1 /* if_ec.c 4.34 83/05/27 */ 2 3 #include "ec.h" 4 5 /* 6 * 3Com Ethernet Controller interface 7 */ 8 #include "../machine/pte.h" 9 10 #include "../h/param.h" 11 #include "../h/systm.h" 12 #include "../h/mbuf.h" 13 #include "../h/buf.h" 14 #include "../h/protosw.h" 15 #include "../h/socket.h" 16 #include "../h/vmmac.h" 17 #include <errno.h> 18 19 #include "../net/if.h" 20 #include "../net/netisr.h" 21 #include "../net/route.h" 22 #include "../netinet/in.h" 23 #include "../netinet/in_systm.h" 24 #include "../netinet/ip.h" 25 #include "../netinet/ip_var.h" 26 #include "../netinet/if_ether.h" 27 #include "../netpup/pup.h" 28 29 #include "../vax/cpu.h" 30 #include "../vax/mtpr.h" 31 #include "../vaxif/if_ecreg.h" 32 #include "../vaxif/if_uba.h" 33 #include "../vaxuba/ubareg.h" 34 #include "../vaxuba/ubavar.h" 35 36 #define ECMEM 0000000 37 38 int ecprobe(), ecattach(), ecrint(), ecxint(), eccollide(); 39 struct uba_device *ecinfo[NEC]; 40 u_short ecstd[] = { 0 }; 41 struct uba_driver ecdriver = 42 { ecprobe, 0, ecattach, 0, ecstd, "ec", ecinfo }; 43 #define ECUNIT(x) minor(x) 44 45 int ecinit(),ecoutput(),ecreset(); 46 struct mbuf *ecget(); 47 48 extern struct ifnet loif; 49 50 /* 51 * Ethernet software status per interface. 52 * 53 * Each interface is referenced by a network interface structure, 54 * es_if, which the routing code uses to locate the interface. 55 * This structure contains the output queue for the interface, its address, ... 56 * We also have, for each interface, a UBA interface structure, which 57 * contains information about the UNIBUS resources held by the interface: 58 * map registers, buffered data paths, etc. Information is cached in this 59 * structure for use by the if_uba.c routines in running the interface 60 * efficiently. 61 */ 62 struct ec_softc { 63 struct arpcom es_ac; /* common Ethernet structures */ 64 #define es_if es_ac.ac_if /* network-visible interface */ 65 #define es_addr es_ac.ac_enaddr /* hardware Ethernet address */ 66 struct ifuba es_ifuba; /* UNIBUS resources */ 67 short es_mask; /* mask for current output delay */ 68 short es_oactive; /* is output active? */ 69 u_char *es_buf[16]; /* virtual addresses of buffers */ 70 } ec_softc[NEC]; 71 72 /* 73 * Do output DMA to determine interface presence and 74 * interrupt vector. DMA is too short to disturb other hosts. 75 */ 76 ecprobe(reg) 77 caddr_t reg; 78 { 79 register int br, cvec; /* r11, r10 value-result */ 80 register struct ecdevice *addr = (struct ecdevice *)reg; 81 register caddr_t ecbuf = (caddr_t) &umem[numuba][ECMEM]; 82 83 #ifdef lint 84 br = 0; cvec = br; br = cvec; 85 ecrint(0); ecxint(0); eccollide(0); 86 #endif 87 /* 88 * Make sure memory is turned on 89 */ 90 addr->ec_rcr = EC_AROM; 91 /* 92 * Disable map registers for ec unibus space, 93 * but don't allocate yet. 94 */ 95 (void) ubamem(numuba, ECMEM, 32*2, 0); 96 /* 97 * Check for existence of buffers on Unibus. 98 */ 99 if (badaddr((caddr_t)ecbuf, 2)) { 100 bad1: 101 printf("ec: buffer mem not found\n"); 102 bad2: 103 (void) ubamem(numuba, 0, 0, 0); /* reenable map (780 only) */ 104 addr->ec_rcr = EC_MDISAB; /* disable memory */ 105 return (0); 106 } 107 #if VAX780 108 if (cpu == VAX_780 && uba_hd[numuba].uh_uba->uba_sr) { 109 uba_hd[numuba].uh_uba->uba_sr = uba_hd[numuba].uh_uba->uba_sr; 110 goto bad1; 111 } 112 #endif 113 114 /* 115 * Tell the system that the board has memory here, so it won't 116 * attempt to allocate the addresses later. 