1 /* 2 * Copyright (c) 1983, 1993, 1994 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. 32 */ 33 34 #if defined(LIBC_SCCS) && !defined(lint) 35 /* from: static char sccsid[] = "@(#)rcmd.c 8.3 (Berkeley) 3/26/94"; */ 36 static char *rcsid = "$Id: rcmd.c,v 1.9 1994/06/01 19:32:43 pk Exp $"; 37 #endif /* LIBC_SCCS and not lint */ 38 39 #include <sys/param.h> 40 #include <sys/socket.h> 41 #include <sys/stat.h> 42 43 #include <netinet/in.h> 44 #include <arpa/inet.h> 45 46 #include <signal.h> 47 #include <fcntl.h> 48 #include <netdb.h> 49 #include <unistd.h> 50 #include <pwd.h> 51 #include <errno.h> 52 #include <stdio.h> 53 #include <ctype.h> 54 #include <string.h> 55 56 int __ivaliduser __P((FILE *, u_long, const char *, const char *)); 57 static int __icheckhost __P((u_long, char *)); 58 59 int 60 rcmd(ahost, rport, locuser, remuser, cmd, fd2p) 61 char **ahost; 62 u_short rport; 63 const char *locuser, *remuser, *cmd; 64 int *fd2p; 65 { 66 struct hostent *hp; 67 struct sockaddr_in sin, from; 68 fd_set reads; 69 long oldmask; 70 pid_t pid; 71 int s, lport, timo; 72 char c; 73 74 pid = getpid(); 75 hp = gethostbyname(*ahost); 76 if (hp == NULL) { 77 herror(*ahost); 78 return (-1); 79 } 80 *ahost = hp->h_name; 81 oldmask = sigblock(sigmask(SIGURG)); 82 for (timo = 1, lport = IPPORT_RESERVED - 1;;) { 83 s = rresvport(&lport); 84 if (s < 0) { 85 if (errno == EAGAIN) 86 (void)fprintf(stderr, 87 "rcmd: socket: All ports in use\n"); 88 else 89 (void)fprintf(stderr, "rcmd: socket: %s\n", 90 strerror(errno)); 91 sigsetmask(oldmask); 92 return (-1); 93 } 94 fcntl(s, F_SETOWN, pid); 95 sin.sin_family = hp->h_addrtype; 96 bcopy(hp->h_addr_list[0], &sin.sin_addr, hp->h_length); 97 sin.sin_port = rport; 98 if (connect(s, (struct sockaddr *)&sin, sizeof(sin)) >= 0) 99 break; 100 (void)close(s); 101 if (errno == EADDRINUSE) { 102 lport--; 103 continue; 104 } 105 if (errno == ECONNREFUSED && timo <= 16) { 106 (void)sleep(timo); 107 timo *= 2; 108 continue; 109 } 110 if (hp->h_addr_list[1] != NULL) { 111 int oerrno = errno; 112 113 (void)fprintf(stderr, "connect to address %s: ", 114 inet_ntoa(sin.sin_addr)); 115 errno = oerrno; 116 perror(0); 117 hp->h_addr_list++; 118 bcopy(hp->h_addr_list[0], &sin.sin_addr, hp->h_length); 119 (void)fprintf(stderr, "Trying %s...\n", 120 inet_ntoa(sin.sin_addr)); 121 continue; 122 } 123 (void)fprintf(stderr, "%s: %s\n", hp->h_name, strerror(errno)); 124 sigsetmask(oldmask); 125 return (-1); 126 } 127 lport--; 128 if (fd2p == 0) { 129 write(s, "", 1); 130 lport = 0; 131 } else { 132 char num[8]; 133 int s2 = rresvport(&lport), s3; 134 int len = sizeof(from); 135 136 if (s2 < 0) 137 goto bad; 138 listen(s2, 1); 139 (void)snprintf(num, sizeof(num), "%d", lport); 140 if (write(s, num, strlen(num)+1) != strlen(num)+1) { 141 (void)fprintf(stderr, 142 "rcmd: write (setting up stderr): %s\n", 143 strerror(errno)); 144 (void)close(s2); 145 goto bad; 146 } 147 FD_ZERO(&reads); 148 FD_SET(s, &reads); 149 FD_SET(s2, &reads); 150 errno = 0; 151 if (select(MAX(s, s2) + 1, &reads, 0, 0, 0) < 1 || 152 !FD_ISSET(s2, &reads)) { 153 if (errno != 0) 154 (void)fprintf(stderr, 155 "rcmd: select (setting up stderr): %s\n", 