xref: /freebsd/libexec/pppoed/pppoed.c (revision cd0d51baaa4509a1db83251a601d34404d20c990)
1 /*-
2  * SPDX-License-Identifier: BSD-2-Clause-FreeBSD
3  *
4  * Copyright (c) 1999-2001 Brian Somers <brian@Awfulhak.org>
5  * All rights reserved.
6  *
7  * Redistribution and use in source and binary forms, with or without
8  * modification, are permitted provided that the following conditions
9  * are met:
10  * 1. Redistributions of source code must retain the above copyright
11  *    notice, this list of conditions and the following disclaimer.
12  * 2. Redistributions in binary form must reproduce the above copyright
13  *    notice, this list of conditions and the following disclaimer in the
14  *    documentation and/or other materials provided with the distribution.
15  *
16  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
17  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
18  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
19  * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
20  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
21  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
22  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
23  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
24  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
25  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
26  * SUCH DAMAGE.
27  *
28  * $FreeBSD$
29  */
30 
31 #include <sys/param.h>
32 #include <sys/socket.h>
33 #include <sys/un.h>
34 #include <netinet/in.h>
35 #include <arpa/inet.h>
36 #include <netdb.h>
37 #include <netgraph.h>
38 #include <net/ethernet.h>
39 #include <netinet/in_systm.h>
40 #include <netinet/ip.h>
41 #include <netgraph/ng_ether.h>
42 #include <netgraph/ng_message.h>
43 #include <netgraph/ng_pppoe.h>
44 #include <netgraph/ng_socket.h>
45 
46 #include <errno.h>
47 #include <paths.h>
48 #include <signal.h>
49 #include <stdio.h>
50 #include <stdarg.h>
51 #include <stdlib.h>
52 #include <string.h>
53 #include <sysexits.h>
54 #include <sys/fcntl.h>
55 #ifndef NOKLDLOAD
56 #include <sys/linker.h>
57 #include <sys/module.h>
58 #endif
59 #include <sys/uio.h>
60 #include <sys/wait.h>
61 #include <syslog.h>
62 #include <termios.h>
63 #include <unistd.h>
64 
65 
66 #define	DEFAULT_EXEC_PREFIX	"exec /usr/sbin/ppp -direct "
67 #define	HISMACADDR		"HISMACADDR"
68 #define	SESSION_ID		"SESSION_ID"
69 
70 static void nglogx(const char *, ...) __printflike(1, 2);
71 
72 static int ReceivedSignal;
73 
74 static int
75 usage(const char *prog)
76 {
77   fprintf(stderr, "usage: %s [-Fd] [-P pidfile] [-a name] [-e exec | -l label]"
78           " [-n ngdebug] [-p provider] interface\n", prog);
79   return EX_USAGE;
80 }
81 
82 static void
83 Farewell(int sig)
84 {
85   ReceivedSignal = sig;
86 }
87 
88 static int
89 ConfigureNode(const char *prog, const char *iface, const char *provider,
90               int cs, int ds, int debug, struct ngm_connect *ngc)
91 {
92   /*
93    * We're going to do this with the passed `ds' & `cs' descriptors:
94    *
95    * .---------.
96    * |  ether  |
97    * | <iface> |
98    * `---------'
99    *  (orphan)                                     ds    cs
100    *     |                                         |     |
101    *     |                                         |     |
102    * (ethernet)                                    |     |
103    * .---------.                                .-----------.
104    * |  pppoe  |                                |  socket   |
105    * | <iface> |(pppoe-<pid>)<---->(pppoe-<pid>)| <unnamed> |
106    * `---------                                 `-----------'
107    * (exec-<pid>)
108    *     ^                .-----------.      .-------------.
109    *     |                |   socket  |      | ppp -direct |
110    *     `--->(exec-<pid>)| <unnamed> |--fd--|  provider   |
111    *                      `-----------'      `-------------'
112    *
113    * where there are potentially many ppp processes running off of the
114    * same PPPoE node.
115    * The exec-<pid> hook isn't made 'till we Spawn().
