freebsd-skq/sys/net80211/ieee80211_input.h
adrian 5ff550eae1 [net80211] don't try to follow a NULL rxs pointer down the sink.
It's smelly, and we already checked earlier whether we needed to.
2017-10-13 06:49:07 +00:00

323 lines
10 KiB
C

/*-
* Copyright (c) 2007-2009 Sam Leffler, Errno Consulting
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
*
* THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
* IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
* OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
* IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
* INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
* NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
* DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
* THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
* (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
* THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*
* $FreeBSD$
*/
#ifndef _NET80211_IEEE80211_INPUT_H_
#define _NET80211_IEEE80211_INPUT_H_
/* Verify the existence and length of __elem or get out. */
#define IEEE80211_VERIFY_ELEMENT(__elem, __maxlen, _action) do { \
if ((__elem) == NULL) { \
IEEE80211_DISCARD(vap, IEEE80211_MSG_ELEMID, \
wh, NULL, "%s", "no " #__elem ); \
vap->iv_stats.is_rx_elem_missing++; \
_action; \
} else if ((__elem)[1] > (__maxlen)) { \
IEEE80211_DISCARD(vap, IEEE80211_MSG_ELEMID, \
wh, NULL, "bad " #__elem " len %d", (__elem)[1]); \
vap->iv_stats.is_rx_elem_toobig++; \
_action; \
} \
} while (0)
#define IEEE80211_VERIFY_LENGTH(_len, _minlen, _action) do { \
if ((_len) < (_minlen)) { \
IEEE80211_DISCARD(vap, IEEE80211_MSG_ELEMID, \
wh, NULL, "ie too short, got %d, expected %d", \
(_len), (_minlen)); \
vap->iv_stats.is_rx_elem_toosmall++; \
_action; \
} \
} while (0)
#ifdef IEEE80211_DEBUG
void ieee80211_ssid_mismatch(struct ieee80211vap *, const char *tag,
uint8_t mac[IEEE80211_ADDR_LEN], uint8_t *ssid);
#define IEEE80211_VERIFY_SSID(_ni, _ssid, _action) do { \
if ((_ssid)[1] != 0 && \
((_ssid)[1] != (_ni)->ni_esslen || \
memcmp((_ssid) + 2, (_ni)->ni_essid, (_ssid)[1]) != 0)) { \
if (ieee80211_msg_input(vap)) \
ieee80211_ssid_mismatch(vap, \
ieee80211_mgt_subtype_name(subtype), \
wh->i_addr2, _ssid); \
vap->iv_stats.is_rx_ssidmismatch++; \
_action; \
} \
} while (0)
#else /* !IEEE80211_DEBUG */
#define IEEE80211_VERIFY_SSID(_ni, _ssid, _action) do { \
if ((_ssid)[1] != 0 && \
((_ssid)[1] != (_ni)->ni_esslen || \
memcmp((_ssid) + 2, (_ni)->ni_essid, (_ssid)[1]) != 0)) { \
vap->iv_stats.is_rx_ssidmismatch++; \
_action; \
} \
} while (0)
#endif /* !IEEE80211_DEBUG */
#include <sys/endian.h> /* For le16toh() / le32dec() */
static __inline int
iswpaoui(const uint8_t *frm)
{
return frm[1] > 3 && le32dec(frm+2) == ((WPA_OUI_TYPE<<24)|WPA_OUI);
}
static __inline int
iswmeoui(const uint8_t *frm)
{
return frm[1] > 3 && le32dec(frm+2) == ((WME_OUI_TYPE<<24)|WME_OUI);
}
static __inline int
iswmeparam(const uint8_t *frm)
{
return frm[1] > 5 && le32dec(frm+2) == ((WME_OUI_TYPE<<24)|WME_OUI) &&
frm[6] == WME_PARAM_OUI_SUBTYPE;
}
static __inline int
iswmeinfo(const uint8_t *frm)
{
return frm[1] > 5 && le32dec(frm+2) == ((WME_OUI_TYPE<<24)|WME_OUI) &&
frm[6] == WME_INFO_OUI_SUBTYPE;
}
static __inline int
isatherosoui(const uint8_t *frm)
{
return frm[1] > 3 && le32dec(frm+2) == ((ATH_OUI_TYPE<<24)|ATH_OUI);
}
static __inline int
istdmaoui(const uint8_t *frm)
{
return frm[1] > 3 && le32dec(frm+2) == ((TDMA_OUI_TYPE<<24)|TDMA_OUI);
}
static __inline int
ishtcapoui(const uint8_t *frm)
{
return frm[1] > 3 && le32dec(frm+2) == ((BCM_OUI_HTCAP<<24)|BCM_OUI);
}
static __inline int
ishtinfooui(const uint8_t *frm)
{
return frm[1] > 3 && le32dec(frm+2) == ((BCM_OUI_HTINFO<<24)|BCM_OUI);
}
static __inline int
ieee80211_check_rxseq_amsdu(const struct ieee80211_rx_stats *rxs)
{
return (!! (rxs->c_pktflags & IEEE80211_RX_F_AMSDU));
}
/*
* Return 1 if the rxseq check should increment the sequence
* number. Return 0 if it's part of an AMSDU batch and it isn't
* the final frame in the decap'ed burst.
