[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_NONLOCAL_GROUPNAME "nss-nonlocal-users"
#define MAGIC_LOCAL_GROUPNAME "nss-local-users"


enum nss_status
_nss_nonlocal_getgrnam_r(const char *name, struct group *grp,
			 char *buffer, size_t buflen, int *errnop);

enum nss_status
_nss_nonlocal_getgrgid_r(gid_t gid, struct group *grp,
			 char *buffer, size_t buflen, int *errnop);


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 = sysconf(_SC_GETGR_R_SIZE_MAX);
    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 {
	if (fct.l == _nss_nonlocal_getgrgid_r)
	    status = NSS_STATUS_NOTFOUND;
	else
	    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 = sysconf(_SC_GETGR_R_SIZE_MAX);
    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 {
	if (fct.l == _nss_nonlocal_getgrnam_r)
	    status = NSS_STATUS_NOTFOUND;
	else
	    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 (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 (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 (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
48479fc7 TA	44	#define MAGIC_NONLOCAL_GROUPNAME "nss-nonlocal-users"
48479fc7 TA	45	#define MAGIC_LOCAL_GROUPNAME "nss-local-users"
f7293a54	46
f6903667	47
c1812233 AK	48	enum nss_status
	49	_nss_nonlocal_getgrnam_r(const char name, struct group grp,
	50	char buffer, size_t buflen, int errnop);
	51
	52	enum nss_status
	53	_nss_nonlocal_getgrgid_r(gid_t gid, struct group *grp,
	54	char buffer, size_t buflen, int errnop);
	55
	56
f6903667 AK	57	static service_user *
	58	nss_group_nonlocal_database(void)
	59	{
	60	static service_user *nip = NULL;
	61	if (nip == NULL)
	62	__nss_database_lookup("group_nonlocal", NULL, "", &nip);
48479fc7	63
f6903667 AK	64	return nip;
	65	}
	66
	67
f6903667 AK	68	enum nss_status
	69	check_nonlocal_gid(const char user, gid_t gid, int errnop)
	70	{
30fb3957 AK	71	static const char *fct_name = "getgrgid_r";
	72	static service_user *startp = NULL;
	73	static void *fct_start = NULL;
	74	enum nss_status status;
	75	service_user *nip;
	76	union {
	77	enum nss_status (l)(gid_t gid, struct group grp,
	78	char buffer, size_t buflen, int errnop);
	79	void *ptr;
	80	} fct;
f7293a54	81	struct group gbuf;
f7293a54	82	int old_errno = errno;
c1812233 AK	83
c1812233 AK	84	int buflen = sysconf(_SC_GETGR_R_SIZE_MAX);
f7293a54 AK	85	char *buf = malloc(buflen);
f7293a54 AK	86	if (buf == NULL) {
f6903667	87	*errnop = ENOMEM;
f7293a54	88	errno = old_errno;
f6903667 AK	89	return NSS_STATUS_TRYAGAIN;
f6903667 AK	90	}
30fb3957 AK	91
	92	if (fct_start == NULL &&
	93	__nss_group_lookup(&startp, fct_name, &fct_start) != 0) {
	94	free(buf);
	95	return NSS_STATUS_UNAVAIL;
	96	}
	97	nip = startp;
	98	fct.ptr = fct_start;
	99	do {
c1812233 AK	100	if (fct.l == _nss_nonlocal_getgrgid_r)
	101	status = NSS_STATUS_NOTFOUND;
	102	else
	103	status = DL_CALL_FCT(fct.l, (gid, &gbuf, buf, buflen, errnop));
30fb3957 AK	104	if (status == NSS_STATUS_TRYAGAIN && *errnop == ERANGE)
	105	break;
	106	} while (__nss_next(&nip, fct_name, &fct.ptr, status, 0) == 0);
	107
	108	if (status == NSS_STATUS_SUCCESS) {
f7293a54	109	syslog(LOG_WARNING, "nss_nonlocal: removing local group %u (%s) from non-local user %s\n", gbuf.gr_gid, gbuf.gr_name, user);
f6903667	110	status = NSS_STATUS_NOTFOUND;
