35 36#include "namespace.h" 37#include <sys/param.h> 38#include <sys/socket.h> 39#include <sys/stat.h> 40 41#include <netinet/in.h> 42#include <arpa/inet.h> 43 44#include <signal.h> 45#include <fcntl.h> 46#include <netdb.h> 47#include <stdlib.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#include <rpc/rpc.h> 55#ifdef YP 56#include <rpcsvc/yp_prot.h> 57#include <rpcsvc/ypclnt.h> 58#endif 59#include <arpa/nameser.h> 60#include "un-namespace.h" 61 62extern int innetgr( const char *, const char *, const char *, const char * ); 63 64#define max(a, b) ((a > b) ? a : b) 65 66int __ivaliduser(FILE *, u_int32_t, const char *, const char *); 67int __ivaliduser_af(FILE *,const void *, const char *, const char *, int, int); 68int __ivaliduser_sa(FILE *, const struct sockaddr *, socklen_t, const char *, 69 const char *); 70static int __icheckhost(const struct sockaddr *, socklen_t, const char *); 71 72char paddr[NI_MAXHOST]; 73 74int 75rcmd(ahost, rport, locuser, remuser, cmd, fd2p) 76 char **ahost; 77 u_short rport; 78 const char *locuser, *remuser, *cmd; 79 int *fd2p; 80{ 81 return rcmd_af(ahost, rport, locuser, remuser, cmd, fd2p, AF_INET); 82} 83 84int 85rcmd_af(ahost, rport, locuser, remuser, cmd, fd2p, af) 86 char **ahost; 87 u_short rport; 88 const char *locuser, *remuser, *cmd; 89 int *fd2p; 90 int af; 91{ 92 struct addrinfo hints, *res, *ai; 93 struct sockaddr_storage from; 94 fd_set reads; 95 sigset_t oldmask, newmask; 96 pid_t pid; 97 int s, aport, lport, timo, error; 98 char c, *p; 99 int refused, nres; 100 char num[8]; 101 static char canonnamebuf[MAXDNAME]; /* is it proper here? */ 102 103 /* call rcmdsh() with specified remote shell if appropriate. */ 104 if (!issetugid() && (p = getenv("RSH"))) { 105 struct servent *sp = getservbyname("shell", "tcp"); 106 107 if (sp && sp->s_port == rport) 108 return (rcmdsh(ahost, rport, locuser, remuser, 109 cmd, p)); 110 } 111 112 /* use rsh(1) if non-root and remote port is shell. */ 113 if (geteuid()) { 114 struct servent *sp = getservbyname("shell", "tcp"); 115 116 if (sp && sp->s_port == rport) 117 return (rcmdsh(ahost, rport, locuser, remuser, 118 cmd, NULL)); 119 } 120 121 pid = getpid(); 122 123 memset(&hints, 0, sizeof(hints)); 124 hints.ai_flags = AI_CANONNAME; 125 hints.ai_family = af; 126 hints.ai_socktype = SOCK_STREAM; 127 hints.ai_protocol = 0; 128 (void)snprintf(num, sizeof(num), "%d", ntohs(rport)); 129 error = getaddrinfo(*ahost, num, &hints, &res); 130 if (error) { 131 fprintf(stderr, "rcmd: getaddrinfo: %s\n", 132 gai_strerror(error)); 133 if (error == EAI_SYSTEM) 134 fprintf(stderr, "rcmd: getaddrinfo: %s\n", 135 strerror(errno)); 136 return (-1); 137 } 138 139 if (res->ai_canonname 140 && strlen(res->ai_canonname) + 1 < sizeof(canonnamebuf)) { 141 strncpy(canonnamebuf, res->ai_canonname, sizeof(canonnamebuf)); 142 *ahost = canonnamebuf; 143 } 144 nres = 0; 145 for (ai = res; ai; ai = ai->ai_next) 146 nres++; 147 ai = res; 148 refused = 0; 149 sigemptyset(&newmask); 150 