bsd/net/if_loop.c

   1 /*
   2  * Copyright (c) 2000 Apple Computer, Inc. All rights reserved.
   3  *
   4  * @APPLE_LICENSE_HEADER_START@
   5  *
   6  * The contents of this file constitute Original Code as defined in and
   7  * are subject to the Apple Public Source License Version 1.1 (the
   8  * "License").  You may not use this file except in compliance with the
   9  * License.  Please obtain a copy of the License at
  10  * http://www.apple.com/publicsource and read it before using this file.
  11  *
  12  * This Original Code and all software distributed under the License are
  13  * distributed on an "AS IS" basis, WITHOUT WARRANTY OF ANY KIND, EITHER
  14  * EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES,
  15  * INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY,
  16  * FITNESS FOR A PARTICULAR PURPOSE OR NON-INFRINGEMENT.  Please see the
  17  * License for the specific language governing rights and limitations
  18  * under the License.
  19  *
  20  * @APPLE_LICENSE_HEADER_END@
  21  */
  22 /*
  23  * Copyright (c) 1982, 1986, 1993
  24  *      The Regents of the University of California.  All rights reserved.
  25  *
  26  * Redistribution and use in source and binary forms, with or without
  27  * modification, are permitted provided that the following conditions
  28  * are met:
  29  * 1. Redistributions of source code must retain the above copyright
  30  *    notice, this list of conditions and the following disclaimer.
  31  * 2. Redistributions in binary form must reproduce the above copyright
  32  *    notice, this list of conditions and the following disclaimer in the
  33  *    documentation and/or other materials provided with the distribution.
  34  * 3. All advertising materials mentioning features or use of this software
  35  *    must display the following acknowledgement:
  36  *      This product includes software developed by the University of
  37  *      California, Berkeley and its contributors.
  38  * 4. Neither the name of the University nor the names of its contributors
  39  *    may be used to endorse or promote products derived from this software
  40  *    without specific prior written permission.
  41  *
  42  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
  43  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  44  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  45  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
  46  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  47  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  48  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  49  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  50  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  51  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  52  * SUCH DAMAGE.
  53  *
  54  *      @(#)if_loop.c   8.1 (Berkeley) 6/10/93
  55  */
  56
  57 /*
  58  * Loopback interface driver for protocol testing and timing.
  59  */
  60 #include "loop.h"
  61 #if NLOOP > 0
  62
  63 #include <sys/param.h>
  64 #include <sys/systm.h>
  65 #include <sys/kernel.h>
  66 #include <sys/mbuf.h>
  67 #include <sys/socket.h>
  68 #include <sys/sockio.h>
  69
  70 #include <net/if.h>
  71 #include <net/if_types.h>
  72 #include <net/netisr.h>
  73 #include <net/route.h>
  74 #include <net/bpf.h>
  75 #include <sys/malloc.h>
  76
  77 #if     INET
  78 #include <netinet/in.h>
  79 #include <netinet/in_var.h>
  80 #endif
  81
  82 #if IPX
  83 #include <netipx/ipx.h>
  84 #include <netipx/ipx_if.h>
  85 #endif
  86
  87 #if INET6
  88 #ifndef INET
  89 #include <netinet/in.h>
  90 #endif
  91 #include <netinet6/in6_var.h>
  92 #include <netinet/ip6.h>
  93 #endif
  94
  95 #if NS
  96 #include <netns/ns.h>
  97 #include <netns/ns_if.h>
  98 #endif
  99
 100 #if ISO
 101 #include <netiso/iso.h>
 102 #include <netiso/iso_var.h>
 103 #endif
 104
 105 #include <net/dlil.h>
 106
 107 #if NETAT
 108 extern struct ifqueue atalkintrq;
 109 #endif
 110
 111 #include "bpfilter.h"
 112 #if NBPFILTER > 0
 113 #include <net/bpfdesc.h>
