summaryrefslogtreecommitdiff
path: root/src/include/gnunet_os_lib.h
blob: d43711a99fbe2590640d0076d0ccbb6957735a37 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
591
592
593
594
595
596
597
598
599
600
601
602
603
604
605
606
607
608
609
610
611
612
613
614
615
616
617
618
619
620
621
622
623
624
625
626
627
628
629
630
631
632
633
634
635
636
637
638
639
640
641
642
643
644
645
646
647
648
649
650
651
652
653
654
655
656
657
658
659
660
661
662
663
664
665
666
667
668
669
670
671
672
673
674
675
676
677
678
/*
     This file is part of GNUnet.
     Copyright (C) 2001, 2002, 2003, 2004, 2005, 2006, 2011 GNUnet e.V.

     GNUnet is free software: you can redistribute it and/or modify it
     under the terms of the GNU Affero General Public License as published
     by the Free Software Foundation, either version 3 of the License,
     or (at your option) any later version.

     GNUnet 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
     Affero General Public License for more details.
    
     You should have received a copy of the GNU Affero General Public License
     along with this program.  If not, see <http://www.gnu.org/licenses/>.

     SPDX-License-Identifier: AGPL3.0-or-later
*/

/**
 * @author Christian Grothoff
 * @author Krista Bennett
 * @author Gerd Knorr <kraxel@bytesex.org>
 * @author Ioana Patrascu
 * @author Tzvetan Horozov
 * @author Milan
 *
 * @file
 * Low level process routines
 *
 * @defgroup os  OS library
 * Low level process routines.
 *
 * This code manages child processes.  We can communicate with child
 * processes using signals.  Because signals are not supported on W32
 * and Java (at least not nicely), we can alternatively use a pipe
 * to send signals to the child processes (if the child process is
 * a full-blown GNUnet process that supports reading signals from
 * a pipe, of course).  Naturally, this also only works for 'normal'
 * termination via signals, and not as a replacement for SIGKILL.
 * Thus using pipes to communicate signals should only be enabled if
 * the child is a Java process OR if we are on Windoze.
 *
 * @{
 */

#ifndef GNUNET_OS_LIB_H
#define GNUNET_OS_LIB_H

#ifdef __cplusplus
extern "C"
{
#if 0                           /* keep Emacsens' auto-indent happy */
}
#endif
#endif

#include "gnunet_common.h"
#include "gnunet_configuration_lib.h"
#include "gnunet_scheduler_lib.h"


/**
 * Flags that determine which of the standard streams
 * should be inherited by the child process.
 */
enum GNUNET_OS_InheritStdioFlags
{

  /**
   * No standard streams should be inherited.
   */
  GNUNET_OS_INHERIT_STD_NONE = 0,

  /**
   * When this flag is set, the child process will
   * inherit stdin of the parent.
   */
  GNUNET_OS_INHERIT_STD_IN = 1,

  /**
   * When this flag is set, the child process will
   * inherit stdout of the parent.
   */
  GNUNET_OS_INHERIT_STD_OUT = 2,

  /**
   * When this flag is set, the child process will
   * inherit stderr of the parent.
   */
  GNUNET_OS_INHERIT_STD_ERR = 4,

  /**
   * When these flags are set, the child process will
   * inherit stdout and stderr of the parent.
   */
  GNUNET_OS_INHERIT_STD_OUT_AND_ERR = 6,

  /**
   * Use this option to have all of the standard streams
   * (stdin, stdout and stderror) be inherited.
   */
  GNUNET_OS_INHERIT_STD_ALL = 7
};


/**
 * Process information (OS-dependent)
 */
struct GNUNET_OS_Process;


/**
 * Possible installation paths to request
 */
enum GNUNET_OS_InstallationPathKind
{
  /**
   * Return the "PREFIX" directory given to configure.
   */
  GNUNET_OS_IPK_PREFIX,

  /**
   * Return the directory where the program binaries are installed. (bin/)
   */
  GNUNET_OS_IPK_BINDIR,

  /**
   * Return the directory where libraries are installed. (lib/gnunet/)
   */
  GNUNET_OS_IPK_LIBDIR,

  /**
   * Return the directory where data is installed (share/gnunet/)
   */
  GNUNET_OS_IPK_DATADIR,

