Do another import, shortly before re-release.
There are no actual changes, but as always: to find out
that there are no changes requires large part of the work of
just doing the reimport.
Also, systemd import branch was rebased recently, that means
git-merge does not get this reimport right automatically (because
it thinks that the changes on master should be reverted). Hence,
this reimport required more care. Do it while there are few
changes.
We have our NM specific logging and log levels. Maybe we should
not have that, and instead only rely on syslog (like systemd)
or glog(). Anyway, currently we have one way and it makes sense
that this is also used outside from "src".
Move the helper function to parse log levels from string to
"nm-logging-base.h" so that we can use the same logging levels
outside of core.
This moves code that is currently GPL2+ licensed to
LGPL2.1+. However as far as I see, this code was entirely written
by Red Hat employees who would not object with this change. Also,
it's as obvious and trivial as it gets.
We have "nm-logging-fwd.h", which (as the name implies) is header-only.
Add instead a "nm-logging-base.c", which also contains implementation for
logging functions that are not only useful under "src/nm-logging.c"
No longer use GDBusObjectMangaerClient and gdbus-codegen generated classes
for the NMClient cache. Instead, use GDBusConnection directly and a
custom implementation (NMLDBusObject) for caching D-Bus' ObjectManager
data.
CHANGES
-------
- This is a complete rework. I think the previous implementation was
difficult to understand. There were unfixed bugs and nobody understood
the code well enough to fix them. Maybe somebody out there understood the
code, but I certainly did not. At least nobody provided patches to fix those
issues. I do believe that this implementation is more straightforward and
easier to understand. It removes a lot of layers of code. Whether this claim
of simplicity is true, each reader must decide for himself/herself. Note
that it is still fairly complex.
- There was a lingering performance issue with large number of D-Bus
objects. The patch tries hard that the implementation scales well. Of
course, when we cache N objects that have N-to-M references to other,
we still are fundamentally O(N*M) for runtime and memory consumption (with
M being the number of references between objects). But each part should behave
efficiently and well.
- Play well with GMainContext. libnm code (NMClient) is generally not
thread safe. However, it should work to use multiple instances in
parallel, as long as each access to a NMClient is through the caller's
GMainContext. This follows glib's style and effectively allows to use NMClient
in a multi threaded scenario. This implies to stick to a main context
upon construction and ensure that callbacks are only invoked when
iterating that context. Also, NMClient itself shall never iterate the
caller's context. This also means, libnm must never use g_idle_add() or
g_timeout_add(), as those enqueue sources in the g_main_context_default()
context.
- Get ordering of messages right. All events are consistently enqueued
in a GMainContext and processed strictly in order. For example,
previously "nm-object.c" tried to combine signals and emit them on an
idle handler. That is wrong, signals must be emitted in the right order
and when they happen. Note that when using GInitable's synchronous initialization
to initialize the NMClient instance, NMClient internally still operates fully
asynchronously. In that case NMClient has an internal main context.
- NMClient takes over most of the functionality. When using D-Bus'
ObjectManager interface, one needs to handle basically the entire state
of the D-Bus interface. That cannot be separated well into distinct
parts, and even if you try, you just end up having closely related code
in different source files. Spreading related code does not make it
easier to understand, on the contrary. That means, NMClient is
inherently complex as it contains most of the logic. I think that is
not avoidable, but it's not as bad as it sounds.
- NMClient processes D-Bus messages and state changes in separate steps.
First NMClient unpacks the message (e.g. _dbus_handle_properties_changed()) and
keeps track of the changed data. Then we update the GObject instances
(_dbus_handle_obj_changed_dbus()) without emitting any signals yet. Finally,
we emit all signals and notifications that were collected
(_dbus_handle_changes_commit()). Note that for example during the initial
GetManagedObjects() reply, NMClient receive a large amount of state at once.
But we first apply all the changes to our GObject instances before
emitting any signals. The result is that signals are always emitted in a moment
when the cache is consistent. The unavoidable downside is that when you receive
a property changed signal, possibly many other properties changed
already and more signals are about to be emitted.
