| 1 | #define USER 1 |
| 2 | #include <stdio.h> |
| 3 | #include <sys/pk.p> |
| 4 | #include <sys/param.h> |
| 5 | #include <sys/pk.h> |
| 6 | #include <sys/buf.h> |
| 7 | |
| 8 | /* |
| 9 | * packet driver |
| 10 | */ |
| 11 | |
| 12 | char next[8] ={ 1,2,3,4,5,6,7,0}; /* packet sequence numbers */ |
| 13 | char mask[8] ={ 1,2,4,010,020,040,0100,0200 }; |
| 14 | |
| 15 | struct pack *pklines[NPLINES]; |
| 16 | |
| 17 | |
| 18 | |
| 19 | /* |
| 20 | * receive control messages |
| 21 | */ |
| 22 | pkcntl(c, pk) |
| 23 | register struct pack *pk; |
| 24 | { |
| 25 | register cntl, val; |
| 26 | |
| 27 | val = c & MOD8; |
| 28 | cntl = (c>>3) & MOD8; |
| 29 | |
| 30 | if ( ! ISCNTL(c) ) { |
| 31 | fprintf(stderr, "not cntl\n"); |
| 32 | return; |
| 33 | } |
| 34 | |
| 35 | if (pk->p_mode & 02) |
| 36 | fprintf(stderr, "%o ",c); |
| 37 | switch(cntl) { |
| 38 | |
| 39 | case INITB: |
| 40 | val++; |
| 41 | pk->p_xsize = pksizes[val]; |
| 42 | pk->p_lpsize = val; |
| 43 | pk->p_bits = DTOM(pk->p_xsize); |
| 44 | if (pk->p_state & LIVE) { |
| 45 | pk->p_msg |= M_INITC; |
| 46 | break; |
| 47 | } |
| 48 | pk->p_state |= INITb; |
| 49 | if ((pk->p_state & INITa)==0) { |
| 50 | break; |
| 51 | } |
| 52 | pk->p_rmsg &= ~M_INITA; |
| 53 | pk->p_msg |= M_INITC; |
| 54 | break; |
| 55 | |
| 56 | case INITC: |
| 57 | if ((pk->p_state&INITab)==INITab) { |
| 58 | pk->p_state = LIVE; |
| 59 | WAKEUP(&pk->p_state); |
| 60 | pk->p_rmsg &= ~M_INITB; |
| 61 | } else |
| 62 | pk->p_msg |= M_INITB; |
| 63 | if (val) |
| 64 | pk->p_swindow = val; |
| 65 | break; |
| 66 | case INITA: |
| 67 | if (val==0 && pk->p_state&LIVE) { |
| 68 | fprintf(stderr, "alloc change not implemented\n"); |
| 69 | break; |
| 70 | } |
| 71 | if (val) { |
| 72 | pk->p_state |= INITa; |
| 73 | pk->p_msg |= M_INITB; |
| 74 | pk->p_rmsg |= M_INITB; |
| 75 | pk->p_swindow = val; |
| 76 | } |
| 77 | break; |
| 78 | case RJ: |
| 79 | pk->p_state |= RXMIT; |
| 80 | pk->p_msg |= M_RR; |
| 81 | case RR: |
| 82 | pk->p_rpr = val; |
| 83 | if (pksack(pk)==0) { |
| 84 | WAKEUP(&pk->p_ps); |
| 85 | } |
| 86 | break; |
| 87 | case SRJ: |
| 88 | fprintf(stderr, "srj not implemented\n"); |
| 89 | break; |
| 90 | case CLOSE: |
| 91 | pk->p_state = DOWN+RCLOSE; |
| 92 | SIGNAL; |
| 93 | WAKEUP(&pk->p_pr); |
| 94 | WAKEUP(&pk->p_ps); |
| 95 | WAKEUP(&pk->p_state); |
| 96 | return; |
| 97 | } |
| 98 | out: |
| 99 | if (pk->p_msg) |
| 100 | pkoutput(pk); |
| 101 | } |
| 102 | |
| 103 | |
| 104 | |
| 105 | pkaccept(pk) |
| 106 | register struct pack *pk; |
| 107 | { |
