pex: indicate refused update requests

This is used, in case an unknown peer requests a network update.
That way the peer can know that it is not considered to be a part of
the network by the remote peer.

Signed-off-by: Felix Fietkau <nbd@nbd.name>

5 files changed, 30 insertions, 3 deletions

diff --git a/network.h b/network.h
index aa45b6b..57450cc 100644
--- a/network.h
+++ b/network.h
@@ -57,6 +57,7 @@ struct network {
 	size_t net_data_len;
 	uint64_t net_data_version;
 	int num_net_queries;
+	unsigned int update_refused;
 
 	struct uloop_timeout reload_timer;
 
diff --git a/pex-msg.c b/pex-msg.c
index fef5505..34b3bb9 100644
--- a/pex-msg.c
+++ b/pex-msg.c
@@ -480,6 +480,8 @@ void *pex_msg_update_response_recv(const void *data, int len, enum pex_opcode op
 	uint8_t enc_key[CURVE25519_KEY_SIZE];
 	void *ret;
 
+	if (timestamp)
+		*timestamp = 0;
 	*data_len = 0;
 	if (op == PEX_MSG_UPDATE_RESPONSE) {
 		const struct pex_update_response *res = data;
@@ -510,7 +512,8 @@ void *pex_msg_update_response_recv(const void *data, int len, enum pex_opcode op
 
 		data += sizeof(*res);
 		len -= sizeof(*res);
-	} else if (op == PEX_MSG_UPDATE_RESPONSE_NO_DATA) {
+	} else if (op == PEX_MSG_UPDATE_RESPONSE_NO_DATA ||
+	           op == PEX_MSG_UPDATE_RESPONSE_REFUSED) {
 		const struct pex_update_response_no_data *res = data;
 
 		if (len < sizeof(*res) || !res->cur_version)
@@ -520,6 +523,8 @@ void *pex_msg_update_response_recv(const void *data, int len, enum pex_opcode op
 		if (!ctx)
 			return NULL;
 
+		if (timestamp)
+			*timestamp = be64_to_cpu(res->cur_version);
 		goto error;
 	} else {
 		return NULL;
diff --git a/pex-msg.h b/pex-msg.h
index 36aade2..473d7ed 100644
--- a/pex-msg.h
+++ b/pex-msg.h
@@ -26,6 +26,7 @@ enum pex_opcode {
 	PEX_MSG_ENDPOINT_NOTIFY,
 	PEX_MSG_ENDPOINT_PORT_NOTIFY,
 	PEX_MSG_ENROLL,
+	PEX_MSG_UPDATE_RESPONSE_REFUSED,
 };
 
 #define PEX_ID_LEN		8
diff --git a/pex.c b/pex.c
index cfd238f..a1c602d 100644
--- a/pex.c
+++ b/pex.c
@@ -572,7 +572,7 @@ network_pex_recv_update_request(struct network *net, struct network_peer *peer,
 
 	D("receive update request, local version=%"PRIu64", remote version=%"PRIu64, net->net_data_version, req_version);
 
-	if (req_version && req_version >= net->net_data_version) {
+	if (peer && req_version && req_version >= net->net_data_version) {
 		struct pex_update_response_no_data *res;
 
 		pex_msg_init_ext(net, PEX_MSG_UPDATE_RESPONSE_NO_DATA, !!addr);
@@ -584,6 +584,15 @@ network_pex_recv_update_request(struct network *net, struct network_peer *peer,
 
 	if (req_version > net->net_data_version)
 		network_pex_send_update_request(net, peer, addr);
+	else if (!peer && net->net_data_len) {
+		struct pex_update_response_no_data *res;
+
+		pex_msg_init_ext(net, PEX_MSG_UPDATE_RESPONSE_REFUSED, !!addr);
+		res = pex_msg_append(sizeof(*res));
+		res->req_id = req->req_id;
+		res->cur_version = cpu_to_be64(net->net_data_version);
+		pex_msg_send_ext(net, peer, addr);
+	}
 
 	if (!peer || !net->net_data_len)
 		return;
@@ -628,8 +637,12 @@ network_pex_recv_update_response(struct network *net, const uint8_t *data, size_
 		return;
 
 	net_data = pex_msg_update_response_recv(data, len, op, &net_data_len, &version);
-	if (!net_data)
+	if (!net_data) {
+		if (op == PEX_MSG_UPDATE_RESPONSE_REFUSED && net_data_len == -1 &&
+		    version > net->net_data_version)
+			net->update_refused++;
 		return;
+	}
 
 	if (version <= net->net_data_version) {
 		free(net_data);
@@ -684,6 +697,7 @@ network_pex_recv(struct network *net, struct network_peer *peer, struct pex_hdr
 	case PEX_MSG_UPDATE_RESPONSE:
 	case PEX_MSG_UPDATE_RESPONSE_DATA:
 	case PEX_MSG_UPDATE_RESPONSE_NO_DATA:
+	case PEX_MSG_UPDATE_RESPONSE_REFUSED:
 		network_pex_recv_update_response(net, data, hdr->len,
 					      NULL, hdr->opcode);
 		break;
@@ -1063,6 +1077,7 @@ global_pex_recv(void *msg, size_t msg_len, struct sockaddr_in6 *addr)
 		fallthrough;
 	case PEX_MSG_UPDATE_RESPONSE_DATA:
 	case PEX_MSG_UPDATE_RESPONSE_NO_DATA:
+	case PEX_MSG_UPDATE_RESPONSE_REFUSED:
 		network_pex_recv_update_response(net, data, hdr->len, addr, hdr->opcode);
 		break;
 	case PEX_MSG_ENDPOINT_PORT_NOTIFY:
diff --git a/ubus.c b/ubus.c
index 47fa743..d1852b5 100644
--- a/ubus.c
+++ b/ubus.c
@@ -71,8 +71,13 @@ __network_dump(struct blob_buf *buf, struct network *net)
 		str = blobmsg_alloc_string_buffer(buf, "local_address", INET6_ADDRSTRLEN);
 		inet_ntop(AF_INET6, &local->peer.local_addr.in6, str, INET6_ADDRSTRLEN);
 		blobmsg_add_string_buffer(buf);
+	} else {
+		if (net->net_data_len)
+			blobmsg_add_u8(buf, "no_local_host", true);
 	}
 
+	if (net->update_refused)
+		blobmsg_add_u32(buf, "update_refused", net->update_refused);
 
 	c = blobmsg_open_table(buf, "peers");
 	vlist_for_each_element(&net->peers, peer, node) {