aboutsummaryrefslogtreecommitdiffstats
path: root/util-src/pposix.c
blob: c8c25ba942c60e972c237b2f2694b08f7e1cfb62 (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
679
680
681
682
683
684
685
686
687
688
689
690
691
692
693
694
695
696
697
698
699
700
701
702
703
704
705
706
707
708
709
710
711
712
713
714
715
716
717
718
719
720
721
722
723
724
725
726
727
728
729
730
731
732
733
734
735
736
737
738
739
740
741
742
743
744
745
746
747
748
749
750
751
752
753
754
755
756
757
758
759
760
761
/* Prosody IM
-- Copyright (C) 2008-2010 Matthew Wild
-- Copyright (C) 2008-2010 Waqas Hussain
-- Copyright (C) 2009 Tobias Markmann
--
-- This project is MIT/X11 licensed. Please see the
-- COPYING file in the source package for more information.
--
*/

/*
* pposix.c
* POSIX support functions for Lua
*/

#define MODULE_VERSION "0.3.5"

#include <stdlib.h>
#include <math.h>
#include <unistd.h>
#include <libgen.h>
#include <sys/resource.h>
#include <sys/types.h>
#include <sys/stat.h>
#include <sys/utsname.h>
#include <fcntl.h>

#include <syslog.h>
#include <pwd.h>
#include <grp.h>

#include <string.h>
#include <errno.h>
#include "lua.h"
#include "lualib.h"
#include "lauxlib.h"

#include <fcntl.h>
#if defined(_GNU_SOURCE)
#include <linux/falloc.h>
#endif

#if (defined(_SVID_SOURCE) && !defined(WITHOUT_MALLINFO))
	#include <malloc.h>
	#define WITH_MALLINFO
#endif

/* Daemonization support */

static int lc_daemonize(lua_State *L)
{

	pid_t pid;

	if ( getppid() == 1 )
	{
		lua_pushboolean(L, 0);
		lua_pushstring(L, "already-daemonized");
		return 2;
	}

	/* Attempt initial fork */
	if((pid = fork()) < 0)
	{
		/* Forking failed */
		lua_pushboolean(L, 0);
		lua_pushstring(L, "fork-failed");
		return 2;
	}
	else if(pid != 0)
	{
		/* We are the parent process */
		lua_pushboolean(L, 1);
		lua_pushnumber(L, pid);
		return 2;
	}

	/* and we are the child process */
	if(setsid() == -1)
	{
		/* We failed to become session leader */
		/* (we probably already were) */
		lua_pushboolean(L, 0);
		lua_pushstring(L, "setsid-failed");
		return 2;
	}

	/* Close stdin, stdout, stderr */
	close(0);
	close(1);
	close(2);
	/* Make sure accidental use of FDs 0, 1, 2 don't cause weirdness */
	open("/dev/null", O_RDONLY);
	open("/dev/null", O_WRONLY);
	open("/dev/null", O_WRONLY);

	/* Final fork, use it wisely */
	if(fork())
		exit(0);

	/* Show's over, let's continue */
	lua_pushboolean(L, 1);
	lua_pushnil(L);
	return 2;
}

/* Syslog support */

const char * const facility_strings[] = {
					"auth",
#if !(defined(sun) || defined(__sun))
					"authpriv",
#endif
					"cron",
					"daemon",
#if !(defined(sun) || defined(__sun))
					"ftp",
#endif
					"kern",
					"local0",
					"local1",
					"local2",
					"local3",
					"local4",
					"local5",
					"local6",
					"local7",
					"lpr",
					"mail",
					"syslog",
					"user",
					"uucp",
					NULL
				};
int facility_constants[] =	{
					LOG_AUTH,
#if !(defined(sun) || defined(__sun))
					LOG_AUTHPRIV,
#endif
					LOG_CRON,
					LOG_DAEMON,
#if !(defined(sun) || defined(__sun))
					LOG_FTP,
#endif
					LOG_KERN,
					LOG_LOCAL0,
					LOG_LOCAL1,
					LOG_LOCAL2,
					LOG_LOCAL3,
					LOG_LOCAL4,
					LOG_LOCAL5,
					LOG_LOCAL6,
					LOG_LOCAL7,
					LOG_LPR,
					LOG_MAIL,
					LOG_NEWS,
					LOG_SYSLOG,
					LOG_USER,
					LOG_UUCP,
					-1
				};

