From b51a2ac72a3cbd1b470890d0151a46da28e6754e Mon Sep 17 00:00:00 2001
From: Ivan Nardi <12729895+IvanNardi@users.noreply.github.com>
Date: Thu, 9 Feb 2023 20:02:12 +0100
Subject: 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.
---
 src/lib/protocols/ppstream.c | 27 ---------------------------
 1 file changed, 27 deletions(-)

(limited to 'src/lib/protocols/ppstream.c')

diff --git a/src/lib/protocols/ppstream.c b/src/lib/protocols/ppstream.c
index 78dc25393..dad801ff4 100644
--- a/src/lib/protocols/ppstream.c
+++ b/src/lib/protocols/ppstream.c
@@ -68,9 +68,6 @@ static void ndpi_search_ppstream(struct ndpi_detection_module_struct
 	       packet->payload[13] == 0x00 &&
 	       packet->payload[14] == 0x00) {
 
-	    /* increase count pkt ppstream over udp */
-	    flow->l4.udp.ppstream_stage++;
-	    
 	    ndpi_int_ppstream_add_connection(ndpi_struct, flow);
 	    return;
 	    }       
@@ -92,9 +89,6 @@ static void ndpi_search_ppstream(struct ndpi_detection_module_struct
 		     packet->payload[19] == 0x00 &&
 		     packet->payload[20] == 0x00) {
 
-		    /* increase count pkt ppstream over udp */
-		    flow->l4.udp.ppstream_stage++;
-
 		    ndpi_int_ppstream_add_connection(ndpi_struct, flow);
 		    return;
 		  }
@@ -105,9 +99,6 @@ static void ndpi_search_ppstream(struct ndpi_detection_module_struct
 		     packet->payload[19] == 0xff &&
 		     packet->payload[20] == 0xff) {
 
-		    /* increase count pkt ppstream over udp */
-		    flow->l4.udp.ppstream_stage++;
-		  
 		    ndpi_int_ppstream_add_connection(ndpi_struct, flow);
 		    return;
 		  }
@@ -128,9 +119,6 @@ static void ndpi_search_ppstream(struct ndpi_detection_module_struct
 		 packet->payload[19] == 0x00 &&
 		 packet->payload[20] == 0x00) {
 
-		/* increase count pkt ppstream over udp */
-		flow->l4.udp.ppstream_stage++;
-
 		ndpi_int_ppstream_add_connection(ndpi_struct, flow);
 		return;
 	      }
@@ -147,9 +135,6 @@ static void ndpi_search_ppstream(struct ndpi_detection_module_struct
 		 packet->payload[100] == 0x61 &&
 		 packet->payload[101] == 0x6d) {
 
-		/* increase count pkt ppstream over udp */
-		flow->l4.udp.ppstream_stage++;
-	      
 		ndpi_int_ppstream_add_connection(ndpi_struct, flow);
 		return;
 	      }
@@ -166,9 +151,6 @@ static void ndpi_search_ppstream(struct ndpi_detection_module_struct
 						 packet->payload[19] == 0x00 &&
 						 packet->payload[20] == 0x00 )) {
 
-	    /* increase count pkt ppstream over udp */
-	    flow->l4.udp.ppstream_stage++;
-
 	    ndpi_int_ppstream_add_connection(ndpi_struct, flow);
 	    return;
 	  }
@@ -187,9 +169,6 @@ static void ndpi_search_ppstream(struct ndpi_detection_module_struct
 		   packet->payload[19] == 0x00 &&
 		   packet->payload[20] == 0x00 )) {
 
-	    /* increase count pkt ppstream over udp */
-	    flow->l4.udp.ppstream_stage++;
-	  
 	    ndpi_int_ppstream_add_connection(ndpi_struct, flow);
 	    return;
 	  }
@@ -200,9 +179,6 @@ static void ndpi_search_ppstream(struct ndpi_detection_module_struct
 	if(packet->payload[1] == 0x80 || packet->payload[1] == 0x84 ) {
 	  if(packet->payload[3] == packet->payload[4]) {
 
-	    /* increase count pkt ppstream over udp */
-	    flow->l4.udp.ppstream_stage++;
-	  
 	    ndpi_int_ppstream_add_connection(ndpi_struct, flow);
 	    return;
 	  }
@@ -211,9 +187,6 @@ static void ndpi_search_ppstream(struct ndpi_detection_module_struct
 	else if(packet->payload[1] == 0x53 && packet->payload[3] == 0x00 &&
 		(packet->payload[0] == 0x08 || packet->payload[0] == 0x0c)) {
 
-	  /* increase count pkt ppstream over udp */
-	  flow->l4.udp.ppstream_stage++;
-	
 	  ndpi_int_ppstream_add_connection(ndpi_struct, flow);
 	  return;
 	}
-- 
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