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[glibc.git] / inet / rcmd.c
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1 /*
2 * Copyright (c) 1983, 1993, 1994
3 * The Regents of the University of California. All rights reserved.
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.
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.
34 #if defined(LIBC_SCCS) && !defined(lint)
35 static char sccsid[] = "@(#)rcmd.c 8.3 (Berkeley) 3/26/94";
36 #endif /* LIBC_SCCS and not lint */
38 #include <sys/param.h>
39 #include <sys/poll.h>
40 #include <sys/socket.h>
41 #include <sys/stat.h>
43 #include <netinet/in.h>
44 #include <arpa/inet.h>
46 #include <alloca.h>
47 #include <signal.h>
48 #include <fcntl.h>
49 #include <netdb.h>
50 #include <unistd.h>
51 #include <pwd.h>
52 #include <errno.h>
53 #include <stdio.h>
54 #include <ctype.h>
55 #include <string.h>
58 int __ivaliduser __P ((FILE *, u_int32_t, const char *, const char *));
59 static int __ivaliduser2 __P ((FILE *, u_int32_t, const char *, const char *,
60 const char *));
63 int
64 rcmd(ahost, rport, locuser, remuser, cmd, fd2p)
65 char **ahost;
66 u_short rport;
67 const char *locuser, *remuser, *cmd;
68 int *fd2p;
70 struct hostent hostbuf, *hp;
71 size_t hstbuflen;
72 char *tmphstbuf;
73 struct sockaddr_in sin, from;
74 struct pollfd pfd[2];
75 int32_t oldmask;
76 pid_t pid;
77 int s, lport, timo;
78 char c;
79 int herr;
81 pid = __getpid();
83 hstbuflen = 1024;
84 tmphstbuf = __alloca (hstbuflen);
85 while (__gethostbyname_r (*ahost, &hostbuf, tmphstbuf, hstbuflen,
86 &hp, &herr) < 0)
87 if (herr != NETDB_INTERNAL || errno != ERANGE)
89 __set_h_errno (herr);
90 herror(*ahost);
91 return -1;
93 else
95 /* Enlarge the buffer. */
96 hstbuflen *= 2;
97 tmphstbuf = __alloca (hstbuflen);
100 pfd[0].events = POLLIN;
101 pfd[1].events = POLLIN;
103 *ahost = hp->h_name;
104 oldmask = __sigblock(sigmask(SIGURG));
105 for (timo = 1, lport = IPPORT_RESERVED - 1;;) {
106 s = rresvport(&lport);
107 if (s < 0) {
108 if (errno == EAGAIN)
109 (void)fprintf(stderr,
110 _("rcmd: socket: All ports in use\n"));
111 else
112 (void)fprintf(stderr, "rcmd: socket: %m\n");
113 __sigsetmask(oldmask);
114 return -1;
116 __fcntl(s, F_SETOWN, pid);
117 sin.sin_family = hp->h_addrtype;
118 bcopy(hp->h_addr_list[0], &sin.sin_addr,
119 MIN (sizeof (sin.sin_addr), hp->h_length));
120 sin.sin_port = rport;
121 if (__connect(s, (struct sockaddr *)&sin, sizeof(sin)) >= 0)
122 break;
123 (void)__close(s);
124 if (errno == EADDRINUSE) {
125 lport--;
126 continue;
128 if (errno == ECONNREFUSED && timo <= 16) {
129 (void)__sleep(timo);
130 timo *= 2;
131 continue;
133 if (hp->h_addr_list[1] != NULL) {
134 int oerrno = errno;
136 (void)fprintf(stderr, _("connect to address %s: "),
137 inet_ntoa(sin.sin_addr));
138 __set_errno (oerrno);
139 perror(0);
140 hp->h_addr_list++;
141 bcopy(hp->h_addr_list[0], &sin.sin_addr,
142 MIN (sizeof (sin.sin_addr), hp->h_length));
143 (void)fprintf(stderr, _("Trying %s...\n"),
144 inet_ntoa(sin.sin_addr));
145 continue;
147 (void)fprintf(stderr, "%s: %m\n", hp->h_name);
148 __sigsetmask(oldmask);
149 return -1;
151 lport--;
152 if (fd2p == 0) {
153 __write(s, "", 1);
154 lport = 0;
155 } else {
156 char num[8];
157 int s2 = rresvport(&lport), s3;
158 size_t len = sizeof(from);
160 if (s2 < 0)
161 goto bad;
162 listen(s2, 1);
163 (void)__snprintf(num, sizeof(num), "%d", lport);
164 if (__write(s, num, strlen(num)+1) != strlen(num)+1) {
165 (void)fprintf(stderr,
166 _("rcmd: write (setting up stderr): %m\n"));
167 (void)__close(s2);
168 goto bad;
170 pfd[0].fd = s;
171 pfd[1].fd = s2;
172 __set_errno (0);
173 if (__poll (pfd, 2, -1) < 1 || (pfd[1].revents & POLLIN) == 0){
174 if (errno != 0)
175 (void)fprintf(stderr,
176 _("rcmd: poll (setting up stderr): %m\n"));
