request.c

非常好的dns解析软件

		isc_netaddr_fromsockaddr(&netaddr, destaddr);
		if (dns_acl_match(&netaddr, NULL, blackhole,
				  NULL, &match, NULL) == ISC_R_SUCCESS &&
		    match > 0)
			drop = ISC_TRUE;
	}
	if (drop) {
		isc_netaddr_format(&netaddr, netaddrstr, sizeof(netaddrstr));
		req_log(ISC_LOG_DEBUG(10), "blackholed address %s", netaddrstr);
	}
	return (drop);
}

static isc_result_t
create_tcp_dispatch(dns_requestmgr_t *requestmgr, isc_sockaddr_t *srcaddr,
		    isc_sockaddr_t *destaddr, dns_dispatch_t **dispatchp)
{
	isc_result_t result;
	isc_socket_t *socket = NULL;
	isc_sockaddr_t src;
	unsigned int attrs;
	isc_sockaddr_t bind_any;

	result = isc_socket_create(requestmgr->socketmgr,
				   isc_sockaddr_pf(destaddr),
				   isc_sockettype_tcp, &socket);
	if (result != ISC_R_SUCCESS)
		return (result);
#ifndef BROKEN_TCP_BIND_BEFORE_CONNECT
	if (srcaddr == NULL) {
		isc_sockaddr_anyofpf(&bind_any,
				     isc_sockaddr_pf(destaddr));
		result = isc_socket_bind(socket, &bind_any);
	} else {
		src = *srcaddr;
		isc_sockaddr_setport(&src, 0);
		result = isc_socket_bind(socket, &src);
	}
	if (result != ISC_R_SUCCESS)
		goto cleanup;
#endif
	attrs = 0;
	attrs |= DNS_DISPATCHATTR_TCP;
	attrs |= DNS_DISPATCHATTR_PRIVATE;
	if (isc_sockaddr_pf(destaddr) == AF_INET)
		attrs |= DNS_DISPATCHATTR_IPV4;
	else
		attrs |= DNS_DISPATCHATTR_IPV6;
	attrs |= DNS_DISPATCHATTR_MAKEQUERY;
	result = dns_dispatch_createtcp(requestmgr->dispatchmgr,
					socket, requestmgr->taskmgr,
					4096, 2, 1, 1, 3, attrs,
					dispatchp);
cleanup:
	isc_socket_detach(&socket);
	return (result);
}

static isc_result_t
find_udp_dispatch(dns_requestmgr_t *requestmgr, isc_sockaddr_t *srcaddr,
		  isc_sockaddr_t *destaddr, dns_dispatch_t **dispatchp)
{
	dns_dispatch_t *disp = NULL;
	unsigned int attrs, attrmask;

	if (srcaddr == NULL) {
		switch (isc_sockaddr_pf(destaddr)) {
		case PF_INET:
			disp = requestmgr->dispatchv4;
			break;

		case PF_INET6:
			disp = requestmgr->dispatchv6;
			break;

		default:
			return (ISC_R_NOTIMPLEMENTED);
		}
		if (disp == NULL)
			return (ISC_R_FAMILYNOSUPPORT);
		dns_dispatch_attach(disp, dispatchp);
		return (ISC_R_SUCCESS);
	}
	attrs = 0;
	attrs |= DNS_DISPATCHATTR_UDP;
	switch (isc_sockaddr_pf(srcaddr)) {
	case PF_INET:
		attrs |= DNS_DISPATCHATTR_IPV4;
		break;

	case PF_INET6:
		attrs |= DNS_DISPATCHATTR_IPV6;
		break;

	default:
		return (ISC_R_NOTIMPLEMENTED);
	}
	attrmask = 0;
	attrmask |= DNS_DISPATCHATTR_UDP;
	attrmask |= DNS_DISPATCHATTR_TCP;
	attrmask |= DNS_DISPATCHATTR_IPV4;
	attrmask |= DNS_DISPATCHATTR_IPV6;
	return (dns_dispatch_getudp(requestmgr->dispatchmgr,
				    requestmgr->socketmgr,
				    requestmgr->taskmgr,
				    srcaddr, 4096,
				    1000, 32768, 16411, 16433,
				    attrs, attrmask,
				    dispatchp));
}

static isc_result_t
get_dispatch(isc_boolean_t tcp, dns_requestmgr_t *requestmgr,
	     isc_sockaddr_t *srcaddr, isc_sockaddr_t *destaddr,
	     dns_dispatch_t **dispatchp)
{
	isc_result_t result;
	if (tcp)
		result = create_tcp_dispatch(requestmgr, srcaddr,
					     destaddr, dispatchp);
	else
		result = find_udp_dispatch(requestmgr, srcaddr,
					   destaddr, dispatchp);
	return (result);
}

