summaryrefslogtreecommitdiffstats
path: root/usr.sbin/ppp/filter.c
blob: f59848e0d1d68fc4a8c1f2c82fe6439a6f1dc133 (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
/*-
 * Copyright (c) 1996 - 2001 Brian Somers <brian@Awfulhak.org>
 *          based on work by Toshiharu OHNO <tony-o@iij.ad.jp>
 *                           Internet Initiative Japan, Inc (IIJ)
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the distribution.
 *
 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
 * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
 * SUCH DAMAGE.
 *
 * $FreeBSD$
 */

#include <sys/param.h>
#include <netinet/in.h>
#include <netdb.h>
#include <netinet/in_systm.h>
#include <netinet/ip.h>
#include <sys/socket.h>
#include <sys/un.h>

#include <stdarg.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <termios.h>

#include "layer.h"
#include "defs.h"
#include "command.h"
#include "mbuf.h"
#include "log.h"
#include "iplist.h"
#include "timer.h"
#include "throughput.h"
#include "lqr.h"
#include "hdlc.h"
#include "fsm.h"
#include "lcp.h"
#include "ccp.h"
#include "link.h"
#include "slcompress.h"
#include "ncpaddr.h"
#include "ipcp.h"
#include "filter.h"
#include "descriptor.h"
#include "prompt.h"
#include "mp.h"
#ifndef NORADIUS
#include "radius.h"
#endif
#include "ipv6cp.h"
#include "ncp.h"
#include "bundle.h"

static unsigned filter_Nam2Op(const char *);

static int
ParsePort(const char *service, const char *proto)
{
  struct servent *servent;
  char *cp;
  int port;

  servent = getservbyname(service, proto);
  if (servent != 0)
    return ntohs(servent->s_port);

  port = strtol(service, &cp, 0);
  if (cp == service) {
    log_Printf(LogWARN, "ParsePort: %s is not a port name or number.\n",
	      service);
    return 0;
  }
  return port;
}

/*
 *	ICMP Syntax:	src eq icmp_message_type
 */
static int
ParseIcmp(int argc, char const *const *argv, struct filterent *tgt)
{
  int type;
  char *cp;

  switch (argc) {
  case 0:
    /* permit/deny all ICMP types */
    tgt->f_srcop = tgt->f_dstop = OP_NONE;
    break;

  case 3:
    if (!strcmp(*argv, "src") && !strcmp(argv[1], "eq")) {
      type = strtol(argv[2], &cp, 0);
      if (cp == argv[2]) {
	log_Printf(LogWARN, "ParseIcmp: type is expected.\n");
	return 0;
      }
      tgt->f_srcop = OP_EQ;
      tgt->f_srcport = type;
      tgt->f_dstop = OP_NONE;
    }
    break;

  default:
    log_Printf(LogWARN, "ParseIcmp: bad icmp syntax.\n");
    return 0;
  }
  return 1;
}

/*
 *	UDP Syntax: [src op port] [dst op port]
 */
static int
ParseUdpOrTcp(int argc, char const *const *argv, const struct protoent *pe,
              struct filterent *tgt)
{
  tgt->f_srcop = tgt->f_dstop = OP_NONE;
  tgt->f_estab = tgt->f_syn = tgt->f_finrst = 0;

  if (argc >= 3 && !strcmp(*argv, "src")) {
    tgt->f_srcop = filter_Nam2Op(argv[1]);
    if (tgt->f_srcop == OP_NONE) {
      log_Printf(LogWARN, "ParseUdpOrTcp: bad operator\n");
      return 0;
    }
    if (pe == NULL)
      return 0;
    tgt->f_srcport = ParsePort(argv[2], pe->p_name);
    if (tgt->f_srcport == 0)
      return 0;
    argc -= 3;
    argv += 3;
  }

