initctl.c revision f168c27313e4d7b0aabee037dc9c78a5799f0597
/*-*- Mode: C; c-basic-offset: 8; indent-tabs-mode: nil -*-*/
/***
This file is part of systemd.
Copyright 2010 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 <sys/socket.h>
#include <sys/types.h>
#include <assert.h>
#include <time.h>
#include <string.h>
#include <stdio.h>
#include <errno.h>
#include <unistd.h>
#include <sys/poll.h>
#include <sys/epoll.h>
#include <sys/un.h>
#include <fcntl.h>
#include <ctype.h>
#include "sd-daemon.h"
#include "sd-bus.h"
#include "util.h"
#include "log.h"
#include "list.h"
#include "initreq.h"
#include "special.h"
#include "bus-util.h"
#include "bus-error.h"
#include "def.h"
#define SERVER_FD_MAX 16
#define TIMEOUT_MSEC ((int) (DEFAULT_EXIT_USEC/USEC_PER_MSEC))
typedef struct Fifo Fifo;
typedef struct Server {
int epoll_fd;
LIST_HEAD(Fifo, fifos);
unsigned n_fifos;
sd_bus *bus;
bool quit;
} Server;
struct Fifo {
Server *server;
int fd;
struct init_request buffer;
size_t bytes_read;
LIST_FIELDS(Fifo, fifo);
};
static const char *translate_runlevel(int runlevel, bool *isolate) {
static const struct {
const int runlevel;
const char *special;
bool isolate;
} table[] = {
{ '0', SPECIAL_POWEROFF_TARGET, false },
{ '1', SPECIAL_RESCUE_TARGET, true },
{ 's', SPECIAL_RESCUE_TARGET, true },
{ 'S', SPECIAL_RESCUE_TARGET, true },
{ '2', SPECIAL_RUNLEVEL2_TARGET, true },
{ '3', SPECIAL_RUNLEVEL3_TARGET, true },
{ '4', SPECIAL_RUNLEVEL4_TARGET, true },
{ '5', SPECIAL_RUNLEVEL5_TARGET, true },
{ '6', SPECIAL_REBOOT_TARGET, false },
};
unsigned i;
assert(isolate);
for (i = 0; i < ELEMENTSOF(table); i++)
if (table[i].runlevel == runlevel) {
*isolate = table[i].isolate;
if (runlevel == '6' && kexec_loaded())
return SPECIAL_KEXEC_TARGET;
return table[i].special;
}
return NULL;
}
static void change_runlevel(Server *s, int runlevel) {
const char *target;
_cleanup_bus_error_free_ sd_bus_error error = SD_BUS_ERROR_NULL;
const char *mode;
bool isolate = false;
int r;
assert(s);
target = translate_runlevel(runlevel, &isolate);
if (!target) {
log_warning("Got request for unknown runlevel %c, ignoring.", runlevel);
return;
}
if (isolate)
mode = "isolate";
else
mode = "replace-irreversibly";
log_debug("Running request %s/start/%s", target, mode);
r = sd_bus_call_method(
s->bus,
"org.freedesktop.systemd1",
"/org/freedesktop/systemd1",
"org.freedesktop.systemd1.Manager",
"StartUnit",
&error,
NULL,
"ss", target, mode);
if (r < 0) {
log_error("Failed to change runlevel: %s", bus_error_message(&error, -r));
return;
}
}
static void request_process(Server *s, const struct init_request *req) {
assert(s);
assert(req);
if (req->magic != INIT_MAGIC) {
log_error("Got initctl request with invalid magic. Ignoring.");
return;
}
switch (req->cmd) {
case INIT_CMD_RUNLVL:
if (!isprint(req->runlevel))
log_error("Got invalid runlevel. Ignoring.");
else
switch (req->runlevel) {
/* we are async anyway, so just use kill for reexec/reload */
case 'u':
case 'U':
if (kill(1, SIGTERM) < 0)
log_error("kill() failed: %m");
/* The bus connection will be
* terminated if PID 1 is reexecuted,
* hence let's just exit here, and
* rely on that we'll be restarted on
* the next request */
s->quit = true;
break;
case 'q':
case 'Q':
if (kill(1, SIGHUP) < 0)
log_error("kill() failed: %m");
break;
default:
change_runlevel(s, req->runlevel);
}
return;
case INIT_CMD_POWERFAIL:
case INIT_CMD_POWERFAILNOW:
case INIT_CMD_POWEROK:
log_warning("Received UPS/power initctl request. This is not implemented in systemd. Upgrade your UPS daemon!");
return;
case INIT_CMD_CHANGECONS:
log_warning("Received console change initctl request. This is not implemented in systemd.");
return;
case INIT_CMD_SETENV:
case INIT_CMD_UNSETENV:
log_warning("Received environment initctl request. This is not implemented in systemd.");
