#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 <dbus/dbus.h>

#include "util.h"

#include "log.h"

#include "list.h"

#include "initreq.h"

#define SERVER_FD_START 3

#define SERVER_FD_MAX 16

#define TIMEOUT ((int) (10*MSEC_PER_SEC))

typedef struct Fifo Fifo;

typedef struct Server {

int epoll_fd;

LIST_HEAD(Fifo, fifos);

unsigned n_fifos;

DBusConnection *bus;

} 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) {

switch (runlevel) {

case '0':

return "halt.target";

case '1':

case 's':

case 'S':

return "rescue.target";

case '2':

return "runlevel2.target";

case '3':

return "runlevel3.target";

case '4':

return "runlevel4.target";

case '5':

return "runlevel5.target";

case '6':

return "reboot.target";

default:

return NULL;

}

}

static void change_runlevel(Server *s, int runlevel) {

const char *target;

DBusMessage *m = NULL, *reply = NULL;

DBusError error;

const char *path, *replace = "replace";

assert(s);

dbus_error_init(&error);

if (!(target = translate_runlevel(runlevel))) {

log_warning("Got request for unknown runlevel %c, ignoring.", runlevel);

goto finish;

}

log_debug("Running request %s", target);

if (!(m = dbus_message_new_method_call("org.freedesktop.systemd1", "/org/freedesktop/systemd1", "org.freedesktop.systemd1", "GetUnit"))) {

log_error("Could not allocate message.");

goto finish;

}

if (!dbus_message_append_args(m,

DBUS_TYPE_STRING, &target,

DBUS_TYPE_INVALID)) {

log_error("Could not attach group information to signal message.");

goto finish;

}

if (!(reply = dbus_connection_send_with_reply_and_block(s->bus, m, -1, &error))) {

log_error("Failed to get unit path: %s", error.message);

goto finish;

}

if (!dbus_message_get_args(reply, &error,

DBUS_TYPE_OBJECT_PATH, &path,

DBUS_TYPE_INVALID)) {

log_error("Failed to parse unit path: %s", error.message);

goto finish;

}

dbus_message_unref(m);

if (!(m = dbus_message_new_method_call("org.freedesktop.systemd1", path, "org.freedesktop.systemd1.Unit", "Start"))) {

log_error("Could not allocate message.");

goto finish;

}

if (!dbus_message_append_args(m,

DBUS_TYPE_STRING, &replace,

DBUS_TYPE_INVALID)) {

log_error("Could not attach group information to signal message.");

goto finish;

}

dbus_message_unref(reply);

if (!(reply = dbus_connection_send_with_reply_and_block(s->bus, m, -1, &error))) {

log_error("Failed to start unit: %s", error.message);

goto finish;

}

finish:

if (m)

dbus_message_unref(m);

if (reply)

dbus_message_unref(reply);

dbus_error_free(&error);

}

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

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;

if ((l = read(f->fd, ((uint8_t*) &f->buffer) + f->bytes_read, sizeof(f->buffer) - f->bytes_read)) <= 0) {

if (errno == EAGAIN)

return 0;

log_warning("Failed to read from fifo: %s", strerror(errno));

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, fifo, f->server->fifos, f);

}

if (f->fd >= 0) {

if (f->server)

epoll_ctl(f->server->epoll_fd, EPOLL_CTL_DEL, f->fd, NULL);

assert_se(close_nointr(f->fd) == 0);

}

free(f);

}

static int verify_environment(unsigned *n_sockets) {

unsigned long long pid;

const char *e;

int r;

unsigned ns;

assert_se(n_sockets);

if (!(e = getenv("LISTEN_PID"))) {

log_error("Missing $LISTEN_PID environment variable.");

return -ENOENT;

}

if ((r = safe_atollu(e, &pid)) < 0) {

log_error("Failed to parse $LISTEN_PID: %s", strerror(-r));

return r;

}

if (pid != (unsigned long long) getpid()) {

log_error("Socket nor for me.");

return -ENOENT;

}

if (!(e = getenv("LISTEN_FDS"))) {

log_error("Missing $LISTEN_FDS environment variable.");

return -ENOENT;

}

if ((r = safe_atou(e, &ns)) < 0) {

log_error("Failed to parse $LISTEN_FDS: %s", strerror(-r));

return -E2BIG;

}

if (ns <= 0 || ns > SERVER_FD_MAX) {

log_error("Wrong number of file descriptors passed: %s", e);

return -E2BIG;

}

*n_sockets = ns;

return 0;

}

static void server_done(Server *s) {

assert(s);

while (s->fifos)

fifo_free(s->fifos);

if (s->epoll_fd >= 0)

assert_se(close_nointr(s->epoll_fd) == 0);

if (s->bus)

dbus_connection_unref(s->bus);

}

static int server_init(Server *s, unsigned n_sockets) {

int r;

unsigned i;

DBusError error;

assert(s);

assert(n_sockets > 0);

dbus_error_init(&error);

zero(*s);

if ((s->epoll_fd = epoll_create1(EPOLL_CLOEXEC)) < 0) {

r = -errno;

log_error("Failed to create epoll object: %s", strerror(errno));

goto fail;

}

for (i = 0; i < n_sockets; i++) {

struct epoll_event ev;

Fifo *f;

if (!(f = new0(Fifo, 1))) {

r = -ENOMEM;

log_error("Failed to create fifo object: %s", strerror(errno));

goto fail;

}

f->fd = -1;

zero(ev);

ev.events = EPOLLIN;

ev.data.ptr = f;

if (epoll_ctl(s->epoll_fd, EPOLL_CTL_ADD, SERVER_FD_START+i, &ev) < 0) {

r = -errno;

fifo_free(f);

log_error("Failed to add fifo fd to epoll object: %s", strerror(errno));

goto fail;

}

f->fd = SERVER_FD_START+i;

LIST_PREPEND(Fifo, fifo, s->fifos, f);

f->server = s;

s->n_fifos ++;

}

if (!(s->bus = dbus_bus_get(DBUS_BUS_SYSTEM, &error))) {

log_error("Failed to get D-Bus connection: %s", error.message);

goto fail;

}

return 0;

fail:

server_done(s);

dbus_error_free(&error);

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;

if ((r = fifo_process(f)) < 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 = 3;

unsigned n;

log_info("systemd-initctl running as pid %llu", (unsigned long long) getpid());

if (verify_environment(&n) < 0)

return 1;

if (server_init(&server, n) < 0)

return 2;

for (;;) {

struct epoll_event event;

int k;

if ((k = epoll_wait(server.epoll_fd,

&event, 1,

TIMEOUT)) < 0) {

if (errno == EINTR)

continue;

log_error("epoll_wait() failed: %s", strerror(errno));

goto fail;

}

if (k <= 0)

break;

if ((k = process_event(&server, &event)) < 0)

goto fail;

}

r = 0;

fail:

server_done(&server);

log_info("systemd-initctl stopped as pid %llu", (unsigned long long) getpid());

dbus_shutdown();

return r;

}