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

    if (fct_start == NULL &&
	__nss_group_lookup(&startp, fct_name, &fct_start) != 0) {
	free(buf);
	return NSS_STATUS_UNAVAIL;
    }
    nip = startp;
    fct.ptr = fct_start;
    do {
	status = DL_CALL_FCT(fct.l, (gid, &gbuf, buf, 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) {
	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;
    } else if (status != NSS_STATUS_TRYAGAIN) {
	status = NSS_STATUS_SUCCESS;
    }

    free(buf);
    return status;
}

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

    if (fct_start == NULL &&
	__nss_group_lookup(&startp, fct_name, &fct_start) != 0) {
	free(buf);
	return NSS_STATUS_UNAVAIL;
    }
    nip = startp;
    fct.ptr = fct_start;
    do {
	status = DL_CALL_FCT(fct.l, (name, &gbuf, buf, 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) {
	n = snprintf(buffer, buflen, "%s", gbuf.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", gbuf.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 = gbuf.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);
    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_TRYAGAIN)
	return status;
    else if (status != NSS_STATUS_SUCCESS)
	is_local = 1;

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

    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_TRYAGAIN) {
	    *start = out;
	    *errnop = nonlocal_errno;
	    return status;
	}
    }

    *start = out;
    return NSS_STATUS_SUCCESS;
}
Commit	Line	Data
f6903667 AK	1	/*
	2	* nonlocal-group.c
	3	* group database for nss_nonlocal proxy
	4	*
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	{
30fb3957 AK	63	static const char *fct_name = "getgrgid_r";
	64	static service_user *startp = NULL;
	65	static void *fct_start = NULL;
	66	enum nss_status status;
	67	service_user *nip;
	68	union {
	69	enum nss_status (l)(gid_t gid, struct group grp,
	70	char buffer, size_t buflen, int errnop);
	71	void *ptr;
	72	} fct;
f7293a54	73	struct group gbuf;
f7293a54 AK	74	int old_errno = errno;
	75	int buflen = MAGIC_LOCAL_GR_BUFLEN;
	76	char *buf = malloc(buflen);
	77	if (buf == NULL) {
f6903667	78	*errnop = ENOMEM;
f7293a54	79	errno = old_errno;
f6903667 AK	80	return NSS_STATUS_TRYAGAIN;
f6903667 AK	81	}
30fb3957 AK	82
	83	if (fct_start == NULL &&
	84	__nss_group_lookup(&startp, fct_name, &fct_start) != 0) {
	85	free(buf);
	86	return NSS_STATUS_UNAVAIL;
	87	}
	88	nip = startp;
	89	fct.ptr = fct_start;
	90	do {
	91	status = DL_CALL_FCT(fct.l, (gid, &gbuf, buf, buflen, errnop));
	92	if (status == NSS_STATUS_TRYAGAIN && *errnop == ERANGE)
	93	break;
	94	} while (__nss_next(&nip, fct_name, &fct.ptr, status, 0) == 0);
	95
	96	if (status == NSS_STATUS_SUCCESS) {
f7293a54	97	syslog(LOG_WARNING, "nss_nonlocal: removing local group %u (%s) from non-local user %s\n", gbuf.gr_gid, gbuf.gr_name, user);
f6903667	98	status = NSS_STATUS_NOTFOUND;
30fb3957 AK	99	} else if (status != NSS_STATUS_TRYAGAIN) {
30fb3957 AK	100	status = NSS_STATUS_SUCCESS;
f6903667	101	}
30fb3957	102
f7293a54	103	free(buf);
f6903667 AK	104	return status;
	105	}
	106
48479fc7 TA	107	enum nss_status
	108	get_local_group(const char name, struct group grp, char buffer, size_t buflen, int errnop)