- NMDeviceWifi no longer modifies the content of the cache from client side
during poke_wireless_devices_with_rf_status(). The content of the cache
should be determined by D-Bus alone and follow what NetworkManager
service exposes. Local modifications should be avoided.
- This aims to bring no API/ABI change, though it does of course bring
various subtle changes in behavior. Those should be all for the better, but the
goal is not to break any existing clients. This does change internal
(albeit externally visible) API, like dropping NM_OBJECT_DBUS_OBJECT_MANAGER
property and NMObject no longer implementing GInitableIface and GAsyncInitableIface.
- Some uses of gdbus-codegen classes remain in NMVpnPluginOld, NMVpnServicePlugin
and NMSecretAgentOld. These are independent of NMClient/NMObject and
should be reworked separately.
- While we no longer use generated classes from gdbus-codegen, we don't
need more glue code than before. Also before we constructed NMPropertiesInfo and
a had large amount of code to propagate properties from NMDBus* to NMObject.
That got completely reworked, but did not fundamentally change. You still need
about the same effort to create the NMLDBusMetaIface. Not using
generated bindings did not make anything worse (which tells about the
usefulness of generated code, at least in the way it was used).
- NMLDBusMetaIface and other meta data is static and immutable. This
avoids copying them around. Also, macros like NML_DBUS_META_PROPERTY_INIT_U()
have compile time checks to ensure the property types matches. It's pretty hard
to misuse them because it won't compile.
- The meta data now explicitly encodes the expected D-Bus types and
makes sure never to accept wrong data. That would only matter when the
server (accidentally or intentionally) exposes unexpected types on
D-Bus. I don't think that was previously ensured in all cases.
For example, demarshal_generic() only cared about the GObject property
type, it didn't know the expected D-Bus type.
- Previously GDBusObjectManager would sometimes emit warnings (g_log()). Those
probably indicated real bugs. In any case, it prevented us from running CI
with G_DEBUG=fatal-warnings, because there would be just too many
unrelated crashes. Now we log debug messages that can be enabled with
"LIBNM_CLIENT_DEBUG=trace". Some of these messages can also be turned
into g_warning()/g_critical() by setting LIBNM_CLIENT_DEBUG=warning,error.
Together with G_DEBUG=fatal-warnings, this turns them into assertions.
Note that such "assertion failures" might also happen because of a server
bug (or change). Thus these are not common assertions that indicate a bug
in libnm and are thus not armed unless explicitly requested. In our CI we
should now always run with LIBNM_CLIENT_DEBUG=warning,error and
G_DEBUG=fatal-warnings and to catch bugs. Note that currently
NetworkManager has bugs in this regard, so enabling this will result in
assertion failures. That should be fixed first.
- Note that this changes the order in which we emit "notify:devices" and
"device-added" signals. I think it makes the most sense to emit first
"device-removed", then "notify:devices", and finally "device-added"
signals.
This changes behavior for commit 52ae28f6e5 ('libnm: queue
added/removed signals and suppress uninitialized notifications'),
but I don't think that users should actually rely on the order. Still,
the new order makes the most sense to me.
- In NetworkManager, profiles can be invisible to the user by setting
"connection.permissions". Such profiles would be hidden by NMClient's
nm_client_get_connections() and their "connection-added"/"connection-removed"
signals.
Note that NMActiveConnection's nm_active_connection_get_connection()
and NMDevice's nm_device_get_available_connections() still exposes such
hidden NMRemoteConnection instances. This behavior was preserved.
NUMBERS
-------
I compared 3 versions of libnm.
[1] 962297f908, current tip of nm-1-20 branch
[2] 4fad8c7c64, current master, immediate parent of this patch
[3] this patch
All tests were done on Fedora 31, x86_64, gcc 9.2.1-1.fc31.
The libraries were build with
$ ./contrib/fedora/rpm/build_clean.sh -g -w test -W debug
Note that RPM build already stripped the library.
