PacketPoolWait in autofp can wait for considerable time. Until now
it was essentially spinning, keeping the CPU 100% busy.
This patch introduces a condition to wait in such cases.
Atomically flag pool that consumer is waiting, so that we can sync
the pending pool right away instead of waiting for the
MAX_PENDING_RETURN_PACKETS limit.
Set actions that are set directly from Signatures using the new
utility function DetectSignatureApplyActions. This will apply
the actions and also store info about the 'drop' that first made
the rule drop.
The code was not checking if we had enough room in the direct
data. In case default_packet_size was set really small, this was
resulting in data being written over the data and causing a crash.
The patch fixes the issue by forcing an allocation if the direct
data size in the Packet is to small.
In flow timeout handling we need a function that allocate and blank
a place that will be used to put constructed packet data. This new
function has no other goal.
This will prevent log files that have not been rotated by some
external tool from being deleted, but log files that were
rotated (moved out of the way) will be re-opened.
This is a better default behaviour, especially when not all
log files are rotated at the same time.
Thanks to iro on IRC.
This patch adds the capabilities to log the TLS information the
same way it is currently possible to do with HTTP. As it is
quite hard to read ASN.1 directly in the stream, this will help
people to understand why suricata is firing on alert relative
to TLS.
cc1: warnings being treated as errors
app-layer-smtp.c: In function ‘SMTPParseCommandBDAT’:
app-layer-smtp.c:908: warning: dereferencing type-punned pointer will break strict-aliasing rules
If ETHTOOL_GRXRINGS is undefined we will not be able to build the
RX rings code. So we can make the build conditional to the
definition of ETHTOOL_GRXRINGS.
The HTTP tracking code would parse the content lenght and store it
in the TX user data. It didn't take the possibility or errors into
account though, leading to a possible negative int being cases to
unsigned int. Luckily, the result was unused.
This patch simply removes the offending code.
Reported-by: The Yahoo pentest team
Fix error handling of stub parsers. In case of SCRealloc error the
function would return a non-error code. This could possibly lead to
memory corruption.
Reported-By: The Yahoo pentest team
In case of autofp (or more general, when flow and stream engine
run in different threads) the flow engine should not trigger a flow
reuse as this can lead to race conditions between the flow and the
stream engine.
In such cases, the flow engine can be far ahead of the stream engine
as packets are in a queue between the threads.
Observed:
Flow engine tags packet 10 as start of new flow. Flow is tagged as
'reused'.
Stream engine evaluates packet 5 which belongs to the old flow. It
rejects the flow as it's tagged 'reused'. Attaches packet 5 to the
new flow which is wrong.
Solution:
This patch connects the flow engines handling of reuse cases to
the runmode. It hooks into the RunmodeSetFlowStreamAsync() call to
notify the flow engine that it shouldn't handle the reuse.
For the autofp case, handling TCP reuse in the flow engine didn't work.
The problem is the mismatch between the moment the flow engine looks at
packets and the stream, and the moment the stream engine runs. Flow engine
is invoked in the packet capture thread(s), while the stream engine runs
as part of the stream/detect thread(s). Because of the queues between
those threads the flow manager may already inspect a new SYN while the
stream engine still has to process the previous session.
Moving the flow engine to the stream/detect thread(s) wasn't an option
as the 'autofp' load balancing depends on the flow already being
available in the packet.
The solution here is to add a check for this condition to the stream
engine. At this point the TCP state is up to date. If a TCP reuse case
is encountered, this is the global logic:
- detach packet for old flow
- get a new flow and attach it to the packet
- flag the old flow that it is now obsolete
Additional logic makes sure that the packets already in the queue
between the flow thread(s) and the stream thread are reassigned the
new flow.
Some special handling:
Apply previous 'reuse' before checking for a new reuse. Otherwise we're
tagging the wrong flow in some cases (multiple reuses in the same tuple).
When in a flow/ssn reuse condition, properly remove the packet from
the flow.
Don't 'reuse' if packet is a SYN retransmission.
The old flow is timed out normally by the flow manager.
This replaces the tcp.reused_ssn counter. The flow engine now
enforces the TCP flow reuse logic.
The counter is incremented only when the flow is timed out, so
after the "tcp closed" timeout expired for a flow.
Until now, TCP session reuse was handled in the TCP stream engine.
If the state was TCP_CLOSED, a new SYN packet was received and a few
other conditions were met, the flow was 'reset' and reused for the
'new' TCP session.
There are a number of problems with this approach:
- it breaks the normal flow lifecycle wrt timeout, detection, logging
- new TCP sessions could come in on different threads due to mismatches
in timeouts between suricata and flow balancing hw/nic/drivers
- cleanup code was often causing problems
- it complicated locking because of the possible thread mismatch
This patch implements a different solution, where a new TCP session also
gets a new flow. To do this 2 main things needed to be done:
1. the flow engine needed to be aware of when the TCP reuse case was
happening
2. the flow engine needs to be able to 'skip' the old flow once it was
replaced by a new one
To handle (1), a new function TcpSessionPacketSsnReuse() is introduced
to check for the TCP reuse conditions. It's called from 'FlowCompare()'
for TCP packets / TCP flows that are candidates for reuse. FlowCompare
returns FALSE for the 'old' flow in the case of TCP reuse.
