dbus-sysdeps-unix.c

/* -*- mode: C; c-file-style: "gnu" -*- */
/* dbus-sysdeps-unix.c Wrappers around UNIX system/libc features (internal to D-Bus implementation)
 * 
 * Copyright (C) 2002, 2003, 2006  Red Hat, Inc.
 * Copyright (C) 2003 CodeFactory AB
 *
 * Licensed under the Academic Free License version 2.1
 * 
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation; either version 2 of the License, or
 * (at your option) any later version.
 *
 * This program 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 General Public License for more details.
 * 
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software
 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
 *
 */

#include "dbus-internals.h"
#include "dbus-sysdeps.h"
#include "dbus-sysdeps-unix.h"
#include "dbus-threads.h"
#include "dbus-protocol.h"
#include "dbus-transport.h"
#include "dbus-string.h"
#include "dbus-userdb.h"
#include "dbus-list.h"
#include <sys/types.h>
#include <stdlib.h>
#include <string.h>
#include <signal.h>
#include <unistd.h>
#include <stdio.h>
#include <fcntl.h>
#include <sys/socket.h>
#include <dirent.h>
#include <sys/un.h>
#include <pwd.h>
#include <time.h>
#include <locale.h>
#include <sys/time.h>
#include <sys/stat.h>
#include <sys/wait.h>
#include <netinet/in.h>
#include <netdb.h>
#include <grp.h>

#ifdef HAVE_ERRNO_H
#include <errno.h>
#endif
#ifdef HAVE_WRITEV
#include <sys/uio.h>
#endif
#ifdef HAVE_POLL
#include <sys/poll.h>
#endif
#ifdef HAVE_BACKTRACE
#include <execinfo.h>
#endif
#ifdef HAVE_GETPEERUCRED
#include <ucred.h>
#endif

#ifndef O_BINARY
#define O_BINARY 0
#endif

#ifndef HAVE_SOCKLEN_T
#define socklen_t int
#endif

static dbus_bool_t
_dbus_open_socket (int              *fd_p,
                   int               domain,
                   int               type,
                   int               protocol,
                   DBusError        *error)
{
  *fd_p = socket (domain, type, protocol);
  if (*fd_p >= 0)
    {
      return TRUE;
    }
  else
    {
      dbus_set_error(error,
                     _dbus_error_from_errno (errno),
                     "Failed to open socket: %s",
                     _dbus_strerror (errno));
      return FALSE;
    }
}

dbus_bool_t
_dbus_open_tcp_socket (int              *fd,
                       DBusError        *error)
{
  return _dbus_open_socket(fd, AF_INET, SOCK_STREAM, 0, error);
}

dbus_bool_t
_dbus_open_unix_socket (int              *fd,
                        DBusError        *error)
{
  return _dbus_open_socket(fd, PF_UNIX, SOCK_STREAM, 0, error);
}

dbus_bool_t 
_dbus_close_socket (int               fd,
                    DBusError        *error)
{
  return _dbus_close (fd, error);
}

int
_dbus_read_socket (int               fd,
                   DBusString       *buffer,
                   int               count)
{
  return _dbus_read (fd, buffer, count);
}

int
_dbus_write_socket (int               fd,
                    const DBusString *buffer,
                    int               start,
                    int               len)
{
  return _dbus_write (fd, buffer, start, len);
}

int
_dbus_write_socket_two (int               fd,
                        const DBusString *buffer1,
                        int               start1,
                        int               len1,
                        const DBusString *buffer2,
                        int               start2,
                        int               len2)
{
  return _dbus_write_two (fd, buffer1, start1, len1,
                          buffer2, start2, len2);
}


int
_dbus_read (int               fd,
            DBusString       *buffer,
            int               count)
{
  int bytes_read;
  int start;
  char *data;

  _dbus_assert (count >= 0);
  
  start = _dbus_string_get_length (buffer);

  if (!_dbus_string_lengthen (buffer, count))
    {
      errno = ENOMEM;
      return -1;
    }

  data = _dbus_string_get_data_len (buffer, start, count);

 again:
  
  bytes_read = read (fd, data, count);

  if (bytes_read < 0)
    {
      if (errno == EINTR)
        goto again;
      else
        {
          /* put length back (note that this doesn't actually realloc anything) */
          _dbus_string_set_length (buffer, start);
          return -1;
        }
    }
  else
    {
      /* put length back (doesn't actually realloc) */
      _dbus_string_set_length (buffer, start + bytes_read);

#if 0
      if (bytes_read > 0)
        _dbus_verbose_bytes_of_string (buffer, start, bytes_read);
#endif
      
      return bytes_read;
    }
}

int
_dbus_write (int               fd,
             const DBusString *buffer,
             int               start,
             int               len)
{
  const char *data;
  int bytes_written;
  
  data = _dbus_string_get_const_data_len (buffer, start, len);
  
 again:

  bytes_written = write (fd, data, len);

  if (bytes_written < 0 && errno == EINTR)
    goto again;

#if 0
  if (bytes_written > 0)
    _dbus_verbose_bytes_of_string (buffer, start, bytes_written);
#endif
  
  return bytes_written;
}

int
_dbus_write_two (int               fd,
                 const DBusString *buffer1,
                 int               start1,
                 int               len1,
                 const DBusString *buffer2,
                 int               start2,
                 int               len2)
{
  _dbus_assert (buffer1 != NULL);
  _dbus_assert (start1 >= 0);
  _dbus_assert (start2 >= 0);
  _dbus_assert (len1 >= 0);
  _dbus_assert (len2 >= 0);
  
#ifdef HAVE_WRITEV
  {
    struct iovec vectors[2];
    const char *data1;
    const char *data2;
    int bytes_written;

    data1 = _dbus_string_get_const_data_len (buffer1, start1, len1);

    if (buffer2 != NULL)
      data2 = _dbus_string_get_const_data_len (buffer2, start2, len2);
    else
      {
        data2 = NULL;
        start2 = 0;
        len2 = 0;
      }
   
    vectors[0].iov_base = (char*) data1;
    vectors[0].iov_len = len1;
    vectors[1].iov_base = (char*) data2;
    vectors[1].iov_len = len2;

  again:
   
    bytes_written = writev (fd,
                            vectors,
                            data2 ? 2 : 1);

    if (bytes_written < 0 && errno == EINTR)
      goto again;
   
    return bytes_written;
  }
#else /* HAVE_WRITEV */
  {
    int ret1;
    
    ret1 = _dbus_write (fd, buffer1, start1, len1);
    if (ret1 == len1 && buffer2 != NULL)
      {
        ret2 = _dbus_write (fd, buffer2, start2, len2);
        if (ret2 < 0)
          ret2 = 0; /* we can't report an error as the first write was OK */
       
        return ret1 + ret2;
      }
    else
      return ret1;
  }
#endif /* !HAVE_WRITEV */   
}

#define _DBUS_MAX_SUN_PATH_LENGTH 99

int
_dbus_connect_unix_socket (const char     *path,
                           dbus_bool_t     abstract,
                           DBusError      *error)
{
  int fd;
  size_t path_len;
  struct sockaddr_un addr;  

  _DBUS_ASSERT_ERROR_IS_CLEAR (error);

  _dbus_verbose ("connecting to unix socket %s abstract=%d\n",
                 path, abstract);
  
  
  if (!_dbus_open_unix_socket (&fd, error))
    {
      _DBUS_ASSERT_ERROR_IS_SET(error);
      return -1;
    }
  _DBUS_ASSERT_ERROR_IS_CLEAR(error);

