chat.c revision 36285 
1/*-
2 * Copyright (c) 1998 Brian Somers <brian@Awfulhak.org>
3 * All rights reserved.
4 *
5 * Redistribution and use in source and binary forms, with or without
6 * modification, are permitted provided that the following conditions
7 * are met:
8 * 1. Redistributions of source code must retain the above copyright
9 *    notice, this list of conditions and the following disclaimer.
10 * 2. Redistributions in binary form must reproduce the above copyright
11 *    notice, this list of conditions and the following disclaimer in the
12 *    documentation and/or other materials provided with the distribution.
13 *
14 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
15 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
16 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
17 * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
18 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
19 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
20 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
21 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
22 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
23 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
24 * SUCH DAMAGE.
25 *
26 *	$Id: chat.c,v 1.44.2.29 1998/05/01 19:24:11 brian Exp $
27 */
28
29#include <sys/types.h>
30#include <netinet/in.h>
31#include <netinet/in_systm.h>
32#include <netinet/ip.h>
33#include <sys/un.h>
34
35#include <errno.h>
36#include <fcntl.h>
37#include <paths.h>
38#include <signal.h>
39#include <stdio.h>
40#include <stdlib.h>
41#include <string.h>
42#include <sys/wait.h>
43#include <termios.h>
44#include <unistd.h>
45
46#include "mbuf.h"
47#include "log.h"
48#include "defs.h"
49#include "timer.h"
50#include "lqr.h"
51#include "hdlc.h"
52#include "throughput.h"
53#include "fsm.h"
54#include "lcp.h"
55#include "ccp.h"
56#include "link.h"
57#include "async.h"
58#include "descriptor.h"
59#include "physical.h"
60#include "chat.h"
61#include "mp.h"
62#include "auth.h"
63#include "chap.h"
64#include "slcompress.h"
65#include "iplist.h"
66#include "ipcp.h"
67#include "filter.h"
68#include "datalink.h"
69#include "bundle.h"
70
71#define BUFLEFT(c) (sizeof (c)->buf - ((c)->bufend - (c)->buf))
72#define	issep(c)	((c) == '\t' || (c) == ' ')
73
74static void ExecStr(struct physical *, char *, char *, int);
75static char *ExpandString(struct chat *, const char *, char *, int, int);
76
77static void
78chat_PauseTimer(void *v)
79{
80  struct chat *c = (struct chat *)v;
81  timer_Stop(&c->pause);
82  c->pause.load = 0;
83}
84
85static void
86chat_Pause(struct chat *c, u_long load)
87{
88  timer_Stop(&c->pause);
89  c->pause.load += load;
90  c->pause.func = chat_PauseTimer;
91  c->pause.name = "chat pause";
92  c->pause.arg = c;
93  timer_Start(&c->pause);
94}
95
96static void
97chat_TimeoutTimer(void *v)
98{
99  struct chat *c = (struct chat *)v;
100  timer_Stop(&c->timeout);
101  c->TimedOut = 1;
102}
103
104static void
105chat_SetTimeout(struct chat *c)
106{
107  timer_Stop(&c->timeout);
108  if (c->TimeoutSec > 0) {
109    c->timeout.load = SECTICKS * c->TimeoutSec;
110    c->timeout.func = chat_TimeoutTimer;
111    c->timeout.name = "chat timeout";
112    c->timeout.arg = c;
113    timer_Start(&c->timeout);
114  }
115}
116
117static char *
118chat_NextChar(char *ptr, char ch)
119{
120  for (; *ptr; ptr++)
121    if (*ptr == ch)
122      return ptr;
123    else if (*ptr == '\\')
124      if (*++ptr == '\0')
125        return NULL;
126
127  return NULL;
128}
129
130static int
131chat_UpdateSet(struct descriptor *d, fd_set *r, fd_set *w, fd_set *e, int *n)
132{
133  struct chat *c = descriptor2chat(d);
134  int special, gotabort, gottimeout, needcr;