This in turn will lead to the flow engine not finding a flow for the TCP
SYN packet, resulting in the creation of a new flow.
To handle (2), FlowCompare flags the 'old' flow. This flag causes future
FlowCompare calls to always return FALSE on it. In other words, the flow
can't be found anymore. It can only be accessed by:
1. existing packets with a reference to it
2. flow timeout handling as this logic gets the flows from walking the
hash directly
3. flow timeout pseudo packets, as they are set up by (2)
The old flow will time out normally, as governed by the "tcp closed"
flow timeout setting. At timeout, the normal detection, logging and
cleanup code will process it.
The flagging of a flow making it 'unfindable' in the flow hash is a bit
of a hack. The reason for this approach over for example putting the
old flow into a forced timeout queue where it could be timed out, is
that such a queue could easily become a contention point. The TCP
session reuse case can easily be created by an attacker. In case of
multiple packet handlers, this could lead to contention on such a flow
timeout queue.
The flow keyword used flag names that were shared with the
Packet::flowflags field. Some of the flags were'nt used by the packet
though. This lead to waste of some 'flag space'.
This patch defines dedicated flags for the flow keyword and removes
the otherwise unused flags from the FLOW_PKT_* space.
FilePrune would clear the files, but not free them and remove them
from the list. This lead to ever growing lists in some cases.
Especially in HTTP sessions with many transactions, this could slow
us down.
Until this point, the flow manager would check for timed out flows
by walking the flow hash, locking first the hash row and then each
individual flow to get it's state and timestamp. To not be too
intrusive trylocks were used so that a busy flow wouldn't cause the
flow manager to wait for a long time while holding the hash row lock.
Building on the changes in handling of the flow state and lastts
fields, this patch changes the flow managers behavior.
It can now get a flows state atomically and the lastts can be safely
read while holding just the flow hash row lock. This allows the flow
manager to do the basic time out check much more cheaply:
1. it doesn't have to wait for getting a lock
2. it doesn't interupt the packet path
As a consequence the trylock is now also gone. A flow that returns
'true' on timeout is pretty much certainly not going to be busy so
we can safely lock it unconditionally. This also means the flow
manager now walks the entire row unconditionally and is guaranteed
to inspect each flow in the row.
To make sure the functions called before the flow lock don't
accidentally change the flow (which would require a lock) the args
to these flows are changed to const pointers.
In the lastts timeval struct field in the flow the timestamp of the
last packet to update is recorded. This allows for tracking the timeout
of the flow. So far, this value was updated under the flow lock and also
read under the flow lock.
This patch moves the updating of this field to the FlowGetFlowFromHash
function, where it updated at the point where both the Flow and the
Flow Hash Row lock are held. This guarantees that the field is only
updated when both locks are held.
This makes reading the field safe when either lock is held, which is the
purpose of this patch.
The flow manager, while holding the flow hash row lock, can now safely
read the lastts value. This allows it to do the flow timeout check
without actually locking the flow.
A flow has 3 states: NEW, ESTABLISHED and CLOSED.
For all protocols except TCP, a flow is in state NEW as long as just one
side of the conversation has been seen. When both sides have been
observed the state is moved to ESTABLISHED.
TCP has a different logic, controlled by the stream engine. Here the TCP
state is leading.
Until now, when parts of the engine needed to know the flow state, it
would invoke a per protocol callback 'GetProtoState'. For TCP this would
return the state based on the TcpSession.
This patch changes this logic. It introduces an atomic variable in the
flow 'flow_state'. It defaults to NEW and is set to ESTABLISHED for non-
TCP protocols when we've seen both sides of the conversation.
For TCP, the state is updated from the TCP engine directly.
The goal is to allow for access to the state without holding the Flow's
main mutex lock. This will later allow the Flow Manager(s) to evaluate
the Flow w/o interupting it.
The option sets in bytes the value at which segment data is passed to
the app layer API directly. Data sizes equal to and higher than the
value set are passed on directly.
Default is 128.
Create 2 'fast paths' for app layer reassembly. Both are about reducing
copying. In the cases described below, we pass the segment's data
directly to the app layer API, instead of first copying it into a buffer
than we then pass. This safes a copy.
The first is for the case when we have just one single segment that was
just ack'd. As we know that we won't use any other segment this round,
we can just use the segment data.
The second case is more aggressive. When the segment meets a certain
size limit (currently hardcoded at 128 bytes), we pass it to the
app-layer API directly. Thus invoking the app-layer somewhat more often
to safe some copies.
When reaching the end of either list, merging is no longer required,
simply walk down the other list.
If the non-MPM list can't have duplicates, it would be worth removing
the duplicate check for the non-MPM list when it is the only non-empty list
remaining.
