Simple Socket Client

Hi Redbeard,

Funny, I have a similar requirement. First, take a look at this sockets tutorial.... http://www.cs.rpi.edu/courses/sysprog/sockets/sock.html (http://www.cs.rpi.edu/courses/sysprog/sockets/sock.html)

The simplest approach is to implement a socket client on NIOS. So here's a trivial socket client (modelled on the tutorial). BTW, this code runs nicely on NIOS (under uClinux, with network support and LAN91C111 driver enabled).....

// tty2sock.cpp
// ============# include <stdio.h># include <stdlib.h># include <string.h># include <unistd.h># include <sys/types.h># include <sys/socket.h># include <netinet/in.h># include <netdb.h> 
# define SERVER_NAME    "192.168.0.78"           // Your server IP goes here# define SERVER_PORT    4000
void error(char *msg)
{
   perror(msg);
   exit(0);
}
int main(int argc, char *argv)
{
  struct sockaddr_in serv_addr;
  char buffer    = { 0 };
  printf  ("Hello from tty2sock!\n");
  FILE*    ttyPort  = fopen    ("/dev/tty", "r");
  int portNumber    = SERVER_PORT;
  printf  ("portNumber=0x%8x\n", portNumber);
  int sockHandle    = socket(AF_INET, SOCK_STREAM, 0);
  printf  ("sockHandle=0x%8x\n", sockHandle);
  if (sockHandle < 0)
  { 
    error  ("ERROR opening socket");
  }
  struct hostent* server = gethostbyname(SERVER_NAME);
  if (server == NULL)
  {
    fprintf(stderr,"ERROR, no such host\n");
    exit(0);
  }
  
  memset    (&serv_addr, 0, sizeof(serv_addr));
  serv_addr.sin_family    = AF_INET;
  bcopy  ((char *)server->h_addr, (char *)&serv_addr.sin_addr.s_addr, server->h_length);
  serv_addr.sin_port    = htons(SERVER_PORT);
  if (connect(sockHandle,(const sockaddr*)&serv_addr,sizeof(serv_addr)) < 0)
  { 
    error  ("ERROR connecting");
  }
  printf  ("Enter a message: ");
  bzero      (buffer, 256);
  fgets      (buffer, 255, stdin);
  printf  ("buffer=\n", buffer);
  int n      = write(sockHandle,buffer,strlen(buffer));
  if (n < 0)
  { 
    error  ("ERROR writing to socket");
  }
  return  0;
}

Next, here's the corresponding socket server (also modelled on the tutorial). BTW, this server is running on a Debian Linux box...

// socketServer.cpp
// ================
// A simple server in the internet domain using TCP
// The port number is passed as an argument # include <stdio.h># include <stdlib.h># include <string.h># include <netinet/in.h># include <sys/types.h> # include <sys/socket.h># include <unistd.h>
void error(char *msg)
{
  perror    (msg);
  exit  (1);
}
int main    (int argc, char *argv)
{
  int sockfd, newsockfd, portno;
  socklen_t clilen    = 0;
  char buffer;
  struct sockaddr_in serv_addr, cli_addr;
  int n;
  
  if (argc < 2)
  {
    fprintf(stderr,"ERROR, no port provided\n");
    exit(1);
  }
  
  sockfd = socket(AF_INET, SOCK_STREAM, 0);
  
  if (sockfd < 0)
  { 
    error("ERROR opening socket");
  }
  
//bzero((char *) &serv_addr, sizeof(serv_addr));
  memset    (&serv_addr,
      0,
      sizeof(serv_addr));
  portno = atoi(argv);
  serv_addr.sin_family = AF_INET;
  serv_addr.sin_addr.s_addr = INADDR_ANY;
  serv_addr.sin_port = htons(portno);
  if (bind(sockfd, (struct sockaddr *) &serv_addr, sizeof(serv_addr)) < 0)
  {
    error("ERROR on binding");
  }
  
  listen(sockfd,5);
  clilen = sizeof(cli_addr);
  newsockfd = accept(sockfd, 
      (struct sockaddr *)&cli_addr, 
       (socklen_t*)&clilen);
  if (newsockfd < 0)
  {
    error("ERROR on accept");
  }
  
  bzero(buffer,256);
  n = read(newsockfd,buffer,255);
  if (n < 0)
  {
    error("ERROR reading from socket");
  }
  
  printf("Here is the message: %s\n",buffer);
  return 0; 
}

How to run it...

