Commit graph

158 commits

Author SHA1 Message Date
John Johansen
26e85c17bd Merge parser: fix definitely and possibly lost memory leaks
MR: https://gitlab.com/apparmor/apparmor/-/merge_requests/992
Approved-by: John Johansen <john@jjmx.net>
Merged-by: John Johansen <john@jjmx.net>
(cherry picked from commit 05595eccda)
Signed-off-by: John Johansen <john.johansen@canonical.com>
2023-03-28 20:21:09 -07:00
John Johansen
8c8da7c67d parser: move ifdefs for capabilities to single common file
Unfortunately the parser was doing ifdef checks for capabilities
in two places. Move all the capability ifdefs into capability.h

MR: https://gitlab.com/apparmor/apparmor/-/merge_requests/768
Signed-off-by: John Johansen <john.johansen@canonical.com>
Acked-by: Georgia Garcia  <georgia.garcia@canonical.com>
2021-07-02 12:48:47 -07:00
John Johansen
7dcf013bca parser: add include dedup cache to handle include loops
Profile includes can be setup to loop and expand in a pathalogical
manner that causes build failures. Fix this by caching which includes
have already been seen in a given profile context.

In addition this can speed up some profile compiles, that end up
re-including common abstractions. By not only deduping the files
being included but skipping the need to reprocess and dedup the
rules within the include.

Fixes: https://bugzilla.suse.com/show_bug.cgi?id=1184779
MR: https://gitlab.com/apparmor/apparmor/-/merge_requests/743
Signed-off-by: John Johansen <john.johansen@canonical.com>
Acked-by: Steve Beattie <steve.beattie@canonical.com>
2021-04-27 20:26:57 -07:00
John Johansen
761008f1b6 parser: fix yyerror message to not duplicate file name output
yyerror is outputting the file name twice when not in a profile or
the profilename global is not defined. Drop the second output of
the file name as it just clutters up the error message.

MR: https://gitlab.com/apparmor/apparmor/-/merge_requests/610
Signed-off-by: John Johansen <john.johansen@canonical.com>
Acked-by: Mike Salvatore <mike.salvatore@canonical.com>
2020-09-03 07:19:21 -07:00
John Johansen
f5c4927c85 parser: convert remaining pwarn() to flag controlled warns
Make all warnings that go through pwarn() controllable by warning
flags. This adds several new warning control flags, documented in

  --help=warn

Convert --debug-cache to be unified with warning flags. So it can be
set by either
    --debug-cache
  or
    --warn=debug-cache

Also add an "all" option to be able to turn on all warnings.

MR: https://gitlab.com/apparmor/apparmor/-/merge_requests/600
Signed-off-by: John Johansen <john.johansen@canonical.com>
2020-09-01 19:42:38 -07:00
John Johansen
c530c880b1 parser: Add warning flag that can toggle deprecation warnings
Add the flag
  --warn=deprecated

to be able to toggle deprecation warnings

MR: https://gitlab.com/apparmor/apparmor/-/merge_requests/600
Signed-off-by: John Johansen <john.johansen@canonical.com>
2020-09-01 19:42:38 -07:00
John Johansen
0d0686becc parser: Add warning flag for ABI messages
ABI warnings can be to much for a deployed system. Add

  --warn=abi

to control output of abi warnings

MR: https://gitlab.com/apparmor/apparmor/-/merge_requests/600
Signed-off-by: John Johansen <john.johansen@canonical.com>
2020-09-01 19:42:38 -07:00
John Johansen
dcc2918665 parser: add an option to allow overriding feature ABI rules
Add an option to allow setting/pinning the feature ABI and overriding
of ABI rules if they exist.

  --override-policy-abi

This option is primarily for profile development and testing without
allowing adjusting feature abis temporarily without modifying the
profile.

