source: heimdal/trunk/appl/rsh/rshd.c@ 4

Last change on this file since 4 was 4, checked in by Paul Smedley, 10 years ago

heimdal: applied os2 patches, added conf.cmd
File size: 25.3 KB
Line 
1/*
2 * Copyright (c) 1997-2007 Kungliga Tekniska Högskolan
3 * (Royal Institute of Technology, Stockholm, Sweden).
4 * All rights reserved.
5 *
6 * Redistribution and use in source and binary forms, with or without
7 * modification, are permitted provided that the following conditions
8 * are met:
9 *
10 * 1. Redistributions of source code must retain the above copyright
11 * notice, this list of conditions and the following disclaimer.
12 *
13 * 2. Redistributions in binary form must reproduce the above copyright
14 * notice, this list of conditions and the following disclaimer in the
15 * documentation and/or other materials provided with the distribution.
16 *
17 * 3. Neither the name of the Institute 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 INSTITUTE 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 INSTITUTE 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.
32 */
33
34#include "rsh_locl.h"
35#include "login_locl.h"
36RCSID("$Id$");
37
38int
39login_access( struct passwd *user, char *from);
40int
41read_limits_conf(const char *file, const struct passwd *pwd);
42
43#ifdef NEED_IRUSEROK_PROTO
44int iruserok(uint32_t, int, const char *, const char *);
45#endif
46
47enum auth_method auth_method;
48
49#ifdef KRB5
50krb5_context context;
51krb5_keyblock *keyblock;
52krb5_crypto crypto;
53#endif
54
55#ifdef KRB5
56krb5_ccache ccache, ccache2;
57int kerberos_status = 0;
58#endif
59
60int do_encrypt = 0;
61
62static int do_unique_tkfile = 0;
63static char tkfile[MAXPATHLEN] = "";
64
65static int do_inetd = 1;
66static char *port_str;
67static int do_rhosts = 1;
68static int do_kerberos = 0;
69#define DO_KRB5 4
70static int do_vacuous = 0;
71static int do_log = 1;
72static int do_newpag = 1;
73static int do_addr_verify = 0;
74static int do_keepalive = 1;
75static int do_version;
76static int do_help = 0;
77
78static void
79syslog_and_die (const char *m, ...)
80 __attribute__ ((format (printf, 1, 2)));
81
82static void
83syslog_and_die (const char *m, ...)
84{
85 va_list args;
86
87 va_start(args, m);
88 vsyslog (LOG_ERR, m, args);
89 va_end(args);
90 exit (1);
91}
92
93static void
94fatal (int, const char*, const char *, ...)
95 __attribute__ ((noreturn, format (printf, 3, 4)));
96
97static void
98fatal (int sock, const char *what, const char *m, ...)
99{
100 va_list args;
101 char buf[BUFSIZ];
102 size_t len;
103
104 *buf = 1;
105 va_start(args, m);
106 len = vsnprintf (buf + 1, sizeof(buf) - 1, m, args);
107 len = min(len, sizeof(buf) - 1);
108 va_end(args);
109 if(what != NULL)
110 syslog (LOG_ERR, "%s: %s: %s", what, strerror(errno), buf + 1);
111 else
112 syslog (LOG_ERR, "%s", buf + 1);
113 net_write (sock, buf, len + 1);
114 exit (1);
115}
116
117static char *
118read_str (int s, size_t sz, char *expl)
119{
120 char *str = malloc(sz);
121 char *p = str;
122 if(str == NULL)
123 fatal(s, NULL, "%s too long", expl);
124 while(p < str + sz) {
125 if(net_read(s, p, 1) != 1)
126 syslog_and_die("read: %s", strerror(errno));
127 if(*p == '\0')
