xref: /openbsd/usr.sbin/pppd/sys-bsd.c (revision 6b5bf2e8)
1 /*	$OpenBSD: sys-bsd.c,v 1.37 2024/11/04 11:12:52 deraadt Exp $	*/
2 
3 /*
4  * sys-bsd.c - System-dependent procedures for setting up
5  * PPP interfaces on bsd-4.4-ish systems (including 386BSD, NetBSD, etc.)
6  *
7  * Copyright (c) 1984-2000 Carnegie Mellon University. All rights reserved.
8  *
9  * Redistribution and use in source and binary forms, with or without
10  * modification, are permitted provided that the following conditions
11  * are met:
12  *
13  * 1. Redistributions of source code must retain the above copyright
14  *    notice, this list of conditions and the following disclaimer.
15  *
16  * 2. Redistributions in binary form must reproduce the above copyright
17  *    notice, this list of conditions and the following disclaimer in
18  *    the documentation and/or other materials provided with the
19  *    distribution.
20  *
21  * 3. The name "Carnegie Mellon University" must not be used to
22  *    endorse or promote products derived from this software without
23  *    prior written permission. For permission or any legal
24  *    details, please contact
25  *      Office of Technology Transfer
26  *      Carnegie Mellon University
27  *      5000 Forbes Avenue
28  *      Pittsburgh, PA  15213-3890
29  *      (412) 268-4387, fax: (412) 268-7395
30  *      tech-transfer@andrew.cmu.edu
31  *
32  * 4. Redistributions of any form whatsoever must retain the following
33  *    acknowledgment:
34  *    "This product includes software developed by Computing Services
35  *     at Carnegie Mellon University (http://www.cmu.edu/computing/)."
36  *
37  * CARNEGIE MELLON UNIVERSITY DISCLAIMS ALL WARRANTIES WITH REGARD TO
38  * THIS SOFTWARE, INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY
39  * AND FITNESS, IN NO EVENT SHALL CARNEGIE MELLON UNIVERSITY BE LIABLE
40  * FOR ANY SPECIAL, INDIRECT OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
41  * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN
42  * AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING
43  * OUT OF OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
44  *
45  * Copyright (c) 1989-2002 Paul Mackerras. All rights reserved.
46  *
47  * Redistribution and use in source and binary forms, with or without
48  * modification, are permitted provided that the following conditions
49  * are met:
50  *
51  * 1. Redistributions of source code must retain the above copyright
52  *    notice, this list of conditions and the following disclaimer.
53  *
54  * 2. Redistributions in binary form must reproduce the above copyright
55  *    notice, this list of conditions and the following disclaimer in
56  *    the documentation and/or other materials provided with the
57  *    distribution.
58  *
59  * 3. The name(s) of the authors of this software must not be used to
60  *    endorse or promote products derived from this software without
61  *    prior written permission.
62  *
63  * 4. Redistributions of any form whatsoever must retain the following
64  *    acknowledgment:
65  *    "This product includes software developed by Paul Mackerras
66  *     <paulus@samba.org>".
67  *
68  * THE AUTHORS OF THIS SOFTWARE DISCLAIM ALL WARRANTIES WITH REGARD TO
69  * THIS SOFTWARE, INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY
70  * AND FITNESS, IN NO EVENT SHALL THE AUTHORS BE LIABLE FOR ANY
71  * SPECIAL, INDIRECT OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
72  * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN
73  * AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING
74  * OUT OF OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
75  */
76 
77 /*
78  * TODO:
79  */
80 
81 #include <sys/types.h>
82 #include <sys/ioctl.h>
83 #include <sys/socket.h>
84 #include <sys/time.h>
85 #include <sys/stat.h>
86 
87 #include <stdio.h>
88 #include <syslog.h>
89 #include <string.h>
90 #include <stdlib.h>
91 #include <unistd.h>
92 #include <err.h>
93 #include <errno.h>
94 #include <fcntl.h>
95 #include <termios.h>
96 #include <signal.h>
97 #include <util.h>
98 #include <ifaddrs.h>
99 
100 #ifdef PPP_FILTER
101 #include <net/bpf.h>
102 #endif
103 #include <net/if.h>
104 #include <net/ppp_defs.h>
105 #include <net/if_ppp.h>
106 #include <net/route.h>
107 #include <net/if_dl.h>
108 #include <netinet/in.h>
109 #include <netinet/if_ether.h>
110 
111 #include "pppd.h"
112 #include "fsm.h"
113 #include "ipcp.h"
114 
115 #define ok_error(num) ((num)==EIO)
116 
117 static int initdisc = -1;	/* Initial TTY discipline for ppp_fd */
118 static int initfdflags = -1;	/* Initial file descriptor flags for ppp_fd */
119 static int ppp_fd = -1;		/* fd which is set to PPP discipline */
120 static int rtm_seq;
121 
122 static int restore_term;	/* 1 => we've munged the terminal */
123 static struct termios inittermios; /* Initial TTY termios */
124 static struct winsize wsinfo;	/* Initial window size info */
125 
126 static char *lock_file;		/* name of lock file created */
127 
128 static int loop_slave = -1;
129 static int loop_master;
130 static char loop_name[20];
131 
132 static unsigned char inbuf[512]; /* buffer for chars read from loopback */
133 
134 static int sockfd;		/* socket for doing interface ioctls */
135 
136 static int if_is_up;		/* the interface is currently up */
137 static u_int32_t ifaddrs[2];	/* local and remote addresses we set */
138 static u_int32_t default_route_gateway;	/* gateway addr for default route */
139 static u_int32_t proxy_arp_addr;	/* remote addr for proxy arp */
140 
141 /* Prototypes for procedures local to this file. */
142 static int dodefaultroute(u_int32_t, int);
143 static int get_ether_addr(u_int32_t, struct sockaddr_dl *);
144 
145 
146 /*
147  * sys_init - System-dependent initialization.
148  */
149 void
sys_init(void)150 sys_init(void)
151 {
152     /* Get an internet socket for doing socket ioctl's on. */
153     if ((sockfd = socket(AF_INET, SOCK_DGRAM, 0)) == -1) {
154 	syslog(LOG_ERR, "Couldn't create IP socket: %m");
155 	die(1);
156     }
157 }
158 
159 /*
160  * sys_cleanup - restore any system state we modified before exiting:
161  * mark the interface down, delete default route and/or proxy arp entry.
162  * This should call die() because it's called from die().
163  */
164 void
sys_cleanup(void)165 sys_cleanup(void)
166 {
167     struct ifreq ifr;
168 
169     if (if_is_up) {
170 	strlcpy(ifr.ifr_name, ifname, sizeof(ifr.ifr_name));
171 	if (ioctl(sockfd, SIOCGIFFLAGS, &ifr) == 0
172 	    && ((ifr.ifr_flags & IFF_UP) != 0)) {
173 	    ifr.ifr_flags &= ~IFF_UP;
174 	    ioctl(sockfd, SIOCSIFFLAGS, &ifr);
175 	}
176     }
177     if (ifaddrs[0] != 0)
178 	cifaddr(0, ifaddrs[0], ifaddrs[1]);
179     if (default_route_gateway)
180 	cifdefaultroute(0, 0, default_route_gateway);
181     if (proxy_arp_addr)
182 	cifproxyarp(0, proxy_arp_addr);
183 }
184 
185 /*
186  * sys_close - Clean up in a child process before execing.
