[nss_nonlocal.git] / nonlocal-group.c

/*
 * nonlocal-group.c
 * group database for nss_nonlocal proxy
 *
 * Copyright © 2007–2010 Anders Kaseorg <andersk@mit.edu> and Tim
 * Abbott <tabbott@mit.edu>
 *
 * This file is part of nss_nonlocal.
 *
 * nss_nonlocal is free software; you can redistribute it and/or
 * modify it under the terms of the GNU Lesser General Public License
 * as published by the Free Software Foundation; either version 2.1 of
 * the License, or (at your option) any later version.
 *
 * nss_nonlocal is distributed in the hope that it will be useful, but
 * WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
 * Lesser General Public License for more details.
 *
 * You should have received a copy of the GNU Lesser General Public
 * License along with nss_nonlocal; if not, write to the Free Software
 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
 * 02110-1301  USA
 */

#define _GNU_SOURCE
#include <sys/types.h>
#include <unistd.h>
#include <stdlib.h>
#include <stdint.h>
#include <string.h>
#include <dlfcn.h>
#include <stdio.h>
#include <syslog.h>
#include <errno.h>
#include <grp.h>
#include <nss.h>
#include "nsswitch-internal.h"
#include "nonlocal.h"

#define MAGIC_NONLOCAL_GROUPNAME "nss-nonlocal-users"
#define MAGIC_LOCAL_GROUPNAME "nss-local-users"


enum nss_status
_nss_nonlocal_getgrnam_r(const char *name, struct group *grp,
			 char *buffer, size_t buflen, int *errnop);

enum nss_status
_nss_nonlocal_getgrgid_r(gid_t gid, struct group *grp,
			 char *buffer, size_t buflen, int *errnop);


static service_user *
nss_group_nonlocal_database(void)
{
    static service_user *nip = NULL;
    if (nip == NULL)
	__nss_database_lookup("group_nonlocal", NULL, "", &nip);

    return nip;
}


enum nss_status
check_nonlocal_gid(const char *user, gid_t gid, int *errnop)
{
    static const char *fct_name = "getgrgid_r";
    static service_user *startp = NULL;
    static void *fct_start = NULL;
    enum nss_status status;
    service_user *nip;
    union {
	enum nss_status (*l)(gid_t gid, struct group *grp,
			     char *buffer, size_t buflen, int *errnop);
	void *ptr;
    } fct;
    struct group gbuf;
    int old_errno = errno;

    size_t buflen = sysconf(_SC_GETGR_R_SIZE_MAX);
    char *buf = malloc(buflen);
    if (buf == NULL) {
	*errnop = ENOMEM;
	errno = old_errno;
	return NSS_STATUS_TRYAGAIN;
    }

    if (fct_start == NULL &&
	__nss_group_lookup(&startp, fct_name, &fct_start) != 0) {
	free(buf);
	return NSS_STATUS_UNAVAIL;
    }
    nip = startp;
    fct.ptr = fct_start;
    do {
    morebuf:
	if (fct.l == _nss_nonlocal_getgrgid_r)
	    status = NSS_STATUS_NOTFOUND;
	else
	    status = DL_CALL_FCT(fct.l, (gid, &gbuf, buf, buflen, errnop));
	if (status == NSS_STATUS_TRYAGAIN && *errnop == ERANGE) {
	    free(buf);
	    buflen *= 2;
	    buf = malloc(buflen);
	    if (buf == NULL) {
		*errnop = ENOMEM;
		errno = old_errno;
		return NSS_STATUS_TRYAGAIN;
	    }
	    goto morebuf;
	}
    } while (__nss_next(&nip, fct_name, &fct.ptr, status, 0) == 0);

    if (status == NSS_STATUS_SUCCESS) {
	syslog(LOG_DEBUG, "nss_nonlocal: removing local group %u (%s) from non-local user %s\n", gbuf.gr_gid, gbuf.gr_name, user);
	status = NSS_STATUS_NOTFOUND;
    } else if (status != NSS_STATUS_TRYAGAIN) {
	status = NSS_STATUS_SUCCESS;
    }

    free(buf);
    return status;
}

enum nss_status
check_nonlocal_group(const char *user, struct group *grp, int *errnop)
{
    enum nss_status status = NSS_STATUS_SUCCESS;
    int old_errno = errno;
    char *end;
    unsigned long gid;

    errno = 0;
    gid = strtoul(grp->gr_name, &end, 10);
    if (errno == 0 && *end == '\0' && (gid_t)gid == gid)
	status = check_nonlocal_gid(user, gid, errnop);
    errno = old_errno;
    if (status != NSS_STATUS_SUCCESS)
	return status;

    return check_nonlocal_gid(user, grp->gr_gid, errnop);
}

enum nss_status
get_local_group(const char *name, struct group *grp, char **buffer, int *errnop)
{
    static const char *fct_name = "getgrnam_r";
    static service_user *startp = NULL;
    static void *fct_start = NULL;
    enum nss_status status;
    service_user *nip;
    union {
	enum nss_status (*l)(const char *name, struct group *grp,
			     char *buffer, size_t buflen, int *errnop);
	void *ptr;
    } fct;
    size_t buflen;
    int old_errno = errno;

