In order to avoid that the kernel uses virtual tunnel IPs for traffic
over physical interfaces we previously deprecated the virtual IP. While
this is working it is not ideal. This patch adds address labels for
virtual IPs, which should force the kernel to avoid such addresses to
reach any destination unless there is an explicit route that uses it as
source address.
%unique (and the upcoming %same key) are usable in specific contexts only.
To restrict the user from using it in other places where it does not get the
expected results, reject such keywords unless explicitly allowed.
We now check if there are other routes tracked for the same destination
and replace the installed route instead of just removing it. Same during
installation, where we previously didn't replace existing routes due to
NLM_F_EXCL. Routes with virtual IPs as source address are preferred over
routes without.
This should allow using trap policies with virtual IPs on Linux.
Fixes#85, #2162.
This can be useful if routing rules (instead of e.g. route metrics) are used
to switch from one to another interface (i.e. from one to another
routing table). Since we currently don't evaluate routing rules when
doing the route lookup this is only useful if the kernel-based route
lookup is used.
Resolvesstrongswan/strongswan#88.
If an interface is renamed we already have an entry (based on the
ifindex) allocated but previously only set the usable state once
based on the original name.
Fixes#2403.
For table dumps the kernel accepts RTA_PREFSRC to filter the routes, which is
what we do when doing userspace route calculations. For kernel-based route
lookups, however, the RTA_PREFSRC attribute is ignored and we must specify
RTA_SRC for policy based route lookups.
For gateways with many connections, installing routes is often disabled,
as we can use a static route configuration to achieve proper routing with
a single rule. If this is the case, there is no need to dump all routes and
do userspace route lookups, as there is no need to exclude routes we installed
ourself.
Doing kernel-based route lookups is not only faster with may routes, but also
can use the full power of Linux policy based routing; something we can hardly
rebuild in userspace when calculating routes.
The Optimistic Duplicate Address Detection (DAD) seems to fail in some
cases (`dadfailed` in `ip addr`) rendering the virtual IP address unusable.
Fixes#2183.
This implements rule 6 of RFC 6724 using the default priority table,
so that e.g. global addresses are preferred over ULAs (which also have
global scope) when the destination is a global address.
Fixes#2138.
A wrong variable is used (route instead of best), so much that the
returned interface belongs to the last seen route instead of the best
choice route.
get_route() may therefore return mismatching interface and gateway.
Fixes: 66e9165bc6 ("kernel-netlink: Return outbound interface in get_nexthop()")
Signed-off-by: Christophe Gouault <christophe.gouault@6wind.com>
Metrics are basically defined to order routes with equal prefix, so ordering
routes by metric first makes not much sense as that could prefer totally
unspecific routes over very specific ones.
For instance, the previous code did break installation of routes for
passthrough policies with two routes like these in the main routing table:
default via 192.168.2.1 dev eth0 proto static
192.168.2.0/24 dev eth0 proto kernel scope link src 192.168.2.10 metric 1
Because the default route has no metric set (0) it was used, instead of the
more specific other one, to determine src and next hop when installing a route
for a passthrough policy for 192.168.2.0/24. Therefore, the installed route
in table 220 did then incorrectly redirect all local traffic to "next hop"
192.168.2.1.
The same issue occurred when determining the source address while
installing trap policies.
Fixes 6b57790270 ("kernel-netlink: Respect kernel routing priorities for IKE routes").
Fixes#1416.
Tobias Brunner