/*-*- 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 .
***/
#include
#include
#include
#include
#include
#include
#include
#include
#include
#include "util.h"
#include "macro.h"
#include "strv.h"
#include "set.h"
#include "missing.h"
#include "sd-bus.h"
#include "bus-internal.h"
#include "bus-message.h"
#include "bus-type.h"
#include "bus-socket.h"
#include "bus-kernel.h"
#include "bus-control.h"
#include "bus-introspect.h"
#include "bus-signature.h"
#include "bus-objects.h"
static int bus_poll(sd_bus *bus, bool need_more, uint64_t timeout_usec);
static void bus_close_fds(sd_bus *b) {
assert(b);
if (b->input_fd >= 0)
close_nointr_nofail(b->input_fd);
if (b->output_fd >= 0 && b->output_fd != b->input_fd)
close_nointr_nofail(b->output_fd);
b->input_fd = b->output_fd = -1;
}
static void bus_node_destroy(sd_bus *b, struct node *n) {
struct node_callback *c;
struct node_vtable *v;
struct node_enumerator *e;
assert(b);
if (!n)
return;
while (n->child)
bus_node_destroy(b, n->child);
while ((c = n->callbacks)) {
LIST_REMOVE(callbacks, n->callbacks, c);
free(c);
}
while ((v = n->vtables)) {
LIST_REMOVE(vtables, n->vtables, v);
free(v->interface);
free(v);
}
while ((e = n->enumerators)) {
LIST_REMOVE(enumerators, n->enumerators, e);
free(e);
}
if (n->parent)
LIST_REMOVE(siblings, n->parent->child, n);
assert_se(hashmap_remove(b->nodes, n->path) == n);
free(n->path);
free(n);
}
static void bus_free(sd_bus *b) {
struct filter_callback *f;
struct node *n;
unsigned i;
assert(b);
bus_close_fds(b);
if (b->kdbus_buffer)
munmap(b->kdbus_buffer, KDBUS_POOL_SIZE);
free(b->rbuffer);
free(b->unique_name);
free(b->auth_buffer);
free(b->address);
free(b->kernel);
free(b->exec_path);
strv_free(b->exec_argv);
close_many(b->fds, b->n_fds);
free(b->fds);
for (i = 0; i < b->rqueue_size; i++)
sd_bus_message_unref(b->rqueue[i]);
free(b->rqueue);
for (i = 0; i < b->wqueue_size; i++)
sd_bus_message_unref(b->wqueue[i]);
free(b->wqueue);
hashmap_free_free(b->reply_callbacks);
prioq_free(b->reply_callbacks_prioq);
while ((f = b->filter_callbacks)) {
LIST_REMOVE(callbacks, b->filter_callbacks, f);
free(f);
}
bus_match_free(&b->match_callbacks);
hashmap_free_free(b->vtable_methods);
hashmap_free_free(b->vtable_properties);
while ((n = hashmap_first(b->nodes)))
bus_node_destroy(b, n);
hashmap_free(b->nodes);
bus_kernel_flush_memfd(b);
assert_se(pthread_mutex_destroy(&b->memfd_cache_mutex) == 0);
free(b);
}
int sd_bus_new(sd_bus **ret) {
sd_bus *r;
if (!ret)
return -EINVAL;
r = new0(sd_bus, 1);
if (!r)
return -ENOMEM;
r->n_ref = REFCNT_INIT;
r->input_fd = r->output_fd = -1;
r->message_version = 1;
r->hello_flags |= KDBUS_HELLO_ACCEPT_FD;
r->original_pid = getpid();
assert_se(pthread_mutex_init(&r->memfd_cache_mutex, NULL) == 0);
/* We guarantee that wqueue always has space for at least one
* entry */
r->wqueue = new(sd_bus_message*, 1);
if (!r->wqueue) {
free(r);
return -ENOMEM;
}
*ret = r;
return 0;
}
int sd_bus_set_address(sd_bus *bus, const char *address) {
char *a;
if (!bus)
return -EINVAL;
if (bus->state != BUS_UNSET)
return -EPERM;
if (!address)
return -EINVAL;
if (bus_pid_changed(bus))
return -ECHILD;
a = strdup(address);
if (!a)
return -ENOMEM;
free(bus->address);
bus->address = a;
return 0;
}
int sd_bus_set_fd(sd_bus *bus, int input_fd, int output_fd) {
if (!bus)
return -EINVAL;
if (bus->state != BUS_UNSET)
return -EPERM;
if (input_fd < 0)
return -EINVAL;
if (output_fd < 0)
return -EINVAL;
if (bus_pid_changed(bus))
return -ECHILD;
bus->input_fd = input_fd;
bus->output_fd = output_fd;
return 0;
}
int sd_bus_set_exec(sd_bus *bus, const char *path, char *const argv[]) {
char *p, **a;
if (!bus)
return -EINVAL;
if (bus->state != BUS_UNSET)
return -EPERM;
if (!path)
return -EINVAL;
if (strv_isempty(argv))
return -EINVAL;
if (bus_pid_changed(bus))
return -ECHILD;
p = strdup(path);
if (!p)
return -ENOMEM;
a = strv_copy(argv);
if (!a) {
free(p);
return -ENOMEM;
}
free(bus->exec_path);
strv_free(bus->exec_argv);
bus->exec_path = p;
bus->exec_argv = a;
return 0;
}
int sd_bus_set_bus_client(sd_bus *bus, int b) {
if (!bus)
return -EINVAL;
if (bus->state != BUS_UNSET)
return -EPERM;
if (bus_pid_changed(bus))
return -ECHILD;
bus->bus_client = !!b;
return 0;
}
int sd_bus_negotiate_fds(sd_bus *bus, int b) {
if (!bus)
return -EINVAL;
if (bus->state != BUS_UNSET)
return -EPERM;
if (bus_pid_changed(bus))
return -ECHILD;
SET_FLAG(bus->hello_flags, KDBUS_HELLO_ACCEPT_FD, b);
return 0;
}
int sd_bus_negotiate_attach_comm(sd_bus *bus, int b) {
if (!bus)
return -EINVAL;
if (bus->state != BUS_UNSET)
return -EPERM;
if (bus_pid_changed(bus))
return -ECHILD;
SET_FLAG(bus->hello_flags, KDBUS_HELLO_ATTACH_COMM, b);
return 0;
}
int sd_bus_negotiate_attach_exe(sd_bus *bus, int b) {
if (!bus)
return -EINVAL;