Create a copy of the SigMatch data in the sig_lists linked-lists and store
it in an array for faster access and not next and previous pointers. The
array is then used when calling the Match() functions.
Gives a 7.7% speed up on one test.
The Match functions don't need a pointer to the SigMatch object, just the
context pointer contained inside, so pass the Context to the Match function
rather than the SigMatch object. This allows for further optimization.
Change SigMatch->ctx to have type SigMatchCtx* rather than void* for better
type checking. This requires adding type casts when using or assigning it.
The SigMatch contex should not be changed by the Match() funciton, so pass it
as a const SigMatchCtx*.
Read one signature pointer ahead to prefetch the value.
Use a variable, sflags, for s->flags, since it is used many times and the
compiles doesn't know that the signatures structure doesn't change, so it
will reload s->flags.
Use an MPM specific pattern index, which is simply an index starting
at zero and incremented for each pattern added to the MPM, rather than
the externally provided Pattern ID (pid), since that can be much
larger than the number of patterns. The Pattern ID is shared across at
MPMs. For example, an MPM with one pattern with pid=8000 would result
in a max_pid of 8000, so the pid_pat_list would have 8000 entries.
The pid_pat_list[] is replaced by a array of pattern indexes. The PID is
moved to the SCACTilePatternList as a single value. The PatternList is
also indexed by the Pattern Index.
max_pat_id is no longer needed and mpm_ctx->pattern_cnt is used instead.
The local bitarray is then also indexed by pattern index instead of PID, making
it much smaller. The local bit array sets a bit for each pattern found
for this MPM. It is only kept during one MPM search (stack allocated).
One note, the local bit array is checked first and if the pattern has already
been found, it will stop checking, but count a match. This could result in
over counting matches of case-sensitve matches, since following case-insensitive
matches will also be counted. For example, finding "Foo" in "foo Foo foo" would
report finding "Foo" 2 times, mis-counting the third word as "Foo".
In PmqMerge() use MpmAddSids() instead of blindly copying the src
rule list onto the end of the dst rule list, since there might not
be enough room in the dst list. MpmAddSids() will resize the dst array
if needed.
Also add code to MpmAddSids() MpmAddPid() to better handle the case
that realloc fails to get more space. It first tries 2x the needed
space, but if that fails, it tries for just 1x. If that fails resize
returns 0. For MpmAddPid(), if resize fails, the new pid is lost. For
MpmAddSids(), as many SIDs as will fit are added, but some will be
lost.
Rather than creating the array of size maxpatid, dynamically resize as needed.
This also handles the case where duplicate pid are added to the array.
Also fix error in bitarray allocation (local version) to always use bitarray_size.
Rather than statically allocate 64K entries in every rule_id_array,
increase the size only when needed. Created a new function MpmAddSids()
to check the size before adding the new sids. If the array is not large
enough, it calls MpmAddSidsResize() that calls realloc and does error
checking. If the realloc fails, it prints an error and drops the new sids
on the floor, which seems better than exiting Suricata.
The size is increased to (current_size + new_count) * 2. This handles the
case where new_count > current_size, which would not be handled by simply
using current_size * 2. It should also be faster than simply reallocing to
current_size + new_count, which would then require another realloc for each
new addition.
Use a local pattern bit array to making sure we don't match more than
once, in addition to the pmq bitarray that is still used for results
validation higher up in the rule matching process.
Why: pmq->pattern_id_bitarray is currently sometimes used in a
'stateful' way, meaning that for a single packet we run multiple
MPM's on the same pmq w/o resetting it.
The new bitarray is used to determine wherther we need to append the
patterns associated 'sids' list to the pmq rule_id_array.
It has been observed that MPM1 matches for PAT1, and MPM2 matches for
PAT1 as well. However, in MPM1 PAT1 doesn't have the same sids list.
In this case MPM2 would not add it's sids to the list, leading to missed
detection.
Use MPM and non-MPM lists to build our match array. Both lists are
sorted, and are merged and sorted into the match array.
This disables the old match array building code and thus also bypasses
the mask checking.
Treat negated MPM sigs as if non-MPM, so we consider them always.
As MPM results and non-MPM rules lists are now merged and considered
for further inspection, rules that need to be considerd when a pattern
is absent are caught in the middle.
As a HACK/workaround this patch adds them to the non-MPM list. This
causes them to be inspected each time.
Array of rule id's that are not using MPM prefiltering. These will be
merged with the MPM results array. Together these should lead to a
list of all the rules that can possibly match.
Pmq add rule list: Array of uint32_t's to store (internal) sids from the MPM.
AC: store sids in the pattern list, append to Pmq::rule_id_array on match.
Detect: sort rule_id_array after it was set up by the MPM. Rule id's
(Signature::num) are ordered, and the rule's with the lowest id are to
be inspected first. As the MPM doesn't fill the array in order, but instead
'randomly' we need this sort step to assure proper inspection order.
Creates an inline wrapper to check for flowvarlist == NULL before calling
DetectFlowvarProcessList() to remove the overhead of checking since the
list is usually empty.
