bus-match.c revision 4afd3348c7506dd1d36305b7bcb9feb8952b9d6b
/*-*- 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 "alloc-util.h"
#include "bus-internal.h"
#include "bus-match.h"
#include "bus-message.h"
#include "bus-util.h"
#include "fd-util.h"
#include "fileio.h"
#include "hexdecoct.h"
#include "string-util.h"
#include "strv.h"
/* Example:
*
* A: type=signal,sender=foo,interface=bar
* B: type=signal,sender=quux,interface=fips
* C: type=signal,sender=quux,interface=waldo
* D: type=signal,member=test
* E: sender=miau
* F: type=signal
* G: type=signal
*
* results in this tree:
*
* BUS_MATCH_ROOT
* + BUS_MATCH_MESSAGE_TYPE
* | ` BUS_MATCH_VALUE: value == signal
* | + DBUS_MATCH_SENDER
* | | + BUS_MATCH_VALUE: value == foo
* | | | ` DBUS_MATCH_INTERFACE
* | | | ` BUS_MATCH_VALUE: value == bar
* | | | ` BUS_MATCH_LEAF: A
* | | ` BUS_MATCH_VALUE: value == quux
* | | ` DBUS_MATCH_INTERFACE
* | | | BUS_MATCH_VALUE: value == fips
* | | | ` BUS_MATCH_LEAF: B
* | | ` BUS_MATCH_VALUE: value == waldo
* | | ` BUS_MATCH_LEAF: C
* | + DBUS_MATCH_MEMBER
* | | ` BUS_MATCH_VALUE: value == test
* | | ` BUS_MATCH_LEAF: D
* | + BUS_MATCH_LEAF: F
* | ` BUS_MATCH_LEAF: G
* ` BUS_MATCH_SENDER
* ` BUS_MATCH_VALUE: value == miau
* ` BUS_MATCH_LEAF: E
*/
static inline bool BUS_MATCH_IS_COMPARE(enum bus_match_node_type t) {
return t >= BUS_MATCH_SENDER && t <= BUS_MATCH_ARG_HAS_LAST;
}
static inline bool BUS_MATCH_CAN_HASH(enum bus_match_node_type t) {
return (t >= BUS_MATCH_MESSAGE_TYPE && t <= BUS_MATCH_PATH) ||
(t >= BUS_MATCH_ARG && t <= BUS_MATCH_ARG_LAST) ||
(t >= BUS_MATCH_ARG_HAS && t <= BUS_MATCH_ARG_HAS_LAST);
}
static void bus_match_node_free(struct bus_match_node *node) {
assert(node);
assert(node->parent);
assert(!node->child);
assert(node->type != BUS_MATCH_ROOT);
assert(node->type < _BUS_MATCH_NODE_TYPE_MAX);
if (node->parent->child) {
/* We are apparently linked into the parent's child
* list. Let's remove us from there. */
if (node->prev) {
assert(node->prev->next == node);
node->prev->next = node->next;
} else {
assert(node->parent->child == node);
node->parent->child = node->next;
}
if (node->next)
node->next->prev = node->prev;
}
if (node->type == BUS_MATCH_VALUE) {
/* We might be in the parent's hash table, so clean
* this up */
if (node->parent->type == BUS_MATCH_MESSAGE_TYPE)
hashmap_remove(node->parent->compare.children, UINT_TO_PTR(node->value.u8));
else if (BUS_MATCH_CAN_HASH(node->parent->type) && node->value.str)
hashmap_remove(node->parent->compare.children, node->value.str);
free(node->value.str);
}
if (BUS_MATCH_IS_COMPARE(node->type)) {
assert(hashmap_isempty(node->compare.children));
hashmap_free(node->compare.children);
}
free(node);
}
static bool bus_match_node_maybe_free(struct bus_match_node *node) {
assert(node);
if (node->type == BUS_MATCH_ROOT)
return false;
if (node->child)
return false;
if (BUS_MATCH_IS_COMPARE(node->type) && !hashmap_isempty(node->compare.children))
return true;
bus_match_node_free(node);
return true;
}
