Linux Audio

Check our new training course

Embedded Linux training

Mar 10-20, 2025, special US time zones
Register
Loading...
Note: File does not exist in v3.1.
  1/*
  2 * This file contains the handling of RX in wlan driver.
  3 */
  4
  5#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
  6
  7#include <linux/etherdevice.h>
  8#include <linux/hardirq.h>
  9#include <linux/slab.h>
 10#include <linux/types.h>
 11#include <linux/export.h>
 12#include <net/cfg80211.h>
 13
 14#include "defs.h"
 15#include "host.h"
 16#include "radiotap.h"
 17#include "decl.h"
 18#include "dev.h"
 19#include "mesh.h"
 20
 21struct eth803hdr {
 22	u8 dest_addr[6];
 23	u8 src_addr[6];
 24	u16 h803_len;
 25} __packed;
 26
 27struct rfc1042hdr {
 28	u8 llc_dsap;
 29	u8 llc_ssap;
 30	u8 llc_ctrl;
 31	u8 snap_oui[3];
 32	u16 snap_type;
 33} __packed;
 34
 35struct rxpackethdr {
 36	struct eth803hdr eth803_hdr;
 37	struct rfc1042hdr rfc1042_hdr;
 38} __packed;
 39
 40struct rx80211packethdr {
 41	struct rxpd rx_pd;
 42	void *eth80211_hdr;
 43} __packed;
 44
 45static int process_rxed_802_11_packet(struct lbs_private *priv,
 46	struct sk_buff *skb);
 47
 48/**
 49 * lbs_process_rxed_packet - processes received packet and forwards it
 50 * to kernel/upper layer
 51 *
 52 * @priv:	A pointer to &struct lbs_private
 53 * @skb:	A pointer to skb which includes the received packet
 54 * returns:	0 or -1
 55 */
 56int lbs_process_rxed_packet(struct lbs_private *priv, struct sk_buff *skb)
 57{
 58	int ret = 0;
 59	struct net_device *dev = priv->dev;
 60	struct rxpackethdr *p_rx_pkt;
 61	struct rxpd *p_rx_pd;
 62	int hdrchop;
 63	struct ethhdr *p_ethhdr;
 64	static const u8 rfc1042_eth_hdr[] = {
 65		0xaa, 0xaa, 0x03, 0x00, 0x00, 0x00
 66	};
 67
 68	BUG_ON(!skb);
 69
 70	skb->ip_summed = CHECKSUM_NONE;
 71
 72	if (priv->wdev->iftype == NL80211_IFTYPE_MONITOR) {
 73		ret = process_rxed_802_11_packet(priv, skb);
 74		goto done;
 75	}
 76
 77	p_rx_pd = (struct rxpd *) skb->data;
 78	p_rx_pkt = (struct rxpackethdr *) ((u8 *)p_rx_pd +
 79		le32_to_cpu(p_rx_pd->pkt_ptr));
 80
 81	dev = lbs_mesh_set_dev(priv, dev, p_rx_pd);
 82
 83	lbs_deb_hex(LBS_DEB_RX, "RX Data: Before chop rxpd", skb->data,
 84		 min_t(unsigned int, skb->len, 100));
 85
 86	if (skb->len < (ETH_HLEN + 8 + sizeof(struct rxpd))) {
 87		lbs_deb_rx("rx err: frame received with bad length\n");
 88		dev->stats.rx_length_errors++;
 89		ret = -EINVAL;
 90		dev_kfree_skb(skb);
 91		goto done;
 92	}
 93
 94	lbs_deb_rx("rx data: skb->len - pkt_ptr = %d-%zd = %zd\n",
 95		skb->len, (size_t)le32_to_cpu(p_rx_pd->pkt_ptr),
 96		skb->len - (size_t)le32_to_cpu(p_rx_pd->pkt_ptr));
 97
 98	lbs_deb_hex(LBS_DEB_RX, "RX Data: Dest", p_rx_pkt->eth803_hdr.dest_addr,
 99		sizeof(p_rx_pkt->eth803_hdr.dest_addr));
100	lbs_deb_hex(LBS_DEB_RX, "RX Data: Src", p_rx_pkt->eth803_hdr.src_addr,
101		sizeof(p_rx_pkt->eth803_hdr.src_addr));
102
103	if (memcmp(&p_rx_pkt->rfc1042_hdr,
104		   rfc1042_eth_hdr, sizeof(rfc1042_eth_hdr)) == 0) {
105		/*
106		 *  Replace the 803 header and rfc1042 header (llc/snap) with an
107		 *    EthernetII header, keep the src/dst and snap_type (ethertype)
108		 *
109		 *  The firmware only passes up SNAP frames converting
110		 *    all RX Data from 802.11 to 802.2/LLC/SNAP frames.
