hostapd: Maintain single wpa_driver_nl80211_data (drv) object across interfaces

Currently, the first BSS of each hostapd interface (struct hostapd_iface)
creates a new driver data object (struct wpa_driver_nl80211_data, referred
to as drv). When a non-first BSS of an interface initializes, it copies the
drv_priv and thus uses the first BSS’s drv object. This can lead to
situations where multiple drv objects are maintained for the same
underlying hardware in hostapd.

Some of such situations are:

1. Two different configs for two different wlanX interface but on the
   same underlying radio. In this case, two drv objects will be
   maintained.

2. MLO case - 5 GHz config having two BSS. 6 GHz config having one BSS.
   5 GHz's second BSS is partnering with 6 GHz's BSS and forming MLD.
   And 6 GHz config is enabled first and then 5 GHz. In this case, two
   different driver instance will be maintained - one having 5 GHz BSS
   and other having 5 GHz + 6 GHz MLO BSS. To visualize this:

Assumption: Only 1 phy (say phy0 exist on system). On this phy, the driver
            has grouped both 5 GHz and 6 GHz underlying radio as a single
            radio.
Config:
     +--------------------+     +------------------+
     |     5 GHz config   |     |   6 GHz config   |
     |                    |     |                  |
     |                    |     |                  |
     | +----------------+ |     |                  |
     | |     BSS 1      | |     |                  |
     | | ssid: guest_ap | |     |                  |
     | +----------------+ |     |                  |
     |                    |     |                  |
   +------------------------------------------------------------------+
   | | +----------------+ |     | +--------------+ |                  |
   | | |     BSS 2      | |     | |     BSS 1    | |                  |
   | | | ssid: mlo_ap   | |     | | ssid: mlo_ap | |   2 Link MLO AP  |
   | | +----------------+ |     | +--------------+ |                  |
   | +--------------------+     +------------------+                  |
   +------------------------------------------------------------------+

Expectation:
+-----------------------------------+
|   wpa_driver_nl80211_data (drv)   |
|          (for the phy0)           |
|                                   |
|        +----------------+         |        +----------------+
|        |    first_bss   -------------------|   second_bss   |
|        |                |         |        |                |
|        | ssid: guest_ap |         |        | ssid: mlo_ap   |
|        +----------------+         |        +----------------+
+-----------------------------------+

Current situation (without this change):
+-----------------------------+   +-----------------------------+
|wpa_driver_nl80211_data (drv)|   |wpa_driver_nl80211_data (drv)|
|       (for the phy0)        |   |       (again for the phy0)  |
|                             |   |                             |
|     +----------------+      |   |     +----------------+      |
|     |    first_bss   |      |   |     |    first_bss   |      |
|     |                |      |   |     |                |      |
|     | ssid: guest_ap |      |   |     | ssid: mlo_ap   |      |
|     +----------------+      |   |     +----------------+      |
+-----------------------------+   +-----------------------------+

With this change, it will behave as per the expectation.

3. Three different underlying hardwares - 2.4 GHz, 5 GHz, 6 GHz, capable
   of three different bands and they are grouped together and advertised
   as single hardware supporting all bands to upper layer. In this case,
   if one interface (wlanX) is enabled in each hardware (three
   independent configs) three different drv will be maintained.

Because of this, at times during de-initialization, proper
deinitialization will not happen and WPA_TRACE could be seen:

nl80211: 1 interface(s) remain at nl80211_global_deinit
ELOOP: remaining socket: sock=12 eloop_data=0x5500292620 user_data=(nil) handler=0x55000f6cb0
WPA_TRACE: eloop unregistered socket handler: 0x55000f6cb0
     rfkill_receive() ../src/drivers/rfkill.c:56
WPA_TRACE: eloop sock - START
[0]: ../../hostapd/hostapd(+0x82fe1) [0x5500082fe1]
     eloop_sock_table_add_sock() ../src/utils/eloop.c:367
[1]: ../../hostapd/hostapd(rfkill_init+0x1ea) [0x55000f700a]
     rfkill_init() ../src/drivers/rfkill.c:200
[2]: ../../hostapd/hostapd(+0xe5325) [0x55000e5325]
     wpa_driver_nl80211_drv_init_rfkill() ../src/drivers/driver_nl80211.c:2276
     wpa_driver_nl80211_finish_drv_init() ../src/drivers/driver_nl80211.c:3036
[3]: ../../hostapd/hostapd(+0xe89f1) [0x55000e89f1]
     wpa_driver_nl80211_drv_init() ../src/drivers/driver_nl80211.c:2350
[4]: ../../hostapd/hostapd(+0xe8c6e) [0x55000e8c6e]
     i802_init() ../src/drivers/driver_nl80211.c:8714
[5]: ../../hostapd/hostapd(+0x32605) [0x5500032605]
     hostapd_driver_init() main.c:257
[6]: ../../hostapd/hostapd(main+0xd08) [0x5500031ad8]
     main() main.c:1021
[7]: /lib/x86_64-linux-gnu/libc.so.6(+0x29d90) [0x409acd90]
WPA_TRACE: eloop sock - EN

