1 /* 2 * Copyright (c) 1980 Regents of the University of California. 3 * All rights reserved. The Berkeley software License Agreement 4 * specifies the terms and conditions for redistribution. 5 */ 6 7 #ifndef lint 8 static char *sccsid = "@(#)optim.c 5.8 (Berkeley) 09/28/87"; 9 #endif not lint 10 11 /* 12 * Mail -- a program for sending and receiving mail. 13 * 14 * Network name modification routines. 15 */ 16 17 #include "rcv.h" 18 #include "configdefs.h" 19 20 /* 21 * Map a name into the correct network "view" of the 22 * name. This is done by prepending the name with the 23 * network address of the sender, then optimizing away 24 * nonsense. 25 */ 26 27 char * 28 netmap(name, from) 29 char name[], from[]; 30 { 31 char nbuf[BUFSIZ], ret[BUFSIZ]; 32 register char *cp; 33 34 if (strlen(from) == 0) 35 return(name); 36 if (any('@', name) || any('%', name)) 37 return(savestr(arpafix(name, from))); 38 cp = revarpa(from); 39 if (cp == NOSTR) 40 return(name); 41 strcpy(nbuf, cp); 42 cp = &nbuf[strlen(nbuf) - 1]; 43 while (!any(*cp, metanet) && cp > nbuf) 44 cp--; 45 if (cp == nbuf) 46 return(name); 47 *++cp = 0; 48 if ((cp = revarpa(name)) != NOSTR) 49 strcat(nbuf, cp); 50 optim(nbuf, ret); 51 cp = revarpa(ret); 52 if (cp && !icequal(name, cp)) 53 return(savestr(cp)); 54 return(name); 55 } 56 57 /* 58 * Turn a network machine name into a unique character 59 */ 60 netlook(machine, attnet) 61 char machine[]; 62 { 63 register struct netmach *np; 64 register char *cp, *cp2; 65 char nbuf[BUFSIZ]; 66 67 /* 68 * Make into lower case. 69 */ 70 71 for (cp = machine, cp2 = nbuf; *cp; *cp2++ = little(*cp++)) 72 if (cp2 >= &nbuf[sizeof(nbuf)-1]) 73 break; 74 *cp2 = 0; 75 76 /* 77 * If a single letter machine, look through those first. 78 */ 79 80 if (strlen(nbuf) == 1) 81 for (np = netmach; np->nt_mid != 0; np++) 82 if (np->nt_mid == nbuf[0]) 83 return(nbuf[0]); 84 85 /* 86 * Look for usual name 87 */ 88 89 for (np = netmach; np->nt_mid != 0; np++) 90 if (strcmp(np->nt_machine, nbuf) == 0) 91 return(np->nt_mid); 92 93 /* 94 * Look in side hash table. 95 */ 96 97 return(mstash(nbuf, attnet)); 98 } 99 100 /* 101 * Make a little character. 102 */ 103 104 little(c) 105 register int c; 106 { 107 108 if (c >= 'A' && c <= 'Z') 109 c += 'a' - 'A'; 110 return(c); 111 } 112 113 /* 114 * Turn a network unique character identifier into a network name. 115 */ 116 117 char * 118 netname(mid) 119 { 120 register struct netmach *np; 121 char *mlook(); 122 123 if (mid & 0200) 124 return(mlook(mid)); 125 for (np = netmach; np->nt_mid != 0; np++) 126 if (np->nt_mid == mid) 127 return(np->nt_machine); 128 return(NOSTR); 129 } 130 131 /* 132 * Deal with arpa net addresses. The way this is done is strange. 133 * In particular, if the destination arpa net host is not Berkeley, 134 * then the address is correct as stands. Otherwise, we strip off 135 * the trailing @Berkeley, then cook up a phony person for it to 136 * be from and optimize the result. 137 */ 138 char * 139 arpafix(name, from) 140 char name[]; 141 char from[]; 142 { 143 register char *cp; 144 register int arpamach; 145 char newname[BUFSIZ]; 146 char fake[5]; 147 char fakepath[20]; 148 149 if (debug) { 150 fprintf(stderr, "arpafix(%s, %s)\n", name, from); 151 } 152 cp = rindex(name, '@'); 153 if (cp == NOSTR) 154 cp = rindex(name, '%'); 155 if (cp == NOSTR) { 156 fprintf(stderr, "Somethings amiss -- no @ or %% in arpafix\n"); 157 return(name); 158 } 159 cp++; 160 arpamach = netlook(cp, '@'); 161 if (arpamach == 0) { 162 if (debug) 163 fprintf(stderr, "machine %s unknown, uses: %s\n", cp, name); 