1 /* 2 * Copyright (c) 1983 Regents of the University of California. 3 * 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 = "from: @(#)rcmd.c 5.24 (Berkeley) 2/24/91";*/ 36 static char *rcsid = "$Id: rcmd.c,v 1.4 1993/12/05 14:42:26 deraadt 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 #include <netinet/in.h> 43 #include <arpa/inet.h> 44 #include <signal.h> 45 #include <fcntl.h> 46 #include <netdb.h> 47 #include <pwd.h> 48 #include <errno.h> 49 #include <stdio.h> 50 #include <ctype.h> 51 #include <unistd.h> 52 #include <string.h> 53 54 rcmd(ahost, rport, locuser, remuser, cmd, fd2p) 55 char **ahost; 56 u_short rport; 57 const char *locuser, *remuser, *cmd; 58 int *fd2p; 59 { 60 int s, timo = 1, pid; 61 long oldmask; 62 struct sockaddr_in sin, from; 63 char c; 64 int lport = IPPORT_RESERVED - 1; 65 struct hostent *hp; 66 fd_set reads; 67 68 pid = getpid(); 69 hp = gethostbyname(*ahost); 70 if (hp == 0) { 71 herror(*ahost); 72 return (-1); 73 } 74 *ahost = hp->h_name; 75 oldmask = sigblock(sigmask(SIGURG)); 76 for (;;) { 77 s = rresvport(&lport); 78 if (s < 0) { 79 if (errno == EAGAIN) 80 fprintf(stderr, "socket: All ports in use\n"); 81 else 82 perror("rcmd: socket"); 83 sigsetmask(oldmask); 84 return (-1); 85 } 86 fcntl(s, F_SETOWN, pid); 87 bzero((char *)&sin, sizeof sin); 88 sin.sin_family = hp->h_addrtype; 89 bcopy(hp->h_addr_list[0], (caddr_t)&sin.sin_addr, hp->h_length); 90 sin.sin_port = rport; 91 if (connect(s, (struct sockaddr *)&sin, sizeof(sin)) >= 0) 92 break; 93 (void) close(s); 94 if (errno == EADDRINUSE) { 95 lport--; 96 continue; 97 } 98 if (errno == ECONNREFUSED && timo <= 16) { 99 sleep(timo); 100 timo *= 2; 101 continue; 102 } 103 if (hp->h_addr_list[1] != NULL) { 104 int oerrno = errno; 105 106 fprintf(stderr, 107 "connect to address %s: ", inet_ntoa(sin.sin_addr)); 108 errno = oerrno; 109 perror(0); 110 hp->h_addr_list++; 111 bcopy(hp->h_addr_list[0], (caddr_t)&sin.sin_addr, 112 hp->h_length); 113 fprintf(stderr, "Trying %s...\n", 114 inet_ntoa(sin.sin_addr)); 115 continue; 116 } 117 perror(hp->h_name); 118 sigsetmask(oldmask); 119 return (-1); 120 } 121 lport--; 122 if (fd2p == 0) { 123 write(s, "", 1); 124 lport = 0; 125 } else { 126 char num[8]; 127 int s2 = rresvport(&lport), s3; 128 int len = sizeof (from); 129 130 if (s2 < 0) 131 goto bad; 132 listen(s2, 1); 133 (void) sprintf(num, "%d", lport); 134 if (write(s, num, strlen(num)+1) != strlen(num)+1) { 135 perror("write: setting up stderr"); 136 (void) close(s2); 137 goto bad; 138 } 139 FD_ZERO(&reads); 140 FD_SET(s, &reads); 141 FD_SET(s2, &reads); 142 errno = 0; 143 if (select(32, &reads, 0, 0, 0) < 1 || 144 !FD_ISSET(s2, &reads)) { 145 if (errno != 0) 146 perror("select: setting up stderr"); 147 else 148 fprintf(stderr, 149 "select: protocol failure in circuit setup.\n"); 150 (void) close(s2); 151 goto bad; 152 } 153 s3 = accept(s2, (struct sockaddr *)&from, &len); 154 (void) close(s2); 155 if (s3 < 0) { 156 perror("accept"); 157 lport = 0; 158 goto bad; 159 } 160 *fd2p = s3; 161 from.sin_port = ntohs((u_short)from.sin_port); 162 if (from.sin_family != AF_INET || 163 from.sin_port >= IPPORT_RESERVED || 164 from.sin_port < IPPORT_RESERVED / 2) { 165 fprintf(stderr, 166 "socket: protocol failure in circuit setup.