daemon: Connect to dbus

Signed-off-by: Michael Tremer <michael.tremer@ipfire.org>

diff --git a/Makefile.am b/Makefile.am
index b6ba4150b130e552b9666635585dc2717ac27702..352aef3f05d5b36d876f15decff79f8216e6bc84 100644 (file)
--- a/Makefile.am
+++ b/Makefile.am
@@ -92,6 +92,8 @@ bin_PROGRAMS += \
 dist_collectyd_SOURCES = \
        src/daemon/args.c \
        src/daemon/args.h \
+       src/daemon/bus.c \
+       src/daemon/bus.h \
        src/daemon/ctx.c \
        src/daemon/ctx.h \
        src/daemon/daemon.c \

diff --git a/src/daemon/bus.c b/src/daemon/bus.c
new file mode 100644 (file)
index 0000000..223e134
--- /dev/null
+++ b/src/daemon/bus.c
@@ -0,0 +1,193 @@
+/*#############################################################################
+#                                                                             #
+# collecty - A system statistics collection daemon for IPFire                 #
+# Copyright (C) 2025 IPFire Development Team                                  #
+#                                                                             #
+# This program is free software: you can redistribute it and/or modify        #
+# it under the terms of the GNU General Public License as published by        #
+# the Free Software Foundation, either version 3 of the License, or           #
+# (at your option) any later version.                                         #
+#                                                                             #
+# This program is distributed in the hope that it will be useful,             #
+# but WITHOUT ANY WARRANTY; without even the implied warranty of              #
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the               #
+# GNU General Public License for more details.                                #
+#                                                                             #
+# You should have received a copy of the GNU General Public License           #
+# along with this program.  If not, see <http://www.gnu.org/licenses/>.       #
+#                                                                             #
+#############################################################################*/
+
+#include <errno.h>
+#include <stdlib.h>
+
+#include <systemd/sd-bus.h>
+#include <systemd/sd-event.h>
+
+#include "bus.h"
+#include "ctx.h"
+#include "daemon.h"
+#include "util.h"
+
+#define DEFAULT_SYSTEM_BUS_ADDRESS "unix:path=/run/dbus/system_bus_socket"
+
+static int collecty_bus_on_connect(sd_bus_message* m, void* data, sd_bus_error* error) {
+       collecty_ctx* ctx = data;
+
+       // Log action
+       DEBUG(ctx, "Connected to D-Bus\n");
+
+       return 0;
+}
+
+static int collecty_bus_register_implementation(collecty_ctx* ctx,
+               sd_bus* bus, const struct collecty_bus_implementation* impl, void* data) {
+       int r;
+
+       DEBUG(ctx, "Registering bus object implementation for path=%s iface=%s\n",
+               impl->path, impl->interface);
+
+       // Register vtables
+       for (const sd_bus_vtable** vtable = impl->vtables; vtable && *vtable; vtable++) {
+               r = sd_bus_add_object_vtable(bus, NULL, impl->path, impl->interface, *vtable, data);
+               if (r < 0) {
+                       ERROR(ctx, "Could not register bus path %s with interface %s: %m\n",
+                               impl->path, impl->interface);
+                       return r;
+               }
+       }
+
+       // Register fallback vtables
+       for (const struct collecty_bus_vtable_pair* p = impl->fallback_vtables; p && p->vtable; p++) {
+               r = sd_bus_add_fallback_vtable(bus, NULL, impl->path, impl->interface,
+                               p->vtable, p->object_find, data);
+               if (r < 0) {
+                       ERROR(ctx, "Could not register bus path %s with interface %s: %m\n",
+                               impl->path, impl->interface);
+                       return r;
+               }
+       }
+
+       // Register the node enumerator
+       if (impl->node_enumerator) {
+               r = sd_bus_add_node_enumerator(bus, NULL, impl->path, impl->node_enumerator, data);
+               if (r < 0) {
+                       ERROR(ctx, "Could not add the node enumerator for %s: %m\n", impl->path);
+                       return r;
+               }
+       }
+
+       // Register any child implementations
+       for (int i = 0; impl->children && impl->children[i]; i++) {
+               r = collecty_bus_register_implementation(ctx, bus, impl->children[i], data);
+               if (r)
+                       return r;
+       }
+
+       return 0;
+}
+
+int collecty_bus_connect(collecty_ctx* ctx, sd_bus** bus, sd_event* loop, collecty_daemon* daemon) {
+       const char* address = NULL;
+       sd_bus* b = NULL;
+       int r;
+
+       // Create a bus object
+       r = sd_bus_new(&b);
+       if (r < 0) {
+               ERROR(ctx, "Could not allocate a bus object: %s\n", strerror(-r));
+               goto ERROR;
+       }
+
+       // Set description
+       r = sd_bus_set_description(b, "collectyd");
+       if (r < 0) {
+               ERROR(ctx, "Could not set bus description: %s\n", strerror(-r));
+               goto ERROR;
+       }
+
+       // Fetch the bus address
+       address = secure_getenv("DBUS_SYSTEM_BUS_ADDRESS");
+       if (!address)
+               address = DEFAULT_SYSTEM_BUS_ADDRESS;
+
+       // Set bus address
+       r = sd_bus_set_address(b, address);
+       if (r < 0) {
+               ERROR(ctx, "Could not set bus address: %s\n", strerror(-r));
+               goto ERROR;
+       }
+
+       // Set bus client
+       r = sd_bus_set_bus_client(b, 1);
+       if (r < 0) {
+               ERROR(ctx, "Could not set bus client: %s\n", strerror(-r));
+               goto ERROR;
+       }
+
+       // Request some credentials for all messages
+       r = sd_bus_negotiate_creds(b, 1,
+                       SD_BUS_CREDS_UID|SD_BUS_CREDS_EUID|SD_BUS_CREDS_EFFECTIVE_CAPS);
+       if (r < 0) {
+               ERROR(ctx, "Could not negotiate creds: %s\n", strerror(-r));
+               goto ERROR;
+       }
+
+       // Automatically bind when the socket is available
+       r = sd_bus_set_watch_bind(b, 1);
+       if (r < 0) {
+               ERROR(ctx, "Could not watch socket: %s\n", strerror(-r));
+               goto ERROR;
+       }
+
+       // Emit a connected signal when we are connected
+       r = sd_bus_set_connected_signal(b, 1);
+       if (r < 0) {
+               ERROR(ctx, "Could not enable sending a connect signal: %s\n", strerror(-r));
+               goto ERROR;
+       }
+
+       // Connect to the bus
+       r = sd_bus_start(b);
+       if (r < 0) {
+               ERROR(ctx, "Could not connect to bus: %s\n", strerror(-r));
+               goto ERROR;
+       }
+
+       // Register the implementation
+       r = collecty_bus_register_implementation(ctx, b, &daemon_bus_impl, daemon);
+       if (r < 0)
+               goto ERROR;
+
+       // Request interface name
+       r = sd_bus_request_name_async(b, NULL, "org.ipfire.collecty1", 0, NULL, NULL);
+       if (r < 0) {
+               ERROR(ctx, "Could not request bus name: %s\n", strerror(-r));
+               goto ERROR;
+       }
+
+       // Attach the event loop
+       r = sd_bus_attach_event(b, loop, 0);
+       if (r < 0) {
+               ERROR(ctx, "Could not attach bus to event loop: %s\n", strerror(-r));
+               goto ERROR;
+       }
+
+       // Request receiving a connect signal
+       r = sd_bus_match_signal_async(b, NULL, "org.freedesktop.DBus.Local", NULL,
+                       "org.freedesktop.DBus.Local", "Connected", collecty_bus_on_connect, NULL, ctx);
+       if (r < 0) {
+               ERROR(ctx, "Could not request match on Connected signal: %s\n", strerror(-r));
+               goto ERROR;
+       }
+
+       // Return reference
+       *bus = b;
+       return 0;
+
+ERROR:
+       if (b)
+               sd_bus_unref(b);
+
+       return r;
+}