117 */ 118 if (ubamem(numuba, ECMEM, 32*2, 1) == 0) { 119 printf("ecprobe: cannot reserve uba addresses\n"); 120 goto bad2; 121 } 122 123 /* 124 * Make a one byte packet in what should be buffer #0. 125 * Submit it for sending. This whould cause an xmit interrupt. 126 * The xmit interrupt vector is 8 bytes after the receive vector, 127 * so adjust for this before returning. 128 */ 129 *(u_short *)ecbuf = (u_short) 03777; 130 ecbuf[03777] = '\0'; 131 addr->ec_xcr = EC_XINTEN|EC_XWBN; 132 DELAY(100000); 133 addr->ec_xcr = EC_XCLR; 134 if (cvec > 0 && cvec != 0x200) { 135 if (cvec & 04) { /* collision interrupt */ 136 cvec -= 04; 137 br += 1; /* rcv is collision + 1 */ 138 } else { /* xmit interrupt */ 139 cvec -= 010; 140 br += 2; /* rcv is xmit + 2 */ 141 } 142 } 143 return (1); 144 } 145 146 /* 147 * Interface exists: make available by filling in network interface 148 * record. System will initialize the interface when it is ready 149 * to accept packets. 150 */ 151 ecattach(ui) 152 struct uba_device *ui; 153 { 154 struct ec_softc *es = &ec_softc[ui->ui_unit]; 155 register struct ifnet *ifp = &es->es_if; 156 register struct ecdevice *addr = (struct ecdevice *)ui->ui_addr; 157 struct sockaddr_in *sin; 158 int i, j; 159 u_char *cp; 160 161 ifp->if_unit = ui->ui_unit; 162 ifp->if_name = "ec"; 163 ifp->if_mtu = ETHERMTU; 164 165 /* 166 * Read the ethernet address off the board, one nibble at a time. 167 */ 168 addr->ec_xcr = EC_UECLR; 169 addr->ec_rcr = EC_AROM; 170 cp = es->es_addr; 171 #define NEXTBIT addr->ec_rcr = EC_AROM|EC_ASTEP; addr->ec_rcr = EC_AROM 172 for (i=0; i<6; i++) { 173 *cp = 0; 174 for (j=0; j<=4; j+=4) { 175 *cp |= ((addr->ec_rcr >> 8) & 0xf) << j; 176 NEXTBIT; NEXTBIT; NEXTBIT; NEXTBIT; 177 } 178 cp++; 179 } 180 sin = (struct sockaddr_in *)&es->es_if.if_addr; 181 sin->sin_family = AF_INET; 182 sin->sin_addr = arpmyaddr((struct arpcom *)0); 183 ifp->if_init = ecinit; 184 ifp->if_output = ecoutput; 185 ifp->if_reset = ecreset; 186 for (i=0; i<16; i++) 187 es->es_buf[i] = (u_char *)&umem[ui->ui_ubanum][ECMEM+2048*i]; 188 if_attach(ifp); 189 } 190 191 /* 192 * Reset of interface after UNIBUS reset. 193 * If interface is on specified uba, reset its state. 194 */ 195 ecreset(unit, uban) 196 int unit, uban; 197 { 198 register struct uba_device *ui; 199 200 if (unit >= NEC || (ui = ecinfo[unit]) == 0 || ui->ui_alive == 0 || 201 ui->ui_ubanum != uban) 202 return; 203 printf(" ec%d", unit); 204 (void) ubamem(uban, ECMEM, 32*2, 0); /* mr disable (no alloc) */ 205 ecinit(unit); 206 } 207 208 /* 209 * Initialization of interface; clear recorded pending 210 * operations, and reinitialize UNIBUS usage. 211 */ 212 ecinit(unit) 213 int unit; 214 { 215 struct ec_softc *es = &ec_softc[unit]; 216 struct ecdevice *addr; 217 int i, s; 218 register struct ifnet *ifp = &es->es_if; 219 register struct sockaddr_in *sin, *sinb; 220 221 sin = (struct sockaddr_in *)&ifp->if_addr; 222 if (sin->sin_addr.s_addr == 0) /* if address still unknown */ 223 return; 224 ifp->if_net = in_netof(sin->sin_addr); 225 ifp->if_host[0] = in_lnaof(sin->sin_addr); 226 sinb = (struct sockaddr_in *)&ifp->if_broadaddr; 227 sinb->sin_family = AF_INET; 228 sinb->sin_addr = if_makeaddr(ifp->if_net, INADDR_ANY); 229 ifp->if_flags = IFF_BROADCAST; 230 231 /* 232 * Hang receive buffers and start any pending writes. 