diff options
author | Lennart Poettering <lennart@poettering.net> | 2014-03-03 01:33:45 +0100 |
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committer | Lennart Poettering <lennart@poettering.net> | 2014-03-03 02:34:13 +0100 |
commit | 8f8f05a919355095518911135c3d630f4620a9b0 (patch) | |
tree | cb7b75f124dd743d2bcaf366a4a64125d1c34253 /src/core/dbus-client-track.c | |
parent | d9256bac4da4241cb5d97960c899390839f2c6e5 (diff) |
bus: add sd_bus_track object for tracking peers, and port core over to it
This is primarily useful for services that need to track clients which
reference certain objects they maintain, or which explicitly want to
subscribe to certain events. Something like this is done in a large
number of services, and not trivial to do. Hence, let's unify this at
one place.
This also ports over PID 1 to use this to ensure that subscriptions to
job and manager events are correctly tracked. As a side-effect this
makes sure we properly serialize and restore the track list across
daemon reexec/reload, which didn't work correctly before.
This also simplifies how we distribute messages to broadcast to the
direct busses: we only track subscriptions for the API bus and
implicitly assume that all direct busses are subscribed. This should be
a pretty OK simplification since clients connected via direct bus
connections are shortlived anyway.
Diffstat (limited to 'src/core/dbus-client-track.c')
-rw-r--r-- | src/core/dbus-client-track.c | 251 |
1 files changed, 0 insertions, 251 deletions
diff --git a/src/core/dbus-client-track.c b/src/core/dbus-client-track.c deleted file mode 100644 index 07dfea49e6..0000000000 --- a/src/core/dbus-client-track.c +++ /dev/null @@ -1,251 +0,0 @@ -/*-*- 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 "bus-util.h" -#include "dbus-client-track.h" - -static unsigned long tracked_client_hash(const void *a, const uint8_t hash_key[HASH_KEY_SIZE]) { - const BusTrackedClient *x = a; - - return string_hash_func(x->name, hash_key) ^ trivial_hash_func(x->bus, hash_key); -} - -static int tracked_client_compare(const void *a, const void *b) { - const BusTrackedClient *x = a, *y = b; - int r; - - r = strcmp(x->name, y->name); - if (r != 0) - return r; - - if (x->bus < y->bus) - return -1; - if (x->bus > y->bus) - return 1; - - return 0; -} - -static int on_name_owner_changed(sd_bus *bus, sd_bus_message *message, void *userdata, sd_bus_error *error) { - BusTrackedClient *c = userdata; - const char *name, *old, *new; - int r; - - assert(bus); - assert(message); - - r = sd_bus_message_read(message, "sss", &name, &old, &new); - if (r < 0) { - bus_log_parse_error(r); - return r; - } - - bus_client_untrack(c->set, bus, name); - return 0; -} - -static char *build_match(const char *name) { - - return strjoin("type='signal'," - "sender='org.freedesktop.DBus'," - "path='/org/freedesktop/DBus'," - "interface='org.freedesktop.DBus'," - "member='NameOwnerChanged'," - "arg0='", name, "'", NULL); -} - -int bus_client_track(Set **s, sd_bus *bus, const char *name) { - BusTrackedClient *c, *found; - size_t l; - int r; - - assert(s); - assert(bus); - - r = set_ensure_allocated(s, tracked_client_hash, tracked_client_compare); - if (r < 0) - return r; - - name = strempty(name); - - l = strlen(name); - - c = alloca(offsetof(BusTrackedClient, name) + l + 1); - c->set = *s; - c->bus = bus; - strcpy(c->name, name); - - found = set_get(*s, c); - if (found) - return 0; - - c = memdup(c, offsetof(BusTrackedClient, name) + l + 1); - if (!c) - return -ENOMEM; - - r = set_put(*s, c); - if (r < 0) { - free(c); - return r; - } - - if (!isempty(name)) { - _cleanup_free_ char *match = NULL; - - match = build_match(name); - if (!match) { - set_remove(*s, c); - free(c); - return -ENOMEM; - } - - r = sd_bus_add_match(bus, match, on_name_owner_changed, c); - if (r < 0) { - set_remove(*s, c); - free(c); - return r; - } - } - - sd_bus_ref(c->bus); - return 1; -} - -static void bus_client_free_one(Set *s, BusTrackedClient *c) { - assert(s); - assert(c); - - if (!isempty(c->name)) { - _cleanup_free_ char *match = NULL; - - match = build_match(c->name); - if (match) - sd_bus_remove_match(c->bus, match, on_name_owner_changed, c); - } - - sd_bus_unref(c->bus); - set_remove(s, c); - free(c); -} - -int bus_client_untrack(Set *s, sd_bus *bus, const char *name) { - BusTrackedClient *c, *found; - size_t l; - - assert(bus); - assert(s); - assert(name); - - name = strempty(name); - - l = strlen(name); - - c = alloca(offsetof(BusTrackedClient, name) + l + 1); - c->bus = bus; - strcpy(c->name, name); - - found = set_get(s, c); - if (!found) - return 0; - - bus_client_free_one(s, found); - return 1; -} - -void bus_client_track_free(Set *s) { - BusTrackedClient *c; - - while ((c = set_first(s))) - bus_client_free_one(s, c); - - set_free(s); -} - -int bus_client_untrack_bus(Set *s, sd_bus *bus) { - BusTrackedClient *c; - Iterator i; - int r = 0; - - SET_FOREACH(c, s, i) - if (c->bus == bus) { - bus_client_free_one(s, c); - r++; - } - - return r; -} - -void bus_client_track_serialize(Manager *m, FILE *f, Set *s) { - BusTrackedClient *c; - Iterator i; - - assert(m); - assert(f); - - SET_FOREACH(c, s, i) { - if (c->bus == m->api_bus) - fprintf(f, "subscribed=%s\n", isempty(c->name) ? "*" : c->name); - else - fprintf(f, "subscribed=%p %s\n", c->bus, isempty(c->name) ? "*" : c->name); - } -} - -int bus_client_track_deserialize_item(Manager *m, Set **s, const char *line) { - const char *e, *q, *name; - sd_bus *bus; - void *p; - int r; - - e = startswith(line, "subscribed="); - if (!e) - return 0; - - q = strpbrk(e, WHITESPACE); - if (!q) { - if (m->api_bus) { - bus = m->api_bus; - name = e; - goto finish; - } - - return 1; - } - - if (sscanf(e, "%p", &p) != 1) { - log_debug("Failed to parse subscription pointer."); - return -EINVAL; - } - - bus = set_get(m->private_buses, p); - if (!bus) - return 1; - - name = q + strspn(q, WHITESPACE); - -finish: - r = bus_client_track(s, bus, streq(name, "*") ? NULL : name); - if (r < 0) { - log_debug("Failed to deserialize client subscription: %s", strerror(-r)); - return r; - } - - return 1; -} |