    buflen = sysconf(_SC_GETGR_R_SIZE_MAX);
    *buffer = malloc(buflen);
    if (*buffer == NULL) {
	*errnop = ENOMEM;
	errno = old_errno;
	return NSS_STATUS_TRYAGAIN;
    }

    if (fct_start == NULL &&
	__nss_group_lookup(&startp, fct_name, &fct_start) != 0) {
	free(*buffer);
	*buffer = NULL;
	return NSS_STATUS_UNAVAIL;
    }
    nip = startp;
    fct.ptr = fct_start;
    do {
    morebuf:
	if (fct.l == _nss_nonlocal_getgrnam_r)
	    status = NSS_STATUS_NOTFOUND;
	else
	    status = DL_CALL_FCT(fct.l, (name, grp, *buffer, buflen, errnop));
	if (status == NSS_STATUS_TRYAGAIN && *errnop == ERANGE) {
	    free(*buffer);
	    buflen *= 2;
	    *buffer = malloc(buflen);
	    if (*buffer == NULL) {
		*errnop = ENOMEM;
		errno = old_errno;
		return NSS_STATUS_TRYAGAIN;
	    }
	    goto morebuf;
	}
    } while (__nss_next(&nip, fct_name, &fct.ptr, status, 0) == 0);

    if (status != NSS_STATUS_SUCCESS) {
	free(*buffer);
	*buffer = NULL;
    }

    return status;
}

static service_user *grent_nip = NULL;
static void *grent_fct_start;
static union {
    enum nss_status (*l)(struct group *grp, char *buffer, size_t buflen,
			 int *errnop);
    void *ptr;
} grent_fct;
static const char *grent_fct_name = "getgrent_r";

enum nss_status
_nss_nonlocal_setgrent(int stayopen)
{
    static const char *fct_name = "setgrent";
    static void *fct_start = NULL;
    enum nss_status status;
    service_user *nip;
    union {
	enum nss_status (*l)(int stayopen);
	void *ptr;
    } fct;

    nip = nss_group_nonlocal_database();
    if (nip == NULL)
	return NSS_STATUS_UNAVAIL;
    if (fct_start == NULL)
	fct_start = __nss_lookup_function(nip, fct_name);
    fct.ptr = fct_start;
    do {
	if (fct.ptr == NULL)
	    status = NSS_STATUS_UNAVAIL;
	else
	    status = DL_CALL_FCT(fct.l, (stayopen));
    } while (__nss_next(&nip, fct_name, &fct.ptr, status, 0) == 0);
    if (status != NSS_STATUS_SUCCESS)
	return status;

    grent_nip = nip;
    if (grent_fct_start == NULL)
	grent_fct_start = __nss_lookup_function(nip, grent_fct_name);
    grent_fct.ptr = grent_fct_start;
    return NSS_STATUS_SUCCESS;
}

enum nss_status
_nss_nonlocal_endgrent(void)
{
    static const char *fct_name = "endgrent";
    static void *fct_start = NULL;
    enum nss_status status;
    service_user *nip;
    union {
	enum nss_status (*l)(void);
	void *ptr;
    } fct;

    grent_nip = NULL;

    nip = nss_group_nonlocal_database();
    if (nip == NULL)
	return NSS_STATUS_UNAVAIL;
    if (fct_start == NULL)
	fct_start = __nss_lookup_function(nip, fct_name);
    fct.ptr = fct_start;
    do {
	if (fct.ptr == NULL)
	    status = NSS_STATUS_UNAVAIL;
	else
	    status = DL_CALL_FCT(fct.l, ());
    } while (__nss_next(&nip, fct_name, &fct.ptr, status, 0) == 0);
    return status;
}

enum nss_status
_nss_nonlocal_getgrent_r(struct group *grp, char *buffer, size_t buflen,
			 int *errnop)
{
    enum nss_status status;

    char *nonlocal_ignore = getenv(NONLOCAL_IGNORE_ENV);
    if (nonlocal_ignore != NULL && nonlocal_ignore[0] != '\0')
	return NSS_STATUS_UNAVAIL;

    if (grent_nip == NULL) {
	status = _nss_nonlocal_setgrent(0);
	if (status != NSS_STATUS_SUCCESS)
	    return status;
    }
    do {
	if (grent_fct.ptr == NULL)
	    status = NSS_STATUS_UNAVAIL;
	else {
	    int nonlocal_errno;
	    do
		status = DL_CALL_FCT(grent_fct.l, (grp, buffer, buflen, errnop));
	    while (status == NSS_STATUS_SUCCESS &&
		   check_nonlocal_group("(unknown)", grp, &nonlocal_errno) != NSS_STATUS_SUCCESS);
	}
	if (status == NSS_STATUS_TRYAGAIN && *errnop == ERANGE)
	    return status;

	if (status == NSS_STATUS_SUCCESS)
	    return NSS_STATUS_SUCCESS;
    } while (__nss_next(&grent_nip, grent_fct_name, &grent_fct.ptr, status, 0) == 0);

    grent_nip = NULL;
    return NSS_STATUS_NOTFOUND;
}


enum nss_status
_nss_nonlocal_getgrnam_r(const char *name, struct group *grp,
			 char *buffer, size_t buflen, int *errnop)
{
    static const char *fct_name = "getgrnam_r";
    static void *fct_start = NULL;
    enum nss_status status;
    service_user *nip;
    union {
	enum nss_status (*l)(const char *name, struct group *grp,
			     char *buffer, size_t buflen, int *errnop);
	void *ptr;
    } fct;

