/*
Autor: Kiriost
*/
 
#include <stdio.h>
#include <string.h>
#include <sys/socket.h>
#include <sys/types.h>
#include <netinet/in.h>
#include <netdb.h>
 
int main(int argc, char *argv[]) {
	if(argc != 4) {
		printf("TO USE: ./downloader www.host.com /file.exe saveas.exen");
		return 0;
	}
 
	char *shost;
	char *sfile;
	char *ssave;
 
	shost = argv[1];
	sfile = argv[2];
	ssave = argv[3];
 
	int sock;
	struct sockaddr_in conn;
	struct hostent *host;
	char data[512];
	sprintf(data, "GET %s HTTP/1.1\nHost: %s\nUser-Agent: Mozilla/4.0\n\n", sfile, shost);
 
	char buffer[1024];
	memset(buffer, 0, 1024);
	int numbytes;
	int bytes = 0;
	int i = 0;
 
	sock = socket(AF_INET, SOCK_STREAM, 0);
	host = gethostbyname(shost);
 
	conn.sin_family = AF_INET;
	conn.sin_port = htons(80);
	conn.sin_addr = *((struct in_addr *)host->h_addr);
	memset(&conn.sin_zero, 0, 8);
 
	connect(sock, (struct sockaddr *)&conn, sizeof(struct sockaddr));
 
	FILE *fp = fopen(ssave, "wb");
 
	send(sock, data, strlen(data), 0);
 
	for(;;) {
		recv(sock, buffer + i, 1, 0);
		i++;
		if(strncmp(buffer+i-4, "\r\n\r\n", 4) == 0) {
			break;
		}
	}
 
	for(;;) {
		memset(buffer, 0, 1024);
		numbytes = recv(sock, buffer, 1024, 0);
		bytes += numbytes;
		printf("%d KB\n", bytes/1024);
		fwrite(buffer, sizeof(char), numbytes, fp);
		if(numbytes <= 0) {
			break;
		}
	}
 
	printf("Bytes: %d\n", bytes);
	fclose(fp);
	close(sock);
}

gcc -o downloader_http downloader_http.c

./downloader_http godsys.comxa.com /SDL.dll SDLdown.dll

//...
char buffer[1452];
char data[] = "GET /pag.html HTTP/1.1\n"
                     "Host: www.paginaweb.com\n"
                     "User-Agent: Mozilla/4.0\n\n";
 
send(sock, data, strlen(data), 0);
recv(sock, buffer, 1452, 0);
 
printf("%s\n", buffer);

HTTP/1.1 OK
Content-Length: 145233
Accept: arch...
Content-Type: ....

Aquí empiezar el contenido del archivo...bla bla bla
ASDadasdasdasd