Add UPower driver

NEWS.adoc

@@ -199,6 +199,11 @@ https://github.com/networkupstools/nut/milestone/12
    * Fixed default `unit_id`, apparently broken by changes in NUT v2.8.1.
      [issue #3191, PR #3192]
 
+ - Introduced a new NUT driver named `nut-upower` which provides support
+   for monitoring UPS and battery devices managed by the UPower daemon
+   via D-Bus. This also introduces a new category of drivers that talk to
+   operating system services to obtain power state information. [PR #3279]
+
  - `usbhid-ups` driver updates:
    * Declared support for APC with USB ID `051d:0005` (details may evolve
      as the devices become better known). [issue #3047, PR #3081]

UPGRADING.adoc

@@ -125,6 +125,11 @@ Changes from 2.8.4 to 2.8.5
   updated, either to explicitly package the binding for several versions,
   or to not-deliver files no longer installed into the prototype area. [#1792]
 
+- Introduced a new driver category for interaction with OS-reported UPS
+  devices via D-Bus, with the `nut-upower` driver as the first implementation.
+  This driver requires `glib-2.0` and `gio-2.0` development libraries to be
+  available at build time. For packagers, this adds new dependencies if the
+  build should include this driver. [PR #3279]
 
 Changes from 2.8.3 to 2.8.4
 ---------------------------

configure.ac

@@ -2316,6 +2316,7 @@ AC_ARG_WITH(drivers,
 		if test -z "${with_powerman}"; then with_powerman="yes"; fi
 		if test -z "${with_modbus}"; then with_modbus="yes"; fi
 		if test -z "${with_ipmi}"; then with_ipmi="yes"; fi
+		if test -z "${with_upower}"; then with_upower="yes"; fi
 
 		dnl Platform-dependent snowflakes that are required or auto:
 		if test -z "${with_gpio}"; then
@@ -2353,6 +2354,7 @@ AC_ARG_WITH(drivers,
 		if test -z "${with_powerman}"; then with_powerman="${withval}"; fi
 		if test -z "${with_modbus}"; then with_modbus="${withval}"; fi
 		if test -z "${with_ipmi}"; then with_ipmi="${withval}"; fi
+		if test -z "${with_upower}"; then with_upower="${withval}"; fi
 		if test -z "${with_gpio}"; then with_gpio="${withval}"; fi
 		if test -z "${with_linux_i2c}"; then with_linux_i2c="${withval}"; fi
 		if test -z "${with_macosx_ups}"; then with_macosx_ups="${withval}"; fi
@@ -2369,7 +2371,8 @@ AC_ARG_WITH(drivers,
 				SERIAL_DRIVERLIST USB_LIBUSB_DRIVERLIST SERIAL_USB_DRIVERLIST
 				SNMP_DRIVERLIST NEONXML_DRIVERLIST
 				MACOSX_DRIVERLIST MODBUS_DRIVERLIST LINUX_I2C_DRIVERLIST
-				POWERMAN_DRIVERLIST IPMI_DRIVERLIST GPIO_DRIVERLIST"
+				POWERMAN_DRIVERLIST IPMI_DRIVERLIST GPIO_DRIVERLIST
+				UPOWER_DRIVERLIST"
 
 			dnl Gets ONE Makefile assignment value
 			get_drivers_makefile_value() (
@@ -2520,6 +2523,11 @@ AC_ARG_WITH(drivers,
 										[AC_MSG_NOTICE([Requiring --with-gpio=yes for driver "$DRV"])
 										with_gpio=yes]
 									)],
+								[UPOWER_DRIVERLIST], [
+									AS_IF([test -z "${with_upower}"],
+										[AC_MSG_NOTICE([Requiring --with-upower=yes for driver "$DRV"])
+										with_upower=yes]
+									)],
 
 								[AC_MSG_WARN([Unhandled DRVLIST_NAME=$DRVLIST_NAME])]
 							)
@@ -2553,7 +2561,7 @@ dnl check for --with-all (or --without-all, or --with-all=auto) flag
 