111		 *
112		 *  To create the Ethernet II, just move the src, dst address right
113		 *    before the snap_type.
114		 */
115		p_ethhdr = (struct ethhdr *)
116		    ((u8 *) &p_rx_pkt->eth803_hdr
117		     + sizeof(p_rx_pkt->eth803_hdr) + sizeof(p_rx_pkt->rfc1042_hdr)
118		     - sizeof(p_rx_pkt->eth803_hdr.dest_addr)
119		     - sizeof(p_rx_pkt->eth803_hdr.src_addr)
120		     - sizeof(p_rx_pkt->rfc1042_hdr.snap_type));
121
122		memcpy(p_ethhdr->h_source, p_rx_pkt->eth803_hdr.src_addr,
123		       sizeof(p_ethhdr->h_source));
124		memcpy(p_ethhdr->h_dest, p_rx_pkt->eth803_hdr.dest_addr,
125		       sizeof(p_ethhdr->h_dest));
126
127		/* Chop off the rxpd + the excess memory from the 802.2/llc/snap header
128		 *   that was removed
129		 */
130		hdrchop = (u8 *)p_ethhdr - (u8 *)p_rx_pd;
131	} else {
132		lbs_deb_hex(LBS_DEB_RX, "RX Data: LLC/SNAP",
133			(u8 *) &p_rx_pkt->rfc1042_hdr,
134			sizeof(p_rx_pkt->rfc1042_hdr));
135
136		/* Chop off the rxpd */
137		hdrchop = (u8 *)&p_rx_pkt->eth803_hdr - (u8 *)p_rx_pd;
138	}
139
140	/* Chop off the leading header bytes so the skb points to the start of
141	 *   either the reconstructed EthII frame or the 802.2/llc/snap frame
142	 */
143	skb_pull(skb, hdrchop);
144
145	priv->cur_rate = lbs_fw_index_to_data_rate(p_rx_pd->rx_rate);
146
147	lbs_deb_rx("rx data: size of actual packet %d\n", skb->len);
148	dev->stats.rx_bytes += skb->len;
149	dev->stats.rx_packets++;
150
151	skb->protocol = eth_type_trans(skb, dev);
152	if (in_interrupt())
153		netif_rx(skb);
154	else
155		netif_rx_ni(skb);
156
157	ret = 0;
158done:
159	return ret;
160}
161EXPORT_SYMBOL_GPL(lbs_process_rxed_packet);
162
163/**
164 * convert_mv_rate_to_radiotap - converts Tx/Rx rates from Marvell WLAN format
165 * (see Table 2 in Section 3.1) to IEEE80211_RADIOTAP_RATE units (500 Kb/s)
166 *
167 * @rate:	Input rate
168 * returns:	Output Rate (0 if invalid)
169 */
170static u8 convert_mv_rate_to_radiotap(u8 rate)
171{
172	switch (rate) {
173	case 0:		/*   1 Mbps */
174		return 2;
175	case 1:		/*   2 Mbps */
176		return 4;
177	case 2:		/* 5.5 Mbps */
178		return 11;
179	case 3:		/*  11 Mbps */
180		return 22;
181	/* case 4: reserved */
182	case 5:		/*   6 Mbps */
183		return 12;
184	case 6:		/*   9 Mbps */
185		return 18;
186	case 7:		/*  12 Mbps */
187		return 24;
188	case 8:		/*  18 Mbps */
189		return 36;
190	case 9:		/*  24 Mbps */
191		return 48;
192	case 10:		/*  36 Mbps */
193		return 72;
194	case 11:		/*  48 Mbps */
195		return 96;
196	case 12:		/*  54 Mbps */
197		return 108;
198	}
199	pr_alert("Invalid Marvell WLAN rate %i\n", rate);
