Victor Julien [Tue, 11 Apr 2023 09:40:35 +0000 (11:40 +0200)]
pcap: improve pcap_breakloop support
When pcap_breakloop has been issued on a handle, the current pcap_dispatch
call may return -2 (PCAP_ERROR_BREAK), but it can also return the number
of processed packets if lower than the desired number. So add this condition
as a check.
Maxim Korotkov [Thu, 16 Feb 2023 17:16:19 +0000 (20:16 +0300)]
output: fix logic error
The logical error may have been made here. Comparison with the upper
bound of the variable type does not make sense. It may be worth adding
the cast of one of the multiplication operands to the 64-bit type for
avoiding overflow.
Found by Security Code with Svace static analyzer
Bug: #5789
Old behavior:
With RFC4648, the decoded bytes were reset to 0 in case an unusual
character was encountered in the encoded string. This worked out fine
for small test cases where there weren't many bytes to be decoded.
Problem:
If a big encoded string had a character outside of the base alphabet,
the processing would stop and the number of decoded bytes were set to 0.
However, even though the processing should stop at the invalid
character, the number of decoded bytes should correctly store the bytes
decoded up until the point an invalid characted was encountered.
New behavor:
For any base64 encoded string given to the base64 decoder in RFC4648
mode, we make sure that the number of decoded bytes correctly reflect
the number of bytes processed up until the string was valid. This makes
sure any further calculations/use of the decoded data is done correctly.
Jason Ish [Wed, 15 Mar 2023 22:23:49 +0000 (16:23 -0600)]
app-layer: add direction to transaction creation where needed
Build on Eric's but set the direction on transaction creation when
needed. I think this makes it a little more clear, and easier to
document when creating single direction transactions.
This also somewhat abstracts the inner-workings of a directional
transaction from the implementation.
Eric Leblond [Mon, 23 Jan 2023 19:08:07 +0000 (20:08 +0100)]
dnp3: activate unidirectional TX flag
By implementing the no inspection flag we can now set
the unidirectional TX flag. Which means that the alstate
progress function can now be simplified to always return
1 f the transaction is complete.
Eric Leblond [Mon, 23 Jan 2023 19:01:05 +0000 (20:01 +0100)]
app-layer: add flag to skip detection on TX
Stamus team did discover a problem were a signature can shadow
other signatures.
For example, on a PCAP only containing Kerberos protocol and where the
following signature is matching:
alert krb5 $HOME_NET any -> any any (msg:"krb match"; krb5_cname; content:"marlo"; sid:3; rev:1;)
If we add the following signature to the list of signature
alert ssh $HOME_NET any -> any any (msg:"rr"; content:"rr"; flow:established,to_server; sid:4; rev:2;)
Then the Kerberos signature is not matching anymore.
To understand this case, we need some information:
- The krb5_cname is a to_client keyword
- The signal on ssh is to_server
- Kerberos has unidirectional transaction
- kerberos application state progress is a function always returning 1
As the two signatures are in opposite side, they end up in separate
sig group head.
Another fact is that, in the PCAP, the to_server side of the session
is sent first to the detection. It thus hit the sig group head of
the SSH signature. When Suricata runs detection in this direction
the Kerberos application layer send the transaction as it is existing
and because the alstate progress function just return 1 if the transaction
exists. So Suricata runs DetectRunTx() and stops when it sees that
sgh->tx_engines is NULL.
But the transaction is consumed by the engine as it has been evaluated
in one direction and the kerberos transaction are unidirectional so
there is no need to continue looking at it.
This results in no matching of the kerberos signature as the match
should occur in the evaluation of the other side but the transaction
with the data is already seen has been handled.
This problem was discovered on this Kerberos signature but all
the application layer with unidirectional transaction are impacted.
This patch introduces a flag that can be used by application layer
to signal that the TX should not be inspected. By using this flag
on the directional detect_flags_[ts|tc] the application layer can
prevent the TX to be consumed in the wrong direction.
Application layers with unidirectional TX will be updated
in separate commits to set the flag on the direction opposite
to the one they are.
Eric Leblond [Fri, 20 Jan 2023 09:35:59 +0000 (10:35 +0100)]
app-layer-parser: give direction to progress func
The tx progress functions are expecting a direction and were given
a flow flags. As a result, they were not reporting correctly the
status if a DetectRunScratchPad flow_flags was containing some other
bits in the flag.
One case was when a signature was alterating the stream analysis
and triggering the addition of the STREAM_FLUSH flags.
The consequences are quite severe as the transactions are pilling
up waiting to be inspected causing sometimes a 10x performance hit
on pcap parsing. Also as the inspection was not done, Suricata is
missing a part of the alerts.
This was discovered when working on the following set of signatures:
alert ssh $HOME_NET any -> any any (msg:"pcre without content"; pcre:"/rabbit/"; sid:1; rev:1;)
alert smb $HOME_NET any -> any any (msg:"smb share content"; smb.share; content:"C"; sid:2; rev:1;)
When the first one is present the second is not triggering even
though the pcap file had no ssh inside. This is due to the fact
that the ssh signature was triggering the STREAM_FLUSH flag to
be set on the flowflags of the packet. But the application
layer will ask the smb state progress via
r = alp_ctx.ctxs[FlowGetProtoMapping(ipproto)][alproto].
