1/* -*- mode: C; c-file-style: "gnu" -*- */
2/* dbus-sysdeps.h Wrappers around system/libc features (internal to D-Bus implementation)
3 *
4 * Copyright (C) 2002, 2003  Red Hat, Inc.
5 * Copyright (C) 2003 CodeFactory AB
6 *
7 * Licensed under the Academic Free License version 2.1
8 *
9 * This program is free software; you can redistribute it and/or modify
10 * it under the terms of the GNU General Public License as published by
11 * the Free Software Foundation; either version 2 of the License, or
12 * (at your option) any later version.
13 *
14 * This program is distributed in the hope that it will be useful,
15 * but WITHOUT ANY WARRANTY; without even the implied warranty of
16 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
17 * GNU General Public License for more details.
18 *
19 * You should have received a copy of the GNU General Public License
20 * along with this program; if not, write to the Free Software
21 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
22 *
23 */
24
25#ifndef DBUS_SYSDEPS_H
26#define DBUS_SYSDEPS_H
27
28#include <config.h>
29
30#include <dbus/dbus-errors.h>
31
32/* this is perhaps bogus, but strcmp() etc. are faster if we use the
33 * stuff straight out of string.h, so have this here for now.
34 */
35#include <string.h>
36
37/* and it would just be annoying to abstract this */
38#include <errno.h>
39
40#include <stdarg.h>
41
42DBUS_BEGIN_DECLS
43
44/* Forward declarations */
45
46/** An opaque string type */
47typedef struct DBusString DBusString;
48
49/** An opaque list type */
50typedef struct DBusList DBusList;
51
52/**
53 * @addtogroup DBusSysdeps
54 *
55 * @{
56 */
57
58/* The idea of this file is to encapsulate everywhere that we're
59 * relying on external libc features, for ease of security
60 * auditing. The idea is from vsftpd. This also gives us a chance to
61 * make things more convenient to use, e.g.  by reading into a
62 * DBusString. Operating system headers aren't intended to be used
63 * outside of this file and a limited number of others (such as
64 * dbus-memory.c)
65 */
66
67#if     __GNUC__ > 2 || (__GNUC__ == 2 && __GNUC_MINOR__ > 4)
68#define _DBUS_GNUC_PRINTF( format_idx, arg_idx )    \
69  __attribute__((__format__ (__printf__, format_idx, arg_idx)))
70#define _DBUS_GNUC_NORETURN                         \
71  __attribute__((__noreturn__))
72#else   /* !__GNUC__ */
73#define _DBUS_GNUC_PRINTF( format_idx, arg_idx )
74#define _DBUS_GNUC_NORETURN
75#endif  /* !__GNUC__ */
76
77/** @def _DBUS_GNUC_PRINTF
78 * used to tell gcc about printf format strings
79 */
80/** @def _DBUS_GNUC_NORETURN
81 * used to tell gcc about functions that never return, such as _dbus_abort()
82 */
83
84void _dbus_abort (void) _DBUS_GNUC_NORETURN;
85
86const char* _dbus_getenv (const char *varname);
87dbus_bool_t _dbus_setenv (const char *varname,
88			  const char *value);
89
90/** A process ID */
91typedef unsigned long dbus_pid_t;
92/** A user ID */
93typedef unsigned long dbus_uid_t;
94/** A group ID */
95typedef unsigned long dbus_gid_t;
96
97/** an invalid PID used to represent an uninitialized dbus_pid_t field */
98#define DBUS_PID_UNSET ((dbus_pid_t) -1)
99/** an invalid UID used to represent an uninitialized dbus_uid_t field */
100#define DBUS_UID_UNSET ((dbus_uid_t) -1)
101/** an invalid GID used to represent an uninitialized dbus_gid_t field */
102#define DBUS_GID_UNSET ((dbus_gid_t) -1)
103
104/** an appropriate printf format for dbus_pid_t */
105#define DBUS_PID_FORMAT "%lu"
106/** an appropriate printf format for dbus_uid_t */
107#define DBUS_UID_FORMAT "%lu"
108/** an appropriate printf format for dbus_gid_t */
109#define DBUS_GID_FORMAT "%lu"
110
111
112/**
113 * Socket interface
114 *
115 *  @todo Use for the file descriptors a struct
116 *           - struct DBusSocket{ int d; }; -
117 *        instead of int to get type-safety which
118 *        will be checked by the compiler.
