network: receive genl multicast messages about wlan connections

src/network/networkd-link.c

@@ -53,7 +53,6 @@
 #include "networkd-sriov.h"
 #include "networkd-state-file.h"
 #include "networkd-sysctl.h"
-#include "networkd-wifi.h"
 #include "set.h"
 #include "socket-util.h"
 #include "stat-util.h"
@@ -1295,28 +1294,15 @@ static int link_reconfigure_impl(Link *link, bool force) {
         return 1;
 }
 
-static int link_reconfigure_handler_internal(sd_netlink *rtnl, sd_netlink_message *m, Link *link, bool force, bool update_wifi) {
-        bool link_was_lower_up;
+static int link_reconfigure_handler_internal(sd_netlink *rtnl, sd_netlink_message *m, Link *link, bool force) {
         int r;
 
         assert(link);
 
-        link_was_lower_up = link->flags & IFF_LOWER_UP;
-
         r = link_getlink_handler_internal(rtnl, m, link, "Failed to update link state");
         if (r <= 0)
                 return r;
 
-        if (update_wifi && link_was_lower_up && link->flags & IFF_LOWER_UP) {
-                /* If the interface's L1 was not up, then wifi_get_info() is already called in
-                 * link_update_flags(). So, it is not necessary to re-call here. */
-                r = wifi_get_info(link);
-                if (r < 0) {
-                        link_enter_failed(link);
-                        return 0;
-                }
-        }
-
         r = link_reconfigure_impl(link, force);
         if (r < 0) {
                 link_enter_failed(link);
@@ -1327,11 +1313,11 @@ static int link_reconfigure_handler_internal(sd_netlink *rtnl, sd_netlink_messag
 }
 
 static int link_reconfigure_handler(sd_netlink *rtnl, sd_netlink_message *m, Link *link) {
-        return link_reconfigure_handler_internal(rtnl, m, link, /* force = */ false, /* update_wifi = */ false);
+        return link_reconfigure_handler_internal(rtnl, m, link, /* force = */ false);
 }
 
 static int link_force_reconfigure_handler(sd_netlink *rtnl, sd_netlink_message *m, Link *link) {
-        return link_reconfigure_handler_internal(rtnl, m, link, /* force = */ true, /* update_wifi = */ false);
+        return link_reconfigure_handler_internal(rtnl, m, link, /* force = */ true);
 }
 
 static int link_reconfigure_after_sleep_handler(sd_netlink *rtnl, sd_netlink_message *m, Link *link) {
@@ -1339,7 +1325,7 @@ static int link_reconfigure_after_sleep_handler(sd_netlink *rtnl, sd_netlink_mes
 
         assert(link);
 
-        r = link_reconfigure_handler_internal(rtnl, m, link, /* force = */ false, /* update_wifi = */ true);
+        r = link_reconfigure_handler_internal(rtnl, m, link, /* force = */ false);
         if (r != 0)
                 return r;
 
@@ -1421,10 +1407,6 @@ static int link_initialized_and_synced(Link *link) {
                 return r;
 
         if (!link->network) {
-                r = wifi_get_info(link);
-                if (r < 0)
-                        return r;
-
                 r = link_get_network(link, &network);
                 if (r == -ENOENT) {
                         link_set_state(link, LINK_STATE_UNMANAGED);
@@ -1893,7 +1875,7 @@ void link_update_operstate(Link *link, bool also_update_master) {
          : "")
 
 static int link_update_flags(Link *link, sd_netlink_message *message) {
-        bool link_was_lower_up, link_was_admin_up, had_carrier;
+        bool link_was_admin_up, had_carrier;
         uint8_t operstate;
         unsigned flags;
         int r;
@@ -1955,7 +1937,6 @@ static int link_update_flags(Link *link, sd_netlink_message *message) {
                         log_link_debug(link, "Unknown link flags lost, ignoring: %#.5x", unknown_flags_removed);
         }
 