sigaddset(&newmask, SIGURG); 151 _sigprocmask(SIG_BLOCK, (const sigset_t *)&newmask, &oldmask); 152 for (timo = 1, lport = IPPORT_RESERVED - 1;;) { 153 s = rresvport_af(&lport, ai->ai_family); 154 if (s < 0) { 155 if (errno != EAGAIN && ai->ai_next) { 156 ai = ai->ai_next; 157 continue; 158 } 159 if (errno == EAGAIN) 160 (void)fprintf(stderr, 161 "rcmd: socket: All ports in use\n"); 162 else 163 (void)fprintf(stderr, "rcmd: socket: %s\n", 164 strerror(errno)); 165 freeaddrinfo(res); 166 _sigprocmask(SIG_SETMASK, (const sigset_t *)&oldmask, 167 NULL); 168 return (-1); 169 } 170 _fcntl(s, F_SETOWN, pid); 171 if (_connect(s, ai->ai_addr, ai->ai_addrlen) >= 0) 172 break; 173 (void)_close(s); 174 if (errno == EADDRINUSE) { 175 lport--; 176 continue; 177 } 178 if (errno == ECONNREFUSED) 179 refused = 1; 180 if (ai->ai_next == NULL && (!refused || timo > 16)) { 181 (void)fprintf(stderr, "%s: %s\n", 182 *ahost, strerror(errno)); 183 freeaddrinfo(res); 184 _sigprocmask(SIG_SETMASK, (const sigset_t *)&oldmask, 185 NULL); 186 return (-1); 187 } 188 if (nres > 1) { 189 int oerrno = errno; 190 191 getnameinfo(ai->ai_addr, ai->ai_addrlen, paddr, 192 sizeof(paddr), NULL, 0, NI_NUMERICHOST); 193 (void)fprintf(stderr, "connect to address %s: ", 194 paddr); 195 errno = oerrno; 196 perror(0); 197 } 198 if ((ai = ai->ai_next) == NULL) { 199 /* refused && timo <= 16 */ 200 struct timespec time_to_sleep, time_remaining; 201 202 time_to_sleep.tv_sec = timo; 203 time_to_sleep.tv_nsec = 0; 204 (void)_nanosleep(&time_to_sleep, &time_remaining); 205 timo *= 2; 206 ai = res; 207 refused = 0; 208 } 209 if (nres > 1) { 210 getnameinfo(ai->ai_addr, ai->ai_addrlen, paddr, 211 sizeof(paddr), NULL, 0, NI_NUMERICHOST); 212 fprintf(stderr, "Trying %s...\n", paddr); 213 } 214 } 215 lport--; 216 if (fd2p == 0) { 217 _write(s, "", 1); 218 lport = 0; 219 } else { 220 int s2 = rresvport_af(&lport, ai->ai_family), s3; 221 socklen_t len = ai->ai_addrlen; 222 int nfds; 223 224 if (s2 < 0) 225 goto bad; 226 _listen(s2, 1); 227 (void)snprintf(num, sizeof(num), "%d", lport); 228 if (_write(s, num, strlen(num)+1) != strlen(num)+1) { 229 (void)fprintf(stderr, 230 "rcmd: write (setting up stderr): %s\n", 231 strerror(errno)); 232 (void)_close(s2); 233 goto bad; 234 } 235 nfds = max(s, s2)+1; 236 if(nfds > FD_SETSIZE) { 237 fprintf(stderr, "rcmd: too many files\n"); 238 (void)_close(s2); 239 goto bad; 240 } 241again: 242 FD_ZERO(&reads); 243 FD_SET(s, &reads); 244 FD_SET(s2, &reads); 245 errno = 0; 246 if (_select(nfds, &reads, 0, 0, 0) < 1 || !FD_ISSET(s2, &reads)){ 247 if (errno != 0) 248 (void)fprintf(stderr, 249 "rcmd: select (setting up stderr): %s\n", 250 strerror(errno)); 251 else 252 (void)fprintf(stderr, 253 "select: protocol failure in circuit setup\n"); 254 (void)_close(s2); 255 goto bad; 256 } 257 s3 = _accept(s2, (struct sockaddr *)&from, &len); 258 switch (from.ss_family) { 259 case AF_INET: 260 aport = ntohs(((struct sockaddr_in *)&from)->sin_port); 261 break; 262#ifdef INET6 263 case AF_INET6: 264 aport = ntohs(((struct sockaddr_in6 *)&from)->sin6_port); 265 break; 266#endif 267 default: 268 aport = 0; /* error */ 269 break; 270 } 271 /* 272 * XXX careful for ftp bounce attacks. If discovered, shut them 273 * down and check for the real auxiliary channel to connect. 