aboutsummaryrefslogtreecommitdiffstats
path: root/erts/epmd/src/epmd.c
blob: 5dd4a2cc2eda52129ea8d881979128e7dd5d5eec (plain) (blame)
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
/* -*- c-indent-level: 2; c-continued-statement-offset: 2 -*- */ 
/*
 * %CopyrightBegin%
 *
 * Copyright Ericsson AB 1998-2013. All Rights Reserved.
 *
 * The contents of this file are subject to the Erlang Public License,
 * Version 1.1, (the "License"); you may not use this file except in
 * compliance with the License. You should have received a copy of the
 * Erlang Public License along with this software. If not, it can be
 * retrieved online at http://www.erlang.org/.
 *
 * Software distributed under the License is distributed on an "AS IS"
 * basis, WITHOUT WARRANTY OF ANY KIND, either express or implied. See
 * the License for the specific language governing rights and limitations
 * under the License.
 *
 * %CopyrightEnd%
 */

#ifdef HAVE_CONFIG_H
#  include "config.h"
#endif
#include "epmd.h"     /* Renamed from 'epmd_r4.h' */
#include "epmd_int.h"
#include "erl_printf.h"

#ifdef HAVE_STDLIB_H
#  include <stdlib.h>
#endif

/* forward declarations */

static void usage(EpmdVars *);
static void run_daemon(EpmdVars*);
static char* get_addresses(void);
static int get_port_no(void);
static int check_relaxed(void);
#ifdef __WIN32__
static int has_console(void);
#endif

#ifdef DONT_USE_MAIN

static int epmd_main(int, char **, int);

/* VxWorks fill 10 stack words with zero when a function is called
   from the shell. So it is safe to have argv and argc as parameters
   even if they are not given in the call. */

#define MAX_DEBUG 10

int epmd_dbg(int level,int port) /* Utility to debug epmd... */
{
  char* argv[MAX_DEBUG+2];
  char  ibuff[100];
  int   argc = 0;
  
  argv[argc++] = "epmd";
  if(level > MAX_DEBUG)
    level = MAX_DEBUG;
  for(;level;--level)
    argv[argc++] = "-d";
  if(port)
    {
      argv[argc++] = "-port";
      erts_snprintf(ibuff, sizeof(ibuff), "%d",port);
      argv[argc++] = ibuff;
    }
  argv[argc] = NULL;

  return epmd(argc,argv);

}

static char *mystrdup(char *s)
{
    char *r = malloc(strlen(s)+1);
    strcpy(r,s);
    return r;
}

#ifdef VXWORKS
int start_epmd(a0, a1, a2, a3, a4, a5, a6, a7, a8, a9)
char *a0, *a1, *a2, *a3, *a4, *a5, *a6, *a7, *a8, *a9;     
{
  char*  argarr[] = {a0,a1,a2,a3,a4,a5,a6,a7,a8,a9};
  int    i;
  char** argv = malloc(sizeof(char *)*10);
  int    argvsiz = 10;
  int    argc = 1;
  char*  tmp = malloc(100);
  int    tmpsiz = 100;
  char*  pplast;
  char*  token;
  
  argv[0] = mystrdup("epmd");
  argv[1] = NULL;
  
  for(i=0;i<10;++i)
    {
      if(argarr[i] == NULL || *argarr[i] == '\0')
	continue;
      if(strlen(argarr[i]) >= tmpsiz)
	tmp = realloc(tmp, tmpsiz = (strlen(argarr[i])+1));
      strcpy(tmp,argarr[i]);
      for(token = strtok_r(tmp," ",&pplast);
	  token != NULL;
	  token = strtok_r(NULL," ",&pplast))
	{
	  if(argc >= argvsiz - 1)
	    argv = realloc(argv,sizeof(char *) * (argvsiz += 10));
	  argv[argc++] = mystrdup(token);
	  argv[argc] = NULL;
	}
    }
  free(tmp);
  return taskSpawn("epmd",100,VX_FP_TASK,20000,epmd_main,
		   argc,(int) argv,1,
		   0,0,0,0,0,0,0);
}
#endif    /* WxWorks */


