forwP = co->forwP;
   closing = 0;
   ssl = co->ssl;
   ssc = 0;
   if(ssl) {
      char s[128];
      SSL_load_error_strings();
      SSL_library_init();
      LOG(4, "setting SSL contex...");
      if(!(ctxP = SSL_CTX_new(SSLv23_method()))) SSLERR("new SSL CTX");
      SSL_CTX_set_mode(ctxP, SSL_MODE_AUTO_RETRY);
      SSL_CTX_set_verify(ctxP, SSL_VERIFY_FAIL_IF_NO_PEER_CERT, NULL);	// SSL will claim partner certificate
      sprintf(s, "%s/keys/%d.key", csP->cePath.c_str(), locPort);
      LOG(5, "SSL private key used: %s", s);
      if(SSL_CTX_use_PrivateKey_file(ctxP, s, SSL_FILETYPE_PEM) != 1) SSLERR("hh's key file");
      sprintf(s, "%s/certs/%d.pem", csP->cePath.c_str(), locPort);
      LOG(5, "SSL certificate used: %s", s);
      if(SSL_CTX_use_certificate_file(ctxP, s, SSL_FILETYPE_PEM) != 1) SSLERR("hh's cert file");
      LOG(5, "SSL: CApath: %s", csP->caPath.c_str());
      if(SSL_CTX_load_verify_locations(ctxP, NULL, csP->caPath.c_str()) != 1) SSLERR("hh's thrusted certs path");
   }
   LOG(5, "initalized");
}
int NodeC::run() {
   LOG(5, "binding, kicker=%d", kicker);
   bindN();
   if(kicker) {
      data.load(csP->ttl, csP->text.c_str());
      int sci, next;
      next = next_node(); sci = next - first;
      LOG(2, "ready to initial send %s, len=%d to node %d",	data.digest().c_str(), data.dataLen, next);
      conn(sci, next);
      putN(sci);
   }
   mainLoop();
   LOG(5, "closing ssc");
   close(ssc);
   if(closing) closingThread.join();		// wait for closing thread
	struct sigaction sigact;
	sigfillset(&sigact.sa_mask);
	sigact.sa_handler = sighandle;
	if(sigaction(SIGUSR2,&sigact,NULL) < 0) SYSERR("sigaction");
	if(sem_wait(&csP->shP->counterSem) < 0) SYSERR("sem_wait");
	if(--csP->shP->act == 0) {
		if(sem_post(&csP->shP->counterSem) < 0) SYSERR("sem_post");
		kill(0, SIGUSR2);
	}
	else {
		if(sem_post(&(csP->shP->counterSem)) < 0) SYSERR("sem_post");
		pause();
	}
   int exitRc = EXIT_SUCCESS;
   if(kicker && !data.dataOk()) {
   	SOFTERR("input and output differ");
   	exitRc = EXIT_FAILURE;
   }
   LOG(2, "ended");
   exit(exitRc);
}
void NodeC::mainLoop() {
   fd_set rs;
   int nfds;
   struct timeval t = {1, 0};
   nfds = 0; FD_ZERO(&rs);
   if(*(forwP)) { FD_SET(ssc, &rs); if(ssc >= nfds) nfds = ssc + 1; }
   while(nfds) {
   	t.tv_sec = csP->selTO;
		int rc;
		rc = select(nfds, &rs, NULL, NULL, &t);
		if(rc < 0 && errno != EINTR) SYSERR("select");
		if(rc > 0) {
			if(FD_ISSET(ssc, &rs)) {
				int i;
				for(i=0; srvSides[i].sc > -1 && i < nodes; i++);						// find unused slot for accept
				if(i == nodes) HARDERR("can't accept, all slots in use");
				LOG(5, "slot for accept=%d", i);
				acc(i);
				forward(i);
			}
			else
				for(int i = 0; i < nodes; i++) {
					if(srvSides[i].sc > -1 && FD_ISSET(srvSides[i].sc, &rs)) forward(i); }
      }
      FD_ZERO(&rs); nfds = 0; t.tv_sec = 1;
      for(int i = 0; i < nodes; i++) {
      	int sc = srvSides[i].sc;