if (bus->state != BUS_UNSET)
return -EPERM;
if (bus_pid_changed(bus))
return -ECHILD;
SET_FLAG(bus->hello_flags, KDBUS_HELLO_ATTACH_EXE, b);
return 0;
}
int sd_bus_negotiate_attach_cmdline(sd_bus *bus, int b) {
if (!bus)
return -EINVAL;
if (bus->state != BUS_UNSET)
return -EPERM;
if (bus_pid_changed(bus))
return -ECHILD;
SET_FLAG(bus->hello_flags, KDBUS_HELLO_ATTACH_CMDLINE, b);
return 0;
}
int sd_bus_negotiate_attach_cgroup(sd_bus *bus, int b) {
if (!bus)
return -EINVAL;
if (bus->state != BUS_UNSET)
return -EPERM;
if (bus_pid_changed(bus))
return -ECHILD;
SET_FLAG(bus->hello_flags, KDBUS_HELLO_ATTACH_CGROUP, b);
return 0;
}
int sd_bus_negotiate_attach_caps(sd_bus *bus, int b) {
if (!bus)
return -EINVAL;
if (bus->state != BUS_UNSET)
return -EPERM;
if (bus_pid_changed(bus))
return -ECHILD;
SET_FLAG(bus->hello_flags, KDBUS_HELLO_ATTACH_CAPS, b);
return 0;
}
int sd_bus_negotiate_attach_selinux_context(sd_bus *bus, int b) {
if (!bus)
return -EINVAL;
if (bus->state != BUS_UNSET)
return -EPERM;
if (bus_pid_changed(bus))
return -ECHILD;
SET_FLAG(bus->hello_flags, KDBUS_HELLO_ATTACH_SECLABEL, b);
return 0;
}
int sd_bus_negotiate_attach_audit(sd_bus *bus, int b) {
if (!bus)
return -EINVAL;
if (bus->state != BUS_UNSET)
return -EPERM;
if (bus_pid_changed(bus))
return -ECHILD;
SET_FLAG(bus->hello_flags, KDBUS_HELLO_ATTACH_AUDIT, b);
return 0;
}
int sd_bus_set_server(sd_bus *bus, int b, sd_id128_t server_id) {
if (!bus)
return -EINVAL;
if (!b && !sd_id128_equal(server_id, SD_ID128_NULL))
return -EINVAL;
if (bus->state != BUS_UNSET)
return -EPERM;
if (bus_pid_changed(bus))
return -ECHILD;
bus->is_server = !!b;
bus->server_id = server_id;
return 0;
}
int sd_bus_set_anonymous(sd_bus *bus, int b) {
if (!bus)
return -EINVAL;
if (bus->state != BUS_UNSET)
return -EPERM;
if (bus_pid_changed(bus))
return -ECHILD;
bus->anonymous_auth = !!b;
return 0;
}
static int hello_callback(sd_bus *bus, sd_bus_message *reply, void *userdata) {
const char *s;
int r;
assert(bus);
assert(bus->state == BUS_HELLO);
assert(reply);
r = bus_message_to_errno(reply);
if (r < 0)
return r;
r = sd_bus_message_read(reply, "s", &s);
if (r < 0)
return r;
if (!service_name_is_valid(s) || s[0] != ':')
return -EBADMSG;
bus->unique_name = strdup(s);
if (!bus->unique_name)
return -ENOMEM;
bus->state = BUS_RUNNING;
return 1;
}
static int bus_send_hello(sd_bus *bus) {
_cleanup_bus_message_unref_ sd_bus_message *m = NULL;
int r;
assert(bus);
if (!bus->bus_client || bus->is_kernel)
return 0;
r = sd_bus_message_new_method_call(
bus,
"org.freedesktop.DBus",
"/",
"org.freedesktop.DBus",
"Hello",
&m);
if (r < 0)
return r;
return sd_bus_send_with_reply(bus, m, hello_callback, NULL, 0, &bus->hello_serial);
}
int bus_start_running(sd_bus *bus) {
assert(bus);
if (bus->bus_client && !bus->is_kernel) {
bus->state = BUS_HELLO;
return 1;
}
bus->state = BUS_RUNNING;
return 1;
}
static int parse_address_key(const char **p, const char *key, char **value) {
size_t l, n = 0;
const char *a;
char *r = NULL;
assert(p);
assert(*p);
assert(value);
if (key) {
l = strlen(key);
if (strncmp(*p, key, l) != 0)
return 0;
if ((*p)[l] != '=')
return 0;
if (*value)
return -EINVAL;
a = *p + l + 1;
} else
a = *p;
while (*a != ';' && *a != ',' && *a != 0) {
char c, *t;
if (*a == '%') {
int x, y;
x = unhexchar(a[1]);
if (x < 0) {
free(r);
return x;
}
y = unhexchar(a[2]);
if (y < 0) {
free(r);
return y;
}
c = (char) ((x << 4) | y);
a += 3;
} else {
c = *a;
a++;
}
t = realloc(r, n + 2);
if (!t) {
free(r);
return -ENOMEM;
}
r = t;
r[n++] = c;
}
if (!r) {
r = strdup("");
if (!r)
return -ENOMEM;
} else
r[n] = 0;
if (*a == ',')
a++;
*p = a;
free(*value);
*value = r;
return 1;
}
static void skip_address_key(const char **p) {
assert(p);
assert(*p);
*p += strcspn(*p, ",");
if (**p == ',')
(*p) ++;
}
static int parse_unix_address(sd_bus *b, const char **p, char **guid) {
_cleanup_free_ char *path = NULL, *abstract = NULL;
size_t l;
int r;
assert(b);
assert(p);
assert(*p);
assert(guid);
while (**p != 0 && **p != ';') {
r = parse_address_key(p, "guid", guid);
if (r < 0)
return r;
else if (r > 0)
continue;
r = parse_address_key(p, "path", &path);
if (r < 0)
return r;
else if (r > 0)
continue;
r = parse_address_key(p, "abstract", &abstract);
if (r < 0)
return r;
else if (r > 0)
continue;
skip_address_key(p);
}
if (!path && !abstract)
return -EINVAL;
if (path && abstract)
return -EINVAL;
if (path) {
l = strlen(path);
if (l > sizeof(b->sockaddr.un.sun_path))
return -E2BIG;
b->sockaddr.un.sun_family = AF_UNIX;
strncpy(b->sockaddr.un.sun_path, path, sizeof(b->sockaddr.un.sun_path));
b->sockaddr_size = offsetof(struct sockaddr_un, sun_path) + l;
} else if (abstract) {
l = strlen(abstract);
if (l > sizeof(b->sockaddr.un.sun_path) - 1)
return -E2BIG;
