text: /* p80211hdr.h
  *
  * Macros, types, and functions for handling 802.11 MAC headers
  *
  * Copyright (C) 1999 AbsoluteValue Systems, Inc.  All Rights Reserved.
  * --------------------------------------------------------------------
  *
  * linux-wlan
  *
  *   The contents of this file are subject to the Mozilla Public
  *   License Version 1.1 (the "License"); you may not use this file
  *   except in compliance with the License. You may obtain a copy of
  *   the License at http://www.mozilla.org/MPL/
  *
  *   Software distributed under the License is distributed on an "AS
  *   IS" basis, WITHOUT WARRANTY OF ANY KIND, either express or
  *   implied. See the License for the specific language governing
  *   rights and limitations under the License.
  *
  *   Alternatively, the contents of this file may be used under the
  *   terms of the GNU Public License version 2 (the "GPL"), in which
  *   case the provisions of the GPL are applicable instead of the
  *   above.  If you wish to allow the use of your version of this file
  *   only under the terms of the GPL and not to allow others to use
  *   your version of this file under the MPL, indicate your decision
  *   by deleting the provisions above and replace them with the notice
  *   and other provisions required by the GPL.  If you do not delete
  *   the provisions above, a recipient may use your version of this
  *   file under either the MPL or the GPL.
  *
  * --------------------------------------------------------------------
  *
  * Inquiries regarding the linux-wlan Open Source project can be
  * made directly to:
  *
  * AbsoluteValue Systems Inc.
  * info@linux-wlan.com
  * http://www.linux-wlan.com
  *
  * --------------------------------------------------------------------
  *
  * Portions of the development of this software were funded by
  * Intersil Corporation as part of PRISM(R) chipset product development.
  *
  * --------------------------------------------------------------------
  *
  * This file declares the constants and types used in the interface
  * between a wlan driver and the user mode utilities.
  *
  * Note:
  *  - Constant values are always in HOST byte order.  To assign
  *    values to multi-byte fields they _must_ be converted to
  *    ieee byte order.  To retrieve multi-byte values from incoming
  *    frames, they must be converted to host order.
  *
  * All functions declared here are implemented in p80211.c
  * --------------------------------------------------------------------
  */
  
  #ifndef _P80211HDR_H
  #define _P80211HDR_H
  
  #include <linux/if_ether.h>
  
  /*--- Sizes -----------------------------------------------*/
  #define WLAN_CRC_LEN			4
  #define WLAN_BSSID_LEN			6
  #define WLAN_HDR_A3_LEN			24
  #define WLAN_HDR_A4_LEN			30
  #define WLAN_SSID_MAXLEN		32
  #define WLAN_DATA_MAXLEN		2312
  #define WLAN_WEP_IV_LEN			4
  #define WLAN_WEP_ICV_LEN		4
  
  /*--- Frame Control Field -------------------------------------*/
  /* Frame Types */
  #define WLAN_FTYPE_MGMT			0x00
  #define WLAN_FTYPE_CTL			0x01
  #define WLAN_FTYPE_DATA			0x02
  
  /* Frame subtypes */
  /* Management */
  #define WLAN_FSTYPE_ASSOCREQ		0x00
  #define WLAN_FSTYPE_ASSOCRESP		0x01
  #define WLAN_FSTYPE_REASSOCREQ		0x02
  #define WLAN_FSTYPE_REASSOCRESP		0x03
  #define WLAN_FSTYPE_PROBEREQ		0x04
  #define WLAN_FSTYPE_PROBERESP		0x05
  #define WLAN_FSTYPE_BEACON		0x08
  #define WLAN_FSTYPE_ATIM		0x09
  #define WLAN_FSTYPE_DISASSOC		0x0a
  #define WLAN_FSTYPE_AUTHEN		0x0b
  #define WLAN_FSTYPE_DEAUTHEN		0x0c
  
  /* Control */
  #define WLAN_FSTYPE_BLOCKACKREQ		0x8
  #define WLAN_FSTYPE_BLOCKACK		0x9
  #define WLAN_FSTYPE_PSPOLL		0x0a
  #define WLAN_FSTYPE_RTS			0x0b
  #define WLAN_FSTYPE_CTS			0x0c
  #define WLAN_FSTYPE_ACK			0x0d
  #define WLAN_FSTYPE_CFEND		0x0e
  #define WLAN_FSTYPE_CFENDCFACK		0x0f
  
  /* Data */
  #define WLAN_FSTYPE_DATAONLY		0x00
  #define WLAN_FSTYPE_DATA_CFACK		0x01
  #define WLAN_FSTYPE_DATA_CFPOLL		0x02
  #define WLAN_FSTYPE_DATA_CFACK_CFPOLL	0x03
  #define WLAN_FSTYPE_NULL		0x04
  #define WLAN_FSTYPE_CFACK		0x05
  #define WLAN_FSTYPE_CFPOLL		0x06
  #define WLAN_FSTYPE_CFACK_CFPOLL	0x07
  
