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mirror of https://gitlab.com/apparmor/apparmor synced 2025-08-22 01:57:43 +00:00

58 Commits

Author SHA1 Message Date
John Johansen
ae70dc38f8 Merge parser: drop dead code in mount.cc
perms = 0, therefore perms & something is always false.

Fixes: coverity#320937 and coverity#320937

Also remove nop code from mnt_rule::post_parse_profile(Profile &prof) as discussed in this MR.

MR: https://gitlab.com/apparmor/apparmor/-/merge_requests/1759
Approved-by: John Johansen <john@jjmx.net>
Merged-by: John Johansen <john@jjmx.net>
2025-08-05 08:31:10 +00:00
Georgia Garcia
3faddfcf46 parser: fix coverity's "not restoring ostream format"
Save the ostream flags and restore them after the std::hex
modification.

Signed-off-by: Georgia Garcia <georgia.garcia@canonical.com>
2025-08-04 18:55:58 -03:00
Christian Boltz
0de9678d4f
mount.cc: remove nop code from mnt_rule::post_parse_profile(Profile &prof)
... as discussed in https://gitlab.com/apparmor/apparmor/-/merge_requests/1759#note_2665952086
2025-08-04 19:35:26 +02:00
Christian Boltz
617d3021e8
parser: drop dead code in mount.cc
perms = 0, therefore perms & something is always false.

Fixes: coverity#320937 and coverity#320937
2025-08-04 00:08:26 +02:00
John Johansen
e6bedaac1d Merge parser: fix handling of norelatime mount rule flag
Specifying norelatime should set the corresponding MS_RELATIME flag clear
bit. Instead, it ORed in MS_NORELATIME, which expands to 0. Properly set
the clear bit by using MS_RELATIME.

Fixes: c9e31b7f "Add mount rules"

Signed-off-by: Ryan Lee <ryan.lee@canonical.com>

MR: https://gitlab.com/apparmor/apparmor/-/merge_requests/1679
Approved-by: Georgia Garcia <georgia.garcia@canonical.com>
Approved-by: John Johansen <john@jjmx.net>
Merged-by: John Johansen <john@jjmx.net>
2025-05-08 08:50:39 +00:00
Ryan Lee
711bbac5eb parser: fix handling of norelatime mount rule flag
Specifying norelatime should set the corresponding MS_RELATIME flag clear
bit. Instead, it ORed in MS_NORELATIME, which expands to 0. Properly set
the clear bit by using MS_RELATIME.

Fixes: c9e31b7f "Add mount rules"

Signed-off-by: Ryan Lee <ryan.lee@canonical.com>
2025-05-06 16:01:53 -07:00
Eisuke Kawashima
7d5a021023
fix: avoid using namespace std; in header files
using directive in a header file is a bad practice because it may lead
to unexpected results.

https://isocpp.github.io/CppCoreGuidelines/CppCoreGuidelines#Rs-using-directive
2025-05-04 23:14:36 +09:00
John Johansen
89e8fe9c1c parser: Fix special casing for detached move mounts
MR: 1561 Added the ability to specify special a keyword to allow
detached mounts. Unfortunately it updated remount to use the device
and devbuffer when remounts current encoding doesn't support it.

This caused the mount.sh regression test to fail in the following
way.

```
$ sudo bash mount.sh
[sudo] password for jj:
    using mount rules ...
Error: mount failed. Test 'MOUNT (confined cap bind mount remount rprivate conflict)' was expected to 'pass'. Reason for failure 'FAIL: mount /tmp/sdtest.358520-12403-ASaOnn/mountpoint2 on /tmp/sdtest.358520-12403-ASaOnn/mountpoint failed - Permission denied'
    not supported by parser - skipping mount options=(nodirsync),
Error: mount failed. Test 'MOUNT (confined cap mount remount option)' was expected to 'pass'. Reason for failure 'FAIL: mount /dev/loop40 on /tmp/sdtest.358520-12403-ASaOnn/mountpoint failed - Permission denied'
Error: mount failed. Test 'MOUNT (confined cap mount remount)' was expected to 'pass'. Reason for failure 'FAIL: mount /dev/loop40 on /tmp/sdtest.358520-12403-ASaOnn/mountpoint failed - Permission denied'
Error: mount passed. Test 'MOUNT (confined cap mount remount deny option)' was expected to 'fail'
```

Revert the change to remount. This fixes the regression failure.
fa0746f2e parser: add special casing for detached move mounts
Signed-off-by: John Johansen <john.johansen@canonical.com>
2025-04-07 03:07:06 -07:00
John Johansen
fa0746f2e2 parser: add special casing for detached move mounts
upsteam move_mount mediation now allows for a detached (disconnected)
mount to be move mounted into a namespace.

