fuzz: some improvements and add two new fuzzers (#1881)

Remove `FUZZING_BUILD_MODE_UNSAFE_FOR_PRODUCTION` define from
`fuzz/Makefile.am`; it is already included by the main configure script
(when fuzzing).

Add a knob to force disabling of AESNI optimizations: this way we can
fuzz also no-aesni crypto code.

Move CRC32 algorithm into the library.

Add some fake traces to extend fuzzing coverage. Note that these traces
are hand-made (via scapy/curl) and must not be used as "proof" that the
dissectors are really able to identify this kind of traffic.

Some small updates to some dissectors:

CSGO: remove a wrong rule (never triggered, BTW). Any UDP packet starting
with "VS01" will be classified as STEAM (see steam.c around line 111).
Googling it, it seems right so.

XBOX: XBOX only analyses UDP flows while HTTP only TCP ones; therefore
that condition is false.

RTP, STUN: removed useless "break"s

Zattoo: `flow->zattoo_stage` is never set to any values greater or equal
to 5, so these checks are never true.

PPStream: `flow->l4.udp.ppstream_stage` is never read. Delete it.

TeamSpeak: we check for `flow->packet_counter == 3` just above, so the
following check `flow->packet_counter >= 3` is always false.

1 files changed, 0 insertions, 6 deletions

diff --git a/src/lib/protocols/xbox.c b/src/lib/protocols/xbox.c
index f47018a06..d63d8d787 100644
--- a/src/lib/protocols/xbox.c
+++ b/src/lib/protocols/xbox.c
@@ -91,13 +91,7 @@ static void ndpi_search_xbox(struct ndpi_detection_module_struct *ndpi_struct, s
 	return;
     }
 #endif
-
-    /* exclude here all non matched udp traffic, exclude here tcp only if http has been excluded, because xbox could use http */
-    if(NDPI_COMPARE_PROTOCOL_TO_BITMASK(flow->excluded_protocol_bitmask, NDPI_PROTOCOL_HTTP) != 0) {
-      NDPI_EXCLUDE_PROTO(ndpi_struct, flow);
-    }
   }
-  /* to not exclude tcp traffic here, done by http code... */
 }