[nss_nonlocal.git] / nonlocal-group.c

/*
 * nonlocal-group.c
 * group database for nss_nonlocal proxy
 *
 * Copyright © 2007 Anders Kaseorg <andersk@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)


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;
}


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;

    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;

    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) {
	    (*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	*
	5	* Copyright © 2007 Anders Kaseorg <andersk@mit.edu>
	6	*
	7	* Permission is hereby granted, free of charge, to any person
	8	* obtaining a copy of this software and associated documentation
	9	* files (the "Software"), to deal in the Software without
	10	* restriction, including without limitation the rights to use, copy,
	11	* modify, merge, publish, distribute, sublicense, and/or sell copies
	12	* of the Software, and to permit persons to whom the Software is
	13	* furnished to do so, subject to the following conditions:
	14	*
	15	* The above copyright notice and this permission notice shall be
	16	* included in all copies or substantial portions of the Software.
	17	*
	18	* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
	19	* EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
	20	* MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
	21	* NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS
	22	* BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN
	23	* ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
	24	* CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
	25	* SOFTWARE.
	26	*/
	27
	28	#define _GNU_SOURCE
	29	#include <sys/types.h>
	30	#include <unistd.h>
	31	#include <stdlib.h>
	32	#include <stdint.h>
	33	#include <string.h>
	34	#include <dlfcn.h>
	35	#include <stdio.h>
	36	#include <syslog.h>
	37	#include <errno.h>
	38	#include <grp.h>
	39	#include <nss.h>
	40	#include "nsswitch-internal.h"
	41	#include "nonlocal.h"
	42
f7293a54 AK	43	#define MAGIC_LOCAL_GR_BUFLEN (sysconf(_SC_GETGR_R_SIZE_MAX) + 7)
f7293a54 AK	44
f6903667 AK	45
	46	static service_user *
	47	nss_group_nonlocal_database(void)
	48	{
	49	static service_user *nip = NULL;
	50	if (nip == NULL)
	51	__nss_database_lookup("group_nonlocal", NULL, "", &nip);
	52
	53	return nip;
	54	}
	55
	56
f6903667 AK	57	enum nss_status
	58	check_nonlocal_gid(const char user, gid_t gid, int errnop)
	59	{
f7293a54 AK	60	enum nss_status status = NSS_STATUS_SUCCESS;
	61	struct group gbuf;
	62	struct group *gbufp = &gbuf;
	63	int ret;
	64	int old_errno = errno;
	65	int buflen = MAGIC_LOCAL_GR_BUFLEN;
	66	char *buf = malloc(buflen);
	67	if (buf == NULL) {
f6903667	68	*errnop = ENOMEM;
f7293a54	69	errno = old_errno;
f6903667 AK	70	return NSS_STATUS_TRYAGAIN;
f6903667 AK	71	}
f7293a54 AK	72	errno = 0;
	73	ret = getgrgid_r(gid, gbufp, buf, buflen, &gbufp);
	74	if (ret != 0) {
	75	*errnop = old_errno;
	76	status = NSS_STATUS_TRYAGAIN;
	77	} else if (gbufp != NULL) {
	78	syslog(LOG_WARNING, "nss_nonlocal: removing local group %u (%s) from non-local user %s\n", gbuf.gr_gid, gbuf.gr_name, user);
f6903667	79	status = NSS_STATUS_NOTFOUND;
f6903667	80	}
f7293a54 AK	81	free(buf);
f7293a54 AK	82	errno = old_errno;
f6903667 AK	83	return status;
	84	}
	85
	86
	87	static service_user *grent_nip = NULL;
