static tb_long_t tb_dns_looker_resp(tb_dns_looker_impl_t* impl, tb_ipaddr_ref_t addr)
{
// check
tb_check_return_val(!(impl->step & TB_DNS_LOOKER_STEP_RESP), 1);
// need wait if no data
impl->step &= ~TB_DNS_LOOKER_STEP_NEVT;
// recv response data
tb_byte_t rpkt[4096];
while (1)
{
// read data
tb_long_t read = tb_socket_urecv(impl->sock, tb_null, rpkt, 4096);
//tb_trace_d("read %d", read);
tb_assert_and_check_return_val(read >= 0, -1);
// no data?
if (!read)
{
// end? read x, read 0
tb_check_break(!tb_static_buffer_size(&impl->rpkt));
// abort? read 0, read 0
tb_check_return_val(!impl->tryn, -1);
// tryn++
impl->tryn++;
// continue
return 0;
}
else impl->tryn = 0;
// copy data
tb_static_buffer_memncat(&impl->rpkt, rpkt, read);
}
// done
if (!tb_dns_looker_resp_done(impl, addr)) return -1;
// check
tb_assert_and_check_return_val(tb_static_string_size(&impl->name) && !tb_ipaddr_ip_is_empty(addr), -1);
// save address to cache
tb_dns_cache_set(tb_static_string_cstr(&impl->name), addr);
// finish it
impl->step |= TB_DNS_LOOKER_STEP_RESP;
impl->tryn = 0;
// reset rpkt
impl->size = 0;
tb_static_buffer_clear(&impl->rpkt);
// ok
tb_trace_d("response: ok");
return 1;
}
tb_long_t tb_dns_looker_spak(tb_dns_looker_ref_t self, tb_ipaddr_ref_t addr)
{
// check
tb_dns_looker_t* looker = (tb_dns_looker_t*)self;
tb_assert_and_check_return_val(looker && addr, -1);
// init
tb_long_t r = -1;
do
{
// request
r = tb_dns_looker_reqt(looker);
tb_check_break(r > 0);
// response
r = tb_dns_looker_resp(looker, addr);
tb_check_break(r > 0);
} while (0);
// failed?
if (r < 0)
{
// next
if (looker->itor + 1 <= looker->maxn) looker->itor++;
else looker->itor = 0;
// has next?
if (looker->itor)
{
// reset step, no event now, need not wait
looker->step = TB_DNS_LOOKER_STEP_NONE | TB_DNS_LOOKER_STEP_NEVT;
// reset rpkt
looker->size = 0;
tb_static_buffer_clear(&looker->rpkt);
// continue
r = 0;
}
}
// ok?
return r;
}
static tb_long_t tb_dns_looker_resp(tb_dns_looker_t* looker, tb_ipaddr_ref_t addr)
{
// check
tb_check_return_val(!(looker->step & TB_DNS_LOOKER_STEP_RESP), 1);
// need wait if no data
looker->step &= ~TB_DNS_LOOKER_STEP_NEVT;
// recv response data
tb_size_t size = tb_static_buffer_size(&looker->rpkt);
tb_size_t maxn = tb_static_buffer_maxn(&looker->rpkt);
tb_byte_t* data = tb_static_buffer_data(&looker->rpkt);
while (size < maxn)
{
// read data
tb_long_t read = tb_socket_urecv(looker->sock, tb_null, data + size, maxn - size);
tb_assert_and_check_return_val(read >= 0, -1);
// no data?
if (!read)
{
// end? read x, read 0
tb_check_break(!tb_static_buffer_size(&looker->rpkt));
// abort? read 0, read 0
tb_check_return_val(!looker->tryn, -1);
// tryn++
looker->tryn++;
// continue
return 0;
}
else looker->tryn = 0;
// update buffer size
tb_static_buffer_resize(&looker->rpkt, size + read);
size = tb_static_buffer_size(&looker->rpkt);
}
// done
if (!tb_dns_looker_resp_done(looker, addr)) return -1;
// check
tb_assert_and_check_return_val(tb_static_string_size(&looker->name) && !tb_ipaddr_ip_is_empty(addr), -1);
// save address to cache
tb_dns_cache_set(tb_static_string_cstr(&looker->name), addr);
// finish it
looker->step |= TB_DNS_LOOKER_STEP_RESP;
looker->tryn = 0;
// reset rpkt
looker->size = 0;
tb_static_buffer_clear(&looker->rpkt);
// ok
tb_trace_d("response: ok");
return 1;
}
/* //////////////////////////////////////////////////////////////////////////////////////
* implementation
*/
static tb_long_t tb_dns_looker_reqt(tb_dns_looker_t* looker)
{
// check
tb_check_return_val(!(looker->step & TB_DNS_LOOKER_STEP_REQT), 1);
// format it first if the request is null
if (!tb_static_buffer_size(&looker->rpkt))
{
// check size
tb_assert_and_check_return_val(!looker->size, -1);
// format query
tb_static_stream_t stream;
tb_byte_t rpkt[TB_DNS_RPKT_MAXN];
tb_size_t size = 0;
tb_byte_t* p = tb_null;
tb_static_stream_init(&stream, rpkt, TB_DNS_RPKT_MAXN);
// identification number
