opc-client.c

#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>
#include <sys/socket.h>
#include <netinet/in.h>
#include <netinet/tcp.h>
#include <signal.h>
#include <netdb.h>
#include <math.h>
#include <sys/time.h>

#include "opc-client.h"

OpcClient *
opc_client_new (char   *hostport,
                int     default_port,
                int     fb_size,
                double *framebuffer)
{
  char *host, *colon;
  struct addrinfo wish = { 0, 0, SOCK_STREAM, 0, 0, NULL, NULL, NULL };
  int success = 0;

  OpcClient *client = calloc (1, sizeof (OpcClient));

  client->fd = -1;
  client->fb_size = fb_size;
  client->framebuffer = framebuffer;

  host = strdup (hostport);
  colon = strchr (host, ':');
  /* check for ipv6 */
  if (strrchr (host, ':') != colon)
    colon = NULL;

  if (colon)
    {
      *colon = '\0';
    }

  getaddrinfo (*host ? host : "localhost", colon ? colon + 1 : "7890",
               &wish, &client->addresses);

  if (client->addresses)
    success = 1;

  free (host);
  if (!success)
    {
      free (client);
      client = NULL;
    }

  return client;
}


int
opc_client_connect (OpcClient *client)
{
  int flag;
  struct addrinfo *info;

  while (client->fd < 0)
    {
      for (info = client->addresses; info; info = info->ai_next)
        {
          client->fd = socket (info->ai_family,
                               info->ai_socktype,
                               info->ai_protocol);

          if (client->fd >= 0)
            {
              if (connect (client->fd,
                           info->ai_addr,
                           info->ai_addrlen) < 0)
                {
                  perror ("connect");
                }
              else
                {
                  break;
                }

              close (client->fd);
              client->fd = -1;
            }
          else
            {
              perror ("socket");
            }
        }

      if (client->fd < 0)
        {
          sleep (1);
        }
    }

  flag = 1;
  setsockopt (client->fd,
              IPPROTO_TCP,
              TCP_NODELAY,
              (char *) &flag,
              sizeof (flag));

  signal (SIGPIPE, SIG_IGN);

  return 1;
}


int
opc_client_write (OpcClient *client,
                  uint8_t channel,
                  uint8_t command)
{
  int length = 4 + client->fb_size * sizeof (uint8_t);
  uint8_t *buffer;
  uint8_t *data;
  int i;

  if (client->fd < 0)
    return 0;

  buffer = malloc (length);

  buffer[0] = command;
  buffer[1] = channel;
  buffer[2] = (length - 4) >> 8;
  buffer[3] = (length - 4) & 0xff;

  for (i = 0; i < client->fb_size; i++)
    {
      buffer[i + 4] = (uint8_t) (client->framebuffer[i] * 255.0);
    }

  data = (uint8_t *) buffer;

  while (length > 0)
    {
      int res;

      res = send (client->fd, data, length, 0);
      if (res < 0)
        {
          perror ("send");
          opc_client_shutdown (client);
          return 0;
        }

      length -= res;
      data += length;
    }

  free (buffer);
  return 1;
}


void
opc_client_shutdown (OpcClient *client)
{
  if (client->fd >= 0)
    {
      close (client->fd);
      client->fd = -1;
    }

  if (client->addresses)
    freeaddrinfo (client->addresses);
}