From: Roy Marples <roy@marples.name>
Date: Tue, 18 Jun 2013 09:17:28 +0000 (+0000)
Subject: Add a delay to initial Rebind IA_PD message.
X-Git-Tag: v6.0.0~13
X-Git-Url: http://git.ipfire.org/gitweb.cgi?a=commitdiff_plain;h=a945c63ad93e801765afbd4c900740861118abbb;p=thirdparty%2Fdhcpcd.git

Add a delay to initial Rebind IA_PD message.
Delay initial DHCPv6 messages a futher 2 seconds for POINTOPOINT links to
try and ensure dhcpcd receives a reply.
Process link events last so that dhcpcd can process any rejection messages.
When a delegating interface stops, the delegates addresses will be removed.
---

diff --git a/dhcp6.c b/dhcp6.c
index 08a51a87..ecb6a1c0 100644
--- a/dhcp6.c
+++ b/dhcp6.c
@@ -742,7 +742,14 @@ dhcp6_sendmessage(struct interface *ifp, void (*callback)(void *))
 		    state->send->xid[2]);
 	else {
 		if (state->IMD) {
-			state->RT.tv_sec = 0;
+			/* Some buggy PPP servers close the link too early
+			 * after sending an invalid status in their reply
+			 * which means this host won't see it.
+			 * 2 seconds grace seems to be the sweet spot. */
+			if (ifp->flags & IFF_POINTOPOINT)
+				state->RT.tv_sec = 2;
+			else
+				state->RT.tv_sec = 0;
 			state->RT.tv_usec = arc4random() %
 			    (state->IMD * 1000000);
 			timernorm(&state->RT);
@@ -1008,11 +1015,12 @@ dhcp6_startrebind(void *arg)
 
 	/* RFC 3633 section 12.1 */
 	if (ifp->options->ia_type == D6_OPTION_IA_PD) {
-	    state->IRT = CNF_TIMEOUT;
-	    state->MRT = CNF_MAX_RT;
+		state->IMD = CNF_MAX_DELAY;
+		state->IRT = CNF_TIMEOUT;
+		state->MRT = CNF_MAX_RT;
 	} else {
-	    state->IRT = REB_TIMEOUT;
-	    state->MRT = REB_MAX_RT;
+		state->IRT = REB_TIMEOUT;
+		state->MRT = REB_MAX_RT;
 	}
 
 	if (dhcp6_makemessage(ifp) == -1)
@@ -2392,10 +2400,20 @@ dhcp6_freedrop(struct interface *ifp, int drop, const char *reason)
 		if (ifp->options->options & DHCPCD_RELEASE) {
 			if (ifp->carrier != LINK_DOWN)
 				dhcp6_startrelease(ifp);
-			dhcp6_delete_delegates(ifp);
 			unlink(state->leasefile);
 		}
 		dhcp6_freedrop_addrs(ifp, drop, NULL);
+		/* As the interface is going away from dhcpcd we need to
+		 * remove the delegated addresses, otherwise we lose track
+		 * of which interface is delegating as we remeber it by pointer.
+		 * So if we need to change this behaviour, we need to change
+		 * how we remember which interface delegated.
+		 * To make it more interesting, on some OS's with PPP links
+		 * there is no guarantee the delegating interface will have
+		 * the same name or index so think very hard before changing
+		 * this. */
+		if (ifp->options->options & (DHCPCD_STOPPING | DHCPCD_RELEASE))
+			dhcp6_delete_delegates(ifp);
 		if (drop && state->new) {
 			if (reason == NULL)
 				reason = "STOP6";
diff --git a/dhcpcd.c b/dhcpcd.c
index f5781869..0ded685c 100644
--- a/dhcpcd.c
+++ b/dhcpcd.c
@@ -274,6 +274,7 @@ stop_interface(struct interface *ifp)
 {
 
 	syslog(LOG_INFO, "%s: removing interface", ifp->name);
+	ifp->options->options |= DHCPCD_STOPPING;
 
 	// Remove the interface from our list
 	TAILQ_REMOVE(ifaces, ifp, next);
diff --git a/eloop.c b/eloop.c
index 7f7364cd..0a7f69a6 100644
--- a/eloop.c
+++ b/eloop.c
@@ -132,7 +132,13 @@ eloop_event_add(int fd, void (*callback)(void *), void *arg)
 	e->fd = fd;
 	e->callback = callback;
 	e->arg = arg;
-	TAILQ_INSERT_TAIL(&events, e, next);
+	/* The order of events should not matter.
+	 * However, some PPP servers love to close the link right after
+	 * sending their final message. So to ensure dhcpcd processes this
+	 * message (which is likely to be that the DHCP addresses are wrong)
+	 * we insert new events at the queue head as the link fd will be
+	 * the first event added. */
+	TAILQ_INSERT_HEAD(&events, e, next);
 	eloop_event_setup_fds();
 	return 0;
 }
diff --git a/if-options.h b/if-options.h
index 579a0ffa..06cccdf0 100644
--- a/if-options.h
+++ b/if-options.h
@@ -92,7 +92,8 @@
 #define DHCPCD_STARTED			(1ULL << 38)
 #define DHCPCD_NOALIAS			(1ULL << 39)
 #define DHCPCD_IA_FORCED		(1ULL << 40)
-#define DHCPCD_DEPARTED			(1ULL << 41)
+#define DHCPCD_STOPPING			(1ULL << 41)
+#define DHCPCD_DEPARTED			(1ULL << 42)
 
 extern const struct option cf_options[];