Also, for situation #3, during handling of incoming NL commands, the
above is causing issue in routing the events. This is because since all
underlying hardwares are part of same phy, phy index is same in all the
drv objects. Hence when the event comes, it will be given to the first
drv which might not be having the intended BSS. For example, 5 GHz DFS
events (which does not have if_idx). The event can be passed to driver
having 2.4 GHz's BSS or 6 GHz's depending upon which was enabled first.

Hence to avoid these situations, try to maintain single drv object as
much as possible.

Signed-off-by: Aditya Kumar Singh <quic_adisi@quicinc.com>

diff --git a/hostapd/main.c b/hostapd/main.c
index 512cd892bdec6f225289655b7705f637726f852c..43c4fa1fb24eac9328daccf974119f9f9915ddd0 100644 (file)
--- a/hostapd/main.c
+++ b/hostapd/main.c
@@ -160,6 +160,7 @@ static int hostapd_driver_init(struct hostapd_iface *iface)
        struct wpa_driver_capa capa;
 #ifdef CONFIG_IEEE80211BE
        struct hostapd_data *h_hapd = NULL;
+       void *shared_hapd = NULL;
 #endif /* CONFIG_IEEE80211BE */
 
        if (hapd->driver == NULL || hapd->driver->hapd_init == NULL) {
@@ -253,6 +254,42 @@ static int hostapd_driver_init(struct hostapd_iface *iface)
 
        params.own_addr = hapd->own_addr;
 
+#ifdef CONFIG_IEEE80211BE
+       if (hapd->driver->can_share_drv &&
+           hapd->driver->can_share_drv(hapd, &params, &shared_hapd)) {
+               char force_ifname[IFNAMSIZ];
+               const u8 *addr = params.bssid;
+               u8 if_addr[ETH_ALEN];
+
+               if (!shared_hapd) {
+                       wpa_printf(MSG_ERROR, "Failed to get the shared drv");
+                       os_free(params.bridge);
+                       return -1;
+               }
+
+               /* Share an already initialized driver interface instance
+                * using an AP mode BSS in it instead of adding a new driver
+                * interface instance for the same driver. */
+               if (hostapd_if_add(shared_hapd, WPA_IF_AP_BSS,
+                                  params.ifname, addr, hapd,
+                                  &hapd->drv_priv, force_ifname, if_addr,
+                                  params.num_bridge && params.bridge[0] ?
+                                  params.bridge[0] : NULL,
+                                  0)) {
+                       wpa_printf(MSG_ERROR, "Failed to add BSS (BSSID="
+                                  MACSTR ")", MAC2STR(hapd->own_addr));
+                       os_free(params.bridge);
+                       return -1;
+               }
+               os_free(params.bridge);
+
+               hapd->interface_added = 1;
+               os_memcpy(params.own_addr, addr ? addr : if_addr, ETH_ALEN);
+
+               goto pre_setup_mld;
+       }
+#endif /* CONFIG_IEEE80211BE */
+
        hapd->drv_priv = hapd->driver->hapd_init(hapd, &params);
        os_free(params.bridge);
        if (hapd->drv_priv == NULL) {
@@ -263,6 +300,7 @@ static int hostapd_driver_init(struct hostapd_iface *iface)
        }
 
 #ifdef CONFIG_IEEE80211BE
+pre_setup_mld:
        /*
         * This is the first interface added to the AP MLD, so have the
         * interface hardware address be the MLD address, while the link address

diff --git a/src/ap/hostapd.c b/src/ap/hostapd.c
index c6d3c315a417f5b39bfc4e260adcf7e723698d9e..9dfc21e00f3e68f1e08970d5d8e613381e36e61d 100644 (file)
--- a/src/ap/hostapd.c
+++ b/src/ap/hostapd.c
@@ -525,7 +525,10 @@ void hostapd_free_hapd_data(struct hostapd_data *hapd)
 
        authsrv_deinit(hapd);
 