-        link_was_lower_up = link->flags & IFF_LOWER_UP;
         link_was_admin_up = link->flags & IFF_UP;
         had_carrier = link_has_carrier(link);
 
@@ -1964,19 +1945,6 @@ static int link_update_flags(Link *link, sd_netlink_message *message) {
 
         link_update_operstate(link, true);
 
-        if (!link_was_lower_up && (link->flags & IFF_LOWER_UP)) {
-                r = wifi_get_info(link);
-                if (r < 0)
-                        return r;
-                if (r > 0) {
-                        /* All link information is up-to-date. So, it is not necessary to call
-                         * RTM_GETLINK netlink method again. */
-                        r = link_reconfigure_impl(link, /* force = */ false);
-                        if (r < 0)
-                                return r;
-                }
-        }
-
         if (!link_was_admin_up && (link->flags & IFF_UP)) {
                 log_link_info(link, "Link UP");
 
@@ -1994,6 +1962,15 @@ static int link_update_flags(Link *link, sd_netlink_message *message) {
         if (!had_carrier && link_has_carrier(link)) {
                 log_link_info(link, "Gained carrier");
 
+                if (IN_SET(link->state, LINK_STATE_CONFIGURING, LINK_STATE_CONFIGURED)) {
+                        /* At this stage, both wlan and link information should be up-to-date. Hence,
+                         * it is not necessary to call RTM_GETLINK, NL80211_CMD_GET_INTERFACE, or
+                         * NL80211_CMD_GET_STATION commands, and simply call link_reconfigure_impl(). */
+                        r = link_reconfigure_impl(link, /* force = */ false);
+                        if (r < 0)
+                                return r;
+                }
+
                 r = link_carrier_gained(link);
                 if (r < 0)
                         return r;

src/network/networkd-manager.c

@@ -6,6 +6,7 @@
 #include <linux/if.h>
 #include <linux/fib_rules.h>
 #include <linux/nexthop.h>
+#include <linux/nl80211.h>
 
 #include "sd-daemon.h"
 #include "sd-netlink.h"
@@ -38,6 +39,7 @@
 #include "networkd-routing-policy-rule.h"
 #include "networkd-speed-meter.h"
 #include "networkd-state-file.h"
+#include "networkd-wifi.h"
 #include "ordered-set.h"
 #include "path-lookup.h"
 #include "path-util.h"
@@ -246,6 +248,16 @@ static int manager_connect_genl(Manager *m) {
         if (r < 0)
                 return r;
 
+        r = genl_add_match(m->genl, NULL, NL80211_GENL_NAME, NL80211_MULTICAST_GROUP_CONFIG, 0,
+                           &manager_genl_process_nl80211_config, NULL, m, "network-genl_process_nl80211_config");
+        if (r < 0 && r != -EOPNOTSUPP)
+                return r;
+
+        r = genl_add_match(m->genl, NULL, NL80211_GENL_NAME, NL80211_MULTICAST_GROUP_MLME, 0,
+                           &manager_genl_process_nl80211_mlme, NULL, m, "network-genl_process_nl80211_mlme");
+        if (r < 0 && r != -EOPNOTSUPP)
+                return r;
+
         return 0;
 }
 
@@ -690,6 +702,49 @@ static int manager_enumerate_nexthop(Manager *m) {
         return manager_enumerate_internal(m, m->rtnl, req, manager_rtnl_process_nexthop);
 }
 