187  */
188 void
sys_close(void)189 sys_close(void)
190 {
191     close(sockfd);
192     if (loop_slave >= 0) {
193 	close(loop_slave);
194 	close(loop_master);
195     }
196 }
197 
198 /*
199  * sys_check_options - check the options that the user specified
200  */
201 void
sys_check_options(void)202 sys_check_options(void)
203 {
204 }
205 
206 /*
207  * ppp_available - check whether the system has any ppp interfaces
208  * (in fact we check whether we can do an ioctl on ppp0).
209  */
210 int
ppp_available(void)211 ppp_available(void)
212 {
213     int s, ok;
214     struct ifreq ifr;
215     extern char *no_ppp_msg;
216 
217     if ((s = socket(AF_INET, SOCK_DGRAM, 0)) == -1)
218 	return 1;		/* can't tell */
219 
220     strlcpy(ifr.ifr_name, "ppp0", sizeof(ifr.ifr_name));
221     ok = ioctl(s, SIOCGIFFLAGS, (caddr_t) &ifr) == 0;
222     close(s);
223 
224     no_ppp_msg = "\
225 PPP device not available. Make sure the device is created with\n\
226 ifconfig and that the kernel supports PPP. See ifconfig(8) and ppp(4).";
227     return ok;
228 }
229 
230 /*
231  * establish_ppp - Turn the serial port into a ppp interface.
232  */
233 void
establish_ppp(int fd)234 establish_ppp(int fd)
235 {
236     int pppdisc = PPPDISC;
237     int x;
238 
239     if (demand) {
240 	/*
241 	 * Demand mode - prime the old ppp device to relinquish the unit.
242 	 */
243 	if (ioctl(ppp_fd, PPPIOCXFERUNIT, 0) == -1) {
244 	    syslog(LOG_ERR, "ioctl(transfer ppp unit): %m");
245 	    die(1);
246 	}
247     }
248 
249     /*
250      * Save the old line discipline of fd, and set it to PPP.
251      */
252     if (ioctl(fd, TIOCGETD, &initdisc) == -1) {
253 	syslog(LOG_ERR, "ioctl(TIOCGETD): %m");
254 	die(1);
255     }
256     if (ioctl(fd, TIOCSETD, &pppdisc) == -1) {
257 	syslog(LOG_ERR, "ioctl(TIOCSETD): %m");
258 	die(1);
259     }
260 
261     if (!demand) {
262 	/*
263 	 * Find out which interface we were given.
264 	 */
265 	if (ioctl(fd, PPPIOCGUNIT, &ifunit) == -1) {
266 	    syslog(LOG_ERR, "ioctl(PPPIOCGUNIT): %m");
267 	    die(1);
268 	}
269     } else {
270 	/*
271 	 * Check that we got the same unit again.
272 	 */
273 	if (ioctl(fd, PPPIOCGUNIT, &x) == -1) {
274 	    syslog(LOG_ERR, "ioctl(PPPIOCGUNIT): %m");
275 	    die(1);
276 	}
277 	if (x != ifunit) {
278 	    syslog(LOG_ERR, "transfer_ppp failed: wanted unit %d, got %d",
279 		   ifunit, x);
280 	    die(1);
281 	}
282 	x = TTYDISC;
283 	ioctl(loop_slave, TIOCSETD, &x);
284     }
285 
286     ppp_fd = fd;
287 
288     /*
289      * Enable debug in the driver if requested.
290      */
291     if (kdebugflag) {
292 	if (ioctl(fd, PPPIOCGFLAGS, (caddr_t) &x) == -1) {
293 	    syslog(LOG_WARNING, "ioctl (PPPIOCGFLAGS): %m");
294 	} else {
295 	    x |= (kdebugflag & 0xFF) * SC_DEBUG;
296 	    if (ioctl(fd, PPPIOCSFLAGS, (caddr_t) &x) == -1)
297 		syslog(LOG_WARNING, "ioctl(PPPIOCSFLAGS): %m");
298 	}
299     }
300 
301     /*
302      * Set device for non-blocking reads.
303      */
304     if ((initfdflags = fcntl(fd, F_GETFL)) == -1
305 	|| fcntl(fd, F_SETFL, initfdflags | O_NONBLOCK) == -1) {
306 	syslog(LOG_WARNING, "Couldn't set device to non-blocking mode: %m");
307     }
308 }
309 
310 /*
311  * restore_loop - reattach the ppp unit to the loopback.
312  */
313 void
restore_loop(void)314 restore_loop(void)
315 {
316     int x;
317 
318     /*
319      * Transfer the ppp interface back to the loopback.
320      */
321     if (ioctl(ppp_fd, PPPIOCXFERUNIT, 0) == -1) {
322 	syslog(LOG_ERR, "ioctl(transfer ppp unit): %m");
323 	die(1);
324     }
325     x = PPPDISC;
326     if (ioctl(loop_slave, TIOCSETD, &x) == -1) {
327 	syslog(LOG_ERR, "ioctl(TIOCSETD): %m");
328 	die(1);
329     }
330 
331     /*
332      * Check that we got the same unit again.
333      */
334     if (ioctl(loop_slave, PPPIOCGUNIT, &x) == -1) {
335 	syslog(LOG_ERR, "ioctl(PPPIOCGUNIT): %m");
336 	die(1);
337     }
338     if (x != ifunit) {
339 	syslog(LOG_ERR, "transfer_ppp failed: wanted unit %d, got %d",
340 	       ifunit, x);
341 	die(1);
342     }
343     ppp_fd = loop_slave;
344 }
345 
346 /*
347  * disestablish_ppp - Restore the serial port to normal operation.
348  * This shouldn't call die() because it's called from die().
349  */
350 void
disestablish_ppp(int fd)351 disestablish_ppp(int fd)
352 {
353     /* Reset non-blocking mode on fd. */
354     if (initfdflags != -1 && fcntl(fd, F_SETFL, initfdflags) == -1)
355 	syslog(LOG_WARNING, "Couldn't restore device fd flags: %m");
356     initfdflags = -1;
357 
358     /* Restore old line discipline. */
359     if (initdisc >= 0 && ioctl(fd, TIOCSETD, &initdisc) == -1)
360 	syslog(LOG_ERR, "ioctl(TIOCSETD): %m");
361     initdisc = -1;
362 
363     if (fd == ppp_fd)
364 	ppp_fd = -1;
365 }
366 
367 /*
368  * Check whether the link seems not to be 8-bit clean.
369  */
370 void
clean_check(void)371 clean_check(void)
372 {
373     int x;
374     char *s;
375 
376     if (ioctl(ppp_fd, PPPIOCGFLAGS, (caddr_t) &x) == 0) {
377 	s = NULL;
378 	switch (~x & (SC_RCV_B7_0|SC_RCV_B7_1|SC_RCV_EVNP|SC_RCV_ODDP)) {
379 	case SC_RCV_B7_0:
380 	    s = "bit 7 set to 1";
381 	    break;
382 	case SC_RCV_B7_1:
383 	    s = "bit 7 set to 0";
384 	    break;
385 	case SC_RCV_EVNP:
386 	    s = "odd parity";
387 	    break;
388 	case SC_RCV_ODDP:
389 	    s = "even parity";
390 	    break;
391 	}
392 	if (s != NULL) {
393 	    syslog(LOG_WARNING, "Serial link is not 8-bit clean:");
394 	    syslog(LOG_WARNING, "All received characters had %s", s);
395 	}
396     }
397 }
398 
399 /*
400  * set_up_tty: Set up the serial port on `fd' for 8 bits, no parity,
401  * at the requested speed, etc.  If `local' is true, set CLOCAL
402  * regardless of whether the modem option was specified.
