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* misc: consolidate version printing and close_stdout()Karel Zak2019-04-161-6/+6
| | | | Signed-off-by: Karel Zak <kzak@redhat.com>
* unshare: allow to set user ID and group IDLaurent Vivier2018-11-121-3/+27
| | | | | | | | | | | This patch introduces two new parameters to set the user ID and the group ID of the program to be executed. Setting group ID also drops supplementary groups. The option names used are the same as for nsenter, -S, --setuid and -G, --setgid. Signed-off-by: Laurent Vivier <laurent@vivier.eu>
* unshare: allow to set a new rootLaurent Vivier2018-11-121-5/+29
| | | | | | | | | | | | | | | This patch instroduces two new parameters to set the new root and the new working directory in this new root. This allows to combine "unshare chroot" in one command, and doing like this the /proc filesystem is correctly mounted in the new root with "--mount-proc". The new parameters are -R, --root and -w, --wd. The names are the same as for nsenter, except for "-r" that is already used by "--map-root-user" and replaced by "-R". Signed-off-by: Laurent Vivier <laurent@vivier.eu>
* unshare: remove -s from --help outputKarel Zak2018-09-111-4/+7
| | | | | | | | | | | The code and man page do not assume -s to be short alias to --setgroups. This commit also a little bit change --help output formatting to make it more readable and structured. Addresses: https://github.com/karelzak/util-linux/pull/692 Signed-off-by: Karel Zak <kzak@redhat.com>
* sys-utils: use errexec()Karel Zak2018-02-011-1/+1
| | | | Signed-off-by: Karel Zak <kzak@redhat.com>
* unshare: cleanup if-if codeKarel Zak2017-10-231-3/+2Star
| | | | Signed-off-by: Karel Zak <kzak@redhat.com>
* unshare: Allow passing <signame> to --kill-childNiklas Hambüchen2017-10-141-6/+13
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* unshare: Add --kill-child option.Niklas Hambüchen2017-10-141-1/+13
| | | | | | | | | | | This allows to conveniently kill the entire process tree below the forked program, a common problem when scripting tasks that need to reliably fully terminate without leaving reparented subprocesses behind. The example added to the man page shows the most common use. Implemented using prctl(PR_SET_PDEATHSIG, ...).
* misc: consolidate macro style USAGE_HELP_OPTIONSRuediger Meier2017-06-291-2/+2
| | | | | | | | | changed in include/c.h and applied via sed: sed -i 's/fprintf.*\(USAGE_MAN_TAIL.*\)/printf(\1/' $(git ls-files -- "*.c") sed -i 's/print_usage_help_options\(.*\);/printf(USAGE_HELP_OPTIONS\1);/' $(git ls-files -- "*.c") Signed-off-by: Ruediger Meier <ruediger.meier@ga-group.nl>
* misc: introduce print_usage_help_options()Ruediger Meier2017-06-271-2/+1Star
| | | | | | | | | | | | Consolidate --help and --version descriptions. We are now able to align them to the other options. We changed include/c.h. The rest of this patch was generated by sed, plus manually setting the right alignment numbers. We do not change anything but white spaces in the --help output. Signed-off-by: Ruediger Meier <ruediger.meier@ga-group.nl>
* misc: cosmetics, remove argument from usage(int)Ruediger Meier2017-06-261-4/+4
| | | | | | | This patch is trivial and changes nothing, because we were always using usage(0). Signed-off-by: Ruediger Meier <ruediger.meier@ga-group.nl>
* misc: remove stray semicolonsSami Kerola2017-06-141-1/+1
| | | | Signed-off-by: Sami Kerola <kerolasa@iki.fi>
* misc: fix ggc-7 fallthrough warningsSami Kerola2017-06-141-1/+1
| | | | | | | | | | | | | | | | | | | (Original patch and commit message edited by Rudi.) gcc-7 adds -Wimplicit-fallthrough=3 to our default flag -Wextra. This warning can be silenced by using comment /* fallthrough */ which is also recognized by other tools like coverity. There are also other valid comments (see man gcc-7) but we consolidate this style now. We could have also used __attribute__((fallthrough)) but the comment looks nice and does not need to be ifdef'ed for compatibility. Reference: https://gcc.gnu.org/bugzilla/show_bug.cgi?id=7652 Reference: https://developers.redhat.com/blog/2017/03/10/wimplicit-fallthrough-in-gcc-7/ Reviewed-by: Ruediger Meier <ruediger.meier@ga-group.nl> Suggested-by: Karel Zak <kzak@redhat.com> Signed-off-by: Sami Kerola <kerolasa@iki.fi>
