xref: /freebsd/sys/net80211/ieee80211_input.h (revision 0957b409a90fd597c1e9124cbaf3edd2b488f4ac)
1 /*-
2  * SPDX-License-Identifier: BSD-2-Clause-FreeBSD
3  *
4  * Copyright (c) 2007-2009 Sam Leffler, Errno Consulting
5  * All rights reserved.
6  *
7  * Redistribution and use in source and binary forms, with or without
8  * modification, are permitted provided that the following conditions
9  * are met:
10  * 1. Redistributions of source code must retain the above copyright
11  *    notice, this list of conditions and the following disclaimer.
12  * 2. Redistributions in binary form must reproduce the above copyright
13  *    notice, this list of conditions and the following disclaimer in the
14  *    documentation and/or other materials provided with the distribution.
15  *
16  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
17  * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
18  * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
19  * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
20  * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
21  * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
22  * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
23  * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
24  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
25  * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
26  *
27  * $FreeBSD$
28  */
29 #ifndef _NET80211_IEEE80211_INPUT_H_
30 #define _NET80211_IEEE80211_INPUT_H_
31 
32 /* Verify the existence and length of __elem or get out. */
33 #define IEEE80211_VERIFY_ELEMENT(__elem, __maxlen, _action) do {	\
34 	if ((__elem) == NULL) {						\
35 		IEEE80211_DISCARD(vap, IEEE80211_MSG_ELEMID,		\
36 		    wh, NULL, "%s", "no " #__elem );			\
37 		vap->iv_stats.is_rx_elem_missing++;			\
38 		_action;						\
39 	} else if ((__elem)[1] > (__maxlen)) {				\
40 		IEEE80211_DISCARD(vap, IEEE80211_MSG_ELEMID,		\
41 		    wh, NULL, "bad " #__elem " len %d", (__elem)[1]);	\
42 		vap->iv_stats.is_rx_elem_toobig++;			\
43 		_action;						\
44 	}								\
45 } while (0)
46 
47 #define	IEEE80211_VERIFY_LENGTH(_len, _minlen, _action) do {		\
48 	if ((_len) < (_minlen)) {					\
49 		IEEE80211_DISCARD(vap, IEEE80211_MSG_ELEMID,		\
50 		    wh, NULL, "ie too short, got %d, expected %d",	\
51 		    (_len), (_minlen));					\
52 		vap->iv_stats.is_rx_elem_toosmall++;			\
53 		_action;						\
54 	}								\
55 } while (0)
56 
57 #ifdef IEEE80211_DEBUG
58 void	ieee80211_ssid_mismatch(struct ieee80211vap *, const char *tag,
59 	uint8_t mac[IEEE80211_ADDR_LEN], uint8_t *ssid);
60 
61 #define	IEEE80211_VERIFY_SSID(_ni, _ssid, _action) do {			\
62 	if ((_ssid)[1] != 0 &&						\
63 	    ((_ssid)[1] != (_ni)->ni_esslen ||				\
64 	    memcmp((_ssid) + 2, (_ni)->ni_essid, (_ssid)[1]) != 0)) {	\
65 		if (ieee80211_msg_input(vap))				\
66 			ieee80211_ssid_mismatch(vap, 			\
67 			    ieee80211_mgt_subtype_name(subtype),	\
68 				wh->i_addr2, _ssid);			\
69 		vap->iv_stats.is_rx_ssidmismatch++;			\
70 		_action;						\
71 	}								\
72 } while (0)
73 #else /* !IEEE80211_DEBUG */
74 #define	IEEE80211_VERIFY_SSID(_ni, _ssid, _action) do {			\
75 	if ((_ssid)[1] != 0 &&						\
76 	    ((_ssid)[1] != (_ni)->ni_esslen ||				\
77 	    memcmp((_ssid) + 2, (_ni)->ni_essid, (_ssid)[1]) != 0)) {	\
78 		vap->iv_stats.is_rx_ssidmismatch++;			\
79 		_action;						\
80 	}								\
81 } while (0)
82 #endif /* !IEEE80211_DEBUG */
83 
84 #include <sys/endian.h>		/* For le16toh() / le32dec() */
85 
86 static __inline int
87 iswpaoui(const uint8_t *frm)
88 {
89 	return frm[1] > 3 && le32dec(frm+2) == ((WPA_OUI_TYPE<<24)|WPA_OUI);
90 }
91 
92 static __inline int
93 iswmeoui(const uint8_t *frm)
94 {
95 	return frm[1] > 3 && le32dec(frm+2) == ((WME_OUI_TYPE<<24)|WME_OUI);
96 }
97 
98 static __inline int
99 iswmeparam(const uint8_t *frm)
100 {
101 	return frm[1] > 5 && le32dec(frm+2) == ((WME_OUI_TYPE<<24)|WME_OUI) &&
102 		frm[6] == WME_PARAM_OUI_SUBTYPE;
