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	lbs_deb_enter(LBS_DEB_RX);
69
70	BUG_ON(!skb);
71
72	skb->ip_summed = CHECKSUM_NONE;
73
74	if (priv->wdev->iftype == NL80211_IFTYPE_MONITOR) {
75		ret = process_rxed_802_11_packet(priv, skb);
76		goto done;
77	}
78
79	p_rx_pd = (struct rxpd *) skb->data;
80	p_rx_pkt = (struct rxpackethdr *) ((u8 *)p_rx_pd +
81		le32_to_cpu(p_rx_pd->pkt_ptr));
82
83	dev = lbs_mesh_set_dev(priv, dev, p_rx_pd);
84
85	lbs_deb_hex(LBS_DEB_RX, "RX Data: Before chop rxpd", skb->data,
86		 min_t(unsigned int, skb->len, 100));
87
88	if (skb->len < (ETH_HLEN + 8 + sizeof(struct rxpd))) {
89		lbs_deb_rx("rx err: frame received with bad length\n");
90		dev->stats.rx_length_errors++;
91		ret = -EINVAL;
92		dev_kfree_skb(skb);
93		goto done;
94	}
95
96	lbs_deb_rx("rx data: skb->len - pkt_ptr = %d-%zd = %zd\n",
97		skb->len, (size_t)le32_to_cpu(p_rx_pd->pkt_ptr),
98		skb->len - (size_t)le32_to_cpu(p_rx_pd->pkt_ptr));
99
100	lbs_deb_hex(LBS_DEB_RX, "RX Data: Dest", p_rx_pkt->eth803_hdr.dest_addr,
101		sizeof(p_rx_pkt->eth803_hdr.dest_addr));
102	lbs_deb_hex(LBS_DEB_RX, "RX Data: Src", p_rx_pkt->eth803_hdr.src_addr,
103		sizeof(p_rx_pkt->eth803_hdr.src_addr));
104
105	if (memcmp(&p_rx_pkt->rfc1042_hdr,
106		   rfc1042_eth_hdr, sizeof(rfc1042_eth_hdr)) == 0) {
107		/*
108		 *  Replace the 803 header and rfc1042 header (llc/snap) with an
109		 *    EthernetII header, keep the src/dst and snap_type (ethertype)
110		 *
111		 *  The firmware only passes up SNAP frames converting
112		 *    all RX Data from 802.11 to 802.2/LLC/SNAP frames.
113		 *
114		 *  To create the Ethernet II, just move the src, dst address right
115		 *    before the snap_type.
116		 */
117		p_ethhdr = (struct ethhdr *)
118		    ((u8 *) &p_rx_pkt->eth803_hdr
119		     + sizeof(p_rx_pkt->eth803_hdr) + sizeof(p_rx_pkt->rfc1042_hdr)
120		     - sizeof(p_rx_pkt->eth803_hdr.dest_addr)
121		     - sizeof(p_rx_pkt->eth803_hdr.src_addr)
122		     - sizeof(p_rx_pkt->rfc1042_hdr.snap_type));
123
124		memcpy(p_ethhdr->h_source, p_rx_pkt->eth803_hdr.src_addr,
125		       sizeof(p_ethhdr->h_source));
126		memcpy(p_ethhdr->h_dest, p_rx_pkt->eth803_hdr.dest_addr,
127		       sizeof(p_ethhdr->h_dest));
128
129		/* Chop off the rxpd + the excess memory from the 802.2/llc/snap header
130		 *   that was removed
131		 */
132		hdrchop = (u8 *)p_ethhdr - (u8 *)p_rx_pd;
133	} else {
134		lbs_deb_hex(LBS_DEB_RX, "RX Data: LLC/SNAP",
135			(u8 *) &p_rx_pkt->rfc1042_hdr,
136			sizeof(p_rx_pkt->rfc1042_hdr));
137
138		/* Chop off the rxpd */
139		hdrchop = (u8 *)&p_rx_pkt->eth803_hdr - (u8 *)p_rx_pd;
140	}
141
142	/* Chop off the leading header bytes so the skb points to the start of
143	 *   either the reconstructed EthII frame or the 802.2/llc/snap frame
144	 */
145	skb_pull(skb, hdrchop);
146
147	priv->cur_rate = lbs_fw_index_to_data_rate(p_rx_pd->rx_rate);
148
149	lbs_deb_rx("rx data: size of actual packet %d\n", skb->len);
150	dev->stats.rx_bytes += skb->len;
151	dev->stats.rx_packets++;
152
153	skb->protocol = eth_type_trans(skb, dev);
154	if (in_interrupt())
155		netif_rx(skb);
156	else
157		netif_rx_ni(skb);
158
159	ret = 0;
160done:
161	lbs_deb_leave_args(LBS_DEB_RX, "ret %d", ret);
162	return ret;
163}
164EXPORT_SYMBOL_GPL(lbs_process_rxed_packet);
165
166/**
167 * convert_mv_rate_to_radiotap - converts Tx/Rx rates from Marvell WLAN format
168 * (see Table 2 in Section 3.1) to IEEE80211_RADIOTAP_RATE units (500 Kb/s)
