Training courses

Kernel and Embedded Linux

Bootlin training courses

Embedded Linux, kernel,
Yocto Project, Buildroot, real-time,
graphics, boot time, debugging...

Bootlin logo

Elixir Cross Referencer

  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
/*-
 * SPDX-License-Identifier: BSD-2-Clause-FreeBSD
 *
 * Copyright (c) 2000 Brian Somers <brian@Awfulhak.org>
 * 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 <sys/socket.h>
#include <sys/un.h>
#include <netinet/in.h>
#include <arpa/inet.h>
#include <netdb.h>
#include <netgraph.h>
#include <net/ethernet.h>
#include <netinet/in_systm.h>
#include <netinet/ip.h>
#include <netgraph/ng_ether.h>
#include <netgraph/ng_message.h>
#include <netgraph/ng_socket.h>

#include <errno.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <sysexits.h>
#include <sys/fcntl.h>
#include <sys/uio.h>
#include <termios.h>
#include <sys/time.h>
#include <unistd.h>

#include "layer.h"
#include "defs.h"
#include "mbuf.h"
#include "log.h"
#include "timer.h"
#include "lqr.h"
#include "hdlc.h"
#include "throughput.h"
#include "fsm.h"
#include "lcp.h"
#include "ccp.h"
#include "link.h"
#include "async.h"
#include "descriptor.h"
#include "physical.h"
#include "main.h"
#include "mp.h"
#include "chat.h"
#include "auth.h"
#include "chap.h"
#include "cbcp.h"
#include "datalink.h"
#include "slcompress.h"
#include "iplist.h"
#include "ncpaddr.h"
#include "ipcp.h"
#include "ipv6cp.h"
#include "ncp.h"
#include "filter.h"
#ifndef NORADIUS
#include "radius.h"
#endif
#include "bundle.h"
#include "id.h"
#include "netgraph.h"


struct ngdevice {
  struct device dev;			/* What struct physical knows about */
  int cs;				/* Control socket */
  char hook[NG_HOOKSIZ];		/* Our socket node hook */
};

#define device2ng(d)	((d)->type == NG_DEVICE ? (struct ngdevice *)d : NULL)
#define NG_MSGBUFSZ	4096
#define NETGRAPH_PREFIX	"netgraph:"

unsigned
ng_DeviceSize(void)
{
  return sizeof(struct ngdevice);
}

static int
ng_MessageOut(struct ngdevice *dev, const char *data)
{
  char path[NG_PATHSIZ];
  char *fmt;
  size_t len;
  int pos, dpos;

  /*
   * We expect a node path, one or more spaces, a command, one or more
   * spaces and an ascii netgraph structure.
   */
  data += strspn(data, " \t");
  len = strcspn(data, " \t");
  if (len >= sizeof path) {
    log_Printf(LogWARN, "%s: %.*s: Node path too long\n",
                 dev->dev.name, len, data);
    return 0;
  }
  memcpy(path, data, len);
  path[len] = '\0';
  data += len;

  data += strspn(data, " \t");
  len = strcspn(data, " \t");
  for (pos = len; pos >= 0; pos--)
    if (data[pos] == '%')
      len++;
  if ((fmt = alloca(len + 4)) == NULL) {
    log_Printf(LogWARN, "%s: alloca(%d) failure... %s\n",
               dev->dev.name, len + 4, strerror(errno));
    return 0;
  }

  /*
   * This is probably a waste of time, but we really don't want to end
   * up stuffing unexpected % escapes into the kernel....
   */
  for (pos = dpos = 0; pos < (int)len;) {
    if (data[dpos] == '%')
      fmt[pos++] = '%';
    fmt[pos++] = data[dpos++];
  }
  strcpy(fmt + pos, " %s");
  data += dpos;

  data += strspn(data, " \t");
  if (NgSendAsciiMsg(dev->cs, path, fmt, data) < 0) {
    log_Printf(LogDEBUG, "%s: NgSendAsciiMsg (to %s): \"%s\", \"%s\": %s\n",
               dev->dev.name, path, fmt, data, strerror(errno));
    return 0;
  }

  return 1;
}

/*
 * Get a netgraph message
 */
static ssize_t
ng_MessageIn(struct physical *p, char *buf, size_t sz)
{
  char msgbuf[sizeof(struct ng_mesg) * 2 + NG_MSGBUFSZ];
  struct ngdevice *dev = device2ng(p->handler);
  struct ng_mesg *rep = (struct ng_mesg *)msgbuf;
  char path[NG_PATHSIZ];
  size_t len;