403  *
404  * For *BSD, we assume that speed_t values numerically equal bits/second.
405  */
406 void
set_up_tty(int fd,int local)407 set_up_tty(int fd, int local)
408 {
409     struct termios tios;
410 
411     if (tcgetattr(fd, &tios) == -1) {
412 	syslog(LOG_ERR, "tcgetattr: %m");
413 	die(1);
414     }
415 
416     if (!restore_term) {
417 	inittermios = tios;
418 	ioctl(fd, TIOCGWINSZ, &wsinfo);
419     }
420 
421     tios.c_cflag &= ~(CSIZE | CSTOPB | PARENB | CLOCAL);
422     if (crtscts > 0 && modem)
423 	tios.c_cflag |= CRTSCTS;
424     else if (crtscts < 0)
425 	tios.c_cflag &= ~CRTSCTS;
426 
427     tios.c_cflag |= CS8 | CREAD | HUPCL;
428     if (local || !modem)
429 	tios.c_cflag |= CLOCAL;
430     tios.c_iflag = IGNBRK | IGNPAR;
431     tios.c_oflag = 0;
432     tios.c_lflag = 0;
433     tios.c_cc[VMIN] = 1;
434     tios.c_cc[VTIME] = 0;
435 
436     if (crtscts == -2) {
437 	tios.c_iflag |= IXON | IXOFF;
438 	tios.c_cc[VSTOP] = 0x13;	/* DC3 = XOFF = ^S */
439 	tios.c_cc[VSTART] = 0x11;	/* DC1 = XON  = ^Q */
440     }
441 
442     if (inspeed) {
443 	cfsetospeed(&tios, inspeed);
444 	cfsetispeed(&tios, inspeed);
445     } else {
446 	inspeed = cfgetospeed(&tios);
447 	/*
448 	 * We can't proceed if the serial port speed is 0,
449 	 * since that implies that the serial port is disabled.
450 	 */
451 	if (inspeed == 0) {
452 	    syslog(LOG_ERR, "Baud rate for %s is 0; need explicit baud rate",
453 		   devnam);
454 	    die(1);
455 	}
456     }
457     baud_rate = inspeed;
458 
459     if (tcsetattr(fd, TCSAFLUSH, &tios) == -1) {
460 	syslog(LOG_ERR, "tcsetattr: %m");
461 	die(1);
462     }
463 
464     restore_term = 1;
465 }
466 
467 /*
468  * restore_tty - restore the terminal to the saved settings.
469  */
470 void
restore_tty(int fd)471 restore_tty(int fd)
472 {
473     if (restore_term) {
474 	if (!default_device) {
475 	    /*
476 	     * Turn off echoing, because otherwise we can get into
477 	     * a loop with the tty and the modem echoing to each other.
478 	     * We presume we are the sole user of this tty device, so
479 	     * when we close it, it will revert to its defaults anyway.
480 	     */
481 	    inittermios.c_lflag &= ~(ECHO | ECHONL);
482 	}
483 	if (tcsetattr(fd, TCSAFLUSH, &inittermios) == -1)
484 	    if (errno != ENXIO)
485 		syslog(LOG_WARNING, "tcsetattr: %m");
486 	ioctl(fd, TIOCSWINSZ, &wsinfo);
487 	restore_term = 0;
488     }
489 }
490 
491 /*
492  * setdtr - control the DTR line on the serial port.
493  * This is called from die(), so it shouldn't call die().
494  */
495 void
setdtr(int fd,int on)496 setdtr(int fd, int on)
497 {
498     int modembits = TIOCM_DTR;
499 
500     ioctl(fd, (on? TIOCMBIS: TIOCMBIC), &modembits);
501 }
502 
503 
504 /*
505  * open_ppp_loopback - open the device we use for getting
506  * packets in demand mode, and connect it to a ppp interface.
507  * Here we use a pty.
508  */
509 void
open_ppp_loopback(void)510 open_ppp_loopback(void)
511 {
512     int flags;
513     struct termios tios;
514     int pppdisc = PPPDISC;
515 
516     if (openpty(&loop_master, &loop_slave, loop_name, NULL, NULL) == -1) {
517 	syslog(LOG_ERR, "No free pty for loopback");
518 	die(1);
519     }
520     SYSDEBUG((LOG_DEBUG, "using %s for loopback", loop_name));
521 
522     if (tcgetattr(loop_slave, &tios) == 0) {
523 	tios.c_cflag &= ~(CSIZE | CSTOPB | PARENB);
524 	tios.c_cflag |= CS8 | CREAD;
525 	tios.c_iflag = IGNPAR;
526 	tios.c_oflag = 0;
527 	tios.c_lflag = 0;
528 	if (tcsetattr(loop_slave, TCSAFLUSH, &tios) == -1)
529 	    syslog(LOG_WARNING, "couldn't set attributes on loopback: %m");
530     }
531 
532     if ((flags = fcntl(loop_master, F_GETFL)) != -1)
533 	if (fcntl(loop_master, F_SETFL, flags | O_NONBLOCK) == -1)
534 	    syslog(LOG_WARNING, "couldn't set loopback to nonblock: %m");
535 
536     ppp_fd = loop_slave;
537     if (ioctl(ppp_fd, TIOCSETD, &pppdisc) == -1) {
538 	syslog(LOG_ERR, "ioctl(TIOCSETD): %m");
539 	die(1);
540     }
541 
542     /*
543      * Find out which interface we were given.
544      */
545     if (ioctl(ppp_fd, PPPIOCGUNIT, &ifunit) == -1) {
546 	syslog(LOG_ERR, "ioctl(PPPIOCGUNIT): %m");
547 	die(1);
548     }
549 
550     /*
551      * Enable debug in the driver if requested.
552      */
553     if (kdebugflag) {
554 	if (ioctl(ppp_fd, PPPIOCGFLAGS, (caddr_t) &flags) == -1) {
555 	    syslog(LOG_WARNING, "ioctl (PPPIOCGFLAGS): %m");
556 	} else {
557 	    flags |= (kdebugflag & 0xFF) * SC_DEBUG;
558 	    if (ioctl(ppp_fd, PPPIOCSFLAGS, (caddr_t) &flags) == -1)
559 		syslog(LOG_WARNING, "ioctl(PPPIOCSFLAGS): %m");
560 	}
561     }
562 
563 }
564 
565 
566 /*
567  * output - Output PPP packet.
568  */
569 void
output(int unit,u_char * p,int len)570 output(int unit, u_char *p, int len)
571 {
572     if (debug)
573 	log_packet(p, len, "sent ", LOG_DEBUG);
574 
575     if (write(ttyfd, p, len) == -1) {
576 	if (errno != EIO)
577 	    syslog(LOG_ERR, "write: %m");
578     }
579 }
580 
581 
582 /*
583  * wait_input - wait until there is data available on ttyfd,
584  * for the length of time specified by *timo (indefinite
585  * if timo is NULL).
