common/c2/audit_path.c

	audit_path.c revision 7c478bd95313f5f23a4c958a745db2134aa03244
/*
 * CDDL HEADER START
 *
 * The contents of this file are subject to the terms of the
 * Common Development and Distribution License, Version 1.0 only
 * (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 1991-2003 Sun Microsystems, Inc.  All rights reserved.
 * Use is subject to license terms.
 */

#pragma ident   "%Z%%M% %I% %E% SMI"

/*
 * @(#)audit_path.c 2.7 92/02/16 SMI; SunOS CMW
 * @(#)audit_path.c 4.2.1.2 91/05/08 SMI; BSM Module
 *
 * This code does the audit path processes. Part of this is still in
 * audit.c and will be moved here when time permits.
 *
 * Note that audit debuging is enabled here. We will turn it off at
 * beta shipment.
 */

#include <sys/types.h>
#include <sys/param.h>
#include <sys/systm.h>
#include <sys/user.h>
#include <sys/vnode.h>
#include <sys/vfs.h>
#include <sys/kmem.h>       /* for KM_SLEEP */
#include <sys/proc.h>
#include <sys/uio.h>
#include <sys/file.h>
#include <sys/stat.h>
#include <sys/pathname.h>
#include <sys/acct.h>
#include <c2/audit.h>
#include <c2/audit_kernel.h>
#include <c2/audit_record.h>
#include <sys/sysmacros.h>
#include <sys/atomic.h>

/*
 * allocate a new auditpath
 *  newsect = increment sections count,
 *  charincr = change in strings storage
 */
struct audit_path *
au_pathdup(const struct audit_path *oldapp, int newsect, int charincr)
{
    struct audit_path   *newapp;
    int i, alloc_size, oldlen;
    char    *oldcp, *newcp;

    newsect = (newsect != 0);
    oldcp = oldapp->audp_sect[0];
    oldlen = (oldapp->audp_sect[oldapp->audp_cnt] - oldcp);
    alloc_size = sizeof (struct audit_path) +
        (oldapp->audp_cnt + newsect) * sizeof (char *) +
        oldlen + charincr;

    newapp = kmem_alloc(alloc_size, KM_SLEEP);
    newapp->audp_ref = 1;
    newapp->audp_size = alloc_size;

    newapp->audp_cnt = oldapp->audp_cnt + newsect;
    newcp = (char *)(&newapp->audp_sect[newapp->audp_cnt + 1]);
    for (i = 0; i <= oldapp->audp_cnt; i++) {
        newapp->audp_sect[i] = newcp +
            (oldapp->audp_sect[i] - oldcp);
    }
    /*
     * if this is a new section, set its end
     * if this is an extended section, reset its end
     */
    newapp->audp_sect[newapp->audp_cnt] = newcp + oldlen + charincr;
    /* copy all of the old strings */
    bcopy(oldcp, newcp, oldlen);

    return (newapp);
}

/*
 * increment audit path reference count
 */
void
au_pathhold(struct audit_path *app)
{
    atomic_add_32(&app->audp_ref, 1);
}

/*
 * decrement audit path reference count
 */
void
au_pathrele(struct audit_path *app)
{
    if (atomic_add_32_nv(&app->audp_ref, -1) > 0)
        return;
    kmem_free(app, app->audp_size);
}


int
au_token_size(m)
    token_t *m;
{
    int i;

    if (m == (token_t *)0)
        return (0);

    for (i = 0; m != (token_t *)0; m = m->next_buf)
        i += m->len;
    return (i);
}

token_t *
au_set(cp, size)
    caddr_t  cp;
    uint_t    size;
{
    au_buff_t *head;
    au_buff_t *tail;
    au_buff_t *m;
    uint_t  l;

    head = NULL;
    tail = NULL;    /* only to satisfy lint */

    while (size) {
        m = au_get_buff();
        l = MIN(size, AU_BUFSIZE);
        bcopy(cp, memtod(m, char *), l);
        m->len = l;

        if (head)
            tail->next_buf = m; /* tail set if head set */
        else
            head = m;
        tail = m;
        size -= l;
        cp += l;
    }

    return (head);
}

token_t *
au_append_token(chain, m)
    token_t *chain;
    token_t *m;
{
    token_t *mbp;

    if (chain == (token_t *)0)
        return (m);

    if (m == (token_t *)0)
        return (chain);

    for (mbp = chain; mbp->next_buf != (token_t *)0; mbp = mbp->next_buf)
        ;
    mbp->next_buf = m;
    return (chain);
}


void
audit_fixpath(struct audit_path *app, int len)
{
    int id;     /* index of where we are in destination string */
    int is;     /* index of where we are in source string */
    int cnt;    /* # of levels in audit_path */
    int slashseen;  /* have we seen a slash */
    char *s;    /* start of top-level string */
    char c;

    cnt = app->audp_cnt;
    s = app->audp_sect[cnt - 1];
    is = (app->audp_sect[cnt] - s) - len;
    if (is <= 2)
        is = 0; /* catch leading // or ./ */
    slashseen = (is > 0);
    for (id = is; ; is++) {
        if ((c = s[is]) == '\0') {
            /* that's all folks, we've reached the end of input */
            if (id > 1 && s[id-1] == '/') {
                /* remove terminating / */
                --id;
            }
            s[id++] = '\0';
            break;
        }
        if (slashseen) {
            /* previous character was a / */
            if (c == '/') {
                /* another slash, ignore it */
                continue;
            }
        } else if (c == '/') {
            /* we see a /, just copy it and try again */
            slashseen = 1;
            s[id++] = c;
            continue;
        }
        if (c == '.') {
            if ((c = s[is+1]) == '\0') {
                /* XXX/. seen */
                if (id > 1)
                    id--;
                continue;
            }
            if (c == '/') {
                /* XXX/./ seen */
                is += 1;
                continue;
            }
            if (c == '.' && (s[is+2] == '\0' || s[is+2] == '/')) {
                /* XXX/.. or XXX/../ seen */
                is++;
                if (id == 0 && cnt > 1) {
                    char    *s_attr;
                    /* .. refers to attributed object */
                    app->audp_cnt = --cnt;
                    s_attr = s;
                    s = app->audp_sect[cnt - 1];
                    id = s_attr - s;
                    is += id;
                    id--;
                    slashseen = 0;
                    continue;
                }
                /* backup over previous component */
                if (id > 0)
                    id--;
                while (id > 0 && s[id - 1] != '/')
                    id--;
                continue;
            }
        }
        /* copy component name and terminating /, if any */
        for (;;) {
            c = s[is++];
            if (c == '\0' || c == '/')
                break;
            s[id++] = c;
        }
        /* back up to before terminating '\0' or / */
        slashseen = 0;
        is -= 2;
    }
    /* fill empty attribute directory reference */
    if (id == 1 && cnt > 1) {
        s[0] = '.';
        s[1] = '\0';
        id = 2;
    }
    /* correct end pointer */
    app->audp_sect[cnt] = s + id;
}