Beispiel #1
0
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");
}
Beispiel #2
0
/*
********************************************************************************
*              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;
            }
        }
    };
}