fragattacks/wpa_supplicant/mesh.c

/*
 * WPA Supplicant - Basic mesh mode routines
 * Copyright (c) 2013-2014, cozybit, Inc.  All rights reserved.
 *
 * 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/uuid.h"
#include "common/ieee802_11_defs.h"
#include "common/wpa_ctrl.h"
#include "ap/sta_info.h"
#include "ap/hostapd.h"
#include "ap/ieee802_11.h"
#include "config_ssid.h"
#include "config.h"
#include "wpa_supplicant_i.h"
#include "driver_i.h"
#include "notify.h"
#include "mesh_mpm.h"
#include "mesh.h"


static void wpa_supplicant_mesh_deinit(struct wpa_supplicant *wpa_s)
{
	wpa_supplicant_mesh_iface_deinit(wpa_s, wpa_s->ifmsh);
	wpa_s->ifmsh = NULL;
	wpa_s->current_ssid = NULL;
	/* TODO: leave mesh (stop beacon). This will happen on link down
	 * anyway, so it's not urgent */
}


void wpa_supplicant_mesh_iface_deinit(struct wpa_supplicant *wpa_s,
				      struct hostapd_iface *ifmsh)
{
	if (!ifmsh)
		return;

	if (ifmsh->mconf) {
		mesh_mpm_deinit(wpa_s, ifmsh);
		if (ifmsh->mconf->ies) {
			ifmsh->mconf->ies = NULL;
			/* We cannot free this struct
			 * because wpa_authenticator on
			 * hostapd side is also using it
			 * for now just set to NULL and
			 * let hostapd code free it.
			 */
		}
		os_free(ifmsh->mconf);
		ifmsh->mconf = NULL;
	}

	/* take care of shared data */
	hostapd_interface_deinit(ifmsh);
	hostapd_interface_free(ifmsh);
}


static struct mesh_conf * mesh_config_create(struct wpa_ssid *ssid)
{
	struct mesh_conf *conf;

	conf = os_zalloc(sizeof(struct mesh_conf));
	if (!conf)
		return NULL;

	os_memcpy(conf->meshid, ssid->ssid, ssid->ssid_len);
	conf->meshid_len = ssid->ssid_len;

	if (ssid->key_mgmt & WPA_KEY_MGMT_SAE)
		conf->security |= MESH_CONF_SEC_AUTH |
			MESH_CONF_SEC_AMPE;
	else
		conf->security |= MESH_CONF_SEC_NONE;

	/* defaults */
	conf->mesh_pp_id = MESH_PATH_PROTOCOL_HWMP;
	conf->mesh_pm_id = MESH_PATH_METRIC_AIRTIME;
	conf->mesh_cc_id = 0;
	conf->mesh_sp_id = MESH_SYNC_METHOD_NEIGHBOR_OFFSET;
	conf->mesh_auth_id = (conf->security & MESH_CONF_SEC_AUTH) ? 1 : 0;

	return conf;
}


static void wpas_mesh_copy_groups(struct hostapd_data *bss,
				  struct wpa_supplicant *wpa_s)
{
	int num_groups;
	size_t groups_size;

	for (num_groups = 0; wpa_s->conf->sae_groups[num_groups] > 0;
	     num_groups++)
		;

	groups_size = (num_groups + 1) * sizeof(wpa_s->conf->sae_groups[0]);
	bss->conf->sae_groups = os_malloc(groups_size);
	if (bss->conf->sae_groups)
		os_memcpy(bss->conf->sae_groups, wpa_s->conf->sae_groups,
			  groups_size);
}


static int wpa_supplicant_mesh_init(struct wpa_supplicant *wpa_s,
				    struct wpa_ssid *ssid)
{
	struct hostapd_iface *ifmsh;
	struct hostapd_data *bss;
	struct hostapd_config *conf;
	struct mesh_conf *mconf;
	int basic_rates_erp[] = { 10, 20, 55, 60, 110, 120, 240, -1 };
	static int default_groups[] = { 19, 20, 21, 25, 26, -1 };
	size_t len;

	if (!wpa_s->conf->user_mpm) {
		/* not much for us to do here */
		wpa_msg(wpa_s, MSG_WARNING,
			"user_mpm is not enabled in configuration");
		return 0;
	}

