Similarly to the previous commit, let's accept "socket" parameter
in the connection URI. This change will allow us to use
virt-ssh-helper instead of 'nc' in all cases (done in one of
future commits).
Please note, when the parameter is used it effectively disables
automatic daemon spawning and an error is reported. But this is
intentional - so that the helper behaves just like regular
virConnectOpen() with different transport than ssh, e.g. unix.
But this 'change' is acceptable - there's no way for users to
make our remote code pass the argument to virt-ssh-helper, yet.
Signed-off-by: Michal Privoznik <mprivozn@redhat.com>
Reviewed-by: Peter Krempa <pkrempa@redhat.com>
When split daemons were introduced, we also made connection URI
accept new parameter: mode={auto,legacy,direct} so that a client
can force connecting to either old, monolithic daemon, or to
split daemon (see v5.7.0-rc1~257 for more info).
Now, the change was done to the remote driver, but not to
virt-ssh-helper. True, our remote driver code still does not pass
the 'mode' parameter, but that will be addressed in next commits.
Signed-off-by: Michal Privoznik <mprivozn@redhat.com>
Reviewed-by: Peter Krempa <pkrempa@redhat.com>
Adding an exception for the whole file usually defeats the purpose of a
syntax check and is also likely to get forgotten once the file is
removed.
In case of the suggestion of using 'safewrite' instead of write even the
comment for safewrite states that the function needs to be used only in
certain cases.
Remove the blanket exceptions for files and use an exclude string
instead. The only instance where we keep the full file exception is for
src/libvirt-stream.c as there are multiple uses in example code in
comments where I couldn't find a nicer targetted wapproach.
Signed-off-by: Peter Krempa <pkrempa@redhat.com>
Reviewed-by: Ján Tomko <jtomko@redhat.com>
This change was generated using the following spatch:
@ rule1 @
expression a;
identifier f;
@@
<...
- f(*a);
... when != a;
- *a = NULL;
+ g_clear_pointer(a, f);
...>
@ rule2 @
expression a;
identifier f;
@@
<...
- f(a);
... when != a;
- a = NULL;
+ g_clear_pointer(&a, f);
...>
Then, I left some of the changes out, like tools/nss/ (which
doesn't link with glib) and put back a comment in
qemuBlockJobProcessEventCompletedActiveCommit() which coccinelle
decided to remove (I have no idea why).
Signed-off-by: Michal Privoznik <mprivozn@redhat.com>
Reviewed-by: Ján Tomko <jtomko@redhat.com>
And make callers check the return value as well. This helps error out early for
invalid environment variables.
That is desirable because it could lead to deadlocks. This can happen when
resetting logging after fork() reports translated errors because gettext
functions are not reentrant. Well, it is not limited to resetting logging after
fork(), it can be any translation at that phase, but parsing environment
variables is easy to make fail on purpose to show the result, it can also happen
just due to a typo.
Before this commit it is possible to deadlock the daemon on startup
with something like:
LIBVIRT_LOG_FILTERS='1:*' LIBVIRT_LOG_OUTPUTS=1:stdout libvirtd
where filters are used to enable more logging and hence make the race less rare
and outputs are set to invalid
Combined with the previous patches this changes
the following from:
...
<deadlock>
to:
...
libvirtd: initialisation failed
The error message is improved in future commits and is also possible thanks to
this patch.
Signed-off-by: Martin Kletzander <mkletzan@redhat.com>
Reviewed-by: Erik Skultety <eskultet@redhat.com>
Specifically:
* include non-option argument 'URI' in usage summary;
* mention that it's an internal tool not meant to be
called directly;
* exit earlier if required arguments are absent.
Signed-off-by: Andrea Bolognani <abologna@redhat.com>
Reviewed-by: Ján Tomko <jtomko@redhat.com>
It's a getopt interface and we're not using getopt, at least
directly, so even though it works relying on it feels wrong.
GOption takes care of removing any trace of the arguments it
consumes from argc and argv, leaving behind only non-option
arguments, so we can just use those standard variables.
