… implements proper parsing of /etc/passwd and /etc/group, and use that to add support for "docker run -u user:group" and for getting supplementary groups (if ":group" is not specified)

Docker-DCO-1.1-Signed-off-by: Andrew Page <admwiggin@gmail.com> (github: tianon)

Docker-DCO-1.1-Signed-off-by: Michael Crosby <michael@crosbymichael.com> (github: crosbymichael)

Fixes #5647
Docker-DCO-1.1-Signed-off-by: Alexandr Morozov <lk4d4math@gmail.com> (github: LK4D4)

…plementary to return "Home" too

Docker-DCO-1.1-Signed-off-by: Andrew Page <admwiggin@gmail.com> (github: tianon)

This patch refactors most of GetUserGroupSupplementaryHome and its
signature, to make using it much simpler. The private parsing ftunctions
have also been exposed (parsePasswdFile, parseGroupFile) to allow custom
data source to be used (increasing the versatility of the user/ tools).

In addition, file path wrappers around the formerly private API
functions have been added to make usage of the API for callers easier if
the files that are being parsed are on the filesystem (while the
io.Reader APIs are exposed for non-traditional usecases).

Signed-off-by: Aleksa Sarai <cyphar@cyphar.com> (github: cyphar)

This patch adds an os/user-like user lookup API, implemented in pure Go.
It also has some features not present in the standard library
implementation (such as group lookups).

Signed-off-by: Aleksa Sarai <cyphar@cyphar.com> (github: cyphar)

Signed-off-by: Aleksa Sarai <cyphar@cyphar.com> (github: cyphar)

Signed-off-by: Andrey Vagin <avagin@openvz.org>

Signed-off-by: Mrunal Patel <mrunalp@gmail.com>

This parses group file only once to process a list of groups instead of parsing
once for each group. Also added an unit test for GetAdditionalGroupsPath

Signed-off-by: Daniel, Dao Quang Minh <dqminh89@gmail.com>

The old GetAdditionalGroups* API didn't match the rest of
libcontainer/user, we make functions that take io.Readers and then make
wrappers around them. Otherwise we have to do dodgy stuff when testing
our code.

Fixes: b6df94ee65436 ("refactor GetAdditionalGroupsPath")
Signed-off-by: Aleksa Sarai <cyphar@cyphar.com>

Update the tests to use the test-friendly GetAdditionalGroups API,
rather than making random files for no good reason.

Signed-off-by: Aleksa Sarai <cyphar@cyphar.com>

/etc/groups is not needed when specifying numeric group ids. This
change allows containers without /etc/groups to specify numeric
supplemental groups.

Signed-off-by: Sami Wagiaalla <swagiaal@redhat.com>

Export errors as variables when no matching entries are found in passwd or group file.

Signed-off-by: Thomas LE ROUX <thomas@november-eleven.fr>

Most shadow-related tools don't treat numeric ids as potential
usernames, so change our behaviour to match that. Previously, using an
explicit specification like 111:222 could result in the UID and GID not
being 111 and 222 respectively (which is confusing).

Signed-off-by: Aleksa Sarai <asarai@suse.de>

Signed-off-by: Aleksa Sarai <asarai@suse.de>

Some of the code was quite confusing inside libcontainer/user, so
refactor and comment it so future maintainers can understand what's
going and what edge cases we have to deal with.

Signed-off-by: Aleksa Sarai <asarai@suse.de>

Fixes: #941

Signed-off-by: Qiang Huang <h.huangqiang@huawei.com>

Signed-off-by: Lei Jitang <leijitang@huawei.com>

The parameters passed to `GetExecUser` is not correct.
Consider the following code:

```
package main

import (
	"fmt"
	"io"
	"os"
)

func main() {
	passwd, err := os.Open("/etc/passwd1")
	if err != nil {
		passwd = nil
	} else {
		defer passwd.Close()
	}

	err = GetUserPasswd(passwd)
	if err != nil {
		fmt.Printf("%#v\n", err)
	}
}

func GetUserPasswd(r io.Reader) error {
	if r == nil {
		return fmt.Errorf("nil source for passwd-formatted
data")
	} else {
		fmt.Printf("r = %#v\n", r)
	}
	return nil
}
```

If the file `/etc/passwd1` is not exist, we expect to return
`nil source for passwd-formatted data` error, and in fact, the func
`GetUserPasswd` return nil.

The same logic exists in runc code. this patch fix it.

Signed-off-by: Wang Long <long.wanglong@huawei.com>

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>

Signed-off-by: Valentin Rothberg <vrothberg@suse.com>

Signed-off-by: Kenfe-Mickael Laventure <mickael.laventure@gmail.com>

This reverts commit be16efd31c1748d9203905dffe449c655791c6a9, reversing
changes made to 51b501dab1889ca609db9c536ac976f0f53e7021.

Signed-off-by: Kenfe-Mickael Laventure <mickael.laventure@gmail.com>

runc currently only support Linux platform, and since we dont intend to expose
the support to other platform, removing all other platforms placeholder code.

`libcontainer/configs` still being used in
https://github.com/moby/moby/blob/master/daemon/daemon_windows.go so
keeping it for now.

After this, we probably should also rename files to drop linux suffices
if possible.

Signed-off-by: Daniel Dao <dqminh89@gmail.com>

This rearranges a bit of the user and group lookup, such that only a
basic subset is exposed.

Signed-off-by: Vincent Batts <vbatts@hashbangbash.com>

Signed-off-by: Akihiro Suda <suda.akihiro@lab.ntt.co.jp>

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>

subgid is defined per user, not group (see subgid(5))

This commit also adds support for specifying subuid owner with a numeric UID.

