add OpenBMC D-Bus interface

OpenBMC runs a D-Bus interface internally and has the option of
compiling ipmitool so it can run natively on the BMC. This adds the
D-Bus interface to ipmitool so it can be used with the OpenBMC project.

Signed-off-by: Vernon Mauery <vernon.mauery@linux.intel.com>

configure.ac

@@ -59,6 +59,7 @@ dnl
 
 xenable_all_options=yes
 xenable_intf_bmc=no
+xenable_intf_dbus=no
 xenable_intf_dummy=no
 xenable_intf_imb=yes
 xenable_intf_lipmi=yes
@@ -191,6 +192,14 @@ AC_CHECK_LIB([crypto], [MD2_Init],
 	fi],
 	[], [-lcrypto])
 
+dnl check for libsystemd in case dbus-intf is requested
+AC_CHECK_LIB([systemd], [sd_bus_default],
+	[
+		LIBS="$LIBS -lsystemd"
+		have_systemd=yes
+	],
+	[ have_systemd=no],[])
+
 dnl enable IPMIv1.5 LAN interface
 AC_ARG_ENABLE([intf-lan],
 	[AC_HELP_STRING([--enable-intf-lan],
@@ -554,6 +563,25 @@ if test "x$xenable_intf_bmc" = "xyes"; then
 	IPMITOOL_INTF_LIB="$IPMITOOL_INTF_LIB bmc/libintf_bmc.la"
 fi
 
+dnl enable IPMI dbus interface
+AC_ARG_ENABLE([intf-dbus],
+		[AC_HELP_STRING([--enable-intf-dbus],
+			[enable IPMI dbus interface [default=no]])],
+		[xenable_intf_dbus=$enableval],
+		[xenable_intf_dbus=no])
+if test "x$xenable_intf_dbus" != "xno"; then
+	if test "x$have_systemd" != "xyes"; then
+		AC_MSG_ERROR([** Unable to find libsystemd required by dbus-intf.])
+		xenable_intf_dbus=no
+	fi
+fi
+if test "x$xenable_intf_dbus" = "xyes"; then
+	AC_DEFINE(IPMI_INTF_DBUS, [1], [Define to 1 to enable dbus interface.])
+	AC_SUBST(INTF_DBUS, [dbus])
+	AC_SUBST(INTF_DBUS_LIB, [libintf_dbus.la])
+	IPMITOOL_INTF_LIB="$IPMITOOL_INTF_LIB dbus/libintf_dbus.la"
+fi
+
 dnl enable Dummy interface for testing
 AC_ARG_ENABLE([intf-dummy],
 	[AC_HELP_STRING([--enable-intf-dummy],
@@ -664,6 +692,7 @@ AC_CONFIG_FILES([Makefile
 		src/plugins/free/Makefile
 		src/plugins/imb/Makefile
 		src/plugins/bmc/Makefile
+		src/plugins/dbus/Makefile
 		src/plugins/usb/Makefile
 		src/plugins/lipmi/Makefile
 		src/plugins/serial/Makefile
@@ -681,6 +710,7 @@ AC_MSG_RESULT([  open    : $xenable_intf_open])
 AC_MSG_RESULT([  free    : $xenable_intf_free])
 AC_MSG_RESULT([  imb     : $xenable_intf_imb])
 AC_MSG_RESULT([  bmc     : $xenable_intf_bmc])
+AC_MSG_RESULT([  dbus    : $xenable_intf_dbus])
 AC_MSG_RESULT([  usb     : $xenable_intf_usb])
 AC_MSG_RESULT([  lipmi   : $xenable_intf_lipmi])
 AC_MSG_RESULT([  serial  : $xenable_intf_serial])