      	if(sc > -1) { FD_SET(sc, &rs); if(sc >= nfds) nfds = sc + 1; }
      }
      if(*(forwP)) { FD_SET(ssc, &rs); if(ssc >= nfds) nfds = ssc + 1; }
   }
}
void NodeC::forward(int sci) {
   int next, scn;
   if(getN(sci)) {
   	LOG(5, "received data from %u", data.remPort());
      if(kicker) {
      	LOG(3, "received from node %u: %s, ttl=%d", data.remPort(), data.digest().c_str(), data.ttl());
      	if(data.dttl() <= 0) {
      		LOG(1, "received after passing all %s: %s", topo==mash ? "mashes" : "rings", data.digest().c_str());
      		closeClients();
      		*(forwP) = 0;
      		LOG(4, "leaving forward closing");
      		return;
      	}
      }
      next = next_node(); scn = next - first;
      LOG(5, "forwarding len=%d to %d --->", data.dataLen, next);
      if(cliSides[scn].sc < 0) conn(scn, next);
		if(*(forwP)) { LOG(5, "pacing..."); nanosleep(&(csP->pace), NULL); }
      putN(scn);
      LOG(5, "forwarded to %u", next);
   }
   else {
      closeClients();
      closeSocket(sci, server);
   }
   return;
}
void NodeC::bindN() {
   LOG(4, "binding...");
   struct addrinfo *sa = (struct addrinfo*)malloc(sizeof(struct addrinfo));
   memset(sa, 0, sizeof(struct addrinfo));
   sa->ai_family = AF_INET;
   sa->ai_socktype = SOCK_STREAM;
   sa->ai_protocol = 0;
   sa->ai_flags = AI_PASSIVE;
   char s[64];
   sprintf(s, "%d", locPort);
   int e;
   if((e = getaddrinfo(NULL, s, sa, &sa)) != 0) HARDERR(gai_strerror(e));
   GAI(4, sa);
   if((ssc = socket(sa->ai_family, sa->ai_socktype, sa->ai_protocol)) < 0) SYSERR("socket alloc");
   int opt = 1;
   if(setsockopt(ssc, SOL_SOCKET, SO_REUSEADDR, &opt, sizeof(opt)) < 0) SYSERR("set socket options");
   if(bind(ssc, sa->ai_addr, sa->ai_addrlen) < 0) SYSERR("bind");
   if(listen(ssc, 1) < 0) SYSERR("listen");
   LOG(2, "bound to %d", locPort);
}
void NodeC::conn(int i, int remPort) {
   DebugP deP = new DebugC();
   DEBID("%s to %u", this->deP->debid, remPort);
   cliSides[i].remPort = remPort;
   int e;
   LOG(4, "connecting to %u...", remPort);
   int retry = csP->connThreshold;
   struct addrinfo *ai = (struct addrinfo*)malloc(sizeof(struct addrinfo));
   memset(ai, 0, sizeof(struct addrinfo));
   ai->ai_family = AF_INET;
   ai->ai_socktype = SOCK_STREAM;
   ai->ai_protocol = 0;
   ai->ai_flags = 0;
   char port[6];
   sprintf(port, "%d", remPort);
   if((e = getaddrinfo("localhost", port, ai, &ai)) != 0) HARDERR(gai_strerror(e));
   GAI(3, ai);
   if((cliSides[i].sc = socket(ai->ai_family, ai->ai_socktype, ai->ai_protocol)) < 0) SYSERR("socket alloc");
   while(retry--) {
      if(connect(cliSides[i].sc, ai->ai_addr, ai->ai_addrlen) < 0) {
      	if(errno != ECONNREFUSED) SYSERR("connect");
      	usleep(csP->connTO); }
      else break; }
   if(retry < 1) {
      LOG(0, "connection refused threshold %d reached", csP->connThreshold);
      exit(EXIT_FAILURE); }
   if(sem_wait(&(csP->shP->counterSem)) < 0) SYSERR("sem_wait");