  /**
   * Return the directory where translations are installed (share/locale/)
   */
  GNUNET_OS_IPK_LOCALEDIR,

  /**
   * Return the installation directory of this application, not
   * the one of the overall GNUnet installation (in case they
   * are different).
   */
  GNUNET_OS_IPK_SELF_PREFIX,

  /**
   * Return the prefix of the path with application icons (share/icons/).
   */
  GNUNET_OS_IPK_ICONDIR,

  /**
   * Return the prefix of the path with documentation files, including the
   * license (share/doc/gnunet/).
   */
  GNUNET_OS_IPK_DOCDIR,

  /**
   * Return the directory where helper binaries are installed (lib/gnunet/libexec/)
   */
  GNUNET_OS_IPK_LIBEXECDIR
};


/**
 * Process status types
 */
enum GNUNET_OS_ProcessStatusType
{
  /**
   * The process is not known to the OS (or at
   * least not one of our children).
   */
  GNUNET_OS_PROCESS_UNKNOWN,

  /**
   * The process is still running.
   */
  GNUNET_OS_PROCESS_RUNNING,

  /**
   * The process is paused (but could be resumed).
   */
  GNUNET_OS_PROCESS_STOPPED,

  /**
   * The process exited with a return code.
   */
  GNUNET_OS_PROCESS_EXITED,

  /**
   * The process was killed by a signal.
   */
  GNUNET_OS_PROCESS_SIGNALED
};


/**
 * Project-specific data used to help the OS subsystem
 * find installation paths.
 */
struct GNUNET_OS_ProjectData
{
  /**
   * Name of a library that is installed in the "lib/" directory of
   * the project, such as "libgnunetutil".  Used to locate the
   * installation by scanning dependencies of the current process.
   */
  const char *libname;

  /**
   * Name of the project that is used in the "libexec" prefix, For
   * example, "gnunet".  Certain helper binaries are then expected to
   * be installed in "$PREFIX/libexec/gnunet/" and resources in
   * "$PREFIX/share/gnunet/".
   */
  const char *project_dirname;

  /**
   * Name of a project-specific binary that should be in "$PREFIX/bin/".
   * Used to determine installation path from $PATH variable.
   * For example "gnunet-arm".  On W32, ".exe" should be omitted.
   */
  const char *binary_name;

  /**
   * Name of an environment variable that can be used to override
   * installation path detection, for example "GNUNET_PREFIX".
   */
  const char *env_varname;

  /**
   * Alternative name of an environment variable that can be used to
   * override installation path detection, if "env_varname" is not
   * set. Again, for example, "GNUNET_PREFIX".
   */
  const char *env_varname_alt;

  /**
   * Name of an environment variable that can be used to override
   * the location from which default configuration files are loaded
   * from, for example "GNUNET_BASE_CONFIG".
   */
  const char *base_config_varname;

  /**
   * E-mail address for reporting bugs.
   */
  const char *bug_email;

  /**
   * Project homepage.
   */
  const char *homepage;

  /**
   * Configuration file name (in $XDG_CONFIG_HOME) to use.
   */
  const char *config_file;

  /**
   * Configuration file name to use (if $XDG_CONFIG_HOME is not set).
   */
  const char *user_config_file;

  /**
   * String identifying the current project version.
   */
  const char *version;

  /**
   * Non-zero means this project is part of GNU.
   */
  int is_gnu;
};


/**
 * Return default project data used by 'libgnunetutil' for GNUnet.
 */
const struct GNUNET_OS_ProjectData *
GNUNET_OS_project_data_default (void);


/**
 * @return current (actual) project data.
 */
const struct GNUNET_OS_ProjectData *
GNUNET_OS_project_data_get (void);


/**
 * Setup OS subsystem with project data.
 *
 * @param pd project data used to determine paths.
 */
void
GNUNET_OS_init (const struct GNUNET_OS_ProjectData *pd);


/**
 * Get the path to a specific GNUnet installation directory or, with
 * #GNUNET_OS_IPK_SELF_PREFIX, the current running apps installation
 * directory.
 *
 * @param dirkind what kind of directory is desired?
 * @return a pointer to the dir path (to be freed by the caller)
 */
char *
GNUNET_OS_installation_get_path (enum GNUNET_OS_InstallationPathKind dirkind);


