nsec_47.c

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/*
 * Copyright (C) 2004, 2007-2009, 2011  Internet Systems Consortium, Inc. ("ISC")
 * Copyright (C) 2003  Internet Software Consortium.
 *
 * Permission to use, copy, modify, and/or 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 ISC DISCLAIMS ALL WARRANTIES WITH
 * REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY
 * AND FITNESS.  IN NO EVENT SHALL ISC 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.
 */

/* $Id: nsec_47.c,v 1.15 2011/01/13 04:59:26 tbox Exp $ */

/* reviewed: Wed Mar 15 18:21:15 PST 2000 by brister */

/* RFC 3845 */

#ifndef RDATA_GENERIC_NSEC_47_C
#define RDATA_GENERIC_NSEC_47_C

/*
 * The attributes do not include DNS_RDATATYPEATTR_SINGLETON
 * because we must be able to handle a parent/child NSEC pair.
 */
#define RRTYPE_NSEC_ATTRIBUTES (DNS_RDATATYPEATTR_DNSSEC)

static inline isc_result_t
fromtext_nsec(ARGS_FROMTEXT) {
        isc_token_t token;
        dns_name_t name;
        isc_buffer_t buffer;
        unsigned char bm[8*1024]; /* 64k bits */
        dns_rdatatype_t covered;
        int octet;
        int window;

        REQUIRE(type == 47);

        UNUSED(type);
        UNUSED(rdclass);
        UNUSED(callbacks);

        /*
         * Next domain.
         */
        RETERR(isc_lex_getmastertoken(lexer, &token, isc_tokentype_string,
                                      ISC_FALSE));
        dns_name_init(&name, NULL);
        buffer_fromregion(&buffer, &token.value.as_region);
        origin = (origin != NULL) ? origin : dns_rootname;
        RETTOK(dns_name_fromtext(&name, &buffer, origin, options, target));

        memset(bm, 0, sizeof(bm));
        do {
                RETERR(isc_lex_getmastertoken(lexer, &token,
                                              isc_tokentype_string, ISC_TRUE));
                if (token.type != isc_tokentype_string)
                        break;
                RETTOK(dns_rdatatype_fromtext(&covered,
                                              &token.value.as_textregion));
                bm[covered/8] |= (0x80>>(covered%8));
        } while (1);
        isc_lex_ungettoken(lexer, &token);
        for (window = 0; window < 256 ; window++) {
                /*
                 * Find if we have a type in this window.
                 */
                for (octet = 31; octet >= 0; octet--)
                        if (bm[window * 32 + octet] != 0)
                                break;
                if (octet < 0)
                        continue;
                RETERR(uint8_tobuffer(window, target));
                RETERR(uint8_tobuffer(octet + 1, target));
                RETERR(mem_tobuffer(target, &bm[window * 32], octet + 1));
        }
        return (ISC_R_SUCCESS);
}

static inline isc_result_t
totext_nsec(ARGS_TOTEXT) {
        isc_region_t sr;
        unsigned int i, j, k;
        dns_name_t name;
        unsigned int window, len;

        REQUIRE(rdata->type == 47);
        REQUIRE(rdata->length != 0);

        UNUSED(tctx);

        dns_name_init(&name, NULL);
        dns_rdata_toregion(rdata, &sr);
        dns_name_fromregion(&name, &sr);
        isc_region_consume(&sr, name_length(&name));
        RETERR(dns_name_totext(&name, ISC_FALSE, target));


        for (i = 0; i < sr.length; i += len) {
                INSIST(i + 2 <= sr.length);
                window = sr.base[i];
                len = sr.base[i + 1];
                INSIST(len > 0 && len <= 32);
                i += 2;
                INSIST(i + len <= sr.length);
                for (j = 0; j < len; j++) {
                        dns_rdatatype_t t;
                        if (sr.base[i + j] == 0)
                                continue;
                        for (k = 0; k < 8; k++) {
                                if ((sr.base[i + j] & (0x80 >> k)) == 0)
                                        continue;
                                t = window * 256 + j * 8 + k;
                                RETERR(str_totext(" ", target));
                                if (dns_rdatatype_isknown(t)) {
                                        RETERR(dns_rdatatype_totext(t, target));
                                } else {
                                        char buf[sizeof("TYPE65535")];
                                        sprintf(buf, "TYPE%u", t);
                                        RETERR(str_totext(buf, target));
                                }
                        }
                }
        }
        return (ISC_R_SUCCESS);
}

static /* inline */ isc_result_t
fromwire_nsec(ARGS_FROMWIRE) {
        isc_region_t sr;
        dns_name_t name;
        unsigned int window, lastwindow = 0;
        unsigned int len;
        isc_boolean_t first = ISC_TRUE;
        unsigned int i;