Signed-off-by: Akihiro Suda <suda.akihiro@lab.ntt.co.jp>

The Err() method should be called after the Scan() loop, not inside it.

Found by

 git grep -A3 -F '.Scan()' | grep Err

Signed-off-by: Kir Kolyshkin <kolyshkin@gmail.com>

Signed-off-by: tjucoder <chinesecoder@foxmail.com>

Signed-off-by: Sebastiaan van Stijn <github@gone.nl>

Signed-off-by: Amim Knabben <amim.knabben@gmail.com>

Signed-off-by: Shengjing Zhu <zhsj@debian.org>

Signed-off-by: AdamKorcz <adam@adalogics.com>

Commit f1e605bf added these two functions, but they are only used from
Windows code. The v1 of this patch moved these functions to _windows.go
file, but after some discussion we decided to drop windows code
altogether, so this is what this patch now does.

This fixes

> libcontainer/user/user.go:64:6: func `groupFromOS` is unused (unused)
> libcontainer/user/user.go:35:6: func `userFromOS` is unused (unused)

Signed-off-by: Kir Kolyshkin <kolyshkin@gmail.com>

Move the unix-specific code to a file that's not compiled on
Windows.

Some of the errors (ErrUnsupported, ErrNoPasswdEntries, ErrNoGroupEntries)
are used in other parts of the code, so are moved to a non-platform
specific file.

Most of "user" is probably not useful on Windows, although it's possible
that Windows code may have to parse a passwd file, so leaving that code
for now.

Signed-off-by: Sebastiaan van Stijn <github@gone.nl>

Signed-off-by: Sebastiaan van Stijn <github@gone.nl>

gofumpt (mvdan.cc/gofumpt) is a fork of gofmt with stricter rules.

Brought to you by

	git ls-files \*.go | grep -v ^vendor/ | xargs gofumpt -s -w

Looking at the diff, all these changes make sense.

Also, replace gofmt with gofumpt in golangci.yml.

Signed-off-by: Kir Kolyshkin <kolyshkin@gmail.com>

Signed-off-by: Sebastiaan van Stijn <github@gone.nl>

Signed-off-by: Sebastiaan van Stijn <github@gone.nl>

Using fmt.Errorf for errors that do not have %-style formatting
directives is an overkill. Switch to errors.New.

Found by

	git grep fmt.Errorf | grep -v ^vendor | grep -v '%'

Signed-off-by: Kir Kolyshkin <kolyshkin@gmail.com>

This should result in no change when the error is printed, but make the
errors returned unwrappable, meaning errors.As and errors.Is will work.

Signed-off-by: Kir Kolyshkin <kolyshkin@gmail.com>

Every []byte to string conversion results in a new allocation.
Avoid some by using []byte more.

Signed-off-by: Kir Kolyshkin <kolyshkin@gmail.com>

Same as in other places (other parsers here, as well as golang os/user
parser and glibc parser all tolerate extra space at BOL and EOL).

Signed-off-by: Kir Kolyshkin <kolyshkin@gmail.com>

Lines in /etc/group longer than 64 characters breaks the current
implementation of group parser. This is caused by bufio.Scanner
buffer limit.

Fix by re-using the fix for a similar problem in golang os/user,
namely https://go-review.googlesource.com/c/go/+/283601.

Add some tests.

Co-authored-by: Andrey Bokhanko <andreybokhanko@gmail.com>
Signed-off-by: Kir Kolyshkin <kolyshkin@gmail.com>

Go 1.17 introduce this new (and better) way to specify build tags.
For more info, see https://golang.org/design/draft-gobuild.

As a way to seamlessly switch from old to new build tags, gofmt (and
gopls) from go 1.17 adds the new tags along with the old ones.

Later, when go < 1.17 is no longer supported, the old build tags
can be removed.

Now, as I started to use latest gopls (v0.7.1), it adds these tags
while I edit. Rather than to randomly add new build tags, I guess
it is better to do it once for all files.

Mind that previous commits removed some tags that were useless,
so this one only touches packages that can at least be built
on non-linux.

Brought to you by

        go1.17 fmt ./...

Signed-off-by: Kir Kolyshkin <kolyshkin@gmail.com>

Since Go 1.19, godoc recognizes lists, code blocks, headings etc. It
also reformats the sources making it more apparent that these features
are used.

Fix a few places where it misinterpreted the formatting (such as
indented vs unindented), and format the result using the gofumpt
from HEAD, which already incorporates gofmt 1.19 changes.

Some more fixes (and enhancements) might be required.

Signed-off-by: Kir Kolyshkin <kolyshkin@gmail.com>

The exception was fixed by polyfloyd/go-errorlint#12
which eventually made its way into golangci-lint.

Signed-off-by: Kir Kolyshkin <kolyshkin@gmail.com>

This integrate the github.com/opencontainers/runc/libcontainer/user package
at commit [opencontainers/runc@a3a0ec4].

This package was originally authored in a "utils" package in the Docker
repository, after which moved to "libcontainer", which became part of runc.

Some commits were not included in history, due to them being applied in
the Docker repository before moving into "libcontainer". Leaving links
to those for future reference:

- [moby/moby@eb38750]
- [moby/moby@e41507b]
- [moby/moby@b07314e]

[opencontainers/runc@a3a0ec4]: opencontainers/runc@a3a0ec4
[moby/moby@eb38750]: moby/moby@eb38750
[moby/moby@e41507b]: moby/moby@e41507b
[moby/moby@b07314e]: moby/moby@b07314e

Co-authored-by: Tianon Gravi <admwiggin@gmail.com>
Signed-off-by: Sebastiaan van Stijn <github@gone.nl>

Signed-off-by: Sebastiaan van Stijn <github@gone.nl>