xref: /freebsd/usr.sbin/ppp/tty.c (revision ba3c1f5972d7b90feb6e6da47905ff2757e0fe57)
1 /*-
2  * SPDX-License-Identifier: BSD-2-Clause
3  *
4  * Copyright (c) 1999 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/un.h>
33 #if defined(__OpenBSD__) || defined(__NetBSD__)
34 #include <sys/ioctl.h>
35 #endif
36 
37 #include <errno.h>
38 #include <fcntl.h>
39 #include <stdio.h>
40 #include <stdlib.h>
41 #include <string.h>
42 #include <sysexits.h>
43 #include <sys/uio.h>
44 #include <termios.h>
45 #include <ttyent.h>
46 #include <unistd.h>
47 #ifndef NONETGRAPH
48 #include <netgraph.h>
49 #include <netgraph/ng_async.h>
50 #include <netgraph/ng_message.h>
51 #include <netgraph/ng_ppp.h>
52 #include <netgraph/ng_tty.h>
53 #endif
54 
55 #include "layer.h"
56 #include "defs.h"
57 #include "mbuf.h"
58 #include "log.h"
59 #include "timer.h"
60 #include "lqr.h"
61 #include "hdlc.h"
62 #include "throughput.h"
63 #include "fsm.h"
64 #include "lcp.h"
65 #include "ccp.h"
66 #include "link.h"
67 #include "async.h"
68 #include "descriptor.h"
69 #include "physical.h"
70 #include "mp.h"
71 #include "chat.h"
72 #include "auth.h"
73 #include "chap.h"
74 #include "cbcp.h"
75 #include "datalink.h"
76 #include "main.h"
77 #include "id.h"
78 #include "tty.h"
79 
80 #if defined(__mac68k__) || defined(__macppc__)
81 #undef	CRTS_IFLOW
82 #undef	CCTS_OFLOW
83 #define	CRTS_IFLOW	CDTRCTS
84 #define	CCTS_OFLOW	CDTRCTS
85 #endif
86 
87 #define	Online(dev)	((dev)->mbits & TIOCM_CD)
88 
89 struct ttydevice {
90   struct device dev;		/* What struct physical knows about */
91   struct pppTimer Timer;	/* CD checks */
92   int mbits;			/* Current DCD status */
93   int carrier_seconds;		/* seconds before CD is *required* */
94 #ifndef NONETGRAPH
95   struct {
96     unsigned speed;		/* Pre-line-discipline speed */
97     int fd;			/* Pre-line-discipline fd */
98     int disc;			/* Old line-discipline */
99   } real;
100   char hook[sizeof NG_ASYNC_HOOK_SYNC]; /* our ng_socket hook */
101   int cs;			/* A netgraph control socket (maybe) */
102 #endif
103   struct termios ios;		/* To be able to reset from raw mode */
104 };
105 
106 #define device2tty(d) ((d)->type == TTY_DEVICE ? (struct ttydevice *)d : NULL)
107 
108 unsigned
109 tty_DeviceSize(void)
110 {
111   return sizeof(struct ttydevice);
112 }
113 
114 /*
115  * tty_Timeout() watches the DCD signal and mentions it if it's status
116  * changes.