	wpa_s->ifmsh = ifmsh = os_zalloc(sizeof(*wpa_s->ifmsh));
	if (!ifmsh)
		return -ENOMEM;

	ifmsh->num_bss = 1;
	ifmsh->bss = os_calloc(wpa_s->ifmsh->num_bss,
			       sizeof(struct hostapd_data *));
	if (!ifmsh->bss)
		goto out_free;

	ifmsh->bss[0] = bss = os_zalloc(sizeof(struct hostapd_data));
	if (!bss)
		goto out_free;

	os_memcpy(bss->own_addr, wpa_s->own_addr, ETH_ALEN);
	bss->driver = wpa_s->driver;
	bss->drv_priv = wpa_s->drv_priv;
	bss->iface = ifmsh;
	wpa_s->assoc_freq = ssid->frequency;
	wpa_s->current_ssid = ssid;

	/* setup an AP config for auth processing */
	conf = hostapd_config_defaults();
	if (!conf)
		goto out_free;

	bss->conf = *conf->bss;
	bss->conf->start_disabled = 1;
	bss->conf->mesh = MESH_ENABLED;
	bss->iconf = conf;
	ifmsh->conf = conf;

	ifmsh->bss[0]->max_plinks = 99;
	os_strlcpy(bss->conf->iface, wpa_s->ifname, sizeof(bss->conf->iface));

	mconf = mesh_config_create(ssid);
	if (!mconf)
		goto out_free;
	ifmsh->mconf = mconf;

	/* need conf->hw_mode for supported rates. */
	if (ssid->frequency == 0) {
		conf->hw_mode = HOSTAPD_MODE_IEEE80211G;
		conf->channel = 1;
	} else {
		conf->hw_mode = ieee80211_freq_to_chan(ssid->frequency,
						       &conf->channel);
	}
	if (conf->hw_mode == NUM_HOSTAPD_MODES) {
		wpa_printf(MSG_ERROR, "Unsupported mesh mode frequency: %d MHz",
			   ssid->frequency);
		goto out_free;
	}

	/*
	 * XXX: Hack! This is so an MPM which correctly sets the ERP mandatory
	 * rates as BSSBasicRateSet doesn't reject us. We could add a new
	 * hw_mode HOSTAPD_MODE_IEEE80211G_ERP, but this is way easier. This
	 * also makes our BSSBasicRateSet advertised in Beacon frames match the
	 * one in peering frames, sigh.
	 */
	if (conf->hw_mode == HOSTAPD_MODE_IEEE80211G) {
		conf->basic_rates = os_malloc(sizeof(basic_rates_erp));
		if (!conf->basic_rates)
			goto out_free;
		os_memcpy(conf->basic_rates, basic_rates_erp,
			  sizeof(basic_rates_erp));
	}

	if (hostapd_setup_interface(ifmsh)) {
		wpa_printf(MSG_ERROR,
			   "Failed to initialize hostapd interface for mesh");
		return -1;
	}

	if (wpa_drv_init_mesh(wpa_s)) {
		wpa_msg(wpa_s, MSG_ERROR, "Failed to init mesh in driver");
		return -1;
	}

	if (mconf->security != MESH_CONF_SEC_NONE) {
		if (ssid->passphrase == NULL) {
			wpa_printf(MSG_ERROR,
				   "mesh: Passphrase for SAE not configured");
			goto out_free;
		}

		bss->conf->wpa = ssid->proto;
		bss->conf->wpa_key_mgmt = ssid->key_mgmt;

		if (wpa_s->conf->sae_groups &&
		    wpa_s->conf->sae_groups[0] > 0) {
			wpas_mesh_copy_groups(bss, wpa_s);
		} else {
			bss->conf->sae_groups =
				os_malloc(sizeof(default_groups));
			if (!bss->conf->sae_groups)
				goto out_free;
			os_memcpy(bss->conf->sae_groups, default_groups,
				  sizeof(default_groups));
		}

		len = os_strlen(ssid->passphrase);
		bss->conf->ssid.wpa_passphrase =
			dup_binstr(ssid->passphrase, len);
	}