*/
static __inline int
ieee80211_check_rxseq_amsdu_more(const struct ieee80211_rx_stats *rxs)
{
/* No state? ok */
if (rxs == NULL)
return (1);
/* State but no AMSDU set? ok */
if ((rxs->c_pktflags & IEEE80211_RX_F_AMSDU) == 0)
return (1);
/* State, AMSDU set, then _MORE means "don't inc yet" */
if (rxs->c_pktflags & IEEE80211_RX_F_AMSDU_MORE) {
return (0);
}
/* Both are set, so return ok */
return (1);
}
/*
* Check the current frame sequence number against the current TID
* state and return whether it's in sequence or should be dropped.
*
* Since out of order packet and duplicate packet eliminations should
* be done by the AMPDU RX code, this routine blindly accepts all
* frames from a HT station w/ a TID that is currently doing AMPDU-RX.
* HT stations without WME or where the TID is not doing AMPDU-RX
* are checked like non-HT stations.
*
* The routine only eliminates packets whose sequence/fragment
* match or are less than the last seen sequence/fragment number
* AND are retransmits It doesn't try to eliminate out of order packets.
*
* Since all frames after sequence number 4095 will be less than 4095
* (as the seqnum wraps), handle that special case so packets aren't
* incorrectly dropped - ie, if the next packet is sequence number 0
* but a retransmit since the initial packet didn't make it.
*
* XXX TODO: handle sequence number space wrapping with dropped frames;
* especially in high interference conditions under high traffic load
* The RX AMPDU reorder code also needs it.
*
* XXX TODO: update for 802.11-2012 9.3.2.10 Duplicate Detection and Recovery.
*/
static __inline int
ieee80211_check_rxseq(struct ieee80211_node *ni, struct ieee80211_frame *wh,
uint8_t *bssid, const struct ieee80211_rx_stats *rxs)
{
#define SEQ_LEQ(a,b) ((int)((a)-(b)) <= 0)
#define SEQ_EQ(a,b) ((int)((a)-(b)) == 0)
#define SEQNO(a) ((a) >> IEEE80211_SEQ_SEQ_SHIFT)
#define FRAGNO(a) ((a) & IEEE80211_SEQ_FRAG_MASK)
struct ieee80211vap *vap = ni->ni_vap;
uint16_t rxseq;
uint8_t type, subtype;
uint8_t tid;
struct ieee80211_rx_ampdu *rap;
rxseq = le16toh(*(uint16_t *)wh->i_seq);
type = wh->i_fc[0] & IEEE80211_FC0_TYPE_MASK;
subtype = wh->i_fc[0] & IEEE80211_FC0_SUBTYPE_MASK;
/*
* Types with no sequence number (or QoS (+)Null frames)
* are always treated valid.
*/
if (! IEEE80211_HAS_SEQ(type, subtype))
return 1;
/*
* Always allow multicast frames for now - QoS (any TID)
* or not.