274 */ 275 if (aport == 20) { 276 _close(s3); 277 goto again; 278 } 279 (void)_close(s2); 280 if (s3 < 0) { 281 (void)fprintf(stderr, 282 "rcmd: accept: %s\n", strerror(errno)); 283 lport = 0; 284 goto bad; 285 } 286 *fd2p = s3; 287 if (aport >= IPPORT_RESERVED || aport < IPPORT_RESERVED / 2) { 288 (void)fprintf(stderr, 289 "socket: protocol failure in circuit setup.\n"); 290 goto bad2; 291 } 292 } 293 (void)_write(s, locuser, strlen(locuser)+1); 294 (void)_write(s, remuser, strlen(remuser)+1); 295 (void)_write(s, cmd, strlen(cmd)+1); 296 if (_read(s, &c, 1) != 1) { 297 (void)fprintf(stderr, 298 "rcmd: %s: %s\n", *ahost, strerror(errno)); 299 goto bad2; 300 } 301 if (c != 0) { 302 while (_read(s, &c, 1) == 1) { 303 (void)_write(STDERR_FILENO, &c, 1); 304 if (c == '\n') 305 break; 306 } 307 goto bad2; 308 } 309 _sigprocmask(SIG_SETMASK, (const sigset_t *)&oldmask, NULL); 310 freeaddrinfo(res); 311 return (s); 312bad2: 313 if (lport) 314 (void)_close(*fd2p); 315bad: 316 (void)_close(s); 317 _sigprocmask(SIG_SETMASK, (const sigset_t *)&oldmask, NULL); 318 freeaddrinfo(res); 319 return (-1); 320} 321 322int 323rresvport(port) 324 int *port; 325{ 326 return rresvport_af(port, AF_INET); 327} 328 329int 330rresvport_af(alport, family) 331 int *alport, family; 332{ 333 int s; 334 struct sockaddr_storage ss; 335 u_short *sport; 336 337 memset(&ss, 0, sizeof(ss)); 338 ss.ss_family = family; 339 switch (family) { 340 case AF_INET: 341 ((struct sockaddr *)&ss)->sa_len = sizeof(struct sockaddr_in); 342 sport = &((struct sockaddr_in *)&ss)->sin_port; 343 ((struct sockaddr_in *)&ss)->sin_addr.s_addr = INADDR_ANY; 344 break; 345#ifdef INET6 346 case AF_INET6: 347 ((struct sockaddr *)&ss)->sa_len = sizeof(struct sockaddr_in6); 348 sport = &((struct sockaddr_in6 *)&ss)->sin6_port; 349 ((struct sockaddr_in6 *)&ss)->sin6_addr = in6addr_any; 350 break; 351#endif 352 default: 353 errno = EAFNOSUPPORT; 354 return -1; 355 } 356 357 s = _socket(ss.ss_family, SOCK_STREAM, 0); 358 if (s < 0) 359 return (-1); 360#if 0 /* compat_exact_traditional_rresvport_semantics */ 361 sin.sin_port = htons((u_short)*alport); 362 if (_bind(s, (struct sockaddr *)&sin, sizeof(sin)) >= 0) 363 return (s); 364 if (errno != EADDRINUSE) { 365 (void)_close(s); 366 return (-1); 367 } 368#endif 369 *sport = 0; 370 if (bindresvport_sa(s, (struct sockaddr *)&ss) == -1) { 371 (void)_close(s); 372 return (-1); 373 } 374 *alport = (int)ntohs(*sport); 375 return (s); 376} 377 378int __check_rhosts_file = 1; 379char *__rcmd_errstr; 380 381int 382ruserok(rhost, superuser, ruser, luser) 383 const char *rhost, *ruser, *luser; 384 int superuser; 385{ 386 struct addrinfo hints, *res, *r; 387 int error; 388 389 memset(&hints, 0, sizeof(hints)); 