NUL-termination of the .ifr_name field is not required, but is fine
(and preferable to using strncpy and leaving the reader to wonder),
since the first thing the linux kernel does is to clear the last byte.
Besides, using pstrcpy here makes this setting of ifr_name consistent
with the other code (e.g., net/tap-linux.c) that does the same thing.
Reviewed-by: NLuiz Capitulino <lcapitulino@redhat.com>
Signed-off-by: NJim Meyering <meyering@redhat.com>
Signed-off-by: NAnthony Liguori <aliguori@us.ibm.com>

FITRIM is a mounted filesystem feature to discard (or "trim") blocks which
are not in use by the filesystem. This is useful for solid-state drives
(SSDs) and thinly-provisioned storage.  Provide access to the feature
from the host so that filesystems can be trimmed periodically or before
migration.

Here is an example using scsi_debug:

    # modprobe scsi_debug lbpu=1 lbpws=1
    # sg_vpd -p0xb2 /dev/sdb
    Logical block provisioning VPD page (SBC):
      Unmap command supported (LBPU): 1
      Write same (16) with unmap bit supported (LBWS): 1
      Write same (10) with unmap bit supported (LBWS10): 0
    # mke2fs /dev/sdb
    # cat /sys/bus/pseudo/drivers/scsi_debug/map
    1-616,16257-16383
    # mount /dev/sdb /run/media/pbonzini/test
    # dd if=/dev/zero of=/run/media/pbonzini/test/file
    # cat map
    1-616,645-1588,1599-4026,4029-16383
    # rm /run/media/pbonzini/test/file
    # ./qemu-ga /dev/fd/0
    {"execute":"guest-fstrim"}
    {"return": {}}
    # cat map
    1-612
Signed-off-by: NPaolo Bonzini <pbonzini@redhat.com>
Reviewed-by: NLuiz Capitulino <lcapitulino@redhat.com>
Reviewed-by: NMichal Privoznik <mprivozn@redhat.com>
Signed-off-by: NMichael Roth <mdroth@linux.vnet.ibm.com>

We will use these functions and types for more than FSFREEZE, so rename them.
Signed-off-by: NPaolo Bonzini <pbonzini@redhat.com>
Reviewed-by: NLuiz Capitulino <lcapitulino@redhat.com>
Reviewed-by: NMichal Privoznik <mprivozn@redhat.com>
Signed-off-by: NMichael Roth <mdroth@linux.vnet.ibm.com>

Currently we re-read/re-process /etc/mtab to get an updated list of
mounts when guest-fsfreeze-thaw is called. This can cause an atime
update on /etc/mtab, which will block if we're in a frozen state.

Instead, use /proc's version of mtab, which may not be up-to-date with
options passed via -o remount, but is compatible for our use cases since
we only care about the filesystem type.
Reported-by: NMatsuda, Daiki <matsudadik@intellilink.co.jp>
Signed-off-by: NMichael Roth <mdroth@linux.vnet.ibm.com>

Use _NSGetEnviron() helper to access the environment.
Signed-off-by: NAndreas Färber <andreas.faerber@web.de>
Cc: Charlie Somerville <charlie@charliesomerville.com>
Signed-off-by: NMichael Roth <mdroth@linux.vnet.ibm.com>

Commit 3674838c uses the environ global
variable, but is relying on environ to be declared somewhere else.

This worked for me because on F16 environ is declared in <unistd.h>, but
that doesn't happen in OpenBSD for example, causing a build failure.

This commit fixes the build error by declaring environ if it hasn't
being declared yet.

Also fixes a build warning due to a missing <sys/wait.h> include.
Signed-off-by: NLuiz Capitulino <lcapitulino@redhat.com>
Signed-off-by: NMichael Roth <mdroth@linux.vnet.ibm.com>

POSIX mandates[1] that a child process of a multi-thread program uses
only async-signal-safe functions before exec(). We consider qemu-ga
to be multi-thread, because it uses glib.

However, qmp_guest_shutdown() uses functions that are not
async-signal-safe. Fix it the following way:

- fclose() -> reopen_fd_to_null()
- execl() -> execle()
- exit() -> _exit()
- drop slog() usage (which is not safe)

  [1] http://pubs.opengroup.org/onlinepubs/009695399/functions/fork.htmlSigned-off-by: NLuiz Capitulino <lcapitulino@redhat.com>
Reviewed-by: NEric Blake <eblake@redhat.com>
Signed-off-by: NMichael Roth <mdroth@linux.vnet.ibm.com>

Last commit dropped qemu-ga's SIGCHLD handler, used to automatically
reap terminated children processes. This introduced a bug to
qmp_guest_shutdown(): it will generate zombies.

This problem probably doesn't matter in the success case, as the VM
will shutdown anyway, but let's do the right thing and reap the
created process. This ultimately means that guest-shutdown is now a
synchronous command.

An interesting side effect is that guest-shutdown is now able to
report an error to the client if shutting down fails.
Signed-off-by: NLuiz Capitulino <lcapitulino@redhat.com>
Reviewed-by: NEric Blake <eblake@redhat.com>
Signed-off-by: NMichael Roth <mdroth@linux.vnet.ibm.com>

Currently, qemu-ga has a SIGCHLD handler that automatically reaps terminated
children processes. The idea is to avoid having qemu-ga commands blocked
waiting for children to terminate.

