This is an attempt to clean-up the DHCP lease server type code a bit. We
now strictly use the same enum everywhere, and store server info in an
array. Moreover, we use the same nomenclature everywhere.
This only makes the changes in the sd-dhcp code. The networkd code is
untouched so far (but should be fixed up like this too. But it's more
complicated since this would then touch actual settings in .network
files).
Note that this also changes some field names in serialized lease files.
But given that these field names have not been part of a released
version of systemd yet, such a change should be ok.
This is pure renaming/refactoring, shouldn't actually change any
behaviour.
The Router DHCP option may contain a list of one or more
routers ([1]). Extend the API of sd_dhcp_lease to return a
list instead of only the first.
Note that networkd still only uses the first router (if present).
Aside from extending the internal API of the DHCP client, there
is almost no change in behavior. The only visible difference in
behavior is that the "ROUTER" variable in the lease file is now a
list of addresses.
Note how RFC 2132 does not define certain IP addresses as invalid for the
router option. Still, previously sd_dhcp_lease_get_router() would never
return a "0.0.0.0" address. In fact, the previous API could not
differenciate whether no router option was present, whether it
was invalid, or whether its first router was "0.0.0.0". No longer let
the DHCP client library impose additional restrictions that are not
part of RFC. Instead, the caller should handle this. The patch does
that, and networkd only consideres the first router entry if it is not
"0.0.0.0".
[1] https://tools.ietf.org/html/rfc2132#section-3.5
Since sd_dhcp_lease_get_routes() returns the list of all routes,
the caller may need to differenciate whether the route was option
33 (static-routes) or 121 (classless-static-route).
Add an accessor for the internal field.
This part of the copyright blurb stems from the GPL use recommendations:
https://www.gnu.org/licenses/gpl-howto.en.html
The concept appears to originate in times where version control was per
file, instead of per tree, and was a way to glue the files together.
Ultimately, we nowadays don't live in that world anymore, and this
information is entirely useless anyway, as people are very welcome to
copy these files into any projects they like, and they shouldn't have to
change bits that are part of our copyright header for that.
hence, let's just get rid of this old cruft, and shorten our codebase a
bit.
This adds a modified version of dhcp6_option_parse_domainname() that is
able to parse compressed domain names, borrowing the idea from
dns_packet_read_name(). It also adds pieces in networkd-link and
networkd-manager to properly save/load the added option field.
Resolves#2710.
At the moment sd_dhcp_lease_get_routes() returns an array of structs
which are not defined in public headers. Instead, change the function
to return an array of pointers to opaque sd_dhcp_route objects.
GLIB has recently started to officially support the gcc cleanup
attribute in its public API, hence let's do the same for our APIs.
With this patch we'll define an xyz_unrefp() call for each public
xyz_unref() call, to make it easy to use inside a
__attribute__((cleanup())) expression. Then, all code is ported over to
make use of this.
The new calls are also documented in the man pages, with examples how to
use them (well, I only added docs where the _unref() call itself already
had docs, and the examples, only cover sd_bus_unrefp() and
sd_event_unrefp()).
This also renames sd_lldp_free() to sd_lldp_unref(), since that's how we
tend to call our destructors these days.
Note that this defines no public macro that wraps gcc's attribute and
makes it easier to use. While I think it's our duty in the library to
make our stuff easy to use, I figure it's not our duty to make gcc's own
features easy to use on its own. Most likely, client code which wants to
make use of this should define its own:
#define _cleanup_(function) __attribute__((cleanup(function)))
Or similar, to make the gcc feature easier to use.
Making this logic public has the benefit that we can remove three header
files whose only purpose was to define these functions internally.
See #2008.
Exported header files should not include internal headers. Fix that.
Exported header files should not use the bool type. So far we opted to
stick to C89 for exported headers, and hence use "int" for bools in
them. Continue to do so.
Exported header files should have #include lines for everything they use
including inttypes.h and sys/types.h, so that they may be included in
any order.
Exported header files should have C++ guards, hence add them.
Exported header files should not use gcc extensions like #pragma once,
get rid of it.
a) drop handling of obsolete or unused DHCP options time_offset,
mtu_aging_timeout, policy filter, mdr, ttl, ip forwarding settings.
Should this become useful one day we can readd support for this.
b) For subnet mask and broadcast it is not always clear whether 0 or
255.255.255.255 might be valid, hence maintain a boolean indicating
validity next to it.
c) serialize/deserialize broadcast address, lifetime, T1 and T2 together
with the rest of the fields in dhcp_lease_save() and
dhcp_lease_load().
d) consistently return ENODATA from getter functions for data that is
missing in the lease.
e) add missing getter calls for broadcast, lifetime, T1, T2.
f) when decoding DHCP options, generate debug messages on parse
failures, but try to proceed if possible.
g) Similar, when deserializing a lease in dhcp_lease_load(), make sure
we deal nicely with unparsable fields, to provide upgrade compat.
h) fix some memory allocations
When we make sd-dhcp public one day we really should not make
sd_dhcp_lease_save() and sd_dhcp_lease_load() public, since it's pretty
much only useful as internal utility for networkd itself.
This adds support for option 43 (Vendor Specific Information) to
libsystemd-network DHCP code. The option carries an opaque object of n
octets, interpreted by vendor-specific code on the clients and
servers.
[@zonque: adopted to new unhexmem() API]
As long as the number of array entries is relatively small it's nicer to
simply return the number of entries directly, instead of using a size_t*
return parameter for it.
Let's turn resolved into a something truly useful: a fully asynchronous
DNS stub resolver that subscribes to network changes.
(More to come: caching, LLMNR, mDNS/DNS-SD, DNSSEC, IDN, NSS module)
This adds support for DHCP options 33 and 121: Static Route and
Classless Static Route. To enable this feature, set UseRoutes=true
in .network file. Returned routes are added to the routing table.