  _DBUS_ZERO (addr);
  addr.sun_family = AF_UNIX;
  path_len = strlen (path);

  if (abstract)
    {
#ifdef HAVE_ABSTRACT_SOCKETS
      addr.sun_path[0] = '\0'; /* this is what says "use abstract" */
      path_len++; /* Account for the extra nul byte added to the start of sun_path */

      if (path_len > _DBUS_MAX_SUN_PATH_LENGTH)
        {
          dbus_set_error (error, DBUS_ERROR_BAD_ADDRESS,
                      "Abstract socket name too long\n");
          _dbus_close (fd, NULL);
          return -1;
        }
        
      strncpy (&addr.sun_path[1], path, path_len);
      /* _dbus_verbose_bytes (addr.sun_path, sizeof (addr.sun_path)); */
#else /* HAVE_ABSTRACT_SOCKETS */
      dbus_set_error (error, DBUS_ERROR_NOT_SUPPORTED,
                      "Operating system does not support abstract socket namespace\n");
      _dbus_close (fd, NULL);
      return -1;
#endif /* ! HAVE_ABSTRACT_SOCKETS */
    }
  else
    {
      if (path_len > _DBUS_MAX_SUN_PATH_LENGTH)
        {
          dbus_set_error (error, DBUS_ERROR_BAD_ADDRESS,
                      "Socket name too long\n");
          _dbus_close (fd, NULL);
          return -1;
        }

      strncpy (addr.sun_path, path, path_len);
    }
  
  if (connect (fd, (struct sockaddr*) &addr, _DBUS_STRUCT_OFFSET (struct sockaddr_un, sun_path) + path_len) < 0)
    {      
      dbus_set_error (error,
                      _dbus_error_from_errno (errno),
                      "Failed to connect to socket %s: %s",
                      path, _dbus_strerror (errno));

      _dbus_close (fd, NULL);
      fd = -1;
      
      return -1;
    }

  if (!_dbus_set_fd_nonblocking (fd, error))
    {
      _DBUS_ASSERT_ERROR_IS_SET (error);
      
      _dbus_close (fd, NULL);
      fd = -1;

      return -1;
    }

  return fd;
}

static dbus_bool_t
_dbus_set_local_creds (int fd, dbus_bool_t on)
{
  dbus_bool_t retval = TRUE;

#if defined(HAVE_CMSGCRED)
  /* NOOP just to make sure only one codepath is used 
   *      and to prefer CMSGCRED
   */
#elif defined(LOCAL_CREDS) 
  int val = on ? 1 : 0;
  if (setsockopt (fd, 0, LOCAL_CREDS, &val, sizeof (val)) < 0)
    {
      _dbus_verbose ("Unable to set LOCAL_CREDS socket option on fd %d\n", fd);
      retval = FALSE;
    }
  else
    _dbus_verbose ("LOCAL_CREDS %s for further messages on fd %d\n",
                   on ? "enabled" : "disabled", fd);
#endif

  return retval;
}

int
_dbus_listen_unix_socket (const char     *path,
                          dbus_bool_t     abstract,
                          DBusError      *error)
{
  int listen_fd;
  struct sockaddr_un addr;
  size_t path_len;

  _DBUS_ASSERT_ERROR_IS_CLEAR (error);

  _dbus_verbose ("listening on unix socket %s abstract=%d\n",
                 path, abstract);
  
  if (!_dbus_open_unix_socket (&listen_fd, error))
    {
      _DBUS_ASSERT_ERROR_IS_SET(error);
      return -1;
    }
  _DBUS_ASSERT_ERROR_IS_CLEAR(error);

  _DBUS_ZERO (addr);
  addr.sun_family = AF_UNIX;
  path_len = strlen (path);
  
  if (abstract)
    {
#ifdef HAVE_ABSTRACT_SOCKETS
      /* remember that abstract names aren't nul-terminated so we rely
       * on sun_path being filled in with zeroes above.
       */
      addr.sun_path[0] = '\0'; /* this is what says "use abstract" */
      path_len++; /* Account for the extra nul byte added to the start of sun_path */

      if (path_len > _DBUS_MAX_SUN_PATH_LENGTH)
        {
          dbus_set_error (error, DBUS_ERROR_BAD_ADDRESS,
                      "Abstract socket name too long\n");
          _dbus_close (listen_fd, NULL);
          return -1;
        }
      
      strncpy (&addr.sun_path[1], path, path_len);
      /* _dbus_verbose_bytes (addr.sun_path, sizeof (addr.sun_path)); */
#else /* HAVE_ABSTRACT_SOCKETS */
      dbus_set_error (error, DBUS_ERROR_NOT_SUPPORTED,
                      "Operating system does not support abstract socket namespace\n");
      _dbus_close (listen_fd, NULL);
      return -1;
#endif /* ! HAVE_ABSTRACT_SOCKETS */
    }
  else
    {
      /* Discussed security implications of this with Nalin,
       * and we couldn't think of where it would kick our ass, but
       * it still seems a bit sucky. It also has non-security suckage;
       * really we'd prefer to exit if the socket is already in use.
       * But there doesn't seem to be a good way to do this.
       *
       * Just to be extra careful, I threw in the stat() - clearly
       * the stat() can't *fix* any security issue, but it at least
       * avoids inadvertent/accidental data loss.
       */
      {
        struct stat sb;

        if (stat (path, &sb) == 0 &&
            S_ISSOCK (sb.st_mode))
          unlink (path);
      }

      if (path_len > _DBUS_MAX_SUN_PATH_LENGTH)
        {
          dbus_set_error (error, DBUS_ERROR_BAD_ADDRESS,
                      "Abstract socket name too long\n");
          _dbus_close (listen_fd, NULL);
          return -1;
        }
        
      strncpy (addr.sun_path, path, path_len);
    }
  
  if (bind (listen_fd, (struct sockaddr*) &addr, _DBUS_STRUCT_OFFSET (struct sockaddr_un, sun_path) + path_len) < 0)
    {
      dbus_set_error (error, _dbus_error_from_errno (errno),
                      "Failed to bind socket \"%s\": %s",
                      path, _dbus_strerror (errno));
      _dbus_close (listen_fd, NULL);
      return -1;
    }

  if (listen (listen_fd, 30 /* backlog */) < 0)
    {
      dbus_set_error (error, _dbus_error_from_errno (errno),
                      "Failed to listen on socket \"%s\": %s",
                      path, _dbus_strerror (errno));
      _dbus_close (listen_fd, NULL);
      return -1;
    }

  if (!_dbus_set_local_creds (listen_fd, TRUE))
    {
      dbus_set_error (error, _dbus_error_from_errno (errno),
                      "Failed to enable LOCAL_CREDS on socket \"%s\": %s",
                      path, _dbus_strerror (errno));
      close (listen_fd);
      return -1;
    }

  if (!_dbus_set_fd_nonblocking (listen_fd, error))
    {
      _DBUS_ASSERT_ERROR_IS_SET (error);
      _dbus_close (listen_fd, NULL);
      return -1;
    }
  
  /* Try opening up the permissions, but if we can't, just go ahead
   * and continue, maybe it will be good enough.
   */
  if (!abstract && chmod (path, 0777) < 0)
    _dbus_warn ("Could not set mode 0777 on socket %s\n",
                path);
  
  return listen_fd;
}

int
_dbus_connect_tcp_socket (const char     *host,
                          dbus_uint32_t   port,
                          DBusError      *error)
{
  int fd;
  struct sockaddr_in addr;
  struct hostent *he;
  struct in_addr *haddr;

  _DBUS_ASSERT_ERROR_IS_CLEAR (error);
 
  
  if (!_dbus_open_tcp_socket (&fd, error))
    {
      _DBUS_ASSERT_ERROR_IS_SET(error);
      
      return -1;
    }
  _DBUS_ASSERT_ERROR_IS_CLEAR(error);
      
  if (host == NULL)
    host = "localhost";

  he = gethostbyname (host);
  if (he == NULL) 
    {
      dbus_set_error (error,
                      _dbus_error_from_errno (errno),
                      "Failed to lookup hostname: %s",
                      host);
      _dbus_close (fd, NULL);
      return -1;
    }
  
  haddr = ((struct in_addr *) (he->h_addr_list)[0]);

  _DBUS_ZERO (addr);
  memcpy (&addr.sin_addr, haddr, sizeof(struct in_addr));
  addr.sin_family = AF_INET;
  addr.sin_port = htons (port);
  
  if (connect (fd, (struct sockaddr*) &addr, sizeof (addr)) < 0)
    {      
      dbus_set_error (error,
                       _dbus_error_from_errno (errno),
                      "Failed to connect to socket %s:%d %s",
                      host, port, _dbus_strerror (errno));

