[5/8] rmnet: Delete stale RMnet links at startup

Commit Message

Denis Kenzior Nov. 15, 2024, 10 p.m. UTC

Most likely such links could be left over from ofono not exiting
cleanly.  There's unfortunately no easy way to mark links as belonging
to a particular process, so remove all of them.
---
 src/rmnet.c | 119 +++++++++++++++++++++++++++++++++++++++++++++++++++-
 1 file changed, 118 insertions(+), 1 deletion(-)

Patch

diff --git a/src/rmnet.c b/src/rmnet.c
index f784e5cc4bb2..bb5a2ed1805b 100644
--- a/src/rmnet.c
+++ b/src/rmnet.c
@@ -25,10 +25,118 @@ 
 #define RMNET_TYPE "rmnet"
 #define MAX_MUX_IDS 254U
 
+struct rmnet_request {
+	uint32_t parent_ifindex;
+	rmnet_new_interfaces_func_t new_cb;
+	void *user_data;
+	rmnet_destroy_func_t destroy;
+	int id;
+	uint32_t netlink_id;
+	uint16_t request_type;
+	uint8_t current;
+	uint8_t n_interfaces;
+	struct rmnet_ifinfo infos[];
+};
+
 static struct l_netlink *rtnl;
 static uint32_t dump_id;
 static uint32_t link_notify_id;
 static struct l_uintset *mux_ids;
+struct l_queue *request_q;
+
+static void rmnet_request_free(struct rmnet_request *req)
+{
+	if (req->destroy)
+		req->destroy(req->user_data);
+
+	l_free(req);
+}
+
+static struct rmnet_request *__rmnet_del_request_new(unsigned int n_interfaces,
+					const struct rmnet_ifinfo *interfaces)
+{
+	struct rmnet_request *req;
+
+	req = l_malloc(sizeof(struct rmnet_request) +
+				sizeof(struct rmnet_ifinfo) * n_interfaces);
+	memset(req, 0, sizeof(struct rmnet_request));
+	req->request_type = RTM_DELLINK;
+	req->n_interfaces = n_interfaces;
+	memcpy(req->infos, interfaces,
+			sizeof(struct rmnet_ifinfo) * n_interfaces);
+
+	return req;
+}
+
+static int rmnet_link_del(uint32_t ifindex, l_netlink_command_func_t cb,
+				void *userdata, l_netlink_destroy_func_t destroy,
+				uint32_t *out_command_id)
+{
+	struct l_netlink_message *nlm =
+		l_netlink_message_new(RTM_DELLINK, 0);
+	struct ifinfomsg ifi;
+	uint32_t id;
+
+	memset(&ifi, 0, sizeof(ifi));
+	ifi.ifi_family = AF_UNSPEC;
+	ifi.ifi_index = ifindex;
+
+	l_netlink_message_add_header(nlm, &ifi, sizeof(ifi));
+
+	id = l_netlink_send(rtnl, nlm, cb, userdata, destroy);
+	if (!id) {
+		l_netlink_message_unref(nlm);
+		return -EIO;
+	}
+
+	if (out_command_id)
+		*out_command_id = id;
+
+	return 0;
+}
+
+static void rmnet_start_next_request();
+
+static void rmnet_del_link_cb(int error, uint16_t type, const void *data,
+					uint32_t len, void *user_data)
+{
+	struct rmnet_request *req = l_queue_peek_head(request_q);
+
+	DBG("DELLINK %u (%u/%u) complete, error: %d",
+		req->netlink_id, req->current, req->n_interfaces, error);
+
+	req->netlink_id = 0;
+	req->current += 1;
+
+	if (req->current < req->n_interfaces)
+		goto next_request;
+
+	l_queue_pop_head(request_q);
+	rmnet_request_free(req);
+
+next_request:
+	if (l_queue_length(request_q) > 0)
+		rmnet_start_next_request();
+}
+
+static void rmnet_start_next_request()
+{
+	struct rmnet_request *req = l_queue_peek_head(request_q);
+
+	if (!req)
+		return;
+
+	if (req->request_type == RTM_DELLINK) {
+		uint32_t ifindex = req->infos[req->current].ifindex;
+
+		L_WARN_ON(rmnet_link_del(ifindex, rmnet_del_link_cb, NULL, NULL,
+					&req->netlink_id) < 0);
+		DBG("Start DELLINK: ifindex: %u, interface: %u/%u, request: %u",
+				ifindex, req->current,
+				req->n_interfaces, req->netlink_id);
+		return;
+	}
+}
 
 int rmnet_get_interfaces(uint32_t parent_ifindex, unsigned int n_interfaces,
 				rmnet_new_interfaces_func_t cb,
@@ -152,6 +260,9 @@  static int rmnet_parse_link(const void *data, uint32_t len,
 static void rmnet_link_dump_destroy(void *user_data)
 {
 	dump_id = 0;
+
+	if (l_queue_length(request_q) > 0)
+		rmnet_start_next_request();
 }
 
 static void rmnet_link_dump_cb(int error,
@@ -159,6 +270,7 @@  static void rmnet_link_dump_cb(int error,
 				uint32_t len, void *user_data)
 {
 	struct rmnet_ifinfo info;
+	struct rmnet_request *req;
 
 	/* Check conditions that can't happen on a dump */
 	if (error || type != RTM_NEWLINK)
@@ -168,9 +280,12 @@  static void rmnet_link_dump_cb(int error,
 				info.ifname, &info.ifindex, &info.mux_id) < 0)
 		return;
 
-	DBG("Existing rmnet link: %s(%u) mux_id: %u",
+	DBG("Removing existing rmnet link: %s(%u) mux_id: %u",
 			info.ifname, info.ifindex, info.mux_id);
 	l_uintset_put(mux_ids, info.mux_id);
+
+	req = __rmnet_del_request_new(1, &info);
+	l_queue_push_tail(request_q, req);
 }
 
 static int rmnet_link_dump()
@@ -235,6 +350,7 @@  static int rmnet_init(void)
 	link_notify_id = l_netlink_register(rtnl, RTNLGRP_LINK,
 					rmnet_link_notification, NULL, NULL);
 	mux_ids = l_uintset_new_from_range(1, MAX_MUX_IDS);
+	request_q = l_queue_new();
 
 	return 0;
 dump_failed:
@@ -244,6 +360,7 @@  dump_failed:
 
 static void rmnet_exit(void)
 {
+	l_queue_destroy(request_q, (l_queue_destroy_func_t) rmnet_request_free);
 	l_uintset_free(mux_ids);
 	l_netlink_unregister(rtnl, link_notify_id);
 	l_netlink_destroy(rtnl);