---
N1) File size of libnm.so.0.1.0 in bytes. There currently seems to be a issue
on Fedora 31 generating wrong ELF notes. Usually, libnm is smaller but
in these tests it had large (and bogus) ELF notes. Anyway, the point
is to show the relative sizes, so it doesn't matter).
[1] 4075552 (102.7%)
[2] 3969624 (100.0%)
[3] 3705208 ( 93.3%)
---
N2) `size /usr/lib64/libnm.so.0.1.0`:
text data bss dec hex filename
[1] 1314569 (102.0%) 69980 ( 94.8%) 10632 ( 80.4%) 1395181 (101.4%) 1549ed /usr/lib64/libnm.so.0.1.0
[2] 1288410 (100.0%) 73796 (100.0%) 13224 (100.0%) 1375430 (100.0%) 14fcc6 /usr/lib64/libnm.so.0.1.0
[3] 1229066 ( 95.4%) 65248 ( 88.4%) 13400 (101.3%) 1307714 ( 95.1%) 13f442 /usr/lib64/libnm.so.0.1.0
---
N3) Performance test with test-client.py. With checkout of [2], run
```
prepare_checkout() {
rm -rf /tmp/nm-test && \
git checkout -B test 4fad8c7c64 && \
git clean -fdx && \
./autogen.sh --prefix=/tmp/nm-test && \
make -j 5 install && \
make -j 5 check-local-clients-tests-test-client
}
prepare_test() {
NM_TEST_REGENERATE=1 NM_TEST_CLIENT_BUILDDIR="/data/src/NetworkManager" NM_TEST_CLIENT_NMCLI_PATH=/usr/bin/nmcli python3 ./clients/tests/test-client.py -v
}
do_test() {
for i in {1..10}; do
NM_TEST_CLIENT_BUILDDIR="/data/src/NetworkManager" NM_TEST_CLIENT_NMCLI_PATH=/usr/bin/nmcli python3 ./clients/tests/test-client.py -v || return -1
done
echo "done!"
}
prepare_checkout
prepare_test
time do_test
```
[1] real 2m14.497s (101.3%) user 5m26.651s (100.3%) sys 1m40.453s (101.4%)
[2] real 2m12.800s (100.0%) user 5m25.619s (100.0%) sys 1m39.065s (100.0%)
[3] real 1m54.915s ( 86.5%) user 4m18.585s ( 79.4%) sys 1m32.066s ( 92.9%)
---
N4) Performance. Run NetworkManager from build [2] and setup a large number
of profiles (551 profiles and 515 devices, mostly unrealized). This
setup is already at the edge of what NetworkManager currently can
handle. Of course, that is a different issue. Here we just check how
long plain `nmcli` takes on the system.
```
do_cleanup() {
for UUID in $(nmcli -g NAME,UUID connection show | sed -n 's/^xx-c-.*:\([^:]\+\)$/\1/p'); do
nmcli connection delete uuid "$UUID"
done
for DEVICE in $(nmcli -g DEVICE device status | grep '^xx-i-'); do
nmcli device delete "$DEVICE"
done
}
do_setup() {
do_cleanup
for i in {1..30}; do
nmcli connection add type bond autoconnect no con-name xx-c-bond-$i ifname xx-i-bond-$i ipv4.method disabled ipv6.method ignore
for j in $(seq $i 30); do
nmcli connection add type vlan autoconnect no con-name xx-c-vlan-$i-$j vlan.id $j ifname xx-i-vlan-$i-$j vlan.parent xx-i-bond-$i ipv4.method disabled ipv6.method ignore
done
done
systemctl restart NetworkManager.service
sleep 5
}
do_test() {
perf stat -r 50 -B nmcli 1>/dev/null
}
do_test
```
[1]
Performance counter stats for 'nmcli' (50 runs):
456.33 msec task-clock:u # 1.093 CPUs utilized ( +- 0.44% )
0 context-switches:u # 0.000 K/sec
0 cpu-migrations:u # 0.000 K/sec
5,900 page-faults:u # 0.013 M/sec ( +- 0.02% )
1,408,675,453 cycles:u # 3.087 GHz ( +- 0.48% )
1,594,741,060 instructions:u # 1.13 insn per cycle ( +- 0.02% )
368,744,018 branches:u # 808.061 M/sec ( +- 0.02% )
4,566,058 branch-misses:u # 1.24% of all branches ( +- 0.76% )
0.41761 +- 0.00282 seconds time elapsed ( +- 0.68% )
[2]
