bsd/net/if_disc.c

   1 /*
   2  * Copyright (c) 2006 Apple Computer, Inc. All Rights Reserved.
   3  *
   4  * @APPLE_LICENSE_OSREFERENCE_HEADER_START@
   5  *
   6  * This file contains Original Code and/or Modifications of Original Code
   7  * as defined in and that are subject to the Apple Public Source License
   8  * Version 2.0 (the 'License'). You may not use this file except in
   9  * compliance with the License.  The rights granted to you under the
  10  * License may not be used to create, or enable the creation or
  11  * redistribution of, unlawful or unlicensed copies of an Apple operating
  12  * system, or to circumvent, violate, or enable the circumvention or
  13  * violation of, any terms of an Apple operating system software license
  14  * agreement.
  15  *
  16  * Please obtain a copy of the License at
  17  * http://www.opensource.apple.com/apsl/ and read it before using this
  18  * file.
  19  *
  20  * The Original Code and all software distributed under the License are
  21  * distributed on an 'AS IS' basis, WITHOUT WARRANTY OF ANY KIND, EITHER
  22  * EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES,
  23  * INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY,
  24  * FITNESS FOR A PARTICULAR PURPOSE, QUIET ENJOYMENT OR NON-INFRINGEMENT.
  25  * Please see the License for the specific language governing rights and
  26  * limitations under the License.
  27  *
  28  * @APPLE_LICENSE_OSREFERENCE_HEADER_END@
  29  */
  30 /*
  31  * Copyright (c) 1982, 1986, 1993
  32  *      The Regents of the University of California.  All rights reserved.
  33  *
  34  * Redistribution and use in source and binary forms, with or without
  35  * modification, are permitted provided that the following conditions
  36  * are met:
  37  * 1. Redistributions of source code must retain the above copyright
  38  *    notice, this list of conditions and the following disclaimer.
  39  * 2. Redistributions in binary form must reproduce the above copyright
  40  *    notice, this list of conditions and the following disclaimer in the
  41  *    documentation and/or other materials provided with the distribution.
  42  * 3. All advertising materials mentioning features or use of this software
  43  *    must display the following acknowledgement:
  44  *      This product includes software developed by the University of
  45  *      California, Berkeley and its contributors.
  46  * 4. Neither the name of the University nor the names of its contributors
  47  *    may be used to endorse or promote products derived from this software
  48  *    without specific prior written permission.
  49  *
  50  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
  51  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  52  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  53  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
  54  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  55  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  56  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  57  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  58  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  59  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  60  * SUCH DAMAGE.
  61  *
  62  *      From: @(#)if_loop.c     8.1 (Berkeley) 6/10/93
  63  * $FreeBSD: src/sys/net/if_disc.c,v 1.26.2.1 2001/03/06 00:32:09 obrien Exp $
  64  */
  65
  66 /*
  67  * Discard interface driver for protocol testing and timing.
  68  * (Based on the loopback.)
  69  */
  70
  71 #include <sys/param.h>
  72 #include <sys/systm.h>
  73 #include <sys/kernel.h>
  74 #include <sys/mbuf.h>
  75 #include <sys/socket.h>
  76 #include <sys/sockio.h>
  77
  78 #include <net/if.h>
  79 #include <net/if_types.h>
  80 #include <net/route.h>
  81 #include <net/bpf.h>
  82
  83 #ifdef TINY_DSMTU
  84 #define DSMTU   (1024+512)
  85 #else
  86 #define DSMTU   65532
  87 #endif
  88
  89 static void discattach(void);
  90
  91 static struct   ifnet discif;
  92 static int discoutput(struct ifnet *, struct mbuf *, struct sockaddr *,
  93                     struct rtentry *);
  94 static void discrtrequest(int cmd, struct rtentry *rt, struct sockaddr *sa);
  95 static int discioctl(struct ifnet *, u_long, caddr_t);
  96
  97 /* ARGSUSED */
  98 static void
  99 discattach()
 100 {
 101         register struct ifnet *ifp = &discif;
 102
 103         ifp->if_name = "ds";