116    */
117 
118   char *epath, *spath;
119   struct ngpppoe_init_data *data;
120   const struct hooklist *hlist;
121   const struct nodeinfo *ninfo;
122   const struct linkinfo *nlink;
123   struct ngm_mkpeer mkp;
124   struct ng_mesg *resp;
125   u_char rbuf[2048];
126   int f, plen;
127 
128   /*
129    * Ask for a list of hooks attached to the "ether" node.  This node should
130    * magically exist as a way of hooking stuff onto an ethernet device
131    */
132   epath = (char *)alloca(strlen(iface) + 2);
133   sprintf(epath, "%s:", iface);
134 
135   if (debug)
136     fprintf(stderr, "Sending NGM_LISTHOOKS to %s\n", epath);
137 
138   if (NgSendMsg(cs, epath, NGM_GENERIC_COOKIE, NGM_LISTHOOKS, NULL, 0) < 0) {
139     if (errno == ENOENT)
140       fprintf(stderr, "%s Cannot send a netgraph message: Invalid interface\n",
141               epath);
142     else
143       fprintf(stderr, "%s Cannot send a netgraph message: %s\n",
144               epath, strerror(errno));
145     return EX_UNAVAILABLE;
146   }
147 
148   /* Get our list back */
149   resp = (struct ng_mesg *)rbuf;
150   if (NgRecvMsg(cs, resp, sizeof rbuf, NULL) <= 0) {
151     perror("Cannot get netgraph response");
152     return EX_UNAVAILABLE;
153   }
154 
155   hlist = (const struct hooklist *)resp->data;
156   ninfo = &hlist->nodeinfo;
157 
158   if (debug)
159     fprintf(stderr, "Got reply from id [%x]: Type %s with %d hooks\n",
160             ninfo->id, ninfo->type, ninfo->hooks);
161 
162   /* Make sure we've got the right type of node */
163   if (strncmp(ninfo->type, NG_ETHER_NODE_TYPE, sizeof NG_ETHER_NODE_TYPE - 1)) {
164     fprintf(stderr, "%s Unexpected node type ``%s'' (wanted ``"
165             NG_ETHER_NODE_TYPE "'')\n", epath, ninfo->type);
166     return EX_DATAERR;
167   }
168 
169   /* look for a hook already attached.  */
170   for (f = 0; f < ninfo->hooks; f++) {
171     nlink = &hlist->link[f];
172 
173     if (debug)
174       fprintf(stderr, "  Got [%x]:%s -> [%x]:%s\n", ninfo->id,
175               nlink->ourhook, nlink->nodeinfo.id, nlink->peerhook);
176 
177     if (!strcmp(nlink->ourhook, NG_ETHER_HOOK_ORPHAN) ||
178         !strcmp(nlink->ourhook, NG_ETHER_HOOK_DIVERT)) {
179       /*
180        * Something is using the data coming out of this `ether' node.
181        * If it's a PPPoE node, we use that node, otherwise we complain that
182        * someone else is using the node.
183        */
184       if (strcmp(nlink->nodeinfo.type, NG_PPPOE_NODE_TYPE)) {
185         fprintf(stderr, "%s Node type %s is currently active\n",
186                 epath, nlink->nodeinfo.type);
187         return EX_UNAVAILABLE;
188       }
189       break;
190     }
191   }
192 
193   if (f == ninfo->hooks) {
194     /*
195      * Create a new PPPoE node connected to the `ether' node using
196      * the magic `orphan' and `ethernet' hooks
197      */
198     snprintf(mkp.type, sizeof mkp.type, "%s", NG_PPPOE_NODE_TYPE);
199     snprintf(mkp.ourhook, sizeof mkp.ourhook, "%s", NG_ETHER_HOOK_ORPHAN);
200     snprintf(mkp.peerhook, sizeof mkp.peerhook, "%s", NG_PPPOE_HOOK_ETHERNET);
201 
202     if (debug)
203       fprintf(stderr, "Send MKPEER: %s%s -> [type %s]:%s\n", epath,
204               mkp.ourhook, mkp.type, mkp.peerhook);
205 
206     if (NgSendMsg(cs, epath, NGM_GENERIC_COOKIE,
207                   NGM_MKPEER, &mkp, sizeof mkp) < 0) {
208       fprintf(stderr, "%s Cannot create a peer PPPoE node: %s\n",