Signed-off-by: Andrea Bolognani <abologna@redhat.com>
Reviewed-by: Ján Tomko <jtomko@redhat.com>
The "spawnDaemon" and "binary" parameters are co-dependant, with the
latter non-NULL, if-and-only-if the former is true. Getting rid of the
"spawnDaemon" parameter simplifies life for the callers and eliminates
an error checking scenario.
Reviewed-by: Ján Tomko <jtomko@redhat.com>
Signed-off-by: Daniel P. Berrangé <berrange@redhat.com>
The remoteGetUNIXSocket method currently just returns the daemon name
and the caller then converts this to a path. Except the SSH helper
didn't do this, so it was relying on later code expanding $PATH, and
this doesn't allow for build root overrides.
Reviewed-by: Ján Tomko <jtomko@redhat.com>
Signed-off-by: Daniel P. Berrangé <berrange@redhat.com>
We have helper methods that return boolans for ro/user/autostart
properties. We then pack them into a flags parameter, and later
unpack them again. This makes the code consistently use flags
throughout.
Reviewed-by: Ján Tomko <jtomko@redhat.com>
Signed-off-by: Daniel P. Berrangé <berrange@redhat.com>
Historically, we declared pointer type to our types:
typedef struct _virXXX virXXX;
typedef virXXX *virXXXPtr;
But usefulness of such declaration is questionable, at best.
Unfortunately, we can't drop every such declaration - we have to
carry some over, because they are part of public API (e.g.
virDomainPtr). But for internal types - we can do drop them and
use what every other C project uses 'virXXX *'.
This change was generated by a very ugly shell script that
generated sed script which was then called over each file in the
repository. For the shell script refer to the cover letter:
https://listman.redhat.com/archives/libvir-list/2021-March/msg00537.html
Signed-off-by: Michal Privoznik <mprivozn@redhat.com>
Reviewed-by: Peter Krempa <pkrempa@redhat.com>
It was reported that the performance of tunnelled migration and
volume upload/download regressed in 6.9.0, when the virt-ssh-helper
is used for remote SSH tunnelling instead of netcat.
When seeing data available to read from stdin, or the socket,
the current code will allocate at most 1k of extra space in
the buffer it has.
After writing data to the socket, or stdout, if more than 1k
of extra space is in the buffer, it will reallocate to free
up that space.
This results in a huge number of mallocs when doing I/O, as
well as a huge number of syscalls since at most 1k of data
will be read/written at a time.
Also if writing blocks for some reason, it will continue to
read data with no memory bound which is bad.
This changes the code to use a 1 MB fixed size buffer in each
direction. If that buffer becomes full, it will update the
watches to stop reading more data. It will never reallocate
the buffer at runtime.
This increases the performance by orders of magnitude.
Reviewed-by: Daniel Henrique Barboza <danielhb413@gmail.com>
Tested-by: Christian Ehrhardt <christian.ehrhardt@canonical.com>
Signed-off-by: Daniel P. Berrangé <berrange@redhat.com>
When accessing libvirtd over a SSH tunnel, the remote driver needs a way
to proxy the SSH input/output stream to a suitable libvirt daemon. This
is currently done by spawning netcat, pointing it to the libvirtd socket
path. This is problematic for a number of reasons:
- The socket path varies according to the --prefix chosen at build
time. The remote client is seeing the local prefix, but what we
need is the remote prefix
- The socket path varies according to remote env variables, such as
the XDG_RUNTIME_DIR location. Again we see the local XDG_RUNTIME_DIR
value, but what we need is the remote value (if any)
- The remote driver doesn't know whether it must connect to the legacy
libvirtd or the modular daemons, so must always assume legacy
libvirtd for back-compat. This means we'll always end up using the
virtproxyd daemon adding an extra hop in the RPC layer.
- We can not able to autospawn the libvirtd daemon for session mode
access
To address these problems this patch introduces the 'virtd-ssh-helper'
program which takes the URI for the remote driver as a CLI parameter.
It then figures out which daemon to connect to and its socket path,
using the same code that the remote driver client would on the remote
host's build of libvirt.
Signed-off-by: Daniel P. Berrangé <berrange@redhat.com>