+static int manager_enumerate_nl80211_config(Manager *m) {
+        _cleanup_(sd_netlink_message_unrefp) sd_netlink_message *req = NULL;
+        int r;
+
+        assert(m);
+        assert(m->genl);
+
+        r = sd_genl_message_new(m->genl, NL80211_GENL_NAME, NL80211_CMD_GET_INTERFACE, &req);
+        if (r < 0)
+                return r;
+
+        return manager_enumerate_internal(m, m->genl, req, manager_genl_process_nl80211_config);
+}
+
+static int manager_enumerate_nl80211_mlme(Manager *m) {
+        Link *link;
+        int r;
+
+        assert(m);
+        assert(m->genl);
+
+        HASHMAP_FOREACH(link, m->links_by_index) {
+                _cleanup_(sd_netlink_message_unrefp) sd_netlink_message *req = NULL;
+
+                if (link->wlan_iftype != NL80211_IFTYPE_STATION)
+                        continue;
+
+                r = sd_genl_message_new(m->genl, NL80211_GENL_NAME, NL80211_CMD_GET_STATION, &req);
+                if (r < 0)
+                        return r;
+
+                r = sd_netlink_message_append_u32(req, NL80211_ATTR_IFINDEX, link->ifindex);
+                if (r < 0)
+                        return r;
+
+                r = manager_enumerate_internal(m, m->genl, req, manager_genl_process_nl80211_mlme);
+                if (r < 0)
+                        return r;
+        }
+
+        return 0;
+}
+
 int manager_enumerate(Manager *m) {
         int r;
 
@@ -724,6 +779,18 @@ int manager_enumerate(Manager *m) {
         else if (r < 0)
                 return log_error_errno(r, "Could not enumerate routing policy rules: %m");
 
+        r = manager_enumerate_nl80211_config(m);
+        if (r == -EOPNOTSUPP)
+                log_debug_errno(r, "Could not enumerate wireless LAN interfaces, ignoring: %m");
+        else if (r < 0)
+                return log_error_errno(r, "Could not enumerate wireless LAN interfaces: %m");
+
+        r = manager_enumerate_nl80211_mlme(m);
+        if (r == -EOPNOTSUPP)
+                log_debug_errno(r, "Could not enumerate wireless LAN stations, ignoring: %m");
+        else if (r < 0)
+                return log_error_errno(r, "Could not enumerate wireless LAN stations: %m");
+
         return 0;
 }
 

src/network/networkd-wifi.c

@@ -3,11 +3,7 @@
 #include <net/ethernet.h>
 #include <linux/nl80211.h>
 
-#include "sd-bus.h"
-
-#include "bus-util.h"
 #include "ether-addr-util.h"
-#include "netlink-internal.h"
 #include "netlink-util.h"
 #include "networkd-link.h"
 #include "networkd-manager.h"
@@ -15,56 +11,275 @@
 #include "string-util.h"
 #include "wifi-util.h"
 
-int wifi_get_info(Link *link) {
-        _cleanup_free_ char *ssid = NULL;
-        enum nl80211_iftype iftype;
-        bool updated = false;
-        const char *type;
+static int link_get_wlan_interface(Link *link) {
+        _cleanup_(sd_netlink_message_unrefp) sd_netlink_message *req = NULL, *reply = NULL;
         int r;
 
         assert(link);
 
-        if (!link->sd_device)
-                return 0;
-
-        r = sd_device_get_devtype(link->sd_device, &type);
-        if (r == -ENOENT)
-                return 0;
-        else if (r < 0)
-                return r;
-
-        if (!streq(type, "wlan"))
-                return 0;
-
-        r = wifi_get_interface(link->manager->genl, link->ifindex, &iftype, &ssid);
+        r = sd_genl_message_new(link->manager->genl, NL80211_GENL_NAME, NL80211_CMD_GET_INTERFACE, &req);
         if (r < 0)
-                return r;
-        if (r == 0)
-                iftype = link->wlan_iftype; /* Assume iftype is not changed. */
+                return log_link_debug_errno(link, r, "Failed to create generic netlink message: %m");
 
-        if (iftype == NL80211_IFTYPE_STATION) {
-                struct ether_addr bssid;
+        r = sd_netlink_message_append_u32(req, NL80211_ATTR_IFINDEX, link->ifindex);
+        if (r < 0)
+                return log_link_debug_errno(link, r, "Could not append NL80211_ATTR_IFINDEX attribute: %m");
 
