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. Neither the name of the University nor the names of its contributors 14 * may be used to endorse or promote products derived from this software 15 * without specific prior written permission. 16 * 17 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 18 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 19 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 20 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 21 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 22 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 23 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 24 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 25 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 26 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 27 * SUCH DAMAGE. 28 * 29 * From: @(#)if_loop.c 8.1 (Berkeley) 6/10/93 30 * $FreeBSD: src/sys/net/if_disc.c,v 1.26.2.2 2001/12/20 10:30:16 ru Exp $ 31 */ 32 33 /* 34 * Discard interface driver for protocol testing and timing. 35 * (Based on the loopback.) 36 */ 37 38 #include <sys/param.h> 39 #include <sys/systm.h> 40 #include <sys/kernel.h> 41 #include <sys/module.h> 42 #include <sys/mbuf.h> 43 #include <sys/socket.h> 44 #include <sys/sockio.h> 45 46 #include <net/if.h> 47 #include <net/if_types.h> 48 #include <net/ifq_var.h> 49 #include <net/route.h> 50 #include <net/bpf.h> 51 52 #include "opt_inet.h" 53 #include "opt_inet6.h" 54 55 #ifdef TINY_DSMTU 56 #define DSMTU (1024+512) 57 #else 58 #define DSMTU 65532 59 #endif 60 61 static void discattach (void); 62 63 static struct ifnet discif; 64 static int discoutput(struct ifnet *, struct mbuf *, struct sockaddr *, 65 struct rtentry *); 66 static void discrtrequest(int cmd, struct rtentry *rt); 67 static int discioctl(struct ifnet *, u_long, caddr_t, struct ucred *); 68 69 /* ARGSUSED */ 70 static void 71 discattach(void) 72 { 73 struct ifnet *ifp = &discif; 74 75 if_initname(ifp, "ds", IF_DUNIT_NONE); 76 ifp->if_mtu = DSMTU; 77 ifp->if_flags = IFF_LOOPBACK | IFF_MULTICAST; 78 ifp->if_ioctl = discioctl; 79 ifp->if_output = discoutput; 80 ifp->if_type = IFT_LOOP; 81 ifp->if_hdrlen = 0; 82 ifp->if_addrlen = 0; 83 ifq_set_maxlen(&ifp->if_snd, 20); 84 if_attach(ifp, NULL); 85 bpfattach(ifp, DLT_NULL, sizeof(uint32_t)); 86 } 87 88 static int 89 disc_modevent(module_t mod, int type, void *data) 90 { 91 switch (type) { 92 case MOD_LOAD: 93 discattach(); 94 break; 95 case MOD_UNLOAD: 96 kprintf("if_disc module unload - not possible for this module type\n"); 97 return EINVAL; 98 } 99 return 0; 100 } 101 102 static moduledata_t disc_mod = { 103 "if_disc", 104 disc_modevent, 105 NULL 106 }; 107 108 DECLARE_MODULE(if_disc, disc_mod, SI_SUB_PSEUDO, SI_ORDER_ANY); 109 110 static int 111 discoutput(struct ifnet *ifp, struct mbuf *m, struct sockaddr *dst, 112 struct rtentry *rt) 113 { 114 if ((m->m_flags & M_PKTHDR) == 0) 115 panic("discoutput no HDR"); 116 /* BPF write needs to be handled specially */ 117 if (dst->sa_family == AF_UNSPEC) { 118 dst->sa_family = *(mtod(m, int *)); 119 m->m_len -= sizeof(int); 120 m->m_pkthdr.len -= sizeof(int); 121 m->m_data += sizeof(int); 122 } 123 124 if (discif.if_bpf) { 125 bpf_gettoken(); 126 if (discif.if_bpf) { 127 /* 128 * We need to prepend the address family as 129 * a four byte field. 130 */ 131 uint32_t af = dst->sa_family; 132 133 bpf_ptap(discif.if_bpf, m, &af, sizeof(af)); 134 } 135 bpf_reltoken(); 136 } 137 m->m_pkthdr.rcvif = ifp; 138 139 IFNET_STAT_INC(ifp, opackets, 1); 140 IFNET_STAT_INC(ifp, 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) 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 != NULL) 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 == NULL) { 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 } 209