169 *
170 * @rate:	Input rate
171 * returns:	Output Rate (0 if invalid)
172 */
173static u8 convert_mv_rate_to_radiotap(u8 rate)
174{
175	switch (rate) {
176	case 0:		/*   1 Mbps */
177		return 2;
178	case 1:		/*   2 Mbps */
179		return 4;
180	case 2:		/* 5.5 Mbps */
181		return 11;
182	case 3:		/*  11 Mbps */
183		return 22;
184	/* case 4: reserved */
185	case 5:		/*   6 Mbps */
186		return 12;
187	case 6:		/*   9 Mbps */
188		return 18;
189	case 7:		/*  12 Mbps */
190		return 24;
191	case 8:		/*  18 Mbps */
192		return 36;
193	case 9:		/*  24 Mbps */
194		return 48;
195	case 10:		/*  36 Mbps */
196		return 72;
197	case 11:		/*  48 Mbps */
198		return 96;
199	case 12:		/*  54 Mbps */
200		return 108;
201	}
202	pr_alert("Invalid Marvell WLAN rate %i\n", rate);
203	return 0;
204}
205
206/**
207 * process_rxed_802_11_packet - processes a received 802.11 packet and forwards
208 * it to kernel/upper layer
209 *
210 * @priv:	A pointer to &struct lbs_private
211 * @skb:	A pointer to skb which includes the received packet
212 * returns:	0 or -1
213 */
214static int process_rxed_802_11_packet(struct lbs_private *priv,
215	struct sk_buff *skb)
216{
217	int ret = 0;
218	struct net_device *dev = priv->dev;
219	struct rx80211packethdr *p_rx_pkt;
220	struct rxpd *prxpd;
221	struct rx_radiotap_hdr radiotap_hdr;
222	struct rx_radiotap_hdr *pradiotap_hdr;
223
224	lbs_deb_enter(LBS_DEB_RX);
225
226	p_rx_pkt = (struct rx80211packethdr *) skb->data;
227	prxpd = &p_rx_pkt->rx_pd;
228
229	/* lbs_deb_hex(LBS_DEB_RX, "RX Data: Before chop rxpd", skb->data, min(skb->len, 100)); */
230
231	if (skb->len < (ETH_HLEN + 8 + sizeof(struct rxpd))) {
232		lbs_deb_rx("rx err: frame received with bad length\n");
233		dev->stats.rx_length_errors++;
234		ret = -EINVAL;
235		kfree_skb(skb);
236		goto done;
237	}
238
239	lbs_deb_rx("rx data: skb->len-sizeof(RxPd) = %d-%zd = %zd\n",
240	       skb->len, sizeof(struct rxpd), skb->len - sizeof(struct rxpd));
241
242	/* create the exported radio header */
243
244	/* radiotap header */
245	memset(&radiotap_hdr, 0, sizeof(radiotap_hdr));
246	/* XXX must check radiotap_hdr.hdr.it_pad for pad */
247	radiotap_hdr.hdr.it_len = cpu_to_le16 (sizeof(struct rx_radiotap_hdr));
248	radiotap_hdr.hdr.it_present = cpu_to_le32 (RX_RADIOTAP_PRESENT);
249	radiotap_hdr.rate = convert_mv_rate_to_radiotap(prxpd->rx_rate);
250	/* XXX must check no carryout */
251	radiotap_hdr.antsignal = prxpd->snr + prxpd->nf;
252
253	/* chop the rxpd */
254	skb_pull(skb, sizeof(struct rxpd));
255
256	/* add space for the new radio header */
257	if ((skb_headroom(skb) < sizeof(struct rx_radiotap_hdr)) &&
258	    pskb_expand_head(skb, sizeof(struct rx_radiotap_hdr), 0, GFP_ATOMIC)) {
259		netdev_alert(dev, "%s: couldn't pskb_expand_head\n", __func__);
260		ret = -ENOMEM;
261		kfree_skb(skb);
262		goto done;
263	}
264
265	pradiotap_hdr = (void *)skb_push(skb, sizeof(struct rx_radiotap_hdr));
266	memcpy(pradiotap_hdr, &radiotap_hdr, sizeof(struct rx_radiotap_hdr));
267
268	priv->cur_rate = lbs_fw_index_to_data_rate(prxpd->rx_rate);
269
270	lbs_deb_rx("rx data: size of actual packet %d\n", skb->len);
271	dev->stats.rx_bytes += skb->len;
272	dev->stats.rx_packets++;
273
274	skb->protocol = eth_type_trans(skb, priv->dev);
275
276	if (in_interrupt())
277		netif_rx(skb);
278	else
279		netif_rx_ni(skb);
280
281	ret = 0;
282
283done:
284	lbs_deb_leave_args(LBS_DEB_RX, "ret %d", ret);
285	return ret;
286}
287