hostapd: add support for WPS pushbutton station

similar to hostapd, also add a ubus interface for wpa_supplicant
which will allow handling WPS push-button just as it works for hostapd.
In order to have wpa_supplicant running without any network
configuration (so you can use it to retrieve credentials via WPS),
configure wifi-iface in /etc/config/wireless:

  config wifi-iface 'default_radio0'
      option device 'radio0'
      option network 'wwan'
      option mode 'sta'
      option encryption 'wps'

This section will automatically be edited if credentials have
successfully been acquired via WPS.

Size difference (mips_24kc): roughly +4kb for the 'full' variants of
wpa_supplicant and wpad which do support WPS.

Signed-off-by: Daniel Golle <daniel@makrotopia.org>

2 files changed, 302 insertions, 0 deletions

diff --git a/package/network/services/hostapd/src/wpa_supplicant/ubus.c b/package/network/services/hostapd/src/wpa_supplicant/ubus.c
new file mode 100644
index 0000000000..d4ed8e222a
--- /dev/null
+++ b/package/network/services/hostapd/src/wpa_supplicant/ubus.c
@@ -0,0 +1,249 @@
+/*
+ * wpa_supplicant / ubus support
+ * Copyright (c) 2018, Daniel Golle <daniel@makrotopia.org>
+ * Copyright (c) 2013, Felix Fietkau <nbd@nbd.name>
+ *
+ * This software may be distributed under the terms of the BSD license.
+ * See README for more details.
+ */
+
+#include "utils/includes.h"
+#include "utils/common.h"
+#include "utils/eloop.h"
+#include "utils/wpabuf.h"
+#include "common/ieee802_11_defs.h"
+#include "wpa_supplicant_i.h"
+#include "wps_supplicant.h"
+#include "ubus.h"
+
+static struct ubus_context *ctx;
+static struct blob_buf b;
+static int ctx_ref;
+
+static inline struct wpa_supplicant *get_wpas_from_object(struct ubus_object *obj)
+{
+	return container_of(obj, struct wpa_supplicant, ubus.obj);
+}
+
+static void ubus_receive(int sock, void *eloop_ctx, void *sock_ctx)
+{
+	struct ubus_context *ctx = eloop_ctx;
+	ubus_handle_event(ctx);
+}
+
+static void ubus_reconnect_timeout(void *eloop_data, void *user_ctx)
+{
+	if (ubus_reconnect(ctx, NULL)) {
+		eloop_register_timeout(1, 0, ubus_reconnect_timeout, ctx, NULL);
+		return;
+	}
+
+	eloop_register_read_sock(ctx->sock.fd, ubus_receive, ctx, NULL);
+}
+
+static void wpas_ubus_connection_lost(struct ubus_context *ctx)
+{
+	eloop_unregister_read_sock(ctx->sock.fd);
+	eloop_register_timeout(1, 0, ubus_reconnect_timeout, ctx, NULL);
+}
+
+static bool wpas_ubus_init(void)
+{
+	if (ctx)
+		return true;
+
+	ctx = ubus_connect(NULL);
+	if (!ctx)
+		return false;
+
+	ctx->connection_lost = wpas_ubus_connection_lost;
+	eloop_register_read_sock(ctx->sock.fd, ubus_receive, ctx, NULL);
+	return true;
+}
+
+static void wpas_ubus_ref_inc(void)
+{
+	ctx_ref++;
+}
+
+static void wpas_ubus_ref_dec(void)
+{
+	ctx_ref--;
+	if (!ctx)
+		return;
+
+	if (ctx_ref)
+		return;