b->sockaddr.un.sun_family = AF_UNIX;
b->sockaddr.un.sun_path[0] = 0;
strncpy(b->sockaddr.un.sun_path+1, abstract, sizeof(b->sockaddr.un.sun_path)-1);
b->sockaddr_size = offsetof(struct sockaddr_un, sun_path) + 1 + l;
}
return 0;
}
static int parse_tcp_address(sd_bus *b, const char **p, char **guid) {
_cleanup_free_ char *host = NULL, *port = NULL, *family = NULL;
int r;
struct addrinfo *result, hints = {
.ai_socktype = SOCK_STREAM,
.ai_flags = AI_ADDRCONFIG,
};
assert(b);
assert(p);
assert(*p);
assert(guid);
while (**p != 0 && **p != ';') {
r = parse_address_key(p, "guid", guid);
if (r < 0)
return r;
else if (r > 0)
continue;
r = parse_address_key(p, "host", &host);
if (r < 0)
return r;
else if (r > 0)
continue;
r = parse_address_key(p, "port", &port);
if (r < 0)
return r;
else if (r > 0)
continue;
r = parse_address_key(p, "family", &family);
if (r < 0)
return r;
else if (r > 0)
continue;
skip_address_key(p);
}
if (!host || !port)
return -EINVAL;
if (family) {
if (streq(family, "ipv4"))
hints.ai_family = AF_INET;
else if (streq(family, "ipv6"))
hints.ai_family = AF_INET6;
else
return -EINVAL;
}
r = getaddrinfo(host, port, &hints, &result);
if (r == EAI_SYSTEM)
return -errno;
else if (r != 0)
return -EADDRNOTAVAIL;
memcpy(&b->sockaddr, result->ai_addr, result->ai_addrlen);
b->sockaddr_size = result->ai_addrlen;
freeaddrinfo(result);
return 0;
}
static int parse_exec_address(sd_bus *b, const char **p, char **guid) {
char *path = NULL;
unsigned n_argv = 0, j;
char **argv = NULL;
int r;
assert(b);
assert(p);
assert(*p);
assert(guid);
while (**p != 0 && **p != ';') {
r = parse_address_key(p, "guid", guid);
if (r < 0)
goto fail;
else if (r > 0)
continue;
r = parse_address_key(p, "path", &path);
if (r < 0)
goto fail;
else if (r > 0)
continue;
if (startswith(*p, "argv")) {
unsigned ul;
errno = 0;
ul = strtoul(*p + 4, (char**) p, 10);
if (errno > 0 || **p != '=' || ul > 256) {
r = -EINVAL;
goto fail;
}
(*p) ++;
if (ul >= n_argv) {
char **x;
x = realloc(argv, sizeof(char*) * (ul + 2));
if (!x) {
r = -ENOMEM;
goto fail;
}
memset(x + n_argv, 0, sizeof(char*) * (ul - n_argv + 2));
argv = x;
n_argv = ul + 1;
}
r = parse_address_key(p, NULL, argv + ul);
if (r < 0)
goto fail;
continue;
}
skip_address_key(p);
}
if (!path) {
r = -EINVAL;
goto fail;
}
/* Make sure there are no holes in the array, with the
* exception of argv[0] */
for (j = 1; j < n_argv; j++)
if (!argv[j]) {
r = -EINVAL;
goto fail;
}
if (argv && argv[0] == NULL) {
argv[0] = strdup(path);
if (!argv[0]) {
r = -ENOMEM;
goto fail;
}
}
b->exec_path = path;
b->exec_argv = argv;
return 0;
fail:
for (j = 0; j < n_argv; j++)
free(argv[j]);
free(argv);
free(path);
return r;
}
static int parse_kernel_address(sd_bus *b, const char **p, char **guid) {
_cleanup_free_ char *path = NULL;
int r;
assert(b);
assert(p);
assert(*p);
assert(guid);
while (**p != 0 && **p != ';') {
r = parse_address_key(p, "guid", guid);
if (r < 0)
return r;
else if (r > 0)
continue;
r = parse_address_key(p, "path", &path);
if (r < 0)
return r;
else if (r > 0)
continue;
skip_address_key(p);
}
if (!path)
return -EINVAL;
free(b->kernel);
b->kernel = path;
path = NULL;
return 0;
}
static void bus_reset_parsed_address(sd_bus *b) {
assert(b);
zero(b->sockaddr);
b->sockaddr_size = 0;
strv_free(b->exec_argv);
free(b->exec_path);
b->exec_path = NULL;
b->exec_argv = NULL;
b->server_id = SD_ID128_NULL;
free(b->kernel);
b->kernel = NULL;
}
static int bus_parse_next_address(sd_bus *b) {
_cleanup_free_ char *guid = NULL;
const char *a;
int r;
assert(b);
if (!b->address)
return 0;
if (b->address[b->address_index] == 0)
return 0;
bus_reset_parsed_address(b);
a = b->address + b->address_index;
while (*a != 0) {
if (*a == ';') {
a++;
continue;
}
if (startswith(a, "unix:")) {
a += 5;
r = parse_unix_address(b, &a, &guid);
if (r < 0)
return r;
break;
} else if (startswith(a, "tcp:")) {
a += 4;
r = parse_tcp_address(b, &a, &guid);
if (r < 0)
return r;
break;
} else if (startswith(a, "unixexec:")) {
a += 9;
r = parse_exec_address(b, &a, &guid);
if (r < 0)
return r;
break;
} else if (startswith(a, "kernel:")) {
a += 7;
r = parse_kernel_address(b, &a, &guid);
if (r < 0)
return r;
break;
}
a = strchr(a, ';');
if (!a)
return 0;
}
if (guid) {
r = sd_id128_from_string(guid, &b->server_id);
if (r < 0)
return r;
}
b->address_index = a - b->address;
return 1;
}
static int bus_start_address(sd_bus *b) {
int r;
assert(b);
for (;;) {
sd_bus_close(b);
if (b->sockaddr.sa.sa_family != AF_UNSPEC) {
r = bus_socket_connect(b);
if (r >= 0)
return r;
b->last_connect_error = -r;
} else if (b->exec_path) {
r = bus_socket_exec(b);
if (r >= 0)
return r;
b->last_connect_error = -r;
} else if (b->kernel) {
r = bus_kernel_connect(b);
if (r >= 0)
return r;
b->last_connect_error = -r;
}
