Add dbus-announce plugin

The plugin announces start and end of transactions

docs/man/Makefile.am

@@ -23,6 +23,7 @@ man_man8_DATA += rpm-plugin-audit.8
 endif
 if DBUS
 man_man8_DATA += rpm-plugin-systemd-inhibit.8
+man_man8_DATA += rpm-plugin-dbus-announce.8
 endif
 if IMA
 man_man8_DATA += rpm-plugin-ima.8
@@ -42,7 +43,7 @@ endif
 EXTRA_DIST += rpm-plugins.8.md rpm-plugin-prioreset.8.md rpm-plugin-syslog.8.md
 EXTRA_DIST += rpm-plugin-audit.8.md rpm-plugin-systemd-inhibit.8.md
 EXTRA_DIST += rpm-plugin-ima.8.md rpm-plugin-selinux.8.md rpm2archive.8.md
-EXTRA_DIST += rpm-plugin-fapolicyd.8.md
+EXTRA_DIST += rpm-plugin-fapolicyd.8.md rpm-plugin-dbus-announce.8.md
 
 
 man_fr_man8dir = $(mandir)/fr/man8

docs/man/rpm-plugin-dbus-announce.8.md

@@ -0,0 +1,38 @@
+---
+date: 03 Jun 2020
+section: 8
+title: 'RPM-DBUS-ANNOUNCE'
+---
+
+NAME
+====
+
+rpm-plugin-dbus-announce - DBus plugin for the RPM Package Manager
+
+Description
+===========
+
+The plugin writes basic information about rpm transactions to the system
+dbus - like packages installed or removed. Other programs can subscribe
+to the signals to be notified of the packages on the system change.
+
+DBus Signals
+============
+
+Sends **StartTransaction** and **EndTransaction** messages from the
+**/org/rpm/Transaction** object with the **org.rpm.Transaction**
+interface.
+
+The signal passes the DB cookie as a string and the transaction id as an
+unsigned 32 bit integer.
+
+Configuration
+=============
+
+There are currently no options for this plugin in particular. See
+**rpm-plugins**(8) on how to control plugins in general.
+
+SEE ALSO
+========
+
+*dbus-monitor*(1) *rpm-plugins*(8)

macros.in

@@ -1144,6 +1144,7 @@ package or when debugging this package.\
 %__transaction_fsverity		%{__plugindir}/fsverity.so
 %__transaction_prioreset	%{__plugindir}/prioreset.so
 %__transaction_audit		%{__plugindir}/audit.so
+%__transaction_dbus_announce	%{__plugindir}/dbus_announce.so
 
 #------------------------------------------------------------------------------
 # Macros for further automated spec %setup and patch application

plugins/Makefile.am

@@ -27,6 +27,15 @@ systemd_inhibit_la_SOURCES = systemd_inhibit.c
 systemd_inhibit_la_CPPFLAGS = $(AM_CPPFLAGS) @DBUS_CFLAGS@
 systemd_inhibit_la_LIBADD = $(top_builddir)/lib/librpm.la $(top_builddir)/rpmio/librpmio.la @DBUS_LIBS@
 plugins_LTLIBRARIES += systemd_inhibit.la
+
+dbus_announce_la_SOURCES = dbus_announce.c
+dbus_announce_la_CPPFLAGS = $(AM_CPPFLAGS) @DBUS_CFLAGS@
+dbus_announce_la_LIBADD = $(top_builddir)/lib/librpm.la $(top_builddir)/rpmio/librpmio.la @DBUS_LIBS@
+plugins_LTLIBRARIES += dbus_announce.la
+
+dbus_confdir=$(sysconfdir)/dbus-1/system.d/
+dbus_conf_DATA = org.rpm.conf
+EXTRA_DIST = org.rpm.conf
 endif
 
