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Try yet again to deal with timing out nodes. We cannot hold the

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node lock while sending a management frame as this will potentially
result in a LOR with a driver lock.  This doesn't happen for the
Atheros driver but does for the wi driver.  Use a generation number
to help process each node once when scanning the node table and
drop the node lock if we need to timeout a node and send a frame.
This commit is contained in:
Sam Leffler 2003-09-26 17:00:44 +00:00
parent ef39d4be37
commit 303ebc3c87
Notes: svn2git 2020-12-20 02:59:44 +00:00 
svn path=/head/; revision=120483
3 changed files with 27 additions and 6 deletions
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31
sys/net80211/ieee80211_node.c
View File

@ -92,6 +92,7 @@ ieee80211_node_attach(struct ifnet *ifp)
ic->ic_node_free = ieee80211_node_free;
ic->ic_node_copy = ieee80211_node_copy;
ic->ic_node_getrssi = ieee80211_node_getrssi;
ic->ic_scangen = 1;
}
void
@ -541,29 +542,47 @@ ieee80211_free_allnodes(struct ieee80211com *ic)
mtx_unlock(&ic->ic_nodelock);
}
/*
* Timeout inactive nodes. Note that we cannot hold the node
* lock while sending a frame as this would lead to a LOR.
* Instead we use a generation number to mark nodes that we've
* scanned and drop the lock and restart a scan if we have to
* time out a node. Since we are single-threaded by virtue of
* controlling the inactivity timer we can be sure this will
* process each node only once.
*/
void
ieee80211_timeout_nodes(struct ieee80211com *ic)
{
struct ieee80211_node *ni, *nextbs;
struct ieee80211_node *ni;
u_int gen = ic->ic_scangen++; /* NB: ok 'cuz single-threaded*/
restart:
mtx_lock(&ic->ic_nodelock);
for (ni = TAILQ_FIRST(&ic->ic_node); ni != NULL;) {
TAILQ_FOREACH(ni, &ic->ic_node, ni_list) {
if (ni->ni_scangen == gen) /* previously handled */
continue;
ni->ni_scangen = gen;
if (++ni->ni_inact > IEEE80211_INACT_MAX) {
IEEE80211_DPRINTF(("station %s timed out "
"due to inactivity (%u secs)\n",
ether_sprintf(ni->ni_macaddr),
ni->ni_inact));
nextbs = TAILQ_NEXT(ni, ni_list);
/*
* Send a deauthenticate frame.
*
* Drop the node lock before sending the
* deauthentication frame in case the driver takes
* a lock, as this will result in a LOR between the
* node lock and the driver lock.
*/
mtx_unlock(&ic->ic_nodelock);
IEEE80211_SEND_MGMT(ic, ni,
IEEE80211_FC0_SUBTYPE_DEAUTH,
IEEE80211_REASON_AUTH_EXPIRE);
ieee80211_free_node(ic, ni);
ni = nextbs;
} else
ni = TAILQ_NEXT(ni, ni_list);
goto restart;
}
}
if (!TAILQ_EMPTY(&ic->ic_node))
ic->ic_inact_timer = IEEE80211_INACT_WAIT;

1
sys/net80211/ieee80211_node.h
View File

@ -62,6 +62,7 @@ struct ieee80211_node {
TAILQ_ENTRY(ieee80211_node) ni_list;
LIST_ENTRY(ieee80211_node) ni_hash;
u_int ni_refcnt;
u_int ni_scangen; /* gen# for timeout scan */
/* hardware */
u_int32_t ni_rstamp; /* recv timestamp */

1
sys/net80211/ieee80211_var.h
View File

@ -165,6 +165,7 @@ struct ieee80211com {
u_int16_t ic_rtsthreshold;
u_int16_t ic_fragthreshold;
struct mtx ic_nodelock; /* on node table */
u_int ic_scangen; /* gen# for timeout scan */
struct ieee80211_node *(*ic_node_alloc)(struct ieee80211com *);
void (*ic_node_free)(struct ieee80211com *,
struct ieee80211_node *);