bsd/net/if_disc.c

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