 114 #endif
 115
 116 #define NLOOP_ATTACHMENTS (NLOOP * 12)
 117
 118 struct lo_statics_str {
 119         int     bpf_mode;
 120         int     (*bpf_callback)(struct ifnet *, struct mbuf *);
 121 };
 122
 123 static struct if_proto *lo_array[NLOOP_ATTACHMENTS];
 124 static struct lo_statics_str lo_statics[NLOOP];
 125 static lo_count = 0;
 126
 127
 128 #ifdef TINY_LOMTU
 129 #define LOMTU   (1024+512)
 130 #else
 131 #define LOMTU   16384
 132 #endif
 133
 134 struct  ifnet loif[NLOOP];
 135
 136 void lo_reg_if_mods();
 137
 138
 139
 140
 141 int lo_demux(ifp, m, frame_header, proto)
 142     struct ifnet *ifp;
 143     struct mbuf  *m;
 144     char         *frame_header;
 145     struct if_proto **proto;
 146 {
 147     int i;
 148     struct if_proto **proto_ptr;
 149
 150     proto_ptr = mtod(m, struct if_proto **);
 151     *proto = *proto_ptr;
 152     m_adj(m, sizeof(u_long));
 153     return 0;
 154 }
 155
 156
 157 int lo_framer(ifp, m, dest, dest_linkaddr, frame_type)
 158     struct ifnet    *ifp;
 159     struct mbuf     **m;
 160     struct sockaddr *dest;
 161     char            *dest_linkaddr;
 162     char            *frame_type;
 163
 164 {
 165     char  *to_ptr;
 166
 167         M_PREPEND(*m, (4 * sizeof(u_long)), M_WAITOK);
 168         to_ptr = mtod(*m, char *);
 169         bcopy(dest_linkaddr, to_ptr, (4 * sizeof(u_long)));
 170         return 0;
 171 }
 172
 173 static
 174 int  lo_add_if(struct ifnet *ifp)
 175 {
 176     ifp->if_demux  = lo_demux;
 177     ifp->if_framer = lo_framer;
 178     ifp->if_event  = 0;
 179     return 0;
 180 }
 181
 182 static
 183 int  lo_del_if(struct ifnet *ifp)
 184 {
 185     return 0;
 186 }
 187
 188
 189
 190
 191 static
 192 int  lo_add_proto(struct ddesc_head_str *desc_head, struct if_proto *proto, u_long dl_tag)
 193 {
 194     int i;
 195
 196     for (i=0; i < lo_count; i++)
 197         if (lo_array[i] == 0) {
 198             lo_array[lo_count] = proto;
 199             return 0;
 200         }
 201
 202     if ((i == lo_count) && (lo_count == NLOOP_ATTACHMENTS))
 203        panic("lo_add_proto -- Too many attachments\n");
 204
 205     lo_array[lo_count++] = proto;
 206     return 0;
 207 }
 208
 209
 210 static
 211 int  lo_del_proto(struct if_proto *proto, u_long dl_tag)
 212 {
 213     int i;
 214
 215     for (i=0; i < lo_count; i++)
 216         if (lo_array[i] == proto) {
 217             lo_array[i] = 0;
 218             return 0;
 219         }
 220
 221     return ENOENT;
 222 }
 223
 224 static int
 225 lo_output(ifp, m)
 226         struct ifnet *ifp;
 227         register struct mbuf *m;
 228 {       u_int  *prepend_ptr;
 229         u_int  af;
 230         u_long saved_header[3];
 231
 232         if ((m->m_flags & M_PKTHDR) == 0)
 233                 panic("lo_output: no HDR");
 234
 235         /*
 236          * Don't overwrite the rcvif field if it is in use.
 237          *  This is used to match multicast packets, sent looping
 238          *  back, with the appropriate group record on input.
 239          */
 240         if (m->m_pkthdr.rcvif == NULL)
 241                 m->m_pkthdr.rcvif = ifp;
 242         prepend_ptr = mtod(m, u_int *);
 243         af = *prepend_ptr;
 244         m_adj(m, sizeof(u_int));
 245
 246
 247 #if NBPFILTER > 0
 248         if (lo_statics[ifp->if_unit].bpf_mode != BPF_TAP_DISABLE) {
 249                 struct mbuf m0, *n;
 250
 251                 bcopy(mtod(m, caddr_t), &saved_header[0], (3 * sizeof(u_long)));
 252                 m_adj(m, (3 * sizeof(u_long)));
 253
 254                 n = m;
 255                 if (ifp->if_bpf->bif_dlt == DLT_NULL) {
 256                         /*
 257                          * We need to prepend the address family as
 258                          * a four byte field.  Cons up a dummy header
 259                          * to pacify bpf.  This is safe because bpf
 260                          * will only read from the mbuf (i.e., it won't
 261                          * try to free it or keep a pointer a to it).
