1 /* -*- mode: C; c-file-style: "gnu"; indent-tabs-mode: nil; -*- */
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., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301  USA
22  *
23  */
24 
25 #ifndef DBUS_SYSDEPS_H
26 #define DBUS_SYSDEPS_H
27 
28 #include "config.h"
29 
30 #ifdef HAVE_STDINT_H
31 #include <stdint.h>
32 #endif
33 
34 #ifdef HAVE_INTTYPES_H
35 #include <inttypes.h>
36 #endif
37 
38 #include <dbus/dbus-errors.h>
39 #include <dbus/dbus-file.h>
40 #include <dbus/dbus-string.h>
41 
42 /* this is perhaps bogus, but strcmp() etc. are faster if we use the
43  * stuff straight out of string.h, so have this here for now.
44  */
45 #include <string.h>
46 #include <stdarg.h>
47 
48 /* AIX sys/poll.h does #define events reqevents, and other
49  * wonderousness, so must include sys/poll before declaring
50  * DBusPollFD
51  */
52 #ifdef HAVE_POLL
53 #include <sys/poll.h>
54 #endif
55 
56 #ifdef DBUS_WINCE
57 /* Windows CE lacks some system functions (such as errno and clock).
58    We bring them in here.  */
59 #include "dbus-sysdeps-wince-glue.h"
60 #endif
61 
62 DBUS_BEGIN_DECLS
63 
64 #ifdef DBUS_WIN
65 #define _DBUS_PATH_SEPARATOR ";"
66 #else
67 #define _DBUS_PATH_SEPARATOR ":"
68 #endif
69 
70 /* Forward declarations */
71 
72 
73 /** An opaque list type */
74 typedef struct DBusList DBusList;
75 
76 /** Object that contains a list of credentials such as UNIX or Windows user ID */
77 typedef struct DBusCredentials DBusCredentials;
78 
79 /** A wrapper around a pipe descriptor or handle */
80 typedef struct DBusPipe DBusPipe;
81 
82 /**
83  * @addtogroup DBusSysdeps
84  *
85  * @{
86  */
87 
88 void _dbus_abort (void) _DBUS_GNUC_NORETURN;
89 
90 dbus_bool_t _dbus_check_setuid (void);
91 const char* _dbus_getenv (const char *varname);
92 dbus_bool_t _dbus_setenv (const char *varname,
93 			  const char *value);
94 dbus_bool_t _dbus_clearenv (void);
95 char **     _dbus_get_environment (void);
96 
97 /** A process ID */
98 typedef unsigned long dbus_pid_t;
99 /** A user ID */
100 typedef unsigned long dbus_uid_t;
101 /** A group ID */
102 typedef unsigned long dbus_gid_t;
103 
104 /** an invalid PID used to represent an uninitialized dbus_pid_t field */
105 #define DBUS_PID_UNSET ((dbus_pid_t) -1)
106 /** an invalid UID used to represent an uninitialized dbus_uid_t field */
107 #define DBUS_UID_UNSET ((dbus_uid_t) -1)
108 /** an invalid GID used to represent an uninitialized dbus_gid_t field */
109 #define DBUS_GID_UNSET ((dbus_gid_t) -1)
110 
111 /** an appropriate printf format for dbus_pid_t */
112 #define DBUS_PID_FORMAT "%lu"
113 /** an appropriate printf format for dbus_uid_t */
114 #define DBUS_UID_FORMAT "%lu"
115 /** an appropriate printf format for dbus_gid_t */
116 #define DBUS_GID_FORMAT "%lu"
117 
118 
119 /**
120  * Socket interface
121  *
122  *  @todo Use for the file descriptors a struct
123  *           - struct DBusSocket{ int d; }; -
124  *        instead of int to get type-safety which
125  *        will be checked by the compiler.