 104         ifp->if_family = APPLE_IF_FAM_DISC;
 105         ifp->if_mtu = DSMTU;
 106         ifp->if_flags = IFF_LOOPBACK | IFF_MULTICAST;
 107         ifp->if_ioctl = discioctl;
 108         ifp->if_output = discoutput;
 109         ifp->if_type = IFT_LOOP;
 110         ifp->if_hdrlen = 0;
 111         ifp->if_addrlen = 0;
 112         if_attach(ifp);
 113         bpfattach(ifp, DLT_NULL, sizeof(u_int));
 114 }
 115
 116 #ifndef __APPLE__
 117 static int
 118 disc_modevent(module_t mod, int type, void *data)
 119 {
 120         switch (type) {
 121         case MOD_LOAD:
 122                 discattach();
 123                 break;
 124         case MOD_UNLOAD:
 125                 printf("if_disc module unload - not possible for this module type\n");
 126                 return EINVAL;
 127         }
 128         return 0;
 129 }
 130
 131 static moduledata_t disc_mod = {
 132         "if_disc",
 133         disc_modevent,
 134         NULL
 135 };
 136
 137 DECLARE_MODULE(if_disc, disc_mod, SI_SUB_PSEUDO, SI_ORDER_ANY);
 138 #endif
 139
 140 static int
 141 discoutput(ifp, m, dst, rt)
 142         struct ifnet *ifp;
 143         register struct mbuf *m;
 144         struct sockaddr *dst;
 145         register struct rtentry *rt;
 146 {
 147         if ((m->m_flags & M_PKTHDR) == 0)
 148                 panic("discoutput no HDR");
 149         /* BPF write needs to be handled specially */
 150         if (dst->sa_family == AF_UNSPEC) {
 151                 dst->sa_family = *(mtod(m, int *));
 152                 m->m_len -= sizeof(int);
 153                 m->m_pkthdr.len -= sizeof(int);
 154                 m->m_data += sizeof(int);
 155         }
 156
 157         if (discif.if_bpf) {
 158                 /*
 159                  * We need to prepend the address family as
 160                  * a four byte field.  Cons up a dummy header
 161                  * to pacify bpf.  This is safe because bpf
 162                  * will only read from the mbuf (i.e., it won't
 163                  * try to free it or keep a pointer a to it).
 164                  */
 165                 struct mbuf m0;
 166                 u_int af = dst->sa_family;
 167
 168                 m0.m_next = m;
 169                 m0.m_len = 4;
 170                 m0.m_data = (char *)&af;
 171
 172                 bpf_mtap(&discif, &m0);
 173         }
 174         m->m_pkthdr.rcvif = ifp;
 175
 176         ifp->if_opackets++;
 177         ifp->if_obytes += m->m_pkthdr.len;
 178
 179         m_freem(m);
 180         return 0;
 181 }
 182
 183 /* ARGSUSED */
 184 static void
 185 discrtrequest(cmd, rt, sa)
 186         int cmd;
 187         struct rtentry *rt;
 188         struct sockaddr *sa;
 189 {
 190         if (rt)
 191                 rt->rt_rmx.rmx_mtu = DSMTU;
 192 }
 193
 194 /*
 195  * Process an ioctl request.
 196  */
 197 /* ARGSUSED */
 198 static int
 199 discioctl(ifp, cmd, data)
 200         register struct ifnet *ifp;
 201         u_long cmd;
 202         caddr_t data;
 203 {
 204         register struct ifaddr *ifa;
 205         register struct ifreq *ifr = (struct ifreq *)data;
 206         register int error = 0;
 207
 208         switch (cmd) {
 209
 210         case SIOCSIFADDR:
 211                 ifnet_set_flags(ifp, IFF_UP, IFF_UP);
 212                 ifa = (struct ifaddr *)data;
 213                 if (ifa != 0)
 214                         ifa->ifa_rtrequest = discrtrequest;
 215                 /*
 216                  * Everything else is done at a higher level.
 217                  */
 218                 break;
 219
 220         case SIOCADDMULTI:
 221         case SIOCDELMULTI:
 222                 if (ifr == 0) {
 223                         error = EAFNOSUPPORT;           /* XXX */
 224                         break;
 225                 }
 226                 switch (ifr->ifr_addr.sa_family) {
 227
 228 #if INET
 229                 case AF_INET:
 230                         break;
 231 #endif
 232 #if INET6
 233                 case AF_INET6:
 234                         break;
 235 #endif
 236
 237                 default:
 238                         error = EAFNOSUPPORT;
 239                         break;
 240                 }
 241                 break;
 242
 243         case SIOCSIFMTU:
 244                 ifp->if_mtu = ifr->ifr_mtu;
 245                 break;
 246
 247         default:
 248                 error = EINVAL;
 249         }
 250         return (error);
 251 }