static bool value_node_test(
struct bus_match_node *node,
enum bus_match_node_type parent_type,
uint8_t value_u8,
const char *value_str,
char **value_strv,
sd_bus_message *m) {
assert(node);
assert(node->type == BUS_MATCH_VALUE);
/* Tests parameters against this value node, doing prefix
* magic and stuff. */
switch (parent_type) {
case BUS_MATCH_MESSAGE_TYPE:
return node->value.u8 == value_u8;
case BUS_MATCH_SENDER:
if (streq_ptr(node->value.str, value_str))
return true;
if (m->creds.mask & SD_BUS_CREDS_WELL_KNOWN_NAMES) {
char **i;
/* on kdbus we have the well known names list
* in the credentials, let's make use of that
* for an accurate match */
STRV_FOREACH(i, m->creds.well_known_names)
if (streq_ptr(node->value.str, *i))
return true;
} else {
/* If we don't have kdbus, we don't know the
* well-known names of the senders. In that,
* let's just hope that dbus-daemon doesn't
* send us stuff we didn't want. */
if (node->value.str[0] != ':' && value_str && value_str[0] == ':')
return true;
}
return false;
case BUS_MATCH_DESTINATION:
case BUS_MATCH_INTERFACE:
case BUS_MATCH_MEMBER:
case BUS_MATCH_PATH:
case BUS_MATCH_ARG ... BUS_MATCH_ARG_LAST:
if (value_str)
return streq_ptr(node->value.str, value_str);
return false;
case BUS_MATCH_ARG_HAS ... BUS_MATCH_ARG_HAS_LAST: {
char **i;
STRV_FOREACH(i, value_strv)
if (streq_ptr(node->value.str, *i))
return true;
return false;
}
case BUS_MATCH_ARG_NAMESPACE ... BUS_MATCH_ARG_NAMESPACE_LAST:
if (value_str)
return namespace_simple_pattern(node->value.str, value_str);
return false;
case BUS_MATCH_PATH_NAMESPACE:
return path_simple_pattern(node->value.str, value_str);
case BUS_MATCH_ARG_PATH ... BUS_MATCH_ARG_PATH_LAST:
if (value_str)
return path_complex_pattern(node->value.str, value_str);
return false;
default:
assert_not_reached("Invalid node type");
}
}
static bool value_node_same(
struct bus_match_node *node,
enum bus_match_node_type parent_type,
uint8_t value_u8,
const char *value_str) {
/* Tests parameters against this value node, not doing prefix
* magic and stuff, i.e. this one actually compares the match
* itself. */
assert(node);
assert(node->type == BUS_MATCH_VALUE);
switch (parent_type) {
case BUS_MATCH_MESSAGE_TYPE:
return node->value.u8 == value_u8;
case BUS_MATCH_SENDER:
case BUS_MATCH_DESTINATION:
case BUS_MATCH_INTERFACE:
case BUS_MATCH_MEMBER:
case BUS_MATCH_PATH:
case BUS_MATCH_ARG ... BUS_MATCH_ARG_LAST:
case BUS_MATCH_ARG_HAS ... BUS_MATCH_ARG_HAS_LAST:
case BUS_MATCH_ARG_NAMESPACE ... BUS_MATCH_ARG_NAMESPACE_LAST:
case BUS_MATCH_PATH_NAMESPACE:
case BUS_MATCH_ARG_PATH ... BUS_MATCH_ARG_PATH_LAST:
return streq(node->value.str, value_str);
default:
assert_not_reached("Invalid node type");
}
}
int bus_match_run(
sd_bus *bus,
struct bus_match_node *node,
sd_bus_message *m) {
_cleanup_strv_free_ char **test_strv = NULL;
const char *test_str = NULL;
uint8_t test_u8 = 0;
int r;
assert(m);
if (!node)
return 0;
if (bus && bus->match_callbacks_modified)
return 0;
/* Not these special semantics: when traversing the tree we