 262                          */
 263                         m0.m_next = m;
 264                         m0.m_len = 4;
 265                         m0.m_data = (char *)&af;
 266                         n = &m0;
 267                 }
 268
 269                 (*lo_statics[ifp->if_unit].bpf_callback)(ifp, n);
 270
 271                 M_PREPEND(m, (3 * sizeof(u_long)), M_WAITOK);
 272                 bcopy(&saved_header[0], mtod(m, caddr_t), (3 * sizeof(u_long)));
 273
 274         }
 275 #endif
 276
 277         ifp->if_ibytes += m->m_pkthdr.len;
 278         ifp->if_obytes += m->m_pkthdr.len;
 279
 280         ifp->if_opackets++;
 281         ifp->if_ipackets++;
 282
 283         /* WARNING
 284          * This won't work for loopbacked multicast
 285          */
 286         m->m_pkthdr.header = mtod(m, char *);
 287         m->m_pkthdr.aux = ifp; /* HACKERY */
 288         m->m_pkthdr.csum_data = 0xffff; /* loopback checksums are always OK */
 289         m->m_pkthdr.csum_flags = CSUM_DATA_VALID | CSUM_PSEUDO_HDR |
 290                                CSUM_IP_CHECKED | CSUM_IP_VALID;
 291         return dlil_input(ifp, m, m);
 292 }
 293
 294
 295 /*
 296  * This is a common pre-output route used by INET, AT, etc. This could
 297  * (should?) be split into separate pre-output routines for each protocol.
 298  */
 299
 300 static int
 301 lo_pre_output(ifp, m, dst, route, frame_type, dst_addr, dl_tag)
 302         struct ifnet *ifp;
 303         register struct mbuf **m;
 304         struct sockaddr *dst;
 305         void                 *route;
 306         char                 *frame_type;
 307         char                 *dst_addr;
 308         u_long               dl_tag;
 309
 310 {
 311         int s, isr;
 312         register struct ifqueue *ifq = 0;
 313         u_long *prepend_ptr;
 314         register struct rtentry *rt = (struct rtentry *) route;
 315
 316         prepend_ptr = (u_long *) dst_addr;
 317         if (((*m)->m_flags & M_PKTHDR) == 0)
 318                 panic("looutput no HDR");
 319
 320         if (rt && rt->rt_flags & (RTF_REJECT|RTF_BLACKHOLE)) {
 321             if (rt->rt_flags & RTF_BLACKHOLE) {
 322                 m_freem(*m);
 323                 return EJUSTRETURN;
 324             }
 325             else
 326                 return ((rt->rt_flags & RTF_HOST) ? EHOSTUNREACH : ENETUNREACH);
 327         }
 328
 329         switch (dst->sa_family) {
 330 #if INET
 331         case AF_INET:
 332             ifq = &ipintrq;
 333             isr = NETISR_IP;
 334             break;
 335 #endif
 336 #if INET6
 337         case AF_INET6:
 338             ifq = &ip6intrq;
 339             isr = NETISR_IPV6;
 340             break;
 341 #endif
 342 #if IPX
 343         case AF_IPX:
 344             ifq = &ipxintrq;
 345             isr = NETISR_IPX;
 346             break;
 347 #endif
 348 #if NS
 349         case AF_NS:
 350             ifq = &nsintrq;
 351             isr = NETISR_NS;
 352             break;
 353 #endif
 354 #if ISO
 355         case AF_ISO:
 356             ifq = &clnlintrq;
 357             isr = NETISR_ISO;
 358             break;
 359 #endif
 360 #if NETAT
 361         case AF_APPLETALK:
 362             ifq = &atalkintrq;
 363             isr = NETISR_APPLETALK;
 364             break;
 365 #endif NETAT
 366         default:
 367             return (EAFNOSUPPORT);
 368         }
 369
 370         *prepend_ptr++ = dst->sa_family;        /* For lo_output(BPF) */
 371         *prepend_ptr++ = dlttoproto(dl_tag);    /* For lo_demux */
 372         *prepend_ptr++ = (u_long) ifq;          /* For lo_input */
 373         *prepend_ptr   = isr;                   /* For lo_input */
 374
 375         return 0;
 376 }
 377
 378
 379
 380
 381 /*
 382  *  lo_input - This should work for all attached protocols that use the
 383  *             ifq/schednetisr input mechanism.
