1 /* 2 * Copyright (c) 1983 Regents of the University of California. 3 * All rights reserved. 4 * 5 * %sccs.include.redist.c% 6 */ 7 8 #if defined(LIBC_SCCS) && !defined(lint) 9 static char sccsid[] = "@(#)rcmd.c 5.25 (Berkeley) 06/30/92"; 10 #endif /* LIBC_SCCS and not lint */ 11 12 #include <sys/param.h> 13 #include <sys/socket.h> 14 #include <sys/stat.h> 15 16 #include <netinet/in.h> 17 #include <arpa/inet.h> 18 19 #include <signal.h> 20 #include <fcntl.h> 21 #include <netdb.h> 22 #include <unistd.h> 23 #include <pwd.h> 24 #include <errno.h> 25 #include <stdio.h> 26 #include <ctype.h> 27 #include <string.h> 28 29 int __ivaliduser __P((FILE *, u_long, const char *, const char *)); 30 static int __icheckhost __P((u_long, char *)); 31 32 int 33 rcmd(ahost, rport, locuser, remuser, cmd, fd2p) 34 char **ahost; 35 u_short rport; 36 const char *locuser, *remuser, *cmd; 37 int *fd2p; 38 { 39 struct hostent *hp; 40 struct sockaddr_in sin, from; 41 fd_set reads; 42 long oldmask; 43 int s, lport, pid, timo; 44 char c; 45 46 pid = getpid(); 47 hp = gethostbyname(*ahost); 48 if (hp == NULL) { 49 herror(*ahost); 50 return (-1); 51 } 52 *ahost = hp->h_name; 53 oldmask = sigblock(sigmask(SIGURG)); 54 for (timo = 1, lport = IPPORT_RESERVED - 1;;) { 55 s = rresvport(&lport); 56 if (s < 0) { 57 if (errno == EAGAIN) 58 (void)fprintf(stderr, 59 "rcmd: socket: All ports in use\n"); 60 else 61 (void)fprintf(stderr, "rcmd: socket: %s\n", 62 strerror(errno)); 63 sigsetmask(oldmask); 64 return (-1); 65 } 66 fcntl(s, F_SETOWN, pid); 67 sin.sin_family = hp->h_addrtype; 68 bcopy(hp->h_addr_list[0], &sin.sin_addr, hp->h_length); 69 sin.sin_port = rport; 70 if (connect(s, (struct sockaddr *)&sin, sizeof(sin)) >= 0) 71 break; 72 (void)close(s); 73 if (errno == EADDRINUSE) { 74 lport--; 75 continue; 76 } 77 if (errno == ECONNREFUSED && timo <= 16) { 78 (void)sleep(timo); 79 timo *= 2; 80 continue; 81 } 82 if (hp->h_addr_list[1] != NULL) { 83 int oerrno = errno; 84 85 (void)fprintf(stderr, "connect to address %s: ", 86 inet_ntoa(sin.sin_addr)); 87 errno = oerrno; 88 perror(0); 89 hp->h_addr_list++; 90 bcopy(hp->h_addr_list[0], &sin.sin_addr, hp->h_length); 91 (void)fprintf(stderr, "Trying %s...\n", 92 inet_ntoa(sin.sin_addr)); 93 continue; 94 } 95 (void)fprintf(stderr, "%s: %s\n", hp->h_name, strerror(errno)); 96 sigsetmask(oldmask); 97 return (-1); 98 } 99 lport--; 100 if (fd2p == 0) { 101 write(s, "", 1); 102 lport = 0; 103 } else { 104 char num[8]; 105 int s2 = rresvport(&lport), s3; 106 int len = sizeof(from); 107 108 if (s2 < 0) 109 goto bad; 110 listen(s2, 1); 111 (void)snprintf(num, sizeof(num), "%d", lport); 112 if (write(s, num, strlen(num)+1) != strlen(num)+1) { 113 (void)fprintf(stderr, 114 "rcmd: write (setting up stderr): %s\n", 115 strerror(errno)); 116 (void)close(s2); 117 goto bad; 118 } 119 FD_ZERO(&reads); 120 FD_SET(s, &reads); 121 FD_SET(s2, &reads); 122 errno = 0; 123 if (select(32, &reads, 0, 0, 0) < 1 || !FD_ISSET(s2, &reads)) { 124 if (errno != 0) 125 (void)fprintf(stderr, 