NetBSD/lib/libc/gen/getgrent.c
agc 9f1aac5bb3 Move Jason Downs's code from a 4-clause to a 3-clause licence by
removing the advertising clause.  Diffs provided in PR 22410 by Joel
Baker, confirmed to the board by Jason Downs.

With additional thanks to Jason Thorpe.
2003-10-13 15:36:33 +00:00

779 lines
17 KiB
C

/* $NetBSD: getgrent.c,v 1.48 2003/10/13 15:36:33 agc Exp $ */
/*
* Copyright (c) 1989, 1993
* 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. 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.
*/
/*
* Portions Copyright (c) 1994, Jason Downs. 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.
*
* THIS SOFTWARE IS PROVIDED BY THE AUTHOR(S) ``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 AUTHOR(S) 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.
*/
#include <sys/cdefs.h>
#if defined(LIBC_SCCS) && !defined(lint)
#if 0
static char sccsid[] = "@(#)getgrent.c 8.2 (Berkeley) 3/21/94";
#else
__RCSID("$NetBSD: getgrent.c,v 1.48 2003/10/13 15:36:33 agc Exp $");
#endif
#endif /* LIBC_SCCS and not lint */
#include "namespace.h"
#include <sys/types.h>
#include <assert.h>
#include <errno.h>
#include <grp.h>
#include <limits.h>
#include <nsswitch.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <syslog.h>
#include <stdarg.h>
#ifdef HESIOD
#include <hesiod.h>
#endif
#ifdef YP
#include <rpc/rpc.h>
#include <rpcsvc/yp_prot.h>
#include <rpcsvc/ypclnt.h>
#endif
#if defined(YP) || defined(HESIOD)
#define _GROUP_COMPAT
#endif
struct group *_getgrent_user(const char *);
#ifdef __weak_alias
__weak_alias(endgrent,_endgrent)
__weak_alias(getgrent,_getgrent)
__weak_alias(getgrgid,_getgrgid)
__weak_alias(getgrnam,_getgrnam)
__weak_alias(setgrent,_setgrent)
__weak_alias(setgroupent,_setgroupent)
#endif
static FILE *_gr_fp;
static struct group _gr_group;
static int _gr_stayopen;
static int _gr_filesdone;
static void grcleanup(void);
static int grscan(int, gid_t, const char *, const char *);
static int grstart(void);
static int grmatchline(int, gid_t, const char *, const char *);
#define MAXGRP 200
#define MAXLINELENGTH 1024
static __aconst char *members[MAXGRP];
static char line[MAXLINELENGTH];
#ifdef YP
static char *__ypcurrent, *__ypdomain;
static int __ypcurrentlen;
static int _gr_ypdone;
#endif
#ifdef HESIOD
static int _gr_hesnum;
static struct group *_gr_hesgrplist = NULL;
static int _gr_hesgrplistnum;
static int _gr_hesgrplistmax;
#endif
#ifdef _GROUP_COMPAT
enum _grmode { GRMODE_NONE, GRMODE_FULL, GRMODE_NAME };
static enum _grmode __grmode;
#endif
struct group *
getgrent(void)
{
if ((!_gr_fp && !grstart()) || !grscan(0, 0, NULL, NULL))
return (NULL);
return &_gr_group;
}
/*
* _getgrent_user() is designed only to be called by getgrouplist(3) and
* hence makes no guarantees about filling the entire structure that it
* returns. It may only fill in the group name and gid fields.
