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1 /*
2  * NXP Wireless LAN device driver: station RX data handling
3  *
4  * Copyright 2011-2020 NXP
5  *
6  * This software file (the "File") is distributed by NXP
7  * under the terms of the GNU General Public License Version 2, June 1991
8  * (the "License").  You may use, redistribute and/or modify this File in
9  * accordance with the terms and conditions of the License, a copy of which
10  * is available by writing to the Free Software Foundation, Inc.,
11  * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA or on the
12  * worldwide web at http://www.gnu.org/licenses/old-licenses/gpl-2.0.txt.
13  *
14  * THE FILE IS DISTRIBUTED AS-IS, WITHOUT WARRANTY OF ANY KIND, AND THE
15  * IMPLIED WARRANTIES OF MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE
16  * ARE EXPRESSLY DISCLAIMED.  The License provides additional details about
17  * this warranty disclaimer.
18  */
19 
20 #include <uapi/linux/ipv6.h>
21 #include <net/ndisc.h>
22 #include "decl.h"
23 #include "ioctl.h"
24 #include "util.h"
25 #include "fw.h"
26 #include "main.h"
27 #include "11n_aggr.h"
28 #include "11n_rxreorder.h"
29 
30 /* This function checks if a frame is IPv4 ARP or IPv6 Neighbour advertisement
31  * frame. If frame has both source and destination mac address as same, this
32  * function drops such gratuitous frames.
33  */
34 static bool
mwifiex_discard_gratuitous_arp(struct mwifiex_private * priv,struct sk_buff * skb)35 mwifiex_discard_gratuitous_arp(struct mwifiex_private *priv,
36 			       struct sk_buff *skb)
37 {
38 	const struct mwifiex_arp_eth_header *arp;
39 	struct ethhdr *eth;
40 	struct ipv6hdr *ipv6;
41 	struct icmp6hdr *icmpv6;
42 
43 	eth = (struct ethhdr *)skb->data;
44 	switch (ntohs(eth->h_proto)) {
45 	case ETH_P_ARP:
46 		arp = (void *)(skb->data + sizeof(struct ethhdr));
47 		if (arp->hdr.ar_op == htons(ARPOP_REPLY) ||
48 		    arp->hdr.ar_op == htons(ARPOP_REQUEST)) {
49 			if (!memcmp(arp->ar_sip, arp->ar_tip, 4))
50 				return true;
51 		}
52 		break;
53 	case ETH_P_IPV6:
54 		ipv6 = (void *)(skb->data + sizeof(struct ethhdr));
55 		icmpv6 = (void *)(skb->data + sizeof(struct ethhdr) +
56 				  sizeof(struct ipv6hdr));
57 		if (NDISC_NEIGHBOUR_ADVERTISEMENT == icmpv6->icmp6_type) {
58 			if (!memcmp(&ipv6->saddr, &ipv6->daddr,
59 				    sizeof(struct in6_addr)))
60 				return true;
61 		}
62 		break;
63 	default:
64 		break;
65 	}
66 
67 	return false;
68 }
69 
70 /*
71  * This function processes the received packet and forwards it
72  * to kernel/upper layer.
73  *
74  * This function parses through the received packet and determines
75  * if it is a debug packet or normal packet.
76  *
77  * For non-debug packets, the function chops off unnecessary leading
78  * header bytes, reconstructs the packet as an ethernet frame or
79  * 802.2/llc/snap frame as required, and sends it to kernel/upper layer.
80  *
81  * The completion callback is called after processing in complete.
82  */
mwifiex_process_rx_packet(struct mwifiex_private * priv,struct sk_buff * skb)83 int mwifiex_process_rx_packet(struct mwifiex_private *priv,
84 			      struct sk_buff *skb)
85 {
86 	int ret;
87 	struct rx_packet_hdr *rx_pkt_hdr;
88 	struct rxpd *local_rx_pd;
89 	int hdr_chop;
90 	struct ethhdr *eth;
91 	u16 rx_pkt_off, rx_pkt_len;
92 	u8 *offset;
93 	u8 adj_rx_rate = 0;
94 
95 	local_rx_pd = (struct rxpd *) (skb->data);
96 
97 	rx_pkt_off = le16_to_cpu(local_rx_pd->rx_pkt_offset);
98 	rx_pkt_len = le16_to_cpu(local_rx_pd->rx_pkt_length);
99 	rx_pkt_hdr = (void *)local_rx_pd + rx_pkt_off;
100 
101 	if (sizeof(rx_pkt_hdr->eth803_hdr) + sizeof(rfc1042_header) +
102 	    rx_pkt_off > skb->len) {
103 		mwifiex_dbg(priv->adapter, ERROR,
104 			    "wrong rx packet offset: len=%d, rx_pkt_off=%d\n",
105 			    skb->len, rx_pkt_off);
106 		priv->stats.rx_dropped++;
107 		dev_kfree_skb_any(skb);
108 		return -1;
109 	}
110 
111 	if (sizeof(*rx_pkt_hdr) + rx_pkt_off <= skb->len &&
112 	    ((!memcmp(&rx_pkt_hdr->rfc1042_hdr, bridge_tunnel_header,
113 		      sizeof(bridge_tunnel_header))) ||
114 	     (!memcmp(&rx_pkt_hdr->rfc1042_hdr, rfc1042_header,
115 		      sizeof(rfc1042_header)) &&
116 	      ntohs(rx_pkt_hdr->rfc1042_hdr.snap_type) != ETH_P_AARP &&
117 	      ntohs(rx_pkt_hdr->rfc1042_hdr.snap_type) != ETH_P_IPX))) {
118 		/*
119 		 *  Replace the 803 header and rfc1042 header (llc/snap) with an
120 		 *    EthernetII header, keep the src/dst and snap_type
121 		 *    (ethertype).