	109	{
30fb3957 AK	110	static const char *fct_name = "getgrnam_r";
	111	static service_user *startp = NULL;
	112	static void *fct_start = NULL;
	113	enum nss_status status;
	114	service_user *nip;
	115	union {
	116	enum nss_status (l)(const char name, struct group *grp,
	117	char buffer, size_t buflen, int errnop);
	118	void *ptr;
	119	} fct;
48479fc7	120	struct group gbuf;
30fb3957	121	int n;
48479fc7 TA	122	int old_errno = errno;
	123	int len = MAGIC_LOCAL_GR_BUFLEN;
	124	char *buf = malloc(len);
	125	if (buf == NULL) {
	126	*errnop = ENOMEM;
	127	errno = old_errno;
	128	return NSS_STATUS_TRYAGAIN;
	129	}
1e78305d	130
30fb3957 AK	131	if (fct_start == NULL &&
	132	__nss_group_lookup(&startp, fct_name, &fct_start) != 0) {
	133	free(buf);
	134	return NSS_STATUS_UNAVAIL;
	135	}
	136	nip = startp;
	137	fct.ptr = fct_start;
	138	do {
	139	status = DL_CALL_FCT(fct.l, (name, &gbuf, buf, buflen, errnop));
	140	if (status == NSS_STATUS_TRYAGAIN && *errnop == ERANGE)
	141	break;
	142	} while (__nss_next(&nip, fct_name, &fct.ptr, status, 0) == 0);
	143
	144	if (status == NSS_STATUS_SUCCESS) {
	145	n = snprintf(buffer, buflen, "%s", gbuf.gr_name);
1e78305d AK	146	if (n < 0 \|\| n >= buflen) {
	147	*errnop = ERANGE;
	148	status = NSS_STATUS_TRYAGAIN;
	149	goto get_local_group_done;
	150	}
	151	grp->gr_name = buffer;
	152	buffer += n;
	153	buflen -= n;
	154
30fb3957	155	n = snprintf(buffer, buflen, "%s", gbuf.gr_passwd);
1e78305d AK	156	if (n < 0 \|\| n >= buflen) {
	157	*errnop = ERANGE;
	158	status = NSS_STATUS_TRYAGAIN;
	159	goto get_local_group_done;
	160	}
	161	grp->gr_passwd = buffer;
	162	buffer += n;
	163	buflen -= n;
	164
30fb3957	165	grp->gr_gid = gbuf.gr_gid;
1e78305d	166
48479fc7 TA	167	if (buflen < sizeof(void *)) {
	168	*errnop = ERANGE;
	169	status = NSS_STATUS_TRYAGAIN;
1e78305d	170	goto get_local_group_done;
48479fc7	171	}
1e78305d AK	172	(void *)buffer = NULL;
	173	buffer += sizeof(void *);
	174	buflen -= sizeof(void *);
48479fc7	175	}
30fb3957	176
1e78305d	177	get_local_group_done:
48479fc7	178	free(buf);
48479fc7 TA	179	return status;
48479fc7 TA	180	}
f6903667 AK	181
	182	static service_user *grent_nip = NULL;
	183	static void *grent_fct_start;
	184	static union {
	185	enum nss_status (l)(struct group grp, char *buffer, size_t buflen,
	186	int *errnop);
	187	void *ptr;
	188	} grent_fct;
	189	static const char *grent_fct_name = "getgrent_r";
	190
	191	enum nss_status
	192	_nss_nonlocal_setgrent(int stayopen)
	193	{
	194	static const char *fct_name = "setgrent";
	195	static void *fct_start = NULL;
	196	enum nss_status status;
	197	service_user *nip;
	198	union {
	199	enum nss_status (*l)(int stayopen);
	200	void *ptr;
	201	} fct;
	202
	203	nip = nss_group_nonlocal_database();
	204	if (nip == NULL)
	205	return NSS_STATUS_UNAVAIL;
	206	if (fct_start == NULL)
	207	fct_start = __nss_lookup_function(nip, fct_name);
	208	fct.ptr = fct_start;
	209	do {
	210	if (fct.ptr == NULL)
	211	status = NSS_STATUS_UNAVAIL;
	212	else
	213	status = DL_CALL_FCT(fct.l, (stayopen));
	214	} while (__nss_next(&nip, fct_name, &fct.ptr, status, 0) == 0);
	215	if (status != NSS_STATUS_SUCCESS)
	216	return status;
	217
	218	grent_nip = nip;
