@level_desc and @domain_desc are two immutable arrays with information
about logging levels and logging domains. Since they are immutable and
intialized from the start, they are pretty trival w.r.t. tread-safety and
general maintainability (code readability).
Refactor them to be separate variables.
Previously, _nm_logging_clear_platform_logging_cache was an extern variable,
and NMLinuxPlatform would set it to a function pointer at certain points.
That's unnecessary complex, also when trying to make nm-logging thread-safe,
it's just more global variables that need to be considered. Don't do it
that way, but just link in a regular function.
In core ("src/"), we use "nm-logging.h" for all logging. This dispatches
for logging to syslog, glog or systemd-journald.
If we want to log from a shared component under "shared/", we need to
use a common logging function. Add "nm-utils/nm-logging-fwd.h" for
forward declaring the used logging mechaism.
The shared library will still need to link with "src/nm-logging.c"
or an alternative implementation, depending on whether it is used
inside core or not.
nm_utils_get_monotonic_timestamp*() inherrently use static data. Let's
initialize it in a thread safe manner.
nm_utils_get_monotonic_timestamp*() are a fundamental utility function
that should work correctly in all cases. Such a low level function should
be thread safe.
This is independent functionality that only depends on linux API
and glib.
Note how "nm-logging" uses this for getting the timestamps. This
makes "nm-logging.c" itself dependen on "src/nm-core-utils.c",
for little reason.
We commonly don't use the glib typedefs for char/short/int/long,
but their C types directly.
$ git grep '\<g\(char\|short\|int\|long\|float\|double\)\>' | wc -l
587
$ git grep '\<\(char\|short\|int\|long\|float\|double\)\>' | wc -l
21114
One could argue that using the glib typedefs is preferable in
public API (of our glib based libnm library) or where it clearly
is related to glib, like during
g_object_set (obj, PROPERTY, (gint) value, NULL);
However, that argument does not seem strong, because in practice we don't
follow that argument today, and seldomly use the glib typedefs.
Also, the style guide for this would be hard to formalize, because
"using them where clearly related to a glib" is a very loose suggestion.
Also note that glib typedefs will always just be typedefs of the
underlying C types. There is no danger of glib changing the meaning
of these typedefs (because that would be a major API break of glib).
A simple style guide is instead: don't use these typedefs.
No manual actions, I only ran the bash script:
FILES=($(git ls-files '*.[hc]'))
sed -i \
-e 's/\<g\(char\|short\|int\|long\|float\|double\)\>\( [^ ]\)/\1\2/g' \
-e 's/\<g\(char\|short\|int\|long\|float\|double\)\> /\1 /g' \
-e 's/\<g\(char\|short\|int\|long\|float\|double\)\>/\1/g' \
"${FILES[@]}"
"debug" was documentation in `man NetworkManager.conf` as a valid
logging backend. However, it was completely ignored by
nm_logging_syslog_openlog().
In fact, it makes not sense. Passing debug = TRUE to
nm_logging_syslog_openlog(), means that all messages will be
printed to stderr in addition to syslog/journal. However, when
NetworkManager is daemonizing, stderr is closed.
Whether NetworkManager is daemonizing depends entirely on command
line options --no-daemon and --debug. Hence, the logging backend "debug"
from the configuration file either conflicts or is redundant.
Also, adjust logging backend description in `man NetworkManager.conf`.
Also, log a warning about invalid/unsupported logging backend.
(cherry picked from commit 2ccf6168dc)
It just makes more sense to first fully setup logging, and then fetching
the timestamp. In practice, the effect previously was very similar.
(cherry picked from commit 2912155584)
NM_FLAGS_HAS() uses a static-assert that the second argument is a
single flag (power of two). With a single flag, NM_FLAGS_HAS(),
NM_FLAGS_ANY() and NM_FLAGS_ALL() are all identical.
The second argument must be a compile time constant, and if that is
not the case, one must not use NM_FLAGS_HAS().
Use NM_FLAGS_ANY() in these cases.
