rcmd.c

ucLinux is a very good embeded sytem. Most of company use this as their development OS.

/*
 * Copyright (c) 1983, 1993, 1994
 *	The Regents of the University of California.  All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the distribution.
 * 3. All advertising materials mentioning features or use of this software
 *    must display the following acknowledgement:
 *	This product includes software developed by the University of
 *	California, Berkeley and its contributors.
 * 4. Neither the name of the University nor the names of its contributors
 *    may be used to endorse or promote products derived from this software
 *    without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
 * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
 * SUCH DAMAGE.
 */ 

#if 0
static char sccsid[] = "@(#)rcmd.c	8.3 (Berkeley) 3/26/94";
#endif /* LIBC_SCCS and not lint */

#define __FORCE_GLIBC
#include <features.h>

#define __USE_GNU
#include <ctype.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <errno.h>
#include <alloca.h>
#include <signal.h>
#include <fcntl.h>
#include <unistd.h>
#include <pwd.h>
#include <sys/param.h>
#include <sys/poll.h>
#include <sys/socket.h>
#include <sys/stat.h>
#include <netdb.h>
#include <netinet/in.h>
#include <arpa/inet.h>

#ifdef __UCLIBC_HAS_THREADS__
#undef __UCLIBC_HAS_THREADS__
#warning FIXME I am not reentrant yet...
#endif


/* some forward declarations */
static int __ivaliduser2(FILE *hostf, u_int32_t raddr,
			 const char *luser, const char *ruser, const char *rhost);
static int iruserok2 (u_int32_t raddr, int superuser, const char *ruser, 
		      const char *luser, const char *rhost);


int rcmd(ahost, rport, locuser, remuser, cmd, fd2p)
     char **ahost;
     u_short rport;
     const char *locuser, *remuser, *cmd;
     int *fd2p;
{
#ifdef __UCLIBC_HAS_THREADS__
	int herr;
        struct hostent hostbuf;
	size_t hstbuflen;
	char *tmphstbuf;
#endif
        struct hostent *hp;
	struct sockaddr_in sin, from;
	struct pollfd pfd[2];
	int32_t oldmask;
	pid_t pid;
	int s, lport, timo;
	char c;

	pid = getpid();

#ifdef __UCLIBC_HAS_THREADS__
	hstbuflen = 1024;
#ifdef __ARCH_HAS_MMU__
	tmphstbuf = alloca (hstbuflen);
#else
	tmphstbuf = malloc (hstbuflen);
#endif

	while (gethostbyname_r (*ahost, &hostbuf, tmphstbuf, 
		    hstbuflen, &hp, &herr) != 0 || hp == NULL)
	{
	    if (herr != NETDB_INTERNAL || errno != ERANGE)
	    {
		__set_h_errno (herr);
#ifndef __ARCH_HAS_MMU__
		free(tmphstbuf);
#endif
		herror(*ahost);
		return -1;
	    }
	    else
	    {
		/* Enlarge the buffer.  */
		hstbuflen *= 2;
#ifdef __ARCH_HAS_MMU__
		tmphstbuf = alloca (hstbuflen);
#else
		if (tmphstbuf) {
		    free(tmphstbuf);
		}
		tmphstbuf = malloc (hstbuflen);
#endif
	    }
	}
#ifndef __ARCH_HAS_MMU__
	free(tmphstbuf);
#endif
#else /* call the non-reentrant version */
	if ((hp = gethostbyname(*ahost)) == NULL) {
	    return -1;
	}
#endif
	pfd[0].events = POLLIN;
	pfd[1].events = POLLIN;
	
        *ahost = hp->h_name;
        oldmask = sigblock(sigmask(SIGURG)); /* __sigblock */
	for (timo = 1, lport = IPPORT_RESERVED - 1;;) {
		s = rresvport(&lport);
		if (s < 0) {
			if (errno == EAGAIN)
			    (void)fprintf(stderr,
					  "rcmd: socket: All ports in use\n");
			else
			    (void)fprintf(stderr, "rcmd: socket: %m\n");
			sigsetmask(oldmask); /* sigsetmask */
			return -1;
		}
		fcntl(s, F_SETOWN, pid); /* __fcntl */
		sin.sin_family = hp->h_addrtype;
		bcopy(hp->h_addr_list[0], &sin.sin_addr,
		      MIN (sizeof (sin.sin_addr), hp->h_length));
		sin.sin_port = rport;
		if (connect(s, (struct sockaddr *)&sin, sizeof(sin)) >= 0) /* __connect */
			break;
		(void)close(s); /* __close */
		if (errno == EADDRINUSE) {
			lport--;
			continue;
		}
		if (errno == ECONNREFUSED && timo <= 16) {
       		        (void)sleep(timo); /* __sleep */
			timo *= 2;
			continue;
		}
		if (hp->h_addr_list[1] != NULL) {
			int oerrno = errno;