30fb3957 AK	111	} else if (status != NSS_STATUS_TRYAGAIN) {
30fb3957 AK	112	status = NSS_STATUS_SUCCESS;
f6903667	113	}
30fb3957	114
f7293a54	115	free(buf);
f6903667 AK	116	return status;
	117	}
	118
48479fc7 TA	119	enum nss_status
	120	get_local_group(const char name, struct group grp, char buffer, size_t buflen, int errnop)
	121	{
30fb3957 AK	122	static const char *fct_name = "getgrnam_r";
	123	static service_user *startp = NULL;
	124	static void *fct_start = NULL;
	125	enum nss_status status;
	126	service_user *nip;
	127	union {
	128	enum nss_status (l)(const char name, struct group *grp,
	129	char buffer, size_t buflen, int errnop);
	130	void *ptr;
	131	} fct;
48479fc7	132	struct group gbuf;
30fb3957	133	int n;
48479fc7	134	int old_errno = errno;
c1812233 AK	135
c1812233 AK	136	int len = sysconf(_SC_GETGR_R_SIZE_MAX);
48479fc7 TA	137	char *buf = malloc(len);
	138	if (buf == NULL) {
	139	*errnop = ENOMEM;
	140	errno = old_errno;
	141	return NSS_STATUS_TRYAGAIN;
	142	}
1e78305d	143
30fb3957 AK	144	if (fct_start == NULL &&
	145	__nss_group_lookup(&startp, fct_name, &fct_start) != 0) {
	146	free(buf);
	147	return NSS_STATUS_UNAVAIL;
	148	}
	149	nip = startp;
	150	fct.ptr = fct_start;
	151	do {
c1812233 AK	152	if (fct.l == _nss_nonlocal_getgrnam_r)
	153	status = NSS_STATUS_NOTFOUND;
	154	else
	155	status = DL_CALL_FCT(fct.l, (name, &gbuf, buf, buflen, errnop));
30fb3957 AK	156	if (status == NSS_STATUS_TRYAGAIN && *errnop == ERANGE)
	157	break;
	158	} while (__nss_next(&nip, fct_name, &fct.ptr, status, 0) == 0);
	159
	160	if (status == NSS_STATUS_SUCCESS) {
	161	n = snprintf(buffer, buflen, "%s", gbuf.gr_name);
1e78305d AK	162	if (n < 0 \|\| n >= buflen) {
	163	*errnop = ERANGE;
	164	status = NSS_STATUS_TRYAGAIN;
	165	goto get_local_group_done;
	166	}
	167	grp->gr_name = buffer;
	168	buffer += n;
	169	buflen -= n;
	170
30fb3957	171	n = snprintf(buffer, buflen, "%s", gbuf.gr_passwd);
1e78305d AK	172	if (n < 0 \|\| n >= buflen) {
	173	*errnop = ERANGE;
	174	status = NSS_STATUS_TRYAGAIN;
	175	goto get_local_group_done;
	176	}
	177	grp->gr_passwd = buffer;
	178	buffer += n;
	179	buflen -= n;
	180
30fb3957	181	grp->gr_gid = gbuf.gr_gid;
1e78305d	182
48479fc7 TA	183	if (buflen < sizeof(void *)) {
	184	*errnop = ERANGE;
	185	status = NSS_STATUS_TRYAGAIN;
1e78305d	186	goto get_local_group_done;
48479fc7	187	}
1e78305d AK	188	(void *)buffer = NULL;
	189	buffer += sizeof(void *);
	190	buflen -= sizeof(void *);
48479fc7	191	}
30fb3957	192
1e78305d	193	get_local_group_done:
48479fc7	194	free(buf);
48479fc7 TA	195	return status;
48479fc7 TA	196	}
f6903667 AK	197
	198	static service_user *grent_nip = NULL;
	199	static void *grent_fct_start;
	200	static union {
	201	enum nss_status (l)(struct group grp, char *buffer, size_t buflen,
	202	int *errnop);
	203	void *ptr;
	204	} grent_fct;
	205	static const char *grent_fct_name = "getgrent_r";
	206
	207	enum nss_status
	208	_nss_nonlocal_setgrent(int stayopen)
	209	{
	210	static const char *fct_name = "setgrent";
	211	static void *fct_start = NULL;
	212	enum nss_status status;
	213	service_user *nip;
	214	union {
	215	enum nss_status (*l)(int stayopen);
	216	void *ptr;
	217	} fct;
	218
	219	nip = nss_group_nonlocal_database();
	220	if (nip == NULL)
	221	return NSS_STATUS_UNAVAIL;
	222	if (fct_start == NULL)
