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Systemd/src/machine/machine.c
Lennart Poettering 4afd3348c7 tree-wide: expose "p"-suffix unref calls in public APIs to make gcc cleanup easy 
GLIB has recently started to officially support the gcc cleanup
attribute in its public API, hence let's do the same for our APIs.

With this patch we'll define an xyz_unrefp() call for each public
xyz_unref() call, to make it easy to use inside a
__attribute__((cleanup())) expression. Then, all code is ported over to
make use of this.

The new calls are also documented in the man pages, with examples how to
use them (well, I only added docs where the _unref() call itself already
had docs, and the examples, only cover sd_bus_unrefp() and
sd_event_unrefp()).

This also renames sd_lldp_free() to sd_lldp_unref(), since that's how we
tend to call our destructors these days.

Note that this defines no public macro that wraps gcc's attribute and
makes it easier to use. While I think it's our duty in the library to
make our stuff easy to use, I figure it's not our duty to make gcc's own
features easy to use on its own. Most likely, client code which wants to
make use of this should define its own:

       #define _cleanup_(function) __attribute__((cleanup(function)))

Or similar, to make the gcc feature easier to use.

Making this logic public has the benefit that we can remove three header
files whose only purpose was to define these functions internally.

See #2008.
2015-11-27 19:19:36 +01:00

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/*-*- Mode: C; c-basic-offset: 8; indent-tabs-mode: nil -*-*/
/***
This file is part of systemd.
Copyright 2011 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 <errno.h>
#include <string.h>
#include <unistd.h>
#include "sd-messages.h"
#include "alloc-util.h"
#include "bus-error.h"
#include "bus-util.h"
#include "escape.h"
#include "extract-word.h"
#include "fd-util.h"
#include "fileio.h"
#include "formats-util.h"
#include "hashmap.h"
#include "machine-dbus.h"
#include "machine.h"
#include "mkdir.h"
#include "parse-util.h"
#include "process-util.h"
#include "special.h"
#include "string-table.h"
#include "terminal-util.h"
#include "unit-name.h"
#include "util.h"
Machine* machine_new(Manager *manager, MachineClass class, const char *name) {
Machine *m;
assert(manager);
assert(class < _MACHINE_CLASS_MAX);
assert(name);
/* Passing class == _MACHINE_CLASS_INVALID here is fine. It
* means as much as "we don't know yet", and that we'll figure
* it out later when loading the state file. */
m = new0(Machine, 1);
if (!m)
return NULL;
m->name = strdup(name);
if (!m->name)
goto fail;
if (class != MACHINE_HOST) {
m->state_file = strappend("/run/systemd/machines/", m->name);
if (!m->state_file)
goto fail;
}
m->class = class;
if (hashmap_put(manager->machines, m->name, m) < 0)
goto fail;
m->manager = manager;
return m;
fail:
free(m->state_file);
free(m->name);
free(m);
return NULL;
}
void machine_free(Machine *m) {
assert(m);
while (m->operations)
machine_operation_unref(m->operations);
if (m->in_gc_queue)
LIST_REMOVE(gc_queue, m->manager->machine_gc_queue, m);
machine_release_unit(m);
free(m->scope_job);
(void) hashmap_remove(m->manager->machines, m->name);