int epmd(int argc, char **argv)
{
  return epmd_main(argc,argv,0);
}

static int epmd_main(int argc, char** argv, int free_argv)
#else
int main(int argc, char** argv)
#endif /* DONT_USE_MAIN */
{
    EpmdVars g_empd_vars;
    EpmdVars *g = &g_empd_vars;
    int i;
#ifdef __WIN32__
    WORD wVersionRequested;
    WSADATA wsaData;
    int err;

    wVersionRequested = MAKEWORD(1, 1);

    err = WSAStartup(wVersionRequested, &wsaData);
    if (err != 0)
        epmd_cleanup_exit(g,1);

    if (LOBYTE(wsaData.wVersion) != 1 || HIBYTE(wsaData.wVersion ) != 1) {
        WSACleanup();
    	epmd_cleanup_exit(g,1);
    }
#endif
#ifdef DONT_USE_MAIN
    if(free_argv)
	g->argv = argv;
    else 
	g->argv = NULL;
#else
    g->argv = NULL;
#endif

    g->addresses      = get_addresses();
    g->port           = get_port_no();
    g->debug          = 0;

    g->silent         = 0; 
    g->is_daemon      = 0;
    g->brutal_kill    = check_relaxed();
    g->packet_timeout = CLOSE_TIMEOUT; /* Default timeout */
    g->delay_accept   = 0;
    g->delay_write    = 0;
    g->progname       = argv[0];
    g->conn           = NULL;
    g->nodes.reg = g->nodes.unreg = g->nodes.unreg_tail = NULL;
    g->nodes.unreg_count = 0;
    g->active_conn    = 0;

    for (i = 0; i < MAX_LISTEN_SOCKETS; i++)
	g->listenfd[i] = -1;

    argc--;
    argv++;
    while (argc > 0) {
	if ((strcmp(argv[0], "-debug")==0) ||
	    (strcmp(argv[0], "-d")==0)) {
	    g->debug += 1;
	    argv++; argc--;
	} else if (strcmp(argv[0], "-packet_timeout") == 0) {
	    if ((argc == 1) ||
		((g->packet_timeout = atoi(argv[1])) == 0))
		usage(g);
	    argv += 2; argc -= 2;
	} else if (strcmp(argv[0], "-delay_accept") == 0) {
	    if ((argc == 1) ||
		((g->delay_accept = atoi(argv[1])) == 0))
		usage(g);
	    argv += 2; argc -= 2;
	} else if (strcmp(argv[0], "-delay_write") == 0) {
	    if ((argc == 1) ||
		((g->delay_write = atoi(argv[1])) == 0))
		usage(g);
	    argv += 2; argc -= 2;
	} else if (strcmp(argv[0], "-daemon") == 0) {
	    g->is_daemon = 1;
	    argv++; argc--;
	} else if (strcmp(argv[0], "-relaxed_command_check") == 0) {
	    g->brutal_kill = 1;
	    argv++; argc--;
	} else if (strcmp(argv[0], "-kill") == 0) {
	    if (argc == 1)
		kill_epmd(g);
	    else
		usage(g);
	    epmd_cleanup_exit(g,0);
	} else if (strcmp(argv[0], "-address") == 0) {
	    if (argc == 1)
	      usage(g);
	    g->addresses = argv[1];
	    argv += 2; argc -= 2;
	} else if (strcmp(argv[0], "-port") == 0) {
	    if ((argc == 1) ||
		((g->port = atoi(argv[1])) == 0))
	      usage(g);
	    argv += 2; argc -= 2;
	} else if (strcmp(argv[0], "-names") == 0) {
	    if (argc == 1)
		epmd_call(g, EPMD_NAMES_REQ);
	    else
		usage(g);
	    epmd_cleanup_exit(g,0);
	} else if (strcmp(argv[0], "-started") == 0) {
	    g->silent = 1;
	    if (argc == 1)
		epmd_call(g, EPMD_NAMES_REQ);
	    else
		usage(g);
	    epmd_cleanup_exit(g,0);
	} else if (strcmp(argv[0], "-dump") == 0) {
	    if (argc == 1)
		epmd_call(g, EPMD_DUMP_REQ);
	    else
		usage(g);
	    epmd_cleanup_exit(g,0);
	} else if (strcmp(argv[0], "-stop") == 0) {
	    if (argc == 2)
		stop_cli(g, argv[1]);
	    else
		usage(g);
	    epmd_cleanup_exit(g,0);
	}
	else
	    usage(g);
    }
    dbg_printf(g,1,"epmd running - daemon = %d",g->is_daemon);