Performance counter stats for 'nmcli' (50 runs):
477.99 msec task-clock:u # 1.088 CPUs utilized ( +- 0.36% )
0 context-switches:u # 0.000 K/sec
0 cpu-migrations:u # 0.000 K/sec
5,948 page-faults:u # 0.012 M/sec ( +- 0.03% )
1,471,133,482 cycles:u # 3.078 GHz ( +- 0.36% )
1,655,275,369 instructions:u # 1.13 insn per cycle ( +- 0.02% )
382,595,152 branches:u # 800.433 M/sec ( +- 0.02% )
4,746,070 branch-misses:u # 1.24% of all branches ( +- 0.49% )
0.43923 +- 0.00242 seconds time elapsed ( +- 0.55% )
[3]
Performance counter stats for 'nmcli' (50 runs):
352.36 msec task-clock:u # 1.027 CPUs utilized ( +- 0.32% )
0 context-switches:u # 0.000 K/sec
0 cpu-migrations:u # 0.000 K/sec
4,790 page-faults:u # 0.014 M/sec ( +- 0.26% )
1,092,341,186 cycles:u # 3.100 GHz ( +- 0.26% )
1,209,045,283 instructions:u # 1.11 insn per cycle ( +- 0.02% )
281,708,462 branches:u # 799.499 M/sec ( +- 0.01% )
3,101,031 branch-misses:u # 1.10% of all branches ( +- 0.61% )
0.34296 +- 0.00120 seconds time elapsed ( +- 0.35% )
---
N5) same setup as N4), but run `PAGER= /bin/time -v nmcli`:
[1]
Command being timed: "nmcli"
User time (seconds): 0.42
System time (seconds): 0.04
Percent of CPU this job got: 107%
Elapsed (wall clock) time (h:mm:ss or m:ss): 0:00.43
Average shared text size (kbytes): 0
Average unshared data size (kbytes): 0
Average stack size (kbytes): 0
Average total size (kbytes): 0
Maximum resident set size (kbytes): 34456
Average resident set size (kbytes): 0
Major (requiring I/O) page faults: 0
Minor (reclaiming a frame) page faults: 6128
Voluntary context switches: 1298
Involuntary context switches: 1106
Swaps: 0
File system inputs: 0
File system outputs: 0
Socket messages sent: 0
Socket messages received: 0
Signals delivered: 0
Page size (bytes): 4096
Exit status: 0
[2]
Command being timed: "nmcli"
User time (seconds): 0.44
System time (seconds): 0.04
Percent of CPU this job got: 108%
Elapsed (wall clock) time (h:mm:ss or m:ss): 0:00.44
Average shared text size (kbytes): 0
Average unshared data size (kbytes): 0
Average stack size (kbytes): 0
Average total size (kbytes): 0
Maximum resident set size (kbytes): 34452
Average resident set size (kbytes): 0
Major (requiring I/O) page faults: 0
Minor (reclaiming a frame) page faults: 6169
Voluntary context switches: 1849
Involuntary context switches: 142
Swaps: 0
File system inputs: 0
File system outputs: 0
Socket messages sent: 0
Socket messages received: 0
Signals delivered: 0
Page size (bytes): 4096
Exit status: 0
[3]
Command being timed: "nmcli"
User time (seconds): 0.32
System time (seconds): 0.02
Percent of CPU this job got: 102%
Elapsed (wall clock) time (h:mm:ss or m:ss): 0:00.34
Average shared text size (kbytes): 0
Average unshared data size (kbytes): 0
Average stack size (kbytes): 0
Average total size (kbytes): 0
Maximum resident set size (kbytes): 29196
Average resident set size (kbytes): 0
Major (requiring I/O) page faults: 0
Minor (reclaiming a frame) page faults: 5059
Voluntary context switches: 919
Involuntary context switches: 685
Swaps: 0
File system inputs: 0
File system outputs: 0
Socket messages sent: 0
Socket messages received: 0
Signals delivered: 0
Page size (bytes): 4096
Exit status: 0
---
N6) same setup as N4), but run `nmcli monitor` and look at `ps aux` for
the RSS size.