/* "
       The parameter ident in the call of openlog() is probably stored  as-is.
       Thus,  if  the  string  it  points  to  is  changed, syslog() may start
       prepending the changed string, and if the string it points to ceases to
       exist,  the  results  are  undefined.  Most portable is to use a string
       constant.
   " -- syslog manpage
*/
char* syslog_ident = NULL;

int lc_syslog_open(lua_State* L)
{
	int facility = luaL_checkoption(L, 2, "daemon", facility_strings);
	facility = facility_constants[facility];

	luaL_checkstring(L, 1);

	if(syslog_ident)
		free(syslog_ident);

	syslog_ident = strdup(lua_tostring(L, 1));

	openlog(syslog_ident, LOG_PID, facility);
	return 0;
}

const char * const level_strings[] = {
				"debug",
				"info",
				"notice",
				"warn",
				"error",
				NULL
			};
int level_constants[] = 	{
				LOG_DEBUG,
				LOG_INFO,
				LOG_NOTICE,
				LOG_WARNING,
				LOG_CRIT,
				-1
			};
int lc_syslog_log(lua_State* L)
{
	int level = level_constants[luaL_checkoption(L, 1, "notice", level_strings)];

	if(lua_gettop(L) == 3)
		syslog(level, "%s: %s", luaL_checkstring(L, 2), luaL_checkstring(L, 3));
	else
		syslog(level, "%s", lua_tostring(L, 2));

	return 0;
}

int lc_syslog_close(lua_State* L)
{
	closelog();
	if(syslog_ident)
	{
		free(syslog_ident);
		syslog_ident = NULL;
	}
	return 0;
}

int lc_syslog_setmask(lua_State* L)
{
	int level_idx = luaL_checkoption(L, 1, "notice", level_strings);
	int mask = 0;
	do
	{
		mask |= LOG_MASK(level_constants[level_idx]);
	} while (++level_idx<=4);

	setlogmask(mask);
	return 0;
}

/* getpid */

int lc_getpid(lua_State* L)
{
	lua_pushinteger(L, getpid());
	return 1;
}

/* UID/GID functions */

int lc_getuid(lua_State* L)
{
	lua_pushinteger(L, getuid());
	return 1;
}

int lc_getgid(lua_State* L)
{
	lua_pushinteger(L, getgid());
	return 1;
}

int lc_setuid(lua_State* L)
{
	int uid = -1;
	if(lua_gettop(L) < 1)
		return 0;
	if(!lua_isnumber(L, 1) && lua_tostring(L, 1))
	{
		/* Passed UID is actually a string, so look up the UID */
		struct passwd *p;
		p = getpwnam(lua_tostring(L, 1));
		if(!p)
		{
			lua_pushboolean(L, 0);
			lua_pushstring(L, "no-such-user");
			return 2;
		}
		uid = p->pw_uid;
	}
	else
	{
		uid = lua_tonumber(L, 1);
	}

	if(uid>-1)
	{
		/* Ok, attempt setuid */
		errno = 0;
		if(setuid(uid))
		{
			/* Fail */
			lua_pushboolean(L, 0);
			switch(errno)
			{
			case EINVAL:
				lua_pushstring(L, "invalid-uid");
				break;
			case EPERM:
				lua_pushstring(L, "permission-denied");
				break;
			default:
				lua_pushstring(L, "unknown-error");
			}
			return 2;
		}
		else
		{
			/* Success! */
			lua_pushboolean(L, 1);
			return 1;
		}
	}

	/* Seems we couldn't find a valid UID to switch to */
	lua_pushboolean(L, 0);
	lua_pushstring(L, "invalid-uid");
	return 2;
}

int lc_setgid(lua_State* L)
{
	int gid = -1;
	if(lua_gettop(L) < 1)
		return 0;
	if(!lua_isnumber(L, 1) && lua_tostring(L, 1))
	{
		/* Passed GID is actually a string, so look up the GID */
		struct group *g;
		g = getgrnam(lua_tostring(L, 1));
		if(!g)
		{
			lua_pushboolean(L, 0);
			lua_pushstring(L, "no-such-group");
			return 2;
		}
		gid = g->gr_gid;
	}
	else
	{
		gid = lua_tonumber(L, 1);
	}