 AC_MSG_CHECKING(for --with-all)
 AC_ARG_WITH(all,
-	AS_HELP_STRING([--with-all], [enable serial, usb, snmp, neon, ipmi, powerman, modbus, gpio (currently on Linux released after ~2018), linux_i2c (on Linux), macosx-ups (on MacOS), cgi, dev, avahi, nut-scanner, nutconf, dev-libnutconf, pynut]),
+	AS_HELP_STRING([--with-all], [enable serial, usb, snmp, neon, ipmi, powerman, modbus, gpio (currently on Linux released after ~2018), linux_i2c (on Linux), upower, macosx-ups (on MacOS), cgi, dev, avahi, nut-scanner, nutconf, dev-libnutconf, pynut]),
 [
 	if test -n "${withval}"; then
 		dnl Note: we allow "no" as a positive value, because
@@ -2567,6 +2575,7 @@ AC_ARG_WITH(all,
 		if test -z "${with_powerman}"; then with_powerman="${withval}"; fi
 		if test -z "${with_modbus}"; then with_modbus="${withval}"; fi
 		if test -z "${with_ipmi}"; then with_ipmi="${withval}"; fi
+		if test -z "${with_upower}"; then with_upower="${withval}"; fi
 
 		dnl Platform-dependent snowflakes that are required or auto:
 		if test -z "${with_gpio}"; then
@@ -2845,6 +2854,7 @@ dnl Platform-dependent drivers, currently their detection code is directly
 dnl spelled out in configure.ac
 NUT_ARG_WITH([macosx_ups], [build and install Mac OS X Power Sources meta-driver], [auto])
 NUT_ARG_WITH([linux_i2c], [build and install i2c drivers], [auto])
+NUT_ARG_WITH([upower], [build and install UPower driver (requires GLib/GIO)], [auto])
 
 dnl A Python GUI client application for the sysadmin desktop
 dnl (not necessarily on the NUT server itself):
@@ -3136,6 +3146,72 @@ NUT_REPORT_DRIVER([build Mac OS X meta-driver],
 			[${nut_with_macosx_ups}], [${nut_macosx_ups_lib}],
 			[WITH_MACOSX], [Define to enable Mac OS X meta-driver])
 
+dnl ----------------------------------------------------------------------
+dnl Check for libGLib / libGIO (Required for UPower driver)
+dnl NOTE: Do not confuse libglib{2} (GNOME) with glibc (part of compiler)
+dnl ----------------------------------------------------------------------
+
+have_glib=no
+
+AS_IF([test "${with_upower}" != "no"], [
+    AS_IF([test x"$have_PKG_CONFIG" = xyes],
+        [ifdef([PKG_CHECK_MODULES],
+            [PKG_CHECK_MODULES(GLIB, [glib-2.0 gio-2.0], [have_glib=yes], [have_glib=no])],
+            [have_glib=no])
+        ],
+        [AC_MSG_WARN([pkg-config not found, cannot look properly for glib-2.0/gio-2.0])]
+    )
+])
+
+AS_IF([test "${have_glib}" = "yes"], [
+    AC_DEFINE(HAVE_GLIB, 1, [Define to 1 if GLib and GIO are available])
+
+    dnl GLib headers seem incorrect and offensive to many compilers
+    dnl (starting names with underscores and capital characters,
+    dnl varying support for attributes, method pointer mismatches).
+    dnl There is nothing NUT can do about it, except telling the
+    dnl compiler that we take these headers from the system as they
+    dnl are, so strict checks should not apply to them.
+    dnl On newer releases (2025+) the headers and CLANG seem to work
+    dnl together out of the box, but during the decade before this is
+    dnl troublesome.
+    AS_IF([test "${CLANGCC}" = "yes" || test "${GCC}" = "yes"], [
+        myGLIB_CFLAGS=""
+        for TOKEN in ${GLIB_CFLAGS} ; do
+            AS_CASE(["${TOKEN}"],
+                [-I/*], [
+                    _IDIR="`echo \"${TOKEN}\" | sed 's/^-I//'`"
+                    AS_IF([echo " ${GLIB_CFLAGS}" | ${EGREP} " -isystem *${_IDIR}" >/dev/null],
+                        [myGLIB_CFLAGS="${myGLIB_CFLAGS} ${TOKEN}"],
+                        [myGLIB_CFLAGS="${myGLIB_CFLAGS} -isystem ${_IDIR} ${TOKEN}"]
+                    )],
+                    [myGLIB_CFLAGS="${myGLIB_CFLAGS} ${TOKEN}"]
+            )
+        done
+        unset TOKEN
+        unset _IDIR
+        myGLIB_CFLAGS="`echo \"${myGLIB_CFLAGS}\" | sed 's/^ *//'`"
+
+        AS_IF([test x"${GLIB_CFLAGS}" != x -a x"${GLIB_CFLAGS}" != x"${myGLIB_CFLAGS}"], [
+            AC_MSG_NOTICE([Patched libglib/libgio CFLAGS to declare -isystem])
+            AS_IF([test x"${nut_enable_configure_debug}" = xyes], [
+                AC_MSG_NOTICE([(CONFIGURE-DEVEL-DEBUG) old: ${GLIB_CFLAGS}])
+                AC_MSG_NOTICE([(CONFIGURE-DEVEL-DEBUG) new: ${myGLIB_CFLAGS}])
+            ])
+            GLIB_CFLAGS="${myGLIB_CFLAGS}"
+        ])
+        unset myGLIB_CFLAGS
+    ])
+], [
+    AS_CASE(["${with_upower}"],
+        [yes], [AC_MSG_ERROR([GLib/GIO not found but requested via --with-upower])],
+        [auto],[AC_MSG_WARN([GLib/GIO not found. The 'upower' driver will not be built.])]
+    )
+])
+
+AM_CONDITIONAL(HAVE_GLIB, test "${have_glib}" = "yes")
+AC_MSG_RESULT(${have_glib})
+
 dnl ----------------------------------------------------------------------
 dnl checks related to --with_linux_i2c
 dnl Check for i2c header on Linux, used for ASEM UPS driver

