From 7a3ed712706883afc5118e2d09a9334e6c382b2e Mon Sep 17 00:00:00 2001
From: Gerhard Rieger <gerhard@dest-unreach.org>
Date: Tue, 22 Nov 2011 11:24:35 +0100
Subject: [PATCH] port to Cygwin - struct pktinfo.ipi_spec_dst

---
 CHANGES      |  4 ++++
 config.h.in  |  5 ++++-
 configure.in | 17 ++++++++++++++++-
 xio-ip.c     | 13 ++++++++++---
 4 files changed, 34 insertions(+), 5 deletions(-)

diff --git a/CHANGES b/CHANGES
index 30490fb..c112e88 100644
--- a/CHANGES
+++ b/CHANGES
@@ -57,6 +57,10 @@ porting:
 	Cedril Priscal ported socat to Android (using Googles cross compiler).
 	The port includes the socat_buildscript_for_android.sh script
 
+	added check for component ipi_spec_dst in struct in_pktinfo so
+	compilation does not fail on Cygwin (thanks to Peter Wagemans for
+	reporting this problem)
+
 ####################### V 1.7.1.3:
 
 security:
diff --git a/config.h.in b/config.h.in
index a9d0f18..3a59824 100644
--- a/config.h.in
+++ b/config.h.in
@@ -1,5 +1,5 @@
 /* source: config.h.in */
-/* Copyright Gerhard Rieger 2001-2009 */
+/* Copyright Gerhard Rieger 2001-2011 */
 /* Published under the GNU General Public License V.2, see file COPYING */
 
 #ifndef __config_h_included
@@ -364,6 +364,9 @@
 /* define if you have struct in_pktinfo */
 #undef HAVE_STRUCT_IN_PKTINFO
 
+/* define if your struct in_pktinfo has component ipi_spec_dst */
+#undef HAVE_PKTINFO_IPI_SPEC_DST
+
 /* define if your struct ip has ip_hl; otherwise assume ip_vhl */
 #undef HAVE_STRUCT_IP_IP_HL
 
diff --git a/configure.in b/configure.in
index de9b791..65b1597 100644
--- a/configure.in
+++ b/configure.in
@@ -1,5 +1,5 @@
 nl source: configure.in
-dnl Copyright Gerhard Rieger 2001-2009
+dnl Copyright Gerhard Rieger 2001-2011
 dnl Published under the GNU General Public License V.2, see file COPYING
 
 dnl Process this file with autoconf to produce a configure script.
@@ -1161,6 +1161,21 @@ if test $sc_cv_struct_in_pktinfo = yes; then
 fi
 AC_MSG_RESULT($sc_cv_struct_in_pktinfo)
 
+if test $sc_cv_struct_in_pktinfo = 'yes'; then
+   dnl check for component ipi_spec_dst in struct in_pktinfo
+   AC_MSG_CHECKING(for ipi_spec_dst in struct in_pktinfo)
+   AC_CACHE_VAL(sc_cv_pktinfo_ipi_spec_dst,
+   [AC_TRY_COMPILE([#include <sys/types.h>
+   #include <sys/socket.h>
+   #include <netinet/in.h>],[struct in_pktinfo s; s.ipi_spec_dst],
+   [sc_cv_pktinfo_ipi_spec_dst=yes],
+   [sc_cv_pktinfo_ipi_spec_dst=no])])
+   if test $sc_cv_pktinfo_ipi_spec_dst = yes; then
+      AC_DEFINE(HAVE_PKTINFO_IPI_SPEC_DST)
+   fi
+   AC_MSG_RESULT($sc_cv_pktinfo_ipi_spec_dst)
+fi
+
 dnl check for ip_hl in struct ip
 AC_MSG_CHECKING(for struct ip.ip_hl)
 AC_CACHE_VAL(sc_cv_struct_ip_ip_hl,
diff --git a/xio-ip.c b/xio-ip.c
index 812b948..dad647d 100644
--- a/xio-ip.c
+++ b/xio-ip.c
@@ -1,5 +1,5 @@
 /* source: xio-ip.c */
-/* Copyright Gerhard Rieger 2001-2009 */
+/* Copyright Gerhard Rieger 2001-2011 */
 /* Published under the GNU General Public License V.2, see file COPYING */
 
 /* this file contains the source for IP related functions */
@@ -477,8 +477,15 @@ int xiolog_ancillary_ip(struct cmsghdr *cmsg, int *num,
 	       "IP_LOCADDR", '\0', "IP_DSTADDR");
       snprintf(valbuff, vallen, "%s%c%s%c%s",
 	       xiogetifname(pktinfo->ipi_ifindex, scratch1, -1), '\0',
-	       inet4addr_info(ntohl(pktinfo->ipi_spec_dst.s_addr), scratch2, sizeof(scratch2)), '\0',
-	       inet4addr_info(ntohl(pktinfo->ipi_addr.s_addr), scratch3, sizeof(scratch3)));
+#if HAVE_PKTINFO_IPI_SPEC_DST
+	       inet4addr_info(ntohl(pktinfo->ipi_spec_dst.s_addr),
+			      scratch2, sizeof(scratch2)),
+#else
+	       "",
+#endif
+	       '\0',
+	       inet4addr_info(ntohl(pktinfo->ipi_addr.s_addr),
+			      scratch3, sizeof(scratch3)));
    }
       return STAT_OK;
 #endif /* defined(IP_PKTINFO) && HAVE_STRUCT_IN_PKTINFO */