Multi buffer matching is implemented as a way for a rule to match
on multiple buffers within the same transaction.
Before this patch a rule like:
dns.query; content:"example"; dns.query; content:".com";
would be equivalent to:
dns.query; content:"example"; content:".com";
If a DNS query would request more than one name, e.g.:
DNS: [example.net][something.com]
Eeach would be inspected to have both patterns present. Otherwise,
it would not be a match. So the rule above would not match, as neither
example.net and somthing.com satisfy both conditions at the same time.
This patch changes this behavior. Instead of the above, each time the
sticky buffer is specified, it creates a separate detection unit. Each
buffer is a "multi buffer" sticky buffer will now be evaluated against
each "instance" of the sticky buffer.
To continue with the above example:
DNS: [example.net] <- matches 'dns.query; content:"example";'
DNS: [something.com] <- matches 'dns.query; content:".com"'
So this would now be a match.
To make sure both patterns match in a single query string, the expression
'dns.query; content:"example"; content:".com";' still works for this.
This patch doesn't yet enable the behavior for the keywords. That is
done in a follow up patch.
To be able to implement this the internal storage of parsed rules
is changed. Until this patch and array of lists was used, where the
index was the buffer id (e.g. http_uri, dns_query). Therefore there
was only one list of matches per buffer id. As a side effect this
array was always very sparsely populated as many buffers could not
be mixed.
This patch changes the internal representation. The new array is densely
packed:
dns.query; content:"1"; dns.query; bsize:1; content:"2";
[type: dns_query][list: content:"1";]
[type: dns_query][list: bsize:1; content:"2";]
The new scheme allows for multiple instances of the same buffer.
These lists are then translated into multiple inspection engines
during the final setup of the rule.
Ticket: #5784.
Indexing of Signature::init_data::smlists would fail for a rule that
used a frame and fast_pattern w/o content, as the array would only be
expanded when adding a content.
Adding a check to see if there list id is in bounds
is an implicit check for the "no content" case.
Ticket: #5530
Issue: 2982
This commit moves bsize validation with respect to content matches to
the post-parse validation stage. This allows bsize to consider all
content-related values, including those that follow the bsize keyword.
Work towards making `suricata-common.h` only introduce system headers
and other things that are independent of complex internal Suricata
data structures.
Update files to compile after this.
Remove special DPDK handling for strlcpy and strlcat, as this caused
many compilation failures w/o including DPDK headers for all files.
Remove packet macros from decode.h and move them into their own file,
turn them into functions and rename them to match our function naming
policy.
Our unittests were only covering sig parsing for alert actions. As in
environments without LibNet the reject action will not work, we must
ensure that our parser properly fails in such cases, instead of silently
accepting an unsupported action.
Added tests for the reject and drop action.
Task #5496
So 'alert dcerpc' also matches if the DCERPC is over SMB.
Explicitly refuse smb keywords for the 'dcerpc' app proto setting:
`alert dceprc ... smb.share; ...` is rejected.
Remove a now useless special case in the stateless rule processing
matching for dcerpc/smb.
Bug: #5208.
Some unittests used SCMalloc for allocating new Packet the unittests.
While this is valid, it leads to segmentation faults when we move to
dynamic allocation of the maximum alerts allowed to be triggered by a
single packet.
This massive patch uses PacketGetFromAlloc, which initializes a Packet
in such a way that any dynamic allocated structures within will also be
initialized.
Related to
Task #4207
A lot of time was spent in `SigMatchListSMBelongsTo` for the `mpm_sm`.
Optimize this by keeping the value at hand during Signature parsing and
detection engine setup.
Indexing of Signature::init_data::smlists would fail for a rule that
used a frame w/o content, as the array would only be expanded when
adding a content. Adding a check to see if there list id is in bounds
is an implicit check for the "no content" case.
Bug #5011.
Before, if Suricata parsed a rule without a 'sid' option, instead of
failing that rule, the rule was parsed and attributed a sid 0.
Changes to:
detect-parse:
- add logic to filter out rules without sid;
- change unittest which didn't have a sid, but used to pass.
detect-sid: add unittest for rules without sid or with sid: 0
Victor Julien
Philippe Antoine
Jeff Lucovsky
Lukas Sismis
Juliana Fajardini
Juliana Fajardini
Philippe Antoine
Victor Julien
Jeff Lucovsky
Gianni Tedesco
Jason Ish