[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;
    }
    errno = 0;
    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;
    }
    errno = 0;
    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;
    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;

    if (buflen == MAGIC_LOCAL_GR_BUFLEN)
	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;

    if (buflen == MAGIC_LOCAL_GR_BUFLEN)
	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	errno = 0;
	76	ret = getgrgid_r(gid, gbufp, buf, buflen, &gbufp);
	77	if (ret != 0) {
	78	*errnop = old_errno;
	79	status = NSS_STATUS_TRYAGAIN;
	80	} else if (gbufp != NULL) {
	81	syslog(LOG_WARNING, "nss_nonlocal: removing local group %u (%s) from non-local user %s\n", gbuf.gr_gid, gbuf.gr_name, user);
f6903667	82	status = NSS_STATUS_NOTFOUND;
f6903667	83	}
f7293a54 AK	84	free(buf);
f7293a54 AK	85	errno = old_errno;
f6903667 AK	86	return status;
	87	}
	88
48479fc7 TA	89	enum nss_status
	90	get_local_group(const char name, struct group grp, char buffer, size_t buflen, int errnop)
	91	{
	92	enum nss_status status = NSS_STATUS_NOTFOUND;
	93	struct group gbuf;
	94	struct group *gbufp = &gbuf;
1e78305d	95	int ret, n;
48479fc7 TA	96	int old_errno = errno;
	97	int len = MAGIC_LOCAL_GR_BUFLEN;
	98	char *buf = malloc(len);
	99	if (buf == NULL) {
	100	*errnop = ENOMEM;
	101	errno = old_errno;
	102	return NSS_STATUS_TRYAGAIN;
	103	}
	104	errno = 0;
	105	ret = getgrnam_r(name, gbufp, buf, len, &gbufp);
	106	if (ret != 0) {
	107	*errnop = old_errno;
	108	status = NSS_STATUS_TRYAGAIN;
	109	} else if (gbufp != NULL) {
	110	status = NSS_STATUS_SUCCESS;
1e78305d AK	111
	112	n = snprintf(buffer, buflen, "%s", gbufp->gr_name);
	113	if (n < 0 \|\| n >= buflen) {
	114	*errnop = ERANGE;
	115	status = NSS_STATUS_TRYAGAIN;
	116	goto get_local_group_done;
	117	}
	118	grp->gr_name = buffer;
	119	buffer += n;
	120	buflen -= n;
	121
	122	n = snprintf(buffer, buflen, "%s", gbufp->gr_passwd);
	123	if (n < 0 \|\| n >= buflen) {
	124	*errnop = ERANGE;
	125	status = NSS_STATUS_TRYAGAIN;
	126	goto get_local_group_done;
	127	}
	128	grp->gr_passwd = buffer;
	129	buffer += n;
	130	buflen -= n;
	131
48479fc7	132	grp->gr_gid = gbufp->gr_gid;
1e78305d	133
48479fc7 TA	134	if (buflen < sizeof(void *)) {
	135	*errnop = ERANGE;
	136	status = NSS_STATUS_TRYAGAIN;
1e78305d	137	goto get_local_group_done;
48479fc7	138	}
1e78305d AK	139	(void *)buffer = NULL;
	140	buffer += sizeof(void *);
	141	buflen -= sizeof(void *);
48479fc7	142	}
1e78305d	143	get_local_group_done:
48479fc7 TA	144	free(buf);
	145	errno = old_errno;
	146	return status;
	147	}
f6903667 AK	148
	149	static service_user *grent_nip = NULL;
	150	static void *grent_fct_start;
	151	static union {
	152	enum nss_status (l)(struct group grp, char *buffer, size_t buflen,
	153	int *errnop);
	154	void *ptr;
	155	} grent_fct;
	156	static const char *grent_fct_name = "getgrent_r";
	157
	158	enum nss_status
	159	_nss_nonlocal_setgrent(int stayopen)
	160	{
	161	static const char *fct_name = "setgrent";
	162	static void *fct_start = NULL;
	163	enum nss_status status;
	164	service_user *nip;
	165	union {
	166	enum nss_status (*l)(int stayopen);
