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>
The fix to prevent the compiler from SEGV'ing when dumping network
rules in commit 2888 introduced the following compiler warning:
network.c: In function ‘const char* net_find_af_name(unsigned int)’:
network.c:331:16: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
for (i = 0; i < sizeof(network_mappings) / sizeof(*network_mappings); i++) {
The problem is that the counter i is an int, but sizeof returns size_t
which is unsigned. The following patch fixes the issue by converting the
type of i to size_t.
Signed-off-by: Steve Beattie <steve@nxnw.org>
Acked-by: John Johansen <john.johansen@canonical.com>
Like net_find_af_name, this assumed that AF_* values were consecutive.
[smcv: split out from a larger patch, added commit message,
removed dead declaration]
Reviewed-by: Simon McVittie <simon.mcvittie@collabora.co.uk>
The network_families array is automatically built from AF_NAMES, which is
extracted from the defines in <bits/socket.h>. The code assumes that
network_families is indexed by the AF defines. However, since the
defines are sparse, and the gaps in the array are not packed with
zeroes, the array is shorter than expected, and the indexing is wrong.
When this function was written, the network families that were
covered might well have been consecutive, but this is no longer true:
there's a gap between AF_LLC (26) and AF_CAN (29). In addition,
the code that parses <sys/socket.h> does not recognise AF_DECnet (12)
due to the lower-case letters, leading to a gap betwen AF_ROSE (11)
and AF_NETBEUI (13).
This assumption caused a crash in our testing while parsing the rule
"network raw".
[smcv: split out from a larger patch, added commit message]
Reviewed-by: Simon McVittie <simon.mcvittie@collabora.co.uk>
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>
before the af type protocol mappings patch was applied, a single rule could
result in multiple rule entries being created. The af type protocol mappings
patch broke this by apply only the first of the mappings that could be
found.
Restore the previous behavior by search through the entire table until
all matches have been made.
Signed-off-by: John Johansen <john.johansen@canonical.com>
Acked-by: Steve Beattie <steve@nxnw.org>