* usually let bus_match_run() when called for a node
* recursively invoke bus_match_run(). There's are two
* exceptions here though, which are BUS_NODE_ROOT (which
* cannot have a sibling), and BUS_NODE_VALUE (whose siblings
* are invoked anyway by its parent. */
switch (node->type) {
case BUS_MATCH_ROOT:
/* Run all children. Since we cannot have any siblings
* we won't call any. The children of the root node
* are compares or leaves, they will automatically
* call their siblings. */
return bus_match_run(bus, node->child, m);
case BUS_MATCH_VALUE:
/* Run all children. We don't execute any siblings, we
* assume our caller does that. The children of value
* nodes are compares or leaves, they will
* automatically call their siblings */
assert(node->child);
return bus_match_run(bus, node->child, m);
case BUS_MATCH_LEAF:
if (bus) {
if (node->leaf.callback->last_iteration == bus->iteration_counter)
return 0;
node->leaf.callback->last_iteration = bus->iteration_counter;
}
r = sd_bus_message_rewind(m, true);
if (r < 0)
return r;
/* Run the callback. And then invoke siblings. */
if (node->leaf.callback->callback) {
_cleanup_(sd_bus_error_free) sd_bus_error error_buffer = SD_BUS_ERROR_NULL;
sd_bus_slot *slot;
slot = container_of(node->leaf.callback, sd_bus_slot, match_callback);
if (bus) {
bus->current_slot = sd_bus_slot_ref(slot);
bus->current_handler = node->leaf.callback->callback;
bus->current_userdata = slot->userdata;
}
r = node->leaf.callback->callback(m, slot->userdata, &error_buffer);
if (bus) {
bus->current_userdata = NULL;
bus->current_handler = NULL;
bus->current_slot = sd_bus_slot_unref(slot);
}
r = bus_maybe_reply_error(m, r, &error_buffer);
if (r != 0)
return r;
if (bus && bus->match_callbacks_modified)
return 0;
}
return bus_match_run(bus, node->next, m);
case BUS_MATCH_MESSAGE_TYPE:
test_u8 = m->header->type;
break;
case BUS_MATCH_SENDER:
test_str = m->sender;
/* FIXME: resolve test_str from a well-known to a unique name first */
break;
case BUS_MATCH_DESTINATION:
test_str = m->destination;
break;
case BUS_MATCH_INTERFACE:
test_str = m->interface;
break;
case BUS_MATCH_MEMBER:
test_str = m->member;
break;
case BUS_MATCH_PATH:
case BUS_MATCH_PATH_NAMESPACE:
test_str = m->path;
break;
case BUS_MATCH_ARG ... BUS_MATCH_ARG_LAST:
(void) bus_message_get_arg(m, node->type - BUS_MATCH_ARG, &test_str);
break;
case BUS_MATCH_ARG_PATH ... BUS_MATCH_ARG_PATH_LAST:
(void) bus_message_get_arg(m, node->type - BUS_MATCH_ARG_PATH, &test_str);
break;
case BUS_MATCH_ARG_NAMESPACE ... BUS_MATCH_ARG_NAMESPACE_LAST:
(void) bus_message_get_arg(m, node->type - BUS_MATCH_ARG_NAMESPACE, &test_str);
break;
case BUS_MATCH_ARG_HAS ... BUS_MATCH_ARG_HAS_LAST:
(void) bus_message_get_arg_strv(m, node->type - BUS_MATCH_ARG_HAS, &test_strv);
break;
default:
assert_not_reached("Unknown match type.");
}
if (BUS_MATCH_CAN_HASH(node->type)) {
struct bus_match_node *found;
/* Lookup via hash table, nice! So let's jump directly. */
if (test_str)