* misc: do not use plain 0 as NULL [smatch scan]Sami Kerola2017-02-201-17/+17
| | | | | | | | | | text-utils/tailf.c:69:21: warning: Using plain integer as NULL pointer Since many 'struct option' has used zero as NULL make them more readable in same go by reindenting, and using named argument requirements. Reference: https://lwn.net/Articles/93577/ Signed-off-by: Sami Kerola <kerolasa@iki.fi>
* unshare: fix SYNOPSIS and usage()Karel Zak2017-01-091-1/+1
| | | | | | | The "program" is optional and $SHELL is executed by default. Addresses: https://github.com/karelzak/util-linux/issues/389 Signed-off-by: Karel Zak <kzak@redhat.com>
* Use --help suggestion on invalid optionKarel Zak2016-12-191-1/+1
| | | | | | | | The current default is to print all usage() output. This is overkill in many case. Addresses: https://github.com/karelzak/util-linux/issues/338 Signed-off-by: Karel Zak <kzak@redhat.com>
* Implement support for cgroup namespacesSerge Hallyn2016-03-031-13/+21
| | | | | | Currently these are supported in #for-next. Signed-off-by: Serge Hallyn <serge.hallyn@ubuntu.com>
* unshare: fix busyloop and reduce racing probabilityYuriy M. Kaminskiy2016-02-171-10/+30
| | | | | | | | | | | | | | Replace busy-loop with waiting on pipe from parent. Note: reduces racing probability, but still there are window where it is possible (if parent unshare process will be [externally] killed between successful read(fds[0]) and mount() calls). [kzak@redhat.com: - use all-io.h to avoid loops around write() and read(), - use less generic 0x06 byte to sync parent and child] Signed-off-by: Yuriy M. Kaminskiy <yumkam@gmail.com> Signed-off-by: Karel Zak <kzak@redhat.com>
* misc: fix indention [smatch scan]Karel Zak2015-08-051-1/+1
| | | | Signed-off-by: Karel Zak <kzak@redhat.com>
* unshare: remove angular brackets from literal argument in usage textBenno Schulenberg2015-08-031-1/+1
| | | | Signed-off-by: Benno Schulenberg <bensberg@justemail.net>
* unshare: remove duplicate [make checkincludes]Karel Zak2015-07-291-2/+0Star
| | | | Signed-off-by: Karel Zak <kzak@redhat.com>
* unshare: allow persisting mount namespacesKarel Zak2015-04-141-4/+68
| | | | | | | | | | | | | | | | We can create a reference (bind mount) to the new namespace after unshare(2), but it does not make sense to do it within unshared namespace. (And if I read kernel fs/namespace.c: do_loopback() correctly than copy mount bind mounts of /proc/<pid>/ns/mnt between namespaces is unsupported.) This patch bypass this problem by fork() where parent continue as usually (call unshare(2), setup another things, etc.), but child waits for /proc/[ppid]/ns/mnt inode number change (the ino is changed after parent's unshare(2)) and then it bind mounts the new namespaces and exit. Signed-off-by: Karel Zak <kzak@redhat.com>
* unshare: allow persisting namespacesKarel Zak2015-04-141-12/+81
| | | | | | | | | | | | | | | | | | | | | | | For nsenter(1) we already support namespace specification by file (e.g. bind mount to namespace /proc/[pid]/ns/[type] file). For example: # nsenter --uts=/some/path This patch extends unshare(1) to setup the bind mount for specified namespace, for example # touch /some/path # unshare --uts=/some/path hostname FOO # nsenter --uts=/some/path hostname FOO Note that the problem is mount namespace, because create bind mount to ns/mount file within unshared namespace does not make sense. Based on patch from Lubomir Rintel <lkundrak@v3.sk>. Signed-off-by: Karel Zak <kzak@redhat.com>
* unshare: add --propagation, use MS_PRIVATE by defaultKarel Zak2015-03-231-0/+44