#ifdef BROKEN_SELECT
  struct timeval t;
  fd_set *r;
  int ret;

  if (dev->cs < 0)
    return 0;

  if ((r = mkfdset()) == NULL) {
    log_Printf(LogERROR, "DoLoop: Cannot create fd_set\n");
    return -1;
  }
  zerofdset(r);
  FD_SET(dev->cs, r);
  t.tv_sec = t.tv_usec = 0;
  ret = select(dev->cs + 1, r, NULL, NULL, &t);
  free(r);

  if (ret <= 0)
    return 0;
#endif

  if (NgRecvAsciiMsg(dev->cs, rep, sizeof msgbuf, path)) {
    log_Printf(LogWARN, "%s: NgRecvAsciiMsg: %s\n",
               dev->dev.name, strerror(errno));
    return -1;
  }

  /* XXX: Should we check rep->header.version ? */

  if (sz == 0)
    log_Printf(LogWARN, "%s: Unexpected message: %s\n", dev->dev.name,
               rep->header.cmdstr);
  else {
    log_Printf(LogDEBUG, "%s: Received message: %s\n", dev->dev.name,
               rep->header.cmdstr);
    len = strlen(rep->header.cmdstr);
    if (sz > len)
      sz = len;
    memcpy(buf, rep->header.cmdstr, sz);
  }

  return sz;
}

static ssize_t
ng_Write(struct physical *p, const void *v, size_t n)
{
  struct ngdevice *dev = device2ng(p->handler);

  switch (p->dl->state) {
    case DATALINK_DIAL:
    case DATALINK_LOGIN:
      return ng_MessageOut(dev, v) ? (ssize_t)n : -1;
  }
  return NgSendData(p->fd, dev->hook, v, n) == -1 ? -1 : (ssize_t)n;
}

static ssize_t
ng_Read(struct physical *p, void *v, size_t n)
{
  char hook[NG_HOOKSIZ];

  switch (p->dl->state) {
    case DATALINK_DIAL:
    case DATALINK_LOGIN:
      return ng_MessageIn(p, v, n);
  }

  return NgRecvData(p->fd, v, n, hook);
}

static int
ng_RemoveFromSet(struct physical *p, fd_set *r, fd_set *w, fd_set *e)
{
  struct ngdevice *dev = device2ng(p->handler);
  int result;

  if (r && dev->cs >= 0 && FD_ISSET(dev->cs, r)) {
    FD_CLR(dev->cs, r);
    log_Printf(LogTIMER, "%s: fdunset(ctrl) %d\n", p->link.name, dev->cs);
    result = 1;
  } else
    result = 0;

  /* Careful... physical_RemoveFromSet() called us ! */

  p->handler->removefromset = NULL;
  result += physical_RemoveFromSet(p, r, w, e);
  p->handler->removefromset = ng_RemoveFromSet;

  return result;
}

static void
ng_Free(struct physical *p)
{
  struct ngdevice *dev = device2ng(p->handler);

  physical_SetDescriptor(p);
  if (dev->cs != -1)
    close(dev->cs);
  free(dev);
}

static void
ng_device2iov(struct device *d, struct iovec *iov, int *niov,
              int maxiov __unused, int *auxfd, int *nauxfd)
{
  struct ngdevice *dev;
  int sz = physical_MaxDeviceSize();

  iov[*niov].iov_base = d = realloc(d, sz);
  if (d == NULL) {
    log_Printf(LogALERT, "Failed to allocate memory: %d\n", sz);
    AbortProgram(EX_OSERR);
  }
  iov[*niov].iov_len = sz;
  (*niov)++;