103 }
104 
105 static __inline int
106 iswmeinfo(const uint8_t *frm)
107 {
108 	return frm[1] > 5 && le32dec(frm+2) == ((WME_OUI_TYPE<<24)|WME_OUI) &&
109 		frm[6] == WME_INFO_OUI_SUBTYPE;
110 }
111 
112 static __inline int
113 isatherosoui(const uint8_t *frm)
114 {
115 	return frm[1] > 3 && le32dec(frm+2) == ((ATH_OUI_TYPE<<24)|ATH_OUI);
116 }
117 
118 static __inline int
119 istdmaoui(const uint8_t *frm)
120 {
121 	return frm[1] > 3 && le32dec(frm+2) == ((TDMA_OUI_TYPE<<24)|TDMA_OUI);
122 }
123 
124 static __inline int
125 ishtcapoui(const uint8_t *frm)
126 {
127 	return frm[1] > 3 && le32dec(frm+2) == ((BCM_OUI_HTCAP<<24)|BCM_OUI);
128 }
129 
130 static __inline int
131 ishtinfooui(const uint8_t *frm)
132 {
133 	return frm[1] > 3 && le32dec(frm+2) == ((BCM_OUI_HTINFO<<24)|BCM_OUI);
134 }
135 
136 static __inline int
137 ieee80211_check_rxseq_amsdu(const struct ieee80211_rx_stats *rxs)
138 {
139 
140 	return (!! (rxs->c_pktflags & IEEE80211_RX_F_AMSDU));
141 }
142 
143 /*
144  * Return 1 if the rxseq check should increment the sequence
145  * number. Return 0 if it's part of an AMSDU batch and it isn't
146  * the final frame in the decap'ed burst.
147  */
148 static __inline int
149 ieee80211_check_rxseq_amsdu_more(const struct ieee80211_rx_stats *rxs)
150 {
151 	/* No state? ok */
152 	if (rxs == NULL)
153 		return (1);
154 
155 	/* State but no AMSDU set? ok */
156 	if ((rxs->c_pktflags & IEEE80211_RX_F_AMSDU) == 0)
157 		return (1);
158 
159 	/* State, AMSDU set, then _MORE means "don't inc yet" */
160 	if (rxs->c_pktflags & IEEE80211_RX_F_AMSDU_MORE) {
161 		return (0);
162 	}
163 
164 	/* Both are set, so return ok */
165 	return (1);
166 }
167 
168 /*
169  * Check the current frame sequence number against the current TID
170  * state and return whether it's in sequence or should be dropped.
171  *
172  * Since out of order packet and duplicate packet eliminations should
173  * be done by the AMPDU RX code, this routine blindly accepts all
174  * frames from a HT station w/ a TID that is currently doing AMPDU-RX.
175  * HT stations without WME or where the TID is not doing AMPDU-RX
176  * are checked like non-HT stations.
177  *
178  * The routine only eliminates packets whose sequence/fragment
179  * match or are less than the last seen sequence/fragment number
180  * AND are retransmits It doesn't try to eliminate out of order packets.
181  *
182  * Since all frames after sequence number 4095 will be less than 4095
183  * (as the seqnum wraps), handle that special case so packets aren't
184  * incorrectly dropped - ie, if the next packet is sequence number 0
185  * but a retransmit since the initial packet didn't make it.
186  *
187  * XXX TODO: handle sequence number space wrapping with dropped frames;
188  * especially in high interference conditions under high traffic load
189  * The RX AMPDU reorder code also needs it.
190  *
191  * XXX TODO: update for 802.11-2012 9.3.2.10 Duplicate Detection and Recovery.
192  */
193 static __inline int
194 ieee80211_check_rxseq(struct ieee80211_node *ni, struct ieee80211_frame *wh,
195     uint8_t *bssid, const struct ieee80211_rx_stats *rxs)
196 {
197 #define	SEQ_LEQ(a,b)	((int)((a)-(b)) <= 0)
198 #define	SEQ_EQ(a,b)	((int)((a)-(b)) == 0)
199 #define	SEQNO(a)	((a) >> IEEE80211_SEQ_SEQ_SHIFT)
200 #define	FRAGNO(a)	((a) & IEEE80211_SEQ_FRAG_MASK)
201 	struct ieee80211vap *vap = ni->ni_vap;
202 	uint16_t rxseq;
203 	uint8_t type, subtype;
204 	uint8_t tid;
205 	struct ieee80211_rx_ampdu *rap;
206 
207 	rxseq = le16toh(*(uint16_t *)wh->i_seq);
208 	type = wh->i_fc[0] & IEEE80211_FC0_TYPE_MASK;
209 	subtype = wh->i_fc[0] & IEEE80211_FC0_SUBTYPE_MASK;
210 
211 	/*
212 	 * Types with no sequence number (or QoS (+)Null frames)
213 	 * are always treated valid.
214 	 */
215 	if (! IEEE80211_HAS_SEQ(type, subtype))
216 		return 1;
217 
218 	/*
219 	 * Always allow multicast frames for now - QoS (any TID)
220 	 * or not.