119 *
120 */
121
122dbus_bool_t _dbus_open_tcp_socket  (int              *fd,
123                                    DBusError        *error);
124dbus_bool_t _dbus_close_socket     (int               fd,
125                                    DBusError        *error);
126int         _dbus_read_socket      (int               fd,
127                                    DBusString       *buffer,
128                                    int               count);
129int         _dbus_write_socket     (int               fd,
130                                    const DBusString *buffer,
131                                    int               start,
132                                    int               len);
133int         _dbus_write_socket_two (int               fd,
134                                    const DBusString *buffer1,
135                                    int               start1,
136                                    int               len1,
137                                    const DBusString *buffer2,
138                                    int               start2,
139                                    int               len2);
140int _dbus_connect_tcp_socket  (const char     *host,
141                               dbus_uint32_t   port,
142                               DBusError      *error);
143int _dbus_listen_tcp_socket   (const char     *host,
144                               dbus_uint32_t   port,
145                               DBusError      *error);
146int _dbus_accept              (int             listen_fd);
147
148/**
149 * Struct representing socket credentials
150 */
151typedef struct
152{
153  dbus_pid_t pid; /**< process ID or DBUS_PID_UNSET */
154  dbus_uid_t uid; /**< user ID or DBUS_UID_UNSET */
155  dbus_gid_t gid; /**< group ID or DBUS_GID_UNSET */
156} DBusCredentials;
157
158/* FIXME these read/send credentials should get moved to sysdeps-unix.h,
159 * or renamed to reflect what they mean cross-platform
160 */
161dbus_bool_t _dbus_read_credentials_unix_socket (int              client_fd,
162                                                DBusCredentials *credentials,
163                                                DBusError       *error);
164dbus_bool_t _dbus_send_credentials_unix_socket (int              server_fd,
165                                                DBusError       *error);
166
167
168void        _dbus_credentials_clear                (DBusCredentials       *credentials);
169void        _dbus_credentials_from_current_process (DBusCredentials       *credentials);
170dbus_bool_t _dbus_credentials_match                (const DBusCredentials *expected_credentials,
171                                                    const DBusCredentials *provided_credentials);
172
173
174/** Information about a UNIX user */
175typedef struct DBusUserInfo  DBusUserInfo;
176/** Information about a UNIX group */
177typedef struct DBusGroupInfo DBusGroupInfo;
178
179/**
180 * Information about a UNIX user
181 */
182struct DBusUserInfo
183{
184  dbus_uid_t  uid;            /**< UID */
185  dbus_gid_t  primary_gid;    /**< GID */
186  dbus_gid_t *group_ids;      /**< Groups IDs, *including* above primary group */
187  int         n_group_ids;    /**< Size of group IDs array */
188  char       *username;       /**< Username */
189  char       *homedir;        /**< Home directory */
190};
191
192/**
193 * Information about a UNIX group
194 */
195struct DBusGroupInfo
196{
197  dbus_gid_t  gid;            /**< GID */
198  char       *groupname;      /**< Group name */
199};
200
201dbus_bool_t _dbus_user_info_fill     (DBusUserInfo     *info,
202                                      const DBusString *username,
203                                      DBusError        *error);
204dbus_bool_t _dbus_user_info_fill_uid (DBusUserInfo     *info,
205                                      dbus_uid_t        uid,
206                                      DBusError        *error);
207void        _dbus_user_info_free     (DBusUserInfo     *info);
208
209dbus_bool_t _dbus_group_info_fill     (DBusGroupInfo    *info,
210                                       const DBusString *groupname,
211                                       DBusError        *error);
212dbus_bool_t _dbus_group_info_fill_gid (DBusGroupInfo    *info,
213                                       dbus_gid_t        gid,
214                                       DBusError        *error);
215void        _dbus_group_info_free     (DBusGroupInfo    *info);
216
217
218unsigned long _dbus_getpid (void);
219dbus_uid_t    _dbus_getuid (void);
220dbus_gid_t    _dbus_getgid (void);
221
222/** Opaque type representing an atomically-modifiable integer
223 * that can be used from multiple threads.
224 */
225typedef struct DBusAtomic DBusAtomic;
226
227/**
228 * An atomic integer safe to increment or decrement from multiple threads.
229 */
230struct DBusAtomic
231{
232  volatile dbus_int32_t value; /**< Value of the atomic integer. */
233};
234
235dbus_int32_t _dbus_atomic_inc (DBusAtomic *atomic);
236dbus_int32_t _dbus_atomic_dec (DBusAtomic *atomic);
237
238/** There is data to read */
239#define _DBUS_POLLIN      0x0001
240/** There is urgent data to read */
241#define _DBUS_POLLPRI     0x0002
242/** Writing now will not block */
243#define _DBUS_POLLOUT     0x0004
244/** Error condition */
245#define _DBUS_POLLERR     0x0008
246/** Hung up */
247#define _DBUS_POLLHUP     0x0010
248/** Invalid request: fd not open */
249#define _DBUS_POLLNVAL    0x0020
250
251/**
252 * A portable struct pollfd wrapper.
