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Diffstat (limited to 'src/libsystemd-bus/bus-control.c')
-rw-r--r--src/libsystemd-bus/bus-control.c219
1 files changed, 213 insertions, 6 deletions
diff --git a/src/libsystemd-bus/bus-control.c b/src/libsystemd-bus/bus-control.c
index 08c0f49360..988d4265ff 100644
--- a/src/libsystemd-bus/bus-control.c
+++ b/src/libsystemd-bus/bus-control.c
@@ -416,6 +416,183 @@ _public_ int sd_bus_get_owner(
return 0;
}
+static int add_name_change_match(sd_bus *bus,
+ uint64_t cookie,
+ const char *name,
+ const char *old_owner,
+ const char *new_owner) {
+
+ uint64_t name_id = 0, old_owner_id = 0, new_owner_id = 0;
+ int is_name_id = -1, r;
+ struct kdbus_item *item;
+
+ assert(bus);
+
+ /* If we encounter a match that could match against
+ * NameOwnerChanged messages, then we need to create
+ * KDBUS_MATCH_NAME_{ADD,REMOVE,CHANGE} and
+ * KDBUS_MATCH_ID_{ADD,REMOVE} matches for it, possibly
+ * multiple if the match is underspecified.
+ *
+ * The NameOwnerChanged signals take three parameters with
+ * unique or well-known names, but only some forms actually
+ * exist:
+ *
+ * WELLKNOWN, "", UNIQUE → KDBUS_MATCH_NAME_ADD
+ * WELLKNOWN, UNIQUE, "" → KDBUS_MATCH_NAME_REMOVE
+ * WELLKNOWN, UNIQUE, UNIQUE → KDBUS_MATCH_NAME_CHANGE
+ * UNIQUE, "", UNIQUE → KDBUS_MATCH_ID_ADD
+ * UNIQUE, UNIQUE, "" → KDBUS_MATCH_ID_REMOVE
+ *
+ * For the latter two the two unique names must be identical.
+ *
+ * */
+
+ if (name) {
+ is_name_id = bus_kernel_parse_unique_name(name, &name_id);
+ if (is_name_id < 0)
+ return 0;
+ }
+
+ if (old_owner) {
+ r = bus_kernel_parse_unique_name(old_owner, &old_owner_id);
+ if (r < 0)
+ return 0;
+ if (r == 0)
+ return 0;
+ if (is_name_id > 0 && old_owner_id != name_id)
+ return 0;
+ }
+
+ if (new_owner) {
+ r = bus_kernel_parse_unique_name(new_owner, &new_owner_id);
+ if (r < 0)
+ return r;
+ if (r == 0)
+ return 0;
+ if (is_name_id > 0 && new_owner_id != name_id)
+ return 0;
+ }
+
+ if (is_name_id <= 0) {
+ size_t sz, l;
+
+ /* If the name argument is missing or is a well-known
+ * name, then add KDBUS_MATCH_NAME_{ADD,REMOVE,CHANGE}
+ * matches for it */
+
+ l = name ? strlen(name) : 0;
+
+ sz = ALIGN8(offsetof(struct kdbus_cmd_match, items) +
+ offsetof(struct kdbus_item, name_change) +
+ offsetof(struct kdbus_notify_name_change, name) +
+ l+1);
+
+ {
+ union {
+ uint8_t buffer[sz];
+ struct kdbus_cmd_match match;
+ } m;
+
+ memzero(&m, sz);
+
+ m.match.size = sz;
+ m.match.cookie = cookie;
+ m.match.src_id = KDBUS_SRC_ID_KERNEL;
+
+ item = m.match.items;
+ item->size =
+ offsetof(struct kdbus_item, name_change) +
+ offsetof(struct kdbus_notify_name_change, name) +
+ l+1;
+
+ item->name_change.old_id = old_owner_id;
+ item->name_change.new_id = new_owner_id;
+
+ if (name)
+ strcpy(item->name_change.name, name);
+
+ /* If the old name is unset or empty, then
+ * this can match against added names */
+ if (!old_owner || old_owner[0] == 0) {
+ item->type = KDBUS_MATCH_NAME_ADD;
+
+ r = ioctl(bus->input_fd, KDBUS_CMD_MATCH_ADD, m);
+ if (r < 0)
+ return -errno;
+ }
+
+ /* If the new name is unset or empty, then
+ * this can match against removed names */
+ if (!new_owner || new_owner[0] == 0) {
+ item->type = KDBUS_MATCH_NAME_REMOVE;
+
+ r = ioctl(bus->input_fd, KDBUS_CMD_MATCH_ADD, m);
+ if (r < 0)
+ return -errno;
+ }
+
+ /* If the neither name is explicitly set to
+ * the empty string, then this can match
+ * agains changed names */
+ if (!(old_owner && old_owner[0] == 0) &&
+ !(new_owner && new_owner[0] == 0)) {
+ item->type = KDBUS_MATCH_NAME_CHANGE;
+
+ r = ioctl(bus->input_fd, KDBUS_CMD_MATCH_ADD, m);
+ if (r < 0)
+ return -errno;
+ }
+ }
+ }
+
+ if (is_name_id != 0) {
+ uint64_t sz =