return;
default:
log_warning("Received unknown initctl request. Ignoring.");
return;
}
}
static int fifo_process(Fifo *f) {
ssize_t l;
assert(f);
errno = EIO;
l = read(f->fd,
((uint8_t*) &f->buffer) + f->bytes_read,
sizeof(f->buffer) - f->bytes_read);
if (l <= 0) {
if (errno == EAGAIN)
return 0;
log_warning("Failed to read from fifo: %m");
return -1;
}
f->bytes_read += l;
assert(f->bytes_read <= sizeof(f->buffer));
if (f->bytes_read == sizeof(f->buffer)) {
request_process(f->server, &f->buffer);
f->bytes_read = 0;
}
return 0;
}
static void fifo_free(Fifo *f) {
assert(f);
if (f->server) {
assert(f->server->n_fifos > 0);
f->server->n_fifos--;
LIST_REMOVE(fifo, f->server->fifos, f);
}
if (f->fd >= 0) {
if (f->server)
epoll_ctl(f->server->epoll_fd, EPOLL_CTL_DEL, f->fd, NULL);
close_nointr_nofail(f->fd);
}
free(f);
}
static void server_done(Server *s) {
assert(s);
while (s->fifos)
fifo_free(s->fifos);
if (s->epoll_fd >= 0)
close_nointr_nofail(s->epoll_fd);
if (s->bus) {
sd_bus_flush(s->bus);
sd_bus_unref(s->bus);
}
}
static int server_init(Server *s, unsigned n_sockets) {
int r;
unsigned i;
assert(s);
assert(n_sockets > 0);
zero(*s);
s->epoll_fd = epoll_create1(EPOLL_CLOEXEC);
if (s->epoll_fd < 0) {
r = -errno;
log_error("Failed to create epoll object: %m");
goto fail;
}
for (i = 0; i < n_sockets; i++) {
struct epoll_event ev;
Fifo *f;
int fd;
fd = SD_LISTEN_FDS_START+i;
r = sd_is_fifo(fd, NULL);
if (r < 0) {
log_error("Failed to determine file descriptor type: %s",
strerror(-r));
goto fail;
}
if (!r) {
log_error("Wrong file descriptor type.");
r = -EINVAL;
goto fail;
}
f = new0(Fifo, 1);
if (!f) {
r = -ENOMEM;
log_error("Failed to create fifo object: %m");
goto fail;
}
f->fd = -1;
zero(ev);
ev.events = EPOLLIN;
ev.data.ptr = f;
if (epoll_ctl(s->epoll_fd, EPOLL_CTL_ADD, fd, &ev) < 0) {
r = -errno;
fifo_free(f);
log_error("Failed to add fifo fd to epoll object: %m");
goto fail;
}
f->fd = fd;
LIST_PREPEND(fifo, s->fifos, f);
f->server = s;
s->n_fifos ++;
}
r = bus_open_system_systemd(&s->bus);
if (r < 0) {
log_error("Failed to get D-Bus connection: %s", strerror(-r));
r = -EIO;
goto fail;
}
return 0;
fail:
server_done(s);
return r;
}
static int process_event(Server *s, struct epoll_event *ev) {
int r;
Fifo *f;
assert(s);
if (!(ev->events & EPOLLIN)) {
log_info("Got invalid event from epoll. (3)");
return -EIO;
}
f = (Fifo*) ev->data.ptr;
r = fifo_process(f);
if (r < 0) {
log_info("Got error on fifo: %s", strerror(-r));
fifo_free(f);
return r;
}
return 0;
}
int main(int argc, char *argv[]) {
Server server;
int r = EXIT_FAILURE, n;
if (getppid() != 1) {
log_error("This program should be invoked by init only.");
return EXIT_FAILURE;
}
if (argc > 1) {
log_error("This program does not take arguments.");
return EXIT_FAILURE;
}
log_set_target(LOG_TARGET_AUTO);
log_parse_environment();
log_open();
umask(0022);
if ((n = sd_listen_fds(true)) < 0) {
log_error("Failed to read listening file descriptors from environment: %s", strerror(-r));
return EXIT_FAILURE;
}
if (n <= 0 || n > SERVER_FD_MAX) {
log_error("No or too many file descriptors passed.");
return EXIT_FAILURE;
}
if (server_init(&server, (unsigned) n) < 0)
return EXIT_FAILURE;
log_debug("systemd-initctl running as pid %lu", (unsigned long) getpid());
sd_notify(false,
"READY=1\n"
"STATUS=Processing requests...");
while (!server.quit) {
struct epoll_event event;
int k;
if ((k = epoll_wait(server.epoll_fd,
&event, 1,
TIMEOUT_MSEC)) < 0) {
if (errno == EINTR)
continue;
log_error("epoll_wait() failed: %m");
goto fail;
}
if (k <= 0)
break;
if (process_event(&server, &event) < 0)
goto fail;
}
r = EXIT_SUCCESS;
log_debug("systemd-initctl stopped as pid %lu", (unsigned long) getpid());
fail:
sd_notify(false,
"STATUS=Shutting down...");
server_done(&server);
return r;
}