#ifndef NO_SYSCONF
    if ((g->max_conn = sysconf(_SC_OPEN_MAX)) <= 0)
#endif
      g->max_conn = MAX_FILES;
  
    /*
     * max_conn must not be greater than FD_SETSIZE.
     * (at least QNX crashes)
     */
  
    if (g->max_conn > FD_SETSIZE) {
      g->max_conn = FD_SETSIZE;
    }

    if (g->is_daemon)  {
	run_daemon(g);
    } else {
	run(g);
    }
    return 0;
}

#ifndef NO_DAEMON
static void run_daemon(EpmdVars *g)
{
    register int child_pid, fd;
    
    dbg_tty_printf(g,2,"fork a daemon");

    /* fork to make sure first child is not a process group leader */
    if (( child_pid = fork()) < 0)
      {
#ifdef HAVE_SYSLOG_H
	syslog(LOG_ERR,"erlang mapper daemon cant fork %m");
#endif
	epmd_cleanup_exit(g,1);
      }
    else if (child_pid > 0)
      {
	dbg_tty_printf(g,2,"daemon child is %d",child_pid);
	epmd_cleanup_exit(g,0);  /*parent */
      }
    
    if (setsid() < 0)
      {
	dbg_perror(g,"epmd: Cant setsid()");
	epmd_cleanup_exit(g,1);
      }

    /* ???? */


    signal(SIGHUP, SIG_IGN);

    /* We don't want to be session leader so we fork again */

    if ((child_pid = fork()) < 0)
      {
#ifdef HAVE_SYSLOG_H
	syslog(LOG_ERR,"erlang mapper daemon cant fork 2'nd time %m");
#endif
	epmd_cleanup_exit(g,1);
      }
    else if (child_pid > 0)
      {
	dbg_tty_printf(g,2,"daemon 2'nd child is %d",child_pid);
	epmd_cleanup_exit(g,0);  /*parent */
      }

    /* move cwd to root to make sure we are not on a mounted filesystem  */
    if (chdir("/") < 0)
      {
	dbg_perror(g,"epmd: chdir() failed");
	epmd_cleanup_exit(g,1);
      }
    
    umask(0);

    for (fd = 0; fd < g->max_conn ; fd++) /* close all files ... */
        close(fd);
    /* Syslog on linux will try to write to whatever if we dont
       inform it of that the log is closed. */
    closelog();

    /* These chouldn't be needed but for safety... */

    open("/dev/null", O_RDONLY); /* Order is important! */
    open("/dev/null", O_WRONLY);
    open("/dev/null", O_WRONLY);

    errno = 0;  /* if set by open */

    run(g);
}

#endif /* NO_DAEMON */    

#ifdef __WIN32__
static int has_console(void)
{
    HANDLE handle = CreateFile("CONOUT$", GENERIC_WRITE, FILE_SHARE_WRITE,
			       NULL, OPEN_EXISTING, FILE_ATTRIBUTE_NORMAL, NULL);

    if (handle == INVALID_HANDLE_VALUE) {
	return 0;
    } else {
        CloseHandle(handle);
	return 1;
    }
}

static void run_daemon(EpmdVars *g)
{
    if (has_console()) {
	if (spawnvp(_P_DETACH, __argv[0], __argv) == -1) {
	    fprintf(stderr, "Failed to spawn detached epmd\n");
	    exit(1);
	}
	exit(0);
    }

    close(0);
    close(1);
    close(2);

