/* server.c */

#include <stdio.h>

#include <string.h>

#include <netinet/in.h>

#include <arpa/inet.h>

#include <ctype.h>

#include "wrap.h"

#define MAXLINE 80

#define SERV_PORT 8000

int main(void)

{

	struct sockaddr_in servaddr, cliaddr;

	socklen_t cliaddr_len;

	int sockfd;

	char buf[MAXLINE];

	char str[INET_ADDRSTRLEN];

	int i, n;

	sockfd = wrap_socket(AF_INET, SOCK_DGRAM, 0);

	bzero(&servaddr, sizeof(servaddr));

	servaddr.sin_family = AF_INET;

	servaddr.sin_addr.s_addr = htonl(INADDR_ANY);

	servaddr.sin_port = htons(SERV_PORT);

	wrap_bind(sockfd, (struct sockaddr*)&servaddr, sizeof(servaddr));

	printf("Accepting connections ...\n");

	while(1)

	{

		cliaddr_len = sizeof(cliaddr);

		n = recvfrom(sockfd, buf, MAXLINE, 0, (struct sockaddr *)&cliaddr, &cliaddr_len);

		if(n == -1)

		{

			perr_exit("recvfrom error");

		}

		printf("received from %s at port %d\n",

			inet_ntop(AF_INET, &cliaddr.sin_addr, str, sizeof(str)),

			ntohs(cliaddr.sin_port));

		for(i = 0; i < n; ++i)

		{

			buf[i] = toupper(buf[i]);

		}

		n = sendto(sockfd, buf, n, 0, (struct sockaddr *)&cliaddr, sizeof(cliaddr));

		if(n == -1)

			perr_exit("sendto error!");

	}

}

/* client.c */

#include <stdio.h>

#include <string.h>

#include <unistd.h>

#include <netinet/in.h>

#include <arpa/inet.h>

#include "wrap.h"

#define MAXLINE 80

#define SERV_PORT 8000

int main(int argc, char *argv[])

{

	struct sockaddr_in servaddr;

	int sockfd, n;

	char buf[MAXLINE];

	char str[INET_ADDRSTRLEN];

	socklen_t servaddr_len;

	sockfd = wrap_socket(AF_INET, SOCK_DGRAM, 0);

	bzero(&servaddr, sizeof(servaddr));

	servaddr.sin_family = AF_INET;

	inet_pton(AF_INET, "127.0.0.1", &servaddr.sin_addr);

	servaddr.sin_port = htons(SERV_PORT);

	while(fgets(buf, MAXLINE, stdin) != NULL)

	{

		n = sendto(sockfd, buf, strlen(buf), 0, (struct sockaddr *)&servaddr, sizeof(servaddr));

		if(n == -1)

			perr_exit("sendto error");

		n = recvfrom(sockfd, buf, MAXLINE, 0, NULL, 0);

		if(n == -1)

			perr_exit("recvfrom error");

		wrap_write(STDOUT_FILENO, buf, n);

	}

	wrap_close(sockfd);

	return 0;

}