  dev = device2ng(d);
  *auxfd = dev->cs;
  (*nauxfd)++;
}

static const struct device basengdevice = {
  NG_DEVICE,
  "netgraph",
  0,
  { CD_REQUIRED, DEF_NGCDDELAY },
  NULL,
  ng_RemoveFromSet,
  NULL,
  NULL,
  NULL,
  NULL,
  NULL,
  ng_Free,
  ng_Read,
  ng_Write,
  ng_device2iov,
  NULL,
  NULL,
  NULL
};

struct device *
ng_iov2device(int type, struct physical *p, struct iovec *iov, int *niov,
              int maxiov __unused, int *auxfd, int *nauxfd)
{
  if (type == NG_DEVICE) {
    struct ngdevice *dev = (struct ngdevice *)iov[(*niov)++].iov_base;

    dev = realloc(dev, sizeof *dev);	/* Reduce to the correct size */
    if (dev == NULL) {
      log_Printf(LogALERT, "Failed to allocate memory: %d\n",
                 (int)(sizeof *dev));
      AbortProgram(EX_OSERR);
    }

    if (*nauxfd) {
      dev->cs = *auxfd;
      (*nauxfd)--;
    } else
      dev->cs = -1;

    /* Refresh function pointers etc */
    memcpy(&dev->dev, &basengdevice, sizeof dev->dev);

    /* XXX: Are netgraph always synchronous ? */
    physical_SetupStack(p, dev->dev.name, PHYSICAL_FORCE_SYNCNOACF);
    return &dev->dev;
  }

  return NULL;
}

static int
ng_UpdateSet(struct fdescriptor *d, fd_set *r, fd_set *w, fd_set *e, int *n)
{
  struct physical *p = descriptor2physical(d);
  struct ngdevice *dev = device2ng(p->handler);
  int result;

  switch (p->dl->state) {
    case DATALINK_DIAL:
    case DATALINK_LOGIN:
      if (r) {
        FD_SET(dev->cs, r);
        log_Printf(LogTIMER, "%s(ctrl): fdset(r) %d\n", p->link.name, dev->cs);
        result = 1;
      } else
        result = 0;
      break;

    default:
      result = physical_doUpdateSet(d, r, w, e, n, 0);
      break;
  }

  return result;
}

static int
ng_IsSet(struct fdescriptor *d, const fd_set *fdset)
{
  struct physical *p = descriptor2physical(d);
  struct ngdevice *dev = device2ng(p->handler);
  int result;

  result = dev->cs >= 0 && FD_ISSET(dev->cs, fdset);
  result += physical_IsSet(d, fdset);

  return result;
}

static void
ng_DescriptorRead(struct fdescriptor *d, struct bundle *bundle,
                  const fd_set *fdset)
{
  struct physical *p = descriptor2physical(d);
  struct ngdevice *dev = device2ng(p->handler);

  if (dev->cs >= 0 && FD_ISSET(dev->cs, fdset))
    ng_MessageIn(p, NULL, 0);

  if (physical_IsSet(d, fdset))
    physical_DescriptorRead(d, bundle, fdset);
}

static struct device *
ng_Abandon(struct ngdevice *dev, struct physical *p)
{
  /* Abandon our node construction */
  close(dev->cs);
  close(p->fd);
  p->fd = -2;	/* Nobody else need try.. */
  free(dev);

  return NULL;
}


/*
 * Populate the ``word'' (of size ``sz'') named ``what'' from ``from''
 * ending with any character from ``sep''.  Point ``endp'' at the next
 * word.
 */

#define GETSEGMENT(what, from, sep, endp) \
	getsegment(#what, (what), sizeof(what), from, sep, endp)

static int
getsegment(const char *what, char *word, size_t sz, const char *from,
           const char *sep, const char **endp)
{
  size_t len;

  if ((len = strcspn(from, sep)) == 0) {
    log_Printf(LogWARN, "%s name should not be empty !\n", what);
    return 0;
  }

  if (len >= sz) {
    log_Printf(LogWARN, "%s name too long, max %d !\n", what, sz - 1);
    return 0;
  }

  strncpy(word, from, len);
  word[len] = '\0';

