| 1 | # |
| 2 | |
| 3 | /* |
| 4 | * Mail -- a program for sending and receiving mail. |
| 5 | * |
| 6 | * Network name modification routines. |
| 7 | */ |
| 8 | |
| 9 | #include "rcv.h" |
| 10 | #include "configdefs.h" |
| 11 | #include <ctype.h> |
| 12 | |
| 13 | static char *SccsId = "@(#)optim.c 2.7 %G%"; |
| 14 | |
| 15 | /* |
| 16 | * Map a name into the correct network "view" of the |
| 17 | * name. This is done by prepending the name with the |
| 18 | * network address of the sender, then optimizing away |
| 19 | * nonsense. |
| 20 | */ |
| 21 | |
| 22 | char * |
| 23 | netmap(name, from) |
| 24 | char name[], from[]; |
| 25 | { |
| 26 | char nbuf[BUFSIZ], ret[BUFSIZ]; |
| 27 | register char *cp; |
| 28 | |
| 29 | if (strlen(from) == 0) |
| 30 | return(name); |
| 31 | if (any('@', name) || any('%', name)) |
| 32 | return(arpafix(name, from)); |
| 33 | cp = revarpa(from); |
| 34 | if (cp == NOSTR) |
| 35 | return(name); |
| 36 | strcpy(nbuf, cp); |
| 37 | cp = &nbuf[strlen(nbuf) - 1]; |
| 38 | while (!any(*cp, metanet) && cp > nbuf) |
| 39 | cp--; |
| 40 | if (cp == nbuf) |
| 41 | return(name); |
| 42 | *++cp = 0; |
| 43 | strcat(nbuf, revarpa(name)); |
| 44 | optim(nbuf, ret); |
| 45 | cp = revarpa(ret); |
| 46 | if (!icequal(name, cp)) |
| 47 | return((char *) savestr(cp)); |
| 48 | return(name); |
| 49 | } |
| 50 | |
| 51 | /* |
| 52 | * Rename the given network path to use |
| 53 | * the kinds of names that we would right here. |
| 54 | */ |
| 55 | |
| 56 | char * |
| 57 | rename(str) |
| 58 | char str[]; |
| 59 | { |
| 60 | register char *cp, *cp2; |
| 61 | char buf[BUFSIZ], path[BUFSIZ]; |
| 62 | register int c, host; |
| 63 | |
| 64 | strcpy(path, ""); |
| 65 | for (;;) { |
| 66 | if ((c = *cp++) == 0) |
| 67 | break; |
| 68 | cp2 = buf; |
| 69 | while (!any(c, metanet) && c != 0) { |
| 70 | *cp2++ = c; |
| 71 | c = *cp++; |
| 72 | } |
| 73 | *cp2 = 0; |
| 74 | if (c == 0) { |
| 75 | strcat(path, buf); |
| 76 | break; |
| 77 | } |
| 78 | host = netlook(buf, ntype(c)); |
| 79 | strcat(path, netname(host)); |
| 80 | stradd(path, c); |
| 81 | } |
| 82 | if (strcmp(str, path) != 0) |
| 83 | return(savestr(path)); |
| 84 | return(str); |
| 85 | } |
| 86 | |
| 87 | /* |
| 88 | * Turn a network machine name into a unique character |
| 89 | */ |
| 90 | netlook(machine, attnet) |
| 91 | char machine[]; |
| 92 | { |
| 93 | register struct netmach *np; |
| 94 | register char *cp, *cp2; |
| 95 | char nbuf[20]; |
| 96 | |
| 97 | /* |
| 98 | * Make into lower case. |
| 99 | */ |
| 100 | |
| 101 | for (cp = machine, cp2 = nbuf; *cp; *cp2++ = little(*cp++)) |
| 102 | ; |
| 103 | *cp2 = 0; |
| 104 | |
| 105 | /* |
| 106 | * If a single letter machine, look through those first. |
| 107 | */ |
| 108 | |
| 109 | if (strlen(nbuf) == 1) |
| 110 | for (np = netmach; np->nt_mid != 0; np++) |
| 111 | if (np->nt_mid == nbuf[0]) |
| 112 | return(nbuf[0]); |
| 113 | |
| 114 | /* |
| 115 | * Look for usual name |
| 116 | */ |
