PKT_STREAM_EOF flag is set only when a pseudo packet is created. In all
the users of this flag, it suffices to use PKT_PSEUDO_STREAM_END
instead. PKT_PSEUDO_STREAM_END is the more widely used flag as well so
keep it and remove this unneeded flag creating a vacancy.
If there are still frames in the flow, the detection and logging logic
needs to be able to evaluate them. To do this, make the flow timeout
logic aware of the frames. If frames still exist in a direction, trigger
a FFR packet to be created.
Ticket: #7440.
Don't set an ACK value if ACK flag is no longer set. This avoids a bogus
`pkt_broken_ack` event set.
Fixes: ebf465a11b ("tcp: do not assign TCP flags to pseudopackets")
Ticket: #7158.
Store IPv6 decoder vars in a new Packet::l3 section in the packet.
Use inline functions instead of the often multi-layer macro's for
various IPv6 header getters.
Ticket: #6938.
Store IPv4 decoder vars in a new Packet::l3 section in the packet.
Use inline functions instead of the often multi-layer macro's for
various IPv4 header getters.
Ticket: #6938.
Issue: 6957
Rather than selecting the thread_id index by packets traveling to the
server, use the flow flags. If the flow has been reversed, the second
slot is represents the thread id to be used.
Issue: 6835
When injecting a flow, ensure that the selected thread_id has been
initialized. When a flow is picked up midstream, the initialized thread
can be the second thread element.
Previously pseudopackets were assigned with ACK flag which falsely turned
"SYN" flows to "SYN/ACK" flows when Suricata ran with raw content-matching
rules. The problem occured during the flow timeout or Suricata shutdown,
essentially, when the flow was being kicked out (with a pseudopacket).
When Suricata ran without raw content-matching rules (the ruleset did not
contain content matching keywords or it only contained keywords that are
app-layer content-matching) then raw stream reassembly tracking is turned off
(SignatureHasStreamContent()).
This in turn disabled a check in StreamNeedsReassembly() and the right edge
was not checked with the raw stream progress. In turn, it did not generate
a pseudopacket that would go through the detection engine. Suricata with
raw content-matching keywords would therefore on a flow with SYN packet only
return STREAM_HAS_UNPROCESSED_SEGMENTS_NEED_ONLY_DETECTION which would generate
the pseudopacket.
In Suricata versions <= 6.0.x, the flow output was correct because
only the commit 1bb6f44ff0 started to
differentiate the right edge calculation between the raw and application
layer streams. The older Suricata versions used only the application layer
right edge equation and therefore did not generate a pseudopacket.
Ticket: #6733
Issue: 2816
This commit increase the number of VLAN layers supported by Suricata
from 2 to 3. 3-layers are dubbed "Q-in-Q-in-Q".
Note that 3 layers are not compliant with any existing standard but are
often seen in larger deployments.
Issue: 5718
This commit switches the majority of time handling to a new type --
SCTime_t -- which is a 64 bit container for time:
- 44 bits -- seconds
- 20 bits -- useconds
Set pseudo packet datalink to the global one. This fixes the case
where the pcap handle is open with information coming from a
pseudo packet. Without this, we did end up in most cases with
an Ethernet packet being written in a Raw pcap.
Previously the flow manager would share evicted flows with the workers
while keeping the flows mutex locked. This reduced the number of unlock/
lock cycles while there was guaranteed to be no contention.
This turns out to be undefined behavior. A lock is supposed to be locked
and unlocked from the same thread. It appears that FreeBSD is stricter on
this than Linux.
This patch addresses the issue by unlocking before handing a flow off
to another thread, and locking again from the new thread.
Issue was reported and largely analyzed by Bill Meeks.
Bug: #4478
Goals:
- reduce locking
- take advantage of 'hot' caches
- better locality
Locking reduction
New flow spare pool. The global pool is implmented as a list of blocks,
where each block has a 100 spare flows. Worker threads fetch a block at
a time, storing the block in the local thread storage.
Flow Recycler now returns flows to the pool is blocks as well.
Flow Recycler fetches all flows to be processed in one step instead of
one at a time.
Cache 'hot'ness
Worker threads now check the timeout of flows they evaluate during lookup.
The worker will have to read the flow into cache anyway, so the added
overhead of checking the timeout value is minimal. When a flow is considered
timed out, one of 2 things happens:
- if the flow is 'owned' by the thread it is handled locally. Handling means
checking if the flow needs 'timeout' work.
- otherwise, the flow is added to a special 'evicted' list in the flow
bucket where it will be picked up by the flow manager.
Flow Manager timing
By default the flow manager now tries to do passes of the flow hash in
smaller steps, where the goal is to do full pass in 8 x the lowest timeout
value it has to enforce. So if the lowest timeout value is 30s, a full pass
will take 4 minutes. The goal here is to reduce locking overhead and not
get in the way of the workers.
In emergency mode each pass is full, and lower timeouts are used.
Timing of the flow manager is also no longer relying on pthread condition
variables, as these generally cause waking up much quicker than the desired
timout. Instead a simple (u)sleep loop is used.
Both changes reduce the number of hash passes a lot.
Emergency behavior
In emergency mode there a number of changes to the workers. In this scenario
the flow memcap is fully used up and it is unavoidable that some flows won't
be tracked.
1. flow spare pool fetches are reduced to once a second. This avoids locking
overhead, while the chance of success was very low.
