From af2f0960ab48de220895b934bbdb0ae25dbca6b3 Mon Sep 17 00:00:00 2001
From: henri <henri@e0a8ed71-7df4-0310-8962-fdc924857419>
Date: Sat, 18 Aug 2012 16:25:50 +0000
Subject: [PATCH] Automatically enforce the use of the nsock select engine if
 we detect that stdin is a regular file.

Under linux, that provides epoll(7), this allows proper behavior when
redirecting a regular file to stdin (e.g.: 'ncat localhost < file.txt').

Bug was reported by Michal Hlavinka. See
http://seclists.org/nmap-dev/2012/q3/490 for more details.
---
 ncat/ncat_connect.c | 20 ++++++++++++++++++++
 1 file changed, 20 insertions(+)

diff --git a/ncat/ncat_connect.c b/ncat/ncat_connect.c
index f811137d5..969246f2a 100644
--- a/ncat/ncat_connect.c
+++ b/ncat/ncat_connect.c
@@ -458,11 +458,31 @@ bail:
     return -1;
 }
 
+#if defined(LINUX)
+static int stdin_is_reg(void) {
+  struct stat buf;
+
+  if (fstat(STDIN_FILENO, &buf) < 0)
+    fatal("fstat(): %s", strerror(errno));
+
+  return S_ISREG(buf.st_mode);
+}
+#endif
+
 int ncat_connect(void)
 {
     nsock_pool mypool;
     int rc;
 
+#if defined(LINUX)
+    /* -- Hack!!
+     * epoll(7) doesn't support regular files (e.g.: ncat < file.c)
+     * If we detect that STDIN is a regular file, then we enforce
+     * the use of the select-based engine. */
+    if (stdin_is_reg())
+      nsock_set_default_engine("select");
+#endif
+
     /* Create an nsock pool */
     if ((mypool = nsp_new(NULL)) == NULL)
         bye("Failed to create nsock_pool.");