network/queue: introduce RemoveRequest and relevant functions

This is similar to Request, but will be used on removing configuration (e.g. address, route, and so on). By using another queue for removing configuration, then we can avoid to fill the reply callback buffer in sd-netlink by remove message calls. Follow-up for 4e6a35e2b2.
2024-01-12 09:36:00 +09:00
parent 64b74c86d0
commit 85a6f300c1
4 changed files with 163 additions and 0 deletions
@@ -424,6 +424,7 @@ static int manager_connect_rtnl(Manager *m, int fd) {
 static int manager_post_handler(sd_event_source *s, void *userdata) {
        Manager *manager = ASSERT_PTR(userdata);

+        (void) manager_process_remove_requests(manager);
        (void) manager_process_requests(manager);
        (void) manager_clean_all(manager);
        return 0;
@@ -594,6 +595,7 @@ Manager* manager_free(Manager *m) {
                (void) link_stop_engines(link, true);

        m->request_queue = ordered_set_free(m->request_queue);
+        m->remove_request_queue = ordered_set_free(m->remove_request_queue);

        m->dirty_links = set_free_with_destructor(m->dirty_links, link_unref);
        m->new_wlan_ifindices = set_free(m->new_wlan_ifindices);
@@ -102,6 +102,7 @@ struct Manager {

        bool request_queued;
        OrderedSet *request_queue;
+        OrderedSet *remove_request_queue;

        Hashmap *tuntap_fds_by_name;
 };
@@ -224,6 +224,10 @@ int manager_process_requests(Manager *manager) {

        assert(manager);

+        /* Process only when no remove request is queued. */
+        if (!ordered_set_isempty(manager->remove_request_queue))
+                return 0;
+
        manager->request_queued = false;

        ORDERED_SET_FOREACH(req, manager->request_queue) {
@@ -339,3 +343,110 @@ static const char *const request_type_table[_REQUEST_TYPE_MAX] = {
 };

 DEFINE_STRING_TABLE_LOOKUP_TO_STRING(request_type, RequestType);
+
+static RemoveRequest* remove_request_free(RemoveRequest *req) {
+        if (!req)
+                return NULL;
+
+        if (req->manager)
+                ordered_set_remove(req->manager->remove_request_queue, req);
+
+        if (req->unref_func)
+                req->unref_func(req->userdata);
+
+        link_unref(req->link);
+        sd_netlink_unref(req->netlink);
+        sd_netlink_message_unref(req->message);
+
+        return mfree(req);
+}
+
+DEFINE_TRIVIAL_CLEANUP_FUNC(RemoveRequest*, remove_request_free);
+DEFINE_TRIVIAL_DESTRUCTOR(remove_request_destroy_callback, RemoveRequest, remove_request_free);
+DEFINE_PRIVATE_HASH_OPS_WITH_KEY_DESTRUCTOR(
+                remove_request_hash_ops,
+                void,
+                trivial_hash_func,
+                trivial_compare_func,
+                remove_request_free);
+
+int remove_request_add(
+                Manager *manager,
+                Link *link,
+                void *userdata,
+                mfree_func_t unref_func,
+                sd_netlink *netlink,
+                sd_netlink_message *message,
+                remove_request_netlink_handler_t netlink_handler) {
+
+        _cleanup_(remove_request_freep) RemoveRequest *req = NULL;
+        int r;
+
+        assert(manager);
+        assert(userdata);
+        assert(netlink);
+        assert(message);
+
+        req = new(RemoveRequest, 1);
+        if (!req)
+                return -ENOMEM;
+
+        *req = (RemoveRequest) {
+                .link = link_ref(link), /* link may be NULL, but link_ref() handles it gracefully. */
+                .userdata = userdata,
+                .netlink = sd_netlink_ref(netlink),
+                .message = sd_netlink_message_ref(message),
+                .netlink_handler = netlink_handler,
+        };
+
+        r = ordered_set_ensure_put(&manager->remove_request_queue, &remove_request_hash_ops, req);
+        if (r < 0)
+                return r;
+        assert(r > 0);
+
+        req->manager = manager;
+        req->unref_func = unref_func;
+
+        TAKE_PTR(req);
+        return 0;
+}
+
+int manager_process_remove_requests(Manager *manager) {
+        RemoveRequest *req;
+        int r;
+
+        assert(manager);
+
+        while ((req = ordered_set_first(manager->remove_request_queue))) {
+
+                /* Do not make the reply callback queue in sd-netlink full. */
+                if (netlink_get_reply_callback_count(req->netlink) >= REPLY_CALLBACK_COUNT_THRESHOLD)
+                        return 0;
+
+                r = netlink_call_async(
+                                req->netlink, NULL, req->message,
+                                req->netlink_handler,
+                                remove_request_destroy_callback,
+                                req);
+                if (r < 0) {
+                        _cleanup_(link_unrefp) Link *link = link_ref(req->link);
+
+                        log_link_warning_errno(link, r, "Failed to call netlink message: %m");
+
+                        /* First free the request. */
+                        remove_request_free(req);
+
+                        /* Then, make the link enter the failed state. */
+                        if (link)
+                                link_enter_failed(link);
+
+                } else {
+                        /* On success, netlink needs to be unref()ed. Otherwise, the netlink and remove
+                         * request may not freed on shutting down. */
+                        req->netlink = sd_netlink_unref(req->netlink);
+                        ordered_set_remove(manager->remove_request_queue, req);
+                }
+        }
+
+        return 0;
+}
@@ -139,3 +139,52 @@ int manager_process_requests(Manager *manager);
 int request_call_netlink_async(sd_netlink *nl, sd_netlink_message *m, Request *req);

 const char* request_type_to_string(RequestType t) _const_;
+
+typedef struct RemoveRequest RemoveRequest;
+typedef int (*remove_request_netlink_handler_t)(sd_netlink *nl, sd_netlink_message *m, RemoveRequest *req);
+
+struct RemoveRequest {
+        Manager *manager;
+        Link *link;
+        void *userdata; /* e.g. Address */
+        mfree_func_t unref_func; /* e.g. address_unref() */
+        sd_netlink *netlink;
+        sd_netlink_message *message;
+        remove_request_netlink_handler_t netlink_handler;
+};
+
+int remove_request_add(
+                Manager *manager,
+                Link *link,
+                void *userdata, /* This is unref()ed when the call failed. */
+                mfree_func_t unref_func,
+                sd_netlink *netlink,
+                sd_netlink_message *message,
+                remove_request_netlink_handler_t netlink_handler);
+
+#define _remove_request_add(manager, link, data, name, nl, m, handler)  \
+        ({                                                              \
+                typeof(*data) *_data = (data);                          \
+                int _r;                                                 \
+                                                                        \
+                _r = remove_request_add(manager, link, _data,           \
+                                        (mfree_func_t) name##_unref,    \
+                                        nl, m, handler);                \
+                if (_r >= 0)                                            \
+                        name##_ref(_data);                              \
+                _r;                                                     \
+        })
+
+
+#define link_remove_request_add(link, data, name, nl, m, handler)       \
+        ({                                                              \
+                Link *_link = (link);                                   \
+                                                                        \
+                _remove_request_add(_link->manager, _link, data, name,  \
+                                    nl, m, handler);                    \
+        })
+
+#define manager_remove_request_add(manager, data, name, nl, m, handler) \
+        _remove_request_add(manager, NULL, data, name, nl, m, handler)
+
+int manager_process_remove_requests(Manager *manager);