From: Roy Marples <roy@marples.name>
Date: Mon, 6 Aug 2012 19:32:15 +0000 (+0000)
Subject: Change the NS times so that we assume reachable until the reachable
X-Git-Tag: v5.6.2~8
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=ea112ab290d35fe4df41df4f77be50b005934402;p=thirdparty%2Fdhcpcd.git

Change the NS times so that we assume reachable until the reachable
time expires, then send probes at retrans intervals until
DELAY_FIRST_PROBE_TIME is reached at which point we expire the router.
---

diff --git a/common.h b/common.h
index 41101983..e11cc511 100644
--- a/common.h
+++ b/common.h
@@ -37,6 +37,11 @@
 #define UNCONST(a)		((void *)(unsigned long)(const void *)(a))
 
 #define timeval_to_double(tv) ((tv)->tv_sec * 1.0 + (tv)->tv_usec * 1.0e-6)
+#define ms_to_tv(tv, ms) 						\
+	do {								\
+		(tv)->tv_sec = (ms / 1000);				\
+		(tv)->tv_usec = ((ms % 1000) * 1000);			\
+	} while (0 /* CONSTCOND */);
 #define timernorm(tvp)							\
 	do {								\
 		while ((tvp)->tv_usec >= 1000000) {			\
diff --git a/ipv6ns.c b/ipv6ns.c
index 14e1f570..c66770c2 100644
--- a/ipv6ns.c
+++ b/ipv6ns.c
@@ -158,6 +158,20 @@ ipv6ns_makeprobe(struct ra *rap)
 	return 0;
 }
 
+static void
+ipv6ns_unreachable(void *arg)
+{
+	struct ra *rap = arg;
+
+	/* We could add an unreachable flag and persist the information,
+	 * but that is more effort than it's probably worth. */
+	syslog(LOG_WARNING, "%s: %s is unreachable, expiring it",
+	    rap->iface->name, rap->sfrom);
+	rap->expired = 1;
+	ipv6_build_routes();
+	run_script_reason(rap->iface, "ROUTERADVERT"); /* XXX not RA */
+}
+
 void
 ipv6ns_sendprobe(void *arg)
 {
@@ -168,7 +182,7 @@ ipv6ns_sendprobe(void *arg)
 	int hoplimit = HOPLIMIT;
 	struct timeval tv, rtv;
 
-	if (!rap->nsprobes) {
+	if (!rap->ns) {
 		if (ipv6ns_makeprobe(rap) == -1)
 			return;
 	}
@@ -208,26 +222,18 @@ ipv6ns_sendprobe(void *arg)
 	if (sendmsg(sock, &sndhdr, 0) == -1)
 		syslog(LOG_ERR, "%s: sendmsg: %m", rap->iface->name);
 
-	tv.tv_sec = RETRANS_TIMER;
-	tv.tv_usec = MIN_RANDOM_FACTOR;
+
+	ms_to_tv(&tv, rap->retrans ? rap->retrans : RETRANS_TIMER);
+	ms_to_tv(&rtv, MIN_RANDOM_FACTOR);
+	timeradd(&tv, &rtv, &tv);
 	rtv.tv_sec = 0;
 	rtv.tv_usec = arc4random() % (MAX_RANDOM_FACTOR - MIN_RANDOM_FACTOR);
 	timeradd(&tv, &rtv, &tv);
 	add_timeout_tv(&tv, ipv6ns_sendprobe, rap);
-}
-
-void
-ipv6ns_unreachable(void *arg)
-{
-	struct ra *rap = arg;
 
-	/* We could add an unreachable flag and persist the information,
-	 * but that is more effort than it's probably worth. */
-	syslog(LOG_WARNING, "%s: %s is unreachable, expiring it",
-	    rap->iface->name, rap->sfrom);
-	rap->expired = 1;
-	ipv6_build_routes();
-	run_script_reason(rap->iface, "ROUTERADVERT"); /* XXX not RA */
+	if (rap->nsprobes++ == 0)
+		add_timeout_sec(DELAY_FIRST_PROBE_TIME,
+		    ipv6ns_unreachable, rap);
 }
 