233 * Writing into the rcr also makes sure the memory 234 * is turned on. 235 */ 236 addr = (struct ecdevice *)ecinfo[unit]->ui_addr; 237 s = splimp(); 238 for (i=ECRHBF; i>=ECRLBF; i--) 239 addr->ec_rcr = EC_READ|i; 240 es->es_oactive = 0; 241 es->es_mask = ~0; 242 es->es_if.if_flags |= IFF_UP; 243 if (es->es_if.if_snd.ifq_head) 244 ecstart(unit); 245 splx(s); 246 if_rtinit(&es->es_if, RTF_UP); 247 arpattach(&es->es_ac); 248 arpwhohas(&es->es_ac, &sin->sin_addr); 249 } 250 251 /* 252 * Start or restart output on interface. 253 * If interface is already active, then this is a retransmit 254 * after a collision, and just restuff registers. 255 * If interface is not already active, get another datagram 256 * to send off of the interface queue, and map it to the interface 257 * before starting the output. 258 */ 259 ecstart(dev) 260 dev_t dev; 261 { 262 int unit = ECUNIT(dev); 263 struct ec_softc *es = &ec_softc[unit]; 264 struct ecdevice *addr; 265 struct mbuf *m; 266 267 if (es->es_oactive) 268 goto restart; 269 270 IF_DEQUEUE(&es->es_if.if_snd, m); 271 if (m == 0) { 272 es->es_oactive = 0; 273 return; 274 } 275 ecput(es->es_buf[ECTBF], m); 276 277 restart: 278 addr = (struct ecdevice *)ecinfo[unit]->ui_addr; 279 addr->ec_xcr = EC_WRITE|ECTBF; 280 es->es_oactive = 1; 281 } 282 283 /* 284 * Ethernet interface transmitter interrupt. 285 * Start another output if more data to send. 286 */ 287 ecxint(unit) 288 int unit; 289 { 290 register struct ec_softc *es = &ec_softc[unit]; 291 register struct ecdevice *addr = 292 (struct ecdevice *)ecinfo[unit]->ui_addr; 293 294 if (es->es_oactive == 0) 295 return; 296 if ((addr->ec_xcr&EC_XDONE) == 0 || (addr->ec_xcr&EC_XBN) != ECTBF) { 297 printf("ec%d: stray xmit interrupt, xcr=%b\n", unit, 298 addr->ec_xcr, EC_XBITS); 299 es->es_oactive = 0; 300 addr->ec_xcr = EC_XCLR; 301 return; 302 } 303 es->es_if.if_opackets++; 304 es->es_oactive = 0; 305 es->es_mask = ~0; 306 addr->ec_xcr = EC_XCLR; 307 if (es->es_if.if_snd.ifq_head) 308 ecstart(unit); 309 } 310 311 /* 312 * Collision on ethernet interface. Do exponential 313 * backoff, and retransmit. If have backed off all 314 * the way print warning diagnostic, and drop packet. 315 */ 316 eccollide(unit) 317 int unit; 318 { 319 struct ec_softc *es = &ec_softc[unit]; 320 321 es->es_if.if_collisions++; 322 if (es->es_oactive) 323 ecdocoll(unit); 324 } 325 326 ecdocoll(unit) 327 int unit; 328 { 329 register struct ec_softc *es = &ec_softc[unit]; 330 register struct ecdevice *addr = 331 (struct ecdevice *)ecinfo[unit]->ui_addr; 332 register i; 333 int delay; 334 335 /* 336 * Es_mask is a 16 bit number with n low zero bits, with 337 * n the number of backoffs. When es_mask is 0 we have 338 * backed off 16 times, and give up. 339 */ 340 if (es->es_mask == 0) { 341 es->es_if.if_oerrors++; 342 printf("ec%d: send error\n", unit); 343 /* 344 * Reset interface, then requeue rcv buffers. 345 * Some incoming packets may be lost, but that 346 * can't be helped. 347 */ 348 addr->ec_xcr = EC_UECLR; 349 for (i=ECRHBF; i>=ECRLBF; i--) 350 addr->ec_rcr = EC_READ|i; 351 /* 352 * Reset and transmit next packet (if any). 