MR: https://gitlab.com/apparmor/apparmor/-/merge_requests/579
Signed-off-by: John Johansen <john.johansen@canonical.com>
2020-08-20 01:22:03 -07:00
John Johansen
acb45dc4b0 parser: fix abi rule and pinned feature file interaction
In AppArmor 2 distros could pin the feature file being used by setting
the feature-file option in the config file.

With AppArmor 3 policy is now explicitly tagged with an abi rule.

The problem is the interaction on systems that have a mixture of
AppArmor 2 and AppArmor 3 policy and use feature pinning.

The feature pinning is required to make the apparmor 2 policy behave
as expected but it also overrides the abi rules that are explicitly
set as part of the policy. This means we either have the apparmor 2
pinned policy working as desired or the apparmor 3 policy, but not
both.

To fix this make setting the flag on command line or in config file
lower priority than an abi rule specified in policy. The ability
to override abi rules will be added in a separate patch.

The Priority ordering to determine the policy abi to use is
1. Use abi rules if present
2. if no abi rule use command line option
3. if no abi rule or command line option use config setting
4. if none of the above use the default abi

PR: https://gitlab.com/apparmor/apparmor/-/merge_requests/579
Signed-off-by: John Johansen <john.johansen@canonical.com>
2020-08-20 01:22:03 -07:00
John Johansen
c810c755b1 parser: allow backwards mapping of a capability
If a capability is known in policy but not by the kernel, check to see if it has
a backwards mapping to a different capability and use that instead.

Signed-off-by: John Johansen <john.johansen@canonical.com>
2020-07-07 09:43:48 -07:00
John Johansen
3880ef5b54 parser: Use the kernel and policy abis to detect new capabilities
The kernel and policy abis can be used to detect and support new
capabilities without having to update base_cap_names.h and and
rebuilding the compiler.

This is not perfect however in that the does not provide any backwards
compatibility mappings, so we still need to keep the internal
capability table.

Signed-off-by: John Johansen <john.johansen@canonical.com>
2020-07-07 09:43:48 -07:00
John Johansen
0c9884550c parser: support enforce, kill and unconfined profile modes
The enforce profile mode is the default but specifying it explicitly
has not been supported. Allow enforce to be specified as a mode. If
no mode is specified the default is still enforce.

The kernel has supported kill and unconfined profile modes for a
long time now. And support to the parser so that profiles can make
use of these modes.

MR: https://gitlab.com/apparmor/apparmor/-/merge_requests/440
Fixes: https://gitlab.com/apparmor/apparmor/-/issues/7
Signed-off-by: John Johansen <john.johansen@canonical.com>
Acked-by: Steve Beattie <sbeattie@ubuntu.com>
2020-06-10 05:35:37 -07:00
John Johansen
162da1ba48 parser: add basic support for feature abis
Add basic support for policy to specify a feature abi. Under the
current implementation the first feature abi specified will be
used as the policy abi for the entire profile.

If no feature abi is defined before rules are processed then the
default policy abi will be used.

If multiple feature abi rules are encountered and the specified
abi is different then a warning will be issued, and the initial abi
will continue to be used. The ability to support multiple policy
feature abis during a compile will be added in a future patch.

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 00:23:37 -07:00
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
John Johansen
91deb0cf13 parser: Display a deprecated warning when using filenames as a profile name
The use of filenames for a profile name has been deprecated in
AppArmor 3.0 so output a warning when ever a profile with a filename
based name is encountered.

PR: https://gitlab.com/apparmor/apparmor/-/merge_requests/506
Acked-by: Steve Beattie <steve.beattie@canonical.com>
Signed-off-by: John Johansen <john.johansen@canonical.com>
2020-05-05 02:16:23 -07:00
John Johansen
2416faac54 parser: support matching xattr keys but not values
Support profiles that choose to match the presence of an extended
attribute without validating its value. This lets AppArmor target xattrs
with binary data, such as security.ima and security.evm values. For
example, it's now possible to write a profile such as:

        profile signed_binaries /** xattrs=(security.ima) {
                # ...
        }

Both presence and value matches can be used in the same profile. To
match a signed xattr, target both the xattr and the security.ima value:

        profile python_script /** xattrs=(
                security.evm
                security.apparmor="python"
        ) {
                # ...
        }

Updated to work using out of band matching instead of separate data
array.