200	return 0;
201}
202
203/**
204 * process_rxed_802_11_packet - processes a received 802.11 packet and forwards
205 * it to kernel/upper layer
206 *
207 * @priv:	A pointer to &struct lbs_private
208 * @skb:	A pointer to skb which includes the received packet
209 * returns:	0 or -1
210 */
211static int process_rxed_802_11_packet(struct lbs_private *priv,
212	struct sk_buff *skb)
213{
214	int ret = 0;
215	struct net_device *dev = priv->dev;
216	struct rx80211packethdr *p_rx_pkt;
217	struct rxpd *prxpd;
218	struct rx_radiotap_hdr radiotap_hdr;
219	struct rx_radiotap_hdr *pradiotap_hdr;
220
221	p_rx_pkt = (struct rx80211packethdr *) skb->data;
222	prxpd = &p_rx_pkt->rx_pd;
223
224	/* lbs_deb_hex(LBS_DEB_RX, "RX Data: Before chop rxpd", skb->data, min(skb->len, 100)); */
225
226	if (skb->len < (ETH_HLEN + 8 + sizeof(struct rxpd))) {
227		lbs_deb_rx("rx err: frame received with bad length\n");
228		dev->stats.rx_length_errors++;
229		ret = -EINVAL;
230		kfree_skb(skb);
231		goto done;
232	}
233
234	lbs_deb_rx("rx data: skb->len-sizeof(RxPd) = %d-%zd = %zd\n",
235	       skb->len, sizeof(struct rxpd), skb->len - sizeof(struct rxpd));
236
237	/* create the exported radio header */
238
239	/* radiotap header */
240	memset(&radiotap_hdr, 0, sizeof(radiotap_hdr));
241	/* XXX must check radiotap_hdr.hdr.it_pad for pad */
242	radiotap_hdr.hdr.it_len = cpu_to_le16 (sizeof(struct rx_radiotap_hdr));
243	radiotap_hdr.hdr.it_present = cpu_to_le32 (RX_RADIOTAP_PRESENT);
244	radiotap_hdr.rate = convert_mv_rate_to_radiotap(prxpd->rx_rate);
245	/* XXX must check no carryout */
246	radiotap_hdr.antsignal = prxpd->snr + prxpd->nf;
247
248	/* chop the rxpd */
249	skb_pull(skb, sizeof(struct rxpd));
250
251	/* add space for the new radio header */
252	if ((skb_headroom(skb) < sizeof(struct rx_radiotap_hdr)) &&
253	    pskb_expand_head(skb, sizeof(struct rx_radiotap_hdr), 0, GFP_ATOMIC)) {
254		netdev_alert(dev, "%s: couldn't pskb_expand_head\n", __func__);
255		ret = -ENOMEM;
256		kfree_skb(skb);
257		goto done;
258	}
259
260	pradiotap_hdr = skb_push(skb, sizeof(struct rx_radiotap_hdr));
261	memcpy(pradiotap_hdr, &radiotap_hdr, sizeof(struct rx_radiotap_hdr));
262
263	priv->cur_rate = lbs_fw_index_to_data_rate(prxpd->rx_rate);
264
265	lbs_deb_rx("rx data: size of actual packet %d\n", skb->len);
266	dev->stats.rx_bytes += skb->len;
267	dev->stats.rx_packets++;
268
269	skb->protocol = eth_type_trans(skb, priv->dev);
270
271	if (in_interrupt())
272		netif_rx(skb);
273	else
274		netif_rx_ni(skb);
275
276	ret = 0;
277
278done:
279	return ret;
280}