This macro will read a pointer of any type, return it, and set the
pointer to NULL. This is useful as an explicit concept of passing
ownership of a memory area between pointers.
This takes inspiration from Rust:
https://doc.rust-lang.org/std/option/enum.Option.html#method.take
and was suggested by Alan Jenkins (@sourcejedi).
It drops ~160 lines of code from our codebase, which makes me like it.
Also, I think it clarifies passing of ownership, and thus helps
readability a bit (at least for the initiated who know the new macro)
When the DHCP server returns both a Classless Static Routes
option and a Static Routes option, the DHCP client MUST ignore the
Static Routes option.
Closes#7792
Let's replace usage of fputc_unlocked() and friends by __fsetlocking(f,
FSETLOCKING_BYCALLER). This turns off locking for the entire FILE*,
instead of doing individual per-call decision whether to use normal
calls or _unlocked() calls.
This has various benefits:
1. It's easier to read and easier not to forget
2. It's more comprehensive, as fprintf() and friends are covered too
(as these functions have no _unlocked() counterpart)
3. Philosophically, it's a bit more correct, because it's more a
property of the file handle really whether we ever pass it on to another
thread, not of the operations we then apply to it.
This patch reworks all pieces of codes that so far used fxyz_unlocked()
calls to use __fsetlocking() instead. It also reworks all places that
use open_memstream(), i.e. use stdio FILE* for string manipulations.
Note that this in some way a revert of 4b61c87511.
Using strlen() to declare a buffer results in a variable-length array,
even if the compiler likely optimizes it to be a compile time constant.
When building with -Wvla, certain versions of gcc complain about such
buffers. Compiling with -Wvla has the advantage of preventing variably
length array, which defeat static asserts that are implemented by
declaring an array of negative length.
Let's rename all our functions that process IPv4 in_addr structures
in4_addr_xyz(), following the already establishing naming logic for
this.
Leave the in_addr_xyz() prefix for functions that process the IPv4/IPv6
in_addr_union union instead.
As a follow-up for db3f45e2d2 let's do the
same for all other cases where we create a FILE* with local scope and
know that no other threads hence can have access to it.
For most cases this shouldn't change much really, but this should speed
dbus introspection and calender time formatting up a bit.
Let's downgrade the warning introduced by
955d99edc7 to debug, as we really
shouldn't log at more than debug level from library code.
(And while we are at it, print the MTU as the right (unsigned) type in
the format string.)
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.
Initialize auto variables with cleanup attribute, otherwise we
get a compiler warning with -fexceptions.
./configure CFLAGS='-Wmaybe-uninitialized -fexceptions -O2'
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.
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.
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.
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.
Previoulsy, we just checked whether the domain names specified in
incoming DHCP leases are valid. Given that validation code actually
internally normalizes anyway, it's a good idea to simply do the full
normalization and store that in the lease structure. This allows us to
remove the manual removal of a trailing dot, if there is one.
Tests are modified to check behaviour with relax and without relax.
New tests are added for hostname_cleanup().
Tests are moved a new file (test-hostname-util) because there's
now a bunch of them.
New parameter is not used anywhere, except in tests, so there should
be no observable change.
This stores private-zone DHCP options inside of their respective DHCP
lease. These options aren't used by networkd (what would it do with
them?), but saving them will allow other programs to query the values.
To improve performance, the options are stored in ascending order by
tag.
Some places invoked fflush() directly with their own manual error
checking, let's unify all that by using fflush_and_check().
This also unifies the general error paths of fflush()+rename() file
writers.
sd-dhcp-lease: fix handling of multiple routers
We only support one router, but in case more than one is given, we now ignore subsequent ones, rather than fall over.
Lennart Poettering