586  */
587 void
wait_input(struct timeval * timo)588 wait_input(struct timeval *timo)
589 {
590     fd_set *fdsp = NULL;
591     int fdsn;
592     int n;
593 
594     fdsn = howmany(ttyfd+1, NFDBITS) * sizeof(fd_mask);
595     if ((fdsp = (fd_set *)malloc(fdsn)) == NULL)
596 	err(1, "malloc");
597     memset(fdsp, 0, fdsn);
598     FD_SET(ttyfd, fdsp);
599 
600     n = select(ttyfd+1, fdsp, NULL, fdsp, timo);
601     if (n == -1 && errno != EINTR) {
602 	syslog(LOG_ERR, "select: %m");
603 	free(fdsp);
604 	die(1);
605     }
606     free(fdsp);
607 }
608 
609 
610 /*
611  * wait_loop_output - wait until there is data available on the
612  * loopback, for the length of time specified by *timo (indefinite
613  * if timo is NULL).
614  */
615 void
wait_loop_output(struct timeval * timo)616 wait_loop_output(struct timeval *timo)
617 {
618     fd_set *fdsp = NULL;
619     int fdsn;
620     int n;
621 
622     fdsn = howmany(loop_master+1, NFDBITS) * sizeof(fd_mask);
623     if ((fdsp = (fd_set *)malloc(fdsn)) == NULL)
624 	err(1, "malloc");
625     memset(fdsp, 0, fdsn);
626     FD_SET(loop_master, fdsp);
627 
628     n = select(loop_master + 1, fdsp, NULL, fdsp, timo);
629     if (n == -1 && errno != EINTR) {
630 	syslog(LOG_ERR, "select: %m");
631 	free(fdsp);
632 	die(1);
633     }
634     free(fdsp);
635 }
636 
637 
638 /*
639  * wait_time - wait for a given length of time or until a
640  * signal is received.
641  */
642 void
wait_time(struct timeval * timo)643 wait_time(struct timeval *timo)
644 {
645     int n;
646 
647     n = select(0, NULL, NULL, NULL, timo);
648     if (n == -1 && errno != EINTR) {
649 	syslog(LOG_ERR, "select: %m");
650 	die(1);
651     }
652 }
653 
654 
655 /*
656  * read_packet - get a PPP packet from the serial device.
657  */
658 int
read_packet(u_char * buf)659 read_packet(u_char *buf)
660 {
661     int len;
662 
663     if ((len = read(ttyfd, buf, PPP_MTU + PPP_HDRLEN)) == -1) {
664 	if (errno == EWOULDBLOCK || errno == EINTR)
665 	    return -1;
666 	syslog(LOG_ERR, "read: %m");
667 	die(1);
668     }
669     return len;
670 }
671 
672 
673 /*
674  * get_loop_output - read characters from the loopback, form them
675  * into frames, and detect when we want to bring the real link up.
676  * Return value is 1 if we need to bring up the link, 0 otherwise.
677  */
678 int
get_loop_output(void)679 get_loop_output(void)
680 {
681     int rv = 0;
682     int n;
683 
684     while ((n = read(loop_master, inbuf, sizeof(inbuf))) >= 0) {
685 	if (loop_chars(inbuf, n))
686 	    rv = 1;
687     }
688 
689     if (n == 0) {
690 	syslog(LOG_ERR, "eof on loopback");
691 	die(1);
692     } else if (errno != EWOULDBLOCK){
693 	syslog(LOG_ERR, "read from loopback: %m");
694 	die(1);
695     }
696 
697     return rv;
698 }
699 
700 
701 /*
702  * ppp_send_config - configure the transmit characteristics of
703  * the ppp interface.
704  */
705 void
ppp_send_config(int unit,int mtu,u_int32_t asyncmap,int pcomp,int accomp)706 ppp_send_config(int unit, int mtu, u_int32_t asyncmap, int pcomp, int accomp)
707 {
708     u_int x;
709     struct ifreq ifr;
710 
711     strlcpy(ifr.ifr_name, ifname, sizeof(ifr.ifr_name));
712     ifr.ifr_mtu = mtu;
713     if (ioctl(sockfd, SIOCSIFMTU, (caddr_t) &ifr) == -1) {
714 	syslog(LOG_ERR, "ioctl(SIOCSIFMTU): %m");
715 	quit();
716     }
717 
718     if (ioctl(ppp_fd, PPPIOCSASYNCMAP, (caddr_t) &asyncmap) == -1) {
719 	syslog(LOG_ERR, "ioctl(PPPIOCSASYNCMAP): %m");
720 	quit();
721     }
722 
723     if (ioctl(ppp_fd, PPPIOCGFLAGS, (caddr_t) &x) == -1) {
724 	syslog(LOG_ERR, "ioctl (PPPIOCGFLAGS): %m");
725 	quit();
726     }
727     x = pcomp? x | SC_COMP_PROT: x &~ SC_COMP_PROT;
728     x = accomp? x | SC_COMP_AC: x &~ SC_COMP_AC;
729     if (ioctl(ppp_fd, PPPIOCSFLAGS, (caddr_t) &x) == -1) {
730 	syslog(LOG_ERR, "ioctl(PPPIOCSFLAGS): %m");
731 	quit();
732     }
733 }
734 
735 
736 /*
737  * ppp_set_xaccm - set the extended transmit ACCM for the interface.
738  */
739 void
ppp_set_xaccm(int unit,ext_accm accm)740 ppp_set_xaccm(int unit, ext_accm accm)
741 {
742     if (ioctl(ppp_fd, PPPIOCSXASYNCMAP, accm) == -1 && errno != ENOTTY)
743 	syslog(LOG_WARNING, "ioctl(set extended ACCM): %m");
744 }
745 
746 
747 /*
748  * ppp_recv_config - configure the receive-side characteristics of
749  * the ppp interface.
750  */
751 void
ppp_recv_config(int unit,int mru,u_int32_t asyncmap,int pcomp,int accomp)752 ppp_recv_config(int unit, int mru, u_int32_t asyncmap, int pcomp, int accomp)
753 {
754     int x;
755 
756     if (ioctl(ppp_fd, PPPIOCSMRU, (caddr_t) &mru) == -1) {
757 	syslog(LOG_ERR, "ioctl(PPPIOCSMRU): %m");
758 	quit();
759     }
760     if (ioctl(ppp_fd, PPPIOCSRASYNCMAP, (caddr_t) &asyncmap) == -1) {
761 	syslog(LOG_ERR, "ioctl(PPPIOCSRASYNCMAP): %m");
762 	quit();
763     }
764     if (ioctl(ppp_fd, PPPIOCGFLAGS, (caddr_t) &x) == -1) {
765 	syslog(LOG_ERR, "ioctl (PPPIOCGFLAGS): %m");
766 	quit();
767     }
768     x = !accomp? x | SC_REJ_COMP_AC: x &~ SC_REJ_COMP_AC;
769     if (ioctl(ppp_fd, PPPIOCSFLAGS, (caddr_t) &x) == -1) {
770 	syslog(LOG_ERR, "ioctl(PPPIOCSFLAGS): %m");
771 	quit();
772     }
773 }
774 
775 /*
776  * ccp_test - ask kernel whether a given compression method
777  * is acceptable for use.  Returns 1 if the method and parameters
778  * are OK, 0 if the method is known but the parameters are not OK
779  * (e.g. code size should be reduced), or -1 if the method is unknown.
