diff options
Diffstat (limited to 'src/libsystemd/src/sd-bus/bus-track.c')
-rw-r--r-- | src/libsystemd/src/sd-bus/bus-track.c | 338 |
1 files changed, 338 insertions, 0 deletions
diff --git a/src/libsystemd/src/sd-bus/bus-track.c b/src/libsystemd/src/sd-bus/bus-track.c new file mode 100644 index 0000000000..86b321bdea --- /dev/null +++ b/src/libsystemd/src/sd-bus/bus-track.c @@ -0,0 +1,338 @@ +/*** + 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 <systemd/sd-bus.h> + +#include "systemd-basic/alloc-util.h" + +#include "bus-internal.h" +#include "bus-track.h" +#include "bus-util.h" + +struct sd_bus_track { + unsigned n_ref; + sd_bus *bus; + sd_bus_track_handler_t handler; + void *userdata; + Hashmap *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(strlen(MATCH_PREFIX)+_l+strlen(MATCH_SUFFIX)+1); \ + 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); + + if (!bus->bus_client) + return -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) { + + if (!track) + return 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 = hashmap_first_key(track->names))) + sd_bus_track_remove_name(track, n); + + bus_track_remove_from_queue(track); + hashmap_free(track->names); + sd_bus_unref(track->bus); + free(track); + + return NULL; +} + +static int on_name_owner_changed(sd_bus_message *message, void *userdata, sd_bus_error *error) { + sd_bus_track *track = userdata; + const char *name, *old, *new; + int r; + + 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_(sd_bus_slot_unrefp) sd_bus_slot *slot = NULL; + _cleanup_free_ char *n = NULL; + const char *match; + int r; + + assert_return(track, -EINVAL); + assert_return(service_name_is_valid(name), -EINVAL); + + r = hashmap_ensure_allocated(&track->names, &string_hash_ops); + if (r < 0) + return r; + + n = strdup(name); + if (!n) + return -ENOMEM; + + /* First, subscribe to this name */ + match = MATCH_FOR_NAME(n); + r = sd_bus_add_match(track->bus, &slot, match, on_name_owner_changed, track); + if (r < 0) + return r; + + r = hashmap_put(track->names, n, slot); + if (r == -EEXIST) + return 0; + if (r < 0) + return r; + + /* Second, check if it is currently existing, or maybe + * doesn't, or maybe disappeared already. */ + r = sd_bus_get_name_creds(track->bus, n, 0, NULL); + if (r < 0) { + hashmap_remove(track->names, n); + return r; + } + + n = NULL; + slot = 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) { + _cleanup_(sd_bus_slot_unrefp) sd_bus_slot *slot = NULL; + _cleanup_free_ char *n = NULL; + + assert_return(name, -EINVAL); + + if (!track) + return 0; + + slot = hashmap_remove2(track->names, (char*) name, (void**) &n); + if (!slot) + return 0; + + if (hashmap_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 hashmap_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 hashmap_get(track->names, (void*) name) ? name : NULL; +} + +_public_ const char* sd_bus_track_first(sd_bus_track *track) { + const char *n = NULL; + + if (!track) + return NULL; + + track->modified = false; + track->iterator = ITERATOR_FIRST; + + hashmap_iterate(track->names, &track->iterator, NULL, (const void**) &n); + return n; +} + +_public_ const char* sd_bus_track_next(sd_bus_track *track) { + const char *n = NULL; + + if (!track) + return NULL; + + if (track->modified) + return NULL; + + hashmap_iterate(track->names, &track->iterator, NULL, (const void**) &n); + return n; +} + +_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_errno(r, "Failed to process track handler: %m"); + else if (r == 0) + bus_track_add_to_queue(track); + + sd_bus_track_unref(track); +} + +_public_ void *sd_bus_track_get_userdata(sd_bus_track *track) { + assert_return(track, NULL); + + return track->userdata; +} + +_public_ void *sd_bus_track_set_userdata(sd_bus_track *track, void *userdata) { + void *ret; + + assert_return(track, NULL); + + ret = track->userdata; + track->userdata = userdata; + + return ret; +} |