Ejemplo n.º 1
0
static isc_result_t
add_rdata_to_list(dns_message_t *msg, dns_name_t *name, dns_rdata_t *rdata,
		isc_uint32_t ttl, dns_namelist_t *namelist)
{
	isc_result_t result;
	isc_region_t r, newr;
	dns_rdata_t *newrdata = NULL;
	dns_name_t *newname = NULL;
	dns_rdatalist_t *newlist = NULL;
	dns_rdataset_t *newset = NULL;
	isc_buffer_t *tmprdatabuf = NULL;

	RETERR(dns_message_gettemprdata(msg, &newrdata));

	dns_rdata_toregion(rdata, &r);
	RETERR(isc_buffer_allocate(msg->mctx, &tmprdatabuf, r.length));
	isc_buffer_availableregion(tmprdatabuf, &newr);
	memcpy(newr.base, r.base, r.length);
	dns_rdata_fromregion(newrdata, rdata->rdclass, rdata->type, &newr);
	dns_message_takebuffer(msg, &tmprdatabuf);

	RETERR(dns_message_gettempname(msg, &newname));
	dns_name_init(newname, NULL);
	RETERR(dns_name_dup(name, msg->mctx, newname));

	RETERR(dns_message_gettemprdatalist(msg, &newlist));
	newlist->rdclass = newrdata->rdclass;
	newlist->type = newrdata->type;
	newlist->covers = 0;
	newlist->ttl = ttl;
	ISC_LIST_INIT(newlist->rdata);
	ISC_LIST_APPEND(newlist->rdata, newrdata, link);

	RETERR(dns_message_gettemprdataset(msg, &newset));
	dns_rdataset_init(newset);
	RETERR(dns_rdatalist_tordataset(newlist, newset));

	ISC_LIST_INIT(newname->list);
	ISC_LIST_APPEND(newname->list, newset, link);

	ISC_LIST_APPEND(*namelist, newname, link);

	return (ISC_R_SUCCESS);

 failure:
	if (newrdata != NULL) {
		if (ISC_LINK_LINKED(newrdata, link))
			ISC_LIST_UNLINK(newlist->rdata, newrdata, link);
		dns_message_puttemprdata(msg, &newrdata);
	}
	if (newname != NULL)
		dns_message_puttempname(msg, &newname);
	if (newset != NULL) {
		dns_rdataset_disassociate(newset);
		dns_message_puttemprdataset(msg, &newset);
	}
	if (newlist != NULL)
		dns_message_puttemprdatalist(msg, &newlist);
	return (result);
}
Ejemplo n.º 2
0
/*
 * Arrange to send as much as we can of "stream" without blocking.
 *
 * Requires:
 *	The stream iterator is initialized and points at an RR,
 *      or possibly at the end of the stream (that is, the
 *      _first method of the iterator has been called).
 */
static void
sendstream(xfrout_ctx_t *xfr) {
	dns_message_t *tcpmsg = NULL;
	dns_message_t *msg = NULL; /* Client message if UDP, tcpmsg if TCP */
	isc_result_t result;
	isc_region_t used;
	isc_region_t region;
	dns_rdataset_t *qrdataset;
	dns_name_t *msgname = NULL;
	dns_rdata_t *msgrdata = NULL;
	dns_rdatalist_t *msgrdl = NULL;
	dns_rdataset_t *msgrds = NULL;
	dns_compress_t cctx;
	isc_boolean_t cleanup_cctx = ISC_FALSE;
	isc_boolean_t is_tcp;

	int n_rrs;

	isc_buffer_clear(&xfr->buf);
	isc_buffer_clear(&xfr->txlenbuf);
	isc_buffer_clear(&xfr->txbuf);

	is_tcp = ISC_TF((xfr->client->attributes & NS_CLIENTATTR_TCP) != 0);
	if (!is_tcp) {
		/*
		 * In the UDP case, we put the response data directly into
		 * the client message.
		 */
		msg = xfr->client->message;
		CHECK(dns_message_reply(msg, ISC_TRUE));
	} else {
		/*
		 * TCP. Build a response dns_message_t, temporarily storing
		 * the raw, uncompressed owner names and RR data contiguously
		 * in xfr->buf.  We know that if the uncompressed data fits
		 * in xfr->buf, the compressed data will surely fit in a TCP
		 * message.
		 */

