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.
Victor Julien [Sat, 18 Feb 2023 09:48:51 +0000 (10:48 +0100)]
stream: fix spurious retransmission handling
Fix spurious retransmissions getting dropped, stalling connections in IPS
mode.
There are several reasons why benign spurious retransmissions can happen,
with the most obvious one that an ACK is lost so the sender retransmits
while the receiver has ACK'd it. If Suricata sees the ACK but afterwards
it gets lost, we can get in this condition. Packet loss can have a wide
range of causes here, including packets reaching a host but getting
dropped in the NIC queue or kernel queues due to resource constraints.
So these packets are no longer an "error" in this patch.
Next to this, the accuracy of the spurious retransmission has been
improved. Use SEQ macros to compare sequence numbers. Only use base_seq
if reassembly is still enabled for a stream.
A special case is added for cases where a segment is before last_ack
but after base_seq, which can happen when protocol detection isn't
finished yet. In this case the segment is tagged as spurious, but still
processed. This way we can check for overlaps.
Victor Julien [Wed, 22 Feb 2023 14:17:53 +0000 (15:17 +0100)]
stream: add liberal timetamps option
Linux is slightly more permissive wrt timestamps than many
other OS'. To avoid many events/issues with linux hosts, add an
option to allow for this slightly more permissive behavior.
Ideally the host-os config would be used, but in practice this
setting is rarely set up correctly, if at all.
Victor Julien [Sat, 18 Feb 2023 14:36:55 +0000 (15:36 +0100)]
stream: fix next_seq updates after temporary gap
On every accepted packet in established state, update next_seq if
packet seq+len is larger than existing next_seq. This allows it to
catch up after large gaps that are filled again a bit later.
Victor Julien [Sat, 11 Feb 2023 12:14:53 +0000 (13:14 +0100)]
stream/tcp: fix wrong ACK trigger FIN1 to FIN2
An ACK that ACK'd older data while still being in-window could
lead to FIN_WAIT1 to FIN_WAIT2 state transition. Detect this
case and generally harden the check.
Victor Julien [Thu, 9 Feb 2023 16:11:21 +0000 (17:11 +0100)]
stream: SYN queue support
Support case where there are multiple SYN retransmits, where
each has a new timestamp.
Before this patch, Suricata would only accept a SYN/ACK that
matches the last timestamp. However, observed behavior is that
the server may choose to only respond to the first. In IPS mode
this could lead to a connection timing out as Suricata drops
the SYN/ACK it considers wrong, and the server continues to
retransmit it.
This patch reuses the SYN/ACK queuing logic to keep a list
of SYN packets and their window, timestamp, wscale and sackok
settings. Then when the SYN/ACK arrives, it is first evaluated
against the normal session state. But if it fails due to a
timestamp mismatch, it will look for queued SYN's and see if
any of them match the timestamp. If one does, the ssn is updated
to use that SYN and the SYN/ACK is accepted.
Philippe Antoine [Wed, 18 Jan 2023 15:47:56 +0000 (16:47 +0100)]
smb: handles records with trailing nbss data
If a file (read/write) SMB record has padding/trailing data
after the buffer being read or written, and that Suricata falls
in one case where it skips the data, it should skip until
the very end of the NBSS record, meaning it should also skip the
padding/trailing data.
Otherwise, an attacker may smuggle some NBSS/SMB record in this
trailing data, that will be interpreted by Suricata, but not
by the SMB client/server, leading to evasions.
Philippe Antoine [Tue, 27 Dec 2022 16:34:47 +0000 (17:34 +0100)]
smb: checks against nbss records length
When Suricata handles files over SMB, it does not wait for the
NBSS record to be complete, and can stream the payload to the
file... But it did not check the consistency of the SMB record
length being read or written against the NBSS record length.
This could lead to an evasion where an attacker crafts a SMB
write with a too big Length field, and then sends its evil
payload, even if the server returned an error for the write request.
Victor Julien [Thu, 2 Feb 2023 13:45:30 +0000 (14:45 +0100)]
stream/tcp: allow tcp session reuse on null sessions
When a "stream starter" packet finds an existing TCP flow, the flow will be
evaluated for reuse.
The following scenario wasn't handled well:
1. Suricata starts after a tool has just stopped using lots of connections
(e.g. ab stress testing a webserver)
2. even though the client is closed already, the server is still doing
connection cleanup sending many FINs and later RSTs
3. Suricata creates flows for these packets, but no TCP sessions
4. client resumes testing, creating flows that have the same 5 tuple as the
flows created for the FIN/RST packets
5. Suricata refuses to "reuse" the flows as the condition "tcp flow w/o session"
is not considered valid for session reuse
6. new TCP connection is not properly tracked and evaluated in parsing and
detection
There may be other vectors into this, like a flow w/o session because of
memcap issues.
Victor Julien [Mon, 30 Jan 2023 10:27:37 +0000 (11:27 +0100)]
flow: enforce flow assumption
Enforce assumption that packets in ThreadVars::decode_pq have no flow
attached to it because this is only true for packets while they are
in the FlowWorker.
Victor Julien [Fri, 27 Jan 2023 19:47:46 +0000 (20:47 +0100)]
flow: remove use_cnt
Packets only ever reference the flow while holding its lock. This
means than any code possibly evicting the flow will have to wait
for the existing users to complete their work. Therefore the use_cnt
serves no function anymore and can be removed.