        REQUIRE(type == 47);

        UNUSED(type);
        UNUSED(rdclass);

        dns_decompress_setmethods(dctx, DNS_COMPRESS_NONE);

        dns_name_init(&name, NULL);
        RETERR(dns_name_fromwire(&name, source, dctx, options, target));

        isc_buffer_activeregion(source, &sr);
        for (i = 0; i < sr.length; i += len) {
                /*
                 * Check for overflow.
                 */
                if (i + 2 > sr.length)
                        RETERR(DNS_R_FORMERR);
                window = sr.base[i];
                len = sr.base[i + 1];
                i += 2;
                /*
                 * Check that bitmap windows are in the correct order.
                 */
                if (!first && window <= lastwindow)
                        RETERR(DNS_R_FORMERR);
                /*
                 * Check for legal lengths.
                 */
                if (len < 1 || len > 32)
                        RETERR(DNS_R_FORMERR);
                /*
                 * Check for overflow.
                 */
                if (i + len > sr.length)
                        RETERR(DNS_R_FORMERR);
                /*
                 * The last octet of the bitmap must be non zero.
                 */
                if (sr.base[i + len - 1] == 0)
                        RETERR(DNS_R_FORMERR);
                lastwindow = window;
                first = ISC_FALSE;
        }
        if (i != sr.length)
                return (DNS_R_EXTRADATA);
        if (first)
                RETERR(DNS_R_FORMERR);
        RETERR(mem_tobuffer(target, sr.base, sr.length));
        isc_buffer_forward(source, sr.length);
        return (ISC_R_SUCCESS);
}

static inline isc_result_t
towire_nsec(ARGS_TOWIRE) {
        isc_region_t sr;
        dns_name_t name;
        dns_offsets_t offsets;

        REQUIRE(rdata->type == 47);
        REQUIRE(rdata->length != 0);

        dns_compress_setmethods(cctx, DNS_COMPRESS_NONE);
        dns_name_init(&name, offsets);
        dns_rdata_toregion(rdata, &sr);
        dns_name_fromregion(&name, &sr);
        isc_region_consume(&sr, name_length(&name));
        RETERR(dns_name_towire(&name, cctx, target));

        return (mem_tobuffer(target, sr.base, sr.length));
}

static inline int
compare_nsec(ARGS_COMPARE) {
        isc_region_t r1;
        isc_region_t r2;

        REQUIRE(rdata1->type == rdata2->type);
        REQUIRE(rdata1->rdclass == rdata2->rdclass);
        REQUIRE(rdata1->type == 47);
        REQUIRE(rdata1->length != 0);
        REQUIRE(rdata2->length != 0);

        dns_rdata_toregion(rdata1, &r1);
        dns_rdata_toregion(rdata2, &r2);
        return (isc_region_compare(&r1, &r2));
}

static inline isc_result_t
fromstruct_nsec(ARGS_FROMSTRUCT) {
        dns_rdata_nsec_t *nsec = source;
        isc_region_t region;
        unsigned int i, len, window, lastwindow = 0;
        isc_boolean_t first = ISC_TRUE;

        REQUIRE(type == 47);
        REQUIRE(source != NULL);
        REQUIRE(nsec->common.rdtype == type);
        REQUIRE(nsec->common.rdclass == rdclass);
        REQUIRE(nsec->typebits != NULL || nsec->len == 0);