135  int TimedOut = c->TimedOut;
136  static char arg_term;
137
138  if (c->pause.state == TIMER_RUNNING)
139    return 0;
140
141  if (TimedOut) {
142    log_Printf(LogCHAT, "Expect timeout\n");
143    if (c->nargptr == NULL)
144      c->state = CHAT_FAILED;
145    else {
146      /* c->state = CHAT_EXPECT; */
147      c->argptr = &arg_term;
148    }
149    c->TimedOut = 0;
150  }
151
152  if (c->state != CHAT_EXPECT && c->state != CHAT_SEND)
153    return 0;
154
155  gottimeout = gotabort = 0;
156
157  if (c->arg < c->argc && (c->arg < 0 || *c->argptr == '\0')) {
158    /* Go get the next string */
159    if (c->arg < 0 || c->state == CHAT_SEND)
160      c->state = CHAT_EXPECT;
161    else
162      c->state = CHAT_SEND;
163
164    special = 1;
165    while (special && (c->nargptr || c->arg < c->argc - 1)) {
166      if (c->arg < 0 || (!TimedOut && c->state == CHAT_SEND))
167        c->nargptr = NULL;
168
169      if (c->nargptr != NULL) {
170        /* We're doing expect-send-expect.... */
171        c->argptr = c->nargptr;
172        /* Put the '-' back in case we ever want to rerun our script */
173        c->nargptr[-1] = '-';
174        c->nargptr = chat_NextChar(c->nargptr, '-');
175        if (c->nargptr != NULL)
176          *c->nargptr++ = '\0';
177      } else {
178        int minus;
179
180        c->argptr = c->argv[++c->arg];
181
182        if (c->state == CHAT_EXPECT) {
183          /* Look for expect-send-expect sequence */
184          c->nargptr = c->argptr;
185          minus = 0;
186          while ((c->nargptr = chat_NextChar(c->nargptr, '-'))) {
187            c->nargptr++;
188            minus++;
189          }
190
191          if (minus % 2)
192            log_Printf(LogWARN, "chat_UpdateSet: \"%s\": Uneven number of"
193                      " '-' chars, all ignored\n", c->argptr);
194          else if (minus) {
195            c->nargptr = chat_NextChar(c->argptr, '-');
196            *c->nargptr++ = '\0';
197          }
198        }
199      }
200
201      /*
202       * c->argptr now temporarily points into c->script (via c->argv)
203       * If it's an expect-send-expect sequence, we've just got the correct
204       * portion of that sequence.
205       */
206
207      needcr = c->state == CHAT_SEND && *c->argptr != '!';
208
209      /* We leave room for a potential HDLC header in the target string */
210      ExpandString(c, c->argptr, c->exp + 2, sizeof c->exp - 2, needcr);
211
212      if (gotabort) {
213        if (c->abort.num < MAXABORTS) {
214          int len, i;
215
216          len = strlen(c->exp+2);
217          for (i = 0; i < c->abort.num; i++)
218            if (len > c->abort.string[i].len) {
219              int last;
220
221              for (last = c->abort.num; last > i; last--) {
222                c->abort.string[last].data = c->abort.string[last-1].data;
223                c->abort.string[last].len = c->abort.string[last-1].len;
224              }
225              break;
226            }
227          c->abort.string[i].len = len;
228          c->abort.string[i].data = (char *)malloc(len+1);
229          memcpy(c->abort.string[i].data, c->exp+2, len+1);
230          c->abort.num++;
231        } else
232          log_Printf(LogERROR, "chat_UpdateSet: too many abort strings\n");
233        gotabort = 0;
234      } else if (gottimeout) {
235        c->TimeoutSec = atoi(c->exp + 2);
236        if (c->TimeoutSec <= 0)
237          c->TimeoutSec = 30;
238        gottimeout = 0;
239      } else if (c->nargptr == NULL && !strcmp(c->exp+2, "ABORT"))
240        gotabort = 1;
241      else if (c->nargptr == NULL && !strcmp(c->exp+2, "TIMEOUT"))
242        gottimeout = 1;
243      else {
244        if (c->exp[2] == '!')