*/
struct group *
_getgrent_user(const char *user)
{
if ((!_gr_fp && !grstart()) || !grscan(0, 0, NULL, user))
return (NULL);
return &_gr_group;
}
struct group *
getgrnam(const char *name)
{
int rval;
_DIAGASSERT(name != NULL);
if (!grstart())
return NULL;
rval = grscan(1, 0, name, NULL);
if (!_gr_stayopen)
endgrent();
return (rval) ? &_gr_group : NULL;
}
struct group *
getgrgid(gid_t gid)
{
int rval;
if (!grstart())
return NULL;
rval = grscan(1, gid, NULL, NULL);
if (!_gr_stayopen)
endgrent();
return (rval) ? &_gr_group : NULL;
}
void
grcleanup(void)
{
_gr_filesdone = 0;
#ifdef YP
if (__ypcurrent)
free(__ypcurrent);
__ypcurrent = NULL;
_gr_ypdone = 0;
#endif
#ifdef HESIOD
_gr_hesnum = 0;
if (!_gr_hesgrplist)
free(_gr_hesgrplist);
_gr_hesgrplist = NULL;
_gr_hesgrplistnum = -1;
_gr_hesgrplistmax = 0;
#endif
#ifdef _GROUP_COMPAT
__grmode = GRMODE_NONE;
#endif
}
static int
grstart(void)
{
grcleanup();
if (_gr_fp) {
rewind(_gr_fp);
return 1;
}
return (_gr_fp = fopen(_PATH_GROUP, "r")) ? 1 : 0;
}
void
setgrent(void)
{
(void) setgroupent(0);
}
int
setgroupent(int stayopen)
{
if (!grstart())
return 0;
_gr_stayopen = stayopen;
return 1;
}
void
endgrent(void)
{
grcleanup();
if (_gr_fp) {
(void)fclose(_gr_fp);
_gr_fp = NULL;
}
}
static int _local_grscan(void *, void *, va_list);
/*ARGSUSED*/
static int
_local_grscan(void *rv, void *cb_data, va_list ap)
{
int search = va_arg(ap, int);
gid_t gid = va_arg(ap, gid_t);
const char *name = va_arg(ap, const char *);
const char *user = va_arg(ap, const char *);
if (_gr_filesdone)
return NS_NOTFOUND;
for (;;) {
if (!fgets(line, sizeof(line), _gr_fp)) {
if (!search)
_gr_filesdone = 1;
return NS_NOTFOUND;
}
/* skip lines that are too big */
if (!strchr(line, '\n')) {
int ch;
while ((ch = getc(_gr_fp)) != '\n' && ch != EOF)
;
continue;
}
if (grmatchline(search, gid, name, user))
return NS_SUCCESS;
}
/* NOTREACHED */
}
#ifdef HESIOD
static int _dns_grscan(void *, void *, va_list);
static int _dns_grplist(const char *);
/*ARGSUSED*/
static int
_dns_grscan(void *rv, void *cb_data, va_list ap)
{
int search = va_arg(ap, int);
gid_t gid = va_arg(ap, gid_t);
const char *name = va_arg(ap, const char *);
const char *user = va_arg(ap, const char *);
char **hp;
void *context;
int r;
r = NS_UNAVAIL;
if (!search && user && _gr_hesgrplistmax != -1) {
r = _dns_grplist(user);
/* if we did not find user.grplist, just iterate */
if (!_gr_hesgrplist) {
_gr_hesgrplistmax = -1;
if (r != NS_NOTFOUND)
return r;
} else
return r;
}
if (!search && _gr_hesnum == -1)
return NS_NOTFOUND;
if (hesiod_init(&context) == -1)
return (r);
for (;;) {
if (search) {
if (name)
strlcpy(line, name, sizeof(line));
else
snprintf(line, sizeof(line), "%u",
(unsigned int)gid);
} else {
snprintf(line, sizeof(line), "group-%u", _gr_hesnum);
_gr_hesnum++;
}
hp = NULL;
if (search && !name) {
hp = hesiod_resolve(context, line, "gid");
if (hp == NULL && errno != ENOENT)
break;
}
if (hp == NULL)
hp = hesiod_resolve(context, line, "group");
if (hp == NULL) {
if (errno == ENOENT) {
if (!search)
_gr_hesnum = -1;
r = NS_NOTFOUND;
}
break;
}
/* only check first elem */
strlcpy(line, hp[0], sizeof(line));
hesiod_free_list(context, hp);
if (grmatchline(search, gid, name, user)) {
r = NS_SUCCESS;
break;
} else if (search) {
r = NS_NOTFOUND;
break;
}
}
hesiod_end(context);
return (r);
}
static int
_dns_grplist(const char *user)
{
void *context;
int r;
char **hp;
char *cp;
r = NS_UNAVAIL;
if (!_gr_hesgrplist) {
if (hesiod_init(&context) == -1)
return r;
_gr_hesgrplistnum = -1;
hp = hesiod_resolve(context, user, "grplist");
if (!hp) {
if (errno == ENOENT)
r = NS_NOTFOUND;
hesiod_end(context);
return r;
}
strlcpy(line, hp[0], sizeof(line));
hesiod_free_list(context, hp);
_gr_hesgrplistmax = 0;
for (cp=line; *cp; cp++)
if (*cp == ':')
_gr_hesgrplistmax++;
_gr_hesgrplistmax /= 2;
_gr_hesgrplistmax++;
_gr_hesgrplist = malloc(_gr_hesgrplistmax *
sizeof(*_gr_hesgrplist));
if (!_gr_hesgrplist) {
hesiod_end(context);
return NS_UNAVAIL;
}
cp = line;
_gr_hesgrplistmax = 0;
for (;;) {
char *name;
char *num;
gid_t gid;
char *ep;
/* XXXrcd: error handling */
if (!(name = strsep(&cp, ":")))
break;
if (!(num = strsep(&cp, ":")))
break;
gid = (gid_t) strtoul(num, &ep, 10);
if (gid > GID_MAX || *ep != '\0')
break;
_gr_hesgrplist[_gr_hesgrplistmax].gr_name = name;
_gr_hesgrplist[_gr_hesgrplistmax].gr_gid = gid;
_gr_hesgrplistmax++;
}
hesiod_end(context);
}
/* we assume that _gr_hesgrplist is now defined */
if (++_gr_hesgrplistnum >= _gr_hesgrplistmax)
return NS_NOTFOUND;
/*
* Now we copy the relevant information into _gr_group, so that
* it can be returned. Note that we only fill in the bare necessities
* as this will be used exclusively by getgrouplist(3) and we do
* not want to have to look up all of the information.
