From: Roy Marples <roy@marples.name>
Date: Fri, 1 May 2015 15:52:34 +0000 (+0000)
Subject: On carrier down, rebuild routes and expire RA's if keeping IP addressses.
X-Git-Tag: v6.8.2~5
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=2f53bfd408f7c26fbe73febf466ec3bfe8bbdf61;p=thirdparty%2Fdhcpcd.git

On carrier down, rebuild routes and expire RA's if keeping IP addressses.
On carrier up, set RA's to expire comletely after a few seconds.
If no valid RA's are available, kill DHCPv6.
---

diff --git a/dhcpcd.c b/dhcpcd.c
index 76205e20..18c19e99 100644
--- a/dhcpcd.c
+++ b/dhcpcd.c
@@ -640,6 +640,8 @@ dhcpcd_handlecarrier(struct dhcpcd_ctx *ctx, int carrier, unsigned int flags,
 			script_runreason(ifp, "NOCARRIER");
 #ifdef NOCARRIER_PRESERVE_IP
 			arp_close(ifp);
+			ipv4_buildroutes(ifp->ctx);
+			ipv6nd_expire(ifp, 0);
 #else
 			dhcpcd_drop(ifp, 0);
 #endif
@@ -671,6 +673,12 @@ dhcpcd_handlecarrier(struct dhcpcd_ctx *ctx, int carrier, unsigned int flags,
 			}
 			dhcpcd_initstate(ifp, 0);
 			script_runreason(ifp, "CARRIER");
+#ifdef NOCARRIER_PRESERVE_IP
+			/* Set any IPv6 Routers we remembered to expire
+			 * faster than they would normally as we
+			 * maybe on a new network. */
+			ipv6nd_expire(ifp, RTR_CARRIER_EXPIRE);
+#endif
 			/* RFC4941 Section 3.5 */
 			if (ifp->options->options & DHCPCD_IPV6RA_OWN)
 				ipv6_gentempifid(ifp);
diff --git a/ipv4.c b/ipv4.c
index e517bcbb..d088d803 100644
--- a/ipv4.c
+++ b/ipv4.c
@@ -720,12 +720,14 @@ ipv4_buildroutes(struct dhcpcd_ctx *ctx)
 	}
 
 	/* Remove old routes we used to manage */
-	TAILQ_FOREACH(rt, ctx->ipv4_routes, next) {
-		if (find_route(nrs, rt, NULL) == NULL &&
-		    (rt->iface->options->options &
-		    (DHCPCD_EXITING | DHCPCD_PERSISTENT)) !=
-		    (DHCPCD_EXITING | DHCPCD_PERSISTENT))
-			d_route(rt);
+	if (ctx->ipv4_routes) {
+		TAILQ_FOREACH(rt, ctx->ipv4_routes, next) {
+			if (find_route(nrs, rt, NULL) == NULL &&
+			    (rt->iface->options->options &
+			    (DHCPCD_EXITING | DHCPCD_PERSISTENT)) !=
+			    (DHCPCD_EXITING | DHCPCD_PERSISTENT))
+				d_route(rt);
+		}
 	}
 	ipv4_freeroutes(ctx->ipv4_routes);
 	ctx->ipv4_routes = nrs;
diff --git a/ipv6nd.c b/ipv6nd.c
index ff389a44..89f6782f 100644
--- a/ipv6nd.c
+++ b/ipv6nd.c
@@ -54,9 +54,6 @@
 /* Debugging Router Solicitations is a lot of spam, so disable it */
 //#define DEBUG_RS
 
