src/common/ieee802_11_common.c - third_party/hostap - Git at Google

 /*
  * IEEE 802.11 Common routines
  * Copyright (c) 2002-2009, Jouni Malinen <j@w1.fi>
  *
  * This software may be distributed under the terms of the BSD license.
  * See README for more details.
  */

 #include "includes.h"

 #include "common.h"
 #include "ieee802_11_defs.h"
 #include "ieee802_11_common.h"


 static int ieee802_11_parse_vendor_specific(const u8 *pos, size_t elen,
 					    struct ieee802_11_elems *elems,
 					    int show_errors)
 {
 	unsigned int oui;

 	/* first 3 bytes in vendor specific information element are the IEEE
 	 * OUI of the vendor. The following byte is used a vendor specific
 	 * sub-type. */
 	if (elen < 4) {
 		if (show_errors) {
 			wpa_printf(MSG_MSGDUMP, "short vendor specific "
 				   "information element ignored (len=%lu)",
 				   (unsigned long) elen);
 		}
 		return -1;
 	}

 	oui = WPA_GET_BE24(pos);
 	switch (oui) {
 	case OUI_MICROSOFT:
 		/* Microsoft/Wi-Fi information elements are further typed and
 		 * subtyped */
 		switch (pos[3]) {
 		case 1:
 			/* Microsoft OUI (00:50:F2) with OUI Type 1:
 			 * real WPA information element */
 			elems->wpa_ie = pos;
 			elems->wpa_ie_len = elen;
 			break;
 		case WMM_OUI_TYPE:
 			/* WMM information element */
 			if (elen < 5) {
 				wpa_printf(MSG_MSGDUMP, "short WMM "
 					   "information element ignored "
 					   "(len=%lu)",
 					   (unsigned long) elen);
 				return -1;
 			}
 			switch (pos[4]) {
 			case WMM_OUI_SUBTYPE_INFORMATION_ELEMENT:
 			case WMM_OUI_SUBTYPE_PARAMETER_ELEMENT:
 				/*
 				 * Share same pointer since only one of these
 				 * is used and they start with same data.
 				 * Length field can be used to distinguish the
 				 * IEs.
 				 */
 				elems->wmm = pos;
 				elems->wmm_len = elen;
 				break;
 			case WMM_OUI_SUBTYPE_TSPEC_ELEMENT:
 				elems->wmm_tspec = pos;
 				elems->wmm_tspec_len = elen;
 				break;
 			default:
 				wpa_printf(MSG_EXCESSIVE, "unknown WMM "
 					   "information element ignored "
 					   "(subtype=%d len=%lu)",
 					   pos[4], (unsigned long) elen);
 				return -1;
 			}
 			break;
 		case 4:
 			/* Wi-Fi Protected Setup (WPS) IE */
 			elems->wps_ie = pos;
 			elems->wps_ie_len = elen;
 			break;
 		default:
 			wpa_printf(MSG_EXCESSIVE, "Unknown Microsoft "
 				   "information element ignored "
 				   "(type=%d len=%lu)",
 				   pos[3], (unsigned long) elen);
 			return -1;
 		}
 		break;

 	case OUI_WFA:
 		switch (pos[3]) {
 		case P2P_OUI_TYPE:
 			/* Wi-Fi Alliance - P2P IE */
 			elems->p2p = pos;
 			elems->p2p_len = elen;
 			break;
 		default:
 			wpa_printf(MSG_MSGDUMP, "Unknown WFA "
 				   "information element ignored "
 				   "(type=%d len=%lu)\n",
 				   pos[3], (unsigned long) elen);
 			return -1;
 		}
 		break;

 	case OUI_BROADCOM:
 		switch (pos[3]) {
 		case VENDOR_HT_CAPAB_OUI_TYPE:
 			elems->vendor_ht_cap = pos;
 			elems->vendor_ht_cap_len = elen;
 			break;
 		default:
 			wpa_printf(MSG_EXCESSIVE, "Unknown Broadcom "
 				   "information element ignored "
 				   "(type=%d len=%lu)",
 				   pos[3], (unsigned long) elen);
 			return -1;
 		}
 		break;