   csP->shP->conns++;
   if(sem_post(&(csP->shP->counterSem)) < 0) SYSERR("sem_post");
   socklen_t l = sizeof(struct sockaddr);
   struct sockaddr *sa = (sockaddr*)malloc(l);
   if(getpeername(cliSides[i].sc, sa, &l) < 0) SYSERR("getpeername");
   LOG(4, "peer: %s on sc=%d", gpa(sa), cliSides[i].sc); free(sa);
   if(ssl) {
      ERR_clear_error();
      if(!(cliSides[i].sslP = SSL_new(ctxP))) SSLERR("new SSL");
      if(!SSL_set_fd(cliSides[i].sslP, cliSides[i].sc)) SSLERR("client SSL set fd");
      if((e = SSL_connect(cliSides[i].sslP)) < 1) {
      	switch(SSL_get_error(cliSides[i].sslP, e)) {
      	case SSL_ERROR_SYSCALL:
      		ssl_err((char*)"SSL connect", deP);
      		if(e == 0) LOG(0, "SSL connect: EOF on socket");
      		else LOG(0, "SSL connect: %s (%d)", strerror(errno), errno);
      		abend(deP);
      		break;
			default:
				SSLERR("SSL connect");
				break;
      	}
      }
   }
   LOG(2, "connected via sc=%d after %d retries", cliSides[i].sc, csP->connThreshold - (retry + 1));
}
void NodeC::acc(int i) {
   LOG(4, "accepting...");
   if((srvSides[i].sc = accept(ssc, NULL, NULL)) < 0) SYSERR("accept");
   socklen_t l = sizeof(struct sockaddr);
   struct sockaddr *sa = (sockaddr*)malloc(l);
   if(getpeername(srvSides[i].sc, sa, &l) < 0) SYSERR("getpeername");
   LOG(4, "peer: %s on sc=%d", gpa(sa), srvSides[i].sc); free(sa);
   if(ssl) {
      int e;
      ERR_clear_error();
      if(!(srvSides[i].sslP = SSL_new(ctxP))) SSLERR("new SSL");
      if(!SSL_set_fd(srvSides[i].sslP, srvSides[i].sc)) SSLERR("server SSL set fd");
      if((e = SSL_accept(srvSides[i].sslP)) < 1) {
      	switch(SSL_get_error(srvSides[i].sslP, e)) {
      	case SSL_ERROR_SYSCALL:	SYSERR("SSL accept"); break;
      	default: 					SSLERR("SSL accept"); break;
      	}
      }
   }
   LOG(2, "accepted");
}
void NodeC::closeSocket(int i, nodeside side) {
   SocketP sc;
   if(side) sc = srvSides; else sc = cliSides;
   LOG(5, "closing sc=%d...", sc[i].sc);
   if(ssl) {
   	int e;
   	if((e = SSL_shutdown(sc[i].sslP)) < 0) SYSERR("SSL shutdown (1)");
   	if(!e) {
   		LOG(5, "SSL shutdown rc=0");
   		if((e = SSL_shutdown(sc[i].sslP)) < 0) {
   			switch(SSL_get_error(sc[i].sslP, e)) {
   			case SSL_ERROR_SYSCALL: {
   				long e;
   				if(!(e = ERR_get_error()) && errno) SYSERR("SSL shutdown (2)");
   				break;
   			}
   			default:
   				SSLERR("SSL shutdown (2)");
   				break;
   			}
   		}
   	}
   }
   close(sc[i].sc);
   LOG(4, "closed sc=%d", sc[i].sc);
   sc[i].sc = -1;
}
void closeCliTh(void *p) {
   NodeP nP = (NodeP)p;
   char *callerid = nP->deP->debid;
   DebugP deP = new DebugC();
   DEBID("%s CLOSE clients thread", callerid);
   LOG(5, "start...");
   for (int i = 0; i < nP->nodes; i++) if(nP->cliSides[i].sc > -1) nP->closeSocket(i, client);
   LOG(4, "all clients closed");
}
void NodeC::closeClients() {