found = hashmap_get(node->compare.children, test_str);
else if (test_strv) {
char **i;
STRV_FOREACH(i, test_strv) {
found = hashmap_get(node->compare.children, *i);
if (found) {
r = bus_match_run(bus, found, m);
if (r != 0)
return r;
}
}
found = NULL;
} else if (node->type == BUS_MATCH_MESSAGE_TYPE)
found = hashmap_get(node->compare.children, UINT_TO_PTR(test_u8));
else
found = NULL;
if (found) {
r = bus_match_run(bus, found, m);
if (r != 0)
return r;
}
} else {
struct bus_match_node *c;
/* No hash table, so let's iterate manually... */
for (c = node->child; c; c = c->next) {
if (!value_node_test(c, node->type, test_u8, test_str, test_strv, m))
continue;
r = bus_match_run(bus, c, m);
if (r != 0)
return r;
}
}
if (bus && bus->match_callbacks_modified)
return 0;
/* And now, let's invoke our siblings */
return bus_match_run(bus, node->next, m);
}
static int bus_match_add_compare_value(
struct bus_match_node *where,
enum bus_match_node_type t,
uint8_t value_u8,
const char *value_str,
struct bus_match_node **ret) {
struct bus_match_node *c = NULL, *n = NULL;
int r;
assert(where);
assert(where->type == BUS_MATCH_ROOT || where->type == BUS_MATCH_VALUE);
assert(BUS_MATCH_IS_COMPARE(t));
assert(ret);
for (c = where->child; c && c->type != t; c = c->next)
;
if (c) {
/* Comparison node already exists? Then let's see if
* the value node exists too. */
if (t == BUS_MATCH_MESSAGE_TYPE)
n = hashmap_get(c->compare.children, UINT_TO_PTR(value_u8));
else if (BUS_MATCH_CAN_HASH(t))
n = hashmap_get(c->compare.children, value_str);
else {
for (n = c->child; n && !value_node_same(n, t, value_u8, value_str); n = n->next)
;
}
if (n) {
*ret = n;
return 0;
}
} else {
/* Comparison node, doesn't exist yet? Then let's
* create it. */
c = new0(struct bus_match_node, 1);
if (!c) {
r = -ENOMEM;
goto fail;
}
c->type = t;
c->parent = where;
c->next = where->child;
if (c->next)
c->next->prev = c;
where->child = c;
if (t == BUS_MATCH_MESSAGE_TYPE) {
c->compare.children = hashmap_new(NULL);
if (!c->compare.children) {
r = -ENOMEM;
goto fail;
}
} else if (BUS_MATCH_CAN_HASH(t)) {
c->compare.children = hashmap_new(&string_hash_ops);
if (!c->compare.children) {
r = -ENOMEM;
goto fail;
}
}
}
n = new0(struct bus_match_node, 1);
if (!n) {
r = -ENOMEM;
goto fail;
}
n->type = BUS_MATCH_VALUE;
n->value.u8 = value_u8;
if (value_str) {
n->value.str = strdup(value_str);
if (!n->value.str) {
r = -ENOMEM;
goto fail;
}
}
n->parent = c;
if (c->compare.children) {
if (t == BUS_MATCH_MESSAGE_TYPE)
r = hashmap_put(c->compare.children, UINT_TO_PTR(value_u8), n);
else
r = hashmap_put(c->compare.children, n->value.str, n);
if (r < 0)
goto fail;
} else {
n->next = c->child;
if (n->next)
n->next->prev = n;
c->child = n;
}
*ret = n;
return 1;
fail:
if (c)
bus_match_node_maybe_free(c);
if (n) {
free(n->value.str);
free(n);
}
return r;
}
static int bus_match_find_compare_value(
struct bus_match_node *where,
enum bus_match_node_type t,
uint8_t value_u8,
const char *value_str,
struct bus_match_node **ret) {
