ssize_t dg_send_recv(int fd, const void *outbuff, size_t outbytes,
void *inbuff, size_t inbytes,
const SA *destaddr, socklen_t destlen)
{
ssize_t n;
struct iovec iovsend[2], iovrecv[2];
if (rttinit == 0) {
rtt_init(&rttinfo); /* first time we're called */
rttinit = 1;
rtt_d_flags = 1;
}
sendhdr.seq++;
msgsend.msg_name = destaddr;
msgsend.msg_namelen = destlen;
msgsend.msg_iov = iovsend;
msgsend.msg_iovlen = 2;
iovsend[0].iov_base = &sendhdr;
iovsend[0].iov_len = sizeof(struct hdr);
iovsend[1].iov_base = outbuff;
iovsend[1].iov_len = outbytes;
msgrecv.msg_name = NULL;
msgrecv.msg_namelen = 0;
msgrecv.msg_iov = iovrecv;
msgrecv.msg_iovlen = 2;
iovrecv[0].iov_base = &recvhdr;
iovrecv[0].iov_len = sizeof(struct hdr);
iovrecv[1].iov_base = inbuff;
iovrecv[1].iov_len = inbytes;
Signal(SIGALRM, sig_alrm);
rtt_newpack(&rttinfo); /* initialize for this packet */
sendagain:
sendhdr.ts = rtt_ts(&rttinfo);
Sendmsg(fd, &msgsend, 0);
alarm(rtt_start(&rttinfo)); /* calc timeout value & start timer */
if (sigsetjmp(jmpbuf, 1) != 0) {
if (rtt_timeout(&rttinfo) < 0) {
err_msg("dg_send_recv: no response from server, giving up");
rtt_init = 0; /* reinit in case we're called again */
errno = ETIMEDOUT;
return -1;
}
goto sendagain;
}
do {
n = Recvmsg(fd, &msgrecv, 0);
} while (n < sizeof(struct hdr) || recvhdr.seq != sendhdr.seq);
alarm(0); /* stop SIGALRM timer. */
/* calculate & store new RTT estimator value. */
rtt_stop(&rttinfo, rtt_ts(&rttinfo) - recvhdr.ts);
return (n - sizeof(struct hdr)); /* return size of received datagram. */
}
struct hdr cli_recv(int fd, void *inbuff, size_t inbytes)
{
ssize_t n;
struct iovec iovrecv[2];
struct rtt_info rttinfo;
msgrecv.msg_name = NULL;
msgrecv.msg_namelen = 0;
msgrecv.msg_iov = iovrecv;
msgrecv.msg_iovlen = 2;
iovrecv[0].iov_base = &recvhdr;
iovrecv[0].iov_len = sizeof(struct hdr);
iovrecv[1].iov_base = inbuff;
iovrecv[1].iov_len = inbytes;
rttinfo.rtt_rto = CLI_TIMEOUT; //8 sec time out
if (rttinit == 0) {
rtt_init(&rttinfo); /* first time we're called */
rttinit = 1;
rtt_d_flag = 1;
}
Signal(SIGALRM, sig_alrm);
rtt_newpack(&rttinfo); /* initialize for this packet */
alarm(rtt_start(&rttinfo)/1000); /* calc timeout value & start timer */
//#ifdef RTT_DEBUG
rtt_debug(&rttinfo);
//#endif
if (sigsetjmp(jmpbuf, 1) != 0) {
err_msg("cli_recv: no response from server, giving up");
rttinit = 0; /* reinit in case we're called again */
errno = ETIMEDOUT;
err_sys("[ERROR]: Timeout");
return recvhdr;
}
n = Recvmsg(fd, &msgrecv, 0);
if (n < sizeof(struct hdr)){
err_sys("[ERROR]: Received packet incomplete");
}
printf("Length: %d\n", (int)n);
//printf("BUFFER: %s\n", (char *)iovrecv[1].iov_base);
printf("SEQ NUM: %u\n", recvhdr.seq);
printf("IS FIN: %u\n", recvhdr.fin);
alarm(0); /* stop SIGALRM timer */
return(recvhdr); /* return size of received datagram */
}
ssize_t
dg_send_recv(int fd, const void *outbuff, size_t outbytes,
void *inbuff, size_t inbytes,
const SA *destaddr, socklen_t destlen)
{
ssize_t n;
struct iovec iovsend[2], iovrecv[2];
if (rttinit == 0) {
rtt_init(&rttinfo); /* first time we're called */
rttinit = 1;
rtt_d_flag = 1;
}
sendhdr.seq++;
msgsend.msg_name = destaddr;
msgsend.msg_namelen = destlen;
msgsend.msg_iov = iovsend;
msgsend.msg_iovlen = 2;
iovsend[0].iov_base = &sendhdr;
iovsend[0].iov_len = sizeof(struct hdr);
iovsend[1].iov_base = outbuff;
iovsend[1].iov_len = outbytes;
msgrecv.msg_name = NULL;
msgrecv.msg_namelen = 0;
msgrecv.msg_iov = iovrecv;
msgrecv.msg_iovlen = 2;
iovrecv[0].iov_base = &recvhdr;
iovrecv[0].iov_len = sizeof(struct hdr);
iovrecv[1].iov_base = inbuff;
iovrecv[1].iov_len = inbytes;
/* end dgsendrecv1 */
/* include dgsendrecv2 */
if (signal(SIGALRM, sig_alrm) == SIG_ERR) {
perror("signal error");
exit(1);
}
rtt_newpack(&rttinfo); /* initialize for this packet */
sendagain:
#ifdef RTT_DEBUG
fprintf(stderr, "send %4d: ", sendhdr.seq);
#endif
sendhdr.ts = rtt_ts(&rttinfo);
int nbytes = 0; /* must first figure out what return value should be */
int i;
for (i = 0; i < msgsend.msg_iovlen; i++)
nbytes += msgsend.msg_iov[i].iov_len;
if (sendmsg(fd, &msgsend, 0) != nbytes) {
perror("sendmsg error");
exit(1);
}
alarm(rtt_start(&rttinfo)); /* calc timeout value & start timer */
#ifdef RTT_DEBUG
rtt_debug(&rttinfo);
#endif
if (sigsetjmp(jmpbuf, 1) != 0) {
if (rtt_timeout(&rttinfo) < 0) {
fprintf(stderr, "dg_send_recv: no response from server, giving up\n");
rttinit = 0; /* reinit in case we're called again */
errno = ETIMEDOUT;
return(-1);
}
#ifdef RTT_DEBUG
fprintf(stderr, "dg_send_recv: timeout, retransmitting\n");
#endif
goto sendagain;
}
do {
if ((n = recvmsg(fd, &msgrecv, 0)) < 0) {
perror("recvmsg error");
exit(1);
}
#ifdef RTT_DEBUG
fprintf(stderr, "recv %4d\n", recvhdr.seq);
#endif
} while (n < sizeof(struct hdr) || recvhdr.seq != sendhdr.seq);
alarm(0); /* stop SIGALRM timer */
/* 4calculate & store new RTT estimator values */
rtt_stop(&rttinfo, rtt_ts(&rttinfo) - recvhdr.ts);
return(n - sizeof(struct hdr)); /* return size of received datagram */
}
/* This routine does the first phase of the client-server Setup.
* On successfule return, the out parameter sockfd will have the
* connection socket fd.
* */
int connection_setup(int *sockfd, ifi_t *ifi_array[], int num_ifi,
circ_buffer_t *rcv_buf, client_config_t *config)
{
packet_t *send_pkt;
int n, optval=1;
char in_packet[PACKET_LEN],client_ip[IP_MAX];
struct sockaddr_in serv_addr, cliaddr, tempaddr;
unsigned int ack_seq;
unsigned short curr_win;
bool is_error = FALSE;
packet_info_t *rcv_pkt_info, *send_pkt_info = calloc(1, sizeof(packet_info_t));
*sockfd = Socket(AF_INET, SOCK_DGRAM, 0);
if(server_on_same_subnet(config->server_ip,ifi_array, num_ifi, client_ip))
{
printf("server on same subnet, SO_DONTROUTE set\n");
//printf("client ip set to: %s\n",client_ip);
setsockopt(*sockfd,SOL_SOCKET, SO_DONTROUTE, &optval, sizeof(optval));
}
//update cli_ip after if it's on the same host or n/w
bzero(&cliaddr, sizeof(cliaddr));
cliaddr.sin_family = AF_INET;
cliaddr.sin_port = 0;
inet_pton(AF_INET,client_ip,&cliaddr.sin_addr);
Bind(*sockfd, (SA*) &cliaddr, sizeof(cliaddr));
//cli addr and port using getsockname
int cli_port;
char cli_ip[IP_MAX];
socklen_t len = sizeof(tempaddr);
bzero(&tempaddr, sizeof(tempaddr));
getsockname(*sockfd, (SA*) &tempaddr, &len);
Inet_ntop(AF_INET, &tempaddr.sin_addr, cli_ip, IP_MAX);
printf("[Info]client bound to ip:%s\n",cli_ip);
cli_port = ntohs(tempaddr.sin_port);
//connect
bzero(&serv_addr, sizeof(serv_addr));
serv_addr.sin_family = AF_INET;
serv_addr.sin_port = htons(config->server_port);
Inet_pton(AF_INET, config->server_ip, &serv_addr.sin_addr);
Connect(*sockfd, (SA *)&serv_addr, sizeof(serv_addr));
assert(send_pkt_info);
Signal(SIGALRM, sig_alarm);
rtt_newpack(&rttinfo); /* initialize for this packet */
/* Prepare to send file name */
send_pkt_info->seq = 0;
send_pkt_info->ack = 0;
send_pkt_info->window_size = config->window_size;
SET_FILE_FLAG(send_pkt_info);
send_pkt_info->data = strdup(config->file_name);
send_pkt_info->data_len = strlen(config->file_name) + 1;
printf("[Info] Sending file name %s to server ..\n", send_pkt_info->data);
sendagain:
send_pkt_info->timestamp = rtt_ts(&rttinfo);
send_pkt = build_packet(send_pkt_info);
Write(*sockfd, (char *)send_pkt, send_pkt_info->data_len+HEADER_SIZE);
/* set alarm for RTO seconds using setitimer */
set_alarm(rtt_start(&rttinfo));
if (sigsetjmp(jmpbuf, 1) != 0)
{
if (rtt_timeout(&rttinfo))
{
printf("[Error] Timed out Sending File Name, giving Up\n");
free_pkt_info(send_pkt_info);
free(send_pkt);
errno = ETIMEDOUT;
return -1;
}
printf("[Timeout] Retransmitting file name, next RTO:%d ms\n", rttinfo.rtt_rto);