static isc_result_t
set_timer(isc_timer_t *timer, unsigned int timeout, unsigned int udpresend) {
	isc_time_t expires;
	isc_interval_t interval;
	isc_result_t result;
	isc_timertype_t timertype;

	isc_interval_set(&interval, timeout, 0);
	result = isc_time_nowplusinterval(&expires, &interval);
	isc_interval_set(&interval, udpresend, 0);

	timertype = udpresend != 0 ? isc_timertype_limited : isc_timertype_once;
	if (result == ISC_R_SUCCESS)
		result = isc_timer_reset(timer, timertype, &expires,
					 &interval, ISC_FALSE);
	return (result);
}

isc_result_t
dns_request_createraw(dns_requestmgr_t *requestmgr, isc_buffer_t *msgbuf,
		      isc_sockaddr_t *srcaddr, isc_sockaddr_t *destaddr,
		      unsigned int options, unsigned int timeout,
		      isc_task_t *task, isc_taskaction_t action, void *arg,
		      dns_request_t **requestp)
{
	return(dns_request_createraw3(requestmgr, msgbuf, srcaddr, destaddr,
				      options, timeout, 0, 0, task, action,
				      arg, requestp));
}

isc_result_t
dns_request_createraw2(dns_requestmgr_t *requestmgr, isc_buffer_t *msgbuf,
		       isc_sockaddr_t *srcaddr, isc_sockaddr_t *destaddr,
		       unsigned int options, unsigned int timeout,
		       unsigned int udptimeout, isc_task_t *task,
		       isc_taskaction_t action, void *arg,
		       dns_request_t **requestp)
{
	unsigned int udpretries = 0;

	if (udptimeout != 0)
		udpretries = timeout / udptimeout;

	return (dns_request_createraw3(requestmgr, msgbuf, srcaddr, destaddr,
				       options, timeout, udptimeout,
				       udpretries, task, action, arg,
				       requestp));
}

isc_result_t
dns_request_createraw3(dns_requestmgr_t *requestmgr, isc_buffer_t *msgbuf,
		       isc_sockaddr_t *srcaddr, isc_sockaddr_t *destaddr,
		       unsigned int options, unsigned int timeout,
		       unsigned int udptimeout, unsigned int udpretries,
		       isc_task_t *task, isc_taskaction_t action, void *arg,
		       dns_request_t **requestp)
{
	dns_request_t *request = NULL;
	isc_task_t *tclone = NULL;
	isc_socket_t *socket = NULL;
	isc_result_t result;
	isc_mem_t *mctx;
	dns_messageid_t	id;
	isc_boolean_t tcp = ISC_FALSE;
	isc_region_t r;

	REQUIRE(VALID_REQUESTMGR(requestmgr));
	REQUIRE(msgbuf != NULL);
	REQUIRE(destaddr != NULL);
	REQUIRE(task != NULL);
	REQUIRE(action != NULL);
	REQUIRE(requestp != NULL && *requestp == NULL);
	REQUIRE(timeout > 0);
	if (srcaddr != NULL) 
		REQUIRE(isc_sockaddr_pf(srcaddr) == isc_sockaddr_pf(destaddr));

	mctx = requestmgr->mctx;

	req_log(ISC_LOG_DEBUG(3), "dns_request_createraw");

	if (isblackholed(requestmgr->dispatchmgr, destaddr))
		return (DNS_R_BLACKHOLED);

	request = NULL;
	result = new_request(mctx, &request);
	if (result != ISC_R_SUCCESS)
		return (result);

	if (udptimeout == 0 && udpretries != 0) {
		udptimeout = timeout / (udpretries + 1);
		if (udptimeout == 0)
			udptimeout = 1;
	}
	request->udpcount = udpretries;

	/*
	 * Create timer now.  We will set it below once.
	 */
	result = isc_timer_create(requestmgr->timermgr, isc_timertype_inactive,
				  NULL, NULL, task, req_timeout, request,
				  &request->timer);
	if (result != ISC_R_SUCCESS)
		goto cleanup;

	request->event = (dns_requestevent_t *)
		isc_event_allocate(mctx, task, DNS_EVENT_REQUESTDONE,
				   action, arg, sizeof(dns_requestevent_t));
	if (request->event == NULL) {
		result = ISC_R_NOMEMORY;
		goto cleanup;
	}
	isc_task_attach(task, &tclone);
	request->event->ev_sender = task;
	request->event->request = request;
	request->event->result = ISC_R_FAILURE;