128 return str;
129 p++;
130 }
131 fatal(s, NULL, "%s too long", expl);
132}
133
134static int
135recv_bsd_auth (int s, u_char *buf,
136 struct sockaddr_in *thisaddr,
137 struct sockaddr_in *thataddr,
138 char **client_username,
139 char **server_username,
140 char **cmd)
141{
142 struct passwd *pwd;
143
144 *client_username = read_str (s, USERNAME_SZ, "local username");
145 *server_username = read_str (s, USERNAME_SZ, "remote username");
146 *cmd = read_str (s, ARG_MAX + 1, "command");
147 pwd = getpwnam(*server_username);
148 if (pwd == NULL)
149 fatal(s, NULL, "Login incorrect.");
150 if (iruserok(thataddr->sin_addr.s_addr, pwd->pw_uid == 0,
151 *client_username, *server_username))
152 fatal(s, NULL, "Login incorrect.");
153 return 0;
154}
155
156#ifdef KRB5
157static int
158save_krb5_creds (int s,
159 krb5_auth_context auth_context,
160 krb5_principal client)
161
162{
163 int ret;
164 krb5_data remote_cred;
165
166 krb5_data_zero (&remote_cred);
167 ret= krb5_read_message (context, (void *)&s, &remote_cred);
168 if (ret) {
169 krb5_data_free(&remote_cred);
170 return 0;
171 }
172 if (remote_cred.length == 0)
173 return 0;
174
175 ret = krb5_cc_new_unique(context, krb5_cc_type_memory, NULL, &ccache);
176 if (ret) {
177 krb5_data_free(&remote_cred);
178 return 0;
179 }
180
181 krb5_cc_initialize(context,ccache,client);
182 ret = krb5_rd_cred2(context, auth_context, ccache, &remote_cred);
183 if(ret != 0)
184 syslog(LOG_INFO|LOG_AUTH,
185 "reading creds: %s", krb5_get_err_text(context, ret));
186 krb5_data_free (&remote_cred);
187 if (ret)
188 return 0;
189 return 1;
190}
191
192static void
193krb5_start_session (void)
194{
195 krb5_error_code ret;
196 char *estr;
197
198 ret = krb5_cc_resolve (context, tkfile, &ccache2);
199 if (ret) {
200 estr = krb5_get_error_string(context);
201 syslog(LOG_WARNING, "resolve cred cache %s: %s",
202 tkfile,
203 estr ? estr : krb5_get_err_text(context, ret));
204 free(estr);
205 krb5_cc_destroy(context, ccache);
206 return;
207 }
208
209 ret = krb5_cc_copy_cache (context, ccache, ccache2);
210 if (ret) {
211 estr = krb5_get_error_string(context);
212 syslog(LOG_WARNING, "storing credentials: %s",
213 estr ? estr : krb5_get_err_text(context, ret));
214 free(estr);
215 krb5_cc_destroy(context, ccache);
216 return ;
217 }
218
219 krb5_cc_close(context, ccache2);
220 krb5_cc_destroy(context, ccache);
221 return;
222}
223
224static int protocol_version;
225
226static krb5_boolean
227match_kcmd_version(const void *data, const char *version)
228{
229 if(strcmp(version, KCMD_NEW_VERSION) == 0) {
230 protocol_version = 2;
231 return TRUE;
232 }
233 if(strcmp(version, KCMD_OLD_VERSION) == 0) {
234 protocol_version = 1;
235 key_usage = KRB5_KU_OTHER_ENCRYPTED;
236 return TRUE;
237 }
238 return FALSE;
239}
240
241
242static int
243recv_krb5_auth (int s, u_char *buf,
244 struct sockaddr *thisaddr,
245 struct sockaddr *thataddr,
246 char **client_username,
247 char **server_username,
248 char **cmd)
249{
250 uint32_t len;
251 krb5_auth_context auth_context = NULL;
252 krb5_ticket *ticket;
253 krb5_error_code status;
254 krb5_data cksum_data;
255 krb5_principal server;
256 char *str;
257
258 if (memcmp (buf, "\x00\x00\x00\x13", 4) != 0)