	if(gid>-1)
	{
		/* Ok, attempt setgid */
		errno = 0;
		if(setgid(gid))
		{
			/* Fail */
			lua_pushboolean(L, 0);
			switch(errno)
			{
			case EINVAL:
				lua_pushstring(L, "invalid-gid");
				break;
			case EPERM:
				lua_pushstring(L, "permission-denied");
				break;
			default:
				lua_pushstring(L, "unknown-error");
			}
			return 2;
		}
		else
		{
			/* Success! */
			lua_pushboolean(L, 1);
			return 1;
		}
	}

	/* Seems we couldn't find a valid GID to switch to */
	lua_pushboolean(L, 0);
	lua_pushstring(L, "invalid-gid");
	return 2;
}

int lc_initgroups(lua_State* L)
{
	int ret;
	gid_t gid;
	struct passwd *p;

	if(!lua_isstring(L, 1))
	{
		lua_pushnil(L);
		lua_pushstring(L, "invalid-username");
		return 2;
	}
	p = getpwnam(lua_tostring(L, 1));
	if(!p)
	{
		lua_pushnil(L);
		lua_pushstring(L, "no-such-user");
		return 2;
	}
	if(lua_gettop(L) < 2)
		lua_pushnil(L);
	switch(lua_type(L, 2))
	{
	case LUA_TNIL:
		gid = p->pw_gid;
		break;
	case LUA_TNUMBER:
		gid = lua_tointeger(L, 2);
		break;
	default:
		lua_pushnil(L);
		lua_pushstring(L, "invalid-gid");
		return 2;
	}
	ret = initgroups(lua_tostring(L, 1), gid);
	if(ret)
	{
		switch(errno)
		{
		case ENOMEM:
			lua_pushnil(L);
			lua_pushstring(L, "no-memory");
			break;
		case EPERM:
			lua_pushnil(L);
			lua_pushstring(L, "permission-denied");
			break;
		default:
			lua_pushnil(L);
			lua_pushstring(L, "unknown-error");
		}
	}
	else
	{
		lua_pushboolean(L, 1);
		lua_pushnil(L);
	}
	return 2;
}

int lc_umask(lua_State* L)
{
	char old_mode_string[7];
	mode_t old_mode = umask(strtoul(luaL_checkstring(L, 1), NULL, 8));

	snprintf(old_mode_string, sizeof(old_mode_string), "%03o", old_mode);
	old_mode_string[sizeof(old_mode_string)-1] = 0;
	lua_pushstring(L, old_mode_string);

	return 1;
}

int lc_mkdir(lua_State* L)
{
	int ret = mkdir(luaL_checkstring(L, 1), S_IRUSR | S_IWUSR | S_IXUSR
		| S_IRGRP | S_IWGRP | S_IXGRP
		| S_IROTH | S_IXOTH); /* mode 775 */

	lua_pushboolean(L, ret==0);
	if(ret)
	{
		lua_pushstring(L, strerror(errno));
		return 2;
	}
	return 1;
}

/*	Like POSIX's setrlimit()/getrlimit() API functions.
 *
 *	Syntax:
 *	pposix.setrlimit( resource, soft limit, hard limit)
 *
 *	Any negative limit will be replace with the current limit by an additional call of getrlimit().
 *
 *	Example usage:
 *	pposix.setrlimit("NOFILE", 1000, 2000)
 */
int string2resource(const char *s) {
	if (!strcmp(s, "CORE")) return RLIMIT_CORE;
	if (!strcmp(s, "CPU")) return RLIMIT_CPU;
	if (!strcmp(s, "DATA")) return RLIMIT_DATA;
	if (!strcmp(s, "FSIZE")) return RLIMIT_FSIZE;
	if (!strcmp(s, "NOFILE")) return RLIMIT_NOFILE;
	if (!strcmp(s, "STACK")) return RLIMIT_STACK;
#if !(defined(sun) || defined(__sun))
	if (!strcmp(s, "MEMLOCK")) return RLIMIT_MEMLOCK;
	if (!strcmp(s, "NPROC")) return RLIMIT_NPROC;
	if (!strcmp(s, "RSS")) return RLIMIT_RSS;
#endif
#ifdef RLIMIT_NICE
	if (!strcmp(s, "NICE")) return RLIMIT_NICE;
#endif
	return -1;
}