	219	if (grent_fct_start == NULL)
	220	grent_fct_start = __nss_lookup_function(nip, grent_fct_name);
	221	grent_fct.ptr = grent_fct_start;
	222	return NSS_STATUS_SUCCESS;
	223	}
	224
	225	enum nss_status
	226	_nss_nonlocal_endgrent(void)
	227	{
	228	static const char *fct_name = "endgrent";
	229	static void *fct_start = NULL;
	230	enum nss_status status;
	231	service_user *nip;
	232	union {
	233	enum nss_status (*l)(void);
	234	void *ptr;
	235	} fct;
	236
	237	grent_nip = NULL;
	238
	239	nip = nss_group_nonlocal_database();
	240	if (nip == NULL)
	241	return NSS_STATUS_UNAVAIL;
	242	if (fct_start == NULL)
	243	fct_start = __nss_lookup_function(nip, fct_name);
	244	fct.ptr = fct_start;
245	do {
246	if (fct.ptr == NULL)
247	status = NSS_STATUS_UNAVAIL;
248	else
249	status = DL_CALL_FCT(fct.l, ());
250	} while (__nss_next(&nip, fct_name, &fct.ptr, status, 0) == 0);
251	return status;
252	}
253
254	enum nss_status
255	_nss_nonlocal_getgrent_r(struct group grp, char buffer, size_t buflen,
256	int *errnop)
257	{
258	enum nss_status status;
a360549e TA	259
	260	char *nonlocal_ignore = getenv(NONLOCAL_IGNORE_ENV);
	261	if (buflen == MAGIC_LOCAL_GR_BUFLEN \|\|
	262	(nonlocal_ignore != NULL && nonlocal_ignore[0] != '\0'))
	263	return NSS_STATUS_UNAVAIL;
	264
f6903667 AK	265	if (grent_nip == NULL) {
	266	status = _nss_nonlocal_setgrent(0);
	267	if (status != NSS_STATUS_SUCCESS)
	268	return status;
	269	}
	270	do {
	271	if (grent_fct.ptr == NULL)
	272	status = NSS_STATUS_UNAVAIL;
	273	else {
	274	int nonlocal_errno;
	275	do
	276	status = DL_CALL_FCT(grent_fct.l, (grp, buffer, buflen, errnop));
	277	while (status == NSS_STATUS_SUCCESS &&
	278	check_nonlocal_gid("(unknown)", grp->gr_gid, &nonlocal_errno) != NSS_STATUS_SUCCESS);
	279	}
	280	if (status == NSS_STATUS_TRYAGAIN && *errnop == ERANGE)
	281	return status;
	282
	283	if (status == NSS_STATUS_SUCCESS)
	284	return NSS_STATUS_SUCCESS;
	285	} while (__nss_next(&grent_nip, grent_fct_name, &grent_fct.ptr, status, 0) == 0);
	286
	287	grent_nip = NULL;
	288	return NSS_STATUS_NOTFOUND;
	289	}
	290
	291
	292	enum nss_status
	293	_nss_nonlocal_getgrnam_r(const char name, struct group grp,
	294	char buffer, size_t buflen, int errnop)
	295	{
	296	static const char *fct_name = "getgrnam_r";
	297	static void *fct_start = NULL;
	298	enum nss_status status;
	299	service_user *nip;
	300	union {
	301	enum nss_status (l)(const char name, struct group *grp,
	302	char buffer, size_t buflen, int errnop);
	303	void *ptr;
	304	} fct;
	305
a360549e TA	306	char *nonlocal_ignore = getenv(NONLOCAL_IGNORE_ENV);
	307	if (buflen == MAGIC_LOCAL_GR_BUFLEN \|\|
	308	(nonlocal_ignore != NULL && nonlocal_ignore[0] != '\0'))
48479fc7 TA	309	return NSS_STATUS_UNAVAIL;
48479fc7 TA	310
f6903667 AK	311	nip = nss_group_nonlocal_database();
	312	if (nip == NULL)
	313	return NSS_STATUS_UNAVAIL;
	314	if (fct_start == NULL)
	315	fct_start = __nss_lookup_function(nip, fct_name);
	316	fct.ptr = fct_start;
	317	do {
	318	if (fct.ptr == NULL)
	319	status = NSS_STATUS_UNAVAIL;
	320	else
	321	status = DL_CALL_FCT(fct.l, (name, grp, buffer, buflen, errnop));
	322	if (status == NSS_STATUS_TRYAGAIN && *errnop == ERANGE)
	323	break;
	324	} while (__nss_next(&nip, fct_name, &fct.ptr, status, 0) == 0);