    /* These chouldn't be needed but for safety... */

    open("nul", O_RDONLY);
    open("nul", O_WRONLY);
    open("nul", O_WRONLY);

    run(g);
}
#endif

#if defined(VXWORKS) || defined(__OSE__)
static void run_daemon(EpmdVars *g)
{
    run(g);
}
#endif


/***************************************************************************
 *  Misc support routines
 *
 */

static void usage(EpmdVars *g)
{
    fprintf(stderr, "usage: epmd [-d|-debug] [DbgExtra...] [-address List]\n");
    fprintf(stderr, "            [-port No] [-daemon] [-relaxed_command_check]\n");
    fprintf(stderr, "       epmd [-d|-debug] [-port No] [-names|-kill|-stop name]\n\n");
    fprintf(stderr, "See the Erlang epmd manual page for info about the usage.\n\n");
    fprintf(stderr, "Regular options\n");
    fprintf(stderr, "    -address List\n");
    fprintf(stderr, "        Let epmd listen only on the comma-separated list of IP\n");
    fprintf(stderr, "        addresses (and on the loopback interface).\n");
    fprintf(stderr, "    -port No\n");
    fprintf(stderr, "        Let epmd listen to another port than default %d\n",
	    EPMD_PORT_NO);
    fprintf(stderr, "    -d\n");
    fprintf(stderr, "    -debug\n");
    fprintf(stderr, "        Enable debugging. This will give a log to\n");
    fprintf(stderr, "        the standard error stream. It will shorten\n");
    fprintf(stderr, "        the number of saved used node names to 5.\n\n");
    fprintf(stderr, "        If you give more than one debug flag you may\n");
    fprintf(stderr, "        get more debugging information.\n");
    fprintf(stderr, "    -daemon\n");
    fprintf(stderr, "        Start epmd detached (as a daemon)\n");
    fprintf(stderr, "    -relaxed_command_check\n");
    fprintf(stderr, "        Allow this instance of epmd to be killed with\n");
    fprintf(stderr, "        epmd -kill even if there "
	    "are registered nodes.\n");
    fprintf(stderr, "        Also allows forced unregister (epmd -stop).\n");
    fprintf(stderr, "\nDbgExtra options\n");
    fprintf(stderr, "    -packet_timeout Seconds\n");
    fprintf(stderr, "        Set the number of seconds a connection can be\n");
    fprintf(stderr, "        inactive before epmd times out and closes the\n");
    fprintf(stderr, "        connection (default 60).\n\n");
    fprintf(stderr, "    -delay_accept Seconds\n");
    fprintf(stderr, "        To simulate a busy server you can insert a\n");
    fprintf(stderr, "        delay between epmd gets notified about that\n");
    fprintf(stderr, "        a new connection is requested and when the\n");
    fprintf(stderr, "        connections gets accepted.\n\n");
    fprintf(stderr, "    -delay_write Seconds\n");
    fprintf(stderr, "        Also a simulation of a busy server. Inserts\n");
    fprintf(stderr, "        a delay before a reply is sent.\n");
    fprintf(stderr, "\nInteractive options\n");
    fprintf(stderr, "    -names\n");
    fprintf(stderr, "        List names registered with the currently "
	    "running epmd\n");
    fprintf(stderr, "    -kill\n");
    fprintf(stderr, "        Kill the currently running epmd\n");
    fprintf(stderr, "        (only allowed if -names show empty database or\n");
    fprintf(stderr, "        -relaxed_command_check was given when epmd was started).\n");
    fprintf(stderr, "    -stop Name\n");
    fprintf(stderr, "        Forcibly unregisters a name with epmd\n");
    fprintf(stderr, "        (only allowed if -relaxed_command_check was given when \n");
    fprintf(stderr, "        epmd was started).\n");
    epmd_cleanup_exit(g,1);
}