126 "rcmd: select (setting up stderr): %s\n", 127 strerror(errno)); 128 else 129 (void)fprintf(stderr, 130 "select: protocol failure in circuit setup\n"); 131 (void)close(s2); 132 goto bad; 133 } 134 s3 = accept(s2, (struct sockaddr *)&from, &len); 135 (void)close(s2); 136 if (s3 < 0) { 137 (void)fprintf(stderr, 138 "rcmd: accept: %s\n", strerror(errno)); 139 lport = 0; 140 goto bad; 141 } 142 *fd2p = s3; 143 from.sin_port = ntohs((u_short)from.sin_port); 144 if (from.sin_family != AF_INET || 145 from.sin_port >= IPPORT_RESERVED || 146 from.sin_port < IPPORT_RESERVED / 2) { 147 (void)fprintf(stderr, 148 "socket: protocol failure in circuit setup.\n"); 149 goto bad2; 150 } 151 } 152 (void)write(s, locuser, strlen(locuser)+1); 153 (void)write(s, remuser, strlen(remuser)+1); 154 (void)write(s, cmd, strlen(cmd)+1); 155 if (read(s, &c, 1) != 1) { 156 (void)fprintf(stderr, 157 "rcmd: %s: %s\n", *ahost, strerror(errno)); 158 goto bad2; 159 } 160 if (c != 0) { 161 while (read(s, &c, 1) == 1) { 162 (void) write(2, &c, 1); 163 if (c == '\n') 164 break; 165 } 166 goto bad2; 167 } 168 sigsetmask(oldmask); 169 return (s); 170 bad2: 171 if (lport) 172 (void)close(*fd2p); 173 bad: 174 (void)close(s); 175 sigsetmask(oldmask); 176 return (-1); 177 } 178 179 int 180 rresvport(alport) 181 int *alport; 182 { 183 struct sockaddr_in sin; 184 int s; 185 186 sin.sin_family = AF_INET; 187 sin.sin_addr.s_addr = INADDR_ANY; 188 s = socket(AF_INET, SOCK_STREAM, 0); 189 if (s < 0) 190 return (-1); 191 for (;;) { 192 sin.sin_port = htons((u_short)*alport); 193 if (bind(s, (struct sockaddr *)&sin, sizeof (sin)) >= 0) 194 return (s); 195 if (errno != EADDRINUSE) { 196 (void)close(s); 197 return (-1); 198 } 199 (*alport)--; 200 if (*alport == IPPORT_RESERVED/2) { 201 (void)close(s); 202 errno = EAGAIN; /* close */ 203 return (-1); 204 } 205 } 206 } 207 208 int __check_rhosts_file = 1; 209 char *__rcmd_errstr; 210 211 int 212 ruserok(rhost, superuser, ruser, luser) 213 const char *rhost, *ruser, *luser; 214 int superuser; 215 { 216 struct hostent *hp; 217 u_long addr; 218 char **ap; 219 220 if ((hp = gethostbyname(rhost)) == NULL) 221 return (-1); 222 for (ap = hp->h_addr_list; *ap; ++ap) { 223 bcopy(*ap, &addr, sizeof(addr)); 224 if (iruserok(addr, superuser, ruser, luser) == 0) 225 return (0); 226 } 227 return (-1); 228 } 229 230 /* 231 * New .rhosts strategy: We are passed an ip address. We spin through 232 * hosts.equiv and .rhosts looking for a match. When the .rhosts only 233 * has ip addresses, we don't have to trust a nameserver. When it 234 * contains hostnames, we spin through the list of addresses the nameserver 235 * gives us and look for a match. 