test/select/test06_srv.c

   1 /*
   2  * Test name: test06_srv.c
   3  *
   4  * Objective: Test a simple TCP server
   5  *
   6  * Description: Implements a simple echo server using the TCP protocol. Instead
   7  * of blocking on read(), it performs a select call first blocking there
   8  * until there is data to be read
   9  */
  10
  11 #include <sys/types.h>
  12 #include <sys/ioctl.h>
  13 #include <sys/select.h>
  14 #include <sys/wait.h>
  15 #include <stdio.h>
  16 #include <string.h>
  17 #include <stdlib.h>
  18 #include <stdarg.h>
  19 #include <fcntl.h>
  20 #include <errno.h>
  21 #include <unistd.h>
  22 #include <net/netlib.h>
  23 #include <net/gen/netdb.h>
  24 #include <net/gen/in.h>
  25 #include <net/gen/tcp.h>
  26 #include <net/gen/tcp_io.h>
  27 #include <net/hton.h>
  28 #include <net/gen/inet.h>
  29
  30 #define PORT 6060L
  31
  32 int my_listen(long port) {
  33
  34   char *tcp_device;
  35   int netfd;
  36   nwio_tcpconf_t tcpconf;
  37   nwio_tcpcl_t tcplistenopt;
  38
  39   /* Get default UDP device */
  40   if ((tcp_device = getenv("TCP_DEVICE")) == NULL)
  41     tcp_device = TCP_DEVICE;
  42
  43   /* Open TCP connection */
  44   if ((netfd = open(tcp_device, O_RDWR)) < 0)
  45   {
  46     fprintf(stderr,"Error opening TCP connection\n");
  47     return -1;
  48   }
  49
  50   /* Configure TCP connection */
  51   tcpconf.nwtc_flags = NWTC_LP_SET | NWTC_UNSET_RA | NWTC_UNSET_RP;
  52   tcpconf.nwtc_locport = (tcpport_t) htons(port);
  53
  54   if ((ioctl(netfd, NWIOSTCPCONF, &tcpconf))<0)
  55   {
  56     fprintf(stderr,"Error configuring the connection\n");
  57     close(netfd);
  58     return -1;
  59   }
  60
  61   /* Get communication options */
  62   if ((ioctl(netfd, NWIOGTCPCONF, &tcpconf)) < 0) {
  63     fprintf(stderr, "Error getting configuration\n");
  64     close(netfd);
  65     return -1;
  66    }
  67
  68   /* Set conf options */
  69   tcplistenopt.nwtcl_flags = 0;
  70   printf("Waiting for connections...\n");
  71   while ((ioctl(netfd, NWIOTCPLISTEN, &tcplistenopt)) == -1)
  72   {
  73     if (errno != EAGAIN)
  74     {
  75         fprintf(stderr,"Unable to listen for connections\n");
  76         close(netfd);
  77     }
  78     sleep(-1);
  79   }
  80   return netfd;
  81 }
  82
  83 int main(int argc,char *argv[]) {
  84   int fd;
  85   ssize_t data_read;
  86   char buffer[1024];
  87   int ret;
  88   fd_set fds_read;
  89
  90   if ((fd = my_listen(PORT)) < 0) {
  91         exit(-1);
  92   }
  93   printf("Waiting for messages on port: %ld\n", PORT);
  94   fflush(stdout);
  95   /* Initialize fd_set */
  96   FD_ZERO(&fds_read);
  97   FD_SET(fd, &fds_read);
  98
  99   while (1)
 100   {
 101     /* Wait for data available to be read (no timeout) */
 102
 103     ret = select(4, &fds_read, NULL, NULL, NULL);
 104     if (ret < 0) {
 105         fprintf(stderr, "Error on select: %d\n", errno);
 106         exit(-1);
 107     }
 108     if (!FD_ISSET(fd, &fds_read)) {
 109         printf("Error: network fd is not ready (?)\n");
 110         exit(-1);
 111     }
 112
 113     printf("Ready to receive...\n");
 114     /* Read received data */
 115     data_read = read(fd, &buffer, 1024);
 116     printf("Received data: %s\n", buffer);
 117
 118     /* Can exit if the received string == exit */
 119     if (!strcmp(buffer,"exit"))
 120       break;
 121
 122     /* Write the same back  */
 123     write(fd, &buffer, data_read);
 124   }
 125   printf("Connection finished\n");
 126   close(fd);
 127 }