
/****** socket/rcmd  *************************************************
*
*	NAME
*		rcmd - Allow superuser to execute commands on remote machines
*
*	SYNOPSIS
*		rem = rcmd( ahost, inport, luser, ruser, cmd, fd2p )
*
*		int rcmd( char **, u_short, char *, char *, char *, int )
*
*	FUNCTION

*		The rcmd subroutine looks up the host *ahost using gethostbyname,
*		returning (-1) if the host does not exist. Otherwise *ahost is
*		set to the standard name of the host and a connection is
*		established to a server residing at the well-known Internet port 
*		inport.
*		
*		If the call succeeds, a socket of type SOCK_STREAM is returned to
*		the caller and given to the remote command as stdin and stdout.
*		If fd2p is nonzero, then an auxiliary channel to a control
*		process will be set up, and a descriptor for it will be placed in
*		*fd2p. The control process will return diagnostic output from the
*		command (unit 2) on this channel, and will also accept bytes on
*		this channel as being UNIX signal numbers, to be forwarded to the
*		process group of the command. If fd2p is 0, then the stderr (unit
*		2 of the remote command) will be made the same as the stdout and
*		no provision is made for sending arbitrary signals to the remote
*		process, although you may be able to get its attention by using
*		out-of-band data. 
*
*
*	INPUTS
*		ahost  - pointer to host name.
*		inport - an Internet port
*		luser  - the local user's name
*		ruser  - the remote user's name
*		cmd    - the command string to be executed
*       fd2p   - a flag telling whether to use an auxillary channel
*
*	RESULT
*		
*       rem = A socket of type SOCK_STREAM if successful. (-1) upon failure.
*
*   
********************************************************************
*
*
*/

/*
 * rcmd.c
 *
 * mods for Lattice/ANSI  8-3-90 -bj
 *
 * Copyright (c) 1983 Regents of the University of California.
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms are permitted
 * provided that the above copyright notice and this paragraph are
 * duplicated in all such forms and that any documentation,
 * advertising materials, and other materials related to such
 * distribution and use acknowledge that the software was developed
 * by the University of California, Berkeley.  The name of the
 * University may not be used to endorse or promote products derived
 * from this software without specific prior written permission.
 * THIS SOFTWARE IS PROVIDED ``AS IS'' AND WITHOUT ANY EXPRESS OR
 * IMPLIED WARRANTIES, INCLUDING, WITHOUT LIMITATION, THE IMPLIED
 * WARRANTIES OF MERCHANTIBILITY AND FITNESS FOR A PARTICULAR PURPOSE.
 */

#include <sys/param.h>
#include <stdio.h>
#include <string.h>
#include <ctype.h>
#include <pwd.h>
#include <sys/file.h>
#include <sys/signal.h>
#include <sys/socket.h>
#include <sys/stat.h>

#include <netinet/in.h>

#include <netdb.h>
#include <errno.h>
#include <bstr.h>

extern	errno;

/* prototypes */
rresvport(int *alport);
ruserok( char *rhost, int superuser, char *ruser, char *luser);
_validuser( FILE *hostf, char *rhost, char *luser, char *ruser,int baselen);
static _checkhost( char *rhost, char *lhost, int len);
int sigmask( int arg1 );
long sigblock( int arg1 );
int sigsetmask( int mask );
int fcntl( int fd, int request, int arg);


rcmd(char **ahost, u_short rport, char *locuser, char *remuser, char *cmd, int *fd2p)
{
	int s, timo = 1, pid;
	long oldmask;
	struct sockaddr_in sin, from;
	char c;
	int lport = IPPORT_RESERVED - 1;
	struct hostent *hp;
	fd_set reads;