		CHECK(dns_message_create(xfr->mctx,
					 DNS_MESSAGE_INTENTRENDER, &tcpmsg));
		msg = tcpmsg;

		msg->id = xfr->id;
		msg->rcode = dns_rcode_noerror;
		msg->flags = DNS_MESSAGEFLAG_QR | DNS_MESSAGEFLAG_AA;
		if ((xfr->client->attributes & NS_CLIENTATTR_RA) != 0)
			msg->flags |= DNS_MESSAGEFLAG_RA;
		CHECK(dns_message_settsigkey(msg, xfr->tsigkey));
		CHECK(dns_message_setquerytsig(msg, xfr->lasttsig));
		if (xfr->lasttsig != NULL)
			isc_buffer_free(&xfr->lasttsig);

		/*
		 * Add a EDNS option to the message?
		 */
		if ((xfr->client->attributes & NS_CLIENTATTR_WANTOPT) != 0) {
			dns_rdataset_t *opt = NULL;

			CHECK(ns_client_addopt(xfr->client, msg, &opt));
			CHECK(dns_message_setopt(msg, opt));
			/*
			 * Add to first message only.
			 */
			xfr->client->attributes &= ~NS_CLIENTATTR_WANTNSID;
			xfr->client->attributes &= ~NS_CLIENTATTR_HAVEEXPIRE;
		}

		/*
		 * Account for reserved space.
		 */
		if (xfr->tsigkey != NULL)
			INSIST(msg->reserved != 0U);
		isc_buffer_add(&xfr->buf, msg->reserved);

		/*
		 * Include a question section in the first message only.
		 * BIND 8.2.1 will not recognize an IXFR if it does not
		 * have a question section.
		 */
		if (xfr->nmsg == 0) {
			dns_name_t *qname = NULL;
			isc_region_t r;

			/*
			 * Reserve space for the 12-byte message header
			 * and 4 bytes of question.
			 */
			isc_buffer_add(&xfr->buf, 12 + 4);

			qrdataset = NULL;
			result = dns_message_gettemprdataset(msg, &qrdataset);
			if (result != ISC_R_SUCCESS)
				goto failure;
			dns_rdataset_makequestion(qrdataset,
					xfr->client->message->rdclass,
					xfr->qtype);

			result = dns_message_gettempname(msg, &qname);
			if (result != ISC_R_SUCCESS)
				goto failure;
			dns_name_init(qname, NULL);
			isc_buffer_availableregion(&xfr->buf, &r);
			INSIST(r.length >= xfr->qname->length);
			r.length = xfr->qname->length;
			isc_buffer_putmem(&xfr->buf, xfr->qname->ndata,
					  xfr->qname->length);
			dns_name_fromregion(qname, &r);
			ISC_LIST_INIT(qname->list);
			ISC_LIST_APPEND(qname->list, qrdataset, link);

			dns_message_addname(msg, qname, DNS_SECTION_QUESTION);
		} else {
			/*
			 * Reserve space for the 12-byte message header
			 */
			isc_buffer_add(&xfr->buf, 12);
			msg->tcp_continuation = 1;
		}
	}

	/*
	 * Try to fit in as many RRs as possible, unless "one-answer"
	 * format has been requested.
	 */
	for (n_rrs = 0; ; n_rrs++) {
		dns_name_t *name = NULL;
		isc_uint32_t ttl;
		dns_rdata_t *rdata = NULL;

		unsigned int size;
		isc_region_t r;

		msgname = NULL;
		msgrdata = NULL;
		msgrdl = NULL;
		msgrds = NULL;

		xfr->stream->methods->current(xfr->stream,
					      &name, &ttl, &rdata);
		size = name->length + 10 + rdata->length;
		isc_buffer_availableregion(&xfr->buf, &r);
		if (size >= r.length) {
			/*
			 * RR would not fit.  If there are other RRs in the
			 * buffer, send them now and leave this RR to the
			 * next message.  If this RR overflows the buffer
			 * all by itself, fail.
			 *
			 * In theory some RRs might fit in a TCP message
			 * when compressed even if they do not fit when
			 * uncompressed, but surely we don't want
			 * to send such monstrosities to an unsuspecting
			 * slave.
			 */
			if (n_rrs == 0) {
				xfrout_log(xfr, ISC_LOG_WARNING,
					   "RR too large for zone transfer "
					   "(%d bytes)", size);
				/* XXX DNS_R_RRTOOLARGE? */
				result = ISC_R_NOSPACE;
				goto failure;
			}
			break;
		}