+ ALIGN8(offsetof(struct kdbus_cmd_match, items) +
+ offsetof(struct kdbus_item, id_change));
+ union {
+ uint8_t buffer[sz];
+ struct kdbus_cmd_match match;
+ } m;
+
+ /* If the name argument is missing or is a unique
+ * name, then add KDBUS_MATCH_ID_{ADD,REMOVE} matches
+ * for it */
+
+ memzero(&m, sz);
+
+ m.match.size = sz;
+ m.match.cookie = cookie;
+ m.match.src_id = KDBUS_SRC_ID_KERNEL;
+
+ item = m.match.items;
+ item->size = offsetof(struct kdbus_item, id_change) + sizeof(struct kdbus_notify_id_change);
+ item->id_change.id = name_id;
+
+ /* If the old name is unset or empty, then this can
+ * match against added ids */
+ if (!old_owner || old_owner[0] == 0) {
+ item->type = KDBUS_MATCH_ID_ADD;
+
+ r = ioctl(bus->input_fd, KDBUS_CMD_MATCH_ADD, m);
+ if (r < 0)
+ return -errno;
+ }
+
+ /* If thew new name is unset or empty, then this can
+ match against removed ids */
+ if (!new_owner || new_owner[0] == 0) {
+ item->type = KDBUS_MATCH_ID_REMOVE;
+
+ r = ioctl(bus->input_fd, KDBUS_CMD_MATCH_ADD, m);
+ if (r < 0)
+ return -errno;
+ }
+ }
+
+ return 0;
+}
+
int bus_add_match_internal(
sd_bus *bus,
const char *match,
@@ -438,6 +615,8 @@ int bus_add_match_internal(
uint64_t src_id = KDBUS_MATCH_SRC_ID_ANY;
bool using_bloom = false;
unsigned i;
+ bool matches_name_change = true;
+ const char *name_change_arg[3] = {};
zero(bloom);
@@ -449,6 +628,9 @@ int bus_add_match_internal(
switch (c->type) {
case BUS_MATCH_SENDER:
+ if (!streq(c->value_str, "org.freedesktop.DBus"))
+ matches_name_change = false;
+
r = bus_kernel_parse_unique_name(c->value_str, &src_id);
if (r < 0)
return r;
@@ -462,21 +644,33 @@ int bus_add_match_internal(
break;
case BUS_MATCH_MESSAGE_TYPE:
+ if (c->value_u8 != SD_BUS_MESSAGE_SIGNAL)
+ matches_name_change = false;
+
bloom_add_pair(bloom, "message-type", bus_message_type_to_string(c->value_u8));
using_bloom = true;
break;
case BUS_MATCH_INTERFACE:
+ if (!streq(c->value_str, "org.freedesktop.DBus"))
+ matches_name_change = false;
+
bloom_add_pair(bloom, "interface", c->value_str);
using_bloom = true;
break;
case BUS_MATCH_MEMBER:
+ if (!streq(c->value_str, "NameOwnerChanged"))
+ matches_name_change = false;
+
bloom_add_pair(bloom, "member", c->value_str);
using_bloom = true;
break;
case BUS_MATCH_PATH:
+ if (!streq(c->value_str, "/org/freedesktop/DBus"))
+ matches_name_change = false;
+
bloom_add_pair(bloom, "path", c->value_str);
using_bloom = true;
break;
@@ -491,6 +685,9 @@ int bus_add_match_internal(
case BUS_MATCH_ARG...BUS_MATCH_ARG_LAST: {
char buf[sizeof("arg")-1 + 2 + 1];
+ if (c->type - BUS_MATCH_ARG < 3)
+ name_change_arg[c->type - BUS_MATCH_ARG] = c->value_str;
+
snprintf(buf, sizeof(buf), "arg%u", c->type - BUS_MATCH_ARG);
bloom_add_pair(bloom, buf, c->value_str);
using_bloom = true;
@@ -560,7 +757,20 @@ int bus_add_match_internal(
if (r < 0)
return -errno;
- } else {
+ if (matches_name_change) {
+
+ /* If this match could theoretically match
+ * NameOwnerChanged messages, we need to
+ * install a second non-bloom filter explitly
+ * for it */
+
+ r = add_name_change_match(bus, cookie, name_change_arg[0], name_change_arg[1], name_change_arg[2]);
+ if (r < 0)
+ return r;
+ }
+
+ return 0;
+ } else
return sd_bus_call_method(
bus,
"org.freedesktop.DBus",
@@ -571,9 +781,6 @@ int bus_add_match_internal(
NULL,
"s",
match);
- }
-
- return 0;
}
int bus_remove_match_internal(
@@ -597,6 +804,8 @@ int bus_remove_match_internal(
if (r < 0)
return -errno;
+ return 0;
+
} else {
return sd_bus_call_method(
bus,
@@ -609,8 +818,6 @@ int bus_remove_match_internal(
"s",
match);
}
-
- return 0;
}
_public_ int sd_bus_get_owner_machine_id(sd_bus *bus, const char *name, sd_id128_t *machine) {
generated by cgit v1.2.3-54-g00ecf (git 2.45.2) at 2024-11-07 23:37:18 +0000