| 108 | register x,seq; |
| 109 | char m, cntl, *p, imask, **bp; |
| 110 | int bad,accept,skip,s,t,h,cc; |
| 111 | unsigned short sum; |
| 112 | |
| 113 | bad = accept = skip = 0; |
| 114 | /* |
| 115 | * wait for input |
| 116 | */ |
| 117 | LOCK; |
| 118 | x = next[pk->p_pr]; |
| 119 | while ((imask=pk->p_imap) == 0 && pk->p_rcount==0) { |
| 120 | PKGETPKT(pk); |
| 121 | SLEEP(&pk->p_pr, PKIPRI); |
| 122 | } |
| 123 | pk->p_imap = 0; |
| 124 | UNLOCK; |
| 125 | |
| 126 | |
| 127 | /* |
| 128 | * determine input window in m. |
| 129 | */ |
| 130 | t = (~(-1<<pk->p_rwindow)) <<x; |
| 131 | m = t; |
| 132 | m |= t>>8; |
| 133 | |
| 134 | |
| 135 | /* |
| 136 | * mark newly accepted input buffers |
| 137 | */ |
| 138 | for(x=0; x<8; x++) { |
| 139 | |
| 140 | if ((imask & mask[x]) == 0) |
| 141 | continue; |
| 142 | |
| 143 | if (((cntl=pk->p_is[x])&0200)==0) { |
| 144 | bad++; |
| 145 | free: |
| 146 | bp = (char **)pk->p_ib[x]; |
| 147 | LOCK; |
| 148 | *bp = (char *)pk->p_ipool; |
| 149 | pk->p_ipool = bp; |
| 150 | pk->p_is[x] = 0; |
| 151 | UNLOCK; |
| 152 | continue; |
| 153 | } |
| 154 | |
| 155 | pk->p_is[x] = ~(B_COPY+B_MARK); |
| 156 | sum = (unsigned)chksum(pk->p_ib[x], pk->p_rsize) ^ (unsigned)cntl; |
| 157 | sum += pk->p_isum[x]; |
| 158 | if (sum == CHECK) { |
| 159 | seq = (cntl>>3) & MOD8; |
| 160 | if (m & mask[seq]) { |
| 161 | if (pk->p_is[seq] & (B_COPY | B_MARK)) { |
| 162 | dup: |
| 163 | pk->p_msg |= M_RR; |
| 164 | skip++; |
| 165 | goto free; |
| 166 | } |
| 167 | if (x != seq) { |
| 168 | LOCK; |
| 169 | p = pk->p_ib[x]; |
| 170 | pk->p_ib[x] = pk->p_ib[seq]; |
| 171 | pk->p_is[x] = pk->p_is[seq]; |
| 172 | pk->p_ib[seq] = p; |
| 173 | UNLOCK; |
| 174 | } |
| 175 | pk->p_is[seq] = B_MARK; |
| 176 | accept++; |
| 177 | cc = 0; |
| 178 | if (cntl&B_SHORT) { |
| 179 | pk->p_is[seq] = B_MARK+B_SHORT; |
| 180 | p = pk->p_ib[seq]; |
| 181 | cc = (unsigned)*p++; |
| 182 | if (cc & 0200) { |
| 183 | cc &= 0177; |
| 184 | cc |= *p << 7; |
| 185 | } |
| 186 | } |
| 187 | pk->p_isum[seq] = pk->p_rsize - cc; |
| 188 | } else { |
| 189 | goto dup; |
| 190 | } |
| 191 | } else { |
| 192 | bad++; |
| 193 | goto free; |
| 194 | } |
| 195 | } |
| 196 | |
| 197 | /* |
| 198 | * scan window again turning marked buffers into |
| 199 | * COPY buffers and looking for missing sequence |
| 200 | * numbers. |
| 201 | */ |
| 202 | accept = 0; |
| 203 | for(x=next[pk->p_pr],t=h= -1; m & mask[x]; x = next[x]) { |
| 204 | if (pk->p_is[x] & B_MARK) |
| 205 | pk->p_is[x] |= B_COPY; |
| 206 | /* hole code |