177 else
178 (void)fprintf(stderr,
179 _("poll: protocol failure in circuit setup\n"));
180 (void)__close(s2);
181 goto bad;
183 s3 = accept(s2, (struct sockaddr *)&from, &len);
184 (void)__close(s2);
185 if (s3 < 0) {
186 (void)fprintf(stderr,
187 "rcmd: accept: %m\n");
188 lport = 0;
189 goto bad;
191 *fd2p = s3;
192 from.sin_port = ntohs((u_short)from.sin_port);
193 if (from.sin_family != AF_INET ||
194 from.sin_port >= IPPORT_RESERVED ||
195 from.sin_port < IPPORT_RESERVED / 2) {
196 (void)fprintf(stderr,
197 _("socket: protocol failure in circuit setup\n"));
198 goto bad2;
201 (void)__write(s, locuser, strlen(locuser)+1);
202 (void)__write(s, remuser, strlen(remuser)+1);
203 (void)__write(s, cmd, strlen(cmd)+1);
204 if (__read(s, &c, 1) != 1) {
205 (void)fprintf(stderr,
206 "rcmd: %s: %m\n", *ahost);
207 goto bad2;
209 if (c != 0) {
210 while (__read(s, &c, 1) == 1) {
211 (void)__write(STDERR_FILENO, &c, 1);
212 if (c == '\n')
213 break;
215 goto bad2;
217 __sigsetmask(oldmask);
218 return s;
219 bad2:
220 if (lport)
221 (void)__close(*fd2p);
222 bad:
223 (void)__close(s);
224 __sigsetmask(oldmask);
225 return -1;
229 rresvport(alport)
230 int *alport;
232 struct sockaddr_in sin;
233 int s;
235 sin.sin_family = AF_INET;
236 sin.sin_addr.s_addr = INADDR_ANY;
237 s = __socket(AF_INET, SOCK_STREAM, 0);
238 if (s < 0)
239 return -1;
240 for (;;) {
241 sin.sin_port = htons((u_short)*alport);
242 if (bind(s, (struct sockaddr *)&sin, sizeof(sin)) >= 0)
243 return s;
244 if (errno != EADDRINUSE) {
245 (void)__close(s);
246 return -1;
248 (*alport)--;
249 if (*alport == IPPORT_RESERVED/2) {
250 (void)__close(s);
251 __set_errno (EAGAIN); /* close */
252 return -1;
257 int __check_rhosts_file = 1;
258 char *__rcmd_errstr;
261 ruserok(rhost, superuser, ruser, luser)
262 const char *rhost, *ruser, *luser;
263 int superuser;
265 struct hostent hostbuf, *hp;
266 size_t buflen;
267 char *buffer;
268 u_int32_t addr;
269 char **ap;
270 int herr;
272 buflen = 1024;
273 buffer = __alloca (buflen);
275 while (__gethostbyname_r (rhost, &hostbuf, buffer, buflen, &hp, &herr)
276 < 0)
277 if (herr != NETDB_INTERNAL || errno != ERANGE)
278 return -1;
279 else
281 /* Enlarge the buffer. */
282 buflen *= 2;
283 buffer = __alloca (buflen);
286 for (ap = hp->h_addr_list; *ap; ++ap) {
287 bcopy(*ap, &addr, sizeof(addr));
288 if (iruserok(addr, superuser, ruser, luser, rhost) == 0)
289 return 0;
291 return -1;
294 /* Extremely paranoid file open function. */
295 static FILE *
296 iruserfopen (char *file, uid_t okuser)
298 struct stat st;
299 char *cp = NULL;
300 FILE *res = NULL;
302 /* If not a regular file, if owned by someone other than user or
303 root, if writeable by anyone but the owner, or if hardlinked
304 anywhere, quit. */
305 cp = NULL;
306 if (__lxstat (_STAT_VER, file, &st))
307 cp = _("lstat failed");
308 else if (!S_ISREG (st.st_mode))
309 cp = _("not regular file");
310 else
312 res = fopen (file, "r");
313 if (!res)
314 cp = _("cannot open");
315 else if (__fxstat (_STAT_VER, fileno (res), &st) < 0)
316 cp = _("fstat failed");
317 else if (st.st_uid && st.st_uid != okuser)
318 cp = _("bad owner");
319 else if (st.st_mode & (S_IWGRP|S_IWOTH))
320 cp = _("writeable by other than owner");
321 else if (st.st_nlink > 1)
322 cp = _("hard linked somewhere");
325 /* If there were any problems, quit. */
326 if (cp != NULL)
328 __rcmd_errstr = cp;
329 if (res)
330 fclose (res);
331 return NULL;
334 return res;
338 * New .rhosts strategy: We are passed an ip address. We spin through
339 * hosts.equiv and .rhosts looking for a match. When the .rhosts only
340 * has ip addresses, we don't have to trust a nameserver. When it
341 * contains hostnames, we spin through the list of addresses the nameserver
342 * gives us and look for a match.
