Net_client

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gsicht

Dec 27 2003, 12:26 PM

hi, i have coded a little net client. it can be used as telnet or netcat client. for windows compilation take cygnus as compiler.

CODE

/***************** net_client 1.0 **********************
* net_client is a lame alternative to netcat or telnet
* coded by done (23.12.03)
******************************************************/

#include <stdio.h>
#include <unistd.h>
#include <getopt.h>
#include <netinet/in.h>
#include <sys/socket.h>
#include <netdb.h>

#define TOPIC "\nnet_client by gsicht\nversion: 1.0 23.12.03\n"

void usage(char *prog)
{
printf("USAGE:\n");
printf("%s -d HOST -p PORT\n",prog);
printf(" -d [host]\tdest host\n");
printf(" -p [port]\tport to connect\n");
printf("example: %s -d www.google.com -p 80\n\n",prog);
}

void connected(int sock)
{
char rb[1500];
fd_set fdreadme;
int i;
FD_ZERO(&fdreadme);
FD_SET(sock, &fdreadme);
FD_SET(0, &fdreadme);

while(1)
{
FD_SET(sock, &fdreadme);
FD_SET(0, &fdreadme);
if(select(FD_SETSIZE, &fdreadme, NULL, NULL, NULL) < 0 ) break;
if(FD_ISSET(sock, &fdreadme))
{
if((i = recv(sock, rb, sizeof(rb), 0)) < 0)
{
printf("[-] Connection lost..\n");
exit(1);
}
if(write(1, rb, i) < 0) break;
}

if(FD_ISSET(0, &fdreadme))
{
if((i = read(0, rb, sizeof(rb))) < 0)
{
printf("[-] Connection lost..\n");
exit(1);
}
if (send(sock, rb, i, 0) < 0) break;
}
sleep(1);
}
printf("[-] Connection closed by foreign host..\n");
exit(0);
}

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

int port,sock,c;
struct sockaddr_in addr;
struct hostent *host;
static char *hostname=NULL;

puts(TOPIC);

if(argc < 2)
{
usage(argv[0]);
return 0;
}

while((c = getopt(argc, argv, "d:p:"))!= EOF)
{
switch (c)
{
case 'd':
hostname = optarg;
if(hostname == NULL)
{
printf("do this: -d host\n");
exit(0);
}
break;

case 'p':
port = atoi(optarg);

if((port > 65535) || (port < 1))
{
printf("select a port between 1-65535\n");
exit(0);
}
break;

default:
usage(argv[0]);
return 1;
}
}

sock = socket(AF_INET, SOCK_STREAM, 0);
if(sock == -1)
{
printf("socket() failed\n");
exit(0);
}

if((host = gethostbyname(hostname)) == NULL)
{
printf("gethostbyname() failed\n");
exit(1);
}

addr.sin_addr = *((struct in_addr *)host->h_addr);
addr.sin_family = AF_INET;
addr.sin_port = htons(port);

printf("\n[+] connecting to %s:%d...\n",hostname,port);

if(connect(sock,(struct sockaddr *)&addr, sizeof(struct sockaddr)) == -1)
{
printf("[-] couldn't connect to server\n");
exit(0);
}

printf("[~] connected\n");
connected(sock);
close(sock);
return 0;
}
// EOF

liquidSilver

Dec 27 2003, 12:47 PM

Not bad

Oh, well, I will compile this now..

virus

Dec 27 2003, 02:15 PM

For once we can see some good constructive work going on here ....

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