[nss_nonlocal.git] / nonlocal-group.c

/*
 * nonlocal-group.c
 * group database for nss_nonlocal proxy
 *
 * Copyright © 2007 Anders Kaseorg <andersk@mit.edu> and Tim Abbott
 * <tabbott@mit.edu>
 *
 * Permission is hereby granted, free of charge, to any person
 * obtaining a copy of this software and associated documentation
 * files (the "Software"), to deal in the Software without
 * restriction, including without limitation the rights to use, copy,
 * modify, merge, publish, distribute, sublicense, and/or sell copies
 * of the Software, and to permit persons to whom the Software is
 * furnished to do so, subject to the following conditions:
 *
 * The above copyright notice and this permission notice shall be
 * included in all copies or substantial portions of the Software.
 *
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
 * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
 * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
 * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS
 * BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN
 * ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
 * CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
 * SOFTWARE.
 */

#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_LOCAL_GR_BUFLEN (sysconf(_SC_GETGR_R_SIZE_MAX) + 7)
#define MAGIC_NONLOCAL_GROUPNAME "nss-nonlocal-users"
#define MAGIC_LOCAL_GROUPNAME "nss-local-users"


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)
{
    enum nss_status status = NSS_STATUS_SUCCESS;
    struct group gbuf;
    struct group *gbufp = &gbuf;
    int ret;
    int old_errno = errno;
    int buflen = MAGIC_LOCAL_GR_BUFLEN;
    char *buf = malloc(buflen);
    if (buf == NULL) {
	*errnop = ENOMEM;
	errno = old_errno;
	return NSS_STATUS_TRYAGAIN;
    }
    ret = getgrgid_r(gid, gbufp, buf, buflen, &gbufp);
    if (ret != 0) {
	*errnop = old_errno;
	status = NSS_STATUS_TRYAGAIN;
    } else if (gbufp != NULL) {
	syslog(LOG_WARNING, "nss_nonlocal: removing local group %u (%s) from non-local user %s\n", gbuf.gr_gid, gbuf.gr_name, user);
	status = NSS_STATUS_NOTFOUND;
    }
    free(buf);
    errno = old_errno;
    return status;
}

enum nss_status
get_local_group(const char *name, struct group *grp, char *buffer, size_t buflen, int *errnop)
{
    enum nss_status status = NSS_STATUS_NOTFOUND;
    struct group gbuf;
    struct group *gbufp = &gbuf;
    int ret, n;
    int old_errno = errno;
    int len = MAGIC_LOCAL_GR_BUFLEN;
    char *buf = malloc(len);
    if (buf == NULL) {
	*errnop = ENOMEM;
	errno = old_errno;
	return NSS_STATUS_TRYAGAIN;
    }
    ret = getgrnam_r(name, gbufp, buf, len, &gbufp);
    if (ret != 0) {
	*errnop = old_errno;
	status = NSS_STATUS_TRYAGAIN;
    } else if (gbufp != NULL) {
	status = NSS_STATUS_SUCCESS;

	n = snprintf(buffer, buflen, "%s", gbufp->gr_name);
	if (n < 0 || n >= buflen) {
	    *errnop = ERANGE;
	    status = NSS_STATUS_TRYAGAIN;
	    goto get_local_group_done;
	}
	grp->gr_name = buffer;
	buffer += n;
	buflen -= n;

	n = snprintf(buffer, buflen, "%s", gbufp->gr_passwd);
	if (n < 0 || n >= buflen) {
	    *errnop = ERANGE;
	    status = NSS_STATUS_TRYAGAIN;
	    goto get_local_group_done;
	}
	grp->gr_passwd = buffer;
	buffer += n;
	buflen -= n;

	grp->gr_gid = gbufp->gr_gid;

	if (buflen < sizeof(void *)) {
	    *errnop = ERANGE;
	    status = NSS_STATUS_TRYAGAIN;
	    goto get_local_group_done;
	}
	*(void **)buffer = NULL;
	buffer += sizeof(void *);
	buflen -= sizeof(void *);
    }
 get_local_group_done:
    free(buf);
    errno = old_errno;
    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 (buflen == MAGIC_LOCAL_GR_BUFLEN ||
	(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_gid("(unknown)", grp->gr_gid, &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 (buflen == MAGIC_LOCAL_GR_BUFLEN ||
	(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;

    return check_nonlocal_gid(name, grp->gr_gid, 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 (buflen == MAGIC_LOCAL_GR_BUFLEN ||
	(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;

    return check_nonlocal_gid(grp->gr_name, grp->gr_gid, 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;
    int buflen;
    char *buffer;

