150 lines
		
	
	
		
			3.5 KiB
		
	
	
	
		
			C
		
	
	
		
			Executable File
		
	
	
	
	
			
		
		
	
	
			150 lines
		
	
	
		
			3.5 KiB
		
	
	
	
		
			C
		
	
	
		
			Executable File
		
	
	
	
	
| /*
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|  * Test name: test04_cli.c
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|  *
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|  * Objective: Test a simple UDP client
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|  *
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|  * Description: Implements a simple echo client using the UDP protocol. First
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|  * it waits until it is possible to write (which is always).
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|  */
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| 
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| #include <sys/types.h>
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| #include <sys/ioctl.h>
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| #include <sys/select.h>
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| #include <stdio.h>
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| #include <string.h>
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| #include <stdlib.h>
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| #include <stdarg.h>
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| #include <fcntl.h>
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| #include <errno.h>
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| #include <unistd.h>
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| #include <net/netlib.h>
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| #include <net/gen/netdb.h>
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| #include <net/gen/in.h>
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| #include <net/gen/udp.h>
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| #include <net/gen/udp_hdr.h>
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| #include <net/gen/udp_io.h>
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| #include <net/hton.h>
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| 
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| #define PORT 6000L
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| 
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| /* Type for received data */
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| typedef struct
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| {
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|   udp_io_hdr_t header;
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|   char data[1024];
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| } udp_buffer_t;
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| 
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| 
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| int udp_conf(char *host, long port, udp_io_hdr_t *header)
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| {
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|   /* configures UDP connection */
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|   char *udp_device;
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|   struct hostent *hp;
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|   int netfd;
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|   nwio_udpopt_t udpopt;
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|   ipaddr_t dirhost;
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|   int result;
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|   
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|   /* get host address */
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|   if ((hp = gethostbyname(host)) == (struct hostent*) NULL) 
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|   {
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|     fprintf(stderr,"Unknown host\n");
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|     return(-1);
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|   }
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|   memcpy((char *)&dirhost, (char *)hp->h_addr, hp->h_length);
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|   
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|   /* Get UDP device */
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|   if (( udp_device = getenv("UDP_DEVICE") ) == NULL) 
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|     udp_device = UDP_DEVICE;
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|   
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|   /* Get UDP connection */ 
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|   if ((netfd = open(udp_device, O_RDWR)) < 0) 
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|   {
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|     fprintf(stderr,"Error opening UDP device\n");
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|     return -1;
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|   }
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|   
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|   /* Configure UDP connection */
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|   udpopt.nwuo_flags = NWUO_COPY | NWUO_LP_SEL | NWUO_EN_LOC | NWUO_DI_BROAD 
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|                    | NWUO_RP_SET | NWUO_RA_SET | NWUO_RWDATALL | NWUO_DI_IPOPT;
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|   udpopt.nwuo_remaddr = dirhost;
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|   udpopt.nwuo_remport = (udpport_t) htons(port);
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|   
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|   if ((result = ioctl(netfd, NWIOSUDPOPT, &udpopt) ) <0) 
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|   {
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|     fprintf(stderr, "Error establishing communication\n");
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|     printf("Error:  %d\n",result);
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|     close(netfd);
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|     return -1;
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|   }
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|   
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|   /* Get configuration for UDP comm */ 
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|   if ((result = ioctl(netfd, NWIOGUDPOPT, &udpopt) ) < 0) 
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|   {
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|     fprintf(stderr,"Error getting configuration\n");
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|     printf("Error: %d\n", result);
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|     close(netfd);
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|     return -1;
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|   }
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| 
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|   header->uih_src_addr = udpopt.nwuo_locaddr;
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|   header->uih_dst_addr = udpopt.nwuo_remaddr;
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|   header->uih_src_port = udpopt.nwuo_locport;
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|   header->uih_dst_port = udpopt.nwuo_remport;
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|  
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|   return netfd;
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| }
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| 
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| int main(int argc,char *argv[]) {
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|   int fd;
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|   ssize_t data_read;
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|   udp_buffer_t buffer_send, buffer_rec;
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|   fd_set fds_write;
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|   int ret;
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| 
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|   /* Check parameters */
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|   if (argc !=2) {
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|     fprintf(stderr,"Usage: %s host\n", argv[0]);
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|     exit(-1);
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|   }
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| 
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|   if ((fd = udp_conf(argv[1], PORT, &buffer_send.header) ) < 0) 
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|     exit(-1);	
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| 
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|   /* init fd_set */
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|   FD_ZERO(&fds_write);
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|   FD_SET(fd, &fds_write);
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| 
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|   while (1) 
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|   {
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|     /* Wait until it is possible to write with select */
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| 
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|     ret = select(4, NULL, &fds_write, NULL, NULL);
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|     if (ret < 0) {
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|     	fprintf(stderr, "Error on select waiting for write: %d\n", errno);
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|     	exit(-1);
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|     }
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|     if (!FD_ISSET(fd, &fds_write)) {
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|     	fprintf(stderr, "Error: The net connection is not ready for writing (?)\n"); 
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|     	exit(-1);
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|     }
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| 
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|     /* Get a string and send it */
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|     printf("Ready to write...\n");
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|     printf("Send data: ");
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|     gets(buffer_send.data);
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|     write(fd, &buffer_send, sizeof(udp_buffer_t));
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|   
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|     /* If data sent is exit then break */
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|     if (!strcmp(buffer_send.data,"exit")) 
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|       break;
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|   		
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|     /* Get server response */
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|     data_read = read(fd, &buffer_rec, sizeof(udp_buffer_t));
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|     printf("Received: %s\n\n", buffer_rec.data);
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|   }
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|   
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|   /* Close UDP communication */
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|   close(fd);
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| }
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