126  *
127  */
128 
129 dbus_bool_t _dbus_close_socket     (int               fd,
130                                     DBusError        *error);
131 int         _dbus_read_socket      (int               fd,
132                                     DBusString       *buffer,
133                                     int               count);
134 int         _dbus_write_socket     (int               fd,
135                                     const DBusString *buffer,
136                                     int               start,
137                                     int               len);
138 int         _dbus_write_socket_two (int               fd,
139                                     const DBusString *buffer1,
140                                     int               start1,
141                                     int               len1,
142                                     const DBusString *buffer2,
143                                     int               start2,
144                                     int               len2);
145 
146 int _dbus_read_socket_with_unix_fds      (int               fd,
147                                           DBusString       *buffer,
148                                           int               count,
149                                           int              *fds,
150                                           int              *n_fds);
151 int _dbus_write_socket_with_unix_fds     (int               fd,
152                                           const DBusString *buffer,
153                                           int               start,
154                                           int               len,
155                                           const int        *fds,
156                                           int               n_fds);
157 int _dbus_write_socket_with_unix_fds_two (int               fd,
158                                           const DBusString *buffer1,
159                                           int               start1,
160                                           int               len1,
161                                           const DBusString *buffer2,
162                                           int               start2,
163                                           int               len2,
164                                           const int        *fds,
165                                           int               n_fds);
166 
167 dbus_bool_t _dbus_socket_is_invalid (int              fd);
168 
169 int _dbus_connect_tcp_socket  (const char     *host,
170                                const char     *port,
171                                const char     *family,
172                                DBusError      *error);
173 int _dbus_connect_tcp_socket_with_nonce  (const char     *host,
174                                           const char     *port,
175                                           const char     *family,
176                                           const char     *noncefile,
177                                           DBusError      *error);
178 int _dbus_listen_tcp_socket   (const char     *host,
179                                const char     *port,
180                                const char     *family,
181                                DBusString     *retport,
182                                int           **fds_p,
183                                DBusError      *error);
184 int _dbus_accept              (int             listen_fd);
185 
186 
187 dbus_bool_t _dbus_read_credentials_socket (int               client_fd,
188                                            DBusCredentials  *credentials,
189                                            DBusError        *error);
190 dbus_bool_t _dbus_send_credentials_socket (int              server_fd,
191                                            DBusError       *error);
192 
193 dbus_bool_t _dbus_credentials_add_from_user            (DBusCredentials  *credentials,
194                                                         const DBusString *username);
195 dbus_bool_t _dbus_credentials_add_from_current_process (DBusCredentials  *credentials);
196 dbus_bool_t _dbus_append_user_from_current_process     (DBusString        *str);
197 
198 dbus_bool_t _dbus_parse_unix_user_from_config   (const DBusString  *username,
199                                                  dbus_uid_t        *uid_p);
200 dbus_bool_t _dbus_parse_unix_group_from_config  (const DBusString  *groupname,
201                                                  dbus_gid_t        *gid_p);
202 dbus_bool_t _dbus_unix_groups_from_uid          (dbus_uid_t         uid,
203                                                  dbus_gid_t       **group_ids,
204                                                  int               *n_group_ids);
205 dbus_bool_t _dbus_unix_user_is_at_console       (dbus_uid_t         uid,
206                                                  DBusError         *error);
207 dbus_bool_t _dbus_unix_user_is_process_owner    (dbus_uid_t         uid);
208 dbus_bool_t _dbus_windows_user_is_process_owner (const char        *windows_sid);
209 
210 dbus_bool_t _dbus_append_keyring_directory_for_credentials (DBusString      *directory,
211                                                             DBusCredentials *credentials);
212 
213 dbus_bool_t _dbus_daemon_is_session_bus_address_published (const char *scope);
214 
215 dbus_bool_t _dbus_daemon_publish_session_bus_address (const char* address, const char* shm_name);
216 
217 void _dbus_daemon_unpublish_session_bus_address (void);
218 
219 dbus_bool_t _dbus_socket_can_pass_unix_fd(int fd);
220 
221 /** Opaque type representing an atomically-modifiable integer
222  * that can be used from multiple threads.
223  */
224 typedef struct DBusAtomic DBusAtomic;
225 
226 /**
227  * An atomic integer safe to increment or decrement from multiple threads.