/**
 * Given the name of a gnunet-helper, gnunet-service or gnunet-daemon
 * binary, try to prefix it with the libexec/-directory to get the
 * full path.
 *
 * @param progname name of the binary
 * @return full path to the binary, if possible, otherwise copy of 'progname'
 */
char *
GNUNET_OS_get_libexec_binary_path (const char *progname);


/**
 * Given the name of a helper, service or daemon binary construct the full
 * path to the binary using the SUID_BINARY_PATH in the PATHS section of the
 * configuration. If that option is not present, fall back to
 * GNUNET_OS_get_libexec_binary_path. If @a progname is an absolute path, a
 * copy of this path is returned.
 *
 * @param cfg configuration to inspect
 * @param progname name of the binary
 * @return full path to the binary, if possible, a copy of @a progname
 *         otherwise
 */
char *
GNUNET_OS_get_suid_binary_path (const struct GNUNET_CONFIGURATION_Handle *cfg,
                                const char *progname);


/**
 * Callback function invoked for each interface found.
 *
 * @param cls closure
 * @param name name of the interface (can be NULL for unknown)
 * @param isDefault is this presumably the default interface
 * @param addr address of this interface (can be NULL for unknown or unassigned)
 * @param broadcast_addr the broadcast address (can be NULL for unknown or unassigned)
 * @param netmask the network mask (can be NULL for unknown or unassigned)
 * @param addrlen length of the address
 * @return #GNUNET_OK to continue iteration, #GNUNET_SYSERR to abort
 */
typedef int
(*GNUNET_OS_NetworkInterfaceProcessor) (void *cls,
                                        const char *name,
                                        int isDefault,
                                        const struct sockaddr *addr,
                                        const struct sockaddr *broadcast_addr,
                                        const struct sockaddr *netmask,
                                        socklen_t addrlen);


/**
 * @brief Enumerate all network interfaces
 *
 * @param proc the callback function
 * @param proc_cls closure for @a proc
 */
void
GNUNET_OS_network_interfaces_list (GNUNET_OS_NetworkInterfaceProcessor proc,
                                   void *proc_cls);

/**
 * @brief Get maximum string length returned by gethostname()
 */
#if HAVE_SYSCONF && defined(_SC_HOST_NAME_MAX)
#define GNUNET_OS_get_hostname_max_length() ({ int __sc_tmp = sysconf(_SC_HOST_NAME_MAX); __sc_tmp <= 0 ? 255 : __sc_tmp; })
#elif defined(HOST_NAME_MAX)
#define GNUNET_OS_get_hostname_max_length() HOST_NAME_MAX
#else
#define GNUNET_OS_get_hostname_max_length() 255
#endif


/**
 * Get process structure for current process
 *
 * The pointer it returns points to static memory location and must not be
 * deallocated/closed
 *
 * @return pointer to the process sturcutre for this process
 */
struct GNUNET_OS_Process *
GNUNET_OS_process_current (void);


/**
 * Sends a signal to the process
 *
 * @param proc pointer to process structure
 * @param sig signal
 * @return 0 on success, -1 on error
 */
int
GNUNET_OS_process_kill (struct GNUNET_OS_Process *proc,
                        int sig);


/**
 * Cleans up process structure contents (OS-dependent) and deallocates it
 *
 * @param proc pointer to process structure
 */
void
GNUNET_OS_process_destroy (struct GNUNET_OS_Process *proc);


/**
 * Get the pid of the process in question
 *
 * @param proc the process to get the pid of
 *
 * @return the current process id
 */
pid_t
GNUNET_OS_process_get_pid (struct GNUNET_OS_Process *proc);


