bsd/net/if_disc.c

   1 /*
   2  * Copyright (c) 2000 Apple Computer, Inc. All rights reserved.
   3  *
   4  * @APPLE_LICENSE_HEADER_START@
   5  *
   6  * Copyright (c) 1999-2003 Apple Computer, Inc.  All Rights Reserved.
   7  *
   8  * This file contains Original Code and/or Modifications of Original Code
   9  * as defined in and that are subject to the Apple Public Source License
  10  * Version 2.0 (the 'License'). You may not use this file except in
  11  * compliance with the License. Please obtain a copy of the License at
  12  * http://www.opensource.apple.com/apsl/ and read it before using this
  13  * file.
  14  *
  15  * The Original Code and all software distributed under the License are
  16  * distributed on an 'AS IS' basis, WITHOUT WARRANTY OF ANY KIND, EITHER
  17  * EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES,
  18  * INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY,
  19  * FITNESS FOR A PARTICULAR PURPOSE, QUIET ENJOYMENT OR NON-INFRINGEMENT.
  20  * Please see the License for the specific language governing rights and
  21  * limitations under the License.
  22  *
  23  * @APPLE_LICENSE_HEADER_END@
  24  */
  25 /*
  26  * Copyright (c) 1982, 1986, 1993
  27  *      The Regents of the University of California.  All rights reserved.
  28  *
  29  * Redistribution and use in source and binary forms, with or without
  30  * modification, are permitted provided that the following conditions
  31  * are met:
  32  * 1. Redistributions of source code must retain the above copyright
  33  *    notice, this list of conditions and the following disclaimer.
  34  * 2. Redistributions in binary form must reproduce the above copyright
  35  *    notice, this list of conditions and the following disclaimer in the
  36  *    documentation and/or other materials provided with the distribution.
  37  * 3. All advertising materials mentioning features or use of this software
  38  *    must display the following acknowledgement:
  39  *      This product includes software developed by the University of
  40  *      California, Berkeley and its contributors.
  41  * 4. Neither the name of the University nor the names of its contributors
  42  *    may be used to endorse or promote products derived from this software
  43  *    without specific prior written permission.
  44  *
  45  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
  46  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  47  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  48  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
  49  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  50  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  51  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  52  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  53  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  54  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  55  * SUCH DAMAGE.
  56  *
  57  *      From: @(#)if_loop.c     8.1 (Berkeley) 6/10/93
  58  * $FreeBSD: src/sys/net/if_disc.c,v 1.26.2.1 2001/03/06 00:32:09 obrien Exp $
  59  */
  60
  61 /*
  62  * Discard interface driver for protocol testing and timing.
  63  * (Based on the loopback.)
  64  */
  65
  66 #include <sys/param.h>
  67 #include <sys/systm.h>
  68 #include <sys/kernel.h>
  69 #include <sys/mbuf.h>
  70 #include <sys/socket.h>
  71 #include <sys/sockio.h>
  72
  73 #include <net/if.h>
  74 #include <net/if_types.h>
  75 #include <net/route.h>
  76 #include <net/bpf.h>
  77
  78 #ifdef TINY_DSMTU
  79 #define DSMTU   (1024+512)
  80 #else
  81 #define DSMTU   65532
  82 #endif
  83
  84 static void discattach __P((void));
  85
  86 static struct   ifnet discif;
  87 static int discoutput(struct ifnet *, struct mbuf *, struct sockaddr *,
  88                     struct rtentry *);
  89 static void discrtrequest(int cmd, struct rtentry *rt, struct sockaddr *sa);
  90 static int discioctl(struct ifnet *, u_long, caddr_t);
  91
  92 /* ARGSUSED */
  93 static void
  94 discattach()
  95 {
  96         register struct ifnet *ifp = &discif;
  97
  98         ifp->if_name = "ds";
  99         ifp->if_family = APPLE_IF_FAM_DISC;
 100         ifp->if_mtu = DSMTU;
 101         ifp->if_flags = IFF_LOOPBACK | IFF_MULTICAST;
 102         ifp->if_ioctl = discioctl;
