Systemd/src/libsystemd/sd-bus/bus-control.c
Lennart Poettering 532f808fd1 sd-bus: drop match cookie concept
THe match cookie was used by kdbus to identify matches we install
uniquely. But given that kdbus is gone, the cookie serves no process
anymore, let's kill it.
2017-09-29 17:57:34 +02:00

742 lines
26 KiB
C

/***
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/>.
***/
#ifdef HAVE_VALGRIND_MEMCHECK_H
#include <valgrind/memcheck.h>
#endif
#include <errno.h>
#include <stddef.h>
#include "sd-bus.h"
#include "alloc-util.h"
#include "bus-bloom.h"
#include "bus-control.h"
#include "bus-internal.h"
#include "bus-message.h"
#include "bus-util.h"
#include "capability-util.h"
#include "stdio-util.h"
#include "string-util.h"
#include "strv.h"
#include "user-util.h"
_public_ int sd_bus_get_unique_name(sd_bus *bus, const char **unique) {
int r;
assert_return(bus, -EINVAL);
assert_return(unique, -EINVAL);
assert_return(!bus_pid_changed(bus), -ECHILD);
if (!bus->bus_client)
return -EINVAL;
r = bus_ensure_running(bus);
if (r < 0)
return r;
*unique = bus->unique_name;
return 0;
}
static int bus_request_name_dbus1(sd_bus *bus, const char *name, uint64_t flags) {
_cleanup_(sd_bus_message_unrefp) sd_bus_message *reply = NULL;
uint32_t ret, param = 0;
int r;
assert(bus);
assert(name);
if (flags & SD_BUS_NAME_ALLOW_REPLACEMENT)
param |= BUS_NAME_ALLOW_REPLACEMENT;
if (flags & SD_BUS_NAME_REPLACE_EXISTING)
param |= BUS_NAME_REPLACE_EXISTING;
if (!(flags & SD_BUS_NAME_QUEUE))
param |= BUS_NAME_DO_NOT_QUEUE;
r = sd_bus_call_method(
bus,
"org.freedesktop.DBus",
"/org/freedesktop/DBus",
"org.freedesktop.DBus",
"RequestName",
NULL,
&reply,
"su",
name,
param);
if (r < 0)
return r;
r = sd_bus_message_read(reply, "u", &ret);
if (r < 0)
return r;
if (ret == BUS_NAME_ALREADY_OWNER)
return -EALREADY;
else if (ret == BUS_NAME_EXISTS)
return -EEXIST;
else if (ret == BUS_NAME_IN_QUEUE)
return 0;
else if (ret == BUS_NAME_PRIMARY_OWNER)
return 1;
return -EIO;
}
_public_ int sd_bus_request_name(sd_bus *bus, const char *name, uint64_t flags) {
assert_return(bus, -EINVAL);
assert_return(name, -EINVAL);
assert_return(!bus_pid_changed(bus), -ECHILD);
assert_return(!(flags & ~(SD_BUS_NAME_ALLOW_REPLACEMENT|SD_BUS_NAME_REPLACE_EXISTING|SD_BUS_NAME_QUEUE)), -EINVAL);
assert_return(service_name_is_valid(name), -EINVAL);
assert_return(name[0] != ':', -EINVAL);
if (!bus->bus_client)
return -EINVAL;
/* Don't allow requesting the special driver and local names */
if (STR_IN_SET(name, "org.freedesktop.DBus", "org.freedesktop.DBus.Local"))
return -EINVAL;
if (!BUS_IS_OPEN(bus->state))
return -ENOTCONN;
return bus_request_name_dbus1(bus, name, flags);
}
static int bus_release_name_dbus1(sd_bus *bus, const char *name) {
_cleanup_(sd_bus_message_unrefp) sd_bus_message *reply = NULL;
uint32_t ret;
int r;
assert(bus);
assert(name);
r = sd_bus_call_method(
bus,
"org.freedesktop.DBus",
