Drop the reference to the libapparmor policy_cache pseudo object when
the parser is done.
Signed-off-by: Steve Beattie <steve@nxnw.org>
Acked-by: Seth Arnold <seth.arnold@canonical.com>
The errno values libapparmor's aa_policy_cache_new() uses to indicate
when the cache directory does not exist and when an existing, invalid
cache already exists needed to be separated out. They were both ENOENT
but now the latter situation uses EEXIST.
libapparmor also needed to be updated to not print an error message to
the syslog from aa_policy_cache_new() when the max_caches parameter is
0, indicating that a new cache should not be created, and the cache
directory does not exist. This is an error situation but a debug message
is more appropriate.
Signed-off-by: Tyler Hicks <tyhicks@canonical.com>
Acked-by: John Johansen <john.johansen@canonical.com>
The aa_policy_cache_new() and aa_policy_cache_remove() functions are
changed to accept a dirfd parameter.
The cache dirfd (by default, /etc/apparmor.d/cache) is opened earlier in
aa_policy_cache_new(). Previously, the directory wasn't accessed until
later in the following call chain:
aa_policy_cache_new() -> init_cache_features() -> create_cache()
Because of this change, the logic to create the cache dir must be moved
from create_cache() to aa_policy_cache_new().
Signed-off-by: Tyler Hicks <tyhicks@canonical.com>
Acked-by: John Johansen <john.johansen@canonical.com>
Instead of only accepting a path in the aa_features API, accept a
directory file descriptor and a path like then openat() family of
syscalls. This type of interface is better since it can operate exactly
like a path-only interface, by passing AT_FDCWD or -1 as the dirfd.
However, using the dirfd/path combination, it can eliminate string
allocations needed to open files in subdirectories along with the
even more important benefits mentioned in the open(2) man page.
Signed-off-by: Tyler Hicks <tyhicks@canonical.com>
Acked-by: Seth Arnold <seth.arnold@canonical.com>
The _aa_dirat_for_each() function used the DIR * type for its first
parameter. It then switched back and forth between the directory file
descriptors, retrieved with dirfd(), and directory streams, retrieved
with fdopendir(), when making syscalls and calling the call back
function.
This patch greatly simplifies the function by simply using directory
file descriptors. No functionality is lost since callers can still
easily use the function after calling dirfd() to retrieve the underlying
file descriptor.
Signed-off-by: Tyler Hicks <tyhicks@canonical.com>
Acked-by: Seth Arnold <seth.arnold@canonical.com>
This patch changes the aa_policy_cache_new() prototype and gets rid of
aa_policy_cache_is_valid() and aa_policy_cache_create().
The create bool of aa_policy_cache_new() is replaced with a 16 bit
unsigned int used to specify the maximum number of caches that should be
present in the specified cache directory. If the number is exceeded, the
old cache directories are reaped. The definition of "old" is private to
libapparmor and only 1 cache directory is currently supported. However,
that will change in the near future and multiple cache directories will
be supported.
If 0 is specified for the max_caches parameter, no new caches can be
created and only an existing, valid cache can be used. An error is
returned if no valid caches exist in that case.
If UINT16_MAX is specified, an unlimited amount of caches can be created
and reaping is disabled.
This means that 0 to (2^16)-2, or infinite, caches will be supported in
the future.
This change allows for the parser to continue to support the
--skip-bad-cache (by passing 0 for max_caches) and the --write-cache
option (by passing 1 or more for max_caches) without confusing
libapparmor users with the aa_policy_cache_{is_valid,create}()
functions.
Signed-off-by: Tyler Hicks <tyhicks@canonical.com>
Acked-by: John Johansen <john.johansen@canonical.com>
Currently the cache file has its mtime set at creation time, but this
can lead to cache issues when a policy file is updated separately from
the cache. This makes it possible for an update to ship a policy file
that is newer than the what the cache file was generated from, but
result in a cache hit because the cache file was local compiled after
the policy file was package into an update (this requires the update
to set the mtime of the file when locally installed to the mtime of
the file in its update archive but this is commonly done, especially
in image based updates).
Signed-off-by: John Johansen <john.johansen@canonical.com>
Acked-by: Seth Arnold <seth.arnold@canonical.com>
With create_cache() headed for libapparmor, we can't use the show_cache
or write_cache globals.
Signed-off-by: Tyler Hicks <tyhicks@canonical.com>
Acked-by: John Johansen <john.johansen@canonical.com>
Create new, ref, and unref functions for aa_kernel_interface. The "new"
function allows for the caller to pass in an aa_features object that is
then used to check if the kernel supports set load operations.
