1// SPDX-License-Identifier: GPL-2.0-only
2/*
3 * This file contains the handling of RX in wlan driver.
4 */
5
6#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
7
8#include <linux/etherdevice.h>
9#include <linux/hardirq.h>
10#include <linux/slab.h>
11#include <linux/types.h>
12#include <linux/export.h>
13#include <net/cfg80211.h>
14
15#include "defs.h"
16#include "host.h"
17#include "radiotap.h"
18#include "decl.h"
19#include "dev.h"
20#include "mesh.h"
21
22struct eth803hdr {
23	u8 dest_addr[6];
24	u8 src_addr[6];
25	u16 h803_len;
26} __packed;
27
28struct rfc1042hdr {
29	u8 llc_dsap;
30	u8 llc_ssap;
31	u8 llc_ctrl;
32	u8 snap_oui[3];
33	u16 snap_type;
34} __packed;
35
36struct rxpackethdr {
37	struct eth803hdr eth803_hdr;
38	struct rfc1042hdr rfc1042_hdr;
39} __packed;
40
41struct rx80211packethdr {
42	struct rxpd rx_pd;
43	void *eth80211_hdr;
44} __packed;
45
46static int process_rxed_802_11_packet(struct lbs_private *priv,
47	struct sk_buff *skb);
48
49/**
50 * lbs_process_rxed_packet - processes received packet and forwards it
51 * to kernel/upper layer
52 *
53 * @priv:	A pointer to &struct lbs_private
54 * @skb:	A pointer to skb which includes the received packet
55 * returns:	0 or -1
56 */
57int lbs_process_rxed_packet(struct lbs_private *priv, struct sk_buff *skb)
58{
59	int ret = 0;
60	struct net_device *dev = priv->dev;
61	struct rxpackethdr *p_rx_pkt;
62	struct rxpd *p_rx_pd;
63	int hdrchop;
64	struct ethhdr *p_ethhdr;
65
66	BUG_ON(!skb);
67
68	skb->ip_summed = CHECKSUM_NONE;
69
70	if (priv->wdev->iftype == NL80211_IFTYPE_MONITOR) {
71		ret = process_rxed_802_11_packet(priv, skb);
72		goto done;
73	}
74
75	p_rx_pd = (struct rxpd *) skb->data;
76	p_rx_pkt = (struct rxpackethdr *) ((u8 *)p_rx_pd +
77		le32_to_cpu(p_rx_pd->pkt_ptr));
78
79	dev = lbs_mesh_set_dev(priv, dev, p_rx_pd);
80
81	lbs_deb_hex(LBS_DEB_RX, "RX Data: Before chop rxpd", skb->data,
82		 min_t(unsigned int, skb->len, 100));
83
84	if (skb->len < (ETH_HLEN + 8 + sizeof(struct rxpd))) {
85		lbs_deb_rx("rx err: frame received with bad length\n");
86		dev->stats.rx_length_errors++;
87		ret = -EINVAL;
88		dev_kfree_skb(skb);
89		goto done;
90	}
91
92	lbs_deb_rx("rx data: skb->len - pkt_ptr = %d-%zd = %zd\n",
93		skb->len, (size_t)le32_to_cpu(p_rx_pd->pkt_ptr),
94		skb->len - (size_t)le32_to_cpu(p_rx_pd->pkt_ptr));
95
96	lbs_deb_hex(LBS_DEB_RX, "RX Data: Dest", p_rx_pkt->eth803_hdr.dest_addr,
97		sizeof(p_rx_pkt->eth803_hdr.dest_addr));
98	lbs_deb_hex(LBS_DEB_RX, "RX Data: Src", p_rx_pkt->eth803_hdr.src_addr,
99		sizeof(p_rx_pkt->eth803_hdr.src_addr));
100
101	if (memcmp(&p_rx_pkt->rfc1042_hdr,
102		   rfc1042_header, sizeof(rfc1042_header)) == 0) {
103		/*
104		 *  Replace the 803 header and rfc1042 header (llc/snap) with an
105		 *    EthernetII header, keep the src/dst and snap_type (ethertype)
106		 *
107		 *  The firmware only passes up SNAP frames converting
108		 *    all RX Data from 802.11 to 802.2/LLC/SNAP frames.
109		 *
110		 *  To create the Ethernet II, just move the src, dst address right
111		 *    before the snap_type.