-                r = wifi_get_station(link->manager->genl, link->ifindex, &bssid);
-                if (r < 0)
-                        return r;
-
-                updated = !ether_addr_equal(&link->bssid, &bssid);
-                link->bssid = bssid;
+        r = sd_netlink_call(link->manager->genl, req, 0, &reply);
+        if (r < 0)
+                return log_link_debug_errno(link, r, "Failed to request information about wlan interface: %m");
+        if (!reply) {
+                log_link_debug(link, "No reply received to request for information about wifi interface, ignoring.");
+                return 0;
         }
 
-        updated = updated || link->wlan_iftype != iftype;
-        link->wlan_iftype = iftype;
-        updated = updated || !streq_ptr(link->ssid, ssid);
-        free_and_replace(link->ssid, ssid);
+        return manager_genl_process_nl80211_config(link->manager->genl, reply, link->manager);
+}
+
+int manager_genl_process_nl80211_config(sd_netlink *genl, sd_netlink_message *message, Manager *manager) {
+        _cleanup_free_ char *ssid = NULL;
+        uint32_t ifindex, wlan_iftype;
+        const char *family, *ifname;
+        uint8_t cmd;
+        size_t len;
+        Link *link;
+        int r;
+
+        assert(genl);
+        assert(message);
+        assert(manager);
+
+        if (sd_netlink_message_is_error(message)) {
+                r = sd_netlink_message_get_errno(message);
+                if (r < 0)
+                        log_message_warning_errno(message, r, "nl80211: received error message, ignoring");
+
+                return 0;
+        }
+
+        r = sd_genl_message_get_family_name(genl, message, &family);
+        if (r < 0) {
+                log_debug_errno(r, "nl80211: failed to determine genl family, ignoring: %m");
+                return 0;
+        }
+        if (!streq(family, NL80211_GENL_NAME)) {
+                log_debug("nl80211: received message of unexpected genl family '%s', ignoring.", family);
+                return 0;
+        }
+
+        r = sd_genl_message_get_command(genl, message, &cmd);
+        if (r < 0) {
+                log_debug_errno(r, "nl80211: failed to determine genl message command, ignoring: %m");
+                return 0;
+        }
+        if (!IN_SET(cmd, NL80211_CMD_SET_INTERFACE, NL80211_CMD_NEW_INTERFACE, NL80211_CMD_DEL_INTERFACE)) {
+                log_debug("nl80211: ignoring nl80211 %s(%u) message.",
+                          strna(nl80211_cmd_to_string(cmd)), cmd);
+                return 0;
+        }
+
+        r = sd_netlink_message_read_u32(message, NL80211_ATTR_IFINDEX, &ifindex);
+        if (r < 0) {
+                log_debug_errno(r, "nl80211: received %s(%u) message without valid ifindex, ignoring: %m",
+                                strna(nl80211_cmd_to_string(cmd)), cmd);
+                return 0;
+        }
+
+        r = link_get_by_index(manager, ifindex, &link);
+        if (r < 0) {
+                log_debug_errno(r, "nl80211: received %s(%u) message for link '%"PRIu32"' we don't know about, ignoring.",
+                                strna(nl80211_cmd_to_string(cmd)), cmd, ifindex);
+                return 0;
+        }
+
+        r = sd_netlink_message_read_string(message, NL80211_ATTR_IFNAME, &ifname);
+        if (r < 0) {
+                log_link_debug_errno(link, r, "nl80211: received %s(%u) message without valid interface name, ignoring: %m",
+                                     strna(nl80211_cmd_to_string(cmd)), cmd);
+                return 0;
+        }
+
+        if (!streq(ifname, link->ifname)) {
+                log_link_debug_errno(link, r, "nl80211: received %s(%u) message with invalid interface name '%s', ignoring: %m",
+                                     strna(nl80211_cmd_to_string(cmd)), cmd, ifname);
+                return 0;
+        }
+
+        r = sd_netlink_message_read_u32(message, NL80211_ATTR_IFTYPE, &wlan_iftype);
+        if (r < 0) {
+                log_link_debug_errno(link, r, "nl80211: received %s(%u) message without valid wlan interface type, ignoring: %m",
+                                     strna(nl80211_cmd_to_string(cmd)), cmd);
+                return 0;
+        }
+
+        r = sd_netlink_message_read_data_suffix0(message, NL80211_ATTR_SSID, &len, (void**) &ssid);
+        if (r < 0 && r != -ENODATA) {
+                log_link_debug_errno(link, r, "nl80211: received %s(%u) message without valid SSID, ignoring: %m",
+                                     strna(nl80211_cmd_to_string(cmd)), cmd);
+                return 0;
+        }
+        if (r >= 0) {
+                if (len == 0) {
+                        log_link_debug(link, "nl80211: received SSID has zero length, ignoring the received SSID: %m");
+                        ssid = mfree(ssid);
+                } else if (strlen_ptr(ssid) != len) {
+                        log_link_debug(link, "nl80211: received SSID contains NUL character(s), ignoring the received SSID.");
+                        ssid = mfree(ssid);
+                }
+        }
+
+        log_link_debug(link, "nl80211: received %s(%u) message: iftype=%s, ssid=%s",
+                       strna(nl80211_cmd_to_string(cmd)), cmd,
+                       strna(nl80211_iftype_to_string(wlan_iftype)), ssid);
+