		if (isc_log_wouldlog(ns_g_lctx, XFROUT_RR_LOGLEVEL))
			log_rr(name, rdata, ttl); /* XXX */

		result = dns_message_gettempname(msg, &msgname);
		if (result != ISC_R_SUCCESS)
			goto failure;
		dns_name_init(msgname, NULL);
		isc_buffer_availableregion(&xfr->buf, &r);
		INSIST(r.length >= name->length);
		r.length = name->length;
		isc_buffer_putmem(&xfr->buf, name->ndata, name->length);
		dns_name_fromregion(msgname, &r);

		/* Reserve space for RR header. */
		isc_buffer_add(&xfr->buf, 10);

		result = dns_message_gettemprdata(msg, &msgrdata);
		if (result != ISC_R_SUCCESS)
			goto failure;
		isc_buffer_availableregion(&xfr->buf, &r);
		r.length = rdata->length;
		isc_buffer_putmem(&xfr->buf, rdata->data, rdata->length);
		dns_rdata_init(msgrdata);
		dns_rdata_fromregion(msgrdata,
				     rdata->rdclass, rdata->type, &r);

		result = dns_message_gettemprdatalist(msg, &msgrdl);
		if (result != ISC_R_SUCCESS)
			goto failure;
		msgrdl->type = rdata->type;
		msgrdl->rdclass = rdata->rdclass;
		msgrdl->ttl = ttl;
		if (rdata->type == dns_rdatatype_sig ||
		    rdata->type == dns_rdatatype_rrsig)
			msgrdl->covers = dns_rdata_covers(rdata);
		else
			msgrdl->covers = dns_rdatatype_none;
		ISC_LIST_APPEND(msgrdl->rdata, msgrdata, link);

		result = dns_message_gettemprdataset(msg, &msgrds);
		if (result != ISC_R_SUCCESS)
			goto failure;
		result = dns_rdatalist_tordataset(msgrdl, msgrds);
		INSIST(result == ISC_R_SUCCESS);

		ISC_LIST_APPEND(msgname->list, msgrds, link);

		dns_message_addname(msg, msgname, DNS_SECTION_ANSWER);
		msgname = NULL;

		result = xfr->stream->methods->next(xfr->stream);
		if (result == ISC_R_NOMORE) {
			xfr->end_of_stream = ISC_TRUE;
			break;
		}
		CHECK(result);

		if (! xfr->many_answers)
			break;
		/*
		 * At this stage, at least 1 RR has been rendered into
		 * the message. Check if we want to clamp this message
		 * here (TCP only). 20480 was set as an upper limit to
		 * improve message compression.
		 */
		if ((isc_buffer_usedlength(&xfr->buf) >= 20480) && is_tcp)
			break;
	}

	if (is_tcp) {
		CHECK(dns_compress_init(&cctx, -1, xfr->mctx));
		dns_compress_setsensitive(&cctx, ISC_TRUE);
		cleanup_cctx = ISC_TRUE;
		CHECK(dns_message_renderbegin(msg, &cctx, &xfr->txbuf));
		CHECK(dns_message_rendersection(msg, DNS_SECTION_QUESTION, 0));
		CHECK(dns_message_rendersection(msg, DNS_SECTION_ANSWER, 0));
		CHECK(dns_message_renderend(msg));
		dns_compress_invalidate(&cctx);
		cleanup_cctx = ISC_FALSE;

		isc_buffer_usedregion(&xfr->txbuf, &used);
		isc_buffer_putuint16(&xfr->txlenbuf,
				     (isc_uint16_t)used.length);
		region.base = xfr->txlenbuf.base;
		region.length = 2 + used.length;
		xfrout_log(xfr, ISC_LOG_DEBUG(8),
			   "sending TCP message of %d bytes",
			   used.length);
		CHECK(isc_socket_send(xfr->client->tcpsocket, /* XXX */
				      &region, xfr->client->task,
				      xfrout_senddone,
				      xfr));
		xfr->sends++;
	} else {
		xfrout_log(xfr, ISC_LOG_DEBUG(8), "sending IXFR UDP response");
		ns_client_send(xfr->client);
		xfr->stream->methods->pause(xfr->stream);
		xfrout_ctx_destroy(&xfr);
		return;
	}

