/*      $OpenBSD: ypmatch_cache.c,v 1.18 2022/08/02 16:59:30 deraadt Exp $ */
/*
 * Copyright (c) 1992, 1993 Theo de Raadt <deraadt@theos.com>
 * 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/types.h>
#include <stdlib.h>
#include <string.h>
#include <limits.h>
#include <rpc/rpc.h>
#include <rpc/xdr.h>
#include <rpcsvc/yp.h>
#include <rpcsvc/ypclnt.h>
#include "ypinternal.h"

#ifdef YPMATCHCACHE
static bool_t ypmatch_add(const char *, const char *, u_int, char *, u_int);
static bool_t ypmatch_find(const char *, const char *, u_int, char **, u_int *);

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

int _yplib_cache = 5;

static bool_t
ypmatch_add(const char *map, const char *key, u_int keylen, char *val,
    u_int vallen)
{
        struct ypmatch_ent *ep;
        char *newmap = NULL, *newkey = NULL, *newval = NULL;
        time_t t;

        if (keylen == 0 || vallen == 0)
                return (0);

        (void)time(&t);

        /* Allocate all required memory first. */
        if ((newmap = strdup(map)) == NULL ||
            (newkey = malloc(keylen)) == NULL ||
            (newval = malloc(vallen)) == NULL) {
                free(newkey);
                free(newmap);
                return 0;
        }

        for (ep = ypmc; ep; ep = ep->next)
                if (ep->expire_t < t)
                        break;

        if (ep == NULL) {
                /* No expired node, create a new one. */
                if ((ep = malloc(sizeof *ep)) == NULL) {
                        free(newval);
                        free(newkey);
                        free(newmap);
                        return 0;
                }
                ep->next = ypmc;
                ypmc = ep;
        } else {
                /* Reuse the first expired node from the list. */
                free(ep->val);
                free(ep->key);
                free(ep->map);
        }

        /* Now we have all the memory we need, copy the data in. */
        (void)memcpy(newkey, key, keylen);
        (void)memcpy(newval, val, vallen);
        ep->map = newmap;
        ep->key = newkey;
        ep->val = newval;
        ep->keylen = keylen;
        ep->vallen = vallen;
        ep->expire_t = t + _yplib_cache;
        return 1;
}

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

        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, 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 timeval  tv;
        struct ypreq_key yprk;
        int tries = 0, r;

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

        *outval = NULL;
        *outvallen = 0;

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

#ifdef YPMATCHCACHE
        if (!strcmp(_yp_domain, indomain) && ypmatch_find(inmap, inkey,
            inkeylen, &yprv.val.valdat_val, &yprv.val.valdat_len)) {
                *outvallen = yprv.val.valdat_len;
                if ((*outval = malloc(*outvallen + 1)) == NULL) {
                        _yp_unbind(ysd);
                        return YPERR_RESRC;
                }
                (void)memcpy(*outval, yprv.val.valdat_val, *outvallen);
                (*outval)[*outvallen] = '\0';
                _yp_unbind(ysd);
                return 0;
        }
#endif

        tv.tv_sec = _yplib_timeout;
        tv.tv_usec = 0;

        yprk.domain = (char *)indomain;
        yprk.map = (char *)inmap;
        yprk.key.keydat_val = (char *) inkey;
        yprk.key.keydat_len = inkeylen;

        memset(&yprv, 0, sizeof yprv);

        r = clnt_call(ysd->dom_client, YPPROC_MATCH,
            xdr_ypreq_key, &yprk, xdr_ypresp_val, &yprv, tv);
        if (r != RPC_SUCCESS) {
                if (tries++)
                        clnt_perror(ysd->dom_client, "yp_match: clnt_call");
                _yp_unbind(ysd);
                goto again;
        }
        if (!(r = ypprot_err(yprv.stat))) {
                *outvallen = yprv.val.valdat_len;
                if ((*outval = malloc(*outvallen + 1)) == NULL) {
                        r = YPERR_RESRC;
                        goto out;
                }
                (void)memcpy(*outval, yprv.val.valdat_val, *outvallen);
                (*outval)[*outvallen] = '\0';
#ifdef YPMATCHCACHE
                if (strcmp(_yp_domain, indomain) == 0)
                        (void)ypmatch_add(inmap, inkey, inkeylen,
                            *outval, *outvallen);
#endif
        }
out:
        xdr_free(xdr_ypresp_val, (char *) &yprv);
        _yp_unbind(ysd);
        return r;
}
DEF_WEAK(yp_match);

int
yp_next(const char *indomain, const char *inmap, const char *inkey,
    int inkeylen, char **outkey, int *outkeylen, char **outval, int *outvallen)
{
        struct ypresp_key_val yprkv;
        struct ypreq_key yprk;
        struct dom_binding *ysd;
        struct timeval  tv;
        int tries = 0, r;

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

        *outkey = *outval = NULL;
        *outkeylen = *outvallen = 0;

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

        tv.tv_sec = _yplib_timeout;
        tv.tv_usec = 0;

        yprk.domain = (char *)indomain;
        yprk.map = (char *)inmap;
        yprk.key.keydat_val = (char *)inkey;
        yprk.key.keydat_len = inkeylen;
        (void)memset(&yprkv, 0, sizeof yprkv);

        r = clnt_call(ysd->dom_client, YPPROC_NEXT,
            xdr_ypreq_key, &yprk, xdr_ypresp_key_val, &yprkv, tv);
        if (r != RPC_SUCCESS) {
                if (tries++)
                        clnt_perror(ysd->dom_client, "yp_next: clnt_call");
                _yp_unbind(ysd);
                goto again;
        }
        if (!(r = ypprot_err(yprkv.stat))) {
                *outkeylen = yprkv.key.keydat_len;
                *outvallen = yprkv.val.valdat_len;
                if ((*outkey = malloc(*outkeylen + 1)) == NULL ||
                    (*outval = malloc(*outvallen + 1)) == NULL) {
                        free(*outkey);
                        r = YPERR_RESRC;
                } else {
                        (void)memcpy(*outkey, yprkv.key.keydat_val, *outkeylen);
                        (*outkey)[*outkeylen] = '\0';
                        (void)memcpy(*outval, yprkv.val.valdat_val, *outvallen);
                        (*outval)[*outvallen] = '\0';
                }
        }
        xdr_free(xdr_ypresp_key_val, (char *) &yprkv);
        _yp_unbind(ysd);
        return r;
}
DEF_WEAK(yp_next);