 	default:
 		wpa_printf(MSG_EXCESSIVE, "unknown vendor specific "
 			   "information element ignored (vendor OUI "
 			   "%02x:%02x:%02x len=%lu)",
 			   pos[0], pos[1], pos[2], (unsigned long) elen);
 		return -1;
 	}

 	return 0;
 }


 /**
  * ieee802_11_parse_elems - Parse information elements in management frames
  * @start: Pointer to the start of IEs
  * @len: Length of IE buffer in octets
  * @elems: Data structure for parsed elements
  * @show_errors: Whether to show parsing errors in debug log
  * Returns: Parsing result
  */
 ParseRes ieee802_11_parse_elems(const u8 *start, size_t len,
 				struct ieee802_11_elems *elems,
 				int show_errors)
 {
 	size_t left = len;
 	const u8 *pos = start;
 	int unknown = 0;

 	os_memset(elems, 0, sizeof(*elems));

 	while (left >= 2) {
 		u8 id, elen;

 		id = *pos++;
 		elen = *pos++;
 		left -= 2;

 		if (elen > left) {
 			if (show_errors) {
 				wpa_printf(MSG_DEBUG, "IEEE 802.11 element "
 					   "parse failed (id=%d elen=%d "
 					   "left=%lu)",
 					   id, elen, (unsigned long) left);
 				wpa_hexdump(MSG_MSGDUMP, "IEs", start, len);
 			}
 			return ParseFailed;
 		}

 		switch (id) {
 		case WLAN_EID_SSID:
 			elems->ssid = pos;
 			elems->ssid_len = elen;
 			break;
 		case WLAN_EID_SUPP_RATES:
 			elems->supp_rates = pos;
 			elems->supp_rates_len = elen;
 			break;
 		case WLAN_EID_FH_PARAMS:
 			elems->fh_params = pos;
 			elems->fh_params_len = elen;
 			break;
 		case WLAN_EID_DS_PARAMS:
 			elems->ds_params = pos;
 			elems->ds_params_len = elen;
 			break;
 		case WLAN_EID_CF_PARAMS:
 			elems->cf_params = pos;
 			elems->cf_params_len = elen;
 			break;
 		case WLAN_EID_TIM:
 			elems->tim = pos;
 			elems->tim_len = elen;
 			break;
 		case WLAN_EID_IBSS_PARAMS:
 			elems->ibss_params = pos;
 			elems->ibss_params_len = elen;
 			break;
 		case WLAN_EID_CHALLENGE:
 			elems->challenge = pos;
 			elems->challenge_len = elen;
 			break;
 		case WLAN_EID_ERP_INFO:
 			elems->erp_info = pos;
 			elems->erp_info_len = elen;
 			break;
 		case WLAN_EID_EXT_SUPP_RATES:
 			elems->ext_supp_rates = pos;
 			elems->ext_supp_rates_len = elen;
 			break;
 		case WLAN_EID_VENDOR_SPECIFIC:
 			if (ieee802_11_parse_vendor_specific(pos, elen,
 							     elems,
 							     show_errors))
 				unknown++;
 			break;
 		case WLAN_EID_RSN:
 			elems->rsn_ie = pos;
 			elems->rsn_ie_len = elen;
 			break;
 		case WLAN_EID_PWR_CAPABILITY:
 			elems->power_cap = pos;
 			elems->power_cap_len = elen;
 			break;
 		case WLAN_EID_SUPPORTED_CHANNELS:
 			elems->supp_channels = pos;
 			elems->supp_channels_len = elen;
 			break;
 		case WLAN_EID_MOBILITY_DOMAIN:
 			elems->mdie = pos;
 			elems->mdie_len = elen;
 			break;
 		case WLAN_EID_FAST_BSS_TRANSITION:
 			elems->ftie = pos;
 			elems->ftie_len = elen;
 			break;
 		case WLAN_EID_TIMEOUT_INTERVAL:
 			elems->timeout_int = pos;
 			elems->timeout_int_len = elen;
 			break;
 		case WLAN_EID_HT_CAP:
 			elems->ht_capabilities = pos;
 			elems->ht_capabilities_len = elen;
 			break;
 		case WLAN_EID_HT_OPERATION:
 			elems->ht_operation = pos;
 			elems->ht_operation_len = elen;
 			break;
 		case WLAN_EID_LINK_ID:
 			if (elen < 18)
 				break;
 			elems->link_id = pos;
 			break;
 		case WLAN_EID_INTERWORKING:
 			elems->interworking = pos;
 			elems->interworking_len = elen;
 			break;
 		default:
 			unknown++;
 			if (!show_errors)
 				break;
 			wpa_printf(MSG_MSGDUMP, "IEEE 802.11 element parse "
 				   "ignored unknown element (id=%d elen=%d)",
 				   id, elen);
 			break;
 		}

