bsd/net/if_disc.c

   1 /*
   2  * Copyright (c) 2000 Apple Computer, Inc. All rights reserved.
   3  *
   4  * @APPLE_OSREFERENCE_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. The rights granted to you under the License
  10  * may not be used to create, or enable the creation or redistribution of,
  11  * unlawful or unlicensed copies of an Apple operating system, or to
  12  * circumvent, violate, or enable the circumvention or violation of, any
  13  * terms of an Apple operating system software license agreement.
  14  *
  15  * Please obtain a copy of the License at
  16  * http://www.opensource.apple.com/apsl/ and read it before using this file.
  17  *
  18  * The Original Code and all software distributed under the License are
  19  * distributed on an 'AS IS' basis, WITHOUT WARRANTY OF ANY KIND, EITHER
  20  * EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES,
  21  * INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY,
  22  * FITNESS FOR A PARTICULAR PURPOSE, QUIET ENJOYMENT OR NON-INFRINGEMENT.
  23  * Please see the License for the specific language governing rights and
  24  * limitations under the License.
  25  *
  26  * @APPLE_OSREFERENCE_LICENSE_HEADER_END@
  27  */
  28 /*
  29  * Copyright (c) 1982, 1986, 1993
  30  *      The Regents of the University of California.  All rights reserved.
  31  *
  32  * Redistribution and use in source and binary forms, with or without
  33  * modification, are permitted provided that the following conditions
  34  * are met:
  35  * 1. Redistributions of source code must retain the above copyright
  36  *    notice, this list of conditions and the following disclaimer.
  37  * 2. Redistributions in binary form must reproduce the above copyright
  38  *    notice, this list of conditions and the following disclaimer in the
  39  *    documentation and/or other materials provided with the distribution.
  40  * 3. All advertising materials mentioning features or use of this software
  41  *    must display the following acknowledgement:
  42  *      This product includes software developed by the University of
  43  *      California, Berkeley and its contributors.
  44  * 4. Neither the name of the University nor the names of its contributors
  45  *    may be used to endorse or promote products derived from this software
  46  *    without specific prior written permission.
  47  *
  48  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
  49  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  50  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  51  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
  52  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  53  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  54  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  55  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  56  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  57  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  58  * SUCH DAMAGE.
  59  *
  60  *      From: @(#)if_loop.c     8.1 (Berkeley) 6/10/93
  61  * $FreeBSD: src/sys/net/if_disc.c,v 1.26.2.1 2001/03/06 00:32:09 obrien Exp $
  62  */
  63
  64 /*
  65  * Discard interface driver for protocol testing and timing.
  66  * (Based on the loopback.)
  67  */
  68
  69 #include <sys/param.h>
  70 #include <sys/systm.h>
  71 #include <sys/kernel.h>
  72 #include <sys/mbuf.h>
  73 #include <sys/socket.h>
  74 #include <sys/sockio.h>
  75
  76 #include <net/if.h>
  77 #include <net/if_types.h>
  78 #include <net/route.h>
  79 #include <net/bpf.h>
  80
  81 #ifdef TINY_DSMTU
  82 #define DSMTU   (1024+512)
  83 #else
  84 #define DSMTU   65532
  85 #endif
  86
  87 static void discattach(void);
  88
  89 static struct   ifnet discif;
  90 static int discoutput(struct ifnet *, struct mbuf *, struct sockaddr *,
  91                     struct rtentry *);
  92 static void discrtrequest(int cmd, struct rtentry *rt, struct sockaddr *sa);
  93 static int discioctl(struct ifnet *, u_long, caddr_t);
  94
  95 /* ARGSUSED */
  96 static void
  97 discattach()
  98 {
  99         register struct ifnet *ifp = &discif;
 100
 101         ifp->if_name = "ds";
 102         ifp->if_family = APPLE_IF_FAM_DISC;
 103         ifp->if_mtu = DSMTU;
 104         ifp->if_flags = IFF_LOOPBACK | IFF_MULTICAST;
