1 /* if_en.c 4.43 82/03/19 */ 2 3 #include "en.h" 4 5 /* 6 * Xerox prototype (3 Mb) Ethernet interface driver. 7 */ 8 9 #include "../h/param.h" 10 #include "../h/systm.h" 11 #include "../h/mbuf.h" 12 #include "../h/pte.h" 13 #include "../h/buf.h" 14 #include "../h/protosw.h" 15 #include "../h/socket.h" 16 #include "../h/ubareg.h" 17 #include "../h/ubavar.h" 18 #include "../h/enreg.h" 19 #include "../h/cpu.h" 20 #include "../h/mtpr.h" 21 #include "../h/vmmac.h" 22 #include "../net/in.h" 23 #include "../net/in_systm.h" 24 #include "../net/if.h" 25 #include "../net/if_en.h" 26 #include "../net/if_uba.h" 27 #include "../net/ip.h" 28 #include "../net/ip_var.h" 29 #include "../net/pup.h" 30 31 #define ENMTU (1024+512) 32 33 int enprobe(), enattach(), enrint(), enxint(), encollide(); 34 struct uba_device *eninfo[NEN]; 35 u_short enstd[] = { 0 }; 36 struct uba_driver endriver = 37 { enprobe, 0, enattach, 0, enstd, "en", eninfo }; 38 #define ENUNIT(x) minor(x) 39 40 int eninit(),enoutput(),enreset(); 41 42 /* 43 * Ethernet software status per interface. 44 * 45 * Each interface is referenced by a network interface structure, 46 * es_if, which the routing code uses to locate the interface. 47 * This structure contains the output queue for the interface, its address, ... 48 * We also have, for each interface, a UBA interface structure, which 49 * contains information about the UNIBUS resources held by the interface: 50 * map registers, buffered data paths, etc. Information is cached in this 51 * structure for use by the if_uba.c routines in running the interface 52 * efficiently. 53 */ 54 struct en_softc { 55 struct ifnet es_if; /* network-visible interface */ 56 struct ifuba es_ifuba; /* UNIBUS resources */ 57 short es_delay; /* current output delay */ 58 short es_mask; /* mask for current output delay */ 59 u_char es_lastx; /* host last transmitted to */ 60 short es_oactive; /* is output active? */ 61 short es_olen; /* length of last output */ 62 } en_softc[NEN]; 63 64 /* 65 * Do output DMA to determine interface presence and 66 * interrupt vector. DMA is too short to disturb other hosts. 67 */ 68 enprobe(reg) 69 caddr_t reg; 70 { 71 register int br, cvec; /* r11, r10 value-result */ 72 register struct endevice *addr = (struct endevice *)reg; 73 74 COUNT(ENPROBE); 75 #ifdef lint 76 br = 0; cvec = br; br = cvec; 77 enrint(0); enxint(0); encollide(0); 78 #endif 79 addr->en_istat = 0; 80 addr->en_owc = -1; 81 addr->en_oba = 0; 82 addr->en_ostat = EN_IEN|EN_GO; 83 DELAY(100000); 84 addr->en_ostat = 0; 85 return (1); 86 } 87 88 /* 89 * Interface exists: make available by filling in network interface 90 * record. System will initialize the interface when it is ready 91 * to accept packets. 