1 /* 2 * Copyright (c) 1980 Regents of the University of California. 3 * All rights reserved. 4 * 5 * Redistribution and use in source and binary forms are permitted 6 * provided that this notice is preserved and that due credit is given 7 * to the University of California at Berkeley. The name of the University 8 * may not be used to endorse or promote products derived from this 9 * software without specific prior written permission. This software 10 * is provided ``as is'' without express or implied warranty. 11 */ 12 13 #ifdef notdef 14 static char sccsid[] = "@(#)optim.c 5.9 (Berkeley) 02/18/88"; 15 #endif /* notdef */ 16 17 /* 18 * Mail -- a program for sending and receiving mail. 19 * 20 * Network name modification routines. 21 */ 22 23 #include "rcv.h" 24 #include "configdefs.h" 25 26 /* 27 * Map a name into the correct network "view" of the 28 * name. This is done by prepending the name with the 29 * network address of the sender, then optimizing away 30 * nonsense. 31 */ 32 33 char * 34 netmap(name, from) 35 char name[], from[]; 36 { 37 char nbuf[BUFSIZ], ret[BUFSIZ]; 38 register char *cp; 39 40 if (strlen(from) == 0) 41 return(name); 42 if (any('@', name) || any('%', name)) 43 return(savestr(arpafix(name, from))); 44 cp = revarpa(from); 45 if (cp == NOSTR) 46 return(name); 47 strcpy(nbuf, cp); 48 cp = &nbuf[strlen(nbuf) - 1]; 49 while (!any(*cp, metanet) && cp > nbuf) 50 cp--; 51 if (cp == nbuf) 52 return(name); 53 *++cp = 0; 54 if ((cp = revarpa(name)) != NOSTR) 55 strcat(nbuf, cp); 56 optim(nbuf, ret); 57 cp = revarpa(ret); 58 if (cp && !icequal(name, cp)) 59 return(savestr(cp)); 60 return(name); 61 } 62 63 /* 64 * Turn a network machine name into a unique character 65 */ 66 netlook(machine, attnet) 67 char machine[]; 68 { 69 register struct netmach *np; 70 register char *cp, *cp2; 71 char nbuf[BUFSIZ]; 72 73 /* 74 * Make into lower case. 75 */ 76 77 for (cp = machine, cp2 = nbuf; *cp; *cp2++ = little(*cp++)) 78 if (cp2 >= &nbuf[sizeof(nbuf)-1]) 79 break; 80 *cp2 = 0; 81 82 /* 83 * If a single letter machine, look through those first. 84 */ 85 86 if (strlen(nbuf) == 1) 87 for (np = netmach; np->nt_mid != 0; np++) 88 if (np->nt_mid == nbuf[0]) 89 return(nbuf[0]); 90 91 /* 92 * Look for usual name 93 */ 94 95 for (np = netmach; np->nt_mid != 0; np++) 96 if (strcmp(np->nt_machine, nbuf) == 0) 97 return(np->nt_mid); 98 99 /* 100 * Look in side hash table. 101 */ 102 103 return(mstash(nbuf, attnet)); 104 } 105 106 /* 107 * Make a little character. 108 */ 109 110 little(c) 111 register int c; 112 { 113 114 if (c >= 'A' && c <= 'Z') 115 c += 'a' - 'A'; 116 return(c); 117 } 118 119 /* 120 * Turn a network unique character identifier into a network name. 121 */ 122 123 char * 124 netname(mid) 125 { 126 register struct netmach *np; 127 char *mlook(); 128 129 if (mid & 0200) 130 return(mlook(mid)); 131 for (np = netmach; np->nt_mid != 0; np++) 132 if (np->nt_mid == mid) 133 return(np->nt_machine); 134 return(NOSTR); 135 } 136 137 /* 138 * Deal with arpa net addresses. The way this is done is strange. 139 * In particular, if the destination arpa net host is not Berkeley, 140 * then the address is correct as stands. Otherwise, we strip off 141 * the trailing @Berkeley, then cook up a phony person for it to 142 * be from and optimize the result. 