| 207 | if (pk->p_is[x] & B_COPY) { |
| 208 | if (h<0 && t>=0) |
| 209 | h = x; |
| 210 | } else { |
| 211 | if (t<0) |
| 212 | t = x; |
| 213 | } |
| 214 | */ |
| 215 | if (pk->p_is[x] & B_COPY) { |
| 216 | if (t >= 0) { |
| 217 | bp = (char **)pk->p_ib[x]; |
| 218 | LOCK; |
| 219 | *bp = (char *)pk->p_ipool; |
| 220 | pk->p_ipool = bp; |
| 221 | pk->p_is[x] = 0; |
| 222 | UNLOCK; |
| 223 | skip++; |
| 224 | } else |
| 225 | accept++; |
| 226 | } else { |
| 227 | if (t<0) |
| 228 | t = x; |
| 229 | } |
| 230 | } |
| 231 | |
| 232 | if (bad) { |
| 233 | pk->p_msg |= M_RJ; |
| 234 | } |
| 235 | |
| 236 | if (skip) { |
| 237 | pk->p_msg |= M_RR; |
| 238 | } |
| 239 | |
| 240 | pk->p_rcount = accept; |
| 241 | return(accept); |
| 242 | } |
| 243 | |
| 244 | |
| 245 | pkread(S) |
| 246 | SDEF; |
| 247 | { |
| 248 | register struct pack *pk; |
| 249 | register x,s; |
| 250 | int is,cc,xfr,count; |
| 251 | char *cp, **bp; |
| 252 | |
| 253 | pk = PADDR; |
| 254 | xfr = 0; |
| 255 | count = 0; |
| 256 | while (pkaccept(pk)==0); |
| 257 | |
| 258 | |
| 259 | while (UCOUNT) { |
| 260 | |
| 261 | x = next[pk->p_pr]; |
| 262 | is = pk->p_is[x]; |
| 263 | |
| 264 | if (is & B_COPY) { |
| 265 | cc = MIN(pk->p_isum[x], UCOUNT); |
| 266 | if (cc==0 && xfr) { |
| 267 | break; |
| 268 | } |
| 269 | if (is & B_RESID) |
| 270 | cp = pk->p_rptr; |
| 271 | else { |
| 272 | cp = pk->p_ib[x]; |
| 273 | if (is & B_SHORT) { |
| 274 | if (*cp++ & 0200) |
| 275 | *cp++; |
| 276 | } |
| 277 | } |
| 278 | IOMOVE(cp,cc,B_READ); |
| 279 | count += cc; |
| 280 | xfr++; |
| 281 | pk->p_isum[x] -= cc; |
| 282 | if (pk->p_isum[x] == 0) { |
| 283 | pk->p_pr = x; |
| 284 | bp = (char **)pk->p_ib[x]; |
| 285 | LOCK; |
| 286 | *bp = (char *)pk->p_ipool; |
| 287 | pk->p_ipool = bp; |
| 288 | pk->p_is[x] = 0; |
| 289 | pk->p_rcount--; |
| 290 | UNLOCK; |
| 291 | pk->p_msg |= M_RR; |
| 292 | } else { |
| 293 | pk->p_rptr = cp+cc; |
| 294 | pk->p_is[x] |= B_RESID; |
| 295 | } |
| 296 | if (cc==0) |
| 297 | break; |
| 298 | } else |
| 299 | break; |
| 300 | } |
| 301 | pkoutput(pk); |
| 302 | return(count); |
| 303 | } |
| 304 | |
| 305 | |
| 306 | |
| 307 | |
| 308 | pkwrite(S) |
| 309 | SDEF; |
| 310 | { |
| 311 | register struct pack *pk; |
| 312 | register x; |
| 313 | int partial; |
| 314 | caddr_t cp; |
| 315 | int cc, s, fc, count; |
| 316 | int pktimeout(); |
| 317 | |
| 318 | pk = PADDR; |
| 319 | if (pk->p_state&DOWN || !pk->p_state&LIVE) { |
| 320 | SETERROR; |
| 321 | return(-1); |
| 322 | } |
| 323 | |
| 324 | count = UCOUNT; |
| 325 | do { |