** CID 1257764: Dereference after null check (FORWARD_NULL)
/src/defrag.c: 291 in Defrag4Reassemble()
** CID 1257763: Dereference after null check (FORWARD_NULL)
/src/defrag.c: 409 in Defrag6Reassemble()
In the error case 'rp' can be both NULL or non-NULL.
MemcmpLowercase would not compare the first byte of both input buffers
leading to two non-identical buffers to be considered the same.
Affects SSE_4_1 and SSE_4_2 implementations of SCMemcmpLowercase, as well
as the non-SIMD implementation. SSE_3 and Tile version are not affected.
Work around OS X 10.10 Yosemite returning EDEADLK on a rwlock wrlocked
then tested by wrtrylock. All other OS' (and versions of OS X that I
tested) seem to return EBUSY instead.
Fix issue where SMTPStateGetTxCnt would return the actual active tx'.
The 'GetCnt' API call is not named correctly. It should be 'GetMaxId',
as this is actually the expected behavior.
This patches is fixing a issue in the OutputJSONBuffer function. It
was writing to file the content of the buffer starting from the start
to the final offset. But as the writing is done for each JSON string
we are duplicating the previous events if we are reusing the same
buffer.
Duplication was for example triggered when we have multiple alerts
attached to a packet. In the case of two alerts, the first one was
logged twice more as the second one.
Update pktacq loop to process flow timeouts in a running engine.
Add a new step to the shutdown phase of packet acquisition loop
threads (pktacqloop).
The shutdown code lets the pktacqloop break out of it's packet
acquisition loop. The thread then enters a flow timeout loop, where
it processes packets from it's tv->stream_pq queue until it's
empty _and_ the KILL flag is set.
Make sure receive threads are done before moving on to flow hash
cleanup (recycle all). Without this the flow recycler could start
it's unconditional hash clean up while detect threads are still
running on the flows.
Update unix socket to match live modes.
Add function TmThreadsInjectPacketById that is to be used to inject flow
timeout packets into the threads stream_pq queue.
TmThreadsInjectPacketById will also wake up listening threads if
applicable.
Packets are passed all packets together in an NULL terminated array
to reduce locking overhead.
Create thread registration and unregistration API for assigning unique
thread id's.
Threadvars is static even if a thread restarts, so we can do the
registration before the threads start.
A thread is unregistered when the ThreadVars are freed.
- Added the suricata.yaml configurations and updated the comments
- Renamed the field in the configuration structure to something generic
- Added two new constants and the warning codes
- Created app-layer-htp-xff.c and app-layer-htp-xff.h
- Added entries in the Makefile.am
- Added the necessary configuration options to EVE alert section
- Updated Unified2 XFF configuration comments and removed unnecessary whitespace
- Created a generic function to parse the configuration
- Release the flow locks sooner and remove debug logging
- Added XFF support to EVE alert output
Incorrectly reallocing the goto table after it was freed by calling
SCACTileReallocState() when really only want to realloc the output table.
This was causing a large goto table to be allocated and never used or
freed.
Free some memory at exit that was not getting freed.
Change pid_pat_list to store copy of case-strings in the same block
of memory as the array of pointers.
Due to a logic error in AppLayerProtoDetectGetProtoByName invalid
protocols would not be detected as such. Instead of ALPROTO_UNKNOWN
ALPROTO_MAX was returned.
Bug #1329
This patch fixes the following errors:
[src/unix-manager.c:306]: (error) Memory pointed to by 'client' is freed twice.
[src/unix-manager.c:313]: (error) Memory pointed to by 'client' is freed twice.
[src/unix-manager.c:323]: (error) Memory pointed to by 'client' is freed twice.
[src/unix-manager.c:334]: (error) Memory pointed to by 'client' is freed twice.
Unix manager was treating the packet after closing the socket if message was
too long.
MLD messages should have a hop limit of 1 only. All others are invalid.
Written at MLD talk of Enno Rey, Antonios Atlasis & Jayson Salazar during
Deepsec 2014.
Have -T / --init-errors-fatal process all rules so that it's easier
to debug problems in ruleset. Otherwise it can be a lengthy fix, test
error cycle if multiple rules have issues.
Convert empty rulefile error into a warning.
Bug #977
If we manage to read the number of RSS queues from an interface,
this means that the optimal number of capture threads is equal
to the minimum of this number and of the number of cores on the
system.
This patch implements this logic thanks to the newly introduced
function GetIfaceRSSQueuesNum.
Add a new default value for the 'threads:' setting in af-packet: "auto".
This will create as many capture threads as there are cores.
Default runmode of af-packet to workers.
For some of the buffer users it's hard to predict how big the data
will be. In the stats.log case this depends on chosen runmode and
number of threads.
To deal with this case a 'MemBufferExpand' call is added. This realloc's
the buffer.
