/* $OpenBSD: getrrsetbyname.c,v 1.10 2005/03/30 02:58:28 tedu Exp $ */

/*
 * Copyright (c) 2007 Simon Vallet / Genoscope <svallet@genoscope.cns.fr>
 *
 * 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.
 */

/*
 * Portions Copyright (c) 1999-2001 Internet Software Consortium.
 *
 * Permission to use, copy, modify, and distribute this software for any
 * purpose with or without fee is hereby granted, provided that the above
 * copyright notice and this permission notice appear in all copies.
 *
 * THE SOFTWARE IS PROVIDED "AS IS" AND INTERNET SOFTWARE CONSORTIUM
 * DISCLAIMS ALL WARRANTIES WITH REGARD TO THIS SOFTWARE INCLUDING ALL
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL
 * INTERNET SOFTWARE CONSORTIUM BE LIABLE FOR ANY SPECIAL, DIRECT,
 * INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING
 * FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN ACTION OF CONTRACT,
 * NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION
 * WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
 */

#include "includes.h"

#if !defined (HAVE_GETRRSETBYNAME) && defined (HAVE_LDNS)

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

#include <ldns/ldns.h>

#include "getrrsetbyname.h"
#include "log.h"
#include "xmalloc.h"

#define malloc(x)       (xmalloc(x))
#define calloc(x, y)    (xcalloc((x),(y)))

int
getrrsetbyname(const char *hostname, unsigned int rdclass,
               unsigned int rdtype, unsigned int flags,
               struct rrsetinfo **res)
{
        int result;
        unsigned int i, j, index_ans, index_sig;
        struct rrsetinfo *rrset = NULL;
        struct rdatainfo *rdata;
        size_t len;
        ldns_resolver *ldns_res = NULL;
        ldns_rdf *domain = NULL;
        ldns_pkt *pkt = NULL;
        ldns_rr_list *rrsigs = NULL, *rrdata = NULL;
        ldns_status err;
        ldns_rr *rr;

        /* check for invalid class and type */
        if (rdclass > 0xffff || rdtype > 0xffff) {
                result = ERRSET_INVAL;
                goto fail;
        }

        /* don't allow queries of class or type ANY */
        if (rdclass == 0xff || rdtype == 0xff) {
                result = ERRSET_INVAL;
                goto fail;
        }

        /* don't allow flags yet, unimplemented */
        if (flags) {
                result = ERRSET_INVAL;
                goto fail;
        }

        /* Initialize resolver from resolv.conf */
        domain = ldns_dname_new_frm_str(hostname);
        if ((err = ldns_resolver_new_frm_file(&ldns_res, NULL)) != \
            LDNS_STATUS_OK) {
                result = ERRSET_FAIL;
                goto fail;
        }

#ifdef LDNS_DEBUG
        ldns_resolver_set_debug(ldns_res, true);
#endif /* LDNS_DEBUG */

        ldns_resolver_set_dnssec(ldns_res, true); /* Use DNSSEC */

        /* make query */
        pkt = ldns_resolver_query(ldns_res, domain, rdtype, rdclass, LDNS_RD);

        /*** TODO: finer errcodes -- see original **/
        if (!pkt || ldns_pkt_ancount(pkt) < 1) {
                result = ERRSET_FAIL;
                goto fail;
        }

        /* initialize rrset */
        rrset = calloc(1, sizeof(struct rrsetinfo));
        if (rrset == NULL) {
                result = ERRSET_NOMEMORY;
                goto fail;
        }

        rrdata = ldns_pkt_rr_list_by_type(pkt, rdtype, LDNS_SECTION_ANSWER);
        rrset->rri_nrdatas = ldns_rr_list_rr_count(rrdata);
        if (!rrset->rri_nrdatas) {
                result = ERRSET_NODATA;
                goto fail;
        }

        /* copy name from answer section */
        len = ldns_rdf_size(ldns_rr_owner(ldns_rr_list_rr(rrdata, 0)));
        if ((rrset->rri_name = malloc(len)) == NULL) {
                result = ERRSET_NOMEMORY;
                goto fail;
        }
        memcpy(rrset->rri_name,
            ldns_rdf_data(ldns_rr_owner(ldns_rr_list_rr(rrdata, 0))), len);

        rrset->rri_rdclass = ldns_rr_get_class(ldns_rr_list_rr(rrdata, 0));
        rrset->rri_rdtype = ldns_rr_get_type(ldns_rr_list_rr(rrdata, 0));
        rrset->rri_ttl = ldns_rr_ttl(ldns_rr_list_rr(rrdata, 0));

        debug2("ldns: got %u answers from DNS", rrset->rri_nrdatas);

