1// SPDX-License-Identifier: GPL-2.0-only
2/*
3 * NXP Wireless LAN device driver: station RX data handling
4 *
5 * Copyright 2011-2020 NXP
6 */
7
8#include <uapi/linux/ipv6.h>
9#include <net/ndisc.h>
10#include "decl.h"
11#include "ioctl.h"
12#include "util.h"
13#include "fw.h"
14#include "main.h"
15#include "11n_aggr.h"
16#include "11n_rxreorder.h"
17
18/* This function checks if a frame is IPv4 ARP or IPv6 Neighbour advertisement
19 * frame. If frame has both source and destination mac address as same, this
20 * function drops such gratuitous frames.
21 */
22static bool
23mwifiex_discard_gratuitous_arp(struct mwifiex_private *priv,
24			       struct sk_buff *skb)
25{
26	const struct mwifiex_arp_eth_header *arp;
27	struct ethhdr *eth;
28	struct ipv6hdr *ipv6;
29	struct icmp6hdr *icmpv6;
30
31	eth = (struct ethhdr *)skb->data;
32	switch (ntohs(eth->h_proto)) {
33	case ETH_P_ARP:
34		arp = (void *)(skb->data + sizeof(struct ethhdr));
35		if (arp->hdr.ar_op == htons(ARPOP_REPLY) ||
36		    arp->hdr.ar_op == htons(ARPOP_REQUEST)) {
37			if (!memcmp(arp->ar_sip, arp->ar_tip, 4))
38				return true;
39		}
40		break;
41	case ETH_P_IPV6:
42		ipv6 = (void *)(skb->data + sizeof(struct ethhdr));
43		icmpv6 = (void *)(skb->data + sizeof(struct ethhdr) +
44				  sizeof(struct ipv6hdr));
45		if (NDISC_NEIGHBOUR_ADVERTISEMENT == icmpv6->icmp6_type) {
46			if (!memcmp(&ipv6->saddr, &ipv6->daddr,
47				    sizeof(struct in6_addr)))
48				return true;
49		}
50		break;
51	default:
52		break;
53	}
54
55	return false;
56}
57
58/*
59 * This function processes the received packet and forwards it
60 * to kernel/upper layer.
61 *
62 * This function parses through the received packet and determines
63 * if it is a debug packet or normal packet.
64 *
65 * For non-debug packets, the function chops off unnecessary leading
66 * header bytes, reconstructs the packet as an ethernet frame or
67 * 802.2/llc/snap frame as required, and sends it to kernel/upper layer.
68 *
69 * The completion callback is called after processing in complete.
70 */
71int mwifiex_process_rx_packet(struct mwifiex_private *priv,
72			      struct sk_buff *skb)
73{
74	int ret;
75	struct rx_packet_hdr *rx_pkt_hdr;
76	struct rxpd *local_rx_pd;
77	int hdr_chop;
78	struct ethhdr *eth;
79	u16 rx_pkt_off, rx_pkt_len;
80	u8 *offset;
81	u8 adj_rx_rate = 0;
82
83	local_rx_pd = (struct rxpd *) (skb->data);
84
85	rx_pkt_off = le16_to_cpu(local_rx_pd->rx_pkt_offset);
86	rx_pkt_len = le16_to_cpu(local_rx_pd->rx_pkt_length);
87	rx_pkt_hdr = (void *)local_rx_pd + rx_pkt_off;
88
89	if (sizeof(rx_pkt_hdr->eth803_hdr) + sizeof(rfc1042_header) +
90	    rx_pkt_off > skb->len) {
91		mwifiex_dbg(priv->adapter, ERROR,
92			    "wrong rx packet offset: len=%d, rx_pkt_off=%d\n",
93			    skb->len, rx_pkt_off);
94		priv->stats.rx_dropped++;
95		dev_kfree_skb_any(skb);
96		return -1;
97	}
98
99	if (sizeof(*rx_pkt_hdr) + rx_pkt_off <= skb->len &&
100	    ((!memcmp(&rx_pkt_hdr->rfc1042_hdr, bridge_tunnel_header,
101		      sizeof(bridge_tunnel_header))) ||
102	     (!memcmp(&rx_pkt_hdr->rfc1042_hdr, rfc1042_header,
103		      sizeof(rfc1042_header)) &&
104	      ntohs(rx_pkt_hdr->rfc1042_hdr.snap_type) != ETH_P_AARP &&
105	      ntohs(rx_pkt_hdr->rfc1042_hdr.snap_type) != ETH_P_IPX))) {
106		/*
107		 *  Replace the 803 header and rfc1042 header (llc/snap) with an
108		 *    EthernetII header, keep the src/dst and snap_type
109		 *    (ethertype).