r = bus_parse_next_address(b);
if (r < 0)
return r;
if (r == 0)
return b->last_connect_error ? -b->last_connect_error : -ECONNREFUSED;
}
}
int bus_next_address(sd_bus *b) {
assert(b);
bus_reset_parsed_address(b);
return bus_start_address(b);
}
static int bus_start_fd(sd_bus *b) {
struct stat st;
int r;
assert(b);
assert(b->input_fd >= 0);
assert(b->output_fd >= 0);
r = fd_nonblock(b->input_fd, true);
if (r < 0)
return r;
r = fd_cloexec(b->input_fd, true);
if (r < 0)
return r;
if (b->input_fd != b->output_fd) {
r = fd_nonblock(b->output_fd, true);
if (r < 0)
return r;
r = fd_cloexec(b->output_fd, true);
if (r < 0)
return r;
}
if (fstat(b->input_fd, &st) < 0)
return -errno;
if (S_ISCHR(b->input_fd))
return bus_kernel_take_fd(b);
else
return bus_socket_take_fd(b);
}
int sd_bus_start(sd_bus *bus) {
int r;
if (!bus)
return -EINVAL;
if (bus->state != BUS_UNSET)
return -EPERM;
if (bus_pid_changed(bus))
return -ECHILD;
bus->state = BUS_OPENING;
if (bus->is_server && bus->bus_client)
return -EINVAL;
if (bus->input_fd >= 0)
r = bus_start_fd(bus);
else if (bus->address || bus->sockaddr.sa.sa_family != AF_UNSPEC || bus->exec_path || bus->kernel)
r = bus_start_address(bus);
else
return -EINVAL;
if (r < 0)
return r;
return bus_send_hello(bus);
}
int sd_bus_open_system(sd_bus **ret) {
const char *e;
sd_bus *b;
int r;
if (!ret)
return -EINVAL;
r = sd_bus_new(&b);
if (r < 0)
return r;
e = secure_getenv("DBUS_SYSTEM_BUS_ADDRESS");
if (e) {
r = sd_bus_set_address(b, e);
if (r < 0)
goto fail;
} else {
b->sockaddr.un.sun_family = AF_UNIX;
strncpy(b->sockaddr.un.sun_path, "/run/dbus/system_bus_socket", sizeof(b->sockaddr.un.sun_path));
b->sockaddr_size = offsetof(struct sockaddr_un, sun_path) + sizeof("/run/dbus/system_bus_socket") - 1;
}
b->bus_client = true;
r = sd_bus_start(b);
if (r < 0)
goto fail;
*ret = b;
return 0;
fail:
bus_free(b);
return r;
}
int sd_bus_open_user(sd_bus **ret) {
const char *e;
sd_bus *b;
size_t l;
int r;
if (!ret)
return -EINVAL;
r = sd_bus_new(&b);
if (r < 0)
return r;
e = secure_getenv("DBUS_SESSION_BUS_ADDRESS");
if (e) {
r = sd_bus_set_address(b, e);
if (r < 0)
goto fail;
} else {
e = secure_getenv("XDG_RUNTIME_DIR");
if (!e) {
r = -ENOENT;
goto fail;
}
l = strlen(e);
if (l + 4 > sizeof(b->sockaddr.un.sun_path)) {
r = -E2BIG;
goto fail;
}
b->sockaddr.un.sun_family = AF_UNIX;
memcpy(mempcpy(b->sockaddr.un.sun_path, e, l), "/bus", 4);
b->sockaddr_size = offsetof(struct sockaddr_un, sun_path) + l + 4;
}
b->bus_client = true;
r = sd_bus_start(b);
if (r < 0)
goto fail;
*ret = b;
return 0;
fail:
bus_free(b);
return r;
}
void sd_bus_close(sd_bus *bus) {
if (!bus)
return;
if (bus->state == BUS_CLOSED)
return;
if (bus_pid_changed(bus))
return;
bus->state = BUS_CLOSED;
if (!bus->is_kernel)
bus_close_fds(bus);
/* We'll leave the fd open in case this is a kernel bus, since
* there might still be memblocks around that reference this
* bus, and they might need to invoke the
* KDBUS_CMD_MSG_RELEASE ioctl on the fd when they are
* freed. */
}
sd_bus *sd_bus_ref(sd_bus *bus) {
if (!bus)
return NULL;
assert_se(REFCNT_INC(bus->n_ref) >= 2);
return bus;
}
sd_bus *sd_bus_unref(sd_bus *bus) {
if (!bus)
return NULL;
if (REFCNT_DEC(bus->n_ref) <= 0)
bus_free(bus);
return NULL;
}
int sd_bus_is_open(sd_bus *bus) {
if (!bus)
return -EINVAL;
if (bus_pid_changed(bus))
return -ECHILD;
return BUS_IS_OPEN(bus->state);
}
int sd_bus_can_send(sd_bus *bus, char type) {
int r;
if (!bus)
return -EINVAL;
if (bus->state == BUS_UNSET)
return -ENOTCONN;
if (bus_pid_changed(bus))
return -ECHILD;
if (type == SD_BUS_TYPE_UNIX_FD) {
if (!(bus->hello_flags & KDBUS_HELLO_ACCEPT_FD))
return 0;
r = bus_ensure_running(bus);
if (r < 0)
return r;
return bus->can_fds;
}
return bus_type_is_valid(type);
}
int sd_bus_get_server_id(sd_bus *bus, sd_id128_t *server_id) {
int r;
if (!bus)
return -EINVAL;
if (!server_id)
return -EINVAL;
if (bus_pid_changed(bus))
return -ECHILD;
r = bus_ensure_running(bus);
if (r < 0)
return r;
*server_id = bus->server_id;
return 0;
}
static int bus_seal_message(sd_bus *b, sd_bus_message *m) {
assert(m);
if (m->header->version > b->message_version)
return -EPERM;
if (m->sealed)
return 0;
return bus_message_seal(m, ++b->serial);
}
static int dispatch_wqueue(sd_bus *bus) {
int r, ret = 0;
assert(bus);
assert(bus->state == BUS_RUNNING || bus->state == BUS_HELLO);
while (bus->wqueue_size > 0) {
if (bus->is_kernel)
r = bus_kernel_write_message(bus, bus->wqueue[0]);
else
r = bus_socket_write_message(bus, bus->wqueue[0], &bus->windex);
if (r < 0) {
sd_bus_close(bus);
return r;
} else if (r == 0)
/* Didn't do anything this time */
return ret;
else if (bus->is_kernel || bus->windex >= BUS_MESSAGE_SIZE(bus->wqueue[0])) {
/* Fully written. Let's drop the entry from
* the queue.