      _dbus_close (fd, NULL);
      fd = -1;
      
      return -1;
    }

  if (!_dbus_set_fd_nonblocking (fd, error))
    {
      _dbus_close (fd, NULL);
      fd = -1;

      return -1;
    }

  return fd;
}

int
_dbus_listen_tcp_socket (const char     *host,
                         dbus_uint32_t   port,
                         DBusError      *error)
{
  int listen_fd;
  struct sockaddr_in addr;
  struct hostent *he;
  struct in_addr *haddr;

  _DBUS_ASSERT_ERROR_IS_CLEAR (error);
  
  
  if (!_dbus_open_tcp_socket (&listen_fd, error))
    {
      _DBUS_ASSERT_ERROR_IS_SET(error);
      return -1;
    }
  _DBUS_ASSERT_ERROR_IS_CLEAR(error);

  he = gethostbyname (host);
  if (he == NULL) 
    {
      dbus_set_error (error,
                      _dbus_error_from_errno (errno),
                      "Failed to lookup hostname: %s",
                      host);
      _dbus_close (listen_fd, NULL);
      return -1;
    }
  
  haddr = ((struct in_addr *) (he->h_addr_list)[0]);

  _DBUS_ZERO (addr);
  memcpy (&addr.sin_addr, haddr, sizeof (struct in_addr));
  addr.sin_family = AF_INET;
  addr.sin_port = htons (port);

  if (bind (listen_fd, (struct sockaddr*) &addr, sizeof (struct sockaddr)))
    {
      dbus_set_error (error, _dbus_error_from_errno (errno),
                      "Failed to bind socket \"%s:%d\": %s",
                      host, port, _dbus_strerror (errno));
      _dbus_close (listen_fd, NULL);
      return -1;
    }

  if (listen (listen_fd, 30 /* backlog */) < 0)
    {
      dbus_set_error (error, _dbus_error_from_errno (errno),  
                      "Failed to listen on socket \"%s:%d\": %s",
                      host, port, _dbus_strerror (errno));
      _dbus_close (listen_fd, NULL);
      return -1;
    }

  if (!_dbus_set_fd_nonblocking (listen_fd, error))
    {
      _dbus_close (listen_fd, NULL);
      return -1;
    }
  
  return listen_fd;
}

static dbus_bool_t
write_credentials_byte (int             server_fd,
                        DBusError      *error)
{
  int bytes_written;
  char buf[1] = { '\0' };
#if defined(HAVE_CMSGCRED) 
  struct {
          struct cmsghdr hdr;
          struct cmsgcred cred;
  } cmsg;
  struct iovec iov;
  struct msghdr msg;
  iov.iov_base = buf;
  iov.iov_len = 1;

  memset (&msg, 0, sizeof (msg));
  msg.msg_iov = &iov;
  msg.msg_iovlen = 1;

  msg.msg_control = &cmsg;
  msg.msg_controllen = sizeof (cmsg);
  memset (&cmsg, 0, sizeof (cmsg));
  cmsg.hdr.cmsg_len = sizeof (cmsg);
  cmsg.hdr.cmsg_level = SOL_SOCKET;
  cmsg.hdr.cmsg_type = SCM_CREDS;
#endif

  _DBUS_ASSERT_ERROR_IS_CLEAR (error);
  
 again:

#if defined(HAVE_CMSGCRED) 
  bytes_written = sendmsg (server_fd, &msg, 0);
#else
  bytes_written = write (server_fd, buf, 1);
#endif

  if (bytes_written < 0 && errno == EINTR)
    goto again;

  if (bytes_written < 0)
    {
      dbus_set_error (error, _dbus_error_from_errno (errno),
                      "Failed to write credentials byte: %s",
                     _dbus_strerror (errno));
      return FALSE;
    }
  else if (bytes_written == 0)
    {
      dbus_set_error (error, DBUS_ERROR_IO_ERROR,
                      "wrote zero bytes writing credentials byte");
      return FALSE;
    }
  else
    {
      _dbus_assert (bytes_written == 1);
      _dbus_verbose ("wrote credentials byte\n");
      return TRUE;
    }
}

dbus_bool_t
_dbus_read_credentials_unix_socket  (int              client_fd,
                                     DBusCredentials *credentials,
                                     DBusError       *error)
{
  struct msghdr msg;
  struct iovec iov;
  char buf;

#ifdef HAVE_CMSGCRED 
  struct {
          struct cmsghdr hdr;
          struct cmsgcred cred;
  } cmsg;

#elif defined(LOCAL_CREDS)
  struct {
          struct cmsghdr hdr;
          struct sockcred cred;
  } cmsg;
#endif

  _DBUS_ASSERT_ERROR_IS_CLEAR (error);
  
  /* The POSIX spec certainly doesn't promise this, but
   * we need these assertions to fail as soon as we're wrong about
   * it so we can do the porting fixups
   */
  _dbus_assert (sizeof (pid_t) <= sizeof (credentials->pid));
  _dbus_assert (sizeof (uid_t) <= sizeof (credentials->uid));
  _dbus_assert (sizeof (gid_t) <= sizeof (credentials->gid));

  _dbus_credentials_clear (credentials);

  /* Systems supporting LOCAL_CREDS are configured to have this feature
   * enabled (if it does not conflict with HAVE_CMSGCRED) prior accepting
   * the connection.  Therefore, the received message must carry the
   * credentials information without doing anything special.
   */

  iov.iov_base = &buf;
  iov.iov_len = 1;

  memset (&msg, 0, sizeof (msg));
  msg.msg_iov = &iov;
  msg.msg_iovlen = 1;

#if defined(HAVE_CMSGCRED) || defined(LOCAL_CREDS)
  memset (&cmsg, 0, sizeof (cmsg));
  msg.msg_control = &cmsg;
  msg.msg_controllen = sizeof (cmsg);
#endif

 again:
  if (recvmsg (client_fd, &msg, 0) < 0)
    {
      if (errno == EINTR)
        goto again;

      dbus_set_error (error, _dbus_error_from_errno (errno),
                      "Failed to read credentials byte: %s",
                      _dbus_strerror (errno));
      return FALSE;
    }

  if (buf != '\0')
    {
      dbus_set_error (error, DBUS_ERROR_FAILED,
                      "Credentials byte was not nul");
      return FALSE;
    }

#if defined(HAVE_CMSGCRED) || defined(LOCAL_CREDS)
  if (cmsg.hdr.cmsg_len < sizeof (cmsg) || cmsg.hdr.cmsg_type != SCM_CREDS)
    {
      dbus_set_error (error, DBUS_ERROR_FAILED,
                      "Message from recvmsg() was not SCM_CREDS");
      return FALSE;
    }
#endif

  _dbus_verbose ("read credentials byte\n");

  {
#ifdef SO_PEERCRED
    struct ucred cr;   
    int cr_len = sizeof (cr);
   
    if (getsockopt (client_fd, SOL_SOCKET, SO_PEERCRED, &cr, &cr_len) == 0 &&
        cr_len == sizeof (cr))
      {
        credentials->pid = cr.pid;
        credentials->uid = cr.uid;
        credentials->gid = cr.gid;
      }
    else
      {
        _dbus_verbose ("Failed to getsockopt() credentials, returned len %d/%d: %s\n",
                       cr_len, (int) sizeof (cr), _dbus_strerror (errno));
      }
#elif defined(HAVE_CMSGCRED)
    credentials->pid = cmsg.cred.cmcred_pid;
    credentials->uid = cmsg.cred.cmcred_euid;
    credentials->gid = cmsg.cred.cmcred_groups[0];
#elif defined(LOCAL_CREDS)
    credentials->pid = DBUS_PID_UNSET;
    credentials->uid = cmsg.cred.sc_uid;
    credentials->gid = cmsg.cred.sc_gid;
    /* Since we have already got the credentials from this socket, we can
     * disable its LOCAL_CREDS flag if it was ever set. */
    _dbus_set_local_creds (client_fd, FALSE);
#elif defined(HAVE_GETPEEREID)
    uid_t euid;
    gid_t egid;
    if (getpeereid (client_fd, &euid, &egid) == 0)
      {
        credentials->uid = euid;
        credentials->gid = egid;
      }
    else
      {
        _dbus_verbose ("Failed to getpeereid() credentials: %s\n", _dbus_strerror (errno));
      }
#elif defined(HAVE_GETPEERUCRED)
    ucred_t * ucred = NULL;
    if (getpeerucred (client_fd, &ucred) == 0)
      {
        credentials->pid = ucred_getpid (ucred);
        credentials->uid = ucred_geteuid (ucred);
        credentials->gid = ucred_getegid (ucred);
      }
    else
      {
        _dbus_verbose ("Failed to getpeerucred() credentials: %s\n", _dbus_strerror (errno));
      }
    if (ucred != NULL)
      ucred_free (ucred);
#else /* !SO_PEERCRED && !HAVE_CMSGCRED && !HAVE_GETPEEREID && !HAVE_GETPEERUCRED */
    _dbus_verbose ("Socket credentials not supported on this OS\n");
#endif
  }

