xref: /freebsd/libexec/pppoed/pppoed.c (revision 7bc6d0158f0e9863a2a13a951321185d214cd3be)
1 /*-
2  * Copyright (c) 1999 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  * $FreeBSD$
27  */
28 
29 #include <sys/param.h>
30 #include <sys/socket.h>
31 #include <sys/un.h>
32 #include <netinet/in.h>
33 #include <arpa/inet.h>
34 #include <netdb.h>
35 #include <netgraph.h>
36 #include <net/ethernet.h>
37 #include <netinet/in_systm.h>
38 #include <netinet/ip.h>
39 #include <netgraph/ng_ether.h>
40 #include <netgraph/ng_message.h>
41 #include <netgraph/ng_pppoe.h>
42 #include <netgraph/ng_socket.h>
43 
44 #include <errno.h>
45 #include <paths.h>
46 #include <signal.h>
47 #include <stdio.h>
48 #include <stdarg.h>
49 #include <stdlib.h>
50 #include <string.h>
51 #include <sysexits.h>
52 #include <sys/fcntl.h>
53 #ifndef NOKLDLOAD
54 #include <sys/linker.h>
55 #include <sys/module.h>
56 #endif
57 #include <sys/uio.h>
58 #include <sys/wait.h>
59 #include <syslog.h>
60 #include <termios.h>
61 #include <unistd.h>
62 
63 
64 #define DEFAULT_EXEC_PREFIX "exec /usr/sbin/ppp -direct "
65 
66 static int ReceivedSignal;
67 
68 static int
69 usage(const char *prog)
70 {
71   fprintf(stderr, "Usage: %s [-Fd] [-P pidfile] [-a name] [-e exec]"
72           " [-p provider] interface\n", prog);
73   return EX_USAGE;
74 }
75 
76 static void
77 Farewell(int sig)
78 {
79   ReceivedSignal = sig;
80   signal(sig, SIG_DFL);		/* If something makes us block... */
81 }
82 
83 static int
84 ConfigureNode(const char *prog, const char *iface, const char *provider,
85               int cs, int ds, int debug, struct ngm_connect *ngc)
86 {
87   /*
88    * We're going to do this with the passed `ds' & `cs' descriptors:
89    *
90    * .---------.
91    * |  ether  |
92    * | <iface> |
93    * `---------'
94    *  (orphan)                                     ds    cs
95    *     |                                         |     |
96    *     |                                         |     |
97    * (ethernet)                                    |     |
98    * .---------.                                .-----------.
99    * |  pppoe  |                                |  socket   |
100    * | <iface> |(pppoe-<pid>)<---->(pppoe-<pid>)| <unnamed> |
101    * `---------                                 `-----------'
102    * (exec-<pid>)
103    *     ^                .-----------.      .-------------.
104    *     |                |   socket  |      | ppp -direct |
105    *     `--->(exec-<pid>)| <unnamed> |--fd--|  provider   |
106    *                      `-----------'      `-------------'
107    *
108    * where there are potentially many ppp processes running off of the
109    * same PPPoE node.
110    * The exec-<pid> hook isn't made 'till we Spawn().