 105         ifp->if_ioctl = discioctl;
 106         ifp->if_output = discoutput;
 107         ifp->if_type = IFT_LOOP;
 108         ifp->if_hdrlen = 0;
 109         ifp->if_addrlen = 0;
 110         if_attach(ifp);
 111         bpfattach(ifp, DLT_NULL, sizeof(u_int));
 112 }
 113
 114 #ifndef __APPLE__
 115 static int
 116 disc_modevent(module_t mod, int type, void *data)
 117 {
 118         switch (type) {
 119         case MOD_LOAD:
 120                 discattach();
 121                 break;
 122         case MOD_UNLOAD:
 123                 printf("if_disc module unload - not possible for this module type\n");
 124                 return EINVAL;
 125         }
 126         return 0;
 127 }
 128
 129 static moduledata_t disc_mod = {
 130         "if_disc",
 131         disc_modevent,
 132         NULL
 133 };
 134
 135 DECLARE_MODULE(if_disc, disc_mod, SI_SUB_PSEUDO, SI_ORDER_ANY);
 136 #endif
 137
 138 static int
 139 discoutput(ifp, m, dst, rt)
 140         struct ifnet *ifp;
 141         register struct mbuf *m;
 142         struct sockaddr *dst;
 143         register struct rtentry *rt;
 144 {
 145         if ((m->m_flags & M_PKTHDR) == 0)
 146                 panic("discoutput no HDR");
 147         /* BPF write needs to be handled specially */
 148         if (dst->sa_family == AF_UNSPEC) {
 149                 dst->sa_family = *(mtod(m, int *));
 150                 m->m_len -= sizeof(int);
 151                 m->m_pkthdr.len -= sizeof(int);
 152                 m->m_data += sizeof(int);
 153         }
 154
 155         if (discif.if_bpf) {
 156                 /*
 157                  * We need to prepend the address family as
 158                  * a four byte field.  Cons up a dummy header
 159                  * to pacify bpf.  This is safe because bpf
 160                  * will only read from the mbuf (i.e., it won't
 161                  * try to free it or keep a pointer a to it).
 162                  */
 163                 struct mbuf m0;
 164                 u_int af = dst->sa_family;
 165
 166                 m0.m_next = m;
 167                 m0.m_len = 4;
 168                 m0.m_data = (char *)&af;
 169
 170                 bpf_mtap(&discif, &m0);
 171         }
 172         m->m_pkthdr.rcvif = ifp;
 173
 174         ifp->if_opackets++;
 175         ifp->if_obytes += m->m_pkthdr.len;
 176
 177         m_freem(m);
 178         return 0;
 179 }
 180
 181 /* ARGSUSED */
 182 static void
 183 discrtrequest(cmd, rt, sa)
 184         int cmd;
 185         struct rtentry *rt;
 186         struct sockaddr *sa;
 187 {
 188         if (rt)
 189                 rt->rt_rmx.rmx_mtu = DSMTU;
 190 }
 191
 192 /*
 193  * Process an ioctl request.
 194  */
 195 /* ARGSUSED */
 196 static int
 197 discioctl(ifp, cmd, data)
 198         register struct ifnet *ifp;
 199         u_long cmd;
 200         caddr_t data;
 201 {
 202         register struct ifaddr *ifa;
 203         register struct ifreq *ifr = (struct ifreq *)data;
 204         register int error = 0;
 205
 206         switch (cmd) {
 207
 208         case SIOCSIFADDR:
 209                 ifnet_set_flags(ifp, IFF_UP, IFF_UP);
 210                 ifa = (struct ifaddr *)data;
 211                 if (ifa != 0)
 212                         ifa->ifa_rtrequest = discrtrequest;
 213                 /*
 214                  * Everything else is done at a higher level.
 215                  */
 216                 break;
 217
 218         case SIOCADDMULTI:
 219         case SIOCDELMULTI:
 220                 if (ifr == 0) {
 221                         error = EAFNOSUPPORT;           /* XXX */
 222                         break;
 223                 }
 224                 switch (ifr->ifr_addr.sa_family) {
 225
 226 #if INET
 227                 case AF_INET:
 228                         break;
 229 #endif
 230 #if INET6
 231                 case AF_INET6:
 232                         break;
 233 #endif
 234
 235                 default:
 236                         error = EAFNOSUPPORT;
 237                         break;
 238                 }
 239                 break;
 240
 241         case SIOCSIFMTU:
 242                 ifp->if_mtu = ifr->ifr_mtu;
 243                 break;
 244
 245         default:
 246                 error = EINVAL;
 247         }
 248         return (error);
 249 }