390 hints.ai_family = PF_UNSPEC; 391 hints.ai_socktype = SOCK_DGRAM; /*dummy*/ 392 error = getaddrinfo(rhost, "0", &hints, &res); 393 if (error) 394 return (-1); 395 396 for (r = res; r; r = r->ai_next) { 397 if (iruserok_sa(r->ai_addr, r->ai_addrlen, superuser, ruser, 398 luser) == 0) { 399 freeaddrinfo(res); 400 return (0); 401 } 402 } 403 freeaddrinfo(res); 404 return (-1); 405} 406 407/* 408 * New .rhosts strategy: We are passed an ip address. We spin through 409 * hosts.equiv and .rhosts looking for a match. When the .rhosts only 410 * has ip addresses, we don't have to trust a nameserver. When it 411 * contains hostnames, we spin through the list of addresses the nameserver 412 * gives us and look for a match. 413 * 414 * Returns 0 if ok, -1 if not ok. 415 */ 416int 417iruserok(raddr, superuser, ruser, luser) 418 unsigned long raddr; 419 int superuser; 420 const char *ruser, *luser; 421{ 422 struct sockaddr_in sin; 423 424 memset(&sin, 0, sizeof(sin)); 425 sin.sin_family = AF_INET; 426 sin.sin_len = sizeof(struct sockaddr_in); 427 memcpy(&sin.sin_addr, &raddr, sizeof(sin.sin_addr)); 428 return iruserok_sa((struct sockaddr *)&sin, sin.sin_len, superuser, 429 ruser, luser); 430} 431 432/* 433 * AF independent extension of iruserok. 434 * 435 * Returns 0 if ok, -1 if not ok. 436 */ 437int 438iruserok_sa(ra, rlen, superuser, ruser, luser) 439 const void *ra; 440 int rlen; 441 int superuser; 442 const char *ruser, *luser; 443{ 444 char *cp; 445 struct stat sbuf; 446 struct passwd *pwd; 447 FILE *hostf; 448 uid_t uid; 449 int first; 450 char pbuf[MAXPATHLEN]; 451 const struct sockaddr *raddr; 452 struct sockaddr_storage ss; 453 454 /* avoid alignment issue */ 455 if (rlen > sizeof(ss)) 456 return(-1); 457 memcpy(&ss, ra, rlen); 458 raddr = (struct sockaddr *)&ss; 459 460 first = 1;
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485 (void)seteuid(uid); 486 487 if (hostf == NULL) 488 return (-1); 489 /* 490 * If not a regular file, or is owned by someone other than 491 * user or root or if writeable by anyone but the owner, quit. 492 */ 493 cp = NULL; 494 if (lstat(pbuf, &sbuf) < 0) 495 cp = ".rhosts lstat failed"; 496 else if (!S_ISREG(sbuf.st_mode)) 497 cp = ".rhosts not regular file"; 498 else if (_fstat(fileno(hostf), &sbuf) < 0) 499 cp = ".rhosts fstat failed"; 500 else if (sbuf.st_uid && sbuf.st_uid != pwd->pw_uid) 501 cp = "bad .rhosts owner"; 502 else if (sbuf.st_mode & (S_IWGRP|S_IWOTH)) 503 cp = ".rhosts writeable by other than owner"; 504 /* If there were any problems, quit. */ 505 if (cp) { 506 __rcmd_errstr = cp; 507 (void)fclose(hostf); 508 return (-1); 509 } 510 goto again; 511 } 512 return (-1); 513} 514 515/* 516 * XXX 517 * Don't make static, used by lpd(8). 