+
+	eloop_unregister_read_sock(ctx->sock.fd);
+	ubus_free(ctx);
+	ctx = NULL;
+}
+
+static int
+wpas_bss_get_features(struct ubus_context *ctx, struct ubus_object *obj,
+			struct ubus_request_data *req, const char *method,
+			struct blob_attr *msg)
+{
+	struct wpa_supplicant *wpa_s = get_wpas_from_object(obj);
+
+	blob_buf_init(&b, 0);
+	blobmsg_add_u8(&b, "ht_supported", ht_supported(wpa_s->hw.modes));
+	blobmsg_add_u8(&b, "vht_supported", vht_supported(wpa_s->hw.modes));
+	ubus_send_reply(ctx, req, b.head);
+
+	return 0;
+}
+
+#ifdef CONFIG_WPS
+static int
+wpas_bss_wps_start(struct ubus_context *ctx, struct ubus_object *obj,
+			struct ubus_request_data *req, const char *method,
+			struct blob_attr *msg)
+{
+	int rc;
+	struct wpa_supplicant *wpa_s = get_wpas_from_object(obj);
+
+	rc = wpas_wps_start_pbc(wpa_s, NULL, 0);
+
+	if (rc != 0)
+		return UBUS_STATUS_NOT_SUPPORTED;
+
+	return 0;
+}
+
+static int
+wpas_bss_wps_cancel(struct ubus_context *ctx, struct ubus_object *obj,
+			struct ubus_request_data *req, const char *method,
+			struct blob_attr *msg)
+{
+	int rc;
+	struct wpa_supplicant *wpa_s = get_wpas_from_object(obj);
+
+	rc = wpas_wps_cancel(wpa_s);
+
+	if (rc != 0)
+		return UBUS_STATUS_NOT_SUPPORTED;
+
+	return 0;
+}
+#endif
+
+static const struct ubus_method bss_methods[] = {
+#ifdef CONFIG_WPS
+	UBUS_METHOD_NOARG("wps_start", wpas_bss_wps_start),
+	UBUS_METHOD_NOARG("wps_cancel", wpas_bss_wps_cancel),
+#endif
+	UBUS_METHOD_NOARG("get_features", wpas_bss_get_features),
+};
+
+static struct ubus_object_type bss_object_type =
+	UBUS_OBJECT_TYPE("wpas_bss", bss_methods);
+
+void wpas_ubus_add_bss(struct wpa_supplicant *wpa_s)
+{
+	struct ubus_object *obj = &wpa_s->ubus.obj;
+	char *name;
+	int ret;
+
+	if (!wpas_ubus_init())
+		return;
+
+	if (asprintf(&name, "wpa_supplicant.%s", wpa_s->ifname) < 0)
+		return;
+
+	obj->name = name;
+	obj->type = &bss_object_type;
+	obj->methods = bss_object_type.methods;
+	obj->n_methods = bss_object_type.n_methods;
+	ret = ubus_add_object(ctx, obj);
+	wpas_ubus_ref_inc();
+}
+
+void wpas_ubus_free_bss(struct wpa_supplicant *wpa_s)
+{
+	struct ubus_object *obj = &wpa_s->ubus.obj;
+	char *name = (char *) obj->name;
+
+	if (!ctx)
+		return;
+
+	if (obj->id) {
+		ubus_remove_object(ctx, obj);
+		wpas_ubus_ref_dec();
+	}
+
+	free(name);
+}
+
+#ifdef CONFIG_WPS
+void wpas_ubus_notify(struct wpa_supplicant *wpa_s, const struct wps_credential *cred)
+{
+	u16 auth_type;
+	char *ifname, *encryption, *ssid, *key;
+	size_t ifname_len;
+
+	if (!cred)
+		return;
+
+	auth_type = cred->auth_type;
+
+	if (auth_type == (WPS_AUTH_WPAPSK | WPS_AUTH_WPA2PSK))
+		auth_type = WPS_AUTH_WPA2PSK;
+
+	if (auth_type != WPS_AUTH_OPEN &&
+	    auth_type != WPS_AUTH_WPAPSK &&
+	    auth_type != WPS_AUTH_WPA2PSK) {
+		wpa_printf(MSG_DEBUG, "WPS: Ignored credentials for "