    char *nonlocal_ignore = getenv(NONLOCAL_IGNORE_ENV);
    if (nonlocal_ignore != NULL && nonlocal_ignore[0] != '\0')
	return NSS_STATUS_UNAVAIL;

    nip = nss_group_nonlocal_database();
    if (nip == NULL)
	return NSS_STATUS_UNAVAIL;
    if (fct_start == NULL)
	fct_start = __nss_lookup_function(nip, fct_name);
    fct.ptr = fct_start;
    do {
	if (fct.ptr == NULL)
	    status = NSS_STATUS_UNAVAIL;
	else
	    status = DL_CALL_FCT(fct.l, (name, grp, buffer, buflen, errnop));
	if (status == NSS_STATUS_TRYAGAIN && *errnop == ERANGE)
	    break;
    } while (__nss_next(&nip, fct_name, &fct.ptr, status, 0) == 0);
    if (status != NSS_STATUS_SUCCESS)
	return status;

    if (strcmp(name, grp->gr_name) != 0) {
	syslog(LOG_ERR, "nss_nonlocal: discarding group %s from lookup for group %s\n", grp->gr_name, name);
	return NSS_STATUS_NOTFOUND;
    }

    return check_nonlocal_group(name, grp, errnop);
}

enum nss_status
_nss_nonlocal_getgrgid_r(gid_t gid, struct group *grp,
			 char *buffer, size_t buflen, int *errnop)
{
    static const char *fct_name = "getgrgid_r";
    static void *fct_start = NULL;
    enum nss_status status;
    service_user *nip;
    union {
	enum nss_status (*l)(gid_t gid, struct group *grp,
			     char *buffer, size_t buflen, int *errnop);
	void *ptr;
    } fct;

    char *nonlocal_ignore = getenv(NONLOCAL_IGNORE_ENV);
    if (nonlocal_ignore != NULL && nonlocal_ignore[0] != '\0')
	return NSS_STATUS_UNAVAIL;

    nip = nss_group_nonlocal_database();
    if (nip == NULL)
	return NSS_STATUS_UNAVAIL;
    if (fct_start == NULL)
	fct_start = __nss_lookup_function(nip, fct_name);
    fct.ptr = fct_start;
    do {
	if (fct.ptr == NULL)
	    status = NSS_STATUS_UNAVAIL;
	else
	    status = DL_CALL_FCT(fct.l, (gid, grp, buffer, buflen, errnop));
	if (status == NSS_STATUS_TRYAGAIN && *errnop == ERANGE)
	    break;
    } while (__nss_next(&nip, fct_name, &fct.ptr, status, 0) == 0);
    if (status != NSS_STATUS_SUCCESS)
	return status;

    if (gid != grp->gr_gid) {
	syslog(LOG_ERR, "nss_nonlocal: discarding gid %d from lookup for gid %d\n", grp->gr_gid, gid);
	return NSS_STATUS_NOTFOUND;
    }

    return check_nonlocal_group(grp->gr_name, grp, errnop);
}

enum nss_status
_nss_nonlocal_initgroups_dyn(const char *user, gid_t group, long int *start,
			     long int *size, gid_t **groupsp, long int limit,
			     int *errnop)
{
    static const char *fct_name = "initgroups_dyn";
    static void *fct_start = NULL;
    enum nss_status status;
    service_user *nip;
    union {
	enum nss_status (*l)(const char *user, gid_t group, long int *start,
			     long int *size, gid_t **groupsp, long int limit,
			     int *errnop);
	void *ptr;
    } fct;

    struct group local_users_group, nonlocal_users_group;
    gid_t local_users_gid, gid;
    int is_local = 0;
    char *buffer;
    int old_errno;
    int in, out, i;

    /* Check that the user is a nonlocal user before adding any groups. */
    status = check_nonlocal_user(user, errnop);
    if (status == NSS_STATUS_TRYAGAIN)
	return status;
    else if (status != NSS_STATUS_SUCCESS)
	is_local = 1;

    old_errno = errno;

    status = get_local_group(MAGIC_LOCAL_GROUPNAME,
			     &local_users_group, &buffer, errnop);
    if (status == NSS_STATUS_SUCCESS) {
	local_users_gid = local_users_group.gr_gid;
	free(buffer);
    } else if (status == NSS_STATUS_TRYAGAIN) {
	return status;
    } else {
	syslog(LOG_WARNING, "nss_nonlocal: Group %s does not exist locally!",
	       MAGIC_LOCAL_GROUPNAME);
	local_users_gid = -1;
    }

    if (is_local) {
	gid = local_users_gid;
    } else {
 	status = get_local_group(MAGIC_NONLOCAL_GROUPNAME,
				 &nonlocal_users_group, &buffer, errnop);
	if (status == NSS_STATUS_SUCCESS) {
	    gid = nonlocal_users_group.gr_gid;
	    free(buffer);
	} else if (status == NSS_STATUS_TRYAGAIN) {
	    return status;
	} else {
	    syslog(LOG_WARNING, "nss_nonlocal: Group %s does not exist locally!",
		   MAGIC_NONLOCAL_GROUPNAME);
	    gid = -1;
	}
    }

