contrib: add libsmb2

contrib/src/smb2/SHA512SUMS

+5e7101e54a4a95eae2ed5b05dfb51a33e9d4ce19275a405fbb1e86f9e9fe197de53b41c301ca992f19a03e5117ccc90d0acb174eb9c000c71674a0dbacf57614  libsmb2-2.0.0.tar.gz

contrib/src/smb2/rules.mak

+# SMB2
+SMB2_VERSION := 2.0.0
+SMB2_URL := https://github.com/sahlberg/libsmb2/archive/v$(SMB2_VERSION).tar.gz
+
+ifdef BUILD_NETWORK
+ifndef HAVE_WIN32
+PKGS += smb2
+endif
+endif
+ifeq ($(call need_pkg,"smb2"),)
+PKGS_FOUND += smb2
+endif
+
+$(TARBALLS)/libsmb2-$(SMB2_VERSION).tar.gz:
+	$(call download_pkg,$(SMB2_URL),smb2)
+
+.sum-smb2: libsmb2-$(SMB2_VERSION).tar.gz
+
+smb2: libsmb2-$(SMB2_VERSION).tar.gz .sum-smb2
+	$(UNPACK)
+	$(MOVE)
+
+.smb2: smb2
+	cd $< && ./bootstrap
+	cd $< && $(HOSTVARS) ./configure --disable-examples --disable-werror --without-libkrb5 $(HOSTCONF)
+	cd $< && $(MAKE) install
+	touch $@