fragattacks/wpa_supplicant/interworking.c

/*
 * Interworking (IEEE 802.11u)
 * Copyright (c) 2011, Qualcomm Atheros
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License version 2 as
 * published by the Free Software Foundation.
 *
 * Alternatively, this software may be distributed under the terms of BSD
 * license.
 *
 * See README and COPYING for more details.
 */

#include "includes.h"

#include "common.h"
#include "common/ieee802_11_defs.h"
#include "common/gas.h"
#include "common/wpa_ctrl.h"
#include "drivers/driver.h"
#include "eap_common/eap_defs.h"
#include "wpa_supplicant_i.h"
#include "config.h"
#include "bss.h"
#include "scan.h"
#include "gas_query.h"
#include "interworking.h"


static void interworking_next_anqp_fetch(struct wpa_supplicant *wpa_s);


static struct wpabuf * anqp_build_req(u16 info_ids[], size_t num_ids,
				      struct wpabuf *extra)
{
	struct wpabuf *buf;
	size_t i;
	u8 *len_pos;

	buf = gas_anqp_build_initial_req(0, 4 + num_ids * 2 +
					 (extra ? wpabuf_len(extra) : 0));
	if (buf == NULL)
		return NULL;

	len_pos = gas_anqp_add_element(buf, ANQP_QUERY_LIST);
	for (i = 0; i < num_ids; i++)
		wpabuf_put_le16(buf, info_ids[i]);
	gas_anqp_set_element_len(buf, len_pos);
	if (extra)
		wpabuf_put_buf(buf, extra);

	gas_anqp_set_len(buf);

	return buf;
}


static void interworking_anqp_resp_cb(void *ctx, const u8 *dst,
				      u8 dialog_token,
				      enum gas_query_result result,
				      const struct wpabuf *adv_proto,
				      const struct wpabuf *resp,
				      u16 status_code)
{
	struct wpa_supplicant *wpa_s = ctx;

	anqp_resp_cb(wpa_s, dst, dialog_token, result, adv_proto, resp,
		     status_code);
	interworking_next_anqp_fetch(wpa_s);
}


static int interworking_anqp_send_req(struct wpa_supplicant *wpa_s,
				      struct wpa_bss *bss)
{
	struct wpabuf *buf;
	int ret = 0;
	int res;
	u16 info_ids[] = {
		ANQP_CAPABILITY_LIST,
		ANQP_VENUE_NAME,
		ANQP_NETWORK_AUTH_TYPE,
		ANQP_ROAMING_CONSORTIUM,
		ANQP_IP_ADDR_TYPE_AVAILABILITY,
		ANQP_NAI_REALM,
		ANQP_3GPP_CELLULAR_NETWORK,
		ANQP_DOMAIN_NAME
	};
	struct wpabuf *extra = NULL;

	wpa_printf(MSG_DEBUG, "Interworking: ANQP Query Request to " MACSTR,
		   MAC2STR(bss->bssid));

	buf = anqp_build_req(info_ids, sizeof(info_ids) / sizeof(info_ids[0]),
			     extra);
	wpabuf_free(extra);
	if (buf == NULL)
		return -1;

	res = gas_query_req(wpa_s->gas, bss->bssid, bss->freq, buf,
			    interworking_anqp_resp_cb, wpa_s);
	if (res < 0) {
		wpa_printf(MSG_DEBUG, "ANQP: Failed to send Query Request");
		ret = -1;
	} else
		wpa_printf(MSG_DEBUG, "ANQP: Query started with dialog token "
			   "%u", res);

	wpabuf_free(buf);
	return ret;
}


struct nai_realm_eap {
	u8 method;
	u8 inner_method;
	enum nai_realm_eap_auth_inner_non_eap inner_non_eap;
	u8 cred_type;
	u8 tunneled_cred_type;
};

struct nai_realm {
	u8 encoding;
	char *realm;
	u8 eap_count;
	struct nai_realm_eap *eap;
};


static void nai_realm_free(struct nai_realm *realms, u16 count)
{
	u16 i;

