Right now we have an ability to launch the C/R service from root
and execure dump requests from unpriviledged users. Not to be bad
guys, we deny dumping tasks belonging to user, that cannot be
"watched" (traced, read /proc, etc.) by the dumper.
In the future we will use this "engine" when launched with suid
bit, and (probably) will have more sophisticated policy.
Signed-off-by: Pavel Emelyanov <xemul@parallels.com>
We are going to replace pid on id in names of image files. The id is
uniq for each namespace, so it's more convient, if image files are
opened per namespace.
Signed-off-by: Andrey Vagin <avagin@openvz.org>
Signed-off-by: Pavel Emelyanov <xemul@parallels.com>
We are going to replace pid on id in names of image files. The id is
uniq for each namespace, so it's more convient, if image files are
opened per namespace.
Signed-off-by: Andrey Vagin <avagin@openvz.org>
Signed-off-by: Pavel Emelyanov <xemul@parallels.com>
We are going to replace pid on id in names of image files. The id is
uniq for each namespace, so it's more convient, if image files are
opened per namespace.
Signed-off-by: Andrey Vagin <avagin@openvz.org>
Signed-off-by: Pavel Emelyanov <xemul@parallels.com>
We are going to replace pid on id in names of image files. The id is
uniq for each namespace, so it's more convient, if image files are
opened per namespace.
Signed-off-by: Andrey Vagin <avagin@openvz.org>
Signed-off-by: Pavel Emelyanov <xemul@parallels.com>
Currently all values of constants should be continuous,
because cr_fdset_open is used for opening images for all namespaces.
The next patches will rework this code and image files will be opened
per namespace, then all these ugly settings of one constant to another
will be removed.
Signed-off-by: Andrey Vagin <avagin@openvz.org>
Signed-off-by: Pavel Emelyanov <xemul@parallels.com>
We can restore task's pgid which is not equal to its pid,
only when the respective group leader is alive. To make
restore reliable we wait for all group leaders to restore
using separate restore stage.
It's better to optimize this -- each task has a pointer on
its group leader and waits for one to become such.
Signed-off-by: Pavel Emelyanov <xemul@parallels.com>
We restore chroot before doing this, so if we might need to
open one, we may have no access to the /proc/... paths.
Signed-off-by: Pavel Emelyanov <xemul@parallels.com>
All process VMA-s are in "premmaped area". All restorer stuff are in
bootstap "area", so we have two areas.
So we don't need to unmap extra VMA-s one by one. We can call munmap
three times for the region before the first area, for the hole between
areas and for the region after the second area.
The old scheme didn't work, because the list of VMA-s can be changed
after collecting. It can be due to memory allocations by libc or due to
increased stack.
v2: improve readability at the expense of beautiness
v3: print return code of munmap in error messages
Signed-off-by: Andrey Vagin <avagin@openvz.org>
Signed-off-by: Pavel Emelyanov <xemul@parallels.com>
This patch adds a new parasite command, which unmaps the parasite blob.
This command never returns and the criu process traps the target process
on the exit from the munmap syscall.
v2: rename the function for unmaping a parasite blob to not intersects
with criu's functions.
Signed-off-by: Andrey Vagin <avagin@openvz.org>
Signed-off-by: Pavel Emelyanov <xemul@parallels.com>
This patch adds a function for removing the restorer blob. This function
never returns and the process must be trapped on the exit from the
munmap syscall.
v2: * release parasite_ctl sturcture and use the new interface of
parasite_prep_ctl
Signed-off-by: Andrey Vagin <avagin@openvz.org>
Signed-off-by: Pavel Emelyanov <xemul@parallels.com>
It will be used in cr-restore.c for stopping threads on the exit from
sigreturn.
Signed-off-by: Andrey Vagin <avagin@openvz.org>
Signed-off-by: Pavel Emelyanov <xemul@parallels.com>
The munmap syscall must be executed from a process memory. The code can
be injected in memory and then removed. But we can avoid all these
actions, if the code will be in the blob and a process will be trapped
on the exit from the munmap syscall.
