xref: /freebsd/sys/net80211/ieee80211_input.h (revision 3416500aef140042c64bc149cb1ec6620483bc44)
1 /*-
2  * Copyright (c) 2007-2009 Sam Leffler, Errno Consulting
3  * All rights reserved.
4  *
5  * Redistribution and use in source and binary forms, with or without
6  * modification, are permitted provided that the following conditions
7  * are met:
8  * 1. Redistributions of source code must retain the above copyright
9  *    notice, this list of conditions and the following disclaimer.
10  * 2. Redistributions in binary form must reproduce the above copyright
11  *    notice, this list of conditions and the following disclaimer in the
12  *    documentation and/or other materials provided with the distribution.
13  *
14  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
15  * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
16  * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
17  * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
18  * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
19  * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
20  * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
21  * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
22  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
23  * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
24  *
25  * $FreeBSD$
26  */
27 #ifndef _NET80211_IEEE80211_INPUT_H_
28 #define _NET80211_IEEE80211_INPUT_H_
29 
30 /* Verify the existence and length of __elem or get out. */
31 #define IEEE80211_VERIFY_ELEMENT(__elem, __maxlen, _action) do {	\
32 	if ((__elem) == NULL) {						\
33 		IEEE80211_DISCARD(vap, IEEE80211_MSG_ELEMID,		\
34 		    wh, NULL, "%s", "no " #__elem );			\
35 		vap->iv_stats.is_rx_elem_missing++;			\
36 		_action;						\
37 	} else if ((__elem)[1] > (__maxlen)) {				\
38 		IEEE80211_DISCARD(vap, IEEE80211_MSG_ELEMID,		\
39 		    wh, NULL, "bad " #__elem " len %d", (__elem)[1]);	\
40 		vap->iv_stats.is_rx_elem_toobig++;			\
41 		_action;						\
42 	}								\
43 } while (0)
44 
45 #define	IEEE80211_VERIFY_LENGTH(_len, _minlen, _action) do {		\
46 	if ((_len) < (_minlen)) {					\
47 		IEEE80211_DISCARD(vap, IEEE80211_MSG_ELEMID,		\
48 		    wh, NULL, "ie too short, got %d, expected %d",	\
49 		    (_len), (_minlen));					\
50 		vap->iv_stats.is_rx_elem_toosmall++;			\
51 		_action;						\
52 	}								\
53 } while (0)
54 
55 #ifdef IEEE80211_DEBUG
56 void	ieee80211_ssid_mismatch(struct ieee80211vap *, const char *tag,
57 	uint8_t mac[IEEE80211_ADDR_LEN], uint8_t *ssid);
58 
59 #define	IEEE80211_VERIFY_SSID(_ni, _ssid, _action) do {			\
60 	if ((_ssid)[1] != 0 &&						\
61 	    ((_ssid)[1] != (_ni)->ni_esslen ||				\
62 	    memcmp((_ssid) + 2, (_ni)->ni_essid, (_ssid)[1]) != 0)) {	\
63 		if (ieee80211_msg_input(vap))				\
64 			ieee80211_ssid_mismatch(vap, 			\
65 			    ieee80211_mgt_subtype_name(subtype),	\
66 				wh->i_addr2, _ssid);			\
67 		vap->iv_stats.is_rx_ssidmismatch++;			\
68 		_action;						\
69 	}								\
70 } while (0)
71 #else /* !IEEE80211_DEBUG */
72 #define	IEEE80211_VERIFY_SSID(_ni, _ssid, _action) do {			\
73 	if ((_ssid)[1] != 0 &&						\
74 	    ((_ssid)[1] != (_ni)->ni_esslen ||				\
75 	    memcmp((_ssid) + 2, (_ni)->ni_essid, (_ssid)[1]) != 0)) {	\
76 		vap->iv_stats.is_rx_ssidmismatch++;			\
77 		_action;						\
78 	}								\
79 } while (0)
80 #endif /* !IEEE80211_DEBUG */
81 
82 #include <sys/endian.h>		/* For le16toh() / le32dec() */
83 
84 static __inline int