src/plugins/Makefile.am

@@ -32,8 +32,8 @@ MAINTAINERCLEANFILES		= Makefile.in
 
 AM_CPPFLAGS			= -I$(top_srcdir)/include
 
-SUBDIRS				= @INTF_LAN@ @INTF_LANPLUS@ @INTF_OPEN@ @INTF_LIPMI@ @INTF_IMB@ @INTF_BMC@ @INTF_FREE@ @INTF_SERIAL@ @INTF_DUMMY@ @INTF_USB@
+SUBDIRS				= @INTF_LAN@ @INTF_LANPLUS@ @INTF_OPEN@ @INTF_LIPMI@ @INTF_IMB@ @INTF_BMC@ @INTF_FREE@ @INTF_SERIAL@ @INTF_DUMMY@ @INTF_USB@ @INTF_DBUS@
-DIST_SUBDIRS			= lan lanplus open lipmi imb bmc free serial dummy usb
+DIST_SUBDIRS			= lan lanplus open lipmi imb bmc free serial dummy usb dbus
 
 noinst_LTLIBRARIES		= libintf.la
 libintf_la_SOURCES		= ipmi_intf.c

src/plugins/dbus/Makefile.am

@@ -0,0 +1,41 @@
+ #
+ # Copyright (c) 2015 IBM Corporation
+ # All rights reserved.
+ #
+ # Redistribution and use in source and binary forms, with or without
+ # modification,are permitted provided that the following conditions are met:
+ #
+ # 1. Redistributions of source code must retain the above copyright notice,
+ #    this list of conditions and the following disclaimer.
+ #
+ # 2. Redistributions in binary form must reproduce the above copyright notice,
+ #    this list of conditions and the following disclaimer in the documentation
+ #    and/or other materials provided with the distribution.
+ #
+ # 3. Neither the name of the copyright holder nor the names of its contributors
+ #    may be used to endorse or promote products derived from this software
+ #    without specific prior written permission.
+ #
+ # THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
+ # AND ANY EXPRESS OR IMPLIED WARRANTIES,INCLUDING, BUT NOT LIMITED TO, THE
+ # IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ # ARE DISCLAIMED.  IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE
+ # LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
+ # CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
+ # SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
+ # INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
+ # CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
+ # ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
+ # POSSIBILITY OF SUCH DAMAGE.
+ #
+
+MAINTAINERCLEANFILES	= Makefile.in
+
+INCLUDES		= -I$(top_srcdir)/include
+
+EXTRA_LTLIBRARIES	= libintf_dbus.la
+noinst_LTLIBRARIES	= @INTF_DBUS_LIB@
+libintf_dbus_la_LDFLAGS	= -lsystemd
+libintf_dbus_la_LIBADD	= $(top_builddir)/lib/libipmitool.la
+libintf_dbus_la_SOURCES	= dbus.c
+

