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 8.2 (Berkeley) 1/9/95 34 * $FreeBSD$ 35 */ 36 37 /* 38 * Loopback interface driver for protocol testing and timing. 39 */ 40 41 #include "opt_atalk.h" 42 #include "opt_inet.h" 43 #include "opt_inet6.h" 44 #include "opt_ipx.h" 45 #include "opt_mac.h" 46 47 #include <sys/param.h> 48 #include <sys/systm.h> 49 #include <sys/kernel.h> 50 #include <sys/mac.h> 51 #include <sys/malloc.h> 52 #include <sys/mbuf.h> 53 #include <sys/module.h> 54 #include <machine/bus.h> 55 #include <sys/rman.h> 56 #include <sys/socket.h> 57 #include <sys/sockio.h> 58 #include <sys/sysctl.h> 59 60 #include <net/if.h> 61 #include <net/if_types.h> 62 #include <net/netisr.h> 63 #include <net/route.h> 64 #include <net/bpf.h> 65 #include <net/bpfdesc.h> 66 67 #ifdef INET 68 #include <netinet/in.h> 69 #include <netinet/in_var.h> 70 #endif 71 72 #ifdef IPX 73 #include <netipx/ipx.h> 74 #include <netipx/ipx_if.h> 75 #endif 76 77 #ifdef INET6 78 #ifndef INET 79 #include <netinet/in.h> 80 #endif 81 #include <netinet6/in6_var.h> 82 #include <netinet/ip6.h> 83 #endif 84 85 #ifdef NETATALK 86 #include <netatalk/at.h> 87 #include <netatalk/at_var.h> 88 #endif 89 90 #ifdef TINY_LOMTU 91 #define LOMTU (1024+512) 92 #elif defined(LARGE_LOMTU) 93 #define LOMTU 131072 94 #else 95 #define LOMTU 16384 96 #endif 97 98 #define LONAME "lo" 99 100 struct lo_softc { 101 struct ifnet sc_if; /* network-visible interface */ 102 LIST_ENTRY(lo_softc) sc_next; 103 }; 104 105 int loioctl(struct ifnet *, u_long, caddr_t); 106 static void lortrequest(int, struct rtentry *, struct rt_addrinfo *); 107 int looutput(struct ifnet *ifp, struct mbuf *m, 108 struct sockaddr *dst, struct rtentry *rt); 109 int lo_clone_create(struct if_clone *, int); 110 void lo_clone_destroy(struct ifnet *); 111 112 struct ifnet *loif = NULL; /* Used externally */ 113 114 static MALLOC_DEFINE(M_LO, LONAME, "Loopback Interface"); 115 116 static LIST_HEAD(lo_list, lo_softc) lo_list; 117 118 struct if_clone lo_cloner = IF_CLONE_INITIALIZER(LONAME, 119 lo_clone_create, lo_clone_destroy, 1, IF_MAXUNIT); 120 121 void 122 lo_clone_destroy(ifp) 123 struct ifnet *ifp; 124 { 125 struct lo_softc *sc; 126 127 sc = ifp->if_softc; 128 129 /* XXX: destroying lo0 will lead to panics. */ 130 KASSERT(loif != ifp, ("%s: destroying lo0", __func__)); 131 132 bpfdetach(ifp); 133 if_detach(ifp); 134 LIST_REMOVE(sc, sc_next); 135 free(sc, M_LO); 136 } 137 138 int 139 lo_clone_create(ifc, unit) 140 struct if_clone *ifc; 141 int unit; 142 { 143 struct lo_softc *sc; 144 145 MALLOC(sc, struct lo_softc *, sizeof(*sc), M_LO, M_WAITOK | M_ZERO); 146 147 sc->sc_if.if_name = LONAME; 148 sc->sc_if.if_unit = unit; 149 sc->sc_if.if_mtu = LOMTU; 150 sc->sc_if.if_flags = IFF_LOOPBACK | IFF_MULTICAST; 151 sc->sc_if.if_ioctl = loioctl; 152 sc->sc_if.if_output = looutput; 153 sc->sc_if.if_type = IFT_LOOP; 154 sc->sc_if.if_snd.ifq_maxlen = ifqmaxlen; 155 sc->sc_if.if_softc = sc; 156 if_attach(&sc->sc_if); 157 bpfattach(&sc->sc_if, DLT_NULL, sizeof(u_int)); 