    if (gid != -1) {
	int i;
	for (i = 0; i < *start; ++i)
	    if ((*groupsp)[i] == gid)
		break;
	if (i >= *start) {
	    if (*start + 1 > *size) {
		gid_t *newgroups;
		long int newsize = 2 * *size;
		if (limit > 0) {
		    if (*size >= limit)
			return NSS_STATUS_SUCCESS;
		    if (newsize > limit)
			newsize = limit;
		}
		newgroups = realloc(*groupsp, newsize * sizeof((*groupsp)[0]));
		if (newgroups == NULL) {
		    *errnop = ENOMEM;
		    errno = old_errno;
		    return NSS_STATUS_TRYAGAIN;
		}
		*groupsp = newgroups;
		*size = newsize;
	    }
	    (*groupsp)[(*start)++] = gid;
	}
    }

    if (is_local)
	return NSS_STATUS_SUCCESS;

    in = out = *start;

    nip = nss_group_nonlocal_database();
    if (nip == NULL)
	return NSS_STATUS_UNAVAIL;
    if (fct_start == NULL)
	fct_start = __nss_lookup_function(nip, fct_name);
    fct.ptr = fct_start;

    do {
	if (fct.ptr == NULL)
	    status = NSS_STATUS_UNAVAIL;
	else
	    status = DL_CALL_FCT(fct.l, (user, group, start, size, groupsp, limit, errnop));
        if (status == NSS_STATUS_TRYAGAIN && *errnop == ERANGE)
            break;
    } while (__nss_next(&nip, fct_name, &fct.ptr, status, 0) == 0);
    if (status != NSS_STATUS_SUCCESS)
        return status;

    for (; in < *start; ++in) {
	int nonlocal_errno = *errnop;

	for (i = 0; i < out; ++i)
	    if ((*groupsp)[i] == (*groupsp)[in])
		break;
	if (i < out)
	    continue;

	/* Don't let users get into MAGIC_LOCAL_GROUPNAME from nonlocal reasons. */
	if (local_users_gid == (*groupsp)[in]) {
	    syslog(LOG_WARNING, "nss_nonlocal: Nonlocal user %s removed from special local users group %s",
		   user, MAGIC_LOCAL_GROUPNAME);
	    continue;
	}

	status = check_nonlocal_gid(user, (*groupsp)[in], &nonlocal_errno);
	if (status == NSS_STATUS_SUCCESS) {
	    (*groupsp)[out++] = (*groupsp)[in];
	} else if (status == NSS_STATUS_TRYAGAIN) {
	    *start = out;
	    *errnop = nonlocal_errno;
	    return status;
	}
    }