docs/config-prereqs.txt

@@ -259,6 +259,7 @@ metadata about recently published package revisions:
     libssl-dev libnss3-dev \
     augeas-tools libaugeas-dev augeas-lenses \
     libusb-dev libusb-1.0-0-dev \
+    libglib2.0-dev \
     libi2c-dev \
     libmodbus-dev \
     libsnmp-dev \
@@ -459,6 +460,7 @@ drivers in distro packaging of NUT. Resolution and doc PRs are welcome.
     openssl-devel nss-devel \
     augeas augeas-devel \
     libusb-devel libusbx-devel \
+    glib2-devel \
     i2c-tools \
     libmodbus-devel \
     net-snmp-devel \
@@ -561,6 +563,7 @@ Install tools and prerequisites for NUT:
     openssl nss \
     augeas \
     libusb \
+    glib2 \
     neon \
     net-snmp \
     freeipmi \
@@ -732,6 +735,7 @@ For NUT dependencies and build tools:
 :; slackpkg-install \
     openssl openssl-solibs mozilla-nss \
     libusb \
+    glib2 \
     net-snmp \
     neon
 
@@ -870,6 +874,8 @@ below.
     cppunit \
     nss \
     augeas \
+    libusb \
+    glib \
     libmodbus \
     neon \
     net-snmp \
@@ -1041,6 +1047,7 @@ Finally, as `root` add the packages:
     openssl nss \
     augeas \
     libusb1 \
+    glib2 \
     net-snmp \
     avahi
 
@@ -1232,6 +1239,7 @@ but can be created in `/etc/` and is honoured by `pkgin`:
     openssl nss \
     augeas \
     libusb libusb1 \
+    glib2 \
     neon \
     net-snmp \
     avahi
@@ -1366,6 +1374,7 @@ Typical tooling would include:
     library/augeas python/augeas \
     libusb-1 libusbugen system/library/usb/libusb \
     system/header/header-usb driver/usb/ugen \
+    glib2 \
     libmodbus \
     library/neon \
     system/management/snmp/net-snmp \
@@ -1508,6 +1517,7 @@ site for setup details.
     developer/build/libtool library/libtool/libltdl \
     build-essential ccache git developer/pkg-config \
     runtime/perl \
+    glib \
     asciidoc \
     libgd
 
@@ -1725,7 +1735,7 @@ Currently known dependencies for basic build include:
 # Required:
 :; brew install ccache bash libtool binutils autoconf automake git m4 \
         pkg-config aspell asciidoc docbook-xsl cppunit gd \
-        libusb neon net-snmp \
+        libusb glib neon net-snmp \
         nss openssl \
         libmodbus freeipmi powerman
 
@@ -1935,7 +1945,8 @@ export PATH
 
 # This also pulls *-devel of several other projects:
 :; pacman -S --needed \
-    mingw-w64-x86_64-neon libneon-devel
+    mingw-w64-x86_64-neon libneon-devel \
+    mingw-w64-x86_64-glib2
 
 # Other dependencies:
 :; pacman -S --needed \

docs/configure.txt

@@ -209,6 +209,20 @@ This allows to monitor numerous Power Supply Units (PSU) found on servers.
 Note that you need to install freeipmi (0.8.5 or higher, for nut-scanner;
 and 1.0.1 or higher, for nut-ipmipsu) development package or files.
 
