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/reader_util.c | 11 ++++++-----
 1 file changed, 6 insertions(+), 5 deletions(-)

(limited to 'example/reader_util.c')

diff --git a/example/reader_util.c b/example/reader_util.c
index d5638d183..de8192845 100644
--- a/example/reader_util.c
+++ b/example/reader_util.c
@@ -1078,7 +1078,8 @@ void process_ndpi_collected_info(struct ndpi_workflow * workflow, struct ndpi_fl
       flow->dhcp_fingerprint = ndpi_strdup(flow->ndpi_flow->protos.dhcp.fingerprint);
     if(flow->ndpi_flow->protos.dhcp.class_ident[0] != '\0')
       flow->dhcp_class_ident = ndpi_strdup(flow->ndpi_flow->protos.dhcp.class_ident);
-  } else if(is_ndpi_proto(flow, NDPI_PROTOCOL_BITTORRENT)) {
+  } else if(is_ndpi_proto(flow, NDPI_PROTOCOL_BITTORRENT) &&
+            !is_ndpi_proto(flow, NDPI_PROTOCOL_TLS)) {
     u_int j;
 
     if(flow->ndpi_flow->protos.bittorrent.hash[0] != '\0') {
@@ -1116,11 +1117,11 @@ void process_ndpi_collected_info(struct ndpi_workflow * workflow, struct ndpi_fl
 	  || /* IMAP */ is_ndpi_proto(flow, NDPI_PROTOCOL_MAIL_IMAP)
 	  || /* POP */  is_ndpi_proto(flow, NDPI_PROTOCOL_MAIL_POP)
 	  || /* SMTP */ is_ndpi_proto(flow, NDPI_PROTOCOL_MAIL_SMTP)) {
-    if(flow->ndpi_flow->ftp_imap_pop_smtp.username[0] != '\0')
+    if(flow->ndpi_flow->l4.tcp.ftp_imap_pop_smtp.username[0] != '\0')
       snprintf(flow->info, sizeof(flow->info), "User: %s][Pwd: %s%s",
-	       flow->ndpi_flow->ftp_imap_pop_smtp.username,
-	       flow->ndpi_flow->ftp_imap_pop_smtp.password,
-	       flow->ndpi_flow->ftp_imap_pop_smtp.auth_failed ? "][Auth Failed" : "");
+	       flow->ndpi_flow->l4.tcp.ftp_imap_pop_smtp.username,
+	       flow->ndpi_flow->l4.tcp.ftp_imap_pop_smtp.password,
+	       flow->ndpi_flow->l4.tcp.ftp_imap_pop_smtp.auth_failed ? "][Auth Failed" : "");
   }
   /* KERBEROS */
   else if(is_ndpi_proto(flow, NDPI_PROTOCOL_KERBEROS)) {
-- 
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