Allow nDPI to process the entire flows and not only the first N packets.
Usefull when the application is interested in some metadata spanning the
entire life of the session.
As initial step, only STUN flows can be put in monitoring.
See `doc/monitoring.md` for further details.
This feature is disabled by default.
Close#2583
ndpiReader --cfg=dpi.address_cache_size,1000 -i <pcap>.pcap
In the above example the cache has up to 1000 entries.
In jcase ndpiReader exports data in JSON, the cache hostname (if found) is exported in the field server_hostname
Some fuzzers don't really need a real and complete local context.
Try to avoid setting it up, creating a simpler fake version with only the
features really needed.
That is a kind of experiment: if it works, we can extend the same logic
to other fuzzers
Export some metadata (for the moment, SNI and TLS fingerprints) to
Wireshark/tshark via extcap.
Note that:
* metadata are exported only once per flow
* metadata are exported (all together) when nDPI stopped processing
the flow
Still room for a lot of improvements!
In particular:
* we need to add some boundary checks (if we are going to export other
attributes)
* we should try to have a variable length trailer
Enable parsing of Mapped-Address attribute for all STUN flows: that
means that STUN classification might require more packets.
Add a configuration knob to enable/disable this feature.
Note that we can have (any) STUN metadata also for flows *not*
classified as STUN (because of DTLS).
Add support for ipv6.
Restore the correct extra dissection logic for Telegram flows.
Add the concept of "global context".
Right now every instance of `struct ndpi_detection_module_struct` (we
will call it "local context" in this description) is completely
independent from each other. This provide optimal performances in
multithreaded environment, where we pin each local context to a thread,
and each thread to a specific CPU core: we don't have any data shared
across the cores.
Each local context has, internally, also some information correlating
**different** flows; something like:
```
if flow1 (PeerA <-> Peer B) is PROTOCOL_X; then
flow2 (PeerC <-> PeerD) will be PROTOCOL_Y
```
To get optimal classification results, both flow1 and flow2 must be
processed by the same local context. This is not an issue at all in the far
most common scenario where there is only one local context, but it might
be impractical in some more complex scenarios.
Create the concept of "global context": multiple local contexts can use
the same global context and share some data (structures) using it.
This way the data correlating multiple flows can be read/write from
different local contexts.
This is an optional feature, disabled by default.
Obviously data structures shared in a global context must be thread safe.
This PR updates the code of the LRU implementation to be, optionally,
thread safe.
Right now, only the LRU caches can be shared; the other main structures
(trees and automas) are basically read-only: there is little sense in
sharing them. Furthermore, these structures don't have any information
correlating multiple flows.
Every LRU cache can be shared, independently from the others, via
`ndpi_set_config(ndpi_struct, NULL, "lru.$CACHE_NAME.scope", "1")`.
It's up to the user to find the right trade-off between performances
(i.e. without shared data) and classification results (i.e. with some
shared data among the local contexts), depending on the specific traffic
patterns and on the algorithms used to balance the flows across the
threads/cores/local contexts.
Add some basic examples of library initialization in
`doc/library_initialization.md`.
This code needs libpthread as external dependency. It shouldn't be a big
issue; however a configure flag has been added to disable global context
support. A new CI job has been added to test it.
TODO: we should need to find a proper way to add some tests on
multithreaded enviroment... not an easy task...
*** API changes ***
If you are not interested in this feature, simply add a NULL parameter to
any `ndpi_init_detection_module()` calls.
Allow to disable this check.
I don't know how much sense these limits have in the application
(especially with those default values...) since we have always had a
hard limit on the library itself (`max_packets_to_process` set to 32).
The only value might be that they provide different limits for TCP and
UDP traffic.
Keep them for the time being...
Remove some unreached/duplicated code.
Add error checking for `atoi()` calls.
About `isdigit()` and similar functions. The warning reported is:
```
Negative Character Value help
isdigit() is invoked here with an argument of signed type char, but only
has defined behavior for int arguments that are either representable
as unsigned char or equal to the value of macro EOF(-1).
Casting the argument to unsigned char will avoid the undefined behavior.
In a number of libc implementations, isdigit() is implemented using lookup
tables (arrays): passing in a negative value can result in a read underrun.
```
Switching to our macros fix that.
Add a check to `check_symbols.sh` to avoid using the original functions
from libc.
* logging is instead redirected to `ndpi_debug_printf`
Signed-off-by: lns <matzeton@googlemail.com>
Signed-off-by: Toni Uhlig <matzeton@googlemail.com>
The option NSID (RFC5001) is used by Google DNS to report the
airport code of the metro where the DNS query is handled.
This option is quite rare, but the added overhead in DNS code is pretty
much zero for "normal" DNS traffic