	pid = getpid();
	hp = gethostbyname(*ahost);
	if (hp == 0) {
		herror(*ahost);
		return (-1);
	}
	*ahost = hp->h_name;
	oldmask = sigblock(sigmask(SIGURG));
	for (;;) {
		s = rresvport(&lport);
		if (s < 0) {
			if (errno == EAGAIN)
				fprintf(stderr, "socket: All ports in use\n");
			else
				perror("rcmd: socket");
			sigsetmask(oldmask);
			return (-1);
		}
		fcntl(s, F_SETOWN, pid);
		sin.sin_family = hp->h_addrtype;
		bcopy(hp->h_addr_list[0], (caddr_t)&sin.sin_addr, hp->h_length);
		sin.sin_port = rport;
		if (connect(s, (caddr_t)&sin, sizeof (sin), 0) >= 0)
			break;
		(void) close(s);
		if (errno == EADDRINUSE) {
			lport--;
			continue;
		}
		if (errno == ECONNREFUSED && timo <= 16) {
			sleep(timo);
			timo *= 2;
			continue;
		}
		if (hp->h_addr_list[1] != NULL) {
			int oerrno = errno;

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

		if (s2 < 0)
			goto bad;
		listen(s2, 1);
		(void) sprintf(num, "%d", lport);
		if (write(s, num, strlen(num)+1) != strlen(num)+1) {
			perror("write: setting up stderr");
			(void) close(s2);
			goto bad;
		}
		FD_ZERO(&reads);
		FD_SET(s, &reads);
		FD_SET(s2, &reads);
		errno = 0;
		if (select(32, &reads, 0, 0, 0) < 1 ||
		    !FD_ISSET(s2, &reads)) {
			if (errno != 0)
				perror("select: setting up stderr");
			else
			    fprintf(stderr,
				"select: protocol failure in circuit setup.\n");
			(void) close(s2);
			goto bad;
		}
		s3 = accept(s2, &from, &len, 0);
		(void) close(s2);
		if (s3 < 0) {
			perror("accept");
			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) {
			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) {
		perror(*ahost);
		goto bad2;
	}
	if (c != 0) {
		while (read(s, &c, 1) == 1) {
			(void) write(2, &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);
}

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, (caddr_t)&sin, sizeof (sin)) >= 0)
			return (s);
		if (errno != EADDRINUSE) {
			(void) close(s);
			return (-1);
		}
		(*alport)--;
		if (*alport == IPPORT_RESERVED/2) {
			(void) close(s);
			errno = EAGAIN;		/* close */
			return (-1);
		}
	}
}



/****** socket/ruserok  *************************************************
*
*	NAME
*		ruserok - authenticate clients requesting service with rcmd.
*
*	SYNOPSIS
*		valid = ruserok( rhost, superuser, ruser, luser )
*
*		int = ruser( char *, int, char *, char * )
*
*	FUNCTION
*
*		The ruserok subroutine takes a remote host's name, as          
*		returned by a gethostent(3n) routine, two user names and a     
*		flag indicating if the local user's name is the superuser.     
*		It then checks the files /etc/hosts.equiv and .rhosts in the   
*		user's home directory to see if the request for service is     
*		allowed.  A 1 is returned if the machine name is listed in     
*		the hosts.equiv file, or the host and remote user name are     
*		found in the .rhosts file. Otherwise ruserok returns -1. If  
*		the superuser flag is 1, the checking of the hosts.equiv       
*		file is bypassed.                                              
*
*	INPUT
*
*		rhost     - The desired remote hosts name
*		suoeruser - Flag telling if local user's name is superuser.
*		ruser     - The remote user's name.
*		luser     - The local user's name.
*
*	RESULT
*		valid - (-1) on error or invalid user. Zero (0) upon success.
*
*
*
*	SEE ALSO
*
*   
********************************************************************
*
*
*/


int	_check_rhosts_file = 1;

ruserok( char *rhost, int superuser, char *ruser, char *luser)
{
	FILE *hostf;
	char fhost[MAXHOSTNAMELEN];
	int first = 1;
	register char *sp, *p;
	int baselen = -1;