-       if (hapd->interface_added) {
+       /* For single drv, first bss would have interface_added flag set.
+        * Don't remove interface now. Driver deinit part will take care
+        */
+       if (hapd->interface_added && hapd->iface->bss[0] != hapd) {
                hapd->interface_added = 0;
                if (hostapd_if_remove(hapd, WPA_IF_AP_BSS, hapd->conf->iface)) {
                        wpa_printf(MSG_WARNING,
@@ -3462,8 +3465,7 @@ static void hostapd_cleanup_driver(const struct wpa_driver_ops *driver,
         * still being used by some other BSS before de-initiallizing. */
        if (!iface->bss[0]->conf->mld_ap) {
                driver->hapd_deinit(drv_priv);
-       } else if (hostapd_mld_is_first_bss(iface->bss[0]) &&
-                  driver->is_drv_shared &&
+       } else if (driver->is_drv_shared &&
                   !driver->is_drv_shared(drv_priv,
                                          iface->bss[0]->mld_link_id)) {
                driver->hapd_deinit(drv_priv);

diff --git a/src/drivers/driver.h b/src/drivers/driver.h
index b28046db38c32d8488e284dc7c63af90783955ab..6db740223dcb0a3b146d8c421259491c261d0ad1 100644 (file)
--- a/src/drivers/driver.h
+++ b/src/drivers/driver.h
@@ -5331,6 +5331,25 @@ struct wpa_driver_ops {
         */
        int (*nan_cancel_subscribe)(void *priv, int subscribe_id);
 
+       /**
+        * can_share_drv - Check whether driver interface can be shared
+        * @ctx: Pointer to hostapd context
+        * @params: Configuration for the driver wrapper
+        * @hapd: Pointer for overwriting the hapd context or %NULL
+        *      if can't find a shared drv
+        *
+        * Checks whether the driver interface with same phy name is
+        * already present under the global driver which can be shared
+        * instead of creating a new driver interface instance. If present,
+        * @hapd will be overwritten with the hapd pointer which this shared
+        * drv's first BSS is using. This will help the caller to later call
+        * if_add().
+        *
+        * Returns: true if it can be shared or else false.
+        */
+       bool (*can_share_drv)(void *ctx, struct wpa_init_params *params,
+                             void **hapd);
+
 #ifdef CONFIG_TESTING_OPTIONS
        int (*register_frame)(void *priv, u16 type,
                              const u8 *match, size_t match_len,

diff --git a/src/drivers/driver_nl80211.c b/src/drivers/driver_nl80211.c
index a8434fdbfe1131d8d4effe0c141c23686c1d2e9a..034f24e3625c27126f408c297972eea7d8029e64 100644 (file)
--- a/src/drivers/driver_nl80211.c
+++ b/src/drivers/driver_nl80211.c
@@ -14481,6 +14481,7 @@ static int nl80211_link_add(void *priv, u8 link_id, const u8 *addr,
 
 
 #ifdef CONFIG_IEEE80211BE
+
 static int wpa_driver_nl80211_link_sta_remove(void *priv, u8 link_id,
                                              const u8 *addr)
 {
@@ -14507,6 +14508,124 @@ static int wpa_driver_nl80211_link_sta_remove(void *priv, u8 link_id,
 
