Fix bug for segfault

Author: raditya1710

src/receiver.cpp

@@ -52,7 +52,7 @@ void createSocket(char* addr, char* port);
 
 /* Functions declaration */
 static Byte* q_get(QTYPE *);
-static int rcvframe(int sockfd, QTYPE *q);
+static int rcvframe(QTYPE *q);
 pair<int, string> convbuf(char* c);
 string convRESPtostr(int res, int msgno);
 
@@ -63,7 +63,7 @@ socklen_t addrlen = sizeof(serv_addr), clilen = sizeof(cli_addr);
 void *childProcess(void *threadid);
 void sendACK(int framenum);
 void sendNAK(int framenum);
-
+void initRXQ(QTYPE*);
 // SERVER PROGRAM
 int main(int argc, char *argv[]){
 // create socket
@@ -72,7 +72,7 @@ int main(int argc, char *argv[]){
 /* Initialize XON/XOFF flags */
 send_xon = true;
 send_xoff = false;
-
+initRXQ(rxq);
 /* Create child process */
 pthread_t child_thread;
 int rc = pthread_create(&child_thread, NULL, childProcess, (void *)0);
@@ -83,23 +83,22 @@ int main(int argc, char *argv[]){
 
 /*** IF PARENT PROCESS ***/
 while(true){
-printf("parent thread\n");
-int ret = rcvframe(sockfd, rxq);
-printf("selesai parent\n");
+int ret = rcvframe(rxq);
 }
 
 pthread_join(child_thread, NULL);
 pthread_exit(NULL);
 return 0;
 }
-
 /* function for reading character and put it to the receive buffer*/
 
 /* q_get returns a pointer to the buffer where data is read
  * or NULL if buffer is empty
  */
 static Byte* q_get(QTYPE *q){
 Byte* current;
+puts("MASUK QGET");
+printf("%d\n", q->count);
 /* Nothing in the queue */
 if(!q->count) return (NULL);
 if(q->data[q->front] == 0xFF) return (NULL);
@@ -127,21 +126,16 @@ static Byte* q_get(QTYPE *q){
 return current;
 }
 
-static int rcvframe(int sockfd, QTYPE *q){
+static int rcvframe(QTYPE *q){
 memset(recvbuf, 0, sizeof recvbuf);
-printf("masuk recvframe\n");
 int byte_recv = recvfrom(sockfd, recvbuf, sizeof(recvbuf), 0, (struct sockaddr*)&cli_addr, &clilen);
-// printf("%d\n", byte_recv);
 if(byte_recv < 0){ //error receiving character
 printf("Error receiving: %d", byte_recv);
+return -1;
 }
-for(int i = 0; recvbuf[i] != ETX; ++i){
-printf("%d ", recvbuf[i]);
-}
-puts("");
 pair<int,string> M = convbuf(recvbuf);
 printf("M.first dari convbuf(recvbuf): %d\n", M.first);
-if(M.se != ""){ // dia ga error
+if(M.se != "" && M.fi != -1 && q->data[M.fi] == 0xFF){ // dia ga error
 printf("Menerima frame ke-%d: %s\n", M.fi, M.se.c_str());
 // receive buffer above minimum upperlimit
 // sending XOFF
@@ -151,16 +145,19 @@ static int rcvframe(int sockfd, QTYPE *q){
 if(M.fi <= q->rear){
 if(M.fi >= q->front){
 strncpy((char*)msg[M.fi], M.se.c_str(), M.se.length());
+q->data[M.fi] = M.fi;
 }
 else if(q->front > q->rear){
 strncpy((char*)msg[M.fi], M.se.c_str(), M.se.length());
+q->data[M.fi] = M.fi;
 }
 else{
 //bagi dua lagi, apakah ada didalem batas apa nggak, ini ditulis soalnya bisa aja dia sebenernya lanjutannya tapi udah muter
 if((M.fi + 1) + RXQSIZE - q->front < WINDOWSIZE){
 q->count = M.fi + 1 + RXQSIZE - q->front;
 q->rear = M.fi;
 strncpy((char*)msg[q->rear], M.se.c_str(), M.se.length());
+q->data[M.fi] = M.fi;
 lastrecv = q->rear;
 }
 else {
@@ -175,6 +172,7 @@ static int rcvframe(int sockfd, QTYPE *q){
 q->count = M.fi + 1 + RXQSIZE - q->front;
 q->rear = M.fi;
 strncpy((char*)msg[q->rear], M.se.c_str(), M.se.length());
+q->data[M.fi] = M.fi;
 lastrecv = q->rear;
 }
 }
@@ -184,6 +182,7 @@ static int rcvframe(int sockfd, QTYPE *q){
 q->count = M.fi - q->front + 1;
 q->rear = M.fi;
 strncpy((char*)msg[q->rear], M.se.c_str(), M.se.length());
+q->data[M.fi] = M.fi;
 lastrecv = q->rear;
 }
 }
@@ -199,9 +198,7 @@ static int rcvframe(int sockfd, QTYPE *q){
 }
 }
 else{
-printf("di recvframe\n");
 sendNAK(q->front);
-printf("di recvframe\n");
 }
 return M.fi;
 }
@@ -249,15 +246,11 @@ pair<int, string> convbuf(char* buf){
 }
 unsigned char t[MAXLEN << 1]; //for checksum
 memset(t,0,sizeof t);
-printf("HAHAHAHA");
 for(int i = 0;i < checkstr.length(); ++i){
 t[i] = (Byte)checkstr[i];
-printf(" %d", t[i]);
 }
-puts("");
+
 unsigned int checksum = crc32a(t);
-//////////debug checksum. status : belum lewat///////////////////////
-printf("%u %u\n", checksum, check);
 if(checksum != check) return make_pair(-1, "");
 return res;
 }
@@ -266,16 +259,17 @@ string convRESPtostr(int res, int msgno){
 RESP R;
 R.res = res;
 R.msgno = msgno;
-unsigned char* uc = new unsigned char[3];
+unsigned char uc[3];
+memset(uc, 0, sizeof uc);
 uc[0] = R.res;
 uc[1] = R.msgno;
 R.checksum = crc32a(uc);
-memset(sendbuf, 0, sizeof sendbuf);
 string s = "";
 s += (char)R.res;
 s += (char)R.msgno;
 s += to_string(R.checksum);
-strncpy(sendbuf, s.c_str(), s.length());
+return s;
+
 }
 