	/* Advance lasttsig to be the last TSIG generated */
	CHECK(dns_message_getquerytsig(msg, xfr->mctx, &xfr->lasttsig));

	xfr->nmsg++;

 failure:
	if (msgname != NULL) {
		if (msgrds != NULL) {
			if (dns_rdataset_isassociated(msgrds))
				dns_rdataset_disassociate(msgrds);
			dns_message_puttemprdataset(msg, &msgrds);
		}
		if (msgrdl != NULL) {
			ISC_LIST_UNLINK(msgrdl->rdata, msgrdata, link);
			dns_message_puttemprdatalist(msg, &msgrdl);
		}
		if (msgrdata != NULL)
			dns_message_puttemprdata(msg, &msgrdata);
		dns_message_puttempname(msg, &msgname);
	}

	if (tcpmsg != NULL)
		dns_message_destroy(&tcpmsg);

	if (cleanup_cctx)
		dns_compress_invalidate(&cctx);
	/*
	 * Make sure to release any locks held by database
	 * iterators before returning from the event handler.
	 */
	xfr->stream->methods->pause(xfr->stream);

	if (result == ISC_R_SUCCESS)
		return;

	xfrout_fail(xfr, result, "sending zone data");
}
Ejemplo n.º 3
0
isc_result_t
dns_tsig_sign(dns_message_t *msg) {
	dns_tsigkey_t *key;
	dns_rdata_any_tsig_t tsig, querytsig;
	unsigned char data[128];
	isc_buffer_t databuf, sigbuf;
	isc_buffer_t *dynbuf;
	dns_name_t *owner;
	dns_rdata_t *rdata = NULL;
	dns_rdatalist_t *datalist;
	dns_rdataset_t *dataset;
	isc_region_t r;
	isc_stdtime_t now;
	isc_mem_t *mctx;
	dst_context_t *ctx = NULL;
	isc_result_t ret;
	unsigned char badtimedata[BADTIMELEN];
	unsigned int sigsize = 0;
	isc_boolean_t response = is_response(msg);

	REQUIRE(msg != NULL);
	REQUIRE(VALID_TSIG_KEY(dns_message_gettsigkey(msg)));

	/*
	 * If this is a response, there should be a query tsig.
	 */
	if (response && msg->querytsig == NULL)
		return (DNS_R_EXPECTEDTSIG);

	dynbuf = NULL;

	mctx = msg->mctx;
	key = dns_message_gettsigkey(msg);

	tsig.mctx = mctx;
	tsig.common.rdclass = dns_rdataclass_any;
	tsig.common.rdtype = dns_rdatatype_tsig;
	ISC_LINK_INIT(&tsig.common, link);
	dns_name_init(&tsig.algorithm, NULL);
	dns_name_clone(key->algorithm, &tsig.algorithm);

	isc_stdtime_get(&now);
	tsig.timesigned = now + msg->timeadjust;
	tsig.fudge = DNS_TSIG_FUDGE;

	tsig.originalid = msg->id;

	isc_buffer_init(&databuf, data, sizeof(data));

	if (response)
		tsig.error = msg->querytsigstatus;
	else
		tsig.error = dns_rcode_noerror;

	if (tsig.error != dns_tsigerror_badtime) {
		tsig.otherlen = 0;
		tsig.other = NULL;
	} else {
		isc_buffer_t otherbuf;

		tsig.otherlen = BADTIMELEN;
		tsig.other = badtimedata;
		isc_buffer_init(&otherbuf, tsig.other, tsig.otherlen);
		isc_buffer_putuint48(&otherbuf, tsig.timesigned);
	}

	if (key->key != NULL && tsig.error != dns_tsigerror_badsig) {
		unsigned char header[DNS_MESSAGE_HEADERLEN];
		isc_buffer_t headerbuf;
		isc_uint16_t digestbits;

		ret = dst_context_create3(key->key, mctx,
					  DNS_LOGCATEGORY_DNSSEC,
					  ISC_TRUE, &ctx);
		if (ret != ISC_R_SUCCESS)
			return (ret);