122 		 *  The firmware only passes up SNAP frames converting
123 		 *    all RX Data from 802.11 to 802.2/LLC/SNAP frames.
124 		 *  To create the Ethernet II, just move the src, dst address
125 		 *    right before the snap_type.
126 		 */
127 		eth = (struct ethhdr *)
128 			((u8 *) &rx_pkt_hdr->eth803_hdr
129 			 + sizeof(rx_pkt_hdr->eth803_hdr) +
130 			 sizeof(rx_pkt_hdr->rfc1042_hdr)
131 			 - sizeof(rx_pkt_hdr->eth803_hdr.h_dest)
132 			 - sizeof(rx_pkt_hdr->eth803_hdr.h_source)
133 			 - sizeof(rx_pkt_hdr->rfc1042_hdr.snap_type));
134 
135 		memcpy(eth->h_source, rx_pkt_hdr->eth803_hdr.h_source,
136 		       sizeof(eth->h_source));
137 		memcpy(eth->h_dest, rx_pkt_hdr->eth803_hdr.h_dest,
138 		       sizeof(eth->h_dest));
139 
140 		/* Chop off the rxpd + the excess memory from the 802.2/llc/snap
141 		   header that was removed. */
142 		hdr_chop = (u8 *) eth - (u8 *) local_rx_pd;
143 	} else {
144 		/* Chop off the rxpd */
145 		hdr_chop = (u8 *) &rx_pkt_hdr->eth803_hdr -
146 			(u8 *) local_rx_pd;
147 	}
148 
149 	/* Chop off the leading header bytes so the it points to the start of
150 	   either the reconstructed EthII frame or the 802.2/llc/snap frame */
151 	skb_pull(skb, hdr_chop);
152 
153 	if (priv->hs2_enabled &&
154 	    mwifiex_discard_gratuitous_arp(priv, skb)) {
155 		mwifiex_dbg(priv->adapter, INFO, "Bypassed Gratuitous ARP\n");
156 		dev_kfree_skb_any(skb);
157 		return 0;
158 	}
159 
160 	if (ISSUPP_TDLS_ENABLED(priv->adapter->fw_cap_info) &&
161 	    ntohs(rx_pkt_hdr->eth803_hdr.h_proto) == ETH_P_TDLS) {
162 		offset = (u8 *)local_rx_pd + rx_pkt_off;
163 		mwifiex_process_tdls_action_frame(priv, offset, rx_pkt_len);
164 	}
165 
166 	/* Only stash RX bitrate for unicast packets. */
167 	if (likely(!is_multicast_ether_addr(rx_pkt_hdr->eth803_hdr.h_dest))) {
168 		priv->rxpd_rate = local_rx_pd->rx_rate;
169 		priv->rxpd_htinfo = local_rx_pd->ht_info;
170 	}
171 
172 	if (GET_BSS_ROLE(priv) == MWIFIEX_BSS_ROLE_STA ||
173 	    GET_BSS_ROLE(priv) == MWIFIEX_BSS_ROLE_UAP) {
174 		adj_rx_rate = mwifiex_adjust_data_rate(priv,
175 						       local_rx_pd->rx_rate,
176 						       local_rx_pd->ht_info);
177 		mwifiex_hist_data_add(priv, adj_rx_rate, local_rx_pd->snr,
178 				      local_rx_pd->nf);
179 	}
180 
181 	ret = mwifiex_recv_packet(priv, skb);
182 	if (ret == -1)
183 		mwifiex_dbg(priv->adapter, ERROR,
184 			    "recv packet failed\n");
185 
186 	return ret;
187 }
188 
189 /*
190  * This function processes the received buffer.
191  *
192  * The function looks into the RxPD and performs sanity tests on the
193  * received buffer to ensure its a valid packet, before processing it
194  * further. If the packet is determined to be aggregated, it is
195  * de-aggregated accordingly. Non-unicast packets are sent directly to
196  * the kernel/upper layers. Unicast packets are handed over to the
197  * Rx reordering routine if 11n is enabled.