src/plugins/dbus/dbus.c

@@ -0,0 +1,241 @@
+/*
+ * Copyright (c) 2015 IBM Corporation
+ * Copyright (c) 2019 Intel Corporation
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ *
+ * 1. Redistributions of source code must retain the above copyright notice,
+ *    this list of conditions and the following disclaimer.
+ *
+ * 2. Redistributions in binary form must reproduce the above copyright notice,
+ *    this list of conditions and the following disclaimer in the documentation
+ *    and/or other materials provided with the distribution.
+ *
+ * 3. Neither the name of the copyright holder nor the names of its
+ *    contributors may be used to endorse or promote products derived from this
+ *    software without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
+ * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ * ARE DISCLAIMED.  IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE
+ * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
+ * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
+ * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
+ * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
+ * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
+ * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
+ * POSSIBILITY OF SUCH DAMAGE.
+ */
+
+#include <sys/file.h>
+#include <sys/stat.h>
+#include <sys/types.h>
+#include <fcntl.h>
+#include <errno.h>
+#include <unistd.h>
+#include <stdbool.h>
+
+#include <systemd/sd-bus.h>
+
+#include <ipmitool/log.h>
+#include <ipmitool/ipmi.h>
+#include <ipmitool/ipmi_intf.h>
+
+static sd_bus *bus;
+
+static
+struct ipmi_rs *
+ipmi_dbus_sendrecv(struct ipmi_intf *intf,
+                   struct ipmi_rq *req)
+{
+	static const char *destination = "xyz.openbmc_project.Ipmi.Host";
+	static const char *object_path = "/xyz/openbmc_project/Ipmi";
+	static const char *interface = "xyz.openbmc_project.Ipmi.Server";
+	static const char *method_name = "execute";
+	static const char SD_BUS_TYPE_3_BYTES[] = {
+		SD_BUS_TYPE_BYTE, SD_BUS_TYPE_BYTE, SD_BUS_TYPE_BYTE, 0
+	};
+	static const char SD_BUS_TYPE_4_BYTES[] = {
+		SD_BUS_TYPE_BYTE, SD_BUS_TYPE_BYTE,
+		SD_BUS_TYPE_BYTE, SD_BUS_TYPE_BYTE, 0
+	};
+	static const char SD_BUS_TYPE_DICT_OF_VARIANTS[] = {
+		SD_BUS_TYPE_ARRAY,
+		SD_BUS_TYPE_DICT_ENTRY_BEGIN,
+		SD_BUS_TYPE_STRING, SD_BUS_TYPE_VARIANT,
+		SD_BUS_TYPE_DICT_ENTRY_END, 0
+	};
+	static const char SD_BUS_TYPE_IPMI_RESPONSE[] = {
+		SD_BUS_TYPE_BYTE, SD_BUS_TYPE_BYTE,
+		SD_BUS_TYPE_BYTE, SD_BUS_TYPE_BYTE,
+		SD_BUS_TYPE_ARRAY, SD_BUS_TYPE_BYTE, 0
+	};
+
+	sd_bus_message *request = NULL;
+	int rc;
+	sd_bus_error error = SD_BUS_ERROR_NULL;
+	sd_bus_message* reply = NULL;
+	uint8_t recv_netfn;
+	uint8_t recv_lun;
+	uint8_t recv_cmd;
+	uint8_t recv_cc;
+	const void *data;
+	size_t data_len;
+	static struct ipmi_rs rsp;
+	struct ipmi_rs *ipmi_response = NULL;
+
+	if (!intf->opened || !bus)
+	{
+		goto out_no_free;
+	}
+
+	rsp.ccode = IPMI_CC_UNSPECIFIED_ERROR;
+	rsp.data_len = 0;
+	memset(rsp.data, 0, sizeof(rsp.data));
+
+	/* The D-Bus xyz.openbmc_project.Ipmi.Server.execute interface
+	 * looks like this:
+	 *
+	 * Request:
+	 *   byte: net function
+	 *   byte: lun
+	 *   byte: command
+	 *   byte array: data (possibly zero length)
+	 *   array of (string,variant): options
+	 * Response:
+	 *   byte: net function
+	 *   byte: lun
+	 *   byte: command
+	 *   byte: completion code
+	 *   byte array: response data (possibly zero length)
+	 */
+	rc = sd_bus_message_new_method_call(bus, &request, destination,
+	                                    object_path, interface,
+					    method_name);
+	if (rc < 0) {
+		lprintf(LOG_ERR, "%s: failed to create message: %s\n",
+		        __func__, strerror(-rc));
+		goto out_no_free;
