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.
Configuration through environment variable is inconvenient with meson, because
they cannot be convieniently changed and/or are not preserved during
reconfiguration (https://github.com/mesonbuild/meson/issues/1503).
This adds -Dvalgrind=true/false, which has the advantage that it can be set
at any time with meson configure -Dvalgrind=... and ninja will rebuild targets
as necessary. Additional minor advantages are better consistency with the
options for hashmap debugging, and typo avoidance with '#if' instead of '#ifdef'.
Files which are installed as-is (any .service and other unit files, .conf
files, .policy files, etc), are left as is. My assumption is that SPDX
identifiers are not yet that well known, so it's better to retain the
extended header to avoid any doubt.
I also kept any copyright lines. We can probably remove them, but it'd nice to
obtain explicit acks from all involved authors before doing that.
Technically DNS allows any ASCII character to be used in the
domain name. Also the DHCP specification for the FQDN option
(RFC 4702) does not put restriction on labels.
However, hostnames do have stricter requirements and typically
should only use characters from a-z (case insensitve), 0-9 and
minus.
Currently we require hostname/FQDN to be either a hostname or
a valid DNS name. Since dns_name_is_valid() allows any ASCII
characters this allows to specify hostnames which are typically
not valid.
Check hostname/FQDN more strictly and require them to pass both
tests. Specifically this requires the entire FQDN to be below 63.
A field "index" is not particularly precise and also might conflict with libc's
index() function definition. Also, pretty much everywhere else we call this
concept "ifindex", including in networkd, the primary user of these libraries.
Hence, let's fix this up and call this "ifindex" everywhere here too.
libsystemd-network provides the public function
sd_dhcp_client_set_request_option() to enable the request of a given
DHCP option. However the enum defining such options is defined in the
internal header dhcp-protocol.h. Move the enum definition to the
public header sd-dhcp-client.h and properly namespace values.
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.
If a client sends a DECLINE or a server sends a NAK, they can include
a string with a message to explain the error. Parse this and print it
at debug level.
There are more than enough calls doing string manipulations to deserve
its own files, hence do something about it.
This patch also sorts the #include blocks of all files that needed to be
updated, according to the sorting suggestions from CODING_STYLE. Since
pretty much every file needs our string manipulation functions this
effectively means that most files have sorted #include blocks now.
Also touches a few unrelated include files.
In our API design, getter-functions don't ref objects. Calls like
foo_get_bar() will not ref 'bar'. We never do that and there is no real
reason to do it in single threaded APIs. If you need a ref-count, you
better take it yourself *BEFORE* doing anything else on the parent object
(as this might invalidate your pointer).
Right now, sd_dhcp?_get_lease() refs the lease it returns. A lot of
code-paths in systemd do not expect this and thus leak the lease
reference. Fix this by changing the API to not ref returned objects.
This patch removes includes that are not used. The removals were found with
include-what-you-use which checks if any of the symbols from a header is
in use.
./test-dhcp-client would attempt to operate fd 0, i.e. stdin.
For example, './test-dhcp-client </dev/null' would fail with EPERM
because /dev/null cannot be used with epoll.
https://bugzilla.redhat.com/show_bug.cgi?id=1076119
In addition to the benefits listed in the RFC, this allows DHCP to work also in
case several interfaces share the same MAC address on the same link (IPVLAN).
Note that this will make the ClientID (so probably the assigned IP address)
change on upgrades. If it is desired to avoid that we would have to remember and
write back the ID (which the library supports, but networkd currently does not).
Like Infiniband. See RFC 4390 section 2.1 for details on DHCP
and Infiniband; chaddr is zeroed, hlen is set to 0, and htype
is set to ARPHRD_INFINIBAND because IB hardware addresses
are 20 bytes in length.
The timeouts in the networking library (DHCP lease timeouts and similar) should not be affected
by suspend. In the cases where CLOCK_BOOTTIME is not implemented, it is still safe to fallback to
CLOCK_MONOTONIC, as the consumers of the library (i.e., networkd) _should_ renew the leases when
coming out of suspend.
Check that received DHCP packets actually include our MAC address in
chaddr field. BPF interpreter has 32 bit wide registers but MAC address
is 48 bits long so we have to do check in two steps.
For efficiency, we group bytes together before adding them up. This
is guaranteed to always work (regardless of the byte order) as long
as the i-th byte in each group lign up with the i-th byte in each
other group.
On big-endian machines this broke when handling the trailing few bytes
which did not make up a full group of 4 bytes. This patch fixes the
problem by explicitly creating a 4 byte zero-padded group out of the
trailing bytes.
Reported and tested by Thomas Ritter <th.ritter@gmx.at>.
- Also only allow positive ifindex on both dhcp and ipv4ll
[tomegun: the kernel always sets a positive ifindex, but some APIs accept
ifindex=0 with various meanings, so we should protect against
accidentally passing ifindex=0 along.]
The DHCP library user can decide to free the DHCP client any time
the callback is called. After the callback has been called, other
computations may still be needed - the best example being a full
restart of the DHCP procedure in case of lease expiry.
Fix this by introducing proper reference counting. Properly handle
a returned NULL from the notify and stop functions if the DHCP
client was freed.
Try a bit harder to make the kernel drop packets not for us. This should reduce
the number of wakeups from n^2 to n in the number of dhcp clients, which admittedly
only makes a differenc in very extreme cases.
One end of the socketpair is closed by the library, so only close our end. Also switch to
the safe_close() so we get notified about problems with closing.
Zbigniew Jędrzejewski-Szmek