test/select/test04_cli.c

   1 /*
   2  * Test name: test04_cli.c
   3  *
   4  * Objective: Test a simple UDP client
   5  *
   6  * Description: Implements a simple echo client using the UDP protocol. First
   7  * it waits until it is possible to write (which is always).
   8  */
   9
  10 #include <sys/types.h>
  11 #include <sys/ioctl.h>
  12 #include <sys/select.h>
  13 #include <stdio.h>
  14 #include <string.h>
  15 #include <stdlib.h>
  16 #include <stdarg.h>
  17 #include <fcntl.h>
  18 #include <errno.h>
  19 #include <unistd.h>
  20 #include <net/netlib.h>
  21 #include <net/gen/netdb.h>
  22 #include <net/gen/in.h>
  23 #include <net/gen/udp.h>
  24 #include <net/gen/udp_hdr.h>
  25 #include <net/gen/udp_io.h>
  26 #include <net/hton.h>
  27
  28 #define PORT 6000L
  29
  30 /* Type for received data */
  31 typedef struct
  32 {
  33   udp_io_hdr_t header;
  34   char data[1024];
  35 } udp_buffer_t;
  36
  37 int udp_conf(char *host, long port, udp_io_hdr_t *header)
  38 {
  39   /* configures UDP connection */
  40   char *udp_device;
  41   struct hostent *hp;
  42   int netfd;
  43   nwio_udpopt_t udpopt;
  44   ipaddr_t dirhost;
  45   int result;
  46
  47   /* get host address */
  48   if ((hp = gethostbyname(host)) == (struct hostent*) NULL)
  49   {
  50     fprintf(stderr,"Unknown host\n");
  51     return(-1);
  52   }
  53   memcpy((char *)&dirhost, (char *)hp->h_addr, hp->h_length);
  54
  55   /* Get UDP device */
  56   if (( udp_device = getenv("UDP_DEVICE") ) == NULL)
  57     udp_device = UDP_DEVICE;
  58
  59   /* Get UDP connection */
  60   if ((netfd = open(udp_device, O_RDWR)) < 0)
  61   {
  62     fprintf(stderr,"Error opening UDP device\n");
  63     return -1;
  64   }
  65
  66   /* Configure UDP connection */
  67   udpopt.nwuo_flags = NWUO_COPY | NWUO_LP_SEL | NWUO_EN_LOC | NWUO_DI_BROAD
  68                    | NWUO_RP_SET | NWUO_RA_SET | NWUO_RWDATALL | NWUO_DI_IPOPT;
  69   udpopt.nwuo_remaddr = dirhost;
  70   udpopt.nwuo_remport = (udpport_t) htons(port);
  71
  72   if ((result = ioctl(netfd, NWIOSUDPOPT, &udpopt) ) <0)
  73   {
  74     fprintf(stderr, "Error establishing communication\n");
  75     printf("Error:  %d\n",result);
  76     close(netfd);
  77     return -1;
  78   }
  79
  80   /* Get configuration for UDP comm */
  81   if ((result = ioctl(netfd, NWIOGUDPOPT, &udpopt) ) < 0)
  82   {
  83     fprintf(stderr,"Error getting configuration\n");
  84     printf("Error: %d\n", result);
  85     close(netfd);
  86     return -1;
  87   }
  88
  89   header->uih_src_addr = udpopt.nwuo_locaddr;
  90   header->uih_dst_addr = udpopt.nwuo_remaddr;
  91   header->uih_src_port = udpopt.nwuo_locport;
  92   header->uih_dst_port = udpopt.nwuo_remport;
  93
  94   return netfd;
  95 }
  96
  97 int main(int argc,char *argv[]) {
  98   int fd;
  99   ssize_t data_read;
 100   udp_buffer_t buffer_send, buffer_rec;
 101   fd_set fds_write;
 102   int ret;
 103
 104   /* Check parameters */
 105   if (argc !=2) {
 106     fprintf(stderr,"Usage: %s host\n", argv[0]);
 107     exit(-1);
 108   }
 109
 110   if ((fd = udp_conf(argv[1], PORT, &buffer_send.header) ) < 0)
 111     exit(-1);
 112
 113   /* init fd_set */
 114   FD_ZERO(&fds_write);
 115   FD_SET(fd, &fds_write);
 116
 117   while (1)
 118   {
 119     /* Wait until it is possible to write with select */
 120
 121     ret = select(4, NULL, &fds_write, NULL, NULL);
 122     if (ret < 0) {
 123         fprintf(stderr, "Error on select waiting for write: %d\n", errno);
 124         exit(-1);
 125     }
 126     if (!FD_ISSET(fd, &fds_write)) {
 127         fprintf(stderr, "Error: The net connection is not ready for writing (?)\n");
 128         exit(-1);
 129     }
 130
 131     /* Get a string and send it */
 132     printf("Ready to write...\n");
 133     printf("Send data: ");
 134     gets(buffer_send.data);
 135     write(fd, &buffer_send, sizeof(udp_buffer_t));
 136
 137     /* If data sent is exit then break */
 138     if (!strcmp(buffer_send.data,"exit"))
 139       break;
 140
 141     /* Get server response */
 142     data_read = read(fd, &buffer_rec, sizeof(udp_buffer_t));
 143     printf("Received: %s\n\n", buffer_rec.data);
 144   }
 145
 146   /* Close UDP communication */
 147   close(fd);
 148 }