| 326 | LOCK; |
| 327 | while (pk->p_xcount>=pk->p_swindow) { |
| 328 | pkoutput(pk); |
| 329 | PKGETPKT(pk); |
| 330 | SLEEP(&pk->p_ps,PKOPRI); |
| 331 | } |
| 332 | x = next[pk->p_pscopy]; |
| 333 | while (pk->p_os[x]!=B_NULL) { |
| 334 | PKGETPKT(pk); |
| 335 | SLEEP(&pk->p_ps,PKOPRI); |
| 336 | } |
| 337 | pk->p_os[x] = B_MARK; |
| 338 | pk->p_pscopy = x; |
| 339 | pk->p_xcount++; |
| 340 | UNLOCK; |
| 341 | |
| 342 | cp = pk->p_ob[x] = GETEPACK; |
| 343 | partial = 0; |
| 344 | if ((int)UCOUNT < pk->p_xsize) { |
| 345 | cc = UCOUNT; |
| 346 | fc = pk->p_xsize - cc; |
| 347 | *cp = fc&0177; |
| 348 | if (fc > 127) { |
| 349 | *cp++ |= 0200; |
| 350 | *cp++ = fc>>7; |
| 351 | } else |
| 352 | cp++; |
| 353 | partial = B_SHORT; |
| 354 | } else |
| 355 | cc = pk->p_xsize; |
| 356 | IOMOVE(cp,cc,B_WRITE); |
| 357 | pk->p_osum[x] = chksum(pk->p_ob[x], pk->p_xsize); |
| 358 | pk->p_os[x] = B_READY+partial; |
| 359 | pkoutput(pk); |
| 360 | } while (UCOUNT); |
| 361 | |
| 362 | return(count); |
| 363 | } |
| 364 | |
| 365 | pksack(pk) |
| 366 | register struct pack *pk; |
| 367 | { |
| 368 | register x, i; |
| 369 | |
| 370 | i = 0; |
| 371 | for(x=pk->p_ps; x!=pk->p_rpr; ) { |
| 372 | x = next[x]; |
| 373 | if (pk->p_os[x]&B_SENT) { |
| 374 | i++; |
| 375 | pk->p_os[x] = B_NULL; |
| 376 | pk->p_state &= ~WAITO; |
| 377 | pk->p_xcount--; |
| 378 | FREEPACK(pk->p_ob[x], pk->p_bits); |
| 379 | pk->p_ps = x; |
| 380 | WAKEUP(&pk->p_ps); |
| 381 | } |
| 382 | } |
| 383 | return(i); |
| 384 | } |
| 385 | |
| 386 | |
| 387 | |
| 388 | pkoutput(pk) |
| 389 | register struct pack *pk; |
| 390 | { |
| 391 | register x,rx; |
| 392 | int s; |
| 393 | char bstate; |
| 394 | int i; |
| 395 | SDEF; |
| 396 | int flag; |
| 397 | |
| 398 | flag = 0; |
| 399 | ISYSTEM; |
| 400 | LOCK; |
| 401 | if (pk->p_obusy++ || OBUSY) { |
| 402 | pk->p_obusy--; |
| 403 | UNLOCK; |
| 404 | return; |
| 405 | } |
| 406 | UNLOCK; |
| 407 | |
| 408 | |
| 409 | /* |
| 410 | * find seq number and buffer state |
| 411 | * of next output packet |
| 412 | */ |
| 413 | if (pk->p_state&RXMIT) { |
| 414 | pk->p_nxtps = next[pk->p_rpr]; |
| 415 | flag++; |
| 416 | } |
| 417 | x = pk->p_nxtps; |
| 418 | bstate = pk->p_os[x]; |
| 419 | |
| 420 | |
| 421 | /* |
| 422 | * Send control packet if indicated |
| 423 | */ |
| 424 | if (pk->p_msg) { |
| 425 | if (pk->p_msg & ~M_RR || !(bstate&B_READY) ) { |
| 426 | x = pk->p_msg; |
| 427 | for(i=0; i<8; i++) |
| 428 | if (x&1) |
| 429 | break; else |
| 430 | x >>= 1; |
| 431 | x = i; |
| 432 | x <<= 3; |
