If a neighbor solictation or neighbor advertisement isn't from the
[dragonfly.git] / libexec / rlogind / rlogind.c
CommitLineData
984263bc
MD
1/*-
2 * Copyright (c) 1983, 1988, 1989, 1993
3 * The Regents of the University of California. 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 * 3. All advertising materials mentioning features or use of this software
14 * must display the following acknowledgement:
15 * This product includes software developed by the University of
16 * California, Berkeley and its contributors.
17 * 4. Neither the name of the University nor the names of its contributors
18 * may be used to endorse or promote products derived from this software
19 * without specific prior written permission.
20 *
21 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
22 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
23 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
24 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
25 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
26 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
27 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
28 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
29 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
30 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
31 * SUCH DAMAGE.
1de703da
MD
32 *
33 * @(#) Copyright (c) 1983, 1988, 1989, 1993 The Regents of the University of California. All rights reserved.
34 * @(#)rlogind.c 8.1 (Berkeley) 6/4/93
35 * $FreeBSD: src/libexec/rlogind/rlogind.c,v 1.29.2.5 2000/12/07 15:02:31 ru Exp $
e5d03018 36 * $DragonFly: src/libexec/rlogind/rlogind.c,v 1.5 2007/05/18 17:05:12 dillon Exp $
984263bc
MD
37 */
38
984263bc
MD
39/*
40 * remote login server:
41 * \0
42 * remuser\0
43 * locuser\0
44 * terminal_type/speed\0
45 * data
46 */
47
48#define FD_SETSIZE 16 /* don't need many bits for select */
49#include <sys/types.h>
50#include <sys/param.h>
51#include <sys/stat.h>
52#include <sys/ioctl.h>
53#include <signal.h>
54#include <termios.h>
55
56#include <sys/socket.h>
57#include <netinet/in.h>
58#include <netinet/in_systm.h>
59#include <netinet/ip.h>
60#include <netinet/tcp.h>
61#include <arpa/inet.h>
62#include <netdb.h>
63
64#include <errno.h>
65#include <libutil.h>
66#include <pwd.h>
67#include <syslog.h>
68#include <stdio.h>
69#include <stdlib.h>
70#include <string.h>
71#include <unistd.h>
72#include "pathnames.h"
73
74
75#ifndef TIOCPKT_WINDOW
76#define TIOCPKT_WINDOW 0x80
77#endif
78
79#define ARGSTR "Dalnx"
80
81/* wrapper for KAME-special getnameinfo() */
82#ifndef NI_WITHSCOPEID
83#define NI_WITHSCOPEID 0
84#endif
85
3b84bfb8
SW
86extern int __check_rhosts_file;
87extern char **environ;
88
984263bc
MD
89char *env[2];
90#define NMAX 30
91char lusername[NMAX+1], rusername[NMAX+1];
92static char term[64] = "TERM=";
93#define ENVSIZE (sizeof("TERM=")-1) /* skip null for concatenation */
94int keepalive = 1;
95int check_all = 0;
96int no_delay;
97
98struct passwd *pwd;
99
100union sockunion {
101 struct sockinet {
102 u_char si_len;
103 u_char si_family;
104 u_short si_port;
105 } su_si;
106 struct sockaddr_in su_sin;
107 struct sockaddr_in6 su_sin6;
108};
109#define su_len su_si.si_len