780  */
781 int
ccp_test(int unit,u_char * opt_ptr,int opt_len,int for_transmit)782 ccp_test(int unit, u_char *opt_ptr, int opt_len, int for_transmit)
783 {
784     struct ppp_option_data data;
785 
786     data.ptr = opt_ptr;
787     data.length = opt_len;
788     data.transmit = for_transmit;
789     if (ioctl(ttyfd, PPPIOCSCOMPRESS, (caddr_t) &data) >= 0)
790 	return 1;
791     return (errno == ENOBUFS)? 0: -1;
792 }
793 
794 /*
795  * ccp_flags_set - inform kernel about the current state of CCP.
796  */
797 void
ccp_flags_set(int unit,int isopen,int isup)798 ccp_flags_set(int unit, int isopen, int isup)
799 {
800     int x;
801 
802     if (ioctl(ppp_fd, PPPIOCGFLAGS, (caddr_t) &x) == -1) {
803 	syslog(LOG_ERR, "ioctl (PPPIOCGFLAGS): %m");
804 	return;
805     }
806     x = isopen? x | SC_CCP_OPEN: x &~ SC_CCP_OPEN;
807     x = isup? x | SC_CCP_UP: x &~ SC_CCP_UP;
808     if (ioctl(ppp_fd, PPPIOCSFLAGS, (caddr_t) &x) == -1)
809 	syslog(LOG_ERR, "ioctl(PPPIOCSFLAGS): %m");
810 }
811 
812 /*
813  * ccp_fatal_error - returns 1 if decompression was disabled as a
814  * result of an error detected after decompression of a packet,
815  * 0 otherwise.  This is necessary because of patent nonsense.
816  */
817 int
ccp_fatal_error(int unit)818 ccp_fatal_error(int unit)
819 {
820     int x;
821 
822     if (ioctl(ppp_fd, PPPIOCGFLAGS, (caddr_t) &x) == -1) {
823 	syslog(LOG_ERR, "ioctl(PPPIOCGFLAGS): %m");
824 	return 0;
825     }
826     return x & SC_DC_FERROR;
827 }
828 
829 /*
830  * get_idle_time - return how long the link has been idle.
831  */
832 int
get_idle_time(int u,struct ppp_idle * ip)833 get_idle_time(int u, struct ppp_idle *ip)
834 {
835     return ioctl(ppp_fd, PPPIOCGIDLE, ip) >= 0;
836 }
837 
838 
839 #ifdef PPP_FILTER
840 /*
841  * set_filters - transfer the pass and active filters to the kernel.
842  */
843 int
set_filters(struct bpf_program * pass,struct bpf_program * active)844 set_filters(struct bpf_program *pass, struct bpf_program *active)
845 {
846     int ret = 1;
847 
848     if (pass->bf_len > 0) {
849 	if (ioctl(ppp_fd, PPPIOCSPASS, pass) == -1) {
850 	    syslog(LOG_ERR, "Couldn't set pass-filter in kernel: %m");
851 	    ret = 0;
852 	}
853     }
854     if (active->bf_len > 0) {
855 	if (ioctl(ppp_fd, PPPIOCSACTIVE, active) == -1) {
856 	    syslog(LOG_ERR, "Couldn't set active-filter in kernel: %m");
857 	    ret = 0;
858 	}
859     }
860     return ret;
861 }
862 #endif
863 
864 /*
865  * sifvjcomp - config tcp header compression
866  */
867 int
sifvjcomp(int u,int vjcomp,int cidcomp,int maxcid)868 sifvjcomp(int u, int vjcomp, int cidcomp, int maxcid)
869 {
870     u_int x;
871 
872     if (ioctl(ppp_fd, PPPIOCGFLAGS, (caddr_t) &x) == -1) {
873 	syslog(LOG_ERR, "ioctl (PPPIOCGFLAGS): %m");
874 	return 0;
875     }
876     x = vjcomp ? x | SC_COMP_TCP: x &~ SC_COMP_TCP;
877     x = cidcomp? x & ~SC_NO_TCP_CCID: x | SC_NO_TCP_CCID;
878     if (ioctl(ppp_fd, PPPIOCSFLAGS, (caddr_t) &x) == -1) {
879 	syslog(LOG_ERR, "ioctl(PPPIOCSFLAGS): %m");
880 	return 0;
881     }
882     if (vjcomp && ioctl(ppp_fd, PPPIOCSMAXCID, (caddr_t) &maxcid) == -1) {
883 	syslog(LOG_ERR, "ioctl(PPPIOCSFLAGS): %m");
884 	return 0;
885     }
886     return 1;
887 }
888 
889 /*
890  * sifup - Config the interface up and enable IP packets to pass.
891  */
892 int
sifup(int u)893 sifup(int u)
894 {
895     struct ifreq ifr;
896 
897     strlcpy(ifr.ifr_name, ifname, sizeof(ifr.ifr_name));
898     if (ioctl(sockfd, SIOCGIFFLAGS, (caddr_t) &ifr) == -1) {
899 	syslog(LOG_ERR, "ioctl (SIOCGIFFLAGS): %m");
900 	return 0;
901     }
902     ifr.ifr_flags |= IFF_UP;
903     if (ioctl(sockfd, SIOCSIFFLAGS, (caddr_t) &ifr) == -1) {
904 	syslog(LOG_ERR, "ioctl(SIOCSIFFLAGS): %m");
905 	return 0;
906     }
907     if_is_up = 1;
908     return 1;
909 }
910 
911 /*
912  * sifnpmode - Set the mode for handling packets for a given NP.
913  */
914 int
sifnpmode(int u,int proto,enum NPmode mode)915 sifnpmode(int u, int proto, enum NPmode mode)
916 {
917     struct npioctl npi;
918 
919     npi.protocol = proto;
920     npi.mode = mode;
921     if (ioctl(ppp_fd, PPPIOCSNPMODE, &npi) == -1) {
922 	syslog(LOG_ERR, "ioctl(set NP %d mode to %d): %m", proto, mode);
923 	return 0;
924     }
925     return 1;
926 }
927 
928 /*
929  * sifdown - Config the interface down and disable IP.
930  */
931 int
sifdown(int u)932 sifdown(int u)
933 {
934     struct ifreq ifr;
935     int rv;
936     struct npioctl npi;
937 
938     rv = 1;
939     npi.protocol = PPP_IP;
940     npi.mode = NPMODE_ERROR;
941     ioctl(ppp_fd, PPPIOCSNPMODE, (caddr_t) &npi);
942     /* ignore errors, because ppp_fd might have been closed by now. */
943 
944     strlcpy(ifr.ifr_name, ifname, sizeof(ifr.ifr_name));
945     if (ioctl(sockfd, SIOCGIFFLAGS, (caddr_t) &ifr) == -1) {
946 	syslog(LOG_ERR, "ioctl (SIOCGIFFLAGS): %m");
947 	rv = 0;
948     } else {
949 	ifr.ifr_flags &= ~IFF_UP;
950 	if (ioctl(sockfd, SIOCSIFFLAGS, (caddr_t) &ifr) == -1) {
951 	    syslog(LOG_ERR, "ioctl(SIOCSIFFLAGS): %m");
952 	    rv = 0;
953 	} else
954 	    if_is_up = 0;
955     }
956     return rv;
957 }
958 
959 /*
960  * SET_SA_FAMILY - set the sa_family field of a struct sockaddr,
961  * if it exists.
962  */
963 #define SET_SA_FAMILY(addr, family)		\
964     BZERO((char *) &(addr), sizeof(addr));	\
965     addr.sa_family = (family); 			\
966     addr.sa_len = sizeof(addr);
967 
968 /*
969  * sifaddr - Config the interface IP addresses and netmask.