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

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

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

    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, *size * sizeof((*groupsp)[0]));
		if (newgroups == NULL) {
		    *errnop = ENOMEM;
		    errno = old_errno;
		    return NSS_STATUS_TRYAGAIN;
		}
		*groupsp = newgroups;
		*size = newsize;
	    }
	    (*groupsp)[(*start)++] = gid;
	}
    }

    errno = old_errno;

    if (is_local)
	return NSS_STATUS_SUCCESS;

    int in = *start, out = *start, i;

    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_NOTFOUND) {
	    *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	*
48479fc7 TA	5	* Copyright © 2007 Anders Kaseorg <andersk@mit.edu> and Tim Abbott
48479fc7 TA	6	* <tabbott@mit.edu>
f6903667 AK	7	*
	8	* Permission is hereby granted, free of charge, to any person
	9	* obtaining a copy of this software and associated documentation
	10	* files (the "Software"), to deal in the Software without
	11	* restriction, including without limitation the rights to use, copy,
	12	* modify, merge, publish, distribute, sublicense, and/or sell copies
	13	* of the Software, and to permit persons to whom the Software is
	14	* furnished to do so, subject to the following conditions:
	15	*
	16	* The above copyright notice and this permission notice shall be
	17	* included in all copies or substantial portions of the Software.
	18	*
	19	* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
	20	* EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
	21	* MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
	22	* NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS
	23	* BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN
	24	* ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
	25	* CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
	26	* SOFTWARE.
	27	*/
	28
	29	#define _GNU_SOURCE
	30	#include <sys/types.h>
	31	#include <unistd.h>
	32	#include <stdlib.h>
	33	#include <stdint.h>
	34	#include <string.h>
	35	#include <dlfcn.h>
	36	#include <stdio.h>
	37	#include <syslog.h>
	38	#include <errno.h>
	39	#include <grp.h>
	40	#include <nss.h>
	41	#include "nsswitch-internal.h"
	42	#include "nonlocal.h"
	43
f7293a54	44	#define MAGIC_LOCAL_GR_BUFLEN (sysconf(_SC_GETGR_R_SIZE_MAX) + 7)
48479fc7 TA	45	#define MAGIC_NONLOCAL_GROUPNAME "nss-nonlocal-users"
48479fc7 TA	46	#define MAGIC_LOCAL_GROUPNAME "nss-local-users"
f7293a54	47
f6903667 AK	48
	49	static service_user *
	50	nss_group_nonlocal_database(void)
	51	{
	52	static service_user *nip = NULL;
	53	if (nip == NULL)
	54	__nss_database_lookup("group_nonlocal", NULL, "", &nip);
48479fc7	55
f6903667 AK	56	return nip;
	57	}
	58
	59
f6903667 AK	60	enum nss_status
	61	check_nonlocal_gid(const char user, gid_t gid, int errnop)
	62	{
f7293a54 AK	63	enum nss_status status = NSS_STATUS_SUCCESS;
	64	struct group gbuf;
	65	struct group *gbufp = &gbuf;
	66	int ret;
	67	int old_errno = errno;
	68	int buflen = MAGIC_LOCAL_GR_BUFLEN;
	69	char *buf = malloc(buflen);
	70	if (buf == NULL) {
f6903667	71	*errnop = ENOMEM;
f7293a54	72	errno = old_errno;
f6903667 AK	73	return NSS_STATUS_TRYAGAIN;