143 */ 144 char * 145 arpafix(name, from) 146 char name[]; 147 char from[]; 148 { 149 register char *cp; 150 register int arpamach; 151 char newname[BUFSIZ]; 152 char fake[5]; 153 char fakepath[20]; 154 155 if (debug) { 156 fprintf(stderr, "arpafix(%s, %s)\n", name, from); 157 } 158 cp = rindex(name, '@'); 159 if (cp == NOSTR) 160 cp = rindex(name, '%'); 161 if (cp == NOSTR) { 162 fprintf(stderr, "Somethings amiss -- no @ or %% in arpafix\n"); 163 return(name); 164 } 165 cp++; 166 arpamach = netlook(cp, '@'); 167 if (arpamach == 0) { 168 if (debug) 169 fprintf(stderr, "machine %s unknown, uses: %s\n", cp, name); 170 return(name); 171 } 172 if (((nettype(arpamach) & nettype(LOCAL)) & ~AN) == 0) { 173 if (debug) 174 fprintf(stderr, "machine %s known but remote, uses: %s\n", 175 cp, name); 176 return(name); 177 } 178 strcpy(newname, name); 179 cp = rindex(newname, '@'); 180 if (cp == NOSTR) 181 cp = rindex(newname, '%'); 182 *cp = 0; 183 fake[0] = arpamach; 184 fake[1] = ':'; 185 fake[2] = LOCAL; 186 fake[3] = ':'; 187 fake[4] = 0; 188 prefer(fake); 189 strcpy(fakepath, netname(fake[0])); 190 stradd(fakepath, fake[1]); 191 strcat(fakepath, "daemon"); 192 if (debug) 193 fprintf(stderr, "machine local, call netmap(%s, %s)\n", 194 newname, fakepath); 195 return(netmap(newname, fakepath)); 196 } 197 198 /* 199 * Take a network machine descriptor and find the types of connected 200 * nets and return it. 201 */ 202 203 nettype(mid) 204 { 205 register struct netmach *np; 206 207 if (mid & 0200) 208 return(mtype(mid)); 209 for (np = netmach; np->nt_mid != 0; np++) 210 if (np->nt_mid == mid) 211 return(np->nt_type); 212 return(0); 213 } 214 215 /* 216 * Hashing routines to salt away machines seen scanning 217 * networks paths that we don't know about. 218 */ 219 220 #define XHSIZE 19 /* Size of extra hash table */ 221 #define NXMID (XHSIZE*3/4) /* Max extra machines */ 222 223 struct xtrahash { 224 char *xh_name; /* Name of machine */ 225 short xh_mid; /* Machine ID */ 226 short xh_attnet; /* Attached networks */ 227 } xtrahash[XHSIZE]; 228 229 struct xtrahash *xtab[XHSIZE]; /* F: mid-->machine name */ 230 231 short midfree; /* Next free machine id */ 232 233 /* 234 * Initialize the extra host hash table. 235 * Called by sreset. 236 */ 237 238 minit() 239 { 240 register struct xtrahash *xp, **tp; 241 242 midfree = 0; 243 tp = &xtab[0]; 244 for (xp = &xtrahash[0]; xp < &xtrahash[XHSIZE]; xp++) { 245 xp->xh_name = NOSTR; 246 xp->xh_mid = 0; 247 xp->xh_attnet = 0; 248 *tp++ = (struct xtrahash *) 0; 249 } 250 } 251 252 /* 253 * Stash a net name in the extra host hash table. 254 * If a new entry is put in the hash table, deduce what 255 * net the machine is attached to from the net character. 256 * 257 * If the machine is already known, add the given attached 258 * net to those already known. 259 */ 260 261 mstash(name, attnet) 262 char name[]; 263 { 264 register struct xtrahash *xp; 265 struct xtrahash *xlocate(); 266 int x; 267 268 xp = xlocate(name); 269 if (xp == (struct xtrahash *) 0) { 270 printf("Ran out of machine id spots\n"); 271 return(0); 272 } 273 if (xp->xh_name == NOSTR) { 274 if (midfree >= XHSIZE) { 275 printf("Out of machine ids\n"); 276 return(0); 277 } 278 xtab[midfree] = xp; 279 xp->xh_name = savestr(name); 280 xp->xh_mid = 0200 + midfree++; 281 } 282 x = ntype(attnet); 283 if (x == 0) 284 xp->xh_attnet |= SN; 285 else 286 xp->xh_attnet |= x; 287 return(xp->xh_mid); 288 } 289 290 /* 291 * Search for the given name in the hash table 292 * and return the pointer to it if found, or to the first 293 * empty slot if not found. 294 * 295 * If no free slots can be found, return 0. 