	if (realms == NULL)
		return;
	for (i = 0; i < count; i++) {
		os_free(realms[i].eap);
		os_free(realms[i].realm);
	}
	os_free(realms);
}


static const u8 * nai_realm_parse_eap(struct nai_realm_eap *e, const u8 *pos,
				      const u8 *end)
{
	u8 elen, auth_count, a;
	const u8 *e_end;

	if (pos + 3 > end) {
		wpa_printf(MSG_DEBUG, "No room for EAP Method fixed fields");
		return NULL;
	}

	elen = *pos++;
	if (pos + elen > end || elen < 2) {
		wpa_printf(MSG_DEBUG, "No room for EAP Method subfield");
		return NULL;
	}
	e_end = pos + elen;
	e->method = *pos++;
	auth_count = *pos++;
	wpa_printf(MSG_DEBUG, "EAP Method: len=%u method=%u auth_count=%u",
		   elen, e->method, auth_count);

	for (a = 0; a < auth_count; a++) {
		u8 id, len;

		if (pos + 2 > end || pos + 2 + pos[1] > end) {
			wpa_printf(MSG_DEBUG, "No room for Authentication "
				   "Parameter subfield");
			return NULL;
		}

		id = *pos++;
		len = *pos++;

		switch (id) {
		case NAI_REALM_EAP_AUTH_NON_EAP_INNER_AUTH:
			if (len < 1)
				break;
			e->inner_non_eap = *pos;
			if (e->method != EAP_TYPE_TTLS)
				break;
			switch (*pos) {
			case NAI_REALM_INNER_NON_EAP_PAP:
				wpa_printf(MSG_DEBUG, "EAP-TTLS/PAP");
				break;
			case NAI_REALM_INNER_NON_EAP_CHAP:
				wpa_printf(MSG_DEBUG, "EAP-TTLS/CHAP");
				break;
			case NAI_REALM_INNER_NON_EAP_MSCHAP:
				wpa_printf(MSG_DEBUG, "EAP-TTLS/MSCHAP");
				break;
			case NAI_REALM_INNER_NON_EAP_MSCHAPV2:
				wpa_printf(MSG_DEBUG, "EAP-TTLS/MSCHAPV2");
				break;
			}
			break;
		case NAI_REALM_EAP_AUTH_INNER_AUTH_EAP_METHOD:
			if (len < 1)
				break;
			e->inner_method = *pos;
			wpa_printf(MSG_DEBUG, "Inner EAP method: %u",
				   e->inner_method);
			break;
		case NAI_REALM_EAP_AUTH_CRED_TYPE:
			if (len < 1)
				break;
			e->cred_type = *pos;
			wpa_printf(MSG_DEBUG, "Credential Type: %u",
				   e->cred_type);
			break;
		case NAI_REALM_EAP_AUTH_TUNNELED_CRED_TYPE:
			if (len < 1)
				break;
			e->tunneled_cred_type = *pos;
			wpa_printf(MSG_DEBUG, "Tunneled EAP Method Credential "
				   "Type: %u", e->tunneled_cred_type);
			break;
		default:
			wpa_printf(MSG_DEBUG, "Unsupported Authentication "
				   "Parameter: id=%u len=%u", id, len);
			wpa_hexdump(MSG_DEBUG, "Authentication Parameter "
				    "Value", pos, len);
			break;
		}

		pos += len;
	}

	return e_end;
}


static const u8 * nai_realm_parse_realm(struct nai_realm *r, const u8 *pos,
					const u8 *end)
{
	u16 len;
	const u8 *f_end;
	u8 realm_len, e;

	if (end - pos < 4) {
		wpa_printf(MSG_DEBUG, "No room for NAI Realm Data "
			   "fixed fields");
		return NULL;
	}

	len = WPA_GET_LE16(pos); /* NAI Realm Data field Length */
	pos += 2;
	if (pos + len > end || len < 3) {
		wpa_printf(MSG_DEBUG, "No room for NAI Realm Data "
			   "(len=%u; left=%u)",
			   len, (unsigned int) (end - pos));
		return NULL;
	}
	f_end = pos + len;