111    */
112 
113   char *epath, *spath;
114   struct ngpppoe_init_data *data;
115   const struct hooklist *hlist;
116   const struct nodeinfo *ninfo;
117   const struct linkinfo *nlink;
118   struct ngm_mkpeer mkp;
119   struct ng_mesg *resp;
120   u_char rbuf[2048];
121   int f, plen;
122 
123   /*
124    * Ask for a list of hooks attached to the "ether" node.  This node should
125    * magically exist as a way of hooking stuff onto an ethernet device
126    */
127   epath = (char *)alloca(strlen(iface) + 2);
128   sprintf(epath, "%s:", iface);
129 
130   if (debug)
131     fprintf(stderr, "Sending NGM_LISTHOOKS to %s\n", epath);
132 
133   if (NgSendMsg(cs, epath, NGM_GENERIC_COOKIE, NGM_LISTHOOKS, NULL, 0) < 0) {
134     if (errno == ENOENT)
135       fprintf(stderr, "%s Cannot send a netgraph message: Invalid interface\n",
136               epath);
137     else
138       fprintf(stderr, "%s Cannot send a netgraph message: %s\n",
139               epath, strerror(errno));
140     return EX_UNAVAILABLE;
141   }
142 
143   /* Get our list back */
144   resp = (struct ng_mesg *)rbuf;
145   if (NgRecvMsg(cs, resp, sizeof rbuf, NULL) < 0) {
146     perror("Cannot get netgraph response");
147     return EX_UNAVAILABLE;
148   }
149 
150   hlist = (const struct hooklist *)resp->data;
151   ninfo = &hlist->nodeinfo;
152 
153   if (debug)
154     fprintf(stderr, "Got reply from id [%x]: Type %s with %d hooks\n",
155             ninfo->id, ninfo->type, ninfo->hooks);
156 
157   /* Make sure we've got the right type of node */
158   if (strncmp(ninfo->type, NG_ETHER_NODE_TYPE, sizeof NG_ETHER_NODE_TYPE - 1)) {
159     fprintf(stderr, "%s Unexpected node type ``%s'' (wanted ``"
160             NG_ETHER_NODE_TYPE "'')\n", epath, ninfo->type);
161     return EX_DATAERR;
162   }
163 
164   /* look for a hook already attached.  */
165   for (f = 0; f < ninfo->hooks; f++) {
166     nlink = &hlist->link[f];
167 
168     if (debug)
169       fprintf(stderr, "  Got [%x]:%s -> [%x]:%s\n", ninfo->id,
170               nlink->ourhook, nlink->nodeinfo.id, nlink->peerhook);
171 
172     if (!strcmp(nlink->ourhook, NG_ETHER_HOOK_ORPHAN) ||
173         !strcmp(nlink->ourhook, NG_ETHER_HOOK_DIVERT)) {
174       /*
175        * Something is using the data coming out of this `ether' node.
176        * If it's a PPPoE node, we use that node, otherwise we complain that
177        * someone else is using the node.
178        */
179       if (strcmp(nlink->nodeinfo.type, NG_PPPOE_NODE_TYPE)) {
180         fprintf(stderr, "%s Node type %s is currently active\n",
181                 epath, nlink->nodeinfo.type);
182         return EX_UNAVAILABLE;
183       }
184       break;
185     }
186   }
187 
188   if (f == ninfo->hooks) {
189     /*
190      * Create a new PPPoE node connected to the `ether' node using
191      * the magic `orphan' and `ethernet' hooks
192      */
193     snprintf(mkp.type, sizeof mkp.type, "%s", NG_PPPOE_NODE_TYPE);
194     snprintf(mkp.ourhook, sizeof mkp.ourhook, "%s", NG_ETHER_HOOK_ORPHAN);
195     snprintf(mkp.peerhook, sizeof mkp.peerhook, "%s", NG_PPPOE_HOOK_ETHERNET);
196 
197     if (debug)
198       fprintf(stderr, "Send MKPEER: %s%s -> [type %s]:%s\n", epath,
199               mkp.ourhook, mkp.type, mkp.peerhook);
200 
201     if (NgSendMsg(cs, epath, NGM_GENERIC_COOKIE,
202                   NGM_MKPEER, &mkp, sizeof mkp) < 0) {
203       fprintf(stderr, "%s Cannot create a peer PPPoE node: %s\n",