158 LIST_INSERT_HEAD(&lo_list, sc, sc_next); 159 if (loif == NULL) 160 loif = &sc->sc_if; 161 162 return (0); 163 } 164 165 static int 166 loop_modevent(module_t mod, int type, void *data) 167 { 168 switch (type) { 169 case MOD_LOAD: 170 LIST_INIT(&lo_list); 171 if_clone_attach(&lo_cloner); 172 break; 173 case MOD_UNLOAD: 174 printf("loop module unload - not possible for this module type\n"); 175 return EINVAL; 176 } 177 return 0; 178 } 179 180 static moduledata_t loop_mod = { 181 "loop", 182 loop_modevent, 183 0 184 }; 185 186 DECLARE_MODULE(loop, loop_mod, SI_SUB_PSEUDO, SI_ORDER_ANY); 187 188 int 189 looutput(ifp, m, dst, rt) 190 struct ifnet *ifp; 191 register struct mbuf *m; 192 struct sockaddr *dst; 193 register struct rtentry *rt; 194 { 195 #ifdef INET6 196 struct mbuf *n; 197 #endif 198 199 M_ASSERTPKTHDR(m); /* check if we have the packet header */ 200 201 if (rt && rt->rt_flags & (RTF_REJECT|RTF_BLACKHOLE)) { 202 m_freem(m); 203 return (rt->rt_flags & RTF_BLACKHOLE ? 0 : 204 rt->rt_flags & RTF_HOST ? EHOSTUNREACH : ENETUNREACH); 205 } 206 #ifdef INET6 207 /* 208 * KAME requires that the packet to be contiguous on the 209 * mbuf. We need to make that sure. 210 * this kind of code should be avoided. 211 * 212 * XXX: KAME may no longer need contiguous packets. Once 213 * that has been verified, the following code _should_ be 214 * removed. 215 */ 216 217 if (m && m->m_next != NULL) { 218 219 n = m_defrag(m, M_DONTWAIT); 220 221 if (n == NULL) { 222 m_freem(m); 223 return (ENOBUFS); 224 } else { 225 m = n; 226 } 227 } 228 #endif 229 230 ifp->if_opackets++; 231 ifp->if_obytes += m->m_pkthdr.len; 232 #if 1 /* XXX */ 233 switch (dst->sa_family) { 234 case AF_INET: 235 case AF_INET6: 236 case AF_IPX: 237 case AF_APPLETALK: 238 break; 239 default: 240 printf("looutput: af=%d unexpected\n", dst->sa_family); 241 m_freem(m); 242 return (EAFNOSUPPORT); 243 } 244 #endif 245 return(if_simloop(ifp, m, dst->sa_family, 0)); 246 } 247 248 /* 249 * if_simloop() 250 * 251 * This function is to support software emulation of hardware loopback, 252 * i.e., for interfaces with the IFF_SIMPLEX attribute. Since they can't 253 * hear their own broadcasts, we create a copy of the packet that we 254 * would normally receive via a hardware loopback. 255 * 256 * This function expects the packet to include the media header of length hlen. 257 */ 258 259 int 260 if_simloop(ifp, m, af, hlen) 261 struct ifnet *ifp; 262 struct mbuf *m; 263 int af; 264 int hlen; 265 { 266 int isr; 267 268 M_ASSERTPKTHDR(m); 269 m->m_pkthdr.rcvif = ifp; 270 271 /* BPF write needs to be handled specially */ 272 if (af == AF_UNSPEC) { 273 KASSERT(m->m_len >= sizeof(int), ("if_simloop: m_len")); 274 af = *(mtod(m, int *)); 275 m->m_len -= sizeof(int); 276 m->m_pkthdr.len -= sizeof(int); 277 m->m_data += sizeof(int); 278 } 279 280 /* Let BPF see incoming packet */ 281 if (ifp->if_bpf) { 282 struct mbuf m0, *n = m; 283 284 if (ifp->if_bpf->bif_dlt == DLT_NULL) { 285 /* 286 * We need to prepend the address family as 287 * a four byte field. Cons up a dummy header 288 * to pacify bpf. This is safe because bpf 289 * will only read from the mbuf (i.e., it won't 290 * try to free it or keep a pointer a to it). 