1/*
2 * Copyright (c) 1996, 2003 VIA Networking Technologies, Inc.
3 * All rights reserved.
4 *
5 * This program is free software; you can redistribute it and/or modify
6 * it under the terms of the GNU General Public License as published by
7 * the Free Software Foundation; either version 2 of the License, or
8 * (at your option) any later version.
9 *
10 * This program is distributed in the hope that it will be useful,
11 * but WITHOUT ANY WARRANTY; without even the implied warranty of
12 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
13 * GNU General Public License for more details.
14 *
15 * You should have received a copy of the GNU General Public License along
16 * with this program; if not, write to the Free Software Foundation, Inc.,
17 * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
18 *
19 * File: wctl.c
20 *
21 * Purpose: handle WMAC duplicate filter & defragment
22 *
23 * Author: Jerry Chen
24 *
25 * Date: Jun. 27, 2002
26 *
27 * Functions:
28 *      WCTLbIsDuplicate - Test if duplicate packet
29 *      WCTLuSearchDFCB - Search DeFragment Control Database
30 *      WCTLuInsertDFCB - Insert DeFragment Control Database
31 *      WCTLbHandleFragment - Handle received fragment packet
32 *
33 * Revision History:
34 *
35 */
36
37#include "wctl.h"
38#include "device.h"
39#include "card.h"
40
41/*---------------------  Static Definitions -------------------------*/
42
43/*---------------------  Static Classes  ----------------------------*/
44
45/*---------------------  Static Variables  --------------------------*/
46// static int          msglevel                =MSG_LEVEL_INFO;
47/*---------------------  Static Functions  --------------------------*/
48
49/*---------------------  Export Variables  --------------------------*/
50
51
52
53/*
54 * Description:
55 *      Scan Rx cache.  Return true if packet is duplicate, else
56 *      inserts in receive cache and returns false.
57 *
58 * Parameters:
59 *  In:
60 *      pCache      - Receive packets history
61 *      pMACHeader  - 802.11 MAC Header of received packet
62 *  Out:
63 *      none
64 *
65 * Return Value: true if packet duplicate; otherwise false
66 *
67 */
68
69bool WCTLbIsDuplicate (PSCache pCache, PS802_11Header pMACHeader)
70{
71    unsigned int uIndex;
72    unsigned int ii;
73    PSCacheEntry    pCacheEntry;
74
75    if (IS_FC_RETRY(pMACHeader)) {
76
77        uIndex = pCache->uInPtr;
78        for (ii = 0; ii < DUPLICATE_RX_CACHE_LENGTH; ii++) {
79            pCacheEntry = &(pCache->asCacheEntry[uIndex]);
80            if ((pCacheEntry->wFmSequence == pMACHeader->wSeqCtl) &&
81                (!compare_ether_addr(&(pCacheEntry->abyAddr2[0]), &(pMACHeader->abyAddr2[0])))
82                ) {
83                /* Duplicate match */
84                return true;
85            }
86            ADD_ONE_WITH_WRAP_AROUND(uIndex, DUPLICATE_RX_CACHE_LENGTH);
87        }
88    }
89    /* Not fount in cache - insert */
90    pCacheEntry = &pCache->asCacheEntry[pCache->uInPtr];
91    pCacheEntry->wFmSequence = pMACHeader->wSeqCtl;
92    memcpy(&(pCacheEntry->abyAddr2[0]), &(pMACHeader->abyAddr2[0]), ETH_ALEN);
93    ADD_ONE_WITH_WRAP_AROUND(pCache->uInPtr, DUPLICATE_RX_CACHE_LENGTH);
94    return false;
95}
96
97/*
98 * Description:
99 *      Found if sequence number of received fragment packet in Defragment Database
100 *
101 * Parameters:
102 *  In:
103 *      pDevice     - Pointer to adapter
104 *      pMACHeader  - 802.11 MAC Header of received packet
105 *  Out:
106 *      none
107 *
108 * Return Value: index number in Defragment Database
109 *
110 */
111unsigned int WCTLuSearchDFCB (PSDevice pDevice, PS802_11Header pMACHeader)
112{
113unsigned int ii;
114
115    for(ii=0;ii<pDevice->cbDFCB;ii++) {
116        if ((pDevice->sRxDFCB[ii].bInUse == true) &&
117            (!compare_ether_addr(&(pDevice->sRxDFCB[ii].abyAddr2[0]), &(pMACHeader->abyAddr2[0])))
118            ) {
119            //
120            return(ii);
121        }
122    }
123    return(pDevice->cbDFCB);
124}
125
126
127/*
128 * Description:
129 *      Insert received fragment packet in Defragment Database
130 *
131 * Parameters:
132 *  In:
133 *      pDevice     - Pointer to adapter
134 *      pMACHeader  - 802.11 MAC Header of received packet
135 *  Out:
136 *      none
137 *
138 * Return Value: index number in Defragment Database
139 *
140 */
141unsigned int WCTLuInsertDFCB (PSDevice pDevice, PS802_11Header pMACHeader)
142{
143unsigned int ii;
144
145    if (pDevice->cbFreeDFCB == 0)
146        return(pDevice->cbDFCB);
147    for(ii=0;ii<pDevice->cbDFCB;ii++) {
148        if (pDevice->sRxDFCB[ii].bInUse == false) {