85 iswpaoui(const uint8_t *frm)
86 {
87 	return frm[1] > 3 && le32dec(frm+2) == ((WPA_OUI_TYPE<<24)|WPA_OUI);
88 }
89 
90 static __inline int
91 iswmeoui(const uint8_t *frm)
92 {
93 	return frm[1] > 3 && le32dec(frm+2) == ((WME_OUI_TYPE<<24)|WME_OUI);
94 }
95 
96 static __inline int
97 iswmeparam(const uint8_t *frm)
98 {
99 	return frm[1] > 5 && le32dec(frm+2) == ((WME_OUI_TYPE<<24)|WME_OUI) &&
100 		frm[6] == WME_PARAM_OUI_SUBTYPE;
101 }
102 
103 static __inline int
104 iswmeinfo(const uint8_t *frm)
105 {
106 	return frm[1] > 5 && le32dec(frm+2) == ((WME_OUI_TYPE<<24)|WME_OUI) &&
107 		frm[6] == WME_INFO_OUI_SUBTYPE;
108 }
109 
110 static __inline int
111 isatherosoui(const uint8_t *frm)
112 {
113 	return frm[1] > 3 && le32dec(frm+2) == ((ATH_OUI_TYPE<<24)|ATH_OUI);
114 }
115 
116 static __inline int
117 istdmaoui(const uint8_t *frm)
118 {
119 	return frm[1] > 3 && le32dec(frm+2) == ((TDMA_OUI_TYPE<<24)|TDMA_OUI);
120 }
121 
122 static __inline int
123 ishtcapoui(const uint8_t *frm)
124 {
125 	return frm[1] > 3 && le32dec(frm+2) == ((BCM_OUI_HTCAP<<24)|BCM_OUI);
126 }
127 
128 static __inline int
129 ishtinfooui(const uint8_t *frm)
130 {
131 	return frm[1] > 3 && le32dec(frm+2) == ((BCM_OUI_HTINFO<<24)|BCM_OUI);
132 }
133 
134 /*
135  * Check the current frame sequence number against the current TID
136  * state and return whether it's in sequence or should be dropped.
137  *
138  * Since out of order packet and duplicate packet eliminations should
139  * be done by the AMPDU RX code, this routine blindly accepts all
140  * frames from a HT station w/ a TID that is currently doing AMPDU-RX.
141  * HT stations without WME or where the TID is not doing AMPDU-RX
142  * are checked like non-HT stations.
143  *
144  * The routine only eliminates packets whose sequence/fragment
145  * match or are less than the last seen sequence/fragment number
146  * AND are retransmits It doesn't try to eliminate out of order packets.
147  *
148  * Since all frames after sequence number 4095 will be less than 4095
149  * (as the seqnum wraps), handle that special case so packets aren't
150  * incorrectly dropped - ie, if the next packet is sequence number 0
151  * but a retransmit since the initial packet didn't make it.
152  *
153  * XXX TODO: handle sequence number space wrapping with dropped frames;
154  * especially in high interference conditions under high traffic load
155  * The RX AMPDU reorder code also needs it.
156  *
157  * XXX TODO: update for 802.11-2012 9.3.2.10 Duplicate Detection and Recovery.
158  */
159 static __inline int
160 ieee80211_check_rxseq(struct ieee80211_node *ni, struct ieee80211_frame *wh,
161     uint8_t *bssid, const struct ieee80211_rx_stats *rxs)
162 {
163 #define	SEQ_LEQ(a,b)	((int)((a)-(b)) <= 0)
164 #define	SEQ_EQ(a,b)	((int)((a)-(b)) == 0)
165 #define	SEQNO(a)	((a) >> IEEE80211_SEQ_SEQ_SHIFT)
166 #define	FRAGNO(a)	((a) & IEEE80211_SEQ_FRAG_MASK)
167 	struct ieee80211vap *vap = ni->ni_vap;
168 	uint16_t rxseq;
169 	uint8_t type, subtype;
170 	uint8_t tid;
171 	struct ieee80211_rx_ampdu *rap;
172 
173 	rxseq = le16toh(*(uint16_t *)wh->i_seq);
174 	type = wh->i_fc[0] & IEEE80211_FC0_TYPE_MASK;
175 	subtype = wh->i_fc[0] & IEEE80211_FC0_SUBTYPE_MASK;
176 
177 	/*
178 	 * Types with no sequence number (or QoS (+)Null frames)
179 	 * are always treated valid.
180 	 */
181 	if (! IEEE80211_HAS_SEQ(type, subtype))
182 		return 1;
183 
184 	/*
185 	 * Always allow multicast frames for now - QoS (any TID)
186 	 * or not.