	325	if (status != NSS_STATUS_SUCCESS)
	326	return status;
	327
	328	return check_nonlocal_gid(name, grp->gr_gid, errnop);
	329	}
	330
	331	enum nss_status
	332	_nss_nonlocal_getgrgid_r(gid_t gid, struct group *grp,
	333	char buffer, size_t buflen, int errnop)
	334	{
	335	static const char *fct_name = "getgrgid_r";
	336	static void *fct_start = NULL;
	337	enum nss_status status;
	338	service_user *nip;
	339	union {
	340	enum nss_status (l)(gid_t gid, struct group grp,
	341	char buffer, size_t buflen, int errnop);
	342	void *ptr;
	343	} fct;
	344
a360549e TA	345	char *nonlocal_ignore = getenv(NONLOCAL_IGNORE_ENV);
	346	if (buflen == MAGIC_LOCAL_GR_BUFLEN \|\|
	347	(nonlocal_ignore != NULL && nonlocal_ignore[0] != '\0'))
f6903667 AK	348	return NSS_STATUS_UNAVAIL;
	349
	350	nip = nss_group_nonlocal_database();
	351	if (nip == NULL)
	352	return NSS_STATUS_UNAVAIL;
	353	if (fct_start == NULL)
	354	fct_start = __nss_lookup_function(nip, fct_name);
	355	fct.ptr = fct_start;
	356	do {
	357	if (fct.ptr == NULL)
	358	status = NSS_STATUS_UNAVAIL;
	359	else
	360	status = DL_CALL_FCT(fct.l, (gid, grp, buffer, buflen, errnop));
	361	if (status == NSS_STATUS_TRYAGAIN && *errnop == ERANGE)
	362	break;
	363	} while (__nss_next(&nip, fct_name, &fct.ptr, status, 0) == 0);
	364	if (status != NSS_STATUS_SUCCESS)
	365	return status;
	366
	367	return check_nonlocal_gid(grp->gr_name, grp->gr_gid, errnop);
	368	}
	369
	370	enum nss_status
	371	_nss_nonlocal_initgroups_dyn(const char user, gid_t group, long int start,
	372	long int size, gid_t *groupsp, long int limit,
	373	int *errnop)
	374	{
	375	static const char *fct_name = "initgroups_dyn";
	376	static void *fct_start = NULL;
	377	enum nss_status status;
	378	service_user *nip;
	379	union {
	380	enum nss_status (l)(const char user, gid_t group, long int *start,
	381	long int size, gid_t *groupsp, long int limit,
	382	int *errnop);
	383	void *ptr;
	384	} fct;
1e78305d AK	385
	386	struct group local_users_group, nonlocal_users_group;
	387	gid_t local_users_gid, gid;
48479fc7	388	int is_local = 0;
1e78305d AK	389	int buflen;
1e78305d AK	390	char *buffer;
48479fc7	391
1e78305d	392	/* Check that the user is a nonlocal user before adding any groups. */
48479fc7	393	status = check_nonlocal_user(user, errnop);
5879a696	394	if (status == NSS_STATUS_TRYAGAIN)
48479fc7	395	return status;
5879a696 AK	396	else if (status != NSS_STATUS_SUCCESS)
5879a696 AK	397	is_local = 1;
48479fc7	398
1e78305d AK	399	int old_errno = errno;
	400
	401	buflen = sysconf(_SC_GETGR_R_SIZE_MAX);
	402	buffer = malloc(buflen);
48479fc7 TA	403	if (buffer == NULL) {
48479fc7 TA	404	*errnop = ENOMEM;
1e78305d	405	errno = old_errno;
48479fc7 TA	406	return NSS_STATUS_TRYAGAIN;
48479fc7 TA	407	}
48479fc7 TA	408	status = get_local_group(MAGIC_LOCAL_GROUPNAME,
48479fc7 TA	409	&local_users_group, buffer, buflen, errnop);
5879a696 AK	410	if (status == NSS_STATUS_SUCCESS) {
	411	local_users_gid = local_users_group.gr_gid;
	412	} else if (status == NSS_STATUS_TRYAGAIN) {
dc94c928	413	free(buffer);
5879a696 AK	414	return status;
5879a696 AK	415	} else {
48479fc7 TA	416	syslog(LOG_WARNING, "nss_nonlocal: Group %s does not exist locally!",