USER PID %CPU %MEM VSZ RSS TTY STAT START TIME COMMAND
[1] me 1492900 21.0 0.2 461348 33248 pts/10 Sl+ 15:02 0:00 nmcli monitor
[2] me 1490721 5.0 0.2 461496 33548 pts/10 Sl+ 15:00 0:00 nmcli monitor
[3] me 1495801 16.5 0.1 459476 28692 pts/10 Sl+ 15:04 0:00 nmcli monitor
We will rework NMClient entirely. Then, the synchronous initialization will also use
the asynchronous code paths. The difference will be that with synchronous initialization,
all D-Bus interaction will be done with an internal GMainContext as current thread default,
and that internal context will run until initialization completes.
Note that even after initialization completes, it cannot be swapped back to the user's
(outer) GMainContext. That is because contexts are essentially the queue for our
D-Bus events, and we cannot swap from one queue to the other in a race
free manner (or a full resync). In other words, the two contexts are not in sync,
so after using the internal context NMClient needs to stick to that (at least, until
the name owner gets lost, which gives an opportunity to resync and switch back to the
user's main context).
We thus need to hook the internal (inner) GMainContext with the user's (outer) context,
so when the user iterates the outer context, events on the inner context get dispatched.
Add nm_utils_g_main_context_create_integrate_source() to create such a GSource for
integrating two contexts.
Note that the use-case here is limited: the integrated, inner main context must
not be explicitly iterated except from being dispatched by the integrating
source. Otherwise, you'd get recursive runs, possible deadlocks and general
ugliness. NMClient must show restrain how to use the inner context while it is
integrated.
Some compilers don't convert arrays as _Generic() type selectors to
their pointer type. That means, for those compilers the generic type
would be an array and not a pointer. Work around that by adding zero
to the pointer/array argument.
Also, I cannot get this to work with "clang-3.4.2-9.el7". Disable it
for that compiler. The value of the generic check is anyway that it only
needs to work with some compiler combinations. That will trigger a
compilation failure and we can fix the implementation also for compilers
that don't support the macro.
See-also: http://www.open-std.org/jtc1/sc22/wg14/www/docs/n1930.htm
There are two macros: NM_GOBJECT_PROPERTIES_DEFINE_BASE() and
NM_GOBJECT_PROPERTIES_DEFINE(). The former just defines the
property enums and the obj_properties array. The latter also
defines the functions _notify() and _nm_gobject_notify_together_impl().
That means, depending on whether you actually use _notify(), you have
to choose one of the macros. I think that is unnecessarily cumbersome.
Let's mark the function as _nm_unused so that the compiler doesn't
complain about the unused function. I don't think it's a problem
to use NM_GOBJECT_PROPERTIES_DEFINE() even if you don't actually use
_notify().
We don't need such data duplicated. The build setup should
have only one configuration_data() for patching such values.
Now we only have one global, immutable data_conf dictionary with
configuration values. Note that none of the users of data_conf uses all
entries, but as the entries are basically only dependent on the
meson/configure option and valid for the entire project, this simplifies
to handling.
We preferably should use our convenience macros like _LOGD().
Since those macros expand to _NMLOG() (which needs to be defined
separately), we can move it to "nm-logging-fwd.h" and reuse.
glib really likes the numeric source IDs. That is, g_idle_add(), g_timeout_add(),
etc. return those IDs, that can then be destroyed with g_remove_source() (or
nm_clear_g_source()).