free(send_pkt);
goto sendagain;
}
/* Now Attempt to read the Port message from the Server */
while (1)
{
if ((n = read(*sockfd, in_packet, PACKET_LEN)) < 0)
{
if (errno == EINTR)
continue;
else
err_sys("[Error] Read Error while waiting for Port number");
}
rcv_pkt_info = get_packet_info(in_packet, n);
if (consume_random_packet(rcv_pkt_info, config->prob_loss, TRUE))
{
free_pkt_info(rcv_pkt_info);
continue;
}
if (IS_ACK(rcv_pkt_info) && (rcv_pkt_info->ack == (send_pkt_info->seq+1)))
{
break;
}
else
{
free_pkt_info(rcv_pkt_info);
continue;
}
}
set_alarm(0); /* Turn off the Alarm */
free_pkt_info(send_pkt_info);
free(send_pkt);
assert(rcv_pkt_info->data_len == sizeof(short));
/* Fetch the new port from the server message */
memcpy(&serv_addr.sin_port, rcv_pkt_info->data, sizeof(short));
printf("[Info] Received new Port number %hu from Server.\n", ntohs(serv_addr.sin_port));
/* Connect to the new port of the server child process */
if (connect(*sockfd, (SA *)&serv_addr, sizeof(serv_addr)) < 0) {
printf("[Error] Connect failure to server child: [%s : %hu]\n", config->server_ip, ntohs(serv_addr.sin_port));
return -1;
}
printf("[Info] Connected to server's child process.\n");
/* Advance the Circular buffer's read/write pointers to rcv_pkt_info->seq+1.
* Basically, we are simulating the producer/consumer behavior here, in that we
* have written and read from the buffer.
* Note: The server has to continue the file transfer starting from rcv_pkt_info->seq+1
* as we will not accept anything lower than this sequence for this session
* This is similar to the SYN+ACK in TCP
*/
rcv_buf->next_read_seq = rcv_buf->next_contig_write_seq = rcv_pkt_info->seq+1;
printf("rcv_buf->next_read_seq = rcv_buf->next_contig_write_seq = %u", rcv_pkt_info->seq+1);
curr_win = window_size(rcv_buf);
ack_seq = NEXT_ACK(rcv_buf);
/* Exit if the file does not exist on the server after sending ACK.
* In the event this ACK is lost, the server ichild timeout mechanism will kick in
* and eventually it will timeout and give up
*/
if(is_error = IS_ERR(rcv_pkt_info))
{
printf("[Info] Received Error message from server [Seq: %u] Responding with [Ack:%u] [Window Size:%hu]\n",
rcv_pkt_info->seq, ack_seq, curr_win);
}
else
{
printf("[Info] Received Port message [Seq: %u] Responding with [Ack:%u] [Window Size:%hu]\n",
rcv_pkt_info->seq, ack_seq, curr_win);
}
/* Simulate Loss On Tx */
if (!consume_random_packet(rcv_pkt_info, config->prob_loss, FALSE))
{
send_ack(*sockfd, curr_win, rcv_pkt_info->seq, ack_seq, rcv_pkt_info->timestamp, config->prob_loss);
}
free_pkt_info(rcv_pkt_info);
if(is_error)
{
printf("[Error] File %s does not exist, terminating..\n", config->file_name);
errno = EBADF;
return -1;
}
printf("[Info] Successful Connection Setup with [%s:%u], ready for file reception\n",
config->server_ip, ntohs(serv_addr.sin_port));
return 0;
}
void mydg_echo( int sockfd, SA *servaddr, socklen_t servlen, SA *cliaddr , socklen_t clilen, char *filename )
{
int n, persist_timer_flag=0;
char mesg[MAXLINE];
socklen_t len, slen, slen1;
int connfd;
struct sockaddr_in ss, ss1;
char IPServer[20], IPClient[20];
FILE *ifp;
ssize_t bytes;
char sendline[MAXLINE], recvline[MAXLINE + 1];
const int on=1;
int onlength;
onlength = sizeof( on );
printf( "\n******************* CHILD SERVER INITIATED *********************\n" );
//printf( "Creating Datagram...\n" );
if( ( connfd = socket( AF_INET, SOCK_DGRAM, 0 ) ) == NULL )
{
printf( "socket error\n" );
exit(1);
}
getsockopt( sockfd, SOL_SOCKET, SO_DONTROUTE, &on, &onlength ) ;
setsockopt( connfd, SOL_SOCKET, SO_DONTROUTE, &on, sizeof( on ) );
printf("Setting connection socket to SO_DONTROUTE..\n", on );
/* Bind to IPServer and EPHEMERAL PORT and return EPHEMERAL PORT */
bind( connfd, (SA *) servaddr, sizeof( struct sockaddr_in ) );
