1 /*
2  * Marvell Wireless LAN device driver: station RX data handling
3  *
4  * Copyright (C) 2011-2014, Marvell International Ltd.
5  *
6  * This software file (the "File") is distributed by Marvell International
7  * Ltd. 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
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  */
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 ((!memcmp(&rx_pkt_hdr->rfc1042_hdr, bridge_tunnel_header,
102 		     sizeof(bridge_tunnel_header))) ||
103 	    (!memcmp(&rx_pkt_hdr->rfc1042_hdr, rfc1042_header,
104 		     sizeof(rfc1042_header)) &&
105 	     ntohs(rx_pkt_hdr->rfc1042_hdr.snap_type) != ETH_P_AARP &&
106 	     ntohs(rx_pkt_hdr->rfc1042_hdr.snap_type) != ETH_P_IPX)) {
107 		/*
108 		 *  Replace the 803 header and rfc1042 header (llc/snap) with an
109 		 *    EthernetII header, keep the src/dst and snap_type
110 		 *    (ethertype).
111 		 *  The firmware only passes up SNAP frames converting
112 		 *    all RX Data from 802.11 to 802.2/LLC/SNAP frames.
113 		 *  To create the Ethernet II, just move the src, dst address
114 		 *    right before the snap_type.
115 		 */
116 		eth = (struct ethhdr *)
117 			((u8 *) &rx_pkt_hdr->eth803_hdr
118 			 + sizeof(rx_pkt_hdr->eth803_hdr) +
119 			 sizeof(rx_pkt_hdr->rfc1042_hdr)
120 			 - sizeof(rx_pkt_hdr->eth803_hdr.h_dest)
121 			 - sizeof(rx_pkt_hdr->eth803_hdr.h_source)
122 			 - sizeof(rx_pkt_hdr->rfc1042_hdr.snap_type));
123 
124 		memcpy(eth->h_source, rx_pkt_hdr->eth803_hdr.h_source,
125 		       sizeof(eth->h_source));
126 		memcpy(eth->h_dest, rx_pkt_hdr->eth803_hdr.h_dest,
127 		       sizeof(eth->h_dest));
128 
129 		/* Chop off the rxpd + the excess memory from the 802.2/llc/snap
130 		   header that was removed. */
131 		hdr_chop = (u8 *) eth - (u8 *) local_rx_pd;
132 	} else {
133 		/* Chop off the rxpd */
134 		hdr_chop = (u8 *) &rx_pkt_hdr->eth803_hdr -
135 			(u8 *) local_rx_pd;
136 	}
137 
138 	/* Chop off the leading header bytes so the it points to the start of
139 	   either the reconstructed EthII frame or the 802.2/llc/snap frame */
140 	skb_pull(skb, hdr_chop);
141 
142 	if (priv->hs2_enabled &&
143 	    mwifiex_discard_gratuitous_arp(priv, skb)) {
144 		mwifiex_dbg(priv->adapter, INFO, "Bypassed Gratuitous ARP\n");
145 		dev_kfree_skb_any(skb);
146 		return 0;
147 	}
148 
149 	if (ISSUPP_TDLS_ENABLED(priv->adapter->fw_cap_info) &&
150 	    ntohs(rx_pkt_hdr->eth803_hdr.h_proto) == ETH_P_TDLS) {
151 		offset = (u8 *)local_rx_pd + rx_pkt_off;
152 		mwifiex_process_tdls_action_frame(priv, offset, rx_pkt_len);
153 	}
154 
155 	priv->rxpd_rate = local_rx_pd->rx_rate;
156 
157 	priv->rxpd_htinfo = local_rx_pd->ht_info;
158 
159 	if (GET_BSS_ROLE(priv) == MWIFIEX_BSS_ROLE_STA ||
160 	    GET_BSS_ROLE(priv) == MWIFIEX_BSS_ROLE_UAP) {
161 		adj_rx_rate = mwifiex_adjust_data_rate(priv, priv->rxpd_rate,
162 						       priv->rxpd_htinfo);
163 		mwifiex_hist_data_add(priv, adj_rx_rate, local_rx_pd->snr,
164 				      local_rx_pd->nf);
165 	}
166 
167 	ret = mwifiex_recv_packet(priv, skb);
168 	if (ret == -1)
169 		mwifiex_dbg(priv->adapter, ERROR,
170 			    "recv packet failed\n");
171 
172 	return ret;
173 }
174 
175 /*
176  * This function processes the received buffer.
177  *
178  * The function looks into the RxPD and performs sanity tests on the
179  * received buffer to ensure its a valid packet, before processing it
180  * further. If the packet is determined to be aggregated, it is
181  * de-aggregated accordingly. Non-unicast packets are sent directly to
182  * the kernel/upper layers. Unicast packets are handed over to the
183  * Rx reordering routine if 11n is enabled.