        return ret;
 }
+
+
+static int wpa_driver_get_wiphy_name_handler(struct nl_msg *msg, void *arg)
+{
+       struct nlattr *tb[NL80211_ATTR_MAX + 1];
+       struct genlmsghdr *gnlh = nlmsg_data(nlmsg_hdr(msg));
+       struct wpa_driver_nl80211_data *drv = arg;
+
+       nla_parse(tb, NL80211_ATTR_MAX, genlmsg_attrdata(gnlh, 0),
+                 genlmsg_attrlen(gnlh, 0), NULL);
+
+       if (!tb[NL80211_ATTR_WIPHY_NAME])
+               return NL_SKIP;
+
+       os_strlcpy(drv->phyname, nla_get_string(tb[NL80211_ATTR_WIPHY_NAME]),
+                  sizeof(drv->phyname));
+
+       return NL_SKIP;
+}
+
+
+static int wpa_driver_get_phyname(struct wpa_driver_nl80211_data *drv)
+{
+       struct nl_msg *msg;
+       u32 feat, nl_flags;
+
+       feat = get_nl80211_protocol_features(drv);
+       if (feat & NL80211_PROTOCOL_FEATURE_SPLIT_WIPHY_DUMP)
+               nl_flags = NLM_F_DUMP;
+
+       if (!(msg = nl80211_cmd_msg(drv->first_bss, nl_flags,
+                                   NL80211_CMD_GET_WIPHY)) ||
+           nla_put_flag(msg, NL80211_ATTR_SPLIT_WIPHY_DUMP)) {
+               nlmsg_free(msg);
+               return -1;
+       }
+
+       if (send_and_recv_resp(drv, msg, wpa_driver_get_wiphy_name_handler,
+                              drv))
+               return -1;
+
+       return 0;
+}
+
+
+static bool
+wpa_driver_nl80211_name_match(struct wpa_driver_nl80211_data *drv,
+                             struct wpa_driver_nl80211_data **match_drv)
+{
+       struct wpa_driver_nl80211_data *drv2;
+
+       dl_list_for_each(drv2, &drv->global->interfaces,
+                        struct wpa_driver_nl80211_data, list) {
+               if (os_strcmp(drv2->phyname, drv->phyname) == 0) {
+                       if (match_drv)
+                               *match_drv = drv2;
+                       return true;
+               }
+       }
+
+       return false;
+}
+
+
+static bool wpa_driver_nl80211_can_share_drv(void *ctx,
+                                            struct wpa_init_params *params,
+                                            void **hapd)
+{
+       struct wpa_driver_nl80211_data *drv, *match_drv = NULL;
+       struct i802_bss *bss;
+       bool ret = false;
+
+       if (!params->global_priv)
+               return false;
+
+       /* Create a temporary drv to read the phyname */
+       drv = os_zalloc(sizeof(*drv));
+       if (!drv)
+               return false;
+       drv->global = params->global_priv;
+       drv->ctx = ctx;
+
+       drv->first_bss = os_zalloc(sizeof(*drv->first_bss));
+       if (!drv->first_bss) {
+               os_free(drv);
+               return false;
+       }
+
+       bss = drv->first_bss;
+       bss->drv = drv;
+       bss->ctx = ctx;
+
+       os_strlcpy(bss->ifname, params->ifname, sizeof(bss->ifname));
+
+       if (nl80211_init_bss(bss))
+               goto free_all;
+
+       drv->ifindex = if_nametoindex(bss->ifname);
+       bss->ifindex = drv->ifindex;
+
+       if (wpa_driver_get_phyname(drv) ||
+           !wpa_driver_nl80211_name_match(drv, &match_drv) ||
+           !match_drv)
+               goto free_all;
+
+       wpa_printf(MSG_DEBUG, "nl80211: Driver for phy %s already exist",
+                  match_drv->phyname);
+
+       *hapd = match_drv->first_bss->ctx;
+       ret = true;
+
+free_all:
+       nl80211_destroy_bss(bss);
+       os_free(bss);
+       os_free(drv);
+       return ret;
+}
+
 #endif /* CONFIG_IEEE80211BE */
 
 
@@ -14725,6 +14844,7 @@ const struct wpa_driver_ops wpa_driver_nl80211_ops = {
        .link_remove = driver_nl80211_link_remove,
        .is_drv_shared = nl80211_is_drv_shared,
        .link_sta_remove = wpa_driver_nl80211_link_sta_remove,
+       .can_share_drv = wpa_driver_nl80211_can_share_drv,
 #endif /* CONFIG_IEEE80211BE */
 #ifdef CONFIG_TESTING_OPTIONS
        .register_frame = testing_nl80211_register_frame,

diff --git a/src/drivers/driver_nl80211.h b/src/drivers/driver_nl80211.h
index 40941ea7da6868af1071d600be53223837c77f69..7fd234c8a4b73f35200ceaf2687fb3c8651bb5c9 100644 (file)
--- a/src/drivers/driver_nl80211.h
+++ b/src/drivers/driver_nl80211.h
@@ -414,5 +414,6 @@ int wpa_driver_nl80211_vendor_scan(struct i802_bss *bss,
 int nl80211_set_default_scan_ies(void *priv, const u8 *ies, size_t ies_len);
 struct hostapd_multi_hw_info *
 nl80211_get_multi_hw_info(struct i802_bss *bss, unsigned int *num_multi_hws);
+u32 get_nl80211_protocol_features(struct wpa_driver_nl80211_data *drv);
 
 #endif /* DRIVER_NL80211_H */

diff --git a/src/drivers/driver_nl80211_capa.c b/src/drivers/driver_nl80211_capa.c
index c4a23d542e78401f04122b6b07838b09fe6ba7f6..c950ddffcc5752bc3ceeea40c73ab9316e051be3 100644 (file)
--- a/src/drivers/driver_nl80211_capa.c
+++ b/src/drivers/driver_nl80211_capa.c
@@ -36,7 +36,7 @@ static int protocol_feature_handler(struct nl_msg *msg, void *arg)
 }
 
 
-static u32 get_nl80211_protocol_features(struct wpa_driver_nl80211_data *drv)
+u32 get_nl80211_protocol_features(struct wpa_driver_nl80211_data *drv)
 {
        u32 feat = 0;
        struct nl_msg *msg;