164 return(name); 165 } 166 if (((nettype(arpamach) & nettype(LOCAL)) & ~AN) == 0) { 167 if (debug) 168 fprintf(stderr, "machine %s known but remote, uses: %s\n", 169 cp, name); 170 return(name); 171 } 172 strcpy(newname, name); 173 cp = rindex(newname, '@'); 174 if (cp == NOSTR) 175 cp = rindex(newname, '%'); 176 *cp = 0; 177 fake[0] = arpamach; 178 fake[1] = ':'; 179 fake[2] = LOCAL; 180 fake[3] = ':'; 181 fake[4] = 0; 182 prefer(fake); 183 strcpy(fakepath, netname(fake[0])); 184 stradd(fakepath, fake[1]); 185 strcat(fakepath, "daemon"); 186 if (debug) 187 fprintf(stderr, "machine local, call netmap(%s, %s)\n", 188 newname, fakepath); 189 return(netmap(newname, fakepath)); 190 } 191 192 /* 193 * Take a network machine descriptor and find the types of connected 194 * nets and return it. 195 */ 196 197 nettype(mid) 198 { 199 register struct netmach *np; 200 201 if (mid & 0200) 202 return(mtype(mid)); 203 for (np = netmach; np->nt_mid != 0; np++) 204 if (np->nt_mid == mid) 205 return(np->nt_type); 206 return(0); 207 } 208 209 /* 210 * Hashing routines to salt away machines seen scanning 211 * networks paths that we don't know about. 212 */ 213 214 #define XHSIZE 19 /* Size of extra hash table */ 215 #define NXMID (XHSIZE*3/4) /* Max extra machines */ 216 217 struct xtrahash { 218 char *xh_name; /* Name of machine */ 219 short xh_mid; /* Machine ID */ 220 short xh_attnet; /* Attached networks */ 221 } xtrahash[XHSIZE]; 222 223 struct xtrahash *xtab[XHSIZE]; /* F: mid-->machine name */ 224 225 short midfree; /* Next free machine id */ 226 227 /* 228 * Initialize the extra host hash table. 229 * Called by sreset. 230 */ 231 232 minit() 233 { 234 register struct xtrahash *xp, **tp; 235 236 midfree = 0; 237 tp = &xtab[0]; 238 for (xp = &xtrahash[0]; xp < &xtrahash[XHSIZE]; xp++) { 239 xp->xh_name = NOSTR; 240 xp->xh_mid = 0; 241 xp->xh_attnet = 0; 242 *tp++ = (struct xtrahash *) 0; 243 } 244 } 245 246 /* 247 * Stash a net name in the extra host hash table. 248 * If a new entry is put in the hash table, deduce what 249 * net the machine is attached to from the net character. 250 * 251 * If the machine is already known, add the given attached 252 * net to those already known. 253 */ 254 255 mstash(name, attnet) 256 char name[]; 257 { 258 register struct xtrahash *xp; 259 struct xtrahash *xlocate(); 260 int x; 261 262 xp = xlocate(name); 263 if (xp == (struct xtrahash *) 0) { 264 printf("Ran out of machine id spots\n"); 265 return(0); 266 } 267 if (xp->xh_name == NOSTR) { 268 if (midfree >= XHSIZE) { 269 printf("Out of machine ids\n"); 270 return(0); 271 } 272 xtab[midfree] = xp; 273 xp->xh_name = savestr(name); 274 xp->xh_mid = 0200 + midfree++; 275 } 276 x = ntype(attnet); 277 if (x == 0) 278 xp->xh_attnet |= SN; 279 else 280 xp->xh_attnet |= x; 281 return(xp->xh_mid); 282 } 283 284 /* 285 * Search for the given name in the hash table 286 * and return the pointer to it if found, or to the first 287 * empty slot if not found. 288 * 289 * If no free slots can be found, return 0. 290 */ 291 292 struct xtrahash * 293 xlocate(name) 294 char name[]; 295 { 296 register int h, q, i; 297 register char *cp; 298 register struct xtrahash *xp; 299 300 for (h = 0, cp = name; *cp; h = (h << 2) + *cp++) 301 ; 302 if (h < 0 && (h = -h) < 0) 303 h = 0; 304 h = h % XHSIZE; 305 cp = name; 306 for (i = 0, q = 0; q < XHSIZE; i++, q = i * i) { 307 xp = &xtrahash[(h + q) % XHSIZE]; 308 if (xp->xh_name == NOSTR) 309 return(xp); 310 if (strcmp(cp, xp->xh_name) == 0) 311 return(xp); 312 if (h - q < 0) 313 h += XHSIZE; 314 xp = &xtrahash[(h - q) % XHSIZE]; 315 if (xp->xh_name == NOSTR) 316 return(xp); 317 if (strcmp(cp, xp->xh_name) == 0) 318 return(xp); 319 } 320 return((struct xtrahash *) 0); 321 } 322 323 /* 324 * Return the name from the extra host hash table corresponding 325 * to the passed machine id. 326 */ 327 328 char * 329 mlook(mid) 330 { 331 register int m; 332 333 if ((mid & 0200) == 0) 334 return(NOSTR); 335 m = mid & 0177; 336 if (m >= midfree) { 337 printf("Use made of undefined machine id\n"); 338 return(NOSTR); 339 } 340 return(xtab[m]->xh_name); 341 } 342 343 /* 344 * Return the bit mask of net's that the given extra host machine 345 * id has so far. 346 */ 347 348 mtype(mid) 349 { 350 register int m; 351 352 if ((mid & 0200) == 0) 353 return(0); 354 m = mid & 0177; 355 if (m >= midfree) { 356 printf("Use made of undefined machine id\n"); 357 return(0); 358 } 359 return(xtab[m]->xh_attnet); 360 } 361 362 /* 363 * Take a network name and optimize it. This gloriously messy 364 * operation takes place as follows: the name with machine names 365 * in it is tokenized by mapping each machine name into a single 366 * character machine id (netlook). The separator characters (network 367 * metacharacters) are left intact. The last component of the network 368 * name is stripped off and assumed to be the destination user name -- 369 * it does not participate in the optimization. As an example, the 370 * name "research!vax135!research!ucbvax!bill" becomes, tokenized, 371 * "r!x!r!v!" and "bill" A low level routine, optim1, fixes up the 372 * network part (eg, "r!x!r!v!"), then we convert back to network 373 * machine names and tack the user name on the end. 374 * 375 * The result of this is copied into the parameter "name" 376 */ 377 378 optim(net, name) 379 char net[], name[]; 380 { 381 char netcomp[BUFSIZ], netstr[40], xfstr[40]; 382 register char *cp, *cp2; 383 register int c; 384 385 strcpy(netstr, ""); 386 cp = net; 387 for (;;) { 388 /* 389 * Rip off next path component into netcomp 390 */ 391 cp2 = netcomp; 392 while (*cp && !any(*cp, metanet)) 393 *cp2++ = *cp++; 394 *cp2 = 0; 395 /* 396 * If we hit null byte, then we just scanned 397 * the destination user name. Go off and optimize 398 * if its so. 399 */ 400 if (*cp == 0) 401 break; 402 if ((c = netlook(netcomp, *cp)) == 0) { 403 printf("No host named \"%s\"\n", netcomp); 404 err: 405 strcpy(name, net); 406 return; 407 } 408 stradd(netstr, c); 409 stradd(netstr, *cp++); 410 /* 411 * If multiple network separators given, 412 * throw away the extras. 413 */ 414 while (any(*cp, metanet)) 415 cp++; 416 } 417 if (strlen(netcomp) == 0) { 418 printf("net name syntax\n"); 419 goto err; 420 } 421 optim1(netstr, xfstr); 422 423 /* 424 * Convert back to machine names. 425 */ 426 427 cp = xfstr; 428 strcpy(name, ""); 429 while (*cp) { 430 if ((cp2 = netname(*cp++)) == NOSTR) { 431 printf("Made up bad net name\n"); 432 printf("Machine code %c (0%o)\n", cp[-1], cp[-1]); 433 printf("Sorry -- dumping now. Alert K. Shoens\n"); 434 core(); 435 goto err; 436 } 437 strcat(name, cp2); 438 stradd(name, *cp++); 439 } 440 strcat(name, netcomp); 441 } 442 443 /* 444 * Take a string of network machine id's and separators and 445 * optimize them. We process these by pulling off maximal 446 * leading strings of the same type, passing these to the appropriate 447 * optimizer and concatenating the results. 