diff --git a/src/daemon/bus.h b/src/daemon/bus.h
new file mode 100644 (file)
index 0000000..a996099
--- /dev/null
+++ b/src/daemon/bus.h
@@ -0,0 +1,51 @@
+/*#############################################################################
+#                                                                             #
+# collecty - A system statistics collection daemon for IPFire                 #
+# Copyright (C) 2025 IPFire Development Team                                  #
+#                                                                             #
+# This program is free software: you can redistribute it and/or modify        #
+# it under the terms of the GNU General Public License as published by        #
+# the Free Software Foundation, either version 3 of the License, or           #
+# (at your option) any later version.                                         #
+#                                                                             #
+# This program is distributed in the hope that it will be useful,             #
+# but WITHOUT ANY WARRANTY; without even the implied warranty of              #
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the               #
+# GNU General Public License for more details.                                #
+#                                                                             #
+# You should have received a copy of the GNU General Public License           #
+# along with this program.  If not, see <http://www.gnu.org/licenses/>.       #
+#                                                                             #
+#############################################################################*/
+
+#ifndef COLLECTY_BUS_H
+#define COLLECTY_BUS_H
+
+#include <systemd/sd-bus.h>
+#include <systemd/sd-event.h>
+
+struct collecty_bus_vtable_pair {
+       const sd_bus_vtable* vtable;
+       sd_bus_object_find_t object_find;
+};
+
+typedef struct collecty_bus_implementation {
+       const char* path;
+       const char* interface;
+       const sd_bus_vtable** vtables;
+       const struct collecty_bus_vtable_pair* fallback_vtables;
+       sd_bus_node_enumerator_t node_enumerator;
+       const struct collecty_bus_implementation** children;
+} collecty_bus_implementation;
+
+#include "ctx.h"
+#include "daemon.h"
+
+#define BUS_FALLBACK_VTABLES(...) ((const struct collecty_bus_vtable_pair[]) { __VA_ARGS__, {} })
+#define BUS_IMPLEMENTATIONS(...) ((const collecty_bus_implementation* []) { __VA_ARGS__, NULL })
+#define BUS_VTABLES(...) ((const sd_bus_vtable* []){ __VA_ARGS__, NULL })
+
+int collecty_bus_connect(collecty_ctx* ctx,
+       sd_bus** bus, sd_event* loop, collecty_daemon* daemon);
+
+#endif /* COLLECTY_BUS_H */