117  */
118 static void
119 tty_Timeout(void *data)
120 {
121   struct physical *p = data;
122   struct ttydevice *dev = device2tty(p->handler);
123   int ombits, change;
124 
125   timer_Stop(&dev->Timer);
126   dev->Timer.load = SECTICKS;		/* Once a second please */
127   timer_Start(&dev->Timer);
128   ombits = dev->mbits;
129 
130   if (p->fd >= 0) {
131     if (ioctl(p->fd, TIOCMGET, &dev->mbits) < 0) {
132       /* we must be a pty ? */
133       if (p->cfg.cd.necessity != CD_DEFAULT)
134         log_Printf(LogWARN, "%s: Carrier ioctl not supported, "
135                    "using ``set cd off''\n", p->link.name);
136       timer_Stop(&dev->Timer);
137       dev->mbits = TIOCM_CD;
138       return;
139     }
140   } else
141     dev->mbits = 0;
142 
143   if (ombits == -1) {
144     /* First time looking for carrier */
145     if (Online(dev))
146       log_Printf(LogPHASE, "%s: %s: CD detected\n", p->link.name, p->name.full);
147     else if (++dev->carrier_seconds >= dev->dev.cd.delay) {
148       if (dev->dev.cd.necessity == CD_REQUIRED)
149         log_Printf(LogPHASE, "%s: %s: Required CD not detected\n",
150                    p->link.name, p->name.full);
151       else {
152         log_Printf(LogPHASE, "%s: %s doesn't support CD\n",
153                    p->link.name, p->name.full);
154         dev->mbits = TIOCM_CD;		/* Dodgy null-modem cable ? */
155       }
156       timer_Stop(&dev->Timer);
157       /* tty_AwaitCarrier() will notice */
158     } else {
159       /* Keep waiting */
160       log_Printf(LogDEBUG, "%s: %s: Still no carrier (%d/%d)\n",
161                  p->link.name, p->name.full, dev->carrier_seconds,
162                  dev->dev.cd.delay);
163       dev->mbits = -1;
164     }
165   } else {
166     change = ombits ^ dev->mbits;
167     if (change & TIOCM_CD) {
168       if (dev->mbits & TIOCM_CD)
169         log_Printf(LogDEBUG, "%s: offline -> online\n", p->link.name);
170       else {
171         log_Printf(LogDEBUG, "%s: online -> offline\n", p->link.name);
172         log_Printf(LogPHASE, "%s: Carrier lost\n", p->link.name);
173         datalink_Down(p->dl, CLOSE_NORMAL);
174         timer_Stop(&dev->Timer);
175       }
176     } else
177       log_Printf(LogDEBUG, "%s: Still %sline\n", p->link.name,
178                  Online(dev) ? "on" : "off");
179   }
180 }
181 
182 static void
183 tty_StartTimer(struct physical *p)
184 {
185   struct ttydevice *dev = device2tty(p->handler);
186 
187   timer_Stop(&dev->Timer);
188   dev->Timer.load = SECTICKS;
189   dev->Timer.func = tty_Timeout;
190   dev->Timer.name = "tty CD";
191   dev->Timer.arg = p;
192   log_Printf(LogDEBUG, "%s: Using tty_Timeout [%p]\n",
193              p->link.name, tty_Timeout);
194   timer_Start(&dev->Timer);
195 }
196 
197 static int
198 tty_AwaitCarrier(struct physical *p)
199 {
200   struct ttydevice *dev = device2tty(p->handler);
201 
202   if (dev->dev.cd.necessity == CD_NOTREQUIRED || physical_IsSync(p))
203     return CARRIER_OK;
204 
205   if (dev->mbits == -1) {
206     if (dev->Timer.state == TIMER_STOPPED) {
207       dev->carrier_seconds = 0;
208       tty_StartTimer(p);
209     }
210     return CARRIER_PENDING;			/* Not yet ! */
211   }
212 
213   return Online(dev) ? CARRIER_OK : CARRIER_LOST;
214 }
215 
216 #ifdef NONETGRAPH
217 #define tty_SetAsyncParams	NULL
218 #define tty_Write		NULL
219 #define tty_Read		NULL