| 117 | |
| 118 | for (np = netmach; np->nt_mid != 0; np++) |
| 119 | if (strcmp(np->nt_machine, nbuf) == 0) |
| 120 | return(np->nt_mid); |
| 121 | |
| 122 | /* |
| 123 | * Look in side hash table. |
| 124 | */ |
| 125 | |
| 126 | return(mstash(nbuf, attnet)); |
| 127 | } |
| 128 | |
| 129 | /* |
| 130 | * Make a little character. |
| 131 | */ |
| 132 | |
| 133 | little(c) |
| 134 | register int c; |
| 135 | { |
| 136 | |
| 137 | if (c >= 'A' && c <= 'Z') |
| 138 | c += 'a' - 'A'; |
| 139 | return(c); |
| 140 | } |
| 141 | |
| 142 | /* |
| 143 | * Turn a network unique character identifier into a network name. |
| 144 | */ |
| 145 | |
| 146 | char * |
| 147 | netname(mid) |
| 148 | { |
| 149 | register struct netmach *np; |
| 150 | char *mlook(); |
| 151 | |
| 152 | if (mid & 0200) |
| 153 | return(mlook(mid)); |
| 154 | for (np = netmach; np->nt_mid != 0; np++) |
| 155 | if (np->nt_mid == mid) |
| 156 | return(np->nt_machine); |
| 157 | return(NOSTR); |
| 158 | } |
| 159 | |
| 160 | /* |
| 161 | * Deal with arpa net addresses. The way this is done is strange. |
| 162 | * In particular, if the destination arpa net host is not Berkeley, |
| 163 | * then the address is correct as stands. Otherwise, we strip off |
| 164 | * the trailing @Berkeley, then cook up a phony person for it to |
| 165 | * be from and optimize the result. |
| 166 | */ |
| 167 | char * |
| 168 | arpafix(name, from) |
| 169 | char name[]; |
| 170 | char from[]; |
| 171 | { |
| 172 | register char *cp; |
| 173 | register int arpamach; |
| 174 | char newname[BUFSIZ]; |
| 175 | char fake[5]; |
| 176 | char fakepath[20]; |
| 177 | |
| 178 | if (debug) { |
| 179 | fprintf(stderr, "arpafix(%s, %s)\n", name, from); |
| 180 | } |
| 181 | cp = rindex(name, '@'); |
| 182 | if (cp == NOSTR) |
| 183 | cp = rindex(name, '%'); |
| 184 | if (cp == NOSTR) { |
| 185 | fprintf(stderr, "Somethings amiss -- no @ or % in arpafix\n"); |
| 186 | return(name); |
| 187 | } |
| 188 | cp++; |
| 189 | arpamach = netlook(cp, '@'); |
| 190 | if (arpamach == 0) { |
| 191 | if (debug) |
| 192 | fprintf(stderr, "machine %s unknown, uses: %s\n", cp, name); |
| 193 | return(name); |
| 194 | } |
| 195 | if (((nettype(arpamach) & nettype(LOCAL)) & ~AN) == 0) { |
| 196 | if (debug) |
| 197 | fprintf(stderr, "machine %s known but remote, uses: %s\n", |
| 198 | cp, name); |
| 199 | return(name); |
| 200 | } |
| 201 | strcpy(newname, name); |
| 202 | cp = rindex(newname, '@'); |
| 203 | if (cp == NOSTR) |
| 204 | cp = rindex(newname, '%'); |
| 205 | *cp = 0; |
| 206 | fake[0] = arpamach; |
| 207 | fake[1] = ':'; |
| 208 | fake[2] = LOCAL; |
| 209 | fake[3] = ':'; |
| 210 | fake[4] = 0; |
| 211 | prefer(fake); |
| 212 | strcpy(fakepath, netname(fake[0])); |
| 213 | stradd(fakepath, fake[1]); |
| 214 | strcat(fakepath, "daemon"); |
| 215 | if (debug) |
| 216 | fprintf(stderr, "machine local, call netmap(%s, %s)\n", |
| 217 | newname, fakepath); |
| 218 | return(netmap(newname, fakepath)); |