296 */ 297 298 struct xtrahash * 299 xlocate(name) 300 char name[]; 301 { 302 register int h, q, i; 303 register char *cp; 304 register struct xtrahash *xp; 305 306 for (h = 0, cp = name; *cp; h = (h << 2) + *cp++) 307 ; 308 if (h < 0 && (h = -h) < 0) 309 h = 0; 310 h = h % XHSIZE; 311 cp = name; 312 for (i = 0, q = 0; q < XHSIZE; i++, q = i * i) { 313 xp = &xtrahash[(h + q) % XHSIZE]; 314 if (xp->xh_name == NOSTR) 315 return(xp); 316 if (strcmp(cp, xp->xh_name) == 0) 317 return(xp); 318 if (h - q < 0) 319 h += XHSIZE; 320 xp = &xtrahash[(h - q) % XHSIZE]; 321 if (xp->xh_name == NOSTR) 322 return(xp); 323 if (strcmp(cp, xp->xh_name) == 0) 324 return(xp); 325 } 326 return((struct xtrahash *) 0); 327 } 328 329 /* 330 * Return the name from the extra host hash table corresponding 331 * to the passed machine id. 332 */ 333 334 char * 335 mlook(mid) 336 { 337 register int m; 338 339 if ((mid & 0200) == 0) 340 return(NOSTR); 341 m = mid & 0177; 342 if (m >= midfree) { 343 printf("Use made of undefined machine id\n"); 344 return(NOSTR); 345 } 346 return(xtab[m]->xh_name); 347 } 348 349 /* 350 * Return the bit mask of net's that the given extra host machine 351 * id has so far. 352 */ 353 354 mtype(mid) 355 { 356 register int m; 357 358 if ((mid & 0200) == 0) 359 return(0); 360 m = mid & 0177; 361 if (m >= midfree) { 362 printf("Use made of undefined machine id\n"); 363 return(0); 364 } 365 return(xtab[m]->xh_attnet); 366 } 367 368 /* 369 * Take a network name and optimize it. This gloriously messy 370 * operation takes place as follows: the name with machine names 371 * in it is tokenized by mapping each machine name into a single 372 * character machine id (netlook). The separator characters (network 373 * metacharacters) are left intact. The last component of the network 374 * name is stripped off and assumed to be the destination user name -- 375 * it does not participate in the optimization. As an example, the 376 * name "research!vax135!research!ucbvax!bill" becomes, tokenized, 377 * "r!x!r!v!" and "bill" A low level routine, optim1, fixes up the 378 * network part (eg, "r!x!r!v!"), then we convert back to network 379 * machine names and tack the user name on the end. 380 * 381 * The result of this is copied into the parameter "name" 382 */ 383 384 optim(net, name) 385 char net[], name[]; 386 { 387 char netcomp[BUFSIZ], netstr[40], xfstr[40]; 388 register char *cp, *cp2; 389 register int c; 390 391 strcpy(netstr, ""); 392 cp = net; 393 for (;;) { 394 /* 395 * Rip off next path component into netcomp 396 */ 397 cp2 = netcomp; 398 while (*cp && !any(*cp, metanet)) 399 *cp2++ = *cp++; 400 *cp2 = 0; 401 /* 402 * If we hit null byte, then we just scanned 403 * the destination user name. Go off and optimize 404 * if its so. 405 */ 406 if (*cp == 0) 407 break; 408 if ((c = netlook(netcomp, *cp)) == 0) { 409 printf("No host named \"%s\"\n", netcomp); 410 err: 411 strcpy(name, net); 412 return; 413 } 414 stradd(netstr, c); 415 stradd(netstr, *cp++); 416 /* 417 * If multiple network separators given, 418 * throw away the extras. 419 */ 420 while (any(*cp, metanet)) 421 cp++; 422 } 423 if (strlen(netcomp) == 0) { 424 printf("net name syntax\n"); 425 goto err; 426 } 427 optim1(netstr, xfstr); 428 429 /* 430 * Convert back to machine names. 431 */ 432 433 cp = xfstr; 434 strcpy(name, ""); 435 while (*cp) { 436 if ((cp2 = netname(*cp++)) == NOSTR) { 437 printf("Made up bad net name\n"); 438 printf("Machine code %c (0%o)\n", cp[-1], cp[-1]); 439 printf("Sorry -- dumping now. Alert K. Shoens\n"); 440 core(); 441 goto err; 442 } 443 strcat(name, cp2); 444 stradd(name, *cp++); 445 } 446 strcat(name, netcomp); 447 } 448 449 /* 450 * Take a string of network machine id's and separators and 451 * optimize them. We process these by pulling off maximal 452 * leading strings of the same type, passing these to the appropriate 453 * optimizer and concatenating the results. 