f6903667 AK	74	}
f7293a54 AK	75	ret = getgrgid_r(gid, gbufp, buf, buflen, &gbufp);
	76	if (ret != 0) {
	77	*errnop = old_errno;
	78	status = NSS_STATUS_TRYAGAIN;
	79	} else if (gbufp != NULL) {
	80	syslog(LOG_WARNING, "nss_nonlocal: removing local group %u (%s) from non-local user %s\n", gbuf.gr_gid, gbuf.gr_name, user);
f6903667	81	status = NSS_STATUS_NOTFOUND;
f6903667	82	}
f7293a54 AK	83	free(buf);
f7293a54 AK	84	errno = old_errno;
f6903667 AK	85	return status;
	86	}
	87
48479fc7 TA	88	enum nss_status
	89	get_local_group(const char name, struct group grp, char buffer, size_t buflen, int errnop)
	90	{
	91	enum nss_status status = NSS_STATUS_NOTFOUND;
	92	struct group gbuf;
	93	struct group *gbufp = &gbuf;
1e78305d	94	int ret, n;
48479fc7 TA	95	int old_errno = errno;
	96	int len = MAGIC_LOCAL_GR_BUFLEN;
	97	char *buf = malloc(len);
	98	if (buf == NULL) {
	99	*errnop = ENOMEM;
	100	errno = old_errno;
	101	return NSS_STATUS_TRYAGAIN;
	102	}
48479fc7 TA	103	ret = getgrnam_r(name, gbufp, buf, len, &gbufp);
	104	if (ret != 0) {
	105	*errnop = old_errno;
	106	status = NSS_STATUS_TRYAGAIN;
	107	} else if (gbufp != NULL) {
	108	status = NSS_STATUS_SUCCESS;
1e78305d AK	109
	110	n = snprintf(buffer, buflen, "%s", gbufp->gr_name);
	111	if (n < 0 \|\| n >= buflen) {
	112	*errnop = ERANGE;
	113	status = NSS_STATUS_TRYAGAIN;
	114	goto get_local_group_done;
	115	}
	116	grp->gr_name = buffer;
	117	buffer += n;
	118	buflen -= n;
	119
	120	n = snprintf(buffer, buflen, "%s", gbufp->gr_passwd);
	121	if (n < 0 \|\| n >= buflen) {
	122	*errnop = ERANGE;
	123	status = NSS_STATUS_TRYAGAIN;
	124	goto get_local_group_done;
	125	}
	126	grp->gr_passwd = buffer;
	127	buffer += n;
	128	buflen -= n;
	129
48479fc7	130	grp->gr_gid = gbufp->gr_gid;
1e78305d	131
48479fc7 TA	132	if (buflen < sizeof(void *)) {
	133	*errnop = ERANGE;
	134	status = NSS_STATUS_TRYAGAIN;
1e78305d	135	goto get_local_group_done;
48479fc7	136	}
1e78305d AK	137	(void *)buffer = NULL;
	138	buffer += sizeof(void *);
	139	buflen -= sizeof(void *);
48479fc7	140	}
1e78305d	141	get_local_group_done:
48479fc7 TA	142	free(buf);
	143	errno = old_errno;
	144	return status;
	145	}
f6903667 AK	146
	147	static service_user *grent_nip = NULL;
	148	static void *grent_fct_start;
	149	static union {
	150	enum nss_status (l)(struct group grp, char *buffer, size_t buflen,
	151	int *errnop);
	152	void *ptr;
	153	} grent_fct;
	154	static const char *grent_fct_name = "getgrent_r";
	155
	156	enum nss_status
	157	_nss_nonlocal_setgrent(int stayopen)
	158	{
	159	static const char *fct_name = "setgrent";
	160	static void *fct_start = NULL;
	161	enum nss_status status;
	162	service_user *nip;
	163	union {
	164	enum nss_status (*l)(int stayopen);
	165	void *ptr;
	166	} fct;
	167
	168	nip = nss_group_nonlocal_database();
	169	if (nip == NULL)
	170	return NSS_STATUS_UNAVAIL;
	171	if (fct_start == NULL)
	172	fct_start = __nss_lookup_function(nip, fct_name);
	173	fct.ptr = fct_start;
	174	do {
	175	if (fct.ptr == NULL)
	176	status = NSS_STATUS_UNAVAIL;
	177	else
	178	status = DL_CALL_FCT(fct.l, (stayopen));
	179	} while (__nss_next(&nip, fct_name, &fct.ptr, status, 0) == 0);