Signed-off-by: Eric Chiang <ericchiang@google.com>
Signed-off-by: John Johansen <john.johansen@canonical.com>
2019-11-26 21:32:08 -08:00
John Johansen
9b0a98d00e parser: make sure xattr cond_entry_list is not leaked
Signed-off-by: John Johansen <john.johansen@canonical.com>
2019-11-26 21:32:08 -08:00
Eric Chiang
a42fd8c6f4 parser: add support for matching based on extended file attributes
Add userland support for matching based on extended file attributes.
This leverages DFA based matching already in the kernel:

https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=8e51f908
https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=73f488cd

Matching is exposed via flags on the profile:

  /usr/bin/* xattrs=(user.foo=bar user.bar=**) {
      # ...
  }

Profiles list the set of extended attributes that a file MUST have, and
a regex to match the value of that extended attributes. Additional
extended attributes on the file don't effect the match.

Signed-off-by: Eric Chiang <ericchiang@google.com>
2019-03-14 10:47:54 -07:00
John Johansen
83df7c4747 parser: ignore feature abi rules
AppArmor 3.0 requires policy to use a feature abi rule for access to
new features. However some policy may start using abi rules even if
they don't have rules that require new features.  This is especially
true for out of tree policy being shipped in other packages.

Add enough support to older releases that the parser will ignore the
abi rule and warn that it is falling back to the apparmor 2.x
technique of using the system abi.

If the profile contains rules that the older parser does not
understand it will fail policy compilation at the unknown rule instead
of the abi rule.

PR: https://gitlab.com/apparmor/apparmor/merge_requests/196
Signed-off-by: John Johansen <john.johansen@canonical.com>
Acked-by: Seth Arnold <seth.arnold@canonical.com>
2018-10-12 22:14:38 -07:00
Patrick Steinhardt
41c1e30e9b parser: fix compilation with missing RLIMIT macros
The define `RLIMIT_OFILE` is a historic macro originating from
the BSDs, which is nowadays an alias for `RLIMIT_NOFILE`. On some
implementations, it has thus been dropped in favor of the new
define, but we still assume it will always be defined in our
rlimit keywords table. Wrap it in an `ifdef` to fix compilation
on systems where it does not exist.

For the second macro `RLIMIT_RTTIME`, we do check for its
existence in our keywords table, but then forgot to do so in the
YACC rules. Wrap it into an `ifdef`, as well.

Both patches serve the goal to fix compilation on musl libc.

Signed-off-by: Patrick Steinhardt <ps@pks.im>
2017-09-27 11:31:10 +02:00
John Johansen
40e193e623 Fix: make sure overlapping safe and unsafe exec rules conflict
BugLink: https://launchpad.net/bugs/1588069

Currently

  change_profile /** -> A,
  change_profile unsafe /** -> A,

do not conflict because the safe rules only set the change_profile
permission where the unsafe set unsafe exec. To fix this we have the
safe version set exec bits as well with out setting unsafe exec.
This allows the exec conflict logic to detect any conflicts.

This is safe to do even for older kernels as the exec bits off of the
2nd term encoding in the change_onexec rules are unused.

Test files
  tst/simple_tests/change_profile/onx_no_conflict_safe1.sd
  tst/simple_tests/change_profile/onx_no_conflict_safe2.sd
by Christian Boltz <apparmor@cboltz.de>

Signed-off-by: John Johansen <john.johansen@canonical.com>
Acked-by: Tyler Hicks <tyhicks@canonical.com>
2016-06-02 22:24:22 -07:00
Tyler Hicks
fe14a337ef parser: Clean up exec mode parsing
The opt_unsafe token was being used to represent 'safe' and 'unsafe' so
it is renamed to opt_exec_mode. Create helpfully named macros to compare
opt_exec_mode's value against instead of hard-coded '0', '1', and '2'
values.

