lib/dns/rdata.c

	rdata.c revision bfb2a81b65579882a80855c279cedc45aebd62e8
/*
 * Copyright (C) 1998  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 <isc/buffer.h>
#include <isc/lex.h>
#include <dns/types.h>
#include <dns/result.h>
#include <dns/rdata.h>
#include <dns/region.h>
#include <stdio.h>
#include <isc/assertions.h>

static dns_result_t txt_totext(isc_region_t *source, isc_buffer_t *target);
static dns_result_t txt_fromtext(isc_textregion_t *source,
                     isc_buffer_t *target);
static dns_result_t txt_fromwire(isc_buffer_t *source,
                    isc_buffer_t *target);
static isc_boolean_t    name_prefix(dns_name_t *name, dns_name_t *origin,
                    dns_name_t *target);
static unsigned int     name_length(dns_name_t *name);
static dns_result_t str_totext(char *source, isc_buffer_t *target);
static isc_boolean_t    buffer_empty(isc_buffer_t *source);
static void     buffer_fromregion(isc_buffer_t *buffer,
                      isc_region_t *region,
                      unsigned int type);
static isc_result_t uint32_fromtext(unsigned long value,
                    isc_buffer_t *target);
static isc_result_t uint16_fromtext(unsigned long value,
                    isc_buffer_t *target);
static unsigned long    uint32_fromregion(isc_region_t *region);
static unsigned short   uint16_fromregion(isc_region_t *region);

#include "code.h"

/***
 *** Initialization
 ***/

void
dns_rdata_init(dns_rdata_t *rdata) {

    REQUIRE(rdata != NULL);

    rdata->data = NULL;
    rdata->length = 0;
    rdata->class = 0;
    rdata->type = 0;
    ISC_LINK_INIT(rdata, link);
    /* ISC_LIST_INIT(rdata->list); */
}

/***
 *** Comparisons
 ***/

int
dns_rdata_compare(dns_rdata_t *rdata1, dns_rdata_t *rdata2) {
    int result;
    int l;

    REQUIRE(rdata1 != NULL);
    REQUIRE(rdata2 != NULL);
    REQUIRE(rdata1->data != NULL);
    REQUIRE(rdata2->data != NULL);

    if (rdata1->class != rdata2->class)
        return (rdata1->class < rdata2->class ? -1 : 1);

    if (rdata1->type != rdata2->type)
        return (rdata1->type < rdata2->type ? -1 : 1);

    COMPARESWITCH

    if (result == -2) {
        l = (rdata1->length > rdata2->length) ?
            rdata1->length : rdata2->length;
        if ((result = memcmp(rdata1->data, rdata2->data, l)) == 0)
            result = (result < 0) ? -1 : 1;
        else
            result = (rdata1->length < rdata2->length) ? -1 : 1;
    }
    return (result);
}

/***
 *** Conversions
 ***/

void
dns_rdata_fromregion(dns_rdata_t *rdata,
              dns_rdataclass_t class, dns_rdatatype_t type,
              isc_region_t *r) {

    rdata->data = r->base;
    rdata->length = r->length;
    rdata->class = class;
    rdata->type = type;
}

void
dns_rdata_toregion(dns_rdata_t *rdata, isc_region_t *r) {

    r->base = rdata->data;
    r->length = rdata->length;
}

dns_result_t
dns_rdata_fromwire(dns_rdata_t *rdata,
           dns_rdataclass_t class, dns_rdatatype_t type,
           isc_buffer_t *source,
           dns_decompress_t *dctx,
           isc_boolean_t downcase,
           isc_buffer_t *target) {
    dns_result_t result;
    isc_region_t region;
    isc_buffer_t ss;
    isc_buffer_t st;

    ss = *source;
    st = *target;
    region.base = target->base + target->used;

    FROMWIRESWITCH

    if (result == DNS_R_DEFAULT)
        result = DNS_R_NOTIMPLEMENTED;