110#define su_family su_si.si_family
111#define su_port su_si.si_port
112
3b84bfb8
SW
113void doit(int, union sockunion *);
114int control(int, char *, int);
115void protocol(int, int);
116void cleanup(int);
117void fatal(int, const char *, int);
118int do_rlogin(union sockunion *);
119void getstr(char *, int, const char *);
120void setup_term(int);
121int do_krb_login(struct sockaddr_in *);
122void usage(void);
984263bc
MD
123
124
125int
3b84bfb8 126main(int argc, char *argv[])
984263bc 127{
984263bc 128 union sockunion from;
3b84bfb8
SW
129 socklen_t fromlen;
130 int ch, on;
984263bc
MD
131
132 openlog("rlogind", LOG_PID | LOG_CONS, LOG_AUTH);
133
134 opterr = 0;
135 while ((ch = getopt(argc, argv, ARGSTR)) != -1)
136 switch (ch) {
137 case 'D':
138 no_delay = 1;
139 break;
140 case 'a':
141 check_all = 1;
142 break;
143 case 'l':
144 __check_rhosts_file = 0;
145 break;
146 case 'n':
147 keepalive = 0;
148 break;
149#ifdef CRYPT
150 case 'x':
151 doencrypt = 1;
152 break;
153#endif
154 case '?':
155 default:
156 usage();
157 break;
158 }
159 argc -= optind;
160 argv += optind;
161
162 fromlen = sizeof (from);
163 if (getpeername(0, (struct sockaddr *)&from, &fromlen) < 0) {
164 syslog(LOG_ERR,"Can't get peer name of remote host: %m");
165 fatal(STDERR_FILENO, "Can't get peer name of remote host", 1);
166 }
167 on = 1;
168 if (keepalive &&
169 setsockopt(0, SOL_SOCKET, SO_KEEPALIVE, &on, sizeof (on)) < 0)
170 syslog(LOG_WARNING, "setsockopt (SO_KEEPALIVE): %m");
171 if (no_delay &&
172 setsockopt(0, IPPROTO_TCP, TCP_NODELAY, &on, sizeof(on)) < 0)
173 syslog(LOG_WARNING, "setsockopt (TCP_NODELAY): %m");
174 if (from.su_family == AF_INET)
175 {
176 on = IPTOS_LOWDELAY;
177 if (setsockopt(0, IPPROTO_IP, IP_TOS, (char *)&on, sizeof(int)) < 0)
178 syslog(LOG_WARNING, "setsockopt (IP_TOS): %m");
179 }
180
181 doit(0, &from);
182 return 0;
183}
184
185int child;
186int netf;
187char line[MAXPATHLEN];
188int confirmed;
189
190struct winsize win = { 0, 0, 0, 0 };
191
192
193void
3b84bfb8 194doit(int f, union sockunion *fromp)
984263bc
MD
195{
196 int master, pid, on = 1;
197 int authenticated = 0;
198 char hostname[2 * MAXHOSTNAMELEN + 1];
199 char nameinfo[2 * INET6_ADDRSTRLEN + 1];
3b84bfb8 200 u_char c;
984263bc
MD
201
202 alarm(60);
203 read(f, &c, 1);
204
205 if (c != 0)
206 exit(1);
207
208 alarm(0);
209
210 realhostname_sa(hostname, sizeof(hostname) - 1,
211 (struct sockaddr *)fromp, fromp->su_len);
212 /* error check ? */
213 fromp->su_port = ntohs((u_short)fromp->su_port);
214 hostname[sizeof(hostname) - 1] = '\0';
215
216 {
217 if ((fromp->su_family != AF_INET
218#ifdef INET6
219 && fromp->su_family != AF_INET6
220#endif
221 ) ||
222 fromp->su_port >= IPPORT_RESERVED ||
223 fromp->su_port < IPPORT_RESERVED/2) {
224 getnameinfo((struct sockaddr *)fromp,
225 fromp->su_len,
226 nameinfo, sizeof(nameinfo), NULL, 0,
227 NI_NUMERICHOST|NI_WITHSCOPEID);
228 /* error check ? */
229 syslog(LOG_NOTICE, "Connection from %s on illegal port",
230 nameinfo);
231 fatal(f, "Permission denied", 0);
232 }
233#ifdef IP_OPTIONS
234 if (fromp->su_family == AF_INET)
235 {
236 u_char optbuf[BUFSIZ/3];
3b84bfb8
SW
237 socklen_t optsize = sizeof(optbuf), i;
238 int ipproto;
984263bc