Signed-off-by: Tyler Hicks <tyhicks@canonical.com>
Acked-by: John Johansen <john.johansen@canonical.com>
2016-05-31 15:38:36 -05:00
Tyler Hicks
0c4c975509 parser: Allow change_profile rules to accept an exec mode modifier
https://launchpad.net/bugs/1584069

This patch allows policy authors to specify how exec transitions should
be handled with respect to setting AT_SECURE in the new process'
auxiliary vector and, ultimately, having libc scrub (or not scrub) the
environment.

An exec mode of 'safe' means that the environment will be scrubbed and
this is the default in kernels that support AppArmor profile stacking.
An exec mode of 'unsafe' means that the environment will not be scrubbed
and this is the default and only supported change_profile exec mode in
kernels that do not support AppArmor profile stacking.

Signed-off-by: Tyler Hicks <tyhicks@canonical.com>
Acked-by: John Johansen <john.johansen@canonical.com>
2016-05-31 15:32:08 -05:00
Tyler Hicks
0801b3a72f parser: Simplify change_profile grammar rules
Make future modifications to the change_profile grammar rules easier by
simplifying things. First, the change_profile rule handling is collapsed
into a single grammar rule. The inputs to the grammar rule are given
helpful variable names to make it harder to mix up which variable we're
dealing with. Finally, the two separate calls to new_entry() are unified
into a single call.

Signed-off-by: Tyler Hicks <tyhicks@canonical.com>
Acked-by: John Johansen <john.johansen@canonical.com>
2016-05-28 11:58:41 -05:00
Tyler Hicks
1a7663e89a parser: Check kernel stacking support when handling stacked transitions
Check if the current kernel supports stacking. If not, ensure that named
transitions (exec, change_profile, etc.) do not attempt to stack their
targets.

Also, set up the change_profile vector according to whether or not the
kernel supports stacking. Earlier kernels expect the policy namespace to
be in its own NUL-terminated vector element rather than passing the
entire label (namespace and profile name) as a single string to the
kernel.

Signed-off-by: Tyler Hicks <tyhicks@canonical.com>
Acked-by: Seth Arnold <seth.arnold@canonical.com>
2016-03-18 17:28:51 -05:00
Tyler Hicks
00fb4e94ab parser: Support stacking in exec and change_profile rules
Allow for a leading '&' character to be present in the named transition
target strings to indicate that the transition should stack the current
profile with the specified profile.

Signed-off-by: Tyler Hicks <tyhicks@canonical.com>
Acked-by: John Johansen <john.johansen@canonical.com>
2016-03-18 17:28:51 -05:00
Tyler Hicks
a83d03a6a7 parser: Stop splitting the namespace from the named transition targets
The parser was splitting up the namespace and profile name from named
transition targets only to rejoin it later when creating the binary
policy. This complicated the changes needed to support the stacking
identifier '&' in named transition targets.

To keep the stacking support simple, this patch keeps the entire named
transition target string intact from initial profile parsing to writing
out the binary.

All of these changes are straightforward except the hunk that removes
the namespace string addition to the vector in the process_dfa_entry()
function. After speaking with John, kernels with stacking have support
for consuming the namespace with the profile name.

Signed-off-by: Tyler Hicks <tyhicks@canonical.com>
Acked-by: John Johansen <john.johansen@canonical.com>
2016-03-18 17:28:51 -05:00
Tyler Hicks
4ae6ad03ba parser: Clean up pivot_root target parsing
Instead of reusing opt_named_transition and be forced to reconstruct the
target path when is looks like ":odd:target", create simpler grammer
rules that have nothing to do with named transitions and namespaces.