| 219 | } |
| 220 | |
| 221 | /* |
| 222 | * Take a network machine descriptor and find the types of connected |
| 223 | * nets and return it. |
| 224 | */ |
| 225 | |
| 226 | nettype(mid) |
| 227 | { |
| 228 | register struct netmach *np; |
| 229 | |
| 230 | if (mid & 0200) |
| 231 | return(mtype(mid)); |
| 232 | for (np = netmach; np->nt_mid != 0; np++) |
| 233 | if (np->nt_mid == mid) |
| 234 | return(np->nt_type); |
| 235 | return(0); |
| 236 | } |
| 237 | |
| 238 | /* |
| 239 | * Hashing routines to salt away machines seen scanning |
| 240 | * networks paths that we don't know about. |
| 241 | */ |
| 242 | |
| 243 | #define XHSIZE 19 /* Size of extra hash table */ |
| 244 | #define NXMID (XHSIZE*3/4) /* Max extra machines */ |
| 245 | |
| 246 | struct xtrahash { |
| 247 | char *xh_name; /* Name of machine */ |
| 248 | short xh_mid; /* Machine ID */ |
| 249 | short xh_attnet; /* Attached networks */ |
| 250 | } xtrahash[XHSIZE]; |
| 251 | |
| 252 | struct xtrahash *xtab[XHSIZE]; /* F: mid-->machine name */ |
| 253 | |
| 254 | short midfree; /* Next free machine id */ |
| 255 | |
| 256 | /* |
| 257 | * Initialize the extra host hash table. |
| 258 | * Called by sreset. |
| 259 | */ |
| 260 | |
| 261 | minit() |
| 262 | { |
| 263 | register struct xtrahash *xp, **tp; |
| 264 | register int i; |
| 265 | |
| 266 | midfree = 0; |
| 267 | tp = &xtab[0]; |
| 268 | for (xp = &xtrahash[0]; xp < &xtrahash[XHSIZE]; xp++) { |
| 269 | xp->xh_name = NOSTR; |
| 270 | xp->xh_mid = 0; |
| 271 | xp->xh_attnet = 0; |
| 272 | *tp++ = (struct xtrahash *) 0; |
| 273 | } |
| 274 | } |
| 275 | |
| 276 | /* |
| 277 | * Stash a net name in the extra host hash table. |
| 278 | * If a new entry is put in the hash table, deduce what |
| 279 | * net the machine is attached to from the net character. |
| 280 | * |
| 281 | * If the machine is already known, add the given attached |
| 282 | * net to those already known. |
| 283 | */ |
| 284 | |
| 285 | mstash(name, attnet) |
| 286 | char name[]; |
| 287 | { |
| 288 | register struct xtrahash *xp; |
| 289 | struct xtrahash *xlocate(); |
| 290 | int x; |
| 291 | |
| 292 | xp = xlocate(name); |
| 293 | if (xp == (struct xtrahash *) 0) { |
| 294 | printf("Ran out of machine id spots\n"); |
| 295 | return(0); |
| 296 | } |
| 297 | if (xp->xh_name == NOSTR) { |
| 298 | if (midfree >= XHSIZE) { |
| 299 | printf("Out of machine ids\n"); |
| 300 | return(0); |
| 301 | } |
| 302 | xtab[midfree] = xp; |
| 303 | xp->xh_name = savestr(name); |
| 304 | xp->xh_mid = 0200 + midfree++; |
| 305 | } |
| 306 | x = ntype(attnet); |
| 307 | if (x == 0) |
| 308 | xp->xh_attnet |= SN; |
| 309 | else |
| 310 | xp->xh_attnet |= x; |
| 311 | return(xp->xh_mid); |
| 312 | } |
| 313 | |
| 314 | /* |
| 315 | * Search for the given name in the hash table |
| 316 | * and return the pointer to it if found, or to the first |
| 317 | * empty slot if not found. |
| 318 | * |
| 319 | * If no free slots can be found, return 0. |