StateGetProgress(alstate, flags);
passing it the flow flags but the smb function is expecting
a direction so we end up in a unplanned case
pub unsafe extern "C" fn rs_smb_tx_get_alstate_progress(tx: *mut ffi::c_void,
direction: u8)
...
if direction == Direction::ToServer as u8 && tx.request_done {
This leads the signature to not be evaluated correctly.
Philippe Antoine [Thu, 26 Jan 2023 08:28:46 +0000 (09:28 +0100)]
http: complete multipart until request.body-limit
In the case we are truncating a multipart file because of reaching
request.body-limit, we used to not consume the whole buffer, but
keep expected_boundary_len bytes in case a new boundary begins
in these bytes.
Even if we cannot check the complete boundary, we can still check
the first bytes, as will be done in the rust version.
Jason Ish [Fri, 24 Mar 2023 05:51:11 +0000 (23:51 -0600)]
conf: deprecate multiple "include" statements at same level
The YAML spec considers duplicate keys to be an error, as do some YAML
implementations, most notably Rust's serde_yaml which would be nice to
use in the future.
Multiple include lines at the same level will still work, but a warning
will be emitted.
These can be fixed by moving to an "include" array:
As flow.memcap-policy and defrag.memcap-policy do not support flow
actions, clarify that in the documentation. Also fix some typos, and
add missing values in some places where the exception policies were
explained.
exception/policy: use pkt action if no flow support
Defrag memcap and flow memcap do not support flow action for the
exception policies, as there is no flow when the exception condition is
hit. In such cases, the exception policy must be considered for the
packet only, when that makes sense, or should be ignored, in case of
`bypass`.
Updated all cases where flow_config.prealloc was used in a division.
*** CID 1524506: Integer handling issues (DIVIDE_BY_ZERO)
/src/flow-manager.c: 858 in FlowManager()
852 "flow_spare_q status: %" PRIu32 "%% flows at the queue",
853 spare_pool_len, flow_config.prealloc,
854 spare_pool_len * 100 / flow_config.prealloc);
855
856 /* only if we have pruned this "emergency_recovery" percentage
857 * of flows, we will unset the emergency bit */
>>> CID 1524506: Integer handling issues (DIVIDE_BY_ZERO)
>>> In expression "spare_pool_len * 100U / flow_config.prealloc", division by expression "flow_config.prealloc" which may be zero has undefined behavior.
858 if (spare_pool_len * 100 / flow_config.prealloc > flow_config.emergency_recovery) {
859 emerg_over_cnt++;
860 } else {
861 emerg_over_cnt = 0;
862 }
Jason Ish [Wed, 22 Mar 2023 21:13:46 +0000 (15:13 -0600)]
source-xf-xdp: update for deprecated function in libbpf
libbpf 0.8 deprecates bpf_get_link_xpd_id, and 1.0 removes it. Add
./configure check to see if this method is available and use it if so,
otherwise use the deprecated method which is not available on older
but still supported Linux distributions.
Victor Julien [Tue, 21 Mar 2023 19:20:48 +0000 (20:20 +0100)]
eve/drop: don't log drops unless packet is dropped
In pass/drop combinations where the pass rule took precendence over
the drop, a "drop" false positive could still be logged due to the
storing of the drop record in the packet drop alert store.
Victor Julien [Sun, 19 Mar 2023 16:46:02 +0000 (17:46 +0100)]
detect: apply within as depth where possible
The rule lang allows for within and distance to act as depth/offset,
but internally this was not handle the same way. This patch converts
within/distance w/o a prior pattern to depth/within.
Victor Julien [Sat, 18 Mar 2023 18:05:07 +0000 (19:05 +0100)]
detect: split mpm per alproto for file.data & others
Instead of a shared mpm context for just "file.data" or "file.magic"
use per alproto mpms. This way http file.data rules won't affect smb
file.data performance.
Jason Ish [Tue, 14 Mar 2023 22:11:25 +0000 (16:11 -0600)]
smtp: apply suricata.yaml defaults to in-code defaults
Currently the default suricata.yaml sets some values that do not
reflect the default values in the code. As most users are probably
using a default suricata.yaml, make the code have the same defaults as
in suricata.yaml:
Jason Ish [Thu, 9 Feb 2023 17:16:18 +0000 (11:16 -0600)]
source-xdp: only allow busy poll if headers support it
Wrap the enabling of busy poll in a compile time conditional checking
for the required defines to be set. While we have runtime support for
kernels less than 5.11, we also need a compile time check as the headers
may be old as well.
Jason Ish [Thu, 9 Mar 2023 17:48:53 +0000 (11:48 -0600)]
rust/clippy: allow derivable impls
The latest Rust will automatically "fix" derivable default
implementation, which is nice, but makes changes that don't meet our
current MSRV, so allow derivable impls for now.
In a case of the line buffer being over 255 bytes, the consumed bytes
would reset to 0 as it was uint8_t. Fix this integer overflow by setting
the type to uint32_t.
Jason Ish [Mon, 30 Jan 2023 23:13:04 +0000 (17:13 -0600)]
config: put version in configuration as a proper value
Adds a new field, "suricata-version" to the configuration file with
the major and minor version of the Suricata that generated the
configuration file.
This may be useful in the future for presenting warnings about
important changes, or even providing different defaults based on what
the user might expect.