Arch Linux

ettercap has a patch, 01_pointers_and_ints_dont_mix.diff.

The contents are:
See debian bug #521857, patch from Timothy Redaelli <timothy@redaelli.eu>

--- ettercap-0.7.3.orig/src/protocols/ec_tcp.c
+++ ettercap-0.7.3/src/protocols/ec_tcp.c
@@ -116,7 +116,7 @@
tcp = (struct tcp_header *)DECODE_DATA;

opt_start = (u_char *)(tcp + 1);
- opt_end = (u_char *)((int)tcp + tcp->off * 4);
+ opt_end = (u_char *)(tcp + tcp->off * 4);

DECODED_LEN = (u_int32)(tcp->off * 4);


However, this is an old version of the correct patch. As noted here: http://ubuntuforums.org/showthread.php?t=1555044
It causes issues with ettercap's operation.
The poster in that thread recommends casting to long, but even that was decided against in the bug thread: http://bugs.debian.org/cgi-bin/bugreport.cgi?bug=521857

Eventually, it was settled to cast to u_char. This has no issues. Check the bug thread to see the latest patch (which patches our (and their) current patch).