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                                 IEEE80211_FC0_SUBTYPE_SHIFT],           \
  67                                 wh->i_addr2, _ssid);                    \
  68                 vap->iv_stats.is_rx_ssidmismatch++;                     \
  69                 _action;                                                \
  70         }                                                               \
  71 } while (0)
  72 #else /* !IEEE80211_DEBUG */
  73 #define IEEE80211_VERIFY_SSID(_ni, _ssid, _action) do {                 \
  74         if ((_ssid)[1] != 0 &&                                          \
  75             ((_ssid)[1] != (_ni)->ni_esslen ||                          \
  76             memcmp((_ssid) + 2, (_ni)->ni_essid, (_ssid)[1]) != 0)) {   \
  77                 vap->iv_stats.is_rx_ssidmismatch++;                     \
  78                 _action;                                                \
  79         }                                                               \
  80 } while (0)
  81 #endif /* !IEEE80211_DEBUG */
  82
  83 /* unalligned little endian access */
  84 #define LE_READ_2(p)                                    \
  85         ((uint16_t)                                     \
  86          ((((const uint8_t *)(p))[0]      ) |           \
  87           (((const uint8_t *)(p))[1] <<  8)))
  88 #define LE_READ_4(p)                                    \
  89         ((uint32_t)                                     \
  90          ((((const uint8_t *)(p))[0]      ) |           \
  91           (((const uint8_t *)(p))[1] <<  8) |           \
  92           (((const uint8_t *)(p))[2] << 16) |           \
  93           (((const uint8_t *)(p))[3] << 24)))
  94
  95 static __inline int
  96 iswpaoui(const uint8_t *frm)
  97 {
  98         return frm[1] > 3 && LE_READ_4(frm+2) == ((WPA_OUI_TYPE<<24)|WPA_OUI);
  99 }
 100
 101 static __inline int
 102 iswmeoui(const uint8_t *frm)
 103 {
 104         return frm[1] > 3 && LE_READ_4(frm+2) == ((WME_OUI_TYPE<<24)|WME_OUI);
 105 }
 106
 107 static __inline int
 108 iswmeparam(const uint8_t *frm)
 109 {
 110         return frm[1] > 5 && LE_READ_4(frm+2) == ((WME_OUI_TYPE<<24)|WME_OUI) &&
 111                 frm[6] == WME_PARAM_OUI_SUBTYPE;
 112 }
 113
 114 static __inline int
 115 iswmeinfo(const uint8_t *frm)
 116 {
 117         return frm[1] > 5 && LE_READ_4(frm+2) == ((WME_OUI_TYPE<<24)|WME_OUI) &&
 118                 frm[6] == WME_INFO_OUI_SUBTYPE;
 119 }
 120
 121 static __inline int
 122 isatherosoui(const uint8_t *frm)
 123 {
 124         return frm[1] > 3 && LE_READ_4(frm+2) == ((ATH_OUI_TYPE<<24)|ATH_OUI);
 125 }
 126
 127 static __inline int
 128 istdmaoui(const uint8_t *frm)
 129 {
 130         return frm[1] > 3 && LE_READ_4(frm+2) == ((TDMA_OUI_TYPE<<24)|TDMA_OUI);
 131 }
 132
 133 static __inline int
 134 ishtcapoui(const uint8_t *frm)
 135 {
 136         return frm[1] > 3 && LE_READ_4(frm+2) == ((BCM_OUI_HTCAP<<24)|BCM_OUI);
 137 }
 138
 139 static __inline int
 140 ishtinfooui(const uint8_t *frm)
 141 {
 142         return frm[1] > 3 && LE_READ_4(frm+2) == ((BCM_OUI_HTINFO<<24)|BCM_OUI);
 143 }
 144
 145 #include <sys/endian.h>         /* For le16toh() */
 146
 147 /*
 148  * Check the current frame sequence number against the current TID
 149  * state and return whether it's in sequence or should be dropped.
 150  *
 151  * Since out of order packet and duplicate packet eliminations should
 152  * be done by the AMPDU RX code, this routine blindly accepts all
 153  * frames from a HT station w/ a TID that is currently doing AMPDU-RX.
 154  * HT stations without WME or where the TID is not doing AMPDU-RX
 155  * are checked like non-HT stations.
 156  *
 157  * The routine only eliminates packets whose sequence/fragment
 158  * match or are less than the last seen sequence/fragment number
 159  * AND are retransmits It doesn't try to eliminate out of order packets.
 160  *
 161  * Since all frames after sequence number 4095 will be less than 4095
 162  * (as the seqnum wraps), handle that special case so packets aren't
 163  * incorrectly dropped - ie, if the next packet is sequence number 0
 164  * but a retransmit since the initial packet didn't make it.
