The current behavior of priority rules can be non-intuitive with
higher priority rules completely overriding lower priority rules even in
permissions not held in common. This behavior does have use cases but
its can be very confusing, and does not normal policy behavior
Eg.
priority=0 allow r /**,
priority=1 deny w /**,
will result in no allowed permissions even though the deny rule is
only removing the w permission, beause the higher priority rule
completely over ride lower priority permissions sets (including
none shared permissions).
Instead move to tracking the priority at a per permission level. This
allows the w permission to still override at priority 1, while the
read permission is allowed at priority 0.
The final constructed state will still drop priority for the final
permission set on the state.
Note: this patch updates the equality tests for the cases where
the complete override behavior was being tested for.
The complete override behavior will be reintroduced in a future
patch with a keyword extension, enabling that behavior to be used
for ordered blocks etc.
Signed-off-by: John Johansen <john.johansen@canonical.com>
Construction of the chfa can reorder states from what the numbering
given during the hfa constuctions because of reordering for better
compression, dead state removal to ensure better packing etc.
This however means the dfa dump is difficult (it is possible using
multiple dumpes) to match up to the chfa that the kernel is
using. Make this easier by making the dfa dump be able to take the
emapping as input, and provide an option to dump the chfa equivalent
hfa.
Renumbered states will show up as {new <== {orig}} in the dump
Eg.
--D dfa-states
{1} <== priority (allow/deny/prompt/audit/quiet)
{5} 0 (0x 4/0//0/0/0)
{1} perms: none
0x2 -> {5} 0 (0x 4/0//0/0/0)
0x4 -> {5} 0 (0x 4/0//0/0/0)
\a 0x7 -> {5} 0 (0x 4/0//0/0/0)
\t 0x9 -> {5} 0 (0x 4/0//0/0/0)
\n 0xa -> {5} 0 (0x 4/0//0/0/0)
\ 0x20 -> {5} 0 (0x 4/0//0/0/0)
4 0x34 -> {3}
{3} perms: none
0x0 -> {6}
{6} perms: none
1 0x31 -> {5} 0 (0x 4/0//0/0/0)
-D dfa-compressed-states
{1} <== priority (allow/deny/prompt/audit/quiet)
{2 == {5}} 0 (0x 4/0//0/0/0)
{1} perms: none
0x2 -> {2 == {5}} 0 (0x 4/0//0/0/0)
0x4 -> {2 == {5}} 0 (0x 4/0//0/0/0)
\a 0x7 -> {2 == {5}} 0 (0x 4/0//0/0/0)
\t 0x9 -> {2 == {5}} 0 (0x 4/0//0/0/0)
\n 0xa -> {2 == {5}} 0 (0x 4/0//0/0/0)
\ 0x20 -> {2 == {5}} 0 (0x 4/0//0/0/0)
4 0x34 -> {3}
{3} perms: none
0x0 -> {4 == {6}}
{4 == {6}} perms: none
1 0x31 -> {2 == {5}} 0 (0x 4/0//0/0/0)
Signed-off-by: John Johansen <john.johansen@canonical.com>
The dfa goes through several stages during the build. Allow dumping it
at the various stages instead of only at the end.
Signed-off-by: John Johansen <john.johansen@canonical.com>
The hfa stores next/check transitions in 16 bit fields to reduce memory
usage. However this means the state machine can on contain 2^16
states.
Allow the next/check tables to be 32 bit. This theoretically could allow
for 2^32 states however the base table uses the top 8 bits as flags
giving us only 2^24 bits to index into the next/check tables. With
most states having at least 1 transition this effectively caps the
number of states at 2^24.
To obtain 2^32 possible states a flags table needs to be added. Add
a skeleton around supporting a flags table, so we can note the remaining
work that needs to be done. This patch will only allow for 2^24 states.
Bug: https://gitlab.com/apparmor/apparmor/-/issues/419
Signed-off-by: John Johansen <john.johansen@canonical.com>
Instead of having multiple tables, since we have room post split
of optimization and dump flags just move all the optimization and
dump flags into a common table.
We can if needed switch the flag entry size to a long in the future.
Signed-off-by: John Johansen <john.johansen@canonical.com>
Add the ability to control whether rule merging is done.
TODO: in the furture cleanup display of flags split accross two tables
Signed-off-by: John Johansen <john.johansen@canonical.com>
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>
Add the ability to show which warnings are enabled by specifying "show"
as an to the --dump, --warn, and --Optimize options
Eg.
--warn=show
MR: https://gitlab.com/apparmor/apparmor/-/merge_requests/600
Signed-off-by: John Johansen <john.johansen@canonical.com>