Add support for this by detecting 'detached' as a keyword for the
source/device and using it to create a null match. Because existing
mount encoding using a null separator between the mount terms null
match followed by the null seperator will separate detached mounts
within the existing encoding.

Eg.
  mount detached -> /destination,
  mount options=(ro) fstype=ext4 detached -> /destination,

This is functionally equivalent to using

  mount "" -> /destination,

However using "" does not provide any context that about what the rule is allowing or why so the 'detached' form is preferred.

This is not a perfect solution, but is what can be currently supported
by the kernel without more LSM hooks.

On kernels that don't support detached mount detection, rules using
the detached souce conditional will be ignored (never matched).

This encoding also allows the existing

  mount,
  mount options=(move),
  mount options=(move) -> /destination,

to continue to work with both detached and regular mounts on kernels
that support the move_mount() syscall.

Signed-off-by: John Johansen <john.johansen@canonical.com>
2025-04-05 00:19:09 -07:00
Ryan Lee
96718ea4d1 Add separator between mount flags in dump_flags
The previous code would concatenate all of them together without spacing.
While dump_flags and the corresponding operator<< function aren't currently used,
this will help for when dump_flags is used to debug parser problems.

Signed-off-by: Ryan Lee <ryan.lee@canonical.com>
2024-12-17 11:50:35 -08:00
Zygmunt Krynicki
d164e877f5 Use MS_SYNCHRONOUS instead of MS_SYNC
MS_SYNC is a flag for msync(2) while MS_SYNCHRONOUS is a flag for mount(2).
The header used to define MS_SYNC but IMO this is confusing since that's an
unrelated flag.

Signed-off-by: Zygmunt Krynicki <zygmunt.krynicki@canonical.com>
2024-12-10 09:09:45 +01:00
Ryan Lee
ae5a16bfd1 Use list_remove_at macro in mount.cc:extract_flags
Signed-off-by: Ryan Lee <ryan.lee@canonical.com>
2024-11-14 10:36:30 -08:00
Ryan Lee
d9ee417dc3 Add missing null check in mount.cc:extract_flags
There is a null check before storing invflags into inv, but not before initializing the value at inv to 0.
Assuming the null check is needed, it should be there in both places.

Signed-off-by: Ryan Lee <ryan.lee@canonical.com>
2024-11-13 14:45:55 -08:00
Ryan Lee
6a1e9f916b Replace BOOL,TRUE,FALSE macros with actual C++ boolean type
Signed-off-by: Ryan Lee <ryan.lee@canonical.com>
2024-10-28 12:35:57 +01:00
John Johansen
2737cb2c2b parser: minimization - remove unnecessary second minimization pass
Moving apply_and_clear_deny() before the first minimization pass, which
was necessary to propperly support building accept information for
older none extended permission dfas, allows us to also get rid of doing a
second minimization pass if we want to force clearing explicit deny
info from extended permission tables.

Signed-off-by: John Johansen <john.johansen@canonical.com>
2024-08-14 17:15:24 -07:00
John Johansen
5c2bd20720 parser: pass rule mode prompt through to backend
Signed-off-by: John Johansen <john.johansen@canonical.com>
2024-08-14 15:47:13 -07:00
John Johansen
2e18cb9aed parser: rename rules.h perms_t to perm32_t
There are two distinct declarations of perms_t.
  rule.h: typedef uint32_t perms_t
  hfa.h: class perms_t

these definitions clash when the front end and backend share more info.
To avoid this rename rule.h to perm32_t, and move the definition into
perms.h and use it in struct aa_perms.

Signed-off-by: John Johansen <john.johansen@canonical.com>
2024-08-14 14:39:18 -07:00
Christian Boltz
4e546291a5
MountRule: sync flags_keywords with parser code
... based on /mount.cc mnt_opts_table

Several keywords and aliases were missing in flags_keywords:
- B
- M
- make-private
- make-rprivate
- make-rshared
- make-rslave
- make-runbindable
- make-shared
- make-slave
- make-unbindable
- r
- R
- read-only
- w

Also sort the keywords in the same order as in mount.cc.

Note: AARE handling is still a TODO.

