- Fix the polling code to work with media settings in dhclient.conf.

- Rename linkstatus to linkstate which is more correct.

- Sort any leases each time we loose and regain link. With the first
  version we spammed the dhclient.leases file.

- When there was no link on a interface, polling has been done twice.
  This has been fixed with a bigger sleep interval.

- interface_active() now returns only a assumed state of the link.
  If we are using media settings, we cannot be sure that the link
  actually works. That means we assume that the link is working and
  continue to send requests as usual on the interface and loop over
  all possible media options. Polling is still done. If your interface
  gets suddenly link, dhclient will send a dhcp discover request.

After all media settings have been tried a few times, dhclient will
sleep. If one does change networks very often, it can help to set the
"retry timeout" to a low value like 100 seconds. The default is over
six minutes.

Tested by:	Larry Rosenman <ler@lerctr.org>, imp

2 files changed, 189 insertions, 38 deletions

diff --git a/contrib/isc-dhcp/client/dhclient.c b/contrib/isc-dhcp/client/dhclient.c
index 820205f..f1bd5c4 100644
--- a/contrib/isc-dhcp/client/dhclient.c
+++ b/contrib/isc-dhcp/client/dhclient.c
@@ -257,8 +257,11 @@ int main (argc, argv, envp)
 			    log_fatal ("%s: interface name too long (max %ld)",
 				       argv [i], (long)strlen (argv [i]));
  		    strlcpy (tmp -> name, argv [i], IFNAMSIZ);
+#ifdef __FreeBSD__
 		    set_ieee80211 (tmp);
-		    tmp -> linkstatus = interface_active (tmp);
+#endif
+		    tmp -> forcediscover = 0;
+		    tmp -> linkstate = 0;
 		    if (interfaces) {
 			    interface_reference (&tmp -> next,
 						 interfaces, MDL);
@@ -412,7 +415,15 @@ int main (argc, argv, envp)
 					     INTERFACE_AUTOMATIC)) !=
 			     INTERFACE_REQUESTED))
 				continue;
+#ifdef __FreeBSD__
 			set_ieee80211 (ip);
+#endif
+			ip -> forcediscover = 0;
+			if (ip -> client -> config -> media != NULL)
+				ip -> havemedia = 1;
+			else
+				ip -> havemedia = 0;
+
 			script_init (ip -> client,
 				     "PREINIT", (struct string_list *)0);
 			if (ip -> client -> alias)
@@ -909,6 +920,15 @@ void bind_lease (client)
 	/* Write out the new lease. */
 	write_client_lease (client, client -> new, 0, 0);
 
+	/*
+	 * It's now possible that state_reboot can be called
+	 * after a interface link went down and is up again.
+	 * To prevent tons of equal leases saved on disk, we rewrite
+	 * them.
+	 */
+	read_client_leases ();
+	rewrite_client_leases ();
+
 	/* Replace the old active lease with the new one. */
 	if (client -> active)
 		destroy_client_lease (client -> active);
@@ -923,6 +943,10 @@ void bind_lease (client)
 	      piaddr (client -> active -> address),
 	      (long)(client -> active -> renewal - cur_time));
 	client -> state = S_BOUND;
+#ifdef ENABLE_POLLING_MODE
+	client -> interface -> linkstate = HAVELINK;
+	client -> interface -> forcediscover = 0;
+#endif /* ifdef ENABLE_POLLING_MODE */
 	reinitialize_interfaces ();
 	go_daemon ();
 	if (client -> config -> do_forward_update) {
@@ -1385,9 +1409,6 @@ void send_discover (cpp)
 	int interval;
 	int increase = 1;
 
-	if (interface_active (client -> interface) == 0)
-		return;
-
 	/* Figure out how long it's been since we started transmitting. */
 	interval = cur_time - client -> first_sending;
 