220 #else
221 
222 static int
223 isngtty(struct ttydevice *dev)
224 {
225   return dev->real.fd != -1;
226 }
227 
228 static void
229 tty_SetAsyncParams(struct physical *p, u_int32_t mymap, u_int32_t hismap)
230 {
231   struct ttydevice *dev = device2tty(p->handler);
232   char asyncpath[NG_PATHSIZ];
233   struct ng_async_cfg cfg;
234 
235   if (isngtty(dev)) {
236     /* Configure the async converter node */
237 
238     snprintf(asyncpath, sizeof asyncpath, ".:%s", dev->hook);
239     memset(&cfg, 0, sizeof cfg);
240     cfg.enabled = 1;
241     cfg.accm = mymap | hismap;
242     cfg.amru = MAX_MTU;
243     cfg.smru = MAX_MRU;
244     log_Printf(LogDEBUG, "Configure async node at %s\n", asyncpath);
245     if (NgSendMsg(dev->cs, asyncpath, NGM_ASYNC_COOKIE,
246                   NGM_ASYNC_CMD_SET_CONFIG, &cfg, sizeof cfg) < 0)
247       log_Printf(LogWARN, "%s: Can't configure async node at %s\n",
248                  p->link.name, asyncpath);
249   } else
250     /* No netgraph node, just config the async layer */
251     async_SetLinkParams(&p->async, mymap, hismap);
252 }
253 
254 static int
255 LoadLineDiscipline(struct physical *p)
256 {
257   struct ttydevice *dev = device2tty(p->handler);
258   u_char rbuf[sizeof(struct ng_mesg) + sizeof(struct nodeinfo)];
259   struct ng_mesg *reply;
260   struct nodeinfo *info;
261   char ttypath[NG_NODESIZ];
262   struct ngm_mkpeer ngm;
263   struct ngm_connect ngc;
264   int ldisc, cs, ds, hot;
265   unsigned speed;
266 
267   /*
268    * Don't use the netgraph line discipline for now.  Using it works, but
269    * carrier cannot be detected via TIOCMGET and the device doesn't become
270    * selectable with 0 bytes to read when carrier is lost :(
271    */
272   return 0;
273 
274   reply = (struct ng_mesg *)rbuf;
275   info = (struct nodeinfo *)reply->data;
276 
277   loadmodules(LOAD_VERBOSLY, "netgraph", "ng_tty", "ng_async", "ng_socket",
278               NULL);
279 
280   /* Get the speed before loading the line discipline */
281   speed = physical_GetSpeed(p);
282 
283   if (ioctl(p->fd, TIOCGETD, &dev->real.disc) < 0) {
284     log_Printf(LogDEBUG, "%s: Couldn't get tty line discipline\n",
285                p->link.name);
286     return 0;
287   }
288   ldisc = NETGRAPHDISC;
289   if (ID0ioctl(p->fd, TIOCSETD, &ldisc) < 0) {
290     log_Printf(LogDEBUG, "%s: Couldn't set NETGRAPHDISC line discipline\n",
291                p->link.name);
292     return 0;
293   }
294 
295   /* Get the name of the tty node */
296   if (ioctl(p->fd, NGIOCGINFO, info) < 0) {
297     log_Printf(LogWARN, "%s: ioctl(NGIOCGINFO): %s\n", p->link.name,
298                strerror(errno));
299     ID0ioctl(p->fd, TIOCSETD, &dev->real.disc);
300     return 0;
301   }
302   snprintf(ttypath, sizeof ttypath, "%s:", info->name);
303 
304   /* Create a socket node for our endpoint (and to send messages via) */
305   if (ID0NgMkSockNode(NULL, &cs, &ds) == -1) {
306     log_Printf(LogWARN, "%s: NgMkSockNode: %s\n", p->link.name,
307                strerror(errno));
308     ID0ioctl(p->fd, TIOCSETD, &dev->real.disc);
309     return 0;
310   }
311 
312   /* Set the ``hot char'' on the TTY node */
313   hot = HDLC_SYN;
314   log_Printf(LogDEBUG, "%s: Set tty hotchar to 0x%02x\n", p->link.name, hot);
315   if (NgSendMsg(cs, ttypath, NGM_TTY_COOKIE,
316       NGM_TTY_SET_HOTCHAR, &hot, sizeof hot) < 0) {