			(void)fprintf(stderr, "connect to address %s: ",
			    inet_ntoa(sin.sin_addr));
			__set_errno (oerrno);
			perror(0);
			hp->h_addr_list++;
			bcopy(hp->h_addr_list[0], &sin.sin_addr,
			      MIN (sizeof (sin.sin_addr), hp->h_length));
			(void)fprintf(stderr, "Trying %s...\n",
			    inet_ntoa(sin.sin_addr));
			continue;
		}
		(void)fprintf(stderr, "%s: %m\n", hp->h_name);
		sigsetmask(oldmask); /* __sigsetmask */
		return -1;
	}
	lport--;
	if (fd2p == 0) {
		write(s, "", 1); /* __write */		    
		lport = 0;
	} else {
		char num[8];
		int s2 = rresvport(&lport), s3;
		socklen_t len = sizeof(from);

		if (s2 < 0)
			goto bad;
		listen(s2, 1);
		(void)snprintf(num, sizeof(num), "%d", lport); /* __snprintf */
		if (write(s, num, strlen(num)+1) != strlen(num)+1) {
			(void)fprintf(stderr,
				      "rcmd: write (setting up stderr): %m\n");
			(void)close(s2); /* __close */
			goto bad;
		}
		pfd[0].fd = s;
		pfd[1].fd = s2;
		__set_errno (0);
		if (poll (pfd, 2, -1) < 1 || (pfd[1].revents & POLLIN) == 0){
		    if (errno != 0)
			(void)fprintf(stderr, "rcmd: poll (setting up stderr): %m\n");
		    else
			(void)fprintf(stderr, "poll: protocol failure in circuit setup\n");
			(void)close(s2);
			goto bad;
		}
		s3 = accept(s2, (struct sockaddr *)&from, &len);
		(void)close(s2);
		if (s3 < 0) {
			(void)fprintf(stderr,
			    "rcmd: accept: %m\n");
			lport = 0;
			goto bad;
		}
		*fd2p = s3;
		from.sin_port = ntohs((u_short)from.sin_port);
		if (from.sin_family != AF_INET ||
		    from.sin_port >= IPPORT_RESERVED ||
		    from.sin_port < IPPORT_RESERVED / 2) {
			(void)fprintf(stderr,
			    "socket: protocol failure in circuit setup\n");
			goto bad2;
		}
	}
	(void)write(s, locuser, strlen(locuser)+1);
	(void)write(s, remuser, strlen(remuser)+1);
	(void)write(s, cmd, strlen(cmd)+1);
	if (read(s, &c, 1) != 1) {
		(void)fprintf(stderr,
		    "rcmd: %s: %m\n", *ahost);
		goto bad2;
	}
	if (c != 0) {
		while (read(s, &c, 1) == 1) {
			(void)write(STDERR_FILENO, &c, 1);
			if (c == '\n')
				break;
		}
		goto bad2;
	}
	sigsetmask(oldmask);
	return s;
bad2:
	if (lport)
		(void)close(*fd2p);
bad:
	(void)close(s);
	sigsetmask(oldmask);
	return -1;
}

int rresvport(int *alport)
{
    struct sockaddr_in sin;
    int s;

    sin.sin_family = AF_INET;
    sin.sin_addr.s_addr = INADDR_ANY;
    s = socket(AF_INET, SOCK_STREAM, 0);
    if (s < 0)
	return -1;
    for (;;) {
	sin.sin_port = htons((u_short)*alport);
	if (bind(s, (struct sockaddr *)&sin, sizeof(sin)) >= 0)
	    return s;
	if (errno != EADDRINUSE) {
	    (void)close(s);
	    return -1;
	}
	(*alport)--;
	if (*alport == IPPORT_RESERVED/2) {
	    (void)close(s);
	    __set_errno (EAGAIN);		/* close */
	    return -1;
	}
    }
    
    return -1;
}

int	__check_rhosts_file = 1;
char    *__rcmd_errstr;

int ruserok(rhost, superuser, ruser, luser)
	const char *rhost, *ruser, *luser;
	int superuser;
{
        struct hostent *hp;
	u_int32_t addr;
	char **ap;
#ifdef __UCLIBC_HAS_THREADS__
	size_t buflen;
	char *buffer;
	int herr;
	struct hostent hostbuf;
#endif

#ifdef __UCLIBC_HAS_THREADS__
	buflen = 1024;
#ifdef __ARCH_HAS_MMU__
	buffer = alloca (buflen);
#else
	buffer = malloc (buflen);
#endif

	while (gethostbyname_r (rhost, &hostbuf, buffer, 
		    buflen, &hp, &herr) != 0 || hp == NULL) 
	{
	    if (herr != NETDB_INTERNAL || errno != ERANGE) {
#ifndef __ARCH_HAS_MMU__
		free(buffer);
#endif
		return -1;
	    } else
	    {
		/* Enlarge the buffer.  */
		buflen *= 2;
#ifdef __ARCH_HAS_MMU__
		buffer = alloca (buflen);
#else
		if (buffer) {
		    free(buffer);
		}
		buffer = malloc (buflen);
#endif
	    }
	}
#ifndef __ARCH_HAS_MMU__
	free(buffer);
#endif
#else
	if ((hp = gethostbyname(rhost)) == NULL) {
		return -1;
	}
#endif
	for (ap = hp->h_addr_list; *ap; ++ap) {
		bcopy(*ap, &addr, sizeof(addr));
		if (iruserok2(addr, superuser, ruser, luser, rhost) == 0)
			return 0;
	}
	return -1;
}