if_loop.c revision 16287
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 * @(#)if_loop.c 8.1 (Berkeley) 6/10/93 34 * $Id: if_loop.c,v 1.20 1996/05/24 01:35:10 julian Exp $ 35 */ 36 37/* 38 * Loopback interface driver for protocol testing and timing. 39 */ 40#include "loop.h" 41#if NLOOP > 0 42 43#include <sys/param.h> 44#include <sys/systm.h> 45#include <sys/kernel.h> 46#include <sys/mbuf.h> 47#include <sys/socket.h> 48#include <sys/errno.h> 49#include <sys/ioctl.h> 50#include <sys/time.h> 51 52#include <net/if.h> 53#include <net/if_types.h> 54#include <net/netisr.h> 55#include <net/route.h> 56#include <net/bpf.h> 57 58#ifdef INET 59#include <netinet/in.h> 60#include <netinet/in_systm.h> 61#include <netinet/in_var.h> 62#include <netinet/ip.h> 63#endif 64 65#ifdef IPX 66#include <netipx/ipx.h> 67#include <netipx/ipx_if.h> 68#endif 69 70#ifdef NS 71#include <netns/ns.h> 72#include <netns/ns_if.h> 73#endif 74 75#ifdef ISO 76#include <netiso/iso.h> 77#include <netiso/iso_var.h> 78#endif 79 80#ifdef NETATALK 81#include <netinet/if_ether.h> 82#include <netatalk/at.h> 83#include <netatalk/at_var.h> 84#endif NETATALK 85 86#include "bpfilter.h" 87 88static int loioctl __P((struct ifnet *, int, caddr_t)); 89static void lortrequest __P((int, struct rtentry *, struct sockaddr *)); 90 91static void loopattach __P((void *)); 92PSEUDO_SET(loopattach, if_loop); 93 94#ifdef TINY_LOMTU 95#define LOMTU (1024+512) 96#else 97#define LOMTU 16384 98#endif 99 100struct ifnet loif[NLOOP]; 101 102/* ARGSUSED */ 103static void 104loopattach(dummy) 105 void *dummy; 106{ 107 register struct ifnet *ifp; 108 register int i = 0; 109 110 for (ifp = loif; i < NLOOP; ifp++) { 111 ifp->if_name = "lo"; 112 ifp->if_next = NULL; 113 ifp->if_unit = i++; 114 ifp->if_mtu = LOMTU; 115 ifp->if_flags = IFF_LOOPBACK | IFF_MULTICAST; 116 ifp->if_ioctl = loioctl; 117 ifp->if_output = looutput; 118 ifp->if_type = IFT_LOOP; 119 ifp->if_hdrlen = 0; 120 ifp->if_addrlen = 0; 121 if_attach(ifp); 122#if NBPFILTER > 0 123 bpfattach(ifp, DLT_NULL, sizeof(u_int)); 124#endif 125 } 126} 127 128int 129looutput(ifp, m, dst, rt) 130 struct ifnet *ifp; 131 register struct mbuf *m; 132 struct sockaddr *dst; 133 register struct rtentry *rt; 134{ 135 int s, isr; 136 register struct ifqueue *ifq = 0; 137 138 if ((m->m_flags & M_PKTHDR) == 0) 139 panic("looutput no HDR"); 140#if NBPFILTER > 0 141 /* BPF write needs to be handled specially */ 142 if (dst->sa_family == AF_UNSPEC) { 143 dst->sa_family = *(mtod(m, int *)); 144 m->m_len -= sizeof(int); 145 m->m_pkthdr.len -= sizeof(int); 146 m->m_data += sizeof(int); 147 } 148 149 if (ifp->if_bpf) { 150 /* 151 * We need to prepend the address family as 152 * a four byte field. Cons up a dummy header 153 * to pacify bpf. This is safe because bpf 154 * will only read from the mbuf (i.e., it won't 155 * try to free it or keep a pointer a to it). 