317     log_Printf(LogWARN, "%s: Can't set hot char\n", p->link.name);
318     goto failed;
319   }
320 
321   /* Attach an async converter node */
322   snprintf(ngm.type, sizeof ngm.type, "%s", NG_ASYNC_NODE_TYPE);
323   snprintf(ngm.ourhook, sizeof ngm.ourhook, "%s", NG_TTY_HOOK);
324   snprintf(ngm.peerhook, sizeof ngm.peerhook, "%s", NG_ASYNC_HOOK_ASYNC);
325   log_Printf(LogDEBUG, "%s: Send mkpeer async:%s to %s:%s\n", p->link.name,
326              ngm.peerhook, ttypath, ngm.ourhook);
327   if (NgSendMsg(cs, ttypath, NGM_GENERIC_COOKIE,
328       NGM_MKPEER, &ngm, sizeof ngm) < 0) {
329     log_Printf(LogWARN, "%s: Can't create %s node\n", p->link.name,
330                NG_ASYNC_NODE_TYPE);
331     goto failed;
332   }
333 
334   /* Connect the async node to our socket */
335   snprintf(ngc.path, sizeof ngc.path, "%s%s", ttypath, NG_TTY_HOOK);
336   snprintf(ngc.peerhook, sizeof ngc.peerhook, "%s", NG_ASYNC_HOOK_SYNC);
337   memcpy(ngc.ourhook, ngc.peerhook, sizeof ngc.ourhook);
338   log_Printf(LogDEBUG, "%s: Send connect %s:%s to .:%s\n", p->link.name,
339              ngc.path, ngc.peerhook, ngc.ourhook);
340   if (NgSendMsg(cs, ".:", NGM_GENERIC_COOKIE, NGM_CONNECT,
341       &ngc, sizeof ngc) < 0) {
342     log_Printf(LogWARN, "%s: Can't connect .:%s -> %s.%s: %s\n",
343                p->link.name, ngc.ourhook, ngc.path, ngc.peerhook,
344                strerror(errno));
345     goto failed;
346   }
347 
348   /* Get the async node id */
349   if (NgSendMsg(cs, ngc.path, NGM_GENERIC_COOKIE, NGM_NODEINFO, NULL, 0) < 0) {
350     log_Printf(LogWARN, "%s: Can't request async node info at %s: %s\n",
351                p->link.name, ngc.path, strerror(errno));
352     goto failed;
353   }
354   if (NgRecvMsg(cs, reply, sizeof rbuf, NULL) < 0) {
355     log_Printf(LogWARN, "%s: Can't obtain async node info at %s: %s\n",
356                p->link.name, ngc.path, strerror(errno));
357     goto failed;
358   }
359 
360   /* All done, set up our device state */
361   snprintf(dev->hook, sizeof dev->hook, "%s", ngc.ourhook);
362   dev->cs = cs;
363   dev->real.fd = p->fd;
364   p->fd = ds;
365   dev->real.speed = speed;
366   physical_SetSync(p);
367 
368   tty_SetAsyncParams(p, 0xffffffff, 0xffffffff);
369   physical_SetupStack(p, dev->dev.name, PHYSICAL_NOFORCE);
370   log_Printf(LogPHASE, "%s: Loaded netgraph tty line discipline\n",
371              p->link.name);
372 
373   return 1;
374 
375 failed:
376   ID0ioctl(p->fd, TIOCSETD, &dev->real.disc);
377   close(ds);
378   close(cs);
379 
380   return 0;
381 }
382 
383 static void
384 UnloadLineDiscipline(struct physical *p)
385 {
386   struct ttydevice *dev = device2tty(p->handler);
387 
388   if (isngtty(dev)) {
389     if (!physical_SetSpeed(p, dev->real.speed))
390       log_Printf(LogWARN, "Couldn't reset tty speed to %d\n", dev->real.speed);
391     dev->real.speed = 0;
392     close(p->fd);
393     p->fd = dev->real.fd;
394     dev->real.fd = -1;
395     close(dev->cs);
396     dev->cs = -1;
397     *dev->hook = '\0';
398     if (ID0ioctl(p->fd, TIOCSETD, &dev->real.disc) == 0) {
399       physical_SetupStack(p, dev->dev.name, PHYSICAL_NOFORCE);
400       log_Printf(LogPHASE, "%s: Unloaded netgraph tty line discipline\n",
401                  p->link.name);
402     } else
403       log_Printf(LogWARN, "%s: Failed to unload netgraph tty line discipline\n",