I think these numeric IDs are really not great.
- API like g_idle_add() and g_remove_source() only works with the g_main_context_get_default()
instance. That means, you cannot use this API for any other contexts. If you'd insist on using
numeric IDs, you'd need to call g_main_context_find_source_by_id() on the right context
first (but you'd also have to track the context alongside the ID).
- g_remove_source() requires first a call to g_main_context_find_source_by_id(). This involves
taking a mutex and doing an extra hash lookup.
Instead, it often seems preferable to use the GSource instance directly. It works
with any context, it can be referenced and unreferenced, and it can be destroyed, and
avoids the overhead of g_main_context_find_source_by_id().
The only downside really is that keeping a GSource pointer takes one pointer size, while
the guint source ID is usually only 4 bytes.
Anyway, I think we should deal more with GSource instances directly. Hence, add this
convenience macro, that works like nm_clear_g_source().
In some cases it is useful to have the library log what it is doing
for debugging purposes; add a simple API that allows setting a
syslog-style logging level and specifying a logging function.
https://github.com/nettools/n-dhcp4/pull/8
Currently in any of the BOUND, RENEWING and REBINDING states the probe
checks the expiration of T1, T2 and lifetime. This is not correct
because, for example, if the timer fires in the RENEWING state, the
probe must not transition to RENEWING again (i.e. check again that
now >= T1). Note that there is no guarantee that the timer triggers
exactly once for T1, T2 and lifetime expirations because the timer is
also used for the retransmission logic in NDhcp4CConnection.
Therefore, add some checks to ensure that only correct transitions are
allowed.
https://gitlab.freedesktop.org/NetworkManager/NetworkManager/merge_requests/341https://bugzilla.redhat.com/show_bug.cgi?id=1773456
The API already had n_dhcp4_client_lease_get_lifetime(), which is the CLOCK_BOOTTIME
when the lease expires (or ((uint64_t)-1)). But it might be interesting to
know the actual lease duration and when the lease was received (and the
time started to count).
Expose an API for that. With this, one can also calculate the original, exact lease
lifetime, by subtracting n_dhcp4_client_lease_get_basetime() from n_dhcp4_client_lease_get_lifetime(),
while taking care of ((uint64_t)-1).
First of all, from the naming of n_dhcp4_incoming_query_u32() it is
confusing to coerce 0xFFFFFFFF to zero. It should just return the
plain value.
Also note that n_dhcp4_incoming_query_u32() only has three callers:
n_dhcp4_incoming_query_lifetime(), n_dhcp4_incoming_query_t1() and
n_dhcp4_incoming_query_t2().
Looking further, those three functions only have one caller:
n_dhcp4_incoming_get_timeouts(). Note how the code there already tries
to handle UINT32_MAX and interprets it as infinity (UINT64_MAX).
But as it was, UINT32_MAX never actually was returned.
It seems that RFC [1] does not specially define the meanings of
0xFFFFFFFF and 0. It sounds reasonable to assume that 0 just means
0 lifetime, and 0xFFFFFFFF means infinity. On the other hand, compare
this to systemd's code [2], which coerces 0 to 1. This does not seem
right to me though. Note how systemd returns 0xFFFFFFFF as-is.
Drop the special handling of 0xFFFFFFFF from n_dhcp4_incoming_query_u32().
It now just returns the plain value and it's up to n_dhcp4_incoming_get_timeouts()
to make sense of that. This will fix behavior, so that 0xFFFFFFFF will be
reported as infinity, and not as zero.
[1] https://tools.ietf.org/html/rfc2132#section-9.2
[2] 68c2b5ddb1/src/libsystemd-network/sd-dhcp-lease.c (L553)
It is error prone when a function consumes an input only in certain
cases (and telling the caller via the return code). At least in these
cases, the message is never used afterwards, and we can always pass
it on.
The majority of sources in "libnm/" are implementations of NMObject.
"nm-libnm-utils.h" will contain common definitions for handling such
objects. This means, most of the source files under libnm will require
this include. Include it by default.
