From: Hans Dedecker <dedeckeh@gmail.com>
Date: Fri, 16 Aug 2019 19:22:11 +0000 (+0200)
Subject: router: speed up initial router advertisements
X-Git-Url: https://git.librecmc.org/?a=commitdiff_plain;h=752fc2c278dc01f0b3ed2faf67a11f9bc1f3c627;p=oweals%2Fodhcpd.git

router: speed up initial router advertisements

Speed up sending initial router advertisement messages as documented in
RFC2461 point 6.2.4

Signed-off-by: Hans Dedecker <dedeckeh@gmail.com>
---

diff --git a/src/odhcpd.h b/src/odhcpd.h
index 8715ca7..4a07252 100644
--- a/src/odhcpd.h
+++ b/src/odhcpd.h
@@ -212,6 +212,7 @@ struct interface {
 	// RA runtime data
 	struct odhcpd_event router_event;
 	struct uloop_timeout timer_rs;
+	uint32_t ra_sent;
 
 	// DHCPv6 runtime data
 	struct odhcpd_event dhcpv6_event;
diff --git a/src/router.c b/src/router.c
index 34d43b0..07dd146 100644
--- a/src/router.c
+++ b/src/router.c
@@ -176,6 +176,7 @@ int router_setup_interface(struct interface *iface, bool enable)
 			}
 
 			iface->router_event.handle_dgram = handle_icmpv6;
+			iface->ra_sent = 0;
 			odhcpd_register(&iface->router_event);
 		} else {
 			uloop_timeout_cancel(&iface->timer_rs);
@@ -358,6 +359,13 @@ static int calc_adv_interval(struct interface *iface, uint32_t minvalid,
 	msecs = (labs(msecs) % ((*maxival != minival) ? (*maxival - minival)*1000 : 500)) +
 			minival*1000;
 
+	/* RFC 2461 6.2.4 For the first MAX_INITIAL_RTR_ADVERTISEMENTS advertisements */
+	/* if the timer is bigger than MAX_INITIAL_RTR_ADVERT_INTERVAL it should be   */
+	/* set to MAX_INITIAL_RTR_ADVERT_INTERVAL                                     */
+	/* Off by one as an initial interval timer has already expired                */
+	if ((iface->ra_sent + 1) < MaxInitialRtAdvs && msecs > MaxInitialRtrAdvInterval*1000)
+		msecs = MaxInitialRtrAdvInterval*1000;
+
 	return msecs;
 }
 
@@ -730,7 +738,8 @@ static int send_router_advert(struct interface *iface, const struct in6_addr *fr
 
 	syslog(LOG_NOTICE, "Sending a RA on %s", iface->name);
 
-	odhcpd_send(iface->router_event.uloop.fd, &dest, iov, ARRAY_SIZE(iov), iface);
+	if (odhcpd_send(iface->router_event.uloop.fd, &dest, iov, ARRAY_SIZE(iov), iface) > 0)
+		iface->ra_sent++;
 
 	free(pfxs);
 	free(routes);
diff --git a/src/router.h b/src/router.h
index bdfe52c..0444da8 100644
--- a/src/router.h
+++ b/src/router.h
@@ -30,9 +30,11 @@ struct icmpv6_opt {
 	(void*)(opt + opt->len) <= (void*)(end); opt += opt->len)
 
 
-#define MaxRtrAdvInterval	1800
-#define MinRtrAdvInterval	3
+#define MaxInitialRtrAdvInterval	16
+#define MaxInitialRtAdvs		3
+#define MaxRtrAdvInterval		1800
+#define MinRtrAdvInterval		3
 
-#define ND_RA_FLAG_PROXY	0x4
-#define ND_RA_PREF_HIGH		(1 << 3)
-#define ND_RA_PREF_LOW		(3 << 3)
+#define ND_RA_FLAG_PROXY		0x4
+#define ND_RA_PREF_HIGH			(1 << 3)
+#define ND_RA_PREF_LOW			(3 << 3)