Signed-off-by: Tyler Hicks <tyhicks@canonical.com>
Acked-by: John Johansen <john.johansen@canonical.com>
2016-02-26 18:44:16 -06:00
Tyler Hicks
e7accd8485 parser: Properly parse named transition targets
https://launchpad.net/bugs/1540666

Reuse the new parse_label() function to initialize named_transition
structs so that transition targets, when used with change_profile, are
properly seperated into a profile namespace and profile name.

Signed-off-by: Tyler Hicks <tyhicks@canonical.com>
Acked-by: John Johansen <john.johansen@canonical.com>
Bug: https://launchpad.net/bugs/1379874
2016-02-18 15:58:11 -06:00
Tyler Hicks
349b4a4ba1 parser: Allow the profile keyword to be used with namespaces
https://launchpad.net/bugs/1544387

Don't split namespaces from profile names using YACC grammar. Instead,
treat the entire string as a label in the grammer. The label can then be
split into a namespace and a profile name using the new parse_label()
function.

This fixes a bug that caused the profile keyword to not be used with a
label containing a namespace in the profile declaration.

Fixing this bug uncovered a bad parser test case at
simple_tests/profile/profile_ns_ok1.sd. The test case mistakenly
included two definitions of the :foo:unattached profile despite being
marked as expected to pass. I've adjusted the name of one of the
profiles to :foo:unattached2.

Signed-off-by: Tyler Hicks <tyhicks@canonical.com>
Acked-by: John Johansen <john.johansen@canonical.com>
2016-02-18 15:58:06 -06:00
Steve Beattie
61a7b23757 parser: fix memory leaks in variable failure cases
This patch frees some leaked memory that occur when errors are
detected while adding variables to the parser's symbol table. While not
a significant issue currently due to the parser exiting on failures, as
the process of library-ifying the parser continues, these need to be
addressed. It also makes it easier to use tools like Address Sanitizer
on the parser against our test suite.

Signed-off-by: Steve Beattie <steve@nxnw.org>
Acked-by: Tyler Hicks <tyhicks@canonical.com>
2016-01-25 15:27:16 -08:00
Tyler Hicks
67eb25939d parser: Honor the --namespace-string commandline option
https://launchpad.net/bugs/1526085

Revno 2934 'Add fns to handle profile removal to the kernel interface'
introduced a regression in the parser's namespace support by causing the
--namespace-string option to be ignored. This resulted in the profile(s)
being loaded into the global namespace rather than the namespace
specified on the command line.

This patch fixes the bug by setting the Profile object's ns member, if
the --namespace-string option was specified, immediately after the
Profile object is allocated.

Signed-off-by: Tyler Hicks <tyhicks@canonical.com>
Acked-by: Seth Arnold <seth.arnold@canonical.com>
2015-12-15 16:41:38 -06:00
John Johansen
5fd832f004 fix: rlimit unit parsing for time
currently the parser supports ambiguous units like m for time,
which could mean minutes or milliseconds. Fix this and refactor the
time parsing into a single routine.

Signed-off-by: John Johansen <john.johansen@canonical.com>
Signed-off-by: Steve Beattie <steve@nxnw.org>
2015-07-10 18:16:09 -07:00
John Johansen
835605a647 Add support for variable expansion in profile names, and attachments
allow
  @{FOO}=bar
  /foo@{FOO} { }

to be expanded into
  /foobar { }

and
  @{FOO}=bar baz
  /foo@{FOO} { }

to be expanded into
  /foo{bar,baz} { }
which is used as a regular expression for attachment purposes