Register with type 'stats':
function init (args)
local needs = {}
needs["type"] = "stats"
return needs
end
The stats are passed as an array of tables:
{ 1, { name=<name>, tmname=<tm_name>, value=<value>, pvalue=<pvalue>}}
{ 2, { name=<name>, tmname=<tm_name>, value=<value>, pvalue=<pvalue>}}
etc
Name is the counter name (e.g. decoder.invalid), tm_name is the thread name
(e.g. AFPacketeth05), value is current value, and pvalue is the value of the
last time the script was invoked.
As the stats api calls the loggers at a global interval, the global
interval should be configured globally.
# global stats configuration
stats:
enabled: yes
# The interval field (in seconds) controls at what interval
# the loggers are invoked.
interval: 8
If this config isn't found, the old config will be supported.
Convert regular 'stats.log' output to this new API.
In addition to the current stats value, also give the last value. This
makes it easy to display the difference.
The SCStreamingBuffer call now also returns two booleans:
data, data_open, data_close = SCStreamingBuffer()
The first indicates this is the first data of this type for this
TCP session or HTTP transaction.
The second indicates this is the last data.
Ticket #1317.
sfd->target.value was always being set, even if the targettype was
not FLOWINT_TARGET_VAL. This would cause the tvar to be overwritten
with garbage data.
Add the modbus.function and subfunction) keywords for public function match in rules (Modbus layer).
Matching based on code function, and if necessary, sub-function code
or based on category (assigned, unassigned, public, user or reserved)
and negation is permitted.
Add the modbus.access keyword for read/write Modbus function match in rules (Modbus layer).
Matching based on access type (read or write),
and/or function type (discretes, coils, input or holding)
and, if necessary, read or write address access,
and, if necessary, value to write.
For address and value matching, "<", ">" and "<>" is permitted.
Based on TLS source code and file size source code (address and value matching).
Signed-off-by: David DIALLO <diallo@et.esia.fr>
Decode Modbus request and response messages, and extracts
MODBUS Application Protocol header and the code function.
In case of read/write function, extracts message contents
(read/write address, quantity, count, data to write).
Links request and response messages in a transaction according to
Transaction Identifier (transaction management based on DNS source code).
MODBUS Messaging on TCP/IP Implementation Guide V1.0b
(http://www.modbus.org/docs/Modbus_Messaging_Implementation_Guide_V1_0b.pdf)
MODBUS Application Protocol Specification V1.1b3
(http://www.modbus.org/docs/Modbus_Application_Protocol_V1_1b3.pdf)
Based on DNS source code.
Signed-off-by: David DIALLO <diallo@et.esia.fr>
A tx is considered complete after the data command completed. However,
this would lead to RSET and QUIT commands setting up a new tx.
This patch simply adds a check that refuses to setup a new tx when these
commands are encountered after the data portion is complete.
SigMatch would be added to list, then the alproto check failed, leading
to freeing of sm. But as it was still in the list, the list now contained
a dangling pointer.
When multiple email addresses were in the 'to' field, sometimes
they would be logged as "\r\n \"Name\" <email>".
The \r\n was added by GetFullValue in the mime decoder, for unknown
reasons. Disabling this seems to have no drawbacks.
Turn all buffers into uint8_t (from char) and no longer use the
string functions like strncpy/strncasecmp on them.
Store url and field names as lowercase, and also search/compare
them as lowercase. This allows us to use SCMemcmp.
The global variable suricata_ctl_flags needs to volatile, otherwise the
compiler might not cause the variable to be read every time because it
doesn't know other threads might write the variable.
This was causing Suricata to not exit under some conditions.
For these 2 cases:
1. Missing SYN:
-> syn <= missing
<- syn/ack
-> ack
-> data
2. Missing SYN and 3whs ACK:
-> syn <= missing
<- syn/ack
-> ack <= missing
-> data
Fix session pickup. The next_win settings weren't correctly set, so that
packets were rejected.
Bug 1190.
If 3whs SYN/ACK and ACK are missing we can still pick up the session if
in async-oneside mode.
-> syn
<- syn/ack <= missing
-> ack <= missing
-> data
Bug 1190.
The entire body of these functions are protected by ifdef PROFILING.
If the functions are inlined, then this check removes the need for the
function entirely.
Previously, the empty function was still called, even when not built
for profiling. The functions showed as being 0.25% of total CPU time
without being built for profiling.
If vlan is disabled the cluster_flow mode will still take VLAN tags
into account due to using pf_ring's 6-tuple mode.
So this forces to use pf_ring's 5-tuple mode.
Bug #1292
Implements new API to expand the IP reputation
to netblocks with CIDR notation
A new object 'srepCIDRTree' is kept in the DetectionEngineCtx,
which contains two tree (one for ipv4 and one for ipv6)
where the reputation values are stored.
ACK packets completing a valid FIN shutdown could be flagged as
'bad window update' if they would shrink the window.
This patch detects this case before doing the bad window update
check.
If the 3whs ACK and some data after this is lost, we would get stuck
in the 'SYN_RECV' state, where from there each packet might be
considered invalid.
This patch improves the handling of this case.
The keyword would not allow matching on "OpenSSH_5.5p1 Debian-6+squeeze5"
as the + and space characters were not allowed.