245          ExecStr(c->physical, c->exp + 3, c->exp + 2, sizeof c->exp - 2);
246
247        if (c->exp[2] == '\0') {
248          /* Empty string, reparse (this may be better as a `goto start') */
249          c->argptr = &arg_term;
250          return chat_UpdateSet(d, r, w, e, n);
251        }
252
253        special = 0;
254      }
255    }
256
257    if (special) {
258      if (gottimeout)
259        log_Printf(LogWARN, "chat_UpdateSet: TIMEOUT: Argument expected\n");
260      else if (gotabort)
261        log_Printf(LogWARN, "chat_UpdateSet: ABORT: Argument expected\n");
262
263      /* End of script - all ok */
264      c->state = CHAT_DONE;
265      return 0;
266    }
267
268    /* set c->argptr to point in the right place */
269    c->argptr = c->exp + 2;
270    c->arglen = strlen(c->argptr);
271
272    if (c->state == CHAT_EXPECT) {
273      /* We must check to see if the string's already been found ! */
274      char *begin, *end;
275
276      end = c->bufend - c->arglen + 1;
277      if (end < c->bufstart)
278        end = c->bufstart;
279      for (begin = c->bufstart; begin < end; begin++)
280        if (!strncmp(begin, c->argptr, c->arglen)) {
281          c->bufstart = begin + c->arglen;
282          c->argptr += c->arglen;
283          c->arglen = 0;
284          /* Continue - we've already read our expect string */
285          return chat_UpdateSet(d, r, w, e, n);
286        }
287
288      log_Printf(LogCHAT, "Expect(%d): %s\n", c->TimeoutSec, c->argptr);
289      chat_SetTimeout(c);
290    }
291  }
292
293  /*
294   * We now have c->argptr pointing at what we want to expect/send and
295   * c->state saying what we want to do... we now know what to put in
296   * the fd_set :-)
297   */
298
299  if (c->state == CHAT_EXPECT)
300    return physical_UpdateSet(&c->physical->desc, r, NULL, e, n, 1);
301  else
302    return physical_UpdateSet(&c->physical->desc, NULL, w, e, n, 1);
303}
304
305static int
306chat_IsSet(struct descriptor *d, const fd_set *fdset)
307{
308  struct chat *c = descriptor2chat(d);
309  return physical_IsSet(&c->physical->desc, fdset);
310}
311
312static void
313chat_UpdateLog(struct chat *c, int in)
314{
315  if (log_IsKept(LogCHAT) || log_IsKept(LogCONNECT)) {
316    /*
317     * If a linefeed appears in the last `in' characters of `c's input
318     * buffer, output from there, all the way back to the last linefeed.
319     * This is called for every read of `in' bytes.
320     */
321    char *ptr, *end, *stop, ch;
322    int level;
323
324    level = log_IsKept(LogCHAT) ? LogCHAT : LogCONNECT;
325    if (in == -1)
326      end = ptr = c->bufend;
327    else {
328      ptr = c->bufend - in;
329      for (end = c->bufend - 1; end >= ptr; end--)
330        if (*end == '\n')
331          break;
332    }
333
334    if (end >= ptr) {
335      for (ptr = c->bufend - (in == -1 ? 1 : in + 1); ptr >= c->bufstart; ptr--)
336        if (*ptr == '\n')
337          break;
338      ptr++;
339      stop = NULL;
340      while (stop < end) {
341        if ((stop = memchr(ptr, '\n', end - ptr)) == NULL)
342          stop = end;
343        ch = *stop;
344        *stop = '\0';
345        if (level == LogCHAT || strstr(ptr, "CONNECT"))
346          log_Printf(level, "Received: %s\n", ptr);
347        *stop = ch;
348        ptr = stop + 1;
349      }
350    }
351  }
352}
353
354static void
355chat_Read(struct descriptor *d, struct bundle *bundle, const fd_set *fdset)
356{
357  struct chat *c = descriptor2chat(d);
358
359  if (c->state == CHAT_EXPECT) {
360    ssize_t in;
361    char *abegin, *ebegin, *begin, *aend, *eend, *end;
362    int n;
363
364    /*
365     * XXX - should this read only 1 byte to guarantee that we don't
366     * swallow any ppp talk from the peer ?