MD
239 struct protoent *ip;
240
241 if ((ip = getprotobyname("ip")) != NULL)
242 ipproto = ip->p_proto;
243 else
244 ipproto = IPPROTO_IP;
245 if (getsockopt(0, ipproto, IP_OPTIONS, (char *)optbuf,
246 &optsize) == 0 && optsize != 0) {
247 for (i = 0; i < optsize; ) {
3b84bfb8 248 c = optbuf[i];
984263bc
MD
249 if (c == IPOPT_LSRR || c == IPOPT_SSRR) {
250 syslog(LOG_NOTICE,
251 "Connection refused from %s with IP option %s",
252 inet_ntoa(fromp->su_sin.sin_addr),
253 c == IPOPT_LSRR ? "LSRR" : "SSRR");
254 exit(1);
255 }
256 if (c == IPOPT_EOL)
257 break;
258 i += (c == IPOPT_NOP) ? 1 : optbuf[i+1];
259 }
260 }
261 }
262#endif
263 if (do_rlogin(fromp) == 0)
264 authenticated++;
265 }
266 if (confirmed == 0) {
267 write(f, "", 1);
268 confirmed = 1; /* we sent the null! */
269 }
270#ifdef CRYPT
3b84bfb8
SW
271 if (doencrypt) {
272 des_enc_write(f, SECURE_MESSAGE, strlen(SECURE_MESSAGE),
273 schedule, &kdata->session);
274 }
984263bc
MD
275#endif
276 netf = f;
277
278 pid = forkpty(&master, line, NULL, &win);
279 if (pid < 0) {
280 if (errno == ENOENT)
281 fatal(f, "Out of ptys", 0);
282 else
283 fatal(f, "Forkpty", 1);
284 }
285 if (pid == 0) {
286 if (f > 2) /* f should always be 0, but... */
3b84bfb8 287 close(f);
984263bc
MD
288 setup_term(0);
289 if (*lusername=='-') {
290 syslog(LOG_ERR, "tried to pass user \"%s\" to login",
291 lusername);
292 fatal(STDERR_FILENO, "invalid user", 0);
293 }
294 if (authenticated) {
295 execl(_PATH_LOGIN, "login", "-p",
296 "-h", hostname, "-f", lusername, (char *)NULL);
297 } else
298 execl(_PATH_LOGIN, "login", "-p",
299 "-h", hostname, lusername, (char *)NULL);
300 fatal(STDERR_FILENO, _PATH_LOGIN, 1);
301 /*NOTREACHED*/
302 }
303#ifdef CRYPT
304 /*
305 * If encrypted, don't turn on NBIO or the des read/write
306 * routines will croak.
307 */
308
309 if (!doencrypt)
310#endif
311 ioctl(f, FIONBIO, &on);
312 ioctl(master, FIONBIO, &on);
313 ioctl(master, TIOCPKT, &on);
314 signal(SIGCHLD, cleanup);
315 protocol(f, master);
316 signal(SIGCHLD, SIG_IGN);
317 cleanup(0);
318}
319
320char magic[2] = { 0377, 0377 };
321char oobdata[] = {TIOCPKT_WINDOW};
322
323/*
324 * Handle a "control" request (signaled by magic being present)
325 * in the data stream. For now, we are only willing to handle
326 * window size changes.
327 */
328int
3b84bfb8 329control(int pty, char *cp, int n)
984263bc
MD
330{
331 struct winsize w;
332
3b84bfb8 333 if (n < 4 + (int)sizeof(w) || cp[2] != 's' || cp[3] != 's')
984263bc
MD
334 return (0);
335 oobdata[0] &= ~TIOCPKT_WINDOW; /* we know he heard */
336 bcopy(cp+4, (char *)&w, sizeof(w));
337 w.ws_row = ntohs(w.ws_row);
338 w.ws_col = ntohs(w.ws_col);
339 w.ws_xpixel = ntohs(w.ws_xpixel);
340 w.ws_ypixel = ntohs(w.ws_ypixel);
3b84bfb8 341 ioctl(pty, TIOCSWINSZ, &w);
984263bc
MD
342 return (4+sizeof (w));
343}
344
345/*
346 * rlogin "protocol" machine.
347 */
348void
3b84bfb8 349protocol(int f, int p)
984263bc
MD
350{
351 char pibuf[1024+1], fibuf[1024], *pbp = NULL, *fbp = NULL;
352 int pcc = 0, fcc = 0;
353 int cc, nfd, n;
354 char cntl;
355
356 /*
357 * Must ignore SIGTTOU, otherwise we'll stop
358 * when we try and set slave pty's window shape
359 * (our controlling tty is the master pty).
