Probably sys_recvmsg was used earlier, which returns a error code.
Signed-off-by: Andrey Vagin <avagin@openvz.org>
Signed-off-by: Pavel Emelyanov <xemul@parallels.com>

No need to panic if image corrupted and we can exit
out graciously.
Signed-off-by: Cyrill Gorcunov <gorcunov@openvz.org>
Signed-off-by: Pavel Emelyanov <xemul@parallels.com>

Signed-off-by: Pavel Emelyanov <xemul@parallels.com>

By default crtools shouldn't modify the environment, except for
killing the dumped tasks. The link remap does so and should sit
under explicit cmdline option.
Signed-off-by: Pavel Emelyanov <xemul@parallels.com>

Same as unlink_fstat0x, but leave one link alive.
Signed-off-by: Pavel Emelyanov <xemul@parallels.com>

These are not ghost, as they are still on fs, so we cannot take
them with us in the image. Neither we can easily find the other name
of that file. Sad :(

To make it work we linkat() the new name to that file using the
AT_EMPTY_PATH flag to link directly to the opened fd. If we could
openat() the fd's parent we would better do it, but we can't and
thus have to create the link name by explicit absolute path :(

This modifies the fs we're dumping, so I'll introduce one more cmd
line option for that soon.
Signed-off-by: Pavel Emelyanov <xemul@parallels.com>

For linked remaps we'll use similar technique as for ghost
files, but lighter. For that sake make reg_file_info remap
to file_remap, not to the whole host_file.
Signed-off-by: Pavel Emelyanov <xemul@parallels.com>

Signed-off-by: Pavel Emelyanov <xemul@parallels.com>

Signed-off-by: Pavel Emelyanov <xemul@parallels.com>

Restore of namespaces requires executions of external tools
(ip, tar, etc). We want to know return codes, so we should
block a default sigchld handler. Before we did that for each
command, I suggest to block SIGCHLD, then restore namespace and
unblock SIGCHLD.

The default sigchld handler is used for catching target processes,
but all this processes (except a current one ) are started after
restoring namespaces.

Currently we forgot to block SIGCHLD before executing "ip",
and this bug was caught.
Reported-by: Stanislav Kinsbursky <skinsbursky@parallels.com>
Signed-off-by: Andrey Vagin <avagin@openvz.org>
Signed-off-by: Pavel Emelyanov <xemul@parallels.com>

Forgot to handle an error path in a one place.
Signed-off-by: Andrey Vagin <avagin@openvz.org>
Signed-off-by: Pavel Emelyanov <xemul@parallels.com>

It seems otherwise older gcc compilers do treat this
statement as incomplete.
Signed-off-by: Cyrill Gorcunov <gorcunov@openvz.org>
Reported-by: Huang Qiang <h.huangqiang@huawei.com>
Signed-off-by: Pavel Emelyanov <xemul@parallels.com>

The biggest acheivement since v0.1 -- initial support for LXC containers!

Other less notable (but still great) things done are:

* Implemented support for TTY-s
* Added support for packet sockets
* Bug-fix here and there

Note, that images generated by v0.1 tool are accepted by v0.2 one.
Signed-off-by: Pavel Emelyanov <xemul@parallels.com>

We don't support yet detached terminals migration,
so fail early if we can't proceed.
Signed-off-by: Cyrill Gorcunov <gorcunov@openvz.org>
Acked-by: Andrew Vagin <avagin@parallels.com>
Signed-off-by: Pavel Emelyanov <xemul@parallels.com>

Will need it to verify that live tty pairs exist.
Signed-off-by: Cyrill Gorcunov <gorcunov@openvz.org>
Acked-by: Andrew Vagin <avagin@parallels.com>
Signed-off-by: Pavel Emelyanov <xemul@parallels.com>

To trace paired ttys we will need one more bitmap
so rename tty_test_and_set_index to tty_test_and_set
because we will need this helper in another context.
Signed-off-by: Cyrill Gorcunov <gorcunov@openvz.org>
Acked-by: Andrew Vagin <avagin@parallels.com>
Signed-off-by: Pavel Emelyanov <xemul@parallels.com>

  CC       ipc_ns.o
  ipc_ns.c: In function ‘dump_ipc_msg’:
  ipc_ns.c:240:2: error: ‘message’ may be used uninitialized in this function [-Werror=uninitialized]
  ipc_ns.c:192:17: note: ‘message’ was declared here
  cc1: all warnings being treated as errors
Signed-off-by: Pavel Emelyanov <xemul@parallels.com>

Signed-off-by: Stanislav Kinsbursky <skinsbursky@openvz.org>
Tested-by: Cyrill Gorcunov <gorcunov@openvz.org>
Signed-off-by: Pavel Emelyanov <xemul@parallels.com>

Signed-off-by: Cyrill Gorcunov <gorcunov@openvz.org>
Signed-off-by: Pavel Emelyanov <xemul@parallels.com>

We do have build-time tests for that but it's not enough, better to
be on safe side and double check the arguments size.
Signed-off-by: Cyrill Gorcunov <gorcunov@openvz.org>
Signed-off-by: Pavel Emelyanov <xemul@parallels.com>

rcv_wscale is a symetric parameter with snd_wscale.

Both this parameters are set on a connection handshake.

Without this value a remote window size can't be interpreted correctly,
because a value from a packet should be shifted on rcv_wscale.

