tgt: iSCSI target support

This is a port from old packages repo with the following improvements:
- allow to select multiple addresses and ports to listent to
- support both address- and name-based ACLs
  (note: config option has been changed from "allow" to "allow_address", "allow_name")
- support more optionf for LUNs
- support various device types (disk, cd, sg passthrough)
- bind accounts to multiple targets
- use uci_validate_section in the init script
- improve error reporting, use logger instead of echo
- set number of IO threads to 2 by default (affects memory footprint)
- configure keepalive
- update to 1.0.48

Signed-off-by: Maxim Storchak <m.storchak@gmail.com>

net/tgt/Makefile

@@ -0,0 +1,59 @@
+#
+# Copyright (C) 2012-2014 OpenWrt.org
+#
+# This is free software, licensed under the GNU General Public License v2.
+# See /LICENSE for more information.
+
+include $(TOPDIR)/rules.mk
+
+PKG_NAME:=tgt
+PKG_VERSION:=1.0.46
+PKG_REV:=601a44d6c833f59d9d2472ad11d421481a25b2e7
+PKG_RELEASE:=2
+
+PKG_SOURCE_PROTO:=git
+PKG_SOURCE_URL:=https://github.com/fujita/tgt.git
+
+PKG_SOURCE_VERSION:=$(PKG_REV)
+PKG_SOURCE:=$(PKG_NAME)-$(PKG_VERSION)-$(PKG_REV).tar.gz
+PKG_SOURCE_SUBDIR:=$(PKG_NAME)-$(PKG_VERSION)
+
+PKG_BUILD_DIR:=$(BUILD_DIR)/$(PKG_SOURCE_SUBDIR)
+
+include $(INCLUDE_DIR)/package.mk
+
+define Package/tgt
+  SECTION:=net
+  CATEGORY:=Network
+  URL:=http://stgt.sourceforge.net/
+  TITLE:=userspace iSCSI target
+  DEPENDS:=+libpthread +libaio +@KERNEL_AIO +@KERNEL_DIRECT_IO
+endef
+
+define Package/tgt/description
+Linux SCSI target framework (tgt) aims to simplify various SCSI target driver (iSCSI, Fibre Channel, SRP, etc) creation and maintenance.
+Key goals of the project are the clean integration into the scsi-mid layer and implementing a great portion of tgt in user space.
+Tgt consists of kernel-space and user-space code. The kernel-space component is included in upstream as of 2.6.20.
+Note that if you are interested in only iSCSI (probably you are), you need only the user-space code (any kernel version is fine).
+endef
+
+define Build/Compile
+	CC=$(TARGET_CC) CFLAGS="$(TARGET_CFLAGS)" $(MAKE) -C $(PKG_BUILD_DIR) \
+		DESTDIR="$(PKG_INSTALL_DIR)" \
+		LD="$(TARGET_CC)" \
+		install-programs
+endef
+
+define Package/tgt/conffiles
+/etc/config/tgt
+endef
+
+define Package/tgt/install
+	$(INSTALL_DIR) $(1)/
+	$(INSTALL_DIR) $(1)/usr/sbin
+	$(CP) ./files/* $(1)/
+	$(INSTALL_BIN) $(PKG_INSTALL_DIR)/usr/sbin/tgtd $(1)/usr/sbin/
+	$(INSTALL_BIN) $(PKG_INSTALL_DIR)/usr/sbin/tgtadm $(1)/usr/sbin/
+endef
+
+$(eval $(call BuildPackage,tgt))