network: expose carrier and address states over dbus

Previously, when a bridge or bonding interface is in degraded-carrier
state, then we cannot judge the interface has addresses or not.
By using the new states, dbus clients can distinguish such situation.

src/libsystemd/sd-network/network-util.c

@@ -32,3 +32,22 @@ static const char* const link_operstate_table[_LINK_OPERSTATE_MAX] = {
 };
 
 DEFINE_STRING_TABLE_LOOKUP(link_operstate, LinkOperationalState);
+
+static const char* const link_carrier_state_table[_LINK_CARRIER_STATE_MAX] = {
+        [LINK_CARRIER_STATE_OFF]              = "off",
+        [LINK_CARRIER_STATE_NO_CARRIER]       = "no-carrier",
+        [LINK_CARRIER_STATE_DORMANT]          = "dormant",
+        [LINK_CARRIER_STATE_DEGRADED_CARRIER] = "degraded-carrier",
+        [LINK_CARRIER_STATE_CARRIER]          = "carrier",
+        [LINK_CARRIER_STATE_ENSLAVED]         = "enslaved",
+};
+
+DEFINE_STRING_TABLE_LOOKUP(link_carrier_state, LinkCarrierState);
+
+static const char* const link_address_state_table[_LINK_ADDRESS_STATE_MAX] = {
+        [LINK_ADDRESS_STATE_OFF]      = "off",
+        [LINK_ADDRESS_STATE_DEGRADED] = "degraded",
+        [LINK_ADDRESS_STATE_ROUTABLE] = "routable",
+};
+
+DEFINE_STRING_TABLE_LOOKUP(link_address_state, LinkAddressState);

src/libsystemd/sd-network/network-util.h

@@ -41,3 +41,9 @@ typedef enum LinkAddressState {
 
 const char* link_operstate_to_string(LinkOperationalState s) _const_;
 LinkOperationalState link_operstate_from_string(const char *s) _pure_;
+
+const char* link_carrier_state_to_string(LinkCarrierState s) _const_;
+LinkCarrierState link_carrier_state_from_string(const char *s) _pure_;
+
+const char* link_address_state_to_string(LinkAddressState s) _const_;
+LinkAddressState link_address_state_from_string(const char *s) _pure_;

src/network/networkd-link-bus.c

@@ -9,7 +9,9 @@
 #include "parse-util.h"
 #include "strv.h"
 
-static BUS_DEFINE_PROPERTY_GET_ENUM(property_get_operational_state, link_operstate, LinkOperationalState);
+BUS_DEFINE_PROPERTY_GET_ENUM(property_get_operational_state, link_operstate, LinkOperationalState);
+BUS_DEFINE_PROPERTY_GET_ENUM(property_get_carrier_state, link_carrier_state, LinkCarrierState);
+BUS_DEFINE_PROPERTY_GET_ENUM(property_get_address_state, link_address_state, LinkAddressState);
 static BUS_DEFINE_PROPERTY_GET_ENUM(property_get_administrative_state, link_state, LinkState);
 
 static int property_get_bit_rates(
@@ -60,6 +62,8 @@ const sd_bus_vtable link_vtable[] = {
         SD_BUS_VTABLE_START(0),
 
         SD_BUS_PROPERTY("OperationalState", "s", property_get_operational_state, offsetof(Link, operstate), SD_BUS_VTABLE_PROPERTY_EMITS_CHANGE),
+        SD_BUS_PROPERTY("CarrierState", "s", property_get_carrier_state, offsetof(Link, carrier_state), SD_BUS_VTABLE_PROPERTY_EMITS_CHANGE),
+        SD_BUS_PROPERTY("AddressState", "s", property_get_address_state, offsetof(Link, address_state), SD_BUS_VTABLE_PROPERTY_EMITS_CHANGE),
         SD_BUS_PROPERTY("AdministrativeState", "s", property_get_administrative_state, offsetof(Link, state), SD_BUS_VTABLE_PROPERTY_EMITS_CHANGE),
         SD_BUS_PROPERTY("BitRates", "(dd)", property_get_bit_rates, 0, 0),
 

src/network/networkd-link-bus.h

@@ -14,3 +14,7 @@ int link_node_enumerator(sd_bus *bus, const char *path, void *userdata, char ***
 int link_object_find(sd_bus *bus, const char *path, const char *interface, void *userdata, void **found, sd_bus_error *error);
 int link_send_changed_strv(Link *link, char **properties);
 int link_send_changed(Link *link, const char *property, ...) _sentinel_;
+
+int property_get_operational_state(sd_bus *bus, const char *path, const char *interface, const char *property, sd_bus_message *reply, void *userdata, sd_bus_error *error);
+int property_get_carrier_state(sd_bus *bus, const char *path, const char *interface, const char *property, sd_bus_message *reply, void *userdata, sd_bus_error *error);
+int property_get_address_state(sd_bus *bus, const char *path, const char *interface, const char *property, sd_bus_message *reply, void *userdata, sd_bus_error *error);

src/network/networkd-link.c

@@ -362,7 +362,9 @@ void link_update_operstate(Link *link, bool also_update_master) {
         LinkOperationalState operstate;
         LinkCarrierState carrier_state;
         LinkAddressState address_state;
+        _cleanup_strv_free_ char **p = NULL;
         uint8_t scope = RT_SCOPE_NOWHERE;
+        bool changed = false;
         Address *address;
         Iterator i;
 
@@ -436,15 +438,32 @@ void link_update_operstate(Link *link, bool also_update_master) {
         else
                 operstate = LINK_OPERSTATE_ENSLAVED;
 
-        link->carrier_state = carrier_state;
-        link->address_state = address_state;
+        if (link->carrier_state != carrier_state) {
+                link->carrier_state = carrier_state;
+                changed = true;
+                if (strv_extend(&p, "CarrierState") < 0)
+                        log_oom();
+        }
+
+        if (link->address_state != address_state) {
+                link->address_state = address_state;
+                changed = true;
+                if (strv_extend(&p, "AddressState") < 0)
+                        log_oom();
+        }
 
         if (link->operstate != operstate) {
                 link->operstate = operstate;
-                link_send_changed(link, "OperationalState", NULL);
-                link_dirty(link);
+                changed = true;
+                if (strv_extend(&p, "OperationalState") < 0)
+                        log_oom();
         }
 
+        if (p)
+                link_send_changed_strv(link, p);
+        if (changed)
+                link_dirty(link);
+
         if (also_update_master && link->network) {
                 link_update_master_operstate(link, link->network->bond);
                 link_update_master_operstate(link, link->network->bridge);