	isc_buffer_usedregion(msgbuf, &r);
	if (r.length < DNS_MESSAGE_HEADERLEN || r.length > 65535) {
		result = DNS_R_FORMERR;
		goto cleanup;
	}
		
	if ((options & DNS_REQUESTOPT_TCP) != 0 || r.length > 512)
		tcp = ISC_TRUE;

	result = get_dispatch(tcp, requestmgr, srcaddr, destaddr,
			      &request->dispatch);
	if (result != ISC_R_SUCCESS)
		goto cleanup;

	socket = dns_dispatch_getsocket(request->dispatch);
	INSIST(socket != NULL);
	result = dns_dispatch_addresponse(request->dispatch, destaddr, task,
					  req_response, request, &id,
					  &request->dispentry);
	if (result != ISC_R_SUCCESS)
		goto cleanup;

	result = isc_buffer_allocate(mctx, &request->query,
				     r.length + (tcp ? 2 : 0));
	if (result != ISC_R_SUCCESS)
		goto cleanup;
	if (tcp)
		isc_buffer_putuint16(request->query, (isc_uint16_t)r.length);
	result = isc_buffer_copyregion(request->query, &r);
	if (result != ISC_R_SUCCESS)
		goto cleanup;

	/* Add message ID. */
	isc_buffer_usedregion(request->query, &r);
	if (tcp)
		isc_region_consume(&r, 2);
	r.base[0] = (id>>8) & 0xff;
	r.base[1] = id & 0xff;

	LOCK(&requestmgr->lock);
	if (requestmgr->exiting) {
		UNLOCK(&requestmgr->lock);
		result = ISC_R_SHUTTINGDOWN;
		goto cleanup;
	}
	requestmgr_attach(requestmgr, &request->requestmgr);
	request->hash = mgr_gethash(requestmgr);
	ISC_LIST_APPEND(requestmgr->requests, request, link);
	UNLOCK(&requestmgr->lock);

	result = set_timer(request->timer, timeout, tcp ? 0 : udptimeout);
	if (result != ISC_R_SUCCESS)
		goto unlink;

	request->destaddr = *destaddr;
	if (tcp) {
		result = isc_socket_connect(socket, destaddr, task,
					    req_connected, request);
		if (result != ISC_R_SUCCESS)
			goto unlink;
		request->flags |= DNS_REQUEST_F_CONNECTING|DNS_REQUEST_F_TCP;
	} else {
		result = req_send(request, task, destaddr);
		if (result != ISC_R_SUCCESS)
			goto unlink;
	}

	req_log(ISC_LOG_DEBUG(3), "dns_request_createraw: request %p",
		request);
	*requestp = request;
	return (ISC_R_SUCCESS);

 unlink:
	LOCK(&requestmgr->lock);
	ISC_LIST_UNLINK(requestmgr->requests, request, link);
	UNLOCK(&requestmgr->lock);

 cleanup:
	if (tclone != NULL)
		isc_task_detach(&tclone);
	req_destroy(request);
	req_log(ISC_LOG_DEBUG(3), "dns_request_createraw: failed %s",
		dns_result_totext(result));
	return (result);
}

isc_result_t
dns_request_create(dns_requestmgr_t *requestmgr, dns_message_t *message,
		   isc_sockaddr_t *address, unsigned int options,
		   dns_tsigkey_t *key,
		   unsigned int timeout, isc_task_t *task,
		   isc_taskaction_t action, void *arg,
		   dns_request_t **requestp)
{
	return (dns_request_createvia3(requestmgr, message, NULL, address,
				       options, key, timeout, 0, 0, task,
				       action, arg, requestp));
}

isc_result_t
dns_request_createvia(dns_requestmgr_t *requestmgr, dns_message_t *message,
		      isc_sockaddr_t *srcaddr, isc_sockaddr_t *destaddr,
		      unsigned int options, dns_tsigkey_t *key,
		      unsigned int timeout, isc_task_t *task,
		      isc_taskaction_t action, void *arg,
		      dns_request_t **requestp)
{
	return(dns_request_createvia3(requestmgr, message, srcaddr, destaddr,
				      options, key, timeout, 0, 0, task,
				      action, arg, requestp));
}

isc_result_t
dns_request_createvia2(dns_requestmgr_t *requestmgr, dns_message_t *message,
		       isc_sockaddr_t *srcaddr, isc_sockaddr_t *destaddr,
		       unsigned int options, dns_tsigkey_t *key,
		       unsigned int timeout, unsigned int udptimeout,
		       isc_task_t *task, isc_taskaction_t action, void *arg,
		       dns_request_t **requestp)
{
	unsigned int udpretries = 0;