*
* This isn't particularly optimized, but
* well, this is supposed to be our worst-case
* buffer only, and the socket buffer is
* supposed to be our primary buffer, and if
* it got full, then all bets are off
* anyway. */
sd_bus_message_unref(bus->wqueue[0]);
bus->wqueue_size --;
memmove(bus->wqueue, bus->wqueue + 1, sizeof(sd_bus_message*) * bus->wqueue_size);
bus->windex = 0;
ret = 1;
}
}
return ret;
}
static int dispatch_rqueue(sd_bus *bus, sd_bus_message **m) {
sd_bus_message *z = NULL;
int r, ret = 0;
assert(bus);
assert(m);
assert(bus->state == BUS_RUNNING || bus->state == BUS_HELLO);
if (bus->rqueue_size > 0) {
/* Dispatch a queued message */
*m = bus->rqueue[0];
bus->rqueue_size --;
memmove(bus->rqueue, bus->rqueue + 1, sizeof(sd_bus_message*) * bus->rqueue_size);
return 1;
}
/* Try to read a new message */
do {
if (bus->is_kernel)
r = bus_kernel_read_message(bus, &z);
else
r = bus_socket_read_message(bus, &z);
if (r < 0) {
sd_bus_close(bus);
return r;
}
if (r == 0)
return ret;
ret = 1;
} while (!z);
*m = z;
return ret;
}
int sd_bus_send(sd_bus *bus, sd_bus_message *m, uint64_t *serial) {
int r;
if (!bus)
return -EINVAL;
if (!BUS_IS_OPEN(bus->state))
return -ENOTCONN;
if (!m)
return -EINVAL;
if (bus_pid_changed(bus))
return -ECHILD;
if (m->n_fds > 0) {
r = sd_bus_can_send(bus, SD_BUS_TYPE_UNIX_FD);
if (r < 0)
return r;
if (r == 0)
return -ENOTSUP;
}
/* If the serial number isn't kept, then we know that no reply
* is expected */
if (!serial && !m->sealed)
m->header->flags |= SD_BUS_MESSAGE_NO_REPLY_EXPECTED;
r = bus_seal_message(bus, m);
if (r < 0)
return r;
/* If this is a reply and no reply was requested, then let's
* suppress this, if we can */
if (m->dont_send && !serial)
return 0;
if ((bus->state == BUS_RUNNING || bus->state == BUS_HELLO) && bus->wqueue_size <= 0) {
size_t idx = 0;
if (bus->is_kernel)
r = bus_kernel_write_message(bus, m);
else
r = bus_socket_write_message(bus, m, &idx);
if (r < 0) {
sd_bus_close(bus);
return r;
} else if (!bus->is_kernel && idx < BUS_MESSAGE_SIZE(m)) {
/* Wasn't fully written. So let's remember how
* much was written. Note that the first entry
* of the wqueue array is always allocated so
* that we always can remember how much was
* written. */
bus->wqueue[0] = sd_bus_message_ref(m);
bus->wqueue_size = 1;
bus->windex = idx;
}
} else {
sd_bus_message **q;
/* Just append it to the queue. */
if (bus->wqueue_size >= BUS_WQUEUE_MAX)
return -ENOBUFS;
q = realloc(bus->wqueue, sizeof(sd_bus_message*) * (bus->wqueue_size + 1));
if (!q)
return -ENOMEM;
bus->wqueue = q;
q[bus->wqueue_size ++] = sd_bus_message_ref(m);
}
if (serial)
*serial = BUS_MESSAGE_SERIAL(m);
return 0;
}
static usec_t calc_elapse(uint64_t usec) {
if (usec == (uint64_t) -1)
return 0;
if (usec == 0)
usec = BUS_DEFAULT_TIMEOUT;
return now(CLOCK_MONOTONIC) + usec;
}
static int timeout_compare(const void *a, const void *b) {
const struct reply_callback *x = a, *y = b;
if (x->timeout != 0 && y->timeout == 0)
return -1;
if (x->timeout == 0 && y->timeout != 0)
return 1;
if (x->timeout < y->timeout)
return -1;
if (x->timeout > y->timeout)
return 1;
return 0;
}
int sd_bus_send_with_reply(
sd_bus *bus,
sd_bus_message *m,
sd_bus_message_handler_t callback,
void *userdata,
uint64_t usec,
uint64_t *serial) {
struct reply_callback *c;
int r;
if (!bus)
return -EINVAL;
if (!BUS_IS_OPEN(bus->state))
return -ENOTCONN;
if (!m)
return -EINVAL;
if (!callback)
return -EINVAL;
if (m->header->type != SD_BUS_MESSAGE_TYPE_METHOD_CALL)
return -EINVAL;
if (m->header->flags & SD_BUS_MESSAGE_NO_REPLY_EXPECTED)
return -EINVAL;
if (bus_pid_changed(bus))
return -ECHILD;
r = hashmap_ensure_allocated(&bus->reply_callbacks, uint64_hash_func, uint64_compare_func);
if (r < 0)
return r;
if (usec != (uint64_t) -1) {
r = prioq_ensure_allocated(&bus->reply_callbacks_prioq, timeout_compare);
if (r < 0)
return r;
}
r = bus_seal_message(bus, m);
if (r < 0)
return r;
c = new0(struct reply_callback, 1);
if (!c)
return -ENOMEM;
c->callback = callback;
c->userdata = userdata;
c->serial = BUS_MESSAGE_SERIAL(m);
c->timeout = calc_elapse(usec);
r = hashmap_put(bus->reply_callbacks, &c->serial, c);
if (r < 0) {
free(c);
return r;
}
if (c->timeout != 0) {
r = prioq_put(bus->reply_callbacks_prioq, c, &c->prioq_idx);
if (r < 0) {
c->timeout = 0;
sd_bus_send_with_reply_cancel(bus, c->serial);
return r;
}
}
r = sd_bus_send(bus, m, serial);
if (r < 0) {
sd_bus_send_with_reply_cancel(bus, c->serial);
return r;
}
return r;
}
int sd_bus_send_with_reply_cancel(sd_bus *bus, uint64_t serial) {
struct reply_callback *c;
if (!bus)
return -EINVAL;
if (serial == 0)
