e117e7a5b0
- Clean up the manpage. - style(9) rcmdsh.c. Committed from: BSDCon/EU 2k+1 terminal room
128 lines
2.9 KiB
C
128 lines
2.9 KiB
C
/* $OpenBSD: rcmdsh.c,v 1.5 1998/04/25 16:23:58 millert Exp $ */
|
|
|
|
/*
|
|
* This is an rcmd() replacement originally by
|
|
* Chris Siebenmann <cks@utcc.utoronto.ca>.
|
|
*/
|
|
|
|
#include <sys/cdefs.h>
|
|
__FBSDID("$FreeBSD$");
|
|
|
|
#include <sys/types.h>
|
|
#include <sys/socket.h>
|
|
#include <sys/wait.h>
|
|
|
|
#include <errno.h>
|
|
#include <netdb.h>
|
|
#include <paths.h>
|
|
#include <pwd.h>
|
|
#include <stdio.h>
|
|
#include <string.h>
|
|
#include <unistd.h>
|
|
|
|
#ifndef _PATH_RSH
|
|
#define _PATH_RSH "/usr/bin/rsh"
|
|
#endif
|
|
|
|
/*
|
|
* This is a replacement rcmd() function that uses the rsh(1)
|
|
* program in place of a direct rcmd(3) function call so as to
|
|
* avoid having to be root. Note that rport is ignored.
|
|
*/
|
|
/* ARGSUSED */
|
|
int
|
|
rcmdsh(ahost, rport, locuser, remuser, cmd, rshprog)
|
|
char **ahost;
|
|
int rport __unused;
|
|
const char *locuser, *remuser, *cmd, *rshprog;
|
|
{
|
|
struct hostent *hp;
|
|
int cpid, sp[2];
|
|
char *p;
|
|
struct passwd *pw;
|
|
|
|
/* What rsh/shell to use. */
|
|
if (rshprog == NULL)
|
|
rshprog = _PATH_RSH;
|
|
|
|
/* locuser must exist on this host. */
|
|
if ((pw = getpwnam(locuser)) == NULL) {
|
|
(void)fprintf(stderr, "rcmdsh: unknown user: %s\n", locuser);
|
|
return (-1);
|
|
}
|
|
|
|
/* Validate remote hostname. */
|
|
if (strcmp(*ahost, "localhost") != 0) {
|
|
if ((hp = gethostbyname(*ahost)) == NULL) {
|
|
herror(*ahost);
|
|
return (-1);
|
|
}
|
|
*ahost = hp->h_name;
|
|
}
|
|
|
|
/* Get a socketpair we'll use for stdin and stdout. */
|
|
if (socketpair(AF_UNIX, SOCK_STREAM, PF_UNSPEC, sp) == -1) {
|
|
perror("rcmdsh: socketpair");
|
|
return (-1);
|
|
}
|
|
|
|
cpid = fork();
|
|
if (cpid == -1) {
|
|
perror("rcmdsh: fork failed");
|
|
return (-1);
|
|
} else 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) == -1 || dup2(0, 1) == -1) {
|
|
perror("rcmdsh: dup2 failed");
|
|
_exit(255);
|
|
}
|
|
/* Fork again to lose parent. */
|
|
cpid = fork();
|
|
if (cpid == -1) {
|
|
perror("rcmdsh: fork to lose parent failed");
|
|
_exit(255);
|
|
}
|
|
if (cpid > 0)
|
|
_exit(0);
|
|
|
|
/* In grandchild here. Become local user for rshprog. */
|
|
if (setuid(pw->pw_uid) == -1) {
|
|
(void)fprintf(stderr, "rcmdsh: setuid(%u): %s\n",
|
|
pw->pw_uid, strerror(errno));
|
|
_exit(255);
|
|
}
|
|
|
|
/*
|
|
* If remote host is "localhost" and local and remote users
|
|
* are the same, avoid running remote shell for efficiency.
|
|
*/
|
|
if (strcmp(*ahost, "localhost") == 0 &&
|
|
strcmp(locuser, remuser) == 0) {
|
|
if (pw->pw_shell[0] == '\0')
|
|
rshprog = _PATH_BSHELL;
|
|
else
|
|
rshprog = pw->pw_shell;
|
|
p = strrchr(rshprog, '/');
|
|
execlp(rshprog, p ? p + 1 : rshprog, "-c", cmd,
|
|
(char *)NULL);
|
|
} else {
|
|
p = strrchr(rshprog, '/');
|
|
execlp(rshprog, p ? p + 1 : rshprog, *ahost, "-l",
|
|
remuser, cmd, (char *)NULL);
|
|
}
|
|
(void)fprintf(stderr, "rcmdsh: execlp %s failed: %s\n",
|
|
rshprog, strerror(errno));
|
|
_exit(255);
|
|
} else {
|
|
/* Parent. close sp[1], return sp[0]. */
|
|
(void)close(sp[1]);
|
|
/* Reap child. */
|
|
(void)wait(NULL);
|
|
return (sp[0]);
|
|
}
|
|
/* NOTREACHED */
|
|
}
|