	180	if (status != NSS_STATUS_SUCCESS)
	181	return status;
	182
	183	grent_nip = nip;
	184	if (grent_fct_start == NULL)
	185	grent_fct_start = __nss_lookup_function(nip, grent_fct_name);
	186	grent_fct.ptr = grent_fct_start;
	187	return NSS_STATUS_SUCCESS;
	188	}
	189
	190	enum nss_status
	191	_nss_nonlocal_endgrent(void)
	192	{
	193	static const char *fct_name = "endgrent";
	194	static void *fct_start = NULL;
	195	enum nss_status status;
	196	service_user *nip;
	197	union {
	198	enum nss_status (*l)(void);
	199	void *ptr;
	200	} fct;
	201
	202	grent_nip = NULL;
	203
	204	nip = nss_group_nonlocal_database();
	205	if (nip == NULL)
	206	return NSS_STATUS_UNAVAIL;
	207	if (fct_start == NULL)
	208	fct_start = __nss_lookup_function(nip, fct_name);
	209	fct.ptr = fct_start;
210	do {
211	if (fct.ptr == NULL)
212	status = NSS_STATUS_UNAVAIL;
213	else
214	status = DL_CALL_FCT(fct.l, ());
215	} while (__nss_next(&nip, fct_name, &fct.ptr, status, 0) == 0);
216	return status;
217	}
218
219	enum nss_status
220	_nss_nonlocal_getgrent_r(struct group grp, char buffer, size_t buflen,
221	int *errnop)
222	{
223	enum nss_status status;
a360549e TA	224
	225	char *nonlocal_ignore = getenv(NONLOCAL_IGNORE_ENV);
	226	if (buflen == MAGIC_LOCAL_GR_BUFLEN \|\|
	227	(nonlocal_ignore != NULL && nonlocal_ignore[0] != '\0'))
	228	return NSS_STATUS_UNAVAIL;
	229
f6903667 AK	230	if (grent_nip == NULL) {
	231	status = _nss_nonlocal_setgrent(0);
	232	if (status != NSS_STATUS_SUCCESS)
	233	return status;
	234	}
	235	do {
	236	if (grent_fct.ptr == NULL)
	237	status = NSS_STATUS_UNAVAIL;
	238	else {
	239	int nonlocal_errno;
	240	do
	241	status = DL_CALL_FCT(grent_fct.l, (grp, buffer, buflen, errnop));
	242	while (status == NSS_STATUS_SUCCESS &&
	243	check_nonlocal_gid("(unknown)", grp->gr_gid, &nonlocal_errno) != NSS_STATUS_SUCCESS);
	244	}
	245	if (status == NSS_STATUS_TRYAGAIN && *errnop == ERANGE)
	246	return status;
	247
	248	if (status == NSS_STATUS_SUCCESS)
	249	return NSS_STATUS_SUCCESS;
	250	} while (__nss_next(&grent_nip, grent_fct_name, &grent_fct.ptr, status, 0) == 0);
	251
	252	grent_nip = NULL;
	253	return NSS_STATUS_NOTFOUND;
	254	}
	255
	256
	257	enum nss_status
	258	_nss_nonlocal_getgrnam_r(const char name, struct group grp,
	259	char buffer, size_t buflen, int errnop)
	260	{
	261	static const char *fct_name = "getgrnam_r";
	262	static void *fct_start = NULL;
	263	enum nss_status status;
	264	service_user *nip;
	265	union {
	266	enum nss_status (l)(const char name, struct group *grp,
	267	char buffer, size_t buflen, int errnop);
	268	void *ptr;
	269	} fct;
	270
a360549e TA	271	char *nonlocal_ignore = getenv(NONLOCAL_IGNORE_ENV);
	272	if (buflen == MAGIC_LOCAL_GR_BUFLEN \|\|
	273	(nonlocal_ignore != NULL && nonlocal_ignore[0] != '\0'))
48479fc7 TA	274	return NSS_STATUS_UNAVAIL;
48479fc7 TA	275
f6903667 AK	276	nip = nss_group_nonlocal_database();
	277	if (nip == NULL)
	278	return NSS_STATUS_UNAVAIL;
	279	if (fct_start == NULL)
	280	fct_start = __nss_lookup_function(nip, fct_name);
	281	fct.ptr = fct_start;
	282	do {
	283	if (fct.ptr == NULL)
	284	status = NSS_STATUS_UNAVAIL;
	285	else
	286	status = DL_CALL_FCT(fct.l, (name, grp, buffer, buflen, errnop));