454 */ 455 456 optim1(netstr, name) 457 char netstr[], name[]; 458 { 459 char path[40], rpath[40]; 460 register char *cp, *cp2; 461 register int tp, nc; 462 463 cp = netstr; 464 prefer(cp); 465 strcpy(name, ""); 466 /* 467 * If the address ultimately points back to us, 468 * just return a null network path. 469 */ 470 if (strlen(cp) > 1 && cp[strlen(cp) - 2] == LOCAL) 471 return; 472 while (*cp != 0) { 473 strcpy(path, ""); 474 tp = ntype(cp[1]); 475 nc = cp[1]; 476 while (*cp && tp == ntype(cp[1])) { 477 stradd(path, *cp++); 478 cp++; 479 } 480 switch (netkind(tp)) { 481 default: 482 strcpy(rpath, path); 483 break; 484 485 case IMPLICIT: 486 optimimp(path, rpath); 487 break; 488 489 case EXPLICIT: 490 optimex(path, rpath); 491 break; 492 } 493 for (cp2 = rpath; *cp2 != 0; cp2++) { 494 stradd(name, *cp2); 495 stradd(name, nc); 496 } 497 } 498 optiboth(name); 499 prefer(name); 500 } 501 502 /* 503 * Return the network of the separator -- 504 * AN for arpa net 505 * BN for Bell labs net 506 * SN for Schmidt (berkeley net) 507 * 0 if we don't know. 508 */ 509 510 ntype(nc) 511 register int nc; 512 { 513 register struct ntypetab *np; 514 515 for (np = ntypetab; np->nt_char != 0; np++) 516 if (np->nt_char == nc) 517 return(np->nt_bcode); 518 return(0); 519 } 520 521 /* 522 * Return the kind of routing used for the particular net 523 * EXPLICIT means explicitly routed 524 * IMPLICIT means implicitly routed 525 * 0 means don't know 526 */ 527 528 netkind(nt) 529 register int nt; 530 { 531 register struct nkindtab *np; 532 533 for (np = nkindtab; np->nk_type != 0; np++) 534 if (np->nk_type == nt) 535 return(np->nk_kind); 536 return(0); 537 } 538 539 /* 540 * Do name optimization for an explicitly routed network (eg BTL network). 541 */ 542 543 optimex(net, name) 544 char net[], name[]; 545 { 546 register char *cp, *rp; 547 register int m; 548 549 strcpy(name, net); 550 cp = name; 551 if (strlen(cp) == 0) 552 return(-1); 553 if (cp[strlen(cp)-1] == LOCAL) { 554 name[0] = 0; 555 return(0); 556 } 557 for (cp = name; *cp; cp++) { 558 m = *cp; 559 rp = rindex(cp+1, m); 560 if (rp != NOSTR) 561 strcpy(cp, rp); 562 } 563 return(0); 564 } 565 566 /* 567 * Do name optimization for implicitly routed network (eg, arpanet, 568 * Berkeley network) 569 */ 570 571 optimimp(net, name) 572 char net[], name[]; 573 { 574 register char *cp; 575 register int m; 576 577 cp = net; 578 if (strlen(cp) == 0) 579 return(-1); 580 m = cp[strlen(cp) - 1]; 581 if (m == LOCAL) { 582 strcpy(name, ""); 583 return(0); 584 } 585 name[0] = m; 586 name[1] = 0; 587 return(0); 588 } 589 590 /* 591 * Perform global optimization on the given network path. 592 * The trick here is to look ahead to see if there are any loops 593 * in the path and remove them. The interpretation of loops is 594 * more strict here than in optimex since both the machine and net 595 * type must match. 596 */ 597 598 optiboth(net) 599 char net[]; 600 { 601 register char *cp, *cp2; 602 char *rpair(); 603 604 cp = net; 605 if (strlen(cp) == 0) 606 return; 607 if ((strlen(cp) % 2) != 0) { 608 printf("Strange arg to optiboth\n"); 609 return; 610 } 611 while (*cp) { 612 cp2 = rpair(cp+2, *cp); 613 if (cp2 != NOSTR) 614 strcpy(cp, cp2); 615 cp += 2; 616 } 617 } 618 619 /* 620 * Find the rightmost instance of the given (machine, type) pair. 621 */ 622 623 char * 624 rpair(str, mach) 625 char str[]; 626 { 627 register char *cp, *last; 628 629 cp = str; 630 last = NOSTR; 631 while (*cp) { 632 if (*cp == mach) 633 last = cp; 634 cp += 2; 635 } 636 return(last); 637 } 638 639 /* 640 * Change the network separators in the given network path 641 * to the preferred network transmission means. 