Additionally, the "new" function allows for the apparmorfs path to be
discovered once instead of during every policy load.
Signed-off-by: Tyler Hicks <tyhicks@canonical.com>
Acked-by: John Johansen <john.johansen@canonical.com>
This is the start of the kernel_interface API that allows callers to
specify a buffer, a file path, or a file descriptor that should be
copied to the proper kernel interface for loading, replacing, or
removing in-kernel policies.
Support exists for reading from a file path or file descriptor into a
buffer and then writing that buffer to the appropriate apparmorfs
interface file.
An aa_kernel_interface_write_policy() function is also provided for
callers that want to route a buffer to an arbitrary file descriptor
instead of to an apparmorfs file. This is useful when an admin instructs
apparmor_parser to write to stdout or a file.
Additionally, it removes some parser-specific globals from the
kernel_interface.c file, such as OPTION_{ADD,REPLACE,REMOVE}, in
preparation for moving the code into a library.
Signed-off-by: Tyler Hicks <tyhicks@canonical.com>
Acked-by: John Johansen <john.johansen@canonical.com>
This function allows for a policy cache to be removed without having a
previously instatiated aa_policy_cache object. It simply works off of a
path.
Signed-off-by: Tyler Hicks <tyhicks@canonical.com>
Acked-by: John Johansen <john.johansen@canonical.com>
This API has the same look-and-feel of the previous aa_features API.
The cache setup code was heavily dependent on globals set by CLI
options. Options such as "skip the read cache", or "skip the write
cache", or "don't clear the cache if it isn't valid", won't be useful
for all aa_policy_cache API users so some of that logic was lifted out
of the API. The constructor function still provides a bool parameter
that specifies if the cache should be created or not.
If the policy cache is invalid (currently meaning that the cache
features file doesn't match the kernel features file), then a new
aa_policy_cache object is still created but a call to
aa_policy_cache_is_valid() will return false. The caller can then decide
what to do (create a new valid cache, stop, etc.)
Signed-off-by: Tyler Hicks <tyhicks@canonical.com>
Acked-by: John Johansen <john.johansen@canonical.com>
This option adds unneeded complexity to the parser CLI and the upcoming
aa_policy_cache API. Get rid of it and simply create the cache dir if
--write-cache is specified.
Signed-off-by: Tyler Hicks <tyhicks@canonical.com>
Acked-by: John Johansen <john.johansen@canonical.com>
Defines a function that can be called to test features support. It is
string based which allows the support tests to work with new kernel
features without any changes.
The use of global variables in the parser to store and check features
support is still preserved. The parser should probably move over to
passing the aa_features object around but that's left for later.
Signed-off-by: Tyler Hicks <tyhicks@canonical.com>
Acked-by: John Johansen <john.johansen@canonical.com>
The aa_features_new_*() functions create an aa_features object. They can
be thought of as the constructor of aa_features objects. A number of
constructors are available depending on whether the features are coming
from a file in the policy cache, a string specified on the command line,
or from apparmorfs.
The aa_features_ref() and aa_features_unref() functions are used to grab
and give up references to an aa_features. When the ref count hits zero,
all allocated memory is freed. Like with free(), aa_features_unref() can
be called with a NULL pointer for convenience.
Pre-processor macros are hidden behind functions so that they don't
become part of our ABI when we move this code into libapparmor later on.
A temporary convenience function, aa_features_get_string(), is provided
while code that uses aa_features is migrated from expecting raw features
string access to something more abstract. The function will be removed
in an upcoming patch.
Signed-off-by: Tyler Hicks <tyhicks@canonical.com>
Acked-by: John Johansen <john.johansen@canonical.com>
This keeps us from having to use the force_clear_cache global in
policy_cache.c.
Signed-off-by: Tyler Hicks <tyhicks@canonical.com>
Acked-by: John Johansen <john.johansen@canonical.com>
Require the caller of setup_cache() to pass in a valid cache location
string. This removes the use of the basedir global from the
policy_cache.c file.
Additionally, it is no longer necessary to return the "cache dir" path
from setup_cache() since it will always be the same as the input path.
The return value is changed to an int so an error code can be returned
instead of using exit().
Signed-off-by: Tyler Hicks <tyhicks@canonical.com>
Acked-by: John Johansen <john.johansen@canonical.com>
Modify setup_cache() to accept the user-supplied cacheloc and return the
validated or created cache directory. The caller must then track that
variable and pass it into any parser/policy_cache.c functions that need
it.
The main reason for this change is that the cache location and the cache
directory will soon be two different paths. The cache location will
typically be the parent of the cache directory.