	287	if (status == NSS_STATUS_TRYAGAIN && *errnop == ERANGE)
	288	break;
	289	} while (__nss_next(&nip, fct_name, &fct.ptr, status, 0) == 0);
	290	if (status != NSS_STATUS_SUCCESS)
	291	return status;
	292
	293	return check_nonlocal_gid(name, grp->gr_gid, errnop);
	294	}
	295
	296	enum nss_status
	297	_nss_nonlocal_getgrgid_r(gid_t gid, struct group *grp,
	298	char buffer, size_t buflen, int errnop)
	299	{
	300	static const char *fct_name = "getgrgid_r";
	301	static void *fct_start = NULL;
	302	enum nss_status status;
	303	service_user *nip;
	304	union {
	305	enum nss_status (l)(gid_t gid, struct group grp,
	306	char buffer, size_t buflen, int errnop);
	307	void *ptr;
	308	} fct;
	309
a360549e TA	310	char *nonlocal_ignore = getenv(NONLOCAL_IGNORE_ENV);
	311	if (buflen == MAGIC_LOCAL_GR_BUFLEN \|\|
	312	(nonlocal_ignore != NULL && nonlocal_ignore[0] != '\0'))
f6903667 AK	313	return NSS_STATUS_UNAVAIL;
	314
	315	nip = nss_group_nonlocal_database();
	316	if (nip == NULL)
	317	return NSS_STATUS_UNAVAIL;
	318	if (fct_start == NULL)
	319	fct_start = __nss_lookup_function(nip, fct_name);
	320	fct.ptr = fct_start;
	321	do {
	322	if (fct.ptr == NULL)
	323	status = NSS_STATUS_UNAVAIL;
	324	else
	325	status = DL_CALL_FCT(fct.l, (gid, grp, buffer, buflen, errnop));
	326	if (status == NSS_STATUS_TRYAGAIN && *errnop == ERANGE)
	327	break;
	328	} while (__nss_next(&nip, fct_name, &fct.ptr, status, 0) == 0);
	329	if (status != NSS_STATUS_SUCCESS)
	330	return status;
	331
	332	return check_nonlocal_gid(grp->gr_name, grp->gr_gid, errnop);
	333	}
	334
	335	enum nss_status
	336	_nss_nonlocal_initgroups_dyn(const char user, gid_t group, long int start,
	337	long int size, gid_t *groupsp, long int limit,
	338	int *errnop)
	339	{
	340	static const char *fct_name = "initgroups_dyn";
	341	static void *fct_start = NULL;
	342	enum nss_status status;
	343	service_user *nip;
	344	union {
	345	enum nss_status (l)(const char user, gid_t group, long int *start,
	346	long int size, gid_t *groupsp, long int limit,
	347	int *errnop);
	348	void *ptr;
	349	} fct;
1e78305d AK	350
	351	struct group local_users_group, nonlocal_users_group;
	352	gid_t local_users_gid, gid;
48479fc7	353	int is_local = 0;
1e78305d AK	354	int buflen;
1e78305d AK	355	char *buffer;
48479fc7	356
1e78305d	357	/* Check that the user is a nonlocal user before adding any groups. */
48479fc7	358	status = check_nonlocal_user(user, errnop);
1e78305d	359	if (status == NSS_STATUS_NOTFOUND)
48479fc7	360	is_local = 1;
1e78305d	361	else if (status != NSS_STATUS_SUCCESS)
48479fc7	362	return status;
48479fc7	363
1e78305d AK	364	int old_errno = errno;
	365
	366	buflen = sysconf(_SC_GETGR_R_SIZE_MAX);
	367	buffer = malloc(buflen);
48479fc7 TA	368	if (buffer == NULL) {
48479fc7 TA	369	*errnop = ENOMEM;
1e78305d	370	errno = old_errno;
48479fc7 TA	371	return NSS_STATUS_TRYAGAIN;
48479fc7 TA	372	}
48479fc7 TA	373	status = get_local_group(MAGIC_LOCAL_GROUPNAME,
48479fc7 TA	374	&local_users_group, buffer, buflen, errnop);
48479fc7 TA	375	if (status == NSS_STATUS_NOTFOUND) {
	376	syslog(LOG_WARNING, "nss_nonlocal: Group %s does not exist locally!",
	377	MAGIC_LOCAL_GROUPNAME);
1e78305d AK	378	local_users_gid = -1;