This patch adds support for them.
Stream pseudo packets are taken from the packet pool, which can be empty.
In this case a pseudo packet will not be created and processed.
This patch adds a counter "tcp.pseudo_failed" to track this.
doesn't need the gpu results and to release the packet for the next run.
Previously the inspection engine wouldn't inform the cuda module, if it
didn't need the results. As a consequence, when the packet is next taken
for re-use, and if the packet is still being processed by the cuda module,
the engine would wait till the cuda module frees the packet.
This commits updates this functionality to inform the cuda module to
release the packet for the afore-mentioned case.
Add option (disabled by default) to honor pass rules. This means that
when a pass rule matches in a flow, it's packets are no longer stored
by the pcap-log module.
SigMatchGetLastSMFromLists() is finding the sm with the largest
index among all of the values returned from SigMatchGetLastSM() on
the set of (list and type) tuples passed as arguments.
The function was creating an array of the types, then creating an array
of the results of SigMatchGetLastSM(), sorting that list completely, then
only returning the first values from the list.
The new code, gets one set of arguments from the variable arguments, calls
SigMatchGetLastSM() and if the returned sm has a larger index, keeps that
as the last sm.
Allow a script to set the 'stream' buffer type. This will add the
script to the PMATCH list.
Example script:
alert tcp any any -> any any (content:"html"; lua:stream.lua; sid:1;)
function init (args)
local needs = {}
needs["stream"] = tostring(true)
return needs
end
-- return match via table
function match(args)
local result = {}
b = tostring(args["stream"])
o = tostring(args["offset"])
bo = string.sub(b, o);
print (bo)
return result
end
return 0
To prevent accidental writes into the orignal packet buffer, use
const pointers for the extension header pointers used by IPv6. This
will cause compiler warnings in case of writes.
A logic error in the IPv6 Routing header parsing caused accidental
updating of the original packet buffer. The calculated extension
header lenght was set to the length field of the routing header,
causing it to be wrong.
This has 2 consequences:
1. defrag failure. As the now modified payload was used in defrag,
the decoding of the reassembled packet now contained a broken length
field for the routing header. This would lead to decoding failure.
The potential here is evasion, although it would trigger:
[1:2200014:1] SURICATA IPv6 truncated extension header
2. in IPS mode, especially the AF_PACKET mode, the modified and now
broken packet would be transmitted on the wire. It's likely that
end hosts and/or routers would reject this packet.
NFQ based IPS mode would be less affected, as it 'verdicts' based on
the packet handle. In case of replacing the packet (replace keyword
or stream normalization) it could broadcast the bad packet.
Additionally, the RH Type 0 address parsing was also broken. It too
would modify the original packet. As the result of this code was not
used anywhere else in the engine, this code is now disabled.
Reported-By: Rafael Schaefer <rschaefer@ernw.de>
AF_PACKET is not setting the engine mode to IPS when some
interfaces are peered and use IPS mode. This is due to the
fact, it is possible to peer 2 interfaces and run an IPS on
them and have a third one that is running in normal IDS mode.
In fact this choice is the bad one as unwanted side effect is
that there is no drop log and that stream inline is not used.
To fix that, this patch puts suricata in IPS mode as soon as
there is two interfaces in IPS mode. And it displays a error
message to warn user that the accuracy of detection on IDS only
interfaces will be low.
When using AMATCH, continue detection would fail if the tx part
had already run. This lead to start detection rerunning, causing
multiple alerts for the same issue.
As there is no inspection engine for request_line, the sigmatch was
added to the AMATCH list. However, no AppLayerMatch function for
lua scripts was defined.
This patch defines a AppLayerMatch function.
Bug #1273.
I found three somewhat serious IPv6 address bugs within the Suricata 2.0.x source code. Two are in the source module "detect-engine-address.c", and the third is in "util-radix-tree.c".
The first bug occurs within the function DetectAddressParse2(). When parsing an address string and a negated block is encountered (such as when parsing !$HOME_NET, for example), any corresponding IPv6 addresses were not getting added to the Group Heads in the DetectAddressList. Only IPv4 addresses were being added.
I discovered another bug related to IPv6 address ranges in the Signature Match Address Array comparison code for IPv6 addresses. The function DetectAddressMatchIPv6() walks a signature's source or destination match address list comparing each to the current packet's corresponding address value. The match address list consists of value pairs representing a lower and upper IP address range. If the packet's address is within that range (including equal to either the lower or upper bound), then a signature match flag is returned.
The original test of each signature match address to the packet was performed using a set of four compounded AND comparisons looking at each of the four 32-bit blocks that comprise an IPv6 address. The problem with the old comparison is that if ANY of the four 32-bit blocks failed the test, then a "no-match" was returned. This is incorrect. If one or more of the more significant 32-bit blocks met the condition, then it is a match no matter if some of the less significant 32-bit blocks did not meet the condition. Consider this example where Packet represents the packet address being checked, and Target represents the upper bound of a match address pair. We are testing if Packet is less than Target.
