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/* $OpenBSD: rshrcmd.c,v 1.6 1996/09/07 03:15:52 millert Exp $ */
/*
* This is an rcmd() replacement originally by
* Chris Siebenmann <cks@utcc.utoronto.ca>.
*/
#ifndef lint
static char RCSid[] =
"$OpenBSD: rshrcmd.c,v 1.6 1996/09/07 03:15:52 millert Exp $";
#endif
#include "defs.h"
#if !defined(DIRECT_RCMD)
#include <sys/types.h>
#include <sys/socket.h>
#include <sys/wait.h>
#include <signal.h>
#include <errno.h>
#include <netdb.h>
#include <stdio.h>
/*
* This is a replacement rcmd() function that uses the rsh(1c)
* program in place of a direct rcmd() function call so as to
* avoid having to be root.
*/
rshrcmd(ahost, port, luser, ruser, cmd, fd2p)
char **ahost;
u_short port;
char *luser, *ruser, *cmd;
int *fd2p;
{
int cpid;
struct hostent *hp;
int sp[2];
/* insure that we are indeed being used as we thought. */
if (fd2p != 0)
return -1;
/* validate remote hostname. */
hp = gethostbyname(*ahost);
if (hp == 0) {
error("%s: unknown host", *ahost);
return -1;
}
/* *ahost = hp->h_name; /* This makes me nervous. */
/* get a socketpair we'll use for stdin and stdout. */
if (getsocketpair(AF_UNIX, SOCK_STREAM, 0, sp) < 0) {
error("socketpair(AF_UNIX, SOCK_STREAM, 0) failed: %s.",
SYSERR);
return -1;
}
cpid = fork();
if (cpid < 0) {
error("fork failed: %s.", SYSERR);
return -1; /* error. */
}
if (cpid == 0) {
/* child. we use sp[1] to be stdin/stdout, and close
sp[0]. */
(void) close(sp[0]);
if (dup2(sp[1], 0) < 0 || dup2(0, 1) < 0) {
error("dup2 failed: %s.", SYSERR);
_exit(255);
}
/* fork again to lose parent. */
cpid = fork();
if (cpid < 0) {
error("fork to lose parent failed: %s.", SYSERR);
_exit(255);
}
if (cpid > 0)
_exit(0);
/* in grandchild here. */
/*
* If we are rdist'ing to "localhost" as the same user
* as we are, then avoid running remote shell for efficiency.
*/
if (strcmp(*ahost, "localhost") == 0 &&
strcmp(luser, ruser) == 0) {
execlp(_PATH_BSHELL, xbasename(_PATH_BSHELL), "-c",
cmd, (char *) NULL);
error("execlp %s failed: %s.", _PATH_BSHELL, SYSERR);
} else {
execlp(path_remsh, xbasename(path_remsh),
*ahost, "-l", ruser, cmd, (char *) NULL);
error("execlp %s failed: %s.", path_remsh, SYSERR);
}
_exit(255);
}
if (cpid > 0) {
/* parent. close sp[1], return sp[0]. */
(void) close(sp[1]);
/* reap child. */
(void) wait(0);
return sp[0];
}
/*NOTREACHED*/
}
#endif /* !DIRECT_RCMD */
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