-#define RTR_SOLICITATION_INTERVAL       4 /* seconds */
-#define MAX_RTR_SOLICITATIONS           3 /* times */
-
 #ifndef ND_OPT_RDNSS
 #define ND_OPT_RDNSS			25
 struct nd_opt_rdnss {           /* RDNSS option RFC 6106 */
@@ -311,9 +308,48 @@ ipv6nd_sendrsprobe(void *arg)
 	if (state->rsprobes++ < MAX_RTR_SOLICITATIONS)
 		eloop_timeout_add_sec(ifp->ctx->eloop,
 		    RTR_SOLICITATION_INTERVAL, ipv6nd_sendrsprobe, ifp);
-	else
+	else {
 		logger(ifp->ctx, LOG_WARNING,
 		    "%s: no IPv6 Routers available", ifp->name);
+		ipv6nd_drop(ifp);
+		dhcp6_drop(ifp, "EXPIRE6");
+	}
+}
+
+void
+ipv6nd_expire(struct interface *ifp, uint32_t seconds)
+{
+	struct ra *rap;
+	struct timespec now;
+
+	get_monotonic(&now);
+
+	TAILQ_FOREACH(rap, ifp->ctx->ipv6->ra_routers, next) {
+		if (rap->iface == ifp) {
+			rap->received = now;
+			rap->expired = seconds ? 0 : 1;
+			if (seconds) {
+				struct ra_opt *rao;
+				struct ipv6_addr *ap;
+
+				rap->lifetime = seconds;
+				TAILQ_FOREACH(ap, &rap->addrs, next) {
+					if (ap->prefix_vltime) {
+						ap->prefix_vltime = seconds;
+						ap->prefix_pltime = seconds / 2;
+					}
+				}
+				ipv6_addaddrs(&rap->addrs);
+				TAILQ_FOREACH(rao, &rap->options, next) {
+					timespecclear(&rao->expire);
+				}
+			}
+		}
+	}
+	if (seconds)
+		ipv6nd_expirera(ifp);
+	else
+		ipv6_buildroutes(ifp->ctx);
 }
 
 static void
@@ -407,7 +443,6 @@ void ipv6nd_freedrop_ra(struct ra *rap, int drop)
 	ipv6nd_free_opts(rap);
 	free(rap->data);
 	free(rap);
-
 }
 
 ssize_t
@@ -1388,13 +1423,14 @@ ipv6nd_expirera(void *arg)
 	struct ra *rap, *ran;
 	struct ra_opt *rao, *raon;
 	struct timespec now, lt, expire, next;
-	uint8_t expired, valid;
+	uint8_t expired, valid, validone;
 
 	ifp = arg;
 	get_monotonic(&now);
 	expired = 0;
 	timespecclear(&next);
 
+	validone = 0;
 	TAILQ_FOREACH_SAFE(rap, ifp->ctx->ipv6->ra_routers, next, ran) {
 		if (rap->iface != ifp)
 			continue;
@@ -1410,6 +1446,7 @@ ipv6nd_expirera(void *arg)
 					    "%s: %s: router expired",
 					    ifp->name, rap->sfrom);
 					rap->expired = expired = 1;
+					rap->lifetime = 0;
 				}
 			} else {
 				valid = 1;
@@ -1462,6 +1499,8 @@ ipv6nd_expirera(void *arg)
 		 * as well punt it. */
 		if (!valid && TAILQ_FIRST(&rap->addrs) == NULL)
 			ipv6nd_free_ra(rap);
+		else
+			validone = 1;
 	}
 
 	if (timespecisset(&next))
@@ -1471,6 +1510,10 @@ ipv6nd_expirera(void *arg)
 		ipv6_buildroutes(ifp->ctx);
 		script_runreason(ifp, "ROUTERADVERT");
 	}
+
+	/* No valid routers? Kill any DHCPv6. */
+	if (!validone)
+		dhcp6_drop(ifp, "EXPIRE6");
 }
 
 void
diff --git a/ipv6nd.h b/ipv6nd.h
index cb71d746..2ab76df3 100644
--- a/ipv6nd.h
+++ b/ipv6nd.h
@@ -73,6 +73,14 @@ struct rs_state {
 
 #define MAX_RTR_SOLICITATION_DELAY	1	/* seconds */
 #define MAX_UNICAST_SOLICIT		3	/* 3 transmissions */
+#define RTR_SOLICITATION_INTERVAL	4	/* seconds */
+#define MAX_RTR_SOLICITATIONS		3	/* times */
+
+/* On carrier up, expire known routers after RTR_CARRIER_EXPIRE seconds. */
+#define RTR_CARRIER_EXPIRE		\
+    (MAX_RTR_SOLICITATION_DELAY +	\
+    (MAX_RTR_SOLICITATIONS + 1) *	\
+    RTR_SOLICITATION_INTERVAL)
 
 #define MAX_REACHABLE_TIME		3600000	/* milliseconds */
 #define REACHABLE_TIME			30000	/* milliseconds */
@@ -98,6 +106,7 @@ void ipv6nd_runignoredra(struct interface *);
 void ipv6nd_handleifa(struct dhcpcd_ctx *, int,
     const char *, const struct in6_addr *, int);
 int ipv6nd_dadcompleted(const struct interface *);
+void ipv6nd_expire(struct interface *, uint32_t);
 void ipv6nd_drop(struct interface *);
 void ipv6nd_neighbour(struct dhcpcd_ctx *, struct in6_addr *, int);
 #else