   if(!closing) try { closingThread = thread(closeCliTh, this); } catch(exception e) {
   		cout << "closing tread: " << e.what() << '\n'; }
   closing = 1;
}
int NodeC::readN(int i) {
   LOG(5, "to read len=%d from sc=%d...", data.dataLen, srvSides[i].sc);
   int n, rest = data.dataLen;
   char *buf = (char*)data.contP;
   while(rest > 0) {
   	if(ssl) { if((n = SSL_read(srvSides[i].sslP, buf, rest)) < 0) SSLERR("read socket"); }
   	else { if((n = read(srvSides[i].sc, buf, rest)) < 0) SYSERR("read socket"); }
   	if(n == 0) {
   		LOG(4, "read EOF");
   		return 0;
   	}
   	else {
   		buf += n; rest -= n;
   		if(rest > 0) LOG(5, "partly read %d bytes, buf=%p", n, buf);
   	}
   }
	if(sem_wait(&(csP->shP->counterSem)) < 0) SYSERR("sem_wait");
	csP->shP->msgs++;
	if(sem_post(&(csP->shP->counterSem)) < 0) SYSERR("sem_post");
	LOG(5, "read %d from %u", data.dataLen, data.remPort());
	return (data.dataLen);
}
int NodeC::writeN(int i) {
   LOG(5, "to write len=%d to sc=%d...", data.dataLen, cliSides[i].sc);
   int n, rest = data.dataLen;
   char *buf = (char*)data.contP;
   while(rest > 0) {
		if(ssl) { if((n = SSL_write(cliSides[i].sslP, data.contP, data.dataLen)) < 0) SSLERR("socket write"); }
		else { if((n = write(cliSides[i].sc, data.contP, data.dataLen)) < 0) SYSERR("socket write"); }
		buf += n; rest -= n;
		if(rest > 0) LOG(5, "partly written %d bytes", n);
	}
   LOG(5, "written %d", data.dataLen);
   return data.dataLen;
}
int NodeC::getN(int i) { return readN(i) > 0; }
int NodeC::putN(int i) {
	data.remPort(locPort);
	return writeN(i) > 0; }
int NodeC::next_node() {
   int next;
   if(topo == ring) {
      next = locPort + 1;
      if(next > last) next = first;
   }
   else while((next = first + nodes * ((float)random() / RAND_MAX)) == locPort);
   return next;
}
ConstellationC::ConstellationC() {
   deP = NULL;
   forwP = NULL;
   topo = ring;
   ssl = first = nodes = 0;
};
ConstellationC::ConstellationC(topology topo, int ssl) {
   deP = new DebugC();
   DEBID("%sSSL %s", ssl ? "" : "non", topo==mash ? "MASH" : "RING");
   this->topo = topo;
   if(topo == ring) { first=csP->rp0; nodes=csP->rn; }
   if(topo == mash) { first=csP->mp0; nodes=csP->mn; }
   this->ssl = ssl;
   first += ssl*500;
   forwP = NULL;
}
int ConstellationC::run() {
	int stat = 0, pid = 0, exitRc = EXIT_SUCCESS;
   if(nodes == 0) exit(0);
   if(nodes == 1) { LOG(0, "1 node configuration not implemented"); exit(0); }
	pid_t *pids = new pid_t[nodes];
   LOG(1, "%d nodes starting...", nodes);
   if((forwP = (int*)mmap(NULL, sizeof(int), PROT_READ|PROT_WRITE, MAP_SHARED|MAP_ANONYMOUS, -1, 0)) < 0) SYSERR("mmap");
   *forwP = 1;
   for(int port = first; port < first + nodes; port++) {
      if(!(pid = fork())) (new NodeC(this, port))->run();
      else { pids[port-first] = pid; LOG(4, "node %u established in process %u", port, pid); }
   }
   LOG(2, "all nodes established");
   while((pid = wait(&stat)) > 0)
     if(WIFEXITED(stat)) {
