libbsm/common/audit_class.c

	audit_class.c revision 004388ebfdfe2ed7dfd2d153a876dfcc22d2c006
/*
 * 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 2006 Sun Microsystems, Inc.  All rights reserved.
 * Use is subject to license terms.
 */

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

/*
 * Interfaces to audit_class(5)  (/etc/security/audit_class)
 */

#include <stdlib.h>
#include <stdio.h>
#include <limits.h>
#include <sys/types.h>
#include <bsm/audit.h>
#include <bsm/libbsm.h>
#include <string.h>
#include <synch.h>

static char au_class_fname[PATH_MAX] = AUDITCLASSFILE;
static FILE *au_class_file = NULL;
static mutex_t  mutex_classfile = DEFAULTMUTEX;
static mutex_t  mutex_classcache = DEFAULTMUTEX;

extern int _mutex_lock(mutex_t *);
extern int _mutex_unlock(mutex_t *);

int
#ifdef __STDC__
setauclassfile(char *fname)
#else
setauclassfile(fname)
    char    *fname;
#endif
{
    _mutex_lock(&mutex_classfile);
    if (fname) {
        (void) strcpy(au_class_fname, fname);
    }
    _mutex_unlock(&mutex_classfile);
    return (0);
}


void
setauclass()
{
    _mutex_lock(&mutex_classfile);
    if (au_class_file) {
        (void) fseek(au_class_file, 0L, 0);
    }
    _mutex_unlock(&mutex_classfile);
}


void
endauclass()
{
    _mutex_lock(&mutex_classfile);
    if (au_class_file) {
        (void) fclose(au_class_file);
        au_class_file = NULL;
    }
    _mutex_unlock(&mutex_classfile);
}

/*
 * getauclassent():
 *  This is not MT-safe because of the static variables.
 */
au_class_ent_t *
getauclassent()
{
    static au_class_ent_t e;
    static char cname[AU_CLASS_NAME_MAX];
    static char cdesc[AU_CLASS_DESC_MAX];

    e.ac_name = cname;
    e.ac_desc = cdesc;

    return (getauclassent_r(&e));
}

/*
 * getauclassent_r
 *  This is MT-safe if each thread passes in its own pointer
 *  to the space where the class entry is returned.  Becareful
 *  to also allocate space from the cname and cdesc pointers
 *  in the au_class_ent structure.
 */
au_class_ent_t *
getauclassent_r(au_class_entry)
    au_class_ent_t *au_class_entry;
{
    int i, error = 0, found = 0;
    char    *s, input[256];
    unsigned long v;

    if (au_class_entry == (au_class_ent_t *)NULL ||
        au_class_entry->ac_name == (char *)NULL ||
        au_class_entry->ac_desc == (char *)NULL) {
            return ((au_class_ent_t *)NULL);
    }

    /* open audit class file if it isn't already */
    _mutex_lock(&mutex_classfile);
    if (!au_class_file) {
        if (!(au_class_file = fopen(au_class_fname, "rF"))) {
            _mutex_unlock(&mutex_classfile);
            return ((au_class_ent_t *)0);
        }
    }

    while (fgets(input, 256, au_class_file)) {
        if (input[0] != '#') {
            s = input + strspn(input, " \t\r\n");
            if ((*s == '\0') || (*s == '#')) {
                continue;
            }
            found = 1;
            s = input;

            /* parse bitfield */
            i = strcspn(s, ":");
            s[i] = '\0';
            if (strncmp(s, "0x", 2) == 0) {
                (void) sscanf(&s[2], "%lx", &v);
            } else {
                (void) sscanf(s, "%lu", &v);
            }
            au_class_entry->ac_class = v;
            s = &s[i+1];

            /* parse class name */
            i = strcspn(s, ":");
            s[i] = '\0';
            (void) strncpy(au_class_entry->ac_name, s,
                AU_CLASS_NAME_MAX);
            s = &s[i+1];

            /* parse class description */
            i = strcspn(s, "\n\0");
            s[i] = '\0';
            (void) strncpy(au_class_entry->ac_desc, s,
                AU_CLASS_DESC_MAX);

            break;
        }
    }

    _mutex_unlock(&mutex_classfile);

    if (!error && found) {
        return (au_class_entry);
    } else {
        return ((au_class_ent_t *)0);
    }
}


au_class_ent_t *
#ifdef __STDC__
getauclassnam(char *name)
#else
getauclassnam(name)
    char *name;
#endif
{
    static au_class_ent_t e;
    static char cname[AU_CLASS_NAME_MAX];
    static char cdesc[AU_CLASS_DESC_MAX];

    e.ac_name = cname;
    e.ac_desc = cdesc;

    return (getauclassnam_r(&e, name));
}

au_class_ent_t *
#ifdef __STDC__
getauclassnam_r(au_class_ent_t *e, char *name)
#else
getauclassnam_r()
    au_class_ent_t *e;
    char *name;
#endif
{
    while (getauclassent_r(e) != NULL) {
        if (strcmp(e->ac_name, name) == 0) {
            return (e);
        }
    }
    return ((au_class_ent_t *)NULL);
}


