Modified version of Todd Vierling's datapipe, where you can specify a name that will be displayed instead of the process' name. Linux - c source. Courtesy of soft project digital security for y2k
d23b53bdf0ea1b506dff4e2c80c97ab54f38030dedca8bb1aad3509be2f43820
/*
The following is an interesting snippet of code I wrote recently. It
makes a data pipe between a listen port on the machine it's being run on
and a port on a remote machine. For example, running
datapipe 2222 23 your.machine.com
would create a port 2222 on the local machine that, if telnetted to, would
be the same as telnetting to port 23 on your.machine.com. This can be used
for a variety of purposes: redirect IRC connections so that identd shows
the username of the datapipe process; redirect sendmail direct connections
for the same reason; even use on a firewall machine to give access to an
internal service (ftpd, for instance). Cascaded datapipes make for
interesting traceback dilemmas. Questions and comments accepted.
Compile with:
cc -o datapipe -O datapipe.c
On boxes without strerror() (like SunOS 4.x), compile with:
cc -o datapipe -O -DSTRERROR datapipe.c
Run as:
datapipe localport remoteport remotehost [fakeps (tested on Linux)]
It will fork itself into the background.
/*
* Datapipe - Create a listen socket to pipe connections to another
* machine/port. 'localport' accepts connections on the machine running
* datapipe, which will connect to 'remoteport' on 'remotehost'. Fairly
* standard 500 xxxx extended errors are used if something drastic
* happens.
*
* (c) 1995 Todd Vierling
* fakeps no(c) 1998 fusys
*
* Define STRERROR while compiling on a SunOS 4.x box
*/
#include <sys/types.h>
#include <sys/socket.h>
#include <sys/wait.h>
#include <netinet/in.h>
#include <stdio.h>
#include <stdlib.h>
#include <errno.h>
#include <unistd.h>
#include <netdb.h>
#include <time.h>
#ifdef STRERROR
extern char *sys_errlist[];
extern int sys_nerr;
char *undef = "Undefined error";
char *strerror(error)
int error;
{
if (error > sys_nerr)
return undef;
return sys_errlist[error];
}
#endif
#define CIAO_PS "bfi_2"
main(argc, argv)
int argc;
char **argv;
{
int lsock, csock, osock;
FILE *cfile;
char buf[4096];
struct sockaddr_in laddr, caddr, oaddr;
int caddrlen = sizeof(caddr);
fd_set fdsr, fdse;
struct hostent *h;
struct servent *s;
int nbyt;
unsigned long a;
unsigned short oport;
int i, j, argvlen;
char *bfiargv[argc+1];
char *fintops = CIAO_PS ;
if (argc < 4) {
fprintf(stderr,"Usage: %s localport remoteport remotehost fakeps\n",argv[0]);
return 30;
}
for(i=0; i < argc; i++) {
bfiargv[i] = malloc(strlen(argv[i]) + 1);
strncpy(bfiargv[i], argv[i], strlen(argv[i]) + 1);
}
bfiargv[argc] = NULL;
argvlen = strlen(argv[0]);
if (argvlen < strlen(CIAO_PS)) {
printf("Se vuoi fregare davvero ps vedi di lanciarmi almeno come superFunkyDataPipe !\n") ;
abort();
}
if(bfiargv[4]) fintops=bfiargv[4] ;
strncpy(argv[0], fintops, strlen(fintops));
for(i = strlen(fintops); i < argvlen; i++) argv[0][i] = '\0';
for(i=1; i < argc; i++) {
argvlen = strlen(argv[i]);
for(j=0; j <= argvlen; j++)
argv[i][j] = '\0';
}
a = inet_addr(argv[3]);
if (!(h = gethostbyname(bfiargv[3])) &&
!(h = gethostbyaddr(&a, 4, AF_INET))) {
perror(bfiargv[3]);
return 25;
}
oport = atol(bfiargv[2]);
laddr.sin_port = htons((unsigned short)(atol(bfiargv[1])));
if ((lsock = socket(PF_INET, SOCK_STREAM, IPPROTO_TCP)) == -1) {
perror("socket");
return 20;
}
laddr.sin_family = htons(AF_INET);
laddr.sin_addr.s_addr = htonl(0);
if (bind(lsock, &laddr, sizeof(laddr))) {
perror("bind");
return 20;
}
if (listen(lsock, 1)) {
perror("listen");
return 20;
}
if ((nbyt = fork()) == -1) {
perror("fork");
return 20;
}
if (nbyt > 0)
return 0;
setsid();
while ((csock = accept(lsock, &caddr, &caddrlen)) != -1) {
cfile = fdopen(csock,"r+");
if ((nbyt = fork()) == -1) {
fprintf(cfile, "500 fork: %s\n", strerror(errno));
shutdown(csock,2);
fclose(cfile);
continue;
}
if (nbyt == 0)
goto gotsock;
fclose(cfile);
while (waitpid(-1, NULL, WNOHANG) > 0);
}
return 20;
gotsock:
if ((osock = socket(PF_INET, SOCK_STREAM, IPPROTO_TCP)) == -1) {
fprintf(cfile, "500 socket: %s\n", strerror(errno));
goto quit1;
}
oaddr.sin_family = h->h_addrtype;
oaddr.sin_port = htons(oport);
memcpy(&oaddr.sin_addr, h->h_addr, h->h_length);
if (connect(osock, &oaddr, sizeof(oaddr))) {
fprintf(cfile, "500 connect: %s\n", strerror(errno));
goto quit1;
}
while (1) {
FD_ZERO(&fdsr);
FD_ZERO(&fdse);
FD_SET(csock,&fdsr);
FD_SET(csock,&fdse);
FD_SET(osock,&fdsr);
FD_SET(osock,&fdse);
if (select(20, &fdsr, NULL, &fdse, NULL) == -1) {
fprintf(cfile, "500 select: %s\n", strerror(errno));
goto quit2;
}
if (FD_ISSET(csock,&fdsr) || FD_ISSET(csock,&fdse)) {
if ((nbyt = read(csock,buf,4096)) <= 0)
goto quit2;
if ((write(osock,buf,nbyt)) <= 0)
goto quit2;
} else if (FD_ISSET(osock,&fdsr) || FD_ISSET(osock,&fdse)) {
if ((nbyt = read(osock,buf,4096)) <= 0)
goto quit2;
if ((write(csock,buf,nbyt)) <= 0)
goto quit2;
}
}
quit2:
shutdown(osock,2);
close(osock);
quit1:
fflush(cfile);
shutdown(csock,2);
quit0:
fclose(cfile);
return 0;
}