Packet -- 2001:0470 : 1f07:00e2 : 1988:01f1 : d468:27ab
Target -- 2001:0470 : 1f07:00e2 : a48c:2e52 : d121:101e
In this example the Packet's address is less than the target and it should give a match. However, the old code would compare each 32-bit block (shown spaced out above for clarity) and logically AND the result with the next least significant block comparison. If any of the four blocks failed the comparison, that kicked out the whole address. The flaw is illustrated above. The first two blocks are 2001:0470 and 1f07:00e2 and yield TRUE; the next less significant block is 1988:01f1 and a48c:2e52, and also yields TRUE (that is, Packet is less than Target); but the last block compare is FALSE (d468:27ab is not less than d121:101e). That last block is the least significant block, though, so its FALSE determination should not invalidate a TRUE from any of the more significant blocks. However, in the previous code using the compound logical AND block, that last least significant block would invalidate the tests done with the more significant blocks.
The other bug I found for IPv6 occurs when trying to parse and insert an IPv6 address into a Radix Tree using the function SCRadixAddKeyIPV6String(). The test for min and max values for an IPv6 CIDR mask incorrectly tests the upper limit as 32 when it should be 128 for an IPv6 address. I think this perhaps is an old copy-paste error if the IPv6 version of this function was initially copied from the corresponding IPv4 version directly above it in the code. Without this patch, the function will return null when you attempt to add an IPv6 network whose CIDR mask is larger than 32 (for example, the popular /64 mask will cause the function to return the NULL error condition).
(amended by Victor Julien)
When using the inspection engines, track the current tx_id in the
thread storage the detect thread uses. As 0 is a valid tx_id, add
a simple bool that indicates if the tx_id field is set.
Allow use of the Flow Logging API through Lua scripts.
Minimal script:
function init (args)
local needs = {}
needs["type"] = "flow"
return needs
end
function setup (args)
end
function log(args)
startts = SCFlowTimeString()
ipver, srcip, dstip, proto, sp, dp = SCFlowTuple()
print ("Flow IPv" .. ipver .. " src " .. srcip .. " dst " .. dstip ..
" proto " .. proto .. " sp " .. sp .. " dp " .. dp)
end
function deinit (args)
end
Add SCStreamingBuffer lua function to retrieve the data passed
to the script per streaming API invocation.
Example:
function log(args)
data = SCStreamingBuffer()
hex_dump(data)
end
Make normalized body data available to the script through
HttpGetRequestBody and HttpGetResponseBody.
There no guarantees that all of the body will be availble.
Example:
function log(args)
a, o, e = HttpGetResponseBody();
--print("offset " .. o .. " end " .. e)
for n, v in ipairs(a) do
print(v)
end
end
Get the host from libhtp's tx->request_hostname, which can either be
the host portion of the url or the host portion of the Host header.
Example:
http_host = HttpGetRequestHost()
if http_host == nil then
http_host = "<hostname unknown>"
end
SCFlowAppLayerProto: get alproto as string from the flow. If alproto
is not (yet) known, it returns "unknown".
function log(args)
alproto = SCFlowAppLayerProto()
if alproto ~= nil then
print (alproto)
end
end
A new callback to give access to thread id, name and group name:
SCThreadInfo. It gives: tid (integer), tname (string), tgroup (string)
function log(args)
tid, tname, tgroup = SCThreadInfo()
SCFlowTimeString: returns string form of start time of a flow
Example:
function log(args)
startts = SCFlowTimeString()
ts = SCPacketTimeString()
if ts == startts then
print("new flow")
end
Add SCPacketTimeString to get the packets time string in the format:
11/24/2009-18:57:25.179869
Example use:
function log(args)
ts = SCPacketTimeString()
SCRuleIds(): returns sid, rev, gid:
function log(args)
sid, rev, gid = SCRuleIds()
SCRuleMsg(): returns msg
function log(args)
msg = SCRuleMsg()
SCRuleClass(): returns class msg and prio:
function log(args)
class, prio = SCRuleClass()
if class == nil then
class = "unknown"
end
Add flow store and retrieval wrappers for accessing the flow through
Lua's lightuserdata method.
The flow functions store/retrieve a lock hint as well.
If the script needing a packet doesn't specify a filter, it will
be run against all packets. This patch adds the support for this
mode. It is a packet logger with a condition function that always
returns true.
Add a lua callback for getting Suricata's log path, so that lua scripts
can easily get the logging directory Suricata uses.
Update the Setup logic to register callbacks before the scripts 'setup'
is called.
Example:
name = "fast_lua.log"
function setup (args)
filename = SCLogPath() .. "/" .. name
file = assert(io.open(filename, "a"))
end
Add file logger support. The script uses:
function init (args)
local needs = {}
needs['type'] = 'file'
return needs
end
The type is set to file to make it a file logger.
Add utility functions for placing things on the stack for use
by the scripts. Functions for numbers, strings and byte arrays.