/**
 * Start a process.
 *
 * @param pipe_control should a pipe be used to send signals to the child?
 * @param std_inheritance a set of GNUNET_OS_INHERIT_STD_* flags
 * @param pipe_stdin pipe to use to send input to child process (or NULL)
 * @param pipe_stdout pipe to use to get output from child process (or NULL)
 * @param pipe_stderr pipe to use to get error output from child process (or NULL)
 * @param filename name of the binary
 * @param argv NULL-terminated array of arguments to the process
 * @return pointer to process structure of the new process, NULL on error
 */
struct GNUNET_OS_Process *
GNUNET_OS_start_process_vap (int pipe_control,
                             enum GNUNET_OS_InheritStdioFlags std_inheritance,
			     struct GNUNET_DISK_PipeHandle *pipe_stdin,
			     struct GNUNET_DISK_PipeHandle *pipe_stdout,
			     struct GNUNET_DISK_PipeHandle *pipe_stderr,
			     const char *filename,
			     char *const argv[]);


/**
 * Start a process.
 *
 * @param pipe_control should a pipe be used to send signals to the child?
 * @param std_inheritance a set of GNUNET_OS_INHERIT_STD_* flags
 * @param pipe_stdin pipe to use to send input to child process (or NULL)
 * @param pipe_stdout pipe to use to get output from child process (or NULL)
 * @param pipe_stderr pipe to use to get error output from child process (or NULL)
 * @param filename name of the binary
 * @param ... NULL-terminated list of arguments to the process
 * @return pointer to process structure of the new process, NULL on error
 */
struct GNUNET_OS_Process *
GNUNET_OS_start_process (int pipe_control,
                         enum GNUNET_OS_InheritStdioFlags std_inheritance,
			 struct GNUNET_DISK_PipeHandle *pipe_stdin,
                         struct GNUNET_DISK_PipeHandle *pipe_stdout,
                         struct GNUNET_DISK_PipeHandle *pipe_stderr,
                         const char *filename, ...);


/**
 * Start a process.
 *
 * @param pipe_control should a pipe be used to send signals to the child?
 * @param std_inheritance a set of GNUNET_OS_INHERIT_STD_* flags
 * @param pipe_stdin pipe to use to send input to child process (or NULL)
 * @param pipe_stdout pipe to use to get output from child process (or NULL)
 * @param pipe_stderr pipe to use to get error output from child process (or NULL)
 * @param filename name of the binary
 * @param va NULL-terminated list of arguments to the process
 * @return pointer to process structure of the new process, NULL on error
 */
struct GNUNET_OS_Process *
GNUNET_OS_start_process_va (int pipe_control,
                            enum GNUNET_OS_InheritStdioFlags std_inheritance,
			    struct GNUNET_DISK_PipeHandle *pipe_stdin,
                            struct GNUNET_DISK_PipeHandle *pipe_stdout,
                            struct GNUNET_DISK_PipeHandle *pipe_stderr,
                            const char *filename, va_list va);

/**
 * Start a process.
 *
 * @param pipe_control should a pipe be used to send signals to the child?
 * @param std_inheritance a set of GNUNET_OS_INHERIT_STD_* flags
 * @param lsocks array of listen sockets to dup systemd-style (or NULL);
 *         must be NULL on platforms where dup is not supported
 * @param filename name of the binary
 * @param argv NULL-terminated list of arguments to the process,
 *             including the process name as the first argument
 * @return pointer to process structure of the new process, NULL on error
 */
struct GNUNET_OS_Process *
GNUNET_OS_start_process_v (int pipe_control,
                           enum GNUNET_OS_InheritStdioFlags std_inheritance,
			   const SOCKTYPE *lsocks,
			   const char *filename,
                           char *const argv[]);


/**
 * Start a process.  This function is similar to the GNUNET_OS_start_process_*
 * except that the filename and arguments can have whole strings which contain
 * the arguments.  These arguments are to be separated by spaces and are parsed
 * in the order they appear.  Arguments containing spaces can be used by
 * quoting them with @em ".
 *
 * @param pipe_control should a pipe be used to send signals to the child?
 * @param std_inheritance a set of GNUNET_OS_INHERIT_STD_* flags
 * @param lsocks array of listen sockets to dup systemd-style (or NULL);
 *         must be NULL on platforms where dup is not supported
 * @param filename name of the binary.  It is valid to have the arguments
 *         in this string when they are separated by spaces.
 * @param ... more arguments.  Should be of type `char *`.  It is valid
 *         to have the arguments in these strings when they are separated by
 *         spaces.  The last argument MUST be NULL.
 * @return pointer to process structure of the new process, NULL on error
 */
struct GNUNET_OS_Process *
GNUNET_OS_start_process_s (int pipe_control,
                           unsigned int std_inheritance,
                           const SOCKTYPE * lsocks,
                           const char *filename, ...);


