nl80211: clean up netlink code

This is a port of commit cafe38cae01b0fcbc3b795ce02decf4ad93bee8f
from Johannes Berg <johannes@sipsolutions.net> for hostapd to
wpa_supplicant driver_nl80211.c.

diff --git a/src/drivers/driver_nl80211.c b/src/drivers/driver_nl80211.c
index a207363..50a772b 100644 (file)
--- a/src/drivers/driver_nl80211.c
+++ b/src/drivers/driver_nl80211.c
@@ -93,6 +93,62 @@ static void
 wpa_driver_nl80211_finish_drv_init(struct wpa_driver_nl80211_data *drv);
 
 
+/* nl80211 code */
+static int ack_handler(struct nl_msg *msg, void *arg)
+{
+       int *err = arg;
+       *err = 0;
+       return NL_STOP;
+}
+
+static int finish_handler(struct nl_msg *msg, void *arg)
+{
+       return NL_SKIP;
+}
+
+static int error_handler(struct sockaddr_nl *nla, struct nlmsgerr *err,
+                        void *arg)
+{
+       int *ret = arg;
+       *ret = err->error;
+       return NL_SKIP;
+}
+
+static int send_and_recv_msgs(struct wpa_driver_nl80211_data *drv,
+                             struct nl_msg *msg,
+                             int (*valid_handler)(struct nl_msg *, void *),
+                             void *valid_data)
+{
+       struct nl_cb *cb;
+       int err = -ENOMEM;
+
+       cb = nl_cb_clone(drv->nl_cb);
+       if (!cb)
+               goto out;
+
+       err = nl_send_auto_complete(drv->nl_handle, msg);
+       if (err < 0)
+               goto out;
+
+       err = 1;
+
+       nl_cb_err(cb, NL_CB_CUSTOM, error_handler, &err);
+       nl_cb_set(cb, NL_CB_FINISH, NL_CB_CUSTOM, finish_handler, NULL);
+       nl_cb_set(cb, NL_CB_ACK, NL_CB_CUSTOM, ack_handler, &err);
+
+       if (valid_handler)
+               nl_cb_set(cb, NL_CB_VALID, NL_CB_CUSTOM,
+                         valid_handler, valid_data);
+
+       while (err > 0)
+               nl_recvmsgs(drv->nl_handle, cb);
+ out:
+       nl_cb_put(cb);
+       nlmsg_free(msg);
+       return err;
+}
+
+
 static int wpa_driver_nl80211_send_oper_ifla(
        struct wpa_driver_nl80211_data *drv,
        int linkmode, int operstate)
@@ -911,7 +967,7 @@ static int nl80211_set_vif(struct wpa_driver_nl80211_data *drv,
 
        msg = nlmsg_alloc();
        if (!msg)
-               goto out;
+               return -ENOMEM;
 
        genlmsg_put(msg, 0, 0, genl_family_get_id(drv->nl80211), 0, 0,
                    NL80211_CMD_SET_VIF, 0);
@@ -927,16 +983,11 @@ static int nl80211_set_vif(struct wpa_driver_nl80211_data *drv,
 
        NLA_PUT_U32(msg, NL80211_ATTR_IFINDEX, drv->ifindex);
 
-       if (nl_send_auto_complete(drv->nl_handle, msg) < 0 ||
-           nl_wait_for_ack(drv->nl_handle) < 0) {
-               ret = -1;
-       }
+       ret = send_and_recv_msgs(drv, msg, NULL, NULL);
+       return ret;
 