    /* We should have consumed all out buffer */
    if (!buffer_empty(source))
        result = DNS_R_WIRE;

    if (rdata && result == DNS_R_SUCCESS) {
        region.length = target->used - st.used;
        dns_rdata_fromregion(rdata, class, type, &region);
    }

    if (result != DNS_R_SUCCESS) {
        *source = ss;
        *target = st;
    }
    return (result);
}

dns_result_t
dns_rdata_towire(dns_rdata_t *rdata, dns_compress_t *cctx,
             isc_buffer_t *target) {
    dns_result_t result;

    TOWIRESWITCH

    if (result == DNS_R_DEFAULT) {
        if (target->length < rdata->length)
            return (DNS_R_NOSPACE);
        memcpy(target->base, rdata->data, rdata->length);
        target->length = rdata->length;
        return (DNS_R_SUCCESS);
    }
    return (result);
}

dns_result_t
dns_rdata_fromtext(dns_rdata_t *rdata,
           dns_rdataclass_t class, dns_rdatatype_t type,
           isc_lex_t *lexer, dns_name_t *origin,
           isc_boolean_t downcase,
           isc_buffer_t *target) {
    dns_result_t result;
    isc_region_t region;
    isc_buffer_t st;

    st = *target;
    region.base = target->base + target->used;

    FROMTEXTSWITCH

    if (result == DNS_R_DEFAULT)
        result = DNS_R_NOTIMPLEMENTED;

    if (rdata != NULL && result == DNS_R_SUCCESS) {
        region.length = target->used - st.used;
        dns_rdata_fromregion(rdata, class, type, &region);
    }
    if (result != DNS_R_SUCCESS) {
        *target = st;
    }
    return (result);
}

dns_result_t
dns_rdata_totext(dns_rdata_t *rdata, isc_buffer_t *target) {
    dns_result_t result;
    dns_name_t *origin = NULL;

    TOTEXTSWITCH

    if (result == DNS_R_DEFAULT)
        result = DNS_R_NOTIMPLEMENTED;
    return (result);
}

dns_result_t
dns_rdata_fromstruct(dns_rdata_t *rdata,
             dns_rdataclass_t class, dns_rdatatype_t type,
             void *source,
             isc_buffer_t *target) {
    dns_result_t result;
    isc_buffer_t st;
    isc_region_t region;

    region.base = target->base + target->used;
    st = *target;

    FROMSTRUCTSWITCH

    if (result == DNS_R_DEFAULT)
        result = DNS_R_NOTIMPLEMENTED;

    if (rdata != NULL && result == DNS_R_SUCCESS) {
        region.length = target->used - st.used;
        dns_rdata_fromregion(rdata, class, type, &region);
    }
    if (result != DNS_R_SUCCESS)
        *target = st;
    return (result);
}

dns_result_t
dns_rdata_tostruct(dns_rdata_t *rdata, void *target) {
    dns_result_t result;

    TOSTRUCTSWITCH

    if (result == DNS_R_DEFAULT)
        result = DNS_R_NOTIMPLEMENTED;
    return (result);
}

static unsigned int
name_length(dns_name_t *name) {
    return (name->length);
}

static dns_result_t
txt_totext(isc_region_t *source, isc_buffer_t *target) {
    unsigned int tl;
    unsigned int n;
    unsigned char *sp;
    unsigned char *tp;
    isc_region_t region;

    isc_buffer_available(target, &region);
    sp = source->base;
    tp = region.base;
    tl = region.length;

    n = *sp++;

    INSIST(n + 1 <= source->length);

    if (tl < 1)
        return (DNS_R_NOSPACE);
    *tp++ = '"';
    tl--;
    while (n--) {
        if (*sp < 0x20 || *sp > 0x7f) {
            if (tl < 4)
                return (DNS_R_NOSPACE);
            sprintf(tp, "\\%03u", *sp++);
            tp += 4;
            tl -= 4;
            continue;
        }
        if (*sp == 0x22 || *sp == 0x3b || *sp == 0x5c) {
            if (tl < 2)
                return (DNS_R_NOSPACE);
            *tp++ = '\\';
            tl--;
        }
        if (tl < 1)
            return (DNS_R_NOSPACE);
        *tp++ = *sp++;
        tl--;
    }
    if (tl < 1)
        return (DNS_R_NOSPACE);
    *tp++ = '"';
    tl--;
    isc_buffer_add(target, tp - region.base);
    isc_region_consume(source, *source->base + 1);
    return (DNS_R_SUCCESS);
}

