/* -*- mode: c; c-basic-offset: 4; indent-tabs-mode: nil -*- */
/* lib/krb5/ccache/cccursor.c */
/*
 * Copyright 2006, 2007 by the Massachusetts Institute of Technology.
 * All Rights Reserved.
 *
 * Export of this software from the United States of America may
 *   require a specific license from the United States Government.
 *   It is the responsibility of any person or organization contemplating
 *   export to obtain such a license before exporting.
 *
 * WITHIN THAT CONSTRAINT, permission to use, copy, modify, and
 * distribute this software and its documentation for any purpose and
 * without fee is hereby granted, provided that the above copyright
 * notice appear in all copies and that both that copyright notice and
 * this permission notice appear in supporting documentation, and that
 * the name of M.I.T. not be used in advertising or publicity pertaining
 * to distribution of the software without specific, written prior
 * permission.  Furthermore if you modify this software you must label
 * your software as modified software and not distribute it in such a
 * fashion that it might be confused with the original M.I.T. software.
 * M.I.T. makes no representations about the suitability of
 * this software for any purpose.  It is provided "as is" without express
 * or implied warranty.
 */

/*
 * cursor for sequential traversal of ccaches
 */

#include "cc-int.h"

#include <assert.h>

struct _krb5_cccol_cursor {
    krb5_cc_typecursor typecursor;
    const krb5_cc_ops *ops;
    krb5_cc_ptcursor ptcursor;
};
/* typedef of krb5_cccol_cursor is in krb5.h */

krb5_error_code KRB5_CALLCONV
krb5_cccol_cursor_new(krb5_context context,
                      krb5_cccol_cursor *cursor)
{
    krb5_error_code ret = 0;
    krb5_cccol_cursor n = NULL;

    *cursor = NULL;
    n = malloc(sizeof(*n));
    if (n == NULL)
        return ENOMEM;

    n->typecursor = NULL;
    n->ptcursor = NULL;
    n->ops = NULL;

    ret = krb5int_cc_typecursor_new(context, &n->typecursor);
    if (ret)
        goto errout;

    do {
        /* Find first backend with ptcursor functionality. */
        ret = krb5int_cc_typecursor_next(context, n->typecursor, &n->ops);
        if (ret || n->ops == NULL)
            goto errout;
    } while (n->ops->ptcursor_new == NULL);

    ret = n->ops->ptcursor_new(context, &n->ptcursor);
    if (ret)
        goto errout;

errout:
    if (ret) {
        krb5_cccol_cursor_free(context, &n);
    }
    *cursor = n;
    return ret;
}

krb5_error_code KRB5_CALLCONV
krb5_cccol_cursor_next(krb5_context context,
                       krb5_cccol_cursor cursor,
                       krb5_ccache *ccache_out)
{
    krb5_error_code ret = 0;
    krb5_ccache ccache;

    *ccache_out = NULL;

    /* Are we out of backends? */
    if (cursor->ops == NULL)
        return 0;

    while (1) {
        ret = cursor->ops->ptcursor_next(context, cursor->ptcursor, &ccache);
        if (ret)
            return ret;
        if (ccache != NULL) {
            *ccache_out = ccache;
            return 0;
        }

        ret = cursor->ops->ptcursor_free(context, &cursor->ptcursor);
        if (ret)
            return ret;

        do {
            /* Find next type with ptcursor functionality. */
            ret = krb5int_cc_typecursor_next(context, cursor->typecursor,
                                             &cursor->ops);
            if (ret)
                return ret;
            if (cursor->ops == NULL)
                return 0;
        } while (cursor->ops->ptcursor_new == NULL);

        ret = cursor->ops->ptcursor_new(context, &cursor->ptcursor);
        if (ret)
            return ret;
    }
}

krb5_error_code KRB5_CALLCONV
krb5_cccol_cursor_free(krb5_context context,
                       krb5_cccol_cursor *cursor)
{
    krb5_cccol_cursor c = *cursor;

    if (c == NULL)
        return 0;

    if (c->ptcursor != NULL)
        c->ops->ptcursor_free(context, &c->ptcursor);
    if (c->typecursor != NULL)
        krb5int_cc_typecursor_free(context, &c->typecursor);
    free(c);

    *cursor = NULL;
    return 0;
}

krb5_error_code KRB5_CALLCONV
krb5_cccol_last_change_time(krb5_context context,
                            krb5_timestamp *change_time)
{
    krb5_error_code ret = 0;
    krb5_cccol_cursor c = NULL;
    krb5_ccache ccache = NULL;
    krb5_timestamp last_time = 0;
    krb5_timestamp max_change_time = 0;

    *change_time = 0;

    ret = krb5_cccol_cursor_new(context, &c);

    while (!ret) {
        ret = krb5_cccol_cursor_next(context, c, &ccache);
        if (ccache) {
            ret = krb5_cc_last_change_time(context, ccache, &last_time);
            if (!ret && last_time > max_change_time) {
                max_change_time = last_time;
            }
            ret = 0;
        }
        else {
            break;
        }
    }
    *change_time = max_change_time;
    return ret;
}

/*
 * krb5_cccol_lock and krb5_cccol_unlock are defined in ccbase.c
 */

krb5_error_code KRB5_CALLCONV
krb5_cc_cache_match(krb5_context context, krb5_principal client,
                    krb5_ccache *cache_out)
{
    krb5_error_code ret;
    krb5_cccol_cursor cursor;
    krb5_ccache cache = NULL;
    krb5_principal princ;
    char *name;
    krb5_boolean eq;

    *cache_out = NULL;
    ret = krb5_cccol_cursor_new(context, &cursor);
    if (ret)
        return ret;

    while ((ret = krb5_cccol_cursor_next(context, cursor, &cache)) == 0 &&
           cache != NULL) {
        ret = krb5_cc_get_principal(context, cache, &princ);
        if (ret == 0) {
            eq = krb5_principal_compare(context, princ, client);
            krb5_free_principal(context, princ);
            if (eq)
                break;
        }
        krb5_cc_close(context, cache);
    }
    krb5_cccol_cursor_free(context, &cursor);
    if (ret)
        return ret;
    if (cache == NULL) {
        ret = krb5_unparse_name(context, client, &name);
        if (ret == 0) {
            krb5_set_error_message(context, KRB5_CC_NOTFOUND,
                                   _("Can't find client principal %s in "
                                     "cache collection"), name);
            krb5_free_unparsed_name(context, name);
        }
        ret = KRB5_CC_NOTFOUND;
    } else
        *cache_out = cache;
    return ret;
}