[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;
    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;
	grp->gr_name = strncpy(buffer, gbufp->gr_name, buflen);
	buffer = buffer + strlen(grp->gr_name);
	buflen = buflen - strlen(grp->gr_name);
	grp->gr_passwd = strncpy(buffer, gbufp->gr_passwd, buflen);
	buffer = buffer + strlen(grp->gr_passwd);
	buflen = buflen - strlen(grp->gr_passwd);
	grp->gr_gid = gbufp->gr_gid;
	if (buflen < sizeof(void *)) {
	    *errnop = ERANGE;
	    status = NSS_STATUS_TRYAGAIN;
	}
	else {
	    grp->gr_mem = memset(buffer, 0, sizeof(void *));
	}
    }
    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;
    int in = *start, out = *start, i;
    gid_t local_users_gid;
    int is_local = 0;

    // 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 buflen = sysconf(_SC_GETGR_R_SIZE_MAX);
    char *buffer = malloc(buflen);
    if (buffer == NULL) {
	*errnop = ENOMEM;
	return NSS_STATUS_TRYAGAIN;
    }
    struct group local_users_group;
    status = get_local_group(MAGIC_LOCAL_GROUPNAME,
			     &local_users_group, buffer, buflen, errnop);
    free(buffer);
    if (status == NSS_STATUS_NOTFOUND) {
	syslog(LOG_WARNING, "nss_nonlocal: Group %s does not exist locally!",
	       MAGIC_LOCAL_GROUPNAME);
	local_users_gid = 0;
    }
    else if (status == NSS_STATUS_SUCCESS) {
	if (is_local == 1) {
	    // add the (local) user to the magic local users group, and finish
	    (*groupsp)[out++] = local_users_group.gr_gid;
	    syslog(LOG_DEBUG, "nss_nonlocal: Added %s to special group %s",
		   user, MAGIC_LOCAL_GROUPNAME);
	    *start = out;
	    return NSS_STATUS_SUCCESS;
	}
	else {
	    local_users_gid = local_users_group.gr_gid;
	}
    }
    else {
	return status;
    }

    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;

	status = check_nonlocal_gid(user, (*groupsp)[in], &nonlocal_errno);
	if (status == NSS_STATUS_SUCCESS) {
	    // Don't let users get into MAGIC_LOCAL_GROUPNAME from nonlocal reasons.
	    if ((*groupsp)[in] == local_users_gid) {
		syslog(LOG_WARNING, "nss_nonlocal: Nonlocal user %s removed from special local users group %s",
		       user, MAGIC_LOCAL_GROUPNAME);
	    }
	    else {
		(*groupsp)[out++] = (*groupsp)[in];
	    }
	} else if (status != NSS_STATUS_NOTFOUND) {
	    *start = out;
	    *errnop = nonlocal_errno;
	    return status;
	}
    }

    // add the (nonlocal) user to the magic nonlocal users group
    buflen = sysconf(_SC_GETGR_R_SIZE_MAX);
    buffer = malloc(buflen);
    if (buffer == NULL) {
	*errnop = ENOMEM;
	return NSS_STATUS_TRYAGAIN;
    }
    struct group nonlocal_users_group;
    status = get_local_group(MAGIC_NONLOCAL_GROUPNAME,
			     &nonlocal_users_group, buffer, buflen, errnop);
    if (status == NSS_STATUS_NOTFOUND) {
	syslog(LOG_WARNING, "nss_nonlocal: (local) group %s does not exist!",
	       MAGIC_NONLOCAL_GROUPNAME);
    }
    else if (status == NSS_STATUS_SUCCESS) {
	(*groupsp)[out++] = nonlocal_users_group.gr_gid;
	syslog(LOG_DEBUG, "nss_nonlocal: Added %s to special group %s",
	       user, MAGIC_NONLOCAL_GROUPNAME);
    }
    free(buffer);

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