/***************************************************************************
 *  Error reporting - dbg_printf() & dbg_tty_printf & dbg_perror()
 *
 *  The first form will print out on tty or syslog depending on
 *  if it runs as deamon or not. The second form will never print
 *  out on syslog.
 *
 *  The arguments are
 *
 *      g            Epmd variables
 *      from_level   From what debug level we print. 0 means always.
 *                   (This argument is missing from dbg_perror() )
 *      format       Format string
 *      args...      Arguments to print out according to the format
 *      
 */
#define DEBUG_BUFFER_SIZE 2048
static void dbg_gen_printf(int onsyslog,int perr,int from_level,
			   EpmdVars *g,const char *format, va_list args)
{
  time_t now;
  char *timestr;
  char buf[DEBUG_BUFFER_SIZE];

  if (g->is_daemon)
    {
#ifdef HAVE_SYSLOG_H
      if (onsyslog)
	{
	  int len;
	  len = erts_vsnprintf(buf, DEBUG_BUFFER_SIZE, format, args);
	  if (perr != 0 && len < sizeof(buf)) {
	      erts_snprintf(buf+len, sizeof(buf)-len, ": %s", strerror(perr));
	  }
	  syslog(LOG_ERR,"epmd: %s",buf);
	}
#endif
    }
  else
    {
      int len;

      time(&now);
      timestr = (char *)ctime(&now);
      erts_snprintf(buf, DEBUG_BUFFER_SIZE, "epmd: %.*s: ",
		    (int) strlen(timestr)-1, timestr);
      len = strlen(buf);
      erts_vsnprintf(buf + len, DEBUG_BUFFER_SIZE - len, format, args);
      if (perr != 0)
	fprintf(stderr,"%s: %s\r\n",buf,strerror(perr));
      else
	fprintf(stderr,"%s\r\n",buf);
    }
}


void dbg_perror(EpmdVars *g,const char *format,...)
{
  va_list args;
  va_start(args, format);
  dbg_gen_printf(1,errno,0,g,format,args);
  va_end(args);
}


void dbg_tty_printf(EpmdVars *g,int from_level,const char *format,...)
{
  if (g->debug >= from_level) {
    va_list args;
    va_start(args, format);
    dbg_gen_printf(0,0,from_level,g,format,args);
    va_end(args);
  }
}

void dbg_printf(EpmdVars *g,int from_level,const char *format,...)
{
  if (g->debug >= from_level) {
    va_list args;
    va_start(args, format);
    dbg_gen_printf(1,0,from_level,g,format,args);
    va_end(args);
  }
}


/***************************************************************************
 *
 * This function is to clean up all filedescriptors and free up memory on 
 * VxWorks.
 * This function exits, there is nothing else to do when all here is run.
 *
 */

static void free_all_nodes(EpmdVars *g)
{
    Node *tmp;
    for(tmp=g->nodes.reg; tmp != NULL; tmp = g->nodes.reg){
	g->nodes.reg = tmp->next;
	free(tmp);
    }
    for(tmp=g->nodes.unreg; tmp != NULL; tmp = g->nodes.unreg){
	g->nodes.unreg = tmp->next;
	free(tmp);
    }
}
void epmd_cleanup_exit(EpmdVars *g, int exitval)
{
  int i;

  if(g->conn){
      for (i = 0; i < g->max_conn; i++)
	  if (g->conn[i].open == EPMD_TRUE)
	      epmd_conn_close(g,&g->conn[i]);
      free(g->conn);
  }
  for(i=0; i < MAX_LISTEN_SOCKETS; i++)
      if(g->listenfd[i] >= 0)
          close(g->listenfd[i]);
  free_all_nodes(g);
  if(g->argv){
      for(i=0; g->argv[i] != NULL; ++i)
	  free(g->argv[i]);
      free(g->argv);
  }      
      

  exit(exitval);
}

static char* get_addresses(void)
{
    return getenv("ERL_EPMD_ADDRESS");
}
static int get_port_no(void)
{
    char* port_str = getenv("ERL_EPMD_PORT");
    return (port_str != NULL) ? atoi(port_str) : EPMD_PORT_NO;
}
static int check_relaxed(void)
{
    char* port_str = getenv("ERL_EPMD_RELAXED_COMMAND_CHECK");
    return (port_str != NULL) ? 1 : 0;
}