 void *childProcess(void *threadid){
@@ -287,35 +281,28 @@ void *childProcess(void *threadid){
 
 if(now != NULL){
 printf("Mengkonsumsi byte ke-%d.\n", *now);
-printf("numframe : %d\n", *now);
 sendACK(*now);
-printf("ack sent!\n");
-sleep(2);
 // usleep(DELAY * 10000000);
 *now = 0xFF;
 }
 else{
 // printf("ANAK PIPIN :3\n");
 if(rxq->count != 0){
-printf("di child\n");
 sendNAK(rxq->front);
-printf("before usleep\n");
-sleep(2);
 }
 }
+sleep(1);
 }
 pthread_exit(NULL);
 }
 
 void sendACK(int framenum){
 string s = convRESPtostr(ACK, framenum);
 memset(sendbuf, 0, sizeof sendbuf);
-cout << s << endl;
+puts(s.c_str());
 for(int i = 0;i < s.length(); ++i){
-printf("done resp conv : %d\n", s[i]);
 sendbuf[i] = s[i];
 }
-printf("SEND ACK!\n");
 //kayaknya ini masih ngebug
 int send_ack = sendto(sockfd, sendbuf, sizeof(sendbuf), 0, (struct sockaddr*)&cli_addr, clilen);
 if(send_ack < 0){//error sending ACK character
@@ -329,11 +316,13 @@ void sendNAK(int framenum){
 for(int i = 0;i < s.length(); ++i){
 sendbuf[i] = s[i];
 }
-printf("SEND NAK!\n");
 int send_ack = sendto(sockfd, sendbuf, sizeof(sendbuf), 0, (struct sockaddr*)&cli_addr, clilen);
-printf("done send nak\n");
 if(send_ack < 0){//error sending ACK character
 printf("Error send NAK: %d", send_ack);
 }
-printf("out sendNAk\n");
+}
+void initRXQ(QTYPE *q){
+for(int i = 0;i < RXQSIZE; ++i){
+q->data[i] = 0xFF;
+}
 }

src/transmitter.cpp

@@ -20,7 +20,7 @@ using namespace std;
 //build a socket
 struct sockaddr_in serv_addr, cli_addr;
 socklen_t serv_len = sizeof(serv_addr), cli_len = sizeof(cli_addr);
-char receiverAddress[MAXLEN];
+char receiverAddress[MAXLEN + 40];
 int sockfd;
 int NAKnum = -1;
 
@@ -35,7 +35,7 @@ bool done = false;
 