291 */ 292 m0.m_next = m; 293 m0.m_len = 4; 294 m0.m_data = (char *)⁡ 295 n = &m0; 296 } 297 BPF_MTAP(ifp, n); 298 } 299 300 /* Strip away media header */ 301 if (hlen > 0) { 302 m_adj(m, hlen); 303 #if defined(__alpha__) || defined(__ia64__) || defined(__sparc64__) 304 /* The alpha doesn't like unaligned data. 305 * We move data down in the first mbuf */ 306 if (mtod(m, vm_offset_t) & 3) { 307 KASSERT(hlen >= 3, ("if_simloop: hlen too small")); 308 bcopy(m->m_data, 309 (char *)(mtod(m, vm_offset_t) 310 - (mtod(m, vm_offset_t) & 3)), 311 m->m_len); 312 mtod(m,vm_offset_t) -= (mtod(m, vm_offset_t) & 3); 313 } 314 #endif 315 } 316 317 /* Deliver to upper layer protocol */ 318 switch (af) { 319 #ifdef INET 320 case AF_INET: 321 isr = NETISR_IP; 322 break; 323 #endif 324 #ifdef INET6 325 case AF_INET6: 326 m->m_flags |= M_LOOP; 327 isr = NETISR_IPV6; 328 break; 329 #endif 330 #ifdef IPX 331 case AF_IPX: 332 isr = NETISR_IPX; 333 break; 334 #endif 335 #ifdef NETATALK 336 case AF_APPLETALK: 337 isr = NETISR_ATALK2; 338 break; 339 #endif 340 default: 341 printf("if_simloop: can't handle af=%d\n", af); 342 m_freem(m); 343 return (EAFNOSUPPORT); 344 } 345 ifp->if_ipackets++; 346 ifp->if_ibytes += m->m_pkthdr.len; 347 netisr_dispatch(isr, m); 348 return (0); 349 } 350 351 /* ARGSUSED */ 352 static void 353 lortrequest(cmd, rt, info) 354 int cmd; 355 struct rtentry *rt; 356 struct rt_addrinfo *info; 357 { 358 if (rt) { 359 rt->rt_rmx.rmx_mtu = rt->rt_ifp->if_mtu; /* for ISO */ 360 /* 361 * For optimal performance, the send and receive buffers 362 * should be at least twice the MTU plus a little more for 363 * overhead. 364 */ 365 rt->rt_rmx.rmx_recvpipe = 366 rt->rt_rmx.rmx_sendpipe = 3 * LOMTU; 367 } 368 } 369 370 /* 371 * Process an ioctl request. 372 */ 373 /* ARGSUSED */ 374 int 375 loioctl(ifp, cmd, data) 376 register struct ifnet *ifp; 377 u_long cmd; 378 caddr_t data; 379 { 380 register struct ifaddr *ifa; 381 register struct ifreq *ifr = (struct ifreq *)data; 382 register int error = 0; 383 384 switch (cmd) { 385 386 case SIOCSIFADDR: 387 ifp->if_flags |= IFF_UP | IFF_RUNNING; 388 ifa = (struct ifaddr *)data; 389 ifa->ifa_rtrequest = lortrequest; 390 /* 391 * Everything else is done at a higher level. 392 */ 393 break; 394 395 case SIOCADDMULTI: 396 case SIOCDELMULTI: 397 if (ifr == 0) { 398 error = EAFNOSUPPORT; /* XXX */ 399 break; 400 } 401 switch (ifr->ifr_addr.sa_family) { 402 403 #ifdef INET 404 case AF_INET: 405 break; 406 #endif 407 #ifdef INET6 408 case AF_INET6: 409 break; 410 #endif 411 412 default: 413 error = EAFNOSUPPORT; 414 break; 415 } 416 break; 417 418 case SIOCSIFMTU: 419 ifp->if_mtu = ifr->ifr_mtu; 420 break; 421 422 case SIOCSIFFLAGS: 423 break; 424 425 default: 426 error = EINVAL; 427 } 428 return (error); 429 } 430