| 320 | */ |
| 321 | |
| 322 | struct xtrahash * |
| 323 | xlocate(name) |
| 324 | char name[]; |
| 325 | { |
| 326 | register int h, q, i; |
| 327 | register char *cp; |
| 328 | register struct xtrahash *xp; |
| 329 | |
| 330 | for (h = 0, cp = name; *cp; h = (h << 2) + *cp++) |
| 331 | ; |
| 332 | if (h < 0 && (h = -h) < 0) |
| 333 | h = 0; |
| 334 | h = h % XHSIZE; |
| 335 | cp = name; |
| 336 | for (i = 0, q = 0; q < XHSIZE; i++, q = i * i) { |
| 337 | xp = &xtrahash[(h + q) % XHSIZE]; |
| 338 | if (xp->xh_name == NOSTR) |
| 339 | return(xp); |
| 340 | if (strcmp(cp, xp->xh_name) == 0) |
| 341 | return(xp); |
| 342 | if (h - q < 0) |
| 343 | q += XHSIZE; |
| 344 | xp = &xtrahash[(h - q) % XHSIZE]; |
| 345 | if (xp->xh_name == NOSTR) |
| 346 | return(xp); |
| 347 | if (strcmp(cp, xp->xh_name) == 0) |
| 348 | return(xp); |
| 349 | } |
| 350 | return((struct xtrahash *) 0); |
| 351 | } |
| 352 | |
| 353 | /* |
| 354 | * Return the name from the extra host hash table corresponding |
| 355 | * to the passed machine id. |
| 356 | */ |
| 357 | |
| 358 | char * |
| 359 | mlook(mid) |
| 360 | { |
| 361 | register int m; |
| 362 | |
| 363 | if ((mid & 0200) == 0) |
| 364 | return(NOSTR); |
| 365 | m = mid & 0177; |
| 366 | if (m >= midfree) { |
| 367 | printf("Use made of undefined machine id\n"); |
| 368 | return(NOSTR); |
| 369 | } |
| 370 | return(xtab[m]->xh_name); |
| 371 | } |
| 372 | |
| 373 | /* |
| 374 | * Return the bit mask of net's that the given extra host machine |
| 375 | * id has so far. |
| 376 | */ |
| 377 | |
| 378 | mtype(mid) |
| 379 | { |
| 380 | register int m; |
| 381 | |
| 382 | if ((mid & 0200) == 0) |
| 383 | return(0); |
| 384 | m = mid & 0177; |
| 385 | if (m >= midfree) { |
| 386 | printf("Use made of undefined machine id\n"); |
| 387 | return(0); |
| 388 | } |
| 389 | return(xtab[m]->xh_attnet); |
| 390 | } |
| 391 | |
| 392 | /* |
| 393 | * Take a network name and optimize it. This gloriously messy |
| 394 | * operation takes place as follows: the name with machine names |
| 395 | * in it is tokenized by mapping each machine name into a single |
| 396 | * character machine id (netlook). The separator characters (network |
| 397 | * metacharacters) are left intact. The last component of the network |
| 398 | * name is stripped off and assumed to be the destination user name -- |
| 399 | * it does not participate in the optimization. As an example, the |
| 400 | * name "research!vax135!research!ucbvax!bill" becomes, tokenized, |
| 401 | * "r!x!r!v!" and "bill" A low level routine, optim1, fixes up the |
| 402 | * network part (eg, "r!x!r!v!"), then we convert back to network |
| 403 | * machine names and tack the user name on the end. |
| 404 | * |
| 405 | * The result of this is copied into the parameter "name" |
| 406 | */ |
| 407 | |
| 408 | optim(net, name) |
| 409 | char net[], name[]; |
| 410 | { |
| 411 | char netcomp[BUFSIZ], netstr[40], xfstr[40]; |
| 412 | register char *cp, *cp2; |