253 */
254typedef struct
255{
256  int fd;            /**< File descriptor */
257  short events;      /**< Events to poll for */
258  short revents;     /**< Events that occurred */
259} DBusPollFD;
260
261int _dbus_poll (DBusPollFD *fds,
262                int         n_fds,
263                int         timeout_milliseconds);
264
265void _dbus_sleep_milliseconds (int milliseconds);
266
267void _dbus_get_current_time (long *tv_sec,
268                             long *tv_usec);
269
270/**
271 * File/directory interface
272 */
273dbus_bool_t _dbus_file_exists         (const char       *file);
274dbus_bool_t _dbus_file_get_contents   (DBusString       *str,
275                                       const DBusString *filename,
276                                       DBusError        *error);
277dbus_bool_t _dbus_string_save_to_file (const DBusString *str,
278                                       const DBusString *filename,
279                                       DBusError        *error);
280
281dbus_bool_t _dbus_make_file_world_readable   (const DBusString *filename,
282                                              DBusError *error);
283
284dbus_bool_t    _dbus_create_file_exclusively (const DBusString *filename,
285                                              DBusError        *error);
286dbus_bool_t    _dbus_delete_file             (const DBusString *filename,
287                                              DBusError        *error);
288dbus_bool_t    _dbus_create_directory        (const DBusString *filename,
289                                              DBusError        *error);
290dbus_bool_t    _dbus_delete_directory        (const DBusString *filename,
291					      DBusError        *error);
292
293dbus_bool_t _dbus_concat_dir_and_file (DBusString       *dir,
294                                       const DBusString *next_component);
295dbus_bool_t _dbus_string_get_dirname  (const DBusString *filename,
296                                       DBusString       *dirname);
297dbus_bool_t _dbus_path_is_absolute    (const DBusString *filename);
298
299dbus_bool_t _dbus_get_standard_session_servicedirs (DBusList **dirs);
300
301/** Opaque type for reading a directory listing */
302typedef struct DBusDirIter DBusDirIter;
303
304DBusDirIter* _dbus_directory_open          (const DBusString *filename,
305                                            DBusError        *error);
306dbus_bool_t  _dbus_directory_get_next_file (DBusDirIter      *iter,
307                                            DBusString       *filename,
308                                            DBusError        *error);
309void         _dbus_directory_close         (DBusDirIter      *iter);
310
311dbus_bool_t  _dbus_check_dir_is_private_to_user    (DBusString *dir,
312                                                    DBusError *error);
313
314void _dbus_fd_set_close_on_exec (int fd);
315
316const char* _dbus_get_tmpdir      (void);
317
318/**
319 * Random numbers
320 */
321void        _dbus_generate_pseudorandom_bytes_buffer (char *buffer,
322                                                      int   n_bytes);
323void        _dbus_generate_random_bytes_buffer (char       *buffer,
324                                                int         n_bytes);
325dbus_bool_t _dbus_generate_random_bytes        (DBusString *str,
326                                                int         n_bytes);
327dbus_bool_t _dbus_generate_random_ascii        (DBusString *str,
328                                                int         n_bytes);
329
330const char* _dbus_error_from_errno (int error_number);
331
332void _dbus_disable_sigpipe (void);
333
334
335void _dbus_exit (int code) _DBUS_GNUC_NORETURN;
336
337int _dbus_printf_string_upper_bound (const char *format,
338                                     va_list args);
339
340
341/**
342 * Portable struct with stat() results
343 */
344typedef struct
345{
346  unsigned long mode;  /**< File mode */
347  unsigned long nlink; /**< Number of hard links */
348  dbus_uid_t    uid;   /**< User owning file */
349  dbus_gid_t    gid;   /**< Group owning file */
350  unsigned long size;  /**< Size of file */
351  unsigned long atime; /**< Access time */
352  unsigned long mtime; /**< Modify time */
353  unsigned long ctime; /**< Creation time */
354} DBusStat;
355
356dbus_bool_t _dbus_stat             (const DBusString *filename,
357                                    DBusStat         *statbuf,
358                                    DBusError        *error);
359dbus_bool_t _dbus_full_duplex_pipe (int              *fd1,
360                                    int              *fd2,
361                                    dbus_bool_t       blocking,
362                                    DBusError        *error);
363
364void        _dbus_print_backtrace  (void);
365
366dbus_bool_t _dbus_become_daemon   (const DBusString *pidfile,
367				   int               print_pid_fd,
368                                   DBusError        *error);
369dbus_bool_t _dbus_write_pid_file  (const DBusString *filename,
370                                   unsigned long     pid,
371                                   DBusError        *error);
372dbus_bool_t _dbus_change_identity (unsigned long     uid,
373                                   unsigned long     gid,
374                                   DBusError        *error);
375
376/** A UNIX signal handler */
377typedef void (* DBusSignalHandler) (int sig);
378
379void _dbus_set_signal_handler (int               sig,
380                               DBusSignalHandler handler);
381
382dbus_bool_t _dbus_user_at_console (const char *username,
383                                   DBusError  *error);
384
385/* Define DBUS_VA_COPY() to do the right thing for copying va_list variables.