259 return -1;
260 len = (buf[0] << 24) | (buf[1] << 16) | (buf[2] << 8) | (buf[3]);
261
262 if (net_read(s, buf, len) != len)
263 syslog_and_die ("reading auth info: %s", strerror(errno));
264 if (len != sizeof(KRB5_SENDAUTH_VERSION)
265 || memcmp (buf, KRB5_SENDAUTH_VERSION, len) != 0)
266 syslog_and_die ("bad sendauth version: %.8s", buf);
267
268 status = krb5_sock_to_principal (context,
269 s,
270 "host",
271 KRB5_NT_SRV_HST,
272 &server);
273 if (status)
274 syslog_and_die ("krb5_sock_to_principal: %s",
275 krb5_get_err_text(context, status));
276
277 status = krb5_recvauth_match_version(context,
278 &auth_context,
279 &s,
280 match_kcmd_version,
281 NULL,
282 server,
283 KRB5_RECVAUTH_IGNORE_VERSION,
284 NULL,
285 &ticket);
286 krb5_free_principal (context, server);
287 if (status)
288 syslog_and_die ("krb5_recvauth: %s",
289 krb5_get_err_text(context, status));
290
291 *server_username = read_str (s, USERNAME_SZ, "remote username");
292 *cmd = read_str (s, ARG_MAX + 1, "command");
293 *client_username = read_str (s, ARG_MAX + 1, "local username");
294
295 if(protocol_version == 2) {
296 status = krb5_auth_con_getremotesubkey(context, auth_context,
297 &keyblock);
298 if(status != 0 || keyblock == NULL)
299 syslog_and_die("failed to get remote subkey");
300 } else if(protocol_version == 1) {
301 status = krb5_auth_con_getkey (context, auth_context, &keyblock);
302 if(status != 0 || keyblock == NULL)
303 syslog_and_die("failed to get key");
304 }
305 if (status != 0 || keyblock == NULL)
306 syslog_and_die ("krb5_auth_con_getkey: %s",
307 krb5_get_err_text(context, status));
308
309 status = krb5_crypto_init(context, keyblock, 0, &crypto);
310 if(status)
311 syslog_and_die("krb5_crypto_init: %s",
312 krb5_get_err_text(context, status));
313
314
315 cksum_data.length = asprintf (&str,
316 "%u:%s%s",
317 ntohs(socket_get_port (thisaddr)),
318 *cmd,
319 *server_username);
320 if (str == NULL)
321 syslog_and_die ("asprintf: out of memory");
322 cksum_data.data = str;
323
324 status = krb5_verify_authenticator_checksum(context,
325 auth_context,
326 cksum_data.data,
327 cksum_data.length);
328
329 if (status)
330 syslog_and_die ("krb5_verify_authenticator_checksum: %s",
331 krb5_get_err_text(context, status));
332
333 free (cksum_data.data);
334
335 if (strncmp (*client_username, "-u ", 3) == 0) {
336 do_unique_tkfile = 1;
337 memmove (*client_username, *client_username + 3,
338 strlen(*client_username) - 2);
339 }
340
341 if (strncmp (*client_username, "-U ", 3) == 0) {
342 char *end, *temp_tkfile;
343
344 do_unique_tkfile = 1;
345 if (strncmp (*client_username + 3, "FILE:", 5) == 0) {
346 temp_tkfile = tkfile;
347 } else {
348 strlcpy (tkfile, "FILE:", sizeof(tkfile));
349 temp_tkfile = tkfile + 5;
350 }
351 end = strchr(*client_username + 3,' ');
352 if (end == NULL)
353 syslog_and_die("missing argument after -U");
354 snprintf(temp_tkfile, sizeof(tkfile) - (temp_tkfile - tkfile),
355 "%.*s",
356 (int)(end - *client_username - 3),
357 *client_username + 3);
358 memmove (*client_username, end + 1, strlen(end+1)+1);
359 }
360
361 kerberos_status = save_krb5_creds (s, auth_context, ticket->client);
362
363 if(!krb5_kuserok (context,
364 ticket->client,
