1 /**
2 * This file contains the handling of RX in wlan driver.
3 */
4 #include <linux/etherdevice.h>
5 #include <linux/types.h>
6
7 #include "hostcmd.h"
8 #include "radiotap.h"
9 #include "decl.h"
10 #include "dev.h"
11 #include "wext.h"
12
13 struct eth803hdr {
14 u8 dest_addr[6];
15 u8 src_addr[6];
16 u16 h803_len;
17 } __attribute__ ((packed));
18
19 struct rfc1042hdr {
20 u8 llc_dsap;
21 u8 llc_ssap;
22 u8 llc_ctrl;
23 u8 snap_oui[3];
24 u16 snap_type;
25 } __attribute__ ((packed));
26
27 struct rxpackethdr {
28 struct rxpd rx_pd;
29 struct eth803hdr eth803_hdr;
30 struct rfc1042hdr rfc1042_hdr;
31 } __attribute__ ((packed));
32
33 struct rx80211packethdr {
34 struct rxpd rx_pd;
35 void *eth80211_hdr;
36 } __attribute__ ((packed));
37
38 static int process_rxed_802_11_packet(struct lbs_private *priv,
39 struct sk_buff *skb);
40
41 /**
42 * @brief This function computes the avgSNR .
43 *
44 * @param priv A pointer to struct lbs_private structure
45 * @return avgSNR
46 */
lbs_getavgsnr(struct lbs_private * priv)47 static u8 lbs_getavgsnr(struct lbs_private *priv)
48 {
49 u8 i;
50 u16 temp = 0;
51 if (priv->numSNRNF == 0)
52 return 0;
53 for (i = 0; i < priv->numSNRNF; i++)
54 temp += priv->rawSNR[i];
55 return (u8) (temp / priv->numSNRNF);
56
57 }
58
59 /**
60 * @brief This function computes the AvgNF
61 *
62 * @param priv A pointer to struct lbs_private structure
63 * @return AvgNF
64 */
lbs_getavgnf(struct lbs_private * priv)65 static u8 lbs_getavgnf(struct lbs_private *priv)
66 {
67 u8 i;
68 u16 temp = 0;
69 if (priv->numSNRNF == 0)
70 return 0;
71 for (i = 0; i < priv->numSNRNF; i++)
72 temp += priv->rawNF[i];
73 return (u8) (temp / priv->numSNRNF);
74
75 }
76
77 /**
78 * @brief This function save the raw SNR/NF to our internel buffer
79 *
80 * @param priv A pointer to struct lbs_private structure
81 * @param prxpd A pointer to rxpd structure of received packet
82 * @return n/a
83 */
lbs_save_rawSNRNF(struct lbs_private * priv,struct rxpd * p_rx_pd)84 static void lbs_save_rawSNRNF(struct lbs_private *priv, struct rxpd *p_rx_pd)
85 {
86 if (priv->numSNRNF < DEFAULT_DATA_AVG_FACTOR)
87 priv->numSNRNF++;
88 priv->rawSNR[priv->nextSNRNF] = p_rx_pd->snr;
89 priv->rawNF[priv->nextSNRNF] = p_rx_pd->nf;
90 priv->nextSNRNF++;
91 if (priv->nextSNRNF >= DEFAULT_DATA_AVG_FACTOR)
92 priv->nextSNRNF = 0;
93 return;
94 }
95
96 /**
97 * @brief This function computes the RSSI in received packet.