    *start = out;
    return NSS_STATUS_SUCCESS;
}
Commit	Line	Data
f6903667 AK	1	/*
	2	* nonlocal-group.c
	3	* group database for nss_nonlocal proxy
	4	*
96a1ee0f AK	5	* Copyright © 2007–2010 Anders Kaseorg <andersk@mit.edu> and Tim
96a1ee0f AK	6	* Abbott <tabbott@mit.edu>
f6903667	7	*
96a1ee0f	8	* This file is part of nss_nonlocal.
f6903667	9	*
96a1ee0f AK	10	* nss_nonlocal is free software; you can redistribute it and/or
	11	* modify it under the terms of the GNU Lesser General Public License
	12	* as published by the Free Software Foundation; either version 2.1 of
	13	* the License, or (at your option) any later version.
f6903667	14	*
96a1ee0f AK	15	* nss_nonlocal is distributed in the hope that it will be useful, but
	16	* WITHOUT ANY WARRANTY; without even the implied warranty of
	17	* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
	18	* Lesser General Public License for more details.
	19	*
	20	* You should have received a copy of the GNU Lesser General Public
	21	* License along with nss_nonlocal; if not, write to the Free Software
	22	* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
	23	* 02110-1301 USA
f6903667 AK	24	*/
	25
	26	#define _GNU_SOURCE
	27	#include <sys/types.h>
	28	#include <unistd.h>
	29	#include <stdlib.h>
	30	#include <stdint.h>
	31	#include <string.h>
	32	#include <dlfcn.h>
	33	#include <stdio.h>
	34	#include <syslog.h>
	35	#include <errno.h>
	36	#include <grp.h>
	37	#include <nss.h>
	38	#include "nsswitch-internal.h"
	39	#include "nonlocal.h"
	40
48479fc7 TA	41	#define MAGIC_NONLOCAL_GROUPNAME "nss-nonlocal-users"
48479fc7 TA	42	#define MAGIC_LOCAL_GROUPNAME "nss-local-users"
f7293a54	43
f6903667	44
c1812233 AK	45	enum nss_status
	46	_nss_nonlocal_getgrnam_r(const char name, struct group grp,
	47	char buffer, size_t buflen, int errnop);
	48
	49	enum nss_status
	50	_nss_nonlocal_getgrgid_r(gid_t gid, struct group *grp,
	51	char buffer, size_t buflen, int errnop);
	52
	53
f6903667 AK	54	static service_user *
	55	nss_group_nonlocal_database(void)
	56	{
	57	static service_user *nip = NULL;
	58	if (nip == NULL)
	59	__nss_database_lookup("group_nonlocal", NULL, "", &nip);
48479fc7	60
f6903667 AK	61	return nip;
	62	}
	63
	64
f6903667 AK	65	enum nss_status
	66	check_nonlocal_gid(const char user, gid_t gid, int errnop)
	67	{
30fb3957 AK	68	static const char *fct_name = "getgrgid_r";
	69	static service_user *startp = NULL;
	70	static void *fct_start = NULL;
	71	enum nss_status status;
	72	service_user *nip;
	73	union {
	74	enum nss_status (l)(gid_t gid, struct group grp,
	75	char buffer, size_t buflen, int errnop);
	76	void *ptr;
	77	} fct;
f7293a54	78	struct group gbuf;
f7293a54	79	int old_errno = errno;
c1812233	80
8870ee9c	81	size_t buflen = sysconf(_SC_GETGR_R_SIZE_MAX);
f7293a54 AK	82	char *buf = malloc(buflen);
f7293a54 AK	83	if (buf == NULL) {
f6903667	84	*errnop = ENOMEM;
f7293a54	85	errno = old_errno;
f6903667 AK	86	return NSS_STATUS_TRYAGAIN;
f6903667 AK	87	}
30fb3957 AK	88
	89	if (fct_start == NULL &&
	90	__nss_group_lookup(&startp, fct_name, &fct_start) != 0) {
	91	free(buf);
	92	return NSS_STATUS_UNAVAIL;
	93	}
	94	nip = startp;
	95	fct.ptr = fct_start;
	96	do {
d905b369	97	morebuf:
c1812233 AK	98	if (fct.l == _nss_nonlocal_getgrgid_r)
	99	status = NSS_STATUS_NOTFOUND;
	100	else
	101	status = DL_CALL_FCT(fct.l, (gid, &gbuf, buf, buflen, errnop));
d905b369 AK	102	if (status == NSS_STATUS_TRYAGAIN && *errnop == ERANGE) {
	103	free(buf);
	104	buflen *= 2;
	105	buf = malloc(buflen);
	106	if (buf == NULL) {
	107	*errnop = ENOMEM;
	108	errno = old_errno;
	109	return NSS_STATUS_TRYAGAIN;
	110	}
	111	goto morebuf;
	112	}
30fb3957 AK	113	} while (__nss_next(&nip, fct_name, &fct.ptr, status, 0) == 0);
	114
	115	if (status == NSS_STATUS_SUCCESS) {
21b6ddd9	116	syslog(LOG_DEBUG, "nss_nonlocal: removing local group %u (%s) from non-local user %s\n", gbuf.gr_gid, gbuf.gr_name, user);
f6903667	117	status = NSS_STATUS_NOTFOUND;
30fb3957 AK	118	} else if (status != NSS_STATUS_TRYAGAIN) {
30fb3957 AK	119	status = NSS_STATUS_SUCCESS;
f6903667	120	}
30fb3957	121
f7293a54	122	free(buf);
f6903667 AK	123	return status;
	124	}
	125
cf338316 AK	126	enum nss_status
	127	check_nonlocal_group(const char user, struct group grp, int *errnop)
	128	{
a07a7616 AK	129	enum nss_status status = NSS_STATUS_SUCCESS;
