Client-server flood generator

flooder.c

#include <assert.h>
#include <sys/socket.h>
#include <netinet/in.h>
#include <arpa/inet.h>
#include <stdio.h>
#include <stdlib.h>
#include <unistd.h>
#include <errno.h>
#include <string.h>
#include <sys/types.h>
#include <time.h>

#define BUFF_SZ 128
#define PORT 5000
#define SESSION_LENGTH 60

// http://www.thegeekstuff.com/2011/12/c-socket-programming/

void serve(void)
{
	int listenfd = 0, connfd = 0;
	struct sockaddr_in serv_addr; 

	printf("Server mode...\n");

	char sendBuff[BUFF_SZ];
	unsigned long c = 0;
	clock_t started_on, now;

	listenfd = socket(AF_INET, SOCK_STREAM, 0);
	memset(&serv_addr, '0', sizeof(serv_addr));
	memset(sendBuff, '0', sizeof(sendBuff)); 

	serv_addr.sin_family = AF_INET;
	serv_addr.sin_addr.s_addr = htonl(INADDR_ANY);
	serv_addr.sin_port = htons(PORT); 
	printf("Binding to %d:%d... ", INADDR_ANY, PORT);

	while (bind(listenfd, (struct sockaddr*)&serv_addr, sizeof(serv_addr)) == -1) {
		perror("bind");
		printf("retry...");
		sleep(5);
	}
	printf("Bound!\n");

	listen(listenfd, 10); 

	connfd = accept(listenfd, (struct sockaddr*)NULL, NULL); 
	fprintf(stderr, "Client connected!\n");

	memset(sendBuff, 0, sizeof(sendBuff));

	started_on = time(NULL);
	while (time(NULL) < started_on + SESSION_LENGTH) {
		write(connfd, sendBuff, BUFF_SZ);
		++c;
	}

	printf("%lu b/s\n", c * sizeof(sendBuff) / SESSION_LENGTH);

	close(connfd);

	close(listenfd);
}

void client(char *addr)
{
	struct in_addr my_ip;
	printf("Connecting to %s...\n", addr);
	assert(inet_aton(addr, &my_ip));

	int sockfd = 0, n = 0;
	char recvBuff[BUFF_SZ];
	struct sockaddr_in serv_addr; 

	memset(recvBuff, '0',sizeof(recvBuff));
	if((sockfd = socket(AF_INET, SOCK_STREAM, 0)) < 0) {
		perror("Socket error");
		exit(1);
	}

	memset(&serv_addr, '0', sizeof(serv_addr)); 

	serv_addr.sin_family = AF_INET;
	serv_addr.sin_port = htons(PORT); 

	if (inet_pton(AF_INET, addr, &serv_addr.sin_addr)<=0) {
		perror("inet_pton error");
		exit(1);
	}

	if (connect(sockfd, (struct sockaddr *)&serv_addr, sizeof(serv_addr)) < 0) {
		perror("Connect error");
		exit(1);
	} 

	while ((n = read(sockfd, recvBuff, sizeof(recvBuff)-1)) > 0) {}

	if (n < 0) {
		perror("Read error");
	} 
}

int main(int argc, char **argv)
{
	int i;

	while((i = getopt(argc, argv, "sc:")) != -1) {
		switch (i) {
		case 'c':
			client(optarg);
			break;
		case 's':
		default:
			serve();
		}
	}

	return 0;
}