Further allow variable expansion in attachment specifications
  profile foo /foo@{FOO} { }

profile name (if begun with profile keyword) and attachments to begin
with a variable
  profile @{FOO} { }
  profile /foo @{FOO} { }
  profile @{FOO} @{BAR} {}

hats
  ^@{FOO}
  hat @{FOO}

and for subprofiles as well

Signed-off-by: John Johansen <john.johansen@canonical.com>
Acked-by: Steve Beattie <steve@nxnw.org>
2015-07-10 18:11:17 -07:00
John Johansen
f364cd7f6f Refactor change_profile to bring ns and none ns target into one rule
Signed-off-by: John Johansen <john.johansen@canonical.com>
Acked-by: Steve Beattie <steve@nxnw.org>
2015-06-12 15:25:10 -07:00
John Johansen
731718971f Refactor to use a common ns_id for namespace identifiers
Signed-off-by: John Johansen <john.johansen@canonical.com>
Acked-by: Steve Beattie <steve@nxnw.org>
2015-06-12 15:25:10 -07:00
John Johansen
d5c815783b Fix: refactor change_profile to deal with unexpected TOK_ID error
bison isn't properly handling the 3 options of

TOK_CHANGE_PROFILE opt_id TOK_END_OF_RULE
TOK_CHANGE_PROFILE opt_id TOK_ARROW TOK_ID TOK_END_OF_RULE
TOK_CHANGE_PROFILE opt_id TOK_ARROW TOK_COLON TOK_ID TOK_COLON TOK_END_OF_RULE

specifying
  change_profile /exec,

results in an unexpected TOK_ID error

refactor so that they share the 3 options share a common head which fixes
the problem.

Signed-off-by: John Johansen <john.johansen@canonical.com>
Acked-by: Steve Beattie <steve@nxnw.org>
2015-06-12 15:25:10 -07:00
John Johansen
6707489cdc Update change_profile rules to allow specifying the onexec condition
Note: this patch currently overlays onexec with link_name to take
advantage of code already being used on link_name. Ideally what needs
to happen is entry needs to be split into file, link and change_profile
entry classes.

Signed-off-by: John Johansen <john.johansen@canonical.com>
Acked-by: Steve Beattie <steve@nxnw.org>
2015-06-12 15:25:10 -07:00
John Johansen
4ed04c8ada add support for rule prefixes to change_profile rules
Signed-off-by: John Johansen <john.johansen@canonical.com>
Acked-by: Steve Beattie <steve@nxnw.org>
2015-06-06 01:28:43 -07:00
John Johansen
df568c979a Add support for bare change_profile rule
allow specifying the change_profile keyword

  change_profile,

to grant all permissions change_profile permissions

Signed-off-by: John Johansen <john.johansen@canonical.com>
Acked-by: Tyler Hicks <tyhicks@canonical.com>
2015-06-06 01:28:27 -07:00
John Johansen
9460aa042d Fix: link rules to accept a variable
currently
  link @{foo} -> /bar,
  link /bar -> @{foo}
  link @{foo} -> @{bar},

all fail due to illegal TOK_SET_VAR

Signed-off-by: John Johansen <john.johansen@canonical.com>
Acked-by: Tyler Hicks <tyhicks@canonical.com>
Acked-by: Seth Arnold <seth.arnold@canonical.com>
2015-06-06 01:27:59 -07:00
John Johansen
4970d40e0d Add fns to handle profile removal to the kernel interface
Signed-off-by: John Johansen <john.johansen@canonical.com>
[tyhicks: Forward ported patch to trunk]
[tyhicks: remove commented out code]
[tyhicks: fix use after free]
Signed-off-by: Tyler Hicks <tyhicks@canonical.com>
2015-03-25 17:09:26 -05:00
John Johansen
44d2e9dacf fix: auditing of capabilities
BugLink: http://bugs.launchpad.net/bugs/1378091

The audit flags are not being set correctly by the parser so that

  audit capability XXX,

will not result in an audit message being logged when the capability
is used.

Signed-off-by: John Johansen <john.johansen@canonical.com>
Acked-by: Steve Beattie <steve@nxnw.org>
2014-10-07 12:50:23 -07:00
John Johansen
dd44858e60 parser: first step implementing fine grained mediation for unix domain sockets
This patch implements parsing of fine grained mediation for unix domain
sockets, that have abstract and anonymous paths. Sockets with file
system paths are handled by regular file access rules.

