FreeBSD 11 now requires the -s 0, -S no longer working

[lungdart]

On FreeBSD 11-RELEASE-p1 with samplicator 1.3.8.rc1

Running samplicator with the following syntax no longer works. No flows are captured $ samplicator -p <port> <target>/<port>

This however, does work $ samplicator -s 0 -p <port> <target>/<port>

Samplicator is also no longer able to spoof source address. This seems to be due to a change in FreeBSD 11 to no longer convert incoming packet headers ip_len and ip_off fields to host order. They now remain in network order with the rest of the packet header

[lungdart]

Here's the patch file I created to compile correctly from ports. (For spoof support, There's a work around for the source listen issue, so I didn't bother)

--- rawsend.c.orig  2017-02-13 13:51:16.373547000 +0000
+++ rawsend.c   2017-02-13 14:10:51.453719000 +0000
@@ -120,7 +120,7 @@
      BSD-derivatives require host byte order, but at least OpenBSD
      since version 2.1 uses network byte order.  Linux uses network
      byte order for all IP header fields. */
-#if defined (__linux__) || (defined (__OpenBSD__) && (OpenBSD > 199702))
+#if defined (__linux__) || (defined (__OpenBSD__) && (OpenBSD > 199702)) || (defined(__FreeBSD__) && (__FreeBSD__ > 10)) 
   ih.ip_len = htons (length);
   ih.ip_off = htons (0);
 #else

[richardhkirkando]

Hi, recently upgraded my server to FreeBSD 11. Could you clarify what your workaround for spoof support was?

[lungdart]

If the above patch file is no longer valid, you need to modify rawsend.c manually.

The section that has the following code changes some fields byte order.

#if defined (__linux__) || (defined (__OpenBSD__) && (OpenBSD > 199702))
  ih.ip_len = htons (length);
  ih.ip_off = htons (0);
#else

The problem is in FreeBSD 11.0, these fields order were changed at an operating system level, so now this section of code is required, but is not included at compile time due to the if statement.

Changing the above section's if statement to look like this, compiles the relevant code in:

#if defined (__linux__) || (defined (__OpenBSD__) && (OpenBSD > 199702)) || (defined(__FreeBSD__) && (__FreeBSD__ > 10)) 
  ih.ip_len = htons (length);
  ih.ip_off = htons (0);
#else

What I did to get this to work, was create a patch file, and include it as a patch in my local ports tree at /usr/ports/net/samplicator/files/patch-rawsend.c and install it using ports.

[richardhkirkando]

Thanks for the reply - your patched worked for me, I misunderstood and thought you had done something else in addition.

[3fr61n]

Hi guys,

I'm using a container with ubuntu 16.04, and I don't understand why spoofing is not working, it does not preserve source packet, I tried your workaround and still doesn't work

any ideas?

Thanks