	223	fct_start = __nss_lookup_function(nip, fct_name);
	224	fct.ptr = fct_start;
	225	do {
	226	if (fct.ptr == NULL)
	227	status = NSS_STATUS_UNAVAIL;
	228	else
	229	status = DL_CALL_FCT(fct.l, (stayopen));
	230	} while (__nss_next(&nip, fct_name, &fct.ptr, status, 0) == 0);
	231	if (status != NSS_STATUS_SUCCESS)
	232	return status;
	233
	234	grent_nip = nip;
	235	if (grent_fct_start == NULL)
	236	grent_fct_start = __nss_lookup_function(nip, grent_fct_name);
	237	grent_fct.ptr = grent_fct_start;
	238	return NSS_STATUS_SUCCESS;
	239	}
	240
	241	enum nss_status
	242	_nss_nonlocal_endgrent(void)
	243	{
	244	static const char *fct_name = "endgrent";
	245	static void *fct_start = NULL;
	246	enum nss_status status;
	247	service_user *nip;
	248	union {
	249	enum nss_status (*l)(void);
	250	void *ptr;
	251	} fct;
	252
	253	grent_nip = NULL;
	254
	255	nip = nss_group_nonlocal_database();
	256	if (nip == NULL)
	257	return NSS_STATUS_UNAVAIL;
	258	if (fct_start == NULL)
	259	fct_start = __nss_lookup_function(nip, fct_name);
	260	fct.ptr = fct_start;
261	do {
262	if (fct.ptr == NULL)
263	status = NSS_STATUS_UNAVAIL;
264	else
265	status = DL_CALL_FCT(fct.l, ());
266	} while (__nss_next(&nip, fct_name, &fct.ptr, status, 0) == 0);
267	return status;
268	}
269
270	enum nss_status
271	_nss_nonlocal_getgrent_r(struct group grp, char buffer, size_t buflen,
272	int *errnop)
273	{
274	enum nss_status status;
a360549e TA	275
a360549e TA	276	char *nonlocal_ignore = getenv(NONLOCAL_IGNORE_ENV);
c1812233	277	if (nonlocal_ignore != NULL && nonlocal_ignore[0] != '\0')
a360549e TA	278	return NSS_STATUS_UNAVAIL;
a360549e TA	279
f6903667 AK	280	if (grent_nip == NULL) {
	281	status = _nss_nonlocal_setgrent(0);
	282	if (status != NSS_STATUS_SUCCESS)
	283	return status;
	284	}
	285	do {
	286	if (grent_fct.ptr == NULL)
	287	status = NSS_STATUS_UNAVAIL;
	288	else {
	289	int nonlocal_errno;
	290	do
	291	status = DL_CALL_FCT(grent_fct.l, (grp, buffer, buflen, errnop));
	292	while (status == NSS_STATUS_SUCCESS &&
	293	check_nonlocal_gid("(unknown)", grp->gr_gid, &nonlocal_errno) != NSS_STATUS_SUCCESS);
	294	}
	295	if (status == NSS_STATUS_TRYAGAIN && *errnop == ERANGE)
	296	return status;
	297
	298	if (status == NSS_STATUS_SUCCESS)
	299	return NSS_STATUS_SUCCESS;
	300	} while (__nss_next(&grent_nip, grent_fct_name, &grent_fct.ptr, status, 0) == 0);
	301
	302	grent_nip = NULL;
	303	return NSS_STATUS_NOTFOUND;
	304	}
	305
	306
	307	enum nss_status
	308	_nss_nonlocal_getgrnam_r(const char name, struct group grp,
	309	char buffer, size_t buflen, int errnop)
	310	{
	311	static const char *fct_name = "getgrnam_r";
	312	static void *fct_start = NULL;
	313	enum nss_status status;
	314	service_user *nip;
	315	union {
	316	enum nss_status (l)(const char name, struct group *grp,
	317	char buffer, size_t buflen, int errnop);
	318	void *ptr;
	319	} fct;
	320
a360549e	321	char *nonlocal_ignore = getenv(NONLOCAL_IGNORE_ENV);
c1812233	322	if (nonlocal_ignore != NULL && nonlocal_ignore[0] != '\0')
48479fc7 TA	323	return NSS_STATUS_UNAVAIL;
48479fc7 TA	324
f6903667 AK	325	nip = nss_group_nonlocal_database();
	326	if (nip == NULL)
	327	return NSS_STATUS_UNAVAIL;
	328	if (fct_start == NULL)
	329	fct_start = __nss_lookup_function(nip, fct_name);
	330	fct.ptr = fct_start;
	331	do {
	332	if (fct.ptr == NULL)