| | | | | | | | | | | | | | | | | | | | | | | | | | | | After "unshare --mount" users assume that mount operations within the new namespaces are unshared (invisible for the rest of the system). Unfortunately, this is not true and the behavior depends on the current mount propagation setting. The kernel default is "private", but for example systemd based distros use "shared". The solution is to use (for example) "mount --make-private" after unshare(1). I have been requested many times to provide less fragile and more unified unshared mount setting *by default* to make things user friendly. The patch forces unshare(1) to explicitly use MS_REC|MS_PRIVATE for all tree by default. We can use something less (e.g MS_SLAVE), but "private" is the kernel default, so for many users this change (feature) will be invisible. This feature is possible to disable by "--propagation unchanged" or it's possible to specify another propagation flag, supported are: <slave|shared|private|unchanged> Acked-by: "Eric W. Biederman" <ebiederm@xmission.com> Signed-off-by: Karel Zak <kzak@redhat.com>
* textual: fix spellos and inconsistencies in several program messagesBenno Schulenberg2015-01-261-2/+2
| | | | Signed-off-by: Benno Schulenberg <bensberg@justemail.net>
* unshare: add --setgroups=deny|allowKarel Zak2015-01-091-6/+50
| | | | | | | | | | | | | | Since Linux 3.19 the file /proc/self/setgroups controls setgroups(2) syscall usage in user namespaces. This patch provides command line knob for this feature. The new --setgroups does not automatically implies --user to avoid complexity, it's user's responsibility to use it in right context. The exception is --map-root-user which is mutually exclusive to --setgroups=allow. CC: "Eric W. Biederman" <ebiederm@xmission.com> Signed-off-by: Karel Zak <kzak@redhat.com>
* unshare: Fix --map-root-user to work on new kernelsEric W. Biederman2015-01-091-0/+19
| | | | | | | | | | | | | | | In rare cases droping groups with setgroups(0, NULL) is an operation that can grant a user additional privileges. User namespaces were allwoing that operation to unprivileged users and that had to be fixed. Update unshare --map-root-user to disable the setgroups operation before setting the gid_map. This is needed as after the security fix gid_map is restricted to privileged users unless setgroups has been disabled. Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
* textual: add a docstring to most of the utilitiesBenno Schulenberg2015-01-061-0/+3
| | | | | | | | | This adds a concise description of a tool to its usage text. A first form of this patch was proposed by Steven Honeyman (see http://www.spinics.net/lists/util-linux-ng/msg09994.html). Signed-off-by: Benno Schulenberg <bensberg@justemail.net>
* textual: angular brackets around a non-literal argument, singularBenno Schulenberg2014-10-011-2/+2
| | | | Signed-off-by: Benno Schulenberg <bensberg@justemail.net>
* unshare: add + to getopt_long()Karel Zak2014-04-181-1/+1
| | | | Signed-off-by: Karel Zak <kzak@redhat.com>
* unshare: include libmount.h to provide missing MS_* definesRuediger Meier2014-03-171-0/+3
| | | | | | | Since 6728ca10 we are using MS_PRIVATE and MS_REC which are not defined in some systems's sys/mount.h. Signed-off-by: Ruediger Meier <ruediger.meier@ga-group.nl>
* unshare: Add possibility to add mapping into root user in user namespaceLubomir Rintel2014-01-071-2/+34
| | | | | | | | | | | | | | | | | | | | | | | | | | | | This makes it very convenient to use make use of privileged actions on CONFIG_USER_NS enabled kernels, without having to manually tinker with uid_map and gid_map to obtain required credentials (as those given upon unshare() vanish with call to execve() and lot of userspace checks for euid==0 anyway). Usage example: $ unshare --uts unshare: unshare failed: Operation not permitted $ unshare --user --uts [nfsnobody@odvarok ~]$ hostname swag hostname: you must be root to change the host name $ unshare -r --uts [root@odvarok util-linux]# hostname swag [root@odvarok util-linux]# [kzak@redhat.com: - move code to map_id() - use all-io.h - add paths to pathnames.h] Signed-off-by: Lubomir Rintel <lkundrak@v3.sk> Signed-off-by: Karel Zak <kzak@redhat.com>
* nsenter: unshare: use LC_ALLKarel Zak2013-10-181-1/+1
| | | | | Reported-by: Trần Ngọc Quân <vnwildman@gmail.com> Signed-off-by: Karel Zak <kzak@redhat.com>
* unshare: add --mount-proc for pid namespacesKarel Zak2013-07-091-7/+23