149            pDevice->cbFreeDFCB--;
150            pDevice->sRxDFCB[ii].uLifetime = pDevice->dwMaxReceiveLifetime;
151            pDevice->sRxDFCB[ii].bInUse = true;
152            pDevice->sRxDFCB[ii].wSequence = (pMACHeader->wSeqCtl >> 4);
153            pDevice->sRxDFCB[ii].wFragNum = (pMACHeader->wSeqCtl & 0x000F);
154            memcpy(&(pDevice->sRxDFCB[ii].abyAddr2[0]), &(pMACHeader->abyAddr2[0]), ETH_ALEN);
155            return(ii);
156        }
157    }
158    return(pDevice->cbDFCB);
159}
160
161
162/*
163 * Description:
164 *      Handle received fragment packet
165 *
166 * Parameters:
167 *  In:
168 *      pDevice         - Pointer to adapter
169 *      pMACHeader      - 802.11 MAC Header of received packet
170 *      cbFrameLength   - Frame length
171 *      bWEP            - is WEP packet
172 *  Out:
173 *      none
174 *
175 * Return Value: true if it is valid fragment packet and we have resource to defragment; otherwise false
176 *
177 */
178bool WCTLbHandleFragment (PSDevice pDevice, PS802_11Header pMACHeader, unsigned int cbFrameLength, bool bWEP, bool bExtIV)
179{
180unsigned int uHeaderSize;
181
182
183    if (bWEP == true) {
184        uHeaderSize = 28;
185        if (bExtIV)
186        // ExtIV
187            uHeaderSize +=4;
188    }
189    else {
190        uHeaderSize = 24;
191    }
192
193    if (IS_FIRST_FRAGMENT_PKT(pMACHeader)) {
194        pDevice->uCurrentDFCBIdx = WCTLuSearchDFCB(pDevice, pMACHeader);
195        if (pDevice->uCurrentDFCBIdx < pDevice->cbDFCB) {
196            // duplicate, we must flush previous DCB
197            pDevice->sRxDFCB[pDevice->uCurrentDFCBIdx].uLifetime = pDevice->dwMaxReceiveLifetime;
198            pDevice->sRxDFCB[pDevice->uCurrentDFCBIdx].wSequence = (pMACHeader->wSeqCtl >> 4);
199            pDevice->sRxDFCB[pDevice->uCurrentDFCBIdx].wFragNum = (pMACHeader->wSeqCtl & 0x000F);
200        }
201        else {
202            pDevice->uCurrentDFCBIdx = WCTLuInsertDFCB(pDevice, pMACHeader);
203            if (pDevice->uCurrentDFCBIdx == pDevice->cbDFCB) {
204                return(false);
205            }
206        }
207        // reserve 4 byte to match MAC RX Buffer
208        pDevice->sRxDFCB[pDevice->uCurrentDFCBIdx].pbyRxBuffer = (unsigned char *) (pDevice->sRxDFCB[pDevice->uCurrentDFCBIdx].skb->data + 4);
209        memcpy(pDevice->sRxDFCB[pDevice->uCurrentDFCBIdx].pbyRxBuffer, pMACHeader, cbFrameLength);
210        pDevice->sRxDFCB[pDevice->uCurrentDFCBIdx].cbFrameLength = cbFrameLength;
211        pDevice->sRxDFCB[pDevice->uCurrentDFCBIdx].pbyRxBuffer += cbFrameLength;
212        pDevice->sRxDFCB[pDevice->uCurrentDFCBIdx].wFragNum++;
213        //DBG_PRT(MSG_LEVEL_DEBUG, KERN_INFO "First pDevice->uCurrentDFCBIdx= %d\n", pDevice->uCurrentDFCBIdx);
214        return(false);
215    }
216    else {
217        pDevice->uCurrentDFCBIdx = WCTLuSearchDFCB(pDevice, pMACHeader);
218        if (pDevice->uCurrentDFCBIdx != pDevice->cbDFCB) {
219            if ((pDevice->sRxDFCB[pDevice->uCurrentDFCBIdx].wSequence == (pMACHeader->wSeqCtl >> 4)) &&
220                (pDevice->sRxDFCB[pDevice->uCurrentDFCBIdx].wFragNum == (pMACHeader->wSeqCtl & 0x000F)) &&
221                ((pDevice->sRxDFCB[pDevice->uCurrentDFCBIdx].cbFrameLength + cbFrameLength - uHeaderSize) < 2346)) {
222
223                memcpy(pDevice->sRxDFCB[pDevice->uCurrentDFCBIdx].pbyRxBuffer, ((unsigned char *) (pMACHeader) + uHeaderSize), (cbFrameLength - uHeaderSize));
224                pDevice->sRxDFCB[pDevice->uCurrentDFCBIdx].cbFrameLength += (cbFrameLength - uHeaderSize);
225                pDevice->sRxDFCB[pDevice->uCurrentDFCBIdx].pbyRxBuffer += (cbFrameLength - uHeaderSize);
226                pDevice->sRxDFCB[pDevice->uCurrentDFCBIdx].wFragNum++;
227                //DBG_PRT(MSG_LEVEL_DEBUG, KERN_INFO "Second pDevice->uCurrentDFCBIdx= %d\n", pDevice->uCurrentDFCBIdx);
228            }
229            else {
230                // seq error or frag # error flush DFCB
231                pDevice->cbFreeDFCB++;
232                pDevice->sRxDFCB[pDevice->uCurrentDFCBIdx].bInUse = false;
233                return(false);
234            }
235        }
236        else {
237            return(false);
238        }
239        if (IS_LAST_FRAGMENT_PKT(pMACHeader)) {
240            //enq defragcontrolblock
241            pDevice->cbFreeDFCB++;
242            pDevice->sRxDFCB[pDevice->uCurrentDFCBIdx].bInUse = false;
243            //DBG_PRT(MSG_LEVEL_DEBUG, KERN_INFO "Last pDevice->uCurrentDFCBIdx= %d\n", pDevice->uCurrentDFCBIdx);
244            return(true);
245        }
246        return(false);
247    }
248}
249
250
251