return -EINVAL;
if (bus_pid_changed(bus))
return -ECHILD;
c = hashmap_remove(bus->reply_callbacks, &serial);
if (!c)
return 0;
if (c->timeout != 0)
prioq_remove(bus->reply_callbacks_prioq, c, &c->prioq_idx);
free(c);
return 1;
}
int bus_ensure_running(sd_bus *bus) {
int r;
assert(bus);
if (bus->state == BUS_UNSET || bus->state == BUS_CLOSED)
return -ENOTCONN;
if (bus->state == BUS_RUNNING)
return 1;
for (;;) {
r = sd_bus_process(bus, NULL);
if (r < 0)
return r;
if (bus->state == BUS_RUNNING)
return 1;
if (r > 0)
continue;
r = sd_bus_wait(bus, (uint64_t) -1);
if (r < 0)
return r;
}
}
int sd_bus_send_with_reply_and_block(
sd_bus *bus,
sd_bus_message *m,
uint64_t usec,
sd_bus_error *error,
sd_bus_message **reply) {
int r;
usec_t timeout;
uint64_t serial;
bool room = false;
if (!bus)
return -EINVAL;
if (!BUS_IS_OPEN(bus->state))
return -ENOTCONN;
if (!m)
return -EINVAL;
if (m->header->type != SD_BUS_MESSAGE_TYPE_METHOD_CALL)
return -EINVAL;
if (m->header->flags & SD_BUS_MESSAGE_NO_REPLY_EXPECTED)
return -EINVAL;
if (bus_error_is_dirty(error))
return -EINVAL;
if (bus_pid_changed(bus))
return -ECHILD;
r = bus_ensure_running(bus);
if (r < 0)
return r;
r = sd_bus_send(bus, m, &serial);
if (r < 0)
return r;
timeout = calc_elapse(usec);
for (;;) {
usec_t left;
sd_bus_message *incoming = NULL;
if (!room) {
sd_bus_message **q;
if (bus->rqueue_size >= BUS_RQUEUE_MAX)
return -ENOBUFS;
/* Make sure there's room for queuing this
* locally, before we read the message */
q = realloc(bus->rqueue, (bus->rqueue_size + 1) * sizeof(sd_bus_message*));
if (!q)
return -ENOMEM;
bus->rqueue = q;
room = true;
}
if (bus->is_kernel)
r = bus_kernel_read_message(bus, &incoming);
else
r = bus_socket_read_message(bus, &incoming);
if (r < 0)
return r;
if (incoming) {
if (incoming->reply_serial == serial) {
/* Found a match! */
if (incoming->header->type == SD_BUS_MESSAGE_TYPE_METHOD_RETURN) {
if (reply)
*reply = incoming;
else
sd_bus_message_unref(incoming);
return 0;
}
if (incoming->header->type == SD_BUS_MESSAGE_TYPE_METHOD_ERROR) {
int k;
r = sd_bus_error_copy(error, &incoming->error);
if (r < 0) {
sd_bus_message_unref(incoming);
return r;
}
k = bus_error_to_errno(&incoming->error);
sd_bus_message_unref(incoming);
return k;
}
sd_bus_message_unref(incoming);
return -EIO;
}
/* There's already guaranteed to be room for
* this, so need to resize things here */
bus->rqueue[bus->rqueue_size ++] = incoming;
room = false;
/* Try to read more, right-away */
continue;
}
if (r != 0)
continue;
if (timeout > 0) {
usec_t n;
n = now(CLOCK_MONOTONIC);
if (n >= timeout)
return -ETIMEDOUT;
left = timeout - n;
} else
left = (uint64_t) -1;
r = bus_poll(bus, true, left);
if (r < 0)
return r;
r = dispatch_wqueue(bus);
if (r < 0)
return r;
}
}
int sd_bus_get_fd(sd_bus *bus) {
if (!bus)
return -EINVAL;
if (!BUS_IS_OPEN(bus->state))
return -ENOTCONN;
if (bus->input_fd != bus->output_fd)
return -EPERM;
if (bus_pid_changed(bus))
return -ECHILD;
return bus->input_fd;
}
int sd_bus_get_events(sd_bus *bus) {
int flags = 0;
if (!bus)
return -EINVAL;
if (!BUS_IS_OPEN(bus->state))
return -ENOTCONN;
if (bus_pid_changed(bus))
return -ECHILD;
if (bus->state == BUS_OPENING)
flags |= POLLOUT;
else if (bus->state == BUS_AUTHENTICATING) {
if (bus_socket_auth_needs_write(bus))
flags |= POLLOUT;
flags |= POLLIN;
} else if (bus->state == BUS_RUNNING || bus->state == BUS_HELLO) {
if (bus->rqueue_size <= 0)
flags |= POLLIN;
if (bus->wqueue_size > 0)
flags |= POLLOUT;
}
return flags;
}
int sd_bus_get_timeout(sd_bus *bus, uint64_t *timeout_usec) {
struct reply_callback *c;
if (!bus)
return -EINVAL;
if (!timeout_usec)
return -EINVAL;
if (!BUS_IS_OPEN(bus->state))
return -ENOTCONN;
if (bus_pid_changed(bus))
return -ECHILD;
if (bus->state == BUS_AUTHENTICATING) {
*timeout_usec = bus->auth_timeout;
return 1;
}
if (bus->state != BUS_RUNNING && bus->state != BUS_HELLO) {
*timeout_usec = (uint64_t) -1;
return 0;
}
c = prioq_peek(bus->reply_callbacks_prioq);
if (!c) {
*timeout_usec = (uint64_t) -1;
return 0;
}
*timeout_usec = c->timeout;
return 1;
}
static int process_timeout(sd_bus *bus) {
_cleanup_bus_message_unref_ sd_bus_message* m = NULL;
struct reply_callback *c;
usec_t n;
int r;
assert(bus);
c = prioq_peek(bus->reply_callbacks_prioq);
if (!c)
return 0;
n = now(CLOCK_MONOTONIC);
if (c->timeout > n)
return 0;
r = bus_message_new_synthetic_error(
bus,
c->serial,
&SD_BUS_ERROR_MAKE("org.freedesktop.DBus.Error.Timeout", "Timed out"),
&m);
if (r < 0)
return r;
assert_se(prioq_pop(bus->reply_callbacks_prioq) == c);
hashmap_remove(bus->reply_callbacks, &c->serial);
r = c->callback(bus, m, c->userdata);