| 413 | register int c; |
| 414 | |
| 415 | strcpy(netstr, ""); |
| 416 | cp = net; |
| 417 | for (;;) { |
| 418 | /* |
| 419 | * Rip off next path component into netcomp |
| 420 | */ |
| 421 | cp2 = netcomp; |
| 422 | while (*cp && !any(*cp, metanet)) |
| 423 | *cp2++ = *cp++; |
| 424 | *cp2 = 0; |
| 425 | /* |
| 426 | * If we hit null byte, then we just scanned |
| 427 | * the destination user name. Go off and optimize |
| 428 | * if its so. |
| 429 | */ |
| 430 | if (*cp == 0) |
| 431 | break; |
| 432 | if ((c = netlook(netcomp, *cp)) == 0) { |
| 433 | printf("No host named \"%s\"\n", netcomp); |
| 434 | err: |
| 435 | strcpy(name, net); |
| 436 | return; |
| 437 | } |
| 438 | stradd(netstr, c); |
| 439 | stradd(netstr, *cp++); |
| 440 | /* |
| 441 | * If multiple network separators given, |
| 442 | * throw away the extras. |
| 443 | */ |
| 444 | while (any(*cp, metanet)) |
| 445 | cp++; |
| 446 | } |
| 447 | if (strlen(netcomp) == 0) { |
| 448 | printf("net name syntax\n"); |
| 449 | goto err; |
| 450 | } |
| 451 | optim1(netstr, xfstr); |
| 452 | |
| 453 | /* |
| 454 | * Convert back to machine names. |
| 455 | */ |
| 456 | |
| 457 | cp = xfstr; |
| 458 | strcpy(name, ""); |
| 459 | while (*cp) { |
| 460 | if ((cp2 = netname(*cp++)) == NOSTR) { |
| 461 | printf("Made up bad net name\n"); |
| 462 | printf("Machine code %c (0%o)\n", cp[-1], cp[-1]); |
| 463 | printf("Sorry -- dumping now. Alert K. Shoens\n"); |
| 464 | core(0); |
| 465 | goto err; |
| 466 | } |
| 467 | strcat(name, cp2); |
| 468 | stradd(name, *cp++); |
| 469 | } |
| 470 | strcat(name, netcomp); |
| 471 | } |
| 472 | |
| 473 | /* |
| 474 | * Take a string of network machine id's and separators and |
| 475 | * optimize them. We process these by pulling off maximal |
| 476 | * leading strings of the same type, passing these to the appropriate |
| 477 | * optimizer and concatenating the results. |
| 478 | */ |
| 479 | |
| 480 | optim1(netstr, name) |
| 481 | char netstr[], name[]; |
| 482 | { |
| 483 | char path[40], rpath[40]; |
| 484 | register char *cp, *cp2; |
| 485 | register int tp, nc; |
| 486 | |
| 487 | cp = netstr; |
| 488 | prefer(cp); |
| 489 | strcpy(name, ""); |
| 490 | /* |
| 491 | * If the address ultimately points back to us, |
| 492 | * just return a null network path. |
| 493 | */ |
| 494 | if (strlen(cp) > 1 && cp[strlen(cp) - 2] == LOCAL) |
| 495 | return; |
| 496 | while (*cp != 0) { |
| 497 | strcpy(path, ""); |
| 498 | tp = ntype(cp[1]); |
| 499 | nc = cp[1]; |
| 500 | while (*cp && tp == ntype(cp[1])) { |
| 501 | stradd(path, *cp++); |
| 502 | cp++; |
| 503 | } |
| 504 | switch (netkind(tp)) { |
| 505 | default: |
| 506 | strcpy(rpath, path); |
| 507 | break; |
| 508 | |
| 509 | case IMPLICIT: |
| 510 | optimimp(path, rpath); |
| 511 | break; |
| 512 | |
| 513 | case EXPLICIT: |
| 514 | optimex(path, rpath); |
| 515 | break; |
| 516 | } |
| 517 | for (cp2 = rpath; *cp2 != 0; cp2++) { |
| 518 | stradd(name, *cp2); |