92 */ 93 enattach(ui) 94 struct uba_device *ui; 95 { 96 register struct en_softc *es = &en_softc[ui->ui_unit]; 97 COUNT(ENATTACH); 98 99 es->es_if.if_unit = ui->ui_unit; 100 es->es_if.if_name = "en"; 101 es->es_if.if_mtu = ENMTU; 102 es->es_if.if_net = ui->ui_flags; 103 es->es_if.if_host[0] = 104 (~(((struct endevice *)eninfo[ui->ui_unit]->ui_addr)->en_addr)) & 0xff; 105 #ifdef ENKLUDGE 106 if (es->es_if.if_net == 10) { 107 es->es_if.if_host[0] <<= 16; 108 es->es_if.if_host[0] |= 0x4e; 109 } 110 #endif 111 es->es_if.if_addr = 112 if_makeaddr(es->es_if.if_net, es->es_if.if_host[0]); 113 es->es_if.if_broadaddr = 114 if_makeaddr(es->es_if.if_net, 0); 115 es->es_if.if_init = eninit; 116 es->es_if.if_output = enoutput; 117 es->es_if.if_ubareset = enreset; 118 es->es_ifuba.ifu_flags = UBA_NEEDBDP | UBA_NEED16; 119 if_attach(&es->es_if); 120 } 121 122 /* 123 * Reset of interface after UNIBUS reset. 124 * If interface is on specified uba, reset its state. 125 */ 126 enreset(unit, uban) 127 int unit, uban; 128 { 129 register struct uba_device *ui; 130 COUNT(ENRESET); 131 132 if (unit >= NEN || (ui = eninfo[unit]) == 0 || ui->ui_alive == 0 || 133 ui->ui_ubanum != uban) 134 return; 135 printf(" en%d", unit); 136 eninit(unit); 137 } 138 139 /* 140 * Initialization of interface; clear recorded pending 141 * operations, and reinitialize UNIBUS usage. 142 */ 143 eninit(unit) 144 int unit; 145 { 146 register struct en_softc *es = &en_softc[unit]; 147 register struct uba_device *ui = eninfo[unit]; 148 register struct endevice *addr; 149 int s; 150 151 if (if_ubainit(&es->es_ifuba, ui->ui_ubanum, 152 sizeof (struct en_header), (int)btoc(ENMTU)) == 0) { 153 printf("en%d: can't initialize\n", unit); 154 return; 155 } 156 addr = (struct endevice *)ui->ui_addr; 157 addr->en_istat = addr->en_ostat = 0; 158 159 /* 160 * Hang a receive and start any 161 * pending writes by faking a transmit complete. 162 */ 163 s = splimp(); 164 addr->en_iba = es->es_ifuba.ifu_r.ifrw_info; 165 addr->en_iwc = -(sizeof (struct en_header) + ENMTU) >> 1; 166 addr->en_istat = EN_IEN|EN_GO; 167 es->es_oactive = 1; 168 enxint(unit); 169 splx(s); 170 } 171 172 int enlastdel = 25; 173 174 /* 175 * Start or restart output on interface. 176 * If interface is already active, then this is a retransmit 177 * after a collision, and just restuff registers and delay. 178 * If interface is not already active, get another datagram 179 * to send off of the interface queue, and map it to the interface 180 * before starting the output. 181 */ 182 enstart(dev) 183 dev_t dev; 184 { 185 int unit = ENUNIT(dev); 186 struct uba_device *ui = eninfo[unit]; 187 register struct en_softc *es = &en_softc[unit]; 188 register struct endevice *addr; 189 struct mbuf *m; 190 int dest; 191 COUNT(ENSTART); 192 193 if (es->es_oactive) 194 goto restart; 195 196 /* 197 * Not already active: dequeue another request 198 * and map it to the UNIBUS. If no more requests, 199 * just return. 200 */ 201 IF_DEQUEUE(&es->es_if.if_snd, m); 202 if (m == 0) { 203 es->es_oactive = 0; 204 return; 205 } 206 dest = mtod(m, struct en_header *)->en_dhost; 207 es->es_olen = if_wubaput(&es->es_ifuba, m); 208 209 /* 210 * Ethernet cannot take back-to-back packets (no 211 * buffering in interface. To avoid overrunning 212 * receiver, enforce a small delay (about 1ms) in interface 213 * on successive packets sent to same host. 214 */ 215 if (es->es_lastx && es->es_lastx == dest) 216 es->es_delay = enlastdel; 217 else 218 es->es_lastx = dest; 219 220 restart: 221 /* 222 * Have request mapped to UNIBUS for transmission. 