Netlink: Ignore dead routes

With net.ipv4.conf.XXX.ignore_routes_with_linkdown sysctl, a user can
ensure the kernel does not use a route whose target interface is down.
Such route is marked with a 'dead' / RTNH_F_DEAD flag.

Ignore these routes or multipath nexthops during scan.

Thanks to Vincent Bernat for the original patch.
This commit is contained in:
Ondrej Zajicek (work) 2021-01-14 01:51:09 +01:00
parent a40ddf5c61
commit df83f62697

View file

@ -697,6 +697,9 @@ nl_parse_multipath(struct nl_parse_state *s, struct krt_proto *p, struct rtattr
if ((len < sizeof(*nh)) || (len < nh->rtnh_len))
return NULL;
if (nh->rtnh_flags & RTNH_F_DEAD)
goto next;
*last = rv = lp_allocz(s->pool, NEXTHOP_MAX_SIZE);
last = &(rv->next);
@ -772,7 +775,7 @@ nl_parse_multipath(struct nl_parse_state *s, struct krt_proto *p, struct rtattr
}
#endif
next:
len -= NLMSG_ALIGN(nh->rtnh_len);
nh = RTNH_NEXT(nh);
}
@ -1683,6 +1686,9 @@ nl_parse_route(struct nl_parse_state *s, struct nlmsghdr *h)
break;
}
if (i->rtm_flags & RTNH_F_DEAD)
return;
ra->nh.iface = if_find_by_index(oif);
if (!ra->nh.iface)
{