diff --git a/src/daemon/daemon.c b/src/daemon/daemon.c
index f49f349b5e43fea5bec3c838c2dd1947418ee3dc..1539a998e37bd812672c650fbcce64dfbd21daac 100644 (file)
--- a/src/daemon/daemon.c
+++ b/src/daemon/daemon.c
@@ -25,6 +25,7 @@
 #include <systemd/sd-daemon.h>
 #include <systemd/sd-event.h>
 
+#include "bus.h"
 #include "ctx.h"
 #include "daemon.h"
 #include "module.h"
@@ -46,6 +47,9 @@ struct collecty_daemon {
                sd_event_source* modules_init;
        } events;
 
+       // Bus
+       sd_bus* bus;
+
        // Queue
        collecty_queue* queue;
 };
@@ -139,6 +143,8 @@ static void collecty_daemon_free(collecty_daemon* self) {
                collecty_ctx_unref(self->ctx);
        if (self->loop)
                sd_event_unref(self->loop);
+       if (self->bus)
+               sd_bus_unref(self->bus);
        free(self);
 }
 
@@ -162,6 +168,11 @@ int collecty_daemon_create(collecty_daemon** daemon, collecty_ctx* ctx) {
        if (r < 0)
                goto ERROR;
 
+       // Connect to the bus
+       r = collecty_bus_connect(self->ctx, &self->bus, self->loop, self);
+       if (r < 0)
+               goto ERROR;
+
        // Setup the write queue
        r = collecty_queue_create(&self->queue, self->ctx, self);
        if (r < 0)
@@ -227,3 +238,15 @@ int collecty_daemon_submit(collecty_daemon* self,
 
        return collecty_queue_submit(self->queue, module, object, value);
 }
+
+static const sd_bus_vtable daemon_vtable[] = {
+       SD_BUS_VTABLE_START(0),
+       // XXX TODO
+       SD_BUS_VTABLE_END,
+};
+
+const collecty_bus_implementation daemon_bus_impl = {
+       .path = "/org/ipfire/collecty1",
+       .interface = "org.ipfire.collecty1",
+       .vtables = BUS_VTABLES(daemon_vtable),
+};

diff --git a/src/daemon/daemon.h b/src/daemon/daemon.h
index 8c886458fcc1dfabc6dcc0c240bf8047371fafdc..5d965e786243eecbfe7d76d6c134ab61abc96772 100644 (file)
--- a/src/daemon/daemon.h
+++ b/src/daemon/daemon.h
@@ -25,6 +25,7 @@
 
 typedef struct collecty_daemon collecty_daemon;
 
+#include "bus.h"
 #include "ctx.h"
 #include "module.h"
 
@@ -40,4 +41,7 @@ int collecty_daemon_run(collecty_daemon* self);
 int collecty_daemon_submit(collecty_daemon* self,
                collecty_module* module, const char* object, const char* value);
 
+// Bus
+extern const collecty_bus_implementation daemon_bus_impl;
+
 #endif /* COLLECTY_DAEMON_H */