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  */
  56
  57 /*
  58  * Discard interface driver for protocol testing and timing.
  59  * (Based on the loopback.)
  60  */
  61
  62 #include <sys/param.h>
  63 #include <sys/systm.h>
  64 #include <sys/kernel.h>
  65 #include <sys/mbuf.h>
  66 #include <sys/socket.h>
  67 #include <sys/sockio.h>
  68
  69 #include <net/if.h>
  70 #include <net/if_types.h>
  71 #include <net/route.h>
  72 #include <net/bpf.h>
  73
  74 #include "bpfilter.h"
  75 #include "opt_inet.h"
  76
  77 #if TINY_DSMTU
  78 #define DSMTU   (1024+512)
  79 #else
  80 #define DSMTU   65532
  81 #endif
  82
  83 static void discattach __P((void *dummy));
  84 PSEUDO_SET(discattach, if_disc);
  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(dummy)
  95         void *dummy;
  96 {
  97         register struct ifnet *ifp = &discif;
  98
  99         ifp->if_name = "ds";
 100         ifp->if_family = APPLE_IF_FAM_DISC;
 101         ifp->if_mtu = DSMTU;
 102         ifp->if_flags = IFF_LOOPBACK | IFF_MULTICAST;
 103         ifp->if_ioctl = discioctl;
 104         ifp->if_output = discoutput;
 105         ifp->if_type = IFT_LOOP;
 106         ifp->if_hdrlen = 0;
 107         ifp->if_addrlen = 0;
 108         if_attach(ifp);
 109 #if NBPFILTER > 0
 110         bpfattach(ifp, DLT_NULL, sizeof(u_int));
 111 #endif
 112 }
 113
 114 static int
 115 discoutput(ifp, m, dst, rt)
 116         struct ifnet *ifp;
 117         register struct mbuf *m;
 118         struct sockaddr *dst;
 119         register struct rtentry *rt;
 120 {
 121         if ((m->m_flags & M_PKTHDR) == 0)
 122                 panic("discoutput no HDR");
 123 #if NBPFILTER > 0
 124         /* BPF write needs to be handled specially */
 125         if (dst->sa_family == AF_UNSPEC) {
 126                 dst->sa_family = *(mtod(m, int *));
 127                 m->m_len -= sizeof(int);
 128                 m->m_pkthdr.len -= sizeof(int);
 129                 m->m_data += sizeof(int);
 130         }
 131
 132         if (discif.if_bpf) {
 133                 /*
 134                  * We need to prepend the address family as
 135                  * a four byte field.  Cons up a dummy header
 136                  * to pacify bpf.  This is safe because bpf
 137                  * will only read from the mbuf (i.e., it won't
 138                  * try to free it or keep a pointer a to it).
 139                  */
 140                 struct mbuf m0;
 141                 u_int af = dst->sa_family;
 142
 143                 m0.m_next = m;
 144                 m0.m_len = 4;
 145                 m0.m_data = (char *)&af;
 146
 147                 bpf_mtap(&discif, &m0);
 148         }
 149 #endif
 150         m->m_pkthdr.rcvif = ifp;
 151
 152         ifp->if_opackets++;
 153         ifp->if_obytes += m->m_pkthdr.len;
 154
 155         m_freem(m);
 156         return 0;
 157 }
 158
 159 /* ARGSUSED */
 160 static void
 161 discrtrequest(cmd, rt, sa)
 162         int cmd;
 163         struct rtentry *rt;
 164         struct sockaddr *sa;
 165 {
 166         if (rt)
 167                 rt->rt_rmx.rmx_mtu = DSMTU;
 168 }
 169
 170 /*
 171  * Process an ioctl request.
 172  */
 173 /* ARGSUSED */
 174 static int
 175 discioctl(ifp, cmd, data)
 176         register struct ifnet *ifp;
 177         u_long cmd;
 178         caddr_t data;
 179 {
 180         register struct ifaddr *ifa;
 181         register struct ifreq *ifr = (struct ifreq *)data;
 182         register int error = 0;
 183
 184         switch (cmd) {
 185
 186         case SIOCSIFADDR:
 187                 ifp->if_flags |= IFF_UP;
 188                 ifa = (struct ifaddr *)data;
 189                 if (ifa != 0)
 190                         ifa->ifa_rtrequest = discrtrequest;
 191                 /*
 192                  * Everything else is done at a higher level.
 193                  */
 194                 break;
 195
 196         case SIOCADDMULTI:
 197         case SIOCDELMULTI:
 198                 if (ifr == 0) {
 199                         error = EAFNOSUPPORT;           /* XXX */
 200                         break;
 201                 }
 202                 switch (ifr->ifr_addr.sa_family) {
 203
 204 #if INET
 205                 case AF_INET:
 206                         break;
 207 #endif
 208
 209                 default:
 210                         error = EAFNOSUPPORT;
 211                         break;
 212                 }
 213                 break;
 214
 215         case SIOCSIFMTU:
 216                 ifp->if_mtu = ifr->ifr_mtu;
 217                 break;
 218
 219         default:
 220                 error = EINVAL;
 221         }
 222         return (error);
 223 }