mod_pres_counter prevents subscription flood (thanks to Ahmed Omar and Alexey Shchepin)(EJAB-1388)

1 files changed, 35 insertions, 0 deletions

diff --git a/doc/guide.tex b/doc/guide.tex
index f7048f404..d8afbabd7 100644
--- a/doc/guide.tex
+++ b/doc/guide.tex
@@ -80,6 +80,7 @@
 \newcommand{\modoffline}{\module{mod\_offline}}
 \newcommand{\modofflineodbc}{\module{mod\_offline\_odbc}}
 \newcommand{\modping}{\module{mod\_ping}}
+\newcommand{\modprescounter}{\module{mod\_pres\_counter}}
 \newcommand{\modprivacy}{\module{mod\_privacy}}
 \newcommand{\modprivacyodbc}{\module{mod\_privacy\_odbc}}
 \newcommand{\modprivate}{\module{mod\_private}}
@@ -2531,6 +2532,7 @@ The following table lists all modules included in \ejabberd{}.
     \hline \ahrefloc{modoffline}{\modoffline{}} & Offline message storage (\xepref{0160}) &  \\
     \hline \ahrefloc{modoffline}{\modofflineodbc{}} & Offline message storage (\xepref{0160}) & supported DB (*) \\
     \hline \ahrefloc{modping}{\modping{}} & XMPP Ping and periodic keepalives (\xepref{0199}) &  \\
+    \hline \ahrefloc{modprescounter}{\modprivacy{}} & Detect presence subscription flood &  \\
     \hline \ahrefloc{modprivacy}{\modprivacy{}} & Blocking Communication (XMPP IM) &  \\
     \hline \ahrefloc{modprivacy}{\modprivacyodbc{}} & Blocking Communication (XMPP IM) & supported DB (*) \\
     \hline \ahrefloc{modprivate}{\modprivate{}} & Private XML Storage (\xepref{0049}) &  \\
@@ -3555,6 +3557,39 @@ and if a client does not answer to the ping in less than 32 seconds, its connect
  ]}.
 \end{verbatim}
 
+\makesubsection{modprescounter}{\modprescounter{}}
+\ind{modules!\modprescounter{}}
+
+This module detects flood/spam in presence subscription stanza traffic.
+If a user sends or receives more of those stanzas in a time interval,
+the exceeding stanzas are silently dropped, and warning is logged.
+
+Configuration options:
+\begin{description}
+  \titem{\{count, StanzaNumber\}}\ind{options!count}
+  The number of subscription presence stanzas
+  (subscribe, unsubscribe, subscribed, unsubscribed)
+  allowed for any direction (input or output)
+  per time interval.
+  Please note that two users subscribing to each other usually generate
+  4 stanzas, so the recommended value is 4 or more.
+  The default value is: 5.
+  \titem{\{interval, Seconds\}}\ind{options!interval}
+  The time interval defined in seconds.
+  The default value is 60.
+\end{description}
+
+This example enables the module, and allows up to 5 presence subscription stanzas
+to be sent or received by the users in 60 seconds:
+\begin{verbatim}
+{modules,
+ [
+  ...
+  {mod_pres_counter,  [{count, 5}, {interval, 60}]},
+  ...
+ ]}.
+\end{verbatim}
+
 \makesubsection{modprivacy}{\modprivacy{}}
 \ind{modules!\modprivacy{}}\ind{Blocking Communication}\ind{Privacy Rules}\ind{protocols!RFC 3921: XMPP IM}