221 	 */
222 	if (IEEE80211_IS_MULTICAST(wh->i_addr1))
223 		return 1;
224 
225 	tid = ieee80211_gettid(wh);
226 
227 	/*
228 	 * Only do the HT AMPDU check for WME stations; non-WME HT stations
229 	 * shouldn't exist outside of debugging. We should at least
230 	 * handle that.
231 	 */
232 	if (tid < WME_NUM_TID) {
233 		rap = &ni->ni_rx_ampdu[tid];
234 		/* HT nodes currently doing RX AMPDU are always valid */
235 		if ((ni->ni_flags & IEEE80211_NODE_HT) &&
236 		    (rap->rxa_flags & IEEE80211_AGGR_RUNNING))
237 			goto ok;
238 	}
239 
240 	/*
241 	 * Otherwise, retries for packets below or equal to the last
242 	 * seen sequence number should be dropped.
243 	 */
244 
245 	/*
246 	 * Treat frame seqnum 4095 as special due to boundary
247 	 * wrapping conditions.
248 	 */
249 	if (SEQNO(ni->ni_rxseqs[tid]) == 4095) {
250 		/*
251 		 * Drop retransmits on seqnum 4095/current fragment for itself.
252 		 */
253 		if (SEQ_EQ(rxseq, ni->ni_rxseqs[tid]) &&
254 		    (wh->i_fc[1] & IEEE80211_FC1_RETRY))
255 			goto fail;
256 		/*
257 		 * Treat any subsequent frame as fine if the last seen frame
258 		 * is 4095 and it's not a retransmit for the same sequence
259 		 * number. However, this doesn't capture incorrectly ordered
260 	 	 * fragments w/ sequence number 4095. It shouldn't be seen
261 		 * in practice, but see the comment above for further info.
262 		 */
263 		goto ok;
264 	}
265 
266 	/*
267 	 * At this point we assume that retransmitted seq/frag numbers below
268 	 * the current can simply be eliminated.
269 	 */
270 	if ((wh->i_fc[1] & IEEE80211_FC1_RETRY) &&
271 	    SEQ_LEQ(rxseq, ni->ni_rxseqs[tid]))
272 		goto fail;
273 
274 ok:
275 	/*
276 	 * Only bump the sequence number if it's the last frame
277 	 * in a batch.  That way frames in the rest of the batch
278 	 * get included, and the last frame in the batch kicks
279 	 * it next.
280 	 */
281 	if (ieee80211_check_rxseq_amsdu_more(rxs)) {
282 		ni->ni_rxseqs[tid] = rxseq;
283 		if ((rxs != NULL) && ieee80211_check_rxseq_amsdu(rxs))
284 			IEEE80211_NODE_STAT(ni, rx_amsdu_more_end);
285 	} else {
286 		/* .. still waiting */
287 		IEEE80211_NODE_STAT(ni, rx_amsdu_more);
288 	}
289 
290 	return 1;
291 
292 fail:
293 	/* duplicate, discard */
294 	IEEE80211_DISCARD_MAC(vap, IEEE80211_MSG_INPUT, bssid, "duplicate",
295 	    "seqno <%u,%u> fragno <%u,%u> tid %u",
296 	     SEQNO(rxseq),  SEQNO(ni->ni_rxseqs[tid]),
297 	    FRAGNO(rxseq), FRAGNO(ni->ni_rxseqs[tid]), tid);
298 	vap->iv_stats.is_rx_dup++;
299 	IEEE80211_NODE_STAT(ni, rx_dup);
300 
301 	return 0;
302 #undef	SEQ_LEQ
303 #undef	SEQ_EQ
304 #undef	SEQNO
305 #undef	FRAGNO
306 }
307 
308 void	ieee80211_deliver_data(struct ieee80211vap *,
309 		struct ieee80211_node *, struct mbuf *);
310 struct mbuf *ieee80211_defrag(struct ieee80211_node *,
311 		struct mbuf *, int);
312 struct mbuf *ieee80211_realign(struct ieee80211vap *, struct mbuf *, size_t);
313 struct mbuf *ieee80211_decap(struct ieee80211vap *, struct mbuf *, int);
314 struct mbuf *ieee80211_decap1(struct mbuf *, int *);
315 int	ieee80211_setup_rates(struct ieee80211_node *ni,
316 		const uint8_t *rates, const uint8_t *xrates, int flags);
317 void ieee80211_send_error(struct ieee80211_node *,
318 		const uint8_t mac[IEEE80211_ADDR_LEN], int subtype, int arg);
319 int	ieee80211_alloc_challenge(struct ieee80211_node *);
320 int	ieee80211_parse_beacon(struct ieee80211_node *, struct mbuf *,
321 		struct ieee80211_channel *,
322 		struct ieee80211_scanparams *);
323 int	ieee80211_parse_action(struct ieee80211_node *, struct mbuf *);
324 #endif /* _NET80211_IEEE80211_INPUT_H_ */
325