if_disc.c revision 87912
121308Sache/* 221308Sache * Copyright (c) 1982, 1986, 1993 321308Sache * The Regents of the University of California. All rights reserved. 421308Sache * 521308Sache * Redistribution and use in source and binary forms, with or without 621308Sache * modification, are permitted provided that the following conditions 721308Sache * are met: 821308Sache * 1. Redistributions of source code must retain the above copyright 921308Sache * notice, this list of conditions and the following disclaimer. 1021308Sache * 2. Redistributions in binary form must reproduce the above copyright 1121308Sache * notice, this list of conditions and the following disclaimer in the 1221308Sache * documentation and/or other materials provided with the distribution. 1321308Sache * 3. All advertising materials mentioning features or use of this software 1421308Sache * must display the following acknowledgement: 1521308Sache * This product includes software developed by the University of 1621308Sache * California, Berkeley and its contributors. 1721308Sache * 4. Neither the name of the University nor the names of its contributors 1821308Sache * may be used to endorse or promote products derived from this software 1921308Sache * without specific prior written permission. 2021308Sache * 2121308Sache * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 2221308Sache * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 2321308Sache * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 2421308Sache * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 2521308Sache * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 2621308Sache * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 2721308Sache * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 2821308Sache * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 2921308Sache * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 3021308Sache * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 3121308Sache * SUCH DAMAGE. 3221308Sache * 3321308Sache * From: @(#)if_loop.c 8.1 (Berkeley) 6/10/93 3421308Sache * $FreeBSD: head/sys/net/if_disc.c 87912 2001-12-14 19:28:06Z jlemon $ 3521308Sache */ 3621308Sache 3721308Sache/* 3821308Sache * Discard interface driver for protocol testing and timing. 3921308Sache * (Based on the loopback.) 4021308Sache */ 4121308Sache 4221308Sache#include <sys/param.h> 4321308Sache#include <sys/systm.h> 4421308Sache#include <sys/kernel.h> 4526497Sache#include <sys/module.h> 4626497Sache#include <sys/mbuf.h> 4726497Sache#include <sys/socket.h> 4826497Sache#include <sys/sockio.h> 4926497Sache 5026497Sache#include <net/if.h> 5126497Sache#include <net/if_types.h> 5226497Sache#include <net/route.h> 5326497Sache#include <net/bpf.h> 5426497Sache 5526497Sache#include "opt_inet.h" 5626497Sache#include "opt_inet6.h" 5721308Sache 5821308Sache#ifdef TINY_DSMTU 5921308Sache#define DSMTU (1024+512) 6021308Sache#else 6121308Sache#define DSMTU 65532 6221308Sache#endif 6321308Sache 6421308Sachestatic void discattach(void); 6521308Sache 6621308Sachestatic struct ifnet discif; 6721308Sachestatic int discoutput(struct ifnet *, struct mbuf *, 6821308Sache struct sockaddr *, struct rtentry *); 6921308Sachestatic void discrtrequest(int, struct rtentry *, struct rt_addrinfo *); 7021308Sachestatic int discioctl(struct ifnet *, u_long, caddr_t); 7121308Sache 7221308Sachestatic void 7321308Sachediscattach(void) 74{ 75 struct ifnet *ifp = &discif; 76 77 ifp->if_name = "ds"; 78 ifp->if_mtu = DSMTU; 79 ifp->if_flags = IFF_LOOPBACK | IFF_MULTICAST; 80 ifp->if_ioctl = discioctl; 81 ifp->if_output = discoutput; 82 ifp->if_type = IFT_LOOP; 83 ifp->if_hdrlen = 0; 84 ifp->if_addrlen = 0; 85 ifp->if_snd.ifq_maxlen = 20; 86 if_attach(ifp); 87 bpfattach(ifp, DLT_NULL, sizeof(u_int)); 88} 89 90static int 91disc_modevent(module_t mod, int type, void *data) 92{ 93 switch (type) { 94 case MOD_LOAD: 95 discattach(); 96 break; 97 case MOD_UNLOAD: 98 printf("if_disc module unload - not possible for this module type\n"); 99 return EINVAL; 100 } 101 return 0; 102} 103 104static moduledata_t disc_mod = { 105 "if_disc", 106 disc_modevent, 107 NULL 108}; 109 110DECLARE_MODULE(if_disc, disc_mod, SI_SUB_PSEUDO, SI_ORDER_ANY); 111 112static int 113discoutput(struct ifnet *ifp, struct mbuf *m, struct sockaddr *dst, 114 struct rtentry *rt) 115{ 116 if ((m->m_flags & M_PKTHDR) == 0) 117 panic("discoutput no HDR"); 118 /* BPF write needs to be handled specially */ 119 if (dst->sa_family == AF_UNSPEC) { 120 dst->sa_family = *(mtod(m, int *)); 121 m->m_len -= sizeof(int); 122 m->m_pkthdr.len -= sizeof(int); 123 m->m_data += sizeof(int); 124 } 125 126 if (discif.if_bpf) { 127 /* 128 * We need to prepend the address family as 129 * a four byte field. Cons up a dummy header 130 * to pacify bpf. This is safe because bpf 131 * will only read from the mbuf (i.e., it won't 132 * try to free it or keep a pointer a to it). 133 */ 134 struct mbuf m0; 135 u_int af = dst->sa_family; 136 137 m0.m_next = m; 138 m0.m_len = 4; 139 m0.m_data = (char *)⁡ 140 141 bpf_mtap(&discif, &m0); 142 } 143 m->m_pkthdr.rcvif = ifp; 144 145 ifp->if_opackets++; 146 ifp->if_obytes += m->m_pkthdr.len; 147 148 m_freem(m); 149 return 0; 150} 151 152/* ARGSUSED */ 153static void 154discrtrequest(int cmd, struct rtentry *rt, struct rt_addrinfo *info) 155{ 156 if (rt) 157 rt->rt_rmx.rmx_mtu = DSMTU; 158} 159 160/* 161 * Process an ioctl request. 162 */ 163static int 164discioctl(struct ifnet *ifp, u_long cmd, caddr_t data) 165{ 166 struct ifaddr *ifa; 167 struct ifreq *ifr = (struct ifreq *)data; 168 int error = 0; 169 170 switch (cmd) { 171 172 case SIOCSIFADDR: 173 ifp->if_flags |= IFF_UP; 174 ifa = (struct ifaddr *)data; 175 if (ifa != 0) 176 ifa->ifa_rtrequest = discrtrequest; 177 /* 178 * Everything else is done at a higher level. 179 */ 180 break; 181 182 case SIOCADDMULTI: 183 case SIOCDELMULTI: 184 if (ifr == 0) { 185 error = EAFNOSUPPORT; /* XXX */ 186 break; 187 } 188 switch (ifr->ifr_addr.sa_family) { 189 190#ifdef INET 191 case AF_INET: 192 break; 193#endif 194#ifdef INET6 195 case AF_INET6: 196 break; 197#endif 198 199 default: 200 error = EAFNOSUPPORT; 201 break; 202 } 203 break; 204 205 case SIOCSIFMTU: 206 ifp->if_mtu = ifr->ifr_mtu; 207 break; 208 209 default: 210 error = EINVAL; 211 } 212 return (error); 213} 214