209               epath, strerror(errno));
210       return EX_OSERR;
211     }
212   }
213 
214   /* Connect the PPPoE node to our socket node.  */
215   snprintf(ngc->path, sizeof ngc->path, "%s%s", epath, NG_ETHER_HOOK_ORPHAN);
216   snprintf(ngc->ourhook, sizeof ngc->ourhook, "pppoe-%ld", (long)getpid());
217   memcpy(ngc->peerhook, ngc->ourhook, sizeof ngc->peerhook);
218 
219   if (NgSendMsg(cs, ".:", NGM_GENERIC_COOKIE,
220                 NGM_CONNECT, ngc, sizeof *ngc) < 0) {
221     perror("Cannot CONNECT PPPoE and socket nodes");
222     return EX_OSERR;
223   }
224 
225   plen = strlen(provider);
226 
227   data = (struct ngpppoe_init_data *)alloca(sizeof *data + plen);
228   snprintf(data->hook, sizeof data->hook, "%s", ngc->peerhook);
229   memcpy(data->data, provider, plen);
230   data->data_len = plen;
231 
232   spath = (char *)alloca(strlen(ngc->peerhook) + 3);
233   strcpy(spath, ".:");
234   strcpy(spath + 2, ngc->ourhook);
235 
236   if (debug) {
237     if (provider)
238       fprintf(stderr, "Sending PPPOE_LISTEN to %s, provider %s\n",
239               spath, provider);
240     else
241       fprintf(stderr, "Sending PPPOE_LISTEN to %s\n", spath);
242   }
243 
244   if (NgSendMsg(cs, spath, NGM_PPPOE_COOKIE, NGM_PPPOE_LISTEN,
245                 data, sizeof *data + plen) == -1) {
246     fprintf(stderr, "%s: Cannot LISTEN on netgraph node: %s\n",
247             spath, strerror(errno));
248     return EX_OSERR;
249   }
250 
251   return 0;
252 }
253 
254 static void
255 Spawn(const char *prog, const char *acname, const char *provider,
256       const char *exec, struct ngm_connect ngc, int cs, int ds, void *request,
257       int sz, int debug)
258 {
259   char msgbuf[sizeof(struct ng_mesg) + sizeof(struct ngpppoe_sts)];
260   struct ng_mesg *rep = (struct ng_mesg *)msgbuf;
261   struct ngpppoe_sts *sts = (struct ngpppoe_sts *)(msgbuf + sizeof *rep);
262   struct ngpppoe_init_data *data;
263   char env[18], unknown[14], sessionid[5], *path;
264   unsigned char *macaddr;
265   const char *msg;
266   int ret, slen;
267 
268   switch ((ret = fork())) {
269     case -1:
270       syslog(LOG_ERR, "fork: %m");
271       break;
272 
273     case 0:
274       switch (fork()) {
275         case 0:
276           break;
277         case -1:
278           _exit(errno);
279         default:
280           _exit(0);
281       }
282       close(cs);
283       close(ds);
284 
285       /* Create a new socket node */
286       if (debug)
287         syslog(LOG_INFO, "Creating a new socket node");
288 
289       if (NgMkSockNode(NULL, &cs, &ds) == -1) {
290         syslog(LOG_ERR, "Cannot create netgraph socket node: %m");
291         _exit(EX_CANTCREAT);
292       }
293 
294       /* Connect the PPPoE node to our new socket node.  */
295       snprintf(ngc.ourhook, sizeof ngc.ourhook, "exec-%ld", (long)getpid());
296       memcpy(ngc.peerhook, ngc.ourhook, sizeof ngc.peerhook);
297 
298       if (debug)
299         syslog(LOG_INFO, "Sending CONNECT from .:%s -> %s.%s",
300                ngc.ourhook, ngc.path, ngc.peerhook);
301       if (NgSendMsg(cs, ".:", NGM_GENERIC_COOKIE,
302                     NGM_CONNECT, &ngc, sizeof ngc) < 0) {
303         syslog(LOG_ERR, "Cannot CONNECT PPPoE and socket nodes: %m");
304         _exit(EX_OSERR);
305       }
306 
307       /*
308        * If we tell the socket node not to LINGER, it will go away when
309        * the last hook is removed.