| 433 | switch(i) { |
| 434 | case CLOSE: |
| 435 | break; |
| 436 | case RJ: |
| 437 | case RR: |
| 438 | x += pk->p_pr; |
| 439 | break; |
| 440 | case SRJ: |
| 441 | break; |
| 442 | case INITB: |
| 443 | x += pksize(pk->p_rsize); |
| 444 | break; |
| 445 | case INITC: |
| 446 | x += pk->p_rwindow; |
| 447 | break; |
| 448 | case INITA: |
| 449 | x += pk->p_rwindow; |
| 450 | break; |
| 451 | } |
| 452 | |
| 453 | pk->p_msg &= ~mask[i]; |
| 454 | pkxstart(pk, x, -1); |
| 455 | goto out; |
| 456 | } |
| 457 | } |
| 458 | |
| 459 | |
| 460 | /* |
| 461 | * Don't send data packets if line is marked dead. |
| 462 | */ |
| 463 | if (pk->p_state&DOWN) { |
| 464 | WAKEUP(&pk->p_ps); |
| 465 | goto out; |
| 466 | } |
| 467 | /* |
| 468 | * Start transmission (or retransmission) of data packets. |
| 469 | */ |
| 470 | if (bstate & (B_READY|B_SENT)) { |
| 471 | char seq; |
| 472 | |
| 473 | bstate |= B_SENT; |
| 474 | seq = x; |
| 475 | pk->p_nxtps = next[x]; |
| 476 | |
| 477 | x = 0200+pk->p_pr+(seq<<3); |
| 478 | if (bstate & B_SHORT) |
| 479 | x |= 0100; |
| 480 | pkxstart(pk, x, seq); |
| 481 | pk->p_os[seq] = bstate; |
| 482 | pk->p_state &= ~RXMIT; |
| 483 | pk->p_nout++; |
| 484 | goto out; |
| 485 | } |
| 486 | /* |
| 487 | * enable timeout if there's nothing to send |
| 488 | * and transmission buffers are languishing |
| 489 | */ |
| 490 | if (pk->p_xcount) { |
| 491 | pk->p_timer = 2; |
| 492 | pk->p_state |= WAITO; |
| 493 | } else |
| 494 | pk->p_state &= ~WAITO; |
| 495 | WAKEUP(&pk->p_ps); |
| 496 | out: |
| 497 | pk->p_obusy = 0; |
| 498 | } |
| 499 | |
| 500 | |
| 501 | /* |
| 502 | * shut down line by |
| 503 | * ignoring new input |
| 504 | * letting output drain |
| 505 | * releasing space and turning off line discipline |
| 506 | */ |
| 507 | pkclose(S) |
| 508 | SDEF; |
| 509 | { |
| 510 | register struct pack *pk; |
| 511 | register i,s,rbits; |
| 512 | char **bp; |
| 513 | int rcheck; |
| 514 | char *p; |
| 515 | |
| 516 | |
| 517 | pk = PADDR; |
| 518 | pk->p_state |= DRAINO; |
| 519 | |
| 520 | |
| 521 | /* |
| 522 | * try to flush output |
| 523 | */ |
| 524 | i = 0; |
| 525 | LOCK; |
| 526 | pk->p_timer = 2; |
| 527 | while (pk->p_xcount && pk->p_state&LIVE) { |
| 528 | if (pk->p_state&(RCLOSE+DOWN) || ++i > 2) |
| 529 | break; |
| 530 | pkoutput(pk); |
| 531 | SLEEP(&pk->p_ps,PKOPRI); |
| 532 | } |
| 533 | pk->p_timer = 0; |
| 534 | pk->p_state |= DOWN; |
| 535 | UNLOCK; |
| 536 | |
| 537 | |
| 538 | /* |
| 539 | * try to exchange CLOSE messages |
| 540 | */ |
| 541 | i = 0; |
