getgrent.c revision 36e852a172cba914383d7341c988128b2c667fbd
/*
* CDDL HEADER START
*
* The contents of this file are subject to the terms of the
* Common Development and Distribution License (the "License").
* You may not use this file except in compliance with the License.
*
* You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
* or http://www.opensolaris.org/os/licensing.
* See the License for the specific language governing permissions
* and limitations under the License.
*
* When distributing Covered Code, include this CDDL HEADER in each
* file and include the License file at usr/src/OPENSOLARIS.LICENSE.
* If applicable, add the following below this CDDL HEADER, with the
* fields enclosed by brackets "[]" replaced with your own identifying
* information: Portions Copyright [yyyy] [name of copyright owner]
*
* CDDL HEADER END
*/
/*
* Copyright 2009 Sun Microsystems, Inc. All rights reserved.
* Use is subject to license terms.
*/
/*
* nis/getgrent.c -- "nis" backend for nsswitch "group" database
*/
#include <grp.h>
#include <pwd.h>
#include "nis_common.h"
#include <ctype.h>
#include <stdlib.h>
#include <string.h>
#include <rpc/auth.h> /* for MAXNETNAMELEN */
static nss_status_t netid_lookup(struct nss_groupsbymem *argp);
static nss_status_t
getbyname(be, a)
nis_backend_ptr_t be;
void *a;
{
nss_XbyY_args_t *argp = (nss_XbyY_args_t *)a;
return (_nss_nis_lookup(be, argp, 0,
"group.byname", argp->key.name, 0));
}
static nss_status_t
getbygid(be, a)
nis_backend_ptr_t be;
void *a;
{
nss_XbyY_args_t *argp = (nss_XbyY_args_t *)a;
char gidstr[12]; /* More than enough */
if (argp->key.gid > MAXUID)
return (NSS_NOTFOUND);
(void) snprintf(gidstr, 12, "%d", argp->key.gid);
return (_nss_nis_lookup(be, argp, 0, "group.bygid", gidstr, 0));
}
/*
* Validates group entry replacing gid > MAXUID by GID_NOBODY.
*/
int
validate_group_ids(char **linepp, int *linelenp, int allocbuf)
{
char *linep, *limit, *gidp, *newline;
ulong_t gid;
int oldgidlen, idlen;
int linelen = *linelenp, newlinelen;
linep = *linepp;
limit = linep + linelen;
/* +/- entries valid for compat source only */
if (linelen == 0 || *linep == '+' || *linep == '-')
return (NSS_STR_PARSE_SUCCESS);
while (linep < limit && *linep++ != ':') /* skip groupname */
continue;
while (linep < limit && *linep++ != ':') /* skip password */
continue;
if (linep == limit)
return (NSS_STR_PARSE_PARSE);
gidp = linep;
gid = strtoul(gidp, (char **)&linep, 10); /* grab gid */
oldgidlen = linep - gidp;
if (linep >= limit || oldgidlen == 0)
return (NSS_STR_PARSE_PARSE);
if (gid <= MAXUID)
return (NSS_STR_PARSE_SUCCESS);
idlen = snprintf(NULL, 0, "%u", GID_NOBODY);
newlinelen = linelen + idlen - oldgidlen;
if (newlinelen > linelen) {
/* need a larger buffer */
if (!allocbuf || (newline = malloc(newlinelen + 1)) == NULL)
return (NSS_STR_PARSE_ERANGE);
/* Replace ephemeral ids by ID_NOBODY in the new buffer */
*(gidp - 1) = '\0';
(void) snprintf(newline, newlinelen + 1, "%s:%u%s",
*linepp, GID_NOBODY, linep);
free(*linepp);
*linepp = newline;
*linelenp = newlinelen;
return (NSS_STR_PARSE_SUCCESS);
}
/* Replace ephemeral gid by GID_NOBODY in the same buffer */
(void) bcopy(linep, gidp + idlen, limit - linep + 1);
(void) snprintf(gidp, idlen + 1, "%u", GID_NOBODY);
*(gidp + idlen) = ':';
*linelenp = newlinelen;
return (NSS_STR_PARSE_SUCCESS);
}
static nss_status_t
getbymember(be, a)
nis_backend_ptr_t be;
void *a;
{
struct nss_groupsbymem *argp = (struct nss_groupsbymem *)a;
if (strcmp(argp->username, "root") == 0) {
/*
* Assume that "root" can only sensibly be in /etc/group,
* not in NIS
* If we don't do this, a hung name-service may cause
* a root login or su to hang.