386 * config.h may have already defined DBUS_VA_COPY as va_copy or __va_copy.
387 */
388#if !defined (DBUS_VA_COPY)
389#  if defined (__GNUC__) && defined (__PPC__) && (defined (_CALL_SYSV) || defined (_WIN32))
390#    define DBUS_VA_COPY(ap1, ap2)   (*(ap1) = *(ap2))
391#  elif defined (DBUS_VA_COPY_AS_ARRAY)
392#    define DBUS_VA_COPY(ap1, ap2)   memcpy ((ap1), (ap2), sizeof (va_list))
393#  else /* va_list is a pointer */
394#    define DBUS_VA_COPY(ap1, ap2)   ((ap1) = (ap2))
395#  endif /* va_list is a pointer */
396#endif /* !DBUS_VA_COPY */
397
398
399/**
400 * Casts a primitive C type to a byte array and then indexes
401 * a particular byte of the array.
402 */
403#define _DBUS_BYTE_OF_PRIMITIVE(p, i) \
404    (((const char*)&(p))[(i)])
405/** On x86 there is an 80-bit FPU, and if you do "a == b" it may have a
406 * or b in an 80-bit register, thus failing to compare the two 64-bit
407 * doubles for bitwise equality. So this macro compares the two doubles
408 * bitwise.
409 */
410#define _DBUS_DOUBLES_BITWISE_EQUAL(a, b)                                       \
411     (_DBUS_BYTE_OF_PRIMITIVE (a, 0) == _DBUS_BYTE_OF_PRIMITIVE (b, 0) &&       \
412      _DBUS_BYTE_OF_PRIMITIVE (a, 1) == _DBUS_BYTE_OF_PRIMITIVE (b, 1) &&       \
413      _DBUS_BYTE_OF_PRIMITIVE (a, 2) == _DBUS_BYTE_OF_PRIMITIVE (b, 2) &&       \
414      _DBUS_BYTE_OF_PRIMITIVE (a, 3) == _DBUS_BYTE_OF_PRIMITIVE (b, 3) &&       \
415      _DBUS_BYTE_OF_PRIMITIVE (a, 4) == _DBUS_BYTE_OF_PRIMITIVE (b, 4) &&       \
416      _DBUS_BYTE_OF_PRIMITIVE (a, 5) == _DBUS_BYTE_OF_PRIMITIVE (b, 5) &&       \
417      _DBUS_BYTE_OF_PRIMITIVE (a, 6) == _DBUS_BYTE_OF_PRIMITIVE (b, 6) &&       \
418      _DBUS_BYTE_OF_PRIMITIVE (a, 7) == _DBUS_BYTE_OF_PRIMITIVE (b, 7))
419
420dbus_bool_t _dbus_parse_uid (const DBusString  *uid_str,
421                             dbus_uid_t        *uid);
422
423dbus_bool_t _dbus_get_autolaunch_address (DBusString *address,
424					  DBusError *error);
425
426/** Type representing a universally unique ID
427 * @todo rename to UUID instead of GUID
428 */
429typedef union DBusGUID DBusGUID;
430
431dbus_bool_t _dbus_read_local_machine_uuid   (DBusGUID         *machine_id,
432                                             dbus_bool_t       create_if_not_found,
433                                             DBusError        *error);
434
435/**
436 * Initialize threads as in dbus_threads_init_default(), appropriately
437 * for the platform.
438 * @returns #FALSE if no memory
439 */
440dbus_bool_t _dbus_threads_init_platform_specific (void);
441
442/** @} */
443
444DBUS_END_DECLS
445
446#endif /* DBUS_SYSDEPS_H */
447