That approach has two problems:

 1. qemu-ga is unable to detect errors in the child, meaning that qemu-ga
    returns success even if the child fails to perform its task

 2. if a command does depend on the child exit status, the command has to
    play tricks to bypass the automatic reaper

Case 2 impacts the guest-suspend-* API, because it has to execute an external
program to check for suspend support. Today, to bypass the automatic reaper,
suspend code has to double fork and pass exit status information through a
pipe. Besides being complex, this is prone to race condition bugs. Indeed,
the current code does have such bugs.

Making the guest-suspend-* API synchronous (ie. by dropping the SIGCHLD
handler and calling waitpid() from commands) is a much simpler approach,
which fixes current race conditions bugs and enables commands to detect
errors in the child.

This commit does just that. There's a side effect though, guest-shutdown
will generate zombies if shutting down fails. This will be fixed by the
next commit.
Signed-off-by: NLuiz Capitulino <lcapitulino@redhat.com>
Reviewed-by: NEric Blake <eblake@redhat.com>
Signed-off-by: NMichael Roth <mdroth@linux.vnet.ibm.com>

The next commit wants to use it.
Signed-off-by: NLuiz Capitulino <lcapitulino@redhat.com>
Reviewed-by: NEric Blake <eblake@redhat.com>
Signed-off-by: NMichael Roth <mdroth@linux.vnet.ibm.com>

These were identified using: http://github.com/lyda/misspell-check
and run like this to create a bourne shell script using GNU sed's
-i option:

git ls-files|grep -vF .bin | misspellings -f - |grep -v '^ERROR:' |perl \
-pe 's/^(.*?)\[(\d+)\]: (\w+) -> "(.*?)"$/sed -i '\''${2}s!$3!$4!'\'' $1/'

Manually eliding the FP, "rela->real" and resolving "addres" to
address (not "adders") we get this:

  sed -i '450s!thru!through!' Changelog
  sed -i '260s!neccessary!necessary!' coroutine-sigaltstack.c
  sed -i '54s!miniscule!minuscule!' disas.c
  sed -i '1094s!thru!through!' hw/usb/hcd-ehci.c
  sed -i '1095s!thru!through!' hw/usb/hcd-ehci.c
  sed -i '21s!unecessary!unnecessary!' qapi-schema-guest.json
  sed -i '307s!explictly!explicitly!' qemu-ga.c
  sed -i '490s!preceeding!preceding!' qga/commands-posix.c
  sed -i '792s!addres!address!' qga/commands-posix.c
  sed -i '6s!beeing!being!' tests/tcg/test-mmap.c

Also, manually fix "arithmentic", spotted by Peter Maydell:

  sed -i 's!arithmentic!arithmetic!' coroutine-sigaltstack.c
Signed-off-by: NJim Meyering <meyering@redhat.com>
Reviewed-by: NPeter Maydell <peter.maydell@linaro.org>

Currently we rely on fsfreeze/thaw commands disabling/enabling logging
then having other commands check whether logging is disabled to avoid
executing if they aren't safe for running while a filesystem is frozen.

Instead, have an explicit whitelist of fsfreeze-safe commands, and
consolidate logging and command enablement/disablement into a pair
of helper functions: ga_set_frozen()/ga_unset_frozen()
Signed-off-by: NMichael Roth <mdroth@linux.vnet.ibm.com>

guest-fsfreeze-thaw relies on state information obtained from
guest-fsfreeze-freeze to determine what filesystems to unfreeze.
This is unreliable due to the fact that that state does not account
for FIFREEZE being issued by other processes, or previous instances
of qemu-ga. This means in certain situations we cannot thaw
filesystems even with a responsive qemu-ga instance at our disposal.

This patch allows guest-fsfreeze-thaw to be issued unconditionally.
It also adds some additional logic to allow us to thaw filesystems
regardless of how many times the filesystem's "frozen" refcount has
been incremented by any guest processes.

Also, guest-fsfreeze-freeze now operates atomically: on success all
freezable filesystems are frozen, and on error all filesystems are
thawed. The ambiguous "GUEST_FSFREEZE_STATUS_ERROR" state is no
longer entered.
Signed-off-by: NMichael Roth <mdroth@linux.vnet.ibm.com>

When linux-specific commands (including guest-fsfreeze-*) were consolidated
under defined(__linux__), we forgot to account for the case where
defined(__linux__) && !defined(FIFREEZE). As a result stubs are no longer
being generated on linux hosts that don't have FIFREEZE support. Fix
this.
Tested-by: NAndreas Färber <afaerber@suse.de>
Reviewed-by: NLuiz Capitulino <lcapitulino@redhat.com>

guest-sync leaves it as an exercise to the user as to how to reliably
obtain the response to guest-sync if the client had previously read in a
partial response (due qemu-ga previously being restarted mid-"sentence"
due to reboot, forced restart, etc).

qemu-ga handles this situation on its end by having a client precede
their guest-sync request with a 0xFF byte (invalid UTF-8), which
qemu-ga/QEMU JSON parsers will treat as a flush event. Thus we can
reliably flush the qemu-ga parser state in preparation for receiving
the guest-sync request.

guest-sync-delimited provides the same functionality for a client: when
a guest-sync-delimited is issued, qemu-ga will precede it's response
with a 0xFF byte that the client can use as an indicator to flush its
buffer/parser state in preparation for reliably receiving the
guest-sync-delimited response.