  _dbus_verbose ("Credentials:"
                 "  pid "DBUS_PID_FORMAT
                 "  uid "DBUS_UID_FORMAT
                 "  gid "DBUS_GID_FORMAT"\n",
                 credentials->pid,
                 credentials->uid,
                 credentials->gid);
    
  return TRUE;
}

dbus_bool_t
_dbus_send_credentials_unix_socket  (int              server_fd,
                                     DBusError       *error)
{
  _DBUS_ASSERT_ERROR_IS_CLEAR (error);
  
  if (write_credentials_byte (server_fd, error))
    return TRUE;
  else
    return FALSE;
}

int
_dbus_accept  (int listen_fd)
{
  int client_fd;
  struct sockaddr addr;
  socklen_t addrlen;

  addrlen = sizeof (addr);
  
 retry:
  client_fd = accept (listen_fd, &addr, &addrlen);
  
  if (client_fd < 0)
    {
      if (errno == EINTR)
        goto retry;
    }
  
  return client_fd;
}

dbus_bool_t
_dbus_check_dir_is_private_to_user (DBusString *dir, DBusError *error)
{
  const char *directory;
  struct stat sb;
        
  _DBUS_ASSERT_ERROR_IS_CLEAR (error);
    
  directory = _dbus_string_get_const_data (dir);
        
  if (stat (directory, &sb) < 0)
    {
      dbus_set_error (error, _dbus_error_from_errno (errno),
                      "%s", _dbus_strerror (errno));
   
      return FALSE;
    }
    
  if ((S_IROTH & sb.st_mode) || (S_IWOTH & sb.st_mode) ||
      (S_IRGRP & sb.st_mode) || (S_IWGRP & sb.st_mode))
    {
      dbus_set_error (error, DBUS_ERROR_FAILED,
                     "%s directory is not private to the user", directory);
      return FALSE;
    }
    
  return TRUE;
}

static dbus_bool_t
fill_user_info_from_passwd (struct passwd *p,
                            DBusUserInfo  *info,
                            DBusError     *error)
{
  _dbus_assert (p->pw_name != NULL);
  _dbus_assert (p->pw_dir != NULL);
  
  info->uid = p->pw_uid;
  info->primary_gid = p->pw_gid;
  info->username = _dbus_strdup (p->pw_name);
  info->homedir = _dbus_strdup (p->pw_dir);
  
  if (info->username == NULL ||
      info->homedir == NULL)
    {
      dbus_set_error (error, DBUS_ERROR_NO_MEMORY, NULL);
      return FALSE;
    }

  return TRUE;
}

static dbus_bool_t
fill_user_info (DBusUserInfo       *info,
                dbus_uid_t          uid,
                const DBusString   *username,
                DBusError          *error)
{
  const char *username_c;
  
  /* exactly one of username/uid provided */
  _dbus_assert (username != NULL || uid != DBUS_UID_UNSET);
  _dbus_assert (username == NULL || uid == DBUS_UID_UNSET);

  info->uid = DBUS_UID_UNSET;
  info->primary_gid = DBUS_GID_UNSET;
  info->group_ids = NULL;
  info->n_group_ids = 0;
  info->username = NULL;
  info->homedir = NULL;
  
  if (username != NULL)
    username_c = _dbus_string_get_const_data (username);
  else
    username_c = NULL;

  /* For now assuming that the getpwnam() and getpwuid() flavors
   * are always symmetrical, if not we have to add more configure
   * checks
   */
  
#if defined (HAVE_POSIX_GETPWNAM_R) || defined (HAVE_NONPOSIX_GETPWNAM_R)
  {
    struct passwd *p;
    int result;
    char buf[1024];
    struct passwd p_str;

    p = NULL;
#ifdef HAVE_POSIX_GETPWNAM_R
    if (uid != DBUS_UID_UNSET)
      result = getpwuid_r (uid, &p_str, buf, sizeof (buf),
                           &p);
    else
      result = getpwnam_r (username_c, &p_str, buf, sizeof (buf),
                           &p);
#else
    if (uid != DBUS_UID_UNSET)
      p = getpwuid_r (uid, &p_str, buf, sizeof (buf));
    else
      p = getpwnam_r (username_c, &p_str, buf, sizeof (buf));
    result = 0;
#endif /* !HAVE_POSIX_GETPWNAM_R */
    if (result == 0 && p == &p_str)
      {
        if (!fill_user_info_from_passwd (p, info, error))
          return FALSE;
      }
    else
      {
        dbus_set_error (error, _dbus_error_from_errno (errno),
                        "User \"%s\" unknown or no memory to allocate password entry\n",
                        username_c ? username_c : "???");
        _dbus_verbose ("User %s unknown\n", username_c ? username_c : "???");
        return FALSE;
      }
  }
#else /* ! HAVE_GETPWNAM_R */
  {
    /* I guess we're screwed on thread safety here */
    struct passwd *p;

    if (uid != DBUS_UID_UNSET)
      p = getpwuid (uid);
    else
      p = getpwnam (username_c);

    if (p != NULL)
      {
        if (!fill_user_info_from_passwd (p, info, error))
          return FALSE;
      }
    else
      {
        dbus_set_error (error, _dbus_error_from_errno (errno),
                        "User \"%s\" unknown or no memory to allocate password entry\n",
                        username_c ? username_c : "???");
        _dbus_verbose ("User %s unknown\n", username_c ? username_c : "???");
        return FALSE;
      }
  }
#endif  /* ! HAVE_GETPWNAM_R */

  /* Fill this in so we can use it to get groups */
  username_c = info->username;
  
#ifdef HAVE_GETGROUPLIST
  {
    gid_t *buf;
    int buf_count;
    int i;
    
    buf_count = 17;
    buf = dbus_new (gid_t, buf_count);
    if (buf == NULL)
      {
        dbus_set_error (error, DBUS_ERROR_NO_MEMORY, NULL);
        goto failed;
      }
    
    if (getgrouplist (username_c,
                      info->primary_gid,
                      buf, &buf_count) < 0)
      {
        gid_t *new = dbus_realloc (buf, buf_count * sizeof (buf[0]));
        if (new == NULL)
          {
            dbus_set_error (error, DBUS_ERROR_NO_MEMORY, NULL);
            dbus_free (buf);
            goto failed;
          }
        
        buf = new;

        errno = 0;
        if (getgrouplist (username_c, info->primary_gid, buf, &buf_count) < 0)
          {
            dbus_set_error (error,
                            _dbus_error_from_errno (errno),
                            "Failed to get groups for username \"%s\" primary GID "
                            DBUS_GID_FORMAT ": %s\n",
                            username_c, info->primary_gid,
                            _dbus_strerror (errno));
            dbus_free (buf);
            goto failed;
          }
      }

    info->group_ids = dbus_new (dbus_gid_t, buf_count);
    if (info->group_ids == NULL)
      {
        dbus_set_error (error, DBUS_ERROR_NO_MEMORY, NULL);
        dbus_free (buf);
        goto failed;
      }
    
    for (i = 0; i < buf_count; ++i)
      info->group_ids[i] = buf[i];

    info->n_group_ids = buf_count;
    
    dbus_free (buf);
  }
#else  /* HAVE_GETGROUPLIST */
  {
    /* We just get the one group ID */
    info->group_ids = dbus_new (dbus_gid_t, 1);
    if (info->group_ids == NULL)
      {
        dbus_set_error (error, DBUS_ERROR_NO_MEMORY, NULL);
        goto failed;
      }

    info->n_group_ids = 1;

