1 /* if_en.c 4.39 82/03/13 */ 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; 244 COUNT(ENXINT); 245 246 if (es->es_oactive == 0) 247 return; 248 addr = (struct endevice *)ui->ui_addr; 249 es->es_if.if_opackets++; 250 es->es_oactive = 0; 251 es->es_delay = 0; 252 es->es_mask = ~0; 253 if (addr->en_ostat&EN_OERROR) { 254 es->es_if.if_oerrors++; 255 printf("en%d: output error\n", unit); 256 } 257 if (es->es_ifuba.ifu_xtofree) { 258 m_freem(es->es_ifuba.ifu_xtofree); 259 es->es_ifuba.ifu_xtofree = 0; 260 } 261 if (es->es_if.if_snd.ifq_head == 0) { 262 es->es_lastx = 0; 263 return; 264 } 265 enstart(unit); 266 } 267 268 /* 269 * Collision on ethernet interface. Do exponential 270 * backoff, and retransmit. If have backed off all 271 * the way printing warning diagnostic, and drop packet. 272 */ 273 encollide(unit) 274 int unit; 275 { 276 register struct en_softc *es = &en_softc[unit]; 277 COUNT(ENCOLLIDE); 278 279 es->es_if.if_collisions++; 280 if (es->es_oactive == 0) 281 return; 282 /* 283 * Es_mask is a 16 bit number with n low zero bits, with 284 * n the number of backoffs. When es_mask is 0 we have 285 * backed off 16 times, and give up. 286 */ 287 if (es->es_mask == 0) { 288 printf("en%d: send error\n", unit); 289 enxint(unit); 290 return; 291 } 292 /* 293 * Another backoff. Restart with delay based on n low bits 294 * of the interval timer. 295 */ 296 es->es_mask <<= 1; 297 es->es_delay = mfpr(ICR) &~ es->es_mask; 298 enstart(unit); 299 } 300 301 int enprintierrors; 302 struct sockaddr_pup pupsrc = { AF_PUP }; 303 struct sockaddr_pup pupdst = { AF_PUP }; 304 struct sockproto pupproto = { PF_PUP }; 305 /* 306 * Ethernet interface receiver interrupt. 307 * If input error just drop packet. 308 * Otherwise purge input buffered data path and examine 309 * packet to determine type. If can't determine length 310 * from type, then have to drop packet. Othewise decapsulate 311 * packet based on type and pass to type specific higher-level 312 * input routine. 313 */ 314 enrint(unit) 315 int unit; 316 { 317 register struct en_softc *es = &en_softc[unit]; 318 struct endevice *addr = (struct endevice *)eninfo[unit]->ui_addr; 319 register struct en_header *en; 320 struct mbuf *m; 321 int len; 322 register struct ifqueue *inq; 323 int off; 324 COUNT(ENRINT); 325 326 es->es_if.if_ipackets++; 327 328 /* 329 * Purge BDP; drop if input error indicated. 330 */ 331 UBAPURGE(es->es_ifuba.ifu_uba, es->es_ifuba.ifu_r.ifrw_bdp); 332 if (addr->en_istat&EN_IERROR) { 333 es->es_if.if_ierrors++; 334 if (enprintierrors) 335 printf("en%d: input error\n", unit); 336 goto setup; 337 } 338 339 /* 340 * Get pointer to ethernet header (in input buffer). 341 * Deal with trailer protocol: if type is PUP trailer 342 * get true type from first 16-bit word past data. 343 * Remember that type was trailer by setting off. 344 */ 345 en = (struct en_header *)(es->es_ifuba.ifu_r.ifrw_addr); 346 #define endataaddr(en, off, type) ((type)(((caddr_t)((en)+1)+(off)))) 347 if (en->en_type >= ENPUP_TRAIL && 348 en->en_type < ENPUP_TRAIL+ENPUP_NTRAILER) { 349 off = (en->en_type - ENPUP_TRAIL) * 512; 350 if (off >= ENMTU) 351 goto setup; /* sanity */ 352 en->en_type = *endataaddr(en, off, u_short *); 353 } else 354 off = 0; 355 356 /* 357 * Attempt to infer packet length from type; 358 * can't deal with packet if can't infer length. 