	333	status = NSS_STATUS_UNAVAIL;
	334	else
	335	status = DL_CALL_FCT(fct.l, (name, grp, buffer, buflen, errnop));
	336	if (status == NSS_STATUS_TRYAGAIN && *errnop == ERANGE)
	337	break;
	338	} while (__nss_next(&nip, fct_name, &fct.ptr, status, 0) == 0);
	339	if (status != NSS_STATUS_SUCCESS)
	340	return status;
	341
	342	return check_nonlocal_gid(name, grp->gr_gid, errnop);
	343	}
	344
	345	enum nss_status
	346	_nss_nonlocal_getgrgid_r(gid_t gid, struct group *grp,
	347	char buffer, size_t buflen, int errnop)
	348	{
	349	static const char *fct_name = "getgrgid_r";
	350	static void *fct_start = NULL;
	351	enum nss_status status;
	352	service_user *nip;
	353	union {
	354	enum nss_status (l)(gid_t gid, struct group grp,
	355	char buffer, size_t buflen, int errnop);
	356	void *ptr;
	357	} fct;
	358
a360549e	359	char *nonlocal_ignore = getenv(NONLOCAL_IGNORE_ENV);
c1812233	360	if (nonlocal_ignore != NULL && nonlocal_ignore[0] != '\0')
f6903667 AK	361	return NSS_STATUS_UNAVAIL;
	362
	363	nip = nss_group_nonlocal_database();
	364	if (nip == NULL)
	365	return NSS_STATUS_UNAVAIL;
	366	if (fct_start == NULL)
	367	fct_start = __nss_lookup_function(nip, fct_name);
	368	fct.ptr = fct_start;
	369	do {
	370	if (fct.ptr == NULL)
	371	status = NSS_STATUS_UNAVAIL;
	372	else
	373	status = DL_CALL_FCT(fct.l, (gid, grp, buffer, buflen, errnop));
	374	if (status == NSS_STATUS_TRYAGAIN && *errnop == ERANGE)
	375	break;
	376	} while (__nss_next(&nip, fct_name, &fct.ptr, status, 0) == 0);
	377	if (status != NSS_STATUS_SUCCESS)
	378	return status;
	379
	380	return check_nonlocal_gid(grp->gr_name, grp->gr_gid, errnop);
	381	}
	382
	383	enum nss_status
	384	_nss_nonlocal_initgroups_dyn(const char user, gid_t group, long int start,
	385	long int size, gid_t *groupsp, long int limit,
	386	int *errnop)
	387	{
	388	static const char *fct_name = "initgroups_dyn";
	389	static void *fct_start = NULL;
	390	enum nss_status status;
	391	service_user *nip;
	392	union {
	393	enum nss_status (l)(const char user, gid_t group, long int *start,
	394	long int size, gid_t *groupsp, long int limit,
	395	int *errnop);
	396	void *ptr;
	397	} fct;
1e78305d AK	398
	399	struct group local_users_group, nonlocal_users_group;
	400	gid_t local_users_gid, gid;
48479fc7	401	int is_local = 0;
1e78305d AK	402	int buflen;
1e78305d AK	403	char *buffer;
48479fc7	404
1e78305d	405	/* Check that the user is a nonlocal user before adding any groups. */
48479fc7	406	status = check_nonlocal_user(user, errnop);
5879a696	407	if (status == NSS_STATUS_TRYAGAIN)
48479fc7	408	return status;
5879a696 AK	409	else if (status != NSS_STATUS_SUCCESS)
5879a696 AK	410	is_local = 1;
48479fc7	411
1e78305d AK	412	int old_errno = errno;
	413
	414	buflen = sysconf(_SC_GETGR_R_SIZE_MAX);
	415	buffer = malloc(buflen);
48479fc7 TA	416	if (buffer == NULL) {
48479fc7 TA	417	*errnop = ENOMEM;
1e78305d	418	errno = old_errno;
48479fc7 TA	419	return NSS_STATUS_TRYAGAIN;
48479fc7 TA	420	}
48479fc7 TA	421	status = get_local_group(MAGIC_LOCAL_GROUPNAME,
48479fc7 TA	422	&local_users_group, buffer, buflen, errnop);
5879a696 AK	423	if (status == NSS_STATUS_SUCCESS) {
	424	local_users_gid = local_users_group.gr_gid;
	425	} else if (status == NSS_STATUS_TRYAGAIN) {
dc94c928	426	free(buffer);
5879a696 AK	427	return status;
5879a696 AK	428	} else {
