sys/net/disc/if_disc.c

   1 /*
   2  * Copyright (c) 1982, 1986, 1993
   3  *      The Regents of the University of California.  All rights reserved.
   4  *
   5  * Redistribution and use in source and binary forms, with or without
   6  * modification, are permitted provided that the following conditions
   7  * are met:
   8  * 1. Redistributions of source code must retain the above copyright
   9  *    notice, this list of conditions and the following disclaimer.
  10  * 2. Redistributions in binary form must reproduce the above copyright
  11  *    notice, this list of conditions and the following disclaimer in the
  12  *    documentation and/or other materials provided with the distribution.
  13  * 3. All advertising materials mentioning features or use of this software
  14  *    must display the following acknowledgement:
  15  *      This product includes software developed by the University of
  16  *      California, Berkeley and its contributors.
  17  * 4. Neither the name of the University nor the names of its contributors
  18  *    may be used to endorse or promote products derived from this software
  19  *    without specific prior written permission.
  20  *
  21  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
  22  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  23  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  24  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
  25  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  26  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  27  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  28  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  29  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  30  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  31  * SUCH DAMAGE.
  32  *
  33  *      From: @(#)if_loop.c     8.1 (Berkeley) 6/10/93
  34  * $FreeBSD: src/sys/net/if_disc.c,v 1.26.2.2 2001/12/20 10:30:16 ru Exp $
  35  * $DragonFly: src/sys/net/disc/if_disc.c,v 1.10 2006/12/22 23:44:55 swildner Exp $
  36  */
  37
  38 /*
  39  * Discard interface driver for protocol testing and timing.
  40  * (Based on the loopback.)
  41  */
  42
  43 #include <sys/param.h>
  44 #include <sys/systm.h>
  45 #include <sys/kernel.h>
  46 #include <sys/module.h>
  47 #include <sys/mbuf.h>
  48 #include <sys/socket.h>
  49 #include <sys/sockio.h>
  50
  51 #include <net/if.h>
  52 #include <net/if_types.h>
  53 #include <net/route.h>
  54 #include <net/bpf.h>
  55
  56 #include "opt_inet.h"
  57 #include "opt_inet6.h"
  58
  59 #ifdef TINY_DSMTU
  60 #define DSMTU   (1024+512)
  61 #else
  62 #define DSMTU   65532
  63 #endif
  64
  65 static void discattach (void);
  66
  67 static struct   ifnet discif;
  68 static int discoutput(struct ifnet *, struct mbuf *, struct sockaddr *,
  69                     struct rtentry *);
  70 static void discrtrequest(int cmd, struct rtentry *rt, struct rt_addrinfo *info);
  71 static int discioctl(struct ifnet *, u_long, caddr_t, struct ucred *);
  72
  73 /* ARGSUSED */
  74 static void
  75 discattach(void)
  76 {
  77         struct ifnet *ifp = &discif;
  78
  79         if_initname(ifp, "ds", IF_DUNIT_NONE);
  80         ifp->if_mtu = DSMTU;
  81         ifp->if_flags = IFF_LOOPBACK | IFF_MULTICAST;
  82         ifp->if_ioctl = discioctl;
  83         ifp->if_output = discoutput;
  84         ifp->if_type = IFT_LOOP;
  85         ifp->if_hdrlen = 0;
  86         ifp->if_addrlen = 0;
  87         ifp->if_snd.ifq_maxlen = 20;
  88         if_attach(ifp, NULL);
  89         bpfattach(ifp, DLT_NULL, sizeof(u_int));
  90 }
  91
  92 static int
  93 disc_modevent(module_t mod, int type, void *data)
  94 {
  95         switch (type) {
  96         case MOD_LOAD:
  97                 discattach();
  98                 break;
  99         case MOD_UNLOAD:
 100                 kprintf("if_disc module unload - not possible for this module type\n");
 101                 return EINVAL;
 102         }
 103         return 0;
 104 }
 105
 106 static moduledata_t disc_mod = {
 107         "if_disc",
 108         disc_modevent,
 109         NULL
 110 };
 111
 112 DECLARE_MODULE(if_disc, disc_mod, SI_SUB_PSEUDO, SI_ORDER_ANY);
 113
 114 static int
 115 discoutput(struct ifnet *ifp, struct mbuf *m, struct sockaddr *dst,
 116            struct rtentry *rt)
 117 {
 118         if ((m->m_flags & M_PKTHDR) == 0)
 119                 panic("discoutput no HDR");
 120         /* BPF write needs to be handled specially */
 121         if (dst->sa_family == AF_UNSPEC) {
 122                 dst->sa_family = *(mtod(m, int *));
 123                 m->m_len -= sizeof(int);
 124                 m->m_pkthdr.len -= sizeof(int);
 125                 m->m_data += sizeof(int);
 126         }
 127
 128         if (discif.if_bpf) {
 129                 /*
 130                  * We need to prepend the address family as
 131                  * a four byte field.
 132                  */
 133                 uint32_t af = dst->sa_family;
 134
 135                 bpf_ptap(discif.if_bpf, m, &af, sizeof(af));
 136         }
 137         m->m_pkthdr.rcvif = ifp;
 138
 139         ifp->if_opackets++;
 140         ifp->if_obytes += m->m_pkthdr.len;
 141
 142         m_freem(m);
 143         return 0;
 144 }
 145
 146 /* ARGSUSED */
 147 static void
 148 discrtrequest(int cmd, struct rtentry *rt, struct rt_addrinfo *info)
 149 {
 150         if (rt)
 151                 rt->rt_rmx.rmx_mtu = DSMTU;
 152 }
 153
 154 /*
 155  * Process an ioctl request.
 156  */
 157 /* ARGSUSED */
 158 static int
 159 discioctl(struct ifnet *ifp, u_long cmd, caddr_t data, struct ucred *cr)
 160 {
 161         struct ifaddr *ifa;
 162         struct ifreq *ifr = (struct ifreq *)data;
 163         int error = 0;
 164
 165         switch (cmd) {
 166
 167         case SIOCSIFADDR:
 168                 ifp->if_flags |= IFF_UP;
 169                 ifa = (struct ifaddr *)data;
 170                 if (ifa != 0)
 171                         ifa->ifa_rtrequest = discrtrequest;
 172                 /*
 173                  * Everything else is done at a higher level.
 174                  */
 175                 break;
 176
 177         case SIOCADDMULTI:
 178         case SIOCDELMULTI:
 179                 if (ifr == 0) {
 180                         error = EAFNOSUPPORT;           /* XXX */
 181                         break;
 182                 }
 183                 switch (ifr->ifr_addr.sa_family) {
 184
 185 #ifdef INET
 186                 case AF_INET:
 187                         break;
 188 #endif
 189 #ifdef INET6
 190                 case AF_INET6:
 191                         break;
 192 #endif
 193
 194                 default:
 195                         error = EAFNOSUPPORT;
 196                         break;
 197                 }
 198                 break;
 199
 200         case SIOCSIFMTU:
 201                 ifp->if_mtu = ifr->ifr_mtu;
 202                 break;
 203
 204         default:
 205                 error = EINVAL;
 206         }
 207         return (error);
 208 }