223 * Purge any stale data from this BDP, and start the otput. 224 */ 225 UBAPURGE(es->es_ifuba.ifu_uba, es->es_ifuba.ifu_w.ifrw_bdp); 226 addr = (struct endevice *)ui->ui_addr; 227 addr->en_oba = (int)es->es_ifuba.ifu_w.ifrw_info; 228 addr->en_odelay = es->es_delay; 229 addr->en_owc = -((es->es_olen + 1) >> 1); 230 addr->en_ostat = EN_IEN|EN_GO; 231 es->es_oactive = 1; 232 } 233 234 /* 235 * Ethernet interface transmitter interrupt. 236 * Start another output if more data to send. 237 */ 238 enxint(unit) 239 int unit; 240 { 241 register struct uba_device *ui = eninfo[unit]; 242 register struct en_softc *es = &en_softc[unit]; 243 register struct endevice *addr = (struct endevice *)ui->ui_addr; 244 COUNT(ENXINT); 245 246 if (es->es_oactive == 0) 247 return; 248 if (es->es_mask && (addr->en_ostat&EN_OERROR)) { 249 es->es_if.if_oerrors++; 250 if (es->es_if.if_oerrors % 100 == 0) 251 printf("en%d: += 100 output errors\n", unit); 252 endocoll(unit); 253 return; 254 } 255 es->es_if.if_opackets++; 256 es->es_oactive = 0; 257 es->es_delay = 0; 258 es->es_mask = ~0; 259 if (es->es_ifuba.ifu_xtofree) { 260 m_freem(es->es_ifuba.ifu_xtofree); 261 es->es_ifuba.ifu_xtofree = 0; 262 } 263 if (es->es_if.if_snd.ifq_head == 0) { 264 es->es_lastx = 0; 265 return; 266 } 267 enstart(unit); 268 } 269 270 /* 271 * Collision on ethernet interface. Do exponential 272 * backoff, and retransmit. If have backed off all 273 * the way printing warning diagnostic, and drop packet. 274 */ 275 encollide(unit) 276 int unit; 277 { 278 struct en_softc *es = &en_softc[unit]; 279 COUNT(ENCOLLIDE); 280 281 es->es_if.if_collisions++; 282 if (es->es_oactive == 0) 283 return; 284 endocoll(unit); 285 } 286 287 endocoll(unit) 288 int unit; 289 { 290 register struct en_softc *es = &en_softc[unit]; 291 292 /* 293 * Es_mask is a 16 bit number with n low zero bits, with 294 * n the number of backoffs. When es_mask is 0 we have 295 * backed off 16 times, and give up. 296 */ 297 if (es->es_mask == 0) { 298 printf("en%d: send error\n", unit); 299 enxint(unit); 300 return; 301 } 302 /* 303 * Another backoff. Restart with delay based on n low bits 304 * of the interval timer. 305 */ 306 es->es_mask <<= 1; 307 es->es_delay = mfpr(ICR) &~ es->es_mask; 308 enstart(unit); 309 } 310 311 struct sockaddr_pup pupsrc = { AF_PUP }; 312 struct sockaddr_pup pupdst = { AF_PUP }; 313 struct sockproto pupproto = { PF_PUP }; 314 /* 315 * Ethernet interface receiver interrupt. 316 * If input error just drop packet. 317 * Otherwise purge input buffered data path and examine 318 * packet to determine type. If can't determine length 319 * from type, then have to drop packet. Othewise decapsulate 320 * packet based on type and pass to type specific higher-level 321 * input routine. 