free(c);
return r < 0 ? r : 1;
}
static int process_hello(sd_bus *bus, sd_bus_message *m) {
assert(bus);
assert(m);
if (bus->state != BUS_HELLO)
return 0;
/* Let's make sure the first message on the bus is the HELLO
* reply. But note that we don't actually parse the message
* here (we leave that to the usual handling), we just verify
* we don't let any earlier msg through. */
if (m->header->type != SD_BUS_MESSAGE_TYPE_METHOD_RETURN &&
m->header->type != SD_BUS_MESSAGE_TYPE_METHOD_ERROR)
return -EIO;
if (m->reply_serial != bus->hello_serial)
return -EIO;
return 0;
}
static int process_reply(sd_bus *bus, sd_bus_message *m) {
struct reply_callback *c;
int r;
assert(bus);
assert(m);
if (m->header->type != SD_BUS_MESSAGE_TYPE_METHOD_RETURN &&
m->header->type != SD_BUS_MESSAGE_TYPE_METHOD_ERROR)
return 0;
c = hashmap_remove(bus->reply_callbacks, &m->reply_serial);
if (!c)
return 0;
if (c->timeout != 0)
prioq_remove(bus->reply_callbacks_prioq, c, &c->prioq_idx);
r = sd_bus_message_rewind(m, true);
if (r < 0)
return r;
r = c->callback(bus, m, c->userdata);
free(c);
return r;
}
static int process_filter(sd_bus *bus, sd_bus_message *m) {
struct filter_callback *l;
int r;
assert(bus);
assert(m);
do {
bus->filter_callbacks_modified = false;
LIST_FOREACH(callbacks, l, bus->filter_callbacks) {
if (bus->filter_callbacks_modified)
break;
/* Don't run this more than once per iteration */
if (l->last_iteration == bus->iteration_counter)
continue;
l->last_iteration = bus->iteration_counter;
r = sd_bus_message_rewind(m, true);
if (r < 0)
return r;
r = l->callback(bus, m, l->userdata);
if (r != 0)
return r;
}
} while (bus->filter_callbacks_modified);
return 0;
}
static int process_match(sd_bus *bus, sd_bus_message *m) {
int r;
assert(bus);
assert(m);
do {
bus->match_callbacks_modified = false;
r = bus_match_run(bus, &bus->match_callbacks, m);
if (r != 0)
return r;
} while (bus->match_callbacks_modified);
return 0;
}
static int process_builtin(sd_bus *bus, sd_bus_message *m) {
_cleanup_bus_message_unref_ sd_bus_message *reply = NULL;
int r;
assert(bus);
assert(m);
if (m->header->type != SD_BUS_MESSAGE_TYPE_METHOD_CALL)
return 0;
if (!streq_ptr(m->interface, "org.freedesktop.DBus.Peer"))
return 0;
if (m->header->flags & SD_BUS_MESSAGE_NO_REPLY_EXPECTED)
return 1;
if (streq_ptr(m->member, "Ping"))
r = sd_bus_message_new_method_return(bus, m, &reply);
else if (streq_ptr(m->member, "GetMachineId")) {
sd_id128_t id;
char sid[33];
r = sd_id128_get_machine(&id);
if (r < 0)
return r;
r = sd_bus_message_new_method_return(bus, m, &reply);
if (r < 0)
return r;
r = sd_bus_message_append(reply, "s", sd_id128_to_string(id, sid));
} else {
r = sd_bus_message_new_method_errorf(
bus, m, &reply,
"org.freedesktop.DBus.Error.UnknownMethod",
"Unknown method '%s' on interface '%s'.", m->member, m->interface);
}
if (r < 0)
return r;
r = sd_bus_send(bus, reply, NULL);
if (r < 0)
return r;
return 1;
}
static int process_message(sd_bus *bus, sd_bus_message *m) {
int r;
assert(bus);
assert(m);
bus->iteration_counter++;
r = process_hello(bus, m);
if (r != 0)
return r;
r = process_reply(bus, m);
if (r != 0)
return r;
r = process_filter(bus, m);
if (r != 0)
return r;
r = process_match(bus, m);
if (r != 0)
return r;
r = process_builtin(bus, m);
if (r != 0)
return r;
return bus_process_object(bus, m);
}
static int process_running(sd_bus *bus, sd_bus_message **ret) {
_cleanup_bus_message_unref_ sd_bus_message *m = NULL;
int r;
assert(bus);
assert(bus->state == BUS_RUNNING || bus->state == BUS_HELLO);
r = process_timeout(bus);
if (r != 0)
goto null_message;
r = dispatch_wqueue(bus);
if (r != 0)
goto null_message;
r = dispatch_rqueue(bus, &m);
if (r < 0)
return r;
if (!m)
goto null_message;
r = process_message(bus, m);
if (r != 0)
goto null_message;
if (ret) {
r = sd_bus_message_rewind(m, true);
if (r < 0)
return r;
*ret = m;
m = NULL;
return 1;
}
if (m->header->type == SD_BUS_MESSAGE_TYPE_METHOD_CALL) {
r = sd_bus_reply_method_errorf(
bus, m,
"org.freedesktop.DBus.Error.UnknownObject",
"Unknown object '%s'.", m->path);
if (r < 0)
return r;
}
return 1;
null_message:
if (r >= 0 && ret)
*ret = NULL;
return r;
}
int sd_bus_process(sd_bus *bus, sd_bus_message **ret) {
int r;
/* Returns 0 when we didn't do anything. This should cause the
* caller to invoke sd_bus_wait() before returning the next
* time. Returns > 0 when we did something, which possibly
* means *ret is filled in with an unprocessed message. */
if (!bus)
return -EINVAL;
if (bus_pid_changed(bus))
return -ECHILD;
/* We don't allow recursively invoking sd_bus_process(). */
if (bus->processing)