struct bus_match_node *c, *n;
assert(where);
assert(where->type == BUS_MATCH_ROOT || where->type == BUS_MATCH_VALUE);
assert(BUS_MATCH_IS_COMPARE(t));
assert(ret);
for (c = where->child; c && c->type != t; c = c->next)
;
if (!c)
return 0;
if (t == BUS_MATCH_MESSAGE_TYPE)
n = hashmap_get(c->compare.children, UINT_TO_PTR(value_u8));
else if (BUS_MATCH_CAN_HASH(t))
n = hashmap_get(c->compare.children, value_str);
else {
for (n = c->child; n && !value_node_same(n, t, value_u8, value_str); n = n->next)
;
}
if (n) {
*ret = n;
return 1;
}
return 0;
}
static int bus_match_add_leaf(
struct bus_match_node *where,
struct match_callback *callback) {
struct bus_match_node *n;
assert(where);
assert(where->type == BUS_MATCH_ROOT || where->type == BUS_MATCH_VALUE);
assert(callback);
n = new0(struct bus_match_node, 1);
if (!n)
return -ENOMEM;
n->type = BUS_MATCH_LEAF;
n->parent = where;
n->next = where->child;
if (n->next)
n->next->prev = n;
n->leaf.callback = callback;
callback->match_node = n;
where->child = n;
return 1;
}
static int bus_match_find_leaf(
struct bus_match_node *where,
sd_bus_message_handler_t callback,
void *userdata,
struct bus_match_node **ret) {
struct bus_match_node *c;
assert(where);
assert(where->type == BUS_MATCH_ROOT || where->type == BUS_MATCH_VALUE);
assert(ret);
for (c = where->child; c; c = c->next) {
sd_bus_slot *s;
s = container_of(c->leaf.callback, sd_bus_slot, match_callback);
if (c->type == BUS_MATCH_LEAF &&
c->leaf.callback->callback == callback &&
s->userdata == userdata) {
*ret = c;
return 1;
}
}
return 0;
}
enum bus_match_node_type bus_match_node_type_from_string(const char *k, size_t n) {
assert(k);
if (n == 4 && startswith(k, "type"))
return BUS_MATCH_MESSAGE_TYPE;
if (n == 6 && startswith(k, "sender"))
return BUS_MATCH_SENDER;
if (n == 11 && startswith(k, "destination"))
return BUS_MATCH_DESTINATION;
if (n == 9 && startswith(k, "interface"))
return BUS_MATCH_INTERFACE;
if (n == 6 && startswith(k, "member"))
return BUS_MATCH_MEMBER;
if (n == 4 && startswith(k, "path"))
return BUS_MATCH_PATH;
if (n == 14 && startswith(k, "path_namespace"))
return BUS_MATCH_PATH_NAMESPACE;
if (n == 4 && startswith(k, "arg")) {
int j;
j = undecchar(k[3]);
if (j < 0)
return -EINVAL;
return BUS_MATCH_ARG + j;
}
if (n == 5 && startswith(k, "arg")) {
int a, b;
enum bus_match_node_type t;
a = undecchar(k[3]);
b = undecchar(k[4]);
if (a <= 0 || b < 0)
return -EINVAL;
t = BUS_MATCH_ARG + a * 10 + b;
if (t > BUS_MATCH_ARG_LAST)
return -EINVAL;
return t;
}
if (n == 8 && startswith(k, "arg") && startswith(k + 4, "path")) {
int j;
j = undecchar(k[3]);
if (j < 0)
return -EINVAL;
return BUS_MATCH_ARG_PATH + j;
}
if (n == 9 && startswith(k, "arg") && startswith(k + 5, "path")) {
enum bus_match_node_type t;
int a, b;
a = undecchar(k[3]);
b = undecchar(k[4]);
if (a <= 0 || b < 0)
return -EINVAL;
t = BUS_MATCH_ARG_PATH + a * 10 + b;
if (t > BUS_MATCH_ARG_PATH_LAST)
return -EINVAL;
return t;
}
if (n == 13 && startswith(k, "arg") && startswith(k + 4, "namespace")) {