Previously, the daemon would just use syslog with LOG_PERROR when run with
--debug option, even when actually configured to log into the journal.
Let's respect the configuration, but preserve the logging to stderr.
It would be nice that our logging functions are guaranteed to
preserve errno. We are currently not very consistent about handling
errno, let's improve on that.
VPN_PLUGIN is special. With
# nmcli general logging level TRACE domains ALL
the logging verbosity of VPN_PLUGIN domain should not be set higher then
info. The user has to explicitly set it via:
# nmcli general logging level TRACE domains ALL,VPN_PLUGIN:TRACE
This was not the case for
# nmcli general logging level TRACE
Fix that.
nm-logging.c:213:1: error: ‘syslog_identifier_full’ defined but not used [-Werror=unused-function]
syslog_identifier_full (const struct Global *gl)
^
Fixes: fd12aa1b20
For nm-iface-helper we want to use a different syslog-identifier then
"NetworkManager".
Since we build "nm-logging.c" as part of libNetworkManagerBase.la,
it would be cumbersome to compile the logging part multiple times
with different -DG_LOG_DOMAIN settings.
Instead, allow configuring at runtime.
A new object NMPacRunnerManager has been added to manage and interact
PacRunner. It invokes both DBus methods on PacRunner DBus interface.
It stores the returned object path from CreateProxyConfiguration()
to feed as parameter to DestroyProxyCofiguration() when network goes down.
tv.tv_usec is guaranteed to have less then 6 digits, however rounding it up
we might reach 1000000 and thus the value becomes mis-aligned. To round
correctly, we would have to carry over a potential overflow to the seconds.
But that seems too much effort for little gain. Just truncate the value.
Previously, we logged also the location (file:line func). nm-logging.c
supported format flags to control the timestamp, the location, and alignment
of the timestamp.
We want that all our logging backends log the same messages. That is,
both syslog and journal should have our ~default~ logging format, that
is with timestamp but without location.
Drop the unused code.
(cherry picked from commit cc828431b8)
- reorder entries in src/Makefile.am so that general names
are all at the beginning (AM_CPPFLAGS, sbin_PROGRAMS)
and the names for a certain library/binary are grouped
together
- have libNetworkManager.la reuse libNetworkManagerBase.la.
- let all components in src/Makefile.am use the same AM_CPPFLAGS,
except libsystem-nm.la.
- move callouts/nm-dispatcher-api.h to shared/ directory. It
is obviously not internal API to callouts, and callouts is
not a library. Thus, the right place is shared/.
The function name is no longer visible in the default
logging output. It is anyway only used together with
journal logging to set "CODE_FUNC".
Drop it. It allows to remove the strings from the binary,
which decreases the object size of a default build of NetworkManager
from 2437400 to 2412824 bytes (-24k, -1%).
The logging domain VPN_PLUGIN controlls logging of the VPN plugins.
Especially at verbose levels <debug> and <trace>, the plugins might
reveal sensitive information in the logging.
Thus, this level should not be enabled by a
$ nmcli logging general level DEBUG domains ALL
It should only be enabled when requested explicitly.
$ nmcli logging general level DEBUG domains ALL,VPN_PLUGIN:DEBUG
Previously, the special level VPN_PLUGIN was entirely excluded from
ALL and DEFAULT domains and it was entirely disabled by default. That
is however to strict, as it completely silences the VPN plugins by
defult. Now, enable them by default up to level INFO.
VPN plugins should take care that they don't reveal sensitive
information at levels <info> (LOG_NOTICE) and higher (less verbose).
For more verbose levels they may print passwords, but that should
still be avoided as far as possible.
This logging domain will be used to enable debugging of the VPN plugins.
However, the plugins might expose sensitive data in this mode, so exclude
the new domain from "LOGD_ALL".
Basically every logging statement is wrapped by a nm_logging_enabled()
to evaluate the function call of the logging lazy.
Make the function a candidate for inlining, it safes some space. On
a default build it goes for me from 2580584 to 2560104 bytes (20k).
$ ./autogen.sh && make && strip ./src/NetworkManager
We really expect this assertion not to be violated.