204               epath, strerror(errno));
205       return EX_OSERR;
206     }
207   }
208 
209   /* Connect the PPPoE node to our socket node.  */
210   snprintf(ngc->path, sizeof ngc->path, "%s%s", epath, NG_ETHER_HOOK_ORPHAN);
211   snprintf(ngc->ourhook, sizeof ngc->ourhook, "pppoe-%ld", (long)getpid());
212   memcpy(ngc->peerhook, ngc->ourhook, sizeof ngc->peerhook);
213 
214   if (NgSendMsg(cs, ".:", NGM_GENERIC_COOKIE,
215                 NGM_CONNECT, ngc, sizeof *ngc) < 0) {
216     perror("Cannot CONNECT PPPoE and socket nodes");
217     return EX_OSERR;
218   }
219 
220   plen = strlen(provider);
221 
222   data = (struct ngpppoe_init_data *)alloca(sizeof *data + plen);
223   snprintf(data->hook, sizeof data->hook, "%s", ngc->peerhook);
224   memcpy(data->data, provider, plen);
225   data->data_len = plen;
226 
227   spath = (char *)alloca(strlen(ngc->peerhook) + 3);
228   strcpy(spath, ".:");
229   strcpy(spath + 2, ngc->ourhook);
230 
231   if (debug) {
232     if (provider)
233       fprintf(stderr, "Sending PPPOE_LISTEN to %s, provider %s\n",
234               spath, provider);
235     else
236       fprintf(stderr, "Sending PPPOE_LISTEN to %s\n", spath);
237   }
238 
239   if (NgSendMsg(cs, spath, NGM_PPPOE_COOKIE, NGM_PPPOE_LISTEN,
240                 data, sizeof *data + plen) == -1) {
241     fprintf(stderr, "%s: Cannot LISTEN on netgraph node: %s\n",
242             spath, strerror(errno));
243     return EX_OSERR;
244   }
245 
246   return 0;
247 }
248 
249 static void
250 Spawn(const char *prog, const char *acname, const char *provider,
251 	const char *exec,
252       struct ngm_connect ngc, int cs, int ds, void *request, int sz,
253       int debug)
254 {
255   char msgbuf[sizeof(struct ng_mesg) + sizeof(struct ngpppoe_sts)];
256   struct ng_mesg *rep = (struct ng_mesg *)msgbuf;
257   struct ngpppoe_sts *sts = (struct ngpppoe_sts *)(msgbuf + sizeof *rep);
258   struct ngpppoe_init_data *data;
259   char unknown[14], *path;
260   const char *msg;
261   int ret, slen;
262 
263   switch ((ret = fork())) {
264     case -1:
265       syslog(LOG_ERR, "fork: %m");
266       break;
267 
268     case 0:
269       switch (fork()) {
270         case 0:
271           break;
272         case -1:
273           _exit(errno);
274         default:
275           _exit(0);
276       }
277       close(cs);
278       close(ds);
279 
280       /* Create a new socket node */
281       if (debug)
282         syslog(LOG_INFO, "Creating a new socket node");
283 
284       if (NgMkSockNode(NULL, &cs, &ds) == -1) {
285         syslog(LOG_ERR, "Cannot create netgraph socket node: %m");
286         _exit(EX_CANTCREAT);
287       }
288 
289       /* Connect the PPPoE node to our new socket node.  */
290       snprintf(ngc.ourhook, sizeof ngc.ourhook, "exec-%ld", (long)getpid());
291       memcpy(ngc.peerhook, ngc.ourhook, sizeof ngc.peerhook);
292 
293       if (debug)
294         syslog(LOG_INFO, "Sending CONNECT from .:%s -> %s.%s",
295                ngc.ourhook, ngc.path, ngc.peerhook);
296       if (NgSendMsg(cs, ".:", NGM_GENERIC_COOKIE,
297                     NGM_CONNECT, &ngc, sizeof ngc) < 0) {
298         syslog(LOG_ERR, "Cannot CONNECT PPPoE and socket nodes: %m");
299         _exit(EX_OSERR);
300       }
301 
302       /*
303        * If we tell the socket node not to LINGER, it will go away when
304        * the last hook is removed.
