freebsd-skq/sys/net80211/ieee80211_input.h
Adrian Chadd 9764ef21c4 [net80211] address seqno allocation for group addressed frames
After some digging and looking at packet traces, it looks like the
sequence number allocation being done by net80211 doesn't meet
802.11-2012.

Specifically, group addressed frames (broadcast, multicast) have
sequence numbers allocated from a separate pool, even if they're
QoS frames.

This patch starts to try and address this, both on transmit and
receive.

* When receiving, don't throw away multicast frames for now.
  It's sub-optimal, but until we correctly track group addressed
  frames via another TID counter, this is the best we can do.

* When doing A-MPDU checks, don't include group addressed frames
  in the sequence number checks.

* When transmitting, don't allocate group frame sequence numbers
  from the TID, instead use the NONQOS TID for allocation.

This may fix iwn(4) 11n because I /think/ this was one of the
handful of places where ni_txseqs[] was being assigned /outside/
of the driver itself.

This however doesn't completely fix things - notably the way that
TID assignment versus WME assignment for driver hardware queues
will mess up multicast ordering. For example, if all multicast
QoS frames come from one sequence number space but they're
expected to obey the QoS value assigned, they'll end up in
different queues in the hardware and go out in different
orders.

I can't fix that right now and indeed fixing it will require some
pretty heavy lifting of both the WME<->TID QoS assignment, as well
as figuring out what the correct way for drivers to behave.

For example, both iwn(4) and ath(4) shouldn't put QoS multicast
traffic into the same output queue as aggregate traffic, because
the sequence numbers are all wrong. So perhaps the correct thing
to do there is ignore the WME/TID for QoS traffic and map it all
to the best effort queue or something, and ensure it doesn't
muck up the TID/blockack window tracking. However, I'm /pretty/
sure that is still going to happen.

.. maybe I should disable multicast QoS frames in general as well,
but I don't know what that'll do for whatever the current state
of 802.11s mesh support is.

Tested:

* STA mode, ath10k NIC
* AP mode, AR9344/AR9580 AP
* iperf tcp/udp tests with concurrent multicast QoS traffic.

Before this, iperfs would fail pretty quickly because the sending
AP would start sending out QoS multicast frames that would be
out of order from the rest of the TID traffic, causing the blockack
window to get way, way out of sync.

This now doesn't occur.

TODO:

* verify which QoS frames SHOULD be tagged as M_AMPDU_MPDU.
  For example, QoS NULL frames shouldn't be tagged!

Reviewed by: avos
Differential Revision: https://reviews.freebsd.org/D9357
2017-01-30 01:11:30 +00:00

278 lines
8.9 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);
}
/*
* 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)
{
#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:
ni->ni_rxseqs[tid] = rxseq;
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_ */