	167	void *ptr;
	168	} fct;
	169
	170	nip = nss_group_nonlocal_database();
	171	if (nip == NULL)
	172	return NSS_STATUS_UNAVAIL;
	173	if (fct_start == NULL)
	174	fct_start = __nss_lookup_function(nip, fct_name);
	175	fct.ptr = fct_start;
	176	do {
	177	if (fct.ptr == NULL)
	178	status = NSS_STATUS_UNAVAIL;
	179	else
	180	status = DL_CALL_FCT(fct.l, (stayopen));
	181	} while (__nss_next(&nip, fct_name, &fct.ptr, status, 0) == 0);
	182	if (status != NSS_STATUS_SUCCESS)
	183	return status;
	184
	185	grent_nip = nip;
	186	if (grent_fct_start == NULL)
	187	grent_fct_start = __nss_lookup_function(nip, grent_fct_name);
	188	grent_fct.ptr = grent_fct_start;
	189	return NSS_STATUS_SUCCESS;
	190	}
	191
	192	enum nss_status
	193	_nss_nonlocal_endgrent(void)
	194	{
	195	static const char *fct_name = "endgrent";
	196	static void *fct_start = NULL;
	197	enum nss_status status;
	198	service_user *nip;
	199	union {
	200	enum nss_status (*l)(void);
	201	void *ptr;
	202	} fct;
	203
	204	grent_nip = NULL;
	205
	206	nip = nss_group_nonlocal_database();
	207	if (nip == NULL)
	208	return NSS_STATUS_UNAVAIL;
	209	if (fct_start == NULL)
	210	fct_start = __nss_lookup_function(nip, fct_name);
	211	fct.ptr = fct_start;
212	do {
213	if (fct.ptr == NULL)
214	status = NSS_STATUS_UNAVAIL;
215	else
216	status = DL_CALL_FCT(fct.l, ());
217	} while (__nss_next(&nip, fct_name, &fct.ptr, status, 0) == 0);
218	return status;
219	}
220
221	enum nss_status
222	_nss_nonlocal_getgrent_r(struct group grp, char buffer, size_t buflen,
223	int *errnop)
224	{
225	enum nss_status status;
226	if (grent_nip == NULL) {
227	status = _nss_nonlocal_setgrent(0);
228	if (status != NSS_STATUS_SUCCESS)
229	return status;
230	}
231	do {
232	if (grent_fct.ptr == NULL)
233	status = NSS_STATUS_UNAVAIL;
234	else {
235	int nonlocal_errno;
236	do
237	status = DL_CALL_FCT(grent_fct.l, (grp, buffer, buflen, errnop));
238	while (status == NSS_STATUS_SUCCESS &&
239	check_nonlocal_gid("(unknown)", grp->gr_gid, &nonlocal_errno) != NSS_STATUS_SUCCESS);
240	}
241	if (status == NSS_STATUS_TRYAGAIN && *errnop == ERANGE)
242	return status;
243
244	if (status == NSS_STATUS_SUCCESS)
245	return NSS_STATUS_SUCCESS;
246	} while (__nss_next(&grent_nip, grent_fct_name, &grent_fct.ptr, status, 0) == 0);
247
248	grent_nip = NULL;
249	return NSS_STATUS_NOTFOUND;
250	}
251
252
253	enum nss_status
254	_nss_nonlocal_getgrnam_r(const char name, struct group grp,
255	char buffer, size_t buflen, int errnop)
256	{
257	static const char *fct_name = "getgrnam_r";
258	static void *fct_start = NULL;
259	enum nss_status status;
260	service_user *nip;
261	union {
262	enum nss_status (l)(const char name, struct group *grp,
263	char buffer, size_t buflen, int errnop);
264	void *ptr;
265	} fct;
266
48479fc7 TA	267	if (buflen == MAGIC_LOCAL_GR_BUFLEN)
	268	return NSS_STATUS_UNAVAIL;
	269
f6903667 AK	270	nip = nss_group_nonlocal_database();
	271	if (nip == NULL)
	272	return NSS_STATUS_UNAVAIL;
	273	if (fct_start == NULL)
	274	fct_start = __nss_lookup_function(nip, fct_name);
	275	fct.ptr = fct_start;
	276	do {
	277	if (fct.ptr == NULL)
	278	status = NSS_STATUS_UNAVAIL;
	279	else
