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  * $FreeBSD: src/sys/net/if_loop.c,v 1.47.2.5 2001/07/03 11:01:41 ume Exp $
  56  */
  57
  58 /*
  59  * Loopback interface driver for protocol testing and timing.
  60  */
  61 #include "loop.h"
  62 #if NLOOP > 0
  63
  64 #include <sys/param.h>
  65 #include <sys/systm.h>
  66 #include <sys/kernel.h>
  67 #include <sys/mbuf.h>
  68 #include <sys/socket.h>
  69 #include <sys/sockio.h>
  70
  71 #include <net/if.h>
  72 #include <net/if_types.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 #include <net/dlil.h>
  96 #include <net/kpi_protocol.h>
  97
  98 #if NETAT
  99 extern struct ifqueue atalkintrq;
 100 #endif
 101
 102 #include "bpfilter.h"
 103 #if NBPFILTER > 0
 104 #include <net/bpfdesc.h>
 105 #endif
 106
 107 #define NLOOP_ATTACHMENTS (NLOOP * 12)
 108
 109 struct lo_statics_str {
 110         int                             bpf_mode;
 111         bpf_packet_func bpf_callback;
 112 };
 113
 114 void loopattach(void *dummy);
 115
 116 static struct lo_statics_str lo_statics[NLOOP];
 117 int loopattach_done = 0; /* used to sync ip6_init2 loopback configuration */
 118
 119 #ifdef TINY_LOMTU
 120 #define LOMTU   (1024+512)
 121 #else
 122 #define LOMTU   16384
 123 #endif
 124
 125 struct  ifnet loif[NLOOP];
 126 struct ifnet *lo_ifp = &loif[0];
 127
 128 struct  loopback_header {
 129         u_long          protocol;
 130 };
 131
 132 void lo_reg_if_mods(void);
 133
 134 /* Local forward declerations */
 135
 136 static errno_t
 137 lo_demux(
 138     __unused ifnet_t    ifp,
 139     __unused mbuf_t             m,
 140     char                                *frame_header,
 141     protocol_family_t   *protocol_family)
 142 {
 143         struct loopback_header *header = (struct loopback_header *)frame_header;
 144
 145         *protocol_family = header->protocol;
 146
 147         return 0;
 148 }
 149
 150
 151 static errno_t
 152 lo_framer(
 153     __unused ifnet_t                            ifp,
 154     mbuf_t                                                      *m,
 155     __unused const struct sockaddr      *dest,
 156     __unused const char                 *dest_linkaddr,
 157     const char                                          *frame_type)
 158 {
 159         struct loopback_header  *header;
 160
 161         M_PREPEND(*m, sizeof(struct loopback_header), M_WAITOK);
 162         header = mtod(*m, struct loopback_header*);
 163         header->protocol = *(const u_long*)frame_type;
 164         return 0;
 165 }
 166
 167 static errno_t
 168 lo_add_proto(
 169         __unused struct ifnet                   *ifp,
 170         __unused u_long                                 protocol_family,
 171         __unused struct ddesc_head_str  *demux_desc_head)
 172 {
 173     return 0;
 174 }
 175
 176
 177 static errno_t
 178 lo_del_proto(
 179         __unused ifnet_t                        ifp,
 180         __unused protocol_family_t      protocol)
 181 {
 182         return 0;
 183 }
 184
 185 static int
 186 lo_output(
 187         struct ifnet *ifp,
 188         struct mbuf *m)
 189 {
 190
 191         if ((m->m_flags & M_PKTHDR) == 0)
 192                 panic("lo_output: no HDR");
 193
 194         /*
 195          * Don't overwrite the rcvif field if it is in use.
 196          *  This is used to match multicast packets, sent looping
 197          *  back, with the appropriate group record on input.
 198          */
 199         if (m->m_pkthdr.rcvif == NULL)
 200                 m->m_pkthdr.rcvif = ifp;
 201
 202         ifp->if_ibytes += m->m_pkthdr.len;
 203         ifp->if_obytes += m->m_pkthdr.len;
 204
 205         ifp->if_opackets++;
 206         ifp->if_ipackets++;
 207
 208         m->m_pkthdr.header = mtod(m, char *);
 209         m->m_pkthdr.csum_data = 0xffff; /* loopback checksums are always OK */
 210         m->m_pkthdr.csum_flags = CSUM_DATA_VALID | CSUM_PSEUDO_HDR |
 211                                                          CSUM_IP_CHECKED | CSUM_IP_VALID;
 212         m_adj(m, sizeof(struct loopback_header));
 213
 214 #if NBPFILTER > 0
 215         if (lo_statics[ifp->if_unit].bpf_mode != BPF_TAP_DISABLE) {
 216                 struct mbuf m0, *n;
 217
 218                 n = m;
 219                 if (ifp->if_bpf->bif_dlt == DLT_NULL) {
 220                         struct loopback_header  *header;
 221                         /*
 222                          * We need to prepend the address family as
 223                          * a four byte field.  Cons up a dummy header
 224                          * to pacify bpf.  This is safe because bpf
 225                          * will only read from the mbuf (i.e., it won't
 226                          * try to free it or keep a pointer a to it).