+	}
+	/* pack the header: netfn, lun, cmd */
+	rc = sd_bus_message_append(request, SD_BUS_TYPE_3_BYTES, req->msg.netfn,
+	                           req->msg.lun, req->msg.cmd);
+	if (rc < 0) {
+		lprintf(LOG_ERR, "%s: failed to append parameters\n", __func__);
+		goto out_free_request;
+	}
+	/* pack the variable length data */
+	rc = sd_bus_message_append_array(request, SD_BUS_TYPE_BYTE,
+	                                 req->msg.data, req->msg.data_len);
+	if (rc < 0) {
+		lprintf(LOG_ERR, "%s: failed to append body\n", __func__);
+		goto out_free_request;
+	}
+
+	/* Options are only needed for session-based channels, but
+	 * in order to fulfill the correct signature, an empty array
+	 * must be packed */
+	rc = sd_bus_message_append(request, SD_BUS_TYPE_DICT_OF_VARIANTS,
+	                           NULL, 0);
+	if (rc < 0) {
+		lprintf(LOG_ERR, "%s: failed to append options\n", __func__);
+		goto out_free_request;
+	}
+
+	rc = sd_bus_call(bus, request, 0, &error, &reply);
+	if (rc < 0) {
+		lprintf(LOG_ERR, "%s: failed to send dbus message (%s)\n",
+		        __func__, error.message);
+		goto out_free_request;
+	}
+
+	/* unpack the response; check that it has the expected types */
+	rc = sd_bus_message_enter_container(reply, SD_BUS_TYPE_STRUCT,
+	                                    SD_BUS_TYPE_IPMI_RESPONSE);
+	if (rc < 0) {
+		lprintf(LOG_ERR, "%s: failed to parse reply\n", __func__);
+		goto out_free_reply;
+	}
+	/* read the header: CC netfn lun cmd */
+	rc = sd_bus_message_read(reply, SD_BUS_TYPE_4_BYTES, &recv_netfn,
+	                         &recv_lun, &recv_cmd, &recv_cc);
+	if (rc < 0) {
+		lprintf(LOG_ERR, "%s: failed to read reply\n", __func__);
+		goto out_free_reply;
+	}
+	/* read the variable length data */
+	rc = sd_bus_message_read_array(reply, SD_BUS_TYPE_BYTE,
+	                               &data, &data_len);
+	if (rc < 0) {
+		lprintf(LOG_ERR, "%s: failed to read reply data\n", __func__);
+		goto out_free_reply;
+	}
+	rc = sd_bus_message_exit_container(reply);
+	if (rc < 0) {
+		lprintf(LOG_ERR, "%s: final unpack of message failed\n",
+		        __func__);
+		goto out_free_reply;
+	}
+
+	if (data_len > sizeof(rsp.data)) {
+		lprintf(LOG_ERR, "%s: data too long!\n", __func__);
+		goto out_free_reply;
+	}
+
+	/* At this point, all the parts are available for a response
+	 * other than unspecified error. */
+	rsp.ccode = recv_cc;
+	rsp.data_len = data_len;
+	memcpy(rsp.data, data, data_len);
+	ipmi_response = &rsp;
+
+out_free_reply:
+	/* message unref will free resources owned by the message */
+	sd_bus_message_unref(reply);
+out_free_request:
+	sd_bus_message_unref(request);
+out_no_free:
+	return ipmi_response;
+}
+
+static
+int
+ipmi_dbus_setup(struct ipmi_intf *intf)
+{
+	int rc;
+
+	rc = sd_bus_default_system(&bus);
+	if (rc < 0) {
+		lprintf(LOG_ERR, "Can't connect to session bus: %s\n",
+		        strerror(-rc));
+		return -1;
+	}
+	intf->opened = 1;
+
+	return 0;
+}
+
+static
+void
+ipmi_dbus_close(struct ipmi_intf *intf)
+{
+	if (intf->opened)
+	{
+		sd_bus_close(bus);
+	}
+	intf->opened = 0;
+}
+
+struct ipmi_intf ipmi_dbus_intf = {
+	.name = "dbus",
+	.desc = "OpenBMC D-Bus interface",
+	.setup = ipmi_dbus_setup,
+	.close = ipmi_dbus_close,
+	.sendrecv = ipmi_dbus_sendrecv,
+};
+
+

src/plugins/ipmi_intf.c

@@ -86,6 +86,9 @@ extern struct ipmi_intf ipmi_dummy_intf;
 #ifdef IPMI_INTF_USB
 extern struct ipmi_intf ipmi_usb_intf;
 #endif
+#ifdef IPMI_INTF_DBUS
+extern struct ipmi_intf ipmi_dbus_intf;
+#endif
 
 struct ipmi_intf * ipmi_intf_table[] = {
 #ifdef IPMI_INTF_OPEN
@@ -118,6 +121,9 @@ struct ipmi_intf * ipmi_intf_table[] = {
 #endif
 #ifdef IPMI_INTF_USB
 	&ipmi_usb_intf,
+#endif
+#ifdef IPMI_INTF_DBUS
+	&ipmi_dbus_intf,
 #endif
 	NULL
 };