/*
 * xcacheauclass:
 *  Read the entire audit_class file into memory.
 *  Return a pointer to the requested entry in the cache
 *  or a pointer to an invalid entry if the the class
 *  requested is not known.
 *
 *  Return < 0, do not set result pointer, if error.
 *  Return   0, set result pointer to invalid entry, if class not in cache.
 *  Return   1, set result pointer to a valid entry, if class is in cache.
 */
static int
xcacheauclass(result, class_name, class_no, flags)
    au_class_ent_t **result; /* set this pointer to an entry in the cache */
    char    *class_name; /* name of class to look up */
    au_class_t class_no;
    int flags;
{
    static int  invalid;
    static au_class_ent_t **class_tbl;
    static int  called_once;
    static int  lines = 0;

    char        line[256];
    FILE        *fp;
    au_class_ent_t  *p_class;
    int     i;
    int     hit = 0;
    char        *s;

    _mutex_lock(&mutex_classcache);
    if (called_once == 0) {

        /* Count number of lines in the class file */
        if ((fp = fopen(au_class_fname, "rF")) == NULL) {
            _mutex_unlock(&mutex_classcache);
            return (-1);
        }
        while (fgets(line, 256, fp) != NULL) {
            s = line + strspn(line, " \t\r\n");
            if ((*s == '\0') || (*s == '#')) {
                continue;
            }
            lines++;
        }
        (void) fclose(fp);
        class_tbl = (au_class_ent_t **)calloc((size_t)lines + 1,
            sizeof (au_class_ent_t));
        if (class_tbl == NULL) {
            _mutex_unlock(&mutex_classcache);
            return (-2);
        }

        lines = 0;
        setauclass();
        /*
         * This call to getauclassent is protected by
         * mutex_classcache, so we don't need to use the thread-
         * safe version (getauclassent_r).
         */
        while ((p_class = getauclassent()) != NULL) {
            class_tbl[lines] = (au_class_ent_t *)
                malloc(sizeof (au_class_ent_t));
            if (class_tbl[lines] == NULL) {
                _mutex_unlock(&mutex_classcache);
                return (-3);
            }
            class_tbl[lines]->ac_name = strdup(p_class->ac_name);
            class_tbl[lines]->ac_class = p_class->ac_class;
            class_tbl[lines]->ac_desc = strdup(p_class->ac_desc);
#ifdef DEBUG2
            printclass(class_tbl[lines]);
#endif
            lines++;
        }
        endauclass();
        invalid = lines;
        class_tbl[invalid] = (au_class_ent_t *)
            malloc(sizeof (au_class_ent_t));
        if (class_tbl[invalid] == NULL) {
            _mutex_unlock(&mutex_classcache);
            return (-4);
        }
        class_tbl[invalid]->ac_name = "invalid class";
        class_tbl[invalid]->ac_class = 0;
        class_tbl[invalid]->ac_desc = class_tbl[invalid]->ac_name;

        called_once = 1;

#ifdef DEBUG2
        for (i = 0; i <= lines; i++) {
            printclass(class_tbl[i]);
        }
#endif

    } /* END if called_once */
    *result = class_tbl[invalid];
    if (flags & AU_CACHE_NAME) {
        for (i = 0; i < lines; i++) {
            if (strcmp(class_name, class_tbl[i]->ac_name) == 0) {
                *result = class_tbl[i];
                hit = 1;
                break;
            }
        }
    } else if (flags & AU_CACHE_NUMBER) {
        for (i = 0; i < lines; i++) {
            if (class_no == class_tbl[i]->ac_class) {
                *result = class_tbl[i];
                hit = 1;
                break;
            }
        }
    }
    _mutex_unlock(&mutex_classcache);
    return (hit);
}


int
#ifdef __STDC__
cacheauclass(au_class_ent_t **result, au_class_t class_no)
#else
cacheauclass(result, class_no)
    au_class_ent_t **result; /* set this pointer to an entry in the cache */
    au_class_t class_no;
#endif
{
    return (xcacheauclass(result, "", class_no, AU_CACHE_NUMBER));
}


int
#ifdef __STDC__
cacheauclassnam(au_class_ent_t **result, char *class_name)
#else
cacheauclassnam(result, class_name)
    au_class_ent_t **result; /* set this pointer to an entry in the cache */
    char    *class_name;
#endif
{
    return (xcacheauclass(result, class_name, (au_class_t)0,
        AU_CACHE_NAME));
}


#ifdef DEBUG2
void
printclass(p_c)
au_class_ent_t *p_c;
{
    printf("%x:%s:%s\n", p_c->ac_class, p_c->ac_name, p_c->ac_desc);
    fflush(stdout);
}


#endif