@@ -1427,6 +1448,9 @@ void send_discover (cpp)
 		}
 	}
 
+	if (interface_active (client -> interface) == NOLINK)
+		return;
+
 	/* If we're supposed to increase the interval, do so.  If it's
 	   currently zero (i.e., we haven't sent any packets yet), set
 	   it to one; otherwise, add to it a random number between
@@ -1493,7 +1517,7 @@ void state_panic (cpp)
 	struct client_lease *loop;
 	struct client_lease *lp;
 
-	if (interface_active (client -> interface) == 0)
+	if (interface_active (client -> interface) == NOLINK)
 		return;
 
 	loop = lp = client -> active;
@@ -1535,6 +1559,11 @@ void state_panic (cpp)
 				log_info ("bound: immediate renewal.");
 				state_bound (client);
 			    }
+			    /*
+			     * Set the link status back to nolink, even
+			     * if we have media settings.
+			     */
+			    client -> interface -> linkstate = NOLINK;
 			    reinitialize_interfaces ();
 			    go_daemon ();
 			    return;
@@ -2809,7 +2838,7 @@ void client_location_changed ()
 				break;
 			}
 			client -> state = S_INIT;
-			if (interface_active (ip))
+			if (interface_active (ip) == HAVELINK)
 				state_reboot (client);
 		}
 	}
@@ -2971,7 +3000,7 @@ isc_result_t dhclient_interface_startup_hook (struct interface_info *interface)
 			client -> state = S_INIT;
 			/* Set up a timeout to start the initialization
 			   process. */
-			if (interface_active (ip)) {
+			if (interface_active (ip) == HAVELINK) {
 				add_timeout (cur_time + random () % 5,
 					     state_reboot, client, 0, 0);
 			}
@@ -3038,7 +3067,7 @@ isc_result_t dhcp_set_control_state (control_object_state_t oldstate,
 		    break;
 
 		  case server_awaken:
-		    if (interface_active (ip))
+		    if (interface_active (ip) == HAVELINK)
 			    state_reboot (client);
 		    break;
 		}
@@ -3199,38 +3228,69 @@ interface_active(struct interface_info *ip) {
 		 * Interface doesn't support SIOCGIFMEDIA, presume okay
 		 */
 		close (sock);
-		return (1);
+		return (HAVELINK);
 	}
 	close (sock);
 
 	if (ifmr.ifm_count == 0) {
 		/*
-		 * this is unexpected (to me), but we'll just assume
-		 * that this means interface does not support SIOCGIFMEDIA
+		 * Assume that this means interface
+		 * does not support SIOCGIFMEDIA
 		 */
 		log_fatal ("%s: no media types?", ifname);
-		return (1);
+		return (HAVELINK);
 	}
 
 	if (ifmr.ifm_status & IFM_AVALID) {
 		if (ip -> ieee80211) {
+			/*
+			 * Wavelan devices need to be checked if they are
+			 * associated.
+			 */
 			if ((IFM_TYPE(ifmr.ifm_active) == IFM_IEEE80211) &&
-			     (ifmr.ifm_status & IFM_ACTIVE))
-				return (1);
+			     (ifmr.ifm_status & IFM_ACTIVE)) {
+				if (ip -> havemedia &&
+				    ip -> client -> state != S_BOUND)
+					ip -> forcediscover = 1;
+				return (HAVELINK);
+			}
 		} else {
-			if (ifmr.ifm_status & IFM_ACTIVE)
-				return (1);
+			/*
+			 * Media settings can also be possible for normal
+			 * devices. 
+			 */
+			if (ifmr.ifm_status & IFM_ACTIVE) {
+				if (ip -> havemedia &&
+				    ip -> client -> state != S_BOUND)
+					ip -> forcediscover = 1;
+				return (HAVELINK);
+			}
 		}
 	}
 
-	return (0);
+	/*
+	 * If dhclient.conf contains media settings, we cannot
+	 * abort if the interface is not set to active mode.
+	 */
+	if (ip -> havemedia && ip -> client -> state != S_BOUND)
+		return (HAVELINK);
+
+	/*
+	 * We really have no link.
+	 */
+	return (NOLINK);
 #else /* ifdef __FreeBSD__ */
 
