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  *   The contents of this file are subject to the Mozilla Public
12  *   License Version 1.1 (the "License"); you may not use this file
13  *   except in compliance with the License. You may obtain a copy of
14  *   the License at http://www.mozilla.org/MPL/
15  *
16  *   Software distributed under the License is distributed on an "AS
17  *   IS" basis, WITHOUT WARRANTY OF ANY KIND, either express or
18  *   implied. See the License for the specific language governing
19  *   rights and limitations under the License.
20  *
21  *   Alternatively, the contents of this file may be used under the
22  *   terms of the GNU Public License version 2 (the "GPL"), in which
23  *   case the provisions of the GPL are applicable instead of the
24  *   above.  If you wish to allow the use of your version of this file
25  *   only under the terms of the GPL and not to allow others to use
26  *   your version of this file under the MPL, indicate your decision
27  *   by deleting the provisions above and replace them with the notice
28  *   and other provisions required by the GPL.  If you do not delete
29  *   the provisions above, a recipient may use your version of this
30  *   file under either the MPL or the GPL.
31  *
32  * --------------------------------------------------------------------
33  *
34  * Inquiries regarding the linux-wlan Open Source project can be
35  * made directly to:
36  *
37  * AbsoluteValue Systems Inc.
38  * info@linux-wlan.com
39  * http://www.linux-wlan.com
40  *
41  * --------------------------------------------------------------------
42  *
43  * Portions of the development of this software were funded by
44  * Intersil Corporation as part of PRISM(R) chipset product development.
45  *
46  * --------------------------------------------------------------------
47  *
48  * This file declares the constants and types used in the interface
49  * between a wlan driver and the user mode utilities.
50  *
51  * Note:
52  *  - Constant values are always in HOST byte order.  To assign
53  *    values to multi-byte fields they _must_ be converted to
54  *    ieee byte order.  To retrieve multi-byte values from incoming
55  *    frames, they must be converted to host order.
56  *
57  * All functions declared here are implemented in p80211.c
58  * --------------------------------------------------------------------
59  */
60 
61 #ifndef _P80211HDR_H
62 #define _P80211HDR_H
63 
64 #include <linux/if_ether.h>
65 
66 /*--- Sizes -----------------------------------------------*/
67 #define WLAN_CRC_LEN			4
68 #define WLAN_BSSID_LEN			6
69 #define WLAN_HDR_A3_LEN			24
70 #define WLAN_HDR_A4_LEN			30
71 #define WLAN_SSID_MAXLEN		32
72 #define WLAN_DATA_MAXLEN		2312
73 #define WLAN_WEP_IV_LEN			4
74 #define WLAN_WEP_ICV_LEN		4
75 
76 /*--- Frame Control Field -------------------------------------*/
77 /* Frame Types */
78 #define WLAN_FTYPE_MGMT			0x00
79 #define WLAN_FTYPE_CTL			0x01
80 #define WLAN_FTYPE_DATA			0x02
81 
82 /* Frame subtypes */
83 /* Management */
84 #define WLAN_FSTYPE_ASSOCREQ		0x00
85 #define WLAN_FSTYPE_ASSOCRESP		0x01
86 #define WLAN_FSTYPE_REASSOCREQ		0x02
87 #define WLAN_FSTYPE_REASSOCRESP		0x03
88 #define WLAN_FSTYPE_PROBEREQ		0x04
89 #define WLAN_FSTYPE_PROBERESP		0x05
90 #define WLAN_FSTYPE_BEACON		0x08
91 #define WLAN_FSTYPE_ATIM		0x09
92 #define WLAN_FSTYPE_DISASSOC		0x0a
93 #define WLAN_FSTYPE_AUTHEN		0x0b
94 #define WLAN_FSTYPE_DEAUTHEN		0x0c
95 
96 /* Control */
97 #define WLAN_FSTYPE_BLOCKACKREQ		0x8
98 #define WLAN_FSTYPE_BLOCKACK		0x9
99 #define WLAN_FSTYPE_PSPOLL		0x0a
100 #define WLAN_FSTYPE_RTS			0x0b
101 #define WLAN_FSTYPE_CTS			0x0c
102 #define WLAN_FSTYPE_ACK			0x0d
103 #define WLAN_FSTYPE_CFEND		0x0e