365 *server_username))
366 fatal (s, NULL, "Permission denied.");
367
368 if (strncmp (*cmd, "-x ", 3) == 0) {
369 do_encrypt = 1;
370 memmove (*cmd, *cmd + 3, strlen(*cmd) - 2);
371 } else {
372 if(do_encrypt)
373 fatal (s, NULL, "Encryption is required.");
374 do_encrypt = 0;
375 }
376
377 {
378 char *name;
379
380 if (krb5_unparse_name (context, ticket->client, &name) == 0) {
381 char addr_str[256];
382
383 if (inet_ntop (thataddr->sa_family,
384 socket_get_address (thataddr),
385 addr_str, sizeof(addr_str)) == NULL)
386 strlcpy (addr_str, "unknown address",
387 sizeof(addr_str));
388
389 syslog(LOG_INFO|LOG_AUTH,
390 "kerberos v5 shell from %s on %s as %s, cmd '%.80s'",
391 name,
392 addr_str,
393 *server_username,
394 *cmd);
395 free (name);
396 }
397 }
398
399 krb5_auth_con_free(context, auth_context);
400
401 return 0;
402}
403#endif /* KRB5 */
404
405static void
406rshd_loop (int from0, int to0,
407 int to1, int from1,
408 int to2, int from2,
409 int have_errsock)
410{
411 fd_set real_readset;
412 int max_fd;
413 int count = 2;
414 char *buf;
415
416 if(from0 >= FD_SETSIZE || from1 >= FD_SETSIZE || from2 >= FD_SETSIZE)
417 errx (1, "fd too large");
418
419#ifdef KRB5
420 if(auth_method == AUTH_KRB5 && protocol_version == 2)
421 init_ivecs(0, have_errsock);
422#endif
423
424 FD_ZERO(&real_readset);
425 FD_SET(from0, &real_readset);
426 FD_SET(from1, &real_readset);
427 FD_SET(from2, &real_readset);
428 max_fd = max(from0, max(from1, from2)) + 1;
429
430 buf = malloc(max(RSHD_BUFSIZ, RSH_BUFSIZ));
431 if (buf == NULL)
432 syslog_and_die("out of memory");
433
434 for (;;) {
435 int ret;
436 fd_set readset = real_readset;
437
438 ret = select (max_fd, &readset, NULL, NULL, NULL);
439 if (ret < 0) {
440 if (errno == EINTR)
441 continue;
442 else
443 syslog_and_die ("select: %s", strerror(errno));
444 }
445 if (FD_ISSET(from0, &readset)) {
446 ret = do_read (from0, buf, RSHD_BUFSIZ, ivec_in[0]);
447 if (ret < 0)
448 syslog_and_die ("read: %s", strerror(errno));
449 else if (ret == 0) {
450 close (from0);
451 close (to0);
452 FD_CLR(from0, &real_readset);
453 } else
454 net_write (to0, buf, ret);
455 }
456 if (FD_ISSET(from1, &readset)) {
457 ret = read (from1, buf, RSH_BUFSIZ);
458 if (ret < 0)
459 syslog_and_die ("read: %s", strerror(errno));
460 else if (ret == 0) {
461 close (from1);
462 close (to1);
463 FD_CLR(from1, &real_readset);
464 if (--count == 0)
465 exit (0);
466 } else
467 do_write (to1, buf, ret, ivec_out[0]);
468 }
469 if (FD_ISSET(from2, &readset)) {
470 ret = read (from2, buf, RSH_BUFSIZ);
471 if (ret < 0)
472 syslog_and_die ("read: %s", strerror(errno));
473 else if (ret == 0) {
474 close (from2);
475 close (to2);
476 FD_CLR(from2, &real_readset);
477 if (--count == 0)
478 exit (0);
479 } else
480 do_write (to2, buf, ret, ivec_out[1]);
481 }
482 }
483}
484
485/*
486 * Used by `setup_copier' to create some pipe-like means of
487 * communcation. Real pipes would probably be the best thing, but
488 * then the shell doesn't understand it's talking to rshd. If
489 * socketpair doesn't work everywhere, some autoconf magic would have
490 * to be added here.
491 *
492 * If it fails creating the `pipe', it aborts by calling fatal.