322 */ 323 enrint(unit) 324 int unit; 325 { 326 register struct en_softc *es = &en_softc[unit]; 327 struct endevice *addr = (struct endevice *)eninfo[unit]->ui_addr; 328 register struct en_header *en; 329 struct mbuf *m; 330 int len; 331 register struct ifqueue *inq; 332 int off; 333 COUNT(ENRINT); 334 335 es->es_if.if_ipackets++; 336 337 /* 338 * Purge BDP; drop if input error indicated. 339 */ 340 UBAPURGE(es->es_ifuba.ifu_uba, es->es_ifuba.ifu_r.ifrw_bdp); 341 if (addr->en_istat&EN_IERROR) { 342 es->es_if.if_ierrors++; 343 if (es->es_if.if_ierrors % 100 == 0) 344 printf("en%d: += 100 input errors\n", unit); 345 goto setup; 346 } 347 348 /* 349 * Get pointer to ethernet header (in input buffer). 350 * Deal with trailer protocol: if type is PUP trailer 351 * get true type from first 16-bit word past data. 352 * Remember that type was trailer by setting off. 353 */ 354 en = (struct en_header *)(es->es_ifuba.ifu_r.ifrw_addr); 355 #define endataaddr(en, off, type) ((type)(((caddr_t)((en)+1)+(off)))) 356 if (en->en_type >= ENPUP_TRAIL && 357 en->en_type < ENPUP_TRAIL+ENPUP_NTRAILER) { 358 off = (en->en_type - ENPUP_TRAIL) * 512; 359 if (off >= ENMTU) 360 goto setup; /* sanity */ 361 en->en_type = *endataaddr(en, off, u_short *); 362 } else 363 off = 0; 364 365 /* 366 * Attempt to infer packet length from type; 367 * can't deal with packet if can't infer length. 368 */ 369 switch (en->en_type) { 370 371 #ifdef INET 372 case ENPUP_IPTYPE: 373 len = htons((u_short)endataaddr(en, off ? off+2 : 0, struct ip *)->ip_len); 374 if (off) 375 len += 2; 376 break; 377 #endif 378 #ifdef PUP 379 case ENPUP_PUPTYPE: 380 len = endataaddr(en, off, struct pup_header *)->pup_length; 381 if (off) 382 len -= 2; 383 break; 384 #endif 385 386 default: 387 printf("en%d: unknown pkt type 0x%x\n", unit, en->en_type); 388 goto setup; 389 } 390 if (len == 0) 391 goto setup; 392 393 /* 394 * Pull packet off interface. Off is nonzero if packet 395 * has trailing header; if_rubaget will then force this header 396 * information to be at the front, but we still have to drop 397 * the two-byte type which is at the front of any trailer data. 398 */ 399 m = if_rubaget(&es->es_ifuba, len, off); 400 if (m == 0) 401 goto setup; 402 if (off) { 403 m->m_off += 2; 404 m->m_len -= 2; 405 } 406 switch (en->en_type) { 407 408 #ifdef INET 409 case ENPUP_IPTYPE: 410 schednetisr(NETISR_IP); 411 inq = &ipintrq; 412 break; 413 #endif 414 case ENPUP_PUPTYPE: { 415 struct pup_header *pup = mtod(m, struct pup_header *); 416 417 pupproto.sp_protocol = pup->pup_type; 418 pupdst.spup_addr = pup->pup_dport; 419 pupsrc.spup_addr = pup->pup_sport; 420 raw_input(m, &pupproto, (struct sockaddr *)&pupdst, 421 (struct sockaddr *)&pupsrc); 422 goto setup; 423 } 424 } 425 if (IF_QFULL(inq)) { 426 IF_DROP(inq); 427 (void) m_freem(m); 428 } else 429 IF_ENQUEUE(inq, m); 430 431 setup: 432 /* 433 * Reset for next packet. 