228  */
229 struct DBusAtomic
230 {
231 #ifdef DBUS_WIN
232   volatile long value; /**< Value of the atomic integer. */
233 #else
234   volatile dbus_int32_t value; /**< Value of the atomic integer. */
235 #endif
236 };
237 
238 /* The value we get from autofoo is in the form of a cpp expression;
239  * convert that to a conventional defined/undef switch. (We can't get
240  * the conventional defined/undef because of multiarch builds only running
241  * ./configure once, on Darwin.) */
242 #if DBUS_HAVE_ATOMIC_INT_COND
243 #   define DBUS_HAVE_ATOMIC_INT 1
244 #else
245 #   undef DBUS_HAVE_ATOMIC_INT
246 #endif
247 
248 dbus_int32_t _dbus_atomic_inc (DBusAtomic *atomic);
249 dbus_int32_t _dbus_atomic_dec (DBusAtomic *atomic);
250 dbus_int32_t _dbus_atomic_get (DBusAtomic *atomic);
251 
252 
253 /* AIX uses different values for poll */
254 
255 #ifdef _AIX
256 /** There is data to read */
257 #define _DBUS_POLLIN      0x0001
258 /** There is urgent data to read */
259 #define _DBUS_POLLPRI     0x0004
260 /** Writing now will not block */
261 #define _DBUS_POLLOUT     0x0002
262 /** Error condition */
263 #define _DBUS_POLLERR     0x4000
264 /** Hung up */
265 #define _DBUS_POLLHUP     0x2000
266 /** Invalid request: fd not open */
267 #define _DBUS_POLLNVAL    0x8000
268 #elif defined(__HAIKU__)
269 /** There is data to read */
270 #define _DBUS_POLLIN      0x0001
271 /** Writing now will not block */
272 #define _DBUS_POLLOUT     0x0002
273 /** Error condition */
274 #define _DBUS_POLLERR     0x0004
275 /** There is urgent data to read */
276 #define _DBUS_POLLPRI     0x0020
277 /** Hung up */
278 #define _DBUS_POLLHUP     0x0080
279 /** Invalid request: fd not open */
280 #define _DBUS_POLLNVAL    0x1000
281 #else
282 /** There is data to read */
283 #define _DBUS_POLLIN      0x0001
284 /** There is urgent data to read */
285 #define _DBUS_POLLPRI     0x0002
286 /** Writing now will not block */
287 #define _DBUS_POLLOUT     0x0004
288 /** Error condition */
289 #define _DBUS_POLLERR     0x0008
290 /** Hung up */
291 #define _DBUS_POLLHUP     0x0010
292 /** Invalid request: fd not open */
293 #define _DBUS_POLLNVAL    0x0020
294 #endif
295 
296 /**
297  * A portable struct pollfd wrapper.
298  */
299 typedef struct
300 {
301   int fd;            /**< File descriptor */
302   short events;      /**< Events to poll for */
303   short revents;     /**< Events that occurred */
304 } DBusPollFD;
305 
306 int _dbus_poll (DBusPollFD *fds,
307                 int         n_fds,
308                 int         timeout_milliseconds);
309 
310 void _dbus_sleep_milliseconds (int milliseconds);
311 
312 void _dbus_get_monotonic_time (long *tv_sec,
313                                long *tv_usec);
314 
315 void _dbus_get_real_time (long *tv_sec,
316                           long *tv_usec);
317 
318 /**
319  * directory interface
320  */
321 dbus_bool_t    _dbus_create_directory        (const DBusString *filename,
322                                               DBusError        *error);
323 dbus_bool_t    _dbus_delete_directory        (const DBusString *filename,
324 					      DBusError        *error);
325 
326 dbus_bool_t _dbus_concat_dir_and_file (DBusString       *dir,
327                                        const DBusString *next_component);
328 dbus_bool_t _dbus_string_get_dirname  (const DBusString *filename,
329                                        DBusString       *dirname);
330 dbus_bool_t _dbus_path_is_absolute    (const DBusString *filename);
331 
332 dbus_bool_t _dbus_get_standard_session_servicedirs (DBusList **dirs);
333 dbus_bool_t _dbus_get_standard_system_servicedirs (DBusList **dirs);
334 
335 dbus_bool_t _dbus_append_system_config_file  (DBusString *str);
336 dbus_bool_t _dbus_append_session_config_file (DBusString *str);
337 
338 /** Opaque type for reading a directory listing */
339 typedef struct DBusDirIter DBusDirIter;
340 
341 DBusDirIter* _dbus_directory_open          (const DBusString *filename,
342                                             DBusError        *error);
343 dbus_bool_t  _dbus_directory_get_next_file (DBusDirIter      *iter,
344                                             DBusString       *filename,
345                                             DBusError        *error);
346 void         _dbus_directory_close         (DBusDirIter      *iter);
347 
348 dbus_bool_t  _dbus_check_dir_is_private_to_user    (DBusString *dir,
349                                                     DBusError *error);