The unix network rules follow the general fine grained network
rule pattern of

  [<qualifiers>] af_name [<access expr>] [<rule conds>] [<local expr>] [<peer expr>]

specifically for af_unix this is

  [<qualifiers>] 'unix' [<access expr>] [<rule conds>] [<local expr>] [<peer expr>]

  <qualifiers> = [ 'audit' ] [ 'allow' | 'deny' ]

  <access expr> = ( <access> | <access list> )

  <access> = ( 'server' | 'create' | 'bind' | 'listen' | 'accept' |
               'connect' | 'shutdown' | 'getattr' | 'setattr' |
	       'getopt' | 'setopt' |
               'send' | 'receive' | 'r' | 'w' | 'rw' )
  (some access modes are incompatible with some rules or require additional
   parameters)

  <access list> = '(' <access> ( [','] <WS> <access> )* ')'

  <WS> = white space

  <rule conds> = ( <type cond> | <protocol cond> )*
     each cond can appear at most once

  <type cond> = 'type' '='  ( <AARE> | '(' ( '"' <AARE> '"' | <AARE> )+ ')' )

  <protocol cond> = 'protocol' '='  ( <AARE> | '(' ( '"' <AARE> '"' | <AARE> )+ ')' )

  <local expr> = ( <path cond> | <attr cond> | <opt cond> )*
     each cond can appear at most once

  <peer expr> = 'peer' '=' ( <path cond> | <label cond> )+
     each cond can appear at most once

  <path cond> = 'path' '=' ( <AARE> | '(' '"' <AARE> '"' | <AARE> ')' )

  <label cond> = 'label' '=' ( <AARE> | '(' '"' <AARE> '"' | <AARE> ')')

  <attr cond> = 'attr' '=' ( <AARE> | '(' '"' <AARE> '"' | <AARE> ')' )

  <opt cond> = 'opt' '=' ( <AARE> | '(' '"' <AARE> '"' | <AARE> ')' )

  <AARE> = ?*[]{}^ ( see man page )

 unix domain socket rules are accumulated so that the granted unix
 socket permissions are the union of all the listed unix rule permissions.

 unix domain socket rules are broad and general and become more restrictive
 as further information is specified. Policy may be specified down to
 the path and label level. The content of the communication is not
 examined.

 Some permissions are not compatible with all unix rules.

 unix socket rule permissions are implied when a rule does not explicitly
 state an access list. By default if a rule does not have an access list
 all permissions that are compatible with the specified set of local
 and peer conditionals are implied.

 The 'server', 'r', 'w' and 'rw' permissions are aliases for other permissions.
 server = (create, bind, listen, accept)
 r = (receive, getattr, getopt)
 w = (create, connect, send, setattr, setopt)

In addition it supports the v7 kernel abi semantics around generic
network rules. The v7 abi removes the masking unix and netlink
address families from the generic masking and uses fine grained
mediation for an address type if supplied.

This means that the rules

  network unix,
  network netlink,

are now enforced instead of ignored. The parser previously could accept
these but the kernel would ignore anything written to them. If a network
rule is supplied it takes precedence over the finer grained mediation
rule. If permission is not granted via a broad network access rule
fine grained mediation is applied.

Signed-off-by: John Johansen <john.johansen@canonical.com>
Acked-by: Seth Arnold <seth.arnold@canonical.com>
2014-09-03 13:22:26 -07:00
John Johansen
9fe1e72c44 put the gettext define in one place
Signed-off-by: John Johansen <john.johansen@canonical.com>
Acked-by: Seth Arnold <seth.arnold@canonical.com>
Acked-by: Steve Beattie <steve@nxnw.org>
2014-08-23 23:50:43 -07:00
John Johansen
0cc659cdb4 change syntax of ptrace target
change from
  ptrace /foo,

to
  ptrace peer=/foo,

Signed-off-by: John Johansen <john.johansen@canonical.com>
Signed-off-by: Steve Beattie <steve@nxnw.org>
2014-04-23 11:39:59 -07:00
John Johansen
a1a7c78755 Add the ability to specify ptrace rules
ptrace rules currently take the form of

  ptrace [<ptrace_perms>] [<peer_profile_name>],
  ptrace_perm := read|trace|readby|tracedby
  ptrace_perms := ptrace_perm | '(' ptrace_perm+ ')'

After having used the cross check (permission needed in both profiles)
I am not sure it is correct for ptrace.