	280	status = DL_CALL_FCT(fct.l, (name, grp, buffer, buflen, errnop));
	281	if (status == NSS_STATUS_TRYAGAIN && *errnop == ERANGE)
	282	break;
	283	} while (__nss_next(&nip, fct_name, &fct.ptr, status, 0) == 0);
	284	if (status != NSS_STATUS_SUCCESS)
	285	return status;
	286
	287	return check_nonlocal_gid(name, grp->gr_gid, errnop);
	288	}
	289
	290	enum nss_status
	291	_nss_nonlocal_getgrgid_r(gid_t gid, struct group *grp,
	292	char buffer, size_t buflen, int errnop)
	293	{
	294	static const char *fct_name = "getgrgid_r";
	295	static void *fct_start = NULL;
	296	enum nss_status status;
	297	service_user *nip;
	298	union {
	299	enum nss_status (l)(gid_t gid, struct group grp,
	300	char buffer, size_t buflen, int errnop);
	301	void *ptr;
	302	} fct;
	303
f7293a54	304	if (buflen == MAGIC_LOCAL_GR_BUFLEN)
f6903667 AK	305	return NSS_STATUS_UNAVAIL;
	306
	307	nip = nss_group_nonlocal_database();
	308	if (nip == NULL)
	309	return NSS_STATUS_UNAVAIL;
	310	if (fct_start == NULL)
	311	fct_start = __nss_lookup_function(nip, fct_name);
	312	fct.ptr = fct_start;
	313	do {
	314	if (fct.ptr == NULL)
	315	status = NSS_STATUS_UNAVAIL;
	316	else
	317	status = DL_CALL_FCT(fct.l, (gid, grp, buffer, buflen, errnop));
	318	if (status == NSS_STATUS_TRYAGAIN && *errnop == ERANGE)
	319	break;
	320	} while (__nss_next(&nip, fct_name, &fct.ptr, status, 0) == 0);
	321	if (status != NSS_STATUS_SUCCESS)
	322	return status;
	323
	324	return check_nonlocal_gid(grp->gr_name, grp->gr_gid, errnop);
	325	}
	326
	327	enum nss_status
	328	_nss_nonlocal_initgroups_dyn(const char user, gid_t group, long int start,
	329	long int size, gid_t *groupsp, long int limit,
	330	int *errnop)
	331	{
	332	static const char *fct_name = "initgroups_dyn";
	333	static void *fct_start = NULL;
	334	enum nss_status status;
	335	service_user *nip;
	336	union {
	337	enum nss_status (l)(const char user, gid_t group, long int *start,
	338	long int size, gid_t *groupsp, long int limit,
	339	int *errnop);
	340	void *ptr;
	341	} fct;
1e78305d AK	342
	343	struct group local_users_group, nonlocal_users_group;
	344	gid_t local_users_gid, gid;
48479fc7	345	int is_local = 0;
1e78305d AK	346	int buflen;
1e78305d AK	347	char *buffer;
48479fc7	348
1e78305d	349	/* Check that the user is a nonlocal user before adding any groups. */
48479fc7	350	status = check_nonlocal_user(user, errnop);
1e78305d	351	if (status == NSS_STATUS_NOTFOUND)
48479fc7	352	is_local = 1;
1e78305d	353	else if (status != NSS_STATUS_SUCCESS)
48479fc7	354	return status;
48479fc7	355
1e78305d AK	356	int old_errno = errno;
	357
	358	buflen = sysconf(_SC_GETGR_R_SIZE_MAX);
	359	buffer = malloc(buflen);
48479fc7 TA	360	if (buffer == NULL) {
48479fc7 TA	361	*errnop = ENOMEM;
1e78305d	362	errno = old_errno;
48479fc7 TA	363	return NSS_STATUS_TRYAGAIN;
48479fc7 TA	364	}
48479fc7 TA	365	status = get_local_group(MAGIC_LOCAL_GROUPNAME,
48479fc7 TA	366	&local_users_group, buffer, buflen, errnop);
48479fc7 TA	367	if (status == NSS_STATUS_NOTFOUND) {
	368	syslog(LOG_WARNING, "nss_nonlocal: Group %s does not exist locally!",
	369	MAGIC_LOCAL_GROUPNAME);
1e78305d AK	370	local_users_gid = -1;