   	  LOG(4, "node process %u ended with exit(%d)", pid, WEXITSTATUS(stat));
   	  if(WEXITSTATUS(stat)) exitRc = EXIT_FAILURE;
     }
     else exitRc = EXIT_FAILURE;
   LOG(1, "ENDED %s", exitRc == EXIT_SUCCESS ? "OK" : "with ERROR");
   exit(exitRc);
}
CSS::CSS(DebugP deP, char *prgnP) {
   ShareA(shP);
   shP->msgs = 0;
   shP->conns = 0;
   if(sem_init(&shP->counterSem, 1, 1) < 0) SYSERR("sem_init");
   text = "bla bla";
   ttl = 3;
   rp0 = 11000;
   mp0 = 12000;
   rn = 0;
   mn = 0;
   issl = 0;
   const string sslPathSuffP = "../CS";
   caPath = "/home/local/etc/ssl/certs/";
   connThreshold = 77;			// connection retries threshold
   connTO = 0.01 * 1000*1000;	// connection sleep time in usecs
   selTO = 1;						// selection timeout in secs

   if(getArg("DEB") >= 0) DebugC::debug = getArg("DEB");
   if(getenv("T") != NULL) { text = getenv("T"); }
   if(getenv("CEP") != NULL) cePath = getenv("CEP");
   else { cePath = dirname(prgnP); cePath += "/"; cePath += sslPathSuffP; }
   if(getenv("CAP") != NULL)  caPath = getenv("CAP");
   if(getArg("TTL") > 0) ttl = getArg("TTL");
   if(getArg("RP0") > 0) rp0 = getArg("RP0");
   if(getArg("MP0") > 0) mp0 = getArg("MP0");
   if(getArg("N") >= 0) { mn = getArg("N"); rn = mn; }
   if(getArg("SSL") >= 0) issl = getArg("SSL");
   if(getArg("RN") >= 0) rn = getArg("RN");
   if(getArg("MN") >= 0) mn = getArg("MN");
	shP->act = rn + mn;		// initialize active node processes counter
	if(issl > 1) shP->act += shP->act;
	pacing = 0;
   if(getenv("P") != NULL) {
	  	double d = atof(getenv("P"));
	  	pace.tv_sec=(time_t)trunc(d);
	  	pace.tv_nsec=(d-pace.tv_sec)*1000*1000*1000;
	  	if(pace.tv_sec > 0 || pace.tv_nsec > 0) pacing = 1;
   }
   if(getArg("RS") >= 0) srandom(getArg("RS"));
}
int main(int argc, char *argv[]) {
   DebugC::debug_init(argv[0]);
   DebugP deP = new DebugC();
   DEBID("client/server demo");
   csP = new CSS(deP, argv[0]);
   LOG(1, "pgm=%s, ttl=%u, pace=%lu.%03lu, seed=%u, SSL=%u, debug=%d",\
   			argv[0], csP->ttl, csP->pace.tv_sec, csP->pace.tv_nsec/(1000*1000), getArg("RS"), csP->issl, DebugC::debug);
   if(csP->issl > 0) LOG(3, "certs path=%s, CA certs path=%s", csP->cePath.c_str(), csP->caPath.c_str());
   if(csP->issl < 2) {
      if(!fork()) (new ConstellationC(ring, csP->issl))->run();
      if(!fork()) (new ConstellationC(mash, csP->issl))->run();
   } else for(int  ssl = 0; ssl < csP->issl; ssl++) {
      if(!fork()) (new ConstellationC(ring, ssl))->run();
      if(!fork()) (new ConstellationC(mash, ssl))->run();
   }
   int stat, exitRc = EXIT_SUCCESS;
   while(wait(&stat) > 0)
   	if(WIFEXITED(stat)) {
   		LOG(5, "constellation ended with exit(%d)", WEXITSTATUS(stat));
   		if(WEXITSTATUS(stat)) exitRc = EXIT_FAILURE;
   	}
      else exitRc = EXIT_FAILURE;
   LOG(1, "%s end, forwards=%d, connections=%d", exitRc == EXIT_SUCCESS ? "NORMAL" : "BAD", csP->shP->msgs, csP->shP->conns);
   exit(exitRc);
}