network: add support for the local_network option

This lets unetd automatically query netifd for local addresses in order to
add broadcast addresses as PEX hosts for discovering peers.

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

6 files changed, 160 insertions, 4 deletions

diff --git a/network.c b/network.c
index fe1b2c9..721d48e 100644
--- a/network.c
+++ b/network.c
@@ -57,6 +57,7 @@ const struct blobmsg_policy network_policy[__NETWORK_ATTR_MAX] = {
 	[NETWORK_ATTR_DOMAIN] = { "domain", BLOBMSG_TYPE_STRING },
 	[NETWORK_ATTR_UPDATE_CMD] = { "update-cmd", BLOBMSG_TYPE_STRING },
 	[NETWORK_ATTR_TUNNELS] = { "tunnels", BLOBMSG_TYPE_TABLE },
+	[NETWORK_ATTR_LOCAL_NET] = { "local_network", BLOBMSG_TYPE_ARRAY },
 	[NETWORK_ATTR_AUTH_CONNECT] = { "auth_connect", BLOBMSG_TYPE_ARRAY },
 	[NETWORK_ATTR_PEER_DATA] = { "peer_data", BLOBMSG_TYPE_ARRAY },
 };
@@ -656,6 +657,10 @@ network_set_config(struct network *net, struct blob_attr *config)
 	if ((cur = tb[NETWORK_ATTR_TUNNELS]) != NULL)
 		net->config.tunnels = cur;
 
+	if ((cur = tb[NETWORK_ATTR_LOCAL_NET]) != NULL &&
+	    blobmsg_check_array(cur, BLOBMSG_TYPE_STRING) > 0)
+		net->config.local_network = cur;
+
 	if ((cur = tb[NETWORK_ATTR_AUTH_CONNECT]) != NULL &&
 	    blobmsg_check_array(cur, BLOBMSG_TYPE_STRING) > 0)
 		net->config.auth_connect = cur;
diff --git a/network.h b/network.h
index bfd4c78..f713fd3 100644
--- a/network.h
+++ b/network.h
@@ -37,6 +37,7 @@ struct network {
 		const char *domain;
 		struct blob_attr *tunnels;
 		struct blob_attr *net_data;
+		struct blob_attr *local_network;
 		struct blob_attr *auth_connect;
 		struct blob_attr *peer_data;
 	} config;
@@ -87,6 +88,7 @@ enum {
 	NETWORK_ATTR_KEEPALIVE,
 	NETWORK_ATTR_DOMAIN,
 	NETWORK_ATTR_TUNNELS,
+	NETWORK_ATTR_LOCAL_NET,
 	NETWORK_ATTR_AUTH_CONNECT,
 	NETWORK_ATTR_PEER_DATA,
 	__NETWORK_ATTR_MAX,
diff --git a/pex.c b/pex.c
index 8a13c80..db143fc 100644
--- a/pex.c
+++ b/pex.c
@@ -740,8 +740,9 @@ network_pex_fd_cb(struct uloop_fd *fd, unsigned int events)
 	}
 }
 
-void network_pex_create_host(struct network *net, union network_endpoint *ep,
-			     unsigned int timeout)
+struct network_pex_host *
+network_pex_create_host(struct network *net, union network_endpoint *ep,
+			unsigned int timeout)
 {
 	struct network_pex *pex = &net->pex;
 	struct network_pex_host *host;
@@ -768,6 +769,7 @@ void network_pex_create_host(struct network *net, union network_endpoint *ep,
 out:
 	if (timeout && (new_host || host->timeout))
 		host->timeout = timeout + unet_gettime();
+	return host;
 }
 
 static void
@@ -812,6 +814,84 @@ network_pex_open_auth_connect(struct network *net)
 }
 