  /*--- FC Macros ----------------------------------------------*/
  /* Macros to get/set the bitfields of the Frame Control Field */
  /*  GET_FC_??? - takes the host byte-order value of an FC     */
  /*               and retrieves the value of one of the        */
  /*               bitfields and moves that value so its lsb is */
  /*               in bit 0.                                    */
  /*  SET_FC_??? - takes a host order value for one of the FC   */
  /*               bitfields and moves it to the proper bit     */
  /*               location for ORing into a host order FC.     */
  /*               To send the FC produced from SET_FC_???,     */
  /*               one must put the bytes in IEEE order.        */
  /*  e.g.                                                      */
  /*     printf("the frame subtype is %x",                      */
  /*                 GET_FC_FTYPE( ieee2host( rx.fc )))         */
  /*                                                            */
  /*     tx.fc = host2ieee( SET_FC_FTYPE(WLAN_FTYP_CTL) |       */
  /*                        SET_FC_FSTYPE(WLAN_FSTYPE_RTS) );   */
  /*------------------------------------------------------------*/
  
  #define WLAN_GET_FC_FTYPE(n)	((((u16)(n)) & (BIT(2) | BIT(3))) >> 2)
  #define WLAN_GET_FC_FSTYPE(n)	((((u16)(n)) & (BIT(4)|BIT(5)|BIT(6)|BIT(7))) >> 4)
  #define WLAN_GET_FC_TODS(n)	((((u16)(n)) & (BIT(8))) >> 8)
  #define WLAN_GET_FC_FROMDS(n)	((((u16)(n)) & (BIT(9))) >> 9)
  #define WLAN_GET_FC_ISWEP(n)	((((u16)(n)) & (BIT(14))) >> 14)
  
  #define WLAN_SET_FC_FTYPE(n)	(((u16)(n)) << 2)
  #define WLAN_SET_FC_FSTYPE(n)	(((u16)(n)) << 4)
  #define WLAN_SET_FC_TODS(n)	(((u16)(n)) << 8)
  #define WLAN_SET_FC_FROMDS(n)	(((u16)(n)) << 9)
  #define WLAN_SET_FC_ISWEP(n)	(((u16)(n)) << 14)
  
  #define DOT11_RATE5_ISBASIC_GET(r)     (((u8)(r)) & BIT(7))
  
  /* Generic 802.11 Header types */
  
  struct p80211_hdr_a3 {
  	u16 fc;
  	u16 dur;
  	u8 a1[ETH_ALEN];
  	u8 a2[ETH_ALEN];
  	u8 a3[ETH_ALEN];
  	u16 seq;
  } __packed;
  
  struct p80211_hdr_a4 {
  	u16 fc;
  	u16 dur;
  	u8 a1[ETH_ALEN];
  	u8 a2[ETH_ALEN];
  	u8 a3[ETH_ALEN];
  	u16 seq;
  	u8 a4[ETH_ALEN];
  } __packed;
  
  union p80211_hdr {
  	struct p80211_hdr_a3 a3;
  	struct p80211_hdr_a4 a4;
  } __packed;
  
  /* Frame and header length macros */
  
  #define WLAN_CTL_FRAMELEN(fstype) (\
  	(fstype) == WLAN_FSTYPE_BLOCKACKREQ	? 24 : \
  	(fstype) == WLAN_FSTYPE_BLOCKACK	? 152 : \
  	(fstype) == WLAN_FSTYPE_PSPOLL		? 20 : \
  	(fstype) == WLAN_FSTYPE_RTS		? 20 : \
  	(fstype) == WLAN_FSTYPE_CTS		? 14 : \
  	(fstype) == WLAN_FSTYPE_ACK		? 14 : \
  	(fstype) == WLAN_FSTYPE_CFEND		? 20 : \
  	(fstype) == WLAN_FSTYPE_CFENDCFACK	? 20 : 4)
  
  #define WLAN_FCS_LEN			4
  
  /* ftcl in HOST order */
  static inline u16 p80211_headerlen(u16 fctl)
  {
  	u16 hdrlen = 0;
  
  	switch (WLAN_GET_FC_FTYPE(fctl)) {
  	case WLAN_FTYPE_MGMT:
  		hdrlen = WLAN_HDR_A3_LEN;
  		break;
  	case WLAN_FTYPE_DATA:
  		hdrlen = WLAN_HDR_A3_LEN;
  		if (WLAN_GET_FC_TODS(fctl) && WLAN_GET_FC_FROMDS(fctl))
  			hdrlen += ETH_ALEN;
  		break;
  	case WLAN_FTYPE_CTL:
  		hdrlen = WLAN_CTL_FRAMELEN(WLAN_GET_FC_FSTYPE(fctl)) -
  		    WLAN_FCS_LEN;
  		break;
  	default:
  		hdrlen = WLAN_HDR_A3_LEN;
  	}
  
  	return hdrlen;
  }
  
  #endif /* _P80211HDR_H */
  