    (info->group_ids)[0] = info->primary_gid;
  }
#endif /* HAVE_GETGROUPLIST */

  _DBUS_ASSERT_ERROR_IS_CLEAR (error);
  
  return TRUE;
  
 failed:
  _DBUS_ASSERT_ERROR_IS_SET (error);
  return FALSE;
}

dbus_bool_t
_dbus_user_info_fill (DBusUserInfo     *info,
                      const DBusString *username,
                      DBusError        *error)
{
  return fill_user_info (info, DBUS_UID_UNSET,
                         username, error);
}

dbus_bool_t
_dbus_user_info_fill_uid (DBusUserInfo *info,
                          dbus_uid_t    uid,
                          DBusError    *error)
{
  return fill_user_info (info, uid,
                         NULL, error);
}

void
_dbus_credentials_from_current_process (DBusCredentials *credentials)
{
  /* The POSIX spec certainly doesn't promise this, but
   * we need these assertions to fail as soon as we're wrong about
   * it so we can do the porting fixups
   */
  _dbus_assert (sizeof (pid_t) <= sizeof (credentials->pid));
  _dbus_assert (sizeof (uid_t) <= sizeof (credentials->uid));
  _dbus_assert (sizeof (gid_t) <= sizeof (credentials->gid));
  
  credentials->pid = getpid ();
  credentials->uid = getuid ();
  credentials->gid = getgid ();
}

unsigned long
_dbus_getpid (void)
{
  return getpid ();
}

dbus_uid_t
_dbus_getuid (void)
{
  return getuid ();
}

#ifdef DBUS_BUILD_TESTS

dbus_gid_t
_dbus_getgid (void)
{
  return getgid ();
}
#endif

int
_dbus_poll (DBusPollFD *fds,
            int         n_fds,
            int         timeout_milliseconds)
{
#ifdef HAVE_POLL
  /* This big thing is a constant expression and should get optimized
   * out of existence. So it's more robust than a configure check at
   * no cost.
   */
  if (_DBUS_POLLIN == POLLIN &&
      _DBUS_POLLPRI == POLLPRI &&
      _DBUS_POLLOUT == POLLOUT &&
      _DBUS_POLLERR == POLLERR &&
      _DBUS_POLLHUP == POLLHUP &&
      _DBUS_POLLNVAL == POLLNVAL &&
      sizeof (DBusPollFD) == sizeof (struct pollfd) &&
      _DBUS_STRUCT_OFFSET (DBusPollFD, fd) ==
      _DBUS_STRUCT_OFFSET (struct pollfd, fd) &&
      _DBUS_STRUCT_OFFSET (DBusPollFD, events) ==
      _DBUS_STRUCT_OFFSET (struct pollfd, events) &&
      _DBUS_STRUCT_OFFSET (DBusPollFD, revents) ==
      _DBUS_STRUCT_OFFSET (struct pollfd, revents))
    {
      return poll ((struct pollfd*) fds,
                   n_fds, 
                   timeout_milliseconds);
    }
  else
    {
      /* We have to convert the DBusPollFD to an array of
       * struct pollfd, poll, and convert back.
       */
      _dbus_warn ("didn't implement poll() properly for this system yet\n");
      return -1;
    }
#else /* ! HAVE_POLL */

  fd_set read_set, write_set, err_set;
  int max_fd = 0;
  int i;
  struct timeval tv;
  int ready;
  
  FD_ZERO (&read_set);
  FD_ZERO (&write_set);
  FD_ZERO (&err_set);

  for (i = 0; i < n_fds; i++)
    {
      DBusPollFD *fdp = &fds[i];

      if (fdp->events & _DBUS_POLLIN)
        FD_SET (fdp->fd, &read_set);

      if (fdp->events & _DBUS_POLLOUT)
        FD_SET (fdp->fd, &write_set);

      FD_SET (fdp->fd, &err_set);

      max_fd = MAX (max_fd, fdp->fd);
    }
    
  tv.tv_sec = timeout_milliseconds / 1000;
  tv.tv_usec = (timeout_milliseconds % 1000) * 1000;

  ready = select (max_fd + 1, &read_set, &write_set, &err_set,
                  timeout_milliseconds < 0 ? NULL : &tv);

  if (ready > 0)
    {
      for (i = 0; i < n_fds; i++)
        {
          DBusPollFD *fdp = &fds[i];

          fdp->revents = 0;

          if (FD_ISSET (fdp->fd, &read_set))
            fdp->revents |= _DBUS_POLLIN;

          if (FD_ISSET (fdp->fd, &write_set))
            fdp->revents |= _DBUS_POLLOUT;

          if (FD_ISSET (fdp->fd, &err_set))
            fdp->revents |= _DBUS_POLLERR;
        }
    }

  return ready;
#endif
}

void
_dbus_get_current_time (long *tv_sec,
                        long *tv_usec)
{
  struct timeval t;

  gettimeofday (&t, NULL);

  if (tv_sec)
    *tv_sec = t.tv_sec;
  if (tv_usec)
    *tv_usec = t.tv_usec;
}

dbus_bool_t
_dbus_file_get_contents (DBusString       *str,
                         const DBusString *filename,
                         DBusError        *error)
{
  int fd;
  struct stat sb;
  int orig_len;
  int total;
  const char *filename_c;

  _DBUS_ASSERT_ERROR_IS_CLEAR (error);
  
  filename_c = _dbus_string_get_const_data (filename);
  
  /* O_BINARY useful on Cygwin */
  fd = open (filename_c, O_RDONLY | O_BINARY);
  if (fd < 0)
    {
      dbus_set_error (error, _dbus_error_from_errno (errno),
                      "Failed to open \"%s\": %s",
                      filename_c,
                      _dbus_strerror (errno));
      return FALSE;
    }

  if (fstat (fd, &sb) < 0)
    {
      dbus_set_error (error, _dbus_error_from_errno (errno),
                      "Failed to stat \"%s\": %s",
                      filename_c,
                      _dbus_strerror (errno));

      _dbus_verbose ("fstat() failed: %s",
                     _dbus_strerror (errno));
      
      _dbus_close (fd, NULL);
      
      return FALSE;
    }

  if (sb.st_size > _DBUS_ONE_MEGABYTE)
    {
      dbus_set_error (error, DBUS_ERROR_FAILED,
                      "File size %lu of \"%s\" is too large.",
                      (unsigned long) sb.st_size, filename_c);
      _dbus_close (fd, NULL);
      return FALSE;
    }
  
  total = 0;
  orig_len = _dbus_string_get_length (str);
  if (sb.st_size > 0 && S_ISREG (sb.st_mode))
    {
      int bytes_read;

      while (total < (int) sb.st_size)
        {
          bytes_read = _dbus_read (fd, str,
                                   sb.st_size - total);
          if (bytes_read <= 0)
            {
              dbus_set_error (error, _dbus_error_from_errno (errno),
                              "Error reading \"%s\": %s",
                              filename_c,
                              _dbus_strerror (errno));

              _dbus_verbose ("read() failed: %s",
                             _dbus_strerror (errno));
              
              _dbus_close (fd, NULL);
              _dbus_string_set_length (str, orig_len);
              return FALSE;
            }
          else
            total += bytes_read;
        }

