controlconf.c

非常好的dns解析软件

	ccregion.rstart = conn->buffer + 4;
	ccregion.rend = conn->buffer + sizeof(conn->buffer);
	result = isccc_cc_towire(response, &ccregion, &secret);
	if (result != ISC_R_SUCCESS)
		goto cleanup;
	isc_buffer_init(&b, conn->buffer, 4);
	len = sizeof(conn->buffer) - REGION_SIZE(ccregion);
	isc_buffer_putuint32(&b, len - 4);
	r.base = conn->buffer;
	r.length = len;

	result = isc_socket_send(conn->sock, &r, task, control_senddone, conn);
	if (result != ISC_R_SUCCESS)
		goto cleanup;
	conn->sending = ISC_TRUE;

	if (secret.rstart != NULL)
		isc_mem_put(listener->mctx, secret.rstart,
			    REGION_SIZE(secret));
	if (request != NULL)
		isccc_sexpr_free(&request);
	if (response != NULL)
		isccc_sexpr_free(&response);
	return;

 cleanup:
	if (secret.rstart != NULL)
		isc_mem_put(listener->mctx, secret.rstart,
			    REGION_SIZE(secret));
	isc_socket_detach(&conn->sock);
	isccc_ccmsg_invalidate(&conn->ccmsg);
	conn->ccmsg_valid = ISC_FALSE;
	maybe_free_connection(conn);
	maybe_free_listener(listener);
	if (request != NULL)
		isccc_sexpr_free(&request);
	if (response != NULL)
		isccc_sexpr_free(&response);
}

static void
control_timeout(isc_task_t *task, isc_event_t *event) {
	controlconnection_t *conn = event->ev_arg;

	UNUSED(task);

	isc_timer_detach(&conn->timer);
	maybe_free_connection(conn);

	isc_event_free(&event);
}

static isc_result_t
newconnection(controllistener_t *listener, isc_socket_t *sock) {
	controlconnection_t *conn;
	isc_interval_t interval;
	isc_result_t result;

	conn = isc_mem_get(listener->mctx, sizeof(*conn));
	if (conn == NULL)
		return (ISC_R_NOMEMORY);
	
	conn->sock = sock;
	isccc_ccmsg_init(listener->mctx, sock, &conn->ccmsg);
	conn->ccmsg_valid = ISC_TRUE;
	conn->sending = ISC_FALSE;
	conn->timer = NULL;
	isc_interval_set(&interval, 60, 0);
	result = isc_timer_create(ns_g_timermgr, isc_timertype_once,
				  NULL, &interval, listener->task,
				  control_timeout, conn, &conn->timer);
	if (result != ISC_R_SUCCESS)
		goto cleanup;

	conn->listener = listener;
	conn->nonce = 0;
	ISC_LINK_INIT(conn, link);

	result = isccc_ccmsg_readmessage(&conn->ccmsg, listener->task,
					 control_recvmessage, conn);
	if (result != ISC_R_SUCCESS)
		goto cleanup;
	isccc_ccmsg_setmaxsize(&conn->ccmsg, 2048);

	ISC_LIST_APPEND(listener->connections, conn, link);
	return (ISC_R_SUCCESS);

 cleanup:
	isccc_ccmsg_invalidate(&conn->ccmsg);
	if (conn->timer != NULL)
		isc_timer_detach(&conn->timer);
	isc_mem_put(listener->mctx, conn, sizeof(*conn));
	return (result);
}

static void
control_newconn(isc_task_t *task, isc_event_t *event) {
	isc_socket_newconnev_t *nevent = (isc_socket_newconnev_t *)event;
	controllistener_t *listener = event->ev_arg;
	isc_socket_t *sock;
	isc_sockaddr_t peeraddr;
	isc_result_t result;