110		 *  The firmware only passes up SNAP frames converting
111		 *    all RX Data from 802.11 to 802.2/LLC/SNAP frames.
112		 *  To create the Ethernet II, just move the src, dst address
113		 *    right before the snap_type.
114		 */
115		eth = (struct ethhdr *)
116			((u8 *) &rx_pkt_hdr->eth803_hdr
117			 + sizeof(rx_pkt_hdr->eth803_hdr) +
118			 sizeof(rx_pkt_hdr->rfc1042_hdr)
119			 - sizeof(rx_pkt_hdr->eth803_hdr.h_dest)
120			 - sizeof(rx_pkt_hdr->eth803_hdr.h_source)
121			 - sizeof(rx_pkt_hdr->rfc1042_hdr.snap_type));
122
123		memcpy(eth->h_source, rx_pkt_hdr->eth803_hdr.h_source,
124		       sizeof(eth->h_source));
125		memcpy(eth->h_dest, rx_pkt_hdr->eth803_hdr.h_dest,
126		       sizeof(eth->h_dest));
127
128		/* Chop off the rxpd + the excess memory from the 802.2/llc/snap
129		   header that was removed. */
130		hdr_chop = (u8 *) eth - (u8 *) local_rx_pd;
131	} else {
132		/* Chop off the rxpd */
133		hdr_chop = (u8 *) &rx_pkt_hdr->eth803_hdr -
134			(u8 *) local_rx_pd;
135	}
136
137	/* Chop off the leading header bytes so the it points to the start of
138	   either the reconstructed EthII frame or the 802.2/llc/snap frame */
139	skb_pull(skb, hdr_chop);
140
141	if (priv->hs2_enabled &&
142	    mwifiex_discard_gratuitous_arp(priv, skb)) {
143		mwifiex_dbg(priv->adapter, INFO, "Bypassed Gratuitous ARP\n");
144		dev_kfree_skb_any(skb);
145		return 0;
146	}
147
148	if (ISSUPP_TDLS_ENABLED(priv->adapter->fw_cap_info) &&
149	    ntohs(rx_pkt_hdr->eth803_hdr.h_proto) == ETH_P_TDLS) {
150		offset = (u8 *)local_rx_pd + rx_pkt_off;
151		mwifiex_process_tdls_action_frame(priv, offset, rx_pkt_len);
152	}
153
154	/* Only stash RX bitrate for unicast packets. */
155	if (likely(!is_multicast_ether_addr(rx_pkt_hdr->eth803_hdr.h_dest))) {
156		priv->rxpd_rate = local_rx_pd->rx_rate;
157		priv->rxpd_htinfo = local_rx_pd->ht_info;
158	}
159
160	if (GET_BSS_ROLE(priv) == MWIFIEX_BSS_ROLE_STA ||
161	    GET_BSS_ROLE(priv) == MWIFIEX_BSS_ROLE_UAP) {
162		adj_rx_rate = mwifiex_adjust_data_rate(priv,
163						       local_rx_pd->rx_rate,
164						       local_rx_pd->ht_info);
165		mwifiex_hist_data_add(priv, adj_rx_rate, local_rx_pd->snr,
166				      local_rx_pd->nf);
167	}
168
169	ret = mwifiex_recv_packet(priv, skb);
170	if (ret == -1)
171		mwifiex_dbg(priv->adapter, ERROR,
172			    "recv packet failed\n");
173
174	return ret;
175}
176
177/*
178 * This function processes the received buffer.
179 *
180 * The function looks into the RxPD and performs sanity tests on the
181 * received buffer to ensure its a valid packet, before processing it
182 * further. If the packet is determined to be aggregated, it is
183 * de-aggregated accordingly. Non-unicast packets are sent directly to
184 * the kernel/upper layers. Unicast packets are handed over to the
185 * Rx reordering routine if 11n is enabled.
186 *
187 * The completion callback is called after processing in complete.