| 519 | stradd(name, nc); |
| 520 | } |
| 521 | } |
| 522 | optiboth(name); |
| 523 | prefer(name); |
| 524 | } |
| 525 | |
| 526 | /* |
| 527 | * Return the network of the separator -- |
| 528 | * AN for arpa net |
| 529 | * BN for Bell labs net |
| 530 | * SN for Schmidt (berkeley net) |
| 531 | * 0 if we don't know. |
| 532 | */ |
| 533 | |
| 534 | ntype(nc) |
| 535 | register int nc; |
| 536 | { |
| 537 | register struct ntypetab *np; |
| 538 | |
| 539 | for (np = ntypetab; np->nt_char != 0; np++) |
| 540 | if (np->nt_char == nc) |
| 541 | return(np->nt_bcode); |
| 542 | return(0); |
| 543 | } |
| 544 | |
| 545 | /* |
| 546 | * Return the kind of routing used for the particular net |
| 547 | * EXPLICIT means explicitly routed |
| 548 | * IMPLICIT means implicitly routed |
| 549 | * 0 means don't know |
| 550 | */ |
| 551 | |
| 552 | netkind(nt) |
| 553 | register int nt; |
| 554 | { |
| 555 | register struct nkindtab *np; |
| 556 | |
| 557 | for (np = nkindtab; np->nk_type != 0; np++) |
| 558 | if (np->nk_type == nt) |
| 559 | return(np->nk_kind); |
| 560 | return(0); |
| 561 | } |
| 562 | |
| 563 | /* |
| 564 | * Do name optimization for an explicitly routed network (eg BTL network). |
| 565 | */ |
| 566 | |
| 567 | optimex(net, name) |
| 568 | char net[], name[]; |
| 569 | { |
| 570 | register char *cp, *rp; |
| 571 | register int m; |
| 572 | char *rindex(); |
| 573 | |
| 574 | strcpy(name, net); |
| 575 | cp = name; |
| 576 | if (strlen(cp) == 0) |
| 577 | return(-1); |
| 578 | if (cp[strlen(cp)-1] == LOCAL) { |
| 579 | name[0] = 0; |
| 580 | return(0); |
| 581 | } |
| 582 | for (cp = name; *cp; cp++) { |
| 583 | m = *cp; |
| 584 | rp = rindex(cp+1, m); |
| 585 | if (rp != NOSTR) |
| 586 | strcpy(cp, rp); |
| 587 | } |
| 588 | return(0); |
| 589 | } |
| 590 | |
| 591 | /* |
| 592 | * Do name optimization for implicitly routed network (eg, arpanet, |
| 593 | * Berkeley network) |
| 594 | */ |
| 595 | |
| 596 | optimimp(net, name) |
| 597 | char net[], name[]; |
| 598 | { |
| 599 | register char *cp; |
| 600 | register int m; |
| 601 | |
| 602 | cp = net; |
| 603 | if (strlen(cp) == 0) |
| 604 | return(-1); |
| 605 | m = cp[strlen(cp) - 1]; |
| 606 | if (m == LOCAL) { |
| 607 | strcpy(name, ""); |
| 608 | return(0); |
| 609 | } |
| 610 | name[0] = m; |
| 611 | name[1] = 0; |
| 612 | return(0); |
| 613 | } |
| 614 | |
| 615 | /* |
| 616 | * Perform global optimization on the given network path. |
| 617 | * The trick here is to look ahead to see if there are any loops |
| 618 | * in the path and remove them. The interpretation of loops is |
| 619 | * more strict here than in optimex since both the machine and net |
| 620 | * type must match. |
| 621 | */ |
| 622 | |
| 623 | optiboth(net) |
| 624 | char net[]; |
| 625 | { |
| 626 | register char *cp, *cp2; |
| 627 | char *rpair(); |
| 628 | |
| 629 | cp = net; |
| 630 | if (strlen(cp) == 0) |
| 631 | return; |
| 632 | if ((strlen(cp) % 2) != 0) { |
