if_loop.c revision 36908
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 1.32 1998/06/07 17:12:03 dfr 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 "opt_atalk.h" 44#include "opt_inet.h" 45#include "opt_ipx.h" 46 47#include <sys/param.h> 48#include <sys/systm.h> 49#include <sys/kernel.h> 50#include <sys/mbuf.h> 51#include <sys/socket.h> 52#include <sys/sockio.h> 53 54#include <net/if.h> 55#include <net/if_types.h> 56#include <net/netisr.h> 57#include <net/route.h> 58#include <net/bpf.h> 59 60#ifdef INET 61#include <netinet/in.h> 62#include <netinet/in_var.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 <netatalk/at.h> 82#include <netatalk/at_var.h> 83#endif NETATALK 84 85#include "bpfilter.h" 86#if NBPFILTER > 0 87#include <net/bpfdesc.h> 88#endif 89 90static int loioctl __P((struct ifnet *, u_long, caddr_t)); 91static void lortrequest __P((int, struct rtentry *, struct sockaddr *)); 92 93static void loopattach __P((void *)); 94PSEUDO_SET(loopattach, if_loop); 95 96static int looutput __P((struct ifnet *ifp, 97 struct mbuf *m, struct sockaddr *dst, struct rtentry *rt)); 98 99#ifdef TINY_LOMTU 100#define LOMTU (1024+512) 101#else 102#define LOMTU 16384 103#endif 104 105struct ifnet loif[NLOOP]; 106 107/* ARGSUSED */ 108static void 109loopattach(dummy) 110 void *dummy; 111{ 112 register struct ifnet *ifp; 113 register int i = 0; 114 115 for (ifp = loif; i < NLOOP; ifp++) { 116 ifp->if_name = "lo"; 117 ifp->if_unit = i++; 118 ifp->if_mtu = LOMTU; 119 ifp->if_flags = IFF_LOOPBACK | IFF_MULTICAST; 120 ifp->if_ioctl = loioctl; 121 ifp->if_output = looutput; 122 ifp->if_type = IFT_LOOP; 123 if_attach(ifp); 124#if NBPFILTER > 0 125 bpfattach(ifp, DLT_NULL, sizeof(u_int)); 126#endif 127 } 128} 129 130static int 131looutput(ifp, m, dst, rt) 132 struct ifnet *ifp; 133 register struct mbuf *m; 134 struct sockaddr *dst; 135 register struct rtentry *rt; 136{ 137 if ((m->m_flags & M_PKTHDR) == 0) 138 panic("looutput no HDR"); 139 140 if (rt && rt->rt_flags & (RTF_REJECT|RTF_BLACKHOLE)) { 141 m_freem(m); 142 return (rt->rt_flags & RTF_BLACKHOLE ? 0 : 143 rt->rt_flags & RTF_HOST ? EHOSTUNREACH : ENETUNREACH); 144 } 145 ifp->if_opackets++; 146 ifp->if_obytes += m->m_pkthdr.len; 147 return(if_simloop(ifp, m, dst, 0)); 148} 149 150/* 151 * if_simloop() 152 * 153 * This function is to support software emulation of hardware loopback, 154 * i.e., for interfaces with the IFF_SIMPLEX attribute. Since they can't 155 * hear their own broadcasts, we create a copy of the packet that we 156 * would normally receive via a hardware loopback. 157 * 158 * This function expects the packet to include the media header of length hlen. 159 */ 160 161int 162if_simloop(ifp, m, dst, hlen) 163 struct ifnet *ifp; 164 register struct mbuf *m; 165 struct sockaddr *dst; 166 int hlen; 167{ 168 int s, isr; 169 register struct ifqueue *ifq = 0; 170 171 if ((m->m_flags & M_PKTHDR) == 0) 172 panic("%s: no HDR", __FUNCTION__); 173 m->m_pkthdr.rcvif = ifp; 174#if NBPFILTER > 0 175 /* BPF write needs to be handled specially */ 176 if (dst->sa_family == AF_UNSPEC) { 177 dst->sa_family = *(mtod(m, int *)); 178 m->m_len -= sizeof(int); 179 m->m_pkthdr.len -= sizeof(int); 180 m->m_data += sizeof(int); 181 } 182 183 if (ifp->if_bpf) { 184 struct mbuf m0, *n = m; 185 u_int af = dst->sa_family; 186 187 if (ifp->if_bpf->bif_dlt == DLT_NULL) { 188 /* 189 * We need to prepend the address family as 190 * a four byte field. Cons up a dummy header 191 * to pacify bpf. This is safe because bpf 192 * will only read from the mbuf (i.e., it won't 193 * try to free it or keep a pointer a to it). 194 */ 195 m0.m_next = m; 196 m0.m_len = 4; 197 m0.m_data = (char *)⁡ 198 n = &m0; 199 } 200 bpf_mtap(ifp, n); 201 } 202#endif 203 204 /* Strip away media header */ 205 if (hlen > 0) 206 m_adj(m, hlen); 207 208 switch (dst->sa_family) { 209#ifdef INET 210 case AF_INET: 211 ifq = &ipintrq; 212 isr = NETISR_IP; 213 break; 214#endif 215#ifdef IPX 216 case AF_IPX: 217 ifq = &ipxintrq; 218 isr = NETISR_IPX; 219 break; 220#endif 221#ifdef NS 222 case AF_NS: 223 ifq = &nsintrq; 224 isr = NETISR_NS; 225 break; 226#endif 227#ifdef ISO 228 case AF_ISO: 229 ifq = &clnlintrq; 230 isr = NETISR_ISO; 231 break; 232#endif 233#ifdef NETATALK 234 case AF_APPLETALK: 235 ifq = &atintrq2; 236 isr = NETISR_ATALK; 237 break; 238#endif NETATALK 239 default: 240 printf("%s: can't handle af=%d\n", 241 __FUNCTION__, dst->sa_family); 242 m_freem(m); 243 return (EAFNOSUPPORT); 244 } 245 s = splimp(); 246 if (IF_QFULL(ifq)) { 247 IF_DROP(ifq); 248 m_freem(m); 249 splx(s); 250 return (ENOBUFS); 251 } 252 IF_ENQUEUE(ifq, m); 253 schednetisr(isr); 254 ifp->if_ipackets++; 255 ifp->if_ibytes += m->m_pkthdr.len; 256 splx(s); 257 return (0); 258} 259 260/* ARGSUSED */ 261static void 262lortrequest(cmd, rt, sa) 263 int cmd; 264 struct rtentry *rt; 265 struct sockaddr *sa; 266{ 267 if (rt) { 268 rt->rt_rmx.rmx_mtu = rt->rt_ifp->if_mtu; /* for ISO */ 269 /* 270 * For optimal performance, the send and receive buffers 271 * should be at least twice the MTU plus a little more for 272 * overhead. 273 */ 274 rt->rt_rmx.rmx_recvpipe = 275 rt->rt_rmx.rmx_sendpipe = 3 * LOMTU; 276 } 277} 278 279/* 280 * Process an ioctl request. 281 */ 282/* ARGSUSED */ 283static int 284loioctl(ifp, cmd, data) 285 register struct ifnet *ifp; 286 u_long cmd; 287 caddr_t data; 288{ 289 register struct ifaddr *ifa; 290 register struct ifreq *ifr = (struct ifreq *)data; 291 register int error = 0; 292 293 switch (cmd) { 294 295 case SIOCSIFADDR: 296 ifp->if_flags |= IFF_UP | IFF_RUNNING; 297 ifa = (struct ifaddr *)data; 298 ifa->ifa_rtrequest = lortrequest; 299 /* 300 * Everything else is done at a higher level. 301 */ 302 break; 303 304 case SIOCADDMULTI: 305 case SIOCDELMULTI: 306 if (ifr == 0) { 307 error = EAFNOSUPPORT; /* XXX */ 308 break; 309 } 310 switch (ifr->ifr_addr.sa_family) { 311 312#ifdef INET 313 case AF_INET: 314 break; 315#endif 316 317 default: 318 error = EAFNOSUPPORT; 319 break; 320 } 321 break; 322 323 case SIOCSIFMTU: 324 ifp->if_mtu = ifr->ifr_mtu; 325 break; 326 327 case SIOCSIFFLAGS: 328 break; 329 330 default: 331 error = EINVAL; 332 } 333 return (error); 334} 335#endif /* NLOOP > 0 */ 336