 227                          */
 228                         header = (struct loopback_header*)m->m_pkthdr.header;
 229                         m0.m_next = m;
 230                         m0.m_len = 4;
 231                         m0.m_data = (char *)&header->protocol;
 232                         n = &m0;
 233                 }
 234
 235                 lo_statics[ifp->if_unit].bpf_callback(ifp, n);
 236         }
 237 #endif
 238
 239         return dlil_input(ifp, m, m);
 240 }
 241
 242
 243 /*
 244  * This is a common pre-output route used by INET and INET6. This could
 245  * (should?) be split into separate pre-output routines for each protocol.
 246  */
 247
 248 static int
 249 lo_pre_output(
 250         __unused struct ifnet   *ifp,
 251         u_long                  protocol_family,
 252         struct mbuf             **m,
 253         __unused const struct sockaddr  *dst,
 254         caddr_t                 route,
 255         char                    *frame_type,
 256         __unused char   *dst_addr)
 257
 258 {
 259         register struct rtentry *rt = (struct rtentry *) route;
 260
 261         if (((*m)->m_flags & M_PKTHDR) == 0)
 262                 panic("looutput no HDR");
 263
 264         if (rt && rt->rt_flags & (RTF_REJECT|RTF_BLACKHOLE)) {
 265                 if (rt->rt_flags & RTF_BLACKHOLE) {
 266                         m_freem(*m);
 267                         return EJUSTRETURN;
 268                 }
 269                 else
 270                         return ((rt->rt_flags & RTF_HOST) ? EHOSTUNREACH : ENETUNREACH);
 271         }
 272
 273         *(u_long *)frame_type = protocol_family;
 274
 275         return 0;
 276 }
 277
 278 /*
 279  *  lo_input - This should work for all attached protocols that use the
 280  *             ifq/schednetisr input mechanism.
 281  */
 282 static int
 283 lo_input(
 284         struct mbuf                             *m,
 285         __unused char                   *fh,
 286         __unused struct ifnet   *ifp,
 287         __unused u_long                 protocol_family,
 288         __unused int                    sync_ok)
 289 {
 290         if (proto_input(protocol_family, m) != 0)
 291                 m_freem(m);
 292         return (0);
 293 }
 294
 295
 296
 297
 298 /* ARGSUSED */
 299 static void
 300 lortrequest(
 301         __unused int cmd,
 302         struct rtentry *rt,
 303         __unused struct sockaddr *sa)
 304 {
 305         if (rt) {
 306                 rt->rt_rmx.rmx_mtu = rt->rt_ifp->if_mtu; /* for ISO */
 307                 /*
 308                  * For optimal performance, the send and receive buffers
 309                  * should be at least twice the MTU plus a little more for
 310                  * overhead.
 311                  */
 312                 rt->rt_rmx.rmx_recvpipe =
 313                         rt->rt_rmx.rmx_sendpipe = 3 * LOMTU;
 314         }
 315 }
 316
 317 /*
 318  * Process an ioctl request.
 319  */
 320 static errno_t
 321 loioctl(
 322         ifnet_t         ifp,
 323         u_int32_t       cmd,
 324         void*           data)
 325 {
 326         register struct ifaddr *ifa;
 327         register struct ifreq *ifr = (struct ifreq *)data;
 328         register int error = 0;
 329
 330         switch (cmd) {
 331
 332         case SIOCSIFADDR:
 333                 ifnet_set_flags(ifp, IFF_UP | IFF_RUNNING, IFF_UP | IFF_RUNNING);
 334                 ifa = (struct ifaddr *)data;
 335                 ifa->ifa_rtrequest = lortrequest;
 336                 /*
 337                  * Everything else is done at a higher level.