*/
if (IEEE80211_IS_MULTICAST(wh->i_addr1))
return 1;
tid = ieee80211_gettid(wh);
/*
* Only do the HT AMPDU check for WME stations; non-WME HT stations
* shouldn't exist outside of debugging. We should at least
* handle that.
*/
if (tid < WME_NUM_TID) {
rap = &ni->ni_rx_ampdu[tid];
/* HT nodes currently doing RX AMPDU are always valid */
if ((ni->ni_flags & IEEE80211_NODE_HT) &&
(rap->rxa_flags & IEEE80211_AGGR_RUNNING))
goto ok;
}
/*
* Otherwise, retries for packets below or equal to the last
* seen sequence number should be dropped.
*/
/*
* Treat frame seqnum 4095 as special due to boundary
* wrapping conditions.
*/
if (SEQNO(ni->ni_rxseqs[tid]) == 4095) {
/*
* Drop retransmits on seqnum 4095/current fragment for itself.
*/
if (SEQ_EQ(rxseq, ni->ni_rxseqs[tid]) &&
(wh->i_fc[1] & IEEE80211_FC1_RETRY))
goto fail;
/*
* Treat any subsequent frame as fine if the last seen frame
* is 4095 and it's not a retransmit for the same sequence
* number. However, this doesn't capture incorrectly ordered
* fragments w/ sequence number 4095. It shouldn't be seen
* in practice, but see the comment above for further info.
*/
goto ok;
}
/*
* At this point we assume that retransmitted seq/frag numbers below
* the current can simply be eliminated.
*/
if ((wh->i_fc[1] & IEEE80211_FC1_RETRY) &&
SEQ_LEQ(rxseq, ni->ni_rxseqs[tid]))
goto fail;
ok:
/*
* Only bump the sequence number if it's the last frame
* in a batch. That way frames in the rest of the batch
* get included, and the last frame in the batch kicks
* it next.
*/
if (ieee80211_check_rxseq_amsdu_more(rxs)) {
ni->ni_rxseqs[tid] = rxseq;
if ((rxs != NULL) && ieee80211_check_rxseq_amsdu(rxs))
IEEE80211_NODE_STAT(ni, rx_amsdu_more_end);
} else {
/* .. still waiting */
IEEE80211_NODE_STAT(ni, rx_amsdu_more);
}
return 1;
fail:
/* duplicate, discard */
IEEE80211_DISCARD_MAC(vap, IEEE80211_MSG_INPUT, bssid, "duplicate",
"seqno <%u,%u> fragno <%u,%u> tid %u",
SEQNO(rxseq), SEQNO(ni->ni_rxseqs[tid]),
FRAGNO(rxseq), FRAGNO(ni->ni_rxseqs[tid]), tid);
vap->iv_stats.is_rx_dup++;
IEEE80211_NODE_STAT(ni, rx_dup);
return 0;
#undef SEQ_LEQ
#undef SEQ_EQ
#undef SEQNO
#undef FRAGNO
}
void ieee80211_deliver_data(struct ieee80211vap *,
struct ieee80211_node *, struct mbuf *);
struct mbuf *ieee80211_defrag(struct ieee80211_node *,
struct mbuf *, int);
struct mbuf *ieee80211_realign(struct ieee80211vap *, struct mbuf *, size_t);
struct mbuf *ieee80211_decap(struct ieee80211vap *, struct mbuf *, int);
struct mbuf *ieee80211_decap1(struct mbuf *, int *);
int ieee80211_setup_rates(struct ieee80211_node *ni,
const uint8_t *rates, const uint8_t *xrates, int flags);
void ieee80211_send_error(struct ieee80211_node *,
const uint8_t mac[IEEE80211_ADDR_LEN], int subtype, int arg);
int ieee80211_alloc_challenge(struct ieee80211_node *);
int ieee80211_parse_beacon(struct ieee80211_node *, struct mbuf *,
struct ieee80211_channel *,
struct ieee80211_scanparams *);
int ieee80211_parse_action(struct ieee80211_node *, struct mbuf *);
#endif /* _NET80211_IEEE80211_INPUT_H_ */