getgrent.c

来自「<B>Digital的Unix操作系统VAX 4.2源码</B>」· C语言 代码 · 共 830 行 · 第 1/2 页

#ifndef lint
static	char	*sccsid = "@(#)getgrent.c	4.2	(ULTRIX)	9/4/90";
#endif lint
/************************************************************************
 *									*
 *			Copyright (c) 1984-1989 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.	*
 *									*
 ************************************************************************/
/****************************************************************
 *								*
 *  Licensed to Digital Equipment Corporation, Maynard, MA	*
 *		Copyright 1985 Sun Microsystems, Inc.		*
 *			All rights reserved.			*
 *								*
 ****************************************************************/
/*
 * Modification History:
 *
 * 13-Nov-89	sue
 *	Changed svc_getgrflag initial value to -2 and now perform a
 *	check in getgrent to see if the setgrent has been called yet.
 *
 * 24-Jul-89	logcher
 *	Removed generic setgrent and endgrent calls from generic
 *	getgrnam and getgrgid.  Added the specific set and end calls
 *	in the specific get routines.  Changed setgrent_yp to return
 *	NULL on failure, not exit 1.
 *
 * 16-May-89	logcher
 *	Modularized the code to have separate local, yp, bind/hesiod
 *	routines.  Added front end to check the /etc/svc.conf file
 *	for the service ordering.
 *
 */

#include <stdio.h>
#include <grp.h>
#include <rpcsvc/ypclnt.h>
#include <netdb.h>
#include <sys/svcinfo.h>
#include <hesiod.h>

#if defined(lint) && !defined(DEBUG)
#define DEBUG
#endif

#define MAXINT 0x7fffffff
#define	MAXGRP	200

static char *domain;
static char GROUP[] = "/etc/group";
static struct group NULLGP = {NULL, NULL, 0, NULL};
static char *gr_mem[MAXGRP];
static FILE *grf = NULL;	/* pointer into /etc/group */
static char *yp;		/* pointer into yellow pages */
static int yplen;
static char *oldyp = NULL;	
static int oldyplen;
static struct list {
    char *name;
    struct list *nxt
} *minuslist;			/* list of - items */
static struct svcinfo *svcinfo;
int svc_getgrflag = -2;
int svc_getgrbind;

static struct group *interpret();
static struct group *interpretwithsave();
static struct group *save();
static struct group *getnamefromyellow();
static struct group *getgidfromyellow();
char *yellowup();

/*
 * Declare all service routines
 */
int setgrent_local ();
int setent_bind ();
int setgrent_yp ();
int endgrent_local ();
int endent_bind ();
int endgrent_yp ();
struct group *getgrent_local ();
struct group *getgrent_bind ();
struct group *getgrent_yp ();
struct group *getgrgid_local (); 
struct group *getgrgid_bind (); 
struct group *getgrgid_yp (); 
struct group *getgrnam_local ();
struct group *getgrnam_bind ();	
struct group *getgrnam_yp ();

static int	(*setgrents []) ()={
		setgrent_local,
		setgrent_yp,
		setent_bind
};
static int 	(*endgrents []) ()={
		endgrent_local,
		endgrent_yp,
		endent_bind
};
static struct group * (*getgrents []) ()={
		getgrent_local,
		getgrent_yp,
		getgrent_bind
};
static struct group * (*getgrgids []) ()={
		getgrgid_local,
		getgrgid_yp,
		getgrgid_bind
};
static struct group * (*getgrnames []) ()={
		getgrnam_local,
		getgrnam_yp,
		getgrnam_bind
};


/*
 * generic getgr service routines
 */

setgrent ()
{
	register i;

	svc_getgrflag = -1;
	svc_getgrbind = 0;
	if ((svcinfo = getsvc()) != NULL)
		for (i=0; (svc_lastlookup = svcinfo->svcpath[SVC_GROUP][i]) != SVC_LAST; i++)
			(*(setgrents [svcinfo->svcpath[SVC_GROUP][i]])) ();
}

endgrent ()
{
	register i;

	svc_getgrflag = -1;
	svc_getgrbind = 0;
	if ((svcinfo = getsvc()) != NULL)
		for (i=0; (svc_lastlookup = svcinfo->svcpath[SVC_GROUP][i]) != SVC_LAST; i++)
			(*(endgrents [svcinfo->svcpath[SVC_GROUP][i]])) ();
}

struct group *
getgrent()
{
	register struct group *p=NULL;
	register i;

	/*
	 * Check if setgrent was not made yet
	 */
	if (svc_getgrflag == -2)
		setgrent();
	/*
	 * Check if this is the first time through getgrent
	 */
	if (svc_getgrflag == -1) {
		/*
		 * If it is, init the svcinfo structure
		 */
		if ((svcinfo = getsvc()) == NULL)
			return((struct group *)NULL);
		i = 0;
	}
	else {
		/*
		 * If it is not, set the index to the last used one
		 */
		i = svc_getgrflag;
	}
	for (; (svc_lastlookup = svcinfo->svcpath[SVC_GROUP][i]) != SVC_LAST; i++)
		if (p = ((*(getgrents [svcinfo->svcpath[SVC_GROUP][i]])) () )) {
			svc_getgrflag = i;
			break;
		}
	return(p);
}

struct group *
getgrnam (name)
	register char *name;
{
	register struct group *p=NULL;
	register i;