	88	static void *grent_fct_start;
	89	static union {
	90	enum nss_status (l)(struct group grp, char *buffer, size_t buflen,
	91	int *errnop);
	92	void *ptr;
	93	} grent_fct;
	94	static const char *grent_fct_name = "getgrent_r";
	95
	96	enum nss_status
	97	_nss_nonlocal_setgrent(int stayopen)
	98	{
	99	static const char *fct_name = "setgrent";
	100	static void *fct_start = NULL;
	101	enum nss_status status;
	102	service_user *nip;
	103	union {
	104	enum nss_status (*l)(int stayopen);
	105	void *ptr;
	106	} fct;
	107
	108	nip = nss_group_nonlocal_database();
	109	if (nip == NULL)
	110	return NSS_STATUS_UNAVAIL;
	111	if (fct_start == NULL)
	112	fct_start = __nss_lookup_function(nip, fct_name);
	113	fct.ptr = fct_start;
	114	do {
	115	if (fct.ptr == NULL)
	116	status = NSS_STATUS_UNAVAIL;
	117	else
	118	status = DL_CALL_FCT(fct.l, (stayopen));
	119	} while (__nss_next(&nip, fct_name, &fct.ptr, status, 0) == 0);
	120	if (status != NSS_STATUS_SUCCESS)
	121	return status;
	122
	123	grent_nip = nip;
	124	if (grent_fct_start == NULL)
	125	grent_fct_start = __nss_lookup_function(nip, grent_fct_name);
	126	grent_fct.ptr = grent_fct_start;
	127	return NSS_STATUS_SUCCESS;
	128	}
	129
	130	enum nss_status
	131	_nss_nonlocal_endgrent(void)
	132	{
	133	static const char *fct_name = "endgrent";
	134	static void *fct_start = NULL;
	135	enum nss_status status;
	136	service_user *nip;
	137	union {
	138	enum nss_status (*l)(void);
	139	void *ptr;
	140	} fct;
	141
	142	grent_nip = NULL;
	143
	144	nip = nss_group_nonlocal_database();
	145	if (nip == NULL)
	146	return NSS_STATUS_UNAVAIL;
147	if (fct_start == NULL)
148	fct_start = __nss_lookup_function(nip, fct_name);
149	fct.ptr = fct_start;
150	do {
151	if (fct.ptr == NULL)
152	status = NSS_STATUS_UNAVAIL;
153	else
154	status = DL_CALL_FCT(fct.l, ());
155	} while (__nss_next(&nip, fct_name, &fct.ptr, status, 0) == 0);
156	return status;
157	}
158
159	enum nss_status
160	_nss_nonlocal_getgrent_r(struct group grp, char buffer, size_t buflen,
161	int *errnop)
162	{
163	enum nss_status status;
164	if (grent_nip == NULL) {
165	status = _nss_nonlocal_setgrent(0);
166	if (status != NSS_STATUS_SUCCESS)
167	return status;
168	}
169	do {
170	if (grent_fct.ptr == NULL)
171	status = NSS_STATUS_UNAVAIL;
172	else {
173	int nonlocal_errno;
174	do
175	status = DL_CALL_FCT(grent_fct.l, (grp, buffer, buflen, errnop));
176	while (status == NSS_STATUS_SUCCESS &&
177	check_nonlocal_gid("(unknown)", grp->gr_gid, &nonlocal_errno) != NSS_STATUS_SUCCESS);
178	}
179	if (status == NSS_STATUS_TRYAGAIN && *errnop == ERANGE)
180	return status;
181
182	if (status == NSS_STATUS_SUCCESS)
183	return NSS_STATUS_SUCCESS;
184	} while (__nss_next(&grent_nip, grent_fct_name, &grent_fct.ptr, status, 0) == 0);
185
186	grent_nip = NULL;
187	return NSS_STATUS_NOTFOUND;
188	}
189
190
191	enum nss_status
192	_nss_nonlocal_getgrnam_r(const char name, struct group grp,
193	char buffer, size_t buflen, int errnop)
194	{
195	static const char *fct_name = "getgrnam_r";
196	static void *fct_start = NULL;
197	enum nss_status status;
198	service_user *nip;
199	union {
200	enum nss_status (l)(const char name, struct group *grp,
201	char buffer, size_t buflen, int errnop);
202	void *ptr;
203	} fct;
204
205	nip = nss_group_nonlocal_database();
206	if (nip == NULL)
207	return NSS_STATUS_UNAVAIL;