48479fc7 TA	417	MAGIC_LOCAL_GROUPNAME);
1e78305d	418	local_users_gid = -1;
5879a696	419	}
1e78305d AK	420	free(buffer);
	421
	422	if (is_local) {
	423	gid = local_users_gid;
	424	} else {
	425	buflen = sysconf(_SC_GETGR_R_SIZE_MAX);
	426	buffer = malloc(buflen);
	427	if (buffer == NULL) {
	428	*errnop = ENOMEM;
	429	errno = old_errno;
	430	return NSS_STATUS_TRYAGAIN;
48479fc7	431	}
1e78305d AK	432	status = get_local_group(MAGIC_NONLOCAL_GROUPNAME,
1e78305d AK	433	&nonlocal_users_group, buffer, buflen, errnop);
5879a696 AK	434	if (status == NSS_STATUS_SUCCESS) {
	435	gid = nonlocal_users_group.gr_gid;
	436	} else if (status == NSS_STATUS_TRYAGAIN) {
dc94c928	437	free(buffer);
5879a696 AK	438	return status;
5879a696 AK	439	} else {
1e78305d AK	440	syslog(LOG_WARNING, "nss_nonlocal: Group %s does not exist locally!",
	441	MAGIC_NONLOCAL_GROUPNAME);
	442	gid = -1;
5879a696	443	}
1e78305d	444	free(buffer);
48479fc7	445	}
1e78305d AK	446
	447	if (gid != -1) {
	448	int i;
	449	for (i = 0; i < *start; ++i)
	450	if ((*groupsp)[i] == gid)
	451	break;
	452	if (i >= *start) {
	453	if (start + 1 > size) {
	454	gid_t *newgroups;
	455	long int newsize = 2 * *size;
	456	if (limit > 0) {
	457	if (*size >= limit)
	458	return NSS_STATUS_SUCCESS;
	459	if (newsize > limit)
	460	newsize = limit;
	461	}
	462	newgroups = realloc(groupsp, size * sizeof((*groupsp)[0]));
	463	if (newgroups == NULL) {
	464	*errnop = ENOMEM;
	465	errno = old_errno;
	466	return NSS_STATUS_TRYAGAIN;
	467	}
	468	*groupsp = newgroups;
	469	*size = newsize;
	470	}
	471	(groupsp)[(start)++] = gid;
	472	}
48479fc7	473	}
f6903667	474
1e78305d AK	475	if (is_local)
	476	return NSS_STATUS_SUCCESS;
	477
	478	int in = start, out = start, i;
	479
f6903667 AK	480	nip = nss_group_nonlocal_database();
	481	if (nip == NULL)
	482	return NSS_STATUS_UNAVAIL;
	483	if (fct_start == NULL)
	484	fct_start = __nss_lookup_function(nip, fct_name);
	485	fct.ptr = fct_start;
	486
	487	do {
	488	if (fct.ptr == NULL)
	489	status = NSS_STATUS_UNAVAIL;
	490	else
	491	status = DL_CALL_FCT(fct.l, (user, group, start, size, groupsp, limit, errnop));
	492	if (status == NSS_STATUS_TRYAGAIN && *errnop == ERANGE)
	493	break;
	494	} while (__nss_next(&nip, fct_name, &fct.ptr, status, 0) == 0);
	495	if (status != NSS_STATUS_SUCCESS)
	496	return status;
	497
	498	for (; in < *start; ++in) {
	499	int nonlocal_errno = *errnop;
	500
	501	for (i = 0; i < out; ++i)
	502	if ((groupsp)[i] == (groupsp)[in])
	503	break;
	504	if (i < out)
	505	continue;
	506
1e78305d AK	507	/* Don't let users get into MAGIC_LOCAL_GROUPNAME from nonlocal reasons. */
	508	if (local_users_gid == (*groupsp)[in]) {
	509	syslog(LOG_WARNING, "nss_nonlocal: Nonlocal user %s removed from special local users group %s",
	510	user, MAGIC_LOCAL_GROUPNAME);
	511	continue;
	512	}
	513
f6903667 AK	514	status = check_nonlocal_gid(user, (*groupsp)[in], &nonlocal_errno);
f6903667 AK	515	if (status == NSS_STATUS_SUCCESS) {
1e78305d	516	(groupsp)[out++] = (groupsp)[in];
5879a696	517	} else if (status == NSS_STATUS_TRYAGAIN) {
f6903667 AK	518	*start = out;
	519	*errnop = nonlocal_errno;
	520	return status;
	521	}
	522	}
	523
	524	*start = out;
	525	return NSS_STATUS_SUCCESS;
	526	}