int lc_setrlimit(lua_State *L) {
	int arguments = lua_gettop(L);
	int softlimit = -1;
	int hardlimit = -1;
	const char *resource = NULL;
	int rid = -1;
	if(arguments < 1 || arguments > 3) {
		lua_pushboolean(L, 0);
		lua_pushstring(L, "incorrect-arguments");
	}

	resource = luaL_checkstring(L, 1);
	softlimit = luaL_checkinteger(L, 2);
	hardlimit = luaL_checkinteger(L, 3);

	rid = string2resource(resource);
	if (rid != -1) {
		struct rlimit lim;
		struct rlimit lim_current;

		if (softlimit < 0 || hardlimit < 0) {
			if (getrlimit(rid, &lim_current)) {
				lua_pushboolean(L, 0);
				lua_pushstring(L, "getrlimit-failed");
				return 2;
			}
		}

		if (softlimit < 0) lim.rlim_cur = lim_current.rlim_cur;
			else lim.rlim_cur = softlimit;
		if (hardlimit < 0) lim.rlim_max = lim_current.rlim_max;
			else lim.rlim_max = hardlimit;

		if (setrlimit(rid, &lim)) {
			lua_pushboolean(L, 0);
			lua_pushstring(L, "setrlimit-failed");
			return 2;
		}
	} else {
		/* Unsupported resoucrce. Sorry I'm pretty limited by POSIX standard. */
		lua_pushboolean(L, 0);
		lua_pushstring(L, "invalid-resource");
		return 2;
	}
	lua_pushboolean(L, 1);
	return 1;
}

int lc_getrlimit(lua_State *L) {
	int arguments = lua_gettop(L);
	const char *resource = NULL;
	int rid = -1;
	struct rlimit lim;

	if (arguments != 1) {
		lua_pushboolean(L, 0);
		lua_pushstring(L, "invalid-arguments");
		return 2;
	}

	resource = luaL_checkstring(L, 1);
	rid = string2resource(resource);
	if (rid != -1) {
		if (getrlimit(rid, &lim)) {
			lua_pushboolean(L, 0);
			lua_pushstring(L, "getrlimit-failed.");
			return 2;
		}
	} else {
		/* Unsupported resoucrce. Sorry I'm pretty limited by POSIX standard. */
		lua_pushboolean(L, 0);
		lua_pushstring(L, "invalid-resource");
		return 2;
	}
	lua_pushboolean(L, 1);
	lua_pushnumber(L, lim.rlim_cur);
	lua_pushnumber(L, lim.rlim_max);
	return 3;
}

int lc_abort(lua_State* L)
{
	abort();
	return 0;
}

int lc_uname(lua_State* L)
{
	struct utsname uname_info;
	if(uname(&uname_info) != 0)
	{
		lua_pushnil(L);
		lua_pushstring(L, strerror(errno));
		return 2;
	}
	lua_newtable(L);
	lua_pushstring(L, uname_info.sysname);
	lua_setfield(L, -2, "sysname");
	lua_pushstring(L, uname_info.nodename);
	lua_setfield(L, -2, "nodename");
	lua_pushstring(L, uname_info.release);
	lua_setfield(L, -2, "release");
	lua_pushstring(L, uname_info.version);
	lua_setfield(L, -2, "version");
	lua_pushstring(L, uname_info.machine);
	lua_setfield(L, -2, "machine");
	return 1;
}

int lc_setenv(lua_State* L)
{
	const char *var = luaL_checkstring(L, 1);
	const char *value;

