/*

 * Copyright 2016 Red Hat, Inc.

 * Copyright 2016-2022 Collabora Ltd.

 * Copyright 2017-2022 Endless OS Foundation, LLC

 * Copyright 2018 Will Thompson

 *

 * SPDX-License-Identifier: LGPL-2.1-or-later

 *

 * This library 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.

 *

 * This library 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 this library; if not, see <http://www.gnu.org/licenses/>.

 */

#include "gjournal-private.h"

#if defined(__linux__) && !defined(__BIONIC__)

#include <string.h>

#include <sys/socket.h>

#include <sys/un.h>

/*

 * Reimplementation of g_str_has_prefix(), necessary when compiled into

 * gio-launch-desktop.

 */

static int

str_has_prefix (const char *str,

                const char *prefix)

{

  return strncmp (str, prefix, strlen (prefix)) == 0;

}

/*

 * _g_fd_is_journal:

 * @output_fd: output file descriptor to check

 *

 * Same as g_log_writer_is_journald(), but with no GLib dependencies.

 *

 * Returns: 1 if @output_fd points to the journal, 0 otherwise

 */

int

_g_fd_is_journal (int output_fd)

{

  /* FIXME: Use the new journal API for detecting whether we’re writing to the

   * journal. See: https://github.com/systemd/systemd/issues/2473

   */

  union {

    struct sockaddr_storage storage;

    struct sockaddr sa;

    struct sockaddr_un un;

  } addr;

  socklen_t addr_len;

  int err;

  if (output_fd < 0)

    return 0;

  /* Namespaced journals start with `/run/systemd/journal.${name}/` (see

   * `RuntimeDirectory=systemd/journal.%i` in `systemd-journald@.service`. The

   * default journal starts with `/run/systemd/journal/`. */

  memset (&addr, 0, sizeof (addr));

  addr_len = sizeof(addr);

  err = getpeername (output_fd, &addr.sa, &addr_len);

  if (err == 0 && addr.storage.ss_family == AF_UNIX)

    return (str_has_prefix (addr.un.sun_path, "/run/systemd/journal/") ||

            str_has_prefix (addr.un.sun_path, "/run/systemd/journal."));

  return 0;

}

#endif