Insert the new gateway at the end when it has the least preference.
Fixes the following runtime error:
src/ndisc/nm-ndisc.c:204:_ASSERT_data_gateways: assertion failed:
(_preference_to_priority (item_prev->preference) >=
_preference_to_priority (item->preference))
and nm_utils_ip6_property_path(). The API with static buffers
looks a bit nicer. But I think they are dangerous, because
we tend to pass the buffer down several layers of the stack, and
it's not immediately clear, that we don't overwrite the static
buffer again (which we probably did not, but it's hard to verify
that there is no bug there).
- add assert code to check that our internal tracking of
the gateways is consistent.
- assert (gracefully) against libndp returning :: as gateway
address.
We encounter the same enum in 3 forms:
- NMNDiscPreference in NetworkManager
- "enum ndp_route_preference" in <ndp.h>
- ICMPV6_ROUTER_PREF_* in <linux/icmpv6.h>
Move our enum to nm-core-utils.h, so that it can be used
by platform code as well (platform code should not include
ndisc/nm-ndisc.h).
Also, NMNDiscPreference was not numerically identical to their
native values (meaning: it shuffled the names and numbers).
Make them all numerically equal, so that they can be used in
the same context.
This means, while previously we could compare NMNDiscPreference
directly according to their priority, we now need _preference_to_priority().
On the other hand, we could omit translate_preference() -- but actually,
we still have _route_preference_coerce() because pref comes from libndp
and is thus untrusted. We still have to range check it.
We have the timestamp nm_utils_get_monotonic_time_s(), which should be
gint32 type. Then we also have timestamps in the NMNDisc* objects, which
consist of guint32 timestamp and lifetime.
Cleanup handling the times and calculation of the timestamps by using
the correct integer type consistently and ensuring that no integer overflow
occurs.
The @i variable to loop over the arrays should have the same type as
GArray.len, to which it is compared. In this case "guint".
As we remove items from the arrays while iterating over it, it gets
a bit complicated either way. I disliked that
g_array_remove_index (rdata->gateways, i--);
would underflow for unsigned integers. While that would work fine,
I think that is confusing. So, the variable is no longer incremented
in the increment statement of the for loop.
Instead of having 3 properties @gateway, @never_default and @has_gateway
on NMIP4Config/NMIP6Config that determine the default-route, track the
default-route as a regular route.
The gateway setting is the configuration knob for the default-route.
Since an NMIP4Config/NMIP6Config instance only has one gateway property,
it cannot track more then one default-routes (see related bug rh#1445417).
Especially with policy routing, it might be interesting to configure a
default-route in multiple tables.
Also, later it might be interesting to allow adding default-routes as
regular static routes in a connection, so that the user can configure additional
route parameters for the default-route or add default-routes in multiple tables.
With this patch, default-routes now have a rt_source property according to their
origin.
Also, the previous commits of this branch broke handling of the
default-route :) . That should be working now again.
Add an utility function for resetting addresses/routes of NMIP6Config
from NMNDisc data. For one, this de-duplicates code in device and
nm-iface-helper.
Also, we no longer first reset (delete) all addresses and add them anew.
Instead, we first mark all entries as dirty for deletion, merge (append)
the new entires, and delete the remaining dirty entires. This saves a
extra work, in the expected case where NMIP6Config already contains
several of the new entries.
Usecase: when connecting to a public Wi-Fi with MAC address randomization
("wifi.cloned-mac-address=random") you get on every re-connect a new
IP address due to the changing MAC address.
"wifi.cloned-mac-address=stable" is the solution for that. But that
means, every time when reconnecting to this network, the same ID will
be reused. We want an ID that is stable for a while, but at a later
point a new ID should e generated when revisiting the Wi-Fi network.
Extend the stable-id to become dynamic and support templates/substitutions.
Currently supported is "${CONNECTION}", "${BOOT}" and "${RANDOM}".
Any unrecognized pattern is treated verbaim/untranslated.
"$$" is treated special to allow escaping the '$' character. This allows
the user to still embed verbatim '$' characters with the guarantee that
future versions of NetworkManager will still generate the same ID.
Of course, a user could just avoid '$' in the stable-id unless using
it for dynamic substitutions.
Later we might want to add more recognized substitutions. For example, it
could be useful to generate new IDs based on the current time. The ${} syntax
is extendable to support arguments like "${PERIODIC:weekly}".
Also allow "connection.stable-id" to be set as global default value.
Previously that made no sense because the stable-id was static
and is anyway strongly tied to the identity of the connection profile.
Now, with dynamic stable-ids it gets much more useful to specify
a global default.
Note that pre-existing stable-ids don't change and still generate
the same addresses -- unless they contain one of the new ${} patterns.
We require a network-id. Assert that it is set.
Also, we encode the stable-id as uint8. Thus, add
an assertion that we don't use more then 254 IDs.
If we ever make use of stable-type 255, we must extend
the encoding to allow for more values. The assertion
is there to catch that.
Keep the include paths clean and separate. We use directories to group source
files together. That makes sense (I guess), but then we should use this
grouping also when including files. Thus require to #include files with their
path relative to "src/".
Also, we build various artifacts from the "src/" tree. Instead of having
individual CFLAGS for each artifact in Makefile.am, the CFLAGS should be
unified. Previously, the CFLAGS for each artifact differ and are inconsistent
in which paths they add to the search path. Fix the inconsistency by just
don't add the paths at all.
The ndisc config can now be changed by NMDevice as well when the NDisc
is in ROUTER mode. But what we're really interested in is when we
receive a new one from the outside.
We'll soon not only do the router discovery, but announce ourselves as a
reouter. "Neighbor discovery" sounds to be a more appropriate name for
the class than "Router discovery".