| 633 | printf("Strange arg to optiboth\n"); |
| 634 | return; |
| 635 | } |
| 636 | while (*cp) { |
| 637 | cp2 = rpair(cp+2, *cp); |
| 638 | if (cp2 != NOSTR) |
| 639 | strcpy(cp, cp2); |
| 640 | cp += 2; |
| 641 | } |
| 642 | } |
| 643 | |
| 644 | /* |
| 645 | * Find the rightmost instance of the given (machine, type) pair. |
| 646 | */ |
| 647 | |
| 648 | char * |
| 649 | rpair(str, mach) |
| 650 | char str[]; |
| 651 | { |
| 652 | register char *cp, *last; |
| 653 | |
| 654 | last = NOSTR; |
| 655 | while (*cp) { |
| 656 | if (*cp == mach) |
| 657 | last = cp; |
| 658 | cp += 2; |
| 659 | } |
| 660 | return(last); |
| 661 | } |
| 662 | |
| 663 | /* |
| 664 | * Change the network separators in the given network path |
| 665 | * to the preferred network transmission means. |
| 666 | */ |
| 667 | |
| 668 | prefer(name) |
| 669 | char name[]; |
| 670 | { |
| 671 | register char *cp; |
| 672 | register int state, n; |
| 673 | |
| 674 | state = LOCAL; |
| 675 | for (cp = name; *cp; cp += 2) { |
| 676 | n = best(state, *cp); |
| 677 | if (n) |
| 678 | cp[1] = n; |
| 679 | state = *cp; |
| 680 | } |
| 681 | } |
| 682 | |
| 683 | /* |
| 684 | * Return the best network separator for the given machine pair. |
| 685 | */ |
| 686 | |
| 687 | best(src, dest) |
| 688 | { |
| 689 | register int dtype, stype; |
| 690 | register struct netorder *np; |
| 691 | |
| 692 | stype = nettype(src); |
| 693 | dtype = nettype(dest); |
| 694 | fflush(stdout); |
| 695 | if (stype == 0 || dtype == 0) { |
| 696 | printf("ERROR: unknown internal machine id\n"); |
| 697 | return(0); |
| 698 | } |
| 699 | if ((stype & dtype) == 0) |
| 700 | return(0); |
| 701 | np = &netorder[0]; |
| 702 | while ((np->no_stat & stype & dtype) == 0) |
| 703 | np++; |
| 704 | return(np->no_char); |
| 705 | } |
| 706 | |
| 707 | #ifdef GETHOST |
| 708 | /* |
| 709 | * Initialize the network name of the current host. |
| 710 | */ |
| 711 | inithost() |
| 712 | { |
| 713 | register struct netmach *np; |
| 714 | static char host[64]; |
| 715 | |
| 716 | gethostname(host, sizeof host); |
| 717 | for (np = netmach; np->nt_machine != 0; np++) |
| 718 | if (strcmp(np->nt_machine, EMPTY) == 0) |
| 719 | break; |
| 720 | if (np->nt_machine == 0) { |
| 721 | printf("Cannot find empty slot for dynamic host entry\n"); |
| 722 | exit(1); |
| 723 | } |
| 724 | np->nt_machine = host; |
| 725 | } |
| 726 | #endif GETHOST |
| 727 | |
| 728 | /* |
| 729 | * Code to twist around arpa net names. |
| 730 | */ |
| 731 | |
| 732 | #define WORD 257 /* Token for a string */ |
| 733 | |
| 734 | static char netbuf[256]; |
| 735 | static char *yylval; |
| 736 | |
| 737 | /* |
| 738 | * Reverse all of the arpa net addresses in the given name to |
| 739 | * be of the form "host @ user" instead of "user @ host" |
| 740 | * This function is its own inverse. |
| 741 | */ |
| 742 | |
| 743 | char * |
| 744 | revarpa(str) |
| 745 | char str[]; |
| 746 | { |
| 747 | |
| 748 | if (yyinit(str) < 0) |
| 749 | return(NOSTR); |
