/* Copyright 1999-2007 The Apache Software Foundation or its licensors, as
 * applicable.
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

/*
 * Original Copyright (c) Netmask.IT!® 2006-2007
 *
 * DNS Protocol module for Apache 2.x
 */

#include "../rr.h"

static DNS_RDATA_UNSERIALIZE(mx) {
    const char *ptr = data;
    char label[63] = ""; /** RFC 1035 says label can only be 63 octets long */
    apr_byte_t len;
    dns_rdata_t *rrdata;
    
    dns_rdata_mx_t *mx = apr_pcalloc(pool, sizeof(*mx));
    *rdata = rrdata = apr_pcalloc(pool, sizeof(*rrdata));
    dns_init_rdata_const(mx, rrdata);
    rrdata->rdata = mx;

    /** Grab preference */
    memcpy(&(mx->preference), data, sizeof(apr_uint16_t));
    data+=sizeof(apr_uint16_t);
    /** initialize exchange */
    mx->exchange = apr_pstrdup(pool, "");
    
    memcpy(&len, ptr, 1);
    while (len > 0) {
        ptr++;
        apr_cpystrn(label, ptr, len + 1);
        ptr += len;
        mx->exchange = apr_pstrcat(pool, mx->exchange, label, ".", NULL);
        memcpy(&len, ptr, 1);
    }

    return APR_SUCCESS;
}

static DNS_RDATA_SERIALIZE(mx) {
    dns_rdata_mx_t *mx;
    apr_byte_t llen;
    char *ptr, *label, *last = NULL;
    mx = (dns_rdata_mx_t *)rdata;

    /** The length byte takes the same space as a char, so we just need 
     *  strlen(cname) of space (cname should have trailing .) and room 
     * for the first length byte (other length bytes replace "." characters) */

    *dlen = sizeof(apr_uint16_t) + strlen(mx->exchange) + 1;
    if (mx->exchange[*dlen-2] != '.')
        (*dlen)++;

    if (data == NULL)
        return APR_SUCCESS;

    mx = (dns_rdata_mx_t *)rdata;
    memcpy(data, (const void *)&(mx->preference), sizeof(apr_uint16_t));

    /** Point to beginning of data */
    ptr = data;
    label = apr_strtok(mx->exchange, ".", &last);
    while (label != NULL) {
        llen = strlen(label);
        if (llen == 0) {
            /** Trailing . - Set NULL and break */
            *ptr = 0;
            ptr++;
            break;
        }
        /** Write length token */
        *ptr = llen;
        ptr++;
        /** Write label */
        memcpy(ptr, label, llen);
        /** Move pointer */
        ptr+=llen;
        /** Advance to next token */
        label = apr_strtok(NULL, ".", &last);
    }
    *ptr = 0;
    ptr++;
    return APR_SUCCESS;
}

static DNS_RDATA_PSERIALIZE(mx)

DNS_RDATA_IMPLEMENT(mx);