//databuffer format
//type.mvalue.data.type.mvalue.data...
int
// write_back_to_client(uchar * td, enum rrtype otype, uint8_t level, ushort id, int dlen,
write_back_to_client(mbuf_type *mbuf, uchar * fr, int vlen)
{
struct setheader sh = { 0 }; //data in dns header
int main_val = 0, dnslen = 0;
uchar *msg = mbuf->buf, type; //if bigger, use TCP
uchar *from = fr, *to = msg;
struct mvalue *mv = NULL;
int jump = 0;
uint16_t temp = 0;
struct hlpc hlp[100]; //p domians to compression
hlp[0].name = mbuf->td;
hlp[0].off = sizeof(dnsheader);
hlp[0].level = mbuf->lowerdomain.label_count;
hlp[0].ref = -1;
hlp[0].mt = 0;
hlp[0].len = mbuf->dlen;
if (mbuf->dlen == 2) // root
jump = sizeof(dnsheader) + 1 + sizeof(qdns);
else
jump = sizeof(dnsheader) + mbuf->dlen + sizeof(qdns);
to = to + jump;
while (vlen > 1) //vlen include type.mvalue.data.
{
type = from[0];
mv = (struct mvalue *)(from + 1);
to = fill_rrset_in_msg(hlp, from, to, &main_val, msg);
if (to == NULL)
return -1;
// *to = 0;
vlen = vlen - 1 - mv->len - sizeof(struct mvalue);
sh.an += mv->num;
from = from + mv->len + 1 + sizeof(struct mvalue); // type.mv.len.
/**
* if previous record is CNAME(query type can't be ANY, that we don't support now),
* next A & AAAA & CNAME use previous domain name (cname name).
* We duplicate here to make it possible to refer previous one.
*/
if (type == CNAME && vlen > 1 /*&& mbuf->qtype != ANY*/ && (from[0] == A || from[0] == AAAA || from[0] == CNAME))
{
main_val++;
hlp[main_val].name = hlp[main_val - 1].name;
hlp[main_val].off = hlp[main_val - 1].off;
hlp[main_val].level = hlp[main_val - 1].level;
hlp[main_val].len = hlp[main_val - 1].len;
hlp[main_val].ref = -1;
hlp[main_val].mt = 0;
}
}
sh.itor = msg;
sh.dlen = (mbuf->dlen == 2) ? 1: (mbuf->dlen);
sh.od = mbuf->td;
sh.id = mbuf->id;
sh.type = mbuf->qtype;
fill_header_in_msg(&sh);
dnslen = to - msg;
mbuf->buflen = dnslen;
mbuf->addr = &(mbuf->caddr);
if (mbuf->socktype == UDP) {
if (dnslen > MAX_UDP_SIZE)
send_tc_to_client(mbuf);
else
udp_write_info(mbuf, 0); //ignore send error
} else {
temp = DNS_GET16(dnslen);
memcpy(msg - 2, &temp, sizeof(uint16_t));
mbuf->buflen = dnslen + 2;
mbuf->buf = msg - 2;
tcp_write_info(mbuf, 0);
}
////////////////////////////////////////////////////////////
//key, val, vallen, ttl offset
//if now + TTL_UPDATE > ttl
//return
/* ret = transfer_record_to_msg(msgto, td, msg + 2, dnslen, ttloff); */
/* if (ret < 0) */
/* return -1; */
return 0;
}
//databuffer format
//type.mvalue.data.type.mvalue.data...
int
// write_back_to_client(uchar * td, enum rrtype otype, uint8_t level, ushort id, int dlen,
write_back_to_client(mbuf_type *mbuf, uchar * fr, int vlen)
{
struct setheader sh = { 0 }; //data in dns header
int main_val = 0, dnslen = 0;
uchar *msg = mbuf->buf, type; //if bigger, use TCP
uchar *from = fr, *to = msg;
struct mvalue *mv = NULL;
int jump = 0;
uint16_t temp = 0;
struct hlpc hlp[100]; //p domians to compression
hlp[0].name = mbuf->td;
hlp[0].off = sizeof(dnsheader);
hlp[0].level = mbuf->lowerdomain.label_count;
hlp[0].ref = -1;
hlp[0].mt = 0;
hlp[0].len = mbuf->dlen;
jump = sizeof(dnsheader) + mbuf->dlen + sizeof(qdns);
to = to + jump;
while (vlen > 1) //vlen include type.mvalue.data.
{
type = from[0];
mv = (struct mvalue *)(from + 1);
to = fill_rrset_in_msg(hlp, from, to, main_val, msg);
if (to == NULL)
return -1;
// *to = 0;
vlen = vlen - 1 - mv->len - sizeof(struct mvalue);
sh.an += mv->num;
if (type == CNAME) //cname must be 1
main_val++; //no all rdata is the cname's
from = from + mv->len + 1 + sizeof(struct mvalue); // type.mv.len.
}
sh.itor = msg;
sh.dlen = mbuf->dlen;
sh.od = mbuf->td;
sh.id = mbuf->id;
sh.type = mbuf->qtype;
fill_header_in_msg(&sh);
dnslen = to - msg;
mbuf->buflen = dnslen;
mbuf->addr = &(mbuf->caddr);
if (mbuf->socktype == UDP) {
if (dnslen > MAX_UDP_SIZE)
send_tc_to_client(mbuf);
else
udp_write_info(mbuf, 0); //ignore send error
} else {
temp = DNS_GET16(dnslen);
memcpy(msg - 2, &temp, sizeof(uint16_t));
mbuf->buflen = dnslen + 2;
mbuf->buf = msg - 2;
tcp_write_info(mbuf, 0);
}
////////////////////////////////////////////////////////////
//key, val, vallen, ttl offset
//if now + TTL_UPDATE > ttl
//return
/* ret = transfer_record_to_msg(msgto, td, msg + 2, dnslen, ttloff); */
/* if (ret < 0) */
/* return -1; */
return 0;
}