 		left -= elen;
 		pos += elen;
 	}

 	if (left)
 		return ParseFailed;

 	return unknown ? ParseUnknown : ParseOK;
 }


 int ieee802_11_ie_count(const u8 *ies, size_t ies_len)
 {
 	int count = 0;
 	const u8 *pos, *end;

 	if (ies == NULL)
 		return 0;

 	pos = ies;
 	end = ies + ies_len;

 	while (pos + 2 <= end) {
 		if (pos + 2 + pos[1] > end)
 			break;
 		count++;
 		pos += 2 + pos[1];
 	}

 	return count;
 }


 struct wpabuf * ieee802_11_vendor_ie_concat(const u8 *ies, size_t ies_len,
 					    u32 oui_type)
 {
 	struct wpabuf *buf;
 	const u8 *end, *pos, *ie;

 	pos = ies;
 	end = ies + ies_len;
 	ie = NULL;

 	while (pos + 1 < end) {
 		if (pos + 2 + pos[1] > end)
 			return NULL;
 		if (pos[0] == WLAN_EID_VENDOR_SPECIFIC && pos[1] >= 4 &&
 		    WPA_GET_BE32(&pos[2]) == oui_type) {
 			ie = pos;
 			break;
 		}
 		pos += 2 + pos[1];
 	}

 	if (ie == NULL)
 		return NULL; /* No specified vendor IE found */

 	buf = wpabuf_alloc(ies_len);
 	if (buf == NULL)
 		return NULL;

 	/*
 	 * There may be multiple vendor IEs in the message, so need to
 	 * concatenate their data fields.
 	 */
 	while (pos + 1 < end) {
 		if (pos + 2 + pos[1] > end)
 			break;
 		if (pos[0] == WLAN_EID_VENDOR_SPECIFIC && pos[1] >= 4 &&
 		    WPA_GET_BE32(&pos[2]) == oui_type)
 			wpabuf_put_data(buf, pos + 6, pos[1] - 4);
 		pos += 2 + pos[1];
 	}

 	return buf;
 }


 const u8 * get_hdr_bssid(const struct ieee80211_hdr *hdr, size_t len)
 {
 	u16 fc, type, stype;

 	/*
 	 * PS-Poll frames are 16 bytes. All other frames are
 	 * 24 bytes or longer.
 	 */
 	if (len < 16)
 		return NULL;

 	fc = le_to_host16(hdr->frame_control);
 	type = WLAN_FC_GET_TYPE(fc);
 	stype = WLAN_FC_GET_STYPE(fc);