198  *
199  * The completion callback is called after processing in complete.
200  */
mwifiex_process_sta_rx_packet(struct mwifiex_private * priv,struct sk_buff * skb)201 int mwifiex_process_sta_rx_packet(struct mwifiex_private *priv,
202 				  struct sk_buff *skb)
203 {
204 	struct mwifiex_adapter *adapter = priv->adapter;
205 	int ret = 0;
206 	struct rxpd *local_rx_pd;
207 	struct rx_packet_hdr *rx_pkt_hdr;
208 	u8 ta[ETH_ALEN];
209 	u16 rx_pkt_type, rx_pkt_offset, rx_pkt_length, seq_num;
210 	struct mwifiex_sta_node *sta_ptr;
211 
212 	local_rx_pd = (struct rxpd *) (skb->data);
213 	rx_pkt_type = le16_to_cpu(local_rx_pd->rx_pkt_type);
214 	rx_pkt_offset = le16_to_cpu(local_rx_pd->rx_pkt_offset);
215 	rx_pkt_length = le16_to_cpu(local_rx_pd->rx_pkt_length);
216 	seq_num = le16_to_cpu(local_rx_pd->seq_num);
217 
218 	rx_pkt_hdr = (void *)local_rx_pd + rx_pkt_offset;
219 
220 	if ((rx_pkt_offset + rx_pkt_length) > skb->len ||
221 	    sizeof(rx_pkt_hdr->eth803_hdr) + rx_pkt_offset > skb->len) {
222 		mwifiex_dbg(adapter, ERROR,
223 			    "wrong rx packet: len=%d, rx_pkt_offset=%d, rx_pkt_length=%d\n",
224 			    skb->len, rx_pkt_offset, rx_pkt_length);
225 		priv->stats.rx_dropped++;
226 		dev_kfree_skb_any(skb);
227 		return ret;
228 	}
229 
230 	if (rx_pkt_type == PKT_TYPE_MGMT) {
231 		ret = mwifiex_process_mgmt_packet(priv, skb);
232 		if (ret)
233 			mwifiex_dbg(adapter, DATA, "Rx of mgmt packet failed");
234 		dev_kfree_skb_any(skb);
235 		return ret;
236 	}
237 
238 	/*
239 	 * If the packet is not an unicast packet then send the packet
240 	 * directly to os. Don't pass thru rx reordering
241 	 */
242 	if ((!IS_11N_ENABLED(priv) &&
243 	     !(ISSUPP_TDLS_ENABLED(priv->adapter->fw_cap_info) &&
244 	       !(local_rx_pd->flags & MWIFIEX_RXPD_FLAGS_TDLS_PACKET))) ||
245 	    !ether_addr_equal_unaligned(priv->curr_addr, rx_pkt_hdr->eth803_hdr.h_dest)) {
246 		mwifiex_process_rx_packet(priv, skb);
247 		return ret;
248 	}
249 
250 	if (mwifiex_queuing_ra_based(priv) ||
251 	    (ISSUPP_TDLS_ENABLED(priv->adapter->fw_cap_info) &&
252 	     local_rx_pd->flags & MWIFIEX_RXPD_FLAGS_TDLS_PACKET)) {
253 		memcpy(ta, rx_pkt_hdr->eth803_hdr.h_source, ETH_ALEN);
254 		if (local_rx_pd->flags & MWIFIEX_RXPD_FLAGS_TDLS_PACKET &&
255 		    local_rx_pd->priority < MAX_NUM_TID) {
256 			sta_ptr = mwifiex_get_sta_entry(priv, ta);
257 			if (sta_ptr)
258 				sta_ptr->rx_seq[local_rx_pd->priority] =
259 					      le16_to_cpu(local_rx_pd->seq_num);
260 			mwifiex_auto_tdls_update_peer_signal(priv, ta,
261 							     local_rx_pd->snr,
262 							     local_rx_pd->nf);
263 		}
264 	} else {
265 		if (rx_pkt_type != PKT_TYPE_BAR &&
266 		    local_rx_pd->priority < MAX_NUM_TID)
267 			priv->rx_seq[local_rx_pd->priority] = seq_num;
268 		memcpy(ta, priv->curr_bss_params.bss_descriptor.mac_address,
269 		       ETH_ALEN);
270 	}
271 
272 	/* Reorder and send to OS */
273 	ret = mwifiex_11n_rx_reorder_pkt(priv, seq_num, local_rx_pd->priority,
274 					 ta, (u8) rx_pkt_type, skb);
275 
276 	if (ret || (rx_pkt_type == PKT_TYPE_BAR))
277 		dev_kfree_skb_any(skb);
278 
279 	if (ret)
280 		priv->stats.rx_dropped++;
281 
282 	return ret;
283 }
284