*/
_gr_group.gr_name = _gr_hesgrplist[_gr_hesgrplistnum].gr_name;
_gr_group.gr_passwd = NULL;
_gr_group.gr_gid = _gr_hesgrplist[_gr_hesgrplistnum].gr_gid;
_gr_group.gr_mem = NULL;
return NS_SUCCESS;
}
#endif /* HESIOD */
#ifdef YP
static int _nis_grscan(void *, void *, va_list);
/*ARGSUSED*/
static int
_nis_grscan(void *rv, void *cb_data, va_list ap)
{
int search = va_arg(ap, int);
gid_t gid = va_arg(ap, gid_t);
const char *name = va_arg(ap, const char *);
const char *user = va_arg(ap, const char *);
char *key, *data;
int keylen, datalen;
int r;
if(__ypdomain == NULL) {
switch (yp_get_default_domain(&__ypdomain)) {
case 0:
break;
case YPERR_RESRC:
return NS_TRYAGAIN;
default:
return NS_UNAVAIL;
}
}
if (search) { /* specific group or gid */
if (name)
strlcpy(line, name, sizeof(line));
else
snprintf(line, sizeof(line), "%u", (unsigned int)gid);
data = NULL;
r = yp_match(__ypdomain,
(name) ? "group.byname" : "group.bygid",
line, (int)strlen(line), &data, &datalen);
switch (r) {
case 0:
break;
case YPERR_KEY:
if (data)
free(data);
return NS_NOTFOUND;
default:
if (data)
free(data);
return NS_UNAVAIL;
}
data[datalen] = '\0'; /* clear trailing \n */
strlcpy(line, data, sizeof(line));
free(data);
if (grmatchline(search, gid, name, user))
return NS_SUCCESS;
else
return NS_NOTFOUND;
}
/* ! search */
if (_gr_ypdone)
return NS_NOTFOUND;
for (;;) {
data = NULL;
if(__ypcurrent) {
key = NULL;
r = yp_next(__ypdomain, "group.byname",
__ypcurrent, __ypcurrentlen,
&key, &keylen, &data, &datalen);
free(__ypcurrent);
switch (r) {
case 0:
break;
case YPERR_NOMORE:
__ypcurrent = NULL;
if (key)
free(key);
if (data)
free(data);
_gr_ypdone = 1;
return NS_NOTFOUND;
default:
if (key)
free(key);
if (data)
free(data);
return NS_UNAVAIL;
}
__ypcurrent = key;
__ypcurrentlen = keylen;
} else {
if (yp_first(__ypdomain, "group.byname",
&__ypcurrent, &__ypcurrentlen,
&data, &datalen)) {
if (data)
free(data);
return NS_UNAVAIL;
}
}
data[datalen] = '\0'; /* clear trailing \n */
strlcpy(line, data, sizeof(line));
free(data);
if (grmatchline(search, gid, name, user))
return NS_SUCCESS;
}
/* NOTREACHED */
}
#endif /* YP */
#ifdef _GROUP_COMPAT
/*
* log an error if "files" or "compat" is specified in group_compat database
*/
static int _bad_grscan(void *, void *, va_list);
/*ARGSUSED*/
static int
_bad_grscan(void *rv, void *cb_data, va_list ap)
{
static int warned;
_DIAGASSERT(cb_data != NULL);
if (!warned) {
syslog(LOG_ERR,
"nsswitch.conf group_compat database can't use '%s'",
(char *)cb_data);
}
warned = 1;
return NS_UNAVAIL;
}
/*
* when a name lookup in compat mode is required, look it up in group_compat
* nsswitch database. only Hesiod and NIS is supported - it doesn't make
* sense to lookup compat names from 'files' or 'compat'
*/
static int __grscancompat(int, gid_t, const char *, const char *);
static int
__grscancompat(int search, gid_t gid, const char *name, const char *user)
{
static const ns_dtab dtab[] = {
NS_FILES_CB(_bad_grscan, "files")
NS_DNS_CB(_dns_grscan, NULL)
NS_NIS_CB(_nis_grscan, NULL)
NS_COMPAT_CB(_bad_grscan, "compat")
{ 0 }
};
static const ns_src defaultnis[] = {
{ NSSRC_NIS, NS_SUCCESS },
{ 0 }
};
_DIAGASSERT(name != NULL);