156 strerror(errno)); 157 else 158 (void)fprintf(stderr, 159 "select: protocol failure in circuit setup\n"); 160 (void)close(s2); 161 goto bad; 162 } 163 s3 = accept(s2, (struct sockaddr *)&from, &len); 164 (void)close(s2); 165 if (s3 < 0) { 166 (void)fprintf(stderr, 167 "rcmd: accept: %s\n", strerror(errno)); 168 lport = 0; 169 goto bad; 170 } 171 *fd2p = s3; 172 from.sin_port = ntohs((u_short)from.sin_port); 173 if (from.sin_family != AF_INET || 174 from.sin_port >= IPPORT_RESERVED || 175 from.sin_port < IPPORT_RESERVED / 2) { 176 (void)fprintf(stderr, 177 "socket: protocol failure in circuit setup.\n"); 178 goto bad2; 179 } 180 } 181 (void)write(s, locuser, strlen(locuser)+1); 182 (void)write(s, remuser, strlen(remuser)+1); 183 (void)write(s, cmd, strlen(cmd)+1); 184 if (read(s, &c, 1) != 1) { 185 (void)fprintf(stderr, 186 "rcmd: %s: %s\n", *ahost, strerror(errno)); 187 goto bad2; 188 } 189 if (c != 0) { 190 while (read(s, &c, 1) == 1) { 191 (void)write(STDERR_FILENO, &c, 1); 192 if (c == '\n') 193 break; 194 } 195 goto bad2; 196 } 197 sigsetmask(oldmask); 198 return (s); 199 bad2: 200 if (lport) 201 (void)close(*fd2p); 202 bad: 203 (void)close(s); 204 sigsetmask(oldmask); 205 return (-1); 206 } 207 208 int 209 rresvport(alport) 210 int *alport; 211 { 212 struct sockaddr_in sin; 213 int s; 214 215 sin.sin_family = AF_INET; 216 sin.sin_addr.s_addr = INADDR_ANY; 217 s = socket(AF_INET, SOCK_STREAM, 0); 218 if (s < 0) 219 return (-1); 220 for (;;) { 221 sin.sin_port = htons((u_short)*alport); 222 if (bind(s, (struct sockaddr *)&sin, sizeof(sin)) >= 0) 223 return (s); 224 if (errno != EADDRINUSE) { 225 (void)close(s); 226 return (-1); 227 } 228 (*alport)--; 229 if (*alport == IPPORT_RESERVED/2) { 230 (void)close(s); 231 errno = EAGAIN; /* close */ 232 return (-1); 233 } 234 } 235 } 236 237 int __check_rhosts_file = 1; 238 char *__rcmd_errstr; 239 240 int 241 ruserok(rhost, superuser, ruser, luser) 242 const char *rhost, *ruser, *luser; 243 int superuser; 244 { 245 struct hostent *hp; 246 char **ap; 247 int i; 248 #define MAXADDRS 35 249 u_long addrs[MAXADDRS + 1]; 250 251 if ((hp = gethostbyname(rhost)) == NULL) 252 return (-1); 253 for (i = 0, ap = hp->h_addr_list; *ap && i < MAXADDRS; ++ap, ++i) 254 bcopy(*ap, &addrs[i], sizeof(addrs[i])); 255 addrs[i] = 0; 256 257 for (i = 0; i < MAXADDRS && addrs[i]; i++) 258 if (iruserok(addrs[i], superuser, ruser, luser) == 0) 259 return (0); 260 return (-1); 261 } 262 263 /* 264 * New .rhosts strategy: We are passed an ip address. We spin through 265 * hosts.equiv and .rhosts looking for a match. When the .rhosts only 266 * has ip addresses, we don't have to trust a nameserver. When it 267 * contains hostnames, we spin through the list of addresses the nameserver 268 * gives us and look for a match. 