After that, update the list of known parsing failures:
- several valid profiles are now correctly parsed
- some `"make-*" mount opt and an invalid src` bad profiles are no
  longer detected as being invalid
2024-03-03 15:37:59 +01:00
John Johansen
5e8567c9e9 parser: rework perms rule merging
Instead of pushing the cmp logic for rule merging into each rule
class make it the default behavior for the perms_rule_t parent class.
Also save off the original perms for the merged rule.

For classes that don't want perms merging add an alternate
dedup_perms_rule_t clase.

Signed-off-by: John Johansen <john.johansen@canonical.com>
2023-07-10 20:04:53 -07:00
Georgia Garcia
cdb5e501d6 parser: add permission merging
By changing the compare function from each rule to use class_rule_t,
instead of perms_rule_t, we temporarily ignore if permissions are
different. If every rule attribute is the same, then the permissions
can be merged. This is done at the perms_rule_t's level.

Signed-off-by: Georgia Garcia <georgia.garcia@canonical.com>
2023-07-10 18:01:32 -03:00
John Johansen
e84e481263 parser: cleanup and rework optimization and dump flag handling
In preparation for more flags (not all of the backend dfa based),
rework the optimization and dump flag handling which has been exclusively
around the dfa up to this point.

- split dfa control and dump flags into separate fields. This gives more
  room for new flags in the existing DFA set
- rename DFA_DUMP, and DFA_CONTROL to CONTROL_DFA and DUMP_DFA as
  this will provide more uniform naming for none dfa flags
- group dump and control flags into a structure so they can be passed
  together.

Signed-off-by: John Johansen <john.johansen@canonical.com>
2023-07-07 17:47:41 -07:00
John Johansen
3ede2c46cf parser: add rule dedup of mount rules
Signed-off-by: John Johansen <john.johansen@canonical.com>
2023-07-07 17:38:47 -07:00
John Johansen
d4b0fef10a parser: fix rule flag generation change_mount type rules
MR: https://gitlab.com/apparmor/apparmor/-/merge_requests/1048
made it so rules like

  mount slave /snap/bin/** -> /**,

  mount /snap/bin/** -> /**,

would get passed into change_mount_type rule generation when they
shouldn't have been. This would result in two different errors.

1. If kernel mount flags were present on the rule. The error would
   be caught causing an error to be returned, causing profile compilation
   to fail.

2. If the rule did not contain explicit flags then rule would generate
   change_mount_type permissions based on souly the mount point. And
   the implied set of flags. However this is incorrect as it should
   not generate change_mount permissions for this type of rule. Not
   only does it ignore the source/device type condition but it
   generates permissions that were never intended.

   When used in combination with a deny prefix this overly broad
   rule can result in almost all mount rules being denied, as the
   denial takes priority over the allow mount rules.

Fixes: https://bugs.launchpad.net/apparmor/+bug/2023814
Fixes: https://bugzilla.opensuse.org/show_bug.cgi?id=1211989
Fixes: 9d3f8c6cc ("parser: fix parsing of source as mount point for propagation type flags")
Fixes: MR: https://gitlab.com/apparmor/apparmor/-/merge_requests/1048
MR: https://gitlab.com/apparmor/apparmor/-/merge_requests/1054

Signed-off-by: John Johansen <john.johansen@canonical.com>
(cherry picked from commit 86d193e183bf71448e2394734b0f2d8c316bb262)
Signed-off-by: John Johansen <john.johansen@canonical.com>
2023-06-21 01:18:14 -07:00
Georgia Garcia
9d3f8c6cc0 parser: fix parsing of source as mount point for propagation type flags
Before 300889c3a, mount rules would compile policy when using source
as mount point for rules that contain propagation type flags, such as
unbindable, runbindable, private, rprivate, slave, rslave, shared, and
rshared. Even though it compiled, the rule generated would not work as
expected.

This commit fixes both issues. It allows the usage of source as mount
point for the specified flags, albeit with a deprecation warning, and
it correctly generates the mount rule.

The policy fails to load when both source and mount point are
specified, keeping the original behavior (reference
parser/tst/simple_tests/mount/bad_opt_10.sd for example).