	130	int old_errno = errno;
	131	char *end;
	132	unsigned long gid;
	133
	134	errno = 0;
	135	gid = strtoul(grp->gr_name, &end, 10);
	136	if (errno == 0 && *end == '\0' && (gid_t)gid == gid)
	137	status = check_nonlocal_gid(user, gid, errnop);
	138	errno = old_errno;
	139	if (status != NSS_STATUS_SUCCESS)
	140	return status;
	141
cf338316 AK	142	return check_nonlocal_gid(user, grp->gr_gid, errnop);
	143	}
	144
48479fc7	145	enum nss_status
8aa9014e	146	get_local_group(const char name, struct group grp, char *buffer, int errnop)
48479fc7	147	{
30fb3957 AK	148	static const char *fct_name = "getgrnam_r";
	149	static service_user *startp = NULL;
	150	static void *fct_start = NULL;
	151	enum nss_status status;
	152	service_user *nip;
	153	union {
	154	enum nss_status (l)(const char name, struct group *grp,
	155	char buffer, size_t buflen, int errnop);
	156	void *ptr;
	157	} fct;
8aa9014e	158	size_t buflen;
48479fc7	159	int old_errno = errno;
c1812233	160
8aa9014e AK	161	buflen = sysconf(_SC_GETGR_R_SIZE_MAX);
	162	*buffer = malloc(buflen);
	163	if (*buffer == NULL) {
48479fc7 TA	164	*errnop = ENOMEM;
	165	errno = old_errno;
	166	return NSS_STATUS_TRYAGAIN;
	167	}
1e78305d	168
30fb3957 AK	169	if (fct_start == NULL &&
30fb3957 AK	170	__nss_group_lookup(&startp, fct_name, &fct_start) != 0) {
8aa9014e AK	171	free(*buffer);
8aa9014e AK	172	*buffer = NULL;
30fb3957 AK	173	return NSS_STATUS_UNAVAIL;
	174	}
	175	nip = startp;
	176	fct.ptr = fct_start;
	177	do {
d905b369	178	morebuf:
c1812233 AK	179	if (fct.l == _nss_nonlocal_getgrnam_r)
	180	status = NSS_STATUS_NOTFOUND;
	181	else
8aa9014e	182	status = DL_CALL_FCT(fct.l, (name, grp, *buffer, buflen, errnop));
d905b369	183	if (status == NSS_STATUS_TRYAGAIN && *errnop == ERANGE) {
8aa9014e AK	184	free(*buffer);
	185	buflen *= 2;
	186	*buffer = malloc(buflen);
	187	if (*buffer == NULL) {
d905b369 AK	188	*errnop = ENOMEM;
	189	errno = old_errno;
	190	return NSS_STATUS_TRYAGAIN;
	191	}
	192	goto morebuf;
	193	}
30fb3957 AK	194	} while (__nss_next(&nip, fct_name, &fct.ptr, status, 0) == 0);
30fb3957 AK	195
8aa9014e AK	196	if (status != NSS_STATUS_SUCCESS) {
	197	free(*buffer);
	198	*buffer = NULL;
48479fc7	199	}
30fb3957	200
48479fc7 TA	201	return status;
48479fc7 TA	202	}
f6903667 AK	203
	204	static service_user *grent_nip = NULL;
	205	static void *grent_fct_start;
	206	static union {
	207	enum nss_status (l)(struct group grp, char *buffer, size_t buflen,
	208	int *errnop);
	209	void *ptr;
	210	} grent_fct;
	211	static const char *grent_fct_name = "getgrent_r";
	212
	213	enum nss_status
	214	_nss_nonlocal_setgrent(int stayopen)
	215	{
	216	static const char *fct_name = "setgrent";
	217	static void *fct_start = NULL;
	218	enum nss_status status;
	219	service_user *nip;
	220	union {
	221	enum nss_status (*l)(int stayopen);
	222	void *ptr;
	223	} fct;
	224
	225	nip = nss_group_nonlocal_database();
	226	if (nip == NULL)
	227	return NSS_STATUS_UNAVAIL;
	228	if (fct_start == NULL)
	229	fct_start = __nss_lookup_function(nip, fct_name);
	230	fct.ptr = fct_start;
	231	do {
	232	if (fct.ptr == NULL)
	233	status = NSS_STATUS_UNAVAIL;
	234	else
	235	status = DL_CALL_FCT(fct.l, (stayopen));
	236	} while (__nss_next(&nip, fct_name, &fct.ptr, status, 0) == 0);
	237	if (status != NSS_STATUS_SUCCESS)
	238	return status;
	239
	240	grent_nip = nip;
	241	if (grent_fct_start == NULL)
	242	grent_fct_start = __nss_lookup_function(nip, grent_fct_name);
	243	grent_fct.ptr = grent_fct_start;
	244	return NSS_STATUS_SUCCESS;
	245	}
	246
	247	enum nss_status
	248	_nss_nonlocal_endgrent(void)
	249	{
	250	static const char *fct_name = "endgrent";
	251	static void *fct_start = NULL;
	252	enum nss_status status;
	253	service_user *nip;
	254	union {
	255	enum nss_status (*l)(void);
	256	void *ptr;
	257	} fct;
	258
	259	grent_nip = NULL;
	260
	261	nip = nss_group_nonlocal_database();
	262	if (nip == NULL)
	263	return NSS_STATUS_UNAVAIL;
	264	if (fct_start == NULL)
	265	fct_start = __nss_lookup_function(nip, fct_name);
	266	fct.ptr = fct_start;
267	do {
268	if (fct.ptr == NULL)
269	status = NSS_STATUS_UNAVAIL;
270	else
271	status = DL_CALL_FCT(fct.l, ());
272	} while (__nss_next(&nip, fct_name, &fct.ptr, status, 0) == 0);
273	return status;
274	}
275
276	enum nss_status
277	_nss_nonlocal_getgrent_r(struct group grp, char buffer, size_t buflen,