305        */
306       if (debug)
307         syslog(LOG_INFO, "Sending NGM_SOCK_CMD_NOLINGER to socket");
308       if (NgSendMsg(cs, ".:", NGM_SOCKET_COOKIE,
309                     NGM_SOCK_CMD_NOLINGER, NULL, 0) < 0) {
310         syslog(LOG_ERR, "Cannot send NGM_SOCK_CMD_NOLINGER: %m");
311         _exit(EX_OSERR);
312       }
313 
314       /* Put the PPPoE node into OFFER mode */
315       slen = strlen(acname);
316       data = (struct ngpppoe_init_data *)alloca(sizeof *data + slen);
317       snprintf(data->hook, sizeof data->hook, "%s", ngc.ourhook);
318       memcpy(data->data, acname, slen);
319       data->data_len = slen;
320 
321       path = (char *)alloca(strlen(ngc.ourhook) + 3);
322       strcpy(path, ".:");
323       strcpy(path + 2, ngc.ourhook);
324 
325       syslog(LOG_INFO, "Offering to %s as access concentrator %s",
326              path, acname);
327       if (NgSendMsg(cs, path, NGM_PPPOE_COOKIE, NGM_PPPOE_OFFER,
328                     data, sizeof *data + slen) == -1) {
329         syslog(LOG_INFO, "%s: Cannot OFFER on netgraph node: %m", path);
330         _exit(EX_OSERR);
331       }
332       /* If we have a provider code, set it */
333       if (provider ) {
334         slen = strlen(provider);
335         data = (struct ngpppoe_init_data *)alloca(sizeof *data + slen);
336         snprintf(data->hook, sizeof data->hook, "%s", ngc.ourhook);
337         memcpy(data->data, provider, slen);
338         data->data_len = slen;
339 
340         syslog(LOG_INFO, "adding to %s as offered service %s",
341              path, acname);
342         if (NgSendMsg(cs, path, NGM_PPPOE_COOKIE, NGM_PPPOE_SERVICE,
343                     data, sizeof *data + slen) == -1) {
344           syslog(LOG_INFO, "%s: Cannot add service on netgraph node: %m", path);
345           _exit(EX_OSERR);
346         }
347       }
348 
349       /* And send our request data to the waiting node */
350       if (debug)
351         syslog(LOG_INFO, "Sending original request to %s (%d bytes)", path, sz);
352       if (NgSendData(ds, ngc.ourhook, request, sz) == -1) {
353         syslog(LOG_ERR, "Cannot send original request to %s: %m", path);
354         _exit(EX_OSERR);
355       }
356 
357       /* Then wait for a success indication */
358 
359       if (debug)
360         syslog(LOG_INFO, "Waiting for a SUCCESS reply %s", path);
361 
362       do {
363         if (NgRecvMsg(cs, rep, sizeof msgbuf, NULL) < 0) {
364           syslog(LOG_ERR, "%s: Cannot receive a message: %m", path);
365           _exit(EX_OSERR);
366         }
367 
368         if (rep->header.version != NG_VERSION) {
369           syslog(LOG_ERR, "%ld: Unexpected netgraph version, expected %ld",
370                  (long)rep->header.version, (long)NG_VERSION);
371           _exit(EX_PROTOCOL);
372         }
373 
374         if (rep->header.typecookie != NGM_PPPOE_COOKIE) {
375           syslog(LOG_INFO, "%ld: Unexpected netgraph cookie, expected %ld",
376                  (long)rep->header.typecookie, (long)NGM_PPPOE_COOKIE);
377           continue;
378         }
379 
380         switch (rep->header.cmd) {
381           case NGM_PPPOE_SET_FLAG:	msg = "SET_FLAG";	break;
382           case NGM_PPPOE_CONNECT:	msg = "CONNECT";	break;
383           case NGM_PPPOE_LISTEN:	msg = "LISTEN";		break;
384           case NGM_PPPOE_OFFER:		msg = "OFFER";		break;
385           case NGM_PPPOE_SUCCESS:	msg = "SUCCESS";	break;
386           case NGM_PPPOE_FAIL:		msg = "FAIL";		break;
387           case NGM_PPPOE_CLOSE:		msg = "CLOSE";		break;
388           case NGM_PPPOE_GET_STATUS:	msg = "GET_STATUS";	break;
389           default:
390             snprintf(unknown, sizeof unknown, "<%d>", (int)rep->header.cmd);
391             msg = unknown;
392             break;
393         }
394 
395         switch (rep->header.cmd) {