-	return (1);
+	/*
+	 * Always return a successful link if the OS
+	 * is not supported.
+	 */
+	return (HAVELINK);
 #endif /* Other OSs */
 }
 
 #ifdef __FreeBSD__
+void
 set_ieee80211 (struct interface_info *ip) {
 
 	struct ieee80211req     ireq;
@@ -3267,6 +3327,13 @@ set_ieee80211 (struct interface_info *ip) {
 #endif /* __FreeBSD__ */
 
 #ifdef ENABLE_POLLING_MODE
+/* Go to background after some time */
+void state_background (cpp)
+	void *cpp;
+{
+	go_daemon ();
+}
+
 /* Check the state of the NICs if we have link */
 void state_link (cpp)
         void *cpp;
@@ -3278,50 +3345,123 @@ void state_link (cpp)
 	printf ("Polling interface status\n");
 #endif
 	for (ip = interfaces; ip; ip = ip -> next) {
-		if (ip -> linkstatus == 0 || doinitcheck == 0) {
-			if (interface_active (ip)) {
+		
+#ifdef DEBUG
+		for (client = ip -> client;
+		     client; client = client -> next) {
+			printf ("%s: client state of %d\n", ip -> name, ip -> client -> state);
+			printf ("%s: link = %d\n", ip -> name, ip -> linkstate);
+		}
+#endif
+
+		/*
+		 * The last status of the interface tells us
+		 * the we've got no link ...
+		 */
+		if (ip -> linkstate == NOLINK || ! doinitcheck) {
+			/*
+			 * ... but we have now link. Let's send
+			 * requests.
+			 */
+			if (interface_active (ip) == HAVELINK) {
 #ifdef DEBUG
-				printf ("%s: Found Link on interface\n", ip -> name);
+				if (ip -> havemedia)
+					printf ("%s: Trying media settings on interface\n",
+						ip -> name);
+				else
+					printf ("%s: Found Link on interface\n", ip -> name);
 #endif
+				/*
+				 * Set the interface to state_reboot. But of
+				 * course we can not be sure that we really got link,
+				 * we just assume it.
+				 */
 				for (client = ip -> client;
 				     client; client = client -> next) {
-					add_timeout (cur_time + random () % 5,
-					             state_reboot, client, 0, 0);
+						cancel_timeout (state_init, client);
+						cancel_timeout (state_reboot, client);
+						cancel_timeout (state_selecting, client);
+						add_timeout (cur_time + random () % 5,
+							    state_reboot, client, 0, 0);
 				}
-				ip -> linkstatus = 1;
+				ip -> linkstate = HAVELINK;
 			} else {
 #ifdef DEBUG
 				printf ("%s: No Link on interface\n", ip -> name);
 #endif
 				for (client = ip -> client;
 				     client; client = client -> next) {
-					cancel_timeout (state_init, client);
-			 		cancel_timeout (send_discover, client);
-					cancel_timeout (send_request, client);
 					/*
-					 * XXX without this, dhclient does
+					 * Without this add_timout(), dhclient does
 					 * not poll on a interface if there
 					 * is no cable plugged in at startup
-					 * time
+					 * time. Because we add one additional second 
+					 * to the time of a normal timeout, we always
+					 * skip and block a running one. This prevents
+					 * that polling is done twice at the same time.
 					 */
 					if (client -> state == S_INIT) {
-						add_timeout (cur_time + polling_interval,
+						add_timeout (cur_time + (polling_interval + 1),
 						             state_link, client, 0, 0);
 					}
 			 	}
-				ip -> linkstatus = 0;
+				ip -> linkstate = NOLINK;
+				/*
+				 * Automatically go into the background after
+				 * some time. Do this only if there are no
+				 * media options available for a interface.
+				 */
+				if (! ip -> havemedia && ! doinitcheck) {
+					add_timeout (cur_time + (polling_interval * 2),
+					            state_background, client, 0, 0);
+				}
 			}
-		} else {
-			if (interface_active (ip) == 0) {
+		}
+
+		/*
+		 * The last status of the interface tells us
+		 * the we previously had link.
+		 */
+		if (ip -> linkstate == HAVELINK && doinitcheck) {
+			if (interface_active (ip) == NOLINK) {
+				/*
+				 * We lost link on the interface, or it isn't
+				 * associated anymore.
+				 */
 #ifdef DEBUG
 				printf ("%s: Lost Link on interface\n", ip -> name);
 #endif
-				ip -> linkstatus = 0;
+				/*
+				 * After we lost link, cycle again through the
+				 * different media settings if available. Else
+				 * set NOLINK.
+				 */
+				if (ip -> havemedia)
+					ip -> forcediscover = 1;
+				else
+					ip -> linkstate = NOLINK;
 			}
+			/*
+			 * If we happen to have a real link, but no
+			 * active lease, force the interface into
+			 * state_reboot. Do the same if media settings
+			 * are available.
+			 */
+			if (ip -> forcediscover) {
+				for (client = ip -> client;
+				     client; client = client -> next) {
+					if (client -> state != S_REBOOTING &&
+					    client -> state != S_SELECTING) {
+						add_timeout (cur_time + random () % 5,
+							    state_reboot, client, 0, 0);
+					}
+				}
+				ip -> forcediscover = 0;
+				ip -> linkstate = HAVELINK;
+			}
+			/* We still have link, do nothing. */
 		}
 	}
-	if (doinitcheck)
-		go_daemon ();
 	doinitcheck = 1;
 }
 #endif /* ifdef ENABLE_POLLING_MODE */
diff --git a/contrib/isc-dhcp/includes/dhcpd.h b/contrib/isc-dhcp/includes/dhcpd.h
index d647f12..e62e93b 100644
--- a/contrib/isc-dhcp/includes/dhcpd.h
+++ b/contrib/isc-dhcp/includes/dhcpd.h
@@ -101,6 +101,9 @@ typedef struct hash_table class_hash_t;
 	 (((x) >> OPTION_HASH_EXP) & \
 	  (OPTION_HASH_PTWO - 1))) % OPTION_HASH_SIZE;
 