 384  */
 385
 386
 387 int
 388 lo_input(m, fh, ifp, dl_tag, sync_ok)
 389         register struct mbuf *m;
 390         char         *fh;
 391         struct ifnet *ifp;
 392         u_long       dl_tag;
 393         int sync_ok;
 394
 395 {
 396         u_long *prepend_ptr;
 397         int s, isr;
 398         register struct ifqueue *ifq = 0;
 399
 400         prepend_ptr = mtod(m, u_long *);
 401         ifq = (struct ifqueue *) *prepend_ptr++;
 402         isr = *prepend_ptr;
 403         m_adj(m, (2 * sizeof(u_long)));
 404
 405         s = splimp();
 406         if (IF_QFULL(ifq)) {
 407                 IF_DROP(ifq);
 408                 m_freem(m);
 409                 splx(s);
 410                 return (EJUSTRETURN);
 411         }
 412
 413         IF_ENQUEUE(ifq, m);
 414         schednetisr(isr);
 415         splx(s);
 416         return (0);
 417 }
 418
 419
 420
 421
 422 /* ARGSUSED */
 423 static void
 424 lortrequest(cmd, rt, sa)
 425         int cmd;
 426         struct rtentry *rt;
 427         struct sockaddr *sa;
 428 {
 429         if (rt) {
 430                 rt->rt_rmx.rmx_mtu = rt->rt_ifp->if_mtu; /* for ISO */
 431                 /*
 432                  * For optimal performance, the send and receive buffers
 433                  * should be at least twice the MTU plus a little more for
 434                  * overhead.
 435                  */
 436                 rt->rt_rmx.rmx_recvpipe =
 437                         rt->rt_rmx.rmx_sendpipe = 3 * LOMTU;
 438         }
 439 }
 440
 441 /*
 442  * Process an ioctl request.
 443  */
 444 /* ARGSUSED */
 445 static int
 446 loioctl(dl_tag, ifp, cmd, data)
 447         u_long   dl_tag;
 448         register struct ifnet *ifp;
 449         u_long cmd;
 450         void   *data;
 451 {
 452         register struct ifaddr *ifa;
 453         register struct ifreq *ifr = (struct ifreq *)data;
 454         register int error = 0;
 455
 456         switch (cmd) {
 457
 458         case SIOCSIFADDR:
 459                 ifp->if_flags |= IFF_UP | IFF_RUNNING;
 460                 ifa = (struct ifaddr *)data;
 461                 ifa->ifa_rtrequest = lortrequest;
 462                 /*
 463                  * Everything else is done at a higher level.
 464                  */
 465                 break;
 466
 467         case SIOCADDMULTI:
 468         case SIOCDELMULTI:
 469                 if (ifr == 0) {
 470                         error = EAFNOSUPPORT;           /* XXX */
 471                         break;
 472                 }
 473                 switch (ifr->ifr_addr.sa_family) {
 474
 475 #if INET
 476                 case AF_INET:
 477                         break;
 478 #endif
 479 #if INET6
 480                 case AF_INET6:
 481                         break;
 482 #endif
 483
 484                 default:
 485                         error = EAFNOSUPPORT;
 486                         break;
 487                 }
 488                 break;
 489
 490         case SIOCSIFMTU:
 491                 ifp->if_mtu = ifr->ifr_mtu;
 492                 break;
 493
 494         case SIOCSIFFLAGS:
 495                 break;
 496
 497         default:
 498                 error = EOPNOTSUPP;
 499         }
 500         return (error);
 501 }
 502 #endif /* NLOOP > 0 */
 503
 504
 505 int lo_shutdown()
 506 {
 507     return 0;
 508 }
 509
 510
 511 void lo_reg_if_mods()
 512 {
 513      struct dlil_ifmod_reg_str  lo_ifmod;
 514
 515      lo_ifmod.add_if = lo_add_if;