396           case NGM_PPPOE_FAIL:
397           case NGM_PPPOE_CLOSE:
398             syslog(LOG_ERR, "Received NGM_PPPOE_%s (hook \"%s\")",
399                    msg, sts->hook);
400             _exit(0);
401         }
402 
403         syslog(LOG_INFO, "Received NGM_PPPOE_%s (hook \"%s\")", msg, sts->hook);
404       } while (rep->header.cmd != NGM_PPPOE_SUCCESS);
405 
406       dup2(ds, STDIN_FILENO);
407       dup2(ds, STDOUT_FILENO);
408       close(ds);
409       close(cs);
410 
411       setsid();
412       syslog(LOG_INFO, "Executing: %s", exec);
413       execlp(_PATH_BSHELL, _PATH_BSHELL, "-c", exec, (char *)NULL);
414       syslog(LOG_ERR, "execlp failed: %m");
415       _exit(EX_OSFILE);
416 
417     default:
418       wait(&ret);
419       errno = ret;
420       if (errno)
421         syslog(LOG_ERR, "Second fork failed: %m");
422       break;
423   }
424 }
425 
426 #ifndef NOKLDLOAD
427 static int
428 LoadModules(void)
429 {
430   const char *module[] = { "netgraph", "ng_socket", "ng_ether", "ng_pppoe" };
431   int f;
432 
433   for (f = 0; f < sizeof module / sizeof *module; f++)
434     if (modfind(module[f]) == -1 && kldload(module[f]) == -1) {
435       fprintf(stderr, "kldload: %s: %s\n", module[f], strerror(errno));
436       return 0;
437     }
438 
439   return 1;
440 }
441 #endif
442 
443 static void
444 nglog(const char *fmt, ...)
445 {
446   char nfmt[256];
447   va_list ap;
448 
449   snprintf(nfmt, sizeof nfmt, "%s: %s", fmt, strerror(errno));
450   va_start(ap, fmt);
451   vsyslog(LOG_INFO, nfmt, ap);
452   va_end(ap);
453 }
454 
455 static void
456 nglogx(const char *fmt, ...)
457 {
458   va_list ap;
459 
460   va_start(ap, fmt);
461   vsyslog(LOG_INFO, fmt, ap);
462   va_end(ap);
463 }
464 
465 int
466 main(int argc, char **argv)
467 {
468   char hostname[MAXHOSTNAMELEN], *exec, rhook[NG_HOOKLEN + 1];
469   unsigned char response[1024];
470   const char *prog, *provider, *acname;
471   struct ngm_connect ngc;
472   int ch, cs, ds, ret, optF, optd, optn, sz, f;
473   const char *pidfile;
474 
475   prog = strrchr(argv[0], '/');
476   prog = prog ? prog + 1 : argv[0];
477   pidfile = NULL;
478   exec = NULL;
479   acname = NULL;
480   provider = "";
481   optF = optd = optn = 0;
482 
483   while ((ch = getopt(argc, argv, "FP:a:de:n:p:")) != -1) {
484     switch (ch) {
485       case 'F':
486         optF = 1;
487         break;
488 
489       case 'P':
490         pidfile = optarg;
491         break;
492 
493       case 'a':
494         acname = optarg;
495         break;
496 
497       case 'd':
498         optd = 1;
499         break;
500 
501       case 'e':
502         exec = optarg;
503         break;
504 
505       case 'n':
506         optn = 1;
507         NgSetDebug(atoi(optarg));
508         break;
509 
510       case 'p':
511         provider = optarg;
512         break;
513 
514       default:
515         return usage(prog);
516     }
517   }
518 
519   if (optind >= argc || optind + 2 < argc)
520     return usage(prog);
521 
522   if (exec == NULL) {
523     if (provider == NULL) {
524       fprintf(stderr, "%s: Either a provider or an exec command"
525               " must be given\n", prog);
526       return usage(prog);
527     }
528     exec = (char *)alloca(sizeof DEFAULT_EXEC_PREFIX + strlen(provider));
529     if (exec == NULL) {
530       fprintf(stderr, "%s: Cannot allocate %d bytes\n", prog,
531               (int)(sizeof DEFAULT_EXEC_PREFIX) + strlen(provider));
532       return EX_OSERR;
533     }
534     strcpy(exec, DEFAULT_EXEC_PREFIX);
535     strcpy(exec + sizeof DEFAULT_EXEC_PREFIX - 1, provider);
536   }
537 
538   if (acname == NULL) {
539     char *dot;
540 
541     if (gethostname(hostname, sizeof hostname))
542       strcpy(hostname, "localhost");
543     else if ((dot = strchr(hostname, '.')))