Signed-off-by: Tyler Hicks <tyhicks@canonical.com>
Acked-by: John Johansen <john.johansen@canonical.com>
This patch moves the logic that sets up the policy into a new function
in policy_cache.c
Signed-off-by: Tyler Hicks <tyhicks@canonical.com>
Acked-by: John Johansen <john.johansen@canonical.com>
Signed-off-by: John Johansen <john.johansen@canonical.com>
[tyhicks: Fixed build failures]
[tyhicks: Fixed bug where a warning was being printed when it shouldn't]
[tyhicks: Forward ported to trunk]
Signed-off-by: Tyler Hicks <tyhicks@canonical.com>
Signed-off-by: John Johansen <john.johansen@canonical.com>
[tyhicks: Handle inverted return from find_subdomainfs_mountpoint()]
[tyhicks: Link test progs to libapparmor to fix make check build fail]
[tyhicks: Migrate from opendir() to open() for opening apparmorfs]
[tyhicks: Make some of the split out functions static]
Signed-off-by: Tyler Hicks <tyhicks@canonical.com>
While some of these allocations will go away as we convert to C++,
some of these need to stay C as the are going to be moved into a
library to support loading cache from init daemons etc.
For the bits that will eventually be C++ this helps clean things up,
in the interim.
TODO: apply to libapparmor as well
Signed-off-by: John Johansen <john.johansen@canonical.com>
Acked-by: Tyler Hicks <tyhicks@canonical.com>
While some of these allocations will go away as we convert to C++,
some of these need to stay C as the are going to be moved into a
library to support loading cache from init daemons etc.
For the bits that will eventually be C++ this helps clean things up,
in the interim.
TODO: apply to libapparmor as well
Signed-off-by: John Johansen <john.johansen@canonical.com>
Signed-off-by: John Johansen <john.johansen@canonical.com>
[tyhicks: Don't move globals in favor of lifting those out later]
Signed-off-by: Tyler Hicks <tyhicks@canonical.com>
Acked-by: Seth Arnold <seth.arnold@canonical.com>
Currently the cache tracks the most recent timestamp of parsed files
and then compares that to the cache timestamp. This unfortunately
prevents the parser from being able to know which files caused the
cache check failure.
Rework the cache check so that there is a debug option, and that
the cache file timestamp is set first so that we can output
a deug message for each file that causes a cache check failure.
Signed-off-by: John Johansen <john.johansen@canonical.com>
[tyhicks: Forward ported to trunk and minor cleanups]
Signed-off-by: Tyler Hicks <tyhicks@canonical.com>
Acked-by: Steve Beattie <steve@nxnw.org>
The error path was being taken when openat() return 0 but openat()
returns -1 on error.
Signed-off-by: Tyler Hicks <tyhicks@canonical.com>
Acked-by: Seth Arnold <seth.arnold@canonical.com>
Currently the apparmor parser warns about rules that are not enforced or
downgraded. This is a problem for distros that are not carrying the out of
tree kernel patches, as most profile loads result in warnings.
Change the behavior to not output a message unless a warn flag is passed.
This patch adds 2 different warn flags
--warn rule-downgraded # warn if a rule is downgraded
--warn rule-not-enforced # warn if a rule is not enforced at all
If the warnings are desired by default the flags can be set in the
parser.conf file.
v2 of patch
- update man page
- add --warn to usage statement
- make --quiet clear warn flags
Signed-off-by: John Johansen <john.johansen@canonical.com>
Acked-by: Steve Beattie <steve@nxnw.org>
Bug: https://bugzilla.novell.com/show_bug.cgi?id=895495
We define the __unused macro as a shortcut for __attribute__((unused))
to quiet compiler warnings for functions where an argument is unused,
for whatever reason. However, on 64 bit architectures, older glibc's
bits/stat.h header defines an array variable with the name __unused
that collides with our macro and causes the parser to fail to build,
because the resulting macro expansion generates invalid C code.
This commit fixes the issue by removing the __unused macro where it's
not needed (mod_apparmor) and renaming it to 'unused' elsewhere. It also
in some instances reorders the arguments so that the unused macro
appears last consistently.
Signed-off-by: Steve Beattie <steve@nxnw.org>
Acked-by: Seth Arnold <seth.arnold@canonical.com>
Acked-by: John Johansen <john.johansen@canonical.com>
Acked-by: Tyler Hicks <tyhicks@canonical.com>
Currently the parser is bailing when it fails to load a profile,
not processing any potential subsequent profiles in the dir or passed
in list. This results in all policy after the first error failing
to load, instead of just the profile(s) with the error.
