auth_unix.c

<B>Digital的Unix操作系统VAX 4.2源码</B>

#ifndef lint
static char *sccsid = "@(#)auth_unix.c	4.1	ULTRIX	7/3/90";
#endif lint

/************************************************************************
 *									*
 *			Copyright (c) 1986 by				*
 *		Digital Equipment Corporation, Maynard, MA		*
 *			All rights reserved.				*
 *									*
 *   This software is furnished under a license and may be used and	*
 *   copied  only  in accordance with the terms of such license and	*
 *   with the  inclusion  of  the  above  copyright  notice.   This	*
 *   software  or  any  other copies thereof may not be provided or	*
 *   otherwise made available to any other person.  No title to and	*
 *   ownership of the software is hereby transferred.			*
 *									*
 *   This software is  derived  from  software  received  from  the	*
 *   University    of   California,   Berkeley,   and   from   Bell	*
 *   Laboratories.  Use, duplication, or disclosure is  subject  to	*
 *   restrictions  under  license  agreements  with  University  of	*
 *   California and with AT&T.						*
 *									*
 *   The information in this software is subject to change  without	*
 *   notice  and should not be construed as a commitment by Digital	*
 *   Equipment Corporation.						*
 *									*
 *   Digital assumes no responsibility for the use  or  reliability	*
 *   of its software on equipment which is not supplied by Digital.	*
 *									*
 ************************************************************************/

/*
 *	Portions of this software have been licensed to 
 *	Digital Equipment Company, Maynard, MA.
 *	Copyright (c) 1986 Sun Microsystems, Inc.  ALL RIGHTS RESERVED.
 */

/*
 * auth_unix.c, Implements UNIX style authentication parameters. 
 *  
 * The system is very weak.  The client uses no encryption for it's
 * credentials and only sends null verifiers.  The server sends backs
 * null verifiers or optionally a verifier that suggests a new short hand
 * for the credentials.
 *
 */

#ifdef KERNEL
#include "../h/param.h"
#include "../h/systm.h"
#include "../h/user.h"
#include "../h/kernel.h"
#include "../h/proc.h"
#include "../rpc/types.h"
#include "../rpc/xdr.h"
#include "../rpc/auth.h"
#include "../rpc/auth_unix.h"
#else
#include <sys/param.h>
#include <stdio.h>
#include <rpc/types.h>
#include <sys/time.h>
#include <rpc/xdr.h>
#include <rpc/auth.h>
#include <rpc/auth_unix.h>
char *malloc();
#endif

/*
 * Unix authenticator operations vector
 */
static void	authunix_nextverf();
static bool_t	authunix_marshal();
static bool_t	authunix_validate();
static bool_t	authunix_refresh();
static void	authunix_destroy();

static struct auth_ops auth_unix_ops = {
	authunix_nextverf,
	authunix_marshal,
	authunix_validate,
	authunix_refresh,
	authunix_destroy
};

/*
 * This struct is pointed to by the ah_private field of an auth_handle.
 */
struct audata {
	struct opaque_auth	au_origcred;	/* original credentials */
	struct opaque_auth	au_shcred;	/* short hand cred */
	u_long			au_shfaults;	/* short hand cache faults */
	char			au_marshed[MAX_AUTH_BYTES];
	u_int			au_mpos;	/* xdr pos at end of marshed */
};
#define	AUTH_PRIVATE(auth)	((struct audata *)auth->ah_private)

static bool_t marshal_new_auth();


#ifndef KERNEL
/*
 * Create a unix style authenticator.
 * Returns an auth handle with the given stuff in it.
 */
AUTH *
authunix_create(machname, uid, gid, len, aup_gids)
	char *machname;
	int uid;
	int gid;
	register int len;
	int *aup_gids;
{
	struct authunix_parms aup;
	char mymem[MAX_AUTH_BYTES];
	struct timeval now;
	XDR xdrs;
	register AUTH *auth;
	register struct audata *au;

	/*
	 * Allocate and set up auth handle
	 */
	auth = (AUTH *)mem_alloc(0, 0, sizeof(*auth), 0);
#ifndef KERNEL
	if (auth == NULL) {
		fprintf(stderr, "authunix_create: out of memory\n");
		return (NULL);
	}
#endif
	au = (struct audata *)mem_alloc(0, 0, sizeof(*au), 0);
#ifndef KERNEL
	if (au == NULL) {
		fprintf(stderr, "authunix_create: out of memory\n");
		return (NULL);
	}
#endif
	auth->ah_ops = &auth_unix_ops;
	auth->ah_private = (caddr_t)au;
	auth->ah_verf = au->au_shcred = _null_auth;
	au->au_shfaults = 0;

	/*
	 * fill in param struct from the given params
	 */
	(void)gettimeofday(&now,  (struct timezone *)0);
	aup.aup_time = now.tv_sec;
	aup.aup_machname = machname;
	aup.aup_uid = uid;
	aup.aup_gid = gid;
	aup.aup_len = (u_int)len;
	aup.aup_gids = aup_gids;

	/*
	 * Serialize the parameters into origcred
	 */
	xdrmem_create(&xdrs, mymem, MAX_AUTH_BYTES, XDR_ENCODE);
	if (! xdr_authunix_parms(&xdrs, &aup)) 
		abort();
	au->au_origcred.oa_length = len = XDR_GETPOS(&xdrs);
	au->au_origcred.oa_flavor = AUTH_UNIX;
#ifdef KERNEL
	au->au_origcred.oa_base = mem_alloc(0, 0, len, 0);
#else
	if ((au->au_origcred.oa_base = mem_alloc(0, 0, len, 0)) == NULL) {
		fprintf(stderr, "authunix_create: out of memory\n");
		return (NULL);
	}
#endif
	bcopy(mymem, au->au_origcred.oa_base, (u_int)len);