236 * 237 * Returns 0 if ok, -1 if not ok. 238 */ 239 int 240 iruserok(raddr, superuser, ruser, luser) 241 u_long raddr; 242 int superuser; 243 const char *ruser, *luser; 244 { 245 FILE *hostf; 246 uid_t uid; 247 int first; 248 249 first = 1; 250 hostf = superuser ? NULL : fopen(_PATH_HEQUIV, "r"); 251 again: 252 if (hostf) { 253 if (__ivaliduser(hostf, raddr, luser, ruser) == 0) { 254 (void)fclose(hostf); 255 return (0); 256 } 257 (void)fclose(hostf); 258 } 259 if (first == 1 && (__check_rhosts_file || superuser)) { 260 struct stat sbuf; 261 struct passwd *pwd; 262 char pbuf[MAXPATHLEN]; 263 264 first = 0; 265 if ((pwd = getpwnam(luser)) == NULL) 266 return (-1); 267 (void)strcpy(pbuf, pwd->pw_dir); 268 (void)strcat(pbuf, "/.rhosts"); 269 270 /* 271 * Change effective uid while opening .rhosts. If root and 272 * reading an NFS mounted file system, can't read files that 273 * are protected read/write owner only. 274 */ 275 uid = geteuid(); 276 (void)seteuid(pwd->pw_uid); 277 hostf = fopen(pbuf, "r"); 278 (void)seteuid(uid); 279 280 if (hostf == NULL) 281 return (-1); 282 /* 283 * If not a regular file, or is owned by someone other than 284 * user or root or if writeable by anyone but the owner, quit. 285 */ 286 if (lstat(pbuf, &sbuf) < 0) 287 __rcmd_errstr = ".rhosts lstat failed"; 288 else if ((sbuf.st_mode & S_IFMT) != S_IFREG) 289 __rcmd_errstr = ".rhosts not regular file"; 290 else if (fstat(fileno(hostf), &sbuf) < 0) 291 __rcmd_errstr = ".rhosts fstat failed"; 292 else if (sbuf.st_uid && sbuf.st_uid != pwd->pw_uid) 293 __rcmd_errstr = "bad .rhosts owner"; 294 else if (sbuf.st_mode & 022) 295 __rcmd_errstr = "bad .rhosts permissions"; 296 /* If there were any problems, quit. */ 297 if (__rcmd_errstr) { 298 (void)fclose(hostf); 299 return (-1); 300 } 301 goto again; 302 } 303 return (-1); 304 } 305 306 /* 307 * XXX 308 * Don't make static, used by lpd(8). 309 * 310 * Returns 0 if ok, -1 if not ok. 311 */ 312 int 313 __ivaliduser(hostf, raddr, luser, ruser) 314 FILE *hostf; 315 u_long raddr; 316 const char *luser, *ruser; 317 { 318 register char *user, *p; 319 char ahost[MAXHOSTNAMELEN]; 320 321 while (fgets(ahost, sizeof(ahost), hostf)) { 322 p = ahost; 323 while (*p != '\n' && *p != ' ' && *p != '\t' && *p != '\0') { 324 *p = isupper(*p) ? tolower(*p) : *p; 325 p++; 326 } 327 if (*p == ' ' || *p == '\t') { 328 *p++ = '\0'; 329 while (*p == ' ' || *p == '\t') 330 p++; 331 user = p; 332 while (*p != '\n' && *p != ' ' && 333 *p != '\t' && *p != '\0') 334 p++; 335 } else 336 user = p; 337 *p = '\0'; 338 if (__icheckhost(raddr, ahost) && 339 strcmp(ruser, *user ? user : luser) == 0) { 340 return (0); 341 } 342 } 343 return (-1); 344 } 345 346 /* 347 * Returns "true" if match, 0 if no match. 348 */ 349 static int 350 __icheckhost(raddr, lhost) 351 u_long raddr; 352 register char *lhost; 353 { 354 register struct hostent *hp; 355 register u_long laddr; 356 register char **pp; 357 358 /* Try for raw ip address first. */ 359 if (isdigit(*lhost) && (long)(laddr = inet_addr(lhost)) != -1) 360 return (raddr == laddr); 361 362 /* Better be a hostname. */ 363 if ((hp = gethostbyname(lhost)) == NULL) 364 return (0); 365 366 /* Spin through ip addresses. */ 367 for (pp = hp->h_addr_list; *pp; ++pp) 368 if (!bcmp(&raddr, *pp, sizeof(u_long))) 369 return (1); 370 371 /* No match. */ 372 return (0); 373 } 374