448 */ 449 450 optim1(netstr, name) 451 char netstr[], name[]; 452 { 453 char path[40], rpath[40]; 454 register char *cp, *cp2; 455 register int tp, nc; 456 457 cp = netstr; 458 prefer(cp); 459 strcpy(name, ""); 460 /* 461 * If the address ultimately points back to us, 462 * just return a null network path. 463 */ 464 if (strlen(cp) > 1 && cp[strlen(cp) - 2] == LOCAL) 465 return; 466 while (*cp != 0) { 467 strcpy(path, ""); 468 tp = ntype(cp[1]); 469 nc = cp[1]; 470 while (*cp && tp == ntype(cp[1])) { 471 stradd(path, *cp++); 472 cp++; 473 } 474 switch (netkind(tp)) { 475 default: 476 strcpy(rpath, path); 477 break; 478 479 case IMPLICIT: 480 optimimp(path, rpath); 481 break; 482 483 case EXPLICIT: 484 optimex(path, rpath); 485 break; 486 } 487 for (cp2 = rpath; *cp2 != 0; cp2++) { 488 stradd(name, *cp2); 489 stradd(name, nc); 490 } 491 } 492 optiboth(name); 493 prefer(name); 494 } 495 496 /* 497 * Return the network of the separator -- 498 * AN for arpa net 499 * BN for Bell labs net 500 * SN for Schmidt (berkeley net) 501 * 0 if we don't know. 502 */ 503 504 ntype(nc) 505 register int nc; 506 { 507 register struct ntypetab *np; 508 509 for (np = ntypetab; np->nt_char != 0; np++) 510 if (np->nt_char == nc) 511 return(np->nt_bcode); 512 return(0); 513 } 514 515 /* 516 * Return the kind of routing used for the particular net 517 * EXPLICIT means explicitly routed 518 * IMPLICIT means implicitly routed 519 * 0 means don't know 520 */ 521 522 netkind(nt) 523 register int nt; 524 { 525 register struct nkindtab *np; 526 527 for (np = nkindtab; np->nk_type != 0; np++) 528 if (np->nk_type == nt) 529 return(np->nk_kind); 530 return(0); 531 } 532 533 /* 534 * Do name optimization for an explicitly routed network (eg BTL network). 535 */ 536 537 optimex(net, name) 538 char net[], name[]; 539 { 540 register char *cp, *rp; 541 register int m; 542 543 strcpy(name, net); 544 cp = name; 545 if (strlen(cp) == 0) 546 return(-1); 547 if (cp[strlen(cp)-1] == LOCAL) { 548 name[0] = 0; 549 return(0); 550 } 551 for (cp = name; *cp; cp++) { 552 m = *cp; 553 rp = rindex(cp+1, m); 554 if (rp != NOSTR) 555 strcpy(cp, rp); 556 } 557 return(0); 558 } 559 560 /* 561 * Do name optimization for implicitly routed network (eg, arpanet, 562 * Berkeley network) 563 */ 564 565 optimimp(net, name) 566 char net[], name[]; 567 { 568 register char *cp; 569 register int m; 570 571 cp = net; 572 if (strlen(cp) == 0) 573 return(-1); 574 m = cp[strlen(cp) - 1]; 575 if (m == LOCAL) { 576 strcpy(name, ""); 577 return(0); 578 } 579 name[0] = m; 580 name[1] = 0; 581 return(0); 582 } 583 584 /* 585 * Perform global optimization on the given network path. 586 * The trick here is to look ahead to see if there are any loops 587 * in the path and remove them. The interpretation of loops is 588 * more strict here than in optimex since both the machine and net 589 * type must match. 590 */ 591 592 optiboth(net) 593 char net[]; 594 { 595 register char *cp, *cp2; 596 char *rpair(); 597 598 cp = net; 599 if (strlen(cp) == 0) 600 return; 601 if ((strlen(cp) % 2) != 0) { 602 printf("Strange arg to optiboth\n"); 603 return; 604 } 605 while (*cp) { 606 cp2 = rpair(cp+2, *cp); 607 if (cp2 != NOSTR) 608 strcpy(cp, cp2); 609 cp += 2; 610 } 611 } 612 613 /* 614 * Find the rightmost instance of the given (machine, type) pair. 615 */ 616 617 char * 618 rpair(str, mach) 619 char str[]; 620 { 621 register char *cp, *last; 622 623 cp = str; 624 last = NOSTR; 625 while (*cp) { 626 if (*cp == mach) 627 last = cp; 628 cp += 2; 629 } 630 return(last); 631 } 632 633 /* 634 * Change the network separators in the given network path 635 * to the preferred network transmission means. 