/*
 * 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) 1992, 2010, Oracle and/or its affiliates. All rights reserved.
 */

/*
 * 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;

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

void
setauclass()
{
        (void) mutex_lock(&mutex_classfile);
        if (au_class_file) {
                (void) fseek(au_class_file, 0L, 0);
        }
        (void) mutex_unlock(&mutex_classfile);
}


void
endauclass()
{
        (void) mutex_lock(&mutex_classfile);
        if (au_class_file) {
                (void) fclose(au_class_file);
                au_class_file = NULL;
        }
        (void) 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_ent_t *au_class_entry)
{
        int             i, error = 0, found = 0;
        char            *s, input[256];
        au_class_t      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 (NULL);
        }

        /* open audit class file if it isn't already */
        (void) mutex_lock(&mutex_classfile);
        if (!au_class_file) {
                if (!(au_class_file = fopen(au_class_fname, "rF"))) {
                        (void) mutex_unlock(&mutex_classfile);
                        return (NULL);
                }
        }

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

                        /* parse bitfield */
                        i = strcspn(s, ":");
                        s[i] = '\0';
                        if (strncmp(s, "0x", 2) == 0) {
                                (void) sscanf(&s[2], "%x", &v);
                        } else {
                                (void) sscanf(s, "%u", &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;
                }
        }

        (void) mutex_unlock(&mutex_classfile);

        if (!error && found) {
                return (au_class_entry);
        } else {
                return (NULL);
        }
}


au_class_ent_t *
getauclassnam(char *name)
{
        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 *
getauclassnam_r(au_class_ent_t *e, char *name)
{
        while (getauclassent_r(e) != NULL) {
                if (strncmp(e->ac_name, name, AU_CLASS_NAME_MAX) == 0) {
                        return (e);
                }
        }
        return (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(au_class_ent_t **result, char *class_name, 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;

        (void) mutex_lock(&mutex_classcache);
        if (called_once == 0) {

                /* Count number of lines in the class file */
                if ((fp = fopen(au_class_fname, "rF")) == NULL) {
                        (void) 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 (class_tbl));
                if (class_tbl == NULL) {
                        (void) 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) {
                                (void) 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) {
                        (void) 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 (strncmp(class_name, class_tbl[i]->ac_name,
                            AU_CLASS_NAME_MAX) == 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;
                        }
                }
        }
        (void) mutex_unlock(&mutex_classcache);
        return (hit);
}

int
cacheauclass(au_class_ent_t **result, au_class_t class_no)
{
        return (xcacheauclass(result, "", class_no, AU_CACHE_NUMBER));
}

int
cacheauclassnam(au_class_ent_t **result, char *class_name)
{
        return (xcacheauclass(result, class_name, (au_class_t)0,
            AU_CACHE_NAME));
}