  *endp = from + len;
  *endp += strspn(*endp, sep);

  return 1;
}

struct device *
ng_Create(struct physical *p)
{
  struct sockaddr_ng ngsock;
  u_char rbuf[2048];
  struct sockaddr *sock = (struct sockaddr *)&ngsock;
  const struct hooklist *hlist;
  const struct nodeinfo *ninfo;
  const struct linkinfo *nlink;
  struct ngdevice *dev;
  struct ng_mesg *resp;
  struct ngm_mkpeer mkp;
  struct ngm_connect ngc;
  const char *devp, *endp;
  char lasthook[NG_HOOKSIZ];
  char hook[NG_HOOKSIZ];
  char nodetype[NG_TYPESIZ + NG_NODESIZ];
  char modname[NG_TYPESIZ + 3];
  char path[NG_PATHSIZ];
  char *nodename;
  int len, sz, done;
  unsigned f;

  dev = NULL;
  if (p->fd < 0 && !strncasecmp(p->name.full, NETGRAPH_PREFIX,
                                sizeof NETGRAPH_PREFIX - 1)) {
    p->fd--;				/* We own the device - change fd */

    if ((dev = malloc(sizeof *dev)) == NULL)
      return NULL;

    loadmodules(LOAD_VERBOSLY, "netgraph", "ng_socket", NULL);

    /* Create a socket node */
    if (ID0NgMkSockNode(NULL, &dev->cs, &p->fd) == -1) {
      log_Printf(LogWARN, "Cannot create netgraph socket node: %s\n",
                 strerror(errno));
      free(dev);
      p->fd = -2;
      return NULL;
    }

    devp = p->name.full + sizeof NETGRAPH_PREFIX - 1;
    *lasthook = *path = '\0';
    log_Printf(LogDEBUG, "%s: Opening netgraph device \"%s\"\n",
               p->link.name, devp);
    done = 0;

    while (*devp != '\0' && !done) {
      if (*devp != '[') {
        if (*lasthook == '\0') {
          log_Printf(LogWARN, "%s: Netgraph devices must start with"
                     " [nodetype:nodename]\n", p->link.name);
          return ng_Abandon(dev, p);
        }

        /* Get the hook name of the new node */
        if (!GETSEGMENT(hook, devp, ".[", &endp))
          return ng_Abandon(dev, p);
        log_Printf(LogDEBUG, "%s: Got hook \"%s\"\n", p->link.name, hook);
        devp = endp;
        if (*devp == '\0') {
          log_Printf(LogWARN, "%s: Netgraph device must not end with a second"
                     " hook\n", p->link.name);
          return ng_Abandon(dev, p);
        }
        if (devp[-1] != '[') {
          log_Printf(LogWARN, "%s: Expected a [nodetype:nodename] at device"
                     " pos %d\n", p->link.name, devp - p->link.name - 1);
          return ng_Abandon(dev, p);
        }
      } else {
        /* Use lasthook as the hook name */
        strcpy(hook, lasthook);
        devp++;
      }

      /* We've got ``lasthook'' and ``hook'', get the node type */
      if (!GETSEGMENT(nodetype, devp, "]", &endp))
        return ng_Abandon(dev, p);
      log_Printf(LogDEBUG, "%s: Got node \"%s\"\n", p->link.name, nodetype);

      if ((nodename = strchr(nodetype, ':')) != NULL) {
        *nodename++ = '\0';
        if (*nodename == '\0' && *nodetype == '\0') {
          log_Printf(LogWARN, "%s: Empty [nodetype:nodename] at device"
                     " pos %d\n", p->link.name, devp - p->link.name - 1);
          return ng_Abandon(dev, p);
        }
      }