Signed-off-by: Andrey Vagin <avagin@openvz.org>
Signed-off-by: Pavel Emelyanov <xemul@parallels.com>
All processes must be started by PTRACE_SYSCALL. The function calls wait
in a loop and if a process on the exit from the required syscall, it
is stopped, otherwise it will be reexecuted by PTRACE_SYSCALL.
The function doesn't know, which processes should be trapped, so
you should care, that wait() will not catch someone else.
Signed-off-by: Andrey Vagin <avagin@openvz.org>
Signed-off-by: Pavel Emelyanov <xemul@parallels.com>
This patch adds nothing new, just splits the existant function.
Currently a parasite stopped on sigreturn for unmaping a parasite blob.
The same scheme will be used for restorer blob and this function will be
used to stop on exit from the munmap syscall.
Signed-off-by: Andrey Vagin <avagin@openvz.org>
Signed-off-by: Pavel Emelyanov <xemul@parallels.com>
For the root task the clone syscall returns the pid in criu's pidns,
but for other processes the clone syscall returns PID in the restored
namespace.
The /proc/self link contains the PID value of the current process, so if
we want to determing the PID in a criu's pidns, we should use criu's
/proc.
v2: readlink() does not append a null byte to buf, so we must do that
Signed-off-by: Andrey Vagin <avagin@openvz.org>
Signed-off-by: Pavel Emelyanov <xemul@parallels.com>
When service/page server becomes daemon, we may need to know it's pid.
Signed-off-by: Ruslan Kuprieiev<kupruser@gmail.com>
Signed-off-by: Pavel Emelyanov <xemul@parallels.com>
Now we don't have generic criu_msg thing -- instead, we have
explicit request (with per-type args) and explicit responce
(yet again -- with per-type args).
Signed-off-by: Pavel Emelyanov <xemul@parallels.com>
Service connection is actually an 'external' one from unix sockets engine POV,
but we don't want to dump it as such. Thus, we explicitly find one and dump it
as half-closed connection. On restore we push an artificial message into it
to report to the program that the dump-request was served, but the program is
restored.
Signed-off-by: Ruslan Kuprieiev <kupruser@gmail.com>
Signed-off-by: Pavel Emelyanov <xemul@parallels.com>
The need in service is described at http://criu.org/Self_dump
Signed-off-by: Ruslan Kuprieiev <kupruser@gmail.com>
Signed-off-by: Pavel Emelyanov <xemul@parallels.com>
The criu service is a daemon, that opens a unix socket and listens for
incoming requests. The requests will be declared in protobuf/rpc.proto
and for now will only contain the 'dump' request.
Signed-off-by: Ruslan Kuprieiev <kupruser@gmail.com>
Signed-off-by: Pavel Emelyanov <xemul@parallels.com>
A few sentences, which are required for understanging this patch
2a) A shared mount can be replicated to as many mountpoints and all the
replicas continue to be exactly same.
2b) A slave mount is like a shared mount except that mount and umount
events only propagate towards it.
2c) A private mount does not forward or receive propagation.
All rules is there Documentation/filesystems/sharedsubtree.txt
If it's a first mount in a group, all group members should be
bind-mounted from this one.
Each mount propagates to all members of parent's group. The group can
contains a few slaves.
Mounts, which have propagated to slaves, are unmounted, because we can't
be sure, that they propagated in real life. For example:
mount --bind --make-slave /share /slave1
mount --bind --make-slave /share /slave2
mount /share/test
umount /slave2/test
mount --make-share /slave1/test
mount --bind --make-share /slave1/test /slave2/test
41 40 0:33 / /share rw,relatime shared:28 - tmpfs xxx rw
42 40 0:33 / /slave1 rw,relatime master:28 - tmpfs xxx rw
43 40 0:33 / /slave2 rw,relatime master:28 - tmpfs xxx rw
44 41 0:34 / /share/test rw,relatime shared:29 - tmpfs xxx rw
46 42 0:34 / /slave1/test rw,relatime shared:30 master:29 - tmpfs xxx rw
45 43 0:34 / /slave2/test rw,relatime shared:30 master:29 - tmpfs xxx rw
/slave1/test and /slave2/test depend on each other and minimum one of them
doesn't propagate from /share/test
v2: use false and true for bool
Signed-off-by: Andrey Vagin <avagin@openvz.org>
Signed-off-by: Pavel Emelyanov <xemul@parallels.com>
Try to restore mounts while a postpone list isn't empty and check
that each iteration has some progress, otherwice it will fails for
preventing infinite loops
v2: rework logic about postpone list
add more comments
v3: one more attempt to make it more readable
v4: Here is a master class from Pavel how to write self-documented code.
