ESP8266 Community Forum

- Fri Nov 06, 2015 7:10 am #33248 hi all

i am want to adding dns server in ESP8266 (RTOS SDK)

my dns socket code is like as below

Code: Select all#include <stdlib.h>
#include <stdio.h>
#include <unistd.h>
#include <string.h>
#include  "Tinydns.h"
#include <lwip/sockets.h>
#include "freertos/FreeRTOS.h"
#include "freertos/task.h"

#define PORT 53
#define MSG_SIZE 20

char *msg = NULL;
/*
void usage(const char* prog)
{
   printf(stderr, "Usage: %s IP1 IP2 IP3 IP4\n", prog);
   printf(stderr, "Example:\n   %s 192 168 1 1\n", prog);
   printf(stderr, "Fake DNS returning the same IP address for any DNS request.\n");
}
*/

void TinydnsTask(void *pvParameters)
{
   struct sockaddr_in addr, server;
     // socket creation
   int sd = socket(AF_INET, SOCK_DGRAM, 0);
   if (sd < 0) {
      //printf(stderr, "%s: cannot open socket \n", argv[0]);
      //return 1;
      asm("break 1,1");
   }
   printf("TinyDns open socket \n" );
   
   
     // bind local server port
   server.sin_family = AF_INET;
   server.sin_addr.s_addr = INADDR_ANY;//htonl()
   server.sin_port = htons(PORT);
   int rc = bind(sd, (struct sockaddr *) &server, sizeof(server));
   if (rc < 0) {
      //fprintf(stderr,"%s: cannot bind port number %d \n", argv[0],PORT);
      //return 1;
      asm("break 1,1");
   }
   printf("TinyDns Bind socket \n");
   
   
   socklen_t len = sizeof(addr);
   int flags = 0;
   int RxTimeout = 50;
   while (1) {
      if (msg == NULL)
      {
         msg = (char *)malloc(MSG_SIZE);
      }
      //printf("==========TinyDns wait for receiving msg from socket==========");
       int ret = setsockopt(sd, SOL_SOCKET, SO_RCVTIMEO, &RxTimeout, sizeof(int));
      if (ret <= 0) {printf("TinyDns set socket failed \n");}
       // receive message
      int n = recvfrom(sd, msg, MSG_SIZE, flags, (struct sockaddr*)&addr, &len);
      //int n = -1;
      //vTaskDelay(1000);
      if (n <= 0) {continue;}
      
      printf("TinyDns recive msg : %d byte from socket \n",n);
      
      // Same Id
      msg[2] = 0x81; msg[3] = 0x80; // Change Opcode and flags
      msg[6] = 0; msg[7] = 1; // One answer
      msg[8] = 0; msg[9] = 0; // NSCOUNT
      msg[10] = 0; msg[11] = 0; // ARCOUNT
     

      // Keep request in message and add answer
      msg[n++] = 0xC0; msg[n++] = 0x0C; // Offset to the domain name
      msg[n++] = 0x00; msg[n++] = 0x01; // Type 1
      msg[n++] = 0x00; msg[n++] = 0x01; // Class 1
      msg[n++] = 0x00; msg[n++] = 0x00; msg[n++] = 0x00; msg[n++] = 0x3c; // TTL
      msg[n++] = 0x00; msg[n++] = 0x04; // Size --> 4
      msg[n++] = 0x12; msg[n++] = 0x34; msg[n++] = 0x56; msg[n++] = 0x78; // IP
      // Send the answer
      sendto(sd, msg, n, flags, (struct sockaddr *)&addr, len);
      
      if (msg){
         free(msg);
         msg = NULL;
         printf("free msg \n");
      }
   }
   //return 0;
}

and i adding TinydnsTask() funtion as a Task in user_init();
but when i runing the code , it was always shut down when some one join in it


xTaskCreate(TinydnsTask, (signed char *)"Server", 256, NULL, 2, NULL);


Can you give me a hand !!!!!
BR!