344 * Returns 0 if ok, -1 if not ok.
346 static int
347 iruserok2 (raddr, superuser, ruser, luser, rhost)
348 u_int32_t raddr;
349 int superuser;
350 const char *ruser, *luser, *rhost;
352 FILE *hostf = NULL;
353 int isbad;
355 if (!superuser)
356 hostf = iruserfopen (_PATH_HEQUIV, 0);
358 if (hostf)
360 isbad = __ivaliduser2 (hostf, raddr, luser, ruser, rhost);
361 fclose (hostf);
363 if (!isbad)
364 return 0;
367 if (__check_rhosts_file || superuser)
369 char *pbuf;
370 struct passwd pwdbuf, *pwd;
371 size_t dirlen;
372 size_t buflen = __sysconf (_SC_GETPW_R_SIZE_MAX);
373 char *buffer = __alloca (buflen);
374 uid_t uid;
376 if (__getpwnam_r (luser, &pwdbuf, buffer, buflen, &pwd))
377 return -1;
379 dirlen = strlen (pwd->pw_dir);
380 pbuf = alloca (dirlen + sizeof "/.rhosts");
381 __mempcpy (__mempcpy (pbuf, pwd->pw_dir, dirlen),
382 "/.rhosts", sizeof "/.rhosts");
384 /* Change effective uid while reading .rhosts. If root and
385 reading an NFS mounted file system, can't read files that
386 are protected read/write owner only. */
387 uid = __geteuid ();
388 seteuid (pwd->pw_uid);
389 hostf = iruserfopen (pbuf, pwd->pw_uid);
391 if (hostf != NULL)
393 isbad = __ivaliduser2 (hostf, raddr, luser, ruser, rhost);
394 fclose (hostf);
397 seteuid (uid);
398 return isbad;
400 return -1;
403 /* This is the exported version. */
405 iruserok (raddr, superuser, ruser, luser)
406 u_int32_t raddr;
407 int superuser;
408 const char *ruser, *luser;
410 return iruserok2 (raddr, superuser, ruser, luser, "-");
414 * XXX
415 * Don't make static, used by lpd(8).
417 * This function is not used anymore. It is only present because lpd(8)
418 * calls it (!?!). We simply call __invaliduser2() with an illegal rhost
419 * argument. This means that netgroups won't work in .rhost/hosts.equiv
420 * files. If you want lpd to work with netgroups, fix lpd to use ruserok()
421 * or PAM.
422 * Returns 0 if ok, -1 if not ok.