+UPower/D-Bus drivers
+~~~~~~~~~~~~~~~~~~~~
+
+	--with-upower (default: auto-detect)
+
+Build and install the `nut-upower` driver.
+
+This allows to monitor UPS and battery devices managed by the UPower daemon
+via D-Bus. This introduces a new category of drivers that talk to operating
+system services to obtain power state information.
+
+Note that you need to install `glib-2.0` and `gio-2.0` development packages
+or files.
+
 I2C bus drivers
 ~~~~~~~~~~~~~~~
 

docs/man/Makefile.am

@@ -1463,6 +1463,38 @@ else !DOC_INSTALL_SELECTED_MANS_PROGS_BUILT
 LINKMAN_PAGES_DRIVERS += $(SRC_GPIO_PAGES)
 endif !DOC_INSTALL_SELECTED_MANS_PROGS_BUILT
 
+# (--with-upower)
+SRC_UPOWER_PAGES = nut-upower.txt
+INST_MAN_UPOWER_PAGES = nut-upower.$(MAN_SECTION_CMD_SYS)
+DIST_ALL_MAN_PAGES += $(INST_MAN_UPOWER_PAGES)
+
+if ! SOME_DRIVERS
+if WITH_MANS
+MAN_UPOWER_PAGES = $(INST_MAN_UPOWER_PAGES)
+endif WITH_MANS
+
+if HAVE_GLIB
+mansys_DATA += $(MAN_UPOWER_PAGES)
+endif HAVE_GLIB
+endif ! SOME_DRIVERS
+
+INST_HTML_UPOWER_MANS = \
+	nut-upower.html
+DIST_ALL_HTML_PAGES += $(INST_HTML_UPOWER_MANS)
+
+if ! SOME_DRIVERS
+HTML_UPOWER_MANS = $(INST_HTML_UPOWER_MANS)
+endif ! SOME_DRIVERS
+
+# FIXME? Refine for HTML etc.?
+if DOC_INSTALL_SELECTED_MANS_PROGS_BUILT
+if HAVE_GLIB
+LINKMAN_PAGES_DRIVERS += $(SRC_UPOWER_PAGES)
+endif HAVE_GLIB
+else !DOC_INSTALL_SELECTED_MANS_PROGS_BUILT
+LINKMAN_PAGES_DRIVERS += $(SRC_UPOWER_PAGES)
+endif !DOC_INSTALL_SELECTED_MANS_PROGS_BUILT
+
 # Summarize which pages we ultimately install:
 MAN_MANS =
 if WITH_MANS
@@ -1486,7 +1518,8 @@ MAN_MANS += \
 	$(MAN_MACOSX_PAGES) \
 	$(MAN_MODBUS_PAGES) \
 	$(MAN_LINUX_I2C_PAGES) \
-	$(MAN_GPIO_PAGES)
+	$(MAN_GPIO_PAGES) \
+	$(MAN_UPOWER_PAGES)
 endif WITH_MANS
 
 SRC_DRIVERS_PAGES = \
@@ -1500,7 +1533,8 @@ SRC_DRIVERS_PAGES = \
 	$(SRC_MACOSX_PAGES) \
 	$(SRC_MODBUS_PAGES) \
 	$(SRC_LINUX_I2C_PAGES) \
-	$(SRC_GPIO_PAGES)
+	$(SRC_GPIO_PAGES) \
+	$(SRC_UPOWER_PAGES)
 
 if SOME_DRIVERS
 # (Legacy note) The list above probably came up empty in this case, so make sure
@@ -1576,7 +1610,8 @@ HTML_MANS = \
 	$(HTML_MACOSX_MANS) \
 	$(HTML_MODBUS_MANS) \
 	$(HTML_LINUX_I2C_MANS) \
-	$(HTML_GPIO_MANS)
+	$(HTML_GPIO_MANS) \
+	$(HTML_UPOWER_MANS)
 
 # htmlmandir is set by autoconf/automake
 htmlman_DATA =