 165  */
 166 static __inline int
 167 ieee80211_check_rxseq(struct ieee80211_node *ni, struct ieee80211_frame *wh)
 168 {
 169 #define SEQ_LEQ(a,b)    ((int)((a)-(b)) <= 0)
 170 #define SEQ_EQ(a,b)     ((int)((a)-(b)) == 0)
 171 #define HAS_SEQ(type)   ((type & 0x4) == 0)
 172 #define SEQNO(a)        ((a) >> IEEE80211_SEQ_SEQ_SHIFT)
 173 #define FRAGNO(a)       ((a) & IEEE80211_SEQ_FRAG_MASK)
 174         uint16_t rxseq;
 175         uint8_t type;
 176         uint8_t tid;
 177         struct ieee80211_rx_ampdu *rap;
 178
 179         rxseq = le16toh(*(uint16_t *)wh->i_seq);
 180         type = wh->i_fc[0] & IEEE80211_FC0_TYPE_MASK;
 181
 182         /* Types with no sequence number are always treated valid */
 183         if (! HAS_SEQ(type))
 184                 return 1;
 185
 186         tid = ieee80211_gettid(wh);
 187
 188         /*
 189          * Only do the HT AMPDU check for WME stations; non-WME HT stations
 190          * shouldn't exist outside of debugging. We should at least
 191          * handle that.
 192          */
 193         if (tid < WME_NUM_TID) {
 194                 rap = &ni->ni_rx_ampdu[tid];
 195                 /* HT nodes currently doing RX AMPDU are always valid */
 196                 if ((ni->ni_flags & IEEE80211_NODE_HT) &&
 197                     (rap->rxa_flags & IEEE80211_AGGR_RUNNING))
 198                         return 1;
 199         }
 200
 201         /*
 202          * Otherwise, retries for packets below or equal to the last
 203          * seen sequence number should be dropped.
 204          */
 205
 206         /*
 207          * Treat frame seqnum 4095 as special due to boundary
 208          * wrapping conditions.
 209          */
 210         if (SEQNO(ni->ni_rxseqs[tid]) == 4095) {
 211                 /*
 212                  * Drop retransmits on seqnum 4095/current fragment for itself.
 213                  */
 214                 if (SEQ_EQ(rxseq, ni->ni_rxseqs[tid]) &&
 215                     (wh->i_fc[1] & IEEE80211_FC1_RETRY))
 216                         return 0;
 217                 /*
 218                  * Treat any subsequent frame as fine if the last seen frame
 219                  * is 4095 and it's not a retransmit for the same sequence
 220                  * number. However, this doesn't capture incorrectly ordered
 221                  * fragments w/ sequence number 4095. It shouldn't be seen
 222                  * in practice, but see the comment above for further info.
 223                  */
 224                 return 1;
 225         }
 226
 227         /*
 228          * At this point we assume that retransmitted seq/frag numbers below
 229          * the current can simply be eliminated.
 230          */
 231         if ((wh->i_fc[1] & IEEE80211_FC1_RETRY) &&
 232             SEQ_LEQ(rxseq, ni->ni_rxseqs[tid]))
 233                 return 0;
 234
 235         return 1;
 236 #undef  SEQ_LEQ
 237 #undef  SEQ_EQ
 238 #undef  HAS_SEQ
 239 #undef  SEQNO
 240 #undef  FRAGNO
 241 }
 242
 243 void    ieee80211_deliver_data(struct ieee80211vap *,
 244                 struct ieee80211_node *, struct mbuf *);
 245 struct mbuf *ieee80211_defrag(struct ieee80211_node *,
 246                 struct mbuf *, int);
 247 struct mbuf *ieee80211_realign(struct ieee80211vap *, struct mbuf *, size_t);
 248 struct mbuf *ieee80211_decap(struct ieee80211vap *, struct mbuf *, int);
 249 struct mbuf *ieee80211_decap1(struct mbuf *, int *);
 250 int     ieee80211_setup_rates(struct ieee80211_node *ni,
 251                 const uint8_t *rates, const uint8_t *xrates, int flags);
 252 void ieee80211_send_error(struct ieee80211_node *,
 253                 const uint8_t mac[IEEE80211_ADDR_LEN], int subtype, int arg);
 254 int     ieee80211_alloc_challenge(struct ieee80211_node *);
 255 int     ieee80211_parse_beacon(struct ieee80211_node *, struct mbuf *,
 256                 struct ieee80211_scanparams *);
 257 int     ieee80211_parse_action(struct ieee80211_node *, struct mbuf *);
 258 #endif /* _NET80211_IEEE80211_INPUT_H_ */