+        switch(cmd) {
+        case NL80211_CMD_SET_INTERFACE:
+        case NL80211_CMD_NEW_INTERFACE:
+                link->wlan_iftype = wlan_iftype;
+                free_and_replace(link->ssid, ssid);
+                break;
+
+        case NL80211_CMD_DEL_INTERFACE:
+                link->wlan_iftype = NL80211_IFTYPE_UNSPECIFIED;
+                link->ssid = mfree(link->ssid);
+                break;
+
+        default:
+                assert_not_reached();
+        }
+
+        return 0;
+}
+
+int manager_genl_process_nl80211_mlme(sd_netlink *genl, sd_netlink_message *message, Manager *manager) {
+        const char *family;
+        uint32_t ifindex;
+        uint8_t cmd;
+        Link *link;
+        int r;
+
+        assert(genl);
+        assert(message);
+        assert(manager);
+
+        if (sd_netlink_message_is_error(message)) {
+                r = sd_netlink_message_get_errno(message);
+                if (r < 0)
+                        log_message_warning_errno(message, r, "nl80211: received error message, ignoring");
+
+                return 0;
+        }
+
+        r = sd_genl_message_get_family_name(genl, message, &family);
+        if (r < 0) {
+                log_debug_errno(r, "nl80211: failed to determine genl family, ignoring: %m");
+                return 0;
+        }
+        if (!streq(family, NL80211_GENL_NAME)) {
+                log_debug("nl80211: Received message of unexpected genl family '%s', ignoring.", family);
+                return 0;
+        }
+
+        r = sd_genl_message_get_command(genl, message, &cmd);
+        if (r < 0) {
+                log_debug_errno(r, "nl80211: failed to determine genl message command, ignoring: %m");
+                return 0;
+        }
+
+        r = sd_netlink_message_read_u32(message, NL80211_ATTR_IFINDEX, &ifindex);
+        if (r < 0) {
+                log_debug_errno(r, "nl80211: received %s(%u) message without valid ifindex, ignoring: %m",
+                                strna(nl80211_cmd_to_string(cmd)), cmd);
+                return 0;
+        }
+
+        r = link_get_by_index(manager, ifindex, &link);
+        if (r < 0) {
+                log_debug_errno(r, "nl80211: received %s(%u) message for link '%"PRIu32"' we don't know about, ignoring.",
+                                strna(nl80211_cmd_to_string(cmd)), cmd, ifindex);
+                return 0;
+        }
+
+        switch(cmd) {
+        case NL80211_CMD_NEW_STATION:
+        case NL80211_CMD_DEL_STATION: {
+                struct ether_addr bssid;
+
+                r = sd_netlink_message_read_ether_addr(message, NL80211_ATTR_MAC, &bssid);
+                if (r < 0) {
+                        log_link_debug_errno(link, r, "nl80211: received %s(%u) message without valid BSSID, ignoring: %m",
+                                             strna(nl80211_cmd_to_string(cmd)), cmd);
+                        return 0;
+                }
+
+                log_link_debug(link, "nl80211: received %s(%u) message: bssid=%s",
+                               strna(nl80211_cmd_to_string(cmd)), cmd, ETHER_ADDR_TO_STR(&bssid));
+
+                if (cmd == NL80211_CMD_DEL_STATION) {
+                        link->bssid = ETHER_ADDR_NULL;
+                        return 0;
+                }
+
+                link->bssid = bssid;
+
+                if (manager->enumerating &&
+                    link->wlan_iftype == NL80211_IFTYPE_STATION && link->ssid)
+                        log_link_info(link, "Connected WiFi access point: %s (%s)",
+                                      link->ssid, ETHER_ADDR_TO_STR(&link->bssid));
+                break;
+        }
+        case NL80211_CMD_CONNECT: {
+                struct ether_addr bssid;
+                uint16_t status_code;
+
+                r = sd_netlink_message_read_ether_addr(message, NL80211_ATTR_MAC, &bssid);
+                if (r < 0 && r != -ENODATA) {
+                        log_link_debug_errno(link, r, "nl80211: received %s(%u) message without valid BSSID, ignoring: %m",
+                                             strna(nl80211_cmd_to_string(cmd)), cmd);
+                        return 0;
+                }
+
+                r = sd_netlink_message_read_u16(message, NL80211_ATTR_STATUS_CODE, &status_code);
+                if (r < 0) {
+                        log_link_debug_errno(link, r, "nl80211: received %s(%u) message without valid status code, ignoring: %m",
+                                             strna(nl80211_cmd_to_string(cmd)), cmd);
+                        return 0;
+                }
+
+                log_link_debug(link, "nl80211: received %s(%u) message: status=%u, bssid=%s",
+                               strna(nl80211_cmd_to_string(cmd)), cmd, status_code, ETHER_ADDR_TO_STR(&bssid));
+
+                if (status_code != 0)
+                        return 0;
+
+                link->bssid = bssid;
+
+                if (!manager->enumerating) {
+                        r = link_get_wlan_interface(link);
+                        if (r < 0) {
+                                log_link_warning_errno(link, r, "Failed to update wireless LAN interface: %m");
+                                link_enter_failed(link);
+                                return 0;
+                        }
+                }
 
