bsd/net/if_disc.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  *      From: @(#)if_loop.c     8.1 (Berkeley) 6/10/93
  55  * $FreeBSD: src/sys/net/if_disc.c,v 1.26.2.1 2001/03/06 00:32:09 obrien Exp $
  56  */
  57
  58 /*
  59  * Discard interface driver for protocol testing and timing.
  60  * (Based on the loopback.)
  61  */
  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/route.h>
  73 #include <net/bpf.h>
  74
  75 #ifdef TINY_DSMTU
  76 #define DSMTU   (1024+512)
  77 #else
  78 #define DSMTU   65532
  79 #endif
  80
  81 static void discattach __P((void));
  82
  83 static struct   ifnet discif;
  84 static int discoutput(struct ifnet *, struct mbuf *, struct sockaddr *,
  85                     struct rtentry *);
  86 static void discrtrequest(int cmd, struct rtentry *rt, struct sockaddr *sa);
  87 static int discioctl(struct ifnet *, u_long, caddr_t);
  88
  89 /* ARGSUSED */
  90 static void
  91 discattach()
  92 {
  93         register struct ifnet *ifp = &discif;
  94
  95         ifp->if_name = "ds";
  96         ifp->if_family = APPLE_IF_FAM_DISC;
  97         ifp->if_mtu = DSMTU;
  98         ifp->if_flags = IFF_LOOPBACK | IFF_MULTICAST;
  99         ifp->if_ioctl = discioctl;
 100         ifp->if_output = discoutput;
 101         ifp->if_type = IFT_LOOP;
 102         ifp->if_hdrlen = 0;
 103         ifp->if_addrlen = 0;
 104         if_attach(ifp);
 105         bpfattach(ifp, DLT_NULL, sizeof(u_int));
 106 }
 107
 108 #ifndef __APPLE__
 109 static int
 110 disc_modevent(module_t mod, int type, void *data)
 111 {
 112         switch (type) {
 113         case MOD_LOAD:
 114                 discattach();
 115                 break;
 116         case MOD_UNLOAD:
 117                 printf("if_disc module unload - not possible for this module type\n");
 118                 return EINVAL;
 119         }
 120         return 0;
 121 }
 122
 123 static moduledata_t disc_mod = {
 124         "if_disc",
 125         disc_modevent,
 126         NULL
 127 };
 128
 129 DECLARE_MODULE(if_disc, disc_mod, SI_SUB_PSEUDO, SI_ORDER_ANY);
 130 #endif
 131
 132 static int
 133 discoutput(ifp, m, dst, rt)
 134         struct ifnet *ifp;
 135         register struct mbuf *m;
 136         struct sockaddr *dst;
 137         register struct rtentry *rt;
 138 {
 139         if ((m->m_flags & M_PKTHDR) == 0)
 140                 panic("discoutput no HDR");
 141         /* BPF write needs to be handled specially */
 142         if (dst->sa_family == AF_UNSPEC) {
 143                 dst->sa_family = *(mtod(m, int *));
 144                 m->m_len -= sizeof(int);
 145                 m->m_pkthdr.len -= sizeof(int);
 146                 m->m_data += sizeof(int);
 147         }
 148
 149         if (discif.if_bpf) {
 150                 /*
 151                  * We need to prepend the address family as
 152                  * a four byte field.  Cons up a dummy header
 153                  * to pacify bpf.  This is safe because bpf
 154                  * will only read from the mbuf (i.e., it won't
 155                  * try to free it or keep a pointer a to it).
 156                  */
 157                 struct mbuf m0;
 158                 u_int af = dst->sa_family;
 159
 160                 m0.m_next = m;
 161                 m0.m_len = 4;
 162                 m0.m_data = (char *)&af;
 163
 164                 bpf_mtap(&discif, &m0);
 165         }
 166         m->m_pkthdr.rcvif = ifp;
 167
 168         ifp->if_opackets++;
 169         ifp->if_obytes += m->m_pkthdr.len;
 170
 171         m_freem(m);
 172         return 0;
 173 }
 174
 175 /* ARGSUSED */
 176 static void
 177 discrtrequest(cmd, rt, sa)
 178         int cmd;
 179         struct rtentry *rt;
 180         struct sockaddr *sa;
 181 {
 182         if (rt)
 183                 rt->rt_rmx.rmx_mtu = DSMTU;
 184 }
 185
 186 /*
 187  * Process an ioctl request.
 188  */
 189 /* ARGSUSED */
 190 static int
 191 discioctl(ifp, cmd, data)
 192         register struct ifnet *ifp;
 193         u_long cmd;
 194         caddr_t data;
 195 {
 196         register struct ifaddr *ifa;
 197         register struct ifreq *ifr = (struct ifreq *)data;
 198         register int error = 0;
 199
 200         switch (cmd) {
 201
 202         case SIOCSIFADDR:
 203                 ifp->if_flags |= IFF_UP;
 204                 ifa = (struct ifaddr *)data;
 205                 if (ifa != 0)
 206                         ifa->ifa_rtrequest = discrtrequest;
 207                 /*
 208                  * Everything else is done at a higher level.
 209                  */
 210                 break;
 211
 212         case SIOCADDMULTI:
 213         case SIOCDELMULTI:
 214                 if (ifr == 0) {
 215                         error = EAFNOSUPPORT;           /* XXX */
 216                         break;
 217                 }
 218                 switch (ifr->ifr_addr.sa_family) {
 219
 220 #if INET
 221                 case AF_INET:
 222                         break;
 223 #endif
 224 #if INET6
 225                 case AF_INET6:
 226                         break;
 227 #endif
 228
 229                 default:
 230                         error = EAFNOSUPPORT;
 231                         break;
 232                 }
 233                 break;
 234
 235         case SIOCSIFMTU:
 236                 ifp->if_mtu = ifr->ifr_mtu;
 237                 break;
 238
 239         default:
 240                 error = EINVAL;
 241         }
 242         return (error);
 243 }