187 	 */
188 	if (IEEE80211_IS_MULTICAST(wh->i_addr1))
189 		return 1;
190 
191 	tid = ieee80211_gettid(wh);
192 
193 	/*
194 	 * Only do the HT AMPDU check for WME stations; non-WME HT stations
195 	 * shouldn't exist outside of debugging. We should at least
196 	 * handle that.
197 	 */
198 	if (tid < WME_NUM_TID) {
199 		rap = &ni->ni_rx_ampdu[tid];
200 		/* HT nodes currently doing RX AMPDU are always valid */
201 		if ((ni->ni_flags & IEEE80211_NODE_HT) &&
202 		    (rap->rxa_flags & IEEE80211_AGGR_RUNNING))
203 			goto ok;
204 	}
205 
206 	/*
207 	 * Otherwise, retries for packets below or equal to the last
208 	 * seen sequence number should be dropped.
209 	 */
210 
211 	/*
212 	 * Treat frame seqnum 4095 as special due to boundary
213 	 * wrapping conditions.
214 	 */
215 	if (SEQNO(ni->ni_rxseqs[tid]) == 4095) {
216 		/*
217 		 * Drop retransmits on seqnum 4095/current fragment for itself.
218 		 */
219 		if (SEQ_EQ(rxseq, ni->ni_rxseqs[tid]) &&
220 		    (wh->i_fc[1] & IEEE80211_FC1_RETRY))
221 			goto fail;
222 		/*
223 		 * Treat any subsequent frame as fine if the last seen frame
224 		 * is 4095 and it's not a retransmit for the same sequence
225 		 * number. However, this doesn't capture incorrectly ordered
226 	 	 * fragments w/ sequence number 4095. It shouldn't be seen
227 		 * in practice, but see the comment above for further info.
228 		 */
229 		goto ok;
230 	}
231 
232 	/*
233 	 * At this point we assume that retransmitted seq/frag numbers below
234 	 * the current can simply be eliminated.
235 	 */
236 	if ((wh->i_fc[1] & IEEE80211_FC1_RETRY) &&
237 	    SEQ_LEQ(rxseq, ni->ni_rxseqs[tid]))
238 		goto fail;
239 
240 ok:
241 	ni->ni_rxseqs[tid] = rxseq;
242 
243 	return 1;
244 
245 fail:
246 	/* duplicate, discard */
247 	IEEE80211_DISCARD_MAC(vap, IEEE80211_MSG_INPUT, bssid, "duplicate",
248 	    "seqno <%u,%u> fragno <%u,%u> tid %u",
249 	     SEQNO(rxseq),  SEQNO(ni->ni_rxseqs[tid]),
250 	    FRAGNO(rxseq), FRAGNO(ni->ni_rxseqs[tid]), tid);
251 	vap->iv_stats.is_rx_dup++;
252 	IEEE80211_NODE_STAT(ni, rx_dup);
253 
254 	return 0;
255 #undef	SEQ_LEQ
256 #undef	SEQ_EQ
257 #undef	SEQNO
258 #undef	FRAGNO
259 }
260 
261 void	ieee80211_deliver_data(struct ieee80211vap *,
262 		struct ieee80211_node *, struct mbuf *);
263 struct mbuf *ieee80211_defrag(struct ieee80211_node *,
264 		struct mbuf *, int);
265 struct mbuf *ieee80211_realign(struct ieee80211vap *, struct mbuf *, size_t);
266 struct mbuf *ieee80211_decap(struct ieee80211vap *, struct mbuf *, int);
267 struct mbuf *ieee80211_decap1(struct mbuf *, int *);
268 int	ieee80211_setup_rates(struct ieee80211_node *ni,
269 		const uint8_t *rates, const uint8_t *xrates, int flags);
270 void ieee80211_send_error(struct ieee80211_node *,
271 		const uint8_t mac[IEEE80211_ADDR_LEN], int subtype, int arg);
272 int	ieee80211_alloc_challenge(struct ieee80211_node *);
273 int	ieee80211_parse_beacon(struct ieee80211_node *, struct mbuf *,
274 		struct ieee80211_channel *,
275 		struct ieee80211_scanparams *);
276 int	ieee80211_parse_action(struct ieee80211_node *, struct mbuf *);
277 #endif /* _NET80211_IEEE80211_INPUT_H_ */
278