350 
351 void _dbus_fd_set_close_on_exec (intptr_t fd);
352 
353 const char* _dbus_get_tmpdir      (void);
354 
355 /**
356  * Random numbers
357  */
358 void        _dbus_generate_pseudorandom_bytes_buffer (char *buffer,
359                                                       int   n_bytes);
360 void        _dbus_generate_random_bytes_buffer (char       *buffer,
361                                                 int         n_bytes);
362 dbus_bool_t _dbus_generate_random_bytes        (DBusString *str,
363                                                 int         n_bytes);
364 dbus_bool_t _dbus_generate_random_ascii        (DBusString *str,
365                                                 int         n_bytes);
366 
367 const char* _dbus_error_from_errno (int error_number);
368 const char* _dbus_error_from_system_errno (void);
369 
370 void        _dbus_set_errno_to_zero                  (void);
371 dbus_bool_t _dbus_get_is_errno_nonzero               (void);
372 dbus_bool_t _dbus_get_is_errno_eagain_or_ewouldblock (void);
373 dbus_bool_t _dbus_get_is_errno_enomem                (void);
374 dbus_bool_t _dbus_get_is_errno_eintr                 (void);
375 dbus_bool_t _dbus_get_is_errno_epipe                 (void);
376 const char* _dbus_strerror_from_errno                (void);
377 
378 void _dbus_disable_sigpipe (void);
379 
380 
381 void _dbus_exit (int code) _DBUS_GNUC_NORETURN;
382 
383 int _dbus_printf_string_upper_bound (const char *format,
384                                      va_list args);
385 
386 
387 /**
388  * Portable struct with stat() results
389  */
390 typedef struct
391 {
392   unsigned long mode;  /**< File mode */
393   unsigned long nlink; /**< Number of hard links */
394   dbus_uid_t    uid;   /**< User owning file */
395   dbus_gid_t    gid;   /**< Group owning file */
396   unsigned long size;  /**< Size of file */
397   unsigned long atime; /**< Access time */
398   unsigned long mtime; /**< Modify time */
399   unsigned long ctime; /**< Creation time */
400 } DBusStat;
401 
402 dbus_bool_t _dbus_stat             (const DBusString *filename,
403                                     DBusStat         *statbuf,
404                                     DBusError        *error);
405 dbus_bool_t _dbus_full_duplex_pipe (int              *fd1,
406                                     int              *fd2,
407                                     dbus_bool_t       blocking,
408                                     DBusError        *error);
409 
410 void        _dbus_print_backtrace  (void);
411 
412 dbus_bool_t _dbus_become_daemon   (const DBusString *pidfile,
413                                    DBusPipe         *print_pid_pipe,
414                                    DBusError        *error,
415                                    dbus_bool_t       keep_umask);
416 
417 dbus_bool_t _dbus_verify_daemon_user    (const char *user);
418 dbus_bool_t _dbus_change_to_daemon_user (const char *user,
419                                          DBusError  *error);
420 
421 dbus_bool_t _dbus_write_pid_to_file_and_pipe (const DBusString *pidfile,
422                                               DBusPipe         *print_pid_pipe,
423                                               dbus_pid_t        pid_to_write,
424                                               DBusError        *error);
425 
426 dbus_bool_t _dbus_command_for_pid (unsigned long  pid,
427                                    DBusString    *str,
428                                    int            max_len,
429                                    DBusError     *error);
430 
431 /** A UNIX signal handler */
432 typedef void (* DBusSignalHandler) (int sig);
433 
434 void _dbus_set_signal_handler (int               sig,
435                                DBusSignalHandler handler);
436 
437 dbus_bool_t _dbus_user_at_console (const char *username,
438                                    DBusError  *error);
439 
440 void _dbus_init_system_log (void);
441 
442 typedef enum {
443   DBUS_SYSTEM_LOG_INFO,
444   DBUS_SYSTEM_LOG_SECURITY,
445   DBUS_SYSTEM_LOG_FATAL
446 } DBusSystemLogSeverity;
447 
448 void _dbus_system_log (DBusSystemLogSeverity severity, const char *msg, ...) _DBUS_GNUC_PRINTF (2, 3);
449 void _dbus_system_logv (DBusSystemLogSeverity severity, const char *msg, va_list args);
450 
451 /* Define DBUS_VA_COPY() to do the right thing for copying va_list variables.
452  * config.h may have already defined DBUS_VA_COPY as va_copy or __va_copy.