156 */ 157 struct mbuf m0; 158 u_int af = dst->sa_family; 159 160 m0.m_next = m; 161 m0.m_len = 4; 162 m0.m_data = (char *)⁡ 163 164 bpf_mtap(ifp, &m0); 165 } 166#endif 167 m->m_pkthdr.rcvif = ifp; 168 169 if (rt && rt->rt_flags & (RTF_REJECT|RTF_BLACKHOLE)) { 170 m_freem(m); 171 return (rt->rt_flags & RTF_BLACKHOLE ? 0 : 172 rt->rt_flags & RTF_HOST ? EHOSTUNREACH : ENETUNREACH); 173 } 174 ifp->if_opackets++; 175 ifp->if_obytes += m->m_pkthdr.len; 176 switch (dst->sa_family) { 177 178#ifdef INET 179 case AF_INET: 180 ifq = &ipintrq; 181 isr = NETISR_IP; 182 break; 183#endif 184#ifdef IPX 185 case AF_IPX: 186 ifq = &ipxintrq; 187 isr = NETISR_IPX; 188 break; 189#endif 190#ifdef NS 191 case AF_NS: 192 ifq = &nsintrq; 193 isr = NETISR_NS; 194 break; 195#endif 196#ifdef ISO 197 case AF_ISO: 198 ifq = &clnlintrq; 199 isr = NETISR_ISO; 200 break; 201#endif 202#ifdef NETATALK 203 case AF_APPLETALK: 204 ifq = &atintrq2; 205 isr = NETISR_ATALK; 206 break; 207#endif NETATALK 208 default: 209 printf("lo%d: can't handle af%d\n", ifp->if_unit, 210 dst->sa_family); 211 m_freem(m); 212 return (EAFNOSUPPORT); 213 } 214 s = splimp(); 215 if (IF_QFULL(ifq)) { 216 IF_DROP(ifq); 217 m_freem(m); 218 splx(s); 219 return (ENOBUFS); 220 } 221 IF_ENQUEUE(ifq, m); 222 schednetisr(isr); 223 ifp->if_ipackets++; 224 ifp->if_ibytes += m->m_pkthdr.len; 225 splx(s); 226 return (0); 227} 228 229/* ARGSUSED */ 230static void 231lortrequest(cmd, rt, sa) 232 int cmd; 233 struct rtentry *rt; 234 struct sockaddr *sa; 235{ 236 if (rt) { 237 rt->rt_rmx.rmx_mtu = rt->rt_ifp->if_mtu; /* for ISO */ 238 /* 239 * For optimal performance, the send and receive buffers 240 * should be at least twice the MTU plus a little more for 241 * overhead. 242 */ 243 rt->rt_rmx.rmx_recvpipe = 244 rt->rt_rmx.rmx_sendpipe = 3 * LOMTU; 245 } 246} 247 248/* 249 * Process an ioctl request. 250 */ 251/* ARGSUSED */ 252static int 253loioctl(ifp, cmd, data) 254 register struct ifnet *ifp; 255 int cmd; 256 caddr_t data; 257{ 258 register struct ifaddr *ifa; 259 register struct ifreq *ifr = (struct ifreq *)data; 260 register int error = 0; 261 262 switch (cmd) { 263 264 case SIOCSIFADDR: 265 ifp->if_flags |= IFF_UP; 266 ifa = (struct ifaddr *)data; 267 ifa->ifa_rtrequest = lortrequest; 268 /* 269 * Everything else is done at a higher level. 270 */ 271 break; 272 273 case SIOCADDMULTI: 274 case SIOCDELMULTI: 275 if (ifr == 0) { 276 error = EAFNOSUPPORT; /* XXX */ 277 break; 278 } 279 switch (ifr->ifr_addr.sa_family) { 280 281#ifdef INET 282 case AF_INET: 283 break; 284#endif 285 286 default: 287 error = EAFNOSUPPORT; 288 break; 289 } 290 break; 291 292 case SIOCSIFMTU: 293 ifp->if_mtu = ifr->ifr_mtu; 294 break; 295 296 default: 297 error = EINVAL; 298 } 299 return (error); 300} 301#endif /* NLOOP > 0 */ 302