  if (argc >= 3 && !strcmp(argv[0], "dst")) {
    tgt->f_dstop = filter_Nam2Op(argv[1]);
    if (tgt->f_dstop == OP_NONE) {
      log_Printf(LogWARN, "ParseUdpOrTcp: bad operator\n");
      return 0;
    }
    if (pe == NULL)
      return 0;
    tgt->f_dstport = ParsePort(argv[2], pe->p_name);
    if (tgt->f_dstport == 0)
      return 0;
    argc -= 3;
    argv += 3;
  }

  if (pe && pe->p_proto == IPPROTO_TCP) {
    for (; argc > 0; argc--, argv++)
      if (!strcmp(*argv, "estab"))
        tgt->f_estab = 1;
      else if (!strcmp(*argv, "syn"))
        tgt->f_syn = 1;
      else if (!strcmp(*argv, "finrst"))
        tgt->f_finrst = 1;
      else
        break;
  }

  if (argc > 0) {
    log_Printf(LogWARN, "ParseUdpOrTcp: bad src/dst port syntax: %s\n", *argv);
    return 0;
  }

  return 1;
}

static int
ParseGeneric(int argc, struct filterent *tgt)
{
  /*
   * Filter currently is a catch-all. Requests are either permitted or
   * dropped.
   */
  if (argc != 0) {
    log_Printf(LogWARN, "ParseGeneric: Too many parameters\n");
    return 0;
  } else
    tgt->f_srcop = tgt->f_dstop = OP_NONE;

  return 1;
}

static unsigned
addrtype(const char *addr)
{
  if (!strncasecmp(addr, "MYADDR", 6) && (addr[6] == '\0' || addr[6] == '/'))
    return T_MYADDR;
  if (!strncasecmp(addr, "MYADDR6", 7) && (addr[7] == '\0' || addr[7] == '/'))
    return T_MYADDR6;
  if (!strncasecmp(addr, "HISADDR", 7) && (addr[7] == '\0' || addr[7] == '/'))
    return T_HISADDR;
  if (!strncasecmp(addr, "HISADDR6", 8) && (addr[8] == '\0' || addr[8] == '/'))
    return T_HISADDR6;
  if (!strncasecmp(addr, "DNS0", 4) && (addr[4] == '\0' || addr[4] == '/'))
    return T_DNS0;
  if (!strncasecmp(addr, "DNS1", 4) && (addr[4] == '\0' || addr[4] == '/'))
    return T_DNS1;

  return T_ADDR;
}

static const char *
addrstr(struct ncprange *addr, unsigned type)
{
  switch (type) {
    case T_MYADDR:
      return "MYADDR";
    case T_HISADDR:
      return "HISADDR";
    case T_DNS0:
      return "DNS0";
    case T_DNS1:
      return "DNS1";
  }
  return ncprange_ntoa(addr);
}

static int
filter_Parse(struct ncp *ncp, int argc, char const *const *argv,
             struct filterent *ofp)
{
  struct filterent fe;
  struct protoent *pe;
  char *wp;
  int action, family, ruleno, val, width;

  ruleno = strtol(*argv, &wp, 0);
  if (*argv == wp || ruleno >= MAXFILTERS) {
    log_Printf(LogWARN, "Parse: invalid filter number.\n");
    return 0;
  }
  if (ruleno < 0) {
    for (ruleno = 0; ruleno < MAXFILTERS; ruleno++) {
      ofp->f_action = A_NONE;
      ofp++;
    }
    log_Printf(LogWARN, "Parse: filter cleared.\n");
    return 1;
  }
  ofp += ruleno;

  if (--argc == 0) {
    log_Printf(LogWARN, "Parse: missing action.\n");
    return 0;
  }
  argv++;

  memset(&fe, '\0', sizeof fe);