1) Compile the socketServer app on your PC. I'm using Eclipse on Debian.

2) Cross-compile and link the tty2sock app as follows....

nios2-linux-uclibc-c++ tty2sock.cpp -o tty2sock -elf2flt="-s 64000"
cp tty2sock ~/rootfs/bin

3) Startup the server on PC, supplying PORT on the command-line...eg. "socketServer 4000"

4) Execute tty2sock on NIOS

nios-terminal -->

tty2sock -->

"The quick brown fox jumps over the lazy dog"

5) Your message should gurgle out on the server.

Hope this helps

Hi @ all,

for anyone who is interested: I made a udp-server/client with lwip. It's a stand-alone server for EP2S60.

Unfortunately I seem to have lost my udp-server example. But it was based on the stand-alone web server example from the lwip-stack.

Cheers,

Danny

Here is my code based on the Web server LWIp example :

I have files user.h, network_utilities.h, web_server.c (converted in eth_client.c) and my below file send.c :

#include <stdio.h># include <stdlib.h># include <string.h># include <ctype.h># include <sys/param.h># include <sys/fcntl.h># include "lwip/netif.h"# include "lwip/sockets.h"# include "arch/sys_arch.h"# include "sys/alt_alarm.h"# include "alt_types.h"# include "user.h"# include "io.h"
# ifdef DEBUG
 # include alt_debug.h# else
 # define ALT_DEBUG_ASSERT(a) # endif /* DEBUG */
# define   nbc                   100 // 225 // 200# define   nbl                   200 // 200 // 250# define   fps                   75
# define   SEND_PORT             30    // TCP port number to listen on 
int handle_send(int sock)
{
  char* buffer;
  int i, j;
  int n, a, k;
  buffer=(char *)calloc(nbl*nbc, sizeof(char));
  
  for (i=0; i<nbl; i++) //Ecriture sur nbl lignes
  { 
    for(j=0; j<nbc; j++) // une ligne contient nbc pixels
    {  
       buffer = (char)(j+1);
    }
  }   
  printf(" Buffering data finished\n");
  printf(" Buffer length : %d\n", strlen(buffer));
 
  n = send(sock, buffer, strlen(buffer),0);
  //int lwip_send(int s, void *dataptr, int size, unsigned int flags);
  if (n < 0)
    die_with_error(" error writing to socket\n");
  return n;
}
void send_task()
{
  int sock;
  struct  sockaddr_in addr;
  
  printf(" Creating socket\n");
  if ((sock = socket(AF_INET, SOCK_STREAM, 0)) < 0)
    die_with_error(" Listening socket creation failed");
  
  addr.sin_family = AF_INET;
  addr.sin_port = htons(SEND_PORT);
  addr.sin_addr.s_addr = inet_addr("10.0.0.11");
 
  while ((connect(sock,(struct sockaddr *)&addr,sizeof(addr))) < 0)
    printf(" Trying to connect to server\n");
  printf(" Client sending on port %d\n", SEND_PORT);
  
  if ((handle_send(sock)) <0)
      printf(" Transmit failed\n");
  printf(" End of Connection\n");
  close(sock);
}

With that code, i can't send more than a buffer of 100x200 char. And i don't understand why! My pc server seems to correctly receive the data anyway.

So are there parameters to change in LWIP to send a certain amount of data like buffers or stacks?

Thanks for ur future answers.

Regards,

Xavier

Hi hootsmon,

How do you run the code you cross compiled in the Nios processor?

Sorry for the dumb question. I am a newbie on Nios stuff.

Thanks,

Denis

Hi Lord_Redbeard

Is your work is based on the DE2_WEB?Can you tell me how to modify the project to connect to the server on PC?

I made a client in the project, and I could get reply from the DE2 board with commadn "Ping".but it could not connect to the server on PC?Did you have the problem?