Commit Graph

31 Commits

Author SHA1 Message Date
Tibor Vass c205e9fb64 libcontainer: fix compilation on GOARCH=arm GOARM=6 (32 bits)
This fixes the following compilation error on 32bit ARM:
```
$ GOARCH=arm GOARCH=6 go build ./libcontainer/system/
libcontainer/system/linux.go:119:89: constant 4294967295 overflows int
```

Signed-off-by: Tibor Vass <tibor@docker.com>
2018-06-14 18:33:14 +00:00
Akihiro Suda f103de57ec main: support rootless mode in userns
Running rootless containers in userns is useful for mounting
filesystems (e.g. overlay) with mapped euid 0, but without actual root
privilege.

Usage: (Note that `unshare --mount` requires `--map-root-user`)

  user$ mkdir lower upper work rootfs
  user$ curl http://dl-cdn.alpinelinux.org/alpine/v3.7/releases/x86_64/alpine-minirootfs-3.7.0-x86_64.tar.gz | tar Cxz ./lower || ( true; echo "mknod errors were ignored" )
  user$ unshare --mount --map-root-user
  mappedroot# runc spec --rootless
  mappedroot# sed -i 's/"readonly": true/"readonly": false/g' config.json
  mappedroot# mount -t overlay -o lowerdir=./lower,upperdir=./upper,workdir=./work overlayfs ./rootfs
  mappedroot# runc run foo

Signed-off-by: Akihiro Suda <suda.akihiro@lab.ntt.co.jp>
2018-05-10 12:16:43 +09:00
Akihiro Suda 9c7d8bc1fd libcontainer: add parser for /etc/sub{u,g}id and /proc/PID/{u,g}id_map
Signed-off-by: Akihiro Suda <suda.akihiro@lab.ntt.co.jp>
2018-05-10 12:16:43 +09:00
Sebastien Boeuf bb912eb00c libcontainer: Do not wait for signalled processes if subreaper is set
When a subreaper is enabled, it might expect to reap a process and
retrieve its exit code. That's the reason why this patch is giving
the possibility to define the usage of a subreaper as a consumer of
libcontainer. Relying on this information, libcontainer will not
wait for signalled processes in case a subreaper has been set.

Fixes #1677

Signed-off-by: Sebastien Boeuf <sebastien.boeuf@intel.com>
2017-12-14 10:37:38 -08:00
Tobias Klauser 4d27f20db0 libcontainer: drop FreeBSD support
runc is not supported on FreeBSD, so remove all FreeBSD specific bits.

As suggested by @crosbymichael in #1653

Signed-off-by: Tobias Klauser <tklauser@distanz.ch>
2017-11-24 14:51:05 +01:00
Tobias Klauser d2bc081420 libcontainer: merge common syscall implementations
There are essentially two possible implementations for Setuid/Setgid on
Linux, either using SYS_SETUID32/SYS_SETGID32 or SYS_SETUID/SYS_SETGID,
depending on the architecture (see golang/go#1435 for why Setuid/Setgid
aren currently implemented for Linux neither in syscall nor in
golang.org/x/sys/unix).

Reduce duplication by merging the currently implemented variants and
adjusting the build tags accordingly.

Signed-off-by: Tobias Klauser <tklauser@distanz.ch>
2017-10-16 11:11:18 +02:00
Aleksa Sarai d2ac52fe52
merge branch 'pr-1475'
Add support for mips/mips64
  Put signalMap in a separate file, so it may be arch-specific

LGTMs: @crosbymichael @cyphar
Closes #1475
2017-10-16 02:59:34 +11:00
Tobias Klauser 078e903296 libcontainer: use ioctl wrappers from x/sys/unix
Use IoctlGetInt and IoctlGetTermios/IoctlSetTermios instead of manually
reimplementing them.

Because of unlockpt, the ioctl wrapper is still needed as it needs to
pass a pointer to a value, which is not supported by any ioctl function
in x/sys/unix yet.

Signed-off-by: Tobias Klauser <tklauser@distanz.ch>
2017-07-10 10:56:58 +02:00
Tobias Klauser a380fae959 libcontainer: use Prctl() from x/sys/unix
Use unix.Prctl() instead of manually reimplementing it using
unix.RawSyscall. Also use unix.SECCOMP_MODE_FILTER instead of locally
defining it.

Signed-off-by: Tobias Klauser <tklauser@distanz.ch>
2017-07-10 10:56:58 +02:00
W. Trevor King 2bea4c897e libcontainer/system/proc: Add Stat_t.State
And Stat_t.PID and Stat_t.Name while we're at it.  Then use the new
.State property in runType to distinguish between running and
zombie/dead processes, since kill(2) does not [1].  With this change
we no longer claim Running status for zombie/dead processes.

