[Buildroot] [PATCH v3 6/7] package/cups: Add udev rules to assign usb printers group to lp

[Angelo Compagnucci <angelo@amarulasolutions.com>]

This patch is based on patch from the rockchip tree:

commit c8a337593660f27379c30248a11bf08dc8712113
Author: Jeffy Chen <jeffy.chen@rock-chips.com>
Date:   Tue Nov 13 18:59:43 2018 +0800

    package: cups: Add udev rules to assign usb printers' group to lp

    Change-Id: Ieae17deaa7d3623e1f0e1cc826871f1719d98d88
    Signed-off-by: Jeffy Chen <jeffy.chen@rock-chips.com>

but removes a hardcoded device usb vendor/id and keps only the usb
printer class.

Signed-off-by: Angelo Compagnucci <angelo@amarulasolutions.com>
Signed-off-by: Michael Trimarchi <michael@amarulasolutions.com>
---
 package/cups/70-usb-printers.rules | 3 +++
 package/cups/cups.mk               | 9 +++++++++
 2 files changed, 12 insertions(+)
 create mode 100644 package/cups/70-usb-printers.rules

diff --git a/package/cups/70-usb-printers.rules b/package/cups/70-usb-printers.rules
new file mode 100644
index 0000000000..67e7f5e938
--- /dev/null
+++ b/package/cups/70-usb-printers.rules
@@ -0,0 +1,3 @@
+# Allow USB printers in the lp group
+# Match rules converted from usblp.c driver's usblp_ids
+ACTION=="add", SUBSYSTEM=="usb", ATTR{bInterfaceClass}=="07", ATTR{bInterfaceSubClass}=="01", GROUP="lp"
diff --git a/package/cups/cups.mk b/package/cups/cups.mk
index e86374b027..805a80e854 100644
--- a/package/cups/cups.mk
+++ b/package/cups/cups.mk
@@ -75,6 +75,15 @@ else
 CUPS_CONF_OPTS += --disable-avahi
 endif
 
+ifeq ($(BR2_PACKAGE_HAS_UDEV),y)
+define CUPS_INSTALL_UDEV_RULES
+	$(INSTALL) -D -m 0644 package/cups/70-usb-printers.rules \
+		$(TARGET_DIR)/lib/udev/rules.d/70-usb-printers.rules
+endef
+
+CUPS_POST_INSTALL_TARGET_HOOKS += CUPS_INSTALL_UDEV_RULES
+endif
+
 define CUPS_INSTALL_INIT_SYSV
 	$(RM) $(TARGET_DIR)/etc/init.d/cups
 	$(INSTALL) -D -m 0755 package/cups/S81cupsd \
-- 
2.25.1