Signed-off-by: Andrey Vagin <avagin@openvz.org>
Signed-off-by: Pavel Emelyanov <xemul@parallels.com>
All shared mounts from one group are connected to circular list.
All slave are added into the proper master list.
v2: change variable name and fix a bug about adding shared mounts in a
circular list.
v3: handle errors of collect_shared
Signed-off-by: Andrey Vagin <avagin@openvz.org>
Signed-off-by: Pavel Emelyanov <xemul@parallels.com>
Currently pos has type unsigned long, so its size depends on
architecture. pos is saved as 64-bit value in the image file and it
isn't restored, if it is equal to -1. Due to convertation on 32-bit
platforms -1 is converted into UINT_MAX and we get error on restore.
$ zdtm.sh ns/static/tun
...
(00.398513) 5: Error (files-reg.c:534): Can't restore file pos: Illegal seek
(00.398888) 5: Error (files-reg.c:489): Can't open file /dev/net/tun: Illegal seek
...
id: 0x15 flags: 0x2 pos: 0x000000ffffffff fown: { uid: 0 euid: 0 signum: 0 pid_type: 0 pid: 0 } name: "/dev/net/tun"
crtools is compiled with _FILE_OFFSET_BITS=64, so off_t is always 64-bit.
Signed-off-by: Andrew Vagin <avagin@openvz.org>
Signed-off-by: Pavel Emelyanov <xemul@parallels.com>
Same as kernel provides, adopted from Linux sources.
strlcpy is similar to strncpy but _always_ adds \0
at the end of string even if destination is shorter.
Signed-off-by: Cyrill Gorcunov <gorcunov@openvz.org>
Signed-off-by: Pavel Emelyanov <xemul@parallels.com>
We have generic do_pb_show() call and tons of show_foo
routines, that just call one with proper args. Compact
the code by putting the args into array and calling
the do_pb_show() in one place.
Signed-off-by: Pavel Emelyanov <xemul@parallels.com>
These contain linkage between number, data type and routines
for pb messages we write/read to/from image files. Most of them
have simple number-type-routines mapping, so introduce a generating
script for that.
Signed-off-by: Pavel Emelyanov <xemul@parallels.com>
This thing is pretty straightforward -- on netns creation
populate it with tun-s, after this collect tun files, open
and attach them with regular fd-s engine.
One tricky thing -- when populating namespace with tun links
make them all persistent and drop this flag (if required)
later, when the first alive opened appears.
Signed-off-by: Pavel Emelyanov <xemul@parallels.com>
The major issue with dump is -- some info id get via netlink,
some via sysfs and some (!) via opened and attached tun file.
But the latter cannot be created, if there's another one attached
(or the mq device is full with threads).
Thus we have to dump this info via existing tun file and keep one
in memory till the link dump code takes place.
Opposite situation is also possible -- we can have a persistent
unattached device. In this case we have to attach to it, dump
things and detach back.
Signed-off-by: Pavel Emelyanov <xemul@parallels.com>
There will be two entities handled:
1. tun file -- an opened char device with misc major and tun minor
that can be attached to item #2
2. tun netdevice -- another type of links
Signed-off-by: Pavel Emelyanov <xemul@parallels.com>
TUN devices are created with ioctl, but their parameters (e.g.
flags with state, mtu, etc.) are to be restored with generic
RTM_SETLINK message.
Signed-off-by: Pavel Emelyanov <xemul@parallels.com>
Some (most) network devices would like to have NetDeviceEntry with
more fields, than currently present (and enough for lo and veth).
Prepare for that by allowing them to define their own callback that
would fill the resor of the pb entry and call write_netdev_img().
Signed-off-by: Pavel Emelyanov <xemul@parallels.com>