48479fc7 TA	429	syslog(LOG_WARNING, "nss_nonlocal: Group %s does not exist locally!",
48479fc7 TA	430	MAGIC_LOCAL_GROUPNAME);
1e78305d	431	local_users_gid = -1;
5879a696	432	}
1e78305d AK	433	free(buffer);
	434
	435	if (is_local) {
	436	gid = local_users_gid;
	437	} else {
	438	buflen = sysconf(_SC_GETGR_R_SIZE_MAX);
	439	buffer = malloc(buflen);
	440	if (buffer == NULL) {
	441	*errnop = ENOMEM;
	442	errno = old_errno;
	443	return NSS_STATUS_TRYAGAIN;
48479fc7	444	}
1e78305d AK	445	status = get_local_group(MAGIC_NONLOCAL_GROUPNAME,
1e78305d AK	446	&nonlocal_users_group, buffer, buflen, errnop);
5879a696 AK	447	if (status == NSS_STATUS_SUCCESS) {
	448	gid = nonlocal_users_group.gr_gid;
	449	} else if (status == NSS_STATUS_TRYAGAIN) {
dc94c928	450	free(buffer);
5879a696 AK	451	return status;
5879a696 AK	452	} else {
1e78305d AK	453	syslog(LOG_WARNING, "nss_nonlocal: Group %s does not exist locally!",
	454	MAGIC_NONLOCAL_GROUPNAME);
	455	gid = -1;
5879a696	456	}
1e78305d	457	free(buffer);
48479fc7	458	}
1e78305d AK	459
	460	if (gid != -1) {
	461	int i;
	462	for (i = 0; i < *start; ++i)
	463	if ((*groupsp)[i] == gid)
	464	break;
	465	if (i >= *start) {
	466	if (start + 1 > size) {
	467	gid_t *newgroups;
	468	long int newsize = 2 * *size;
	469	if (limit > 0) {
	470	if (*size >= limit)
	471	return NSS_STATUS_SUCCESS;
	472	if (newsize > limit)
	473	newsize = limit;
	474	}
	475	newgroups = realloc(groupsp, size * sizeof((*groupsp)[0]));
	476	if (newgroups == NULL) {
	477	*errnop = ENOMEM;
	478	errno = old_errno;
	479	return NSS_STATUS_TRYAGAIN;
	480	}
	481	*groupsp = newgroups;
	482	*size = newsize;
	483	}
	484	(groupsp)[(start)++] = gid;
	485	}
48479fc7	486	}
f6903667	487
1e78305d AK	488	if (is_local)
	489	return NSS_STATUS_SUCCESS;
	490
	491	int in = start, out = start, i;
	492
f6903667 AK	493	nip = nss_group_nonlocal_database();
	494	if (nip == NULL)
	495	return NSS_STATUS_UNAVAIL;
	496	if (fct_start == NULL)
	497	fct_start = __nss_lookup_function(nip, fct_name);
	498	fct.ptr = fct_start;
	499
	500	do {
	501	if (fct.ptr == NULL)
	502	status = NSS_STATUS_UNAVAIL;
	503	else
	504	status = DL_CALL_FCT(fct.l, (user, group, start, size, groupsp, limit, errnop));
	505	if (status == NSS_STATUS_TRYAGAIN && *errnop == ERANGE)
	506	break;
	507	} while (__nss_next(&nip, fct_name, &fct.ptr, status, 0) == 0);
	508	if (status != NSS_STATUS_SUCCESS)
	509	return status;
	510
	511	for (; in < *start; ++in) {
	512	int nonlocal_errno = *errnop;
	513
	514	for (i = 0; i < out; ++i)
	515	if ((groupsp)[i] == (groupsp)[in])
	516	break;
	517	if (i < out)
	518	continue;
	519
1e78305d AK	520	/* Don't let users get into MAGIC_LOCAL_GROUPNAME from nonlocal reasons. */
	521	if (local_users_gid == (*groupsp)[in]) {
	522	syslog(LOG_WARNING, "nss_nonlocal: Nonlocal user %s removed from special local users group %s",
	523	user, MAGIC_LOCAL_GROUPNAME);
	524	continue;
	525	}
	526
f6903667 AK	527	status = check_nonlocal_gid(user, (*groupsp)[in], &nonlocal_errno);
f6903667 AK	528	if (status == NSS_STATUS_SUCCESS) {
1e78305d	529	(groupsp)[out++] = (groupsp)[in];
5879a696	530	} else if (status == NSS_STATUS_TRYAGAIN) {
f6903667 AK	531	*start = out;
	532	*errnop = nonlocal_errno;
	533	return status;
	534	}
	535	}
	536
	537	*start = out;
	538	return NSS_STATUS_SUCCESS;
	539	}