310        */
311       if (debug)
312         syslog(LOG_INFO, "Sending NGM_SOCK_CMD_NOLINGER to socket");
313       if (NgSendMsg(cs, ".:", NGM_SOCKET_COOKIE,
314                     NGM_SOCK_CMD_NOLINGER, NULL, 0) < 0) {
315         syslog(LOG_ERR, "Cannot send NGM_SOCK_CMD_NOLINGER: %m");
316         _exit(EX_OSERR);
317       }
318 
319       /* Put the PPPoE node into OFFER mode */
320       slen = strlen(acname);
321       data = (struct ngpppoe_init_data *)alloca(sizeof *data + slen);
322       snprintf(data->hook, sizeof data->hook, "%s", ngc.ourhook);
323       memcpy(data->data, acname, slen);
324       data->data_len = slen;
325 
326       path = (char *)alloca(strlen(ngc.ourhook) + 3);
327       strcpy(path, ".:");
328       strcpy(path + 2, ngc.ourhook);
329 
330       syslog(LOG_INFO, "Offering to %s as access concentrator %s",
331              path, acname);
332       if (NgSendMsg(cs, path, NGM_PPPOE_COOKIE, NGM_PPPOE_OFFER,
333                     data, sizeof *data + slen) == -1) {
334         syslog(LOG_INFO, "%s: Cannot OFFER on netgraph node: %m", path);
335         _exit(EX_OSERR);
336       }
337       /* If we have a provider code, set it */
338       if (provider) {
339         slen = strlen(provider);
340         data = (struct ngpppoe_init_data *)alloca(sizeof *data + slen);
341         snprintf(data->hook, sizeof data->hook, "%s", ngc.ourhook);
342         memcpy(data->data, provider, slen);
343         data->data_len = slen;
344 
345         syslog(LOG_INFO, "adding to %s as offered service %s",
346              path, acname);
347         if (NgSendMsg(cs, path, NGM_PPPOE_COOKIE, NGM_PPPOE_SERVICE,
348                     data, sizeof *data + slen) == -1) {
349           syslog(LOG_INFO, "%s: Cannot add service on netgraph node: %m", path);
350           _exit(EX_OSERR);
351         }
352       }
353 
354       /* Put the peer's MAC address in the environment */
355       if (sz >= sizeof(struct ether_header)) {
356         macaddr = ((struct ether_header *)request)->ether_shost;
357         snprintf(env, sizeof(env), "%x:%x:%x:%x:%x:%x",
358                  macaddr[0], macaddr[1], macaddr[2], macaddr[3], macaddr[4],
359                  macaddr[5]);
360         if (setenv(HISMACADDR, env, 1) != 0)
361           syslog(LOG_INFO, "setenv: cannot set %s: %m", HISMACADDR);
362       }
363 
364       /* And send our request data to the waiting node */
365       if (debug)
366         syslog(LOG_INFO, "Sending original request to %s (%d bytes)", path, sz);
367       if (NgSendData(ds, ngc.ourhook, request, sz) == -1) {
368         syslog(LOG_ERR, "Cannot send original request to %s: %m", path);
369         _exit(EX_OSERR);
370       }
371 
372       /* Then wait for a success indication */
373 
374       if (debug)
375         syslog(LOG_INFO, "Waiting for a SUCCESS reply %s", path);
376 
377       do {
378         if ((ret = NgRecvMsg(cs, rep, sizeof msgbuf, NULL)) < 0) {
379           syslog(LOG_ERR, "%s: Cannot receive a message: %m", path);
380           _exit(EX_OSERR);
381         }
382 
383         if (ret == 0) {
384           /* The socket has been closed */
385           syslog(LOG_INFO, "%s: Client timed out", path);
386           _exit(EX_TEMPFAIL);
387         }
388 
389         if (rep->header.version != NG_VERSION) {
390           syslog(LOG_ERR, "%ld: Unexpected netgraph version, expected %ld",
391                  (long)rep->header.version, (long)NG_VERSION);
392           _exit(EX_PROTOCOL);
393         }
394 
395         if (rep->header.typecookie != NGM_PPPOE_COOKIE) {
396           syslog(LOG_INFO, "%ld: Unexpected netgraph cookie, expected %ld",
397                  (long)rep->header.typecookie, (long)NGM_PPPOE_COOKIE);
398           continue;
399         }
400 
401         switch (rep->header.cmd) {
402           case NGM_PPPOE_SET_FLAG:	msg = "SET_FLAG";	break;
403           case NGM_PPPOE_CONNECT:	msg = "CONNECT";	break;
404           case NGM_PPPOE_LISTEN:	msg = "LISTEN";		break;
405           case NGM_PPPOE_OFFER:		msg = "OFFER";		break;
406           case NGM_PPPOE_SUCCESS:	msg = "SUCCESS";	break;
407           case NGM_PPPOE_FAIL:		msg = "FAIL";		break;
408           case NGM_PPPOE_CLOSE:		msg = "CLOSE";		break;
409           case NGM_PPPOE_GET_STATUS:	msg = "GET_STATUS";	break;
410           case NGM_PPPOE_ACNAME:
411             msg = "ACNAME";
412             if (setenv("ACNAME", sts->hook, 1) != 0)
413               syslog(LOG_WARNING, "setenv: cannot set ACNAME=%s: %m",
414                      sts->hook);
415             break;
416           case NGM_PPPOE_SESSIONID:
417             msg = "SESSIONID";
418             snprintf(sessionid, sizeof sessionid, "%04x", *(u_int16_t *)sts);
419             if (setenv("SESSIONID", sessionid, 1) != 0)
420               syslog(LOG_WARNING, "setenv: cannot set SESSIONID=%s: %m",
421                      sessionid);
422             break;
423           default:
424             snprintf(unknown, sizeof unknown, "<%d>", (int)rep->header.cmd);
425             msg = unknown;
426             break;
427         }
428 
429         switch (rep->header.cmd) {
430           case NGM_PPPOE_FAIL:
431           case NGM_PPPOE_CLOSE:
432             syslog(LOG_ERR, "Received NGM_PPPOE_%s (hook \"%s\")",
433                    msg, sts->hook);
434             _exit(0);
435         }
436 
437         syslog(LOG_INFO, "Received NGM_PPPOE_%s (hook \"%s\")", msg, sts->hook);
438       } while (rep->header.cmd != NGM_PPPOE_SUCCESS);
439 
440       dup2(ds, STDIN_FILENO);
441       dup2(ds, STDOUT_FILENO);
442       close(ds);
443       close(cs);
444 
445       setsid();
446       syslog(LOG_INFO, "Executing: %s", exec);
447       execlp(_PATH_BSHELL, _PATH_BSHELL, "-c", exec, (char *)NULL);
448       syslog(LOG_ERR, "execlp failed: %m");
449       _exit(EX_OSFILE);
450 
451     default:
452       wait(&ret);
453       errno = ret;
454       if (errno)
455         syslog(LOG_ERR, "Second fork failed: %m");
456       break;
457   }
458 }
459 
460 #ifndef NOKLDLOAD
461 static int
462 LoadModules(void)
463 {
464   const char *module[] = { "netgraph", "ng_socket", "ng_ether", "ng_pppoe" };
465   int f;
466 
467   for (f = 0; f < sizeof module / sizeof *module; f++)
468     if (modfind(module[f]) == -1 && kldload(module[f]) == -1) {
469       fprintf(stderr, "kldload: %s: %s\n", module[f], strerror(errno));
470       return 0;
471     }
472 
473   return 1;
474 }
475 #endif
476 
477 static void
478 nglog(const char *fmt, ...)
479 {
480   char nfmt[256];
481   va_list ap;
482 
483   snprintf(nfmt, sizeof nfmt, "%s: %s", fmt, strerror(errno));
484   va_start(ap, fmt);
485   vsyslog(LOG_INFO, nfmt, ap);
486   va_end(ap);
487 }
488 
489 static void
490 nglogx(const char *fmt, ...)
491 {
492   va_list ap;
493 
494   va_start(ap, fmt);
495   vsyslog(LOG_INFO, fmt, ap);
496   va_end(ap);
497 }
498 
499 int
500 main(int argc, char *argv[])
501 {
502   char hostname[MAXHOSTNAMELEN], *exec, rhook[NG_HOOKSIZ];
503   unsigned char response[1024];
504   const char *label, *prog, *provider, *acname;
505   struct ngm_connect ngc;
506   struct sigaction act;
507   int ch, cs, ds, ret, optF, optd, optn, sz, f;
508   const char *pidfile;
509 
510   prog = strrchr(argv[0], '/');
511   prog = prog ? prog + 1 : argv[0];
512   pidfile = NULL;
513   exec = NULL;
514   label = NULL;
515   acname = NULL;
516   provider = "";
517   optF = optd = optn = 0;
518 
519   while ((ch = getopt(argc, argv, "FP:a:de:l:n:p:")) != -1) {
520     switch (ch) {
521       case 'F':
522         optF = 1;
523         break;
524 
525       case 'P':
526         pidfile = optarg;
527         break;
528 
529       case 'a':
530         acname = optarg;
531         break;
532 
533       case 'd':
534         optd = 1;
535         break;
536 
537       case 'e':
538         exec = optarg;
539         break;
540 
541       case 'l':
542         label = optarg;
543         break;
544 
545       case 'n':
546         optn = 1;
547         NgSetDebug(atoi(optarg));
548         break;
549 
550       case 'p':
551         provider = optarg;
552         break;
553 
554       default:
555         return usage(prog);
556     }
557   }
558 
559   if (optind >= argc || optind + 2 < argc)
560     return usage(prog);
561 
562   if (exec != NULL && label != NULL)
563     return usage(prog);
564 
565   if (exec == NULL) {
566     if (label == NULL)
567       label = provider;
568     if (label == NULL) {
569       fprintf(stderr, "%s: Either a provider, a label or an exec command"
570               " must be given\n", prog);
571       return usage(prog);
572     }
573     exec = (char *)alloca(sizeof DEFAULT_EXEC_PREFIX + strlen(label));
574     if (exec == NULL) {
575       fprintf(stderr, "%s: Cannot allocate %zu bytes\n", prog,
576               sizeof DEFAULT_EXEC_PREFIX + strlen(label));
577       return EX_OSERR;
578     }
579     strcpy(exec, DEFAULT_EXEC_PREFIX);
580     strcpy(exec + sizeof DEFAULT_EXEC_PREFIX - 1, label);
581   }
582 
583   if (acname == NULL) {
584     char *dot;
585 
586     if (gethostname(hostname, sizeof hostname))
587       strcpy(hostname, "localhost");
588     else if ((dot = strchr(hostname, '.')))
