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Diffstat (limited to 'src/libsystemd/sd-bus/bus-track.c')
-rw-r--r--src/libsystemd/sd-bus/bus-track.c314
1 files changed, 314 insertions, 0 deletions
diff --git a/src/libsystemd/sd-bus/bus-track.c b/src/libsystemd/sd-bus/bus-track.c
new file mode 100644
index 0000000000..4a5056e434
--- /dev/null
+++ b/src/libsystemd/sd-bus/bus-track.c
@@ -0,0 +1,314 @@
+/*-*- Mode: C; c-basic-offset: 8; indent-tabs-mode: nil -*-*/
+
+/***
+ This file is part of systemd.
+
+ Copyright 2013 Lennart Poettering
+
+ systemd is free software; you can redistribute it and/or modify it
+ under the terms of the GNU Lesser General Public License as published by
+ the Free Software Foundation; either version 2.1 of the License, or
+ (at your option) any later version.
+
+ systemd 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
+ Lesser General Public License for more details.
+
+ You should have received a copy of the GNU Lesser General Public License
+ along with systemd; If not, see <http://www.gnu.org/licenses/>.
+***/
+
+#include "sd-bus.h"
+#include "set.h"
+#include "bus-internal.h"
+#include "bus-track.h"
+
+struct sd_bus_track {
+ unsigned n_ref;
+ sd_bus *bus;
+ sd_bus_track_handler_t handler;
+ void *userdata;
+ Set *names;
+ LIST_FIELDS(sd_bus_track, queue);
+ Iterator iterator;
+ bool in_queue;
+ bool modified;
+};
+
+#define MATCH_PREFIX \
+ "type='signal'," \
+ "sender='org.freedesktop.DBus'," \
+ "path='/org/freedesktop/DBus'," \
+ "interface='org.freedesktop.DBus'," \
+ "member='NameOwnerChanged'," \
+ "arg0='"
+
+#define MATCH_SUFFIX \
+ "'"
+
+#define MATCH_FOR_NAME(name) \
+ ({ \
+ char *_x; \
+ size_t _l = strlen(name); \
+ _x = alloca(sizeof(MATCH_PREFIX)-1+_l+sizeof(MATCH_SUFFIX)); \
+ strcpy(stpcpy(stpcpy(_x, MATCH_PREFIX), name), MATCH_SUFFIX); \
+ _x; \
+ })
+
+static void bus_track_add_to_queue(sd_bus_track *track) {
+ assert(track);
+
+ if (track->in_queue)
+ return;
+
+ if (!track->handler)
+ return;
+
+ LIST_PREPEND(queue, track->bus->track_queue, track);
+ track->in_queue = true;
+}
+
+static void bus_track_remove_from_queue(sd_bus_track *track) {
+ assert(track);
+
+ if (!track->in_queue)
+ return;
+
+ LIST_REMOVE(queue, track->bus->track_queue, track);
+ track->in_queue = false;
+}
+
+_public_ int sd_bus_track_new(
+ sd_bus *bus,
+ sd_bus_track **track,
+ sd_bus_track_handler_t handler,
+ void *userdata) {
+
+ sd_bus_track *t;
+
+ assert_return(bus, -EINVAL);
+ assert_return(track, -EINVAL);
+
+ t = new0(sd_bus_track, 1);
+ if (!t)
+ return -ENOMEM;
+
+ t->n_ref = 1;
+ t->handler = handler;
+ t->userdata = userdata;
+ t->bus = sd_bus_ref(bus);
+
+ bus_track_add_to_queue(t);
+
+ *track = t;
+ return 0;
+}
+
+_public_ sd_bus_track* sd_bus_track_ref(sd_bus_track *track) {
+ assert_return(track, NULL);
+
+ assert(track->n_ref > 0);
+
+ track->n_ref++;
+
+ return track;
+}
+
+_public_ sd_bus_track* sd_bus_track_unref(sd_bus_track *track) {
+ const char *n;
+
+ if (!track)
+ return NULL;
+
+ assert(track->n_ref > 0);
+
+ if (track->n_ref > 1) {
+ track->n_ref --;
+ return NULL;
+ }
+
+ while ((n = set_first(track->names)))
+ sd_bus_track_remove_name(track, n);
+
+ bus_track_remove_from_queue(track);
+ set_free(track->names);
+ sd_bus_unref(track->bus);
+ free(track);
+
+ return NULL;
+}
+
+static int on_name_owner_changed(sd_bus *bus, sd_bus_message *message, void *userdata, sd_bus_error *error) {
+ sd_bus_track *track = userdata;
+ const char *name, *old, *new;
+ int r;
+
+ assert(bus);
+ assert(message);
+ assert(track);
+
+ r = sd_bus_message_read(message, "sss", &name, &old, &new);