      _dbus_close (fd, NULL);
      return TRUE;
    }
  else if (sb.st_size != 0)
    {
      _dbus_verbose ("Can only open regular files at the moment.\n");
      dbus_set_error (error, DBUS_ERROR_FAILED,
                      "\"%s\" is not a regular file",
                      filename_c);
      _dbus_close (fd, NULL);
      return FALSE;
    }
  else
    {
      _dbus_close (fd, NULL);
      return TRUE;
    }
}

dbus_bool_t
_dbus_string_save_to_file (const DBusString *str,
                           const DBusString *filename,
                           DBusError        *error)
{
  int fd;
  int bytes_to_write;
  const char *filename_c;
  DBusString tmp_filename;
  const char *tmp_filename_c;
  int total;
  dbus_bool_t need_unlink;
  dbus_bool_t retval;

  _DBUS_ASSERT_ERROR_IS_CLEAR (error);
  
  fd = -1;
  retval = FALSE;
  need_unlink = FALSE;
  
  if (!_dbus_string_init (&tmp_filename))
    {
      dbus_set_error (error, DBUS_ERROR_NO_MEMORY, NULL);
      return FALSE;
    }

  if (!_dbus_string_copy (filename, 0, &tmp_filename, 0))
    {
      dbus_set_error (error, DBUS_ERROR_NO_MEMORY, NULL);
      _dbus_string_free (&tmp_filename);
      return FALSE;
    }
  
  if (!_dbus_string_append (&tmp_filename, "."))
    {
      dbus_set_error (error, DBUS_ERROR_NO_MEMORY, NULL);
      _dbus_string_free (&tmp_filename);
      return FALSE;
    }

#define N_TMP_FILENAME_RANDOM_BYTES 8
  if (!_dbus_generate_random_ascii (&tmp_filename, N_TMP_FILENAME_RANDOM_BYTES))
    {
      dbus_set_error (error, DBUS_ERROR_NO_MEMORY, NULL);
      _dbus_string_free (&tmp_filename);
      return FALSE;
    }
    
  filename_c = _dbus_string_get_const_data (filename);
  tmp_filename_c = _dbus_string_get_const_data (&tmp_filename);

  fd = open (tmp_filename_c, O_WRONLY | O_BINARY | O_EXCL | O_CREAT,
             0600);
  if (fd < 0)
    {
      dbus_set_error (error, _dbus_error_from_errno (errno),
                      "Could not create %s: %s", tmp_filename_c,
                      _dbus_strerror (errno));
      goto out;
    }

  need_unlink = TRUE;
  
  total = 0;
  bytes_to_write = _dbus_string_get_length (str);

  while (total < bytes_to_write)
    {
      int bytes_written;

      bytes_written = _dbus_write (fd, str, total,
                                   bytes_to_write - total);

      if (bytes_written <= 0)
        {
          dbus_set_error (error, _dbus_error_from_errno (errno),
                          "Could not write to %s: %s", tmp_filename_c,
                          _dbus_strerror (errno));
          
          goto out;
        }

      total += bytes_written;
    }

  if (!_dbus_close (fd, NULL))
    {
      dbus_set_error (error, _dbus_error_from_errno (errno),
                      "Could not close file %s: %s",
                      tmp_filename_c, _dbus_strerror (errno));

      goto out;
    }

  fd = -1;
  
  if (rename (tmp_filename_c, filename_c) < 0)
    {
      dbus_set_error (error, _dbus_error_from_errno (errno),
                      "Could not rename %s to %s: %s",
                      tmp_filename_c, filename_c,
                      _dbus_strerror (errno));

      goto out;
    }

  need_unlink = FALSE;
  
  retval = TRUE;
  
 out:
  /* close first, then unlink, to prevent ".nfs34234235" garbage
   * files
   */

  if (fd >= 0)
    _dbus_close (fd, NULL);
        
  if (need_unlink && unlink (tmp_filename_c) < 0)
    _dbus_verbose ("Failed to unlink temp file %s: %s\n",
                   tmp_filename_c, _dbus_strerror (errno));

  _dbus_string_free (&tmp_filename);

  if (!retval)
    _DBUS_ASSERT_ERROR_IS_SET (error);
  
  return retval;
}

dbus_bool_t
_dbus_make_file_world_readable(const DBusString *filename,
                               DBusError *error)
{
  const char *filename_c;

  _DBUS_ASSERT_ERROR_IS_CLEAR (error);

  filename_c = _dbus_string_get_const_data (filename);
  if (chmod (filename_c, 0644) == -1)
    {
      dbus_set_error (error,
                      DBUS_ERROR_FAILED,
                      "Could not change permissions of file %s: %s\n",
                      filename_c,
                      _dbus_strerror (errno));
      return FALSE;
    }
  return TRUE;
}

dbus_bool_t
_dbus_create_file_exclusively (const DBusString *filename,
                               DBusError        *error)
{
  int fd;
  const char *filename_c;

  _DBUS_ASSERT_ERROR_IS_CLEAR (error);
  
  filename_c = _dbus_string_get_const_data (filename);
  
  fd = open (filename_c, O_WRONLY | O_BINARY | O_EXCL | O_CREAT,
             0600);
  if (fd < 0)
    {
      dbus_set_error (error,
                      DBUS_ERROR_FAILED,
                      "Could not create file %s: %s\n",
                      filename_c,
                      _dbus_strerror (errno));
      return FALSE;
    }

  if (!_dbus_close (fd, NULL))
    {
      dbus_set_error (error,
                      DBUS_ERROR_FAILED,
                      "Could not close file %s: %s\n",
                      filename_c,
                      _dbus_strerror (errno));
      return FALSE;
    }
  
  return TRUE;
}

dbus_bool_t
_dbus_delete_file (const DBusString *filename,
                   DBusError        *error)
{
  const char *filename_c;

  _DBUS_ASSERT_ERROR_IS_CLEAR (error);
  
  filename_c = _dbus_string_get_const_data (filename);

  if (unlink (filename_c) < 0)
    {
      dbus_set_error (error, DBUS_ERROR_FAILED,
                      "Failed to delete file %s: %s\n",
                      filename_c, _dbus_strerror (errno));
      return FALSE;
    }
  else
    return TRUE;
}

dbus_bool_t
_dbus_create_directory (const DBusString *filename,
                        DBusError        *error)
{
  const char *filename_c;

  _DBUS_ASSERT_ERROR_IS_CLEAR (error);
  
  filename_c = _dbus_string_get_const_data (filename);

  if (mkdir (filename_c, 0700) < 0)
    {
      if (errno == EEXIST)
        return TRUE;
      
      dbus_set_error (error, DBUS_ERROR_FAILED,
                      "Failed to create directory %s: %s\n",
                      filename_c, _dbus_strerror (errno));
      return FALSE;
    }
  else
    return TRUE;
}

dbus_bool_t
_dbus_concat_dir_and_file (DBusString       *dir,
                           const DBusString *next_component)
{
  dbus_bool_t dir_ends_in_slash;
  dbus_bool_t file_starts_with_slash;

  if (_dbus_string_get_length (dir) == 0 ||
      _dbus_string_get_length (next_component) == 0)
    return TRUE;
  
  dir_ends_in_slash = '/' == _dbus_string_get_byte (dir,
                                                    _dbus_string_get_length (dir) - 1);

  file_starts_with_slash = '/' == _dbus_string_get_byte (next_component, 0);

  if (dir_ends_in_slash && file_starts_with_slash)
    {
      _dbus_string_shorten (dir, 1);
    }
  else if (!(dir_ends_in_slash || file_starts_with_slash))
    {
      if (!_dbus_string_append_byte (dir, '/'))
        return FALSE;
    }

  return _dbus_string_copy (next_component, 0, dir,
                            _dbus_string_get_length (dir));
}