"/org/freedesktop/DBus",
"org.freedesktop.DBus",
"ReleaseName",
NULL,
&reply,
"s",
name);
if (r < 0)
return r;
r = sd_bus_message_read(reply, "u", &ret);
if (r < 0)
return r;
if (ret == BUS_NAME_NON_EXISTENT)
return -ESRCH;
if (ret == BUS_NAME_NOT_OWNER)
return -EADDRINUSE;
if (ret == BUS_NAME_RELEASED)
return 0;
return -EINVAL;
}
_public_ int sd_bus_release_name(sd_bus *bus, const char *name) {
assert_return(bus, -EINVAL);
assert_return(name, -EINVAL);
assert_return(!bus_pid_changed(bus), -ECHILD);
assert_return(service_name_is_valid(name), -EINVAL);
assert_return(name[0] != ':', -EINVAL);
if (!bus->bus_client)
return -EINVAL;
/* Don't allow releasing the special driver and local names */
if (STR_IN_SET(name, "org.freedesktop.DBus", "org.freedesktop.DBus.Local"))
return -EINVAL;
if (!BUS_IS_OPEN(bus->state))
return -ENOTCONN;
return bus_release_name_dbus1(bus, name);
}
static int bus_list_names_dbus1(sd_bus *bus, char ***acquired, char ***activatable) {
_cleanup_(sd_bus_message_unrefp) sd_bus_message *reply = NULL;
_cleanup_strv_free_ char **x = NULL, **y = NULL;
int r;
if (acquired) {
r = sd_bus_call_method(
bus,
"org.freedesktop.DBus",
"/org/freedesktop/DBus",
"org.freedesktop.DBus",
"ListNames",
NULL,
&reply,
NULL);
if (r < 0)
return r;
r = sd_bus_message_read_strv(reply, &x);
if (r < 0)
return r;
reply = sd_bus_message_unref(reply);
}
if (activatable) {
r = sd_bus_call_method(
bus,
"org.freedesktop.DBus",
"/org/freedesktop/DBus",
"org.freedesktop.DBus",
"ListActivatableNames",
NULL,
&reply,
NULL);
if (r < 0)
return r;
r = sd_bus_message_read_strv(reply, &y);
if (r < 0)
return r;
*activatable = y;
y = NULL;
}
if (acquired) {
*acquired = x;
x = NULL;
}
return 0;
}
_public_ int sd_bus_list_names(sd_bus *bus, char ***acquired, char ***activatable) {
assert_return(bus, -EINVAL);
assert_return(acquired || activatable, -EINVAL);
assert_return(!bus_pid_changed(bus), -ECHILD);
if (!bus->bus_client)
return -EINVAL;
if (!BUS_IS_OPEN(bus->state))
return -ENOTCONN;
return bus_list_names_dbus1(bus, acquired, activatable);
}
static int bus_get_name_creds_dbus1(
sd_bus *bus,
const char *name,
uint64_t mask,
sd_bus_creds **creds) {
_cleanup_(sd_bus_message_unrefp) sd_bus_message *reply_unique = NULL, *reply = NULL;
_cleanup_(sd_bus_creds_unrefp) sd_bus_creds *c = NULL;
const char *unique = NULL;
pid_t pid = 0;
int r;
/* Only query the owner if the caller wants to know it or if
* the caller just wants to check whether a name exists */
if ((mask & SD_BUS_CREDS_UNIQUE_NAME) || mask == 0) {
r = sd_bus_call_method(
bus,
"org.freedesktop.DBus",
"/org/freedesktop/DBus",
"org.freedesktop.DBus",
"GetNameOwner",
NULL,
&reply_unique,
"s",
name);
if (r < 0)
return r;
r = sd_bus_message_read(reply_unique, "s", &unique);
if (r < 0)
return r;
}
if (mask != 0) {
_cleanup_(sd_bus_error_free) sd_bus_error error = SD_BUS_ERROR_NULL;
bool need_pid, need_uid, need_selinux, need_separate_calls;
