/*      $NetBSD: yp_match.c,v 1.20 2024/01/03 18:41:53 christos Exp $    */

/*
 * Copyright (c) 1992, 1993 Theo de Raadt <deraadt@fsa.ca>
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the distribution.
 *
 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS
 * OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
 * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
 * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY
 * DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
 * SUCH DAMAGE.
 */

#include <sys/cdefs.h>
#if defined(LIBC_SCCS) && !defined(lint)
__RCSID("$NetBSD: yp_match.c,v 1.20 2024/01/03 18:41:53 christos Exp $");
#endif

#include "namespace.h"

#include <assert.h>
#include <stdlib.h>
#include <string.h>
#include <time.h>

#include <rpc/rpc.h>
#include <rpcsvc/yp_prot.h>
#include <rpcsvc/ypclnt.h>
#include "local.h"

#define YPMATCHCACHE

#ifdef __weak_alias
__weak_alias(yp_match,_yp_match)
#endif

#ifdef YPMATCHCACHE
int _yplib_cache = 5;

static struct ypmatch_ent {
        struct ypmatch_ent      *next;
        char                    *map, *key;
        char                    *val;
        int                      keylen, vallen;
        time_t                   expire_t;
} *ypmc;

static bool_t ypmatch_add(const char *, const char *, int, char *, int);
static bool_t ypmatch_find(const char *, const char *, int, const char **,
    int *);

static bool_t
ypmatch_add(const char *map, const char *key, int keylen, char *val, int vallen)
{
        struct ypmatch_ent *ep;
        time_t t;

        _DIAGASSERT(map != NULL);
        _DIAGASSERT(key != NULL);
        _DIAGASSERT(val != NULL);

        (void)time(&t);

        for (ep = ypmc; ep; ep = ep->next)
                if (ep->expire_t < t)
                        break;
        if (ep == NULL) {
                if ((ep = malloc(sizeof *ep)) == NULL)
                        return 0;
                (void)memset(ep, 0, sizeof *ep);
                if (ypmc)
                        ep->next = ypmc;
                ypmc = ep;
        }

        if (ep->key) {
                free(ep->key);
                ep->key = NULL;
        }
        if (ep->val) {
                free(ep->val);
                ep->val = NULL;
        }

        if ((ep->key = malloc((size_t)keylen)) == NULL)
                return 0;

        if ((ep->val = malloc((size_t)vallen)) == NULL) {
                free(ep->key);
                ep->key = NULL;
                return 0;
        }

        ep->keylen = keylen;
        ep->vallen = vallen;

        (void)memcpy(ep->key, key, (size_t)ep->keylen);
        (void)memcpy(ep->val, val, (size_t)ep->vallen);

        if (ep->map) {
                if (strcmp(ep->map, map)) {
                        free(ep->map);
                        if ((ep->map = strdup(map)) == NULL)
                                return 0;
                }
        } else {
                if ((ep->map = strdup(map)) == NULL)
                        return 0;
        }

        ep->expire_t = t + _yplib_cache;
        return 1;
}

static bool_t
ypmatch_find(const char *map, const char *key, int keylen, const char **val,
        int *vallen)
{
        struct ypmatch_ent *ep;
        time_t          t;

        _DIAGASSERT(map != NULL);
        _DIAGASSERT(key != NULL);
        _DIAGASSERT(val != NULL);

        if (ypmc == NULL)
                return 0;

        (void) time(&t);

        for (ep = ypmc; ep; ep = ep->next) {
                if (ep->keylen != keylen)
                        continue;
                if (strcmp(ep->map, map))
                        continue;
                if (memcmp(ep->key, key, (size_t)keylen))
                        continue;
                if (t > ep->expire_t)
                        continue;

                *val = ep->val;
                *vallen = ep->vallen;
                return 1;
        }
        return 0;
}
#endif

int
yp_match(const char *indomain, const char *inmap, const char *inkey,
        int inkeylen, char **outval, int *outvallen)
{
        struct dom_binding *ysd;
        struct ypresp_val yprv;
        struct ypreq_key yprk;
        int r, nerrs = 0;

        if (outval == NULL || outvallen == NULL)
                return YPERR_BADARGS;
        *outval = NULL;
        *outvallen = 0;

        if (_yp_invalid_domain(indomain))
                return YPERR_BADARGS;
        if (inmap == NULL || *inmap == '\0'
            || strlen(inmap) > YPMAXMAP)
                return YPERR_BADARGS;
        if (inkey == NULL || inkeylen == 0)
                return YPERR_BADARGS;

again:
        if (_yp_dobind(indomain, &ysd) != 0)
                return YPERR_DOMAIN;

#ifdef YPMATCHCACHE
        if (!strcmp(_yp_domain, indomain) && ypmatch_find(inmap, inkey,
                         inkeylen, &yprv.valdat.dptr, &yprv.valdat.dsize)) {
                *outvallen = yprv.valdat.dsize;
                if ((*outval = malloc((size_t)(*outvallen + 1))) == NULL)
                        return YPERR_YPERR;
                (void)memcpy(*outval, yprv.valdat.dptr, (size_t)*outvallen);
                (*outval)[*outvallen] = '\0';
                return 0;
        }
#endif

        yprk.domain = indomain;
        yprk.map = inmap;
        yprk.keydat.dptr = __UNCONST(inkey);
        yprk.keydat.dsize = inkeylen;

        memset(&yprv, 0, sizeof yprv);

        r = clnt_call(ysd->dom_client, (rpcproc_t)YPPROC_MATCH,
                      (xdrproc_t)xdr_ypreq_key, &yprk,
                      (xdrproc_t)xdr_ypresp_val, &yprv, 
                      _yplib_timeout);
        if (r != RPC_SUCCESS) {
                if (_yplib_bindtries <= 0 && ++nerrs == _yplib_nerrs) {
                        clnt_perror(ysd->dom_client, "yp_match: clnt_call");
                        nerrs = 0;
                }
                else if (_yplib_bindtries > 0 && ++nerrs == _yplib_bindtries) {
                        return YPERR_YPSERV;
                }
                ysd->dom_vers = -1;
                goto again;
        }
        if (!(r = ypprot_err(yprv.status))) {
                *outvallen = yprv.valdat.dsize;
                if ((*outval = malloc((size_t)(*outvallen + 1))) == NULL)
                        return YPERR_YPERR;
                (void)memcpy(*outval, yprv.valdat.dptr, (size_t)*outvallen);
                (*outval)[*outvallen] = '\0';
#ifdef YPMATCHCACHE
                if (strcmp(_yp_domain, indomain) == 0)
                        if (!ypmatch_add(inmap, inkey, inkeylen,
                                         *outval, *outvallen))
                                r = YPERR_RESRC;
#endif
        }
        xdr_free((xdrproc_t)xdr_ypresp_val, (char *)(void *)&yprv);
        __yp_unbind(ysd);
        if (r != 0) {
                if (*outval) {
                        free(*outval);
                        *outval = NULL;
                }
        }
        return r;
}