It is also useful as an optimization for clients, since, after issuing a
guest-sync-delimited, clients can safely discard all stale data read
from the channel until the 0xFF is found.

More information available on the wiki:

http://wiki.qemu.org/Features/QAPI/GuestAgent#QEMU_Guest_Agent_ProtocolSigned-off-by: NMichael Roth <mdroth@linux.vnet.ibm.com>

This command returns an array of:

 [ifname, hwaddr, [ipaddr, ipaddr_family, prefix] ]

for each interface in the system.
Currently, only IPv4 and IPv6 are supported.
Signed-off-by: NMichal Privoznik <mprivozn@redhat.com>

Signed-off-by: NLuiz Capitulino <lcapitulino@redhat.com>

Signed-off-by: NLuiz Capitulino <lcapitulino@redhat.com>

As the command name implies, this command suspends the guest to disk.

The suspend operation is implemented by two functions: bios_supports_mode()
and guest_suspend(). Both functions are generic enough to be used by
other suspend modes (introduced by next commits).

Both functions will try to use the scripts provided by the pm-utils
package if it's available. If it's not available, a manual method,
which consists of directly writing to '/sys/power/state', will be used.

To reap terminated children, a new signal handler is installed in the
parent to catch SIGCHLD signals and a non-blocking call to waitpid()
is done to collect their exit statuses. The statuses, however, are
discarded.

The approach used to query the guest for suspend support deserves some
explanation. It's implemented by bios_supports_mode() and shown below:

  qemu-ga
     |
 create pipe
     |
   fork()
     -----------------
     |               |
     |               |
     |             fork()
     |               --------------------------
     |               |                        |
     |               |                        |
     |               |               exec('pm-is-supported')
     |               |
     |              wait()
     |       write exit status to pipe
     |              exit
     |
  read pipe

This might look complex, but the resulting code is quite simple.
The purpose of that approach is to allow qemu-ga to reap its children
(semi-)automatically from its SIGCHLD handler.

Implementing this the obvious way, that's, doing the exec() call from
the first child process, would force us to introduce a more complex way
to reap qemu-ga's children. Like registering PIDs to be reaped and
having a way to wait for them when returning their exit status to
qemu-ga is necessary. The approach explained above avoids that complexity.
Signed-off-by: NLuiz Capitulino <lcapitulino@redhat.com>

Many of the current RPC implementations are very much POSIX-specific
and require complete re-writes for Windows. There are however a small
set of core guest agent commands that are common to both, and other
commands such as guest-file-* which *may* be portable. So we introduce
commands.c for the latter, and will rename guest-agent-commands.c to
commands-posix.c in a future commit. Windows implementations will go in
commands-win32.c, eventually.

Not that there is blacklisting functionality we can no longer infer
the agent's capabilities via version. This patch extends the current
guest-info RPC to also return a list of dictionaries containing the name
of each supported RPC, along with a boolean indicating whether or not
the command has been disabled by a guest administrator/distro.
Signed-off-by: NMichael Roth <mdroth@linux.vnet.ibm.com>
Signed-off-by: NAnthony Liguori <aliguori@us.ibm.com>

qemu_malloc/qemu_free no longer exist after this commit.
Signed-off-by: NAnthony Liguori <aliguori@us.ibm.com>

Signed-off-by: NAnthony Liguori <aliguori@us.ibm.com>

Signed-off-by: NAnthony Liguori <aliguori@us.ibm.com>

FS-Freeze only works with Linux.
Signed-off-by: NAnthony Liguori <aliguori@us.ibm.com>

This adds the initial set of QMP/QAPI commands provided by the guest
agent:

guest-sync
guest-ping
guest-info
guest-shutdown
guest-file-open
guest-file-read
guest-file-write
guest-file-seek
guest-file-flush
guest-file-close
guest-fsfreeze-freeze
guest-fsfreeze-thaw
guest-fsfreeze-status

The input/output specification for these commands are documented in the
schema.

Example usage:

  host:
    qemu -device virtio-serial \
         -chardev socket,path=/tmp/vs0.sock,server,nowait,id=qga0 \
         -device virtserialport,chardev=qga0,name=org.qemu.quest_agent.0
         ...

    echo "{'execute':'guest-info'}" | socat stdio unix-connect:/tmp/qga0.sock

  guest:
    qemu-ga -m virtio-serial -p /dev/virtio-ports/org.qemu.guest_agent.0 \
            -p /var/run/qemu-guest-agent.pid -d
Signed-off-by: NMichael Roth <mdroth@linux.vnet.ibm.com>
Signed-off-by: NLuiz Capitulino <lcapitulino@gmail.com>