  val = strtol(*argv, &wp, 0);
  if (!*wp && val >= 0 && val < MAXFILTERS) {
    if (val <= ruleno) {
      log_Printf(LogWARN, "Parse: Can only jump forward from rule %d\n",
                 ruleno);
      return 0;
    }
    action = val;
  } else if (!strcmp(*argv, "permit")) {
    action = A_PERMIT;
  } else if (!strcmp(*argv, "deny")) {
    action = A_DENY;
  } else if (!strcmp(*argv, "clear")) {
    ofp->f_action = A_NONE;
    return 1;
  } else {
    log_Printf(LogWARN, "Parse: %s: bad action\n", *argv);
    return 0;
  }
  fe.f_action = action;

  argc--;
  argv++;

  if (argc && argv[0][0] == '!' && !argv[0][1]) {
    fe.f_invert = 1;
    argc--;
    argv++;
  }

  ncprange_init(&fe.f_src);
  ncprange_init(&fe.f_dst);

  if (argc == 0)
    pe = NULL;
  else if ((pe = getprotobyname(*argv)) == NULL && strcmp(*argv, "all") != 0) {
    if (argc < 2) {
      log_Printf(LogWARN, "Parse: Protocol or address pair expected\n");
      return 0;
    } else if (strcasecmp(*argv, "any") == 0 ||
               ncprange_aton(&fe.f_src, ncp, *argv)) {
      family = ncprange_family(&fe.f_src);
      if (!ncprange_getwidth(&fe.f_src, &width))
        width = 0;
      if (width == 0)
        ncprange_init(&fe.f_src);
      fe.f_srctype = addrtype(*argv);
      argc--;
      argv++;

      if (strcasecmp(*argv, "any") == 0 ||
          ncprange_aton(&fe.f_dst, ncp, *argv)) {
        if (ncprange_family(&fe.f_dst) != AF_UNSPEC &&
            ncprange_family(&fe.f_src) != AF_UNSPEC &&
            family != ncprange_family(&fe.f_dst)) {
          log_Printf(LogWARN, "Parse: src and dst address families differ\n");
          return 0;
        }
        if (!ncprange_getwidth(&fe.f_dst, &width))
          width = 0;
        if (width == 0)
          ncprange_init(&fe.f_dst);
        fe.f_dsttype = addrtype(*argv);
        argc--;
        argv++;
      } else {
        log_Printf(LogWARN, "Parse: Protocol or address pair expected\n");
        return 0;
      }

      if (argc) {
        if ((pe = getprotobyname(*argv)) == NULL && strcmp(*argv, "all") != 0) {
          log_Printf(LogWARN, "Parse: %s: Protocol expected\n", *argv);
          return 0;
        } else {
          argc--;
          argv++;
        }
      }
    } else {
      log_Printf(LogWARN, "Parse: Protocol or address pair expected\n");
      return 0;
    }
  } else {
    argc--;
    argv++;
  }

  if (argc >= 2 && strcmp(*argv, "timeout") == 0) {
    fe.timeout = strtoul(argv[1], NULL, 10);
    argc -= 2;
    argv += 2;
  }

  val = 1;
  fe.f_proto = (pe == NULL) ? 0 : pe->p_proto;

  switch (fe.f_proto) {
  case IPPROTO_TCP:
  case IPPROTO_UDP:
  case IPPROTO_IPIP:
#ifndef NOINET6
  case IPPROTO_IPV6:
#endif
    val = ParseUdpOrTcp(argc, argv, pe, &fe);
    break;
  case IPPROTO_ICMP:
#ifndef NOINET6
  case IPPROTO_ICMPV6:
#endif
    val = ParseIcmp(argc, argv, &fe);
    break;
  default:
    val = ParseGeneric(argc, &fe);
    break;
  }

  log_Printf(LogDEBUG, "Parse: Src: %s\n", ncprange_ntoa(&fe.f_src));
  log_Printf(LogDEBUG, "Parse: Dst: %s\n", ncprange_ntoa(&fe.f_dst));
  log_Printf(LogDEBUG, "Parse: Proto: %d\n", fe.f_proto);