		/*
		 * If this is a response, digest the query signature.
		 */
		if (response) {
			dns_rdata_t querytsigrdata = DNS_RDATA_INIT;

			ret = dns_rdataset_first(msg->querytsig);
			if (ret != ISC_R_SUCCESS)
				goto cleanup_context;
			dns_rdataset_current(msg->querytsig, &querytsigrdata);
			ret = dns_rdata_tostruct(&querytsigrdata, &querytsig,
						 NULL);
			if (ret != ISC_R_SUCCESS)
				goto cleanup_context;
			isc_buffer_putuint16(&databuf, querytsig.siglen);
			if (isc_buffer_availablelength(&databuf) <
			    querytsig.siglen) {
				ret = ISC_R_NOSPACE;
				goto cleanup_context;
			}
			isc_buffer_putmem(&databuf, querytsig.signature,
					  querytsig.siglen);
			isc_buffer_usedregion(&databuf, &r);
			ret = dst_context_adddata(ctx, &r);
			if (ret != ISC_R_SUCCESS)
				goto cleanup_context;
		}
#if defined(__clang__)  && \
       ( __clang_major__ < 3 || \
	(__clang_major__ == 3 && __clang_minor__ < 2) || \
	(__clang_major__ == 4 && __clang_minor__ < 2))
	/* false positive: http://llvm.org/bugs/show_bug.cgi?id=14461 */
		else memset(&querytsig, 0, sizeof(querytsig));
#endif

		/*
		 * Digest the header.
		 */
		isc_buffer_init(&headerbuf, header, sizeof(header));
		dns_message_renderheader(msg, &headerbuf);
		isc_buffer_usedregion(&headerbuf, &r);
		ret = dst_context_adddata(ctx, &r);
		if (ret != ISC_R_SUCCESS)
			goto cleanup_context;

		/*
		 * Digest the remainder of the message.
		 */
		isc_buffer_usedregion(msg->buffer, &r);
		isc_region_consume(&r, DNS_MESSAGE_HEADERLEN);
		ret = dst_context_adddata(ctx, &r);
		if (ret != ISC_R_SUCCESS)
			goto cleanup_context;

		if (msg->tcp_continuation == 0) {
			/*
			 * Digest the name, class, ttl, alg.
			 */
			dns_name_toregion(&key->name, &r);
			ret = dst_context_adddata(ctx, &r);
			if (ret != ISC_R_SUCCESS)
				goto cleanup_context;

			isc_buffer_clear(&databuf);
			isc_buffer_putuint16(&databuf, dns_rdataclass_any);
			isc_buffer_putuint32(&databuf, 0); /* ttl */
			isc_buffer_usedregion(&databuf, &r);
			ret = dst_context_adddata(ctx, &r);
			if (ret != ISC_R_SUCCESS)
				goto cleanup_context;

			dns_name_toregion(&tsig.algorithm, &r);
			ret = dst_context_adddata(ctx, &r);
			if (ret != ISC_R_SUCCESS)
				goto cleanup_context;

		}
		/* Digest the timesigned and fudge */
		isc_buffer_clear(&databuf);
		if (tsig.error == dns_tsigerror_badtime) {
			INSIST(response);
			tsig.timesigned = querytsig.timesigned;
		}
		isc_buffer_putuint48(&databuf, tsig.timesigned);
		isc_buffer_putuint16(&databuf, tsig.fudge);
		isc_buffer_usedregion(&databuf, &r);
		ret = dst_context_adddata(ctx, &r);
		if (ret != ISC_R_SUCCESS)
			goto cleanup_context;

		if (msg->tcp_continuation == 0) {
			/*
			 * Digest the error and other data length.
			 */
			isc_buffer_clear(&databuf);
			isc_buffer_putuint16(&databuf, tsig.error);
			isc_buffer_putuint16(&databuf, tsig.otherlen);

			isc_buffer_usedregion(&databuf, &r);
			ret = dst_context_adddata(ctx, &r);
			if (ret != ISC_R_SUCCESS)
				goto cleanup_context;