278	int *errnop)
279	{
280	enum nss_status status;
a360549e TA	281
a360549e TA	282	char *nonlocal_ignore = getenv(NONLOCAL_IGNORE_ENV);
c1812233	283	if (nonlocal_ignore != NULL && nonlocal_ignore[0] != '\0')
a360549e TA	284	return NSS_STATUS_UNAVAIL;
a360549e TA	285
f6903667 AK	286	if (grent_nip == NULL) {
	287	status = _nss_nonlocal_setgrent(0);
	288	if (status != NSS_STATUS_SUCCESS)
	289	return status;
	290	}
	291	do {
	292	if (grent_fct.ptr == NULL)
	293	status = NSS_STATUS_UNAVAIL;
	294	else {
	295	int nonlocal_errno;
	296	do
	297	status = DL_CALL_FCT(grent_fct.l, (grp, buffer, buflen, errnop));
	298	while (status == NSS_STATUS_SUCCESS &&
cf338316	299	check_nonlocal_group("(unknown)", grp, &nonlocal_errno) != NSS_STATUS_SUCCESS);
f6903667 AK	300	}
	301	if (status == NSS_STATUS_TRYAGAIN && *errnop == ERANGE)
	302	return status;
	303
	304	if (status == NSS_STATUS_SUCCESS)
	305	return NSS_STATUS_SUCCESS;
	306	} while (__nss_next(&grent_nip, grent_fct_name, &grent_fct.ptr, status, 0) == 0);
	307
	308	grent_nip = NULL;
	309	return NSS_STATUS_NOTFOUND;
	310	}
	311
	312
	313	enum nss_status
	314	_nss_nonlocal_getgrnam_r(const char name, struct group grp,
	315	char buffer, size_t buflen, int errnop)
	316	{
	317	static const char *fct_name = "getgrnam_r";
	318	static void *fct_start = NULL;
	319	enum nss_status status;
	320	service_user *nip;
	321	union {
	322	enum nss_status (l)(const char name, struct group *grp,
	323	char buffer, size_t buflen, int errnop);
	324	void *ptr;
	325	} fct;
	326
a360549e	327	char *nonlocal_ignore = getenv(NONLOCAL_IGNORE_ENV);
c1812233	328	if (nonlocal_ignore != NULL && nonlocal_ignore[0] != '\0')
48479fc7 TA	329	return NSS_STATUS_UNAVAIL;
48479fc7 TA	330
f6903667 AK	331	nip = nss_group_nonlocal_database();
	332	if (nip == NULL)
	333	return NSS_STATUS_UNAVAIL;
	334	if (fct_start == NULL)
	335	fct_start = __nss_lookup_function(nip, fct_name);
	336	fct.ptr = fct_start;
	337	do {
	338	if (fct.ptr == NULL)
	339	status = NSS_STATUS_UNAVAIL;
	340	else
	341	status = DL_CALL_FCT(fct.l, (name, grp, buffer, buflen, errnop));
	342	if (status == NSS_STATUS_TRYAGAIN && *errnop == ERANGE)
	343	break;
	344	} while (__nss_next(&nip, fct_name, &fct.ptr, status, 0) == 0);
	345	if (status != NSS_STATUS_SUCCESS)
	346	return status;
	347
22562df0 AK	348	if (strcmp(name, grp->gr_name) != 0) {
	349	syslog(LOG_ERR, "nss_nonlocal: discarding group %s from lookup for group %s\n", grp->gr_name, name);
	350	return NSS_STATUS_NOTFOUND;
	351	}
	352
cf338316	353	return check_nonlocal_group(name, grp, errnop);
f6903667 AK	354	}
	355
	356	enum nss_status
	357	_nss_nonlocal_getgrgid_r(gid_t gid, struct group *grp,
	358	char buffer, size_t buflen, int errnop)
	359	{
	360	static const char *fct_name = "getgrgid_r";
	361	static void *fct_start = NULL;
	362	enum nss_status status;
	363	service_user *nip;
	364	union {
	365	enum nss_status (l)(gid_t gid, struct group grp,
	366	char buffer, size_t buflen, int errnop);
	367	void *ptr;
	368	} fct;
	369
a360549e	370	char *nonlocal_ignore = getenv(NONLOCAL_IGNORE_ENV);
c1812233	371	if (nonlocal_ignore != NULL && nonlocal_ignore[0] != '\0')
f6903667 AK	372	return NSS_STATUS_UNAVAIL;
	373
	374	nip = nss_group_nonlocal_database();
	375	if (nip == NULL)
	376	return NSS_STATUS_UNAVAIL;
	377	if (fct_start == NULL)
	378	fct_start = __nss_lookup_function(nip, fct_name);
	379	fct.ptr = fct_start;
	380	do {
	381	if (fct.ptr == NULL)
	382	status = NSS_STATUS_UNAVAIL;
	383	else
	384	status = DL_CALL_FCT(fct.l, (gid, grp, buffer, buflen, errnop));
	385	if (status == NSS_STATUS_TRYAGAIN && *errnop == ERANGE)
	386	break;
	387	} while (__nss_next(&nip, fct_name, &fct.ptr, status, 0) == 0);
	388	if (status != NSS_STATUS_SUCCESS)
	389	return status;
	390
8027fdc4 AK	391	if (gid != grp->gr_gid) {
	392	syslog(LOG_ERR, "nss_nonlocal: discarding gid %d from lookup for gid %d\n", grp->gr_gid, gid);
	393	return NSS_STATUS_NOTFOUND;
	394	}
	395
cf338316	396	return check_nonlocal_group(grp->gr_name, grp, errnop);
f6903667 AK	397	}
	398
	399	enum nss_status
	400	_nss_nonlocal_initgroups_dyn(const char user, gid_t group, long int start,
	401	long int size, gid_t *groupsp, long int limit,
	402	int *errnop)
	403	{
	404	static const char *fct_name = "initgroups_dyn";
