Victor Julien [Mon, 19 Dec 2016 10:25:58 +0000 (11:25 +0100)]
detect: http_header_names sticky buffer keyword
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.
Victor Julien [Mon, 19 Dec 2016 10:25:27 +0000 (11:25 +0100)]
detect: global registery for keyword thread data
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.
Victor Julien [Sat, 15 Oct 2016 16:15:17 +0000 (18:15 +0200)]
detect-engine: memory handling of sm_lists
For lists that are registered multiple times, like http_header and
http_cookie, making the engines owner of the lists is complicated.
Multiple engines in a sig may be pointing to the same list. To
address this the 'free' code needs to be extra careful about not
double freeing, so it takes an approach to first fill an array
of the to-free pointers before freeing them.
Victor Julien [Wed, 7 Dec 2016 10:14:20 +0000 (11:14 +0100)]
detect-parse: set ipprotos earlier
A high level proto like HTTP implies TCP. However this wasn't set
until after all the parsing was complete which means that keywords
couldn't test if the ipproto matched.
This patch populates the ipprotos right when the higher level proto
is parsed.
Jason Ish [Sun, 5 Feb 2017 13:57:54 +0000 (07:57 -0600)]
defrag - take protocol into account during re-assembly
The IP protocol was not being used to match fragments with
their packets allowing a carefully constructed packet
with a different protocol to be matched, allowing re-assembly
to complete, creating a packet that would not be re-assembled
by the destination host.
Victor Julien [Thu, 9 Feb 2017 17:22:18 +0000 (18:22 +0100)]
afl: improve packet fuzz testing
Due to the use of AFL_LOOP and initialization/deinit outside of it,
part of the fuzzing relied on the global 'state' in flow and defrag.
Because of this crashes that were found could not be reproduced. The
saved crash input was only the last in the series.
This patch addresses that. It requires a new output directory 'dump'
where the packet fuzzers will store all their input. If the AFL_LOOP
fails the files will not be removed and this 'serie' can be read
again for reproducing the issue.
e.g.: AFL would work with:
--afl-decoder-ppp=@@
and after a crash is found the produced serie can be read with:
--afl-decoder-ppp-serie=1486656919-514163
The series have a timestamp as name and a suffix that controls the
order in which the files will be 'replayed' in Suricata.
The size of a memory buffer to be allocated was kept in a signed int
instead of a size_t, leading to an overflow when large lists of long
and diverse patterns cause the amount of AC states to blow up (>2GB).
Fixes Redmine issues #1827 and #1843.
Victor Julien [Wed, 8 Feb 2017 12:55:34 +0000 (13:55 +0100)]
detect: don't run IP inspection on non-IP packets
The code to get the rule group (sgh) would return the group for
IP proto 0 instead of nothing. This lead to certain types of rules
unintentionally matching (False Positive).
Since the packets weren't actually IP, the logged alert records
were missing the IP header.