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freebsd/sys/net80211/ieee80211_input.h
Adrian Chadd c79f192c09 Begin plumbing ieee80211_rx_stats through the receive path. 
Smart NICs with firmware (eg wpi, iwn, the new atheros parts, the intel 7260
series, etc) support doing a lot of things in firmware.  This includes but
isn't limited to things like scanning, sending probe requests and receiving
probe responses.  However, net80211 doesn't know about any of this - it still
drives the whole scan/probe infrastructure itself.

In order to move towards suppoting smart NICs, the receive path needs to
know about the channel/details for each received packet.  In at least
the iwn and 7260 firmware (and I believe wpi, but I haven't tried it yet)
it will do the scanning, power-save and off-channel buffering for you -
all you need to do is handle receiving beacons and probe responses on
channels that aren't what you're currently on.  However the whole receive
path is peppered with ic->ic_curchan and manual scan/powersave handling.
The beacon parsing code also checks ic->ic_curchan to determine if the
received beacon is on the correct channel or not.[1]

So:

* add freq/ieee values to ieee80211_rx_stats;
* change ieee80211_parse_beacon() to accept the 'current' channel
  as an argument;
* modify the iv_input() and iv_recv_mgmt() methods to include the rx_stats;
* add a new method - ieee80211_lookup_channel_rxstats() - that looks up
  a channel based on the contents of ieee80211_rx_stats;
* if it exists, use it in the mgmt path to switch the current channel
  (which still defaults to ic->ic_curchan) over to something determined
  by rx_stats.

This is enough to kick-start scan offload support in the Intel 7260
driver that Rui/I are working on.  It also is a good start for scan
offload support for a handful of existing NICs (wpi, iwn, some USB
parts) and it'll very likely dramatically improve stability/performance
there.  It's not the whole thing - notably, we don't need to do powersave,
we should not scan all channels, and we should leave probe request sending
to the firmware and not do it ourselves.  But, this allows for continued
development on the above features whilst actually having a somewhat
working NIC.

TODO:

* Finish tidying up how the net80211 input path works.
  Right now ieee80211_input / ieee80211_input_all act as the top-level
  that everything feeds into; it should change so the MIMO input routines
  are those and the legacy routines are phased out.

* The band selection should be done by the driver, not by the net80211
  layer.

* ieee80211_lookup_channel_rxstats() only determines 11b or 11g channels
  for now - this is enough for scanning, but not 100% true in all cases.
  If we ever need to handle off-channel scan support for things like
  static-40MHz or static-80MHz, or turbo-G, or half/quarter rates,
  then we should extend this.

[1] This is a side effect of frequency-hopping and CCK modes - you
    can receive beacons when you think you're on a different channel.
    In particular, CCK (which is used by the low 11b rates, eg beacons!)
    is decodable from adjacent channels - just at a low SNR.
    FH is a side effect of having the hardware/firmware do the frequency
    hopping - it may pick up beacons transmitted from other FH networks
    that are in a different phase of hopping frequencies.
2015-05-25 16:37:41 +00:00

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/*-
* 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 >> \
IEEE80211_FC0_SUBTYPE_SHIFT], \
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 */
/* unalligned little endian access */
#define LE_READ_2(p) \
((uint16_t) \
((((const uint8_t *)(p))[0] ) | \
(((const uint8_t *)(p))[1] << 8)))
#define LE_READ_4(p) \
((uint32_t) \
((((const uint8_t *)(p))[0] ) | \
(((const uint8_t *)(p))[1] << 8) | \
(((const uint8_t *)(p))[2] << 16) | \
(((const uint8_t *)(p))[3] << 24)))
static __inline int
iswpaoui(const uint8_t *frm)
{
return frm[1] > 3 && LE_READ_4(frm+2) == ((WPA_OUI_TYPE<<24)|WPA_OUI);
}
static __inline int
iswmeoui(const uint8_t *frm)
{
return frm[1] > 3 && LE_READ_4(frm+2) == ((WME_OUI_TYPE<<24)|WME_OUI);
}
static __inline int
iswmeparam(const uint8_t *frm)
{
return frm[1] > 5 && LE_READ_4(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 && LE_READ_4(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 && LE_READ_4(frm+2) == ((ATH_OUI_TYPE<<24)|ATH_OUI);
}
static __inline int
istdmaoui(const uint8_t *frm)
{
return frm[1] > 3 && LE_READ_4(frm+2) == ((TDMA_OUI_TYPE<<24)|TDMA_OUI);
}
static __inline int
ishtcapoui(const uint8_t *frm)
{
return frm[1] > 3 && LE_READ_4(frm+2) == ((BCM_OUI_HTCAP<<24)|BCM_OUI);
}
static __inline int
ishtinfooui(const uint8_t *frm)
{
return frm[1] > 3 && LE_READ_4(frm+2) == ((BCM_OUI_HTINFO<<24)|BCM_OUI);
}
#include <sys/endian.h> /* For le16toh() */
/*
* 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.
*/
static __inline int
ieee80211_check_rxseq(struct ieee80211_node *ni, struct ieee80211_frame *wh)
{
#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)
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;
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))
return 1;
}
/*
* 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))
return 0;
/*
* 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.
*/
return 1;
}
/*
* 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]))
return 0;
return 1;
#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_ */
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