367     */
368    in = BUFLEFT(c);
369    if (in > sizeof c->buf / 2)
370      in = sizeof c->buf / 2;
371
372    in = physical_Read(c->physical, c->bufend, in);
373    if (in <= 0)
374      return;
375
376    /* `begin' and `end' delimit where we're going to strncmp() from */
377    ebegin = c->bufend - c->arglen + 1;
378    eend = ebegin + in;
379    if (ebegin < c->bufstart)
380      ebegin = c->bufstart;
381
382    if (c->abort.num) {
383      abegin = c->bufend - c->abort.string[0].len + 1;
384      aend = c->bufend - c->abort.string[c->abort.num-1].len + in + 1;
385      if (abegin < c->bufstart)
386        abegin = c->bufstart;
387    } else {
388      abegin = ebegin;
389      aend = eend;
390    }
391    begin = abegin < ebegin ? abegin : ebegin;
392    end = aend < eend ? eend : aend;
393
394    c->bufend += in;
395
396    chat_UpdateLog(c, in);
397
398    if (c->bufend > c->buf + sizeof c->buf / 2) {
399      /* Shuffle our receive buffer back a bit */
400      int chop;
401
402      for (chop = begin - c->buf; chop; chop--)
403        if (c->buf[chop] == '\n')
404          /* found some already-logged garbage to remove :-) */
405          break;
406
407      if (!chop)
408        chop = begin - c->buf;
409
410      if (chop) {
411        char *from, *to;
412
413        to = c->buf;
414        from = to + chop;
415        while (from < c->bufend)
416          *to++ = *from++;
417        c->bufstart -= chop;
418        c->bufend -= chop;
419        begin -= chop;
420        end -= chop;
421        abegin -= chop;
422        aend -= chop;
423        ebegin -= chop;
424        eend -= chop;
425      }
426    }
427
428    for (; begin < end; begin++)
429      if (begin >= ebegin && begin < eend &&
430          !strncmp(begin, c->argptr, c->arglen)) {
431        /* Got it ! */
432        if (memchr(begin + c->arglen - 1, '\n',
433            c->bufend - begin - c->arglen + 1) == NULL) {
434          /* force it into the log */
435          end = c->bufend;
436          c->bufend = begin + c->arglen;
437          chat_UpdateLog(c, -1);
438          c->bufend = end;
439        }
440        c->bufstart = begin + c->arglen;
441        c->argptr += c->arglen;
442        c->arglen = 0;
443        break;
444      } else if (begin >= abegin && begin < aend) {
445        for (n = c->abort.num - 1; n >= 0; n--) {
446          if (begin + c->abort.string[n].len > c->bufend)
447            break;
448          if (!strncmp(begin, c->abort.string[n].data,
449                       c->abort.string[n].len)) {
450            if (memchr(begin + c->abort.string[n].len - 1, '\n',
451                c->bufend - begin - c->abort.string[n].len + 1) == NULL) {
452              /* force it into the log */
453              end = c->bufend;
454              c->bufend = begin + c->abort.string[n].len;
455              chat_UpdateLog(c, -1);
456              c->bufend = end;
457            }
458            c->bufstart = begin + c->abort.string[n].len;
459            c->state = CHAT_FAILED;
460            return;
461          }
462        }
463      }
464  }
465}
466
467static void
468chat_Write(struct descriptor *d, struct bundle *bundle, const fd_set *fdset)
469{
470  struct chat *c = descriptor2chat(d);
471
472  if (c->state == CHAT_SEND) {
473    int wrote;
474
475    if (strstr(c->argv[c->arg], "\\P"))            /* Don't log the password */
476      log_Printf(LogCHAT, "Send: %s\n", c->argv[c->arg]);
477    else {
478      int sz;
479
480      sz = c->arglen - 1;
481      while (sz >= 0 && c->argptr[sz] == '\n')
482        sz--;
483      log_Printf(LogCHAT, "Send: %.*s\n", sz + 1, c->argptr);
484    }
485
486    if (physical_IsSync(c->physical)) {