| 750 | if (name()) |
| 751 | return(NOSTR); |
| 752 | if (strcmp(str, netbuf) == 0) |
| 753 | return(str); |
| 754 | return(savestr(netbuf)); |
| 755 | } |
| 756 | |
| 757 | /* |
| 758 | * Parse (by recursive descent) network names, using the following grammar: |
| 759 | * name: |
| 760 | * term {':' term} |
| 761 | * term {'^' term} |
| 762 | * term {'!' term} |
| 763 | * term '@' name |
| 764 | * term '%' name |
| 765 | * |
| 766 | * term: |
| 767 | * string of characters. |
| 768 | */ |
| 769 | |
| 770 | name() |
| 771 | { |
| 772 | register int t; |
| 773 | register char *cp; |
| 774 | |
| 775 | for (;;) { |
| 776 | t = yylex(); |
| 777 | if (t != WORD) |
| 778 | return(-1); |
| 779 | cp = yylval; |
| 780 | t = yylex(); |
| 781 | switch (t) { |
| 782 | case 0: |
| 783 | strcat(netbuf, cp); |
| 784 | return(0); |
| 785 | |
| 786 | case '@': |
| 787 | case '%': |
| 788 | if (name()) |
| 789 | return(-1); |
| 790 | stradd(netbuf, '@'); |
| 791 | strcat(netbuf, cp); |
| 792 | return(0); |
| 793 | |
| 794 | case WORD: |
| 795 | return(-1); |
| 796 | |
| 797 | default: |
| 798 | strcat(netbuf, cp); |
| 799 | stradd(netbuf, t); |
| 800 | } |
| 801 | } |
| 802 | } |
| 803 | |
| 804 | /* |
| 805 | * Scanner for network names. |
| 806 | */ |
| 807 | |
| 808 | static char *charp; /* Current input pointer */ |
| 809 | static int nexttok; /* Salted away next token */ |
| 810 | |
| 811 | /* |
| 812 | * Initialize the network name scanner. |
| 813 | */ |
| 814 | |
| 815 | yyinit(str) |
| 816 | char str[]; |
| 817 | { |
| 818 | static char lexbuf[BUFSIZ]; |
| 819 | |
| 820 | netbuf[0] = 0; |
| 821 | if (strlen(str) >= sizeof lexbuf - 1) |
| 822 | return(-1); |
| 823 | nexttok = 0; |
| 824 | strcpy(lexbuf, str); |
| 825 | charp = lexbuf; |
| 826 | return(0); |
| 827 | } |
| 828 | |
| 829 | /* |
| 830 | * Scan and return a single token. |
| 831 | * yylval is set to point to a scanned string. |
| 832 | */ |
| 833 | |
| 834 | yylex() |
| 835 | { |
| 836 | register char *cp, *dot; |
| 837 | register int s; |
| 838 | |
| 839 | if (nexttok) { |
| 840 | s = nexttok; |
| 841 | nexttok = 0; |
| 842 | return(s); |
| 843 | } |
| 844 | cp = charp; |
| 845 | while (*cp && isspace(*cp)) |
| 846 | cp++; |
| 847 | if (*cp == 0) |
| 848 | return(0); |
| 849 | if (any(*cp, metanet)) { |
| 850 | charp = cp+1; |
| 851 | return(*cp); |
| 852 | } |
| 853 | dot = cp; |
| 854 | while (*cp && !any(*cp, metanet) && !any(*cp, " \t")) |
| 855 | cp++; |
| 856 | if (any(*cp, metanet)) |
| 857 | nexttok = *cp; |
| 858 | if (*cp == 0) |
| 859 | charp = cp; |
| 860 | else |
| 861 | charp = cp+1; |
| 862 | *cp = 0; |
| 863 | yylval = dot; |
| 864 | return(WORD); |
| 865 | } |
| 866 | |
| 867 | /* |
| 868 | * Add a single character onto a string. |
| 869 | */ |
| 870 | |
| 871 | stradd(str, c) |
| 872 | register char *str; |
| 873 | register int c; |
| 874 | { |
| 875 | |
| 876 | str += strlen(str); |
| 877 | *str++ = c; |
| 878 | *str = 0; |
| 879 | } |