	371	} else if (status != NSS_STATUS_SUCCESS) {
	372	return status;
	373	} else
	374	local_users_gid = local_users_group.gr_gid;
	375	free(buffer);
	376
	377	if (is_local) {
	378	gid = local_users_gid;
	379	} else {
	380	buflen = sysconf(_SC_GETGR_R_SIZE_MAX);
	381	buffer = malloc(buflen);
	382	if (buffer == NULL) {
	383	*errnop = ENOMEM;
	384	errno = old_errno;
	385	return NSS_STATUS_TRYAGAIN;
48479fc7	386	}
1e78305d AK	387	status = get_local_group(MAGIC_NONLOCAL_GROUPNAME,
	388	&nonlocal_users_group, buffer, buflen, errnop);
	389	if (status == NSS_STATUS_NOTFOUND) {
	390	syslog(LOG_WARNING, "nss_nonlocal: Group %s does not exist locally!",
	391	MAGIC_NONLOCAL_GROUPNAME);
	392	gid = -1;
	393	} else if (status != NSS_STATUS_SUCCESS) {
	394	errno = old_errno;
	395	return status;
	396	} else
	397	gid = nonlocal_users_group.gr_gid;
	398	free(buffer);
48479fc7	399	}
1e78305d AK	400
	401	if (gid != -1) {
	402	int i;
	403	for (i = 0; i < *start; ++i)
	404	if ((*groupsp)[i] == gid)
	405	break;
	406	if (i >= *start) {
	407	if (start + 1 > size) {
	408	gid_t *newgroups;
	409	long int newsize = 2 * *size;
	410	if (limit > 0) {
	411	if (*size >= limit)
	412	return NSS_STATUS_SUCCESS;
	413	if (newsize > limit)
	414	newsize = limit;
	415	}
	416	newgroups = realloc(groupsp, size * sizeof((*groupsp)[0]));
	417	if (newgroups == NULL) {
	418	*errnop = ENOMEM;
	419	errno = old_errno;
	420	return NSS_STATUS_TRYAGAIN;
	421	}
	422	*groupsp = newgroups;
	423	*size = newsize;
	424	}
	425	(groupsp)[(start)++] = gid;
	426	}
48479fc7	427	}
f6903667	428
1e78305d AK	429	errno = old_errno;
	430
	431	if (is_local)
	432	return NSS_STATUS_SUCCESS;
	433
	434	int in = start, out = start, i;
	435
f6903667 AK	436	nip = nss_group_nonlocal_database();
	437	if (nip == NULL)
	438	return NSS_STATUS_UNAVAIL;
	439	if (fct_start == NULL)
	440	fct_start = __nss_lookup_function(nip, fct_name);
	441	fct.ptr = fct_start;
	442
	443	do {
	444	if (fct.ptr == NULL)
	445	status = NSS_STATUS_UNAVAIL;
	446	else
	447	status = DL_CALL_FCT(fct.l, (user, group, start, size, groupsp, limit, errnop));
	448	if (status == NSS_STATUS_TRYAGAIN && *errnop == ERANGE)
	449	break;
	450	} while (__nss_next(&nip, fct_name, &fct.ptr, status, 0) == 0);
	451	if (status != NSS_STATUS_SUCCESS)
	452	return status;
	453
	454	for (; in < *start; ++in) {
	455	int nonlocal_errno = *errnop;
	456
	457	for (i = 0; i < out; ++i)
	458	if ((groupsp)[i] == (groupsp)[in])
	459	break;
	460	if (i < out)
	461	continue;
	462
1e78305d AK	463	/* Don't let users get into MAGIC_LOCAL_GROUPNAME from nonlocal reasons. */
	464	if (local_users_gid == (*groupsp)[in]) {
	465	syslog(LOG_WARNING, "nss_nonlocal: Nonlocal user %s removed from special local users group %s",
	466	user, MAGIC_LOCAL_GROUPNAME);
	467	continue;
	468	}
	469
f6903667 AK	470	status = check_nonlocal_gid(user, (*groupsp)[in], &nonlocal_errno);
f6903667 AK	471	if (status == NSS_STATUS_SUCCESS) {
1e78305d	472	(groupsp)[out++] = (groupsp)[in];
f6903667 AK	473	} else if (status != NSS_STATUS_NOTFOUND) {
	474	*start = out;
	475	*errnop = nonlocal_errno;
	476	return status;
	477	}
	478	}
	479
	480	*start = out;
	481	return NSS_STATUS_SUCCESS;
	482	}