493 */
494
495static void
496pipe_a_like (int fd[2])
497{
498 if (socketpair (AF_UNIX, SOCK_STREAM, 0, fd) < 0)
499 fatal (STDOUT_FILENO, "socketpair", "Pipe creation failed.");
500}
501
502/*
503 * Start a child process and leave the parent copying data to and from it. */
504
505static void
506setup_copier (int have_errsock)
507{
508 int p0[2], p1[2], p2[2];
509 pid_t pid;
510
511 pipe_a_like(p0);
512 pipe_a_like(p1);
513 pipe_a_like(p2);
514 pid = fork ();
515 if (pid < 0)
516 fatal (STDOUT_FILENO, "fork", "Could not create child process.");
517 if (pid == 0) { /* child */
518 close (p0[1]);
519 close (p1[0]);
520 close (p2[0]);
521 dup2 (p0[0], STDIN_FILENO);
522 dup2 (p1[1], STDOUT_FILENO);
523 dup2 (p2[1], STDERR_FILENO);
524 close (p0[0]);
525 close (p1[1]);
526 close (p2[1]);
527 } else { /* parent */
528 close (p0[0]);
529 close (p1[1]);
530 close (p2[1]);
531
532 if (net_write (STDOUT_FILENO, "", 1) != 1)
533 fatal (STDOUT_FILENO, "net_write", "Write failure.");
534
535 rshd_loop (STDIN_FILENO, p0[1],
536 STDOUT_FILENO, p1[0],
537 STDERR_FILENO, p2[0],
538 have_errsock);
539 }
540}
541
542/*
543 * Is `port' a ``reserverd'' port?
544 */
545
546static int
547is_reserved(u_short port)
548{
549 return ntohs(port) < IPPORT_RESERVED;
550}
551
552/*
553 * Set the necessary part of the environment in `env'.
554 */
555
556static void
557setup_environment (char ***env, const struct passwd *pwd)
558{
559 int i, j, path;
560 char **e;
561
562 i = 0;
563 path = 0;
564 *env = NULL;
565
566 i = read_environment(_PATH_ETC_ENVIRONMENT, env);
567 e = *env;
568 for (j = 0; j < i; j++) {
569 if (!strncmp(e[j], "PATH=", 5)) {
570 path = 1;
571 }
572 }
573
574 e = *env;
575 e = realloc(e, (i + 7) * sizeof(char *));
576
577 if (asprintf (&e[i++], "USER=%s", pwd->pw_name) == -1)
578 syslog_and_die ("asprintf: out of memory");
579 if (asprintf (&e[i++], "HOME=%s", pwd->pw_dir) == -1)
580 syslog_and_die ("asprintf: out of memory");
581 if (asprintf (&e[i++], "SHELL=%s", pwd->pw_shell) == -1)
582 syslog_and_die ("asprintf: out of memory");
583 if (! path) {
584 if (asprintf (&e[i++], "PATH=%s", _PATH_DEFPATH) == -1)
585 syslog_and_die ("asprintf: out of memory");
586 }
587 asprintf (&e[i++], "SSH_CLIENT=only_to_make_bash_happy");
588 if (do_unique_tkfile)
589 if (asprintf (&e[i++], "KRB5CCNAME=%s", tkfile) == -1)
590 syslog_and_die ("asprintf: out of memory");
591 e[i++] = NULL;
592 *env = e;
593}
594
595static void
596doit (void)
597{
598 u_char buf[BUFSIZ];
599 u_char *p;
600 struct sockaddr_storage thisaddr_ss;
601 struct sockaddr *thisaddr = (struct sockaddr *)&thisaddr_ss;
602 struct sockaddr_storage thataddr_ss;
603 struct sockaddr *thataddr = (struct sockaddr *)&thataddr_ss;
604 struct sockaddr_storage erraddr_ss;
605 struct sockaddr *erraddr = (struct sockaddr *)&erraddr_ss;
606 socklen_t thisaddr_len, thataddr_len;
607 int port;
608 int errsock = -1;
609 char *client_user = NULL, *server_user = NULL, *cmd = NULL;
610 struct passwd *pwd;
611 int s = STDIN_FILENO;
612 char **env;
613 int ret;
614 char that_host[NI_MAXHOST];
615
616 thisaddr_len = sizeof(thisaddr_ss);
617 if (getsockname (s, thisaddr, &thisaddr_len) < 0)