 nla_put_failure:
-       nlmsg_free(msg);
-
-out:
-       return ret;
+       return -ENOBUFS;
 #else /* NL80211_CMD_SET_VIF */
        return -1;
 #endif /* NL80211_CMD_SET_VIF */
@@ -962,12 +1013,10 @@ static void nl80211_remove_iface(struct wpa_driver_nl80211_data *drv,
        genlmsg_put(msg, 0, 0, genl_family_get_id(drv->nl80211), 0,
                    0, NL80211_CMD_DEL_INTERFACE, 0);
        NLA_PUT_U32(msg, NL80211_ATTR_IFINDEX, ifidx);
-       if (nl_send_auto_complete(drv->nl_handle, msg) < 0 ||
-           nl_wait_for_ack(drv->nl_handle) < 0) {
-       nla_put_failure:
-               wpa_printf(MSG_ERROR, "nl80211: Failed to remove interface.");
-       }
-       nlmsg_free(msg);
+       if (send_and_recv_msgs(drv, msg, NULL, NULL) == 0)
+               return;
+nla_put_failure:
+       wpa_printf(MSG_ERROR, "nl80211: Failed to remove interface.");
 }
 
 
@@ -976,6 +1025,7 @@ static int nl80211_create_iface(struct wpa_driver_nl80211_data *drv,
 {
        struct nl_msg *msg, *flags = NULL;
        int ifidx, err;
+       int ret = -ENOBUFS;
 
        msg = nlmsg_alloc();
        if (!msg)
@@ -1002,26 +1052,14 @@ static int nl80211_create_iface(struct wpa_driver_nl80211_data *drv,
                        goto nla_put_failure;
        }
 
-       err = nl_send_auto_complete(drv->nl_handle, msg);
-       if (err < 0)
-               wpa_printf(MSG_ERROR, "nl80211: nl_send_auto_complete failed: "
-                          "%d (create_iface)", err);
-       else {
-               err = nl_wait_for_ack(drv->nl_handle);
-               if (err < 0)
-                       wpa_printf(MSG_ERROR, "nl80211: nl_wait_for_ack "
-                                  "failed: %d (create_iface)", err);
-       }
-       if (err < 0) {
- nla_put_failure:
-               wpa_printf(MSG_ERROR, "nl80211: Failed to create interface "
-                          "%s.", ifname);
-               nlmsg_free(msg);
-               return -1;
+       ret = send_and_recv_msgs(drv, msg, NULL, NULL);
+       if (ret) {
+       nla_put_failure:
+               wpa_printf(MSG_ERROR, "nl80211: Failed to create interface %d",
+                          ret);
+               return ret;
        }
 
-       nlmsg_free(msg);
-
        ifidx = if_nametoindex(ifname);
        if (ifidx <= 0)
                return -1;
@@ -1953,7 +1991,7 @@ static int wpa_driver_nl80211_set_key(void *priv, wpa_alg alg,
                                      const u8 *key, size_t key_len)
 {
        struct wpa_driver_nl80211_data *drv = priv;
-       int ret = -1, err;
+       int err;
        struct nl_msg *msg;
 
        wpa_printf(MSG_DEBUG, "%s: alg=%d addr=%p key_idx=%d set_tx=%d "
@@ -2001,16 +2039,13 @@ static int wpa_driver_nl80211_set_key(void *priv, wpa_alg alg,
        NLA_PUT_U8(msg, NL80211_ATTR_KEY_IDX, key_idx);
        NLA_PUT_U32(msg, NL80211_ATTR_IFINDEX, drv->ifindex);
 
-       err = 0;
-       if (nl_send_auto_complete(drv->nl_handle, msg) < 0 ||
-           (err = nl_wait_for_ack(drv->nl_handle)) < 0) {
+       err = send_and_recv_msgs(drv, msg, NULL, NULL);
+       if (err) {
                wpa_printf(MSG_DEBUG, "nl80211: set_key failed; err=%d", err);
-               nlmsg_free(msg);
                return -1;
        }
 
        if (set_tx && alg != WPA_ALG_NONE) {
-               nlmsg_free(msg);
                msg = nlmsg_alloc();
                if (msg == NULL)
                        return -1;
@@ -2021,21 +2056,18 @@ static int wpa_driver_nl80211_set_key(void *priv, wpa_alg alg,
                NLA_PUT_U32(msg, NL80211_ATTR_IFINDEX, drv->ifindex);
                NLA_PUT_FLAG(msg, NL80211_ATTR_KEY_DEFAULT);
 