| | | | | | | | | | | | | | | Based on patch from Mike Frysinger <vapier@gentoo.org>. Mike Frysinger wrote: When it comes to pid namespaces, it's also useful for /proc to reflect the current namespace. Again, this is easy to pull off, but annoying to force everyone to do it themselves. So let's add a --mount-proc to do the magic for us. The downside is that this also implies creating a mount namespace as mounting the new pid namespace /proc over top the system one will quickly break all other processes on the system. Signed-off-by: Karel Zak <kzak@redhat.com> Acked-by: Mike Frysinger <vapier@gentoo.or>
* unshare: add --fork options for pid namespacesMike Frysinger2013-07-091-3/+28
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The ability of unshare to launch a new pid namespace is a bit limited. The first process in the namespace is expected to be the "init" for it. When it's not, you get bad behavior. For example, trying to launch a shell in a new pid namespace fails very quickly: $ sudo unshare -p dash # uname -r 3.8.3 # uname -m dash: 2: Cannot fork # ls -ld / dash: 3: Cannot fork # echo $$ 1324 For this to work smoothly, we need an init process to actively watch over things. But forcing people to re-use an existing init or write their own mini init is a bit overkill. So let's add a --fork option to unshare to do this common bit of book keeping. Now we can do: $ sudo unshare -p --fork dash # uname -r 3.8.3 # uname -m x86_64 # ls -ld / drwxr-xr-x 22 root root 4096 May 4 14:01 / # echo $$ 1 Thanks to Michael Kerrisk for his namespace articles on lwn.net [kzak@redhat.com: - fix "forkif logic, remove --mount-proc] Signed-off-by: Mike Frysinger <vapier@gentoo.org> Signed-off-by: Karel Zak <kzak@redhat.com>
* unshare: tweak styleMike Frysinger2013-03-041-3/+3
| | | | Signed-off-by: Mike Frysinger <vapier@gentoo.org>
* unshare,nsenter: spawn shell by defaultZbigniew Jędrzejewski-Szmek2013-02-141-6/+6
| | | | | | | | | | | | | The behaviour mimics chroot. Possibly it would have been nicer to to query the password database in the new namepace and run the shell of the user there, but it's hard to do correctly. getpwuid() might need to load nss plugins, and the arch in the new namespace might be different (in case of NEWNS mounts), or the hostname might be different, etc. So in general it's not possible to do it reliably. Signed-off-by: Zbigniew Jędrzejewski-Szmek <zbyszek@in.waw.pl>
* translation: unify exec error messagesSami Kerola2013-02-061-1/+1
| | | | Signed-off-by: Sami Kerola <kerolasa@iki.fi>
* unshare: make usage() translator friendlySami Kerola2013-01-251-6/+6
| | | | Signed-off-by: Sami Kerola <kerolasa@iki.fi>
* unshare,nsenter: Move the old libc handling into a common header namespace.hEric W. Biederman2013-01-171-28/+1Star
| | | | | | | | | | | | | | Move the defitions of CLONE_NEWNS, CLONE_NEWUTS, CLONE_NEWIPC, CLONE_NEWNET, CLONE_NEWUSER, CLONE_NEWPID into namespace.h in case sched.h does not provide those definitions. Are there systems around that are old enough that still need this? Move the definitions of unshare() and setns() into namespace.h for supporting old versions of libc that does not provice these. I have tested this support with setns as I still have systems old enough that glibc does not wrap setns. Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
* unshare: Add support for the pid and user namespacesEric W. Biederman2013-01-171-9/+18
| | | | | | | | | | | | - Update the unshare application to support the pid and user namespaces. - Update the man page for the new options - Fix typo in the man page where UTS was spelled UTC. - Remove the vestigal support for running a suid unshare. After unsharing a user namespace setuid(getuid()) won't work because no uid or gid mappings have been specified yet. So it is just easier not to have any support for running suid. Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
* Revert "unshare: support the switching of namespaces"Karel Zak2013-01-171-58/+17Star
| | | | | | | The functionality will be replaced with nsenter from Eric W. Biederman. This reverts commit 4bbe8099390d528018890efa914e268de3c4b44b.