  log_Printf(LogDEBUG, "Parse: src:  %s (%d)\n",
            filter_Op2Nam(fe.f_srcop), fe.f_srcport);
  log_Printf(LogDEBUG, "Parse: dst:  %s (%d)\n",
            filter_Op2Nam(fe.f_dstop), fe.f_dstport);
  log_Printf(LogDEBUG, "Parse: estab: %u\n", fe.f_estab);
  log_Printf(LogDEBUG, "Parse: syn: %u\n", fe.f_syn);
  log_Printf(LogDEBUG, "Parse: finrst: %u\n", fe.f_finrst);

  if (val)
    *ofp = fe;

  return val;
}

int
filter_Set(struct cmdargs const *arg)
{
  struct filter *filter;

  if (arg->argc < arg->argn+2)
    return -1;

  if (!strcmp(arg->argv[arg->argn], "in"))
    filter = &arg->bundle->filter.in;
  else if (!strcmp(arg->argv[arg->argn], "out"))
    filter = &arg->bundle->filter.out;
  else if (!strcmp(arg->argv[arg->argn], "dial"))
    filter = &arg->bundle->filter.dial;
  else if (!strcmp(arg->argv[arg->argn], "alive"))
    filter = &arg->bundle->filter.alive;
  else {
    log_Printf(LogWARN, "filter_Set: %s: Invalid filter name.\n",
              arg->argv[arg->argn]);
    return -1;
  }

  filter_Parse(&arg->bundle->ncp, arg->argc - arg->argn - 1,
        arg->argv + arg->argn + 1, filter->rule);
  return 0;
}

const char *
filter_Action2Nam(unsigned act)
{
  static const char * const actname[] = { "  none ", "permit ", "  deny " };
  static char buf[8];

  if (act < MAXFILTERS) {
    snprintf(buf, sizeof buf, "%6d ", act);
    return buf;
  } else if (act >= A_NONE && act < A_NONE + sizeof(actname)/sizeof(char *))
    return actname[act - A_NONE];
  else
    return "?????? ";
}

static void
doShowFilter(struct filterent *fp, struct prompt *prompt)
{
  struct protoent *pe;
  int n;

  for (n = 0; n < MAXFILTERS; n++, fp++) {
    if (fp->f_action != A_NONE) {
      prompt_Printf(prompt, "  %2d %s", n, filter_Action2Nam(fp->f_action));
      prompt_Printf(prompt, "%c ", fp->f_invert ? '!' : ' ');

      if (ncprange_isset(&fp->f_src))
        prompt_Printf(prompt, "%s ", addrstr(&fp->f_src, fp->f_srctype));
      else
        prompt_Printf(prompt, "any ");

      if (ncprange_isset(&fp->f_dst))
        prompt_Printf(prompt, "%s ", addrstr(&fp->f_dst, fp->f_dsttype));
      else
        prompt_Printf(prompt, "any ");

      if (fp->f_proto) {
        if ((pe = getprotobynumber(fp->f_proto)) == NULL)
	  prompt_Printf(prompt, "P:%d", fp->f_proto);
        else
	  prompt_Printf(prompt, "%s", pe->p_name);

	if (fp->f_srcop)
	  prompt_Printf(prompt, " src %s %d", filter_Op2Nam(fp->f_srcop),
		  fp->f_srcport);
	if (fp->f_dstop)
	  prompt_Printf(prompt, " dst %s %d", filter_Op2Nam(fp->f_dstop),
		  fp->f_dstport);
	if (fp->f_estab)
	  prompt_Printf(prompt, " estab");
	if (fp->f_syn)
	  prompt_Printf(prompt, " syn");
	if (fp->f_finrst)
	  prompt_Printf(prompt, " finrst");
      } else
	prompt_Printf(prompt, "all");
      if (fp->timeout != 0)
	  prompt_Printf(prompt, " timeout %u", fp->timeout);
      prompt_Printf(prompt, "\n");
    }
  }
}

int
filter_Show(struct cmdargs const *arg)
{
  if (arg->argc > arg->argn+1)
    return -1;