970  */
971 int
sifaddr(int u,u_int32_t o,u_int32_t h,u_int32_t m)972 sifaddr(int u, u_int32_t o, u_int32_t h, u_int32_t m)
973 {
974     struct ifaliasreq ifra;
975     struct ifreq ifr;
976     char s1[64], s2[64];
977 
978     strlcpy(ifra.ifra_name, ifname, sizeof(ifra.ifra_name));
979     SET_SA_FAMILY(ifra.ifra_addr, AF_INET);
980     ((struct sockaddr_in *) &ifra.ifra_addr)->sin_addr.s_addr = o;
981     SET_SA_FAMILY(ifra.ifra_broadaddr, AF_INET);
982     ((struct sockaddr_in *) &ifra.ifra_broadaddr)->sin_addr.s_addr = h;
983     if (m != 0) {
984 	SET_SA_FAMILY(ifra.ifra_mask, AF_INET);
985 	((struct sockaddr_in *) &ifra.ifra_mask)->sin_addr.s_addr = m;
986     } else
987 	BZERO(&ifra.ifra_mask, sizeof(ifra.ifra_mask));
988     BZERO(&ifr, sizeof(ifr));
989     strlcpy(ifr.ifr_name, ifname, sizeof(ifr.ifr_name));
990     if (ioctl(sockfd, SIOCDIFADDR, (caddr_t) &ifr) == -1) {
991 	if (errno != EADDRNOTAVAIL)
992 	    syslog(LOG_WARNING, "Couldn't remove interface address: %m");
993     }
994     if (ioctl(sockfd, SIOCAIFADDR, (caddr_t) &ifra) == -1) {
995 	if (errno != EEXIST) {
996 	    syslog(LOG_ERR, "Couldn't set interface address: %m");
997 	    return 0;
998 	}
999 	strlcpy(s1, ip_ntoa(o), sizeof(s1));
1000 	strlcpy(s2, ip_ntoa(h), sizeof(s2));
1001 	syslog(LOG_WARNING,
1002 	       "Couldn't set interface address: "
1003 	       "Address %s or destination %s already exists", s1, s2);
1004     }
1005     ifaddrs[0] = o;
1006     ifaddrs[1] = h;
1007     return 1;
1008 }
1009 
1010 /*
1011  * cifaddr - Clear the interface IP addresses, and delete routes
1012  * through the interface if possible.
1013  */
1014 int
cifaddr(int u,u_int32_t o,u_int32_t h)1015 cifaddr(int u, u_int32_t o, u_int32_t h)
1016 {
1017     struct ifaliasreq ifra;
1018 
1019     ifaddrs[0] = 0;
1020     strlcpy(ifra.ifra_name, ifname, sizeof(ifra.ifra_name));
1021     SET_SA_FAMILY(ifra.ifra_addr, AF_INET);
1022     ((struct sockaddr_in *) &ifra.ifra_addr)->sin_addr.s_addr = o;
1023     SET_SA_FAMILY(ifra.ifra_broadaddr, AF_INET);
1024     ((struct sockaddr_in *) &ifra.ifra_broadaddr)->sin_addr.s_addr = h;
1025     BZERO(&ifra.ifra_mask, sizeof(ifra.ifra_mask));
1026     if (ioctl(sockfd, SIOCDIFADDR, (caddr_t) &ifra) == -1) {
1027 	if (errno != EADDRNOTAVAIL)
1028 	    syslog(LOG_WARNING, "Couldn't delete interface address: %m");
1029 	return 0;
1030     }
1031     return 1;
1032 }
1033 
1034 /*
1035  * getrtableid - return routing table id of ppp interface
1036  */
1037 int
getrtableid(void)1038 getrtableid(void)
1039 {
1040     struct ifreq ifr;
1041     int tableid = 0;
1042 
1043     memset(&ifr, 0, sizeof(ifr));
1044     strlcpy(ifr.ifr_name, ifname, sizeof(ifr.ifr_name));
1045     if (ioctl(sockfd, SIOCGIFRDOMAIN, (caddr_t) &ifr) == 0)
1046 	tableid = ifr.ifr_rdomainid;
1047 
1048     return tableid;
1049 }
1050 
1051 /*
1052  * sifdefaultroute - assign a default route through the address given.
1053  */
1054 int
sifdefaultroute(int u,u_int32_t l,u_int32_t g)1055 sifdefaultroute(int u, u_int32_t l, u_int32_t g)
1056 {
1057     return dodefaultroute(g, 's');
1058 }
1059 
1060 /*
1061  * cifdefaultroute - delete a default route through the address given.
1062  */
1063 int
cifdefaultroute(int u,u_int32_t l,u_int32_t g)1064 cifdefaultroute(int u, u_int32_t l, u_int32_t g)
1065 {
1066     return dodefaultroute(g, 'c');
1067 }
1068 
1069 /*
1070  * dodefaultroute - talk to a routing socket to add/delete a default route.
1071  */
1072 static int
dodefaultroute(u_int32_t g,int cmd)1073 dodefaultroute(u_int32_t g, int cmd)
1074 {
1075     int routes;
1076     struct {
1077 	struct rt_msghdr	hdr;
1078 	struct sockaddr_in	dst;
1079 	struct sockaddr_in	gway;
1080 	struct sockaddr_in	mask;
1081     } rtmsg;
1082 
1083     if ((routes = socket(AF_ROUTE, SOCK_RAW, AF_INET)) == -1) {
1084 	syslog(LOG_ERR, "Couldn't %s default route: socket: %m",
1085 	       cmd=='s'? "add": "delete");
1086 	return 0;
1087     }
1088 
1089     memset(&rtmsg, 0, sizeof(rtmsg));
1090     rtmsg.hdr.rtm_type = cmd == 's'? RTM_ADD: RTM_DELETE;
1091     rtmsg.hdr.rtm_flags = RTF_UP | RTF_GATEWAY;
1092     rtmsg.hdr.rtm_version = RTM_VERSION;
1093     rtmsg.hdr.rtm_tableid = getrtableid();
1094     rtmsg.hdr.rtm_seq = ++rtm_seq;
1095     rtmsg.hdr.rtm_addrs = RTA_DST | RTA_GATEWAY | RTA_NETMASK;
1096     rtmsg.dst.sin_len = sizeof(rtmsg.dst);
1097     rtmsg.dst.sin_family = AF_INET;
1098     rtmsg.gway.sin_len = sizeof(rtmsg.gway);
1099     rtmsg.gway.sin_family = AF_INET;
1100     rtmsg.gway.sin_addr.s_addr = g;
1101     rtmsg.mask.sin_len = sizeof(rtmsg.mask);
1102     rtmsg.mask.sin_family = AF_INET;
1103 
1104     rtmsg.hdr.rtm_msglen = sizeof(rtmsg);
1105     if (write(routes, &rtmsg, sizeof(rtmsg)) == -1) {
1106 	syslog(LOG_ERR, "Couldn't %s default route: %m",
1107 	       cmd=='s'? "add": "delete");
1108 	close(routes);
1109 	return 0;
1110     }
1111 
1112     close(routes);
1113     default_route_gateway = (cmd == 's')? g: 0;
1114     return 1;
1115 }
1116 
1117 #if RTM_VERSION >= 3
1118 
1119 /*
1120  * sifproxyarp - Make a proxy ARP entry for the peer.