636 */ 637 638 prefer(name) 639 char name[]; 640 { 641 register char *cp; 642 register int state, n; 643 644 state = LOCAL; 645 for (cp = name; *cp; cp += 2) { 646 n = best(state, *cp); 647 if (n) 648 cp[1] = n; 649 state = *cp; 650 } 651 } 652 653 /* 654 * Return the best network separator for the given machine pair. 655 */ 656 657 best(src, dest) 658 { 659 register int dtype, stype; 660 register struct netorder *np; 661 662 stype = nettype(src); 663 dtype = nettype(dest); 664 fflush(stdout); 665 if (stype == 0 || dtype == 0) { 666 printf("ERROR: unknown internal machine id\n"); 667 return(0); 668 } 669 if ((stype & dtype) == 0) 670 return(0); 671 np = &netorder[0]; 672 while ((np->no_stat & stype & dtype) == 0) 673 np++; 674 return(np->no_char); 675 } 676 677 #ifdef GETHOST 678 /* 679 * Initialize the network name of the current host. 680 */ 681 inithost() 682 { 683 register struct netmach *np; 684 static char host[64]; 685 686 gethostname(host, sizeof host); 687 for (np = netmach; np->nt_machine != 0; np++) 688 if (strcmp(np->nt_machine, EMPTY) == 0) 689 break; 690 if (np->nt_machine == 0) { 691 printf("Cannot find empty slot for dynamic host entry\n"); 692 exit(1); 693 } 694 np->nt_machine = host; 695 } 696 #endif GETHOST 697 698 /* 699 * Code to twist around arpa net names. 700 */ 701 702 #define WORD 257 /* Token for a string */ 703 704 static char netbuf[256]; 705 static char *yylval; 706 707 /* 708 * Reverse all of the arpa net addresses in the given name to 709 * be of the form "host @ user" instead of "user @ host" 710 * This function is its own inverse. 711 */ 712 713 char * 714 revarpa(str) 715 char str[]; 716 { 717 718 if (yyinit(str) < 0) 719 return(NOSTR); 720 if (name()) 721 return(NOSTR); 722 if (strcmp(str, netbuf) == 0) 723 return(str); 724 return(savestr(netbuf)); 725 } 726 727 /* 728 * Parse (by recursive descent) network names, using the following grammar: 729 * name: 730 * term {':' term} 731 * term {'^' term} 732 * term {'!' term} 733 * term '@' name 734 * term '%' name 735 * 736 * term: 737 * string of characters. 738 */ 739 740 name() 741 { 742 register int t; 743 register char *cp; 744 745 for (;;) { 746 t = yylex(); 747 if (t != WORD) 748 return(-1); 749 cp = yylval; 750 t = yylex(); 751 switch (t) { 752 case 0: 753 strcat(netbuf, cp); 754 return(0); 755 756 case '@': 757 case '%': 758 if (name()) 759 return(-1); 760 stradd(netbuf, '@'); 761 strcat(netbuf, cp); 762 return(0); 763 764 case WORD: 765 return(-1); 766 767 default: 768 strcat(netbuf, cp); 769 stradd(netbuf, t); 770 } 771 } 772 } 773 774 /* 775 * Scanner for network names. 776 */ 777 778 static char *charp; /* Current input pointer */ 779 static int nexttok; /* Salted away next token */ 780 781 /* 782 * Initialize the network name scanner. 783 */ 784 785 yyinit(str) 786 char str[]; 787 { 788 static char lexbuf[BUFSIZ]; 789 790 netbuf[0] = 0; 791 if (strlen(str) >= sizeof lexbuf - 1) 792 return(-1); 793 nexttok = 0; 794 strcpy(lexbuf, str); 795 charp = lexbuf; 796 return(0); 797 } 798 799 /* 800 * Scan and return a single token. 801 * yylval is set to point to a scanned string. 802 */ 803 804 yylex() 805 { 806 register char *cp, *dot; 807 register int s; 808 809 if (nexttok) { 810 s = nexttok; 811 nexttok = 0; 812 return(s); 813 } 814 cp = charp; 815 while (*cp && isspace(*cp)) 816 cp++; 817 if (*cp == 0) 818 return(0); 819 if (any(*cp, metanet)) { 820 charp = cp+1; 821 return(*cp); 822 } 823 dot = cp; 824 while (*cp && !any(*cp, metanet) && !any(*cp, " \t")) 825 cp++; 826 if (any(*cp, metanet)) 827 nexttok = *cp; 828 if (*cp == 0) 829 charp = cp; 830 else 831 charp = cp+1; 832 *cp = 0; 833 yylval = dot; 834 return(WORD); 835 } 836