HTTP Client for Chibios with LWiP

[pawelc06]

Hi all,
I was trying to run HTTP client using Chibios and LWIP demo example for stm32 F4 Discovery.
I'm using sockets from LWip.
I wrote client thread which connects (lwip_connect), then sends HTTP request to server (lwip_write), then reads the response (lwip_read).

After running it:
a) connects, but hangs up on blocking lwip_read
b) doesn't connect and returns err_code -10

Has somebody succeeded with connection using Chibios and LWiP?

Could you provide a snippet of code+settings of lwipopts.h?

One remark: I need to download about 100 kB png image from the website.


Best regards
Pawel

[pawelc06]

Here is the code I use:

Code: Select all

#include "ch.h"
#include "lwip/opt.h"
#include "lwip/arch.h"
#include "lwip/api.h"
#include "lwip/sockets.h"
#define PORT 80

#include "client.h"
//#include <string.h>



static char *http_request =
      "GET / HTTP/1.1\r\nHost: 192.168.2.100\r\nConnection: keep-alive\r\nAccept: text/html,application/xhtml+xml,application/xml;q=0.9,image/webp,*/*;q=0.8\r\nUser-Agent: HTTPClient\r\n\r\nAccept-Encoding: gzip,deflate,sdch\r\nAccept-Language: vi,en-US;q=0.8,en;q=0.6\r\n\r\n";



/**
 * Stack area for the http thread.
 */
WORKING_AREA(wa_http_client, WEBC_THREAD_STACK_SIZE);

/**
 * HTTP server thread.
 */
msg_t http_client(void *p) {

  err_t err;

  (void)p;





   int sock;
  char recv_buf[1500];
  int res;

  struct sockaddr_in serv_addr;
     uint32_t bytes;




     lwip_socket_init();

     if ((sock = lwip_socket(AF_INET, SOCK_STREAM, 0)) < 0) {
        LWIP_DEBUGF(SOCKETS_DEBUG,("Error creating socket\n\r"));
        return -1;
     }



     serv_addr.sin_len = sizeof(serv_addr);
     serv_addr.sin_family = AF_INET;
     serv_addr.sin_port = PP_HTONS(PORT);
     //serv_addr.sin_addr.s_addr = inet_addr("140.211.11.131");
     serv_addr.sin_addr.s_addr = inet_addr("192.168.2.100");

     int opt = 3000;

     res = lwip_setsockopt(sock , SOL_SOCKET, SO_RCVTIMEO, &opt,   sizeof(int));

     res = lwip_connect(sock, (struct sockaddr *)&serv_addr, sizeof (serv_addr));

     res =  get_err(sock);


     if (res < 0) {
        LWIP_DEBUGF(SOCKETS_DEBUG,("Could not connect!!!\n\r"));
        lwip_close(sock);

     } else {
        LWIP_DEBUGF(SOCKETS_DEBUG,("Connected!!!\n\r"));
         bytes = lwip_write(sock, http_request, sizeof(http_request));

       res =  get_err(sock);

     LWIP_DEBUGF(SOCKETS_DEBUG,("Bytes wrote: %d\n\r",bytes));


      res = lwip_read(sock, recv_buf, 150);

      res =  get_err(sock);

      LWIP_DEBUGF(SOCKETS_DEBUG,("Read return code: %d\n\r",res));



      LWIP_DEBUGF(SOCKETS_DEBUG,("Buf%s\n\r",recv_buf));

      lwip_close(sock);
     }





  /* Goes to the final priority after initialization.*/
  chThdSetPriority(WEB_THREAD_PRIORITY);

  while(1) {
   ;
  }
  return RDY_OK;
}



/** @} */

[Giovanni]

Sorry if I can't answer this but my experience with lwIP does not go beyond the small HTTP demo provided in ChibiOS. I know there are users much more expert with it, hopefully somebody will answer this.

Giovanni

[pawelc06]

Hi there,
I found the problem!

Whis was in line:
res = lwip_connect(sock, (struct sockaddr *)&serv_addr, sizeof (serv_addr));

Declaration of serv_addr was:
static char *http_request =
"GET / HTTP/1.0\r\nHost: 92.43.118.240\r\nAccept: text/html,application/xhtml+xml,application/xml;q=0.9,image/webp,*/*;q=0.8\r\nUser-Agent: HTTPClient\r\n\r\nAccept-Encoding: gzip,deflate,sdch\r\nAccept-Language: vi,en-US;q=0.8,en;q=0.6\r\n\r\n";

so sizeof(serv_addr) was returning not the request length, but the length of data pointer = 4.

I changed it to:

bytes = lwip_write(sock, http_request, strlen(http_request));

Now it is working, but only when I connect /write/read/ close for the first time.
Next time I'm getting error -10 during lwip_connect attempt.

I'm just wondering, if closing of socket is correct, or should I maybe use shutdown ?

[pawelc06]

Additional information: after some time - several minutes, connection is possible again.
So it looks like web server is resseting this "inproper" state after few minutes.

But my question : how to close the socket correctly remains valid.
Anybody?