	379	} else if (status != NSS_STATUS_SUCCESS) {
	380	return status;
	381	} else
	382	local_users_gid = local_users_group.gr_gid;
	383	free(buffer);
	384
	385	if (is_local) {
	386	gid = local_users_gid;
	387	} else {
	388	buflen = sysconf(_SC_GETGR_R_SIZE_MAX);
	389	buffer = malloc(buflen);
	390	if (buffer == NULL) {
	391	*errnop = ENOMEM;
	392	errno = old_errno;
	393	return NSS_STATUS_TRYAGAIN;
48479fc7	394	}
1e78305d AK	395	status = get_local_group(MAGIC_NONLOCAL_GROUPNAME,
	396	&nonlocal_users_group, buffer, buflen, errnop);
	397	if (status == NSS_STATUS_NOTFOUND) {
	398	syslog(LOG_WARNING, "nss_nonlocal: Group %s does not exist locally!",
	399	MAGIC_NONLOCAL_GROUPNAME);
	400	gid = -1;
	401	} else if (status != NSS_STATUS_SUCCESS) {
	402	errno = old_errno;
	403	return status;
	404	} else
	405	gid = nonlocal_users_group.gr_gid;
	406	free(buffer);
48479fc7	407	}
1e78305d AK	408
	409	if (gid != -1) {
	410	int i;
	411	for (i = 0; i < *start; ++i)
	412	if ((*groupsp)[i] == gid)
	413	break;
	414	if (i >= *start) {
	415	if (start + 1 > size) {
	416	gid_t *newgroups;
	417	long int newsize = 2 * *size;
	418	if (limit > 0) {
	419	if (*size >= limit)
	420	return NSS_STATUS_SUCCESS;
	421	if (newsize > limit)
	422	newsize = limit;
	423	}
	424	newgroups = realloc(groupsp, size * sizeof((*groupsp)[0]));
	425	if (newgroups == NULL) {
	426	*errnop = ENOMEM;
	427	errno = old_errno;
	428	return NSS_STATUS_TRYAGAIN;
	429	}
	430	*groupsp = newgroups;
	431	*size = newsize;
	432	}
	433	(groupsp)[(start)++] = gid;
	434	}
48479fc7	435	}
f6903667	436
1e78305d AK	437	errno = old_errno;
	438
	439	if (is_local)
	440	return NSS_STATUS_SUCCESS;
	441
	442	int in = start, out = start, i;
	443
f6903667 AK	444	nip = nss_group_nonlocal_database();
	445	if (nip == NULL)
	446	return NSS_STATUS_UNAVAIL;
	447	if (fct_start == NULL)
	448	fct_start = __nss_lookup_function(nip, fct_name);
	449	fct.ptr = fct_start;
	450
	451	do {
	452	if (fct.ptr == NULL)
	453	status = NSS_STATUS_UNAVAIL;
	454	else
	455	status = DL_CALL_FCT(fct.l, (user, group, start, size, groupsp, limit, errnop));
	456	if (status == NSS_STATUS_TRYAGAIN && *errnop == ERANGE)
	457	break;
	458	} while (__nss_next(&nip, fct_name, &fct.ptr, status, 0) == 0);
	459	if (status != NSS_STATUS_SUCCESS)
	460	return status;
	461
	462	for (; in < *start; ++in) {
	463	int nonlocal_errno = *errnop;
	464
	465	for (i = 0; i < out; ++i)
	466	if ((groupsp)[i] == (groupsp)[in])
	467	break;
	468	if (i < out)
	469	continue;
	470
1e78305d AK	471	/* Don't let users get into MAGIC_LOCAL_GROUPNAME from nonlocal reasons. */
	472	if (local_users_gid == (*groupsp)[in]) {
	473	syslog(LOG_WARNING, "nss_nonlocal: Nonlocal user %s removed from special local users group %s",
	474	user, MAGIC_LOCAL_GROUPNAME);
	475	continue;
	476	}
	477
f6903667 AK	478	status = check_nonlocal_gid(user, (*groupsp)[in], &nonlocal_errno);
f6903667 AK	479	if (status == NSS_STATUS_SUCCESS) {
1e78305d	480	(groupsp)[out++] = (groupsp)[in];
f6903667 AK	481	} else if (status != NSS_STATUS_NOTFOUND) {
	482	*start = out;
	483	*errnop = nonlocal_errno;
	484	return status;
	485	}
	486	}
	487
	488	*start = out;
	489	return NSS_STATUS_SUCCESS;
	490	}