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| author | Roy Marples <roy@marples.name> | 2019-08-30 11:06:20 +0100 |
|---|---|---|
| committer | Roy Marples <roy@marples.name> | 2019-08-30 11:06:20 +0100 |
| commit | 2c340935edbe3a6e9b1ff50ff7f9f23414986180 (patch) | |
| tree | 57a57bf549309a1a1c4a2044a00aad5db6a61252 /src/ipv6nd.c | |
| parent | 9dff4f78f2ac04d207953982cb649ac927eb4f07 (diff) | |
| download | dhcpcd-2c340935edbe3a6e9b1ff50ff7f9f23414986180.tar.xz | |
inet6: Stop reacting to kernel neighbour messages about a router
It's unreliable and very corner case.
See the comment for the ipv6nd_neighbour() function.
Diffstat (limited to 'src/ipv6nd.c')
| -rw-r--r-- | src/ipv6nd.c | 21 |
1 files changed, 15 insertions, 6 deletions
diff --git a/src/ipv6nd.c b/src/ipv6nd.c index cb9e1086..35401b75 100644 --- a/src/ipv6nd.c +++ b/src/ipv6nd.c @@ -554,8 +554,21 @@ ipv6nd_startexpire(struct interface *ifp) ipv6nd_expire, ifp); } +/* + * Neighbour reachability. + * + * RFC 4681 6.2.5 says when a node is no longer a router it MUST + * send a RA with a zero lifetime. + * All OS's I know of set the NA router flag if they are a router + * or not and disregard that they are actively advertising or + * shutting down. If the interface is disabled, it cant't send a NA at all. + * + * As such we CANNOT rely on the NA Router flag and MUST use + * unreachability or receive a RA with a lifetime of zero to remove + * the node as a default router. + */ void -ipv6nd_neighbour(struct dhcpcd_ctx *ctx, struct in6_addr *addr, int flags) +ipv6nd_neighbour(struct dhcpcd_ctx *ctx, struct in6_addr *addr, bool reachable) { struct ra *rap, *rapr; @@ -570,11 +583,7 @@ ipv6nd_neighbour(struct dhcpcd_ctx *ctx, struct in6_addr *addr, int flags) if (rap == NULL || rap->expired) return; - if (!(flags & IPV6ND_ROUTER) && rap->lifetime != 0) { - loginfox("%s: %s is no longer a router", - rap->iface->name, rap->sfrom); - rap->lifetime = 0; - } else if (flags & IPV6ND_REACHABLE) { + if (reachable) { if (rap->isreachable) return; loginfox("%s: %s is reachable again", |