c = bus_creds_new();
if (!c)
return -ENOMEM;
if ((mask & SD_BUS_CREDS_UNIQUE_NAME) && unique) {
c->unique_name = strdup(unique);
if (!c->unique_name)
return -ENOMEM;
c->mask |= SD_BUS_CREDS_UNIQUE_NAME;
}
need_pid = (mask & SD_BUS_CREDS_PID) ||
((mask & SD_BUS_CREDS_AUGMENT) &&
(mask & (SD_BUS_CREDS_UID|SD_BUS_CREDS_SUID|SD_BUS_CREDS_FSUID|
SD_BUS_CREDS_GID|SD_BUS_CREDS_EGID|SD_BUS_CREDS_SGID|SD_BUS_CREDS_FSGID|
SD_BUS_CREDS_SUPPLEMENTARY_GIDS|
SD_BUS_CREDS_COMM|SD_BUS_CREDS_EXE|SD_BUS_CREDS_CMDLINE|
SD_BUS_CREDS_CGROUP|SD_BUS_CREDS_UNIT|SD_BUS_CREDS_USER_UNIT|SD_BUS_CREDS_SLICE|SD_BUS_CREDS_SESSION|SD_BUS_CREDS_OWNER_UID|
SD_BUS_CREDS_EFFECTIVE_CAPS|SD_BUS_CREDS_PERMITTED_CAPS|SD_BUS_CREDS_INHERITABLE_CAPS|SD_BUS_CREDS_BOUNDING_CAPS|
SD_BUS_CREDS_SELINUX_CONTEXT|
SD_BUS_CREDS_AUDIT_SESSION_ID|SD_BUS_CREDS_AUDIT_LOGIN_UID)));
need_uid = mask & SD_BUS_CREDS_EUID;
need_selinux = mask & SD_BUS_CREDS_SELINUX_CONTEXT;
if (need_pid + need_uid + need_selinux > 1) {
/* If we need more than one of the credentials, then use GetConnectionCredentials() */
r = sd_bus_call_method(
bus,
"org.freedesktop.DBus",
"/org/freedesktop/DBus",
"org.freedesktop.DBus",
"GetConnectionCredentials",
&error,
&reply,
"s",
unique ?: name);
if (r < 0) {
if (!sd_bus_error_has_name(&error, SD_BUS_ERROR_UNKNOWN_METHOD))
return r;
/* If we got an unknown method error, fall back to the invidual calls... */
need_separate_calls = true;
sd_bus_error_free(&error);
} else {
need_separate_calls = false;
r = sd_bus_message_enter_container(reply, 'a', "{sv}");
if (r < 0)
return r;
for (;;) {
const char *m;
r = sd_bus_message_enter_container(reply, 'e', "sv");
if (r < 0)
return r;
if (r == 0)
break;
r = sd_bus_message_read(reply, "s", &m);
if (r < 0)
return r;
if (need_uid && streq(m, "UnixUserID")) {
uint32_t u;
r = sd_bus_message_read(reply, "v", "u", &u);
if (r < 0)
return r;
c->euid = u;
c->mask |= SD_BUS_CREDS_EUID;
} else if (need_pid && streq(m, "ProcessID")) {
uint32_t p;
r = sd_bus_message_read(reply, "v", "u", &p);
if (r < 0)
return r;
pid = p;
if (mask & SD_BUS_CREDS_PID) {
c->pid = p;
c->mask |= SD_BUS_CREDS_PID;
}
} else if (need_selinux && streq(m, "LinuxSecurityLabel")) {
const void *p = NULL;
size_t sz = 0;
r = sd_bus_message_enter_container(reply, 'v', "ay");
if (r < 0)
return r;
r = sd_bus_message_read_array(reply, 'y', &p, &sz);
if (r < 0)
return r;
free(c->label);
c->label = strndup(p, sz);
if (!c->label)
return -ENOMEM;
c->mask |= SD_BUS_CREDS_SELINUX_CONTEXT;
r = sd_bus_message_exit_container(reply);
if (r < 0)
return r;
} else {
r = sd_bus_message_skip(reply, "v");
if (r < 0)
return r;
}
r = sd_bus_message_exit_container(reply);
if (r < 0)
return r;
}
r = sd_bus_message_exit_container(reply);
if (r < 0)
return r;
if (need_pid && pid == 0)
return -EPROTO;
}
} else /* When we only need a single field, then let's use separate calls */
need_separate_calls = true;