	sp = rhost;
	p = fhost;
	while (*sp) {
		if (*sp == '.') {
			if (baselen == -1)
				baselen = sp - rhost;
			*p++ = *sp++;
		} else {
			*p++ = isupper(*sp) ? tolower(*sp++) : *sp++;
		}
	}
	*p = '\0';
	hostf = superuser ? (FILE *)0 : fopen(HOSTSEQUIV, "r");
again:
	if (hostf) {
		if (!_validuser(hostf, fhost, luser, ruser, baselen)) {
			(void) fclose(hostf);
			return(0);
		}
		(void) fclose(hostf);
	}
	if (first == 1 && (_check_rhosts_file || superuser)) {
		struct passwd *pwd;
		char pbuf[MAXPATHLEN];

		first = 0;
		if ((pwd = getpwnam(luser)) == NULL)
			return(-1);
		(void)strcpy(pbuf, pwd->pw_dir);
		(void)strcat(pbuf, "/.rhosts");
		if ((hostf = fopen(pbuf, "r")) == NULL)
			return(-1);
		/*
		 * if owned by someone other than user or root or if
		 * writeable by anyone but the owner, quit
		 */
		 
		goto again;
	}
	return (-1);
}

/* =========================================================
 * internal function 
 * =========================================================
 */


/* don't make static, used by lpd(8) */
_validuser( FILE *hostf, char *rhost, char *luser, char *ruser,int baselen)
{
	char *user;
	char ahost[MAXHOSTNAMELEN];
	register char *p;

	while (fgets(ahost, sizeof (ahost), hostf)) {
		p = ahost;
		while (*p != '\n' && *p != ' ' && *p != '\t' && *p != '\0') {
			*p = isupper(*p) ? tolower(*p) : *p;
			p++;
		}
		if (*p == ' ' || *p == '\t') {
			*p++ = '\0';
			while (*p == ' ' || *p == '\t')
				p++;
			user = p;
			while (*p != '\n' && *p != ' ' && *p != '\t' && *p != '\0')
				p++;
		} else
			user = p;
		*p = '\0';
		if (_checkhost(rhost, ahost, baselen) &&
		    !strcmp(ruser, *user ? user : luser)) {
			return (0);
		}
	}
	return (-1);
}

/* =========================================================
 * internal function 
 * =========================================================
 */


static
_checkhost( char *rhost, char *lhost, int len)
{
	static char ldomain[MAXHOSTNAMELEN + 1];
	static char *domainp = NULL;
	static int nodomain = 0;
	register char *cp;

	if (len == -1)
		return(!strcmp(rhost, lhost));
	if (strncmp(rhost, lhost, len))
		return(0);
	if (!strcmp(rhost, lhost))
		return(1);
	if (*(lhost + len) != '\0')
		return(0);
	if (nodomain)
		return(0);
	if (!domainp) {
		if (gethostname(ldomain, sizeof(ldomain)) == -1) {
			nodomain = 1;
			return(0);
		}
		ldomain[MAXHOSTNAMELEN] = NULL;
		if ((domainp = strchr(ldomain, '.')) == (char *)NULL) {
			nodomain = 1;
			return(0);
		}
		for (cp = ++domainp; *cp; ++cp)
			if (isupper(*cp))
				*cp = tolower(*cp);
	}
	return(!strcmp(domainp, rhost + len +1));
}
/* =========================================================
 * internal function 
 * =========================================================
 */


/* ????????????? */
/* adds the signal(s) in arg1 to the current mask ??? */

int
sigmask( int arg1 )
{
return(0) ;
}


/* =========================================================
 * internal function 
 * =========================================================
 */


/* adds the signals in the mask to the set of signals */
/* that are to be BLOCKED from getting to this proc   */

long
sigblock( int arg1  )
{
return(0L) ;
}

/* =========================================================
 * internal function 
 * =========================================================
 */


/* sets the masked values to block for this process */
int
sigsetmask( int mask  )
{
return(0) ;
}

/* =========================================================
 * internal function 
 * =========================================================
 */


int
fcntl( int fd, int request, int arg)
{
return(0) ;    
}