int j;
j = undecchar(k[3]);
if (j < 0)
return -EINVAL;
return BUS_MATCH_ARG_NAMESPACE + j;
}
if (n == 14 && startswith(k, "arg") && startswith(k + 5, "namespace")) {
enum bus_match_node_type t;
int a, b;
a = undecchar(k[3]);
b = undecchar(k[4]);
if (a <= 0 || b < 0)
return -EINVAL;
t = BUS_MATCH_ARG_NAMESPACE + a * 10 + b;
if (t > BUS_MATCH_ARG_NAMESPACE_LAST)
return -EINVAL;
return t;
}
if (n == 7 && startswith(k, "arg") && startswith(k + 4, "has")) {
int j;
j = undecchar(k[3]);
if (j < 0)
return -EINVAL;
return BUS_MATCH_ARG_HAS + j;
}
if (n == 8 && startswith(k, "arg") && startswith(k + 5, "has")) {
enum bus_match_node_type t;
int a, b;
a = undecchar(k[3]);
b = undecchar(k[4]);
if (a <= 0 || b < 0)
return -EINVAL;
t = BUS_MATCH_ARG_HAS + a * 10 + b;
if (t > BUS_MATCH_ARG_HAS_LAST)
return -EINVAL;
return t;
}
return -EINVAL;
}
static int match_component_compare(const void *a, const void *b) {
const struct bus_match_component *x = a, *y = b;
if (x->type < y->type)
return -1;
if (x->type > y->type)
return 1;
return 0;
}
void bus_match_parse_free(struct bus_match_component *components, unsigned n_components) {
unsigned i;
for (i = 0; i < n_components; i++)
free(components[i].value_str);
free(components);
}
int bus_match_parse(
const char *match,
struct bus_match_component **_components,
unsigned *_n_components) {
const char *p = match;
struct bus_match_component *components = NULL;
size_t components_allocated = 0;
unsigned n_components = 0, i;
_cleanup_free_ char *value = NULL;
int r;
assert(match);
assert(_components);
assert(_n_components);
while (*p != 0) {
const char *eq, *q;
enum bus_match_node_type t;
unsigned j = 0;
size_t value_allocated = 0;
bool escaped = false, quoted;
uint8_t u;
/* Avahi's match rules appear to include whitespace, skip over it */
p += strspn(p, " ");
eq = strchr(p, '=');
if (!eq)
return -EINVAL;
t = bus_match_node_type_from_string(p, eq - p);
if (t < 0)
return -EINVAL;
quoted = eq[1] == '\'';
for (q = eq + 1 + quoted;; q++) {
if (*q == 0) {
if (quoted) {
r = -EINVAL;
goto fail;
} else {
if (value)
value[j] = 0;
break;
}
}
if (!escaped) {
if (*q == '\\') {
escaped = true;
continue;
}
if (quoted) {
if (*q == '\'') {
if (value)
value[j] = 0;
break;
}
} else {
if (*q == ',') {
if (value)
value[j] = 0;
break;
}
}
}
if (!GREEDY_REALLOC(value, value_allocated, j + 2)) {
r = -ENOMEM;
goto fail;
}
value[j++] = *q;
escaped = false;
}
if (!value) {
value = strdup("");
if (!value) {
r = -ENOMEM;
goto fail;
}
}
if (t == BUS_MATCH_MESSAGE_TYPE) {
r = bus_message_type_from_string(value, &u);
if (r < 0)
goto fail;
value = mfree(value);
} else
u = 0;
if (!GREEDY_REALLOC(components, components_allocated, n_components + 1)) {
r = -ENOMEM;
goto fail;
}
components[n_components].type = t;
components[n_components].value_str = value;
components[n_components].value_u8 = u;
n_components++;
value = NULL;
if (q[quoted] == 0)
break;
if (q[quoted] != ',') {
r = -EINVAL;
goto fail;
}
p = q + 1 + quoted;
}
