nl80211: Work around EALREADY from connect command

cfg80211 does not currently allow NL80211_CMD_CONNECT when there
is already an association. This can result in wpa_supplicant being
unable to request a connection if the interface is already in
connected state. Work around this by requesting disconnection if
the connect command fails with EALREADY error. This allows
wpa_supplicant to recover from the unexpected state and complete
the connect request on next attempt.

diff --git a/src/drivers/driver_nl80211.c b/src/drivers/driver_nl80211.c
index 19893255cbe9af26758ae19e73fdd0a027e45949..625d7f2201c67abc348440a5d44ae13f32347297 100644 (file)
--- a/src/drivers/driver_nl80211.c
+++ b/src/drivers/driver_nl80211.c
@@ -248,6 +248,7 @@ struct nl80211_bss_info_arg {
        struct wpa_driver_nl80211_data *drv;
        struct wpa_scan_results *res;
        unsigned int assoc_freq;
+       u8 assoc_bssid[ETH_ALEN];
 };
 
 static int bss_info_handler(struct nl_msg *msg, void *arg);
@@ -757,6 +758,29 @@ static void mlme_event_connect(struct wpa_driver_nl80211_data *drv,
 }
 
 
+static void mlme_event_disconnect(struct wpa_driver_nl80211_data *drv,
+                                 struct nlattr *reason, struct nlattr *addr)
+{
+       union wpa_event_data data;
+
+       if (drv->capa.flags & WPA_DRIVER_FLAGS_SME) {
+               /*
+                * Avoid reporting two disassociation events that could
+                * confuse the core code.
+                */
+               wpa_printf(MSG_DEBUG, "nl80211: Ignore disconnect "
+                          "event when using userspace SME");
+               return;
+       }
+
+       drv->associated = 0;
+       os_memset(&data, 0, sizeof(data));
+       if (reason)
+               data.disassoc_info.reason_code = nla_get_u16(reason);
+       wpa_supplicant_event(drv->ctx, EVENT_DISASSOC, &data);
+}
+
+
 static void mlme_timeout_event(struct wpa_driver_nl80211_data *drv,
                               enum nl80211_commands cmd, struct nlattr *addr)
 {
@@ -1452,7 +1476,6 @@ static int process_event(struct nl_msg *msg, void *arg)
        struct wpa_driver_nl80211_data *drv = arg;
        struct genlmsghdr *gnlh = nlmsg_data(nlmsg_hdr(msg));
        struct nlattr *tb[NL80211_ATTR_MAX + 1];
-       union wpa_event_data data;
 
        nla_parse(tb, NL80211_ATTR_MAX, genlmsg_attrdata(gnlh, 0),
                  genlmsg_attrlen(gnlh, 0), NULL);
@@ -1518,21 +1541,8 @@ static int process_event(struct nl_msg *msg, void *arg)
                                   tb[NL80211_ATTR_RESP_IE]);
                break;
        case NL80211_CMD_DISCONNECT:
-               if (drv->capa.flags & WPA_DRIVER_FLAGS_SME) {
-                       /*
-                        * Avoid reporting two disassociation events that could
-                        * confuse the core code.
-                        */
-                       wpa_printf(MSG_DEBUG, "nl80211: Ignore disconnect "
-                                  "event when using userspace SME");
-                       break;
-               }
-               drv->associated = 0;
-               os_memset(&data, 0, sizeof(data));
-               if (tb[NL80211_ATTR_REASON_CODE])
-                       data.disassoc_info.reason_code =
-                               nla_get_u16(tb[NL80211_ATTR_REASON_CODE]);
-               wpa_supplicant_event(drv->ctx, EVENT_DISASSOC, &data);
+               mlme_event_disconnect(drv, tb[NL80211_ATTR_REASON_CODE],
+                                     tb[NL80211_ATTR_MAC]);
                break;
        case NL80211_CMD_MICHAEL_MIC_FAILURE:
                mlme_event_michael_mic_failure(drv, tb);
@@ -2648,6 +2658,13 @@ static int bss_info_handler(struct nl_msg *msg, void *arg)
                        wpa_printf(MSG_DEBUG, "nl80211: Associated on %u MHz",
                                   _arg->assoc_freq);
                }
+               if (status == NL80211_BSS_STATUS_ASSOCIATED &&
+                   bss[NL80211_BSS_BSSID]) {
+                       os_memcpy(_arg->assoc_bssid,
+                                 nla_data(bss[NL80211_BSS_BSSID]), ETH_ALEN);
+                       wpa_printf(MSG_DEBUG, "nl80211: Associated with "
+                                  MACSTR, MAC2STR(_arg->assoc_bssid));
+               }
        }
        if (!res)
                return NL_SKIP;
@@ -4978,6 +4995,56 @@ nla_put_failure:
 }
 
 
+static unsigned int nl80211_get_assoc_bssid(struct wpa_driver_nl80211_data *drv,
+                                           u8 *bssid)
+{
+       struct nl_msg *msg;
+       int ret;
+       struct nl80211_bss_info_arg arg;
+
+       os_memset(&arg, 0, sizeof(arg));
+       msg = nlmsg_alloc();
+       if (!msg)
+               goto nla_put_failure;
+
+       genlmsg_put(msg, 0, 0, genl_family_get_id(drv->nl80211), 0, NLM_F_DUMP,
+                   NL80211_CMD_GET_SCAN, 0);
+       NLA_PUT_U32(msg, NL80211_ATTR_IFINDEX, drv->ifindex);
+
+       arg.drv = drv;
+       ret = send_and_recv_msgs(drv, msg, bss_info_handler, &arg);
+       msg = NULL;
+       if (ret == 0) {
+               if (is_zero_ether_addr(arg.assoc_bssid))
+                       return -ENOTCONN;
+               os_memcpy(bssid, arg.assoc_bssid, ETH_ALEN);
+               return 0;
+       }
+       wpa_printf(MSG_DEBUG, "nl80211: Scan result fetch failed: ret=%d "
+                  "(%s)", ret, strerror(-ret));
+nla_put_failure:
+       nlmsg_free(msg);
+       return drv->assoc_freq;
+}
+
+
+static int nl80211_disconnect(struct wpa_driver_nl80211_data *drv,
+                             const u8 *bssid)
+{
+       u8 addr[ETH_ALEN];
+
+       if (bssid == NULL) {
+               int res = nl80211_get_assoc_bssid(drv, addr);
+               if (res)
+                       return res;
+               bssid = addr;
+       }
+
+       return wpa_driver_nl80211_disconnect(drv, bssid,
+                                            WLAN_REASON_PREV_AUTH_NOT_VALID);
+}
+
+
 static int wpa_driver_nl80211_connect(
        struct wpa_driver_nl80211_data *drv,
        struct wpa_driver_associate_params *params)
@@ -5127,6 +5194,14 @@ skip_auth_type:
        if (ret) {
                wpa_printf(MSG_DEBUG, "nl80211: MLME connect failed: ret=%d "
                           "(%s)", ret, strerror(-ret));
+               /*
+                * cfg80211 does not currently accept new connection if we are
+                * already connected. As a workaround, force disconnection and
+                * try again once the driver indicates it completed
+                * disconnection.
+                */
+               if (ret == -EALREADY)
+                       nl80211_disconnect(drv, params->bssid);
                goto nla_put_failure;
        }
        ret = 0;