#define NANOSECONDS_PER_SECOND       1000000000

#define MICROSECONDS_PER_SECOND      1000000

#define MILLISECONDS_PER_SECOND      1000

#define NANOSECONDS_PER_MILLISECOND  1000000

#define MICROSECONDS_PER_MILLISECOND 1000

void
_dbus_sleep_milliseconds (int milliseconds)
{
#ifdef HAVE_NANOSLEEP
  struct timespec req;
  struct timespec rem;

  req.tv_sec = milliseconds / MILLISECONDS_PER_SECOND;
  req.tv_nsec = (milliseconds % MILLISECONDS_PER_SECOND) * NANOSECONDS_PER_MILLISECOND;
  rem.tv_sec = 0;
  rem.tv_nsec = 0;

  while (nanosleep (&req, &rem) < 0 && errno == EINTR)
    req = rem;
#elif defined (HAVE_USLEEP)
  usleep (milliseconds * MICROSECONDS_PER_MILLISECOND);
#else /* ! HAVE_USLEEP */
  sleep (MAX (milliseconds / 1000, 1));
#endif
}

static dbus_bool_t
_dbus_generate_pseudorandom_bytes (DBusString *str,
                                   int         n_bytes)
{
  int old_len;
  char *p;
  
  old_len = _dbus_string_get_length (str);

  if (!_dbus_string_lengthen (str, n_bytes))
    return FALSE;

  p = _dbus_string_get_data_len (str, old_len, n_bytes);

  _dbus_generate_pseudorandom_bytes_buffer (p, n_bytes);

  return TRUE;
}

dbus_bool_t
_dbus_generate_random_bytes (DBusString *str,
                             int         n_bytes)
{
  int old_len;
  int fd;

  /* FALSE return means "no memory", if it could
   * mean something else then we'd need to return
   * a DBusError. So we always fall back to pseudorandom
   * if the I/O fails.
   */
  
  old_len = _dbus_string_get_length (str);
  fd = -1;

  /* note, urandom on linux will fall back to pseudorandom */
  fd = open ("/dev/urandom", O_RDONLY);
  if (fd < 0)
    return _dbus_generate_pseudorandom_bytes (str, n_bytes);

  if (_dbus_read (fd, str, n_bytes) != n_bytes)
    {
      _dbus_close (fd, NULL);
      _dbus_string_set_length (str, old_len);
      return _dbus_generate_pseudorandom_bytes (str, n_bytes);
    }

  _dbus_verbose ("Read %d bytes from /dev/urandom\n",
                 n_bytes);
  
  _dbus_close (fd, NULL);
  
  return TRUE;
}

void
_dbus_exit (int code)
{
  _exit (code);
}

const char*
_dbus_strerror (int error_number)
{
  const char *msg;
  
  msg = strerror (error_number);
  if (msg == NULL)
    msg = "unknown";

  return msg;
}

void
_dbus_disable_sigpipe (void)
{
  signal (SIGPIPE, SIG_IGN);
}

void
_dbus_fd_set_close_on_exec (int fd)
{
  int val;
  
  val = fcntl (fd, F_GETFD, 0);
  
  if (val < 0)
    return;

  val |= FD_CLOEXEC;
  
  fcntl (fd, F_SETFD, val);
}

dbus_bool_t
_dbus_close (int        fd,
             DBusError *error)
{
  _DBUS_ASSERT_ERROR_IS_CLEAR (error);
  
 again:
  if (close (fd) < 0)
    {
      if (errno == EINTR)
        goto again;

      dbus_set_error (error, _dbus_error_from_errno (errno),
                      "Could not close fd %d", fd);
      return FALSE;
    }

  return TRUE;
}

dbus_bool_t
_dbus_set_fd_nonblocking (int             fd,
                          DBusError      *error)
{
  int val;

  _DBUS_ASSERT_ERROR_IS_CLEAR (error);
  
  val = fcntl (fd, F_GETFL, 0);
  if (val < 0)
    {
      dbus_set_error (error, _dbus_error_from_errno (errno),
                      "Failed to get flags from file descriptor %d: %s",
                      fd, _dbus_strerror (errno));
      _dbus_verbose ("Failed to get flags for fd %d: %s\n", fd,
                     _dbus_strerror (errno));
      return FALSE;
    }

  if (fcntl (fd, F_SETFL, val | O_NONBLOCK) < 0)
    {
      dbus_set_error (error, _dbus_error_from_errno (errno),
                      "Failed to set nonblocking flag of file descriptor %d: %s",
                      fd, _dbus_strerror (errno));
      _dbus_verbose ("Failed to set fd %d nonblocking: %s\n",
                     fd, _dbus_strerror (errno));

      return FALSE;
    }

  return TRUE;
}

void
_dbus_print_backtrace (void)
{  
#if defined (HAVE_BACKTRACE) && defined (DBUS_BUILT_R_DYNAMIC)
  void *bt[500];
  int bt_size;
  int i;
  char **syms;
  
  bt_size = backtrace (bt, 500);

  syms = backtrace_symbols (bt, bt_size);
  
  i = 0;
  while (i < bt_size)
    {
      /* don't use dbus_warn since it can _dbus_abort() */
      fprintf (stderr, "  %s\n", syms[i]);
      ++i;
    }
  fflush (stderr);

  free (syms);
#elif defined (HAVE_BACKTRACE) && ! defined (DBUS_BUILT_R_DYNAMIC)
  fprintf (stderr, "  D-Bus not built with -rdynamic so unable to print a backtrace\n");
#else
  fprintf (stderr, "  D-Bus not compiled with backtrace support so unable to print a backtrace\n");
#endif
}

dbus_bool_t
_dbus_full_duplex_pipe (int        *fd1,
                        int        *fd2,
                        dbus_bool_t blocking,
                        DBusError  *error)
{
#ifdef HAVE_SOCKETPAIR
  int fds[2];

  _DBUS_ASSERT_ERROR_IS_CLEAR (error);
  
  if (socketpair (AF_UNIX, SOCK_STREAM, 0, fds) < 0)
    {
      dbus_set_error (error, _dbus_error_from_errno (errno),
                      "Could not create full-duplex pipe");
      return FALSE;
    }

  if (!blocking &&
      (!_dbus_set_fd_nonblocking (fds[0], NULL) ||
       !_dbus_set_fd_nonblocking (fds[1], NULL)))
    {
      dbus_set_error (error, _dbus_error_from_errno (errno),
                      "Could not set full-duplex pipe nonblocking");
      
      _dbus_close (fds[0], NULL);
      _dbus_close (fds[1], NULL);
      
      return FALSE;
    }
  
  *fd1 = fds[0];
  *fd2 = fds[1];

  _dbus_verbose ("full-duplex pipe %d <-> %d\n",
                 *fd1, *fd2);
  
  return TRUE;  
#else
  _dbus_warn ("_dbus_full_duplex_pipe() not implemented on this OS\n");
  dbus_set_error (error, DBUS_ERROR_FAILED,
                  "_dbus_full_duplex_pipe() not implemented on this OS");
  return FALSE;
#endif
}


int
_dbus_printf_string_upper_bound (const char *format,
                                 va_list     args)
{
  char c;
  return vsnprintf (&c, 1, format, args);
}

const char*
_dbus_get_tmpdir(void)
{
  static const char* tmpdir = NULL;

  if (tmpdir == NULL)
    {
      /* TMPDIR is what glibc uses, then
       * glibc falls back to the P_tmpdir macro which
       * just expands to "/tmp"
       */
      if (tmpdir == NULL)
        tmpdir = getenv("TMPDIR");

      /* These two env variables are probably
       * broken, but maybe some OS uses them?
       */
      if (tmpdir == NULL)
        tmpdir = getenv("TMP");
      if (tmpdir == NULL)
        tmpdir = getenv("TEMP");

      /* And this is the sane fallback. */
      if (tmpdir == NULL)
        tmpdir = "/tmp";
    }
  
  _dbus_assert(tmpdir != NULL);
  
  return tmpdir;
}

dbus_bool_t
_dbus_get_autolaunch_address (DBusString *address,
                              DBusError  *error)
{
  static char *argv[5];
  int address_pipe[2];
  pid_t pid;
  int ret;
  int status;
  int orig_len;
  int i;
  DBusString uuid;
  dbus_bool_t retval;
  
  _DBUS_ASSERT_ERROR_IS_CLEAR (error);
  retval = FALSE;