98 *
99 * @param priv A pointer to struct lbs_private structure
100 * @param prxpd A pointer to rxpd structure of received packet
101 * @return n/a
102 */
lbs_compute_rssi(struct lbs_private * priv,struct rxpd * p_rx_pd)103 static void lbs_compute_rssi(struct lbs_private *priv, struct rxpd *p_rx_pd)
104 {
105
106 lbs_deb_enter(LBS_DEB_RX);
107
108 lbs_deb_rx("rxpd: SNR %d, NF %d\n", p_rx_pd->snr, p_rx_pd->nf);
109 lbs_deb_rx("before computing SNR: SNR-avg = %d, NF-avg = %d\n",
110 priv->SNR[TYPE_RXPD][TYPE_AVG] / AVG_SCALE,
111 priv->NF[TYPE_RXPD][TYPE_AVG] / AVG_SCALE);
112
113 priv->SNR[TYPE_RXPD][TYPE_NOAVG] = p_rx_pd->snr;
114 priv->NF[TYPE_RXPD][TYPE_NOAVG] = p_rx_pd->nf;
115 lbs_save_rawSNRNF(priv, p_rx_pd);
116
117 priv->SNR[TYPE_RXPD][TYPE_AVG] = lbs_getavgsnr(priv) * AVG_SCALE;
118 priv->NF[TYPE_RXPD][TYPE_AVG] = lbs_getavgnf(priv) * AVG_SCALE;
119 lbs_deb_rx("after computing SNR: SNR-avg = %d, NF-avg = %d\n",
120 priv->SNR[TYPE_RXPD][TYPE_AVG] / AVG_SCALE,
121 priv->NF[TYPE_RXPD][TYPE_AVG] / AVG_SCALE);
122
123 priv->RSSI[TYPE_RXPD][TYPE_NOAVG] =
124 CAL_RSSI(priv->SNR[TYPE_RXPD][TYPE_NOAVG],
125 priv->NF[TYPE_RXPD][TYPE_NOAVG]);
126
127 priv->RSSI[TYPE_RXPD][TYPE_AVG] =
128 CAL_RSSI(priv->SNR[TYPE_RXPD][TYPE_AVG] / AVG_SCALE,
129 priv->NF[TYPE_RXPD][TYPE_AVG] / AVG_SCALE);
130
131 lbs_deb_leave(LBS_DEB_RX);
132 }
133
134 /**
135 * @brief This function processes received packet and forwards it
136 * to kernel/upper layer
137 *
138 * @param priv A pointer to struct lbs_private
139 * @param skb A pointer to skb which includes the received packet
140 * @return 0 or -1
141 */
lbs_process_rxed_packet(struct lbs_private * priv,struct sk_buff * skb)142 int lbs_process_rxed_packet(struct lbs_private *priv, struct sk_buff *skb)
143 {
144 int ret = 0;
145 struct net_device *dev = priv->dev;
146 struct rxpackethdr *p_rx_pkt;
147 struct rxpd *p_rx_pd;
148 int hdrchop;
149 struct ethhdr *p_ethhdr;
150 const u8 rfc1042_eth_hdr[] = { 0xaa, 0xaa, 0x03, 0x00, 0x00, 0x00 };
151
152 lbs_deb_enter(LBS_DEB_RX);
153
154 BUG_ON(!skb);
155
156 skb->ip_summed = CHECKSUM_NONE;
157
158 if (priv->monitormode)
159 return process_rxed_802_11_packet(priv, skb);
160
161 p_rx_pkt = (struct rxpackethdr *) skb->data;
162 p_rx_pd = &p_rx_pkt->rx_pd;
163 if (priv->mesh_dev && (p_rx_pd->rx_control & RxPD_MESH_FRAME))
164 dev = priv->mesh_dev;
165
166 lbs_deb_hex(LBS_DEB_RX, "RX Data: Before chop rxpd", skb->data,
167 min_t(unsigned int, skb->len, 100));
168
169 if (skb->len < (ETH_HLEN + 8 + sizeof(struct rxpd))) {
170 lbs_deb_rx("rx err: frame received with bad length\n");
171 priv->stats.rx_length_errors++;
172 ret = 0;
173 goto done;
174 }
175
176 /*
177 * Check rxpd status and update 802.3 stat,
178 */
179 if (!(p_rx_pd->status & cpu_to_le16(MRVDRV_RXPD_STATUS_OK))) {
180 lbs_deb_rx("rx err: frame received with bad status\n");
181 lbs_pr_alert("rxpd not ok\n");
182 priv->stats.rx_errors++;
183 ret = 0;
184 goto done;
185 }
186
187 lbs_deb_rx("rx data: skb->len-sizeof(RxPd) = %d-%zd = %zd\n",
188 skb->len, sizeof(struct rxpd), skb->len - sizeof(struct rxpd));
189
190 lbs_deb_hex(LBS_DEB_RX, "RX Data: Dest", p_rx_pkt->eth803_hdr.dest_addr,
191 sizeof(p_rx_pkt->eth803_hdr.dest_addr));
192 lbs_deb_hex(LBS_DEB_RX, "RX Data: Src", p_rx_pkt->eth803_hdr.src_addr,
193 sizeof(p_rx_pkt->eth803_hdr.src_addr));
194
195 if (memcmp(&p_rx_pkt->rfc1042_hdr,
196 rfc1042_eth_hdr, sizeof(rfc1042_eth_hdr)) == 0) {
197 /*
198 * Replace the 803 header and rfc1042 header (llc/snap) with an
199 * EthernetII header, keep the src/dst and snap_type (ethertype)
200 *
201 * The firmware only passes up SNAP frames converting
202 * all RX Data from 802.11 to 802.2/LLC/SNAP frames.
