#include "apache-version.h"

/* Copyright (c) 2003 Michael Coulter <mjc@bitz.ca> */

/* connection timeout to server */
#define TIMEOUT 5

void 
usage(const char *cmd)
{
	fprintf(stderr, "%s: <target>\n", cmd);
	exit(-1);
}
void 
ctimeout(int signal)
{
	write(STDOUT_FILENO, "Host unreachable\n", strlen("Host unreachable\n"));
	exit(0);
}
void 
rtimeout(int signal)
{
	write(STDOUT_FILENO, "Port listening, may not be a webserver?\n", strlen("Port listening, may not be a webserver?\n"));
	exit(0);
}

int 
web_connect(struct webserver * webserver)
{

	struct sockaddr_in sa;
	struct servent *service;
	//for searching
		/etc / services
			struct hostent *hp;
	//for storing
		lookups

			bzero(&sa, sizeof(sa));

	webserver->sockfd = socket(AF_INET, SOCK_STREAM, 0);
	//ipv6
		fcntl(webserver->sockfd, O_NONBLOCK);

	hp = gethostbyname2(webserver->server, AF_INET);

	service = getservbyname("www", "tcp");

	if (!service)
		err(0, "could not locate entry in /etc/services for www");

	memcpy(&sa.sin_addr, hp->h_addr, sizeof(struct in_addr));

	sa.sin_port = service->s_port;
	sa.sin_family = hp->h_addrtype;

	signal(SIGALRM, ctimeout);
	alarm(TIMEOUT);
	if (connect(webserver->sockfd, (struct sockaddr *) & sa, sizeof(struct sockaddr)) < 0) {
		printf("No webserver: %s\n", inet_ntoa(sa.sin_addr));
		exit(0);
	}
	alarm(0);

	return;
}

int 
main(int argc, char *argv[])
{
	struct webserver webserver;
	char            buf[MAXLINE];
	char           *a, *b;

	if (argc != 2)
		usage(argv[0]);

	webserver.server = strdup(argv[1]);
	printf("%s: ", webserver.server);
	web_connect(&webserver);
	free(webserver.server);
	signal(SIGALRM, rtimeout);
	alarm(TIMEOUT);
	write(webserver.sockfd, "HEAD / HTTP/1.0\r\n\r\n", 19);
	while (read(webserver.sockfd, buf, MAXLINE)) {
		if (a = strstr(buf, "\nServer: ")) {
			b = ++a;
			while ((*b != '\0') && (*b != '\r') && (*b != '\n')) {
				b++;
			}
			*b = '\0';
			webserver.version = strdup(a + strlen("Server: "));
			printf("%s\n", webserver.version);
			free(webserver.version);
		}
	}
	alarm(0);
	exit(0);

}