return -EBUSY;
switch (bus->state) {
case BUS_UNSET:
case BUS_CLOSED:
return -ENOTCONN;
case BUS_OPENING:
r = bus_socket_process_opening(bus);
if (r < 0)
return r;
if (ret)
*ret = NULL;
return r;
case BUS_AUTHENTICATING:
r = bus_socket_process_authenticating(bus);
if (r < 0)
return r;
if (ret)
*ret = NULL;
return r;
case BUS_RUNNING:
case BUS_HELLO:
bus->processing = true;
r = process_running(bus, ret);
bus->processing = false;
return r;
}
assert_not_reached("Unknown state");
}
static int bus_poll(sd_bus *bus, bool need_more, uint64_t timeout_usec) {
struct pollfd p[2] = {};
int r, e, n;
struct timespec ts;
usec_t until, m;
assert(bus);
if (!BUS_IS_OPEN(bus->state))
return -ENOTCONN;
e = sd_bus_get_events(bus);
if (e < 0)
return e;
if (need_more)
e |= POLLIN;
r = sd_bus_get_timeout(bus, &until);
if (r < 0)
return r;
if (r == 0)
m = (uint64_t) -1;
else {
usec_t nw;
nw = now(CLOCK_MONOTONIC);
m = until > nw ? until - nw : 0;
}
if (timeout_usec != (uint64_t) -1 && (m == (uint64_t) -1 || timeout_usec < m))
m = timeout_usec;
p[0].fd = bus->input_fd;
if (bus->output_fd == bus->input_fd) {
p[0].events = e;
n = 1;
} else {
p[0].events = e & POLLIN;
p[1].fd = bus->output_fd;
p[1].events = e & POLLOUT;
n = 2;
}
r = ppoll(p, n, m == (uint64_t) -1 ? NULL : timespec_store(&ts, m), NULL);
if (r < 0)
return -errno;
return r > 0 ? 1 : 0;
}
int sd_bus_wait(sd_bus *bus, uint64_t timeout_usec) {
if (!bus)
return -EINVAL;
if (!BUS_IS_OPEN(bus->state))
return -ENOTCONN;
if (bus_pid_changed(bus))
return -ECHILD;
if (bus->rqueue_size > 0)
return 0;
return bus_poll(bus, false, timeout_usec);
}
int sd_bus_flush(sd_bus *bus) {
int r;
if (!bus)
return -EINVAL;
if (!BUS_IS_OPEN(bus->state))
return -ENOTCONN;
if (bus_pid_changed(bus))
return -ECHILD;
r = bus_ensure_running(bus);
if (r < 0)
return r;
if (bus->wqueue_size <= 0)
return 0;
for (;;) {
r = dispatch_wqueue(bus);
if (r < 0)
return r;
if (bus->wqueue_size <= 0)
return 0;
r = bus_poll(bus, false, (uint64_t) -1);
if (r < 0)
return r;
}
}
int sd_bus_add_filter(sd_bus *bus, sd_bus_message_handler_t callback, void *userdata) {
struct filter_callback *f;
if (!bus)
return -EINVAL;
if (!callback)
return -EINVAL;
if (bus_pid_changed(bus))
return -ECHILD;
f = new0(struct filter_callback, 1);
if (!f)
return -ENOMEM;
f->callback = callback;
f->userdata = userdata;
bus->filter_callbacks_modified = true;
LIST_PREPEND(callbacks, bus->filter_callbacks, f);
return 0;
}
int sd_bus_remove_filter(sd_bus *bus, sd_bus_message_handler_t callback, void *userdata) {
struct filter_callback *f;
if (!bus)
return -EINVAL;
if (!callback)
return -EINVAL;
if (bus_pid_changed(bus))
return -ECHILD;
LIST_FOREACH(callbacks, f, bus->filter_callbacks) {
if (f->callback == callback && f->userdata == userdata) {
bus->filter_callbacks_modified = true;
LIST_REMOVE(callbacks, bus->filter_callbacks, f);
free(f);
return 1;
}
}
return 0;
}
int sd_bus_add_match(sd_bus *bus, const char *match, sd_bus_message_handler_t callback, void *userdata) {
struct bus_match_component *components = NULL;
unsigned n_components = 0;
uint64_t cookie = 0;
int r = 0;
if (!bus)
return -EINVAL;
if (!match)
return -EINVAL;
if (bus_pid_changed(bus))
return -ECHILD;
r = bus_match_parse(match, &components, &n_components);
if (r < 0)
goto finish;
if (bus->bus_client) {
cookie = ++bus->match_cookie;
r = bus_add_match_internal(bus, match, components, n_components, cookie);
if (r < 0)
goto finish;
}
bus->match_callbacks_modified = true;
r = bus_match_add(&bus->match_callbacks, components, n_components, callback, userdata, cookie, NULL);
if (r < 0) {
if (bus->bus_client)
bus_remove_match_internal(bus, match, cookie);
}
finish:
bus_match_parse_free(components, n_components);
return r;
}
int sd_bus_remove_match(sd_bus *bus, const char *match, sd_bus_message_handler_t callback, void *userdata) {
struct bus_match_component *components = NULL;
unsigned n_components = 0;
int r = 0, q = 0;
uint64_t cookie = 0;
if (!bus)
return -EINVAL;
if (!match)
return -EINVAL;
if (bus_pid_changed(bus))
return -ECHILD;
r = bus_match_parse(match, &components, &n_components);
if (r < 0)
return r;
bus->match_callbacks_modified = true;
r = bus_match_remove(&bus->match_callbacks, components, n_components, callback, userdata, &cookie);
if (bus->bus_client)
q = bus_remove_match_internal(bus, match, cookie);
bus_match_parse_free(components, n_components);
return r < 0 ? r : q;
}
bool bus_pid_changed(sd_bus *bus) {
assert(bus);
/* We don't support people creating a bus connection and
* keeping it around over a fork(). Let's complain. */
return bus->original_pid != getpid();
}