	405	static void *fct_start = NULL;
	406	enum nss_status status;
	407	service_user *nip;
	408	union {
	409	enum nss_status (l)(const char user, gid_t group, long int *start,
	410	long int size, gid_t *groupsp, long int limit,
	411	int *errnop);
	412	void *ptr;
	413	} fct;
1e78305d AK	414
	415	struct group local_users_group, nonlocal_users_group;
	416	gid_t local_users_gid, gid;
48479fc7	417	int is_local = 0;
1e78305d	418	char *buffer;
d7bf1d11 AK	419	int old_errno;
d7bf1d11 AK	420	int in, out, i;
48479fc7	421
1e78305d	422	/* Check that the user is a nonlocal user before adding any groups. */
48479fc7	423	status = check_nonlocal_user(user, errnop);
5879a696	424	if (status == NSS_STATUS_TRYAGAIN)
48479fc7	425	return status;
5879a696 AK	426	else if (status != NSS_STATUS_SUCCESS)
5879a696 AK	427	is_local = 1;
48479fc7	428
d7bf1d11	429	old_errno = errno;
1e78305d	430
48479fc7	431	status = get_local_group(MAGIC_LOCAL_GROUPNAME,
8aa9014e	432	&local_users_group, &buffer, errnop);
5879a696 AK	433	if (status == NSS_STATUS_SUCCESS) {
5879a696 AK	434	local_users_gid = local_users_group.gr_gid;
dc94c928	435	free(buffer);
8aa9014e	436	} else if (status == NSS_STATUS_TRYAGAIN) {
5879a696 AK	437	return status;
5879a696 AK	438	} else {
48479fc7 TA	439	syslog(LOG_WARNING, "nss_nonlocal: Group %s does not exist locally!",
48479fc7 TA	440	MAGIC_LOCAL_GROUPNAME);
1e78305d	441	local_users_gid = -1;
5879a696	442	}
1e78305d AK	443
	444	if (is_local) {
	445	gid = local_users_gid;
	446	} else {
1e78305d	447	status = get_local_group(MAGIC_NONLOCAL_GROUPNAME,
8aa9014e	448	&nonlocal_users_group, &buffer, errnop);
5879a696 AK	449	if (status == NSS_STATUS_SUCCESS) {
5879a696 AK	450	gid = nonlocal_users_group.gr_gid;
dc94c928	451	free(buffer);
8aa9014e	452	} else if (status == NSS_STATUS_TRYAGAIN) {
5879a696 AK	453	return status;
5879a696 AK	454	} else {
1e78305d AK	455	syslog(LOG_WARNING, "nss_nonlocal: Group %s does not exist locally!",
	456	MAGIC_NONLOCAL_GROUPNAME);
	457	gid = -1;
5879a696	458	}
48479fc7	459	}
1e78305d AK	460
	461	if (gid != -1) {
	462	int i;
	463	for (i = 0; i < *start; ++i)
	464	if ((*groupsp)[i] == gid)
	465	break;
	466	if (i >= *start) {
	467	if (start + 1 > size) {
	468	gid_t *newgroups;
	469	long int newsize = 2 * *size;
	470	if (limit > 0) {
	471	if (*size >= limit)
	472	return NSS_STATUS_SUCCESS;
	473	if (newsize > limit)
	474	newsize = limit;
	475	}
ad0399bd	476	newgroups = realloc(groupsp, newsize sizeof((*groupsp)[0]));
1e78305d AK	477	if (newgroups == NULL) {
	478	*errnop = ENOMEM;
	479	errno = old_errno;
	480	return NSS_STATUS_TRYAGAIN;
	481	}
	482	*groupsp = newgroups;
	483	*size = newsize;
	484	}
	485	(groupsp)[(start)++] = gid;
	486	}
48479fc7	487	}
f6903667	488
1e78305d AK	489	if (is_local)
	490	return NSS_STATUS_SUCCESS;
	491
d7bf1d11	492	in = out = *start;
1e78305d	493
f6903667 AK	494	nip = nss_group_nonlocal_database();
	495	if (nip == NULL)
	496	return NSS_STATUS_UNAVAIL;
	497	if (fct_start == NULL)
	498	fct_start = __nss_lookup_function(nip, fct_name);
	499	fct.ptr = fct_start;
	500
	501	do {
	502	if (fct.ptr == NULL)
	503	status = NSS_STATUS_UNAVAIL;
	504	else
	505	status = DL_CALL_FCT(fct.l, (user, group, start, size, groupsp, limit, errnop));
	506	if (status == NSS_STATUS_TRYAGAIN && *errnop == ERANGE)
	507	break;
	508	} while (__nss_next(&nip, fct_name, &fct.ptr, status, 0) == 0);
	509	if (status != NSS_STATUS_SUCCESS)
	510	return status;
	511
	512	for (; in < *start; ++in) {
	513	int nonlocal_errno = *errnop;
	514
	515	for (i = 0; i < out; ++i)
	516	if ((groupsp)[i] == (groupsp)[in])
	517	break;
	518	if (i < out)
	519	continue;
	520
1e78305d AK	521	/* Don't let users get into MAGIC_LOCAL_GROUPNAME from nonlocal reasons. */
	522	if (local_users_gid == (*groupsp)[in]) {
	523	syslog(LOG_WARNING, "nss_nonlocal: Nonlocal user %s removed from special local users group %s",
	524	user, MAGIC_LOCAL_GROUPNAME);
	525	continue;
	526	}
	527
f6903667 AK	528	status = check_nonlocal_gid(user, (*groupsp)[in], &nonlocal_errno);
f6903667 AK	529	if (status == NSS_STATUS_SUCCESS) {
1e78305d	530	(groupsp)[out++] = (groupsp)[in];
5879a696	531	} else if (status == NSS_STATUS_TRYAGAIN) {
f6903667 AK	532	*start = out;
	533	*errnop = nonlocal_errno;
	534	return status;
	535	}
	536	}
	537
	538	*start = out;
	539	return NSS_STATUS_SUCCESS;
	540	}