/* Order the whole thing, so that we always generate the same tree */
qsort_safe(components, n_components, sizeof(struct bus_match_component), match_component_compare);
/* Check for duplicates */
for (i = 0; i+1 < n_components; i++)
if (components[i].type == components[i+1].type) {
r = -EINVAL;
goto fail;
}
*_components = components;
*_n_components = n_components;
return 0;
fail:
bus_match_parse_free(components, n_components);
return r;
}
char *bus_match_to_string(struct bus_match_component *components, unsigned n_components) {
_cleanup_fclose_ FILE *f = NULL;
char *buffer = NULL;
size_t size = 0;
unsigned i;
int r;
if (n_components <= 0)
return strdup("");
assert(components);
f = open_memstream(&buffer, &size);
if (!f)
return NULL;
for (i = 0; i < n_components; i++) {
char buf[32];
if (i != 0)
fputc(',', f);
fputs(bus_match_node_type_to_string(components[i].type, buf, sizeof(buf)), f);
fputc('=', f);
fputc('\'', f);
if (components[i].type == BUS_MATCH_MESSAGE_TYPE)
fputs(bus_message_type_to_string(components[i].value_u8), f);
else
fputs(components[i].value_str, f);
fputc('\'', f);
}
r = fflush_and_check(f);
if (r < 0)
return NULL;
return buffer;
}
int bus_match_add(
struct bus_match_node *root,
struct bus_match_component *components,
unsigned n_components,
struct match_callback *callback) {
unsigned i;
struct bus_match_node *n;
int r;
assert(root);
assert(callback);
n = root;
for (i = 0; i < n_components; i++) {
r = bus_match_add_compare_value(
n, components[i].type,
components[i].value_u8, components[i].value_str, &n);
if (r < 0)
return r;
}
return bus_match_add_leaf(n, callback);
}
int bus_match_remove(
struct bus_match_node *root,
struct match_callback *callback) {
struct bus_match_node *node, *pp;
assert(root);
assert(callback);
node = callback->match_node;
if (!node)
return 0;
assert(node->type == BUS_MATCH_LEAF);
callback->match_node = NULL;
/* Free the leaf */
pp = node->parent;
bus_match_node_free(node);
/* Prune the tree above */
while (pp) {
node = pp;
pp = node->parent;
if (!bus_match_node_maybe_free(node))
break;
}
return 1;
}
int bus_match_find(
struct bus_match_node *root,
struct bus_match_component *components,
unsigned n_components,
sd_bus_message_handler_t callback,
void *userdata,
struct match_callback **ret) {
struct bus_match_node *n, **gc;
unsigned i;
int r;
assert(root);
assert(ret);
gc = newa(struct bus_match_node*, n_components);
n = root;
for (i = 0; i < n_components; i++) {
r = bus_match_find_compare_value(
n, components[i].type,
components[i].value_u8, components[i].value_str,
&n);
if (r <= 0)
return r;
gc[i] = n;
}
r = bus_match_find_leaf(n, callback, userdata, &n);
if (r <= 0)
return r;
*ret = n->leaf.callback;
return 1;
}
void bus_match_free(struct bus_match_node *node) {
struct bus_match_node *c;
if (!node)
return;
if (BUS_MATCH_CAN_HASH(node->type)) {
Iterator i;
HASHMAP_FOREACH(c, node->compare.children, i)
bus_match_free(c);
assert(hashmap_isempty(node->compare.children));
}
while ((c = node->child))
bus_match_free(c);
if (node->type != BUS_MATCH_ROOT)