618 syslog_and_die("getsockname: %s", strerror(errno));
619 thataddr_len = sizeof(thataddr_ss);
620 if (getpeername (s, thataddr, &thataddr_len) < 0)
621 syslog_and_die ("getpeername: %s", strerror(errno));
622
623 /* check for V4MAPPED addresses? */
624
625 if (do_kerberos == 0 && !is_reserved(socket_get_port(thataddr)))
626 fatal(s, NULL, "Permission denied.");
627
628 p = buf;
629 port = 0;
630 for(;;) {
631 if (net_read (s, p, 1) != 1)
632 syslog_and_die ("reading port number: %s", strerror(errno));
633 if (*p == '\0')
634 break;
635 else if (isdigit(*p))
636 port = port * 10 + *p - '0';
637 else
638 syslog_and_die ("non-digit in port number: %c", *p);
639 }
640
641 if (do_kerberos == 0 && !is_reserved(htons(port)))
642 fatal(s, NULL, "Permission denied.");
643
644 if (port) {
645 int priv_port = IPPORT_RESERVED - 1;
646
647 /*
648 * There's no reason to require a ``privileged'' port number
649 * here, but for some reason the brain dead rsh clients
650 * do... :-(
651 */
652
653 erraddr->sa_family = thataddr->sa_family;
654 socket_set_address_and_port (erraddr,
655 socket_get_address (thataddr),
656 htons(port));
657
658 /*
659 * we only do reserved port for IPv4
660 */
661
662#ifndef __OS2__
663 if (erraddr->sa_family == AF_INET)
664 errsock = rresvport (&priv_port);
665 else
666#endif
667 errsock = socket (erraddr->sa_family, SOCK_STREAM, 0);
668 if (errsock < 0)
669 syslog_and_die ("socket: %s", strerror(errno));
670 if (connect (errsock,
671 erraddr,
672 socket_sockaddr_size (erraddr)) < 0) {
673 syslog (LOG_WARNING, "connect: %s", strerror(errno));
674 close (errsock);
675 }
676 }
677
678 if(do_kerberos) {
679 if (net_read (s, buf, 4) != 4)
680 syslog_and_die ("reading auth info: %s", strerror(errno));
681
682#ifdef KRB5
683 if((do_kerberos & DO_KRB5) &&
684 recv_krb5_auth (s, buf, thisaddr, thataddr,
685 &client_user,
686 &server_user,
687 &cmd) == 0)
688 auth_method = AUTH_KRB5;
689 else
690#endif /* KRB5 */
691 syslog_and_die ("unrecognized auth protocol: %x %x %x %x",
692 buf[0], buf[1], buf[2], buf[3]);
693 } else {
694 if(recv_bsd_auth (s, buf,
695 (struct sockaddr_in *)thisaddr,
696 (struct sockaddr_in *)thataddr,
697 &client_user,
698 &server_user,
699 &cmd) == 0) {
700 auth_method = AUTH_BROKEN;
701 if(do_vacuous) {
702 printf("Remote host requires Kerberos authentication\n");
703 exit(0);
704 }
705 } else
706 syslog_and_die("recv_bsd_auth failed");
707 }
708
709 if (client_user == NULL || server_user == NULL || cmd == NULL)
710 syslog_and_die("mising client/server/cmd");
711
712 pwd = getpwnam (server_user);
713 if (pwd == NULL)
714 fatal (s, NULL, "Login incorrect.");
715
716 if (*pwd->pw_shell == '\0')
717 pwd->pw_shell = _PATH_BSHELL;
718
719 if (pwd->pw_uid != 0 && access (_PATH_NOLOGIN, F_OK) == 0)
720 fatal (s, NULL, "Login disabled.");
721
722
723 ret = getnameinfo_verified (thataddr, thataddr_len,
724 that_host, sizeof(that_host),
725 NULL, 0, 0);
726 if (ret)
727 fatal (s, NULL, "getnameinfo: %s", gai_strerror(ret));
728
729 if (login_access(pwd, that_host) == 0) {
730 syslog(LOG_NOTICE, "Kerberos rsh denied to %s from %s",