 	switch (type) {
 	case WLAN_FC_TYPE_DATA:
 		if (len < 24)
 			return NULL;
 		switch (fc & (WLAN_FC_FROMDS | WLAN_FC_TODS)) {
 		case WLAN_FC_FROMDS | WLAN_FC_TODS:
 		case WLAN_FC_TODS:
 			return hdr->addr1;
 		case WLAN_FC_FROMDS:
 			return hdr->addr2;
 		default:
 			return NULL;
 		}
 	case WLAN_FC_TYPE_CTRL:
 		if (stype != WLAN_FC_STYPE_PSPOLL)
 			return NULL;
 		return hdr->addr1;
 	case WLAN_FC_TYPE_MGMT:
 		return hdr->addr3;
 	default:
 		return NULL;
 	}
 }
	/*
	* IEEE 802.11 Common routines
	* Copyright (c) 2002-2009, Jouni Malinen <j@w1.fi>
	*
	* This software may be distributed under the terms of the BSD license.
	* See README for more details.
	*/

	#include "includes.h"

	#include "common.h"
	#include "ieee802_11_defs.h"
	#include "ieee802_11_common.h"


	static int ieee802_11_parse_vendor_specific(const u8 *pos, size_t elen,
	struct ieee802_11_elems *elems,
	int show_errors)
	{
	unsigned int oui;

	/* first 3 bytes in vendor specific information element are the IEEE
	* OUI of the vendor. The following byte is used a vendor specific
	* sub-type. */
	if (elen < 4) {
	if (show_errors) {
	wpa_printf(MSG_MSGDUMP, "short vendor specific "
	"information element ignored (len=%lu)",
	(unsigned long) elen);
	}
	return -1;
	}

	oui = WPA_GET_BE24(pos);
	switch (oui) {
	case OUI_MICROSOFT:
	/* Microsoft/Wi-Fi information elements are further typed and
	* subtyped */
	switch (pos[3]) {
	case 1:
	/* Microsoft OUI (00:50:F2) with OUI Type 1:
	* real WPA information element */
	elems->wpa_ie = pos;
	elems->wpa_ie_len = elen;
	break;
	case WMM_OUI_TYPE:
	/* WMM information element */
	if (elen < 5) {
	wpa_printf(MSG_MSGDUMP, "short WMM "
	"information element ignored "
	"(len=%lu)",
	(unsigned long) elen);
	return -1;
	}
	switch (pos[4]) {
	case WMM_OUI_SUBTYPE_INFORMATION_ELEMENT:
	case WMM_OUI_SUBTYPE_PARAMETER_ELEMENT:
	/*
	* Share same pointer since only one of these
	* is used and they start with same data.
	* Length field can be used to distinguish the
	* IEs.
	*/
	elems->wmm = pos;
	elems->wmm_len = elen;
	break;
	case WMM_OUI_SUBTYPE_TSPEC_ELEMENT:
	elems->wmm_tspec = pos;
	elems->wmm_tspec_len = elen;
	break;
	default:
	wpa_printf(MSG_EXCESSIVE, "unknown WMM "
	"information element ignored "
	"(subtype=%d len=%lu)",
	pos[4], (unsigned long) elen);
	return -1;
	}
	break;
	case 4:
	/* Wi-Fi Protected Setup (WPS) IE */
	elems->wps_ie = pos;
	elems->wps_ie_len = elen;
	break;
	default:
	wpa_printf(MSG_EXCESSIVE, "Unknown Microsoft "
	"information element ignored "
	"(type=%d len=%lu)",
	pos[3], (unsigned long) elen);
	return -1;
	}
	break;

	case OUI_WFA:
	switch (pos[3]) {
	case P2P_OUI_TYPE:
	/* Wi-Fi Alliance - P2P IE */
	elems->p2p = pos;
	elems->p2p_len = elen;
	break;
	default:
	wpa_printf(MSG_MSGDUMP, "Unknown WFA "
	"information element ignored "
	"(type=%d len=%lu)\n",
	pos[3], (unsigned long) elen);
	return -1;
	}
	break;