bus_match_node_free(node);
}
const char* bus_match_node_type_to_string(enum bus_match_node_type t, char buf[], size_t l) {
switch (t) {
case BUS_MATCH_ROOT:
return "root";
case BUS_MATCH_VALUE:
return "value";
case BUS_MATCH_LEAF:
return "leaf";
case BUS_MATCH_MESSAGE_TYPE:
return "type";
case BUS_MATCH_SENDER:
return "sender";
case BUS_MATCH_DESTINATION:
return "destination";
case BUS_MATCH_INTERFACE:
return "interface";
case BUS_MATCH_MEMBER:
return "member";
case BUS_MATCH_PATH:
return "path";
case BUS_MATCH_PATH_NAMESPACE:
return "path_namespace";
case BUS_MATCH_ARG ... BUS_MATCH_ARG_LAST:
snprintf(buf, l, "arg%i", t - BUS_MATCH_ARG);
return buf;
case BUS_MATCH_ARG_PATH ... BUS_MATCH_ARG_PATH_LAST:
snprintf(buf, l, "arg%ipath", t - BUS_MATCH_ARG_PATH);
return buf;
case BUS_MATCH_ARG_NAMESPACE ... BUS_MATCH_ARG_NAMESPACE_LAST:
snprintf(buf, l, "arg%inamespace", t - BUS_MATCH_ARG_NAMESPACE);
return buf;
case BUS_MATCH_ARG_HAS ... BUS_MATCH_ARG_HAS_LAST:
snprintf(buf, l, "arg%ihas", t - BUS_MATCH_ARG_HAS);
return buf;
default:
return NULL;
}
}
void bus_match_dump(struct bus_match_node *node, unsigned level) {
struct bus_match_node *c;
_cleanup_free_ char *pfx = NULL;
char buf[32];
if (!node)
return;
pfx = strrep(" ", level);
printf("%s[%s]", strempty(pfx), bus_match_node_type_to_string(node->type, buf, sizeof(buf)));
if (node->type == BUS_MATCH_VALUE) {
if (node->parent->type == BUS_MATCH_MESSAGE_TYPE)
printf(" <%u>\n", node->value.u8);
else
printf(" <%s>\n", node->value.str);
} else if (node->type == BUS_MATCH_ROOT)
puts(" root");
else if (node->type == BUS_MATCH_LEAF)
printf(" %p/%p\n", node->leaf.callback->callback, container_of(node->leaf.callback, sd_bus_slot, match_callback)->userdata);
else
putchar('\n');
if (BUS_MATCH_CAN_HASH(node->type)) {
Iterator i;
HASHMAP_FOREACH(c, node->compare.children, i)
bus_match_dump(c, level + 1);
}
for (c = node->child; c; c = c->next)
bus_match_dump(c, level + 1);
}
enum bus_match_scope bus_match_get_scope(const struct bus_match_component *components, unsigned n_components) {
bool found_driver = false;
unsigned i;
if (n_components <= 0)
return BUS_MATCH_GENERIC;
assert(components);
/* Checks whether the specified match can only match the
* pseudo-service for local messages, which we detect by
* sender, interface or path. If a match is not restricted to
* local messages, then we check if it only matches on the
* driver. */
for (i = 0; i < n_components; i++) {
const struct bus_match_component *c = components + i;
if (c->type == BUS_MATCH_SENDER) {
if (streq_ptr(c->value_str, "org.freedesktop.DBus.Local"))
return BUS_MATCH_LOCAL;
if (streq_ptr(c->value_str, "org.freedesktop.DBus"))
found_driver = true;
}
if (c->type == BUS_MATCH_INTERFACE && streq_ptr(c->value_str, "org.freedesktop.DBus.Local"))
return BUS_MATCH_LOCAL;
if (c->type == BUS_MATCH_PATH && streq_ptr(c->value_str, "/org/freedesktop/DBus/Local"))
return BUS_MATCH_LOCAL;
}
return found_driver ? BUS_MATCH_DRIVER : BUS_MATCH_GENERIC;
}