As we want for nm_logging_enabled() to become smaller and inline,
remove the runtime assertion from regular builds.
Live fast and dangerous.
Instead of calling _ensure_initialized() at various places
to ensure that we setup logging before any logging commands
are executed, initialize the logging fields in the global variable.
This removes code from nm_logging_enabled(), which we want to
become a static inline function.
In our usage of glib logging, every g_critical()/g_return*()/g_warning()
is considered a bug. They must not occur in a regular program run,
so that we can run NetworkManager with G_DEBUG=fatal-warnings.
On the other hand, all nm_log() statements (even with severity <error>)
are valid conditions that can occur at runtime.
As a consequence, when nm-logging uses glib as backend, we must not use
G_LOG_LEVEL_WARNING level. Otherwise
$ /usr/sbin/NetworkManager --debug --g-fatal-warnings
will dump core on the message
"<warn> glib-version: cannot handle SIGUSR1 and SIGUSR2 signals. Consider upgrading glib to 2.36.0 or newer"
Thereby, downgrade the glib level for "<info>" to G_LOG_LEVEL_INFO.
str_if_set() was added to replace the non-standard gcc extension "?:".
However, "?:" is supported by clang as well and we already use it at
several places.
Also, str_if_set() did not follow our naming scheme and renaming to
nm_str_if_set() would be ugly. So just drop it.
Choose a new logging format.
- the logging format must not be configurable and it must be the
same for all backends. It is neat that journal supports additional
fields, but an average user still posts the output of plain
journalctl, without "--output verbose" (which would also be hard
to read).
Also, we get used to a certain logging format, so having different
formats is confusing. If one format is better then another, it should
be used for all backends: syslog, journal and debug.
The only question is, what is the best format.
- the timestamp: I find it useful to see how much time between two
events passed. The timestamp printed by syslog doesn't have sufficient
granularity, and the internal journal fields are not readily available.
We used to print the timestamps for <error>, <debug> and <trace>,
but ommited them for <info> and <warn> levels. We now print them for
all levels, which has a uniform alignment.
- the location: the "[file:line] func():" part is mostly redundant
and results in wide lines. It also causes a misalignment of the
logging lines, or -- as I recently added alignment of the location --
it results in awkward whitespace and truncation.
But the location is really just necessary because our logging messages
are bad:
"<debug> [1456397604.038226] (9) 11-dhclient succeeded"
The solution to this is not
"<debug> [1456397604.038226] [nm-dispatcher.c:358] dispatcher_results_process(): (9) 11-dhclient succeeded"
but a properly worded message:
"<debug> [1456397604.038226] dispatcher: request #9, script 11-dhclient succeeded"
- logging-message: we need to write better logging messages.
I like some form of "tags" that are easy to grep:
"platform: signal: link changed: 4: ..."
Downside is, that this is not nice to read as a full sentence.
So, especially for <info> and <warn> logging, more human readable
messages are better.
We should find a compromise, where the log message explains what
happens, but is still concise and contains patterns that are easy
to grep and identify visually.
https://mail.gnome.org/archives/networkmanager-list/2016-February/msg00077.html
Most interestingly is also, whether we can link libsystemd.a without
having undefined references (which might be wrongly satisfied by an
externally loaded libsystem shared library.
"NetworkManagerUtils.h" contains a bunch of helper tools for core
daemon ("src/").
Unfortunately, it has dependencies to other parts of core,
such as "nm-device.h" and "nm-platform.h". Split out a part
of tools that are independent so that they can be used without
dragging in other dependencies.
"nm-core-utils.h" should only use libnm-core, "nm-logging.h"
and shared.
"NetworkManagerUtils.h" should provide all "nm-core-utils.h" and
possibly other utilities that have larger dependencies.
"nm-logging.h" is a basic core module that should have few other
dependencies. Instead of letting nm-logging.c directly call a function
from "nm-linux-platform.c", let platform register a handler as needed.
This way, you can build a core library containing nm-logging but no
nm-platform.