Fixes: https://bugs.launchpad.net/bugs/1648245
Fixes: https://bugs.launchpad.net/bugs/2023025

Signed-off-by: Georgia Garcia <georgia.garcia@canonical.com>
2023-06-07 20:16:50 -03:00
John Johansen
89bc617d0d parser: fix conflicting mnt flag values message to have a space
The conflicting flags value message was hard to read
  conflicting flag value = lazytimenolazytime

change it to
  conflicting flag values = lazytime, nolazytime

Signed-off-by: John Johansen <john.johansen@canonical.com>
2023-04-27 04:05:44 -07:00
Oliver Calder
231c469d86 parser: added nosymfollow mount option
Adds the corresponding `MS_NOSYMFOLLOW` flag to parser/mount.h as well,
defined as (1 << 8) just as in the util-linux and the kernel.

Signed-off-by: Oliver Calder <oliver.calder@canonical.com>
Signed-off-by: John Johansen <john.johansen@canonical.com>
2023-04-27 03:21:26 -07:00
Oliver Calder
bc64b824fa Issue 312: added missing kernel mount options
This patch adds the following mount options: 'nostrictatime',
'lazytime', and 'nolazytime'.

The MS_STRICTATIME mount flag already existed, and 'nostrictatime' was
listed along with 'strictatime' in the comments of parser/mount.cc, so
this patch adds a mapping for 'nostrictatime' to clear MS_STRICTATIME.

Additionally, the Linux kernel includes the 'lazytime' option with
MS_LAZYTIME mapping to (1<<25), so this patch adds MS_LAZYTIME to
parser/mount.h and the corresponding mappings in parser/mount.cc for
'lazytime' and 'nolazytime'.

Signed-off-by: Oliver Calder <oliver.calder@canonical.com>
Signed-off-by: John Johansen <john.johansen@canonical.com>
2023-04-27 03:20:34 -07:00
John Johansen
a2d56c3c74 parser: consolidate rule class handling into aa_class
Instead of having each rule individually handle the class info
introduce a class_rule_t into the hierarchy and consolidate.

Signed-off-by: John Johansen <john.johansen@canonical.com>
2023-03-31 02:21:19 -07:00
John Johansen
355730d8c7 parser: convert deny flag from bool to rule_mode
We need to be able to support more rule types than allow and deny so
convert to an enum.

Signed-off-by: John Johansen <john.johansen@canonical.com>
2023-03-31 02:21:11 -07:00
John Johansen
10a75c431f parser: rename post_process() method and move code around
The post_process() method is misnamed, it fires when the profile is
finished parsing but fires before variable expansion. Rename it
to better reflect what it does and move the trigger code into
profile as a start of cleaning this stage up.

Also document the order the hooks fire in

Signed-off-by: John Johansen <john.johansen@canonical.com>
2023-03-31 02:17:28 -07:00
John Johansen
d371458533 parser: make base classes for rules using prefixes and perms and use them
Cleanup the parse code by making shared prefix and perms classes for
rules and convert rules to use them.

Signed-off-by: John Johansen <john.johansen@canonical.com>
2023-03-31 02:17:26 -07:00
John Johansen
fdf5b062a9 parser: fixup audit struct to audit enum
This removes the struct wrapper used in the previous patch to ensure
that all uses are properly converted.

Signed-off-by: John Johansen <john.johansen@canonical.com>
2023-03-31 02:12:35 -07:00
John Johansen
7a318d99f2 parser: convert audit from bool to enum
Audit control support is going to be extended to support allowing
policy to which rules should quiet auditing. Update the frontend
internals to prepare for this.

Signed-off-by: John Johansen <john.johansen@canonical.com>
2023-03-31 02:08:20 -07:00
John Johansen
134e95f783 parser: fixup remove struct from the audit bool conversion
This removes the struct wrapper used in the previous patch to ensure
that all uses are properly converted.

Signed-off-by: John Johansen <john.johansen@canonical.com>
2023-03-31 01:08:25 -07:00
John Johansen
44f3be091a parser: convert the stored audit from a bit mask to a bool
This delays the convertion of the audit flag until passing to the
backend. This is a step towards fix the parser front end so that it
doesn't use encoded permission mappings.

Note: the patch embedds the bool conversion into a struct to ensure
the compiler will fail to build unless every use is fixed. The
struct is removed in the following patch.

Signed-off-by: John Johansen <john.johansen@canonical.com>
2023-03-31 01:05:29 -07:00
John Johansen
4fd1f97102 parser: rename mount->allow to mount->perms and switch to perm_t
Make mount permission set consistent with the other rule types. This
is a step towards refactoring.

Signed-off-by: John Johansen <john.johansen@canonical.com>
2023-03-29 10:52:31 -07:00
John Johansen
fd9a6fe133 parser: int mode to perms
Move from using and int for permissions bit mask to a perms_t type.
Also move any perms mask that uses the name mode to perms to avoid
confusing it with other uses of mode.