  _dbus_string_init (&uuid);
  
  if (!_dbus_get_local_machine_uuid_encoded (&uuid))
    {
      _DBUS_SET_OOM (error);
      goto out;
    }
  
  i = 0;
  argv[i] = "dbus-launch";
  ++i;
  argv[i] = "--autolaunch";
  ++i;
  argv[i] = _dbus_string_get_data (&uuid);
  ++i;
  argv[i] = "--binary-syntax";
  ++i;
  argv[i] = NULL;
  ++i;

  _dbus_assert (i == _DBUS_N_ELEMENTS (argv));
  
  orig_len = _dbus_string_get_length (address);
  
#define READ_END        0
#define WRITE_END       1
  if (pipe (address_pipe) < 0)
    {
      dbus_set_error (error, _dbus_error_from_errno (errno),
                      "Failed to create a pipe: %s",
                      _dbus_strerror (errno));
      _dbus_verbose ("Failed to create a pipe to call dbus-launch: %s\n",
                     _dbus_strerror (errno));
      goto out;
    }

  pid = fork ();
  if (pid < 0)
    {
      dbus_set_error (error, _dbus_error_from_errno (errno),
                      "Failed to fork(): %s",
                      _dbus_strerror (errno));
      _dbus_verbose ("Failed to fork() to call dbus-launch: %s\n",
                     _dbus_strerror (errno));
      goto out;
    }

  if (pid == 0)
    {
      /* child process */
      int fd = open ("/dev/null", O_RDWR);
      if (fd == -1)
        /* huh?! can't open /dev/null? */
        _exit (1);

      /* set-up stdXXX */
      close (address_pipe[READ_END]);
      close (0);                /* close stdin */
      close (1);                /* close stdout */
      close (2);                /* close stderr */

      if (dup2 (fd, 0) == -1)
        _exit (1);
      if (dup2 (address_pipe[WRITE_END], 1) == -1)
        _exit (1);
      if (dup2 (fd, 2) == -1)
        _exit (1);

      close (fd);
      close (address_pipe[WRITE_END]);

      execv (DBUS_BINDIR "/dbus-launch", argv);

      /* failed, try searching PATH */
      execvp ("dbus-launch", argv);

      /* still nothing, we failed */
      _exit (1);
    }

  /* parent process */
  close (address_pipe[WRITE_END]);
  ret = 0;
  do 
    {
      ret = _dbus_read (address_pipe[READ_END], address, 1024);
    }
  while (ret > 0);

  /* reap the child process to avoid it lingering as zombie */
  do
    {
      ret = waitpid (pid, &status, 0);
    }
  while (ret == -1 && errno == EINTR);

  /* We succeeded if the process exited with status 0 and
     anything was read */
  if (!WIFEXITED (status) || WEXITSTATUS (status) != 0 ||
      _dbus_string_get_length (address) == orig_len)
    {
      /* The process ended with error */
      _dbus_string_set_length (address, orig_len);
      dbus_set_error (error, DBUS_ERROR_SPAWN_EXEC_FAILED,
                      "Failed to execute dbus-launch to autolaunch D-Bus session");
      goto out;
    }

  retval = TRUE;
  
 out:
  if (retval)
    _DBUS_ASSERT_ERROR_IS_CLEAR (error);
  else
    _DBUS_ASSERT_ERROR_IS_SET (error);
  
  _dbus_string_free (&uuid);
  return retval;
}

dbus_bool_t
_dbus_read_local_machine_uuid (DBusGUID   *machine_id,
                               dbus_bool_t create_if_not_found,
                               DBusError  *error)
{
  DBusString filename;
  _dbus_string_init_const (&filename, DBUS_MACHINE_UUID_FILE);
  return _dbus_read_uuid_file (&filename, machine_id, create_if_not_found, error);
}

#define DBUS_UNIX_STANDARD_SESSION_SERVICEDIR "/dbus-1/services"

static dbus_bool_t
split_paths_and_append (DBusString *dirs, 
                        const char *suffix, 
                        DBusList **dir_list)
{
  /* split on colon (:) */
   int start;
   int i;
   int len;
   char *cpath;
   const DBusString file_suffix;

   start = 0;
   i = 0;

   _dbus_string_init_const (&file_suffix, suffix);

   len = _dbus_string_get_length (dirs);

   while (_dbus_string_find (dirs, start, ":", &i))
     {
       DBusString path;

       if (!_dbus_string_init (&path))
          goto oom;

       if (!_dbus_string_copy_len (dirs,
                                   start,
                                   i - start,
                                   &path,
                                   0))
          {
            _dbus_string_free (&path);
            goto oom;
          }

        _dbus_string_chop_white (&path);

        /* check for an empty path */
        if (_dbus_string_get_length (&path) == 0)
          goto next;

        if (!_dbus_concat_dir_and_file (&path,
                                        &file_suffix))
          {
            _dbus_string_free (&path);
            goto oom;
          }

        if (!_dbus_string_copy_data(&path, &cpath))
          {
            _dbus_string_free (&path);
            goto oom;
          }

        if (!_dbus_list_append (dir_list, cpath))
          {
            _dbus_string_free (&path);              
            dbus_free (cpath);
            goto oom;
          }

       next:
        _dbus_string_free (&path);
        start = i + 1;
    } 
      
  if (start != len)
    { 
      DBusString path;

      if (!_dbus_string_init (&path))
        goto oom;

      if (!_dbus_string_copy_len (dirs,
                                  start,
                                  len - start,
                                  &path,
                                  0))
        {
          _dbus_string_free (&path);
          goto oom;
        }

      if (!_dbus_concat_dir_and_file (&path,
                                      &file_suffix))
        {
          _dbus_string_free (&path);
          goto oom;
        }

      if (!_dbus_string_copy_data(&path, &cpath))
        {
          _dbus_string_free (&path);
          goto oom;
        }

      if (!_dbus_list_append (dir_list, cpath))
        {
          _dbus_string_free (&path);              
          dbus_free (cpath);
          goto oom;
        }

      _dbus_string_free (&path); 
    }

  return TRUE;

 oom:
  _dbus_list_foreach (dir_list, (DBusForeachFunction)dbus_free, NULL); 
  _dbus_list_clear (dir_list);
  return FALSE;
}

dbus_bool_t 
_dbus_get_standard_session_servicedirs (DBusList **dirs)
{
  const char *xdg_data_home;
  const char *xdg_data_dirs;
  DBusString servicedir_path;

  if (!_dbus_string_init (&servicedir_path))
    return FALSE;

  xdg_data_home = _dbus_getenv ("XDG_DATA_HOME");
  xdg_data_dirs = _dbus_getenv ("XDG_DATA_DIRS");

  if (xdg_data_dirs != NULL)
    {
      if (!_dbus_string_append (&servicedir_path, xdg_data_dirs))
        goto oom;

      if (!_dbus_string_append (&servicedir_path, ":"))
        goto oom;
    }
  else
    {
      if (!_dbus_string_append (&servicedir_path, "/usr/local/share:/usr/share:"))
        goto oom;
    }

  /* 
   * add configured datadir to defaults
   * this may be the same as an xdg dir
   * however the config parser should take 
   * care of duplicates 
   */
  if (!_dbus_string_append (&servicedir_path, DBUS_DATADIR":"))
        goto oom;

  if (xdg_data_home != NULL)
    {
      if (!_dbus_string_append (&servicedir_path, xdg_data_home))
        goto oom;
    }
  else
    {
      const DBusString *homedir;
      const DBusString local_share;

      if (!_dbus_homedir_from_current_process (&homedir))
        goto oom;
       
      if (!_dbus_string_append (&servicedir_path, _dbus_string_get_const_data (homedir)))
        goto oom;

      _dbus_string_init_const (&local_share, "/.local/share");
      if (!_dbus_concat_dir_and_file (&servicedir_path, &local_share))
        goto oom;
    }

  if (!split_paths_and_append (&servicedir_path, 
                               DBUS_UNIX_STANDARD_SESSION_SERVICEDIR, 
                               dirs))
    goto oom;

  _dbus_string_free (&servicedir_path);  
  return TRUE;

 oom:
  _dbus_string_free (&servicedir_path);
  return FALSE;
}

/* tests in dbus-sysdeps-util.c */

---