1/* SPDX-License-Identifier: (GPL-2.0 OR MPL-1.1) */
2/*
3 *
4 * Macros, types, and functions for handling 802.11 MAC headers
5 *
6 * Copyright (C) 1999 AbsoluteValue Systems, Inc.  All Rights Reserved.
7 * --------------------------------------------------------------------
8 *
9 * linux-wlan
10 *
11 * --------------------------------------------------------------------
12 *
13 * Inquiries regarding the linux-wlan Open Source project can be
14 * made directly to:
15 *
16 * AbsoluteValue Systems Inc.
17 * info@linux-wlan.com
18 * http://www.linux-wlan.com
19 *
20 * --------------------------------------------------------------------
21 *
22 * Portions of the development of this software were funded by
23 * Intersil Corporation as part of PRISM(R) chipset product development.
24 *
25 * --------------------------------------------------------------------
26 *
27 * This file declares the constants and types used in the interface
28 * between a wlan driver and the user mode utilities.
29 *
30 * Note:
31 *  - Constant values are always in HOST byte order.  To assign
32 *    values to multi-byte fields they _must_ be converted to
33 *    ieee byte order.  To retrieve multi-byte values from incoming
34 *    frames, they must be converted to host order.
35 *
36 * All functions declared here are implemented in p80211.c
37 * --------------------------------------------------------------------
38 */
39
40#ifndef _P80211HDR_H
41#define _P80211HDR_H
42
43#include <linux/if_ether.h>
44
45/*--- Sizes -----------------------------------------------*/
46#define WLAN_CRC_LEN			4
47#define WLAN_BSSID_LEN			6
48#define WLAN_HDR_A3_LEN			24
49#define WLAN_HDR_A4_LEN			30
50#define WLAN_SSID_MAXLEN		32
51#define WLAN_DATA_MAXLEN		2312
52#define WLAN_WEP_IV_LEN			4
53#define WLAN_WEP_ICV_LEN		4
54
55/*--- Frame Control Field -------------------------------------*/
56/* Frame Types */
57#define WLAN_FTYPE_MGMT			0x00
58#define WLAN_FTYPE_CTL			0x01
59#define WLAN_FTYPE_DATA			0x02
60
61/* Frame subtypes */
62/* Management */
63#define WLAN_FSTYPE_ASSOCREQ		0x00
64#define WLAN_FSTYPE_ASSOCRESP		0x01
65#define WLAN_FSTYPE_REASSOCREQ		0x02
66#define WLAN_FSTYPE_REASSOCRESP		0x03
67#define WLAN_FSTYPE_PROBEREQ		0x04
68#define WLAN_FSTYPE_PROBERESP		0x05
69#define WLAN_FSTYPE_BEACON		0x08
70#define WLAN_FSTYPE_ATIM		0x09
71#define WLAN_FSTYPE_DISASSOC		0x0a
72#define WLAN_FSTYPE_AUTHEN		0x0b
73#define WLAN_FSTYPE_DEAUTHEN		0x0c
74
75/* Control */
76#define WLAN_FSTYPE_BLOCKACKREQ		0x8
77#define WLAN_FSTYPE_BLOCKACK		0x9
78#define WLAN_FSTYPE_PSPOLL		0x0a
79#define WLAN_FSTYPE_RTS			0x0b
80#define WLAN_FSTYPE_CTS			0x0c
81#define WLAN_FSTYPE_ACK			0x0d
82#define WLAN_FSTYPE_CFEND		0x0e
83#define WLAN_FSTYPE_CFENDCFACK		0x0f
84
85/* Data */
86#define WLAN_FSTYPE_DATAONLY		0x00
87#define WLAN_FSTYPE_DATA_CFACK		0x01
88#define WLAN_FSTYPE_DATA_CFPOLL		0x02
89#define WLAN_FSTYPE_DATA_CFACK_CFPOLL	0x03
90#define WLAN_FSTYPE_NULL		0x04
91#define WLAN_FSTYPE_CFACK		0x05
92#define WLAN_FSTYPE_CFPOLL		0x06
93#define WLAN_FSTYPE_CFACK_CFPOLL	0x07
94
95/*--- FC Macros ----------------------------------------------*/