112		 */
113		p_ethhdr = (struct ethhdr *)
114		    ((u8 *) &p_rx_pkt->eth803_hdr
115		     + sizeof(p_rx_pkt->eth803_hdr) + sizeof(p_rx_pkt->rfc1042_hdr)
116		     - sizeof(p_rx_pkt->eth803_hdr.dest_addr)
117		     - sizeof(p_rx_pkt->eth803_hdr.src_addr)
118		     - sizeof(p_rx_pkt->rfc1042_hdr.snap_type));
119
120		memcpy(p_ethhdr->h_source, p_rx_pkt->eth803_hdr.src_addr,
121		       sizeof(p_ethhdr->h_source));
122		memcpy(p_ethhdr->h_dest, p_rx_pkt->eth803_hdr.dest_addr,
123		       sizeof(p_ethhdr->h_dest));
124
125		/* Chop off the rxpd + the excess memory from the 802.2/llc/snap header
126		 *   that was removed
127		 */
128		hdrchop = (u8 *)p_ethhdr - (u8 *)p_rx_pd;
129	} else {
130		lbs_deb_hex(LBS_DEB_RX, "RX Data: LLC/SNAP",
131			(u8 *) &p_rx_pkt->rfc1042_hdr,
132			sizeof(p_rx_pkt->rfc1042_hdr));
133
134		/* Chop off the rxpd */
135		hdrchop = (u8 *)&p_rx_pkt->eth803_hdr - (u8 *)p_rx_pd;
136	}
137
138	/* Chop off the leading header bytes so the skb points to the start of
139	 *   either the reconstructed EthII frame or the 802.2/llc/snap frame
140	 */
141	skb_pull(skb, hdrchop);
142
143	priv->cur_rate = lbs_fw_index_to_data_rate(p_rx_pd->rx_rate);
144
145	lbs_deb_rx("rx data: size of actual packet %d\n", skb->len);
146	dev->stats.rx_bytes += skb->len;
147	dev->stats.rx_packets++;
148
149	skb->protocol = eth_type_trans(skb, dev);
150	netif_rx(skb);
151
152	ret = 0;
153done:
154	return ret;
155}
156EXPORT_SYMBOL_GPL(lbs_process_rxed_packet);
157
158/**
159 * convert_mv_rate_to_radiotap - converts Tx/Rx rates from Marvell WLAN format
160 * (see Table 2 in Section 3.1) to IEEE80211_RADIOTAP_RATE units (500 Kb/s)
161 *
162 * @rate:	Input rate
163 * returns:	Output Rate (0 if invalid)
164 */
165static u8 convert_mv_rate_to_radiotap(u8 rate)
166{
167	switch (rate) {
168	case 0:		/*   1 Mbps */
169		return 2;
170	case 1:		/*   2 Mbps */
171		return 4;
172	case 2:		/* 5.5 Mbps */
173		return 11;
174	case 3:		/*  11 Mbps */
175		return 22;
176	/* case 4: reserved */
177	case 5:		/*   6 Mbps */
178		return 12;
179	case 6:		/*   9 Mbps */
180		return 18;
181	case 7:		/*  12 Mbps */
182		return 24;
183	case 8:		/*  18 Mbps */
184		return 36;
185	case 9:		/*  24 Mbps */
186		return 48;
187	case 10:		/*  36 Mbps */
188		return 72;
189	case 11:		/*  48 Mbps */
190		return 96;
191	case 12:		/*  54 Mbps */
192		return 108;
193	}
194	pr_alert("Invalid Marvell WLAN rate %i\n", rate);
195	return 0;
196}
197
198/**
199 * process_rxed_802_11_packet - processes a received 802.11 packet and forwards
200 * it to kernel/upper layer
201 *
202 * @priv:	A pointer to &struct lbs_private
203 * @skb:	A pointer to skb which includes the received packet
204 * returns:	0 or -1
205 */
206static int process_rxed_802_11_packet(struct lbs_private *priv,
207	struct sk_buff *skb)
208{
209	int ret = 0;
210	struct net_device *dev = priv->dev;
211	struct rx80211packethdr *p_rx_pkt;
212	struct rxpd *prxpd;
213	struct rx_radiotap_hdr radiotap_hdr;
214	struct rx_radiotap_hdr *pradiotap_hdr;
215
216	p_rx_pkt = (struct rx80211packethdr *) skb->data;
217	prxpd = &p_rx_pkt->rx_pd;
218
219	/* lbs_deb_hex(LBS_DEB_RX, "RX Data: Before chop rxpd", skb->data, min(skb->len, 100)); */
220
221	if (skb->len < (ETH_HLEN + 8 + sizeof(struct rxpd))) {
222		lbs_deb_rx("rx err: frame received with bad length\n");
223		dev->stats.rx_length_errors++;
224		ret = -EINVAL;
225		kfree_skb(skb);
226		goto done;
227	}
228
229	lbs_deb_rx("rx data: skb->len-sizeof(RxPd) = %d-%zd = %zd\n",
230	       skb->len, sizeof(struct rxpd), skb->len - sizeof(struct rxpd));
231
232	/* create the exported radio header */
233
234	/* radiotap header */
235	memset(&radiotap_hdr, 0, sizeof(radiotap_hdr));
236	/* XXX must check radiotap_hdr.hdr.it_pad for pad */
237	radiotap_hdr.hdr.it_len = cpu_to_le16 (sizeof(struct rx_radiotap_hdr));
238	radiotap_hdr.hdr.it_present = cpu_to_le32 (RX_RADIOTAP_PRESENT);
239	radiotap_hdr.rate = convert_mv_rate_to_radiotap(prxpd->rx_rate);
240	/* XXX must check no carryout */
241	radiotap_hdr.antsignal = prxpd->snr + prxpd->nf;
242
243	/* chop the rxpd */
244	skb_pull(skb, sizeof(struct rxpd));
245
246	/* add space for the new radio header */
247	if ((skb_headroom(skb) < sizeof(struct rx_radiotap_hdr)) &&
248	    pskb_expand_head(skb, sizeof(struct rx_radiotap_hdr), 0, GFP_ATOMIC)) {
249		netdev_alert(dev, "%s: couldn't pskb_expand_head\n", __func__);
250		ret = -ENOMEM;
251		kfree_skb(skb);
252		goto done;
253	}
254
255	pradiotap_hdr = skb_push(skb, sizeof(struct rx_radiotap_hdr));
256	memcpy(pradiotap_hdr, &radiotap_hdr, sizeof(struct rx_radiotap_hdr));
257
258	priv->cur_rate = lbs_fw_index_to_data_rate(prxpd->rx_rate);
259
260	lbs_deb_rx("rx data: size of actual packet %d\n", skb->len);
261	dev->stats.rx_bytes += skb->len;
262	dev->stats.rx_packets++;
263
264	skb->protocol = eth_type_trans(skb, priv->dev);
265	netif_rx(skb);
266
267	ret = 0;
268
269done:
270	return ret;
271}
272