if (m->manager->host_machine == m)
m->manager->host_machine = NULL;
if (m->leader > 0)
(void) hashmap_remove_value(m->manager->machine_leaders, PID_TO_PTR(m->leader), m);
sd_bus_message_unref(m->create_message);
free(m->name);
free(m->state_file);
free(m->service);
free(m->root_directory);
free(m->netif);
free(m);
}
int machine_save(Machine *m) {
_cleanup_free_ char *temp_path = NULL;
_cleanup_fclose_ FILE *f = NULL;
int r;
assert(m);
if (!m->state_file)
return 0;
if (!m->started)
return 0;
r = mkdir_safe_label("/run/systemd/machines", 0755, 0, 0);
if (r < 0)
goto fail;
r = fopen_temporary(m->state_file, &f, &temp_path);
if (r < 0)
goto fail;
(void) fchmod(fileno(f), 0644);
fprintf(f,
"# This is private data. Do not parse.\n"
"NAME=%s\n",
m->name);
if (m->unit) {
_cleanup_free_ char *escaped;
escaped = cescape(m->unit);
if (!escaped) {
r = -ENOMEM;
goto fail;
}
fprintf(f, "SCOPE=%s\n", escaped); /* We continue to call this "SCOPE=" because it is internal only, and we want to stay compatible with old files */
}
if (m->scope_job)
fprintf(f, "SCOPE_JOB=%s\n", m->scope_job);
if (m->service) {
_cleanup_free_ char *escaped;
escaped = cescape(m->service);
if (!escaped) {
r = -ENOMEM;
goto fail;
}
fprintf(f, "SERVICE=%s\n", escaped);
}
if (m->root_directory) {
_cleanup_free_ char *escaped;
escaped = cescape(m->root_directory);
if (!escaped) {
r = -ENOMEM;
goto fail;
}
fprintf(f, "ROOT=%s\n", escaped);
}
if (!sd_id128_equal(m->id, SD_ID128_NULL))
fprintf(f, "ID=" SD_ID128_FORMAT_STR "\n", SD_ID128_FORMAT_VAL(m->id));
if (m->leader != 0)
fprintf(f, "LEADER="PID_FMT"\n", m->leader);
if (m->class != _MACHINE_CLASS_INVALID)
fprintf(f, "CLASS=%s\n", machine_class_to_string(m->class));
if (dual_timestamp_is_set(&m->timestamp))
fprintf(f,
"REALTIME="USEC_FMT"\n"
"MONOTONIC="USEC_FMT"\n",
m->timestamp.realtime,
m->timestamp.monotonic);
if (m->n_netif > 0) {
unsigned i;
fputs("NETIF=", f);
for (i = 0; i < m->n_netif; i++) {
if (i != 0)
fputc(' ', f);
fprintf(f, "%i", m->netif[i]);
}
fputc('\n', f);
}
r = fflush_and_check(f);
if (r < 0)
goto fail;
if (rename(temp_path, m->state_file) < 0) {
r = -errno;
goto fail;
}
if (m->unit) {
char *sl;
/* Create a symlink from the unit name to the machine
* name, so that we can quickly find the machine for
* each given unit. Ignore error. */
sl = strjoina("/run/systemd/machines/unit:", m->unit);
(void) symlink(m->name, sl);
}
return 0;
fail:
(void) unlink(m->state_file);
if (temp_path)
(void) unlink(temp_path);
return log_error_errno(r, "Failed to save machine data %s: %m", m->state_file);
}
static void machine_unlink(Machine *m) {
assert(m);
if (m->unit) {
char *sl;
sl = strjoina("/run/systemd/machines/unit:", m->unit);
(void) unlink(sl);
}
if (m->state_file)
(void) unlink(m->state_file);
}
int machine_load(Machine *m) {
_cleanup_free_ char *realtime = NULL, *monotonic = NULL, *id = NULL, *leader = NULL, *class = NULL, *netif = NULL;
int r;
assert(m);
if (!m->state_file)
return 0;
r = parse_env_file(m->state_file, NEWLINE,
"SCOPE", &m->unit,
"SCOPE_JOB", &m->scope_job,
"SERVICE", &m->service,
"ROOT", &m->root_directory,
"ID", &id,
"LEADER", &leader,
"CLASS", &class,
"REALTIME", &realtime,
"MONOTONIC", &monotonic,
"NETIF", &netif,
NULL);
if (r < 0) {
if (r == -ENOENT)
return 0;