96/* Macros to get/set the bitfields of the Frame Control Field */
97/*  GET_FC_??? - takes the host byte-order value of an FC     */
98/*               and retrieves the value of one of the        */
99/*               bitfields and moves that value so its lsb is */
100/*               in bit 0.                                    */
101/*  SET_FC_??? - takes a host order value for one of the FC   */
102/*               bitfields and moves it to the proper bit     */
103/*               location for ORing into a host order FC.     */
104/*               To send the FC produced from SET_FC_???,     */
105/*               one must put the bytes in IEEE order.        */
106/*  e.g.                                                      */
107/*     printf("the frame subtype is %x",                      */
108/*                 GET_FC_FTYPE( ieee2host( rx.fc )))         */
109/*                                                            */
110/*     tx.fc = host2ieee( SET_FC_FTYPE(WLAN_FTYP_CTL) |       */
111/*                        SET_FC_FSTYPE(WLAN_FSTYPE_RTS) );   */
112/*------------------------------------------------------------*/
113
114#define WLAN_GET_FC_FTYPE(n)	((((u16)(n)) & GENMASK(3, 2)) >> 2)
115#define WLAN_GET_FC_FSTYPE(n)	((((u16)(n)) & GENMASK(7, 4)) >> 4)
116#define WLAN_GET_FC_TODS(n)	((((u16)(n)) & (BIT(8))) >> 8)
117#define WLAN_GET_FC_FROMDS(n)	((((u16)(n)) & (BIT(9))) >> 9)
118#define WLAN_GET_FC_ISWEP(n)	((((u16)(n)) & (BIT(14))) >> 14)
119
120#define WLAN_SET_FC_FTYPE(n)	(((u16)(n)) << 2)
121#define WLAN_SET_FC_FSTYPE(n)	(((u16)(n)) << 4)
122#define WLAN_SET_FC_TODS(n)	(((u16)(n)) << 8)
123#define WLAN_SET_FC_FROMDS(n)	(((u16)(n)) << 9)
124#define WLAN_SET_FC_ISWEP(n)	(((u16)(n)) << 14)
125
126#define DOT11_RATE5_ISBASIC_GET(r)     (((u8)(r)) & BIT(7))
127
128/* Generic 802.11 Header types */
129
130struct p80211_hdr {
131	__le16	frame_control;
132	u16	duration_id;
133	u8	address1[ETH_ALEN];
134	u8	address2[ETH_ALEN];
135	u8	address3[ETH_ALEN];
136	u16	sequence_control;
137	u8	address4[ETH_ALEN];
138} __packed;
139
140/* Frame and header length macros */
141
142static inline u16 wlan_ctl_framelen(u16 fstype)
143{
144	switch (fstype)	{
145	case WLAN_FSTYPE_BLOCKACKREQ:
146		return 24;
147	case WLAN_FSTYPE_BLOCKACK:
148		return 152;
149	case WLAN_FSTYPE_PSPOLL:
150	case WLAN_FSTYPE_RTS:
151	case WLAN_FSTYPE_CFEND:
152	case WLAN_FSTYPE_CFENDCFACK:
153		return 20;
154	case WLAN_FSTYPE_CTS:
155	case WLAN_FSTYPE_ACK:
156		return 14;
157	default:
158		return 4;
159	}
160}
161
162#define WLAN_FCS_LEN			4
163
164/* ftcl in HOST order */
165static inline u16 p80211_headerlen(u16 fctl)
166{
167	u16 hdrlen = 0;
168
169	switch (WLAN_GET_FC_FTYPE(fctl)) {
170	case WLAN_FTYPE_MGMT:
171		hdrlen = WLAN_HDR_A3_LEN;
172		break;
173	case WLAN_FTYPE_DATA:
174		hdrlen = WLAN_HDR_A3_LEN;
175		if (WLAN_GET_FC_TODS(fctl) && WLAN_GET_FC_FROMDS(fctl))
176			hdrlen += ETH_ALEN;
177		break;
178	case WLAN_FTYPE_CTL:
179		hdrlen = wlan_ctl_framelen(WLAN_GET_FC_FSTYPE(fctl)) -
180		    WLAN_FCS_LEN;
181		break;
182	default:
183		hdrlen = WLAN_HDR_A3_LEN;
184	}
185
186	return hdrlen;
187}
188
189#endif /* _P80211HDR_H */
190