360 */
3b84bfb8 361 signal(SIGTTOU, SIG_IGN);
984263bc
MD
362 send(f, oobdata, 1, MSG_OOB); /* indicate new rlogin */
363 if (f > p)
364 nfd = f + 1;
365 else
366 nfd = p + 1;
367 if (nfd > FD_SETSIZE) {
368 syslog(LOG_ERR, "select mask too small, increase FD_SETSIZE");
369 fatal(f, "internal error (select mask too small)", 0);
370 }
371 for (;;) {
372 fd_set ibits, obits, ebits, *omask;
373
374 FD_ZERO(&ebits);
375 FD_ZERO(&ibits);
376 FD_ZERO(&obits);
377 omask = (fd_set *)NULL;
378 if (fcc) {
379 FD_SET(p, &obits);
380 omask = &obits;
381 } else
382 FD_SET(f, &ibits);
383 if (pcc >= 0) {
384 if (pcc) {
385 FD_SET(f, &obits);
386 omask = &obits;
387 } else
388 FD_SET(p, &ibits);
389 }
390 FD_SET(p, &ebits);
391 if ((n = select(nfd, &ibits, omask, &ebits, 0)) < 0) {
392 if (errno == EINTR)
393 continue;
394 fatal(f, "select", 1);
395 }
396 if (n == 0) {
397 /* shouldn't happen... */
398 sleep(5);
399 continue;
400 }
401#define pkcontrol(c) ((c)&(TIOCPKT_FLUSHWRITE|TIOCPKT_NOSTOP|TIOCPKT_DOSTOP))
402 if (FD_ISSET(p, &ebits)) {
403 cc = read(p, &cntl, 1);
404 if (cc == 1 && pkcontrol(cntl)) {
405 cntl |= oobdata[0];
406 send(f, &cntl, 1, MSG_OOB);
407 if (cntl & TIOCPKT_FLUSHWRITE) {
408 pcc = 0;
409 FD_CLR(p, &ibits);
410 }
411 }
412 }
413 if (FD_ISSET(f, &ibits)) {
414#ifdef CRYPT
415 if (doencrypt)
416 fcc = des_enc_read(f, fibuf, sizeof(fibuf),
417 schedule, &kdata->session);
418 else
419#endif
420 fcc = read(f, fibuf, sizeof(fibuf));
421 if (fcc < 0 && errno == EWOULDBLOCK)
422 fcc = 0;
423 else {
424 register char *cp;
3b84bfb8 425 int left;
984263bc
MD
426
427 if (fcc <= 0)
428 break;
429 fbp = fibuf;
430
431 top:
432 for (cp = fibuf; cp < fibuf+fcc-1; cp++)
433 if (cp[0] == magic[0] &&
434 cp[1] == magic[1]) {
435 left = fcc - (cp-fibuf);
436 n = control(p, cp, left);
437 if (n) {
438 left -= n;
439 if (left > 0)
440 bcopy(cp+n, cp, left);
441 fcc -= n;
442 goto top; /* n^2 */
443 }
444 }
445 FD_SET(p, &obits); /* try write */
446 }
447 }
448
449 if (FD_ISSET(p, &obits) && fcc > 0) {
450 cc = write(p, fbp, fcc);
451 if (cc > 0) {
452 fcc -= cc;
453 fbp += cc;
454 }
455 }
456
457 if (FD_ISSET(p, &ibits)) {
458 pcc = read(p, pibuf, sizeof (pibuf));
459 pbp = pibuf;
460 if (pcc < 0 && errno == EWOULDBLOCK)
461 pcc = 0;
462 else if (pcc <= 0)
463 break;
464 else if (pibuf[0] == 0) {
465 pbp++, pcc--;
466#ifdef CRYPT
467 if (!doencrypt)
468#endif
469 FD_SET(f, &obits); /* try write */
470 } else {
471 if (pkcontrol(pibuf[0])) {
472 pibuf[0] |= oobdata[0];
473 send(f, &pibuf[0], 1, MSG_OOB);
474 }
475 pcc = 0;
476 }
477 }
478 if ((FD_ISSET(f, &obits)) && pcc > 0) {
479#ifdef CRYPT
480 if (doencrypt)
481 cc = des_enc_write(f, pbp, pcc,
482 schedule, &kdata->session);
483 else
484#endif
485 cc = write(f, pbp, pcc);
486 if (cc < 0 && errno == EWOULDBLOCK) {
487 /*
488 * This happens when we try write after read
489 * from p, but some old kernels balk at large
490 * writes even when select returns true.
