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 1.36 1998/06/14 23:53:43 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 "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 90 static int loioctl __P((struct ifnet *, u_long, caddr_t)); 91 static void lortrequest __P((int, struct rtentry *, struct sockaddr *)); 92 93 static void loopattach __P((void *)); 94 PSEUDO_SET(loopattach, if_loop); 95 96 static 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 104 105 struct ifnet loif[NLOOP]; 106 107 /* ARGSUSED */ 108 static void 109 loopattach(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 } 129 130 static int 131 looutput(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 #if 1 /* XXX */ 148 switch (dst->sa_family) { 149 case AF_INET: 150 case AF_IPX: 151 case AF_NS: 152 case AF_ISO: 153 case AF_APPLETALK: 154 break; 155 default: 156 printf("looutput: af=%d unexpected", dst->sa_family); 157 m_freem(m); 158 return (EAFNOSUPPORT); 159 } 160 #endif 161 return(if_simloop(ifp, m, dst, 0)); 162 } 163 164 /* 165 * if_simloop() 166 * 167 * This function is to support software emulation of hardware loopback, 168 * i.e., for interfaces with the IFF_SIMPLEX attribute. Since they can't 169 * hear their own broadcasts, we create a copy of the packet that we 170 * would normally receive via a hardware loopback. 171 * 172 * This function expects the packet to include the media header of length hlen. 173 */ 174 175 int 176 if_simloop(ifp, m, dst, hlen) 177 struct ifnet *ifp; 178 register struct mbuf *m; 179 struct sockaddr *dst; 180 int hlen; 181 { 182 int s, isr; 183 register struct ifqueue *ifq = 0; 184 185 if ((m->m_flags & M_PKTHDR) == 0) 186 panic("if_simloop: no HDR"); 187 m->m_pkthdr.rcvif = ifp; 188 #if NBPFILTER > 0 189 /* BPF write needs to be handled specially */ 190 if (dst->sa_family == AF_UNSPEC) { 191 dst->sa_family = *(mtod(m, int *)); 192 m->m_len -= sizeof(int); 193 m->m_pkthdr.len -= sizeof(int); 194 m->m_data += sizeof(int); 195 } 196 197 if (ifp->if_bpf) { 198 struct mbuf m0, *n = m; 199 u_int af = dst->sa_family; 200 201 if (ifp->if_bpf->bif_dlt == DLT_NULL) { 202 /* 203 * We need to prepend the address family as 204 * a four byte field. Cons up a dummy header 205 * to pacify bpf. This is safe because bpf 206 * will only read from the mbuf (i.e., it won't 207 * try to free it or keep a pointer a to it). 208 */ 209 m0.m_next = m; 210 m0.m_len = 4; 211 m0.m_data = (char *)⁡ 212 n = &m0; 213 } 214 bpf_mtap(ifp, n); 215 } 216 #endif 217 218 /* Strip away media header */ 219 if (hlen > 0) { 220 #ifdef __alpha__ 221 /* The alpha doesn't like unaligned data. 222 * We move data down in the first mbuf */ 223 if (hlen & 3) { 224 bcopy(m->m_data + hlen, m->m_data, m->m_len - hlen); 225 m->m_len -= hlen; 226 if (m->m_flags & M_PKTHDR) 227 m->m_pkthdr.len -= hlen; 228 } else 229 #endif 230 m_adj(m, hlen); 231 } 232 233 switch (dst->sa_family) { 234 #ifdef INET 235 case AF_INET: 236 ifq = &ipintrq; 237 isr = NETISR_IP; 238 break; 239 #endif 240 #ifdef IPX 241 case AF_IPX: 242 ifq = &ipxintrq; 243 isr = NETISR_IPX; 244 break; 245 #endif 246 #ifdef NS 247 case AF_NS: 248 ifq = &nsintrq; 249 isr = NETISR_NS; 250 break; 251 #endif 252 #ifdef ISO 253 case AF_ISO: 254 ifq = &clnlintrq; 255 isr = NETISR_ISO; 256 break; 257 #endif 258 #ifdef NETATALK 259 case AF_APPLETALK: 260 ifq = &atintrq2; 261 isr = NETISR_ATALK; 262 break; 263 #endif NETATALK 264 default: 265 printf("if_simloop: can't handle af=%d\n", dst->sa_family); 266 m_freem(m); 267 return (EAFNOSUPPORT); 268 } 269 s = splimp(); 270 if (IF_QFULL(ifq)) { 271 IF_DROP(ifq); 272 m_freem(m); 273 splx(s); 274 return (ENOBUFS); 275 } 276 IF_ENQUEUE(ifq, m); 277 schednetisr(isr); 278 ifp->if_ipackets++; 279 ifp->if_ibytes += m->m_pkthdr.len; 280 splx(s); 281 return (0); 282 } 283 284 /* ARGSUSED */ 285 static void 286 lortrequest(cmd, rt, sa) 287 int cmd; 288 struct rtentry *rt; 289 struct sockaddr *sa; 290 { 291 if (rt) { 292 rt->rt_rmx.rmx_mtu = rt->rt_ifp->if_mtu; /* for ISO */ 293 /* 294 * For optimal performance, the send and receive buffers 295 * should be at least twice the MTU plus a little more for 296 * overhead. 297 */ 298 rt->rt_rmx.rmx_recvpipe = 299 rt->rt_rmx.rmx_sendpipe = 3 * LOMTU; 300 } 301 } 302 303 /* 304 * Process an ioctl request. 305 */ 306 /* ARGSUSED */ 307 static int 308 loioctl(ifp, cmd, data) 309 register struct ifnet *ifp; 310 u_long cmd; 311 caddr_t data; 312 { 313 register struct ifaddr *ifa; 314 register struct ifreq *ifr = (struct ifreq *)data; 315 register int error = 0; 316 317 switch (cmd) { 318 319 case SIOCSIFADDR: 320 ifp->if_flags |= IFF_UP | IFF_RUNNING; 321 ifa = (struct ifaddr *)data; 322 ifa->ifa_rtrequest = lortrequest; 323 /* 324 * Everything else is done at a higher level. 325 */ 326 break; 327 328 case SIOCADDMULTI: 329 case SIOCDELMULTI: 330 if (ifr == 0) { 331 error = EAFNOSUPPORT; /* XXX */ 332 break; 333 } 334 switch (ifr->ifr_addr.sa_family) { 335 336 #ifdef INET 337 case AF_INET: 338 break; 339 #endif 340 341 default: 342 error = EAFNOSUPPORT; 343 break; 344 } 345 break; 346 347 case SIOCSIFMTU: 348 ifp->if_mtu = ifr->ifr_mtu; 349 break; 350 351 case SIOCSIFFLAGS: 352 break; 353 354 default: 355 error = EINVAL; 356 } 357 return (error); 358 } 359 #endif /* NLOOP > 0 */ 360