if (need_separate_calls) {
if (need_pid) {
uint32_t u;
r = sd_bus_call_method(
bus,
"org.freedesktop.DBus",
"/org/freedesktop/DBus",
"org.freedesktop.DBus",
"GetConnectionUnixProcessID",
NULL,
&reply,
"s",
unique ?: name);
if (r < 0)
return r;
r = sd_bus_message_read(reply, "u", &u);
if (r < 0)
return r;
pid = u;
if (mask & SD_BUS_CREDS_PID) {
c->pid = u;
c->mask |= SD_BUS_CREDS_PID;
}
reply = sd_bus_message_unref(reply);
}
if (need_uid) {
uint32_t u;
r = sd_bus_call_method(
bus,
"org.freedesktop.DBus",
"/org/freedesktop/DBus",
"org.freedesktop.DBus",
"GetConnectionUnixUser",
NULL,
&reply,
"s",
unique ? unique : name);
if (r < 0)
return r;
r = sd_bus_message_read(reply, "u", &u);
if (r < 0)
return r;
c->euid = u;
c->mask |= SD_BUS_CREDS_EUID;
reply = sd_bus_message_unref(reply);
}
if (need_selinux) {
const void *p = NULL;
size_t sz = 0;
r = sd_bus_call_method(
bus,
"org.freedesktop.DBus",
"/org/freedesktop/DBus",
"org.freedesktop.DBus",
"GetConnectionSELinuxSecurityContext",
&error,
&reply,
"s",
unique ? unique : name);
if (r < 0) {
if (!sd_bus_error_has_name(&error, "org.freedesktop.DBus.Error.SELinuxSecurityContextUnknown"))
return r;
/* no data is fine */
} else {
r = sd_bus_message_read_array(reply, 'y', &p, &sz);
if (r < 0)
return r;
c->label = strndup(p, sz);
if (!c->label)
return -ENOMEM;
c->mask |= SD_BUS_CREDS_SELINUX_CONTEXT;
}
}
}
r = bus_creds_add_more(c, mask, pid, 0);
if (r < 0)
return r;
}
if (creds) {
*creds = c;
c = NULL;
}
return 0;
}
_public_ int sd_bus_get_name_creds(
sd_bus *bus,
const char *name,
uint64_t mask,
sd_bus_creds **creds) {
assert_return(bus, -EINVAL);
assert_return(name, -EINVAL);
assert_return((mask & ~SD_BUS_CREDS_AUGMENT) <= _SD_BUS_CREDS_ALL, -EOPNOTSUPP);
assert_return(mask == 0 || creds, -EINVAL);
assert_return(!bus_pid_changed(bus), -ECHILD);
assert_return(service_name_is_valid(name), -EINVAL);
if (!bus->bus_client)
return -EINVAL;
/* Turn off augmenting if this isn't a local connection. If the connection is not local, then /proc is not
* going to match. */
if (!bus->is_local)
mask &= ~SD_BUS_CREDS_AUGMENT;
if (streq(name, "org.freedesktop.DBus.Local"))
return -EINVAL;
if (streq(name, "org.freedesktop.DBus"))
return sd_bus_get_owner_creds(bus, mask, creds);
if (!BUS_IS_OPEN(bus->state))
return -ENOTCONN;
return bus_get_name_creds_dbus1(bus, name, mask, creds);
}
static int bus_get_owner_creds_dbus1(sd_bus *bus, uint64_t mask, sd_bus_creds **ret) {
_cleanup_(sd_bus_creds_unrefp) sd_bus_creds *c = NULL;
pid_t pid = 0;
bool do_label;
int r;
assert(bus);
do_label = bus->label && (mask & SD_BUS_CREDS_SELINUX_CONTEXT);
/* Avoid allocating anything if we have no chance of returning useful data */
if (!bus->ucred_valid && !do_label)
return -ENODATA;
c = bus_creds_new();
if (!c)
return -ENOMEM;
if (bus->ucred_valid) {
if (bus->ucred.pid > 0) {
pid = c->pid = bus->ucred.pid;
c->mask |= SD_BUS_CREDS_PID & mask;