+			   "unsupported authentication type 0x%x",
+			   auth_type);
+		return;
+	}
+
+	if (auth_type == WPS_AUTH_WPAPSK || auth_type == WPS_AUTH_WPA2PSK) {
+		if (cred->key_len < 8 || cred->key_len > 2 * PMK_LEN) {
+			wpa_printf(MSG_ERROR, "WPS: Reject PSK credential with "
+				   "invalid Network Key length %lu",
+				   (unsigned long) cred->key_len);
+			return;
+		}
+	}
+
+	blob_buf_init(&b, 0);
+
+	ifname_len = strlen(wpa_s->ifname);
+	ifname = blobmsg_alloc_string_buffer(&b, "ifname", ifname_len + 1);
+	memcpy(ifname, wpa_s->ifname, ifname_len + 1);
+	ifname[ifname_len] = '\0';
+	blobmsg_add_string_buffer(&b);
+
+	switch (auth_type) {
+		case WPS_AUTH_WPA2PSK:
+			encryption = "psk2";
+			break;
+		case WPS_AUTH_WPAPSK:
+			encryption = "psk";
+			break;
+		default:
+			encryption = "none";
+			break;
+	}
+
+	blobmsg_add_string(&b, "encryption", encryption);
+
+	ssid = blobmsg_alloc_string_buffer(&b, "ssid", cred->ssid_len + 1);
+	memcpy(ssid, cred->ssid, cred->ssid_len);
+	ssid[cred->ssid_len] = '\0';
+	blobmsg_add_string_buffer(&b);
+
+	if (cred->key_len > 0) {
+		key = blobmsg_alloc_string_buffer(&b, "key", cred->key_len + 1);
+		memcpy(key, cred->key, cred->key_len);
+		key[cred->key_len] = '\0';
+		blobmsg_add_string_buffer(&b);
+	}
+
+//	ubus_notify(ctx, &wpa_s->ubus.obj, "wps_credentials", b.head, -1);
+	ubus_send_event(ctx, "wps_credentials", b.head);
+}
+#endif /* CONFIG_WPS */
diff --git a/package/network/services/hostapd/src/wpa_supplicant/ubus.h b/package/network/services/hostapd/src/wpa_supplicant/ubus.h
new file mode 100644
index 0000000000..c37e743e73
--- /dev/null
+++ b/package/network/services/hostapd/src/wpa_supplicant/ubus.h
@@ -0,0 +1,53 @@
+/*
+ * wpa_supplicant / ubus support
+ * Copyright (c) 2018, Daniel Golle <daniel@makrotopia.org>
+ * Copyright (c) 2013, Felix Fietkau <nbd@nbd.name>
+ *
+ * This software may be distributed under the terms of the BSD license.
+ * See README for more details.
+ */
+#ifndef __WPAS_UBUS_H
+#define __WPAS_UBUS_H
+
+struct wpa_supplicant;
+#include "wps_supplicant.h"
+
+#ifdef UBUS_SUPPORT
+#include <libubus.h>
+
+struct wpas_ubus_bss {
+	struct ubus_object obj;
+};
+
+void wpas_ubus_add_bss(struct wpa_supplicant *wpa_s);
+void wpas_ubus_free_bss(struct wpa_supplicant *wpa_s);
+
+#ifdef CONFIG_WPS
+void wpas_ubus_notify(struct wpa_supplicant *wpa_s, const struct wps_credential *cred);
+#endif
+
+#else
+struct wpas_ubus_bss {};
+
+static inline void wpas_ubus_add_iface(struct wpa_supplicant *wpa_s)
+{
+}
+
+static inline void wpas_ubus_free_iface(struct wpa_supplicant *wpa_s)
+{
+}
+
+static inline void wpas_ubus_add_bss(struct wpa_supplicant *wpa_s)
+{
+}
+
+static inline void wpas_ubus_free_bss(struct wpa_supplicant *wpa_s)
+{
+}
+
+static inline void wpas_ubus_notify(struct wpa_supplicant *wpa_s, struct wps_credential *cred)
+{
+}
+#endif
+
+#endif