544       *dot = '\0';
545 
546     acname = hostname;
547   }
548 
549 #ifndef NOKLDLOAD
550   if (!LoadModules())
551     return EX_UNAVAILABLE;
552 #endif
553 
554   /* Create a socket node */
555   if (NgMkSockNode(NULL, &cs, &ds) == -1) {
556     perror("Cannot create netgraph socket node");
557     return EX_CANTCREAT;
558   }
559 
560   /* Connect it up (and fill in `ngc') */
561   if ((ret = ConfigureNode(prog, argv[optind], provider, cs, ds,
562                            optd, &ngc)) != 0) {
563     close(cs);
564     close(ds);
565     return ret;
566   }
567 
568   if (!optF && daemon(1, 0) == -1) {
569     perror("daemon()");
570     close(cs);
571     close(ds);
572     return EX_OSERR;
573   }
574 
575 
576   if (pidfile != NULL) {
577     FILE *fp;
578 
579     if ((fp = fopen(pidfile, "w")) == NULL) {
580       perror(pidfile);
581       close(cs);
582       close(ds);
583       return EX_CANTCREAT;
584     } else {
585       fprintf(fp, "%d\n", (int)getpid());
586       fclose(fp);
587     }
588   }
589 
590   openlog(prog, LOG_PID | (optF ? LOG_PERROR : 0), LOG_DAEMON);
591   if (!optF && optn)
592     NgSetErrLog(nglog, nglogx);
593 
594   signal(SIGHUP, Farewell);
595   signal(SIGINT, Farewell);
596   signal(SIGQUIT, Farewell);
597   signal(SIGTERM, Farewell);
598 
599   while (!ReceivedSignal) {
600     if (*provider)
601       syslog(LOG_INFO, "Listening as provider %s", provider);
602     else
603       syslog(LOG_INFO, "Listening");
604 
605     switch (sz = NgRecvData(ds, response, sizeof response, rhook)) {
606       case -1:
607         syslog(LOG_INFO, "NgRecvData: %m");
608         break;
609       case 0:
610         syslog(LOG_INFO, "NgRecvData: socket closed");
611         break;
612       default:
613         if (optd) {
614           char *dbuf, *ptr;
615 
616           ptr = dbuf = alloca(sz * 2 + 1);
617           for (f = 0; f < sz; f++, ptr += 2)
618             sprintf(ptr, "%02x", (u_char)response[f]);
619           *ptr = '\0';
620           syslog(LOG_INFO, "Got %d bytes of data: %s", sz, dbuf);
621         }
622     }
623     if (sz <= 0) {
624       ret = EX_UNAVAILABLE;
625       break;
626     }
627     Spawn(prog, acname, provider, exec, ngc, cs, ds, response, sz, optd);
628   }
629 
630   if (pidfile)
631     remove(pidfile);
632 
633   if (ReceivedSignal) {
634     syslog(LOG_INFO, "Received signal %d, exiting", ReceivedSignal);
635 
636     signal(ReceivedSignal, SIG_DFL);
637     raise(ReceivedSignal);
638 
639     /* NOTREACHED */
640 
641     ret = -ReceivedSignal;
642   }
643 
644   return ret;
645 }
646