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