void
dns_transmit_free (struct dns_transmit *d)
{
queryfree (d);
socketfree (d);
packetfree (d);
}
int dns_transmit_get(struct dns_transmit *d,const iopause_fd *x,const struct taia *when)
{
char udpbuf[513];
unsigned char ch;
int r;
int fd;
errno = error_io;
fd = d->s1 - 1;
if (!x->revents) {
if (taia_less(when,&d->deadline)) return 0;
errno = error_timeout;
if (d->tcpstate == 0) return nextudp(d);
return nexttcp(d);
}
if (d->tcpstate == 0) {
/*
have attempted to send UDP query to each server udploop times
have sent query to curserver on UDP socket s
*/
r = recv(fd,udpbuf,sizeof udpbuf,0);
if (r <= 0) {
if (errno == error_connrefused) if (d->udploop == 2) return 0;
return nextudp(d);
}
if (r + 1 > sizeof udpbuf) return 0;
if (irrelevant(d,udpbuf,r)) return 0;
if (serverwantstcp(udpbuf,r)) return firsttcp(d);
if (serverfailed(udpbuf,r)) {
if (d->udploop == 2) return 0;
return nextudp(d);
}
socketfree(d);
d->packetlen = r;
d->packet = alloc(d->packetlen);
if (!d->packet) { dns_transmit_free(d); return -1; }
byte_copy(d->packet,d->packetlen,udpbuf);
queryfree(d);
return 1;
}
if (d->tcpstate == 1) {
/*
have sent connection attempt to curserver on TCP socket s
pos not defined
*/
if (!socket_connected(fd)) return nexttcp(d);
d->pos = 0;
d->tcpstate = 2;
return 0;
}
if (d->tcpstate == 2) {
/*
have connection to curserver on TCP socket s
have sent pos bytes of query
*/
r = write(fd,d->query + d->pos,d->querylen - d->pos);
if (r <= 0) return nexttcp(d);
d->pos += r;
if (d->pos == d->querylen) {
struct taia now;
taia_now(&now);
taia_uint(&d->deadline,10);
taia_add(&d->deadline,&d->deadline,&now);
d->tcpstate = 3;
}
return 0;
}
if (d->tcpstate == 3) {
/*
have sent entire query to curserver on TCP socket s
pos not defined
*/
r = read(fd,&ch,1);
if (r <= 0) return nexttcp(d);
d->packetlen = ch;
d->tcpstate = 4;
return 0;
}
if (d->tcpstate == 4) {
/*
have sent entire query to curserver on TCP socket s
pos not defined
have received one byte of packet length into packetlen
*/
r = read(fd,&ch,1);
if (r <= 0) return nexttcp(d);
d->packetlen <<= 8;
d->packetlen += ch;
d->tcpstate = 5;
d->pos = 0;
d->packet = alloc(d->packetlen);
if (!d->packet) { dns_transmit_free(d); return -1; }
return 0;
}
if (d->tcpstate == 5) {
/*
have sent entire query to curserver on TCP socket s
have received entire packet length into packetlen
packet is allocated
have received pos bytes of packet
*/
r = read(fd,d->packet + d->pos,d->packetlen - d->pos);
if (r <= 0) return nexttcp(d);
d->pos += r;
if (d->pos < d->packetlen) return 0;
socketfree(d);
if (irrelevant(d,d->packet,d->packetlen)) return nexttcp(d);
if (serverwantstcp(d->packet,d->packetlen)) return nexttcp(d);
if (serverfailed(d->packet,d->packetlen)) return nexttcp(d);
queryfree(d);
return 1;
}
return 0;
}