	r->encoding = *pos++;
	realm_len = *pos++;
	if (pos + realm_len > f_end) {
		wpa_printf(MSG_DEBUG, "No room for NAI Realm "
			   "(len=%u; left=%u)",
			   realm_len, (unsigned int) (f_end - pos));
		return NULL;
	}
	wpa_hexdump_ascii(MSG_DEBUG, "NAI Realm", pos, realm_len);
	r->realm = os_malloc(realm_len + 1);
	if (r->realm == NULL)
		return NULL;
	os_memcpy(r->realm, pos, realm_len);
	r->realm[realm_len] = '\0';
	pos += realm_len;

	if (pos + 1 > f_end) {
		wpa_printf(MSG_DEBUG, "No room for EAP Method Count");
		return NULL;
	}
	r->eap_count = *pos++;
	wpa_printf(MSG_DEBUG, "EAP Count: %u", r->eap_count);
	if (pos + r->eap_count * 3 > f_end) {
		wpa_printf(MSG_DEBUG, "No room for EAP Methods");
		return NULL;
	}
	r->eap = os_zalloc(r->eap_count * sizeof(struct nai_realm_eap));
	if (r->eap == NULL)
		return NULL;

	for (e = 0; e < r->eap_count; e++) {
		pos = nai_realm_parse_eap(&r->eap[e], pos, f_end);
		if (pos == NULL)
			return NULL;
	}

	return f_end;
}


static struct nai_realm * nai_realm_parse(struct wpabuf *anqp, u16 *count)
{
	struct nai_realm *realm;
	const u8 *pos, *end;
	u16 i, num;

	if (anqp == NULL || wpabuf_len(anqp) < 2)
		return NULL;

	pos = wpabuf_head_u8(anqp);
	end = pos + wpabuf_len(anqp);
	num = WPA_GET_LE16(pos);
	wpa_printf(MSG_DEBUG, "NAI Realm Count: %u", num);
	pos += 2;

	if (num * 5 > end - pos) {
		wpa_printf(MSG_DEBUG, "Invalid NAI Realm Count %u - not "
			   "enough data (%u octets) for that many realms",
			   num, (unsigned int) (end - pos));
		return NULL;
	}

	realm = os_zalloc(num * sizeof(struct nai_realm));
	if (realm == NULL)
		return NULL;

	for (i = 0; i < num; i++) {
		pos = nai_realm_parse_realm(&realm[i], pos, end);
		if (pos == NULL) {
			nai_realm_free(realm, num);
			return NULL;
		}
	}

	*count = num;
	return realm;
}


static int nai_realm_match(struct nai_realm *realm, const char *home_realm)
{
	char *tmp, *pos, *end;
	int match = 0;

	if (realm->realm == NULL)
		return 0;

	if (os_strchr(realm->realm, ';') == NULL)
		return os_strcasecmp(realm->realm, home_realm) == 0;

	tmp = os_strdup(realm->realm);
	if (tmp == NULL)
		return 0;

	pos = tmp;
	while (*pos) {
		end = os_strchr(pos, ';');
		if (end)
			*end = '\0';
		if (os_strcasecmp(pos, home_realm) == 0) {
			match = 1;
			break;
		}
		if (end == NULL)
			break;
		pos = end + 1;
	}

	os_free(tmp);

	return match;
}


int interworking_connect(struct wpa_supplicant *wpa_s, struct wpa_bss *bss)
{
	if (bss == NULL)
		return -1;

	wpa_printf(MSG_DEBUG, "Interworking: Connect with " MACSTR,
		   MAC2STR(bss->bssid));
	/* TODO: create network block and connect */
	return 0;
}


static int interworking_credentials_available(struct wpa_supplicant *wpa_s,
					      struct wpa_bss *bss)
{
	struct nai_realm *realm;
	u16 count, i;
	int found = 0;

	if (bss->anqp_nai_realm == NULL)
		return 0;