188 */
189int mwifiex_process_sta_rx_packet(struct mwifiex_private *priv,
190				  struct sk_buff *skb)
191{
192	struct mwifiex_adapter *adapter = priv->adapter;
193	int ret = 0;
194	struct rxpd *local_rx_pd;
195	struct rx_packet_hdr *rx_pkt_hdr;
196	u8 ta[ETH_ALEN];
197	u16 rx_pkt_type, rx_pkt_offset, rx_pkt_length, seq_num;
198	struct mwifiex_sta_node *sta_ptr;
199
200	local_rx_pd = (struct rxpd *) (skb->data);
201	rx_pkt_type = le16_to_cpu(local_rx_pd->rx_pkt_type);
202	rx_pkt_offset = le16_to_cpu(local_rx_pd->rx_pkt_offset);
203	rx_pkt_length = le16_to_cpu(local_rx_pd->rx_pkt_length);
204	seq_num = le16_to_cpu(local_rx_pd->seq_num);
205
206	rx_pkt_hdr = (void *)local_rx_pd + rx_pkt_offset;
207
208	if ((rx_pkt_offset + rx_pkt_length) > skb->len ||
209	    sizeof(rx_pkt_hdr->eth803_hdr) + rx_pkt_offset > skb->len) {
210		mwifiex_dbg(adapter, ERROR,
211			    "wrong rx packet: len=%d, rx_pkt_offset=%d, rx_pkt_length=%d\n",
212			    skb->len, rx_pkt_offset, rx_pkt_length);
213		priv->stats.rx_dropped++;
214		dev_kfree_skb_any(skb);
215		return ret;
216	}
217
218	if (rx_pkt_type == PKT_TYPE_MGMT) {
219		ret = mwifiex_process_mgmt_packet(priv, skb);
220		if (ret)
221			mwifiex_dbg(adapter, DATA, "Rx of mgmt packet failed");
222		dev_kfree_skb_any(skb);
223		return ret;
224	}
225
226	/*
227	 * If the packet is not an unicast packet then send the packet
228	 * directly to os. Don't pass thru rx reordering
229	 */
230	if ((!IS_11N_ENABLED(priv) &&
231	     !(ISSUPP_TDLS_ENABLED(priv->adapter->fw_cap_info) &&
232	       !(local_rx_pd->flags & MWIFIEX_RXPD_FLAGS_TDLS_PACKET))) ||
233	    !ether_addr_equal_unaligned(priv->curr_addr, rx_pkt_hdr->eth803_hdr.h_dest)) {
234		mwifiex_process_rx_packet(priv, skb);
235		return ret;
236	}
237
238	if (mwifiex_queuing_ra_based(priv) ||
239	    (ISSUPP_TDLS_ENABLED(priv->adapter->fw_cap_info) &&
240	     local_rx_pd->flags & MWIFIEX_RXPD_FLAGS_TDLS_PACKET)) {
241		memcpy(ta, rx_pkt_hdr->eth803_hdr.h_source, ETH_ALEN);
242		if (local_rx_pd->flags & MWIFIEX_RXPD_FLAGS_TDLS_PACKET &&
243		    local_rx_pd->priority < MAX_NUM_TID) {
244			sta_ptr = mwifiex_get_sta_entry(priv, ta);
245			if (sta_ptr)
246				sta_ptr->rx_seq[local_rx_pd->priority] =
247					      le16_to_cpu(local_rx_pd->seq_num);
248			mwifiex_auto_tdls_update_peer_signal(priv, ta,
249							     local_rx_pd->snr,
250							     local_rx_pd->nf);
251		}
252	} else {
253		if (rx_pkt_type != PKT_TYPE_BAR &&
254		    local_rx_pd->priority < MAX_NUM_TID)
255			priv->rx_seq[local_rx_pd->priority] = seq_num;
256		memcpy(ta, priv->curr_bss_params.bss_descriptor.mac_address,
257		       ETH_ALEN);
258	}
259
260	/* Reorder and send to OS */
261	ret = mwifiex_11n_rx_reorder_pkt(priv, seq_num, local_rx_pd->priority,
262					 ta, (u8) rx_pkt_type, skb);
263
264	if (ret || (rx_pkt_type == PKT_TYPE_BAR))
265		dev_kfree_skb_any(skb);
266
267	if (ret)
268		priv->stats.rx_dropped++;
269
270	return ret;
271}
272