return log_error_errno(r, "Failed to read %s: %m", m->state_file);
}
if (id)
sd_id128_from_string(id, &m->id);
if (leader)
parse_pid(leader, &m->leader);
if (class) {
MachineClass c;
c = machine_class_from_string(class);
if (c >= 0)
m->class = c;
}
if (realtime) {
unsigned long long l;
if (sscanf(realtime, "%llu", &l) > 0)
m->timestamp.realtime = l;
}
if (monotonic) {
unsigned long long l;
if (sscanf(monotonic, "%llu", &l) > 0)
m->timestamp.monotonic = l;
}
if (netif) {
size_t allocated = 0, nr = 0;
const char *p;
int *ni = NULL;
p = netif;
for(;;) {
_cleanup_free_ char *word = NULL;
int ifi;
r = extract_first_word(&p, &word, NULL, 0);
if (r == 0)
break;
if (r == -ENOMEM)
return log_oom();
if (r < 0) {
log_warning_errno(r, "Failed to parse NETIF: %s", netif);
break;
}
if (parse_ifindex(word, &ifi) < 0)
continue;
if (!GREEDY_REALLOC(ni, allocated, nr+1)) {
free(ni);
return log_oom();
}
ni[nr++] = ifi;
}
free(m->netif);
m->netif = ni;
m->n_netif = nr;
}
return r;
}
static int machine_start_scope(Machine *m, sd_bus_message *properties, sd_bus_error *error) {
int r = 0;
assert(m);
assert(m->class != MACHINE_HOST);
if (!m->unit) {
_cleanup_free_ char *escaped = NULL;
char *scope, *description, *job = NULL;
escaped = unit_name_escape(m->name);
if (!escaped)
return log_oom();
scope = strjoin("machine-", escaped, ".scope", NULL);
if (!scope)
return log_oom();
description = strjoina(m->class == MACHINE_VM ? "Virtual Machine " : "Container ", m->name);
r = manager_start_scope(m->manager, scope, m->leader, SPECIAL_MACHINE_SLICE, description, properties, error, &job);
if (r < 0) {
log_error("Failed to start machine scope: %s", bus_error_message(error, r));
free(scope);
return r;
} else {
m->unit = scope;
free(m->scope_job);
m->scope_job = job;
}
}
if (m->unit)
hashmap_put(m->manager->machine_units, m->unit, m);
return r;
}
int machine_start(Machine *m, sd_bus_message *properties, sd_bus_error *error) {
int r;
assert(m);
if (!IN_SET(m->class, MACHINE_CONTAINER, MACHINE_VM))
return -EOPNOTSUPP;
if (m->started)
return 0;
r = hashmap_put(m->manager->machine_leaders, PID_TO_PTR(m->leader), m);
if (r < 0)
return r;
/* Create cgroup */
r = machine_start_scope(m, properties, error);
if (r < 0)
return r;
log_struct(LOG_INFO,
LOG_MESSAGE_ID(SD_MESSAGE_MACHINE_START),
"NAME=%s", m->name,
"LEADER="PID_FMT, m->leader,
LOG_MESSAGE("New machine %s.", m->name),
NULL);
if (!dual_timestamp_is_set(&m->timestamp))
dual_timestamp_get(&m->timestamp);
m->started = true;
/* Save new machine data */
machine_save(m);
machine_send_signal(m, true);
return 0;
}
static int machine_stop_scope(Machine *m) {
_cleanup_(sd_bus_error_free) sd_bus_error error = SD_BUS_ERROR_NULL;
char *job = NULL;
int r;
assert(m);
assert(m->class != MACHINE_HOST);
if (!m->unit)
return 0;
r = manager_stop_unit(m->manager, m->unit, &error, &job);
if (r < 0) {
log_error("Failed to stop machine scope: %s", bus_error_message(&error, r));
return r;
}
free(m->scope_job);
m->scope_job = job;
return 0;
}
int machine_stop(Machine *m) {
int r;
assert(m);
if (!IN_SET(m->class, MACHINE_CONTAINER, MACHINE_VM))
return -EOPNOTSUPP;
r = machine_stop_scope(m);
m->stopping = true;
machine_save(m);
return r;
}
int machine_finalize(Machine *m) {
assert(m);
if (m->started)