*/
return (NSS_NOTFOUND);
}
if (argp->force_slow_way != 1) {
switch (netid_lookup(argp)) {
case NSS_SUCCESS:
/*
* Return SUCESS only if array is full. Explained
* in <nss_dbdefs.h>.
*/
return ((argp->numgids == argp->maxgids)
? NSS_SUCCESS
: NSS_NOTFOUND);
case NSS_NOTFOUND:
case NSS_UNAVAIL:
/*
* Failover to group map search if no luck with netid.
*/
break;
case NSS_TRYAGAIN:
return (NSS_TRYAGAIN);
}
}
return (_nss_nis_do_all(be, argp, argp->username,
(nis_do_all_func_t)argp->process_cstr));
}
static nis_backend_op_t group_ops[] = {
_nss_nis_destr,
_nss_nis_endent,
_nss_nis_setent,
_nss_nis_getent_rigid,
getbyname,
getbygid,
getbymember
};
/*ARGSUSED*/
nss_backend_t *
_nss_nis_group_constr(dummy1, dummy2, dummy3)
const char *dummy1, *dummy2, *dummy3;
{
return (_nss_nis_constr(group_ops,
sizeof (group_ops) / sizeof (group_ops[0]),
"group.byname"));
}
/*
* Add gid to gid_array if it's not already there. gid_array must have room
* for one more entry. Return new size of array.
*/
static int
add_gid(gid_t gid_array[], int numgids, gid_t gid)
{
int i = 0;
for (i = 0; i < numgids; i++) {
if (gid_array[i] == gid) {
return (numgids);
}
}
gid_array[numgids++] = gid;
return (numgids);
}
/*
* Given buf, a null-terminated string containing the result of a successful
* netid lookup, add the gids to the gid_array. The string may contain extra
* whitesapce. On parse error, the valid portion of the gid_array is not
* modified.
*/
static int
parse_netid(const char *buf, gid_t gid_array[], int maxgids, int *numgids_ptr)
{
int numgids = *numgids_ptr;
char *buf_next;
gid_t gid;
long value;
/* Scan past "<uid>:" */
while (isspace(*buf) || isdigit(*buf)) {
buf++;
}
if (*buf++ != ':') {
return (NSS_STR_PARSE_PARSE);
}
/* buf should now point to a comma-separated list of gids */
while (*buf != '\0' && *buf != '\n') {
errno = 0;
value = strtol(buf, &buf_next, 10);
if (buf == buf_next) {
return (NSS_STR_PARSE_PARSE);
} else if ((value == LONG_MAX && errno == ERANGE) ||
(ulong_t)value > INT_MAX) {
return (NSS_STR_PARSE_ERANGE);
}
gid = (gid_t)value;
if (numgids < maxgids) {
numgids = add_gid(gid_array, numgids, gid);
}
buf = buf_next;
if (*buf == ',') {
buf++;
}
}
*numgids_ptr = numgids;
return (NSS_STR_PARSE_SUCCESS);
}
/*
* Perform a lookup in the netid map. Fill in the gid_array if successful.
* Return values are like those for _nss_nis_lookup().
*/
static nss_status_t
netid_lookup(struct nss_groupsbymem *argp)
{
const char *domain = _nss_nis_domain();
struct passwd pw;
char pwbuf[NSS_BUFLEN_PASSWD];
char netname[MAXNETNAMELEN + 1];
nss_status_t res;
char *val;
int vallen;
int parse_res;
char *lasts;
/*
* Need to build up the netname for the user manually. Can't use
* user2netname() rpc library call, since that does all sorts of
* extra stuff based upon its own private name-service switch.
*
* Note that "root" has no user netname so return in error.
*/
if ((getpwnam_r(argp->username, &pw, pwbuf, sizeof (pwbuf)) == NULL) ||
(pw.pw_uid == 0)) {
return (NSS_UNAVAIL);
}
if (snprintf(netname, MAXNETNAMELEN + 1, "unix.%d@%s",
pw.pw_uid, domain) < 0) {
return (NSS_UNAVAIL);
}
if ((res = _nss_nis_ypmatch(domain, "netid.byname", netname,
&val, &vallen, 0)) != NSS_SUCCESS) {
return (res);
}
(void) strtok_r(val, "#", &lasts);
parse_res = parse_netid(val, argp->gid_array, argp->maxgids,
&argp->numgids);
free(val);
return ((parse_res == NSS_STR_PARSE_SUCCESS)
? NSS_SUCCESS : NSS_NOTFOUND);
}