\n"); 167 goto bad2; 168 } 169 } 170 (void) write(s, locuser, strlen(locuser)+1); 171 (void) write(s, remuser, strlen(remuser)+1); 172 (void) write(s, cmd, strlen(cmd)+1); 173 if (read(s, &c, 1) != 1) { 174 perror(*ahost); 175 goto bad2; 176 } 177 if (c != 0) { 178 while (read(s, &c, 1) == 1) { 179 (void) write(2, &c, 1); 180 if (c == '\n') 181 break; 182 } 183 goto bad2; 184 } 185 sigsetmask(oldmask); 186 return (s); 187 bad2: 188 if (lport) 189 (void) close(*fd2p); 190 bad: 191 (void) close(s); 192 sigsetmask(oldmask); 193 return (-1); 194 } 195 196 rresvport(alport) 197 int *alport; 198 { 199 struct sockaddr_in sin; 200 int s; 201 202 sin.sin_family = AF_INET; 203 sin.sin_addr.s_addr = INADDR_ANY; 204 s = socket(AF_INET, SOCK_STREAM, 0); 205 if (s < 0) 206 return (-1); 207 for (;;) { 208 sin.sin_port = htons((u_short)*alport); 209 if (bind(s, (struct sockaddr *)&sin, sizeof (sin)) >= 0) 210 return (s); 211 if (errno != EADDRINUSE) { 212 (void) close(s); 213 return (-1); 214 } 215 (*alport)--; 216 if (*alport == IPPORT_RESERVED/2) { 217 (void) close(s); 218 errno = EAGAIN; /* close */ 219 return (-1); 220 } 221 } 222 } 223 224 int _check_rhosts_file = 1; 225 226 ruserok(rhost, superuser, ruser, luser) 227 const char *rhost, *ruser, *luser; 228 int superuser; 229 { 230 FILE *hostf; 231 char fhost[MAXHOSTNAMELEN]; 232 int first = 1; 233 register char *sp, *p; 234 int baselen = -1; 235 236 sp = (char *)rhost; 237 p = fhost; 238 while (*sp) { 239 if (*sp == '.') { 240 if (baselen == -1) 241 baselen = sp - rhost; 242 *p++ = *sp++; 243 } else { 244 *p++ = isupper(*sp) ? tolower(*sp++) : *sp++; 245 } 246 } 247 *p = '\0'; 248 hostf = superuser ? (FILE *)0 : fopen(_PATH_HEQUIV, "r"); 249 again: 250 if (hostf) { 251 if (!_validuser(hostf, fhost, luser, ruser, baselen)) { 252 (void) fclose(hostf); 253 return(0); 254 } 255 (void) fclose(hostf); 256 } 257 if (first == 1 && (_check_rhosts_file || superuser)) { 258 struct stat sbuf; 259 struct passwd *pwd; 260 char pbuf[MAXPATHLEN]; 261 262 first = 0; 263 if ((pwd = getpwnam(luser)) == NULL) 264 return(-1); 265 (void)strcpy(pbuf, pwd->pw_dir); 266 (void)strcat(pbuf, "/.rhosts"); 267 if ((hostf = fopen(pbuf, "r")) == NULL) 268 return(-1); 269 /* 270 * if owned by someone other than user or root or if 271 * writeable by anyone but the owner, quit 272 */ 273 if (fstat(fileno(hostf), &sbuf) || 274 sbuf.st_uid && sbuf.st_uid != pwd->pw_uid || 275 sbuf.st_mode&022) { 276 fclose(hostf); 277 return(-1); 278 } 279 goto again; 280 } 281 return (-1); 282 } 283 284 /* don't make static, used by lpd(8) */ 285 _validuser(hostf, rhost, luser, ruser, baselen) 286 char *rhost, *luser, *ruser; 287 FILE *hostf; 288 int baselen; 289 { 290 register char *p; 291 char *user, ahost[MAXHOSTNAMELEN]; 292 static int _checkhost(); 293 294 while (fgets(ahost, sizeof (ahost), hostf)) { 295 p = ahost; 296 while (*p != '\n' && *p != ' ' && *p != '\t' && *p != '\0') { 297 *p = isupper(*p) ? tolower(*p) : *p; 298 p++; 299 } 300 if (*p == ' ' || *p == '\t') { 301 *p++ = '\0'; 302 while (*p == ' ' || *p == '\t') 303 p++; 304 user = p; 305 while (*p != '\n' && *p != ' ' && *p != '\t' && *p != '\0') 306 p++; 307 } else 308 user = p; 309 *p = '\0'; 310 if (_checkhost(rhost, ahost, baselen) && 311 !strcmp(ruser, *user ? user : luser)) { 312 return (0); 313 } 314 } 315 return (-1); 316 } 317 318 static 319 _checkhost(rhost, lhost, len) 320 char *rhost, *lhost; 321 int len; 322 { 323 static char ldomain[MAXHOSTNAMELEN + 1]; 324 static char *domainp = NULL; 325 static int nodomain = 0; 326 register char *cp; 327 328 if (len == -1) 329 return(!strcmp(rhost, lhost)); 330 if (strncmp(rhost, lhost, len)) 331 return(0); 332 if (!strcmp(rhost, lhost)) 333 return(1); 334 if (*(lhost + len) != '\0') 335 return(0); 336 if (nodomain) 337 return(0); 338 if (!domainp) { 339 if (gethostname(ldomain, sizeof(ldomain)) == -1) { 340 nodomain = 1; 341 return(0); 342 } 343 ldomain[MAXHOSTNAMELEN] = NULL; 344 if ((domainp = index(ldomain, '.')) == (char *)NULL) { 345 nodomain = 1; 346 return(0); 347 } 348 for (cp = ++domainp; *cp; ++cp) 349 if (isupper(*cp)) 350 *cp = tolower(*cp); 351 } 352 return(!strcmp(domainp, rhost + len +1)); 353 } 354