slen = sizeof( ss );
if( getsockname( connfd, (SA *)&ss, &slen ) < 0 )
{
printf( "sockname error\n" );
exit(1);
}
printf("BOUND SOCKET ADDRESSES : %s\n", inet_ntop( AF_INET, &(ss.sin_addr), IPServer, MAXLINE ));
printf( "SERVER PORT: %d\n", ntohl(ss.sin_port) );
/* Connect to IPClient */
if( connect( connfd, cliaddr, clilen ) < 0 )
{
printf( "Error in connecting to server..\n" );
exit(1);
}
slen1 = sizeof( ss1 );
if( getpeername( connfd, (SA *)&ss1, &slen1 ) < 0 )
{
printf( "peername error\n" );
exit(1);
}
inet_ntop( AF_INET, &(ss1.sin_addr), IPClient, MAXLINE );
printf( "DESTINATION ADDRESS : %s\n",IPClient );
printf( "DESTINATION PORT : %d\n", ss1.sin_port);
sprintf( mesg, "%d\n", ss.sin_port );
printf("Sending the Ephemeral port number to client : %s..\n", mesg );
if( sendto( sockfd, mesg, sizeof( mesg ), 0, cliaddr, clilen) < 0 )
{
printf("ERROR IN SENDTO : %d ",errno);
exit(0);
}
printf( "Reading from the newly connected socket..\n" );
n = read( connfd, mesg, MAXLINE );
printf("Received data : %s\n",mesg );
if( n > 0 && strcmp( mesg, "ACK\n" ) == 0 )
{
printf("ACK recieved..\n");
printf("Closing the listening socket on parent..\n");
close( sockfd );
}
printf( "Reading file..\n" );
ifp = fopen( filename, "r" );
swnd1 = malloc( sender_window_size*sizeof(send_buffer) );
int i;
for( i = 0 ; i<sender_window_size; i++)
{
swnd1[i].data[0] = '\0';
}
int buffer_position, send_counter = 0, t, previous_na;
memset( sendline, '\0', sizeof( sendline ) );
printf("Sending file to the client..\n");
int j, sender_usable_window, ack_recieved, closing_child=0 ;
recv_advertisement = INT_MAX;
ssthresh=recv_window_size;
printf("\nSSTHRESH initiated to: %d\n",ssthresh);
while(1)
{
if( cwnd > ( nt - na ) )
sender_usable_window = cwnd - ( nt - na ) ;
else
sender_usable_window = 0 ;
printf("\nCongestion window : \nSender usable window : %d\nReciever window advertisement : %d\n", cwnd, sender_usable_window, recv_advertisement );
if(sender_usable_window==0)
{
printf( "\n*********************BUFFER FULL*************************\n");
}
/* Check for if recv_adv == 0 i.e. no more packets to be sent. */
j = MIN( sender_usable_window , recv_advertisement );
if( (j == 0) || (send_counter == recv_advertisement) )
{
while(1)
{
if( recv_advertisement == 0
&& persist_timer_flag == 0 )
{
persist_timer_flag = 1;
//signal(SIGALRM, sig_alrm);
//rtt_newpack( &rttinfo );
printf("************** PERSIST TIMER **************\n");
printf("Sending Probe packet..\n");
dg_retransmit( connfd, -1 );
}
// previous_na = na;
ack_recieved = dg_recieve_ack( connfd );
if( persist_timer_flag == 1 )
{
if( recv_advertisement > 0)
{
persist_timer_flag = 0;
struct itimerval value, ovalue, pvalue;
value.it_interval.tv_sec = 0; /* Zero seconds */
value.it_interval.tv_usec = 0; /* Two hundred milliseconds */
value.it_value.tv_sec = 0; /* Zero seconds */
value.it_value.tv_usec = 0; /* Five hundred milliseconds */
setitimer( ITIMER_REAL, &value, &ovalue );
//alarm(0);
break;
}
}
if( dup_ack == 3 && persist_timer_flag == 0 )
{
/* DUP ACK's case */
//dup_ack = 0;
ssthresh = MIN( cwnd, recv_advertisement );
ssthresh = ( MAX( ssthresh, 2 ) )/2;
printf("\n****************** 3 DUPLICATE ACK'S REC'VED ******************\n");
printf("Retransmitting the packet %d.. \n", ack_recieved);
printf("Setting ssthresh to half of current window size : '%d'.. \n", ssthresh );
dg_retransmit( connfd, ack_recieved );
}
if( ack_recieved == nt && persist_timer_flag == 0 )
{
/* All Acks have been recieved.. */
printf("All ACK's have been recieved for buffer..\n");
struct itimerval value, ovalue, pvalue;
value.it_interval.tv_sec = 0; /* Zero seconds */
value.it_interval.tv_usec = 0; /* Two hundred milliseconds */
value.it_value.tv_sec = 0; /* Zero seconds */
value.it_value.tv_usec = 0; /* Five hundred milliseconds */
