test/select/test07_srv.c

   1 /*
   2  * Test name: test07_srv.c
   3  *
   4  * Objective: Test an impatient TCP server with a timeout.
   5  *
   6  * Description: Implements an echo server using the TCP protocol. It is
   7  * based on test06_srv.c but has a timeout for receiving data from a client
   8  * and if the time is up it sends an angry message to the client requesting
   9  * for more information.
  10  */
  11
  12 #include <sys/types.h>
  13 #include <sys/ioctl.h>
  14 #include <sys/select.h>
  15 #include <sys/wait.h>
  16 #include <sys/asynchio.h>
  17 #include <stdio.h>
  18 #include <string.h>
  19 #include <stdlib.h>
  20 #include <stdarg.h>
  21 #include <fcntl.h>
  22 #include <errno.h>
  23 #include <unistd.h>
  24 #include <net/netlib.h>
  25 #include <net/gen/netdb.h>
  26 #include <net/gen/in.h>
  27 #include <net/gen/tcp.h>
  28 #include <net/gen/tcp_io.h>
  29 #include <net/hton.h>
  30 #include <net/gen/inet.h>
  31
  32 #define PORT 6060L
  33
  34 int my_listen(long port) {
  35
  36   char *tcp_device;
  37   int netfd;
  38   nwio_tcpconf_t tcpconf;
  39   nwio_tcpcl_t tcplistenopt;
  40
  41   /* Get default UDP device */
  42   if ((tcp_device = getenv("TCP_DEVICE")) == NULL)
  43     tcp_device = TCP_DEVICE;
  44
  45   /* Open TCP connection */
  46   if ((netfd = open(tcp_device, O_RDWR)) < 0)
  47   {
  48     fprintf(stderr,"Error opening TCP connection\n");
  49     return -1;
  50   }
  51
  52   /* Configure TCP connection */
  53   tcpconf.nwtc_flags = NWTC_LP_SET | NWTC_UNSET_RA | NWTC_UNSET_RP;
  54   tcpconf.nwtc_locport = (tcpport_t) htons(port);
  55
  56   if ((ioctl(netfd, NWIOSTCPCONF, &tcpconf))<0)
  57   {
  58     fprintf(stderr,"Error configuring the connection\n");
  59     close(netfd);
  60     return -1;
  61   }
  62
  63   /* Get communication options */
  64   if ((ioctl(netfd, NWIOGTCPCONF, &tcpconf)) < 0) {
  65     fprintf(stderr, "Error getting configuration\n");
  66     close(netfd);
  67     return -1;
  68    }
  69
  70   /* Set conf options */
  71   tcplistenopt.nwtcl_flags = 0;
  72   printf("Waiting for connections...\n");
  73   while ((ioctl(netfd, NWIOTCPLISTEN, &tcplistenopt)) == -1)
  74   {
  75     if (errno != EAGAIN)
  76     {
  77         fprintf(stderr,"Unable to listen for connections\n");
  78         close(netfd);
  79     }
  80     sleep(-1);
  81   }
  82   return netfd;
  83 }
  84
  85 int main(int argc,char *argv[]) {
  86   int fd;
  87   ssize_t data_read;
  88   char buffer[1024];
  89   int ret;
  90   fd_set fds_read;
  91   struct timeval timeout;
  92
  93   if ((fd = my_listen(PORT)) < 0) {
  94         exit(-1);
  95   }
  96   printf("Waiting for messages on port: %ld\n", PORT);
  97   fflush(stdout);
  98   while (1)
  99   {
 100
 101     /* Initialize fd_set */
 102     FD_ZERO(&fds_read);
 103     FD_SET(fd, &fds_read);
 104     /* set timeout */
 105     timeout.tv_sec = 3;
 106     timeout.tv_usec = 0;
 107     /* Wait for data available to be read (no timeout) */
 108     ret = select(4, &fds_read, NULL, NULL, &timeout);
 109     if (ret < 0) {
 110         fprintf(stderr, "Error on select: %d\n", errno);
 111         exit(-1);
 112     }
 113     /* timeout */
 114     if (ret == 0) {
 115         strcpy(buffer, "I want to get some data!!\n");
 116         write(fd, &buffer, 1024);
 117         continue;
 118     }
 119
 120     /* data received from client */
 121     if (FD_ISSET(fd, &fds_read)) {
 122         printf("Ready to receive...\n");
 123         /* Read received data */
 124         data_read = read(fd, &buffer, 1024);
 125         printf("Received data: %s\n", buffer);
 126
 127         /* Can exit if the received string == exit */
 128         if (!strcmp(buffer,"exit"))
 129            break;
 130
 131         /* Write the same back  */
 132         write(fd, &buffer, data_read);
 133      }
 134   }
 135   printf("Connection finished\n");
 136   close(fd);
 137 }