	if (wpa_s->conf->home_realm == NULL)
		return 0;

	wpa_printf(MSG_DEBUG, "Interworking: Parsing NAI Realm list from "
		   MACSTR, MAC2STR(bss->bssid));
	realm = nai_realm_parse(bss->anqp_nai_realm, &count);
	if (realm == NULL) {
		wpa_printf(MSG_DEBUG, "Interworking: Could not parse NAI "
			   "Realm list from " MACSTR, MAC2STR(bss->bssid));
		return 0;
	}

	for (i = 0; i < count; i++) {
		if (nai_realm_match(&realm[i], wpa_s->conf->home_realm)) {
			found++;
			break;
		}
	}

	nai_realm_free(realm, count);

	return found;
}


static void interworking_select_network(struct wpa_supplicant *wpa_s)
{
	struct wpa_bss *bss, *selected = NULL;
	unsigned int count = 0;

	wpa_s->network_select = 0;

	dl_list_for_each(bss, &wpa_s->bss, struct wpa_bss, list) {
		if (!interworking_credentials_available(wpa_s, bss))
			continue;
		count++;
		wpa_msg(wpa_s, MSG_INFO, INTERWORKING_AP MACSTR,
			MAC2STR(bss->bssid));
		if (selected == NULL && wpa_s->auto_select)
			selected = bss;
	}

	if (count == 0) {
		wpa_msg(wpa_s, MSG_INFO, INTERWORKING_NO_MATCH "No network "
			"with matching credentials found");
	}

	if (selected)
		interworking_connect(wpa_s, selected);
}


static void interworking_next_anqp_fetch(struct wpa_supplicant *wpa_s)
{
	struct wpa_bss *bss;
	int found = 0;
	const u8 *ie;

	if (!wpa_s->fetch_anqp_in_progress)
		return;

	dl_list_for_each(bss, &wpa_s->bss, struct wpa_bss, list) {
		if (!(bss->caps & IEEE80211_CAP_ESS))
			continue;
		ie = wpa_bss_get_ie(bss, WLAN_EID_EXT_CAPAB);
		if (ie == NULL || ie[1] < 4 || !(ie[5] & 0x80))
			continue; /* AP does not support Interworking */

		if (!(bss->flags & WPA_BSS_ANQP_FETCH_TRIED)) {
			found++;
			bss->flags |= WPA_BSS_ANQP_FETCH_TRIED;
			wpa_msg(wpa_s, MSG_INFO, "Starting ANQP fetch for "
				MACSTR, MAC2STR(bss->bssid));
			interworking_anqp_send_req(wpa_s, bss);
			break;
		}
	}

	if (found == 0) {
		wpa_msg(wpa_s, MSG_INFO, "ANQP fetch completed");
		wpa_s->fetch_anqp_in_progress = 0;
		if (wpa_s->network_select)
			interworking_select_network(wpa_s);
	}
}


static void interworking_start_fetch_anqp(struct wpa_supplicant *wpa_s)
{
	struct wpa_bss *bss;

	dl_list_for_each(bss, &wpa_s->bss, struct wpa_bss, list)
		bss->flags &= ~WPA_BSS_ANQP_FETCH_TRIED;

	wpa_s->fetch_anqp_in_progress = 1;
	interworking_next_anqp_fetch(wpa_s);
}


int interworking_fetch_anqp(struct wpa_supplicant *wpa_s)
{
	if (wpa_s->fetch_anqp_in_progress || wpa_s->network_select)
		return 0;

	wpa_s->network_select = 0;

	interworking_start_fetch_anqp(wpa_s);

	return 0;
}


void interworking_stop_fetch_anqp(struct wpa_supplicant *wpa_s)
{
	if (!wpa_s->fetch_anqp_in_progress)
		return;

	wpa_s->fetch_anqp_in_progress = 0;
}


int anqp_send_req(struct wpa_supplicant *wpa_s, const u8 *dst,
		  u16 info_ids[], size_t num_ids)
{
	struct wpabuf *buf;
	int ret = 0;
	int freq;
	struct wpa_bss *bss;
	int res;

