nis/common/getpwnam.c

/*
 * 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 2008 Sun Microsystems, Inc.  All rights reserved.
 * Use is subject to license terms.
 *
 *  nis/getpwnam.c -- "nis" backend for nsswitch "passwd" database
 */

#include <pwd.h>
#include "nis_common.h"

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,
                "passwd.byname", argp->key.name, 0));
}

static nss_status_t
getbyuid(be, a)
    nis_backend_ptr_t   be;
    void            *a;
{
    nss_XbyY_args_t     *argp = (nss_XbyY_args_t *)a;
    char            uidstr[12]; /* More than enough */

    if (argp->key.uid > MAXUID)
        return (NSS_NOTFOUND);
    (void) snprintf(uidstr, 12, "%u", argp->key.uid);
    return (_nss_nis_lookup(be, argp, 0, "passwd.byuid", uidstr, 0));
}

/*
 * Validates passwd entry replacing uid/gid > MAXUID by ID_NOBODY.
 */
int
validate_passwd_ids(char **linepp, int *linelenp, int allocbuf)
{
    char    *linep, *limit, *uidp, *gidp, *newline;
    uid_t   uid;
    gid_t   gid;
    ulong_t uidl, gidl;
    int olduidlen, 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 username */
        continue;
    while (linep < limit && *linep++ != ':') /* skip password */
        continue;
    if (linep == limit)
        return (NSS_STR_PARSE_PARSE);

    uidp = linep;
    uidl = strtoul(uidp, (char **)&linep, 10); /* grab uid */
    olduidlen = linep - uidp;
    if (++linep >= limit || olduidlen == 0)
        return (NSS_STR_PARSE_PARSE);

    gidp = linep;
    gidl = strtoul(gidp, (char **)&linep, 10); /* grab gid */
    oldgidlen = linep - gidp;
    if (linep >= limit || oldgidlen == 0)
        return (NSS_STR_PARSE_PARSE);

    if (uidl <= MAXUID && gidl <= MAXUID)
        return (NSS_STR_PARSE_SUCCESS);
    uid = (uidl > MAXUID) ? UID_NOBODY : (uid_t)uidl;
    gid = (gidl > MAXUID) ? GID_NOBODY : (gid_t)gidl;

    /* Check if we have enough space in the buffer */
    idlen = snprintf(NULL, 0, "%u:%u", uid, gid);
    newlinelen = linelen + idlen - olduidlen - oldgidlen - 1;
    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 */
        *(uidp - 1) = '\0';
        (void) snprintf(newline, newlinelen + 1, "%s:%u:%u%s",
            *linepp, uid, gid, linep);
        free(*linepp);
        *linepp = newline;
        *linelenp = newlinelen;
        return (NSS_STR_PARSE_SUCCESS);
    }

    /* Replace ephemeral ids by ID_NOBODY in the same buffer */
    (void) bcopy(linep, uidp + idlen, limit - linep + 1);
    (void) snprintf(uidp, idlen + 1, "%u:%u", uid, gid);
    *(uidp + idlen) = ':'; /* restore : that was overwritten by snprintf */
    *linelenp = newlinelen;
    return (NSS_STR_PARSE_SUCCESS);
}

static nis_backend_op_t passwd_ops[] = {
    _nss_nis_destr,
    _nss_nis_endent,
    _nss_nis_setent,
    _nss_nis_getent_rigid,
    getbyname,
    getbyuid
};

/*ARGSUSED*/
nss_backend_t *
_nss_nis_passwd_constr(dummy1, dummy2, dummy3)
    const char  *dummy1, *dummy2, dummy3;
{
    return (_nss_nis_constr(passwd_ops,
                sizeof (passwd_ops) / sizeof (passwd_ops[0]),
                "passwd.byname"));
}