203 *
204 * To create the Ethernet II, just move the src, dst address right
205 * before the snap_type.
206 */
207 p_ethhdr = (struct ethhdr *)
208 ((u8 *) & p_rx_pkt->eth803_hdr
209 + sizeof(p_rx_pkt->eth803_hdr) + sizeof(p_rx_pkt->rfc1042_hdr)
210 - sizeof(p_rx_pkt->eth803_hdr.dest_addr)
211 - sizeof(p_rx_pkt->eth803_hdr.src_addr)
212 - sizeof(p_rx_pkt->rfc1042_hdr.snap_type));
213
214 memcpy(p_ethhdr->h_source, p_rx_pkt->eth803_hdr.src_addr,
215 sizeof(p_ethhdr->h_source));
216 memcpy(p_ethhdr->h_dest, p_rx_pkt->eth803_hdr.dest_addr,
217 sizeof(p_ethhdr->h_dest));
218
219 /* Chop off the rxpd + the excess memory from the 802.2/llc/snap header
220 * that was removed
221 */
222 hdrchop = (u8 *) p_ethhdr - (u8 *) p_rx_pkt;
223 } else {
224 lbs_deb_hex(LBS_DEB_RX, "RX Data: LLC/SNAP",
225 (u8 *) & p_rx_pkt->rfc1042_hdr,
226 sizeof(p_rx_pkt->rfc1042_hdr));
227
228 /* Chop off the rxpd */
229 hdrchop = (u8 *) & p_rx_pkt->eth803_hdr - (u8 *) p_rx_pkt;
230 }
231
232 /* Chop off the leading header bytes so the skb points to the start of
233 * either the reconstructed EthII frame or the 802.2/llc/snap frame
234 */
235 skb_pull(skb, hdrchop);
236
237 /* Take the data rate from the rxpd structure
238 * only if the rate is auto
239 */
240 if (priv->enablehwauto)
241 priv->cur_rate = lbs_fw_index_to_data_rate(p_rx_pd->rx_rate);
242
243 lbs_compute_rssi(priv, p_rx_pd);
244
245 lbs_deb_rx("rx data: size of actual packet %d\n", skb->len);
246 priv->stats.rx_bytes += skb->len;
247 priv->stats.rx_packets++;
248
249 skb->protocol = eth_type_trans(skb, dev);
250 if (in_interrupt())
251 netif_rx(skb);
252 else
253 netif_rx_ni(skb);
254
255 ret = 0;
256 done:
257 lbs_deb_leave_args(LBS_DEB_RX, "ret %d", ret);
258 return ret;
259 }
260 EXPORT_SYMBOL_GPL(lbs_process_rxed_packet);
261
262 /**
263 * @brief This function converts Tx/Rx rates from the Marvell WLAN format
264 * (see Table 2 in Section 3.1) to IEEE80211_RADIOTAP_RATE units (500 Kb/s)
265 *
266 * @param rate Input rate
267 * @return Output Rate (0 if invalid)
268 */
convert_mv_rate_to_radiotap(u8 rate)269 static u8 convert_mv_rate_to_radiotap(u8 rate)
270 {
271 switch (rate) {
272 case 0: /* 1 Mbps */
273 return 2;
274 case 1: /* 2 Mbps */
275 return 4;
276 case 2: /* 5.5 Mbps */
277 return 11;
278 case 3: /* 11 Mbps */
279 return 22;
280 /* case 4: reserved */
281 case 5: /* 6 Mbps */
282 return 12;
283 case 6: /* 9 Mbps */
284 return 18;
285 case 7: /* 12 Mbps */
286 return 24;
287 case 8: /* 18 Mbps */
288 return 36;
289 case 9: /* 24 Mbps */
290 return 48;
291 case 10: /* 36 Mbps */
292 return 72;
293 case 11: /* 48 Mbps */
294 return 96;
295 case 12: /* 54 Mbps */
296 return 108;
297 }
298 lbs_pr_alert("Invalid Marvell WLAN rate %i\n", rate);
299 return 0;
300 }
301
302 /**
303 * @brief This function processes a received 802.11 packet and forwards it
304 * to kernel/upper layer
305 *
306 * @param priv A pointer to struct lbs_private
307 * @param skb A pointer to skb which includes the received packet
308 * @return 0 or -1
309 */
