Commit Graph

7 Commits

Author SHA1 Message Date
Serge Hallyn
3d670ba7ed nss/libsubid: simplify the ranges variable for list_owner_ranges
Following alexey-tikhonov's suggestion.

Since we've dropped the 'owner' field in the data returned for
get_subid_ranges, we can just return a single allocated array of
simple structs.  This means we can return a ** instead of ***, and
we can get rid of the subid_free_ranges() helper, since the caller
can just free() the returned data.

Signed-off-by: Serge Hallyn <serge@hallyn.com>
2021-05-22 17:59:57 -05:00
Serge Hallyn
322db32971 Don't return owner in list_owner_ranges API call.
Closes: 339

struct subordinate_range is pretty closely tied to the existing
subid code and /etc/subuid format, so it includes an owner.  Dropping
that or even renaming it is more painful than I'd first thought.
So introduce a 'struct subid_range' which is only the start and
count, leaving 'struct subordinate_range' as the owner, start and
count.

Signed-off-by: Serge Hallyn <serge@hallyn.com>
2021-05-16 21:49:53 -05:00
Serge Hallyn
8492dee663 subids: support nsswitch
Closes #154

When starting any operation to do with subuid delegation, check
nsswitch for a module to use.  If none is specified, then use
the traditional /etc/subuid and /etc/subgid files.

Currently only one module is supported, and there is no fallback
to the files on errors.  Several possibilities could be considered:

1. in case of connection error, fall back to files
2. in case of unknown user, also fall back to files

etc...

When non-files nss module is used, functions to edit the range
are not supported.  It may make sense to support it, but it also
may make sense to require another tool to be used.

libsubordinateio also uses the nss_ helpers.  This is how for instance
lxc could easily be converted to supporting nsswitch.

Add a set of test cases, including a dummy libsubid_zzz module.  This
hardcodes values such that:

'ubuntu' gets 200000 - 300000
'user1' gets 100000 - 165536
'error' emulates an nss module error
'unknown' emulates a user unknown to the nss module
'conn' emulates a connection error ot the nss module

Changes to libsubid:

Change the list_owner_ranges api: return a count instead of making the array
null terminated.

This is a breaking change, so bump the libsubid abi major number.

Rename free_subuid_range and free_subgid_range to ungrant_subuid_range,
because otherwise it's confusing with free_subid_ranges which frees
    memory.

Run libsubid tests in jenkins

Switch argument order in find_subid_owners

Move the db locking into subordinateio.c

Signed-off-by: Serge Hallyn <serge@hallyn.com>
2021-04-16 21:02:37 -05:00
Serge Hallyn
0a7888b1fa Create a new libsubid
Closes #154

Currently this has three functions: one which returns the
list of subuid ranges for a user, one returning the subgids,
and one which frees the ranges lists.

I might be mistaken about what -disable-man means;  some of
the code suggests it means just don't re-generate them, but
not totally ignore them.  But that doesn't seem to really work,
so let's just ignore man/ when -disable-man.

Remove --disable-shared.  I'm not sure why it was there, but it stems
from long, long ago, and I suspect it comes from some ancient
toolchain bug.

Create a tests/run_some, a shorter version of run_all.  I'll
slowly add tests to this as I verify they work, then I can
work on fixing the once which don't.

Also, don't touch man/ if not -enable-man.

Changelog:
	Apr 22: change the subid list api as recomended by Dan Walsh.
	Apr 23: implement get_subid_owner
	Apr 24: implement range add/release
	Apr 25: finish tests and rebase
	May 10: make @owner const

Signed-off-by: Serge Hallyn <serge@hallyn.com>
2020-06-07 12:11:58 -05:00
Nicolas François
7d5732cb49 Remove dead code.
* libmisc/find_new_sub_gids.c: Remove dead code.
	find_new_sub_gids() is always called with *range_count set to 0.
	It's more difficult to keep the subordinate GIDs and UIDs
	synchronized, than for the user's UID/GId because the count of
	subordinate IDs may differ.
	* libmisc/find_new_sub_uids.c: Likewise.
	* lib/subordinateio.h, lib/subordinateio.c: Remove APIs that are
	no more needed: is_sub_uid_range_free(), is_sub_gid_range_free(),
	is_range_free().
2013-08-15 17:30:19 +02:00
Nicolas François
d611d54ed4 Allow disabling of subordinate IDs.
* configure.in: Add configure options --enable-subordinate-ids /
	--disable-subordinate-ids. Enabled by default.
	* lib/prototypes.h: Include <config.h> before using its macros.
	* lib/commonio.h, lib/commonio.c: Define commonio_append only when
	ENABLE_SUBIDS is defined.
	* lib/prototypes.h, libmisc/find_new_sub_gids.c,
	libmisc/find_new_sub_uids.c: Likewise.
	* lib/subordinateio.h, lib/subordinateio.c: Likewise.
	* libmisc/user_busy.c: Only check if subordinate IDs are in use if
	ENABLE_SUBIDS is defined.
	* src/Makefile.am: Create newgidmap and newuidmap only if
	ENABLE_SUBIDS is defined.
	* src/newusers.c: Check for ENABLE_SUBIDS to enable support for
	subordinate IDs.
	* src/useradd.c: Likewise.
	* src/userdel.c: Likewise.
	* src/usermod.c: Likewise.
	* man/Makefile.am: Install man1/newgidmap.1, man1/newuidmap.1,
	man5/subgid.5, and man5/subuid.5 only if ENABLE_SUBIDS is defined.
	* man/fr/Makefile.am: Install man1/newgidmap.1, man1/newuidmap.1,
	man5/subgid.5, and man5/subuid.5 (not translated yet).
	* man/generate_mans.mak: Add xsltproc conditionals
	subids/no_subids.
	* man/login.defs.d/SUB_GID_COUNT.xml: Add dependency on subids
	condition.
	* man/login.defs.d/SUB_UID_COUNT.xml: Likewise.
	* man/usermod.8.xml: Document options for subordinate IDs and
	reference subgid(5) / subuid(5) depending on the subids condition.
2013-08-11 15:46:59 +02:00
Eric W. Biederman
f28ad4b251 Add backend support for suboridnate uids and gids
These files list the set of subordinate uids and gids that users are allowed
to use.   The expect use case is with the user namespace but other uses are
allowed.

Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
2013-08-05 10:08:45 -05:00