	/*
	 * set auth handle to reflect new cred.
	 */
	auth->ah_cred = au->au_origcred;
	marshal_new_auth(auth);
	return (auth);
}

/*
 * Returns an auth handle with parameters determined by doing lots of
 * syscalls.
 */
AUTH *
authunix_create_default()
{
	register int len;
	char machname[MAX_MACHINE_NAME + 1];
	register int uid;
	register int gid;
	int gids[NGROUPS];

	if (gethostname(machname, MAX_MACHINE_NAME) == -1)
		abort();
	machname[MAX_MACHINE_NAME] = 0;
	uid = geteuid();
	gid = getegid();
	if ((len = getgroups(NGROUPS, gids)) < 0){
		perror("authunix_create_default: getgroups: ");
		abort();
	}
	if(len > NGRPS)  /* rpc/xdr only allows NGRPS groups */
		len = NGRPS;
	return (authunix_create(machname, uid, gid, len, gids));
}
#endif !KERNEL

/*
 * authunix operations
 */

static void
authunix_nextverf(auth)
	AUTH *auth;
{
	/* no action necessary */
}

static bool_t
authunix_marshal(auth, xdrs)
	AUTH *auth;
	XDR *xdrs;
{
	register struct audata *au = AUTH_PRIVATE(auth);

	return (XDR_PUTBYTES(xdrs, au->au_marshed, au->au_mpos));
}

static bool_t
authunix_validate(auth, verf)
	register AUTH *auth;
	struct opaque_auth verf;
{
	register struct audata *au;
	XDR xdrs;

	if (verf.oa_flavor == AUTH_SHORT) {
		au = AUTH_PRIVATE(auth);
		xdrmem_create(&xdrs, verf.oa_base, verf.oa_length, XDR_DECODE);

		if (au->au_shcred.oa_base != NULL) {
			mem_free(au->au_shcred.oa_base,
			    au->au_shcred.oa_length);
			au->au_shcred.oa_base = NULL;
		}
		if (xdr_opaque_auth(&xdrs, &au->au_shcred)) {
			auth->ah_cred = au->au_shcred;
		} else {
			xdrs.x_op = XDR_FREE;
			(void)xdr_opaque_auth(&xdrs, &au->au_shcred);
			au->au_shcred.oa_base = NULL;
			auth->ah_cred = au->au_origcred;
		}
		marshal_new_auth(auth);
	}
	return (TRUE);
}

static bool_t
authunix_refresh(auth)
	register AUTH *auth;
{
	register struct audata *au = AUTH_PRIVATE(auth);
	struct authunix_parms aup;
#ifndef KERNEL
	struct timeval now;
#endif
	XDR xdrs;
	register int stat;

	if (auth->ah_cred.oa_base == au->au_origcred.oa_base) {
		/* there is no hope.  Punt */
		return (FALSE);
	}
	au->au_shfaults ++;

	/* first deserialize the creds back into a struct authunix_parms */
	aup.aup_machname = NULL;
	aup.aup_gids = (int *)NULL;
	xdrmem_create(&xdrs, au->au_origcred.oa_base,
	    au->au_origcred.oa_length, XDR_DECODE);
	stat = xdr_authunix_parms(&xdrs, &aup);
	if (! stat) 
		goto done;

	/* update the time and serialize in place */
#ifdef KERNEL
	aup.aup_time = time.tv_sec;
#else
	(void)gettimeofday(&now, (struct timezone *)0);
	aup.aup_time = now.tv_sec;
#endif
	xdrs.x_op = XDR_ENCODE;
	XDR_SETPOS(&xdrs, 0);
	stat = xdr_authunix_parms(&xdrs, &aup);
	if (! stat)
		goto done;
	auth->ah_cred = au->au_origcred;
	marshal_new_auth(auth);
done:
	/* free the struct authunix_parms created by deserializing */
	xdrs.x_op = XDR_FREE;
	(void)xdr_authunix_parms(&xdrs, &aup);
	XDR_DESTROY(&xdrs);
	return (stat);
}

static void
authunix_destroy(auth)
	register AUTH *auth;
{
	register struct audata *au = AUTH_PRIVATE(auth);

	mem_free(au->au_origcred.oa_base, au->au_origcred.oa_length);

	if (au->au_shcred.oa_base != NULL)
		mem_free(au->au_shcred.oa_base, au->au_shcred.oa_length);

	mem_free(auth->ah_private, sizeof(struct audata));

	if (auth->ah_verf.oa_base != NULL)
		mem_free(auth->ah_verf.oa_base, auth->ah_verf.oa_length);

	mem_free((caddr_t)auth, sizeof(*auth));
}

/*
 * Marshals (pre-serializes) an auth struct.
 * sets private data, au_marshed and au_mpos
 */
static bool_t
marshal_new_auth(auth)
	register AUTH *auth;
{
	XDR		xdr_stream;
	register XDR	*xdrs = &xdr_stream;
	register struct audata *au = AUTH_PRIVATE(auth);

	xdrmem_create(xdrs, au->au_marshed, MAX_AUTH_BYTES, XDR_ENCODE);
	if ((! xdr_opaque_auth(xdrs, &(auth->ah_cred))) ||
	    (! xdr_opaque_auth(xdrs, &(auth->ah_verf)))) {
#ifdef KERNEL
		printf("auth_none.c - Fatal marshalling problem");
#else
		perror("auth_none.c - Fatal marshalling problem");
#endif
	} else {
		au->au_mpos = XDR_GETPOS(xdrs);
	}
	XDR_DESTROY(xdrs);
}