 103         ifp->if_output = discoutput;
 104         ifp->if_type = IFT_LOOP;
 105         ifp->if_hdrlen = 0;
 106         ifp->if_addrlen = 0;
 107         if_attach(ifp);
 108         bpfattach(ifp, DLT_NULL, sizeof(u_int));
 109 }
 110
 111 #ifndef __APPLE__
 112 static int
 113 disc_modevent(module_t mod, int type, void *data)
 114 {
 115         switch (type) {
 116         case MOD_LOAD:
 117                 discattach();
 118                 break;
 119         case MOD_UNLOAD:
 120                 printf("if_disc module unload - not possible for this module type\n");
 121                 return EINVAL;
 122         }
 123         return 0;
 124 }
 125
 126 static moduledata_t disc_mod = {
 127         "if_disc",
 128         disc_modevent,
 129         NULL
 130 };
 131
 132 DECLARE_MODULE(if_disc, disc_mod, SI_SUB_PSEUDO, SI_ORDER_ANY);
 133 #endif
 134
 135 static int
 136 discoutput(ifp, m, dst, rt)
 137         struct ifnet *ifp;
 138         register struct mbuf *m;
 139         struct sockaddr *dst;
 140         register struct rtentry *rt;
 141 {
 142         if ((m->m_flags & M_PKTHDR) == 0)
 143                 panic("discoutput no HDR");
 144         /* BPF write needs to be handled specially */
 145         if (dst->sa_family == AF_UNSPEC) {
 146                 dst->sa_family = *(mtod(m, int *));
 147                 m->m_len -= sizeof(int);
 148                 m->m_pkthdr.len -= sizeof(int);
 149                 m->m_data += sizeof(int);
 150         }
 151
 152         if (discif.if_bpf) {
 153                 /*
 154                  * We need to prepend the address family as
 155                  * a four byte field.  Cons up a dummy header
 156                  * to pacify bpf.  This is safe because bpf
 157                  * will only read from the mbuf (i.e., it won't
 158                  * try to free it or keep a pointer a to it).
 159                  */
 160                 struct mbuf m0;
 161                 u_int af = dst->sa_family;
 162
 163                 m0.m_next = m;
 164                 m0.m_len = 4;
 165                 m0.m_data = (char *)&af;
 166
 167                 bpf_mtap(&discif, &m0);
 168         }
 169         m->m_pkthdr.rcvif = ifp;
 170
 171         ifp->if_opackets++;
 172         ifp->if_obytes += m->m_pkthdr.len;
 173
 174         m_freem(m);
 175         return 0;
 176 }
 177
 178 /* ARGSUSED */
 179 static void
 180 discrtrequest(cmd, rt, sa)
 181         int cmd;
 182         struct rtentry *rt;
 183         struct sockaddr *sa;
 184 {
 185         if (rt)
 186                 rt->rt_rmx.rmx_mtu = DSMTU;
 187 }
 188
 189 /*
 190  * Process an ioctl request.
 191  */
 192 /* ARGSUSED */
 193 static int
 194 discioctl(ifp, cmd, data)
 195         register struct ifnet *ifp;
 196         u_long cmd;
 197         caddr_t data;
 198 {
 199         register struct ifaddr *ifa;
 200         register struct ifreq *ifr = (struct ifreq *)data;
 201         register int error = 0;
 202
 203         switch (cmd) {
 204
 205         case SIOCSIFADDR:
 206                 ifp->if_flags |= IFF_UP;
 207                 ifa = (struct ifaddr *)data;
 208                 if (ifa != 0)
 209                         ifa->ifa_rtrequest = discrtrequest;
 210                 /*
 211                  * Everything else is done at a higher level.
 212                  */
 213                 break;
 214
 215         case SIOCADDMULTI:
 216         case SIOCDELMULTI:
 217                 if (ifr == 0) {
 218                         error = EAFNOSUPPORT;           /* XXX */
 219                         break;
 220                 }
 221                 switch (ifr->ifr_addr.sa_family) {
 222
 223 #if INET
 224                 case AF_INET:
 225                         break;
 226 #endif
 227 #if INET6
 228                 case AF_INET6:
 229                         break;
 230 #endif
 231
 232                 default:
 233                         error = EAFNOSUPPORT;
 234                         break;
 235                 }
 236                 break;
 237
 238         case SIOCSIFMTU:
 239                 ifp->if_mtu = ifr->ifr_mtu;
 240                 break;
 241
 242         default:
 243                 error = EINVAL;
 244         }
 245         return (error);
 246 }