-        if (updated) {
                 if (link->wlan_iftype == NL80211_IFTYPE_STATION && link->ssid)
                         log_link_info(link, "Connected WiFi access point: %s (%s)",
                                       link->ssid, ETHER_ADDR_TO_STR(&link->bssid));
+                break;
+        }
+        case NL80211_CMD_DISCONNECT:
+                log_link_debug(link, "nl80211: received %s(%u) message.",
+                               strna(nl80211_cmd_to_string(cmd)), cmd);
 
-                return 1; /* Some information is updated. */
+                link->bssid = ETHER_ADDR_NULL;
+                link->ssid = mfree(link->ssid);
+                break;
+
+        default:
+                log_link_debug(link, "nl80211: received %s(%u) message.",
+                               strna(nl80211_cmd_to_string(cmd)), cmd);
         }
 
-        return 0; /* No new information. */
+        return 0;
 }

src/network/networkd-wifi.h

@@ -1,8 +1,9 @@
 /* SPDX-License-Identifier: LGPL-2.1-or-later */
 #pragma once
 
-#include "sd-bus.h"
+#include "sd-netlink.h"
 
-typedef struct Link Link;
+typedef struct Manager Manager;
 
-int wifi_get_info(Link *link);
+int manager_genl_process_nl80211_config(sd_netlink *genl, sd_netlink_message *message, Manager *manager);
+int manager_genl_process_nl80211_mlme(sd_netlink *genl, sd_netlink_message *message, Manager *manager);