log_struct(LOG_INFO,
LOG_MESSAGE_ID(SD_MESSAGE_MACHINE_STOP),
"NAME=%s", m->name,
"LEADER="PID_FMT, m->leader,
LOG_MESSAGE("Machine %s terminated.", m->name),
NULL);
machine_unlink(m);
machine_add_to_gc_queue(m);
if (m->started) {
machine_send_signal(m, false);
m->started = false;
}
return 0;
}
bool machine_check_gc(Machine *m, bool drop_not_started) {
assert(m);
if (m->class == MACHINE_HOST)
return true;
if (drop_not_started && !m->started)
return false;
if (m->scope_job && manager_job_is_active(m->manager, m->scope_job))
return true;
if (m->unit && manager_unit_is_active(m->manager, m->unit))
return true;
return false;
}
void machine_add_to_gc_queue(Machine *m) {
assert(m);
if (m->in_gc_queue)
return;
LIST_PREPEND(gc_queue, m->manager->machine_gc_queue, m);
m->in_gc_queue = true;
}
MachineState machine_get_state(Machine *s) {
assert(s);
if (s->class == MACHINE_HOST)
return MACHINE_RUNNING;
if (s->stopping)
return MACHINE_CLOSING;
if (s->scope_job)
return MACHINE_OPENING;
return MACHINE_RUNNING;
}
int machine_kill(Machine *m, KillWho who, int signo) {
assert(m);
if (!IN_SET(m->class, MACHINE_VM, MACHINE_CONTAINER))
return -EOPNOTSUPP;
if (!m->unit)
return -ESRCH;
if (who == KILL_LEADER) {
/* If we shall simply kill the leader, do so directly */
if (kill(m->leader, signo) < 0)
return -errno;
return 0;
}
/* Otherwise, make PID 1 do it for us, for the entire cgroup */
return manager_kill_unit(m->manager, m->unit, signo, NULL);
}
int machine_openpt(Machine *m, int flags) {
assert(m);
switch (m->class) {
case MACHINE_HOST: {
int fd;
fd = posix_openpt(flags);
if (fd < 0)
return -errno;
if (unlockpt(fd) < 0)
return -errno;
return fd;
}
case MACHINE_CONTAINER:
if (m->leader <= 0)
return -EINVAL;
return openpt_in_namespace(m->leader, flags);
default:
return -EOPNOTSUPP;
}
}
int machine_open_terminal(Machine *m, const char *path, int mode) {
assert(m);
switch (m->class) {
case MACHINE_HOST:
return open_terminal(path, mode);
case MACHINE_CONTAINER:
if (m->leader <= 0)
return -EINVAL;
return open_terminal_in_namespace(m->leader, path, mode);
default:
return -EOPNOTSUPP;
}
}
MachineOperation *machine_operation_unref(MachineOperation *o) {
if (!o)
return NULL;
sd_event_source_unref(o->event_source);
safe_close(o->errno_fd);
if (o->pid > 1)
(void) kill(o->pid, SIGKILL);
sd_bus_message_unref(o->message);
if (o->machine) {
LIST_REMOVE(operations, o->machine->operations, o);
o->machine->n_operations--;
}
free(o);
return NULL;
}
void machine_release_unit(Machine *m) {
assert(m);
if (!m->unit)
return;
(void) hashmap_remove(m->manager->machine_units, m->unit);
m->unit = mfree(m->unit);
}
static const char* const machine_class_table[_MACHINE_CLASS_MAX] = {
[MACHINE_CONTAINER] = "container",
[MACHINE_VM] = "vm",
[MACHINE_HOST] = "host",
};
DEFINE_STRING_TABLE_LOOKUP(machine_class, MachineClass);
static const char* const machine_state_table[_MACHINE_STATE_MAX] = {
[MACHINE_OPENING] = "opening",
[MACHINE_RUNNING] = "running",
[MACHINE_CLOSING] = "closing"
};
DEFINE_STRING_TABLE_LOOKUP(machine_state, MachineState);
static const char* const kill_who_table[_KILL_WHO_MAX] = {
[KILL_LEADER] = "leader",
[KILL_ALL] = "all"
};
DEFINE_STRING_TABLE_LOOKUP(kill_who, KillWho);
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