2. getting an active flow directly from the hash skips flows that had very
recent activity to avoid the scenario where all flows get only into the
NEW state before getting reused. Rather allow some to have a chance of
completing.
3. TCP packets that are not SYN packets will not get a used flow, unless
stream.midstream is enabled. The goal here is again to avoid evicting
active flows unnecessarily.
Better Localily
Flow Manager injects flows into the worker threads now, instead of one or
two packets. Advantage of this is that the worker threads can get packets
from their local packet pools, avoiding constant overhead of packets returning
to 'foreign' pools.
Counters
A lot of flow counters have been added and some have been renamed.
Overall the worker threads increment 'flow.wrk.*' counters, while the flow
manager increments 'flow.mgr.*'.
Additionally, none of the counters are snapshots anymore, they all increment
over time. The flow.memuse and flow.spare counters are exceptions.
Misc
FlowQueue has been split into a FlowQueuePrivate (unlocked) and FlowQueue.
Flow no longer has 'prev' pointers and used a unified 'next' pointer for
both hash and queue use.
Flag the last flow timeout pseudo packet so that we can force
TX logging w/o setting both app-layer flags.
Case this fixes:
1. flow times out when only TS TCP data received, but non of it is ACK'd.
So there is no app-layer proto yet, or app state or Flow::alparser. So
EOF flags can't be set.
2. Flow timeout sees no reason to create pseudo packet in TC direction.
3. TS pseudo packet finds HTTP, creates HTTP state, flag EOF TS.
4. TX logging skips HTTP logging because:
- TC progress not reached
- EOF TC flag not set.
The solution has been to flag the very last packet for the flow as such
and use it has a master-EOF flag.
This fixes redmine bug #2057 by setting pseudopacket iface and vlan from
flow values, solving the problem of missing vlan/iface when psuedopacket
gets logged/alerted on.
Set flags by default:
-Wmissing-prototypes
-Wmissing-declarations
-Wstrict-prototypes
-Wwrite-strings
-Wcast-align
-Wbad-function-cast
-Wformat-security
-Wno-format-nonliteral
-Wmissing-format-attribute
-funsigned-char
Fix minor compiler warnings for these new flags on gcc and clang.
At flow timeout, we no longer need to first run reassembly in
one dir, then inspection in the other. We can do both in single
packet now.
Disable pseudo packets when receiving stream end packets. Instead
call the app-layer parser in the packet direction for stream end
packets and flow end packets.
These changes in handling of those stream end packets make the
pseudo packets unnecessary.
Make stream engine use the streaming buffer API for it's data storage.
This means that the data is stored in a single reassembled sliding
buffer. The subleties of the reassembly, e.g. overlap handling, are
taken care of at segment insertion.
The TcpSegments now have a StreamingBufferSegment that contains an
offset and a length. Using this the segment data can be retrieved
per segment.
Redo segment insertion. The insertion code is moved to it's own file
and is simplified a lot.
A major difference with the previous implementation is that the segment
list now contains overlapping segments if the traffic is that way.
Previously there could be more and smaller segments in the memory list
than what was seen on the wire.
Due to the matching of in memory segments and on the wire segments,
the overlap with different data detection (potential mots attacks)
is much more accurate.
Raw and App reassembly progress is no longer tracked per segment using
flags, but there is now a progress tracker in the TcpStream for each.
When pruning we make sure we don't slide beyond in-use segments. When
both app-layer and raw inspection are beyond the start of the segment
list, the segments might not be freed even though the data in the
streaming buffer is already gone. This is caused by the 'in-use' status
that the segments can implicitly have. This patch accounts for that
when calculating the 'left_edge' of the streaming window.
Raw reassembly still sets up 'StreamMsg' objects for content
inspection. They are set up based on either the full StreamingBuffer,
or based on the StreamingBufferBlocks if there are gaps in the data.
Reworked 'stream needs work' logic. When a flow times out the flow
engine checks whether a TCP flow still needs work. The
StreamNeedsReassembly function is used to test if a stream still has
unreassembled segments or uninspected stream chunks.
This patch updates the function to consider the app and/or raw
progress. It also cleans the function up and adds more meaningful
debug messages. Finally it makes it non-inline.
Unittests have been overhauled, and partly moved into their own files.
Remove lots of dead code.
Issue:
https://redmine.openinfosecfoundation.org/issues/2041
One approach to fixing this issue to just validate the
checksum instead of regenerating it and comparing it. This
method is used in some kernels and other network tools.
When validating, the current checksum is passed in as an
initial argument which will cause the final checksum to be 0
if OK. If generating a checksum, 0 is passed and the result
is the generated checksum.
Store the tenant id in the flow and use the stored id when setting
up pesudo packets.
For tunnel and defrag packets, get tenant from parent. This will only
pass tenant_id's set at capture time.
For defrag packets, the tenant selector based on vlan id will still
work as the vlan id(s) are stored in the defrag tracker before being
passed on.
Set noinspection flags for payloads and packets on flow and stream
pseudo packets. Without these, the pseudo packets could trigger
inspection even though this was disabled for a flow.
Victor Julien
Philippe Antoine
Shivani Bhardwaj
Jeff Lucovsky
Lukas Sismis
Jeff Lucovsky
Eric Leblond
Philippe Antoine
Victor Julien
Bendik Hagen
Jason Ish