	/* avoid null pointer de-reference on mips */
	if (name == 0)
		return(0);
	if ((svcinfo = getsvc()) != NULL)
		for (i=0; (svc_lastlookup = svcinfo->svcpath[SVC_GROUP][i]) != SVC_LAST; i++)
			if (p = ((*(getgrnames [svcinfo->svcpath[SVC_GROUP][i]])) (name) ))
				break;
	return(p);
}

struct group *
getgrgid (gid)
	register gid_t gid;
{
	register struct group *p=NULL;
	register i;

	if ((svcinfo = getsvc()) != NULL)
		for (i=0; (svc_lastlookup = svcinfo->svcpath[SVC_GROUP][i]) != SVC_LAST; i++)
			if (p = ((*(getgrgids [svcinfo->svcpath[SVC_GROUP][i]])) (gid) ))
				break;
	return(p);
}

/*
 * specific getgr service routines
 */

struct group *
getgrgid_local(gid)
	gid_t gid;
{
	struct group *gp;

#ifdef DEBUG
	fprintf(stderr, "getgrgid_local(%d)\n", gid);
#endif DEBUG
	setgrent_local();
	while (gp = getgrent_local()) {
		if (gp->gr_gid == gid)
			break;
	}
	endgrent_local();
	return(gp);
}

struct group *
getgrgid_bind(gid)
	gid_t gid;
{
	char **pp, gidbuf[6];

#ifdef DEBUG
	fprintf(stderr, "getgrgid_bind(%d)\n", gid);
#endif DEBUG
	setent_bind(0);
	sprintf(gidbuf, "%u", gid);
	pp = hes_resolve(gidbuf, "group");
	endent_bind();
	if (pp == NULL)
		return(NULL);
	return interpret(*pp, strlen(*pp));
}

struct group *
getgrgid_yp(gid)
	gid_t gid;
{
	struct group *gp;
	char line[BUFSIZ+1];

#ifdef DEBUG
	fprintf(stderr, "getgrgid_yp(%d)\n", gid);
#endif DEBUG
	setgrent_yp();
	if (!grf)
		return(NULL);
	while (fgets(line, BUFSIZ, grf) != NULL) {
		gp = interpret(line, strlen(line));
		if (gp != NULL)		/* skip any bad group lines */
			if (matchgid(line, &gp, gid)) {
				endgrent_yp();
				return(gp);
			}
	}
	endgrent_yp();
	return(NULL);
}

struct group *
getgrnam_local(name)
register char *name;
{
	register struct group *gp;

#ifdef DEBUG
	fprintf(stderr, "getgrnam_local(%s)\n", name);
#endif DEBUG
	setgrent_local();
	while (gp = getgrent_local()) {
		if (strcmp(gp->gr_name, name) == 0)
			break;
	}
	endgrent_local();
	return(gp);
}

struct group *
getgrnam_bind(name)
	char *name;
{
	char **pp;

#ifdef DEBUG
	fprintf(stderr, "getgrnam_bind(%s)\n", name);
#endif DEBUG
	setent_bind(0);
	pp = hes_resolve(name, "group");
	endent_bind();
	if (pp == NULL)
		return(NULL);
	return interpret(*pp, strlen(*pp));
}

struct group *
getgrnam_yp(name)
	register char *name;
{
	struct group *gp;
	char line[BUFSIZ+1];

#ifdef DEBUG
	fprintf(stderr, "getgrnam_yp(%s)\n", name);
#endif DEBUG
	setgrent_yp();
	if (!grf)
		return(NULL);
	while (fgets(line, BUFSIZ, grf) != NULL) {
		gp = interpret(line, strlen(line));
		if (matchname(line, &gp, name)) {
			endgrent_yp();
			return(gp);
		}
	}
	endgrent_yp();
	return(NULL);
}

setgrent_local()
{
	if (!grf)
		grf = fopen(GROUP, "r");
	else
		rewind(grf);
}

/*
 * setent_bind() in getcommon.c
 */

setgrent_yp()
{
	setgrent_local();
	if ((domain = yellowup(1)) == NULL)
		return(NULL);
	if (yp)
		free(yp);
	yp = NULL;
	freeminuslist();
}

endgrent_local()
{
	if (grf) {
		fclose(grf);
		grf = NULL;
	}
}

/*
 * endent_bind() in getcommon.c
 */

endgrent_yp()
{
	endgrent_local();
	if (yp)
		free(yp);
	yp = NULL;
	freeminuslist();
}

struct group *
getgrent_local()
{
	char line1[BUFSIZ+1];
	static struct group *gp;

#ifdef DEBUG
	fprintf (stderr,"getgrent_local\n");
#endif DEBUG
	if (grf == NULL && (grf = fopen(GROUP, "r")) == NULL)
		return(NULL);
again_local:
	if ((fgets(line1, BUFSIZ, grf)) == NULL) {