setitimer( ITIMER_REAL, &value, &ovalue );
send_counter = 0;
break;
}
}
if( slowstart == 0 )
{
cwnd += 1;
}
}
else if( fread( sendline, 1, PACKET_SIZE, ifp ) != NULL )
{
printf("********************************* SENDING DATA ************************************\n");
printf("DATA being sent : '%s'\n", sendline );
printf("Size : %d\n", strlen(sendline) );
printf("***********************************************************************************\n");
printf("Starting RTT timer..\n");
if( rttinit == 0 )
{
rtt_init( &rttinfo ); /* first time we're called */
rttinit = 1;
rtt_d_flag = 1;
}
if( send_counter == 0 )
{
struct itimerval value, ovalue, pvalue;
signal(SIGALRM, sig_alrm);
rtt_newpack( &rttinfo ); /* initialize for this packet and sets retransmission counter to 0*/
value=rtt_start(&rttinfo);
setitimer( ITIMER_REAL, &value, &ovalue );
}
buffer_position = dg_send( connfd, sendline, strlen( sendline ) );
if ( sigsetjmp( jmpbuf, 1 ) != 0 )
{
if ( rtt_timeout( &rttinfo ) < 0 && persist_timer_flag == 1 )
{
err_msg( "Error : no response from client, giving up" );
rttinit = 0; /* reinit in case we're called again */
errno = ETIMEDOUT;
return(-1);
}
goto sendagain;
}
send_counter++;
status_report();
printf("Buffer position : %d\n", buffer_position );
memset( sendline, '\0', sizeof( sendline ) );
}
else
{
/* the last packets */
while( na != nt || (closing_child == 1) )
{
ack_recieved = dg_recieve_ack( connfd );
if( dup_ack == 3 )
{
/* DUP ACK's case */
ssthresh = MIN( cwnd, recv_advertisement );
ssthresh = ( MAX( ssthresh, 2 ) )/2;
printf("****************** 3 DUPLICATE ACK'S REC'VED ******************\n");
printf("Retransmitting the packet %d.. \n", ack_recieved);
printf("Setting ssthresh to half of current window size : '%d'.. \n", ssthresh );
dg_retransmit( connfd, ack_recieved );
}
status_report();
}
printf("**************** SERVER CHILD SHUTDOWN PROCEDURE INTITIATED *****************\n");
printf("\nCOMPLETED SENDING ALL PACKETS TO CLIENT..\n");
printf("SENDING A FIN..\n");
dg_retransmit(connfd,-3); //FIN PACKET
dg_recieve_ack( connfd );
dg_retransmit(connfd,-4); //final ACK
closing_child = 1;
printf("\nSHUTTING DOWN CHILD SERVER IN 2MSL seconds (ASSUMED AS 10 SECONDS)..\n");
struct itimerval value, ovalue, pvalue;
value.it_interval.tv_sec = 0; /* Zero seconds */
value.it_interval.tv_usec = 0; /* Two hundred milliseconds */
value.it_value.tv_sec = 10; /* Zero seconds */
value.it_value.tv_usec = 0; /* Five hundred milliseconds */
setitimer( ITIMER_REAL, &value, &ovalue );
}
continue;
sendagain :
if( closing_child == 1 )
{
printf("CLOSING THE CHILD PROCESS ON THE SERVER..\n");
exit(0);
break;
// TERMINATE SAFELY
}
if( recv_advertisement == 0 )
{
dg_retransmit( connfd, -1 );
}
else
{
printf("******************RTT TIMEOUT EXPERIENCED******************..\n");
printf("Retransmitting the packet %d.. )\n", na);
dg_retransmit( connfd, na );
}
ssthresh = MIN( cwnd, recv_advertisement );
ssthresh = ( MAX( ssthresh, 2 ) )/2;
cwnd = 1;
slowstart = 1;
printf("\n\nSetting ssthresh to half of current window size : '%d'.. \n", ssthresh );
}
}
/* RETURNS ACK_NO */
int dg_recieve_ack( int fd )
{
ssize_t n;
struct iovec iovrecv[2];
char IPClient[20];
memset( &msgrecv, '\0', sizeof(msgrecv) );
memset( &recvhdr, '\0', sizeof(recvhdr) );
msgrecv.msg_name = NULL;
msgrecv.msg_namelen = 0;
msgrecv.msg_iov = iovrecv;
msgrecv.msg_iovlen = 2;
iovrecv[0].iov_base = &recvhdr;
iovrecv[0].iov_len = sizeof(struct hdr);
if( n = Recvmsg( fd, &msgrecv, 0) < 0 )
{
printf("Error in RecvMsg!!\n");
printf("Error no : %d\n", errno );
exit(0);
}
if( recvhdr.ack_no == -3 )
{
printf("Recieved a FIN-ACK from client..\n");
// struct itimerval value, ovalue, pvalue;
// value.it_interval.tv_sec = 0; /* Zero seconds */
// value.it_interval.tv_usec = 0; /* Two hundred milliseconds */
