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/*********************************************************************\
* Copyright (c) 1991 by Wen-King Su (wen-king@vlsi.cs.caltech.edu) *
* *
* You may copy or modify this file in any manner you wish, provided *
* that this notice is always included, and that you hold the author *
* harmless for any loss or damage resulting from the installation or *
* use of this software. *
\*********************************************************************/
#include "tweak.h"
#include "client_def.h"
#include "c_extern.h"
#include "co_extern.h"
extern int errno;
static int myfd;
static struct sockaddr_in server_addr;
static unsigned short myseq = 0;
static unsigned short key;
int client_trace = 0;
int client_intr_state = 0;
unsigned long target_delay = MIN_DELAY; /* expected max delay */
unsigned long busy_delay = MIN_DELAY; /* busy retransmit timer */
unsigned long idle_delay = MIN_DELAY; /* idle retransmit timer */
unsigned long udp_sent_time;
UBUF *client_interact PROTO6(unsigned int, cmd, unsigned long, pos,
unsigned int, l1, unsigned char *, p1,
unsigned int, l2, unsigned char *, p2)
{
struct sockaddr_in from;
UBUF sbuf;
static UBUF rbuf;
unsigned char *s, *t, *d, seq0, seq1;
unsigned u, n, sum, mask, mlen, rlen;
int retval, bytes, retry_send, retry_recv;
unsigned long w_delay;
sbuf.cmd = cmd;
BB_WRITE2(sbuf.bb_len,l1);
BB_WRITE4(sbuf.bb_pos,pos);
client_intr_state = 1;
for(u = l1, d = (unsigned char *) sbuf.buf; u--; *d++ = *p1++);
for(u = l2; u--; *d++ = *p2++);
mlen = d - (unsigned char *) &sbuf;
key = client_get_key();
for(retry_send = 0; ; retry_send++) {
BB_WRITE2(sbuf.bb_key,key);
sbuf.bb_seq[0] = seq0 = (myseq >> 8) & 0xff;
sbuf.bb_seq[1] = seq1 = (myseq & 0xfc) | (retry_send & 0x0003);
sbuf.sum = 0;
for(t = (unsigned char *) &sbuf, sum = n = mlen; n--; sum += *t++);
sbuf.sum = sum + (sum >> 8);
switch(retry_send) { /* adaptive retry delay adjustments */
case 0:
busy_delay = (target_delay+(busy_delay<<3)-busy_delay)>>3;
w_delay = busy_delay;
break;
case 1:
busy_delay = busy_delay + (busy_delay >> 1);
w_delay = busy_delay;
if(client_trace) write(2,"R",1); break;
default:
#ifdef CLIENT_TIMEOUT
if (!pos && retry_send >= env_timeout ) {
fprintf(stderr, "\rRemote server not responding.\n");
exit(1);
}
#endif
if(idle_delay < 5*60*1000) idle_delay = idle_delay << 1;
w_delay = idle_delay;
if(client_trace) write(2,"I",1);
break;
}
if(sendto(myfd,&sbuf,mlen,0,(struct sockaddr *)&server_addr,
sizeof(server_addr)) == -1) {
perror("sendto");
exit(1);
}
udp_sent_time = time((time_t *) 0);
mask = 1 << myfd;
for(retry_recv = 0; ; retry_recv++) {
if(retry_recv && client_trace) write(2,"E",1);
retval = _x_select(&mask, w_delay);
if((retval == -1) && (errno == EINTR)) continue;
if(retval == 1) { /* an incoming message is waiting */
bytes = sizeof(from);
if((bytes = recvfrom(myfd,(char*)&rbuf,sizeof(rbuf),0,
(struct sockaddr *)&from, &bytes)) < UBUF_HSIZE)
continue;
s = (unsigned char *) &rbuf;
d = s + bytes;
u = rbuf.sum; rbuf.sum = 0;
for(t = s, sum = 0; t < d; sum += *t++);
sum = (sum + (sum >> 8)) & 0xff;
if(sum != u) continue; /* wrong check sum */
rlen = BB_READ2(rbuf.bb_len);
if( (rbuf.bb_seq[0] ^ seq0) ||
((rbuf.bb_seq[1] ^ seq1)&0xfc)) continue; /* wrong seq # */
if((int) (rlen+UBUF_HSIZE) > bytes) continue; /* truncated. */
myseq = (myseq + 0x0004) & 0xfffc; /* seq for next request */
key = BB_READ2(rbuf.bb_key); /* key for next request */
client_put_key(key);
if(client_intr_state == 2) {
if(!key_persists) client_done();
exit(1);
}
return(&rbuf);
} else break; /* go back to re-transmit buffer again */
}
}
}
void init_client PROTO3(char *, host, int, port, int, myport)
{
busy_delay = idle_delay = target_delay;
if((myfd = _x_udp(&myport)) == -1) {
perror("socket open");
exit(1);
}
if(_x_adr(host,port,&server_addr) == -1) {
perror("server addr");
exit(1);
}
client_init_key(server_addr.sin_addr.s_addr,port,getpid());
}
int client_done PROTO0((void))
{
(void) client_interact(CC_BYE, 0L, 0, (unsigned char *)NULLP, 0,
(unsigned char *)NULLP);
}
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