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 * $FreeBSD$ 35 */ 36 37 /* 38 * Discard interface driver for protocol testing and timing. 39 * (Based on the loopback.) 40 */ 41 42 #include <sys/param.h> 43 #include <sys/systm.h> 44 #include <sys/kernel.h> 45 #include <sys/module.h> 46 #include <sys/mbuf.h> 47 #include <sys/socket.h> 48 #include <sys/sockio.h> 49 50 #include <net/if.h> 51 #include <net/if_types.h> 52 #include <net/route.h> 53 #include <net/bpf.h> 54 55 #include "opt_inet.h" 56 #include "opt_inet6.h" 57 58 #ifdef TINY_DSMTU 59 #define DSMTU (1024+512) 60 #else 61 #define DSMTU 65532 62 #endif 63 64 static void discattach(void); 65 66 static struct ifnet discif; 67 static int discoutput(struct ifnet *, struct mbuf *, 68 struct sockaddr *, struct rtentry *); 69 static void discrtrequest(int, struct rtentry *, struct rt_addrinfo *); 70 static int discioctl(struct ifnet *, u_long, caddr_t); 71 72 static void 73 discattach(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 90 static int 91 disc_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 } 103 104 static moduledata_t disc_mod = { 105 "if_disc", 106 disc_modevent, 107 NULL 108 }; 109 110 DECLARE_MODULE(if_disc, disc_mod, SI_SUB_PSEUDO, SI_ORDER_ANY); 111 112 static int 113 discoutput(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 */ 153 static void 154 discrtrequest(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 */ 163 static int 164 discioctl(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