 //sliding window protocol
 char cc[RXQSIZE][MAXLEN + 10]; //size of buffer in chunks
-Byte lastacked = RXQSIZE - 1, lastsent = -1, countBuf = 0;
+char lastacked = -1, lastsent = -1, countBuf = 0;
 
 bool corruptACK(char* s);
 void createSocket(char* addr, char* port);
@@ -54,7 +54,6 @@ int main(int argc, char *argv[]){
 }
 createSocket(argv[1], argv[2]);
 initMESGB();
-printf("\nmesg.stx : %d ----\n", mesg.stx);
 initTimeOut();
 
 /* Create child process for receiving data*/
@@ -77,15 +76,8 @@ int main(int argc, char *argv[]){
 lastsent = (lastsent + 1) % RXQSIZE;
 countBuf = (lastsent - lastacked);
 countBuf %= RXQSIZE;
-
-//set dataformat to mesg
-printf("\nmesg.soh : %d ----\n", mesg.soh);
-printf("\nmesg.stx : %d ----\n", mesg.stx);
-printf("\nmesg.etx : %d ----\n", mesg.etx);
 mesg.msgno = idx % RXQSIZE;
-printf("\nmesg.msgno : %d ----\n", mesg.msgno);
 mesg.data = cc[idx % RXQSIZE];
-printf("\nmesg.data : %s ----\n", mesg.data);
 string s = convMESGBtostr(mesg);
 
 memset(c_sendto, 0, sizeof c_sendto);
@@ -96,11 +88,11 @@ int main(int argc, char *argv[]){
 printf("Mengirim frame ke-%d: \'%s\' \n", idx, cc[lastsent]);
 idx++;
 sendto(sockfd, c_sendto, sizeof(c_sendto), 0, (struct sockaddr*)&serv_addr, serv_len);
-usleep(5000);
+usleep(500000);
 }
 else if(xoff && NAKnum == -1){ // XOFF sent, receive buffer is above minimum upperlimit
 printf("Menunggu XON...\n");
-usleep(20000);
+usleep(50000);
 }
 else{ //NAKnum != -1
 mesg.msgno = NAKnum;
@@ -114,7 +106,7 @@ int main(int argc, char *argv[]){
 
 // printf("Mengirim NAK ke-%d: \'%s\' \n", NAKnum, cc[NAKnum]);
 sendto(sockfd, c_sendto, sizeof(c_sendto), 0, (struct sockaddr*)&serv_addr, serv_len);
-usleep(5000);
+usleep(50000);
 NAKnum = -1;
 }
 }
@@ -129,7 +121,8 @@ bool corruptACK(char* s){
 string ss = "";
 unsigned int checksum = 0;
 unsigned int real_c = 0;
-while(s[i] != 0){
+
+while(s[i] != 0 || i < 2){
 if(i == 0){
 if(s[i] != ACK && s[i] != NAK){
 return true;
@@ -141,7 +134,7 @@ bool corruptACK(char* s){
 else if(i == 1){
 ss += s[i];
 unsigned char ta[MAXLEN + 40];
-memset(ta,0,sizeof ta);
+memset(ta, 0, sizeof ta);
 for(int j = 0; j < ss.length(); ++j){
 ta[j] = ss[j];
 }
@@ -173,8 +166,8 @@ void initMESGB(){
 }
 void initTimeOut(){
 struct timeval tv;
-tv.tv_sec = 0;
-tv.tv_usec = 200000;
+tv.tv_sec = 3;
+tv.tv_usec = 000000;
 if (setsockopt(sockfd, SOL_SOCKET, SO_RCVTIMEO,&tv,sizeof(tv)) < 0) {
 perror("Error");
 }
@@ -188,6 +181,7 @@ void *childProcess(void *threadid){
 if(rc < 0){
 printf("Timeout!\n");
 NAKnum = (lastacked + 1) % RXQSIZE;
+printf("NAK Timeout %d\n", NAKnum);
 }
 if(c_recvfrom[0] == XON){
 printf("XON diterima.\n");
@@ -225,10 +219,12 @@ string convMESGBtostr(MESGB m){
 ret += m.stx;
 ret += m.data;
 ret += m.etx;
-unsigned char t[MAXLEN << 1]; //for checksum
-strcpy( (char*) t, ret.c_str());
+unsigned char t[MAXLEN + 40]; //for checksum
+memset(t,0,sizeof t);
+for(int i = 0;i < ret.length(); ++i){
+t[i] = ret[i];
+}
 m.checksum = crc32a(t);
 ret += to_string(m.checksum);
-printf("Checksum: %u\n", m.checksum);
 return ret;
 }