	freq = wpa_s->assoc_freq;
	bss = wpa_bss_get_bssid(wpa_s, dst);
	if (bss)
		freq = bss->freq;
	if (freq <= 0)
		return -1;

	wpa_printf(MSG_DEBUG, "ANQP: Query Request to " MACSTR " for %u id(s)",
		   MAC2STR(dst), (unsigned int) num_ids);

	buf = anqp_build_req(info_ids, num_ids, NULL);
	if (buf == NULL)
		return -1;

	res = gas_query_req(wpa_s->gas, dst, freq, buf, anqp_resp_cb, wpa_s);
	if (res < 0) {
		wpa_printf(MSG_DEBUG, "ANQP: Failed to send Query Request");
		ret = -1;
	} else
		wpa_printf(MSG_DEBUG, "ANQP: Query started with dialog token "
			   "%u", res);

	wpabuf_free(buf);
	return ret;
}


static void interworking_parse_rx_anqp_resp(struct wpa_supplicant *wpa_s,
					    const u8 *sa, u16 info_id,
					    const u8 *data, size_t slen)
{
	const u8 *pos = data;
	struct wpa_bss *bss = wpa_bss_get_bssid(wpa_s, sa);

	switch (info_id) {
	case ANQP_CAPABILITY_LIST:
		wpa_msg(wpa_s, MSG_INFO, "RX-ANQP " MACSTR
			" ANQP Capability list", MAC2STR(sa));
		break;
	case ANQP_VENUE_NAME:
		wpa_msg(wpa_s, MSG_INFO, "RX-ANQP " MACSTR
			" Venue Name", MAC2STR(sa));
		wpa_hexdump_ascii(MSG_DEBUG, "ANQP: Venue Name", pos, slen);
		if (bss) {
			wpabuf_free(bss->anqp_venue_name);
			bss->anqp_venue_name = wpabuf_alloc_copy(pos, slen);
		}
		break;
	case ANQP_NETWORK_AUTH_TYPE:
		wpa_msg(wpa_s, MSG_INFO, "RX-ANQP " MACSTR
			" Network Authentication Type information",
			MAC2STR(sa));
		wpa_hexdump_ascii(MSG_DEBUG, "ANQP: Network Authentication "
				  "Type", pos, slen);
		if (bss) {
			wpabuf_free(bss->anqp_network_auth_type);
			bss->anqp_network_auth_type =
				wpabuf_alloc_copy(pos, slen);
		}
		break;
	case ANQP_ROAMING_CONSORTIUM:
		wpa_msg(wpa_s, MSG_INFO, "RX-ANQP " MACSTR
			" Roaming Consortium list", MAC2STR(sa));
		wpa_hexdump_ascii(MSG_DEBUG, "ANQP: Roaming Consortium",
				  pos, slen);
		if (bss) {
			wpabuf_free(bss->anqp_roaming_consortium);
			bss->anqp_roaming_consortium =
				wpabuf_alloc_copy(pos, slen);
		}
		break;
	case ANQP_IP_ADDR_TYPE_AVAILABILITY:
		wpa_msg(wpa_s, MSG_INFO, "RX-ANQP " MACSTR
			" IP Address Type Availability information",
			MAC2STR(sa));
		wpa_hexdump(MSG_MSGDUMP, "ANQP: IP Address Availability",
			    pos, slen);
		if (bss) {
			wpabuf_free(bss->anqp_ip_addr_type_availability);
			bss->anqp_ip_addr_type_availability =
				wpabuf_alloc_copy(pos, slen);
		}
		break;
	case ANQP_NAI_REALM:
		wpa_msg(wpa_s, MSG_INFO, "RX-ANQP " MACSTR
			" NAI Realm list", MAC2STR(sa));
		wpa_hexdump_ascii(MSG_DEBUG, "ANQP: NAI Realm", pos, slen);
		if (bss) {
			wpabuf_free(bss->anqp_nai_realm);
			bss->anqp_nai_realm = wpabuf_alloc_copy(pos, slen);
		}
		break;
	case ANQP_3GPP_CELLULAR_NETWORK:
		wpa_msg(wpa_s, MSG_INFO, "RX-ANQP " MACSTR
			" 3GPP Cellular Network information", MAC2STR(sa));
		wpa_hexdump_ascii(MSG_DEBUG, "ANQP: 3GPP Cellular Network",
				  pos, slen);
		if (bss) {
			wpabuf_free(bss->anqp_3gpp);
			bss->anqp_3gpp = wpabuf_alloc_copy(pos, slen);
		}
		break;
	case ANQP_DOMAIN_NAME:
		wpa_msg(wpa_s, MSG_INFO, "RX-ANQP " MACSTR
			" Domain Name list", MAC2STR(sa));
		wpa_hexdump_ascii(MSG_MSGDUMP, "ANQP: Domain Name", pos, slen);
		if (bss) {
			wpabuf_free(bss->anqp_domain_name);
			bss->anqp_domain_name = wpabuf_alloc_copy(pos, slen);
		}
		break;
	case ANQP_VENDOR_SPECIFIC:
		if (slen < 3)
			return;

