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 
22 struct eth803hdr {
23 	u8 dest_addr[6];
24 	u8 src_addr[6];
25 	u16 h803_len;
26 } __packed;
27 
28 struct 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 
36 struct rxpackethdr {
37 	struct eth803hdr eth803_hdr;
38 	struct rfc1042hdr rfc1042_hdr;
39 } __packed;
40 
41 struct rx80211packethdr {
42 	struct rxpd rx_pd;
43 	void *eth80211_hdr;
44 } __packed;
45 
46 static 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  */
57 int 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_any_context(skb);
151 
152 	ret = 0;
153 done:
154 	return ret;
155 }
156 EXPORT_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  */
165 static 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  */
206 static 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_any_context(skb);
266 
267 	ret = 0;
268 
269 done:
270 	return ret;
271 }
272