184  *
185  * The completion callback is called after processing in complete.
186  */
187 int mwifiex_process_sta_rx_packet(struct mwifiex_private *priv,
188 				  struct sk_buff *skb)
189 {
190 	struct mwifiex_adapter *adapter = priv->adapter;
191 	int ret = 0;
192 	struct rxpd *local_rx_pd;
193 	struct rx_packet_hdr *rx_pkt_hdr;
194 	u8 ta[ETH_ALEN];
195 	u16 rx_pkt_type, rx_pkt_offset, rx_pkt_length, seq_num;
196 	struct mwifiex_sta_node *sta_ptr;
197 
198 	local_rx_pd = (struct rxpd *) (skb->data);
199 	rx_pkt_type = le16_to_cpu(local_rx_pd->rx_pkt_type);
200 	rx_pkt_offset = le16_to_cpu(local_rx_pd->rx_pkt_offset);
201 	rx_pkt_length = le16_to_cpu(local_rx_pd->rx_pkt_length);
202 	seq_num = le16_to_cpu(local_rx_pd->seq_num);
203 
204 	rx_pkt_hdr = (void *)local_rx_pd + rx_pkt_offset;
205 
206 	if ((rx_pkt_offset + rx_pkt_length) > (u16) skb->len) {
207 		mwifiex_dbg(adapter, ERROR,
208 			    "wrong rx packet: len=%d, rx_pkt_offset=%d, rx_pkt_length=%d\n",
209 			    skb->len, rx_pkt_offset, rx_pkt_length);
210 		priv->stats.rx_dropped++;
211 		dev_kfree_skb_any(skb);
212 		return ret;
213 	}
214 
215 	if (rx_pkt_type == PKT_TYPE_MGMT) {
216 		ret = mwifiex_process_mgmt_packet(priv, skb);
217 		if (ret)
218 			mwifiex_dbg(adapter, DATA, "Rx of mgmt packet failed");
219 		dev_kfree_skb_any(skb);
220 		return ret;
221 	}
222 
223 	/*
224 	 * If the packet is not an unicast packet then send the packet
225 	 * directly to os. Don't pass thru rx reordering
226 	 */
227 	if ((!IS_11N_ENABLED(priv) &&
228 	     !(ISSUPP_TDLS_ENABLED(priv->adapter->fw_cap_info) &&
229 	       !(local_rx_pd->flags & MWIFIEX_RXPD_FLAGS_TDLS_PACKET))) ||
230 	    !ether_addr_equal_unaligned(priv->curr_addr, rx_pkt_hdr->eth803_hdr.h_dest)) {
231 		mwifiex_process_rx_packet(priv, skb);
232 		return ret;
233 	}
234 
235 	if (mwifiex_queuing_ra_based(priv) ||
236 	    (ISSUPP_TDLS_ENABLED(priv->adapter->fw_cap_info) &&
237 	     local_rx_pd->flags & MWIFIEX_RXPD_FLAGS_TDLS_PACKET)) {
238 		memcpy(ta, rx_pkt_hdr->eth803_hdr.h_source, ETH_ALEN);
239 		if (local_rx_pd->flags & MWIFIEX_RXPD_FLAGS_TDLS_PACKET &&
240 		    local_rx_pd->priority < MAX_NUM_TID) {
241 			sta_ptr = mwifiex_get_sta_entry(priv, ta);
242 			if (sta_ptr)
243 				sta_ptr->rx_seq[local_rx_pd->priority] =
244 					      le16_to_cpu(local_rx_pd->seq_num);
245 			mwifiex_auto_tdls_update_peer_signal(priv, ta,
246 							     local_rx_pd->snr,
247 							     local_rx_pd->nf);
248 		}
249 	} else {
250 		if (rx_pkt_type != PKT_TYPE_BAR)
251 			priv->rx_seq[local_rx_pd->priority] = seq_num;
252 		memcpy(ta, priv->curr_bss_params.bss_descriptor.mac_address,
253 		       ETH_ALEN);
254 	}
255 
256 	/* Reorder and send to OS */
257 	ret = mwifiex_11n_rx_reorder_pkt(priv, seq_num, local_rx_pd->priority,
258 					 ta, (u8) rx_pkt_type, skb);
259 
260 	if (ret || (rx_pkt_type == PKT_TYPE_BAR))
261 		dev_kfree_skb_any(skb);
262 
263 	if (ret)
264 		priv->stats.rx_dropped++;
265 
266 	return ret;
267 }
268