From 91bb77a8806ee2987e856f66674cf3aa8b1d60db Mon Sep 17 00:00:00 2001
From: Ivan Nardi <12729895+IvanNardi@users.noreply.github.com>
Date: Wed, 22 Dec 2021 19:54:06 +0100
Subject: A final(?) effort to reduce memory usage per flow (#1389)

Remove some unused fields and re-organize other ones.
In particular:
* Update the parameters of `ndpi_ssl_version2str()` function
* Zattoo, Thunder: these timestamps aren't really used.
* Ftp/mail: these protocols are dissected only over TCP.
* Attention must be paid to TLS.Bittorrent flows to avoid invalid
read/write to `flow->protos.bittorrent.hash` field.

This is the last(?) commit of a long series (see 22241a1d, 227e586e,
730c2360, a8ffcd8b) aiming to reduce library memory consumption.

Before, at nDPI 4.0 (more precisly, at a6b10cf7, because memory stats
were wrong until that commit):
```
nDPI Memory statistics:
	nDPI Memory (once):      221.15 KB
	Flow Memory (per flow):  2.94 KB
```
Now:
```
nDPI Memory statistics:
	nDPI Memory (once):      231.71 KB
	Flow Memory (per flow):  1008 B       <---------
```
i.e. memory usage per flow has been reduced by 66%, dropping below the
psychological threshold of 1 KB.

To further reduce this value, we probably need to look into #1279:
let's fight this battle another day.
---
 example/ndpiReader.c | 5 +++--
 1 file changed, 3 insertions(+), 2 deletions(-)

(limited to 'example/ndpiReader.c')

diff --git a/example/ndpiReader.c b/example/ndpiReader.c
index 641575c12..abe12b5ec 100644
--- a/example/ndpiReader.c
+++ b/example/ndpiReader.c
@@ -1221,6 +1221,7 @@ static void printFlow(u_int32_t id, struct ndpi_flow_info *flow, u_int16_t threa
   FILE *out = results_file ? results_file : stdout;
   u_int8_t known_tls;
   char buf[32], buf1[64];
+  char buf_ver[16];
   u_int i;
 
   double dos_ge_score;
@@ -1315,7 +1316,7 @@ static void printFlow(u_int32_t id, struct ndpi_flow_info *flow, u_int16_t threa
 	    (flow->ssh_tls.server_info[0] != '\0')  ? flow->ssh_tls.server_info : "");
 
     fprintf(csv_fp, "%s,%s,%s,%s,%s,",
-	    (flow->ssh_tls.ssl_version != 0)        ? ndpi_ssl_version2str(flow->ndpi_flow, flow->ssh_tls.ssl_version, &known_tls) : "0",
+	    (flow->ssh_tls.ssl_version != 0)        ? ndpi_ssl_version2str(buf_ver, sizeof(buf_ver), flow->ssh_tls.ssl_version, &known_tls) : "0",
 	    (flow->ssh_tls.ja3_client[0] != '\0')   ? flow->ssh_tls.ja3_client : "",
 	    (flow->ssh_tls.ja3_client[0] != '\0')   ? is_unsafe_cipher(flow->ssh_tls.client_unsafe_cipher) : "0",
 	    (flow->ssh_tls.ja3_server[0] != '\0')   ? flow->ssh_tls.ja3_server : "",
@@ -1481,7 +1482,7 @@ static void printFlow(u_int32_t id, struct ndpi_flow_info *flow, u_int16_t threa
     fprintf(out, "[Risk Score: %u]", ndpi_risk2score(flow->risk, &cli_score, &srv_score));
   }
   
-  if(flow->ssh_tls.ssl_version != 0) fprintf(out, "[%s]", ndpi_ssl_version2str(flow->ndpi_flow, flow->ssh_tls.ssl_version, &known_tls));
+  if(flow->ssh_tls.ssl_version != 0) fprintf(out, "[%s]", ndpi_ssl_version2str(buf_ver, sizeof(buf_ver), flow->ssh_tls.ssl_version, &known_tls));
 
   if(flow->ssh_tls.client_hassh[0] != '\0') fprintf(out, "[HASSH-C: %s]", flow->ssh_tls.client_hassh);
 
-- 
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