libipsec: Fix Windows build via MinGW

Fixes #2118.

scripts/test.sh

@@ -56,7 +56,7 @@ win*)
 			--enable-constraints --enable-revocation --enable-pem --enable-pkcs1
 			--enable-pkcs8 --enable-x509 --enable-pubkey --enable-acert
 			--enable-eap-tnc --enable-eap-ttls --enable-eap-identity
-			--enable-updown --enable-ext-auth
+			--enable-updown --enable-ext-auth --enable-libipsec
 			--enable-tnccs-20 --enable-imc-attestation --enable-imv-attestation
 			--enable-imc-os --enable-imv-os --enable-tnc-imv --enable-tnc-imc
 			--enable-pki --enable-swanctl --enable-socket-win"

src/libipsec/Makefile.am

@@ -16,6 +16,10 @@ ipsec_sa_mgr.c ipsec_sa_mgr.h
 libipsec_la_LIBADD = \
 	$(top_builddir)/src/libstrongswan/libstrongswan.la
 
+if USE_WINDOWS
+  libipsec_la_LIBADD += -lws2_32
+endif
+
 AM_CPPFLAGS = \
 	-I$(top_srcdir)/src/libstrongswan
 

src/libipsec/esp_packet.c

@@ -25,7 +25,9 @@
 #include <bio/bio_reader.h>
 #include <bio/bio_writer.h>
 
+#ifndef WIN32
 #include <netinet/in.h>
+#endif
 
 typedef struct private_esp_packet_t private_esp_packet_t;
 

src/libipsec/ip_packet.c

@@ -20,11 +20,40 @@
 #include <utils/debug.h>
 
 #include <sys/types.h>
+
+#ifndef WIN32
 #include <netinet/in.h>
 #include <netinet/ip.h>
 #ifdef HAVE_NETINET_IP6_H
 #include <netinet/ip6.h>
 #endif
+#else
+struct ip {
+#if BYTE_ORDER == LITTLE_ENDIAN
+	uint8_t ip_hl: 4;
+	uint8_t ip_v: 4;
+#elif BYTE_ORDER == BIG_ENDIAN
+	uint8_t ip_v: 4;
+	uint8_t ip_hl: 4;
+#endif
+	uint8_t ip_tos;
+	uint16_t ip_len;
+	uint16_t ip_id;
+	uint16_t ip_off;
+	uint8_t ip_ttl;
+	uint8_t ip_p;
+	uint16_t ip_sum;
+	struct in_addr ip_src, ip_dst;
+} __attribute__((packed));
+struct ip6_hdr {
+	uint32_t ip6_flow; /* 4 bit version, 8 bit TC, 20 bit flow label */
+	uint16_t ip6_plen;
+	uint8_t ip6_nxt;
+	uint8_t ip6_hlim;
+	struct in6_addr ip6_src, ip6_dst;
+} __attribute__((packed));
+#define HAVE_NETINET_IP6_H /* not really, but we only need the struct above */
+#endif
 
 /**
  * TCP header, defined here because platforms disagree regarding member names

src/libstrongswan/utils/compat/windows.h

@@ -113,6 +113,13 @@ static inline char* strdup_windows(const char *src)
  */
 char* strndup(const char *s, size_t n);
 
+/**
+ * From winsock2.h
+ */
+#ifndef IPPROTO_IPIP
+#define IPPROTO_IPIP IPPROTO_IPV4
+#endif
+
 /**
  * Provided via ws2_32
  */