404                  p->link.name);
405   }
406 }
407 
408 static ssize_t
409 tty_Write(struct physical *p, const void *v, size_t n)
410 {
411   struct ttydevice *dev = device2tty(p->handler);
412 
413   if (isngtty(dev))
414     return NgSendData(p->fd, dev->hook, v, n) == -1 ? -1 : (ssize_t)n;
415   else
416     return write(p->fd, v, n);
417 }
418 
419 static ssize_t
420 tty_Read(struct physical *p, void *v, size_t n)
421 {
422   struct ttydevice *dev = device2tty(p->handler);
423   char hook[sizeof NG_ASYNC_HOOK_SYNC];
424 
425   if (isngtty(dev))
426     return NgRecvData(p->fd, v, n, hook);
427   else
428     return read(p->fd, v, n);
429 }
430 
431 #endif /* NETGRAPH */
432 
433 static int
434 tty_Raw(struct physical *p)
435 {
436   struct ttydevice *dev = device2tty(p->handler);
437   struct termios ios;
438   int oldflag;
439 
440   log_Printf(LogDEBUG, "%s: Entering tty_Raw\n", p->link.name);
441 
442   if (p->type != PHYS_DIRECT && p->fd >= 0 && !Online(dev))
443     log_Printf(LogDEBUG, "%s: Raw: descriptor = %d, mbits = %x\n",
444               p->link.name, p->fd, dev->mbits);
445 
446   if (!physical_IsSync(p)) {
447 #ifndef NONETGRAPH
448     if (!LoadLineDiscipline(p))
449 #endif
450     {
451       tcgetattr(p->fd, &ios);
452       cfmakeraw(&ios);
453       if (p->cfg.rts_cts)
454         ios.c_cflag |= CLOCAL | CCTS_OFLOW | CRTS_IFLOW;
455       else
456         ios.c_cflag |= CLOCAL;
457 
458       if (p->type != PHYS_DEDICATED)
459         ios.c_cflag |= HUPCL;
460 
461       if (tcsetattr(p->fd, TCSANOW, &ios) == -1)
462         log_Printf(LogWARN, "%s: tcsetattr: Failed configuring device\n",
463                    p->link.name);
464     }
465   }
466 
467   oldflag = fcntl(p->fd, F_GETFL, 0);
468   if (oldflag < 0)
469     return 0;
470   fcntl(p->fd, F_SETFL, oldflag | O_NONBLOCK);
471 
472   return 1;
473 }
474 
475 static void
476 tty_Offline(struct physical *p)
477 {
478   struct ttydevice *dev = device2tty(p->handler);
479 
480   if (p->fd >= 0) {
481     timer_Stop(&dev->Timer);
482     dev->mbits &= ~TIOCM_DTR;	/* XXX: Hmm, what's this supposed to do ? */
483     if (Online(dev)) {
484       struct termios tio;
485 
486       tcgetattr(p->fd, &tio);
487       if (cfsetspeed(&tio, B0) == -1 || tcsetattr(p->fd, TCSANOW, &tio) == -1)
488         log_Printf(LogWARN, "%s: Unable to set physical to speed 0\n",
489                    p->link.name);
490     }
491   }
492 }
493 
494 static void
495 tty_Cooked(struct physical *p)
496 {
497   struct ttydevice *dev = device2tty(p->handler);
498   int oldflag;
499 
500   tty_Offline(p);	/* In case of emergency close()s */
501 
502   tcflush(p->fd, TCIOFLUSH);
503 
504   if (!physical_IsSync(p) && tcsetattr(p->fd, TCSAFLUSH, &dev->ios) == -1)
505     log_Printf(LogWARN, "%s: tcsetattr: Unable to restore device settings\n",
506                p->link.name);
507 
508 #ifndef NONETGRAPH
509   UnloadLineDiscipline(p);
510 #endif
511 
512   if ((oldflag = fcntl(p->fd, F_GETFL, 0)) != -1)
513     fcntl(p->fd, F_SETFL, oldflag & ~O_NONBLOCK);
514 }
515 
516 static void
517 tty_StopTimer(struct physical *p)
518 {
519   struct ttydevice *dev = device2tty(p->handler);
520 
521   timer_Stop(&dev->Timer);
522 }
523 
524 static void
525 tty_Free(struct physical *p)
526 {
527   struct ttydevice *dev = device2tty(p->handler);
528 
529   tty_Offline(p);	/* In case of emergency close()s */
