Instead of killing all reassembly instantly do things slightly more
gracefully:
1. disable app-layer reassembly immediately
2. flag raw reassembly not to accept new data
This will allow the current data to be inspected still.
After detect as run the raw reassembly will be fully disabled and
thus all reassembly will be as well.
If raw reassembly falls behind, for example because no raw mpm is
active, then we need to sync up to the app progress if that is
available, or to the generic tcp tracking otherwise.
Now that detect moves the raw progress forward, it's important
to deal with the case where detect don't consider raw inspection.
If no 'stream' rules are active, disable raw. For this the disable
raw flag is now per stream.
Implement the inline mode for raw content inspection. Packets
are leading, and when a packet's payload has been added to the
stream, the packet is inspected in the context of the stream.
Reassembly will return a buffer with the packet data with older
data in front of it and after it, if available.
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.
Remove the 'StreamMsg' approach from the engine. In this approach the
stream engine would create a list of chunks for inspection by the
detection engine. There were several issues:
1. the messages had a fixed size, so blocks of data bigger than ~4k
would be cut into multiple messages
2. it lead to lots of data copying and unnecessary memory use
3. the StreamMsgs used a central pool
The Stream engine switched over to the streaming buffer API, which
means that the reassembled data is always available. This made the
StreamMsg approach even clunkier.
The new approach exposes the streaming buffer data to the detection
engine. It has to pay attention to an important issue though: packet
loss. The data may have gaps. The streaming buffer API tracks the
blocks of continuous data.
To access the data for inspection a callback approach is used. The
'StreamReassembleRaw' function is called with a callback and data.
This way it runs the MPM and individual rule inspection code. At
the end of each detection run the stream engine is notified that it
can move forward it's 'progress'.
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.
Add list of 'blocks'. This list contains offsets and lengths to
continuous data blocks. This is useful for TCP tracking where we
can have data gaps.
The blocks don't contain any data themselves, instead they contain
lenght and offsets. This way no extra copying is needed.
On inserting new data, existing blocks are expanded instead of
having multiple neighbouring blocks.
Implement common code to easily add more per HTTP header detection
keywords.
Implement http_accept sticky buffer. It operates on the HTTP Accept
header.
We assume session resumption has occurred if the Client Hello message
included a session id, we have not seen the server certificate, but
we have seen a Change Cipher Spec message from the server.
Previously, these transactions were not logged at all because the
server cert was never seen.
Ticket: https://redmine.openinfosecfoundation.org/issues/1969
eve: detects libevent for async redis at configure
eve: moves redis output code to new file - util-log-redis.{c,h}
eve: redis ECHO and QUIT commands for async mode
eve: redis output defaults if conf is missing
If running against a pcap there is no reason to drop events,
a blocking socket is fine here. So only do non-blocking writes
when running off a live device.
Writing to a unix socket can cause Suricata to block in the
packet path. This could happen if the read-endpoint of the
unix socket stays connected, but stops reading, or simply
can't read fast enough as part of its event processing.
To choose packets over events, do non-blocking socket
writes and drop the event if the write would block and
update a dropped counter.
Recursively create new log directories when needed. This makes it
possible to use date modifiers in the file path to create
directories based on date, e.g.:
/var/log/suricata/2017/02/14/
Rotate log file based on time. Support both rotating based on a timer (XXs,
XXm, XXd, XXw) and rotating based on a absolute time, like each minute,
hour or day.
If a subsequent fragment has a lower offset than a previous
one and overlaps, trim off the beginning of the previous
fragment.
Based on an issue reported privately.
UnixManagerThreadInit needs to return a failure code if the socket
fails to initialize to avoid entering the UnixManager loop which
will continuously fail on the call to bind, as no listening
socket was setup.
This can occur when the socket fails to initialize due to a
permissions error and fatal init errors is not on.
app-layer-modbus.c:1226:39: warning: taking address of packed member 'transactionId' of class or structure 'ModbusHeader_' may result in an unaligned pointer value [-Waddress-of-packed-member]
if (ModbusExtractUint16(modbus, &(header->transactionId), input, input_len, &offset) ||
^~~~~~~~~~~~~~~~~~~~~
app-layer-modbus.c:1228:39: warning: taking address of packed member 'protocolId' of class or structure 'ModbusHeader_' may result in an unaligned pointer value [-Waddress-of-packed-member]
ModbusExtractUint16(modbus, &(header->protocolId), input, input_len, &offset) ||
^~~~~~~~~~~~~~~~~~
app-layer-modbus.c:1230:39: warning: taking address of packed member 'length' of class or structure 'ModbusHeader_' may result in an unaligned pointer value [-Waddress-of-packed-member]
ModbusExtractUint16(modbus, &(header->length), input, input_len, &offset) ||
^~~~~~~~~~~~~~
3 warnings generated.