        /* Check for authenticated data */
        if (ldns_pkt_ad(pkt)) {
                rrset->rri_flags |= RRSET_VALIDATED;
        } else { /* AD is not set, try autonomous validation */
                ldns_rr_list * trusted_keys = ldns_rr_list_new();

                debug2("ldns: trying to validate RRset");
                /* Get eventual sigs */
                rrsigs = ldns_pkt_rr_list_by_type(pkt, LDNS_RR_TYPE_RRSIG,
                    LDNS_SECTION_ANSWER);

                rrset->rri_nsigs = ldns_rr_list_rr_count(rrsigs);
                debug2("ldns: got %u signature(s) (RRTYPE %u) from DNS",
                       rrset->rri_nsigs, LDNS_RR_TYPE_RRSIG);

                if ((err = ldns_verify_trusted(ldns_res, rrdata, rrsigs,
                     trusted_keys)) == LDNS_STATUS_OK) {
                        rrset->rri_flags |= RRSET_VALIDATED;
                        debug2("ldns: RRset is signed with a valid key");
                } else {
                        debug2("ldns: RRset validation failed: %s",
                            ldns_get_errorstr_by_id(err));
                }

                ldns_rr_list_deep_free(trusted_keys);
        }

        /* allocate memory for answers */
        rrset->rri_rdatas = calloc(rrset->rri_nrdatas,
           sizeof(struct rdatainfo));

        if (rrset->rri_rdatas == NULL) {
                result = ERRSET_NOMEMORY;
                goto fail;
        }

        /* allocate memory for signatures */
        if (rrset->rri_nsigs > 0) {
                rrset->rri_sigs = calloc(rrset->rri_nsigs,
                    sizeof(struct rdatainfo));

                if (rrset->rri_sigs == NULL) {
                        result = ERRSET_NOMEMORY;
                        goto fail;
                }
        }

        /* copy answers & signatures */
        for (i=0, index_ans=0, index_sig=0; i< pkt->_header->_ancount; i++) {
                rdata = NULL;
                rr = ldns_rr_list_rr(ldns_pkt_answer(pkt), i);

                if (ldns_rr_get_class(rr) == rrset->rri_rdclass &&
                    ldns_rr_get_type(rr) == rrset->rri_rdtype) {
                        rdata = &rrset->rri_rdatas[index_ans++];
                }

                if (rr->_rr_class == rrset->rri_rdclass &&
                    rr->_rr_type == LDNS_RR_TYPE_RRSIG &&
                    rrset->rri_sigs) {
                        rdata = &rrset->rri_sigs[index_sig++];
                }

                if (rdata) {
                        size_t rdata_offset = 0;

                        rdata->rdi_length = 0;
                        for (j=0; j< rr->_rd_count; j++) {
                                rdata->rdi_length +=
                                    ldns_rdf_size(ldns_rr_rdf(rr, j));
                        }

                        rdata->rdi_data = malloc(rdata->rdi_length);
                        if (rdata->rdi_data == NULL) {
                                result = ERRSET_NOMEMORY;
                                goto fail;
                        }

                        /* Re-create the raw DNS RDATA */
                        for (j=0; j< rr->_rd_count; j++) {
                                len = ldns_rdf_size(ldns_rr_rdf(rr, j));
                                memcpy(rdata->rdi_data + rdata_offset,
                                       ldns_rdf_data(ldns_rr_rdf(rr, j)), len);
                                rdata_offset += len;
                        }
                }
        }

        *res = rrset;
        result = ERRSET_SUCCESS;

fail:
        /* freerrset(rrset); */
        ldns_rdf_deep_free(domain);
        ldns_pkt_free(pkt);
        ldns_rr_list_deep_free(rrsigs);
        ldns_rr_list_deep_free(rrdata);
        ldns_resolver_deep_free(ldns_res);

        return result;
}


void
freerrset(struct rrsetinfo *rrset)
{
        u_int16_t i;

        if (rrset == NULL)
                return;

        if (rrset->rri_rdatas) {
                for (i = 0; i < rrset->rri_nrdatas; i++) {
                        if (rrset->rri_rdatas[i].rdi_data == NULL)
                                break;
                        free(rrset->rri_rdatas[i].rdi_data);
                }
                free(rrset->rri_rdatas);
        }

        if (rrset->rri_sigs) {
                for (i = 0; i < rrset->rri_nsigs; i++) {
                        if (rrset->rri_sigs[i].rdi_data == NULL)
                                break;
                        free(rrset->rri_sigs[i].rdi_data);
                }
                free(rrset->rri_sigs);
        }

        if (rrset->rri_name)
                free(rrset->rri_name);
        free(rrset);
}


#endif /* !defined (HAVE_GETRRSETBYNAME) && defined (HAVE_LDNS) */