642 */ 643 644 prefer(name) 645 char name[]; 646 { 647 register char *cp; 648 register int state, n; 649 650 state = LOCAL; 651 for (cp = name; *cp; cp += 2) { 652 n = best(state, *cp); 653 if (n) 654 cp[1] = n; 655 state = *cp; 656 } 657 } 658 659 /* 660 * Return the best network separator for the given machine pair. 661 */ 662 663 best(src, dest) 664 { 665 register int dtype, stype; 666 register struct netorder *np; 667 668 stype = nettype(src); 669 dtype = nettype(dest); 670 fflush(stdout); 671 if (stype == 0 || dtype == 0) { 672 printf("ERROR: unknown internal machine id\n"); 673 return(0); 674 } 675 if ((stype & dtype) == 0) 676 return(0); 677 np = &netorder[0]; 678 while ((np->no_stat & stype & dtype) == 0) 679 np++; 680 return(np->no_char); 681 } 682 683 #ifdef GETHOST 684 /* 685 * Initialize the network name of the current host. 686 */ 687 inithost() 688 { 689 register struct netmach *np; 690 static char host[64]; 691 692 gethostname(host, sizeof host); 693 for (np = netmach; np->nt_machine != 0; np++) 694 if (strcmp(np->nt_machine, EMPTY) == 0) 695 break; 696 if (np->nt_machine == 0) { 697 printf("Cannot find empty slot for dynamic host entry\n"); 698 exit(1); 699 } 700 np->nt_machine = host; 701 } 702 #endif GETHOST 703 704 /* 705 * Code to twist around arpa net names. 706 */ 707 708 #define WORD 257 /* Token for a string */ 709 710 static char netbuf[256]; 711 static char *yylval; 712 713 /* 714 * Reverse all of the arpa net addresses in the given name to 715 * be of the form "host @ user" instead of "user @ host" 716 * This function is its own inverse. 717 */ 718 719 char * 720 revarpa(str) 721 char str[]; 722 { 723 724 if (yyinit(str) < 0) 725 return(NOSTR); 726 if (name()) 727 return(NOSTR); 728 if (strcmp(str, netbuf) == 0) 729 return(str); 730 return(savestr(netbuf)); 731 } 732 733 /* 734 * Parse (by recursive descent) network names, using the following grammar: 735 * name: 736 * term {':' term} 737 * term {'^' term} 738 * term {'!' term} 739 * term '@' name 740 * term '%' name 741 * 742 * term: 743 * string of characters. 744 */ 745 746 name() 747 { 748 register int t; 749 register char *cp; 750 751 for (;;) { 752 t = yylex(); 753 if (t != WORD) 754 return(-1); 755 cp = yylval; 756 t = yylex(); 757 switch (t) { 758 case 0: 759 strcat(netbuf, cp); 760 return(0); 761 762 case '@': 763 case '%': 764 if (name()) 765 return(-1); 766 stradd(netbuf, '@'); 767 strcat(netbuf, cp); 768 return(0); 769 770 case WORD: 771 return(-1); 772 773 default: 774 strcat(netbuf, cp); 775 stradd(netbuf, t); 776 } 777 } 778 } 779 780 /* 781 * Scanner for network names. 782 */ 783 784 static char *charp; /* Current input pointer */ 785 static int nexttok; /* Salted away next token */ 786 787 /* 788 * Initialize the network name scanner. 789 */ 790 791 yyinit(str) 792 char str[]; 793 { 794 static char lexbuf[BUFSIZ]; 795 796 netbuf[0] = 0; 797 if (strlen(str) >= sizeof lexbuf - 1) 798 return(-1); 799 nexttok = 0; 800 strcpy(lexbuf, str); 801 charp = lexbuf; 802 return(0); 803 } 804 805 /* 806 * Scan and return a single token. 807 * yylval is set to point to a scanned string. 808 */ 809 810 yylex() 811 { 812 register char *cp, *dot; 813 register int s; 814 815 if (nexttok) { 816 s = nexttok; 817 nexttok = 0; 818 return(s); 819 } 820 cp = charp; 821 while (*cp && isspace(*cp)) 822 cp++; 823 if (*cp == 0) 824 return(0); 825 if (any(*cp, metanet)) { 826 charp = cp+1; 827 return(*cp); 828 } 829 dot = cp; 830 while (*cp && !any(*cp, metanet) && !any(*cp, " \t")) 831 cp++; 832 if (any(*cp, metanet)) 833 nexttok = *cp; 834 if (*cp == 0) 835 charp = cp; 836 else 837 charp = cp+1; 838 *cp = 0; 839 yylval = dot; 840 return(WORD); 841 } 842