diff options
author | sam <sam@FreeBSD.org> | 2003-09-26 17:00:44 +0000 |
---|---|---|
committer | sam <sam@FreeBSD.org> | 2003-09-26 17:00:44 +0000 |
commit | 04780f09b987e2ef533889f0c8b72c83eeadf3c3 (patch) | |
tree | b1c9d39f8d12ac9b255ebf7ad82967552c1efad0 | |
parent | d39b84f6ea494a7cbeef6071986a4793b0103e77 (diff) | |
download | FreeBSD-src-04780f09b987e2ef533889f0c8b72c83eeadf3c3.zip FreeBSD-src-04780f09b987e2ef533889f0c8b72c83eeadf3c3.tar.gz |
Try yet again to deal with timing out nodes. We cannot hold the
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.
-rw-r--r-- | sys/net80211/ieee80211_node.c | 31 | ||||
-rw-r--r-- | sys/net80211/ieee80211_node.h | 1 | ||||
-rw-r--r-- | sys/net80211/ieee80211_var.h | 1 |
3 files changed, 27 insertions, 6 deletions
diff --git a/sys/net80211/ieee80211_node.c b/sys/net80211/ieee80211_node.c index e688fde..966f812 100644 --- a/sys/net80211/ieee80211_node.c +++ b/sys/net80211/ieee80211_node.c @@ -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; diff --git a/sys/net80211/ieee80211_node.h b/sys/net80211/ieee80211_node.h index de300fa..d61ff7b 100644 --- a/sys/net80211/ieee80211_node.h +++ b/sys/net80211/ieee80211_node.h @@ -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 */ diff --git a/sys/net80211/ieee80211_var.h b/sys/net80211/ieee80211_var.h index 2546bb8..e57d7ca 100644 --- a/sys/net80211/ieee80211_var.h +++ b/sys/net80211/ieee80211_var.h @@ -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 *); |