 prioreset_la_SOURCES = prioreset.c

plugins/dbus_announce.c

@@ -0,0 +1,142 @@
+#include "system.h"
+
+#include <dbus/dbus.h>
+#include <rpm/rpmlog.h>
+#include <rpm/rpmts.h>
+#include <rpm/rpmdb.h>
+#include "lib/rpmplugin.h"
+
+struct dbus_announce_data {
+    DBusConnection * bus;
+};
+
+static rpmRC dbus_announce_init(rpmPlugin plugin, rpmts ts)
+{
+    struct dbus_announce_data * state = rcalloc(1, sizeof(*state));
+    rpmPluginSetData(plugin, state);
+    return RPMRC_OK;
+}
+
+static void dbus_announce_close_bus(struct dbus_announce_data * state)
+{
+    if (state->bus) {
+	dbus_connection_close(state->bus);
+	dbus_connection_unref(state->bus);
+	state->bus = NULL;
+    }
+}
+
+static rpmRC open_dbus(rpmPlugin plugin, rpmts ts)
+{
+    DBusError err;
+    int rc = 0;
+    struct dbus_announce_data * state = rpmPluginGetData(plugin);
+
+    /* Already open */
+    if (state->bus)
+	return RPMRC_OK;
+
+    /* ...don't notify on test transactions */
+    if (rpmtsFlags(ts) & (RPMTRANS_FLAG_TEST|RPMTRANS_FLAG_BUILD_PROBS))
+	return RPMRC_OK;
+
+    /* ...don't notify on chroot transactions */
+    if (!rstreq(rpmtsRootDir(ts), "/"))
+	return RPMRC_OK;
+
+    dbus_error_init(&err);
+
+    state->bus = dbus_bus_get_private(DBUS_BUS_SYSTEM, &err);
+    if (dbus_error_is_set(&err))
+	goto err;
+
+    if (state->bus)
+	rc = dbus_bus_request_name(state->bus, "org.rpm.announce",
+				   DBUS_NAME_FLAG_REPLACE_EXISTING , &err);
+
+    if (dbus_error_is_set(&err))
+	goto err;
+
+    if (DBUS_REQUEST_NAME_REPLY_PRIMARY_OWNER != rc) {
+	dbus_announce_close_bus(state);
+	goto err;
+    }
+    return RPMRC_OK;
+ err:
+    rpmlog(RPMLOG_WARNING,
+	   "dbus_announce plugin: Error connecting to dbus (%s)\n",
+	   err.message);
+    dbus_error_free(&err);
+    return RPMRC_OK;
+}
+
+static void dbus_announce_cleanup(rpmPlugin plugin)
+{
+    struct dbus_announce_data * state = rpmPluginGetData(plugin);
+    dbus_announce_close_bus(state);
+    free(state);
+}
+
+static rpmRC send_ts_message(rpmPlugin plugin,
+			     const char * name,
+			     rpmts ts,
+			     int res)
+{
+    struct dbus_announce_data * state = rpmPluginGetData(plugin);
+    DBusMessage* msg;
+    char * dbcookie = NULL;
+
+    if (!state->bus)
+	return RPMRC_OK;
+
+    msg = dbus_message_new_signal("/org/rpm/Transaction", /* object name */
+				  "org.rpm.Transaction",  /* interface name */
+				  name);                  /* signal name */
+    if (msg == NULL)
+	goto err;
+
+    dbcookie = rpmdbCookie(rpmtsGetRdb(ts));
+    rpm_tid_t tid = rpmtsGetTid(ts);
+    if (!dbus_message_append_args(msg,
+				  DBUS_TYPE_STRING, &dbcookie,
+				  DBUS_TYPE_UINT32, &tid,
+				  DBUS_TYPE_INVALID))
+	goto err;
+
+    if (!dbus_connection_send(state->bus, msg, NULL))
+	goto err;
+
+    dbus_connection_flush(state->bus);
+    dbcookie = _free(dbcookie);
+
+    return RPMRC_OK;
+
+ err:
+    rpmlog(RPMLOG_WARNING,
+	   "dbus_announce plugin: Error sending message (%s)\n",
+	   name);
+    dbcookie = _free(dbcookie);
+    return RPMRC_OK;
+}
+
+static rpmRC dbus_announce_tsm_pre(rpmPlugin plugin, rpmts ts)
+{
+    int rc;
+
+    rc = open_dbus(plugin, ts);
+    if (rc != RPMRC_OK)
+	return rc;
+    return send_ts_message(plugin, "StartTransaction", ts, RPMRC_OK);
+}
+
+static rpmRC dbus_announce_tsm_post(rpmPlugin plugin, rpmts ts, int res)
+{
+    return send_ts_message(plugin, "EndTransaction", ts, res);
+}
+
+struct rpmPluginHooks_s dbus_announce_hooks = {
+    .init = dbus_announce_init,
+    .cleanup = dbus_announce_cleanup,
+    .tsm_pre = dbus_announce_tsm_pre,
+    .tsm_post = dbus_announce_tsm_post,
+};

plugins/org.rpm.conf

@@ -0,0 +1,10 @@
+<!DOCTYPE busconfig PUBLIC
+          "-//freedesktop//DTD D-BUS Bus Configuration 1.0//EN"
+          "http://www.freedesktop.org/standards/dbus/1.0/busconfig.dtd">
+<busconfig>
+
+<policy user="root">
+  <allow own="org.rpm.announce"/>
+</policy>
+
+</busconfig>