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 
WCTLbIsDuplicate(PSCache pCache,PS802_11Header pMACHeader)69 bool 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  */
WCTLuSearchDFCB(PSDevice pDevice,PS802_11Header pMACHeader)111 unsigned int WCTLuSearchDFCB (PSDevice pDevice, PS802_11Header pMACHeader)
112 {
113 unsigned 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  */
WCTLuInsertDFCB(PSDevice pDevice,PS802_11Header pMACHeader)141 unsigned int WCTLuInsertDFCB (PSDevice pDevice, PS802_11Header pMACHeader)
142 {
143 unsigned 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  */
WCTLbHandleFragment(PSDevice pDevice,PS802_11Header pMACHeader,unsigned int cbFrameLength,bool bWEP,bool bExtIV)178 bool WCTLbHandleFragment (PSDevice pDevice, PS802_11Header pMACHeader, unsigned int cbFrameLength, bool bWEP, bool bExtIV)
179 {
180 unsigned 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