-               err = 0;
-               if (nl_send_auto_complete(drv->nl_handle, msg) < 0 ||
-                   (err = nl_wait_for_ack(drv->nl_handle)) < 0) {
+               err = send_and_recv_msgs(drv, msg, NULL, NULL);
+               if (err) {
                        wpa_printf(MSG_DEBUG, "nl80211: set default key "
                                   "failed; err=%d", err);
-                       nlmsg_free(msg);
                        return -1;
                }
        }
 
-       ret = 0;
+       return 0;
 
 nla_put_failure:
-       nlmsg_free(msg);
-       return ret;
+       return -ENOBUFS;
 }
 
 
@@ -2331,15 +2363,14 @@ static int wpa_driver_nl80211_set_mode(void *priv, int mode)
        NLA_PUT_U32(msg, NL80211_ATTR_IFTYPE,
                    mode ? NL80211_IFTYPE_ADHOC : NL80211_IFTYPE_STATION);
 
-       if (nl_send_auto_complete(drv->nl_handle, msg) < 0 ||
-           nl_wait_for_ack(drv->nl_handle) < 0)
+       ret = send_and_recv_msgs(drv, msg, NULL, NULL);
+       if (!ret)
+               return 0;
+       else
                goto try_again;
 
-       nlmsg_free(msg);
-       return 0;
-
 nla_put_failure:
-       nlmsg_free(msg);
+       wpa_printf(MSG_ERROR, "nl80211: Failed to set interface mode");
        return -1;
 
 try_again:
@@ -2351,12 +2382,21 @@ try_again:
                (void) wpa_driver_nl80211_set_ifflags(drv, flags & ~IFF_UP);
 
                /* Try to set the mode again while the interface is down */
-               if (nl_send_auto_complete(drv->nl_handle, msg) < 0 ||
-                   nl_wait_for_ack(drv->nl_handle) < 0) {
+               msg = nlmsg_alloc();
+               if (!msg)
+                       return -1;
+
+               genlmsg_put(msg, 0, 0, genl_family_get_id(drv->nl80211), 0,
+                           0, NL80211_CMD_SET_INTERFACE, 0);
+               NLA_PUT_U32(msg, NL80211_ATTR_IFINDEX, drv->ifindex);
+               NLA_PUT_U32(msg, NL80211_ATTR_IFTYPE,
+                           mode ? NL80211_IFTYPE_ADHOC :
+                           NL80211_IFTYPE_STATION);
+               ret = send_and_recv_msgs(drv, msg, NULL, NULL);
+               if (ret) {
                        wpa_printf(MSG_ERROR, "Failed to set interface %s "
                                   "mode", drv->ifname);
-               } else
-                       ret = 0;
+               }
 
                /* Ignore return value of get_ifflags to ensure that the device
                 * is always up like it was before this function was called.
@@ -2365,7 +2405,6 @@ try_again:
                (void) wpa_driver_nl80211_set_ifflags(drv, flags | IFF_UP);
        }
 
-       nlmsg_free(msg);
        return ret;
 }
 
@@ -2488,19 +2527,9 @@ static int wpa_driver_nl80211_set_param(void *priv, const char *param)
 
 #ifdef CONFIG_CLIENT_MLME
 
-static int ack_wait_handler(struct nl_msg *msg, void *arg)
-{
-       int *finished = arg;
-
-       *finished = 1;
-       return NL_STOP;
-}
-
-
 struct phy_info_arg {
        u16 *num_modes;
        struct wpa_hw_modes *modes;
-       int error;
 };
 
 
@@ -2660,8 +2689,6 @@ static int phy_info_handler(struct nl_msg *msg, void *arg)
                }
        }
 
-       phy_info->error = 0;
-
        return NL_SKIP;
 }
 
@@ -2671,13 +2698,9 @@ wpa_driver_nl80211_get_hw_feature_data(void *priv, u16 *num_modes, u16 *flags)
 {
        struct wpa_driver_nl80211_data *drv = priv;
        struct nl_msg *msg;
-       int err = -1;
-       struct nl_cb *cb = NULL;
-       int finished = 0;
        struct phy_info_arg result = {
                .num_modes = num_modes,
                .modes = NULL,
-               .error = 1,
        };
 