* unshare: support the switching of namespacesNeil Horman2013-01-071-17/+58
| | | | | | | | | | | | | | | | | | | | | In addition to the unshare syscall, there exists the setns syscall, which allows processes to migrate to the namepsaces of other processes. Add this functionality into the unshare command, as they operate in a fairly simmilar fashion. Note: There was discussion of adding a path based namespace argument to unshare in the origional discussion thread, but I opted to leave that out as it didn't seem to fit in nicely with the current argument pattern. I figure we can always add that in later if we need to [kzak@redhat.com: - fix optional arguments - do not call unshare if no flag specified - use O_CLOEXEC - codding style cleanup] Signed-off-by: Neil Horman <nhorman@tuxdriver.com> CC: Karel Zak <kzak@redhat.com> Signed-off-by: Karel Zak <kzak@redhat.com>
* sys-utils: verify writing to streams was successfulSami Kerola2012-04-041-0/+2
| | | | Signed-off-by: Sami Kerola <kerolasa@iki.fi>
* docs: corrections to FSF license files, and postal addressSami Kerola2012-02-241-1/+1
| | | | | | | | | | | | | | The COPYING and Documentation/licenses/COPYING* files are being replaced by files from GNU web site. http://www.gnu.org/licenses/gpl-2.0.txt http://www.gnu.org/licenses/lgpl-2.1.txt Postal addresses to FSF in other files are updated to match with the address in license files. Reference: http://lists.gnu.org/archive/html/freefont-announce/2005-04/msg00001.html Signed-off-by: Sami Kerola <kerolasa@iki.fi>
* unshare: align with howto-usage-function.txtSami Kerola2011-10-301-6/+13
| | | | Signed-off-by: Sami Kerola <kerolasa@iki.fi>
* unshare: cleanup usage()Karel Zak2011-08-161-11/+12
| | | | Signed-off-by: Karel Zak <kzak@redhat.com>
* move struct option to .rodataKarel Zak2011-03-031-1/+1
| | | | | | | It does not make sense to have writable large arrays of "struct option" on the stack. Signed-off-by: Karel Zak <kzak@redhat.com>
* build-sys: provide alternatives for err, errx, warn and warnxFabian Groffen2011-02-141-1/+1
| | | | | | | | Solaris lacks err, errx, warn and warnx. This also means the err.h header doesn't exist. Removed err.h include from all files, and included err.h from c.h instead if it exists, otherwise alternatives are provided. Signed-off-by: Fabian Groffen <grobian@gentoo.org>
* unshare: fix SIGSEGV on invalid command line optionAlexey Gladkov2011-01-051-0/+1
| | | | | | | | | $ unshare --hel Segmentation fault The last element of longopts has to be filled with zeros. Signed-off-by: Kirill A. Shutemov <kirill@shutemov.name>
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