353 */ 354 es->es_oactive = 0; 355 es->es_mask = ~0; 356 if (es->es_if.if_snd.ifq_head) 357 ecstart(unit); 358 return; 359 } 360 /* 361 * Do exponential backoff. Compute delay based on low bits 362 * of the interval timer. Then delay for that number of 363 * slot times. A slot time is 51.2 microseconds (rounded to 51). 364 * This does not take into account the time already used to 365 * process the interrupt. 366 */ 367 es->es_mask <<= 1; 368 delay = mfpr(ICR) &~ es->es_mask; 369 DELAY(delay * 51); 370 /* 371 * Clear the controller's collision flag, thus enabling retransmit. 372 */ 373 addr->ec_xcr = EC_CLEAR; 374 } 375 376 /* 377 * Ethernet interface receiver interrupt. 378 * If input error just drop packet. 379 * Otherwise purge input buffered data path and examine 380 * packet to determine type. If can't determine length 381 * from type, then have to drop packet. Othewise decapsulate 382 * packet based on type and pass to type specific higher-level 383 * input routine. 384 */ 385 ecrint(unit) 386 int unit; 387 { 388 struct ecdevice *addr = (struct ecdevice *)ecinfo[unit]->ui_addr; 389 390 while (addr->ec_rcr & EC_RDONE) 391 ecread(unit); 392 } 393 394 ecread(unit) 395 int unit; 396 { 397 register struct ec_softc *es = &ec_softc[unit]; 398 struct ecdevice *addr = (struct ecdevice *)ecinfo[unit]->ui_addr; 399 register struct ether_header *ec; 400 struct mbuf *m; 401 int len, off, resid, ecoff, rbuf; 402 register struct ifqueue *inq; 403 u_char *ecbuf; 404 405 es->es_if.if_ipackets++; 406 rbuf = addr->ec_rcr & EC_RBN; 407 if (rbuf < ECRLBF || rbuf > ECRHBF) 408 panic("ecrint"); 409 ecbuf = es->es_buf[rbuf]; 410 ecoff = *(short *)ecbuf; 411 if (ecoff <= ECRDOFF || ecoff > 2046) { 412 es->es_if.if_ierrors++; 413 #ifdef notdef 414 if (es->es_if.if_ierrors % 100 == 0) 415 printf("ec%d: += 100 input errors\n", unit); 416 #endif 417 goto setup; 418 } 419 420 /* 421 * Get input data length. 422 * Get pointer to ethernet header (in input buffer). 423 * Deal with trailer protocol: if type is PUP trailer 424 * get true type from first 16-bit word past data. 425 * Remember that type was trailer by setting off. 426 */ 427 len = ecoff - ECRDOFF - sizeof (struct ether_header); 428 ec = (struct ether_header *)(ecbuf + ECRDOFF); 429 ec->ether_type = ntohs((u_short)ec->ether_type); 430 #define ecdataaddr(ec, off, type) ((type)(((caddr_t)((ec)+1)+(off)))) 431 if (ec->ether_type >= ETHERPUP_TRAIL && 432 ec->ether_type < ETHERPUP_TRAIL+ETHERPUP_NTRAILER) { 433 off = (ec->ether_type - ETHERPUP_TRAIL) * 512; 434 if (off >= ETHERMTU) 435 goto setup; /* sanity */ 436 ec->ether_type = ntohs(*ecdataaddr(ec, off, u_short *)); 437 resid = ntohs(*(ecdataaddr(ec, off+2, u_short *))); 438 if (off + resid > len) 439 goto setup; /* sanity */ 440 len = off + resid; 441 } else 442 off = 0; 443 if (len == 0) 444 goto setup; 445 446 /* 447 * Pull packet off interface. Off is nonzero if packet 448 * has trailing header; ecget will then force this header 449 * information to be at the front, but we still have to drop 450 * the type and length which are at the front of any trailer data. 451 */ 452 m = ecget(ecbuf, len, off); 453 if (m == 0) 454 goto setup; 455 if (off) { 456 m->m_off += 2 * sizeof (u_short); 457 m->m_len -= 2 * sizeof (u_short); 458 } 459 switch (ec->ether_type) { 460 461 #ifdef INET 462 case ETHERPUP_IPTYPE: 463 schednetisr(NETISR_IP); 464 inq = &ipintrq; 465 break; 466 467 case ETHERPUP_ARPTYPE: 468 arpinput(&es->es_ac, m); 469 return; 470 #endif 471 default: 472 m_freem(m); 473 goto setup; 474 } 475 476 if (IF_QFULL(inq)) { 477 IF_DROP(inq); 478 m_freem(m); 479 goto setup; 480 } 481 IF_ENQUEUE(inq, m); 482 483 setup: 484 /* 485 * Reset for next packet. 