      /* Ignore optional colons after nodes */
      devp = *endp == ':' ? endp + 1 : endp;
      if (*devp == '.')
        devp++;

      if (*lasthook == '\0') {
        /* This is the first node in the chain */
        if (nodename == NULL || *nodename == '\0') {
          log_Printf(LogWARN, "%s: %s: No initial device nodename\n",
                     p->link.name, devp);
          return ng_Abandon(dev, p);
        }

        if (*nodetype != '\0') {
          /* Attempt to load the module */
          snprintf(modname, sizeof modname, "ng_%s", nodetype);
          log_Printf(LogDEBUG, "%s: Attempting to load %s.ko\n",
                     p->link.name, modname);
          loadmodules(LOAD_QUIETLY, modname, NULL);
        }

        snprintf(path, sizeof path, "%s:", nodename);
        /* XXX: If we have a node type, ensure it's correct */
      } else {
        /*
         * Ask for a list of hooks attached to the previous node.  If we
         * find the one we're interested in, and if it's connected to a
         * node of the right type using the correct hook, use that.
         * If we find the hook connected to something else, fail.
         * If we find no match, mkpeer the new node.
         */
        if (*nodetype == '\0') {
          log_Printf(LogWARN, "%s: Nodetype missing at device offset %d\n",
                     p->link.name,
                     devp - p->name.full + sizeof NETGRAPH_PREFIX - 1);
          return ng_Abandon(dev, p);
        }

        /* Get a list of node hooks */
        if (NgSendMsg(dev->cs, path, NGM_GENERIC_COOKIE, NGM_LISTHOOKS,
                      NULL, 0) < 0) {
          log_Printf(LogWARN, "%s: %s Cannot send a LISTHOOOKS message: %s\n",
                     p->link.name, path, strerror(errno));
          return ng_Abandon(dev, p);
        }

        /* Get our list back */
        resp = (struct ng_mesg *)rbuf;
        if (NgRecvMsg(dev->cs, resp, sizeof rbuf, NULL) <= 0) {
          log_Printf(LogWARN, "%s: Cannot get netgraph response: %s\n",
                     p->link.name, strerror(errno));
          return ng_Abandon(dev, p);
        }

        hlist = (const struct hooklist *)resp->data;
        ninfo = &hlist->nodeinfo;

        log_Printf(LogDEBUG, "List of netgraph node ``%s'' (id %x) hooks:\n",
                   path, ninfo->id);

        /* look for a hook already attached.  */
        for (f = 0; f < ninfo->hooks; f++) {
          nlink = &hlist->link[f];

          log_Printf(LogDEBUG, "  Found %s -> %s (type %s)\n", nlink->ourhook,
                     nlink->peerhook, nlink->nodeinfo.type);

          if (!strcmp(nlink->ourhook, lasthook)) {
            if (strcmp(nlink->peerhook, hook) ||
                strcmp(nlink->nodeinfo.type, nodetype)) {
              log_Printf(LogWARN, "%s: hook %s:%s is already in use\n",
                         p->link.name, nlink->ourhook, path);
              return ng_Abandon(dev, p);
            }
            /* The node is already hooked up nicely.... reuse it */
            break;
          }
        }

        if (f == ninfo->hooks) {
          /* Attempt to load the module */
          snprintf(modname, sizeof modname, "ng_%s", nodetype);
          log_Printf(LogDEBUG, "%s: Attempting to load %s.ko\n",
                     p->link.name, modname);
          loadmodules(LOAD_QUIETLY, modname, NULL);

          /* Create (mkpeer) the new node */

          snprintf(mkp.type, sizeof mkp.type, "%s", nodetype);
          snprintf(mkp.ourhook, sizeof mkp.ourhook, "%s", lasthook);
          snprintf(mkp.peerhook, sizeof mkp.peerhook, "%s", hook);

          log_Printf(LogDEBUG, "%s: Doing MKPEER %s%s -> %s (type %s)\n",
                     p->link.name, path, mkp.ourhook, mkp.peerhook, nodetype);

          if (NgSendMsg(dev->cs, path, NGM_GENERIC_COOKIE,
                        NGM_MKPEER, &mkp, sizeof mkp) < 0) {
            log_Printf(LogWARN, "%s Cannot create %s netgraph node: %s\n",
                       path, nodetype, strerror(errno));
            return ng_Abandon(dev, p);
          }
        }
        len = strlen(path);
        snprintf(path + len, sizeof path - len, "%s%s",
                 path[len - 1] == ':' ? "" : ".", lasthook);
      }

