PERFORCE change 137936 for review

[Sam Leffler]

http://perforce.freebsd.org/chv.cgi?CH=137936

Change 137936 by sam at sam_ebb on 2008/03/17 18:56:44

	Defer state change on disassociate to avoid unnecessarily dropping
	the lease; we set a timer on disassociate and if we re-associate
	to the same ap then we just continue using the current lease; otherwise
	we reboot the state machine as before.
	
	May need to tweak the timer and/or fix other edge cases in the
	dhcp state machine but I think link state change events should
	handle other reasons to clock the state machine.

Affected files ...

.. //depot/projects/vap/sbin/dhclient/dhclient.c#4 edit

Differences ...

==== //depot/projects/vap/sbin/dhclient/dhclient.c#4 (text+ko) ====

@@ -176,8 +176,30 @@
 
 	return (NULL);
 }
+
 struct iaddr defaddr = { 4 };
+uint8_t curbssid[6];
+
+static void
+disassoc(void *arg)
+{
+	struct interface_info *ifi = arg;
 
+	/*
+	 * Clear existing state.
+	 */
+	if (ifi->client->active != NULL) {
+		script_init("EXPIRE", NULL);
+		script_write_params("old_",
+		    ifi->client->active);
+		if (ifi->client->alias)
+			script_write_params("alias_",
+				ifi->client->alias);
+		script_go();
+	}
+	ifi->client->state = S_INIT;
+}
+
 /* ARGSUSED */
 void
 routehandler(struct protocol *p)
@@ -187,6 +209,7 @@
 	struct if_msghdr *ifm;
 	struct ifa_msghdr *ifam;
 	struct if_announcemsghdr *ifan;
+	struct ieee80211_join_event *jev;
 	struct client_lease *l;
 	time_t t = time(NULL);
 	struct sockaddr *sa;
@@ -255,24 +278,28 @@
 		switch (ifan->ifan_what) {
 		case RTM_IEEE80211_ASSOC:
 		case RTM_IEEE80211_REASSOC:
+			cancel_timeout(disassoc, ifi);
+			jev = (struct ieee80211_join_event *) &ifan[1];
+			if (memcmp(curbssid, jev->iev_addr, 6))
+				disassoc(ifi);
 			state_reboot(ifi);
+			memcpy(curbssid, jev->iev_addr, 6);
 			break;
 		case RTM_IEEE80211_DISASSOC:
 			/*
-			 * Clear existing state; transition to the init
-			 * state and then wait for either a link down
-			 * notification or an associate event.
+			 * Defer state change in case we are re-associating
+			 * to the same ap after a deauth (e.g. due to being
+			 * idle).  We'll get an associate event and if we
+			 * roamed we'll handle it (see above).  Otherwise we'll
+			 * eventually clear state.  The only question is how
+			 * long to wait before doing this.  Give it 45 seconds
+			 * as this should be plenty to scan multiple bands
+			 * and complete a WPA handshake.  If this event is a
+			 * precursor to our being marked down or the interface
+			 * going away that'll be handled by the link state
+			 * change.
 			 */
-			if (ifi->client->active != NULL) {
-				script_init("EXPIRE", NULL);
-				script_write_params("old_",
-				    ifi->client->active);
-				if (ifi->client->alias)
-					script_write_params("alias_",
-						ifi->client->alias);
-				script_go();
-			}
-			ifi->client->state = S_INIT;
+			add_timeout(t+45, disassoc, ifi);
 			break;
 		}
 		break;