sys/netproto/802_11/ieee80211_input.h

   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 %ld, expected %ld",    \
  49                     (long)(_len), (long)(_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 static __inline int
 154 ieee80211_check_rxseq(struct ieee80211_node *ni, struct ieee80211_frame *wh,
 155     uint8_t *bssid)
 156 {
 157 #define SEQ_LEQ(a,b)    ((int)((a)-(b)) <= 0)
 158 #define SEQ_EQ(a,b)     ((int)((a)-(b)) == 0)
 159 #define SEQNO(a)        ((a) >> IEEE80211_SEQ_SEQ_SHIFT)
 160 #define FRAGNO(a)       ((a) & IEEE80211_SEQ_FRAG_MASK)
 161         struct ieee80211vap *vap = ni->ni_vap;
 162         uint16_t rxseq;
 163         uint8_t type, subtype;
 164         uint8_t tid;
 165         struct ieee80211_rx_ampdu *rap;
 166
 167         rxseq = le16toh(*(uint16_t *)wh->i_seq);
 168         type = wh->i_fc[0] & IEEE80211_FC0_TYPE_MASK;
 169         subtype = wh->i_fc[0] & IEEE80211_FC0_SUBTYPE_MASK;
 170
 171         /*
 172          * Types with no sequence number (or QoS (+)Null frames)
 173          * are always treated valid.
 174          */
 175         if (! IEEE80211_HAS_SEQ(type, subtype))
 176                 return 1;
 177
 178         tid = ieee80211_gettid(wh);
 179
 180         /*
 181          * Only do the HT AMPDU check for WME stations; non-WME HT stations
 182          * shouldn't exist outside of debugging. We should at least
 183          * handle that.
 184          */
 185         if (tid < WME_NUM_TID) {
 186                 rap = &ni->ni_rx_ampdu[tid];
 187                 /* HT nodes currently doing RX AMPDU are always valid */
 188                 if ((ni->ni_flags & IEEE80211_NODE_HT) &&
 189                     (rap->rxa_flags & IEEE80211_AGGR_RUNNING))
 190                         goto ok;
 191         }
 192
 193         /*
 194          * Otherwise, retries for packets below or equal to the last
 195          * seen sequence number should be dropped.
 196          */
 197
 198         /*
 199          * Treat frame seqnum 4095 as special due to boundary
 200          * wrapping conditions.
 201          */
 202         if (SEQNO(ni->ni_rxseqs[tid]) == 4095) {
 203                 /*
 204                  * Drop retransmits on seqnum 4095/current fragment for itself.
 205                  */
 206                 if (SEQ_EQ(rxseq, ni->ni_rxseqs[tid]) &&
 207                     (wh->i_fc[1] & IEEE80211_FC1_RETRY))
 208                         goto fail;
 209                 /*
 210                  * Treat any subsequent frame as fine if the last seen frame
 211                  * is 4095 and it's not a retransmit for the same sequence
 212                  * number. However, this doesn't capture incorrectly ordered
 213                  * fragments w/ sequence number 4095. It shouldn't be seen
 214                  * in practice, but see the comment above for further info.
 215                  */
 216                 goto ok;
 217         }
 218
 219         /*
 220          * At this point we assume that retransmitted seq/frag numbers below
 221          * the current can simply be eliminated.
 222          */
 223         if ((wh->i_fc[1] & IEEE80211_FC1_RETRY) &&
 224             SEQ_LEQ(rxseq, ni->ni_rxseqs[tid]))
 225                 goto fail;
 226
 227 ok:
 228         ni->ni_rxseqs[tid] = rxseq;
 229
 230         return 1;
 231
 232 fail:
 233         /* duplicate, discard */
 234         IEEE80211_DISCARD_MAC(vap, IEEE80211_MSG_INPUT, bssid, "duplicate",
 235             "seqno <%u,%u> fragno <%u,%u> tid %u",
 236              SEQNO(rxseq),  SEQNO(ni->ni_rxseqs[tid]),
 237             FRAGNO(rxseq), FRAGNO(ni->ni_rxseqs[tid]), tid);
 238         vap->iv_stats.is_rx_dup++;
 239         IEEE80211_NODE_STAT(ni, rx_dup);
 240
 241         return 0;
 242 #undef  SEQ_LEQ
 243 #undef  SEQ_EQ
 244 #undef  SEQNO
 245 #undef  FRAGNO
 246 }
 247
 248 void    ieee80211_deliver_data(struct ieee80211vap *,
 249                 struct ieee80211_node *, struct mbuf *);
 250 struct mbuf *ieee80211_defrag(struct ieee80211_node *,
 251                 struct mbuf *, int);
 252 struct mbuf *ieee80211_realign(struct ieee80211vap *, struct mbuf *, size_t);
 253 struct mbuf *ieee80211_decap(struct ieee80211vap *, struct mbuf *, int);
 254 struct mbuf *ieee80211_decap1(struct mbuf *, int *);
 255 int     ieee80211_setup_rates(struct ieee80211_node *ni,
 256                 const uint8_t *rates, const uint8_t *xrates, int flags);
 257 void ieee80211_send_error(struct ieee80211_node *,
 258                 const uint8_t mac[IEEE80211_ADDR_LEN], int subtype, int arg);
 259 int     ieee80211_alloc_challenge(struct ieee80211_node *);
 260 int     ieee80211_parse_beacon(struct ieee80211_node *, struct mbuf *,
 261                 struct ieee80211_channel *,
 262                 struct ieee80211_scanparams *);
 263 int     ieee80211_parse_action(struct ieee80211_node *, struct mbuf *);
 264 #endif /* _NET80211_IEEE80211_INPUT_H_ */