 /* ARGSUSED */
@@ -244,6 +250,7 @@ ipv6ns_handledata(_unused void *arg)
 	struct nd_neighbor_advert *nd_na;
 	struct ra *rap;
 	int is_router, is_solicited;
+	struct timeval tv;
 
 	len = recvmsg(sock, &rcvhdr, 0);
 	if (len == -1) {
@@ -340,8 +347,14 @@ ipv6ns_handledata(_unused void *arg)
 	}
 
 	if (is_solicited) {
-		rap->nsprobes = 1;
-		add_timeout_sec(REACHABLE_TIME, ipv6ns_unreachable, rap);
-		add_timeout_sec(DELAY_FIRST_PROBE_TIME, ipv6ns_sendprobe, rap);
+		rap->nsprobes = 0;
+		if (rap->reachable) {
+			ms_to_tv(&tv, rap->reachable);
+		} else {
+			tv.tv_sec = REACHABLE_TIME;
+			tv.tv_usec = 0;
+		}
+		add_timeout_tv(&tv, ipv6ns_sendprobe, rap);
+		delete_timeout(ipv6ns_unreachable, rap);
 	}
 }
diff --git a/ipv6ns.h b/ipv6ns.h
index 05636c9e..e71a6e79 100644
--- a/ipv6ns.h
+++ b/ipv6ns.h
@@ -31,12 +31,12 @@
 #include "dhcpcd.h"
 #include "ipv6rs.h"
 
+#define MAX_REACHABLE_TIME	3600	/* seconds */
 #define REACHABLE_TIME		30 	/* seconds */
 #define RETRANS_TIMER		1  	/* second */
 #define DELAY_FIRST_PROBE_TIME	5	/* seconds */
 
 int ipv6ns_open(void);
-void ipv6ns_unreachable(void *);
 void ipv6ns_sendprobe(void *);
 void ipv6ns_handledata(void *);
 #endif
diff --git a/ipv6rs.c b/ipv6rs.c
index 3a837a1d..4d2bd244 100644
--- a/ipv6rs.c
+++ b/ipv6rs.c
@@ -447,6 +447,9 @@ ipv6rs_handledata(_unused void *arg)
 		if (rap) {
 			free(rap->data);
 			rap->data_len = 0;
+			free(rap->ns);
+			rap->ns = NULL;
+			rap->nslen = 0;
 		}
 		syslog(LOG_INFO, "%s: Router Advertisement from %s",
 		    ifp->name, sfrom);
@@ -473,6 +476,13 @@ ipv6rs_handledata(_unused void *arg)
 	nd_ra = (struct nd_router_advert *)icp;
 	rap->flags = nd_ra->nd_ra_flags_reserved;
 	rap->lifetime = ntohs(nd_ra->nd_ra_router_lifetime);
+	if (nd_ra->nd_ra_reachable) {
+		rap->reachable = ntohl(nd_ra->nd_ra_reachable);
+		if (rap->reachable > MAX_REACHABLE_TIME)
+			rap->reachable = 0;
+	}
+	if (nd_ra->nd_ra_retransmit)
+		rap->retrans = ntohl(nd_ra->nd_ra_retransmit);
 	rap->expired = 0;
 
 	len -= sizeof(struct nd_router_advert);
@@ -706,8 +716,7 @@ ipv6rs_handledata(_unused void *arg)
 	    options & DHCPCD_IPV6RA_OWN_DEFAULT)
 	{
 		rap->nsprobes = 0;
-		add_timeout_sec(REACHABLE_TIME, ipv6ns_unreachable, rap);
-		add_timeout_sec(DELAY_FIRST_PROBE_TIME, ipv6ns_sendprobe, rap);
+		ipv6ns_sendprobe(rap);
 	}
 }
 
diff --git a/ipv6rs.h b/ipv6rs.h
index cae4058d..ef8b4068 100644
--- a/ipv6rs.h
+++ b/ipv6rs.h
@@ -52,6 +52,8 @@ struct ra {
 	struct timeval received;
 	unsigned char flags;
 	uint32_t lifetime;
+	uint32_t reachable;
+	uint32_t retrans;
 	uint32_t mtu;
 	TAILQ_HEAD(, ipv6_addr) addrs;
 	TAILQ_HEAD(, ra_opt) options;