files/common/getexecattr.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 (c) 1999, 2011, Oracle and/or its affiliates. All rights reserved.
 */

#include <stdlib.h>
#include "files_common.h"
#include <time.h>
#include <exec_attr.h>
#include <strings.h>
#include <sys/stat.h>
#include <sys/mman.h>
#include <ctype.h>
#include <synch.h>
#include <sys/types.h>
#include <sys/uio.h>
#include <unistd.h>

/*
 * files/getexecattr.c -- "files" backend for nsswitch "exec_attr" database
 *
 * _execattr_files_read_line and _execattr_files_XY_all code based on
 * nss_files_read_line and nss_files_XY_all respectively, from files_common.c
 */


/* externs from libnsl */
extern int _readbufline(char *, int, char *, int, int *);
extern char *_exec_wild_id(char *, const char *);
extern void _exec_cleanup(nss_status_t, nss_XbyY_args_t *);

/*
 * Hashing functions for exec_attr.  We need three.
 *
 * We hash on field 1 (hash_name), field 6 (hash_id) and
 * fields 1 + 6 (nameid).
 */

static uint_t
hash_xname(nss_XbyY_args_t *argp, int keyhash, const char *line,
    int linelen)
{
    if (keyhash) {
        _priv_execattr  *pe = (_priv_execattr *)(argp->key.attrp);
        const char *name = pe->name;
        return (hash_string(name, strlen(name)));
    } else {
        return (hash_field(line, linelen, 1));
    }
}

static uint_t
hash_id(nss_XbyY_args_t *argp, int keyhash, const char *line,
    int linelen)
{
    if (keyhash) {
        _priv_execattr *pe = (_priv_execattr *)(argp->key.attrp);
        const char *id = pe->id;
        return (hash_string(id, strlen(id)));
    } else {
        return (hash_field(line, linelen, 6));
    }
}

static uint_t
hash_nameid(nss_XbyY_args_t *argp, int keyhash, const char *line,
    int linelen)
{
    if (keyhash) {
        _priv_execattr *pe = (_priv_execattr *)(argp->key.attrp);
        const char *name = pe->name;
        const char *id = pe->id;
        return (hash_string(id, strlen(id)) +
            hash_string(name, strlen(name)));
    } else {
        return (hash_field(line, linelen, 1)  +
            hash_field(line, linelen, 6));
    }
}

static files_hash_func hash_exec[3] = { hash_xname, hash_id, hash_nameid };

static files_hash_t hashinfo = {
    DEFAULTMUTEX,
    sizeof (execattr_t),
    NSS_LINELEN_EXECATTR,
    sizeof (hash_exec)/sizeof (files_hash_func),
    hash_exec
};


/*
 * check_match: returns 1 if matching entry found, else returns 0.
 */
static int
check_match_i(nss_XbyY_args_t *argp, const char *line, int linelen, int hashop)
{
    const char  *limit, *linep, *keyp;
    _priv_execattr  *pe = (_priv_execattr *)(argp->key.attrp);
    const char  *exec_field[6];
    int     i;

    if (hashop == 0 || hashop == 2)
        exec_field[0] = pe->name; /* name */
    else
        exec_field[0] = NULL;
    exec_field[1] = pe->policy; /* policy */
    exec_field[2] = pe->type;   /* type */
    exec_field[3] = NULL;           /* res1 */
    exec_field[4] = NULL;           /* res2 */

    if (hashop == 1 || hashop == 2)
        exec_field[5] = pe->id; /* id */
    else
        exec_field[5] = NULL;

    /* No need to check attr field */

    linep = line;
    limit = line + linelen;

    for (i = 0; i < 6; i++) {
        keyp = exec_field[i];
        if (keyp) {
            /* compare field */
            while (*keyp && linep < limit &&
                *linep != ':' && *keyp == *linep) {
                keyp++;
                linep++;
            }
            if (*keyp || linep == limit || *linep != ':')
                return (0);
        } else {
            /* skip field */
            while (linep < limit && *linep != ':')
                linep++;
        }
        linep++;
    }
    return (1);
}

static int
check_match_name(nss_XbyY_args_t *argp, const char *line, int linelen)
{
    return (check_match_i(argp, line, linelen, 0));
}

static int
check_match_id(nss_XbyY_args_t *argp, const char *line, int linelen)
{
    return (check_match_i(argp, line, linelen, 1));
}

static int
check_match_nameid(nss_XbyY_args_t *argp, const char *line, int linelen)
{
    return (check_match_i(argp, line, linelen, 2));
}

static files_XY_check_func cfs[3] = {
    check_match_name, check_match_id, check_match_nameid
};


/*
 * If search for exact match for id failed, get_wild checks if we have
 * a wild-card entry for that id.
 */
static nss_status_t
get_wild(files_backend_ptr_t be, nss_XbyY_args_t *argp, int hashop)
{
    const char  *orig_id = NULL;
    char        *old_id = NULL;
    char        *wild_id = NULL;
    nss_status_t    res = NSS_NOTFOUND;
    _priv_execattr  *pe = (_priv_execattr *)(argp->key.attrp);

    orig_id = pe->id;
    old_id = strdup(pe->id);
    wild_id = old_id;
    while ((wild_id = _exec_wild_id(wild_id, pe->type)) != NULL) {
        pe->id = wild_id;
        res = _nss_files_XY_hash(be, argp, 1, &hashinfo, hashop,
            cfs[hashop]);
        if (res == NSS_SUCCESS)
            break;
    }
    pe->id = orig_id;
    if (old_id)
        free(old_id);

    return (res);
}


static nss_status_t
getbynam(files_backend_ptr_t be, void *a)
{
    nss_status_t    res;
    res = _nss_files_XY_hash(be, a, 1, &hashinfo, 0, check_match_name);

    _exec_cleanup(res, a);

    return (res);
}


static nss_status_t
getbyid(files_backend_ptr_t be, void *a)
{
    nss_status_t    res;

    res = _nss_files_XY_hash(be, a, 1, &hashinfo, 1, check_match_id);

    if (res != NSS_SUCCESS)
        res = get_wild(be, a, 1);

    _exec_cleanup(res, a);

    return (res);
}


static nss_status_t
getbynameid(files_backend_ptr_t be, void *a)
{
    nss_status_t    res;

    res = _nss_files_XY_hash(be, a, 1, &hashinfo, 2, check_match_nameid);

    if (res != NSS_SUCCESS)
        res = get_wild(be, a, 2);

    _exec_cleanup(res, a);

    return (res);
}


static files_backend_op_t execattr_ops[] = {
    _nss_files_destr,
    _nss_files_endent,
    _nss_files_setent,
    _nss_files_getent_netdb,
    getbynam,
    getbyid,
    getbynameid
};

/*ARGSUSED*/
nss_backend_t  *
_nss_files_exec_attr_constr(const char *dummy1,
    const char *dummy2,
    const char *dummy3,
    const char *dummy4,
    const char *dummy5,
    const char *dummy6,
    const char *dummy7)
{
    return (_nss_files_constr(execattr_ops,
        sizeof (execattr_ops)/sizeof (execattr_ops[0]),
        EXECATTR_DIRNAME, NSS_LINELEN_EXECATTR,
        &hashinfo, FC_FLAG_EXECATTR));
}