This is a different behavior than what has been done by initscripts
that have driven it with xargs -n1, passing it a single profile
at a time.
Fix this so that the parser only exits on first error if specifically
told to do so.
Note: this does not fix the various failure points in the parser
that call exit, instead of returning an error.
Signed-off-by: John Johansen <john.johansen@canonical.com>
Acked-by: Steve Beattie <steve@nxnw.org>, thanks.
missing <sys/sysctl.h> header. This header is included by accident, a
vestige of earlier days, and wasn't removed when the sysctls were removed.
(Think Linux 2.0 or Linux 2.2 days.)
See also https://bugs.debian.org/cgi-bin/bugreport.cgi?bug=760378
Thanks to Thorsten Glaser for the discovery and initial fix.
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>
For some strange reason our caching use ctime instead of mtime.
However this can lead to odd cases of the cache missing even though
neither the profile data nor cache data have changed.
Signed-off-by: John Johansen <john.johansen@canonical.com>
Acked-by: Steve Beattie <steve@nxnw.org>
v3: fix freeing of filename when undefined
v2: address tyhicks feedback
refactor to have a common write routine
fix issue with set profile load being done even if !kernel_load
Profile loads from cache files that contain multiple profiles can
result in multiple reloads of the same profile or error messages about
failure to load profiles if the --add option is used. eg.
apparmor="STATUS" operation="profile_load"
name="/usr/lib/apache2/mpm-prefork/apache2" pid=8631
comm="apparmor_parser"
<sth0R> [82932.058388] type=1400 audit(1395415826.937:616):
apparmor="STATUS" operation="profile_load" name="DEFAULT_URI" pid=8631
comm="apparmor_parser"
<sth0R> [82932.058391] type=1400 audit(1395415826.937:617):
apparmor="STATUS" operation="profile_load"
name="HANDLING_UNTRUSTED_INPUT" pid=8631 comm="apparmor_parser"
<sth0R> [82932.058394] type=1400 audit(1395415826.937:618):
apparmor="STATUS" operation="profile_load" name="phpsysinfo" pid=8631
comm="apparmor_parser"
<sth0R> [82932.059058] type=1400 audit(1395415826.937:619):
apparmor="STATUS" operation="profile_replace" info="profile can not be
replaced" error=-17
name="/usr/lib/apache2/mpm-prefork/apache2//DEFAULT_URI" pid=8631
comm="apparmor_parser"
<sth0R> [82932.059574] type=1400 audit(1395415826.937:620):
apparmor="STATUS" operation="profile_replace" info="profile can not be
replaced" error=-17
name="/usr/lib/apache2/mpm-prefork/apache2//HANDLING_UNTRUSTED_INPUT"
pid=8631 comm="apparmor_parser"
The reason this happens is that the cache file is a container that
can contain multiple profiles in sequential order
profile1
profile2
profile3
The parser loads the entire cache file to memory and the writes the
whole file to the kernel interface. It then skips foward in the file
to the next profile and reloads the file from that profile into
the kernel.
eg. First load
profile1
profile2
profile3
advance to profile2, do second load
profile2
profile3
advance to profile3, do third load
profile3
With older kernels the interface would stop after the first profile and
return that it had processed the whole file, thus while wasting compute
resources copying extra data no errors occurred. However newer kernels
now support atomic loading of multipe profiles, so that all the profiles
passed in to the interface get processed.
This means on newer kernels the current parser load behavior results
in multiple loads/replacements when a cache file contains more than
one profile (note: loads from a compile do not have this problem).
To fix this, detect if the kernel supports atomic set loads, and load
the cache file once. If it doesn't only load one profile section
from a cache file at a time.
Signed-off-by: John Johansen <john.johansen@canonical.com>
Acked-by: Seth Arnold <seth.arnold@canonical.com>
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>
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>
This patch makes use of the htoleXX() functions (see endian(3))
defined as part of endian.h (already included in parser_interface.c),
instead of defining a function differently based on the detection of
endian related macros.
This fixes a build failure experienced on powerpc with John's patch
set applied. This patch has been updated with John's feedback to use
letoh16() in the le16_to_cpu() macro.
Signed-off-by: Steve Beattie <steve@nxnw.org>
Acked-by: John Johansen <john.johansen@canonical.com>
Acked-by: Seth Arnold <seth.arnold@canonical.com>
Using the parser timestamp was a work around to force recompilation of
policy that was built with a buggy parser. There are better ways to
handle this so remove checking of the parser timestamp.
Signed-off-by: John Johansen <john.johansen@canonical.com>
Acked-by: Seth Arnold <seth.arnold@canonical.com>
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>
