/* tinypckt.c
   a small TCP packet sender
   in C
   by thedoors
*/

#include <netdb.h>
#include <sys/socket.h>
#include <arpa/inet.h>
#include <netinet/in.h>
#include <stdio.h>
#include <stdlib.h>
#include <unistd.h>
#include <string.h>
#include <stdarg.h>
#include <time.h>
#include <ctype.h>
#include <fcntl.h>
#include <getopt.h>

#define DEFAULT_PORT 	80
#define SIGNATURE 	"tinypckt"
#define CHUNK_SIZE 	100
#define TINYPCKT_VER	"tinypckt.0-2"

void usage(char *);

int main(int argc, char **argv) {
	
	char buffer[CHUNK_SIZE];
	ssize_t n, sent;
	int options;
	char *p, *file = NULL;
	unsigned char mode = 0;
	unsigned short int PORT;
	extern char *optarg;
	int tmpfd, sockfd;
	struct hostent *he;
	struct sockaddr_in server;

	if(argc == 1) usage(argv[0]);
	if(strncmp(argv[1], "--version", sizeof("--version")) == 0) {
		printf(TINYPCKT_VER "\r\n");
		return 0;
	}
	p = strrchr(argv[argc-1], ':'); // checking if a port is given
	if(p == NULL) PORT = DEFAULT_PORT;
	else {
		*p = 0;
		PORT = (unsigned short int)strtol(p+1, NULL, 10);
	}
	if((he = gethostbyname(argv[argc-1])) == NULL) {
		perror("gesthostbyname");
		return 1;
	}

	while((options = getopt(argc, argv, "qf:")) != -1) {
		switch(options) {

			case 'q':
				mode = 1;
			break;

			case 'f':
				file = optarg;
			break;

			default:
				printf("unknown option %c\r\n", options);
				return 1;
			break;
		}
	}

	if(file != NULL) { // reading from stdin or specified file
		tmpfd = open(file, O_RDONLY);
		if(tmpfd < 0) {
			perror("open");
			return 1;
		}
	} else tmpfd = STDIN_FILENO;

	if((sockfd = socket(AF_INET, SOCK_STREAM, 0)) == -1) {
		perror("socket");
		close(tmpfd);
		return 1;
	}

	server.sin_family = AF_INET;
	server.sin_port = htons(PORT);
	server.sin_addr = *((struct in_addr *)he->h_addr);
	memset(&(server.sin_zero), 0, 8);
	
	if(connect(sockfd, (struct sockaddr *)&server, sizeof(struct sockaddr)) == -1) {
		perror("connect");
		close(tmpfd);
		return 1;
	}

	while((n = read(tmpfd, buffer, sizeof(buffer))) > 0) { // reading 100 bytes from file
		sent = send(sockfd, buffer, n, 0); // while there is data to read and sending it
		if(mode == 1) continue; // skipping output on quiet mode
		printf("%ld/%ld sent.\r\n", (signed long int)sent, (signed long int)n);
	}

	close(sockfd);
	close(tmpfd);
	return 0;
}

void usage(char *__s) {

	printf(
		"\t\t%s\r\n"
		"usage: %s -options server:port\r\n"
		"-f [file] -- read from file instead of stdin\r\n"
		"-q quiet  -- do not report packet status\r\n"
		"--version to output version and exit\r\n",
		SIGNATURE, __s
	      );
	exit(0);
}