freebsd-dev/sys/net80211/ieee80211_proto.h
Sam Leffler 0a915fad5d MFp4 changes to fix locking issues and correct reference
count handling of station entries in hostap mode:

Input path:

o driver is now expected to find the node associated with the
  sender of a received frame; use ic_bss if none is located
o driver passes the (referenced) node into ieee80211_input for
  use within the wlan module and is responsible for cleaning up
  on return
o the antenna state is no longer passed up with each frame; this
  is now considered driver-private state and drivers are responsible
  for keeping it in the driver-private part of a node

Output path:

Revamp output path for management frames to eliminate redundant
locking that causes problems and to correct reference counting
bogosity that occurs when stations are timed out due to inactivity
(in AP mode).  On output the refcnt'd node is stashed in the pkthdr's
recvif field (yech) and retrieved by the driver.  This eliminates
an unref/ref scenario and related node table unlock/lock due to the
driver looking up the node.  This is particularly important when
stations are timed out as this causes a lock order reversal that
can result in a deadlock.  As a byproduct we also reduce the overhead
for sending management frames (minimal).  Additional fallout from
this is a change to ieee80211_encap to return a refcn't node for
tieing to the outbound frame.  Node refcnts are not reclaimed until
after a frame is completely processed (e.g. in the tx interrupt
handler).  This is especially important for timed out stations as
this deref will be the final one causing the node entry to be
reclaimed.

Additional semi-related changes:
o replace m_copym use with m_copypacket (optimization)
o add assert to verify ic_bss is never free'd during normal operation
o add comments explaining calling conventions by drivers for frames
  going in each direction
o remove extraneous code that "cannot be executed" (e.g. because
  pointers may never be null)
2003-08-19 22:17:04 +00:00

79 lines
3.3 KiB
C

/*-
* Copyright (c) 2001 Atsushi Onoe
* Copyright (c) 2002, 2003 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.
* 3. The name of the author may not be used to endorse or promote products
* derived from this software without specific prior written permission.
*
* Alternatively, this software may be distributed under the terms of the
* GNU General Public License ("GPL") version 2 as published by the Free
* Software Foundation.
*
* 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_PROTO_H_
#define _NET80211_IEEE80211_PROTO_H_
/*
* 802.11 protocol implementation definitions.
*/
enum ieee80211_state {
IEEE80211_S_INIT = 0, /* default state */
IEEE80211_S_SCAN = 1, /* scanning */
IEEE80211_S_AUTH = 2, /* try to authenticate */
IEEE80211_S_ASSOC = 3, /* try to assoc */
IEEE80211_S_RUN = 4, /* associated */
};
#define IEEE80211_S_MAX (IEEE80211_S_RUN+1)
#define IEEE80211_SEND_MGMT(_ic,_ni,_type,_arg) \
((*(_ic)->ic_send_mgmt)(_ic, _ni, _type, _arg))
extern const char *ieee80211_mgt_subtype_name[];
extern void ieee80211_proto_attach(struct ifnet *);
extern void ieee80211_proto_detach(struct ifnet *);
struct ieee80211_node;
extern void ieee80211_input(struct ifnet *, struct mbuf *,
struct ieee80211_node *, int, u_int32_t);
extern void ieee80211_recv_mgmt(struct ieee80211com *, struct mbuf *,
struct ieee80211_node *, int, int, u_int32_t);
extern int ieee80211_send_mgmt(struct ieee80211com *, struct ieee80211_node *,
int, int);
extern struct mbuf *ieee80211_encap(struct ifnet *, struct mbuf *,
struct ieee80211_node **);
extern struct mbuf *ieee80211_decap(struct ifnet *, struct mbuf *);
extern u_int8_t *ieee80211_add_rates(u_int8_t *frm,
const struct ieee80211_rateset *);
#define ieee80211_new_state(_ic, _nstate, _arg) \
(((_ic)->ic_newstate)((_ic), (_nstate), (_arg)))
extern u_int8_t *ieee80211_add_xrates(u_int8_t *frm,
const struct ieee80211_rateset *);
extern void ieee80211_print_essid(u_int8_t *, int);
extern void ieee80211_dump_pkt(u_int8_t *, int, int, int);
extern const char *ieee80211_state_name[IEEE80211_S_MAX];
#endif /* _NET80211_IEEE80211_PROTO_H_ */