486 */ 487 addr->ec_rcr = EC_READ|EC_RCLR|rbuf; 488 } 489 490 /* 491 * Ethernet output routine. 492 * Encapsulate a packet of type family for the local net. 493 * Use trailer local net encapsulation if enough data in first 494 * packet leaves a multiple of 512 bytes of data in remainder. 495 * If destination is this address or broadcast, send packet to 496 * loop device to kludge around the fact that 3com interfaces can't 497 * talk to themselves. 498 */ 499 ecoutput(ifp, m0, dst) 500 struct ifnet *ifp; 501 struct mbuf *m0; 502 struct sockaddr *dst; 503 { 504 int type, s, error; 505 u_char edst[6]; 506 struct in_addr idst; 507 register struct ec_softc *es = &ec_softc[ifp->if_unit]; 508 register struct mbuf *m = m0; 509 register struct ether_header *ec; 510 register int off; 511 struct mbuf *mcopy = (struct mbuf *)0; 512 513 switch (dst->sa_family) { 514 515 #ifdef INET 516 case AF_INET: 517 idst = ((struct sockaddr_in *)dst)->sin_addr; 518 if (!arpresolve(&es->es_ac, m, &idst, edst)) 519 return (0); /* if not yet resolved */ 520 if (in_lnaof(idst) == INADDR_ANY) 521 mcopy = m_copy(m, 0, (int)M_COPYALL); 522 off = ntohs((u_short)mtod(m, struct ip *)->ip_len) - m->m_len; 523 if (off > 0 && (off & 0x1ff) == 0 && 524 m->m_off >= MMINOFF + 2 * sizeof (u_short)) { 525 type = ETHERPUP_TRAIL + (off>>9); 526 m->m_off -= 2 * sizeof (u_short); 527 m->m_len += 2 * sizeof (u_short); 528 *mtod(m, u_short *) = ntohs((u_short)ETHERPUP_IPTYPE); 529 *(mtod(m, u_short *) + 1) = ntohs((u_short)m->m_len); 530 goto gottrailertype; 531 } 532 type = ETHERPUP_IPTYPE; 533 off = 0; 534 goto gottype; 535 #endif 536 537 case AF_UNSPEC: 538 ec = (struct ether_header *)dst->sa_data; 539 bcopy((caddr_t)ec->ether_dhost, (caddr_t)edst, sizeof (edst)); 540 type = ec->ether_type; 541 goto gottype; 542 543 default: 544 printf("ec%d: can't handle af%d\n", ifp->if_unit, 545 dst->sa_family); 546 error = EAFNOSUPPORT; 547 goto bad; 548 } 549 550 gottrailertype: 551 /* 552 * Packet to be sent as trailer: move first packet 553 * (control information) to end of chain. 554 */ 555 while (m->m_next) 556 m = m->m_next; 557 m->m_next = m0; 558 m = m0->m_next; 559 m0->m_next = 0; 560 m0 = m; 561 562 gottype: 563 /* 564 * Add local net header. If no space in first mbuf, 565 * allocate another. 566 */ 567 if (m->m_off > MMAXOFF || 568 MMINOFF + sizeof (struct ether_header) > m->m_off) { 569 m = m_get(M_DONTWAIT, MT_HEADER); 570 if (m == 0) { 571 error = ENOBUFS; 572 goto bad; 573 } 574 m->m_next = m0; 575 m->m_off = MMINOFF; 576 m->m_len = sizeof (struct ether_header); 577 } else { 578 m->m_off -= sizeof (struct ether_header); 579 m->m_len += sizeof (struct ether_header); 580 } 581 ec = mtod(m, struct ether_header *); 582 bcopy((caddr_t)edst, (caddr_t)ec->ether_dhost, sizeof (edst)); 583 ec->ether_type = htons((u_short)type); 584 bcopy((caddr_t)es->es_addr, (caddr_t)ec->ether_shost, 6); 585 586 /* 587 * Queue message on interface, and start output if interface 588 * not yet active. 