I've also removed the kill(2) call from runType.  It was originally
added in 13841ef3 (new-api: return the Running state only if the init
process is alive, 2014-12-23), but we've been accessing
/proc/[pid]/stat since 14e95b2a (Make state detection precise,
2016-07-05, #930), and with the /stat access the kill(2) check is
redundant.

I also don't see much point to the previously-separate
doesInitProcessExist, so I've inlined that logic in runType.

It would be nice to distinguish between "/proc/[pid]/stat doesn't
exist" and errors parsing its contents, but I've skipped that for the
moment.

The Running -> Stopped change in checkpoint_test.go is because the
post-checkpoint process is a zombie, and with this commit zombie
processes are Stopped (and no longer Running).

[1]: https://github.com/opencontainers/runc/pull/1483#issuecomment-307527789

Signed-off-by: W. Trevor King <wking@tremily.us>
2017-06-20 16:26:55 -07:00
W. Trevor King 439eaa3584 libcontainer/system/proc: Add Stat and Stat_t
So we can extract more than the start time with a single read.

Signed-off-by: W. Trevor King <wking@tremily.us>
2017-06-14 15:28:03 -07:00
Tobias Klauser 553016d7da Use Prctl() from x/sys/unix instead of own wrapper
Use unix.Prctl() instead of reimplemnting it as system.Prctl().

Signed-off-by: Tobias Klauser <tklauser@distanz.ch>
2017-06-07 15:03:15 +02:00
Vladimir Stefanovic d01050e6d4 Add support for mips/mips64
Signed-off-by: Vladimir Stefanovic <vladimir.stefanovic@imgtec.com>
2017-06-02 22:30:00 +02:00
Tobias Klauser d8b5c1c810 Use symlink xattr functions from x/sys/unix
Use the symlink xattr syscall wrappers Lgetxattr, Llistxattr and
Lsetxattr from x/sys/unix (introduced in
golang/sys@b90f89a1e7) instead of
providing own wrappers. Leave the functionality of system.Lgetxattr
intact with respect to the retry with a larger buffer, but switch it to
use unix.Lgetxattr.

Signed-off-by: Tobias Klauser <tklauser@distanz.ch>
2017-05-31 13:50:34 +02:00
Christy Perez 3d7cb4293c Move libcontainer to x/sys/unix
Since syscall is outdated and broken for some architectures,
use x/sys/unix instead.

There are still some dependencies on the syscall package that will
remain in syscall for the forseeable future:

Errno
Signal
SysProcAttr

Additionally:
- os still uses syscall, so it needs to be kept for anything
returning *os.ProcessState, such as process.Wait.

Signed-off-by: Christy Perez <christy@linux.vnet.ibm.com>
2017-05-22 17:35:20 -05:00
Yong Tang a83f5bac28 Fix issue in `GetProcessStartTime`
This fix tries to address the issue raised in docker:
https://github.com/docker/docker/issues/27540

The issue was that `GetProcessStartTime` use space `"  "`
to split the `/proc/[pid]/stat` and take the `22`th value.

However, the `2`th value is inside `(` and `)`, and could
contain space. The following are two examples:
```
ubuntu@ubuntu:~/runc$ cat /proc/90286/stat
90286 (bash) S 90271 90286 90286 34818 90286 4194560 1412 1130576 4 0 2 1 2334 438 20 0 1 0 3093098 20733952 823 18446744073709551615 1 1 0 0 0 0 0 3670020 1266777851 0 0 0 17 1 0 0 0 0 0 0 0 0 0 0 0 0 0
ubuntu@ubuntu:~/runc$ cat /proc/89653/stat
89653 (gunicorn: maste) S 89630 89653 89653 0 -1 4194560 29689 28896 0 3 146 32 76 19 20 0 1 0 2971844 52965376 3920 18446744073709551615 1 1 0 0 0 0 0 16781312 137447943 0 0 0 17 1 0 0 0 0 0 0 0 0 0 0 0 0 0
```

This fix fixes this issue by removing the prefix before `)`,
then finding the `20`th value (instead of `22`th value).

Signed-off-by: Yong Tang <yong.tang.github@outlook.com>
2016-10-20 11:34:21 -07:00
Carl Henrik Lunde 0a45903563 Support 32 bit UID on i386
The original SETUID takes a 16 bit UID.  Linux 2.4 introduced  a new
syscall, SETUID32, with support for 32 bit UIDs.  The setgid wrapper
already uses SETGID32.