 338                  */
 339                 break;
 340
 341         case SIOCADDMULTI:
 342         case SIOCDELMULTI:
 343                 if (ifr == 0) {
 344                         error = EAFNOSUPPORT;           /* XXX */
 345                         break;
 346                 }
 347                 switch (ifr->ifr_addr.sa_family) {
 348
 349 #if INET
 350                 case AF_INET:
 351                         break;
 352 #endif
 353 #if INET6
 354                 case AF_INET6:
 355                         break;
 356 #endif
 357
 358                 default:
 359                         error = EAFNOSUPPORT;
 360                         break;
 361                 }
 362                 break;
 363
 364         case SIOCSIFMTU:
 365                 ifp->if_mtu = ifr->ifr_mtu;
 366                 break;
 367
 368         case SIOCSIFFLAGS:
 369                 break;
 370
 371         default:
 372                 error = EOPNOTSUPP;
 373                 break;
 374         }
 375         return (error);
 376 }
 377 #endif /* NLOOP > 0 */
 378
 379
 380 static int  lo_attach_proto(struct ifnet *ifp, u_long protocol_family)
 381 {
 382         struct dlil_proto_reg_str   reg;
 383         int   stat =0 ;
 384
 385         bzero(&reg, sizeof(reg));
 386         TAILQ_INIT(&reg.demux_desc_head);
 387         reg.interface_family = ifp->if_family;
 388         reg.unit_number      = ifp->if_unit;
 389         reg.input                        = lo_input;
 390         reg.pre_output       = lo_pre_output;
 391         reg.protocol_family  = protocol_family;
 392
 393         stat = dlil_attach_protocol(&reg);
 394
 395         if (stat && stat != EEXIST) {
 396                 printf("lo_attach_proto: dlil_attach_protocol for %d returned=%d\n",
 397                            protocol_family, stat);
 398         }
 399
 400         return stat;
 401 }
 402
 403 void lo_reg_if_mods()
 404 {
 405      int error;
 406
 407         /* Register protocol registration functions */
 408         if ((error = dlil_reg_proto_module(PF_INET, APPLE_IF_FAM_LOOPBACK, lo_attach_proto, NULL)) != 0)
 409                 printf("dlil_reg_proto_module failed for AF_INET error=%d\n", error);
 410
 411         if ((error = dlil_reg_proto_module(PF_INET6, APPLE_IF_FAM_LOOPBACK, lo_attach_proto, NULL)) != 0)
 412                 printf("dlil_reg_proto_module failed for AF_INET6 error=%d\n", error);
 413 }
 414
 415 static errno_t
 416 lo_set_bpf_tap(
 417         ifnet_t                 ifp,
 418         bpf_tap_mode    mode,
 419         bpf_packet_func bpf_callback)
 420 {
 421
 422   /*
 423    * NEED MUTEX HERE XXX
 424    */
 425         if (mode == BPF_TAP_DISABLE) {
 426                 lo_statics[ifp->if_unit].bpf_mode = mode;
 427                 lo_statics[ifp->if_unit].bpf_callback = bpf_callback;
 428         }
 429         else {
 430                 lo_statics[ifp->if_unit].bpf_callback = bpf_callback;
 431                 lo_statics[ifp->if_unit].bpf_mode = mode;
 432         }
 433
 434         return 0;
 435 }
 436
 437
 438 /* ARGSUSED */
 439 void
 440 loopattach(
 441         __unused void *dummy)
 442 {
 443         struct ifnet *ifp;
 444         int i = 0;
 445
 446         lo_reg_if_mods();
 447
 448         for (ifp = loif; i < NLOOP; ifp++) {
 449                 lo_statics[i].bpf_callback = 0;
 450                 lo_statics[i].bpf_mode      = BPF_TAP_DISABLE;
 451                 bzero(ifp, sizeof(struct ifnet));
 452                 ifp->if_name = "lo";
 453                 ifp->if_family = APPLE_IF_FAM_LOOPBACK;
 454                 ifp->if_unit = i++;
 455                 ifp->if_mtu = LOMTU;
 456                 ifp->if_flags = IFF_LOOPBACK | IFF_MULTICAST;
 457                 ifp->if_ioctl = loioctl;
 458                 ifp->if_demux = lo_demux;
 459                 ifp->if_framer = lo_framer;
 460                 ifp->if_add_proto = lo_add_proto;
 461                 ifp->if_del_proto = lo_del_proto;
 462                 ifp->if_set_bpf_tap = lo_set_bpf_tap;
 463                 ifp->if_output = lo_output;
 464                 ifp->if_type = IFT_LOOP;
 465                 ifp->if_hwassist = IF_HWASSIST_CSUM_IP | IF_HWASSIST_CSUM_TCP | IF_HWASSIST_CSUM_UDP;
 466                 ifp->if_hdrlen = sizeof(struct loopback_header);
 467                 lo_ifp = ifp;
 468                 dlil_if_attach(ifp);
 469 #if NBPFILTER > 0
 470                 bpfattach(ifp, DLT_NULL, sizeof(u_int));
 471 #endif
 472         }
 473         loopattach_done = 1;
 474 }