 
+static void
+__network_pex_reload_iface(struct network *net, struct blob_attr *data)
+{
+	static const struct blobmsg_policy policy[] = {
+		{ "address", BLOBMSG_TYPE_STRING },
+		{ "mask", BLOBMSG_TYPE_INT32 },
+	};
+	struct network_pex_host *host;
+	struct blob_attr *tb[2], *cur;
+	size_t rem;
+
+	if (!data)
+		return;
+
+	blobmsg_for_each_attr(cur, data, rem) {
+		union network_endpoint ep = {};
+		uint32_t mask;
+
+		blobmsg_parse_attr(policy, ARRAY_SIZE(policy), tb, cur);
+		if (!tb[0] || !tb[1])
+			continue;
+
+		mask = blobmsg_get_u32(tb[1]);
+		if (mask >= 31 || !mask)
+			continue;
+
+		if (network_get_endpoint(&ep, AF_INET, blobmsg_get_string(tb[0]),
+					 UNETD_GLOBAL_PEX_PORT, 0) < 0)
+			continue;
+
+		*(uint32_t *)&ep.in.sin_addr |= htonl((~0U) >> mask);
+		host = network_pex_create_host(net, &ep, 0);
+		host->interface = true;
+	}
+}
+
+static void
+__network_pex_reload(struct network *net)
+{
+	struct network_pex *pex = &net->pex;
+	struct network_pex_host *host, *tmp;
+	struct blob_attr *cur;
+	size_t rem;
+
+	if (!net->config.local_network)
+		return;
+
+	list_for_each_entry_safe(host, tmp, &pex->hosts, list)
+		if (host->interface)
+			network_pex_free_host(net, host);
+
+	blobmsg_for_each_attr(cur, net->config.local_network, rem) {
+		const char *name = blobmsg_get_string(cur);
+		struct blob_attr *addrs;
+
+		addrs = unetd_ubus_get_network_addr_list(name);
+		__network_pex_reload_iface(net, addrs);
+	}
+}
+
+static void
+network_pex_reload_cb(struct uloop_timeout *t)
+{
+	struct network *net;
+
+	avl_for_each_element(&networks, net, node)
+		__network_pex_reload(net);
+}
+
+void network_pex_reload(void)
+{
+	static struct uloop_timeout timer = {
+		.cb = network_pex_reload_cb,
+	};
+
+	uloop_timeout_set(&timer, 1);
+}
+
 int network_pex_open(struct network *net)
 {
 	struct network_host *local_host = net->net_config.local_host;
@@ -822,6 +902,7 @@ int network_pex_open(struct network *net)
 	int fd;
 
 	network_pex_open_auth_connect(net);
+	__network_pex_reload(net);
 
 	if (!local_host || !local_host->peer.pex_port)
 		return 0;
diff --git a/pex.h b/pex.h
index 271d998..f0173a6 100644
--- a/pex.h
+++ b/pex.h
@@ -18,6 +18,7 @@ struct network_pex_host {
 	uint64_t timeout;
 	uint64_t last_active;
 	uint64_t last_ping;
+	bool interface;
 	union network_endpoint endpoint;
 };
 
@@ -76,11 +77,13 @@ void network_pex_init(struct network *net);
 int network_pex_open(struct network *net);
 void network_pex_close(struct network *net);
 void network_pex_free(struct network *net);
+void network_pex_reload();
 
 void network_pex_event(struct network *net, struct network_peer *peer,
 		       enum pex_event ev);
-void network_pex_create_host(struct network *net, union network_endpoint *ep,
-			     unsigned int timeout);
+struct network_pex_host *
+network_pex_create_host(struct network *net, union network_endpoint *ep,
+			unsigned int timeout);
 
 void network_stun_init(struct network *net);
 void network_stun_free(struct network *net);
diff --git a/ubus.c b/ubus.c
index 2377acc..6e289da 100644
--- a/ubus.c
+++ b/ubus.c
@@ -8,6 +8,7 @@
 #include "enroll.h"
 
 static struct ubus_auto_conn conn;
+static struct ubus_subscriber sub;
 static struct blob_buf b;
 
 static int
@@ -446,6 +447,7 @@ ubus_connect_handler(struct ubus_context *ctx)
 {
 	int ret;
 