	if (udptimeout != 0)
		udpretries = timeout / udptimeout;
	return (dns_request_createvia3(requestmgr, message, srcaddr, destaddr,
				       options, key, timeout, udptimeout,
				       udpretries, task, action, arg,
				       requestp));
}
					
isc_result_t
dns_request_createvia3(dns_requestmgr_t *requestmgr, dns_message_t *message,
		       isc_sockaddr_t *srcaddr, isc_sockaddr_t *destaddr,
		       unsigned int options, dns_tsigkey_t *key,
		       unsigned int timeout, unsigned int udptimeout,
		       unsigned int udpretries, isc_task_t *task,
		       isc_taskaction_t action, void *arg,
		       dns_request_t **requestp)
{
	dns_request_t *request = NULL;
	isc_task_t *tclone = NULL;
	isc_socket_t *socket = NULL;
	isc_result_t result;
	isc_mem_t *mctx;
	dns_messageid_t	id;
	isc_boolean_t tcp;
	isc_boolean_t setkey = ISC_TRUE;

	REQUIRE(VALID_REQUESTMGR(requestmgr));
	REQUIRE(message != NULL);
	REQUIRE(destaddr != NULL);
	REQUIRE(task != NULL);
	REQUIRE(action != NULL);
	REQUIRE(requestp != NULL && *requestp == NULL);
	REQUIRE(timeout > 0);
	if (srcaddr != NULL) 
		REQUIRE(isc_sockaddr_pf(srcaddr) == isc_sockaddr_pf(destaddr));

	mctx = requestmgr->mctx;

	req_log(ISC_LOG_DEBUG(3), "dns_request_createvia");

	if (isblackholed(requestmgr->dispatchmgr, destaddr))
		return (DNS_R_BLACKHOLED);

	request = NULL;
	result = new_request(mctx, &request);
	if (result != ISC_R_SUCCESS)
		return (result);

	if (udptimeout == 0 && udpretries != 0) {
		udptimeout = timeout / (udpretries + 1);
		if (udptimeout == 0)
			udptimeout = 1;
	}
	request->udpcount = udpretries;

	/*
	 * Create timer now.  We will set it below once.
	 */
	result = isc_timer_create(requestmgr->timermgr, isc_timertype_inactive,
				  NULL, NULL, task, req_timeout, request,
				  &request->timer);
	if (result != ISC_R_SUCCESS)
		goto cleanup;

	request->event = (dns_requestevent_t *)
		isc_event_allocate(mctx, task, DNS_EVENT_REQUESTDONE,
				   action, arg, sizeof(dns_requestevent_t));
	if (request->event == NULL) {
		result = ISC_R_NOMEMORY;
		goto cleanup;
	}
	isc_task_attach(task, &tclone);
	request->event->ev_sender = task;
	request->event->request = request;
	request->event->result = ISC_R_FAILURE;
	if (key != NULL)
		dns_tsigkey_attach(key, &request->tsigkey);

 use_tcp:
	tcp = ISC_TF((options & DNS_REQUESTOPT_TCP) != 0);
	result = get_dispatch(tcp, requestmgr, srcaddr, destaddr,
			      &request->dispatch);
	if (result != ISC_R_SUCCESS)
		goto cleanup;

	socket = dns_dispatch_getsocket(request->dispatch);
	INSIST(socket != NULL);
	result = dns_dispatch_addresponse(request->dispatch, destaddr, task,
					  req_response, request, &id,
					  &request->dispentry);
	if (result != ISC_R_SUCCESS)
		goto cleanup;

	message->id = id;
	if (setkey) {
		result = dns_message_settsigkey(message, request->tsigkey);
		if (result != ISC_R_SUCCESS)
			goto cleanup;
	}
	result = req_render(message, &request->query, options, mctx);
	if (result == DNS_R_USETCP &&
	    (options & DNS_REQUESTOPT_TCP) == 0) {
		/*
		 * Try again using TCP.
		 */
		dns_message_renderreset(message);
		dns_dispatch_removeresponse(&request->dispentry, NULL);
		dns_dispatch_detach(&request->dispatch);
		socket = NULL;
		options |= DNS_REQUESTOPT_TCP;
		setkey = ISC_FALSE;
		goto use_tcp;
	}
	if (result != ISC_R_SUCCESS)
		goto cleanup;

	result = dns_message_getquerytsig(message, mctx, &request->tsig);
	if (result != ISC_R_SUCCESS)
		goto cleanup;

	LOCK(&requestmgr->lock);
	if (requestmgr->exiting) {
		UNLOCK(&requestmgr->lock);
		result = ISC_R_SHUTTINGDOWN;