434 */ 435 addr->en_iba = es->es_ifuba.ifu_r.ifrw_info; 436 addr->en_iwc = -(sizeof (struct en_header) + ENMTU) >> 1; 437 addr->en_istat = EN_IEN|EN_GO; 438 } 439 440 /* 441 * Ethernet output routine. 442 * Encapsulate a packet of type family for the local net. 443 * Use trailer local net encapsulation if enough data in first 444 * packet leaves a multiple of 512 bytes of data in remainder. 445 */ 446 enoutput(ifp, m0, pf) 447 struct ifnet *ifp; 448 struct mbuf *m0; 449 int pf; 450 { 451 int type, dest, s, off; 452 register struct mbuf *m = m0; 453 register struct en_header *en; 454 455 COUNT(ENOUTPUT); 456 switch (pf) { 457 458 #ifdef INET 459 case PF_INET: { 460 register struct ip *ip = mtod(m0, struct ip *); 461 462 #ifndef ENKLUDGE 463 dest = ip->ip_dst.s_addr >> 24; 464 #else 465 dest = (ip->ip_dst.s_addr >> 8) & 0xff; 466 #endif 467 off = ntohs((u_short)ip->ip_len) - m->m_len; 468 #ifndef ENKLUDGE 469 if (off > 0 && (off & 0x1ff) == 0 && m->m_off >= MMINOFF + 2) { 470 type = ENPUP_TRAIL + (off>>9); 471 m->m_off -= 2; 472 m->m_len += 2; 473 *mtod(m, u_short *) = ENPUP_IPTYPE; 474 goto gottrailertype; 475 } 476 #endif 477 type = ENPUP_IPTYPE; 478 off = 0; 479 goto gottype; 480 } 481 #endif 482 #ifdef PUP 483 case PF_PUP: { 484 register struct pup_header *pup = mtod(m, struct pup_header *); 485 486 dest = pup->pup_dhost; 487 off = pup->pup_length - m->m_len; 488 if (off > 0 && (off & 0x1ff) == 0 && m->m_off >= MMINOFF + 2) { 489 type = ENPUP_TRAIL + (off>>9); 490 m->m_off -= 2; 491 m->m_len += 2; 492 *mtod(m, u_short *) = ENPUP_PUPTYPE; 493 goto gottrailertype; 494 } 495 type = ENPUP_PUPTYPE; 496 off = 0; 497 goto gottype; 498 } 499 #endif 500 501 default: 502 printf("en%d: can't encapsulate pf%d\n", ifp->if_unit, pf); 503 m_freem(m0); 504 return (0); 505 } 506 507 gottrailertype: 508 /* 509 * Packet to be sent as trailer: move first packet 510 * (control information) to end of chain. 511 */ 512 while (m->m_next) 513 m = m->m_next; 514 m->m_next = m0; 515 m = m0->m_next; 516 m0->m_next = 0; 517 m0 = m; 518 519 gottype: 520 /* 521 * Add local net header. If no space in first mbuf, 522 * allocate another. 523 */ 524 if (m->m_off > MMAXOFF || 525 MMINOFF + sizeof (struct en_header) > m->m_off) { 526 m = m_get(M_DONTWAIT); 527 if (m == 0) { 528 m_freem(m0); 529 return (0); 530 } 531 m->m_next = m0; 532 m->m_off = MMINOFF; 533 m->m_len = sizeof (struct en_header); 534 } else { 535 m->m_off -= sizeof (struct en_header); 536 m->m_len += sizeof (struct en_header); 537 } 538 en = mtod(m, struct en_header *); 539 en->en_shost = ifp->if_host[0]; 540 en->en_dhost = dest; 541 en->en_type = type; 542 543 /* 544 * Queue message on interface, and start output if interface 545 * not yet active. 546 */ 547 s = splimp(); 548 if (IF_QFULL(&ifp->if_snd)) { 549 IF_DROP(&ifp->if_snd); 550 m_freem(m); 551 splx(s); 552 return (0); 553 } 554 IF_ENQUEUE(&ifp->if_snd, m); 555 if (en_softc[ifp->if_unit].es_oactive == 0) 556 enstart(ifp->if_unit); 557 splx(s); 558 return (1); 559 } 560