From 1b4c4a9ef30860a53af46cc3591b8110f15fa423 Mon Sep 17 00:00:00 2001
From: dmiller <dmiller@e0a8ed71-7df4-0310-8962-fdc924857419>
Date: Tue, 10 Nov 2015 21:07:30 +0000
Subject: [PATCH] Add new --no-shutdown option to Ncat. Closes #151, fixes #142

---
 CHANGELOG          |  4 ++++
 ncat/docs/ncat.xml | 13 +++++++++++++
 ncat/ncat_core.c   |  1 +
 ncat/ncat_core.h   |  1 +
 ncat/ncat_listen.c |  2 +-
 ncat/ncat_main.c   |  1 +
 6 files changed, 21 insertions(+), 1 deletion(-)

diff --git a/CHANGELOG b/CHANGELOG
index dd15bf5c2..c1ad164c1 100644
--- a/CHANGELOG
+++ b/CHANGELOG
@@ -1,5 +1,9 @@
 # Nmap Changelog ($Id$); -*-text-*-
 
+o [Ncat] [GH#151] [GH#142] New option --no-shutdown prevents Ncat from shutting
+  down when it reads EOF on stdin. This is the same as traditional netcat's
+  "-d" option. [Adam Saparona]
+
 o [NSE] Added ip-https-discover for detecting support for Microsoft's IP over
   HTTPS tunneling protocol. [Niklaus Schiess]
 
diff --git a/ncat/docs/ncat.xml b/ncat/docs/ncat.xml
index e96e6e767..ee159926a 100644
--- a/ncat/docs/ncat.xml
+++ b/ncat/docs/ncat.xml
@@ -775,6 +775,19 @@
         </listitem>
       </varlistentry>
 
+      <varlistentry>
+        <term>
+          <option>--no-shutdown</option> (Do not shutdown into half-duplex mode)
+          <indexterm><primary><option>--no-shutdown</option> (Ncat option)</primary></indexterm>
+        </term>
+        <listitem>
+          <para>If this option is passed, Ncat will not invoke shutdown on a
+          socket aftering seeing EOF on stdin. This is provided for
+          backward-compatibility with OpenBSD netcat, which exhibits this
+          behavior when executed with its '-d' option.</para>
+        </listitem>
+      </varlistentry>
+
       <varlistentry>
         <term>
           <option>-t</option>,
diff --git a/ncat/ncat_core.c b/ncat/ncat_core.c
index bb5afae6b..128228f29 100644
--- a/ncat/ncat_core.c
+++ b/ncat/ncat_core.c
@@ -168,6 +168,7 @@ void options_init(void)
     o.keepopen = 0;
     o.sendonly = 0;
     o.recvonly = 0;
+    o.noshutdown = 0;
     o.telnet = 0;
     o.linedelay = 0;
     o.chat = 0;
diff --git a/ncat/ncat_core.h b/ncat/ncat_core.h
index 197dab46a..dd35770aa 100644
--- a/ncat/ncat_core.h
+++ b/ncat/ncat_core.h
@@ -161,6 +161,7 @@ struct options {
     int keepopen;
     int sendonly;
     int recvonly;
+    int noshutdown;
     int telnet;
     int linedelay;
     int chat;
diff --git a/ncat/ncat_listen.c b/ncat/ncat_listen.c
index 9f51b6858..3bf7e0e3e 100644
--- a/ncat/ncat_listen.c
+++ b/ncat/ncat_listen.c
@@ -393,7 +393,7 @@ static int ncat_listen_stream(int proto)
                                receiving anything, we can quit here. */
                             return 0;
                         }
-                        shutdown_sockets(SHUT_WR);
+                        if (!o.noshutdown) shutdown_sockets(SHUT_WR);
                     }
                     if (rc < 0)
                         return 1;
diff --git a/ncat/ncat_main.c b/ncat/ncat_main.c
index d7fd5a538..7dbf50c84 100644
--- a/ncat/ncat_main.c
+++ b/ncat/ncat_main.c
@@ -286,6 +286,7 @@ int main(int argc, char *argv[])
         {"source-port",     required_argument,  NULL,         'p'},
         {"source",          required_argument,  NULL,         's'},
         {"send-only",       no_argument,        &o.sendonly,  1},
+        {"no-shutdown",     no_argument,        &o.noshutdown,1},
         {"broker",          no_argument,        NULL,         0},
         {"chat",            no_argument,        NULL,         0},
         {"talk",            no_argument,        NULL,         0},