process_rxed_802_11_packet(struct lbs_private * priv,struct sk_buff * skb)310 static int process_rxed_802_11_packet(struct lbs_private *priv,
311 struct sk_buff *skb)
312 {
313 int ret = 0;
314
315 struct rx80211packethdr *p_rx_pkt;
316 struct rxpd *prxpd;
317 struct rx_radiotap_hdr radiotap_hdr;
318 struct rx_radiotap_hdr *pradiotap_hdr;
319
320 lbs_deb_enter(LBS_DEB_RX);
321
322 p_rx_pkt = (struct rx80211packethdr *) skb->data;
323 prxpd = &p_rx_pkt->rx_pd;
324
325 // lbs_deb_hex(LBS_DEB_RX, "RX Data: Before chop rxpd", skb->data, min(skb->len, 100));
326
327 if (skb->len < (ETH_HLEN + 8 + sizeof(struct rxpd))) {
328 lbs_deb_rx("rx err: frame received with bad length\n");
329 priv->stats.rx_length_errors++;
330 ret = -EINVAL;
331 kfree_skb(skb);
332 goto done;
333 }
334
335 /*
336 * Check rxpd status and update 802.3 stat,
337 */
338 if (!(prxpd->status & cpu_to_le16(MRVDRV_RXPD_STATUS_OK))) {
339 //lbs_deb_rx("rx err: frame received with bad status\n");
340 priv->stats.rx_errors++;
341 }
342
343 lbs_deb_rx("rx data: skb->len-sizeof(RxPd) = %d-%zd = %zd\n",
344 skb->len, sizeof(struct rxpd), skb->len - sizeof(struct rxpd));
345
346 /* create the exported radio header */
347
348 /* radiotap header */
349 radiotap_hdr.hdr.it_version = 0;
350 /* XXX must check this value for pad */
351 radiotap_hdr.hdr.it_pad = 0;
352 radiotap_hdr.hdr.it_len = cpu_to_le16 (sizeof(struct rx_radiotap_hdr));
353 radiotap_hdr.hdr.it_present = cpu_to_le32 (RX_RADIOTAP_PRESENT);
354 /* unknown values */
355 radiotap_hdr.flags = 0;
356 radiotap_hdr.chan_freq = 0;
357 radiotap_hdr.chan_flags = 0;
358 radiotap_hdr.antenna = 0;
359 /* known values */
360 radiotap_hdr.rate = convert_mv_rate_to_radiotap(prxpd->rx_rate);
361 /* XXX must check no carryout */
362 radiotap_hdr.antsignal = prxpd->snr + prxpd->nf;
363 radiotap_hdr.rx_flags = 0;
364 if (!(prxpd->status & cpu_to_le16(MRVDRV_RXPD_STATUS_OK)))
365 radiotap_hdr.rx_flags |= IEEE80211_RADIOTAP_F_RX_BADFCS;
366 //memset(radiotap_hdr.pad, 0x11, IEEE80211_RADIOTAP_HDRLEN - 18);
367
368 /* chop the rxpd */
369 skb_pull(skb, sizeof(struct rxpd));
370
371 /* add space for the new radio header */
372 if ((skb_headroom(skb) < sizeof(struct rx_radiotap_hdr)) &&
373 pskb_expand_head(skb, sizeof(struct rx_radiotap_hdr), 0, GFP_ATOMIC)) {
374 lbs_pr_alert("%s: couldn't pskb_expand_head\n", __func__);
375 ret = -ENOMEM;
376 kfree_skb(skb);
377 goto done;
378 }
379
380 pradiotap_hdr = (void *)skb_push(skb, sizeof(struct rx_radiotap_hdr));
381 memcpy(pradiotap_hdr, &radiotap_hdr, sizeof(struct rx_radiotap_hdr));
382
383 /* Take the data rate from the rxpd structure
384 * only if the rate is auto
385 */
386 if (priv->enablehwauto)
387 priv->cur_rate = lbs_fw_index_to_data_rate(prxpd->rx_rate);
388
389 lbs_compute_rssi(priv, prxpd);
390
391 lbs_deb_rx("rx data: size of actual packet %d\n", skb->len);
392 priv->stats.rx_bytes += skb->len;
393 priv->stats.rx_packets++;
394
395 skb->protocol = eth_type_trans(skb, priv->rtap_net_dev);
396 netif_rx(skb);
397
398 ret = 0;
399
400 done:
401 lbs_deb_leave_args(LBS_DEB_RX, "ret %d", ret);
402 return ret;
403 }
404