// value.it_value.tv_sec = 0; /* Zero seconds */
// value.it_value.tv_usec = 0; /* Five hundred milliseconds */
// setitimer( ITIMER_REAL, &value, &ovalue );
return -3;
}
/* If we recieved the right packet ACKNOWLEDGEMENT, that is one which na was pointing to, we calculate RTT */
if( na == (recvhdr.ack_no - 1) )
{
rtt_stop(&rttinfo,
rtt_ts(&rttinfo) - recvhdr.ts);
rtt_newpack( &rttinfo );
printf("Recieved an ACK-%d from client..\n", recvhdr.ack_no );
}
printf( "Updating the reciever advertisement global variable with %d..\n", recvhdr.recv_window_advertisement );
recv_advertisement = recvhdr.recv_window_advertisement;
update_na( recvhdr.ack_no );
current_ack = recvhdr.ack_no;
if( prev_ack == current_ack )
{
/* We got 3 DUP's */
dup_ack++;
}
else
{
dup_ack = 0;
}
/* swap fpr next ACK */
prev_ack = current_ack;
return recvhdr.ack_no;
}
static int su_serv_send_recv_act(su_serv_t *psvr, SA *destaddr, socklen_t destlen,
const void *outbuff, int outbytes, void *inbuff, int inbytes, int retransmit)
{
int n;
struct iovec iovsend[2]= {{0}};
struct msghdr msgsend = {0}; /* assumed init to 0 */
suhdr_t *r, sendhdr = {0}; /* protocol header */
int ret, waitsec;
struct list *node = 0;
frames_t *packet = 0;
pthread_mutex_lock(&psvr->mutex);
pthread_mutex_lock(&psvr->lock);
if (retransmit == 0) {
psvr->seq++;
psvr->retransmission = 1;
} else {
if (psvr->retransmission == 0) {
pthread_mutex_unlock(&psvr->mutex);
pthread_mutex_unlock(&psvr->lock);
errno = ETIMEDOUT;
return -1;
}
psvr->retransmission --;
}
if (psvr->rttinit == 0) {
rtt_init(&psvr->rttinfo, psvr->retry); /* first time we're called */
psvr->rttinit = 1;
}
sendhdr.act = SU_SYN;
sendhdr.type = SU_RELIABLE;
sendhdr.sid = psvr->sid;
sendhdr.seq = psvr->seq;
msgsend.msg_name = (void*)destaddr;
msgsend.msg_namelen = destlen;
msgsend.msg_iov = iovsend;
msgsend.msg_iovlen = 2;
iovsend[0].iov_base = (void*)&sendhdr;
iovsend[0].iov_len = sizeof(suhdr_t);
iovsend[1].iov_base = (void*)outbuff;
iovsend[1].iov_len = outbytes;
struct timespec abstime = {0};
suhdr_t *precvhdr;
rtt_newpack(&psvr->rttinfo); /* initialize for this packet */
psvr->ackwaitnum ++;
sendagain:
sendhdr.ts = rtt_ts(&psvr->rttinfo);
if (sendmsg(psvr->fd, &msgsend, 0) < 0) {
ERR_RET("sendmsg error");
goto error_ret;
}
waitsec = rtt_start(&psvr->rttinfo); /* calc timeout value & start timer */
#ifdef SU_DEBUG_RTT
fprintf(stderr, ColorRed "send seq %4d: " ColorEnd, sendhdr.seq);
rtt_debug(&psvr->rttinfo);
#endif
/* set timed wait time-point */
maketimeout_seconds(&abstime, waitsec);
#ifdef SU_DEBUG_TIMEVERBOSE
struct timeval now;
gettimeofday(&now, 0);
log_msg( ColorBlue "pthread_cond_timedwait : %u.%u time expire" ColorEnd,
abstime.tv_sec, abstime.tv_nsec);
log_msg( ColorBlue "pthread_cond_timedwait : %d.%d now time" ColorEnd,
now.tv_sec, now.tv_usec*1000);
#endif
timedwaitagain:
ret = pthread_cond_timedwait(&psvr->ackcond, &psvr->lock, &abstime);
if (ret == 0) {
#ifdef SU_DEBUG_TIMEVERBOSE
struct timeval now;
gettimeofday(&now, 0);
log_msg(ColorBlue "pthread_cond_timedwait : %d.%d ack cond interrupt" ColorEnd,
now.tv_sec, now.tv_usec*1000);
#endif
node = psvr->ackrecvls.next;
for (; node != &psvr->ackrecvls; node = node->next) {
packet = container_of(node, frames_t, node);
r = &packet->recvhdr;
if (su_cmp_ack_SU_RELIABLE(&sendhdr, r)) {
break;
}
}
if ( node == &psvr->ackrecvls ) {
/* Be careful of the lock, locked -> timedwait -> unlock */
#ifdef SU_DEBUG_LIST
log_msg("serv %x no found seq %d ack, timed wait again", psvr, sendhdr.seq);
#endif
goto timedwaitagain;
}
/* Find response packet node */
list_remove(&packet->node);
n = packet->len;
precvhdr = &packet->recvhdr;
#if defined SU_DEBUG_PEER_RECV || defined SU_DEBUG_LIST
log_msg("serv %x finded ack " ColorRed "%p" ColorEnd " seq %d datagram len %d",
psvr, packet, r->seq, packet->len);
#endif