269 * 270 * Returns 0 if ok, -1 if not ok. 271 */ 272 int 273 iruserok(raddr, superuser, ruser, luser) 274 u_long raddr; 275 int superuser; 276 const char *ruser, *luser; 277 { 278 register char *cp; 279 struct stat sbuf; 280 struct passwd *pwd; 281 FILE *hostf; 282 uid_t uid; 283 int first; 284 char pbuf[MAXPATHLEN]; 285 286 first = 1; 287 hostf = superuser ? NULL : fopen(_PATH_HEQUIV, "r"); 288 again: 289 if (hostf) { 290 if (__ivaliduser(hostf, raddr, luser, ruser) == 0) { 291 (void)fclose(hostf); 292 return (0); 293 } 294 (void)fclose(hostf); 295 } 296 if (first == 1 && (__check_rhosts_file || superuser)) { 297 first = 0; 298 if ((pwd = getpwnam(luser)) == NULL) 299 return (-1); 300 (void)strcpy(pbuf, pwd->pw_dir); 301 (void)strcat(pbuf, "/.rhosts"); 302 303 /* 304 * Change effective uid while opening .rhosts. If root and 305 * reading an NFS mounted file system, can't read files that 306 * are protected read/write owner only. 307 */ 308 uid = geteuid(); 309 (void)seteuid(pwd->pw_uid); 310 hostf = fopen(pbuf, "r"); 311 (void)seteuid(uid); 312 313 if (hostf == NULL) 314 return (-1); 315 /* 316 * If not a regular file, or is owned by someone other than 317 * user or root or if writeable by anyone but the owner, quit. 318 */ 319 cp = NULL; 320 if (lstat(pbuf, &sbuf) < 0) 321 cp = ".rhosts lstat failed"; 322 else if (!S_ISREG(sbuf.st_mode)) 323 cp = ".rhosts not regular file"; 324 else if (fstat(fileno(hostf), &sbuf) < 0) 325 cp = ".rhosts fstat failed"; 326 else if (sbuf.st_uid && sbuf.st_uid != pwd->pw_uid) 327 cp = "bad .rhosts owner"; 328 else if (sbuf.st_mode & (S_IWGRP|S_IWOTH)) 329 cp = ".rhosts writeable by other than owner"; 330 /* If there were any problems, quit. */ 331 if (cp) { 332 __rcmd_errstr = cp; 333 (void)fclose(hostf); 334 return (-1); 335 } 336 goto again; 337 } 338 return (-1); 339 } 340 341 /* 342 * XXX 343 * Don't make static, used by lpd(8). 344 * 345 * Returns 0 if ok, -1 if not ok. 346 */ 347 int 348 __ivaliduser(hostf, raddr, luser, ruser) 349 FILE *hostf; 350 u_long raddr; 351 const char *luser, *ruser; 352 { 353 register char *user, *p; 354 int ch; 355 char buf[MAXHOSTNAMELEN + 128]; /* host + login */ 356 357 while (fgets(buf, sizeof(buf), hostf)) { 358 p = buf; 359 /* Skip lines that are too long. */ 360 if (strchr(p, '\n') == NULL) { 361 while ((ch = getc(hostf)) != '\n' && ch != EOF); 362 continue; 363 } 364 while (*p != '\n' && *p != ' ' && *p != '\t' && *p != '\0') { 365 *p = isupper(*p) ? tolower(*p) : *p; 366 p++; 367 } 368 if (*p == ' ' || *p == '\t') { 369 *p++ = '\0'; 370 while (*p == ' ' || *p == '\t') 371 p++; 372 user = p; 373 while (*p != '\n' && *p != ' ' && 374 *p != '\t' && *p != '\0') 375 p++; 376 } else 377 user = p; 378 *p = '\0'; 379 if (p == buf) 380 continue; 381 if (__icheckhost(raddr, buf) && 382 strcmp(ruser, *user ? user : luser) == 0) { 383 return (0); 384 } 385 } 386 return (-1); 387 } 388 389 /* 390 * Returns "true" if match, 0 if no match. 391 */ 392 static int 393 __icheckhost(raddr, lhost) 394 u_long raddr; 395 register char *lhost; 396 { 397 register struct hostent *hp; 398 register u_long laddr; 399 register char **pp; 400 401 /* Try for raw ip address first. */ 402 if (isdigit(*lhost) && (long)(laddr = inet_addr(lhost)) != -1) 403 return (raddr == laddr); 404 405 /* Better be a hostname. */ 406 if ((hp = gethostbyname(lhost)) == NULL) 407 return (0); 408 409 /* Spin through ip addresses. */ 410 for (pp = hp->h_addr_list; *pp; ++pp) 411 if (!bcmp(&raddr, *pp, sizeof(u_long))) 412 return (1); 413 414 /* No match. */ 415 return (0); 416 } 417