	return 0;
out_free:
	wpa_supplicant_mesh_deinit(wpa_s);
	return -ENOMEM;
}


void wpa_mesh_notify_peer(struct wpa_supplicant *wpa_s, const u8 *addr,
			  const u8 *ies, size_t ie_len)
{
	struct ieee802_11_elems elems;

	wpa_msg(wpa_s, MSG_INFO,
		"new peer notification for " MACSTR, MAC2STR(addr));

	if (ieee802_11_parse_elems(ies, ie_len, &elems, 0) == ParseFailed) {
		wpa_msg(wpa_s, MSG_INFO, "Could not parse beacon from " MACSTR,
			MAC2STR(addr));
		return;
	}
	wpa_mesh_new_mesh_peer(wpa_s, addr, &elems);
}


void wpa_supplicant_mesh_add_scan_ie(struct wpa_supplicant *wpa_s,
				     struct wpabuf **extra_ie)
{
	/* EID + 0-length (wildcard) mesh-id */
	size_t ielen = 2;

	if (wpabuf_resize(extra_ie, ielen) == 0) {
		wpabuf_put_u8(*extra_ie, WLAN_EID_MESH_ID);
		wpabuf_put_u8(*extra_ie, 0);
	}
}


int wpa_supplicant_join_mesh(struct wpa_supplicant *wpa_s,
			     struct wpa_ssid *ssid)
{
	struct wpa_driver_mesh_join_params params;
	int ret = 0;

	if (!ssid || !ssid->ssid || !ssid->ssid_len || !ssid->frequency) {
		ret = -ENOENT;
		goto out;
	}

	wpa_supplicant_mesh_deinit(wpa_s);

	os_memset(&params, 0, sizeof(params));
	params.meshid = ssid->ssid;
	params.meshid_len = ssid->ssid_len;
	params.freq = ssid->frequency;

	if (ssid->key_mgmt & WPA_KEY_MGMT_SAE) {
		params.flags |= WPA_DRIVER_MESH_FLAG_SAE_AUTH;
		params.flags |= WPA_DRIVER_MESH_FLAG_AMPE;
		wpa_s->conf->user_mpm = 1;
	}

	if (wpa_s->conf->user_mpm) {
		params.flags |= WPA_DRIVER_MESH_FLAG_USER_MPM;
		params.conf.flags &= ~WPA_DRIVER_MESH_CONF_FLAG_AUTO_PLINKS;
	} else {
		params.flags |= WPA_DRIVER_MESH_FLAG_DRIVER_MPM;
		params.conf.flags |= WPA_DRIVER_MESH_CONF_FLAG_AUTO_PLINKS;
	}

	if (wpa_supplicant_mesh_init(wpa_s, ssid)) {
		wpa_msg(wpa_s, MSG_ERROR, "Failed to init mesh");
		ret = -1;
		goto out;
	}

	if (wpa_s->ifmsh) {
		params.ies = wpa_s->ifmsh->mconf->ies;
		params.ie_len = wpa_s->ifmsh->mconf->ie_len;
		params.basic_rates = wpa_s->ifmsh->basic_rates;
	}

	wpa_msg(wpa_s, MSG_INFO, "joining mesh %s",
		wpa_ssid_txt(ssid->ssid, ssid->ssid_len));
	ret = wpa_drv_join_mesh(wpa_s, &params);
	if (ret)
		wpa_msg(wpa_s, MSG_ERROR, "mesh join error=%d\n", ret);

	/* hostapd sets the interface down until we associate */
	wpa_drv_set_operstate(wpa_s, 1);

out:
	return ret;
}


int wpa_supplicant_leave_mesh(struct wpa_supplicant *wpa_s)
{
	int ret = 0;

	wpa_msg(wpa_s, MSG_INFO, "leaving mesh");

	ret = wpa_drv_leave_mesh(wpa_s);
	if (ret)
		wpa_msg(wpa_s, MSG_ERROR, "mesh leave error=%d", ret);

	wpa_drv_set_operstate(wpa_s, 1);

	wpa_supplicant_mesh_deinit(wpa_s);

	return ret;
}