}
if (bus->ucred.uid != UID_INVALID) {
c->euid = bus->ucred.uid;
c->mask |= SD_BUS_CREDS_EUID & mask;
}
if (bus->ucred.gid != GID_INVALID) {
c->egid = bus->ucred.gid;
c->mask |= SD_BUS_CREDS_EGID & mask;
}
}
if (do_label) {
c->label = strdup(bus->label);
if (!c->label)
return -ENOMEM;
c->mask |= SD_BUS_CREDS_SELINUX_CONTEXT;
}
r = bus_creds_add_more(c, mask, pid, 0);
if (r < 0)
return r;
*ret = c;
c = NULL;
return 0;
}
_public_ int sd_bus_get_owner_creds(sd_bus *bus, uint64_t mask, sd_bus_creds **ret) {
assert_return(bus, -EINVAL);
assert_return((mask & ~SD_BUS_CREDS_AUGMENT) <= _SD_BUS_CREDS_ALL, -EOPNOTSUPP);
assert_return(ret, -EINVAL);
assert_return(!bus_pid_changed(bus), -ECHILD);
if (!BUS_IS_OPEN(bus->state))
return -ENOTCONN;
if (!bus->is_local)
mask &= ~SD_BUS_CREDS_AUGMENT;
return bus_get_owner_creds_dbus1(bus, mask, ret);
}
#define internal_match(bus, m) \
((bus)->hello_flags & KDBUS_HELLO_MONITOR \
? (isempty(m) ? "eavesdrop='true'" : strjoina((m), ",eavesdrop='true'")) \
: (m))
static int bus_add_match_internal_dbus1(
sd_bus *bus,
const char *match) {
const char *e;
assert(bus);
assert(match);
e = internal_match(bus, match);
return sd_bus_call_method(
bus,
"org.freedesktop.DBus",
"/org/freedesktop/DBus",
"org.freedesktop.DBus",
"AddMatch",
NULL,
NULL,
"s",
e);
}
int bus_add_match_internal(
sd_bus *bus,
const char *match,
struct bus_match_component *components,
unsigned n_components) {
assert(bus);
if (!bus->bus_client)
return -EINVAL;
return bus_add_match_internal_dbus1(bus, match);
}
static int bus_remove_match_internal_dbus1(
sd_bus *bus,
const char *match) {
const char *e;
assert(bus);
assert(match);
e = internal_match(bus, match);
return sd_bus_call_method(
bus,
"org.freedesktop.DBus",
"/org/freedesktop/DBus",
"org.freedesktop.DBus",
"RemoveMatch",
NULL,
NULL,
"s",
e);
}
int bus_remove_match_internal(
sd_bus *bus,
const char *match) {
assert(bus);
if (!bus->bus_client)
return -EINVAL;
return bus_remove_match_internal_dbus1(bus, match);
}
_public_ int sd_bus_get_name_machine_id(sd_bus *bus, const char *name, sd_id128_t *machine) {
_cleanup_(sd_bus_message_unrefp) sd_bus_message *reply = NULL, *m = NULL;
const char *mid;
int r;
assert_return(bus, -EINVAL);
assert_return(name, -EINVAL);
assert_return(machine, -EINVAL);
assert_return(!bus_pid_changed(bus), -ECHILD);
assert_return(service_name_is_valid(name), -EINVAL);
if (!bus->bus_client)
return -EINVAL;
if (!BUS_IS_OPEN(bus->state))
return -ENOTCONN;
if (streq_ptr(name, bus->unique_name))
return sd_id128_get_machine(machine);
r = sd_bus_message_new_method_call(
bus,
&m,
name,
"/",
"org.freedesktop.DBus.Peer",
"GetMachineId");
if (r < 0)
return r;
r = sd_bus_message_set_auto_start(m, false);
if (r < 0)
return r;
r = sd_bus_call(bus, m, 0, NULL, &reply);
if (r < 0)
return r;
r = sd_bus_message_read(reply, "s", &mid);
if (r < 0)
return r;
return sd_id128_from_string(mid, machine);
}