Signed-off-by: John Johansen <john.johansen@canonical.com>
2023-03-29 10:45:44 -07:00
John Johansen
f09676f5f9 parser: fixup gen_flag_rules
gen_flag_rules has a boolean vs bit and case where parenthesis are
helpful to express the intended order of operations.

It also doesn't handle the case where there are no matches. Fix this
by causing that case to fail.

also improve the debug of option extraction.

Signed-off-by: John Johansen <john.johansen@canonical.com>
2023-03-28 20:06:58 -07:00
John Johansen
1ec39fd437 parser: support multiple mount conditionals in a single rule
Now that flag processing for mount rules with single option
conditionals are fixed e-enable multiple mount conditionals on a
single mount rule. The mount conditionals are equivalent to specifying
multiple rules.

      mount options=(a,b,c) options=(c,d),
    is the same as
      mount options=(a,b,c),
      mount options=(c,d),

    and
      mount options in (a,b,c) options in (c,d),
      is the same as
        mount options in (a,b,c),
        mount options in (c,d),

    when multiple options= and options in are combined in a single rule
    it is the same as the cross product of the options.

    where
      mount options=(a,b,c) options in (d,e),
    is a single rule.

      mount options=(a,b,c) options=(d,e) options in (f),
    is equivalent to
      mount options=(a,b,c) options in (f),
      mount options=(d,e) options in (f),

    and while it is not recommended that multiple options= and options in
    conditions be used in a single rule.
      mount options=(a,b,c) options=(d,e) options in (f) options in (g),
    is equivalent to
      mount options=(a,b,c) options in (f),
      mount options=(a,b,c) options in (g),
      mount options=(d,e) options in (f),
      mount options=(d,e) options in (g),

Bug Link: https://bugs.launchpad.net/apparmor/+bug/1597017

Signed-off-by: John Johansen <john.johansen@canonical.com>
- rebased to bba1a023bf
- fixed infinite loop in mnt_rule::gen_policy_re
Signed-off-by: Alexander Mikhalitsyn <aleksandr.mikhalitsyn@canonical.com>
Acked-by: John Johansen <john.johansen@canonical.com>
2023-03-28 20:05:15 -07:00
John Johansen
ecfaf73300 parser: add conflicting flags check for options= conditionals
Signed-off-by: John Johansen <john.johansen@canonical.com>
- rebased to bba1a023bf
- after this commit tests mount/ok_[16-19].sd are failing,
   but it's correct
Signed-off-by: Alexander Mikhalitsyn <aleksandr.mikhalitsyn@canonical.com>
Acked-by: John Johansen <john.johansen@canonical.com>
2023-03-28 14:58:06 -07:00
John Johansen
300889c3a4 parser: fix option flag processing for single conditional rules
The combined optional flag and exact match flag processing is problematic
separate out the optional flag processing so it is only combined during
match string generation.

While doing so we fix the flag output so that multiple rules are
not output when they shouldn't be.

In addition we temporarily break multiple options= and 'options in'
conditionals in a single rule, which we will fix in a separate patch.

Bug Link: https://bugs.launchpad.net/apparmor/+bug/1597017

Signed-off-by: John Johansen <john.johansen@canonical.com>
- rebased to bba1a023bf
- made tests happy by changing condition in gen_policy_re()
Signed-off-by: Alexander Mikhalitsyn <aleksandr.mikhalitsyn@canonical.com>
Acked-by: John Johansen <john.johansen@canonical.com>
2023-03-28 14:57:11 -07:00
John Johansen
ae1950b004 Cleanup mount commands flag masking for policy generation
Simplify flag masking and fix the MS_MAKE_CMDS flag set. This is a
step in fixing

Bug Link: https://bugs.launchpad.net/apparmor/+bug/1597017

Signed-off-by: John Johansen <john.johansen@canonical.com>
- rebased to bba1a023bf
- fixed MS_MAKE_CMDS definition to the correct one.
We shouldn't add (MS_ALL_FLAGS & ~(MNT_FLAGS)) to this bitmask.
Signed-off-by: Alexander Mikhalitsyn <aleksandr.mikhalitsyn@canonical.com>
Acked-by: John Johansen <john.johansen@canonical.com>
2023-03-28 14:44:44 -07:00
John Johansen
206d199a07 Rework mount rule to specicial case multiple rule generation
A step in cleaning up mount rule generation, split out the handling
of mount rules that imply multiple rules to make it easier to
see what is going on.

