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