Bug #2088
clang-4.0 reported:
util-pool.c:242:13: warning: logical not is only applied to the left hand side of this bitwise operator [-Wlogical-not-parentheses]
if (! pb->flags & POOL_BUCKET_PREALLOCATED) {
^ ~
util-pool.c:242:13: note: add parentheses after the '!' to evaluate the bitwise operator first
if (! pb->flags & POOL_BUCKET_PREALLOCATED) {
^
( )
util-pool.c:242:13: note: add parentheses around left hand side expression to silence this warning
if (! pb->flags & POOL_BUCKET_PREALLOCATED) {
^
( )
util-pool.c:261:13: warning: logical not is only applied to the left hand side of this bitwise operator [-Wlogical-not-parentheses]
if (! pb->flags & POOL_BUCKET_PREALLOCATED) {
^ ~
util-pool.c:261:13: note: add parentheses after the '!' to evaluate the bitwise operator first
if (! pb->flags & POOL_BUCKET_PREALLOCATED) {
^
( )
util-pool.c:261:13: note: add parentheses around left hand side expression to silence this warning
if (! pb->flags & POOL_BUCKET_PREALLOCATED) {
^
( )
2 warnings generated.
In some cases, observed with inspect limits 0, the body tracking could
get confused. When all chunks were already freed, a new chunk would
be considered to be the start of the body. This would overwrite the
bodies 'content_len_so_far' tracker, instead of adding to it. This in
turn could lead to a assertion abort in the inspection code.
This patch redoes the append code to always add the current lenght. It
cleans up the code to remove redundant logic.
Issue: https://redmine.openinfosecfoundation.org/issues/2078
Reported-By: Jørgen Bøhnsdalen
"p" was being used in the macro but was not an argument to
the macro, but it worked due to the context of the macro.
Use the actual macro argument, d2, instead of p.
Results in no change to generated code.
Add SCFlowTimestamps() to return startts and lastts as seconds and
microseconds from flow.
Examples:
startts, lastts = SCFlowTimestamps()
startts_s, lastts_s, startts_us, lastts_us = SCFlowTimestamps()
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.
When detection is running flags are set on flows to indicate if file
hashing is needed. This is based on global output settings and rules.
In the case of --disable-detection this was not happening, so all
files where hashed with all methods. This has a significant
performance impact.
This patch adds logic to set the flow flags in --disable-detect mode.
When bytejump was told to convert some payload data to int from a
string it would print an error to the screen if the conversion
failed. This is unwanted as the payload is controlled by an attacker
and printing is expensive.
A GAP during protocol detection would lead to all reassembly
getting disabled, so also the raw reassembly. In addition, it
could prevent the opposing side from doing protocol detection.
This patch remove the 'disable reassembly' logic. Stream engine
will take the stream with GAP and app-layer will make the proto
detection as complete.
All loggers were wrapping just the write in a lock with some
updating a counter. This moves the lock into the write function.
The log_ctx alerts counter was also removed as many modules have
stopped using this and the alert count is available elsewhere.
Should satisfy Coverity CID 1400798:
CID 1400798 (#1 of 1): Data race condition (MISSING_LOCK) 2.
missing_lock: Accessing log_ctx->rotation_flag without holding lock
LogFileCtx_.fp_mutex. Elsewhere, "LogFileCtx_.rotation_flag" is accessed
with LogFileCtx_.fp_mutex held 4 out of 5 times.
Which appears to be a false positive as all calls to SCLogFileWrite
were done under lock, but this will make it more explicit.
Match on TLS certificate serial number using tls_cert_serial
keyword, e.g.:
alert tls any any -> any any (msg:"TLS cert serial test";
tls_cert_serial; content:"5C:19:B7:B1:32:3B:1C:A1";
sid:12345;)
Add function LuaGetCertSerial to print serial number from TLS
certificate.
