Ticket: 6575
Multi buffers keywords now use a single registration function
DetectAppLayerMultiRegister with a GetBuffer argument.
This GetBuffer function pointer is similar to the ones used by
single-buffer keyword, except that it takes an additional
parameter which is the index of the buffer to get.
Under the hood, an anonymous union between these 2 functions
pointers types is used.
In the end, this deduplicates code, especially the calls to
DetectEngineContentInspection
The old DetectAppLayerMpmRegister has not been around since 4.1.x.
Rename the v2 of this function to a versionless function as there is no
documentation referring to what the 2 means.
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.
Instead of a shared mpm context for just "file.data" or "file.magic"
use per alproto mpms. This way http file.data rules won't affect smb
file.data performance.
Ticket: #4378.
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.
In preparation of more dynamic logic in rule loading also doing
some registration, allow for buffers to be registered as fast_patterns
during rule parsing.
Leaves the register time registrations mostly as-is, but copies the
resulting list into the DetectEngineCtx and works with that onwards.
This list can then be extended.
Instead of a map that is constantly realloc'd, use 2 hash tables for
DetectBufferType entries: one by name (+transforms), the other by
id. Use these everywhere.
Allow progress values in the range 0-47 so we have 48 bits to track
prefilter engines.
Mark bits 48-62 as reserved explicitly.
Add debug validation checks to make sure the reserved space isn't used.
Buffers with transforms are based on the non-transformed "base"
buffer, with a new ID assigned and the transform callbacks added.
This patch stores the id of the original buffer in the new buffer
inspect and prefilter structures. This way the buffers with and
without transforms can share some of the logic are progression
of file and body inspection trackers.
Related tickets: #4361#4199#3616
Replaces all patterns of SCLogError() followed by exit() with
FatalError(). Cocci script to do this:
@@
constant C;
constant char[] msg;
@@
- SCLogError(C,
+ FatalError(SC_ERR_FATAL,
msg);
- exit(EXIT_FAILURE);
Closes redmine ticket 3188.
This commit adds support for transform-specific options. During Setup,
transforms have the signature string available for options detection.
When a transform detects an option, it should convert the option into an
internal format and supply a pointer to this format as the last argument
to DetectSignatureAddTransform.
Transforms that support options must provide a function in their
Sigmatch table entry. When the transform is freed, a pointer to the
internal format of the option is passed to this function.
Philippe Antoine
Victor Julien
Jason Ish
Jeff Lucovsky
Juliana Fajardini
Philippe Antoine
Victor Julien
Shivani Bhardwaj
Jeff Lucovsky