From a30e8dc12157a1c20a92d6dac38fc0ab49a72c17 Mon Sep 17 00:00:00 2001
From: Peter <necmon@yahoo.com>
Date: Sat, 17 Oct 2015 18:02:15 +0000
Subject: [PATCH] native: Check if in_pktinfo exists. If it does not exist,
 `typedef in_addr in_pktinfo`.

---
 src/Native/Common/pal_config.h.in           |  1 +
 src/Native/System.Native/pal_networking.cpp | 19 +++++++++++++++++++
 src/Native/configure.cmake                  | 20 ++++++++++++++++++++
 3 files changed, 40 insertions(+)

diff --git a/src/Native/Common/pal_config.h.in b/src/Native/Common/pal_config.h.in
index 4ca23d988c63..00aeb70732d6 100644
--- a/src/Native/Common/pal_config.h.in
+++ b/src/Native/Common/pal_config.h.in
@@ -32,6 +32,7 @@
 #cmakedefine01 HAVE_ECHO
 #cmakedefine01 HAVE_ICANON
 #cmakedefine01 HAVE_TCSANOW
+#cmakedefine01 HAVE_IN_PKTINFO
 
 // Mac OS X has stat64, but it is deprecated since plain stat now
 // provides the same 64-bit aware struct when targeting OS X > 10.5
diff --git a/src/Native/System.Native/pal_networking.cpp b/src/Native/System.Native/pal_networking.cpp
index a56f2bedc6f5..ab9abe5b5abd 100644
--- a/src/Native/System.Native/pal_networking.cpp
+++ b/src/Native/System.Native/pal_networking.cpp
@@ -27,6 +27,17 @@
 #include <unistd.h>
 #include <vector>
 
+#if !HAVE_IN_PKTINFO
+// On platforms, such as FreeBSD, where in_pktinfo
+// is not available, fallback to custom definition
+// with required members.
+struct in_pktinfo
+{
+    in_addr ipi_addr;
+};
+#define IP_PKTINFO IP_RECVDSTADDR
+#endif
+
 #if !defined(IPV6_ADD_MEMBERSHIP) && defined(IPV6_JOIN_GROUP)
 #define IPV6_ADD_MEMBERSHIP IPV6_JOIN_GROUP
 #endif
@@ -1055,7 +1066,15 @@ static int32_t GetIPv4PacketInformation(cmsghdr* controlMessage, IPPacketInforma
 
     auto* pktinfo = reinterpret_cast<in_pktinfo*>(CMSG_DATA(controlMessage));
     ConvertInAddrToByteArray(&packetInfo->Address.Address[0], NUM_BYTES_IN_IPV4_ADDRESS, pktinfo->ipi_addr);
+#if HAVE_IN_PKTINFO
     packetInfo->InterfaceIndex = static_cast<int32_t>(pktinfo->ipi_ifindex);
+#else
+    // TODO: Figure out how to get interface index with in_addr.
+    // One option is http://www.unix.com/man-page/freebsd/3/if_nametoindex
+    // which requires interface name to be known.
+    // Meanwhile:
+    packetInfo->InterfaceIndex = 0;
+#endif
 
     return 1;
 }
diff --git a/src/Native/configure.cmake b/src/Native/configure.cmake
index 6fe0db30d5ad..49ad5195297f 100644
--- a/src/Native/configure.cmake
+++ b/src/Native/configure.cmake
@@ -5,11 +5,31 @@ include(CheckIncludeFiles)
 include(CheckPrototypeDefinition)
 include(CheckStructHasMember)
 include(CheckSymbolExists)
+include(CheckTypeSize)
 
 #CMake does not include /usr/local/include into the include search path
 #thus add it manually. This is required on FreeBSD.
 include_directories(SYSTEM /usr/local/include)
 
+# in_pktinfo: Find whether this struct exists
+check_include_files(
+    linux/in.h
+    HAVE_LINUX_IN_H)
+
+if (HAVE_LINUX_IN_H)
+    set (SOCKET_INCLUDES ${SOCKET_INCLUDES} linux/in.h)
+else ()
+    set (SOCKET_INCLUDES ${SOCKET_INCLUDES} netinet/in.h)
+endif ()
+
+set(CMAKE_EXTRA_INCLUDE_FILES ${SOCKET_INCLUDES})
+check_type_size(
+    "struct in_pktinfo"
+    HAVE_IN_PKTINFO
+    BUILTIN_TYPES_ONLY)
+set(CMAKE_EXTRA_INCLUDE_FILES) # reset CMAKE_EXTRA_INCLUDE_FILES
+# /in_pktinfo
+
 check_include_files(
     alloca.h
     HAVE_ALLOCA_H)