+ if (r < 0)
+ return 0;
+
+ sd_bus_track_remove_name(track, name);
+ return 0;
+}
+
+_public_ int sd_bus_track_add_name(sd_bus_track *track, const char *name) {
+ _cleanup_free_ char *n = NULL;
+ const char *match;
+ int r;
+
+ assert_return(track, -EINVAL);
+ assert_return(service_name_is_valid(name), -EINVAL);
+
+ r = set_ensure_allocated(&track->names, string_hash_func, string_compare_func);
+ if (r < 0)
+ return r;
+
+ n = strdup(name);
+ if (!n)
+ return -ENOMEM;
+
+ r = set_put(track->names, n);
+ if (r == -EEXIST)
+ return 0;
+ if (r < 0)
+ return r;
+
+ /* First, subscribe to this name */
+ match = MATCH_FOR_NAME(name);
+ r = sd_bus_add_match(track->bus, match, on_name_owner_changed, track);
+ if (r < 0) {
+ set_remove(track->names, n);
+ return r;
+ }
+
+ /* Second, check if it is currently existing, or maybe
+ * doesn't, or maybe disappeared already. */
+ r = sd_bus_get_owner(track->bus, name, 0, NULL);
+ if (r < 0) {
+ set_remove(track->names, n);
+ sd_bus_remove_match(track->bus, match, on_name_owner_changed, track);
+ return r;
+ }
+
+ n = NULL;
+
+ bus_track_remove_from_queue(track);
+ track->modified = true;
+
+ return 1;
+}
+
+_public_ int sd_bus_track_remove_name(sd_bus_track *track, const char *name) {
+ const char *match;
+ _cleanup_free_ char *n;
+
+ assert_return(name, -EINVAL);
+
+ if (!track)
+ return 0;
+
+ n = set_remove(track->names, (char*) name);
+ if (!n)
+ return 0;
+
+ match = MATCH_FOR_NAME(n);
+ sd_bus_remove_match(track->bus, match, on_name_owner_changed, track);
+
+ if (set_isempty(track->names))
+ bus_track_add_to_queue(track);
+
+ track->modified = true;
+
+ return 1;
+}
+
+_public_ unsigned sd_bus_track_count(sd_bus_track *track) {
+ if (!track)
+ return 0;
+
+ return set_size(track->names);
+}
+
+_public_ const char* sd_bus_track_contains(sd_bus_track *track, const char *name) {
+ assert_return(track, NULL);
+ assert_return(name, NULL);
+
+ return set_get(track->names, (void*) name);
+}
+
+_public_ const char* sd_bus_track_first(sd_bus_track *track) {
+ if (!track)
+ return NULL;
+
+ track->modified = false;
+ track->iterator = NULL;
+
+ return set_iterate(track->names, &track->iterator);
+}
+
+_public_ const char* sd_bus_track_next(sd_bus_track *track) {
+ if (!track)
+ return NULL;
+
+ if (track->modified)
+ return NULL;
+
+ return set_iterate(track->names, &track->iterator);
+}
+
+_public_ int sd_bus_track_add_sender(sd_bus_track *track, sd_bus_message *m) {
+ const char *sender;
+
+ assert_return(track, -EINVAL);
+ assert_return(m, -EINVAL);
+
+ sender = sd_bus_message_get_sender(m);
+ if (!sender)
+ return -EINVAL;
+
+ return sd_bus_track_add_name(track, sender);
+}
+
+_public_ int sd_bus_track_remove_sender(sd_bus_track *track, sd_bus_message *m) {
+ const char *sender;
+
+ assert_return(track, -EINVAL);
+ assert_return(m, -EINVAL);
+
+ sender = sd_bus_message_get_sender(m);
+ if (!sender)
+ return -EINVAL;
+
+ return sd_bus_track_remove_name(track, sender);
+}
+
+_public_ sd_bus* sd_bus_track_get_bus(sd_bus_track *track) {
+ assert_return(track, NULL);
+
+ return track->bus;
+}
+
+void bus_track_dispatch(sd_bus_track *track) {
+ int r;
+
+ assert(track);
+ assert(track->in_queue);
+ assert(track->handler);
+
+ bus_track_remove_from_queue(track);
+
+ sd_bus_track_ref(track);
+
+ r = track->handler(track, track->userdata);
+ if (r < 0)
+ log_debug("Failed to process track handler: %s", strerror(-r));
+ else if (r == 0)
+ bus_track_add_to_queue(track);
+
+ sd_bus_track_unref(track);
+}
generated by cgit v1.2.3-54-g00ecf (git 2.45.2) at 2024-11-05 00:26:55 +0000