test/select/test08_srv.c

   1 /*
   2  * Test name: test08_srv.c
   3  *
   4  * Objective: Test a simple TCP server waiting for urgent data.
   5  *
   6  * Description: Implements a echo TCP server as in test06_srv but waits
   7  * for urgent data, using select on exception.
   8  *
   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 listen(long port) {
  33
  34   char *tcp_device;
  35   int netfd;
  36   nwio_tcpconf_t tcpconf;
  37   nwio_tcpcl_t tcpcl;
  38   nwio_tcpopt_t tcpopt;
  39
  40   /* Get default UDP device */
  41   if ((tcp_device = getenv("TCP_DEVICE")) == NULL)
  42     tcp_device = TCP_DEVICE;
  43
  44   /* Open TCP connection */
  45   if ((netfd = open(tcp_device, O_RDWR)) < 0)
  46   {
  47     fprintf(stderr,"Error opening TCP connection\n");
  48     return -1;
  49   }
  50
  51   /* Configure TCP connection */
  52   tcpconf.nwtc_flags = NWTC_LP_SET | NWTC_UNSET_RA | NWTC_UNSET_RP;
  53   tcpconf.nwtc_locport = (tcpport_t) htons(port);
  54
  55   if ((ioctl(netfd, NWIOSTCPCONF, &tcpconf))<0)
  56   {
  57     fprintf(stderr,"Error configuring the connection\n");
  58     close(netfd);
  59     return -1;
  60   }
  61
  62   /* Get communication conf*/
  63   if ((ioctl(netfd, NWIOGTCPCONF, &tcpconf)) < 0) {
  64     fprintf(stderr, "Error getting configuration\n");
  65     close(netfd);
  66     return -1;
  67    }
  68
  69    /* Set comm options */
  70   tcpopt.nwto_flags = NWTO_RCV_URG;
  71
  72   if ((ioctl(netfd, NWIOSTCPOPT, &tcpopt))<0)
  73   {
  74     fprintf(stderr,"Error configuring the connection\n");
  75     close(netfd);
  76     return -1;
  77   }
  78
  79   /* Get communication opt*/
  80   if ((ioctl(netfd, NWIOGTCPOPT, &tcpopt)) < 0) {
  81     fprintf(stderr, "Error getting options\n");
  82     close(netfd);
  83     return -1;
  84    }
  85
  86   /* Set conn options */
  87   tcpcl.nwtcl_flags = 0;
  88   printf("Waiting for connections...\n");
  89   while ((ioctl(netfd, NWIOTCPLISTEN, &tcpcl)) == -1)
  90   {
  91     if (errno != EAGAIN)
  92     {
  93         fprintf(stderr,"Unable to listen for connections\n");
  94         close(netfd);
  95     }
  96     sleep(-1);
  97   }
  98   return netfd;
  99 }
 100
 101 int main(int argc,char *argv[]) {
 102   int fd;
 103   ssize_t data_read;
 104   char buffer[1024];
 105   int ret;
 106   fd_set fds_excep;
 107
 108   if ((fd = listen(PORT)) < 0) {
 109         exit(-1);
 110   }
 111   printf("Waiting for messages on port: %ld\n", PORT);
 112   fflush(stdout);
 113   /* Initialize fd_set */
 114   FD_ZERO(&fds_excep);
 115   FD_SET(fd, &fds_excep);
 116
 117   while (1)
 118   {
 119     /* Wait for data available to be read (no timeout) */
 120
 121     ret = select(4, NULL, NULL, &fds_excep, NULL);
 122     if (ret < 0) {
 123         fprintf(stderr, "Error on select: %d\n", errno);
 124         exit(-1);
 125     }
 126     if (!FD_ISSET(fd, &fds_excep)) {
 127         printf("Error: no URG data received (?)\n");
 128         exit(-1);
 129     }
 130
 131     printf("Ready to receive...\n");
 132     /* Read received data */
 133     data_read = read(fd, &buffer, 1024);
 134     printf("Received data: %s\n", buffer);
 135
 136     /* Can exit if the received string == exit */
 137     if (!strcmp(buffer,"exit"))
 138       break;
 139
 140     /* Write the same back  */
 141     write(fd, &buffer, data_read);
 142   }
 143   printf("Connection finished\n");
 144   close(fd);
 145 }