	case OUI_BROADCOM:
	switch (pos[3]) {
	case VENDOR_HT_CAPAB_OUI_TYPE:
	elems->vendor_ht_cap = pos;
	elems->vendor_ht_cap_len = elen;
	break;
	default:
	wpa_printf(MSG_EXCESSIVE, "Unknown Broadcom "
	"information element ignored "
	"(type=%d len=%lu)",
	pos[3], (unsigned long) elen);
	return -1;
	}
	break;

	default:
	wpa_printf(MSG_EXCESSIVE, "unknown vendor specific "
	"information element ignored (vendor OUI "
	"%02x:%02x:%02x len=%lu)",
	pos[0], pos[1], pos[2], (unsigned long) elen);
	return -1;
	}

	return 0;
	}


	/**
	* ieee802_11_parse_elems - Parse information elements in management frames
	* @start: Pointer to the start of IEs
	* @len: Length of IE buffer in octets
	* @elems: Data structure for parsed elements
	* @show_errors: Whether to show parsing errors in debug log
	* Returns: Parsing result
	*/
	ParseRes ieee802_11_parse_elems(const u8 *start, size_t len,
	struct ieee802_11_elems *elems,
	int show_errors)
	{
	size_t left = len;
	const u8 *pos = start;
	int unknown = 0;

	os_memset(elems, 0, sizeof(*elems));

	while (left >= 2) {
	u8 id, elen;

	id = *pos++;
	elen = *pos++;
	left -= 2;

	if (elen > left) {
	if (show_errors) {
	wpa_printf(MSG_DEBUG, "IEEE 802.11 element "
	"parse failed (id=%d elen=%d "
	"left=%lu)",
	id, elen, (unsigned long) left);
	wpa_hexdump(MSG_MSGDUMP, "IEs", start, len);
	}
	return ParseFailed;
	}

	switch (id) {
	case WLAN_EID_SSID:
	elems->ssid = pos;
	elems->ssid_len = elen;
	break;
	case WLAN_EID_SUPP_RATES:
	elems->supp_rates = pos;
	elems->supp_rates_len = elen;
	break;
	case WLAN_EID_FH_PARAMS:
	elems->fh_params = pos;
	elems->fh_params_len = elen;
	break;
	case WLAN_EID_DS_PARAMS:
	elems->ds_params = pos;
	elems->ds_params_len = elen;
	break;
	case WLAN_EID_CF_PARAMS:
	elems->cf_params = pos;
	elems->cf_params_len = elen;
	break;
	case WLAN_EID_TIM:
	elems->tim = pos;
	elems->tim_len = elen;
	break;
	case WLAN_EID_IBSS_PARAMS:
	elems->ibss_params = pos;
	elems->ibss_params_len = elen;
	break;
	case WLAN_EID_CHALLENGE:
	elems->challenge = pos;
	elems->challenge_len = elen;
	break;
	case WLAN_EID_ERP_INFO:
	elems->erp_info = pos;
	elems->erp_info_len = elen;
	break;
	case WLAN_EID_EXT_SUPP_RATES:
	elems->ext_supp_rates = pos;
	elems->ext_supp_rates_len = elen;
	break;
	case WLAN_EID_VENDOR_SPECIFIC:
	if (ieee802_11_parse_vendor_specific(pos, elen,
	elems,
	show_errors))
	unknown++;
	break;
	case WLAN_EID_RSN:
	elems->rsn_ie = pos;
	elems->rsn_ie_len = elen;
	break;
	case WLAN_EID_PWR_CAPABILITY:
	elems->power_cap = pos;
	elems->power_cap_len = elen;
	break;
	case WLAN_EID_SUPPORTED_CHANNELS:
	elems->supp_channels = pos;
	elems->supp_channels_len = elen;
	break;
	case WLAN_EID_MOBILITY_DOMAIN:
	elems->mdie = pos;
	elems->mdie_len = elen;
	break;
	case WLAN_EID_FAST_BSS_TRANSITION:
	elems->ftie = pos;
	elems->ftie_len = elen;
	break;
	case WLAN_EID_TIMEOUT_INTERVAL:
	elems->timeout_int = pos;
	elems->timeout_int_len = elen;
	break;
	case WLAN_EID_HT_CAP:
	elems->ht_capabilities = pos;
	elems->ht_capabilities_len = elen;
	break;
	case WLAN_EID_HT_OPERATION:
	elems->ht_operation = pos;
	elems->ht_operation_len = elen;
	break;
	case WLAN_EID_LINK_ID:
	if (elen < 18)
	break;
	elems->link_id = pos;
	break;
	case WLAN_EID_INTERWORKING:
	elems->interworking = pos;
	elems->interworking_len = elen;
	break;
	default:
	unknown++;
	if (!show_errors)
	break;
	wpa_printf(MSG_MSGDUMP, "IEEE 802.11 element parse "
	"ignored unknown element (id=%d elen=%d)",
	id, elen);
	break;
	}

