/*

 * Copyright 2010-2017, Tarantool AUTHORS, please see AUTHORS file.

 *

 * Redistribution and use in source and binary forms, with or

 * without modification, are permitted provided that the following

 * conditions are met:

 *

 * 1. Redistributions of source code must retain the above

 *    copyright notice, this list of conditions and the

 *    following disclaimer.

 *

 * 2. Redistributions in binary form must reproduce the above

 *    copyright notice, this list of conditions and the following

 *    disclaimer in the documentation and/or other materials

 *    provided with the distribution.

 *

 * THIS SOFTWARE IS PROVIDED BY <COPYRIGHT HOLDER> ``AS IS'' AND

 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED

 * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR

 * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL

 * <COPYRIGHT HOLDER> OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT,

 * INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL

 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF

 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR

 * BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF

 * LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT

 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF

 * THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF

 * SUCH DAMAGE.

 */

#include "systemd.h"

#if defined(WITH_NOTIFY_SOCKET)

#include <errno.h>

#include <stdio.h>

#include <stdarg.h>

#include <stddef.h>

#include <stdlib.h>

#include <string.h>

#include <fcntl.h>

#include <unistd.h>

#include <netinet/in.h>

#include <sys/socket.h>

#include <sys/un.h>

#include "say.h"

static int systemd_fd = -1;

static const char *sd_unix_path = NULL;

int systemd_init(void) {

  sd_unix_path = getenv_safe("NOTIFY_SOCKET", NULL, 0);

  if (sd_unix_path == NULL) {

    /* Do nothing if the path is not set. */

    return 0;

  }

  if ((sd_unix_path[0] != '@' && sd_unix_path[0] != '/') ||

      (sd_unix_path[1] == '\0')) {

    say_error("systemd: NOTIFY_SOCKET contains bad value");

    goto error;

  }

  /* To be sure, that path to unix socket is OK */

  struct sockaddr_un sa = {

    .sun_family = AF_UNIX,

    .sun_path = { '\0' }

  };

  if (strlen(sd_unix_path) >= sizeof(sa.sun_path)) {

    say_error("systemd: NOTIFY_SOCKET is longer than MAX_UNIX_PATH");

    goto error;

  }

  if ((systemd_fd = socket(AF_UNIX, SOCK_DGRAM, 0)) == -1) {

    say_syserror("systemd: failed to create unix socket");

    goto error;

  }

  if (fcntl(systemd_fd, F_SETFD, FD_CLOEXEC) == -1) {

    say_syserror("systemd: fcntl failed to set FD_CLOEXEC");

    goto error;

  }

#if defined(HAVE_SO_NOSIGPIPE)

  int val = 1;

  if (setsockopt(systemd_fd, SOL_SOCKET, SO_NOSIGPIPE, (void*)&val,

      sizeof(val)) < 0) {

    say_syserror("systemd: failed to set NOSIGPIPE");

    goto error;

  }

#endif

  int sndbuf_sz = 4 * 1024 * 1024;

  if (setsockopt(systemd_fd, SOL_SOCKET, SO_SNDBUF, &sndbuf_sz,

          sizeof(int)) < 0) {

    say_syserror("systemd: failed to set sndbuf size");

    goto error;

  };

  return 0;

error:

  if (systemd_fd > 0) {

    close(systemd_fd);

    systemd_fd = -1;

  }

  free((char *)sd_unix_path);

  sd_unix_path = NULL;

  return -1;

}

void systemd_free(void) {

  if (systemd_fd > 0)

    close(systemd_fd);

  free((char *)sd_unix_path);

}

int systemd_notify(const char *message) {

  if (systemd_fd == -1 || sd_unix_path == NULL)

    return 0;

  struct sockaddr_un sa = {

    .sun_family = AF_UNIX,

  };

  strlcpy(sa.sun_path, sd_unix_path, sizeof(sa.sun_path));

  if (sa.sun_path[0] == '@')

    sa.sun_path[0] = '\0';

  say_debug("systemd: sending message '%s'", message);

  int flags = 0;

#if defined(HAVE_MSG_NOSIGNAL)

  flags |= MSG_NOSIGNAL;

#endif

  ssize_t sent = sendto(systemd_fd, message, (size_t) strlen(message),

    flags, (struct sockaddr *) &sa, sizeof(sa));

  if (sent == -1) {

    say_syserror("systemd: failed to send message");

    return -1;

  }

  return sent;

}

int

systemd_vsnotify(const char *format, va_list ap)

{

  if (systemd_fd == -1 || sd_unix_path == NULL)

    return 0;

  char *buf = NULL;

  int rv = vasprintf(&buf, format, ap);

  if (rv < 0 || buf == NULL) {

    say_syserror("systemd: failed to format string '%s'", format);

    return -1;

  }

  rv = systemd_notify(buf);

  free(buf);

  return rv;

}

CFORMAT(printf, 1, 2) int

systemd_snotify(const char *format, ...)

{

  if (systemd_fd == -1 || sd_unix_path == NULL)

    return 0;

  va_list args;

  va_start(args, format);

  size_t res = systemd_vsnotify(format, args);

  va_end(args);

  return res;

}

#endif /* defined(WITH_NOTIFY_SOCKET) */