	UNUSED(task);

	listener->listening = ISC_FALSE;

	if (nevent->result != ISC_R_SUCCESS) {
		if (nevent->result == ISC_R_CANCELED) {
			shutdown_listener(listener);
			goto cleanup;
		}
		goto restart;
	}

	sock = nevent->newsocket;
	(void)isc_socket_getpeername(sock, &peeraddr);
	if (listener->type == isc_sockettype_tcp &&
	    !address_ok(&peeraddr, listener->acl)) {
		char socktext[ISC_SOCKADDR_FORMATSIZE];
		isc_sockaddr_format(&peeraddr, socktext, sizeof(socktext));
		isc_log_write(ns_g_lctx, NS_LOGCATEGORY_GENERAL,
			      NS_LOGMODULE_CONTROL, ISC_LOG_WARNING,
			      "rejected command channel message from %s",
			      socktext);
		isc_socket_detach(&sock);
		goto restart;
	}

	result = newconnection(listener, sock);
	if (result != ISC_R_SUCCESS) {
		char socktext[ISC_SOCKADDR_FORMATSIZE];
		isc_sockaddr_format(&peeraddr, socktext, sizeof(socktext));
		isc_log_write(ns_g_lctx, NS_LOGCATEGORY_GENERAL,
			      NS_LOGMODULE_CONTROL, ISC_LOG_WARNING,
			      "dropped command channel from %s: %s",
			      socktext, isc_result_totext(result));
		isc_socket_detach(&sock);
		goto restart;
	}

 restart:
	control_next(listener);
 cleanup:
	isc_event_free(&event);
}

static void
controls_shutdown(ns_controls_t *controls) {
	controllistener_t *listener;
	controllistener_t *next;

	for (listener = ISC_LIST_HEAD(controls->listeners);
	     listener != NULL;
	     listener = next)
	{
		/*
		 * This is asynchronous.  As listeners shut down, they will
		 * call their callbacks.
		 */
		next = ISC_LIST_NEXT(listener, link);
		shutdown_listener(listener);
	}
}

void
ns_controls_shutdown(ns_controls_t *controls) {
	controls_shutdown(controls);
	controls->shuttingdown = ISC_TRUE;
}

static isc_result_t
cfgkeylist_find(const cfg_obj_t *keylist, const char *keyname,
	        const cfg_obj_t **objp)
{
	const cfg_listelt_t *element;
	const char *str;
	const cfg_obj_t *obj;

	for (element = cfg_list_first(keylist);
	     element != NULL;
	     element = cfg_list_next(element))
	{
		obj = cfg_listelt_value(element);
		str = cfg_obj_asstring(cfg_map_getname(obj));
		if (strcasecmp(str, keyname) == 0)
			break;
	}
	if (element == NULL)
		return (ISC_R_NOTFOUND);
	obj = cfg_listelt_value(element);
	*objp = obj;
	return (ISC_R_SUCCESS);
}

static isc_result_t
controlkeylist_fromcfg(const cfg_obj_t *keylist, isc_mem_t *mctx,
		       controlkeylist_t *keyids)
{
	const cfg_listelt_t *element;
	char *newstr = NULL;
	const char *str;
	const cfg_obj_t *obj;
	controlkey_t *key;

	for (element = cfg_list_first(keylist);
	     element != NULL;
	     element = cfg_list_next(element))
	{
		obj = cfg_listelt_value(element);
		str = cfg_obj_asstring(obj);
		newstr = isc_mem_strdup(mctx, str);
		if (newstr == NULL)
			goto cleanup;
		key = isc_mem_get(mctx, sizeof(*key));
		if (key == NULL)
			goto cleanup;
		key->keyname = newstr;
		key->secret.base = NULL;
		key->secret.length = 0;
		ISC_LINK_INIT(key, link);
		ISC_LIST_APPEND(*keyids, key, link);
		newstr = NULL;
	}
	return (ISC_R_SUCCESS);

 cleanup:
	if (newstr != NULL)
		isc_mem_free(mctx, newstr);
	free_controlkeylist(keyids, mctx);
	return (ISC_R_NOMEMORY);
}

static void
register_keys(const cfg_obj_t *control, const cfg_obj_t *keylist,
	      controlkeylist_t *keyids, isc_mem_t *mctx, const char *socktext)
{
	controlkey_t *keyid, *next;
	const cfg_obj_t *keydef;
	char secret[1024];
	isc_buffer_t b;
	isc_result_t result;

	/*
	 * Find the keys corresponding to the keyids used by this listener.
	 */
	for (keyid = ISC_LIST_HEAD(*keyids); keyid != NULL; keyid = next) {
		next = ISC_LIST_NEXT(keyid, link);

		result = cfgkeylist_find(keylist, keyid->keyname, &keydef);
		if (result != ISC_R_SUCCESS) {
			cfg_obj_log(control, ns_g_lctx, ISC_LOG_WARNING,
				    "couldn't find key '%s' for use with "
				    "command channel %s",
				    keyid->keyname, socktext);
			ISC_LIST_UNLINK(*keyids, keyid, link);
			free_controlkey(keyid, mctx);
		} else {
			const cfg_obj_t *algobj = NULL;
			const cfg_obj_t *secretobj = NULL;
			const char *algstr = NULL;
			const char *secretstr = NULL;