	left -= elen;
	pos += elen;
	}

	if (left)
	return ParseFailed;

	return unknown ? ParseUnknown : ParseOK;
	}


	int ieee802_11_ie_count(const u8 *ies, size_t ies_len)
	{
	int count = 0;
	const u8 pos, end;

	if (ies == NULL)
	return 0;

	pos = ies;
	end = ies + ies_len;

	while (pos + 2 <= end) {
	if (pos + 2 + pos[1] > end)
	break;
	count++;
	pos += 2 + pos[1];
	}

	return count;
	}


	struct wpabuf * ieee802_11_vendor_ie_concat(const u8 *ies, size_t ies_len,
	u32 oui_type)
	{
	struct wpabuf *buf;
	const u8 end, pos, *ie;

	pos = ies;
	end = ies + ies_len;
	ie = NULL;

	while (pos + 1 < end) {
	if (pos + 2 + pos[1] > end)
	return NULL;
	if (pos[0] == WLAN_EID_VENDOR_SPECIFIC && pos[1] >= 4 &&
	WPA_GET_BE32(&pos[2]) == oui_type) {
	ie = pos;
	break;
	}
	pos += 2 + pos[1];
	}

	if (ie == NULL)
	return NULL; /* No specified vendor IE found */

	buf = wpabuf_alloc(ies_len);
	if (buf == NULL)
	return NULL;

	/*
	* There may be multiple vendor IEs in the message, so need to
	* concatenate their data fields.
	*/
	while (pos + 1 < end) {
	if (pos + 2 + pos[1] > end)
	break;
	if (pos[0] == WLAN_EID_VENDOR_SPECIFIC && pos[1] >= 4 &&
	WPA_GET_BE32(&pos[2]) == oui_type)
	wpabuf_put_data(buf, pos + 6, pos[1] - 4);
	pos += 2 + pos[1];
	}

	return buf;
	}


	const u8 * get_hdr_bssid(const struct ieee80211_hdr *hdr, size_t len)
	{
	u16 fc, type, stype;

	/*
	* PS-Poll frames are 16 bytes. All other frames are
	* 24 bytes or longer.
	*/
	if (len < 16)
	return NULL;

	fc = le_to_host16(hdr->frame_control);
	type = WLAN_FC_GET_TYPE(fc);
	stype = WLAN_FC_GET_STYPE(fc);

	switch (type) {
	case WLAN_FC_TYPE_DATA:
	if (len < 24)
	return NULL;
	switch (fc & (WLAN_FC_FROMDS \| WLAN_FC_TODS)) {
	case WLAN_FC_FROMDS \| WLAN_FC_TODS:
	case WLAN_FC_TODS:
	return hdr->addr1;
	case WLAN_FC_FROMDS:
	return hdr->addr2;
	default:
	return NULL;
	}
	case WLAN_FC_TYPE_CTRL:
	if (stype != WLAN_FC_STYPE_PSPOLL)
	return NULL;
	return hdr->addr1;
	case WLAN_FC_TYPE_MGMT:
	return hdr->addr3;
	default:
	return NULL;
	}
	}