| 542 | while ((pk->p_state&RCLOSE)==0 && i<2) { |
| 543 | pk->p_msg = M_CLOSE; |
| 544 | pk->p_timer = 2; |
| 545 | pkoutput(pk); |
| 546 | SLEEP(&pk->p_ps, PKOPRI); |
| 547 | i++; |
| 548 | } |
| 549 | |
| 550 | |
| 551 | for(i=0;i<NPLINES;i++) |
| 552 | if (pklines[i]==pk) { |
| 553 | pklines[i] = NULL; |
| 554 | } |
| 555 | TURNOFF; |
| 556 | |
| 557 | |
| 558 | /* |
| 559 | * free space |
| 560 | */ |
| 561 | rbits = DTOM(pk->p_rsize); |
| 562 | rcheck = 0; |
| 563 | for (i=0;i<8;i++) { |
| 564 | if (pk->p_os[i]!=B_NULL) { |
| 565 | FREEPACK(pk->p_ob[i],pk->p_bits); |
| 566 | pk->p_xcount--; |
| 567 | } |
| 568 | if (pk->p_is[i]!=B_NULL) { |
| 569 | FREEPACK(pk->p_ib[i],rbits); |
| 570 | rcheck++; |
| 571 | } |
| 572 | } |
| 573 | LOCK; |
| 574 | while (pk->p_ipool != NULL) { |
| 575 | bp = pk->p_ipool; |
| 576 | pk->p_ipool = (char **)*bp; |
| 577 | rcheck++; |
| 578 | FREEPACK(bp, rbits); |
| 579 | } |
| 580 | UNLOCK; |
| 581 | if (rcheck != pk->p_rwindow) { |
| 582 | fprintf(stderr, "r short %d want %d\n",rcheck,pk->p_rwindow); |
| 583 | fprintf(stderr, "rcount = %d\n",pk->p_rcount); |
| 584 | fprintf(stderr, "xcount = %d\n",pk->p_xcount); |
| 585 | } |
| 586 | FREEPACK((caddr_t)pk, npbits); |
| 587 | } |
| 588 | |
| 589 | |
| 590 | |
| 591 | pkreset(pk) |
| 592 | register struct pack *pk; |
| 593 | { |
| 594 | |
| 595 | pk->p_ps = pk->p_pr = pk->p_rpr = 0; |
| 596 | pk->p_nxtps = 1; |
| 597 | } |
| 598 | |
| 599 | chksum(s,n) |
| 600 | register char *s; |
| 601 | register n; |
| 602 | { |
| 603 | register short sum; |
| 604 | register unsigned t; |
| 605 | register x; |
| 606 | |
| 607 | sum = -1; |
| 608 | x = 0; |
| 609 | |
| 610 | do { |
| 611 | if (sum<0) { |
| 612 | sum <<= 1; |
| 613 | sum++; |
| 614 | } else |
| 615 | sum <<= 1; |
| 616 | t = sum; |
| 617 | sum += (unsigned)*s++; |
| 618 | x += sum^n; |
| 619 | if ((unsigned)sum <= t) { |
| 620 | sum ^= x; |
| 621 | } |
| 622 | } while (--n > 0); |
| 623 | |
| 624 | return(sum); |
| 625 | } |
| 626 | |
| 627 | pkline(pk) |
| 628 | register struct pack *pk; |
| 629 | { |
| 630 | register i; |
| 631 | for(i=0;i<NPLINES;i++) { |
| 632 | if (pklines[i]==pk) |
| 633 | return(i); |
| 634 | } |
| 635 | return(-i); |
| 636 | } |
| 637 | |
| 638 | pkzero(s,n) |
| 639 | register char *s; |
| 640 | register n; |
| 641 | { |
| 642 | while (n--) |
| 643 | *s++ = 0; |
| 644 | } |
| 645 | |
| 646 | pksize(n) |
| 647 | register n; |
| 648 | { |
| 649 | register k; |
| 650 | |
| 651 | n >>= 5; |
| 652 | for(k=0; n >>= 1; k++); |
| 653 | return(k); |
| 654 | } |