			(void)cfg_map_get(keydef, "algorithm", &algobj);
			(void)cfg_map_get(keydef, "secret", &secretobj);
			INSIST(algobj != NULL && secretobj != NULL);

			algstr = cfg_obj_asstring(algobj);
			secretstr = cfg_obj_asstring(secretobj);

			if (ns_config_getkeyalgorithm(algstr, NULL, NULL) !=
			    ISC_R_SUCCESS)
			{
				cfg_obj_log(control, ns_g_lctx,
					    ISC_LOG_WARNING,
					    "unsupported algorithm '%s' in "
					    "key '%s' for use with command "
					    "channel %s",
					    algstr, keyid->keyname, socktext);
				ISC_LIST_UNLINK(*keyids, keyid, link);
				free_controlkey(keyid, mctx);
				continue;
			}

			isc_buffer_init(&b, secret, sizeof(secret));
			result = isc_base64_decodestring(secretstr, &b);

			if (result != ISC_R_SUCCESS) {
				cfg_obj_log(keydef, ns_g_lctx, ISC_LOG_WARNING,
					    "secret for key '%s' on "
					    "command channel %s: %s",
					    keyid->keyname, socktext,
					    isc_result_totext(result));
				ISC_LIST_UNLINK(*keyids, keyid, link);
				free_controlkey(keyid, mctx);
				continue;
			}

			keyid->secret.length = isc_buffer_usedlength(&b);
			keyid->secret.base = isc_mem_get(mctx,
							 keyid->secret.length);
			if (keyid->secret.base == NULL) {
				cfg_obj_log(keydef, ns_g_lctx, ISC_LOG_WARNING,
					   "couldn't register key '%s': "
					   "out of memory", keyid->keyname);
				ISC_LIST_UNLINK(*keyids, keyid, link);
				free_controlkey(keyid, mctx);
				break;
			}
			memcpy(keyid->secret.base, isc_buffer_base(&b),
			       keyid->secret.length);
		}
	}
}

#define CHECK(x) \
	do { \
		 result = (x); \
		 if (result != ISC_R_SUCCESS) \
			goto cleanup; \
	} while (0)
		
static isc_result_t
get_rndckey(isc_mem_t *mctx, controlkeylist_t *keyids) {
	isc_result_t result;
	cfg_parser_t *pctx = NULL;
	cfg_obj_t *config = NULL;
	const cfg_obj_t *key = NULL;
	const cfg_obj_t *algobj = NULL;
	const cfg_obj_t *secretobj = NULL;
	const char *algstr = NULL;
	const char *secretstr = NULL;
	controlkey_t *keyid = NULL;
	char secret[1024];
	isc_buffer_t b;

	CHECK(cfg_parser_create(mctx, ns_g_lctx, &pctx));
	CHECK(cfg_parse_file(pctx, ns_g_keyfile, &cfg_type_rndckey, &config));
	CHECK(cfg_map_get(config, "key", &key));

	keyid = isc_mem_get(mctx, sizeof(*keyid));
	if (keyid == NULL) 
		CHECK(ISC_R_NOMEMORY);
	keyid->keyname = isc_mem_strdup(mctx,
					cfg_obj_asstring(cfg_map_getname(key)));
	keyid->secret.base = NULL;
	keyid->secret.length = 0;
	ISC_LINK_INIT(keyid, link);
	if (keyid->keyname == NULL) 
		CHECK(ISC_R_NOMEMORY);

	CHECK(bind9_check_key(key, ns_g_lctx));

