shithub: riscv

Info  •  Files  •  Log  •  Branches

devip: only add interface route for "on-link" prefixes

when a prefix is added with the onlink flag clear, packets
towards that prefix needs to be send to the default gateway
so we omit adding the interface route.

when the on-link flag gets changed to 1 later, we add the
interface route.

the on-link flag is sticky, so theres no way to clear it back
to zero except removing and re-adding the prefix.

--- a/sys/src/9/ip/ipifc.c

+++ b/sys/src/9/ip/ipifc.c

@@ -505,7 +505,14 @@

 	/* ignore if this is already a local address for this ifc */

 	if((lifc = iplocalonifc(ifc, ip)) != nil){

 		if(lifcp != nil) {

-			lifc->onlink = lifcp->onlink;

+			if(!lifc->onlink && lifcp->onlink){

+				lifc->onlink = 1;

+				addroute(f, lifc->remote, lifc->mask, ip, IPallbits,

+					lifc->remote, lifc->type, ifc, tifc);

+				if(v6addrtype(ip) != linklocalv6)

+					addroute(f, lifc->remote, lifc->mask, ip, IPnoaddr,

+						lifc->remote, lifc->type, ifc, tifc);

+			}

 			lifc->autoflag = lifcp->autoflag;

 			lifc->validlt = lifcp->validlt;

 			lifc->preflt = lifcp->preflt;

@@ -546,9 +553,11 @@

 	*l = lifc;

 	/* add route for this logical interface */

-	addroute(f, rem, mask, ip, IPallbits, rem, type, ifc, tifc);

-	if(v6addrtype(ip) != linklocalv6)

-		addroute(f, rem, mask, ip, IPnoaddr, rem, type, ifc, tifc);

+	if(lifc->onlink){

+		addroute(f, rem, mask, ip, IPallbits, rem, type, ifc, tifc);

+		if(v6addrtype(ip) != linklocalv6)

+			addroute(f, rem, mask, ip, IPnoaddr, rem, type, ifc, tifc);

+	}

 	addselfcache(f, ifc, lifc, ip, Runi);

@@ -635,13 +644,15 @@

 		remselfcache(f, ifc, lifc, lifc->link->self->a);

 	/* remove the route for this logical interface */

-	remroute(f, lifc->remote, lifc->mask,

-		lifc->local, IPallbits,

-		lifc->remote, lifc->type, ifc, tifc);

-	if(v6addrtype(lifc->local) != linklocalv6)

+	if(lifc->onlink){

 		remroute(f, lifc->remote, lifc->mask,

-			lifc->local, IPnoaddr,

+			lifc->local, IPallbits,

 			lifc->remote, lifc->type, ifc, tifc);

+		if(v6addrtype(lifc->local) != linklocalv6)

+			remroute(f, lifc->remote, lifc->mask,

+				lifc->local, IPnoaddr,

+				lifc->remote, lifc->type, ifc, tifc);

+	}

 	/* unregister proxy */

 	if(lifc->type & Rptpt){