		switch (WPA_GET_BE24(pos)) {
		default:
			wpa_printf(MSG_DEBUG, "Interworking: Unsupported "
				   "vendor-specific ANQP OUI %06x",
				   WPA_GET_BE24(pos));
			return;
		}
		break;
	default:
		wpa_printf(MSG_DEBUG, "Interworking: Unsupported ANQP Info ID "
			   "%u", info_id);
		break;
	}
}


void anqp_resp_cb(void *ctx, const u8 *dst, u8 dialog_token,
		  enum gas_query_result result,
		  const struct wpabuf *adv_proto,
		  const struct wpabuf *resp, u16 status_code)
{
	struct wpa_supplicant *wpa_s = ctx;
	const u8 *pos;
	const u8 *end;
	u16 info_id;
	u16 slen;

	if (result != GAS_QUERY_SUCCESS)
		return;

	pos = wpabuf_head(adv_proto);
	if (wpabuf_len(adv_proto) < 4 || pos[0] != WLAN_EID_ADV_PROTO ||
	    pos[1] < 2 || pos[3] != ACCESS_NETWORK_QUERY_PROTOCOL) {
		wpa_printf(MSG_DEBUG, "ANQP: Unexpected Advertisement "
			   "Protocol in response");
		return;
	}

	pos = wpabuf_head(resp);
	end = pos + wpabuf_len(resp);

	while (pos < end) {
		if (pos + 4 > end) {
			wpa_printf(MSG_DEBUG, "ANQP: Invalid element");
			break;
		}
		info_id = WPA_GET_LE16(pos);
		pos += 2;
		slen = WPA_GET_LE16(pos);
		pos += 2;
		if (pos + slen > end) {
			wpa_printf(MSG_DEBUG, "ANQP: Invalid element length "
				   "for Info ID %u", info_id);
			break;
		}
		interworking_parse_rx_anqp_resp(wpa_s, dst, info_id, pos,
						slen);
		pos += slen;
	}
}


static void interworking_scan_res_handler(struct wpa_supplicant *wpa_s,
					  struct wpa_scan_results *scan_res)
{
	wpa_printf(MSG_DEBUG, "Interworking: Scan results available - start "
		   "ANQP fetch");
	interworking_start_fetch_anqp(wpa_s);
}


int interworking_select(struct wpa_supplicant *wpa_s, int auto_select)
{
	interworking_stop_fetch_anqp(wpa_s);
	wpa_s->network_select = 1;
	wpa_s->auto_select = !!auto_select;
	wpa_printf(MSG_DEBUG, "Interworking: Start scan for network "
		   "selection");
	wpa_s->scan_res_handler = interworking_scan_res_handler;
	wpa_s->scan_req = 2;
	wpa_supplicant_req_scan(wpa_s, 0, 0);

	return 0;
}