static void ICACHE_FLASH_ATTR dnsQueryReceived(void *arg, char *data, unsigned short length)
{
// parse incoming query domain
char domain[30];
char *writePos=domain;
memset(domain,0,30);
int offSet=12;
int len=data[offSet];
while(len!=0 && offSet<length)
{
offSet++;
memcpy(writePos,data+offSet,len);
writePos+=len; //advance
offSet+=len;
len=data[offSet];
if(len!=0) { *writePos='.'; writePos++; }
}
DNS_DBG("DNS Query Received: %s",domain);
if(!isKnownDNS(domain))
return;
struct espconn *conn=arg;
remot_info *premot = NULL;
if (espconn_get_connection_info(conn,&premot,0) == ESPCONN_OK)
{
os_memcpy(conn->proto.udp->remote_ip, premot->remote_ip, 4);
conn->proto.udp->remote_port = premot->remote_port;
uint8_t *ip1 = conn->proto.udp->remote_ip;
NODE_DBG("UDP:\nremote_ip: %d.%d.%d.%d remote_port: %d\n",ip4_addr1_16(ip1),ip4_addr2_16(ip1), ip4_addr3_16(ip1), ip4_addr4_16(ip1), premot->remote_port);
}
else
{ NODE_ERR("UDP: connection_info == NULL?\n"); }
//build response
char response[100] = {data[0], data[1],
0b10000100 | (0b00000001 & data[2]), //response, authorative answer, not truncated, copy the recursion bit
0b00000000, //no recursion available, no errors
data[4], data[5], //Question count
data[4], data[5], //answer count
0x00, 0x00, //NS record count
0x00, 0x00}; //Resource record count
int idx = 12;
memcpy(response+12, data+12, length-12); //Copy the rest of the query section
idx += length-12;
//Set a pointer to the domain name in the question section
response[idx] = 0xC0;
response[idx+1] = 0x0C;
//Set the type to "Host Address"
response[idx+2] = 0x00;
response[idx+3] = 0x01;
//Set the response class to IN
response[idx+4] = 0x00;
response[idx+5] = 0x01;
//A 32 bit integer specifying TTL in seconds, 0 means no caching
response[idx+6] = 0x00;
response[idx+7] = 0x00;
response[idx+8] = 0x00;
response[idx+9] = 0x00;
//RDATA length
response[idx+10] = 0x00;
response[idx+11] = 0x04; //4 byte IP address
//The IP address
response[idx + 12] = 192;
response[idx + 13] = 168;
response[idx + 14] = 4;
response[idx + 15] = 1;
int ret = espconn_send(conn, (uint8_t*)response, idx+16);
uint8_t *ip = conn->proto.udp->local_ip;
NODE_DBG("local_ip: %d.%d.%d.%d local_port: %d\n",ip4_addr1_16(ip),ip4_addr2_16(ip), ip4_addr3_16(ip), ip4_addr4_16(ip),conn->proto.udp->local_port);
NODE_DBG("DNS reply sent\n");
}
/*
********************************************************************************
* MAKE DNS QUERY AND PARSE THE REPLY
*
* Description : This function makes DNS query message and parses the reply from DNS server.
* Arguments : name - is a pointer to the domain name.
* Returns : if succeeds : 1, fails : -1
* Note :
********************************************************************************
*/
int DNS::query(char *name)
{
int state;
static uint32_t dns_wait_time = 0;
struct dhdr dhp;
uint8_t ip[4];
uint16_t len, port;
uint8_t dns_server_ip[4];
uint8_t BUFPUB[100];
get_local_dns(dns_server_ip);
len = makequery(0, (uint8_t *)name, BUFPUB, MAX_DNS_BUF_SIZE);
DNS_DBG("ÓòÃû:[%s]\r\n", name);
DNS_DBG("ÓòÃû½âÎöÖÐ...\r\n");
while(1)
{
state = socket_status(s);
if(state == SOCK_CLOSED)
{
DNS_DBG("dns's socket closed!,socket: %d\r\n", s);
DNS_DBG("openning dns's socket... !\r\n");
if(_socket(s, Sn_MR_UDP, port, 0) == 1)
DNS_DBG("open dns's socket seccusse!\r\n");
}
if(state == SOCK_UDP)
{
DNS_DBG("sending query cmd...\r\n");
if(_sendto(s, BUFPUB, len, dns_server_ip, IPPORT_DOMAIN) > 0)
DNS_DBG("send dns cmd ok!\r\n");
if ((len = recv_available(s)) > 0)
{
if (len > MAX_DNS_BUF_SIZE)
{
len = MAX_DNS_BUF_SIZE;
}
len = _recvfrom(s, BUFPUB, len, ip, &port);
DNS_DBG("receiv dns's date ok!datelen:%d\r\n", len);
if(parseMSG(&dhp, BUFPUB))
{
_close(s);
DNS_DBG("query is ok!\r\n");
return 1;
}
else
{
DNS_DBG("dns's date is bad!\r\n");
return -1;
}
}
else
{
DNS_DBG("wait dns's date...!\r\n");
delay_ms(1000);
dns_wait_time++;
}
if(dns_wait_time >= 3)
{
_close(s);
return -2;
}
}
};
}