359 */ 360 switch (en->en_type) { 361 362 #ifdef INET 363 case ENPUP_IPTYPE: 364 len = htons((u_short)endataaddr(en, off ? off+2 : 0, struct ip *)->ip_len); 365 if (off) 366 len += 2; 367 break; 368 #endif 369 #ifdef PUP 370 case ENPUP_PUPTYPE: 371 len = endataaddr(en, off, struct pup_header *)->pup_length; 372 if (off) 373 len -= 2; 374 break; 375 #endif 376 377 default: 378 printf("en%d: unknown pkt type 0x%x\n", unit, en->en_type); 379 goto setup; 380 } 381 if (len == 0) 382 goto setup; 383 384 /* 385 * Pull packet off interface. Off is nonzero if packet 386 * has trailing header; if_rubaget will then force this header 387 * information to be at the front, but we still have to drop 388 * the two-byte type which is at the front of any trailer data. 389 */ 390 m = if_rubaget(&es->es_ifuba, len, off); 391 if (m == 0) 392 goto setup; 393 if (off) { 394 m->m_off += 2; 395 m->m_len -= 2; 396 } 397 switch (en->en_type) { 398 399 #ifdef INET 400 case ENPUP_IPTYPE: 401 setipintr(); 402 inq = &ipintrq; 403 break; 404 #endif 405 case ENPUP_PUPTYPE: { 406 struct pup_header *pup = mtod(m, struct pup_header *); 407 408 pupproto.sp_protocol = pup->pup_type; 409 pupdst.spup_addr = pup->pup_dport; 410 pupsrc.spup_addr = pup->pup_sport; 411 raw_input(m, &pupproto, (struct sockaddr *)&pupdst, 412 (struct sockaddr *)&pupsrc); 413 goto setup; 414 } 415 } 416 IF_ENQUEUE(inq, m); 417 418 setup: 419 /* 420 * Reset for next packet. 421 */ 422 addr->en_iba = es->es_ifuba.ifu_r.ifrw_info; 423 addr->en_iwc = -(sizeof (struct en_header) + ENMTU) >> 1; 424 addr->en_istat = EN_IEN|EN_GO; 425 } 426 427 /* 428 * Ethernet output routine. 429 * Encapsulate a packet of type family for the local net. 430 * Use trailer local net encapsulation if enough data in first 431 * packet leaves a multiple of 512 bytes of data in remainder. 432 */ 433 enoutput(ifp, m0, pf) 434 struct ifnet *ifp; 435 struct mbuf *m0; 436 int pf; 437 { 438 int type, dest, s, off; 439 register struct mbuf *m = m0; 440 register struct en_header *en; 441 442 COUNT(ENOUTPUT); 443 switch (pf) { 444 445 #ifdef INET 446 case PF_INET: { 447 register struct ip *ip = mtod(m0, struct ip *); 448 449 #ifndef ENKLUDGE 450 dest = ip->ip_dst.s_addr >> 24; 451 #else 452 dest = (ip->ip_dst.s_addr >> 8) & 0xff; 453 #endif 454 off = ntohs((u_short)ip->ip_len) - m->m_len; 455 #ifndef ENKLUDGE 456 if (off > 0 && (off & 0x1ff) == 0 && m->m_off >= MMINOFF + 2) { 457 type = ENPUP_TRAIL + (off>>9); 458 m->m_off -= 2; 459 m->m_len += 2; 460 *mtod(m, u_short *) = ENPUP_IPTYPE; 461 goto gottrailertype; 462 } 463 #endif 464 type = ENPUP_IPTYPE; 465 off = 0; 466 goto gottype; 467 } 468 #endif 469 #ifdef PUP 470 case PF_PUP: { 471 register struct pup_header *pup = mtod(m, struct pup_header *); 472 473 dest = pup->pup_dhost; 474 off = pup->pup_length - m->m_len; 475 if (off > 0 && (off & 0x1ff) == 0 && m->m_off >= MMINOFF + 2) { 476 type = ENPUP_TRAIL + (off>>9); 477 m->m_off -= 2; 478 m->m_len += 2; 479 *mtod(m, u_short *) = ENPUP_PUPTYPE; 480 goto gottrailertype; 481 } 482 type = ENPUP_PUPTYPE; 483 off = 0; 484 goto gottype; 485 } 486 #endif 487 488 default: 489 printf("en%d: can't encapsulate pf%d\n", ifp->if_unit, pf); 490 m_freem(m0); 491 return (0); 492 } 493 494 gottrailertype: 495 /* 496 * Packet to be sent as trailer: move first packet 497 * (control information) to end of chain. 498 */ 499 while (m->m_next) 500 m = m->m_next; 501 m->m_next = m0; 502 m = m0->m_next; 503 m0->m_next = 0; 504 m0 = m; 505 506 gottype: 507 /* 508 * Add local net header. If no space in first mbuf, 509 * allocate another. 510 */ 511 if (m->m_off > MMAXOFF || 512 MMINOFF + sizeof (struct en_header) > m->m_off) { 513 m = m_get(M_DONTWAIT); 514 if (m == 0) { 515 m_freem(m0); 516 return (0); 517 } 518 m->m_next = m0; 519 m->m_off = MMINOFF; 520 m->m_len = sizeof (struct en_header); 521 } else { 522 m->m_off -= sizeof (struct en_header); 523 m->m_len += sizeof (struct en_header); 524 } 525 en = mtod(m, struct en_header *); 526 en->en_shost = ifp->if_host[0]; 527 en->en_dhost = dest; 528 en->en_type = type; 529 530 /* 531 * Queue message on interface, and start output if interface 532 * not yet active. 533 */ 534 s = splimp(); 535 IF_ENQUEUE(&ifp->if_snd, m); 536 if (en_softc[ifp->if_unit].es_oactive == 0) 537 enstart(ifp->if_unit); 538 splx(s); 539 return (1); 540 } 541