491 */
492 if (!FD_ISSET(p, &ibits))
493 sleep(5);
494 continue;
495 }
496 if (cc > 0) {
497 pcc -= cc;
498 pbp += cc;
499 }
500 }
501 }
502}
503
504void
3b84bfb8 505cleanup(int signo __unused)
984263bc
MD
506{
507 char *p;
508
509 p = line + sizeof(_PATH_DEV) - 1;
510 if (logout(p))
511 logwtmp(p, "", "");
3b84bfb8
SW
512 chflags(line, 0);
513 chmod(line, 0666);
514 chown(line, 0, 0);
984263bc 515 *p = 'p';
3b84bfb8
SW
516 chflags(line, 0);
517 chmod(line, 0666);
518 chown(line, 0, 0);
e5d03018 519 shutdown(netf, SHUT_RDWR);
984263bc
MD
520 exit(1);
521}
522
523void
3b84bfb8 524fatal(int f, const char *msg, int syserr)
984263bc
MD
525{
526 int len;
527 char buf[BUFSIZ], *bp = buf;
528
529 /*
530 * Prepend binary one to message if we haven't sent
531 * the magic null as confirmation.
532 */
533 if (!confirmed)
534 *bp++ = '\01'; /* error indicator */
535 if (syserr)
536 len = snprintf(bp, sizeof(buf), "rlogind: %s: %s.\r\n",
537 msg, strerror(errno));
538 else
539 len = snprintf(bp, sizeof(buf), "rlogind: %s.\r\n", msg);
3b84bfb8 540 write(f, buf, bp + len - buf);
984263bc
MD
541 exit(1);
542}
543
544int
3b84bfb8 545do_rlogin(union sockunion *dest)
984263bc
MD
546{
547
548 getstr(rusername, sizeof(rusername), "remuser too long");
549 getstr(lusername, sizeof(lusername), "locuser too long");
550 getstr(term+ENVSIZE, sizeof(term)-ENVSIZE, "Terminal type too long");
551
552 pwd = getpwnam(lusername);
553 if (pwd == NULL)
554 return (-1);
555 /* XXX why don't we syslog() failure? */
556
557 return (iruserok_sa(dest, dest->su_len, pwd->pw_uid == 0, rusername,
558 lusername));
559}
560
561void
3b84bfb8 562getstr(char *buf, int cnt, const char *errmsg)
984263bc
MD
563{
564 char c;
565
566 do {
567 if (read(0, &c, 1) != 1)
568 exit(1);
569 if (--cnt < 0)
570 fatal(STDOUT_FILENO, errmsg, 0);
571 *buf++ = c;
572 } while (c != 0);
573}
574
984263bc 575void
3b84bfb8 576setup_term(int fd)
984263bc
MD
577{
578 register char *cp = index(term+ENVSIZE, '/');
579 char *speed;
580 struct termios tt;
581
582#ifndef notyet
583 tcgetattr(fd, &tt);
584 if (cp) {
585 *cp++ = '\0';
586 speed = cp;
587 cp = index(speed, '/');
588 if (cp)
589 *cp++ = '\0';
590 cfsetspeed(&tt, atoi(speed));
591 }
592
593 tt.c_iflag = TTYDEF_IFLAG;
594 tt.c_oflag = TTYDEF_OFLAG;
595 tt.c_lflag = TTYDEF_LFLAG;
596 tcsetattr(fd, TCSAFLUSH, &tt);
597#else
598 if (cp) {
599 *cp++ = '\0';
600 speed = cp;
601 cp = index(speed, '/');
602 if (cp)
603 *cp++ = '\0';
604 tcgetattr(fd, &tt);
605 cfsetspeed(&tt, atoi(speed));
606 tcsetattr(fd, TCSAFLUSH, &tt);
607 }
608#endif
609
610 env[0] = term;
611 env[1] = 0;
612 environ = env;
613}
614
615void
3b84bfb8 616usage(void)
984263bc
MD
617{
618 syslog(LOG_ERR, "usage: rlogind [-" ARGSTR "]");
619}