208	if (fct_start == NULL)
209	fct_start = __nss_lookup_function(nip, fct_name);
210	fct.ptr = fct_start;
211	do {
212	if (fct.ptr == NULL)
213	status = NSS_STATUS_UNAVAIL;
214	else
215	status = DL_CALL_FCT(fct.l, (name, grp, buffer, buflen, errnop));
216	if (status == NSS_STATUS_TRYAGAIN && *errnop == ERANGE)
217	break;
218	} while (__nss_next(&nip, fct_name, &fct.ptr, status, 0) == 0);
219	if (status != NSS_STATUS_SUCCESS)
220	return status;
221
222	return check_nonlocal_gid(name, grp->gr_gid, errnop);
223	}
224
225	enum nss_status
226	_nss_nonlocal_getgrgid_r(gid_t gid, struct group *grp,
227	char buffer, size_t buflen, int errnop)
228	{
229	static const char *fct_name = "getgrgid_r";
230	static void *fct_start = NULL;
231	enum nss_status status;
232	service_user *nip;
233	union {
234	enum nss_status (l)(gid_t gid, struct group grp,
235	char buffer, size_t buflen, int errnop);
236	void *ptr;
237	} fct;
238
f7293a54	239	if (buflen == MAGIC_LOCAL_GR_BUFLEN)
f6903667 AK	240	return NSS_STATUS_UNAVAIL;
	241
	242	nip = nss_group_nonlocal_database();
	243	if (nip == NULL)
	244	return NSS_STATUS_UNAVAIL;
	245	if (fct_start == NULL)
	246	fct_start = __nss_lookup_function(nip, fct_name);
	247	fct.ptr = fct_start;
	248	do {
	249	if (fct.ptr == NULL)
	250	status = NSS_STATUS_UNAVAIL;
	251	else
	252	status = DL_CALL_FCT(fct.l, (gid, grp, buffer, buflen, errnop));
	253	if (status == NSS_STATUS_TRYAGAIN && *errnop == ERANGE)
	254	break;
	255	} while (__nss_next(&nip, fct_name, &fct.ptr, status, 0) == 0);
	256	if (status != NSS_STATUS_SUCCESS)
	257	return status;
	258
	259	return check_nonlocal_gid(grp->gr_name, grp->gr_gid, errnop);
	260	}
	261
	262	enum nss_status
	263	_nss_nonlocal_initgroups_dyn(const char user, gid_t group, long int start,
	264	long int size, gid_t *groupsp, long int limit,
	265	int *errnop)
	266	{
	267	static const char *fct_name = "initgroups_dyn";
	268	static void *fct_start = NULL;
	269	enum nss_status status;
	270	service_user *nip;
	271	union {
	272	enum nss_status (l)(const char user, gid_t group, long int *start,
	273	long int size, gid_t *groupsp, long int limit,
	274	int *errnop);
	275	void *ptr;
	276	} fct;
	277	int in = start, out = start, i;
	278
	279	nip = nss_group_nonlocal_database();
	280	if (nip == NULL)
	281	return NSS_STATUS_UNAVAIL;
	282	if (fct_start == NULL)
	283	fct_start = __nss_lookup_function(nip, fct_name);
	284	fct.ptr = fct_start;
	285
	286	do {
	287	if (fct.ptr == NULL)
	288	status = NSS_STATUS_UNAVAIL;
	289	else
	290	status = DL_CALL_FCT(fct.l, (user, group, start, size, groupsp, limit, errnop));
	291	if (status == NSS_STATUS_TRYAGAIN && *errnop == ERANGE)
	292	break;
	293	} while (__nss_next(&nip, fct_name, &fct.ptr, status, 0) == 0);
	294	if (status != NSS_STATUS_SUCCESS)
	295	return status;
	296
	297	for (; in < *start; ++in) {
	298	int nonlocal_errno = *errnop;
	299
	300	for (i = 0; i < out; ++i)
	301	if ((groupsp)[i] == (groupsp)[in])
	302	break;
	303	if (i < out)
304	continue;
305
306	status = check_nonlocal_gid(user, (*groupsp)[in], &nonlocal_errno);
307	if (status == NSS_STATUS_SUCCESS) {
308	(groupsp)[out++] = (groupsp)[in];
309	} else if (status != NSS_STATUS_NOTFOUND) {
310	*start = out;
311	*errnop = nonlocal_errno;
312	return status;
313	}
314	}
315
316	*start = out;
317	return NSS_STATUS_SUCCESS;
318	}