text: /****************************************************************************
   * examples/udp/udp_client.c
   *
   *   Copyright (C) 2007, 2015 Gregory Nutt. All rights reserved.
   *   Author: Gregory Nutt <gnutt@nuttx.org>
   *
   * Redistribution and use in source and binary forms, with or without
   * modification, are permitted provided that the following conditions
   * are met:
   *
   * 1. Redistributions of source code must retain the above copyright
   *    notice, this list of conditions and the following disclaimer.
   * 2. Redistributions in binary form must reproduce the above copyright
   *    notice, this list of conditions and the following disclaimer in
   *    the documentation and/or other materials provided with the
   *    distribution.
   * 3. Neither the name Gregory Nutt nor the names of its contributors may be
   *    used to endorse or promote products derived from this software
   *    without specific prior written permission.
   *
   * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
   * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
   * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
   * FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
   * COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
   * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
   * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS
   * OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
   * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
   * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN
   * ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
   * POSSIBILITY OF SUCH DAMAGE.
   *
   ****************************************************************************/
  
  /****************************************************************************
   * Included Files
   ****************************************************************************/
  
  #include "config.h"
  
  #include <sys/types.h>
  #include <sys/socket.h>
  
  #include <stdio.h>
  #include <stdlib.h>
  #include <unistd.h>
  #include <string.h>
  #include <errno.h>
  
  #include <arpa/inet.h>
  #include <netinet/in.h>
  
  #include "udp.h"
  
  /****************************************************************************
   * Private Functions
   ****************************************************************************/
  
  static int create_socket(void)
  {
    socklen_t addrlen;
    int sockfd;
  
  #ifdef CONFIG_EXAMPLES_UDP_IPv4
    struct sockaddr_in addr;
  
    /* Create a new IPv4 UDP socket */
  
    sockfd = socket(AF_INET, SOCK_DGRAM, 0);
    if (sockfd < 0)
      {
        printf("client ERROR: client socket failure %d\n", errno);
        return -1;
      }
  
    /* Bind the UDP socket to a IPv4 port */
  
    addr.sin_family      = AF_INET;
    addr.sin_port        = HTONS(CONFIG_EXAMPLES_UDP_CLIENT_PORTNO);
    addr.sin_addr.s_addr = HTONL(INADDR_ANY);
    addrlen              = sizeof(struct sockaddr_in);
  
  #else
    struct sockaddr_in6 addr;
  
    /* Create a new IPv6 UDP socket */
  
    sockfd = socket(AF_INET6, SOCK_DGRAM, 0);
    if (sockfd < 0)
      {
        printf("client ERROR: client socket failure %d\n", errno);
        return -1;
      }
  
    /* Bind the UDP socket to a IPv6 port */
  
    addr.sin6_family     = AF_INET6;
    addr.sin6_port       = HTONS(CONFIG_EXAMPLES_UDP_CLIENT_PORTNO);
    memset(addr.sin6_addr.s6_addr, 0, sizeof(struct in6_addr));
    addrlen              = sizeof(struct sockaddr_in6);
  #endif
  
    if (bind(sockfd, (FAR struct sockaddr *)&addr, addrlen) < 0)
      {
        printf("client ERROR: Bind failure: %d\n", errno);
        return -1;
      }
  
    return sockfd;
  }
  
  static inline void fill_buffer(unsigned char *buf, int offset)
  {
    int ch;
    int j;
  
    buf[0] = offset;
    for (ch = 0x20, j = offset + 1; ch < 0x7f; ch++, j++)
      {
        if (j >= SENDSIZE)
          {
            j = 1;
          }
  
        buf[j] = ch;
      }
  }
  
  /****************************************************************************
   * Public Functions
   ****************************************************************************/
  
  void udp_client(void)
  {
  #ifdef CONFIG_EXAMPLES_UDP_IPv6
    struct sockaddr_in6 server;
  #else
    struct sockaddr_in server;
  #endif
    unsigned char outbuf[SENDSIZE];
    socklen_t addrlen;
    int sockfd;
    int nbytes;
    int offset;
  #ifdef CONFIG_EXAMPLES_UDP_BROADCAST
    int optval;
    int ret;
  #endif
  
    /* Create a new UDP socket */
  
    sockfd = create_socket();
    if (sockfd < 0)
      {
        printf("client ERROR: create_socket failed %d\n");
        exit(1);
      }
  
  #ifdef CONFIG_EXAMPLES_UDP_BROADCAST
    optval = 1;
    ret = setsockopt(sockfd, SOL_SOCKET, SO_BROADCAST, &optval, sizeof(int));
    if (ret < 0)
      {
        printf("Failed to set SO_BROADCAST\n");
        exit(1);
      }
  #endif
  
    /* Then send and receive 256 messages */
  
    for (offset = 0; offset < 256; offset++)
      {
        /* Set up the output buffer */
  
        fill_buffer(outbuf, offset);
  
        /* Set up the server address */
  
  #ifdef CONFIG_EXAMPLES_UDP_IPv6
        server.sin6_family     = AF_INET6;
        server.sin6_port       = HTONS(CONFIG_EXAMPLES_UDP_SERVER_PORTNO);
        memcpy(server.sin6_addr.s6_addr16,
               g_udpserver_ipv6, 8 * sizeof(uint16_t));
        addrlen                = sizeof(struct sockaddr_in6);
  #else
        server.sin_family      = AF_INET;
        server.sin_port        = HTONS(CONFIG_EXAMPLES_UDP_SERVER_PORTNO);
        server.sin_addr.s_addr = (in_addr_t)g_udpserver_ipv4;
        addrlen                = sizeof(struct sockaddr_in);
  #endif
  
        /* Send the message */
  
        printf("client: %d. Sending %d bytes\n", offset, SENDSIZE);
        nbytes = sendto(sockfd, outbuf, SENDSIZE, 0,
                        (struct sockaddr *)&server, addrlen);
        printf("client: %d. Sent %d bytes\n", offset, nbytes);
  
        if (nbytes < 0)
          {
            printf("client: %d. sendto failed: %d\n", offset, errno);
            close(sockfd);
            exit(-1);
          }
        else if (nbytes != SENDSIZE)
          {
            printf("client: %d. Bad send length: %d Expected: %d\n",
                   offset, nbytes, SENDSIZE);
            close(sockfd);
            exit(-1);
          }
  
        /* Now, sleep a bit.  No packets should be dropped due to overrunning
         * the server.
         */
  
        sleep(2);
      }
  
    close(sockfd);
  }
  