#include <sys/types.h>
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#include <sys/socket.h>
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#include <netinet/in.h> /* needed for sockaddr_in */
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#include <stdio.h> /* needed for sockaddr_in */
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#include <string.h> /* needed for sockaddr_in */
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#include <netdb.h>
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#include "server.h"
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#define MESSAGESIZE 512
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#define SERVER_PORT 9876
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#define CLIENT_PORT 9879
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#define STR(x) #x
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#define PARAMETER_SERVER localhost
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int socket_setup(int port)
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{
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static int fd = 0; /* our socket */
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if(fd) return fd;
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struct sockaddr_in myaddr; /* our address */
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/* create a UDP socket */
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if ((fd = socket(AF_INET, SOCK_DGRAM, 0)) < 0) {
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perror("cannot create socket\n");
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fd=0;
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return 0;
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}
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/* bind the socket to any valid IP address and a specific port */
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memset((char *)&myaddr, 0, sizeof(myaddr));
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myaddr.sin_family = AF_INET;
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myaddr.sin_addr.s_addr = htonl(INADDR_ANY);
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myaddr.sin_port = htons(port);
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if (bind(fd, (struct sockaddr *)&myaddr, sizeof(myaddr)) < 0) {
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perror("bind failed");
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fd=0;
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return 0;
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}
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return fd;
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}
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void server_update()
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{
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int fd = socket_setup(SERVER_PORT);
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struct sockaddr_in remaddr; /* remote address */
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socklen_t addrlen = sizeof(remaddr); /* length of addresses */
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int recvlen; /* # bytes received */
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unsigned char buf[MESSAGESIZE]; /* receive buffer */
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recvlen = recvfrom(fd, buf, MESSAGESIZE, 0, (struct sockaddr *)&remaddr, &addrlen);
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buf[recvlen] = 0;
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printf("received %d bytes\n", recvlen);
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printf("%s\n", buf);
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}
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void client_update()
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{
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int fd = socket_setup(CLIENT_PORT);
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struct hostent *hp; /* host information */
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struct sockaddr_in servaddr; /* server address */
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char *my_message = "this is a test message";
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/* fill in the server's address and data */
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memset((char*)&servaddr, 0, sizeof(servaddr));
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servaddr.sin_family = AF_INET;
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servaddr.sin_port = htons(SERVER_PORT);
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/* look up the address of the server given its name */
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hp = gethostbyname("localhost");
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if (!hp) {
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fprintf(stderr, "could not obtain address of %s\n", "localhost");
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}
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/* put the host's address into the server address structure */
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memcpy((void *)&servaddr.sin_addr, hp->h_addr_list[0], hp->h_length);
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/* send a message to the server */
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if (sendto(fd, my_message, strlen(my_message), 0, (struct sockaddr *)&servaddr, sizeof(servaddr)) < 0) {
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perror("sendto failed");
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}
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}
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