tb_static_stream_writ_u16_be(&stream, TB_DNS_HEADER_MAGIC);
/* 0x2104: 0 0000 001 0000 0000
*
* tb_uint16_t qr :1; // query/response flag
* tb_uint16_t opcode :4; // purpose of message
* tb_uint16_t aa :1; // authoritive answer
* tb_uint16_t tc :1; // truncated message
* tb_uint16_t rd :1; // recursion desired
* tb_uint16_t ra :1; // recursion available
* tb_uint16_t z :1; // its z! reserved
* tb_uint16_t ad :1; // authenticated data
* tb_uint16_t cd :1; // checking disabled
* tb_uint16_t rcode :4; // response code
*
* this is a query
* this is a standard query
* not authoritive answer
* not truncated
* recursion desired
*
* recursion not available! hey we dont have it (lol)
*
*/
#if 1
tb_static_stream_writ_u16_be(&stream, 0x0100);
#else
tb_static_stream_writ_u1(&stream, 0); // this is a query
tb_static_stream_writ_ubits32(&stream, 0, 4); // this is a standard query
tb_static_stream_writ_u1(&stream, 0); // not authoritive answer
tb_static_stream_writ_u1(&stream, 0); // not truncated
tb_static_stream_writ_u1(&stream, 1); // recursion desired
tb_static_stream_writ_u1(&stream, 0); // recursion not available! hey we dont have it (lol)
tb_static_stream_writ_u1(&stream, 0);
tb_static_stream_writ_u1(&stream, 0);
tb_static_stream_writ_u1(&stream, 0);
tb_static_stream_writ_ubits32(&stream, 0, 4);
#endif
/* we have only one question
*
* tb_uint16_t question; // number of question entries
* tb_uint16_t answer; // number of answer entries
* tb_uint16_t authority; // number of authority entries
* tb_uint16_t resource; // number of resource entries
*
*/
tb_static_stream_writ_u16_be(&stream, 1);
tb_static_stream_writ_u16_be(&stream, 0);
tb_static_stream_writ_u16_be(&stream, 0);
tb_static_stream_writ_u16_be(&stream, 0);
// set questions, see as tb_dns_question_t
// name + question1 + question2 + ...
tb_static_stream_writ_u8(&stream, '.');
p = (tb_byte_t*)tb_static_stream_writ_cstr(&stream, tb_static_string_cstr(&looker->name));
// only one question now.
tb_static_stream_writ_u16_be(&stream, 1); // we are requesting the ipv4 address
tb_static_stream_writ_u16_be(&stream, 1); // it's internet (lol)
// encode dns name
if (!p || !tb_dns_encode_name((tb_char_t*)p - 1)) return -1;
// size
size = tb_static_stream_offset(&stream);
tb_assert_and_check_return_val(size, -1);
// copy
tb_static_buffer_memncpy(&looker->rpkt, rpkt, size);
}
// data && size
tb_byte_t const* data = tb_static_buffer_data(&looker->rpkt);
tb_size_t size = tb_static_buffer_size(&looker->rpkt);
// check
tb_assert_and_check_return_val(data && size && looker->size < size, -1);
// try get addr from the dns list
tb_ipaddr_ref_t addr = tb_null;
if (looker->maxn && looker->itor && looker->itor <= looker->maxn)
addr = &looker->list[looker->itor - 1];
// check
tb_assert_and_check_return_val(addr && !tb_ipaddr_is_empty(addr), -1);
// family have been changed? reinit socket
if (tb_ipaddr_family(addr) != looker->family)
{
// exit the previous socket
if (looker->sock) tb_socket_exit(looker->sock);
// init a new socket for the family
looker->sock = tb_socket_init(TB_SOCKET_TYPE_UDP, tb_ipaddr_family(addr));
tb_assert_and_check_return_val(looker->sock, -1);
// update the new family
looker->family = (tb_uint8_t)tb_ipaddr_family(addr);
}
// need wait if no data
looker->step &= ~TB_DNS_LOOKER_STEP_NEVT;
// trace
tb_trace_d("request: try %{ipaddr}", addr);
// send request
while (looker->size < size)
{
// writ data
tb_long_t writ = tb_socket_usend(looker->sock, addr, data + looker->size, size - looker->size);
tb_assert_and_check_return_val(writ >= 0, -1);
// no data?
if (!writ)
{
// abort?
tb_check_return_val(!looker->size && !looker->tryn, -1);
// tryn++
looker->tryn++;
// continue
return 0;
}
else looker->tryn = 0;
// update size
looker->size += writ;
}
// finish it
looker->step |= TB_DNS_LOOKER_STEP_REQT;
looker->tryn = 0;
// reset rpkt
looker->size = 0;
tb_static_buffer_clear(&looker->rpkt);
// ok
tb_trace_d("request: ok");
return 1;
}