731 server_user, that_host);
732 fatal(s, NULL, "Permission denied.");
733 }
734
735#ifdef HAVE_GETSPNAM
736 {
737 struct spwd *sp;
738 long today;
739
740 sp = getspnam(server_user);
741 if (sp != NULL) {
742 today = time(0)/(24L * 60 * 60);
743 if (sp->sp_expire > 0)
744 if (today > sp->sp_expire)
745 fatal(s, NULL, "Account has expired.");
746 }
747 }
748#endif
749
750
751#ifdef HAVE_SETLOGIN
752 if (setlogin(pwd->pw_name) < 0)
753 syslog(LOG_ERR, "setlogin() failed: %s", strerror(errno));
754#endif
755
756#ifdef HAVE_SETPCRED
757 if (setpcred (pwd->pw_name, NULL) == -1)
758 syslog(LOG_ERR, "setpcred() failure: %s", strerror(errno));
759#endif /* HAVE_SETPCRED */
760
761 /* Apply limits if not root */
762 if(pwd->pw_uid != 0) {
763 const char *file = _PATH_LIMITS_CONF;
764 read_limits_conf(file, pwd);
765 }
766
767 if (initgroups (pwd->pw_name, pwd->pw_gid) < 0)
768 fatal (s, "initgroups", "Login incorrect.");
769
770 if (setgid(pwd->pw_gid) < 0)
771 fatal (s, "setgid", "Login incorrect.");
772
773 if (setuid (pwd->pw_uid) < 0)
774 fatal (s, "setuid", "Login incorrect.");
775
776 if (chdir (pwd->pw_dir) < 0)
777 fatal (s, "chdir", "Remote directory.");
778
779 if (errsock >= 0) {
780 if (dup2 (errsock, STDERR_FILENO) < 0)
781 fatal (s, "dup2", "Cannot dup stderr.");
782 close (errsock);
783 } else {
784 if (dup2 (STDOUT_FILENO, STDERR_FILENO) < 0)
785 fatal (s, "dup2", "Cannot dup stderr.");
786 }
787
788#ifdef KRB5
789 {
790 int fd;
791
792 if (!do_unique_tkfile)
793 snprintf(tkfile,sizeof(tkfile),"FILE:/tmp/krb5cc_%lu",
794 (unsigned long)pwd->pw_uid);
795 else if (*tkfile=='\0') {
796 snprintf(tkfile,sizeof(tkfile),"FILE:/tmp/krb5cc_XXXXXX");
797 fd = mkstemp(tkfile+5);
798 close(fd);
799 unlink(tkfile+5);
800 }
801
802 if (kerberos_status)
803 krb5_start_session();
804 }
805#endif
806
807 setup_environment (&env, pwd);
808
809 if (do_encrypt) {
810 setup_copier (errsock >= 0);
811 } else {
812 if (net_write (s, "", 1) != 1)
813 fatal (s, "net_write", "write failed");
814 }
815
816#if defined(KRB5)
817 if(k_hasafs()) {
818 char cell[64];
819
820 if(do_newpag)
821 k_setpag();
822
823 /* XXX */
824 if (kerberos_status) {
825 krb5_ccache ccache;
826 krb5_error_code status;
827
828 status = krb5_cc_resolve (context, tkfile, &ccache);
829 if (!status) {
830 if (k_afs_cell_of_file (pwd->pw_dir, cell, sizeof(cell)) == 0)
831 krb5_afslog_uid_home(context, ccache, cell, NULL,
832 pwd->pw_uid, pwd->pw_dir);
833 krb5_afslog_uid_home(context, ccache, NULL, NULL,
834 pwd->pw_uid, pwd->pw_dir);
835 krb5_cc_close (context, ccache);
836 }
837 }
838 }
839#endif /* KRB5 */
840 execle (pwd->pw_shell, pwd->pw_shell, "-c", cmd, NULL, env);
841 err(1, "exec %s", pwd->pw_shell);
842}
843
844struct getargs args[] = {
845 { NULL, 'a', arg_flag, &do_addr_verify },
846 { "keepalive", 'n', arg_negative_flag, &do_keepalive },
847 { "inetd", 'i', arg_negative_flag, &do_inetd,
848 "Not started from inetd" },
849#if defined(KRB5)
850 { "kerberos", 'k', arg_flag, &do_kerberos,
851 "Implement kerberised services" },
852 { "encrypt", 'x', arg_flag, &do_encrypt,
853 "Implement encrypted service" },
854#endif