530   free(dev);
531 }
532 
533 static unsigned
534 tty_Speed(struct physical *p)
535 {
536   struct termios ios;
537 
538   if (tcgetattr(p->fd, &ios) == -1)
539     return 0;
540 
541   return SpeedToUnsigned(cfgetispeed(&ios));
542 }
543 
544 static const char *
545 tty_OpenInfo(struct physical *p)
546 {
547   struct ttydevice *dev = device2tty(p->handler);
548   static char buf[13];
549 
550   if (Online(dev))
551     strcpy(buf, "with");
552   else
553     strcpy(buf, "no");
554   strcat(buf, " carrier");
555 
556   return buf;
557 }
558 
559 static int
560 tty_Slot(struct physical *p)
561 {
562   struct ttyent *ttyp;
563   int slot;
564 
565   setttyent();
566   for (slot = 1; (ttyp = getttyent()); ++slot)
567     if (!strcmp(ttyp->ty_name, p->name.base)) {
568       endttyent();
569       return slot;
570     }
571 
572   endttyent();
573   return -1;
574 }
575 
576 static void
577 tty_device2iov(struct device *d, struct iovec *iov, int *niov,
578                int maxiov __unused,
579 #ifndef NONETGRAPH
580                int *auxfd, int *nauxfd
581 #else
582                int *auxfd __unused, int *nauxfd __unused
583 #endif
584                )
585 {
586   struct ttydevice *dev;
587   int sz = physical_MaxDeviceSize();
588 
589   iov[*niov].iov_base = d = realloc(d, sz);
590   if (d == NULL) {
591     log_Printf(LogALERT, "Failed to allocate memory: %d\n", sz);
592     AbortProgram(EX_OSERR);
593   }
594   iov[*niov].iov_len = sz;
595   (*niov)++;
596 
597   dev = device2tty(d);
598 
599 #ifndef NONETGRAPH
600   if (dev->cs >= 0) {
601     *auxfd = dev->cs;
602     (*nauxfd)++;
603   }
604 #endif
605 
606   if (dev->Timer.state != TIMER_STOPPED) {
607     timer_Stop(&dev->Timer);
608     dev->Timer.state = TIMER_RUNNING;
609   }
610 }
611 
612 static struct device basettydevice = {
613   TTY_DEVICE,
614   "tty",
615   0,
616   { CD_VARIABLE, DEF_TTYCDDELAY },
617   tty_AwaitCarrier,
618   NULL,
619   tty_Raw,
620   tty_Offline,
621   tty_Cooked,
622   tty_SetAsyncParams,
623   tty_StopTimer,
624   tty_Free,
625   tty_Read,
626   tty_Write,
627   tty_device2iov,
628   tty_Speed,
629   tty_OpenInfo,
630   tty_Slot
631 };
632 
633 struct device *
634 tty_iov2device(int type, struct physical *p, struct iovec *iov, int *niov,
635                int maxiov __unused,
636 #ifndef NONETGRAPH
637                int *auxfd, int *nauxfd
638 #else
639                int *auxfd __unused, int *nauxfd __unused
640 #endif
641                )
642 {
643   if (type == TTY_DEVICE) {
644     struct ttydevice *dev = (struct ttydevice *)iov[(*niov)++].iov_base;
645 
646     dev = realloc(dev, sizeof *dev);	/* Reduce to the correct size */
647     if (dev == NULL) {
648       log_Printf(LogALERT, "Failed to allocate memory: %d\n",
649                  (int)(sizeof *dev));
650       AbortProgram(EX_OSERR);
651     }
652 
653 #ifndef NONETGRAPH
654     if (*nauxfd) {
655       dev->cs = *auxfd;
656       (*nauxfd)--;
657     } else
658       dev->cs = -1;
659 #endif
660 
661     /* Refresh function pointers etc */
662     memcpy(&dev->dev, &basettydevice, sizeof dev->dev);
663 
664     physical_SetupStack(p, dev->dev.name, PHYSICAL_NOFORCE);
665     if (dev->Timer.state != TIMER_STOPPED) {
666       dev->Timer.state = TIMER_STOPPED;
667       p->handler = &dev->dev;		/* For the benefit of StartTimer */
668       tty_StartTimer(p);
669     }