  if (arg->argc == arg->argn+1) {
    struct filter *filter;

    if (!strcmp(arg->argv[arg->argn], "in"))
      filter = &arg->bundle->filter.in;
    else if (!strcmp(arg->argv[arg->argn], "out"))
      filter = &arg->bundle->filter.out;
    else if (!strcmp(arg->argv[arg->argn], "dial"))
      filter = &arg->bundle->filter.dial;
    else if (!strcmp(arg->argv[arg->argn], "alive"))
      filter = &arg->bundle->filter.alive;
    else
      return -1;
    doShowFilter(filter->rule, arg->prompt);
  } else {
    struct filter *filter[4];
    int f;

    filter[0] = &arg->bundle->filter.in;
    filter[1] = &arg->bundle->filter.out;
    filter[2] = &arg->bundle->filter.dial;
    filter[3] = &arg->bundle->filter.alive;
    for (f = 0; f < 4; f++) {
      if (f)
        prompt_Printf(arg->prompt, "\n");
      prompt_Printf(arg->prompt, "%s:\n", filter[f]->name);
      doShowFilter(filter[f]->rule, arg->prompt);
    }
  }

  return 0;
}

static const char * const opname[] = {"none", "eq", "gt", "lt"};

const char *
filter_Op2Nam(unsigned op)
{
  if (op >= sizeof opname / sizeof opname[0])
    return "unknown";
  return opname[op];

}

static unsigned
filter_Nam2Op(const char *cp)
{
  unsigned op;

  for (op = sizeof opname / sizeof opname[0] - 1; op; op--)
    if (!strcasecmp(cp, opname[op]))
      break;

  return op;
}

void
filter_AdjustAddr(struct filter *filter, struct ncpaddr *local,
                  struct ncpaddr *remote, struct in_addr *dns)
{
  struct filterent *fp;
  int n;

  for (fp = filter->rule, n = 0; n < MAXFILTERS; fp++, n++)
    if (fp->f_action != A_NONE) {
      if (local) {
        if (fp->f_srctype == T_MYADDR && ncpaddr_family(local) == AF_INET)
          ncprange_sethost(&fp->f_src, local);
        if (fp->f_dsttype == T_MYADDR && ncpaddr_family(local) == AF_INET)
          ncprange_sethost(&fp->f_dst, local);
#ifndef NOINET6
        if (fp->f_srctype == T_MYADDR6 && ncpaddr_family(local) == AF_INET6)
          ncprange_sethost(&fp->f_src, local);
        if (fp->f_dsttype == T_MYADDR6 && ncpaddr_family(local) == AF_INET6)
          ncprange_sethost(&fp->f_dst, local);
#endif
      }
      if (remote) {
        if (fp->f_srctype == T_HISADDR && ncpaddr_family(remote) == AF_INET)
          ncprange_sethost(&fp->f_src, remote);
        if (fp->f_dsttype == T_HISADDR && ncpaddr_family(remote) == AF_INET)
          ncprange_sethost(&fp->f_dst, remote);
#ifndef NOINET6
        if (fp->f_srctype == T_HISADDR6 && ncpaddr_family(remote) == AF_INET6)
          ncprange_sethost(&fp->f_src, remote);
        if (fp->f_dsttype == T_HISADDR6 && ncpaddr_family(remote) == AF_INET6)
          ncprange_sethost(&fp->f_dst, remote);
#endif
      }
      if (dns) {
        if (fp->f_srctype == T_DNS0)
          ncprange_setip4host(&fp->f_src, dns[0]);
        if (fp->f_dsttype == T_DNS0)
          ncprange_setip4host(&fp->f_dst, dns[0]);
        if (fp->f_srctype == T_DNS1)
          ncprange_setip4host(&fp->f_src, dns[1]);
        if (fp->f_dsttype == T_DNS1)
          ncprange_setip4host(&fp->f_dst, dns[1]);
      }
    }
}
OpenPOWER on IntegriCloud