855 { "rhosts", 'l', arg_negative_flag, &do_rhosts,
856 "Don't check users .rhosts" },
857 { "port", 'p', arg_string, &port_str, "Use this port",
858 "port" },
859 { "vacuous", 'v', arg_flag, &do_vacuous,
860 "Don't accept non-kerberised connections" },
861#if defined(KRB5)
862 { NULL, 'P', arg_negative_flag, &do_newpag,
863 "Don't put process in new PAG" },
864#endif
865 /* compatibility flag: */
866 { NULL, 'L', arg_flag, &do_log },
867 { "version", 0, arg_flag, &do_version },
868 { "help", 0, arg_flag, &do_help }
869};
870
871static void
872usage (int ret)
873{
874 if(isatty(STDIN_FILENO))
875 arg_printusage (args,
876 sizeof(args) / sizeof(args[0]),
877 NULL,
878 "");
879 else
880 syslog (LOG_ERR, "Usage: %s [-ikxlvPL] [-p port]", getprogname());
881 exit (ret);
882}
883
884
885int
886main(int argc, char **argv)
887{
888 int optind = 0;
889 int on = 1;
890
891 setprogname (argv[0]);
892 roken_openlog ("rshd", LOG_ODELAY | LOG_PID, LOG_AUTH);
893
894 if (getarg(args, sizeof(args) / sizeof(args[0]), argc, argv,
895 &optind))
896 usage(1);
897
898 if(do_help)
899 usage (0);
900
901 if (do_version) {
902 print_version(NULL);
903 exit(0);
904 }
905
906#if defined(KRB5)
907 if (do_encrypt)
908 do_kerberos = 1;
909
910 if(do_kerberos)
911 do_kerberos = DO_KRB5;
912#endif
913
914#ifdef KRB5
915 if((do_kerberos & DO_KRB5) && krb5_init_context (&context) != 0)
916 do_kerberos &= ~DO_KRB5;
917#endif
918
919 if (!do_inetd) {
920 int error;
921 struct addrinfo *ai = NULL, hints;
922 char portstr[NI_MAXSERV];
923
924 memset (&hints, 0, sizeof(hints));
925 hints.ai_flags = AI_PASSIVE;
926 hints.ai_socktype = SOCK_STREAM;
927 hints.ai_family = PF_UNSPEC;
928
929 if(port_str != NULL) {
930 error = getaddrinfo (NULL, port_str, &hints, &ai);
931 if (error)
932 errx (1, "getaddrinfo: %s", gai_strerror (error));
933 }
934 if (ai == NULL) {
935#if defined(KRB5)
936 if (do_kerberos) {
937 if (do_encrypt) {
938 error = getaddrinfo(NULL, "ekshell", &hints, &ai);
939 if(error == EAI_NONAME) {
940 snprintf(portstr, sizeof(portstr), "%d", 545);
941 error = getaddrinfo(NULL, portstr, &hints, &ai);
942 }
943 if(error)
944 errx (1, "getaddrinfo: %s", gai_strerror (error));
945 } else {
946 error = getaddrinfo(NULL, "kshell", &hints, &ai);
947 if(error == EAI_NONAME) {
948 snprintf(portstr, sizeof(portstr), "%d", 544);
949 error = getaddrinfo(NULL, portstr, &hints, &ai);
950 }
951 if(error)
952 errx (1, "getaddrinfo: %s", gai_strerror (error));
953 }
954 } else
955#endif
956 {
957 error = getaddrinfo(NULL, "shell", &hints, &ai);
958 if(error == EAI_NONAME) {
959 snprintf(portstr, sizeof(portstr), "%d", 514);
960 error = getaddrinfo(NULL, portstr, &hints, &ai);
961 }
962 if(error)
963 errx (1, "getaddrinfo: %s", gai_strerror (error));
964 }
965 }
966 mini_inetd_addrinfo (ai, NULL);
967 freeaddrinfo(ai);
968 }
969
970 if (do_keepalive &&
971 setsockopt(0, SOL_SOCKET, SO_KEEPALIVE, (char *)&on,
972 sizeof(on)) < 0)
973 syslog(LOG_WARNING, "setsockopt (SO_KEEPALIVE): %s", strerror(errno));
974
975 /* set SO_LINGER? */
976
977 signal (SIGPIPE, SIG_IGN);
978
979 doit ();
980 return 0;
981}
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