+	ubus_register_subscriber(ctx, &sub);
 	ret = ubus_add_object(ctx, &unetd_object);
 	if (ret)
 		fprintf(stderr, "Failed to add object: %s\n", ubus_strerror(ret));
@@ -514,6 +516,47 @@ void unetd_ubus_netifd_update(struct blob_attr *data)
 	ubus_invoke(&conn.ctx, id, "notify_proto", data, NULL, NULL, 5000);
 }
 
+static void
+ubus_network_status_cb(struct ubus_request *req, int type, struct blob_attr *msg)
+{
+	static const struct blobmsg_policy policy =
+		{ "ipv4-address", BLOBMSG_TYPE_ARRAY };
+	struct blob_attr *attr, *cur;
+	size_t rem;
+
+	blobmsg_parse_attr(&policy, 1, &attr, msg);
+	if (!attr)
+		return;
+
+	if (blobmsg_check_array(attr, BLOBMSG_TYPE_TABLE) < 0)
+		return;
+
+	blobmsg_for_each_attr(cur, attr, rem)
+		blobmsg_add_blob(&b, cur);
+}
+
+struct blob_attr *unetd_ubus_get_network_addr_list(const char *name)
+{
+	char *objname;
+	uint32_t id;
+	size_t len;
+
+	if (strlen(name) > 64)
+		return NULL;
+
+	len = sizeof("network.interface.") + strlen(name) + 1;
+	objname = alloca(len);
+	snprintf(objname, len, "network.interface.%s", name);
+
+	if (ubus_lookup_id(&conn.ctx, objname, &id))
+		return NULL;
+
+	blob_buf_init(&b, 0);
+	ubus_invoke(&conn.ctx, id, "status", b.head, ubus_network_status_cb, NULL, 10000);
+
+	return b.head;
+}
+
 void unetd_ubus_netifd_add_route(struct network *net, union network_endpoint *ep)
 {
 	uint32_t id;
@@ -543,8 +586,25 @@ void unetd_ubus_netifd_add_route(struct network *net, union network_endpoint *ep
 	ubus_invoke(&conn.ctx, id, "add_host_route", b.head, NULL, NULL, -1);
 }
 
+static int
+unetd_netifd_sub_cb(struct ubus_context *ctx, struct ubus_object *obj,
+		    struct ubus_request_data *req,
+		    const char *method, struct blob_attr *msg)
+{
+	network_pex_reload();
+	return 0;
+}
+
+static bool
+unetd_new_object_sub_cb(struct ubus_context *ctx, struct ubus_subscriber *sub, const char *path)
+{
+	return path && !strcmp(path, "network.interface");
+}
+
 void unetd_ubus_init(void)
 {
+	sub.cb = unetd_netifd_sub_cb;
+	sub.new_obj_cb = unetd_new_object_sub_cb;
 	conn.cb = ubus_connect_handler;
 	ubus_auto_connect(&conn);
 }
diff --git a/ubus.h b/ubus.h
index 1c42894..90a6e76 100644
--- a/ubus.h
+++ b/ubus.h
@@ -11,6 +11,7 @@ void unetd_ubus_notify(const char *type, struct blob_attr *data);
 void unetd_ubus_network_notify(struct network *net);
 void unetd_ubus_netifd_update(struct blob_attr *data);
 void unetd_ubus_netifd_add_route(struct network *net, union network_endpoint *ep);
+struct blob_attr *unetd_ubus_get_network_addr_list(const char *name);
 #else
 static inline void unetd_ubus_init(void)
 {
@@ -27,6 +28,10 @@ static inline void unetd_ubus_netifd_update(struct blob_attr *data)
 static inline void unetd_ubus_netifd_add_route(struct network *net, union network_endpoint *ep)
 {
 }
+static inline struct blob_attr *unetd_ubus_get_network_addr_list(const char *name)
+{
+	return NULL;
+}
 #endif
 
 #endif