        *num_modes = 0;
@@ -2692,33 +2715,10 @@ wpa_driver_nl80211_get_hw_feature_data(void *priv, u16 *num_modes, u16 *flags)
 
        NLA_PUT_U32(msg, NL80211_ATTR_IFINDEX, drv->ifindex);
 
-       cb = nl_cb_clone(drv->nl_cb);
-       if (!cb)
-               goto out;
-
-       if (nl_send_auto_complete(drv->nl_handle, msg) < 0)
-               goto out;
-
-       nl_cb_set(cb, NL_CB_VALID, NL_CB_CUSTOM, phy_info_handler, &result);
-       nl_cb_set(cb, NL_CB_ACK, NL_CB_CUSTOM, ack_wait_handler, &finished);
-
-       err = nl_recvmsgs(drv->nl_handle, cb);
-
-       if (!finished)
-               err = nl_wait_for_ack(drv->nl_handle);
-
-       if (err < 0 || result.error) {
-               wpa_supplicant_sta_free_hw_features(result.modes, *num_modes);
-               result.modes = NULL;
-       }
-
- out:
-       nl_cb_put(cb);
- nla_put_failure:
-       if (err)
-               fprintf(stderr, "failed to get information: %d\n", err);
-       nlmsg_free(msg);
-       return result.modes;
+       if (send_and_recv_msgs(drv, msg, phy_info_handler, &result) == 0)
+               return result.modes;
+nla_put_failure:
+       return NULL;
 }
 
 
@@ -2781,7 +2781,7 @@ static int wpa_driver_nl80211_mlme_add_sta(void *priv, const u8 *addr,
 
        msg = nlmsg_alloc();
        if (!msg)
-               goto out;
+               return -ENOMEM;
 
        genlmsg_put(msg, 0, 0, genl_family_get_id(drv->nl80211), 0,
                    0, NL80211_CMD_NEW_STATION, 0);
@@ -2794,19 +2794,12 @@ static int wpa_driver_nl80211_mlme_add_sta(void *priv, const u8 *addr,
                supp_rates);
        NLA_PUT_U16(msg, NL80211_ATTR_STA_LISTEN_INTERVAL, 1);
 
-       ret = nl_send_auto_complete(drv->nl_handle, msg);
-       if (ret < 0)
-               goto nla_put_failure;
-
-       ret = nl_wait_for_ack(drv->nl_handle);
+       ret = send_and_recv_msgs(drv, msg, NULL, NULL);
        /* ignore EEXIST, this happens if a STA associates while associated */
        if (ret == -EEXIST || ret >= 0)
                ret = 0;
 
- nla_put_failure:
-       nlmsg_free(msg);
-
- out:
+nla_put_failure:
        return ret;
 }
 
@@ -2819,7 +2812,7 @@ static int wpa_driver_nl80211_mlme_remove_sta(void *priv, const u8 *addr)
 
        msg = nlmsg_alloc();
        if (!msg)
-               goto out;
+               return -ENOMEM;
 
        genlmsg_put(msg, 0, 0, genl_family_get_id(drv->nl80211), 0,
                    0, NL80211_CMD_DEL_STATION, 0);
@@ -2829,16 +2822,11 @@ static int wpa_driver_nl80211_mlme_remove_sta(void *priv, const u8 *addr)
 
        ret = 0;
 
-       if (nl_send_auto_complete(drv->nl_handle, msg) < 0 ||
-           nl_wait_for_ack(drv->nl_handle) < 0) {
-               ret = -1;
-       }
-
- nla_put_failure:
-       nlmsg_free(msg);
-
- out:
+       ret = send_and_recv_msgs(drv, msg, NULL, NULL);
        return ret;
+
+nla_put_failure:
+       return -ENOBUFS;
 }
 
 #endif /* CONFIG_CLIENT_MLME */