 516      lo_ifmod.del_if = lo_del_if;
 517      lo_ifmod.add_proto = lo_add_proto;
 518      lo_ifmod.del_proto = lo_del_proto;
 519      lo_ifmod.ifmod_ioctl = 0;
 520      lo_ifmod.shutdown    = lo_shutdown;
 521
 522     if (dlil_reg_if_modules(APPLE_IF_FAM_LOOPBACK, &lo_ifmod))
 523         panic("Couldn't register lo modules\n");
 524 }
 525
 526
 527 u_long  lo_attach_inet(struct ifnet *ifp)
 528 {
 529     struct dlil_proto_reg_str   reg;
 530     struct dlil_demux_desc      desc;
 531     u_long                      dl_tag=0;
 532     short native=0;
 533     int   stat;
 534     int i;
 535
 536     for (i=0; i < lo_count; i++) {
 537         if ((lo_array[i]) && (lo_array[i]->ifp == ifp)) {
 538             if (lo_array[i]->protocol_family == PF_INET)
 539                 return lo_array[i]->dl_tag;
 540         }
 541     }
 542
 543     TAILQ_INIT(&reg.demux_desc_head);
 544     desc.type = DLIL_DESC_RAW;
 545     desc.variants.bitmask.proto_id_length = 0;
 546     desc.variants.bitmask.proto_id = 0;
 547     desc.variants.bitmask.proto_id_mask = 0;
 548     desc.native_type = (char *) &native;
 549     TAILQ_INSERT_TAIL(&reg.demux_desc_head, &desc, next);
 550     reg.interface_family = ifp->if_family;
 551     reg.unit_number      = ifp->if_unit;
 552     reg.input            = lo_input;
 553     reg.pre_output       = lo_pre_output;
 554     reg.event            = 0;
 555     reg.offer            = 0;
 556     reg.ioctl            = loioctl;
 557     reg.default_proto    = 0;
 558     reg.protocol_family  = PF_INET;
 559
 560     stat = dlil_attach_protocol(&reg, &dl_tag);
 561     if (stat) {
 562         panic("lo_attach_inet can't attach interface\n");
 563     }
 564
 565     return dl_tag;
 566 }
 567
 568
 569 int lo_set_bpf_tap(struct ifnet *ifp, int mode, int (*bpf_callback)(struct ifnet *, struct mbuf *))
 570 {
 571
 572   /*
 573    * NEED MUTEX HERE XXX
 574    */
 575         if (mode == BPF_TAP_DISABLE) {
 576                 lo_statics[ifp->if_unit].bpf_mode = mode;
 577                 lo_statics[ifp->if_unit].bpf_callback = bpf_callback;
 578         }
 579         else {
 580                 lo_statics[ifp->if_unit].bpf_callback = bpf_callback;
 581                 lo_statics[ifp->if_unit].bpf_mode = mode;
 582         }
 583
 584         return 0;
 585 }
 586
 587
 588 /* ARGSUSED */
 589 void
 590 loopattach(dummy)
 591         void *dummy;
 592 {
 593         register struct ifnet *ifp;
 594         register int i = 0;
 595
 596         thread_funnel_switch(KERNEL_FUNNEL, NETWORK_FUNNEL);
 597         lo_reg_if_mods();
 598
 599         for (ifp = loif; i < NLOOP; ifp++) {
 600                 lo_statics[i].bpf_callback = 0;
 601                 lo_statics[i].bpf_mode      = BPF_TAP_DISABLE;
 602                 ifp->if_name = "lo";
 603                 ifp->if_family = APPLE_IF_FAM_LOOPBACK;
 604                 ifp->if_unit = i++;
 605                 ifp->if_mtu = LOMTU;
 606                 ifp->if_flags = IFF_LOOPBACK | IFF_MULTICAST;
 607                 ifp->if_ioctl = 0;
 608                 ifp->if_set_bpf_tap = lo_set_bpf_tap;
 609                 ifp->if_output = lo_output;
 610                 ifp->if_type = IFT_LOOP;
 611                 ifp->if_hwassist = 0; /* HW cksum on send side breaks Classic loopback */
 612                 dlil_if_attach(ifp);
 613 #if NBPFILTER > 0
 614                 bpfattach(ifp, DLT_NULL, sizeof(u_int));
 615 #endif
 616         }
 617         thread_funnel_switch(NETWORK_FUNNEL, KERNEL_FUNNEL);
 618 }