425 __ivaliduser(hostf, raddr, luser, ruser)
426 FILE *hostf;
427 u_int32_t raddr;
428 const char *luser, *ruser;
430 return __ivaliduser2(hostf, raddr, luser, ruser, "-");
434 /* Returns 1 on positive match, 0 on no match, -1 on negative match. */
435 static int
436 internal_function
437 __icheckhost (raddr, lhost, rhost)
438 u_int32_t raddr;
439 char *lhost;
440 const char *rhost;
442 struct hostent hostbuf, *hp;
443 size_t buflen;
444 char *buffer;
445 int herr;
446 int save_errno;
447 u_int32_t laddr;
448 int negate=1; /* Multiply return with this to get -1 instead of 1 */
449 char **pp, *user;
451 /* Check nis netgroup. */
452 if (strncmp ("+@", lhost, 2) == 0)
453 return innetgr (&lhost[2], rhost, NULL, NULL);
455 if (strncmp ("-@", lhost, 2) == 0)
456 return -innetgr (&lhost[2], rhost, NULL, NULL);
458 /* -host */
459 if (strncmp ("-", lhost,1) == 0) {
460 negate = -1;
461 lhost++;
462 } else if (strcmp ("+",lhost) == 0) {
463 return 1; /* asking for trouble, but ok.. */
466 /* Try for raw ip address first. */
467 if (isdigit (*lhost) && (long) (laddr = inet_addr (lhost)) != -1)
468 return negate * (! (raddr ^ laddr));
470 /* Better be a hostname. */
471 buflen = 1024;
472 buffer = __alloca (buflen);
473 save_errno = errno;
474 while (__gethostbyname_r (lhost, &hostbuf, buffer, buflen, &hp, &herr)
475 < 0)
476 if (herr != NETDB_INTERNAL || errno != ERANGE)
477 return (0);
478 else {
479 /* Enlarge the buffer. */
480 buflen *= 2;
481 buffer = __alloca (buflen);
482 __set_errno (0);
484 __set_errno (save_errno);
485 if (hp == NULL)
486 return 0;
488 /* Spin through ip addresses. */
489 for (pp = hp->h_addr_list; *pp; ++pp)
490 if (!memcmp (&raddr, *pp, sizeof (u_int32_t)))
491 return negate;
493 /* No match. */
494 return (0);
497 /* Returns 1 on positive match, 0 on no match, -1 on negative match. */
498 static int
499 internal_function
500 __icheckuser (luser, ruser)
501 const char *luser, *ruser;
504 luser is user entry from .rhosts/hosts.equiv file
505 ruser is user id on remote host
507 char *user;
509 /* [-+]@netgroup */
510 if (strncmp ("+@", luser, 2) == 0)
511 return innetgr (&luser[2], NULL, ruser, NULL);
513 if (strncmp ("-@", luser,2) == 0)
514 return -innetgr (&luser[2], NULL, ruser, NULL);
516 /* -user */
517 if (strncmp ("-", luser, 1) == 0)
518 return -(strcmp (&luser[1], ruser) == 0);
520 /* + */
521 if (strcmp ("+", luser) == 0)
522 return 1;
524 /* simple string match */
525 return strcmp (ruser, luser) == 0;
529 * Returns 1 for blank lines (or only comment lines) and 0 otherwise
531 static int
532 __isempty(p)
533 char *p;
535 while (*p && isspace (*p)) {
536 ++p;
539 return (*p == '\0' || *p == '#') ? 1 : 0 ;
543 * Returns 0 if positive match, -1 if _not_ ok.
545 static int
546 __ivaliduser2(hostf, raddr, luser, ruser, rhost)
547 FILE *hostf;
548 u_int32_t raddr;
549 const char *luser, *ruser, *rhost;
551 register const char *user;
552 register char *p;
553 int hcheck, ucheck;
554 char *buf = NULL;
555 size_t bufsize = 0;
556 int retval = -1;
558 while (__getline (&buf, &bufsize, hostf) > 0) {
559 buf[bufsize - 1] = '\0'; /* Make sure it's terminated. */
560 p = buf;
562 /* Skip empty or comment lines */
563 if (__isempty (p)) {
564 continue;
567 /* Skip lines that are too long. */
568 if (strchr (p, '\n') == NULL) {
569 int ch = getc (hostf);
571 while (ch != '\n' && ch != EOF)
572 ch = getc (hostf);
573 continue;
576 for (;*p && !isspace(*p); ++p) {
577 *p = tolower (*p);
580 /* Next we want to find the permitted name for the remote user. */
581 if (*p == ' ' || *p == '\t') {
582 /* <nul> terminate hostname and skip spaces */
583 for (*p++='\0'; *p && isspace (*p); ++p);
585 user = p; /* this is the user's name */
586 while (*p && !isspace (*p))
587 ++p; /* find end of user's name */
588 } else
589 user = p;
591 *p = '\0'; /* <nul> terminate username (+host?) */
593 /* buf -> host(?) ; user -> username(?) */
595 /* First check host part */
596 hcheck = __icheckhost (raddr, buf, rhost);
598 if (hcheck < 0)
599 break;
601 if (hcheck) {
602 /* Then check user part */
603 if (! (*user))
604 user = luser;
606 ucheck = __icheckuser (user, ruser);
608 /* Positive 'host user' match? */
609 if (ucheck > 0) {
610 retval = 0;
611 break;
614 /* Negative 'host -user' match? */
615 if (ucheck < 0)
616 break;
618 /* Neither, go on looking for match */
622 if (buf != NULL)
623 free (buf);
625 return retval;