Signed-off-by: Carl Henrik Lunde <chlunde@ifi.uio.no>
2016-08-16 22:47:38 +02:00
Qiang Huang 777ac05e5e Cleanup GetLongBit
Follow up: #962

Signed-off-by: Qiang Huang <h.huangqiang@huawei.com>
2016-08-02 09:04:30 +08:00
Buddha Prakash fcd966f501 Remove kmem Initialization check
Signed-off-by: Buddha Prakash <buddhap@google.com>
2016-08-01 09:47:34 -07:00
Qiang Huang 15c93ee9e0 Revert "Use update time to detect if kmem limits have been set"
Revert: #935
Fixes: #946

I can reproduce #946 on some machines, the problem is on
some machines, it could be very fast that modify time
of `memory.kmem.limit_in_bytes` could be the same as
before it's modified.

And now we'll call `SetKernelMemory` twice on container
creation which cause the second time failure.

Revert this before we find a better solution.

Signed-off-by: Qiang Huang <h.huangqiang@huawei.com>
2016-07-21 19:14:38 +08:00
Vishnu kannan c501cc038a Remove unused GetLongBit() function.
Signed-off-by: Vishnu kannan <vishnuk@google.com>
2016-07-06 15:23:01 -07:00
Kenfe-Mickael Laventure 10a3c26c9a Fix GetLongBit() returns value when _SC_LONG_BIT is not available
Signed-off-by: Kenfe-Mickael Laventure <mickael.laventure@gmail.com>
2016-05-13 09:37:58 -07:00
Kenfe-Mickael Laventure 27814ee120 Allow updating kmem.limit_in_bytes if initialized at cgroup creation
Signed-off-by: Kenfe-Mickael Laventure <mickael.laventure@gmail.com>
2016-05-06 08:05:15 -07:00
Akihiro Suda 1829531241 Fix trivial style errors reported by `go vet` and `golint`
No substantial code change.
Note that some style errors reported by `golint` are not fixed due to possible compatibility issues.

Signed-off-by: Akihiro Suda <suda.kyoto@gmail.com>
2016-04-12 08:13:16 +00:00
Julian Friedman e91b2b8aca Set rlimits using prlimit in parent
Fixes #680

This changes setupRlimit to use the Prlimit syscall (rather than
Setrlimit) and moves the call to the parent process. This is necessary
because Setrlimit would affect the libcontainer consumer if called in
the parent, and would fail if called from the child if the
child process is in a user namespace and the requested rlimit is higher
than that in the parent.

Signed-off-by: Julian Friedman <julz.friedman@uk.ibm.com>
2016-03-25 15:11:44 +00:00
Michael Crosby fdb100d247 Destroy container along with processes before stdio
We need to make sure the container is destroyed before closing the stdio
for the container.  This becomes a big issues when running in the host's
pid namespace because the other processes could have inherited the stdio
of the initial process.  The call to close will just block as they still
have the io open.

Calling destroy before closing io, especially in the host pid namespace
will cause all additional processes to be killed in the container's
cgroup.  This will allow the io to be closed successfuly.

This change makes sure the order for destroy and close is correct as
well as ensuring that if any errors encoutered during start or exec will
be handled by terminating the process and destroying the container.  We
cannot use defers here because we need to enforce the correct ordering
on destroy.

This also sets the subreaper setting for runc so that when running in
pid host, runc can wait on the addiontal processes launched by the
container, useful on destroy, but also good for reaping the additional
processes that were launched.

Signed-off-by: Michael Crosby <crosbymichael@gmail.com>
2016-03-15 13:17:11 -07:00
Phil Estes 009d2835cf Stub RunningInUserNS for non-Linux
Add a stub for non-Linux that always returns false

Docker-DCO-1.1-Signed-off-by: Phil Estes <estesp@linux.vnet.ibm.com> (github: estesp)
2016-03-03 16:33:43 -05:00
Mrunal Patel 38b39645d9 Implement NoNewPrivileges support in libcontainer
Signed-off-by: Mrunal Patel <mrunalp@gmail.com>
2016-02-16 06:57:50 -08:00
Serge Hallyn c0ad40c5e6 Do not create devices when in user namespace
When we launch a container in a new user namespace, we cannot create
devices, so we bind mount the host's devices into place instead.

If we are running in a user namespace (i.e. nested in a container),
then we need to do the same thing.  Add a function to detect that
and check for it before doing mknod.

Signed-off-by: Serge Hallyn <serge.hallyn@ubuntu.com>
---
 Changelog - add a comment clarifying what's going on with the
	     uidmap file.
2016-01-08 12:54:08 -08:00
Alexander Morozov 38c34d6036 Fix build tags
Signed-off-by: Alexander Morozov <lk4d4@docker.com>
2015-07-01 13:22:09 -07:00
Michael Crosby 8f97d39dd2 Move libcontainer into subdirectory
Signed-off-by: Michael Crosby <crosbymichael@gmail.com>
2015-06-21 19:29:15 -07:00