+#define NOLINK 0
+#define HAVELINK 1
+
 enum dhcp_shutdown_state {
 	shutdown_listeners,
 	shutdown_omapi_connections,
@@ -780,8 +783,10 @@ struct interface_info {
 	unsigned remote_id_len;		/* Length of Remote ID. */
 
 	char name [IFNAMSIZ];		/* Its name... */
-	int linkstatus;			/* Link status */
-	int ieee80211;			/* True if media is ieee80211 */
+	int ieee80211;			/* True if media is ieee802.11 */
+	int havemedia;			/* True if we have a media table */
+	int linkstate;			/* True if we have link */
+	int forcediscover;		/* True if a discover is needed */
 	int index;			/* Its index. */
 	int rfdesc;			/* Its read file descriptor. */
 	int wfdesc;			/* Its write file descriptor, if
@@ -1859,6 +1864,7 @@ void send_decline PROTO ((void *));
 void state_reboot PROTO ((void *));
 #ifdef ENABLE_POLLING_MODE
 void state_link PROTO (());
+void state_background PROTO ((void *));
 #endif
 void state_init PROTO ((void *));
 void state_selecting PROTO ((void *));
@@ -1867,6 +1873,11 @@ void state_bound PROTO ((void *));
 void state_stop PROTO ((void *));
 void state_panic PROTO ((void *));
 
+#ifdef __FreeBSD__
+void set_ieee80211 PROTO ((struct interface_info *));
+#endif
+int interface_active PROTO ((struct interface_info *));
+
 void bind_lease PROTO ((struct client_state *));
 
 void make_client_options PROTO ((struct client_state *,