diff options
| -rw-r--r-- | plugins/iwd.c | 87 |
1 files changed, 84 insertions, 3 deletions
diff --git a/plugins/iwd.c b/plugins/iwd.c index 9d437b3d..2fe49a23 100644 --- a/plugins/iwd.c +++ b/plugins/iwd.c @@ -41,7 +41,15 @@ static GDBusClient *client; static GDBusProxy *agent_proxy; static GHashTable *adapters; static GHashTable *devices; +/* + * Mapping from dbus path -> struct iwd_network, tracking the set of Network + * objects seen by iwd. + */ static GHashTable *networks; +/* + * Mapping from dbus path -> struct iwd_network, tracking the set of iwd + * KnownNetwork objects. + */ static GHashTable *known_networks; static GHashTable *stations; static GHashTable *access_points; @@ -84,6 +92,11 @@ struct iwd_device { struct connman_device *device; }; +/* + * Structure tracking an net.connman.iwd.Network D-Bus object. + * + * This is mapped one-to-one to a connman_network object. + */ struct iwd_network { GDBusProxy *proxy; char *path; @@ -95,10 +108,17 @@ struct iwd_network { struct iwd_device *iwdd; struct connman_network *network; - /* service's autoconnect */ + /* + * connman_service's autoconnect. + * + * See Note [Managing autoconnect state] for more details. + */ bool cm_autoconnect; }; +/* + * Structure tracking a net.connman.iwd.KnownNetwork D-Bus object. + */ struct iwd_known_network { GDBusProxy *proxy; char *path; @@ -109,7 +129,11 @@ struct iwd_known_network { bool iwd_auto_connect; int auto_connect_id; - /* service's autoconnect */ + /* + * connman_service's autoconnect. + * + * See Note [Managing autoconnect state] for more details. + */ bool cm_autoconnect; }; @@ -1153,11 +1177,58 @@ static void network_property_change(GDBusProxy *proxy, const char *name, iwdkn = g_hash_table_lookup(known_networks, iwdn->known_network); - if (iwdkn) + if (iwdkn) { + /* See Note [Managing autoconnect state] */ + iwdkn->cm_autoconnect = iwdn->cm_autoconnect; update_auto_connect(iwdkn); + } } } +/* + * Note [Managing autoconnect state]: + * + * We need to set the iwd_known_network's cm_autoconnect status from the + * iwd_network, which has in turn been set to the corresponding + * connman_service's state when it first appeared (due to + * __connman_service_create_from_network). + * + * The management of the autoconnect state between ConnMan and its plugins and + * iwd is rather subtle and prone to bugs: + * - ConnMan itself determines the autoconnect state in struct connman_service, + * which we cannot directly see; we only see cm_network_set_autoconnect + * callbacks. + * + * - The iwd plugin maintains an independent state machine tracking iwd's view of + * the world, which processes events in a non atomic fashion; for + * instance, a iwd.KnownNetwork created event will appear before the + * corresponding PropertyChanged setting the KnownNetwork property of the + * iwd.Network corresponding to the created iwd.KnownNetwork. + * + * A typical flow of a network being newly connected to looks like so: + * - An iwd.Network appears, and add_network registers a connman_network + * structure with ConnMan. ConnMan then in turn creates a service via + * __connman_service_create_from_network. + * + * - The iwd plugin receives a callback from ConnMan to set the autoconnect + * state, setting the cm_autoconnect state of the iwd_network. At this point, + * there is no iwd_known_network yet. + * + * - ConnMan receives a Connect() request on the connman.Service, which is + * forwarded to the iwd plugin via cm_network_connect. The iwd plugin calls + * Connect() on the corresponding iwd.Network (possibly using the iwd + * plugin's agent to get credentials if necessary). + * + * - Around the time that the connection completes, a iwd.KnownNetwork created + * event appears, followed by a PropertyChanged event noting the change in + * the iwd.Network's KnownNetwork property. + * + * This is the first time that we can associate the iwd.KnownNetwork with the + * corresponding iwd.Network and iwd_network. We have the ConnMan-side + * autoconnect status in the iwd_network structure at this point, so we + * synchronize the autoconnect state with iwd here. + */ + static unsigned char calculate_strength(int strength) { unsigned char res; @@ -1742,6 +1813,16 @@ static void create_known_network(GDBusProxy *proxy) iwdkn->name, iwdkn->type, iwdkn->hidden, iwdkn->last_connected_time, iwdkn->iwd_auto_connect); + /* + * Although we initialize the autoconnect state of this + * iwd_known_network here, it is only initialized in the case of + * networks that already existed prior to startup: in the + * case of a new iwd.KnownNetwork appearing, we are called before the + * iwd_network.known_network field is initialized by a subsequent + * PropertyChanged event. + * + * See Note [Managing autoconnect state]. + */ init_auto_connect(iwdkn); g_dbus_proxy_set_property_watch(iwdkn->proxy, |