1121  */
1122 static struct {
1123     struct rt_msghdr		hdr;
1124     struct sockaddr_inarp	dst;
1125     struct sockaddr_dl		hwa;
1126     char			extra[128];
1127 } arpmsg;
1128 
1129 static int arpmsg_valid;
1130 
1131 int
sifproxyarp(int unit,u_int32_t hisaddr)1132 sifproxyarp(int unit, u_int32_t hisaddr)
1133 {
1134     int routes;
1135 
1136     /*
1137      * Get the hardware address of an interface on the same subnet
1138      * as our local address.
1139      */
1140     memset(&arpmsg, 0, sizeof(arpmsg));
1141     if (!get_ether_addr(hisaddr, &arpmsg.hwa)) {
1142 	syslog(LOG_ERR, "Cannot determine ethernet address for proxy ARP");
1143 	return 0;
1144     }
1145 
1146     if ((routes = socket(AF_ROUTE, SOCK_RAW, AF_INET)) == -1) {
1147 	syslog(LOG_ERR, "Couldn't add proxy arp entry: socket: %m");
1148 	return 0;
1149     }
1150 
1151     arpmsg.hdr.rtm_type = RTM_ADD;
1152     arpmsg.hdr.rtm_flags = RTF_ANNOUNCE | RTF_HOST | RTF_STATIC;
1153     arpmsg.hdr.rtm_version = RTM_VERSION;
1154     arpmsg.hdr.rtm_seq = ++rtm_seq;
1155     arpmsg.hdr.rtm_addrs = RTA_DST | RTA_GATEWAY;
1156     arpmsg.hdr.rtm_inits = RTV_EXPIRE;
1157     arpmsg.dst.sin_len = sizeof(struct sockaddr_inarp);
1158     arpmsg.dst.sin_family = AF_INET;
1159     arpmsg.dst.sin_addr.s_addr = hisaddr;
1160     arpmsg.dst.sin_other = SIN_PROXY;
1161 
1162     arpmsg.hdr.rtm_msglen = (char *) &arpmsg.hwa - (char *) &arpmsg
1163 	+ arpmsg.hwa.sdl_len;
1164     if (write(routes, &arpmsg, arpmsg.hdr.rtm_msglen) == -1) {
1165 	syslog(LOG_ERR, "Couldn't add proxy arp entry: %m");
1166 	close(routes);
1167 	return 0;
1168     }
1169 
1170     close(routes);
1171     arpmsg_valid = 1;
1172     proxy_arp_addr = hisaddr;
1173     return 1;
1174 }
1175 
1176 /*
1177  * cifproxyarp - Delete the proxy ARP entry for the peer.
1178  */
1179 int
cifproxyarp(int unit,u_int32_t hisaddr)1180 cifproxyarp(int unit, u_int32_t hisaddr)
1181 {
1182     int routes;
1183 
1184     if (!arpmsg_valid)
1185 	return 0;
1186     arpmsg_valid = 0;
1187 
1188     arpmsg.hdr.rtm_type = RTM_DELETE;
1189     arpmsg.hdr.rtm_seq = ++rtm_seq;
1190 
1191     if ((routes = socket(AF_ROUTE, SOCK_RAW, AF_INET)) == -1) {
1192 	syslog(LOG_ERR, "Couldn't delete proxy arp entry: socket: %m");
1193 	return 0;
1194     }
1195 
1196     if (write(routes, &arpmsg, arpmsg.hdr.rtm_msglen) == -1) {
1197 	syslog(LOG_ERR, "Couldn't delete proxy arp entry: %m");
1198 	close(routes);
1199 	return 0;
1200     }
1201 
1202     close(routes);
1203     proxy_arp_addr = 0;
1204     return 1;
1205 }
1206 
1207 #else	/* RTM_VERSION */
1208 
1209 /*
1210  * sifproxyarp - Make a proxy ARP entry for the peer.
1211  */
1212 int
sifproxyarp(unit,hisaddr)1213 sifproxyarp(unit, hisaddr)
1214     int unit;
1215     u_int32_t hisaddr;
1216 {
1217     struct arpreq arpreq;
1218     struct {
1219 	struct sockaddr_dl	sdl;
1220 	char			space[128];
1221     } dls;
1222 
1223     BZERO(&arpreq, sizeof(arpreq));
1224 
1225     /*
1226      * Get the hardware address of an interface on the same subnet
1227      * as our local address.
1228      */
1229     if (!get_ether_addr(hisaddr, &dls.sdl)) {
1230 	syslog(LOG_ERR, "Cannot determine ethernet address for proxy ARP");
1231 	return 0;
1232     }
1233 
1234     arpreq.arp_ha.sa_len = sizeof(struct sockaddr);
1235     arpreq.arp_ha.sa_family = AF_UNSPEC;
1236     BCOPY(LLADDR(&dls.sdl), arpreq.arp_ha.sa_data, dls.sdl.sdl_alen);
1237     SET_SA_FAMILY(arpreq.arp_pa, AF_INET);
1238     ((struct sockaddr_in *) &arpreq.arp_pa)->sin_addr.s_addr = hisaddr;
1239     arpreq.arp_flags = ATF_PERM | ATF_PUBL;
1240     if (ioctl(sockfd, SIOCSARP, (caddr_t)&arpreq) == -1) {
1241 	syslog(LOG_ERR, "Couldn't add proxy arp entry: %m");
1242 	return 0;
1243     }
1244 
1245     proxy_arp_addr = hisaddr;
1246     return 1;
1247 }
1248 
1249 /*
1250  * cifproxyarp - Delete the proxy ARP entry for the peer.
1251  */
1252 int
cifproxyarp(unit,hisaddr)1253 cifproxyarp(unit, hisaddr)
1254     int unit;
1255     u_int32_t hisaddr;
1256 {
1257     struct arpreq arpreq;
1258 
1259     BZERO(&arpreq, sizeof(arpreq));
1260     SET_SA_FAMILY(arpreq.arp_pa, AF_INET);
1261     ((struct sockaddr_in *) &arpreq.arp_pa)->sin_addr.s_addr = hisaddr;
1262     if (ioctl(sockfd, SIOCDARP, (caddr_t)&arpreq) == -1) {
1263 	syslog(LOG_WARNING, "Couldn't delete proxy arp entry: %m");
1264 	return 0;
1265     }
1266     proxy_arp_addr = 0;
1267     return 1;
1268 }
1269 #endif	/* RTM_VERSION */
1270 
1271 
1272 /*
1273  * get_ether_addr - get the hardware address of an interface on the
1274  * the same subnet as ipaddr.
1275  */
1276 #define MAX_IFS		32
1277 
1278 static int
get_ether_addr(u_int32_t ipaddr,struct sockaddr_dl * hwaddr)1279 get_ether_addr(u_int32_t ipaddr, struct sockaddr_dl *hwaddr)
1280 {
1281     u_int32_t ina, mask;
1282     struct sockaddr_dl *dla;
1283     struct ifaddrs *ifap, *ifa, *ifp;
1284 
1285     if (getifaddrs(&ifap) != 0) {
1286 	syslog(LOG_ERR, "getifaddrs: %m");
1287 	return 0;
1288     }
1289 
1290     /*
1291      * Scan through looking for an interface with an Internet
1292      * address on the same subnet as `ipaddr'.