			/*
			 * Digest other data.
			 */
			if (tsig.otherlen > 0) {
				r.length = tsig.otherlen;
				r.base = tsig.other;
				ret = dst_context_adddata(ctx, &r);
				if (ret != ISC_R_SUCCESS)
					goto cleanup_context;
			}
		}

		ret = dst_key_sigsize(key->key, &sigsize);
		if (ret != ISC_R_SUCCESS)
			goto cleanup_context;
		tsig.signature = (unsigned char *) isc_mem_get(mctx, sigsize);
		if (tsig.signature == NULL) {
			ret = ISC_R_NOMEMORY;
			goto cleanup_context;
		}

		isc_buffer_init(&sigbuf, tsig.signature, sigsize);
		ret = dst_context_sign(ctx, &sigbuf);
		if (ret != ISC_R_SUCCESS)
			goto cleanup_signature;
		dst_context_destroy(&ctx);
		digestbits = dst_key_getbits(key->key);
		if (digestbits != 0) {
			unsigned int bytes = (digestbits + 1) / 8;
			if (response && bytes < querytsig.siglen)
				bytes = querytsig.siglen;
			if (bytes > isc_buffer_usedlength(&sigbuf))
				bytes = isc_buffer_usedlength(&sigbuf);
			tsig.siglen = bytes;
		} else
			tsig.siglen = isc_buffer_usedlength(&sigbuf);
	} else {
		tsig.siglen = 0;
		tsig.signature = NULL;
	}

	ret = dns_message_gettemprdata(msg, &rdata);
	if (ret != ISC_R_SUCCESS)
		goto cleanup_signature;
	ret = isc_buffer_allocate(msg->mctx, &dynbuf, 512);
	if (ret != ISC_R_SUCCESS)
		goto cleanup_rdata;
	ret = dns_rdata_fromstruct(rdata, dns_rdataclass_any,
				   dns_rdatatype_tsig, &tsig, dynbuf);
	if (ret != ISC_R_SUCCESS)
		goto cleanup_dynbuf;

	dns_message_takebuffer(msg, &dynbuf);

	if (tsig.signature != NULL) {
		isc_mem_put(mctx, tsig.signature, sigsize);
		tsig.signature = NULL;
	}

	owner = NULL;
	ret = dns_message_gettempname(msg, &owner);
	if (ret != ISC_R_SUCCESS)
		goto cleanup_rdata;
	dns_name_init(owner, NULL);
	ret = dns_name_dup(&key->name, msg->mctx, owner);
	if (ret != ISC_R_SUCCESS)
		goto cleanup_owner;

	datalist = NULL;
	ret = dns_message_gettemprdatalist(msg, &datalist);
	if (ret != ISC_R_SUCCESS)
		goto cleanup_owner;
	dataset = NULL;
	ret = dns_message_gettemprdataset(msg, &dataset);
	if (ret != ISC_R_SUCCESS)
		goto cleanup_rdatalist;
	datalist->rdclass = dns_rdataclass_any;
	datalist->type = dns_rdatatype_tsig;
	datalist->covers = 0;
	datalist->ttl = 0;
	ISC_LIST_INIT(datalist->rdata);
	ISC_LIST_APPEND(datalist->rdata, rdata, link);
	RUNTIME_CHECK(dns_rdatalist_tordataset(datalist, dataset)
		      == ISC_R_SUCCESS);
	msg->tsig = dataset;
	msg->tsigname = owner;

	/* Windows does not like the tsig name being compressed. */
	msg->tsigname->attributes |= DNS_NAMEATTR_NOCOMPRESS;

	return (ISC_R_SUCCESS);

 cleanup_rdatalist:
	dns_message_puttemprdatalist(msg, &datalist);
 cleanup_owner:
	dns_message_puttempname(msg, &owner);
	goto cleanup_rdata;
 cleanup_dynbuf:
	isc_buffer_free(&dynbuf);
 cleanup_rdata:
	dns_message_puttemprdata(msg, &rdata);
 cleanup_signature:
	if (tsig.signature != NULL)
		isc_mem_put(mctx, tsig.signature, sigsize);
 cleanup_context:
	if (ctx != NULL)
		dst_context_destroy(&ctx);
	return (ret);
}