static dns_result_t
txt_fromtext(isc_textregion_t *source, isc_buffer_t *target) {
    isc_region_t tregion;

    isc_buffer_available(target, &tregion);
    if (tregion.length < source->length + 1)
        return (DNS_R_NOSPACE);
    if (source->length > 255)
        return (DNS_R_UNKNOWN);
    *tregion.base = source->length;
    memcpy(tregion.base + 1, source->base, source->length);
    isc_buffer_add(target, source->length + 1);
    return (DNS_R_SUCCESS);
}

static dns_result_t
txt_fromwire(isc_buffer_t *source, isc_buffer_t *target) {
    unsigned int n;
    isc_region_t sregion;
    isc_region_t tregion;

    isc_buffer_remaining(source, &sregion);
    n = *sregion.base + 1;
    if (n > sregion.length)
        return (DNS_R_UNKNOWN);

    isc_buffer_available(target, &tregion);
    if (n > tregion.length)
        return (DNS_R_NOSPACE);

    memcpy(tregion.base, sregion.base, n);
    isc_buffer_forward(source, n);
    isc_buffer_add(target, n);
    return (DNS_R_SUCCESS);
}

static isc_boolean_t
name_prefix(dns_name_t *name, dns_name_t *origin, dns_name_t *target) {
    int l1, l2;

    if (origin == NULL)
        goto return_false;

    if (dns_name_compare(origin, dns_rootname) == 0)
        goto return_false;

    if (!dns_name_issubdomain(name, origin))
        goto return_false;

    l1 = dns_name_countlabels(name);
    l2 = dns_name_countlabels(origin);

    if (l1 == l2)
        goto return_false;

    dns_name_getlabelsequence(name, 0, l1 - l2, target);
    return (ISC_TRUE);

return_false:
    *target = *name;
    return (ISC_FALSE);
}

static dns_result_t
str_totext(char *source, isc_buffer_t *target) {
    unsigned int l;
    isc_region_t region;

    isc_buffer_available(target, &region);
    l = strlen(source);

    if (l > region.length)
        return (DNS_R_NOSPACE);

    memcpy(region.base, source, l);
    isc_buffer_add(target, l);
    return (DNS_R_SUCCESS);
}

static isc_boolean_t
buffer_empty(isc_buffer_t *source) {
    return((source->current == source->used) ? ISC_TRUE : ISC_FALSE);
}

static void
buffer_fromregion(isc_buffer_t *buffer, isc_region_t *region,
          unsigned int type) {

    isc_buffer_init(buffer, region->base, region->length, type);
    isc_buffer_add(buffer, region->length);
}

static isc_result_t
uint32_fromtext(unsigned long value, isc_buffer_t *target) {
    isc_region_t region;

    isc_buffer_available(target, &region);
    if (region.length < 4)
        return (DNS_R_NOSPACE);
    region.base[0] = (value >> 24) & 0xff;
    region.base[1] = (value >> 16) & 0xff;
    region.base[2] = (value >> 8) & 0xff;
    region.base[3] = value & 0xff;
    isc_buffer_add(target, 4);
    return (DNS_R_SUCCESS);
}

static isc_result_t
uint16_fromtext(unsigned long value, isc_buffer_t *target) {
    isc_region_t region;

    isc_buffer_available(target, &region);
    if (region.length < 2)
        return (DNS_R_NOSPACE);
    region.base[0] = (value >> 8) & 0xff;
    region.base[1] = value & 0xff;
    isc_buffer_add(target, 2);
    return (DNS_R_SUCCESS);
}

static unsigned long
uint32_fromregion(isc_region_t *region) {
    unsigned long value;

    INSIST(region->length >= 4);
    value = region->base[0] << 24;
    value |= region->base[1] << 16;
    value |= region->base[2] << 8;
    value |= region->base[3];
    return(value);
}

static unsigned short
uint16_fromregion(isc_region_t *region) {

    INSIST(region->length >= 2);

    return ((region->base[0] << 8) | region->base[1]);
}