1293      */
1294     for (ifa = ifap; ifa; ifa = ifa->ifa_next) {
1295 	if (ifa->ifa_addr == NULL)
1296 		continue;
1297 	if (ifa->ifa_addr->sa_family == AF_INET) {
1298 	    ina = ((struct sockaddr_in *)ifa->ifa_addr)->sin_addr.s_addr;
1299 	    /*
1300 	     * Check that the interface is up, and not point-to-point
1301 	     * or loopback.
1302 	     */
1303 	    if ((ifa->ifa_flags &
1304 		 (IFF_UP|IFF_BROADCAST|IFF_POINTOPOINT|IFF_LOOPBACK|IFF_NOARP))
1305 		 != (IFF_UP|IFF_BROADCAST))
1306 		continue;
1307 	    /*
1308 	     * Get its netmask and check that it's on the right subnet.
1309 	     */
1310 	    mask = ((struct sockaddr_in *)ifa->ifa_netmask)->sin_addr.s_addr;
1311 	    if ((ipaddr & mask) != (ina & mask))
1312 		continue;
1313 
1314 	    break;
1315 	}
1316     }
1317 
1318     if (ifa == NULL) {
1319 	freeifaddrs(ifap);
1320 	return 0;
1321     }
1322     syslog(LOG_INFO, "found interface %s for proxy arp", ifa->ifa_name);
1323 
1324     /*
1325      * Now scan through again looking for a link-level address
1326      * for this interface.
1327      */
1328     ifp = ifa;
1329     for (ifa = ifap; ifa; ifa = ifa->ifa_next) {
1330 	if (ifa->ifa_addr == NULL)
1331 		continue;
1332 	if (strcmp(ifp->ifa_name, ifa->ifa_name) == 0
1333 	    && ifa->ifa_addr->sa_family == AF_LINK) {
1334 	    /*
1335 	     * Found the link-level address - copy it out
1336 	     */
1337 	    dla = (struct sockaddr_dl *)ifa->ifa_addr;
1338 	    BCOPY(dla, hwaddr, dla->sdl_len);
1339 	    return 1;
1340 	}
1341     }
1342 
1343     freeifaddrs(ifap);
1344     return 0;
1345 }
1346 
1347 /*
1348  * Return user specified netmask, modified by any mask we might determine
1349  * for address `addr' (in network byte order).
1350  * Here we scan through the system's list of interfaces, looking for
1351  * any non-point-to-point interfaces which might appear to be on the same
1352  * network as `addr'.  If we find any, we OR in their netmask to the
1353  * user-specified netmask.
1354  */
1355 u_int32_t
GetMask(u_int32_t addr)1356 GetMask(u_int32_t addr)
1357 {
1358     u_int32_t mask, nmask, ina;
1359     struct ifaddrs *ifap, *ifa;
1360 
1361     addr = ntohl(addr);
1362     if (IN_CLASSA(addr))	/* determine network mask for address class */
1363 	nmask = IN_CLASSA_NET;
1364     else if (IN_CLASSB(addr))
1365 	nmask = IN_CLASSB_NET;
1366     else
1367 	nmask = IN_CLASSC_NET;
1368     /* class D nets are disallowed by bad_ip_adrs */
1369     mask = netmask | htonl(nmask);
1370 
1371     /*
1372      * Scan through the system's network interfaces.
1373      */
1374     if (getifaddrs(&ifap) != 0) {
1375 	syslog(LOG_WARNING, "getifaddrs: %m");
1376 	return mask;
1377     }
1378     for (ifa = ifap; ifa; ifa = ifa->ifa_next) {
1379 	/*
1380 	 * Check the interface's internet address.
1381 	 */
1382 	if (ifa->ifa_addr == NULL ||
1383 	    ifa->ifa_addr->sa_family != AF_INET)
1384 		continue;
1385 	ina = ((struct sockaddr_in *)ifa->ifa_addr)->sin_addr.s_addr;
1386 	if ((ntohl(ina) & nmask) != (addr & nmask))
1387 	    continue;
1388 	/*
1389 	 * Check that the interface is up, and not point-to-point or loopback.
1390 	 */
1391 	if ((ifa->ifa_flags & (IFF_UP|IFF_POINTOPOINT|IFF_LOOPBACK))
1392 	    != IFF_UP)
1393 	    continue;
1394 	/*
1395 	 * Get its netmask and OR it into our mask.
1396 	 */
1397 	mask |= ((struct sockaddr_in *)ifa->ifa_netmask)->sin_addr.s_addr;
1398     }
1399 
1400     freeifaddrs(ifap);
1401     return mask;
1402 }
1403 
1404 /*
1405  * lock - create a lock file for the named lock device
1406  */
1407 #define	LOCK_PREFIX	"/var/spool/lock/LCK.."
1408 
1409 int
lock(char * dev)1410 lock(char *dev)
1411 {
1412     const char *errstr;
1413     char hdb_lock_buffer[12];
1414     int fd, n;
1415     pid_t pid;
1416     char *p;
1417 
1418     if ((p = strrchr(dev, '/')) != NULL)
1419 	dev = p + 1;
1420     if (asprintf(&lock_file, "%s%s", LOCK_PREFIX, dev) == -1)
1421 	novm("lock file name");
1422 
1423     while ((fd = open(lock_file, O_EXCL | O_CREAT | O_RDWR, 0644)) == -1) {
1424 	if (errno == EEXIST
1425 	    && (fd = open(lock_file, O_RDONLY)) >= 0) {
1426 	    /* Read the lock file to find out who has the device locked */
1427 	    n = read(fd, hdb_lock_buffer, 11);
1428 	    if (n <= 0) {
1429 		syslog(LOG_ERR, "Can't read pid from lock file %s", lock_file);
1430 		close(fd);
1431 	    } else {
1432 		hdb_lock_buffer[n] = 0;
1433 		pid = strtonum(hdb_lock_buffer, 1, 65535, &errstr);
1434 		if (errstr)
1435 		    syslog(LOG_NOTICE, "lock file %s contains garbage: %s\n",
1436 			   dev, errstr);
1437 		else if (kill(pid, 0) == -1 && errno == ESRCH) {
1438 		    /* pid no longer exists - remove the lock file */
1439 		    if (unlink(lock_file) == 0) {
1440 			close(fd);
1441 			syslog(LOG_NOTICE, "Removed stale lock on %s (pid %ld)",
1442 			       dev, (long)pid);
1443 			continue;
1444 		    } else
1445 			syslog(LOG_WARNING, "Couldn't remove stale lock on %s",
1446 			       dev);
1447 		} else
1448 		    syslog(LOG_NOTICE, "Device %s is locked by pid %ld",
1449 			   dev, (long)pid);
1450 	    }
1451 	    close(fd);
1452 	} else
1453 	    syslog(LOG_ERR, "Can't create lock file %s: %m", lock_file);
1454 	free(lock_file);
1455 	lock_file = NULL;
1456 	return -1;
1457     }
1458 
1459     snprintf(hdb_lock_buffer, sizeof hdb_lock_buffer, "%10ld\n", (long)getpid());
1460     write(fd, hdb_lock_buffer, 11);
1461 
1462     close(fd);
1463     return 0;
1464 }
1465 
1466 /*
1467  * unlock - remove our lockfile
1468  */
1469 void
unlock(void)1470 unlock(void)
1471 {
1472     if (lock_file) {
1473 	unlink(lock_file);
1474 	free(lock_file);
1475 	lock_file = NULL;
1476     }
1477 }
1478