libtsol/common/setflabel.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) 2006, 2011, Oracle and/or its affiliates. All rights reserved.
 */

/*
 *  Change the label of a file
 */

#include <ctype.h>
#include <locale.h>
#include <stdio.h>
#include <stdlib.h>
#include <strings.h>
#include <errno.h>
#include <sys/mman.h>

#include <tsol/label.h>

#include "labeld.h"
#include <sys/tsol/label_macro.h>

#include <sys/types.h>

#include <zone.h>
#include <sys/zone.h>
#include <sys/param.h>
#include <string.h>

static int abspath(char *, const char *, char *);

/*
 * setflabel(3TSOL) - set file label
 *
 * This is the library interface to the door call.
 */

#define clcall callp->param.acall.cargs.setfbcl_arg
#define clret callp->param.aret.rvals.setfbcl_ret
/*
 *
 *  Exit    error = If error reported, the error indicator,
 *              -1, Unable to access label encodings file;
 *               0, Invalid binary label passed;
 *              >0, Position after the first character in
 *                  string of error, 1 indicates entire string.
 *          Otherwise, unchanged.
 *
 *  Returns 0, If error.
 *      1, If successful.
 *
 *  Calls   __call_labeld(SETFLABEL)
 *
 */

int
setflabel(const char *path, m_label_t *label)
{
    labeld_data_t   call;
    labeld_data_t   *callp = &call;
    size_t  bufsize = sizeof (labeld_data_t);
    size_t  datasize;
    size_t  path_len;
    static char cwd[MAXPATHLEN];
    char        canon[MAXPATHLEN];


    /*
     * If path is relative and we haven't already determined the current
     * working directory, do so now.  Calculating the working directory
     * here lets us do the work once, instead of (potentially) repeatedly
     * in realpath().
     */
    if (*path != '/' && cwd[0] == '\0') {
        if (getcwd(cwd, MAXPATHLEN) == NULL) {
            cwd[0] = '\0';
            return (-1);
        }
    }
    /*
     * Find an absolute pathname in the native file system name space that
     * corresponds to path, stuffing it into canon.
     */
    if (abspath(cwd, path, canon) < 0)
        return (-1);

    path_len = strlen(canon) + 1;

    datasize = CALL_SIZE(setfbcl_call_t, path_len - BUFSIZE);
    datasize += 2; /* PAD */

    if (datasize > bufsize) {
        if ((callp = (labeld_data_t *)malloc(datasize)) == NULL) {
            return (-1);
        }
        bufsize = datasize;
    }

    callp->callop = SETFLABEL;

    clcall.sl = *label;
    (void) strcpy(clcall.pathname, canon);

    if (__call_labeld(&callp, &bufsize, &datasize) == SUCCESS) {
        int err = callp->reterr;

        if (callp != &call)
            (void) munmap((void *)callp, bufsize);

        /*
         * reterr == 0, OK,
         * reterr < 0, invalid binary label,
         */
        if (err == 0) {
            if (clret.status > 0) {
                errno = clret.status;
                return (-1);
            } else {
                return (0);
            }
        } else if (err < 0) {
            err = 0;
        }
        errno = ECONNREFUSED;
        return (-1);
    } else {
        if (callp != &call)
            (void) munmap((void *)callp, bufsize);

        /* server not present */
        errno = ECONNREFUSED;
        return (-1);
    }
}  /* setflabel */

#undef  clcall
#undef  clret

/*
 * Convert the path given in raw to canonical, absolute, symlink-free
 * form, storing the result in the buffer named by canon, which must be
 * at least MAXPATHLEN bytes long.  If wd is non-NULL, assume that it
 * points to a path for the current working directory and use it instead
 * of invoking getcwd; accepting this value as an argument lets our caller
 * cache the value, so that realpath (called from this routine) doesn't have
 * to recalculate it each time it's given a relative pathname.
 *
 * Return 0 on success, -1 on failure.
 */
int
abspath(char *wd, const char *raw, char *canon)
{
    char        absbuf[MAXPATHLEN];

    /*
     * Preliminary sanity check.
     */
    if (raw == NULL || canon == NULL)
        return (-1);

    /*
     * If the path is relative, convert it to absolute form,
     * using wd if it's been supplied.
     */
    if (raw[0] != '/') {
        char    *limit = absbuf + sizeof (absbuf);
        char    *d;

        /* Fill in working directory. */
        if (wd != NULL)
            (void) strncpy(absbuf, wd, sizeof (absbuf));
        else if (getcwd(absbuf, strlen(absbuf)) == NULL)
            return (-1);

        /* Add separating slash. */
        d = absbuf + strlen(absbuf);
        if (d < limit)
            *d++ = '/';

        /* Glue on the relative part of the path. */
        while (d < limit && (*d++ = *raw++))
            continue;

        raw = absbuf;
    }

    /*
     * Call realpath to canonicalize and resolve symlinks.
     */
    return (realpath(raw, canon) == NULL ? -1 : 0);
}