	(void)cfg_map_get(key, "algorithm", &algobj);
	(void)cfg_map_get(key, "secret", &secretobj);
	INSIST(algobj != NULL && secretobj != NULL);

	algstr = cfg_obj_asstring(algobj);
	secretstr = cfg_obj_asstring(secretobj);

	if (ns_config_getkeyalgorithm(algstr, NULL, NULL) != ISC_R_SUCCESS) {
		cfg_obj_log(key, ns_g_lctx,
			    ISC_LOG_WARNING,
			    "unsupported algorithm '%s' in "
			    "key '%s' for use with command "
			    "channel",
			    algstr, keyid->keyname);
		goto cleanup;
	}

	isc_buffer_init(&b, secret, sizeof(secret));
	result = isc_base64_decodestring(secretstr, &b);

	if (result != ISC_R_SUCCESS) {
		cfg_obj_log(key, ns_g_lctx, ISC_LOG_WARNING,
			    "secret for key '%s' on command channel: %s",
			    keyid->keyname, isc_result_totext(result));
		CHECK(result);
	}

	keyid->secret.length = isc_buffer_usedlength(&b);
	keyid->secret.base = isc_mem_get(mctx,
					 keyid->secret.length);
	if (keyid->secret.base == NULL) {
		cfg_obj_log(key, ns_g_lctx, ISC_LOG_WARNING,
			   "couldn't register key '%s': "
			   "out of memory", keyid->keyname);
		CHECK(ISC_R_NOMEMORY);
	}
	memcpy(keyid->secret.base, isc_buffer_base(&b),
	       keyid->secret.length);
	ISC_LIST_APPEND(*keyids, keyid, link);
	keyid = NULL;
	result = ISC_R_SUCCESS;

  cleanup:
	if (keyid != NULL)
		free_controlkey(keyid, mctx);
	if (config != NULL)
		cfg_obj_destroy(pctx, &config);
	if (pctx != NULL)
		cfg_parser_destroy(&pctx);
	return (result);
}
			
/*
 * Ensures that both '*global_keylistp' and '*control_keylistp' are
 * valid or both are NULL.
 */
static void
get_key_info(const cfg_obj_t *config, const cfg_obj_t *control,
	     const cfg_obj_t **global_keylistp,
	     const cfg_obj_t **control_keylistp)
{
	isc_result_t result;
	const cfg_obj_t *control_keylist = NULL;
	const cfg_obj_t *global_keylist = NULL;

	REQUIRE(global_keylistp != NULL && *global_keylistp == NULL);
	REQUIRE(control_keylistp != NULL && *control_keylistp == NULL);

	control_keylist = cfg_tuple_get(control, "keys");

	if (!cfg_obj_isvoid(control_keylist) &&
	    cfg_list_first(control_keylist) != NULL) {
		result = cfg_map_get(config, "key", &global_keylist);

		if (result == ISC_R_SUCCESS) {
			*global_keylistp = global_keylist;
			*control_keylistp = control_keylist;
		}
	}
}

static void
update_listener(ns_controls_t *cp, controllistener_t **listenerp,
		const cfg_obj_t *control, const cfg_obj_t *config,
		isc_sockaddr_t *addr, cfg_aclconfctx_t *aclconfctx,
	        const char *socktext, isc_sockettype_t type)
{
	controllistener_t *listener;
	const cfg_obj_t *allow;
	const cfg_obj_t *global_keylist = NULL;
	const cfg_obj_t *control_keylist = NULL;
	dns_acl_t *new_acl = NULL;
	controlkeylist_t keys;
	isc_result_t result = ISC_R_SUCCESS;

	for (listener = ISC_LIST_HEAD(cp->listeners);
	     listener != NULL;
	     listener = ISC_LIST_NEXT(listener, link))
		if (isc_sockaddr_equal(addr, &listener->address))
			break;

	if (listener == NULL) {
		*listenerp = NULL;
		return;
	}
		
	/*
	 * There is already a listener for this sockaddr.
	 * Update the access list and key information.
	 *
	 * First try to deal with the key situation.  There are a few
	 * possibilities:
	 *  (a)	It had an explicit keylist and still has an explicit keylist.
	 *  (b)	It had an automagic key and now has an explicit keylist.
	 *  (c)	It had an explicit keylist and now needs an automagic key.
	 *  (d) It has an automagic key and still needs the automagic key.
	 *
	 * (c) and (d) are the annoying ones.  The caller needs to know
	 * that it should use the automagic configuration for key information
	 * in place of the named.conf configuration.
	 *
	 * XXXDCL There is one other hazard that has not been dealt with,
	 * the problem that if a key change is being caused by a control
	 * channel reload, then the response will be with the new key
	 * and not able to be decrypted by the client.
	 */
	if (control != NULL)
		get_key_info(config, control, &global_keylist,
			     &control_keylist);

	if (control_keylist != NULL) {
		INSIST(global_keylist != NULL);

		ISC_LIST_INIT(keys);