        UNUSED(type);
        UNUSED(rdclass);

        dns_name_toregion(&nsec->next, &region);
        RETERR(isc_buffer_copyregion(target, &region));
        /*
         * Perform sanity check.
         */
        for (i = 0; i < nsec->len ; i += len) {
                INSIST(i + 2 <= nsec->len);
                window = nsec->typebits[i];
                len = nsec->typebits[i+1];
                i += 2;
                INSIST(first || window > lastwindow);
                INSIST(len > 0 && len <= 32);
                INSIST(i + len <= nsec->len);
                INSIST(nsec->typebits[i + len - 1] != 0);
                lastwindow = window;
                first = ISC_FALSE;
        }
        INSIST(!first);
        return (mem_tobuffer(target, nsec->typebits, nsec->len));
}

static inline isc_result_t
tostruct_nsec(ARGS_TOSTRUCT) {
        isc_region_t region;
        dns_rdata_nsec_t *nsec = target;
        dns_name_t name;

        REQUIRE(rdata->type == 47);
        REQUIRE(target != NULL);
        REQUIRE(rdata->length != 0);

        nsec->common.rdclass = rdata->rdclass;
        nsec->common.rdtype = rdata->type;
        ISC_LINK_INIT(&nsec->common, link);

        dns_name_init(&name, NULL);
        dns_rdata_toregion(rdata, &region);
        dns_name_fromregion(&name, &region);
        isc_region_consume(&region, name_length(&name));
        dns_name_init(&nsec->next, NULL);
        RETERR(name_duporclone(&name, mctx, &nsec->next));

        nsec->len = region.length;
        nsec->typebits = mem_maybedup(mctx, region.base, region.length);
        if (nsec->typebits == NULL)
                goto cleanup;

        nsec->mctx = mctx;
        return (ISC_R_SUCCESS);

 cleanup:
        if (mctx != NULL)
                dns_name_free(&nsec->next, mctx);
        return (ISC_R_NOMEMORY);
}

static inline void
freestruct_nsec(ARGS_FREESTRUCT) {
        dns_rdata_nsec_t *nsec = source;

        REQUIRE(source != NULL);
        REQUIRE(nsec->common.rdtype == 47);

        if (nsec->mctx == NULL)
                return;

        dns_name_free(&nsec->next, nsec->mctx);
        if (nsec->typebits != NULL)
                isc_mem_free(nsec->mctx, nsec->typebits);
        nsec->mctx = NULL;
}

static inline isc_result_t
additionaldata_nsec(ARGS_ADDLDATA) {
        REQUIRE(rdata->type == 47);

        UNUSED(rdata);
        UNUSED(add);
        UNUSED(arg);

        return (ISC_R_SUCCESS);
}

static inline isc_result_t
digest_nsec(ARGS_DIGEST) {
        isc_region_t r;

        REQUIRE(rdata->type == 47);

        dns_rdata_toregion(rdata, &r);
        return ((digest)(arg, &r));
}

static inline isc_boolean_t
checkowner_nsec(ARGS_CHECKOWNER) {

       REQUIRE(type == 47);

       UNUSED(name);
       UNUSED(type);
       UNUSED(rdclass);
       UNUSED(wildcard);

       return (ISC_TRUE);
}

static inline isc_boolean_t
checknames_nsec(ARGS_CHECKNAMES) {

        REQUIRE(rdata->type == 47);

        UNUSED(rdata);
        UNUSED(owner);
        UNUSED(bad);

        return (ISC_TRUE);
}

static inline int
casecompare_nsec(ARGS_COMPARE) {
        isc_region_t region1;
        isc_region_t region2;
        dns_name_t name1;
        dns_name_t name2;
        int order;

        REQUIRE(rdata1->type == rdata2->type);
        REQUIRE(rdata1->rdclass == rdata2->rdclass);
        REQUIRE(rdata1->type == 47);
        REQUIRE(rdata1->length != 0);
        REQUIRE(rdata2->length != 0);

        dns_name_init(&name1, NULL);
        dns_name_init(&name2, NULL);

        dns_rdata_toregion(rdata1, &region1);
        dns_rdata_toregion(rdata2, &region2);

        dns_name_fromregion(&name1, &region1);
        dns_name_fromregion(&name2, &region2);

        order = dns_name_rdatacompare(&name1, &name2);
        if (order != 0)
                return (order);

        isc_region_consume(&region1, name_length(&name1));
        isc_region_consume(&region2, name_length(&name2));

        return (isc_region_compare(&region1, &region2));
}
#endif  /* RDATA_GENERIC_NSEC_47_C */

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