return (nsdispatch(NULL, dtab, NSDB_GROUP_COMPAT, "grscancompat",
defaultnis, search, gid, name, user));
}
#endif /* GROUP_COMPAT */
static int _compat_grscan(void *, void *, va_list);
/*ARGSUSED*/
static int
_compat_grscan(void *rv, void *cb_data, va_list ap)
{
int search = va_arg(ap, int);
gid_t gid = va_arg(ap, gid_t);
const char *name = va_arg(ap, const char *);
const char *user = va_arg(ap, const char *);
#ifdef _GROUP_COMPAT
static char *grname = NULL;
#endif
for (;;) {
#ifdef _GROUP_COMPAT
if(__grmode != GRMODE_NONE) {
int r;
switch(__grmode) {
case GRMODE_FULL:
r = __grscancompat(search, gid, name, user);
if (r == NS_SUCCESS)
return r;
__grmode = GRMODE_NONE;
break;
case GRMODE_NAME:
if(grname == (char *)NULL) {
__grmode = GRMODE_NONE;
break;
}
r = __grscancompat(1, 0, grname, user);
free(grname);
grname = (char *)NULL;
if (r != NS_SUCCESS)
break;
if (!search)
return NS_SUCCESS;
if (name) {
if (! strcmp(_gr_group.gr_name, name))
return NS_SUCCESS;
} else {
if (_gr_group.gr_gid == gid)
return NS_SUCCESS;
}
break;
case GRMODE_NONE:
abort();
}
continue;
}
#endif /* _GROUP_COMPAT */
if (!fgets(line, sizeof(line), _gr_fp))
return NS_NOTFOUND;
/* skip lines that are too big */
if (!strchr(line, '\n')) {
int ch;
while ((ch = getc(_gr_fp)) != '\n' && ch != EOF)
;
continue;
}
#ifdef _GROUP_COMPAT
if (line[0] == '+') {
char *tptr, *bp;
switch(line[1]) {
case ':':
case '\0':
case '\n':
__grmode = GRMODE_FULL;
break;
default:
__grmode = GRMODE_NAME;
bp = line;
tptr = strsep(&bp, ":\n");
grname = strdup(tptr + 1);
break;
}
continue;
}
#endif /* _GROUP_COMPAT */
if (grmatchline(search, gid, name, user))
return NS_SUCCESS;
}
/* NOTREACHED */
}
static int
grscan(int search, gid_t gid, const char *name, const char *user)
{
int r;
static const ns_dtab dtab[] = {
NS_FILES_CB(_local_grscan, NULL)
NS_DNS_CB(_dns_grscan, NULL)
NS_NIS_CB(_nis_grscan, NULL)
NS_COMPAT_CB(_compat_grscan, NULL)
{ 0 }
};
static const ns_src compatsrc[] = {
{ NSSRC_COMPAT, NS_SUCCESS },
{ 0 }
};
/* name may be NULL if search is nonzero */
r = nsdispatch(NULL, dtab, NSDB_GROUP, "grscan", compatsrc,
search, gid, name, user);
return (r == NS_SUCCESS) ? 1 : 0;
}
static int
grmatchline(int search, gid_t gid, const char *name, const char *user)
{
unsigned long id;
__aconst char **m;
char *cp, *bp, *ep;
/* name may be NULL if search is nonzero */
if (line[0] == '+')
return 0; /* sanity check to prevent recursion */
bp = line;
_gr_group.gr_name = strsep(&bp, ":\n");
if (search && name && strcmp(_gr_group.gr_name, name))
return 0;
_gr_group.gr_passwd = strsep(&bp, ":\n");
if (!(cp = strsep(&bp, ":\n")))
return 0;
id = strtoul(cp, &ep, 10);
if (id > GID_MAX || *ep != '\0')
return 0;
_gr_group.gr_gid = (gid_t)id;
if (search && name == NULL && _gr_group.gr_gid != gid)
return 0;
cp = NULL;
if (bp == NULL)
return 0;
for (_gr_group.gr_mem = m = members;; bp++) {
if (m == &members[MAXGRP - 1])
break;
if (*bp == ',') {
if (cp) {
*bp = '\0';
*m++ = cp;
cp = NULL;
}
} else if (*bp == '\0' || *bp == '\n' || *bp == ' ') {
if (cp) {
*bp = '\0';
*m++ = cp;
}
break;
} else if (cp == NULL)
cp = bp;
}
*m = NULL;
if (user) {
for (m = members; *m; m++)
if (!strcmp(user, *m))
return 1;
return 0;
}
return 1;
}