Bug Link: https://bugs.launchpad.net/apparmor/+bug/1597017

Signed-off-by: John Johansen <john.johansen@canonical.com>
2023-03-28 14:42:36 -07:00
John Johansen
f17e43392b refactor: mount gen_policy_re
Do a minimal code refactoring (ie. no functional changes, just moving
code,adding boiler plate and glue) in preparation to fix
bug https://bugs.launchpad.net/apparmor/+bug/1597017

Bug Link: https://bugs.launchpad.net/apparmor/+bug/1597017

Signed-off-by: John Johansen <john.johansen@canonical.com>

- rebased to bba1a023bf
- fixed compiler warnings:
    <built-in>: In member function ‘int mnt_rule::gen_policy_new_mount(Profile&, int&, unsigned int, unsigned int)’:
    <built-in>: note: by argument 1 of type ‘const char*’ to ‘long unsigned int __builtin_strlen(const char*)’ declared here
    mount.cc:880:14: note: ‘class_mount_hdr’ declared here
      880 |         char class_mount_hdr[64];
Signed-off-by: Alexander Mikhalitsyn <aleksandr.mikhalitsyn@canonical.com>
Acked-by: John Johansen <john.johansen@canonical.com>
2023-03-28 14:41:29 -07:00
Steve Beattie
8b708d3b45
treewide: spelling/typo fixes in code strings
Fix spelling errors in code strings. Some strings are translatable.
This fixes are potentially user visible.

Signed-off-by: Steve Beattie <steve.beattie@canonical.com>
Acked-by: Christian Boltz <apparmor@cboltz.de>
MR: https://gitlab.com/apparmor/apparmor/-/merge_requests/687
2020-12-01 12:47:18 -08:00
Steve Beattie
461d9c2294
treewide: spelling/typo fixes in comments and docs
With the exception of the documentation fixes, these should all be
invisible to users.

Signed-off-by: Steve Beattie <steve.beattie@canonical.com>
Acked-by: Christian Boltz <apparmor@cboltz.de>
MR: https://gitlab.com/apparmor/apparmor/-/merge_requests/687
2020-12-01 12:47:11 -08:00
John Johansen
882380ad3d parser: enable variable expansion for mount type= and options=
Currently mount options type= and options= do not expand variables
but they should. Fix it.

Note: this does not treat either as paths because their use is
too device dependent for it to be safe to filter slashes.

MR: https://gitlab.com/apparmor/apparmor/-/merge_requests/638
Signed-off-by: John Johansen <john.johansen@canonical.com>
Acked-by: Steve Beattie <steve.beattie@canonical.com>
2020-10-01 02:11:37 -07:00
John Johansen
a1978fb1b2 parser: call filter slashes for mount conditionals
The mnt_point and devices conditionals in mount rules are generally
paths and should have slashes filtered after variable expansion.

MR: https://gitlab.com/apparmor/apparmor/-/merge_requests/607
Signed-off-by: John Johansen <john.johansen@canonical.com>
2020-09-29 04:14:35 -07:00
Mike Salvatore
52d9529d1b parser: replace duplicate warn_once() with common function
The warn_once() function is duplicated in 6 different places. A common,
reusable version has been added to parser_common.c.

Signed-off-by: Mike Salvatore <mike.salvatore@canonical.com>
2020-08-09 17:56:31 -04:00
John Johansen
a29e232831 parser: feature abi: setup parser to intersect policy and kernel features
The features abi adds the ability to track the policy abi separate
from the kernel. This allow the compiler to determine whether policy
was developed with a certain feature in mind, eg. unix rules.

This allows the compiler to know whether it should tell the kernel to
enforce the feature if the kernel supports the rule but the policy
doesn't use it.

To find if a feature is supported we take the intersection of what is
supported by the policy and what is supported by the kernel.

Policy encoding features like whether to diff_encode policy are not
influenced by policy so these remain kernel only features.

In addition to adding the above intersection of policy rename
--compile-features to --policy-features as better represents what it
represents. --compile-features is left as a hidden item for backwards
compatibility.

MR: https://gitlab.com/apparmor/apparmor/-/merge_requests/491
Signed-off-by: John Johansen <john.johansen@canonical.com>
Acked-by: Steve Beattie <sbeattie@ubuntu.com>
2020-05-29 00:23:17 -07:00