670     return &dev->dev;
671   }
672 
673   return NULL;
674 }
675 
676 struct device *
677 tty_Create(struct physical *p)
678 {
679   struct ttydevice *dev;
680   struct termios ios;
681   int oldflag;
682 
683   if (p->fd < 0 || !isatty(p->fd))
684     /* Don't want this */
685     return NULL;
686 
687   if (*p->name.full == '\0') {
688     physical_SetDevice(p, ttyname(p->fd));
689     log_Printf(LogDEBUG, "%s: Input is a tty (%s)\n",
690                p->link.name, p->name.full);
691   } else
692     log_Printf(LogDEBUG, "%s: Opened %s\n", p->link.name, p->name.full);
693 
694   /* We're gonna return a ttydevice (unless something goes horribly wrong) */
695 
696   if ((dev = malloc(sizeof *dev)) == NULL) {
697     /* Complete failure - parent doesn't continue trying to ``create'' */
698     close(p->fd);
699     p->fd = -1;
700     return NULL;
701   }
702 
703   memcpy(&dev->dev, &basettydevice, sizeof dev->dev);
704   memset(&dev->Timer, '\0', sizeof dev->Timer);
705   dev->mbits = -1;
706 #ifndef NONETGRAPH
707   dev->real.speed = 0;
708   dev->real.fd = -1;
709   dev->real.disc = -1;
710   *dev->hook = '\0';
711 #endif
712   tcgetattr(p->fd, &ios);
713   dev->ios = ios;
714 
715   if (p->cfg.cd.necessity != CD_DEFAULT)
716     /* Any override is ok for the tty device */
717     dev->dev.cd = p->cfg.cd;
718 
719   log_Printf(LogDEBUG, "%s: tty_Create: physical (get): fd = %d,"
720              " iflag = %lx, oflag = %lx, cflag = %lx\n", p->link.name, p->fd,
721              (u_long)ios.c_iflag, (u_long)ios.c_oflag, (u_long)ios.c_cflag);
722 
723   cfmakeraw(&ios);
724   if (p->cfg.rts_cts)
725     ios.c_cflag |= CLOCAL | CCTS_OFLOW | CRTS_IFLOW;
726   else {
727     ios.c_cflag |= CLOCAL;
728     ios.c_iflag |= IXOFF;
729   }
730   ios.c_iflag |= IXON;
731   if (p->type != PHYS_DEDICATED)
732     ios.c_cflag |= HUPCL;
733 
734   if (p->type != PHYS_DIRECT) {
735       /* Change tty speed when we're not in -direct mode */
736       ios.c_cflag &= ~(CSIZE | PARODD | PARENB);
737       ios.c_cflag |= p->cfg.parity;
738       if (cfsetspeed(&ios, UnsignedToSpeed(p->cfg.speed)) == -1)
739 	log_Printf(LogWARN, "%s: %s: Unable to set speed to %d\n",
740 		  p->link.name, p->name.full, p->cfg.speed);
741   }
742 
743   if (tcsetattr(p->fd, TCSADRAIN, &ios) == -1) {
744     log_Printf(LogWARN, "%s: tcsetattr: Failed configuring device\n",
745                p->link.name);
746     if (p->type != PHYS_DIRECT && p->cfg.speed > 115200)
747       log_Printf(LogWARN, "%.*s             Perhaps the speed is unsupported\n",
748                  (int)strlen(p->link.name), "");
749   }
750 
751   log_Printf(LogDEBUG, "%s: physical (put): iflag = %lx, oflag = %lx, "
752             "cflag = %lx\n", p->link.name, (u_long)ios.c_iflag,
753             (u_long)ios.c_oflag, (u_long)ios.c_cflag);
754 
755   oldflag = fcntl(p->fd, F_GETFL, 0);
756   if (oldflag < 0) {
757     /* Complete failure - parent doesn't continue trying to ``create'' */
758 
759     log_Printf(LogWARN, "%s: Open: Cannot get physical flags: %s\n",
760                p->link.name, strerror(errno));
761     tty_Cooked(p);
762     close(p->fd);
763     p->fd = -1;
764     free(dev);
765     return NULL;
766   } else
767     fcntl(p->fd, F_SETFL, oldflag & ~O_NONBLOCK);
768 
769   physical_SetupStack(p, dev->dev.name, PHYSICAL_NOFORCE);
770 
771   return &dev->dev;
772 }
773