/**
 * Handle to a command action.
 */
struct GNUNET_OS_CommandHandle;


/**
 * Type of a function to process a line of output.
 *
 * @param cls closure
 * @param line line of output from a command, NULL for the end
 */
typedef void
(*GNUNET_OS_LineProcessor) (void *cls, const char *line);


/**
 * Stop/kill a command.
 *
 * @param cmd handle to the process
 */
void
GNUNET_OS_command_stop (struct GNUNET_OS_CommandHandle *cmd);


/**
 * Run the given command line and call the given function
 * for each line of the output.
 *
 * @param proc function to call for each line of the output
 * @param proc_cls closure for proc
 * @param timeout when to time out
 * @param binary command to run
 * @param ... arguments to command
 * @return NULL on error
 */
struct GNUNET_OS_CommandHandle *
GNUNET_OS_command_run (GNUNET_OS_LineProcessor proc,
                       void *proc_cls,
                       struct GNUNET_TIME_Relative timeout,
                       const char *binary,
                       ...);


/**
 * Retrieve the status of a process, waiting on it if dead.
 * Nonblocking version.
 *
 * @param proc pointer to process structure
 * @param type status type
 * @param code return code/signal number
 * @return #GNUNET_OK on success, #GNUNET_NO if the process is still running, #GNUNET_SYSERR otherwise
 */
int
GNUNET_OS_process_status (struct GNUNET_OS_Process *proc,
                          enum GNUNET_OS_ProcessStatusType *type,
                          unsigned long *code);


/**
 * Wait for a process to terminate.  The return code is discarded.
 * You must not use #GNUNET_OS_process_status() on the same process
 * after calling this function!  This function is blocking and should
 * thus only be used if the child process is known to have terminated
 * or to terminate very soon.
 *
 * @param proc pointer to process structure of the process to wait for
 * @return #GNUNET_OK on success, #GNUNET_SYSERR otherwise
 */
int
GNUNET_OS_process_wait (struct GNUNET_OS_Process *proc);



/**
 * Retrieve the status of a process, waiting on it if dead.
 * Blocking version.
 *
 * @param proc pointer to process structure
 * @param type status type
 * @param code return code/signal number
 * @return #GNUNET_OK on success, #GNUNET_NO if the process is still running, #GNUNET_SYSERR otherwise
 */
int
GNUNET_OS_process_wait_status (struct GNUNET_OS_Process *proc,
                               enum GNUNET_OS_ProcessStatusType *type,
                               unsigned long *code);


/**
 * Connects this process to its parent via pipe;
 * essentially, the parent control handler will read signal numbers
 * from the #GNUNET_OS_CONTROL_PIPE (as given in an environment
 * variable) and raise those signals.
 *
 * @param cls closure (unused)
 */
void
GNUNET_OS_install_parent_control_handler (void *cls);


/**
 * Check whether an executable exists and possibly
 * if the suid bit is set on the file.
 * Attempts to find the file using the current
 * PATH environment variable as a search path.
 *
 * @param binary the name of the file to check.
 *        W32: must not have an .exe suffix.
 * @param check_suid input true if the binary should be checked for SUID (*nix)
 *        W32: checks if the program has sufficient privileges by executing this
 *             binary with the -d flag. -d omits a programs main loop and only
 *             executes all privileged operations in an binary.
 * @param params parameters used for w32 privilege checking (can be NULL for != w32, or when not checking for suid/permissions )
 * @return #GNUNET_YES if the file is SUID (*nix) or can be executed with current privileges (W32),
 *         #GNUNET_NO if not SUID (but binary exists),
 *         #GNUNET_SYSERR on error (no such binary or not executable)
 */
int
GNUNET_OS_check_helper_binary (const char *binary,
                               int check_suid,
                               const char *params);


#if 0                           /* keep Emacsens' auto-indent happy */
{
#endif
#ifdef __cplusplus
}
#endif

/* ifndef GNUNET_OS_LIB_H */
#endif

/** @} */  /* end of group */

/* end of gnunet_os_lib.h */