104 #define WLAN_FSTYPE_CFENDCFACK		0x0f
105 
106 /* Data */
107 #define WLAN_FSTYPE_DATAONLY		0x00
108 #define WLAN_FSTYPE_DATA_CFACK		0x01
109 #define WLAN_FSTYPE_DATA_CFPOLL		0x02
110 #define WLAN_FSTYPE_DATA_CFACK_CFPOLL	0x03
111 #define WLAN_FSTYPE_NULL		0x04
112 #define WLAN_FSTYPE_CFACK		0x05
113 #define WLAN_FSTYPE_CFPOLL		0x06
114 #define WLAN_FSTYPE_CFACK_CFPOLL	0x07
115 
116 /*--- FC Macros ----------------------------------------------*/
117 /* Macros to get/set the bitfields of the Frame Control Field */
118 /*  GET_FC_??? - takes the host byte-order value of an FC     */
119 /*               and retrieves the value of one of the        */
120 /*               bitfields and moves that value so its lsb is */
121 /*               in bit 0.                                    */
122 /*  SET_FC_??? - takes a host order value for one of the FC   */
123 /*               bitfields and moves it to the proper bit     */
124 /*               location for ORing into a host order FC.     */
125 /*               To send the FC produced from SET_FC_???,     */
126 /*               one must put the bytes in IEEE order.        */
127 /*  e.g.                                                      */
128 /*     printf("the frame subtype is %x",                      */
129 /*                 GET_FC_FTYPE( ieee2host( rx.fc )))         */
130 /*                                                            */
131 /*     tx.fc = host2ieee( SET_FC_FTYPE(WLAN_FTYP_CTL) |       */
132 /*                        SET_FC_FSTYPE(WLAN_FSTYPE_RTS) );   */
133 /*------------------------------------------------------------*/
134 
135 #define WLAN_GET_FC_FTYPE(n)	((((u16)(n)) & GENMASK(3, 2)) >> 2)
136 #define WLAN_GET_FC_FSTYPE(n)	((((u16)(n)) & GENMASK(7, 4)) >> 4)
137 #define WLAN_GET_FC_TODS(n)	((((u16)(n)) & (BIT(8))) >> 8)
138 #define WLAN_GET_FC_FROMDS(n)	((((u16)(n)) & (BIT(9))) >> 9)
139 #define WLAN_GET_FC_ISWEP(n)	((((u16)(n)) & (BIT(14))) >> 14)
140 
141 #define WLAN_SET_FC_FTYPE(n)	(((u16)(n)) << 2)
142 #define WLAN_SET_FC_FSTYPE(n)	(((u16)(n)) << 4)
143 #define WLAN_SET_FC_TODS(n)	(((u16)(n)) << 8)
144 #define WLAN_SET_FC_FROMDS(n)	(((u16)(n)) << 9)
145 #define WLAN_SET_FC_ISWEP(n)	(((u16)(n)) << 14)
146 
147 #define DOT11_RATE5_ISBASIC_GET(r)     (((u8)(r)) & BIT(7))
148 
149 /* Generic 802.11 Header types */
150 
151 struct p80211_hdr {
152 	__le16	frame_control;
153 	u16	duration_id;
154 	u8	address1[ETH_ALEN];
155 	u8	address2[ETH_ALEN];
156 	u8	address3[ETH_ALEN];
157 	u16	sequence_control;
158 	u8	address4[ETH_ALEN];
159 } __packed;
160 
161 /* Frame and header length macros */
162 
wlan_ctl_framelen(u16 fstype)163 static inline u16 wlan_ctl_framelen(u16 fstype)
164 {
165 	switch (fstype)	{
166 	case WLAN_FSTYPE_BLOCKACKREQ:
167 		return 24;
168 	case WLAN_FSTYPE_BLOCKACK:
169 		return 152;
170 	case WLAN_FSTYPE_PSPOLL:
171 	case WLAN_FSTYPE_RTS:
172 	case WLAN_FSTYPE_CFEND:
173 	case WLAN_FSTYPE_CFENDCFACK:
174 		return 20;
175 	case WLAN_FSTYPE_CTS:
176 	case WLAN_FSTYPE_ACK:
177 		return 14;
178 	default:
179 		return 4;
180 	}
181 }
182 
183 #define WLAN_FCS_LEN			4
184 
185 /* ftcl in HOST order */
p80211_headerlen(u16 fctl)186 static inline u16 p80211_headerlen(u16 fctl)
187 {
188 	u16 hdrlen = 0;
189 
190 	switch (WLAN_GET_FC_FTYPE(fctl)) {
191 	case WLAN_FTYPE_MGMT:
192 		hdrlen = WLAN_HDR_A3_LEN;
193 		break;
194 	case WLAN_FTYPE_DATA:
195 		hdrlen = WLAN_HDR_A3_LEN;
196 		if (WLAN_GET_FC_TODS(fctl) && WLAN_GET_FC_FROMDS(fctl))
197 			hdrlen += ETH_ALEN;
198 		break;
199 	case WLAN_FTYPE_CTL:
200 		hdrlen = wlan_ctl_framelen(WLAN_GET_FC_FSTYPE(fctl)) -
201 		    WLAN_FCS_LEN;
202 		break;
203 	default:
204 		hdrlen = WLAN_HDR_A3_LEN;
205 	}
206 
207 	return hdrlen;
208 }
209 
210 #endif /* _P80211HDR_H */
211