This patch doesn't break a back compatibility, a rcv window
will be restored with the same bug (rcv_wscale = 0).

v2: Update to a new kernel interface:
	[PATCH] tcp: restore rcv_wscale in a repair mode (v2)
Signed-off-by: Andrey Vagin <avagin@openvz.org>
Signed-off-by: Pavel Emelyanov <xemul@parallels.com>

Before 256 bytes were used for that, it may be not enough.
For example it was not enough for a NFS point on my test system.
Signed-off-by: Andrey Vagin <avagin@openvz.org>
Signed-off-by: Pavel Emelyanov <xemul@parallels.com>

In commit 97cfb707 we extended scm_fdset structure
up to 7K thus we need to increase the parasite stack
size enough to hold it. It was not noticed simply because
we were poking arguments area of memory.

The memory map of args and stack for parasite look like

  +-----------+   min address
  |           | |
  | arguments | v (8K)
  |           |
  +-----------+
  |           |
  |   stack   | ^ (16K)
  |           | |
  +-----------+   max address
Signed-off-by: Cyrill Gorcunov <gorcunov@openvz.org>
Signed-off-by: Pavel Emelyanov <xemul@parallels.com>

We're under lock anyway.
Signed-off-by: Cyrill Gorcunov <gorcunov@openvz.org>
Signed-off-by: Pavel Emelyanov <xemul@parallels.com>

Otherwise there is a race between files with same names:

link(name -> ghost)                link(name->ghost)
open(name)
unlink(name)
                                   open(name) -> ENOENT
Signed-off-by: Cyrill Gorcunov <gorcunov@openvz.org>
Signed-off-by: Pavel Emelyanov <xemul@parallels.com>

One function is used on restoring and one is used on dumping,
so each function has own prefix rst or cpt.
The both functions have the same effect, so the main part of the names
is same and it describes "unlock_tcp_connections".
Signed-off-by: Andrey Vagin <avagin@openvz.org>
Signed-off-by: Pavel Emelyanov <xemul@parallels.com>

network-script.sh is used for locking and unlocking network in CT.

Here is an example of an LXC config:
lxc.console=none
lxc.utsname = test-lxc
lxc.network.type = veth
lxc.network.flags = up
lxc.network.link = br0
lxc.network.name = eth0
lxc.mount = /root/test-lxc/etc/fstab
lxc.rootfs = /root/test-lxc-root/
Signed-off-by: Andrey Vagin <avagin@openvz.org>
Signed-off-by: Pavel Emelyanov <xemul@parallels.com>

Restore must not fail after unlocking connections.
Signed-off-by: Andrey Vagin <avagin@openvz.org>
Signed-off-by: Pavel Emelyanov <xemul@parallels.com>

Early we moved prepare_shared() to a root task,
because several preparation actions should be executed
in a target namespace set (e.g.: ghost files).

TCP sockets are a subset of init sockets,
they should be unlocked before resume. It's convient to do
from crtools.
An image can't be read more than one time, because we want to
send it via network.

For this two reasons prepare_shared is spitted in two parts,
one for crtools and one for a root task.
Signed-off-by: Andrey Vagin <avagin@openvz.org>
Signed-off-by: Pavel Emelyanov <xemul@parallels.com>

Signed-off-by: Andrey Vagin <avagin@openvz.org>
Signed-off-by: Pavel Emelyanov <xemul@parallels.com>

For another netns we don't need to lock separate connections,
an external chanel can be locked.
Signed-off-by: Andrey Vagin <avagin@openvz.org>
Signed-off-by: Pavel Emelyanov <xemul@parallels.com>

Signed-off-by: Andrey Vagin <avagin@openvz.org>
Signed-off-by: Pavel Emelyanov <xemul@parallels.com>

because here are two types of entries
Signed-off-by: Andrey Vagin <avagin@openvz.org>
Signed-off-by: Pavel Emelyanov <xemul@parallels.com>

Scripts are executed when external actions required.
CRTOOLS_SCRIPT_ACTION contains a required action.
If a script doesn't know a current action, it should exit with 0.

The first usecase will be lock/unlock network.
Signed-off-by: Andrey Vagin <avagin@openvz.org>
Signed-off-by: Pavel Emelyanov <xemul@parallels.com>

TCP_REPAIR should be droppet when a network is unlocked.
A network should be unlocked at the last moment, because
after this moment restore must not failed, otherwise a state of
a tcp connection can be changed and a state of one side in our image
will be invalid.

v2: use xremalloc instead of mmap and remmap
Signed-off-by: Andrey Vagin <avagin@openvz.org>
Signed-off-by: Pavel Emelyanov <xemul@parallels.com>

Use sys_setsockopt and declare a function in a header as "static inline"
Signed-off-by: Andrey Vagin <avagin@openvz.org>
Signed-off-by: Pavel Emelyanov <xemul@parallels.com>

Signed-off-by: Andrey Vagin <avagin@openvz.org>
Signed-off-by: Pavel Emelyanov <xemul@parallels.com>

Signed-off-by: Andrey Vagin <avagin@openvz.org>
Signed-off-by: Pavel Emelyanov <xemul@parallels.com>

It shrinks code a bit.
Signed-off-by: Cyrill Gorcunov <gorcunov@openvz.org>
Signed-off-by: Pavel Emelyanov <xemul@parallels.com>

There are places when we have to select which fd to ->open
and which to ->receive. To avoid deadlocks we sort them in
an ascending order on { pid, fd } pair.

Make this idea more formal by introducing an explicit function
doing this check and call it where appropriate (pipe.c master
selection is also simplified to fit new ... API).
Signed-off-by: Pavel Emelyanov <xemul@parallels.com>