487      /* There's always room for the HDLC header */
488      c->argptr -= 2;
489      c->arglen += 2;
490      memcpy(c->argptr, "\377\003", 2);	/* Prepend HDLC header */
491    }
492
493    wrote = physical_Write(c->physical, c->argptr, c->arglen);
494    if (wrote == -1) {
495      if (errno != EINTR)
496        log_Printf(LogERROR, "chat_Write: %s\n", strerror(errno));
497      if (physical_IsSync(c->physical)) {
498        c->argptr += 2;
499        c->arglen -= 2;
500      }
501    } else if (wrote < 2 && physical_IsSync(c->physical)) {
502      /* Oops - didn't even write our HDLC header ! */
503      c->argptr += 2;
504      c->arglen -= 2;
505    } else {
506      c->argptr += wrote;
507      c->arglen -= wrote;
508    }
509  }
510}
511
512void
513chat_Init(struct chat *c, struct physical *p, const char *data, int emptybuf,
514          const char *phone)
515{
516  c->desc.type = CHAT_DESCRIPTOR;
517  c->desc.next = NULL;
518  c->desc.UpdateSet = chat_UpdateSet;
519  c->desc.IsSet = chat_IsSet;
520  c->desc.Read = chat_Read;
521  c->desc.Write = chat_Write;
522  c->physical = p;
523
524  c->state = CHAT_EXPECT;
525
526  if (data == NULL) {
527    *c->script = '\0';
528    c->argc = 0;
529  } else {
530    strncpy(c->script, data, sizeof c->script - 1);
531    c->script[sizeof c->script - 1] = '\0';
532    c->argc =  MakeArgs(c->script, c->argv, VECSIZE(c->argv));
533  }
534
535  c->arg = -1;
536  c->argptr = NULL;
537  c->nargptr = NULL;
538
539  if (emptybuf)
540    c->bufstart = c->bufend = c->buf;
541
542  c->TimeoutSec = 30;
543  c->TimedOut = 0;
544  c->phone = phone;
545  c->abort.num = 0;
546
547  memset(&c->pause, '\0', sizeof c->pause);
548  memset(&c->timeout, '\0', sizeof c->timeout);
549}
550
551void
552chat_Destroy(struct chat *c)
553{
554  timer_Stop(&c->pause);
555  timer_Stop(&c->timeout);
556  while (c->abort.num)
557    free(c->abort.string[--c->abort.num].data);
558  c->abort.num = 0;
559}
560
561static char *
562findblank(char *p, int instring)
563{
564  if (instring) {
565    while (*p) {
566      if (*p == '\\') {
567	strcpy(p, p + 1);
568	if (!*p)
569	  break;
570      } else if (*p == '"')
571	return (p);
572      p++;
573    }
574  } else {
575    while (*p) {
576      if (issep(*p))
577	return (p);
578      p++;
579    }
580  }
581  return p;
582}
583
584int
585MakeArgs(char *script, char **pvect, int maxargs)
586{
587  int nargs, nb;
588  int instring;
589
590  nargs = 0;
591  while (*script) {
592    nb = strspn(script, " \t");
593    script += nb;
594    if (*script) {
595      if (*script == '"') {
596	instring = 1;
597	script++;
598	if (*script == '\0')
599	  break;		/* Shouldn't return here. Need to null
600				 * terminate below */
601      } else
602	instring = 0;
603      if (nargs >= maxargs - 1)
604	break;
605      *pvect++ = script;
606      nargs++;
607      script = findblank(script, instring);
608      if (*script)
609	*script++ = '\0';
610    }
611  }
612  *pvect = NULL;
613  return nargs;
614}
615
616/*
617 *  \c	don't add a cr
618 *  \d  Sleep a little (delay 2 seconds
619 *  \n  Line feed character
620 *  \P  Auth Key password
621 *  \p  pause 0.25 sec
622 *  \r	Carrige return character
623 *  \s  Space character
624 *  \T  Telephone number(s) (defined via `set phone')
625 *  \t  Tab character
626 *  \U  Auth User
627 */
628static char *
629ExpandString(struct chat *c, const char *str, char *result, int reslen,
630                  int sendmode)
631{
632  int addcr = 0;
633
634  result[--reslen] = '\0';
635  if (sendmode)
636    addcr = 1;
637  while (*str && reslen > 0) {
638    switch (*str) {
639    case '\\':
640      str++;
641      switch (*str) {
642      case 'c':
643	if (sendmode)