Example:
function log (args)
serial = TlsGetCertSerial()
if serial then
file:write(serial .. "\n");
file:flush()
end
end
Give unified2 a nostamp option which will create the file
without the timestamp suffix (like Snort's nostamp option).
Also register for rotation notification on SIGHUP so the file
will be recreated if it is removed by an external rotation
program (only when nostamp is used).
Log src_ip, dst_ip and proto for root packet (p->root) if the
packet that triggered is inside a tunnel, as JSON object
'tunnel'. Also log recursion depth to indicate the depth of
the tunnel.
Move code to get 5-tuple in JSON object to own function 'JsonFiveTuple'.
This enables this code to be reused when printing 'parent' JSON object in
output-json-alert.
add-hostbit adds a named hostbit with an expire time in seconds.
remove-hostbit removes hostbit by name.
add-hostbit, remove-hostbit return success or failure.
list-hostbit returns a json array of hostbits with their name and
expire time:
{
"message": {
"count": 1,
"hostbits":
[{
"expire": 3222,
"name": "firefox-users"
}]
},
"return": "OK"
}
Until now the way to specify a var name in pcre substring capture
into pkt and flow vars was to use the pcre named substring support:
e.g. /(?P<pkt_somename>.*)/
This had 2 drawbacks:
1. limitations of the name. The name could be max 32 chars, only have
alphanumeric and the underscore characters. This imposed limitations
that are not present in flowbits/ints.
2. we didn't actually use the named substrings in pcre through the
API. We parsed the names separately. So putting the names in pcre
would actually be wasteful.
This patch introduces a new way of mapping captures with names:
pcre:"/(.*)/, pkt:somename";
pcre:"/([A-z]+) ([0-9]+)/, pkt:somename,flow:anothername";
The order of the captures and the order of the names are mapped 1 on 1.
This method is no longer limited by the pcre API's naming limits. The
'flow:' and 'pkt:' prefixes indicate what the type of variable is. It's
mandatory to specify one.
The old method is still supported as well.
Flowvars were already using a temporary store in the detect thread
ctx.
Use the same facility for pktvars. The reasons are:
1. packet is not always available, e.g. when running pcre on http
buffers.
2. setting of vars should be done post match. Until now it was also
possible that it is done on a partial match.
Until now variable names, such as flowbit names, were local to a detect
engine. This made sense as they were only ever used in that context.
For the purpose of logging these names, this needs a different approach.
The loggers live outside of the detect engine. Also, in the case of
reloads and multi-tenancy, there are even multiple detect engines, so
it would be even more tricky to access them from the outside.
This patch brings a new approach. A any time, there is a single active
hash table mapping the variable names and their id's. For multiple
tenants the table is shared between tenants.
The table is set up in a 'staging' area, where locking makes sure that
multiple loading threads don't mess things up. Then when the preparing
of a detection engine is ready, but before the detect threads are made
aware of the new detect engine, the active varname hash is swapped with
the staging instance.
For this to work, all the mappings from the 'current' or active mapping
are added to the staging table.
After the threads have reloaded and the new detection engine is active,
the old table can be freed.
For multi tenancy things are similar. The staging area is used for
setting up until the new detection engines / tenants are applied to
the system.
This patch also changes the variable 'id'/'idx' field to uint32_t. Due
to data structure padding and alignment, this should have no practical
drawback while allowing for a lot more vars.
Matches on the start of a HTTP request or response.
Uses a buffer constructed from the request line and normalized request
headers, including the Cookie header.
Or for the response side, it uses the response line plus the
normalized response headers, including the Set-Cookie header.
Both buffers are terminated by an extra \r\n.
A sticky buffer that allows content inspection on a contructed buffer
of HTTP header names. The buffer starts with \r\n, the names are
separated by \r\n and the end of the buffer contains an extra \r\n.
E.g. \r\nHost\r\nUser-Agent\r\n\r\n
The leading \r\n is to make sure one can match on a full name in all
cases.
Some keywords need a scratch space where they can do store the results
of expensive operations that remain valid for the time of a packets
journey through the detection engine.
An example is the reconstructed 'http_header' field, that is needed
in MPM, and then for each rule that manually inspects it. Storing this
data in the flow is a waste, and reconstructing multiple times on
demand as well.
This API allows for registering a keyword with an init and free function.
It it mean to be used an initialization time, when the keyword is
registered.