      /* Get a list of node hooks */
      if (NgSendMsg(dev->cs, path, NGM_GENERIC_COOKIE, NGM_LISTHOOKS,
                    NULL, 0) < 0) {
        log_Printf(LogWARN, "%s: %s Cannot send a LISTHOOOKS message: %s\n",
                   p->link.name, path, strerror(errno));
        return ng_Abandon(dev, p);
      }

      /* Get our list back */
      resp = (struct ng_mesg *)rbuf;
      if (NgRecvMsg(dev->cs, resp, sizeof rbuf, NULL) <= 0) {
        log_Printf(LogWARN, "%s: Cannot get netgraph response: %s\n",
                   p->link.name, strerror(errno));
        return ng_Abandon(dev, p);
      }

      hlist = (const struct hooklist *)resp->data;
      ninfo = &hlist->nodeinfo;

      if (*lasthook != '\0' && nodename != NULL && *nodename != '\0' &&
          strcmp(ninfo->name, nodename) &&
          NgNameNode(dev->cs, path, "%s", nodename) < 0) {
        log_Printf(LogWARN, "%s: %s: Cannot name netgraph node: %s\n",
                   p->link.name, path, strerror(errno));
        return ng_Abandon(dev, p);
      }

      if (!GETSEGMENT(lasthook, devp, " \t.[", &endp))
        return ng_Abandon(dev, p);
      log_Printf(LogDEBUG, "%s: Got hook \"%s\"\n", p->link.name, lasthook);

      len = strlen(lasthook);
      done = strchr(" \t", devp[len]) ? 1 : 0;
      devp = endp;

      if (*devp != '\0') {
        if (devp[-1] == '[')
          devp--;
      } /* else should moan about devp[-1] being '[' ? */
    }

    snprintf(dev->hook, sizeof dev->hook, "%s", lasthook);

    /* Connect the node to our socket node */
    snprintf(ngc.path, sizeof ngc.path, "%s", path);
    snprintf(ngc.ourhook, sizeof ngc.ourhook, "%s", dev->hook);
    memcpy(ngc.peerhook, ngc.ourhook, sizeof ngc.peerhook);

    log_Printf(LogDEBUG, "Connecting netgraph socket .:%s -> %s.%s\n",
               ngc.ourhook, ngc.path, ngc.peerhook);
    if (NgSendMsg(dev->cs, ".:", NGM_GENERIC_COOKIE,
                  NGM_CONNECT, &ngc, sizeof ngc) < 0) {
      log_Printf(LogWARN, "Cannot connect %s and socket netgraph "
                 "nodes: %s\n", path, strerror(errno));
      return ng_Abandon(dev, p);
    }

    /* Hook things up so that we monitor dev->cs */
    p->desc.UpdateSet = ng_UpdateSet;
    p->desc.IsSet = ng_IsSet;
    p->desc.Read = ng_DescriptorRead;

    memcpy(&dev->dev, &basengdevice, sizeof dev->dev);

  } else {
    /* See if we're a netgraph socket */

    sz = sizeof ngsock;
    if (getsockname(p->fd, sock, &sz) != -1 && sock->sa_family == AF_NETGRAPH) {
      /*
       * It's a netgraph node... We can't determine hook names etc, so we
       * stay pretty impartial....
       */
      log_Printf(LogPHASE, "%s: Link is a netgraph node\n", p->link.name);

      if ((dev = malloc(sizeof *dev)) == NULL) {
        log_Printf(LogWARN, "%s: Cannot allocate an ether device: %s\n",
                   p->link.name, strerror(errno));
        return NULL;
      }

      memcpy(&dev->dev, &basengdevice, sizeof dev->dev);
      dev->cs = -1;
      *dev->hook = '\0';
    }
  }

  if (dev) {
    physical_SetupStack(p, dev->dev.name, PHYSICAL_FORCE_SYNCNOACF);
    return &dev->dev;
  }

  return NULL;
}