589       *dot = '\0';
590 
591     acname = hostname;
592   }
593 
594 #ifndef NOKLDLOAD
595   if (!LoadModules())
596     return EX_UNAVAILABLE;
597 #endif
598 
599   /* Create a socket node */
600   if (NgMkSockNode(NULL, &cs, &ds) == -1) {
601     perror("Cannot create netgraph socket node");
602     return EX_CANTCREAT;
603   }
604 
605   /* Connect it up (and fill in `ngc') */
606   if ((ret = ConfigureNode(prog, argv[optind], provider, cs, ds,
607                            optd, &ngc)) != 0) {
608     close(cs);
609     close(ds);
610     return ret;
611   }
612 
613   if (!optF && daemon(1, 0) == -1) {
614     perror("daemon()");
615     close(cs);
616     close(ds);
617     return EX_OSERR;
618   }
619 
620 
621   if (pidfile != NULL) {
622     FILE *fp;
623 
624     if ((fp = fopen(pidfile, "w")) == NULL) {
625       perror(pidfile);
626       close(cs);
627       close(ds);
628       return EX_CANTCREAT;
629     } else {
630       fprintf(fp, "%d\n", (int)getpid());
631       fclose(fp);
632     }
633   }
634 
635   openlog(prog, LOG_PID | (optF ? LOG_PERROR : 0), LOG_DAEMON);
636   if (!optF && optn)
637     NgSetErrLog(nglog, nglogx);
638 
639   memset(&act, '\0', sizeof act);
640   act.sa_handler = Farewell;
641   act.sa_flags = 0;
642   sigemptyset(&act.sa_mask);
643   sigaction(SIGHUP, &act, NULL);
644   sigaction(SIGINT, &act, NULL);
645   sigaction(SIGQUIT, &act, NULL);
646   sigaction(SIGTERM, &act, NULL);
647 
648   while (!ReceivedSignal) {
649     if (*provider)
650       syslog(LOG_INFO, "Listening as provider %s", provider);
651     else
652       syslog(LOG_INFO, "Listening");
653 
654     switch (sz = NgRecvData(ds, response, sizeof response, rhook)) {
655       case -1:
656         syslog(LOG_INFO, "NgRecvData: %m");
657         break;
658       case 0:
659         syslog(LOG_INFO, "NgRecvData: socket closed");
660         break;
661       default:
662         if (optd) {
663           char *dbuf, *ptr;
664 
665           ptr = dbuf = alloca(sz * 2 + 1);
666           for (f = 0; f < sz; f++, ptr += 2)
667             sprintf(ptr, "%02x", (u_char)response[f]);
668           *ptr = '\0';
669           syslog(LOG_INFO, "Got %d bytes of data: %s", sz, dbuf);
670         }
671     }
672     if (sz <= 0) {
673       ret = EX_UNAVAILABLE;
674       break;
675     }
676     Spawn(prog, acname, provider, exec, ngc, cs, ds, response, sz, optd);
677   }
678 
679   if (pidfile)
680     remove(pidfile);
681 
682   if (ReceivedSignal) {
683     syslog(LOG_INFO, "Received signal %d, exiting", ReceivedSignal);
684 
685     signal(ReceivedSignal, SIG_DFL);
686     raise(ReceivedSignal);
687 
688     /* NOTREACHED */
689 
690     ret = -ReceivedSignal;
691   }
692 
693   return ret;
694 }
695