589 */ 590 s = splimp(); 591 if (IF_QFULL(&ifp->if_snd)) { 592 IF_DROP(&ifp->if_snd); 593 error = ENOBUFS; 594 goto qfull; 595 } 596 IF_ENQUEUE(&ifp->if_snd, m); 597 if (es->es_oactive == 0) 598 ecstart(ifp->if_unit); 599 splx(s); 600 return (mcopy ? looutput(&loif, mcopy, dst) : 0); 601 602 qfull: 603 m0 = m; 604 splx(s); 605 bad: 606 m_freem(m0); 607 return (error); 608 } 609 610 /* 611 * Routine to copy from mbuf chain to transmit 612 * buffer in UNIBUS memory. 613 * If packet size is less than the minimum legal size, 614 * the buffer is expanded. We probably should zero out the extra 615 * bytes for security, but that would slow things down. 616 */ 617 ecput(ecbuf, m) 618 u_char *ecbuf; 619 struct mbuf *m; 620 { 621 register struct mbuf *mp; 622 register int off; 623 u_char *bp; 624 625 for (off = 2048, mp = m; mp; mp = mp->m_next) 626 off -= mp->m_len; 627 if (2048 - off < ETHERMIN + sizeof (struct ether_header)) 628 off = 2048 - ETHERMIN - sizeof (struct ether_header); 629 *(u_short *)ecbuf = off; 630 bp = (u_char *)(ecbuf + off); 631 for (mp = m; mp; mp = mp->m_next) { 632 register unsigned len = mp->m_len; 633 u_char *mcp; 634 635 if (len == 0) 636 continue; 637 mcp = mtod(mp, u_char *); 638 if ((unsigned)bp & 01) { 639 *bp++ = *mcp++; 640 len--; 641 } 642 if (off = (len >> 1)) { 643 register u_short *to, *from; 644 645 to = (u_short *)bp; 646 from = (u_short *)mcp; 647 do 648 *to++ = *from++; 649 while (--off > 0); 650 bp = (u_char *)to, 651 mcp = (u_char *)from; 652 } 653 if (len & 01) 654 *bp++ = *mcp++; 655 } 656 m_freem(m); 657 } 658 659 /* 660 * Routine to copy from UNIBUS memory into mbufs. 661 * Similar in spirit to if_rubaget. 662 * 663 * Warning: This makes the fairly safe assumption that 664 * mbufs have even lengths. 665 */ 666 struct mbuf * 667 ecget(ecbuf, totlen, off0) 668 u_char *ecbuf; 669 int totlen, off0; 670 { 671 register struct mbuf *m; 672 struct mbuf *top = 0, **mp = ⊤ 673 register int off = off0, len; 674 u_char *cp; 675 676 cp = ecbuf + ECRDOFF + sizeof (struct ether_header); 677 while (totlen > 0) { 678 register int words; 679 u_char *mcp; 680 681 MGET(m, M_DONTWAIT, MT_DATA); 682 if (m == 0) 683 goto bad; 684 if (off) { 685 len = totlen - off; 686 cp = ecbuf + ECRDOFF + 687 sizeof (struct ether_header) + off; 688 } else 689 len = totlen; 690 if (len >= CLBYTES) { 691 struct mbuf *p; 692 693 MCLGET(p, 1); 694 if (p != 0) { 695 m->m_len = len = CLBYTES; 696 m->m_off = (int)p - (int)m; 697 } else { 698 m->m_len = len = MIN(MLEN, len); 699 m->m_off = MMINOFF; 700 } 701 } else { 702 m->m_len = len = MIN(MLEN, len); 703 m->m_off = MMINOFF; 704 } 705 mcp = mtod(m, u_char *); 706 if (words = (len >> 1)) { 707 register u_short *to, *from; 708 709 to = (u_short *)mcp; 710 from = (u_short *)cp; 711 do 712 *to++ = *from++; 713 while (--words > 0); 714 mcp = (u_char *)to; 715 cp = (u_char *)from; 716 } 717 if (len & 01) 718 *mcp++ = *cp++; 719 *mp = m; 720 mp = &m->m_next; 721 if (off == 0) { 722 totlen -= len; 723 continue; 724 } 725 off += len; 726 if (off == totlen) { 727 cp = ecbuf + ECRDOFF + sizeof (struct ether_header); 728 off = 0; 729 totlen = off0; 730 } 731 } 732 return (top); 733 bad: 734 m_freem(top); 735 return (0); 736 } 737