test/select/test05_srv.c

   1 /*
   2  * Test name: test05_srv.c
   3  *
   4  * Objective: Test an impatient UDP server with timeouts
   5  *
   6  * Description: Implements an echo server using the UDP protocol. It is
   7  * based on test04_srv, but it has a timeout value.
   8  */
   9
  10 #include <sys/types.h>
  11 #include <sys/ioctl.h>
  12 #include <sys/select.h>
  13 #include <sys/asynchio.h>
  14 #include <stdio.h>
  15 #include <string.h>
  16 #include <stdlib.h>
  17 #include <stdarg.h>
  18 #include <fcntl.h>
  19 #include <errno.h>
  20 #include <unistd.h>
  21 #include <net/netlib.h>
  22 #include <net/gen/netdb.h>
  23 #include <net/gen/in.h>
  24 #include <net/gen/udp.h>
  25 #include <net/gen/udp_hdr.h>
  26 #include <net/gen/udp_io.h>
  27 #include <net/hton.h>
  28
  29 #define PORT 6000L
  30
  31 /* type for received data */
  32 typedef struct
  33 {
  34   udp_io_hdr_t header;
  35   char data[1024];
  36 } udp_buffer_t;
  37
  38 int udp_conf(long port) {
  39
  40   char *udp_device;
  41   int netfd;
  42   nwio_udpopt_t udpopt;
  43
  44   /* Get default UDP device */
  45   if ((udp_device = getenv("UDP_DEVICE")) == NULL)
  46     udp_device = UDP_DEVICE;
  47
  48   /* Open UDP connection */
  49   if ((netfd = open(udp_device, O_RDWR)) < 0)
  50   {
  51     fprintf(stderr,"Error opening UDP connection\n");
  52     return -1;
  53   }
  54
  55   /* Configure UDP connection */
  56   udpopt.nwuo_flags = NWUO_COPY | NWUO_LP_SET | NWUO_EN_LOC | NWUO_DI_BROAD
  57                    | NWUO_RP_ANY | NWUO_RA_ANY | NWUO_RWDATALL | NWUO_DI_IPOPT;
  58
  59   udpopt.nwuo_locport = (udpport_t) htons(port);
  60
  61   if ((ioctl(netfd, NWIOSUDPOPT, &udpopt))<0)
  62   {
  63     fprintf(stderr,"Error configuring the connection\n");
  64     close(netfd);
  65     return -1;
  66   }
  67
  68   /* Get conf options */
  69   if ((ioctl(netfd, NWIOGUDPOPT, &udpopt))<0)
  70   {
  71     fprintf(stderr,"Error getting the conf\n");
  72     close(netfd);
  73     return -1;
  74   }
  75
  76   return netfd;
  77 }
  78
  79 int main(int argc,char *argv[]) {
  80   int fd;
  81   ssize_t data_read;
  82   udp_buffer_t buffer;
  83   ipaddr_t tmp_addr;
  84   udpport_t tmp_port;
  85   int ret;
  86   fd_set fds_read;
  87   struct timeval timeout;
  88   ipaddr_t client_addr, this_addr;
  89   udpport_t client_port;
  90
  91   if ((fd = udp_conf(PORT)) < 0) {
  92         fprintf(stderr, "Error configuring UDP connection\n");
  93         exit(-1);
  94   }
  95   printf("Waiting for messages on port: %ld\n", PORT);
  96   fflush(stdout);
  97
  98   /* get a first message so we know who is the client and we can harass it
  99      afterwards */
 100
 101   /* Initialize fd_set */
 102   FD_ZERO(&fds_read);
 103   FD_SET(fd, &fds_read);
 104   /* Set timeout structure */
 105   timeout.tv_sec = 3;
 106   timeout.tv_usec = 0;
 107   ret = select(4, &fds_read, NULL, NULL, NULL);
 108
 109   if (ret < 0) {
 110         fprintf(stderr, "Error in select\n");
 111         exit(-1);
 112   }
 113   if (!FD_ISSET(fd, &fds_read)) {
 114         fprintf(stderr, "Error: Should be receiving some data from network(?)\n");
 115         exit(-1);
 116   }
 117   printf("Ready to receive...\n");
 118   /* Read received data */
 119   data_read = read(fd, &buffer, sizeof(udp_buffer_t));
 120   printf("Received data: %s\n", buffer.data);
 121
 122   /* Can exit if the received string == exit */
 123   if (!strcmp(buffer.data,"exit"))
 124         exit(0);
 125
 126   /* Send data back, swap addresses */
 127   tmp_addr = buffer.header.uih_src_addr;
 128   buffer.header.uih_src_addr = buffer.header.uih_dst_addr;
 129   buffer.header.uih_dst_addr = tmp_addr;
 130   /* save address of both ends */
 131   client_addr = tmp_addr;
 132   this_addr = buffer.header.uih_src_addr;
 133
 134   /* Swap ports */
 135   tmp_port = buffer.header.uih_src_port;
 136   buffer.header.uih_src_port = buffer.header.uih_dst_port;
 137   buffer.header.uih_dst_port = tmp_port;
 138   /* save client port */
 139   client_port = tmp_port;
 140
 141   /* Write the same back  */
 142   write(fd, &buffer, data_read);
 143
 144   while (1)
 145   {
 146
 147     /* Initialize fd_set */
 148     FD_ZERO(&fds_read);
 149     FD_SET(fd, &fds_read);
 150     /* Set timeout structure */
 151     timeout.tv_sec = 3;
 152     timeout.tv_usec = 0;
 153     /* Wait for data available to be read (timeout) */
 154     ret = select(4, &fds_read, NULL, NULL, &timeout);
 155     if (ret < 0) {
 156         fprintf(stderr, "Error on select: %d", errno);
 157         exit(-1);
 158     }
 159     /* if timeout */
 160     if (ret == 0) {
 161         /* Send angry msg to client asking for more */
 162         printf("Tired of waiting, send client an angry message\n");
 163         buffer.header.uih_src_addr = this_addr;
 164         buffer.header.uih_dst_addr = client_addr;
 165         buffer.header.uih_src_port = PORT;
 166         buffer.header.uih_dst_port = client_port;
 167         strcpy(buffer.data, "Hey! I want to receive some data!\n");
 168         write(fd, &buffer, sizeof(udp_buffer_t));
 169     }
 170     /* If receive data from network */
 171     if (FD_ISSET(fd, &fds_read)) {
 172         printf("Ready to receive...\n");
 173         /* Read received data */
 174         data_read = read(fd, &buffer, sizeof(udp_buffer_t));
 175         printf("Received data: %s\n", buffer.data);
 176
 177         /* Can exit if the received string == exit */
 178         if (!strcmp(buffer.data,"exit"))
 179                 break;
 180
 181         /* Send data back, swap addresses */
 182         tmp_addr = buffer.header.uih_src_addr;
 183         buffer.header.uih_src_addr = buffer.header.uih_dst_addr;
 184         buffer.header.uih_dst_addr = tmp_addr;
 185
 186         /* Swap ports */
 187         tmp_port = buffer.header.uih_src_port;
 188         buffer.header.uih_src_port = buffer.header.uih_dst_port;
 189         buffer.header.uih_dst_port = tmp_port;
 190
 191         /* Write the same back  */
 192         write(fd, &buffer, data_read);
 193     }
 194   }
 195   close(fd);
 196 }