644	  addcr = 0;
645	break;
646      case 'd':		/* Delay 2 seconds */
647        chat_Pause(c, 2 * SECTICKS);
648	break;
649      case 'p':
650        chat_Pause(c, SECTICKS / 4);
651	break;			/* Pause 0.25 sec */
652      case 'n':
653	*result++ = '\n';
654	reslen--;
655	break;
656      case 'r':
657	*result++ = '\r';
658	reslen--;
659	break;
660      case 's':
661	*result++ = ' ';
662	reslen--;
663	break;
664      case 't':
665	*result++ = '\t';
666	reslen--;
667	break;
668      case 'P':
669	strncpy(result, c->physical->dl->bundle->cfg.auth.key, reslen);
670	reslen -= strlen(result);
671	result += strlen(result);
672	break;
673      case 'T':
674        strncpy(result, c->phone, reslen);
675        reslen -= strlen(result);
676        result += strlen(result);
677	break;
678      case 'U':
679	strncpy(result, c->physical->dl->bundle->cfg.auth.name, reslen);
680	reslen -= strlen(result);
681	result += strlen(result);
682	break;
683      default:
684	reslen--;
685	*result++ = *str;
686	break;
687      }
688      if (*str)
689	str++;
690      break;
691    case '^':
692      str++;
693      if (*str) {
694	*result++ = *str++ & 0x1f;
695	reslen--;
696      }
697      break;
698    default:
699      *result++ = *str++;
700      reslen--;
701      break;
702    }
703  }
704  if (--reslen > 0) {
705    if (addcr)
706      *result++ = '\r';
707  }
708  if (--reslen > 0)
709    *result++ = '\0';
710  return (result);
711}
712
713static void
714ExecStr(struct physical *physical, char *command, char *out, int olen)
715{
716  pid_t pid;
717  int fids[2];
718  char *vector[MAXARGS], *startout, *endout;
719  int stat, nb;
720
721  log_Printf(LogCHAT, "Exec: %s\n", command);
722  MakeArgs(command, vector, VECSIZE(vector));
723
724  if (pipe(fids) < 0) {
725    log_Printf(LogCHAT, "Unable to create pipe in ExecStr: %s\n",
726	      strerror(errno));
727    *out = '\0';
728    return;
729  }
730  if ((pid = fork()) == 0) {
731    timer_TermService();
732
733    fids[1] = fcntl(fids[1], F_DUPFD, 4);
734    dup2(physical_GetFD(physical), STDIN_FILENO);
735    dup2(STDIN_FILENO, STDOUT_FILENO);
736    dup2(fids[1], STDERR_FILENO);
737    close(3);
738    if (open(_PATH_TTY, O_RDWR) == 3)
739      fcntl(3, F_SETFD, 0);	/* Clear close-on-exec flag */
740    else
741      fcntl(3, F_SETFD, 1);	/* Set close-on-exec flag */
742    setuid(geteuid());
743    execvp(vector[0], vector);
744    fprintf(stderr, "execvp failed: %s: %s\n", vector[0], strerror(errno));
745    exit(127);
746  } else {
747    char *name = strdup(vector[0]);
748
749    close(fids[1]);
750    endout = out + olen - 1;
751    startout = out;
752    while (out < endout) {
753      nb = read(fids[0], out, 1);
754      if (nb <= 0)
755	break;
756      out++;
757    }
758    *out = '\0';
759    close(fids[0]);
760    close(fids[1]);
761    waitpid(pid, &stat, WNOHANG);
762    if (WIFSIGNALED(stat)) {
763      log_Printf(LogWARN, "%s: signal %d\n", name, WTERMSIG(stat));
764      free(name);
765      *out = '\0';
766      return;
767    } else if (WIFEXITED(stat)) {
768      switch (WEXITSTATUS(stat)) {
769        case 0:
770          free(name);
771          break;
772        case 127:
773          log_Printf(LogWARN, "%s: %s\n", name, startout);
774          free(name);
775          *out = '\0';
776          return;
777          break;
778        default:
779          log_Printf(LogWARN, "%s: exit %d\n", name, WEXITSTATUS(stat));
780          free(name);
781          *out = '\0';
782          return;
783          break;
784      }
785    } else {
786      log_Printf(LogWARN, "%s: Unexpected exit result\n", name);
787      free(name);
788      *out = '\0';
789      return;
790    }
791  }
792}
793