#ifdef SU_DEBUG_RTT
fprintf(stderr, ColorRed "recv seq %4d \n" ColorEnd, precvhdr->seq);
#endif
// SU_RELIABLE received response, copy to user buffer
memcpy(inbuff, packet->data, n > inbytes ? inbytes : n);
} else if (ret == EINTR) {
log_msg("pthread_cond_timedwait system EINTR");
goto timedwaitagain;
} else if (ret == ETIMEDOUT) {
#ifdef SU_DEBUG_TIMEVERBOSE
struct timeval now;
gettimeofday(&now, 0);
log_msg(ColorBlue "pthread_cond_timedwait : %u.%u ETIMEOUT have expired" ColorEnd,
now.tv_sec, now.tv_usec*1000);
#endif
if (rtt_timeout(&psvr->rttinfo) < 0) {
#ifdef SU_DEBUG_RTT
err_msg(ColorYel "no response from server, giving up" ColorEnd);
#endif
psvr->rttinit = 0; /* reinit in case we're called again */
errno = ETIMEDOUT;
goto error_ret;
}
#ifdef SU_DEBUG_RTT
err_msg(ColorRed " seq %4d timeout, retransmitting %d" ColorEnd,
sendhdr.seq, ++retransmit);
#endif
goto sendagain;
} else {
errno = ret;
ERR_RET(" su_serv_send_recv_act unknown error[%d]", ret);
goto error_ret;
}
/* calculate & store new RTT estimator values */
rtt_stop(&psvr->rttinfo, rtt_ts(&psvr->rttinfo) - precvhdr->ts);
if (--psvr->ackwaitnum == 0) {
su_serv_list_empty(psvr, &psvr->ackrecvls);
}
pthread_mutex_unlock(&psvr->mutex);
pthread_mutex_unlock(&psvr->lock);
#ifdef SU_DEBUG_LIST
log_msg("serv %x free node " ColorRed "%p"ColorEnd" seq %d", psvr, packet, sendhdr.seq);
#endif
free(packet);
return(n); /* return size of received datagram */
error_ret:
if (--psvr->ackwaitnum == 0) {
su_serv_list_empty(psvr, &psvr->ackrecvls);
}
pthread_mutex_unlock(&psvr->mutex);
pthread_mutex_unlock(&psvr->lock);
return(-1);
}
int sendFileContents(int sockfd,int totalblocks, int windowsize){
//printf("%d\n", totalblocks);
int first_unacknowledged_pos = 0;
int pos_sent = -1;
int prev_ack = 0;
struct dgram recv_packet;
int dups = 0;
int recv_ack = -1;
int retransmit = 0;
int rtt_measured_packet = 0;
uint32_t ts;
int starttimer = 1;
int hasBeenRtransmitted = 0;
int slow_start = 1;
Signal(SIGALRM, sig_alrm);
if (rttinit == 0) {
rtt_init(&rttinfo); /* first time we're called */
rttinit = 1;
rtt_d_flag = 1;
}
while(1){
retransmitpack:
if(retransmit){
printf("RETRANSMIT PACKET: %d\n", first_unacknowledged_pos);
hasBeenRtransmitted = 1;
slow_start = 1;
Sendto(sockfd, (void *)&fileContent[first_unacknowledged_pos], sizeof(struct dgram), 0, NULL, NULL);
retransmit = 0;
}
if (sigsetjmp(jmpbuf, 1) != 0) {
//rtt_debug(&rttinfo);
if (rtt_timeout(&rttinfo) < 0) {
err_msg("no response from client, giving up");
rttinit = 0;
errno = ETIMEDOUT;
return(-1);
}
retransmit = 1;
goto retransmitpack;
}
int sent_packets = 0;
while( (0 < slow_start) && (pos_sent < totalblocks-1) && (pos_sent + 1 < first_unacknowledged_pos + windowsize)){
if(starttimer){
rtt_newpack(&rttinfo);
alarm(rtt_start(&rttinfo));
ts = rtt_ts(&rttinfo);
starttimer = 0;
rtt_measured_packet = fileContent[pos_sent+1].seqNum;
hasBeenRtransmitted = 0;
}
Sendto(sockfd, (void *)&fileContent[pos_sent+1], sizeof(struct dgram), 0, NULL, NULL);
printf("SEND PACKET: %d\n", pos_sent+1);
pos_sent++;
slow_start--;
}
if(Recvfrom(sockfd, &recv_packet, sizeof(struct dgram), 0, NULL, NULL) < 0){
err_msg("Receive error from client");
return -1;
}
else{
//rtt_debug(&rttinfo);
windowsize = recv_packet.windowsize;
if(recv_packet.ack == recv_ack){
dups++;
}
else {
dups = 0;
}
recv_ack = recv_packet.ack;
printf("RECEIVED ACK: %d\n", recv_ack);
if(dups == 0){
alarm(0);
if(!hasBeenRtransmitted && recv_ack > rtt_measured_packet)
rtt_stop(&rttinfo, rtt_ts(&rttinfo) - ts);
starttimer = 1;
slow_start += 2*(recv_ack - prev_ack);
}
prev_ack = recv_ack;
first_unacknowledged_pos = recv_packet.ack;
retransmit = 0;
if(dups >= MAXDUPS){
// retransmit first unack pos
retransmit = 1;
goto retransmitpack;
}
}
if( first_unacknowledged_pos > 0 && fileContent[first_unacknowledged_pos-1].eof){