Add callback for returing IP header info: ip version, src ip,
dst ip, proto, sp, dp (or type and code for icmp and icmpv6):
SCPacketTuple
Through 'needs' the script init function can indicate it wants to
see packets and select a condition function. Currently only alerts
is an option:
function init (args)
local needs = {}
needs["type"] = "packet"
needs["filter"] = "alerts"
return needs
end
Add an argument to the registration to indicate which iterator
needs to be used: Stream or HttpBody
Add HttpBody Iterator, calling the logger(s) for each Http body chunk.
StreamIterator implementation for iterating over ACKed segments.
Flag each segment as logged when the log function has been called for it.
Set a 'OPEN' flag for the first segment in both directions.
Set a 'CLOSE' flag when the stream ends. If the last segment was already
logged, a empty CLOSE call is performed with NULL data.
This patch adds a new Log API for streaming data such as TCP reassembled
data and HTTP body data. It could also replace Filedata API.
Each time a new chunk of data is available, the callback will be called.
- Removed unnecessary assignment of the data field
- Removed else condition (same function called for IPv4 and IPV6)
- Fixed constants to be a power of two (used in bitwise operations)
The field ext_pkt was cleaned before calling the release function.
The result was that IPS mode such as the one of AF_PACKET were not
working anymore because they were not able to send the data which
were initially pointed by ext_pkt.
This patch moves the ext_pkt cleaning to the cleaning macro. This
ensures that the cleaning is done for allocated and pool packets.
Call PACKET_RELEASE_REFS from PacketPoolGetPacket() so that
we only access the large packet structure just before actually
using it. Should give better cache behaviour.
The Source Routing Header had routing defined as a char* for a field
of variable size. Since that field was not being used in the code, I
removed the pointer and added a comment.
Structures that are used to cast packet data into fields need to be packed
so that the compiler doesn't add any padding to these fields. This also helps
Tile-Gx to avoid unaligned loads because the compiler will insert code to
handle the possible unaligned load.
Reported in bug 1238 is an issue where stream reassembly can be
disrupted.
A packet that was in-window, but otherwise unexpected set the
window to a really low value, causing the next *expected* packet
to be considered out of window. This lead to missing data in the
stream reassembly.
The packet was unexpected in various ways:
- it would ack unseen traffic
- it's sequence number would not match the expected next_seq
- set a really low window, while not being a proper window update
Detection however, it greatly hampered by the fact that in case of
packet loss, quite similar packets come in. Alerting in this case
is unwanted. Ignoring/skipping packets in this case as well.
The logic used in this patch is as follows. If:
- the packet is not a window update AND
- packet seq > next_seq AND
- packet acq > next_seq (packet acks unseen data) AND
- packet shrinks window more than it's own data size
THEN set event and skip the packet in the stream engine.
So in case of a segment with no data, any window shrinking is rejected.
Bug #1238.
Until now the time out handling in defrag was done using a single
uint32_t that tracked seconds. This lead to corner cases, where
defrag trackers could be timed out a little too early.
If a next header / protocol is encountered that we can't handle (yet)
set an event. Disabled the rule by default.
decode-event:ipv6.unknown_next_header;
Fix or rather implement handling of unfragmentable exthdrs in ipv6.
The exthdr(s) appearing before the frag header were copied into the
reassembled packet correctly, however the stripping of the frag header
did not work correctly.
Example:
The common case is a frag header directly after the ipv6 header:
[ipv6 header]->[frag header]->[icmpv6 (part1)]
[ipv6 header]->[frag header]->[icmpv6 (part2)]
This would result in:
[ipv6 header]->[icmpv6]
The ipv6 headers 'next header' setting would be updated to point to
whatever the frag header was pointing to.
This would also happen when is this case:
[ipv6 header]->[hop header]->[frag header]->[icmpv6 (part1)]
[ipv6 header]->[hop header]->[frag header]->[icmpv6 (part2)]
The result would be:
[ipv6 header]->[hop header]->[icmpv6]
However, here too the ipv6 header would have been updated to point
to what the frag header pointed at. So it would consider the hop header
as if it was an ICMPv6 header, or whatever the frag header pointed at.
The result is that packets would not be correctly parsed, and thus this
issue can lead to evasion.
This patch implements handling of the unfragmentable part. In the first
segment that is stored in the list for reassembly, this patch detects
unfragmentable headers and updates it to have the last unfragmentable
header point to the layer after the frag header.
Also, the ipv6 headers 'next hdr' is only updated if no unfragmentable
headers are used. If they are used, the original value is correct.
Reported-By: Rafael Schaefer <rschaefer@ernw.de>
Bug #1244.
Some tests are already registered via the function
AppLayerParserRegisterProtocolUnittests. So we don't need to
egister them during runmode initialization.
Victor Julien
Eric Leblond
Jason Ish
Ken Steele
gureedo
Duarte Silva
DIALLO David
Giuseppe Longo
Christophe M
Tom DeCanio
David Abarbanel
Jason Ish
Anoop Saldanha
Mats Klepsland
bmeeks8
sxhlinux