518 * 519 * Returns 0 if ok, -1 if not ok. 520 */ 521int 522__ivaliduser(hostf, raddr, luser, ruser) 523 FILE *hostf; 524 u_int32_t raddr; 525 const char *luser, *ruser; 526{ 527 struct sockaddr_in sin; 528 529 memset(&sin, 0, sizeof(sin)); 530 sin.sin_family = AF_INET; 531 sin.sin_len = sizeof(struct sockaddr_in); 532 memcpy(&sin.sin_addr, &raddr, sizeof(sin.sin_addr)); 533 return __ivaliduser_sa(hostf, (struct sockaddr *)&sin, sin.sin_len, 534 luser, ruser); 535} 536 537/* 538 * Returns 0 if ok, -1 if not ok. 539 * 540 * XXX obsolete API. 541 */ 542int 543__ivaliduser_af(hostf, raddr, luser, ruser, af, len) 544 FILE *hostf; 545 const void *raddr; 546 const char *luser, *ruser; 547 int af, len; 548{ 549 struct sockaddr *sa = NULL; 550 struct sockaddr_in *sin = NULL; 551#ifdef INET6 552 struct sockaddr_in6 *sin6 = NULL; 553#endif 554 struct sockaddr_storage ss; 555 556 memset(&ss, 0, sizeof(ss)); 557 switch (af) { 558 case AF_INET: 559 if (len != sizeof(sin->sin_addr)) 560 return -1; 561 sin = (struct sockaddr_in *)&ss; 562 sin->sin_family = AF_INET; 563 sin->sin_len = sizeof(struct sockaddr_in); 564 memcpy(&sin->sin_addr, raddr, sizeof(sin->sin_addr)); 565 break; 566#ifdef INET6 567 case AF_INET6: 568 if (len != sizeof(sin6->sin6_addr)) 569 return -1; 570 /* you will lose scope info */ 571 sin6 = (struct sockaddr_in6 *)&ss; 572 sin6->sin6_family = AF_INET6; 573 sin6->sin6_len = sizeof(struct sockaddr_in6); 574 memcpy(&sin6->sin6_addr, raddr, sizeof(sin6->sin6_addr)); 575 break; 576#endif 577 default: 578 return -1; 579 } 580 581 sa = (struct sockaddr *)&ss; 582 return __ivaliduser_sa(hostf, sa, sa->sa_len, luser, ruser); 583} 584 585int 586__ivaliduser_sa(hostf, raddr, salen, luser, ruser) 587 FILE *hostf; 588 const struct sockaddr *raddr; 589 socklen_t salen; 590 const char *luser, *ruser; 591{ 592 char *user, *p; 593 int ch; 594 char buf[MAXHOSTNAMELEN + 128]; /* host + login */ 595 char hname[MAXHOSTNAMELEN]; 596 /* Presumed guilty until proven innocent. */ 597 int userok = 0, hostok = 0; 598#ifdef YP 599 char *ypdomain; 600 601 if (yp_get_default_domain(&ypdomain)) 602 ypdomain = NULL; 603#else 604#define ypdomain NULL 605#endif 606 /* We need to get the damn hostname back for netgroup matching. */ 607 if (getnameinfo(raddr, salen, hname, sizeof(hname), NULL, 0, 608 NI_NAMEREQD) != 0) 609 hname[0] = '\0'; 610 611 while (fgets(buf, sizeof(buf), hostf)) { 612 p = buf; 613 /* Skip lines that are too long. */ 614 if (strchr(p, '\n') == NULL) { 615 while ((ch = getc(hostf)) != '\n' && ch != EOF); 616 continue; 617 } 618 if (*p == '\n' || *p == '#') { 619 /* comment... */ 620 continue; 621 } 622 while (*p != '\n' && *p != ' ' && *p != '\t' && *p != '\0') { 623 *p = isupper((unsigned char)*p) ? tolower((unsigned char)*p) : *p; 624 p++; 625 } 626 if (*p == ' ' || *p == '\t') { 627 *p++ = '\0'; 628 while (*p == ' ' || *p == '\t') 629 p++; 630 user = p; 631 while (*p != '\n' && *p != ' ' && 632 *p != '\t' && *p != '\0') 633 p++; 634 } else 635 user = p; 636 *p = '\0'; 637 /* 638 * Do +/- and +@/-@ checking. This looks really nasty, 639 * but it matches SunOS's behavior so far as I can tell. 640 */ 641 switch(buf[0]) { 642 case '+': 643 if (!buf[1]) { /* '+' matches all hosts */ 644 hostok = 1; 645 break; 646 } 647 if (buf[1] == '@') /* match a host by netgroup */ 648 hostok = hname[0] != '\0' && 649 innetgr(&buf[2], hname, NULL, ypdomain); 650 else /* match a host by addr */ 651 hostok = __icheckhost(raddr, salen, 652 (char *)&buf[1]); 653 break; 654 case '-': /* reject '-' hosts and all their users */ 655 if (buf[1] == '@') { 656 if (hname[0] == '\0' || 657 innetgr(&buf[2], hname, NULL, ypdomain)) 658 return(-1); 659 } else { 660 if (__icheckhost(raddr, salen, 661 (char *)&buf[1])) 662 return(-1); 663 } 664 break; 665 default: /* if no '+' or '-', do a simple match */ 666 hostok = __icheckhost(raddr, salen, buf); 667 break; 668 } 669 switch(*user) { 670 case '+': 671 if (!*(user+1)) { /* '+' matches all users */ 672 userok = 1; 673 break; 674 } 675 if (*(user+1) == '@') /* match a user by netgroup */ 676 userok = innetgr(user+2, NULL, ruser, ypdomain); 677 else /* match a user by direct specification */ 678 userok = !(strcmp(ruser, user+1)); 679 break; 680 case '-': /* if we matched a hostname, */ 681 if (hostok) { /* check for user field rejections */ 682 if (!*(user+1)) 683 return(-1); 684 if (*(user+1) == '@') { 685 if (innetgr(user+2, NULL, 686 ruser, ypdomain)) 687 return(-1); 688 } else { 689 if (!strcmp(ruser, user+1)) 690 return(-1); 691 } 692 } 693 break; 694 default: /* no rejections: try to match the user */ 695 if (hostok) 696 userok = !(strcmp(ruser,*user ? user : luser)); 697 break; 698 } 699 if (hostok && userok) 700 return(0); 701 } 702 return (-1); 703} 704 705/* 706 * Returns "true" if match, 0 if no match. 707 */ 708static int 709__icheckhost(raddr, salen, lhost) 710 const struct sockaddr *raddr; 711 socklen_t salen; 712 const char *lhost; 713{ 714 struct sockaddr_in sin; 715 struct sockaddr_in6 *sin6; 716 struct addrinfo hints, *res, *r; 717 int error; 718 char h1[NI_MAXHOST], h2[NI_MAXHOST]; 719 720 if (raddr->sa_family == AF_INET6) { 721 sin6 = (struct sockaddr_in6 *)raddr; 722 if (IN6_IS_ADDR_V4MAPPED(&sin6->sin6_addr)) { 723 memset(&sin, 0, sizeof(sin)); 724 sin.sin_family = AF_INET; 725 sin.sin_len = sizeof(struct sockaddr_in); 726 memcpy(&sin.sin_addr, &sin6->sin6_addr.s6_addr[12], 727 sizeof(sin.sin_addr)); 728 raddr = (struct sockaddr *)&sin; 729 salen = sin.sin_len; 730 } 731 } 732 733 h1[0] = '\0'; 734 if (getnameinfo(raddr, salen, h1, sizeof(h1), NULL, 0, 735 NI_NUMERICHOST) != 0) 736 return (0); 737 738 /* Resolve laddr into sockaddr */ 739 memset(&hints, 0, sizeof(hints)); 740 hints.ai_family = raddr->sa_family; 741 hints.ai_socktype = SOCK_DGRAM; /*XXX dummy*/ 742 res = NULL; 743 error = getaddrinfo(lhost, "0", &hints, &res); 744 if (error) 745 return (0); 746 747 for (r = res; r ; r = r->ai_next) { 748 h2[0] = '\0'; 749 if (getnameinfo(r->ai_addr, r->ai_addrlen, h2, sizeof(h2), 750 NULL, 0, NI_NUMERICHOST) != 0) 751 continue; 752 if (strcmp(h1, h2) == 0) { 753 freeaddrinfo(res); 754 return (1); 755 } 756 } 757 758 /* No match. */ 759 freeaddrinfo(res); 760 return (0); 761}
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