	/* If the second argument is nil or nothing, unset the var */
	if(lua_isnoneornil(L, 2))
	{
		if(unsetenv(var) != 0)
		{
			lua_pushnil(L);
			lua_pushstring(L, strerror(errno));
			return 2;
		}
		lua_pushboolean(L, 1);
		return 1;
	}

	value = luaL_checkstring(L, 2);

	if(setenv(var, value, 1) != 0)
	{
		lua_pushnil(L);
		lua_pushstring(L, strerror(errno));
		return 2;
	}

	lua_pushboolean(L, 1);
	return 1;
}

#ifdef WITH_MALLINFO
int lc_meminfo(lua_State* L)
{
	struct mallinfo info = mallinfo();
	lua_newtable(L);
	/* This is the total size of memory allocated with sbrk by malloc, in bytes. */
	lua_pushinteger(L, info.arena);
	lua_setfield(L, -2, "allocated");
	/* This is the total size of memory allocated with mmap, in bytes. */
	lua_pushinteger(L, info.hblkhd);
	lua_setfield(L, -2, "allocated_mmap");
	/* This is the total size of memory occupied by chunks handed out by malloc. */
	lua_pushinteger(L, info.uordblks);
	lua_setfield(L, -2, "used");
	/* This is the total size of memory occupied by free (not in use) chunks. */
	lua_pushinteger(L, info.fordblks);
	lua_setfield(L, -2, "unused");
	/* This is the size of the top-most releasable chunk that normally borders the
	   end of the heap (i.e., the high end of the virtual address space's data segment). */
	lua_pushinteger(L, info.keepcost);
	lua_setfield(L, -2, "returnable");
	return 1;
}
#endif

/* File handle extraction blatantly stolen from
 * https://github.com/rrthomas/luaposix/blob/master/lposix.c#L631
 * */

#if _XOPEN_SOURCE >= 600 || _POSIX_C_SOURCE >= 200112L || defined(_GNU_SOURCE)
int lc_fallocate(lua_State* L)
{
	off_t offset, len;
	FILE *f = *(FILE**) luaL_checkudata(L, 1, LUA_FILEHANDLE);

	offset = luaL_checkinteger(L, 2);
	len = luaL_checkinteger(L, 3);

#if defined(_GNU_SOURCE)
	if(fallocate(fileno(f), FALLOC_FL_KEEP_SIZE, offset, len) == 0)
	{
		lua_pushboolean(L, 1);
		return 1;
	}

	if(errno != ENOSYS && errno != EOPNOTSUPP)
	{
		lua_pushnil(L);
		lua_pushstring(L, strerror(errno));
		return 2;
	}
#else
#warning Only using posix_fallocate() fallback.
#warning Linux fallocate() is strongly recommended if available: recompile with -D_GNU_SOURCE
#warning Note that posix_fallocate() will still be used on filesystems that dont support fallocate()
#endif

	if(posix_fallocate(fileno(f), offset, len) == 0)
	{
		lua_pushboolean(L, 1);
		return 1;
	}
	else
	{
		lua_pushnil(L);
		lua_pushstring(L, strerror(errno));
		/* posix_fallocate() can leave a bunch of NULs at the end, so we cut that
		 * this assumes that offset == length of the file */
		ftruncate(fileno(f), offset);
		return 2;
	}
}
#endif

/* Register functions */

int luaopen_util_pposix(lua_State *L)
{
	luaL_Reg exports[] = {
		{ "abort", lc_abort },

		{ "daemonize", lc_daemonize },

		{ "syslog_open", lc_syslog_open },
		{ "syslog_close", lc_syslog_close },
		{ "syslog_log", lc_syslog_log },
		{ "syslog_setminlevel", lc_syslog_setmask },

		{ "getpid", lc_getpid },
		{ "getuid", lc_getuid },
		{ "getgid", lc_getgid },

		{ "setuid", lc_setuid },
		{ "setgid", lc_setgid },
		{ "initgroups", lc_initgroups },

		{ "umask", lc_umask },

		{ "mkdir", lc_mkdir },

		{ "setrlimit", lc_setrlimit },
		{ "getrlimit", lc_getrlimit },

		{ "uname", lc_uname },

		{ "setenv", lc_setenv },

#ifdef WITH_MALLINFO
		{ "meminfo", lc_meminfo },
#endif

#if _XOPEN_SOURCE >= 600 || _POSIX_C_SOURCE >= 200112L || defined(_GNU_SOURCE)
		{ "fallocate", lc_fallocate },
#endif

		{ NULL, NULL }
	};

	luaL_register(L, "pposix",  exports);

	lua_pushliteral(L, "pposix");
	lua_setfield(L, -2, "_NAME");

	lua_pushliteral(L, MODULE_VERSION);
	lua_setfield(L, -2, "_VERSION");

	return 1;
}