Signed-off-by: John Johansen <john.johansen@canonical.com>
Acked-by: Seth Arnold <seth.arnold@canonical.com>
2014-04-23 11:38:04 -07:00
John Johansen
f19c9f9511 fix: the what names can treated as a condlistid
The match
  {VARIABLE_NAME}/{WS}*={WS}*\(

is too broad causing mount and dbus rules to fail for sets of values eg.

  mount options=(ro bind)

Instead of doing a broad match, for now lets lock it down to just
peer=(...) being the only cond that can cause entry into CONDLISTID

Signed-off-by: John Johansen <john.johansen@canonical.com>
2014-04-23 11:36:26 -07:00
John Johansen
b222731c4f Add the ability to mediate signals.
Add signal rules and make sure the parser encodes support for them
if the supported feature set reports supporting them.

The current format of the signal rule is

  [audit] [deny] signal [<signal_perms>] [<signal_set>] <target_profile>,

  signal_perm  := 'send'|'receive'|'r'|'w'|'rw'
  signal_perms := <signal_perm> | '(' <signal_perm> ([,]<signal_perm>)* ')'
  signal := ("hup"|"int"|"quit"|"ill"|"trap"|"abrt"|"bus"|"fpe"|"kill"|
             "usr1"|"segv"|"usr2"|"pipe"|"alrm"|"term"|"tkflt"|"chld"|
             "cont"|"stop"|"stp"|"ttin"|"ttou"|"urg"|"xcpu"|"xfsz"|"vtalrm"|
             "prof"|"winch"|"io"|"pwr"|"sys"|"emt"|"exists")
  signal_set   := set=<signal> | '(' <signal> ([,]<signal>)* ')'


it does not currently follow the peer=() format, and there is some question
as to whether it should or not. Input welcome.

Signed-off-by: John Johansen <john.johansen@canonical.com>
Acked-by: Seth Arnold <seth.arnold@canonical.com>
2014-04-23 11:35:29 -07:00
John Johansen
d05313f555 Add the ability to separate policy_version from kernel and parser abi
This will allow for the parser to invalidate its caches separate of whether
the kernel policy version has changed. This can be desirable if a parser
bug is discovered, a new version the parser is shipped and we need to
force cache files to be regenerated.

Policy current stores a 32 bit version number in the header binary policy.
For newer policy (> v5 kernel abi) split this number into 3 separate
fields policy_version, parser_abi, kernel_abi.

If binary policy with a split version number is loaded to an older
kernel it will be correctly rejected as unsupported as those kernels
will see it as a none v5 version. For kernels that only support v5
policy on the kernel abi version is written.

The rules for policy versioning should be
policy_version:
  Set by text policy language version. Parsers that don't understand
  a specified version may fail, or drop rules they are unaware of.

parser_abi_version:
  gets bumped when a userspace bug is discovered that requires policy be
  recompiled. The policy version could be reset for each new kernel version
  but since the parser needs to support multiple kernel versions tracking
  this is extra work and should be avoided.

kernel_abi_version:
  gets bumped when semantic changes need to be applied. Eg unix domain
  sockets being mediated at connect.

  the kernel abi version does not encapsulate all supported features.
  As kernels could have different sets of patches supplied. Basic feature
  support is determined by the policy_mediates() encoding in the policydb.

  As such comparing cache features to kernel features is still needed
  to determine if cached policy is best matched to the kernel.

Signed-off-by: John Johansen <john.johansen@canonical.com>
Acked-by: Seth Arnold <seth.arnold@canonical.com>
2014-04-23 11:00:32 -07:00