453  */
454 #if !defined (DBUS_VA_COPY)
455 #  if defined (__GNUC__) && defined (__PPC__) && (defined (_CALL_SYSV) || defined (_WIN32))
456 #    define DBUS_VA_COPY(ap1, ap2)   (*(ap1) = *(ap2))
457 #  elif defined (DBUS_VA_COPY_AS_ARRAY)
458 #    define DBUS_VA_COPY(ap1, ap2)   memcpy ((ap1), (ap2), sizeof (va_list))
459 #  else /* va_list is a pointer */
460 #    define DBUS_VA_COPY(ap1, ap2)   ((ap1) = (ap2))
461 #  endif /* va_list is a pointer */
462 #endif /* !DBUS_VA_COPY */
463 
464 
465 /**
466  * Casts a primitive C type to a byte array and then indexes
467  * a particular byte of the array.
468  */
469 #define _DBUS_BYTE_OF_PRIMITIVE(p, i) \
470     (((const char*)&(p))[(i)])
471 /** On x86 there is an 80-bit FPU, and if you do "a == b" it may have a
472  * or b in an 80-bit register, thus failing to compare the two 64-bit
473  * doubles for bitwise equality. So this macro compares the two doubles
474  * bitwise.
475  */
476 #define _DBUS_DOUBLES_BITWISE_EQUAL(a, b)                                       \
477      (_DBUS_BYTE_OF_PRIMITIVE (a, 0) == _DBUS_BYTE_OF_PRIMITIVE (b, 0) &&       \
478       _DBUS_BYTE_OF_PRIMITIVE (a, 1) == _DBUS_BYTE_OF_PRIMITIVE (b, 1) &&       \
479       _DBUS_BYTE_OF_PRIMITIVE (a, 2) == _DBUS_BYTE_OF_PRIMITIVE (b, 2) &&       \
480       _DBUS_BYTE_OF_PRIMITIVE (a, 3) == _DBUS_BYTE_OF_PRIMITIVE (b, 3) &&       \
481       _DBUS_BYTE_OF_PRIMITIVE (a, 4) == _DBUS_BYTE_OF_PRIMITIVE (b, 4) &&       \
482       _DBUS_BYTE_OF_PRIMITIVE (a, 5) == _DBUS_BYTE_OF_PRIMITIVE (b, 5) &&       \
483       _DBUS_BYTE_OF_PRIMITIVE (a, 6) == _DBUS_BYTE_OF_PRIMITIVE (b, 6) &&       \
484       _DBUS_BYTE_OF_PRIMITIVE (a, 7) == _DBUS_BYTE_OF_PRIMITIVE (b, 7))
485 
486 dbus_bool_t _dbus_get_autolaunch_address (const char *scope,
487                                           DBusString *address,
488 					                      DBusError  *error);
489 
490 dbus_bool_t _dbus_lookup_session_address (dbus_bool_t *supported,
491                                           DBusString  *address,
492                                           DBusError   *error);
493 
494 /** Type representing a universally unique ID
495  * @todo rename to UUID instead of GUID
496  */
497 typedef union DBusGUID DBusGUID;
498 
499 dbus_bool_t _dbus_read_local_machine_uuid   (DBusGUID         *machine_id,
500                                              dbus_bool_t       create_if_not_found,
501                                              DBusError        *error);
502 
503 /**
504  * Initialize threads as in dbus_threads_init_default(), appropriately
505  * for the platform.
506  * @returns #FALSE if no memory
507  */
508 dbus_bool_t _dbus_threads_init_platform_specific (void);
509 
510 dbus_bool_t _dbus_split_paths_and_append (DBusString *dirs,
511                                           const char *suffix,
512                                           DBusList **dir_list);
513 
514 unsigned long _dbus_pid_for_log (void);
515 
516 /* FIXME move back to dbus-sysdeps-unix.h probably -
517  * the PID file handling just needs a little more abstraction
518  * in the bus daemon first.
519  */
520 dbus_pid_t    _dbus_getpid (void);
521 
522 dbus_bool_t _dbus_change_to_daemon_user (const char *user,
523                                          DBusError  *error);
524 
525 void _dbus_flush_caches (void);
526 
527 void _dbus_request_file_descriptor_limit (unsigned int limit);
528 
529 /*
530  * replaces the term DBUS_PREFIX in configure_time_path by the
531  * current dbus installation directory. On unix this function is a noop
532  *
533  * @param configure_time_path
534  * @return real path
535  */
536 const char *
537 _dbus_replace_install_prefix (const char *configure_time_path);
538 
539 /** @} */
540 
541 DBUS_END_DECLS
542 
543 
544 #ifdef DBUS_WIN
545 #include "dbus-sysdeps-win.h"
546 #endif
547 
548 #endif /* DBUS_SYSDEPS_H */
549