printf("SUCCESS: SENT ENTIRE FILE\n");
break;
}
}
return totalblocks;
}
ssize_t
dg_send_recv(int fd, const void *outbuff, size_t outbytes,
void *inbuff, size_t inbytes,
const SA *destaddr, socklen_t destlen)
{
ssize_t n;
struct iovec iovsend[2], iovrecv[2];
fd_set rset;
int nsel, maxfdp1;
struct timeval tv;
if (rttinit == 0) {
rtt_init(&rttinfo); /* first time we're called */
rttinit = 1;
rtt_d_flag = 1;
}
sendhdr.seq++;
msgsend.msg_name = destaddr;
msgsend.msg_namelen = destlen;
msgsend.msg_iov = iovsend;
msgsend.msg_iovlen = 2;
iovsend[0].iov_base = &sendhdr;
iovsend[0].iov_len = sizeof(struct hdr);
iovsend[1].iov_base = outbuff;
iovsend[1].iov_len = outbytes;
msgrecv.msg_name = NULL;
msgrecv.msg_namelen = 0;
msgrecv.msg_iov = iovrecv;
msgrecv.msg_iovlen = 2;
iovrecv[0].iov_base = &recvhdr;
iovrecv[0].iov_len = sizeof(struct hdr);
iovrecv[1].iov_base = inbuff;
iovrecv[1].iov_len = inbytes;
rtt_newpack(&rttinfo); /* initialize for this packet */
sendagain:
#ifdef RTT_DEBUG
fprintf(stderr, "send %4d: ", sendhdr.seq);
#endif
sendhdr.ts = rtt_ts(&rttinfo);
Sendmsg(fd, &msgsend, 0);
alarm(rtt_start(&rttinfo)); /* calc timeout value & start timer */
#ifdef RTT_DEBUG
rtt_debug(&rttinfo);
#endif
tv.tv_sec = rtt_start(&rttinfo);
tv.tv_usec = 0;
maxfdp1 = fd + 1;
again:
FD_ZERO(&rset);
FD_SET(fd, &rset);
nsel = select(maxfdp1, &rset, NULL, NULL, &tv);
if ((nsel == -1) || (errno == EINTR))
goto again;
else if (nsel == -1)
err_msg("select error");
else if (nsel == 0) {
if (rtt_timeout(&rttinfo) < 0) {
err_msg("dg_send_recv: no response from server, giving up");
rttinit = 0; /* reinit in case we're called again */
errno = ETIMEDOUT;
return(-1);
}
#ifdef RTT_DEBUG
err_msg("dg_send_recv: timeout, retransmitting");
#endif
goto sendagain;
}
if (FD_ISSET(fd, &rset)) {
do {
n = Recvmsg(fd, &msgrecv, 0);
#ifdef RTT_DEBUG
fprintf(stderr, "recv %4d\n", recvhdr.seq);
#endif
} while (n < sizeof(struct hdr) || recvhdr.seq != sendhdr.seq);
}
/* 4calculate & store new RTT estimator values */
rtt_stop(&rttinfo, rtt_ts(&rttinfo) - recvhdr.ts);
return(n - sizeof(struct hdr)); /* return size of received datagram */
}
ssize_t jxclient_sendrecv(struct jxclient* cli, const struct sockaddr* servaddr, jxsocklen_t addrlen, mflag_t mflag)
{
char outbuf[MAX_MSG_LEN];
ssize_t recvbytes;
jxsocklen_t sendlen;
struct jxmsg_header* bufheader = NULL;
if (s_rttinit == 0) {
rtt_init(&s_rttinfo);
s_rttinit = 1;
#ifdef _DEBUG
rtt_d_flag = 1;
#endif
}
if (s_mutex_inited == 0) {
s_sendrecv_init();
}
bufheader = (struct jxmsg_header*)outbuf;
bufheader->mflag = mflag;
bufheader->header.seq = ++s_sendhdr.seq;
rtt_newpack(&s_rttinfo);
sendlen = sizeof(bufheader->addr);
jxsock_getsockname(cli->hsock_sendrecv, &bufheader->addr, &sendlen);
bufheader->addrlen = (uint8_t)sendlen;
bufheader->numbytes = htonl(cli->len_senddata);
if (jxmemcpy(
outbuf + sizeof(struct jxmsg_header),
sizeof(outbuf) - sizeof(struct jxmsg_header),
cli->sendbuf, cli->len_senddata) != 0) {
return 1;
}
s_recv_stat = RECV_RESEND;
while (RECV_RESEND == s_recv_stat) {
bufheader->header.ts = s_sendhdr.ts = rtt_ts(&s_rttinfo);
if (SOCKET_ERROR == sendto(
cli->hsock_sendrecv,
outbuf,
sizeof(struct jxmsg_header) + cli->len_senddata,
0,
servaddr,
(jxsocklen_t)addrlen)) {
fprintf(stderr, "%s sendto() fail, error code: %d.\n", cli->prompt, jxsock_get_last_error());
return -2;
}
if (!JX_MFLAG_WAIT_RECV(mflag)) {
return 0;
}
s_reset_recvtimer();
if ((recvbytes = s_recvmsg(cli->hsock_sendrecv, cli->recvbuf, sizeof(cli->recvbuf))) == -3) {
return -3;
}
}
if (s_recv_stat == RECV_TIMEOUT) {
s_rttinit = 0;
return -1;
}
rtt_stop(&s_rttinfo, rtt_ts(&s_rttinfo) - ((struct jxmsg_header*)cli->recvbuf)->header.ts);
jxmsg_copyaddr((struct jxmsg_header*)cli->recvbuf, servaddr, addrlen);
return recvbytes - sizeof(struct jxmsg_header);
}
