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 { 195 196 M_ASSERTPKTHDR(m); /* check if we have the packet header */ 197 198 if (rt && rt->rt_flags & (RTF_REJECT|RTF_BLACKHOLE)) { 199 m_freem(m); 200 return (rt->rt_flags & RTF_BLACKHOLE ? 0 : 201 rt->rt_flags & RTF_HOST ? EHOSTUNREACH : ENETUNREACH); 202 } 203 /* 204 * KAME requires that the packet to be contiguous on the 205 * mbuf. We need to make that sure. 206 * this kind of code should be avoided. 207 * XXX: fails to join if interface MTU > MCLBYTES. jumbogram? 208 */ 209 if (m && m->m_next != NULL && m->m_pkthdr.len < MCLBYTES) { 210 struct mbuf *n; 211 212 /* XXX MT_HEADER should be m->m_type */ 213 MGETHDR(n, M_DONTWAIT, MT_HEADER); 214 if (!n) 215 goto contiguousfail; 216 M_MOVE_PKTHDR(n, m); 217 MCLGET(n, M_DONTWAIT); 218 if (! (n->m_flags & M_EXT)) { 219 m_freem(n); 220 goto contiguousfail; 221 } 222 223 m_copydata(m, 0, n->m_pkthdr.len, mtod(n, caddr_t)); 224 n->m_len = n->m_pkthdr.len; 225 m_freem(m); 226 m = n; 227 } 228 if (0) { 229 contiguousfail: 230 printf("looutput: mbuf allocation failed\n"); 231 } 232 233 ifp->if_opackets++; 234 ifp->if_obytes += m->m_pkthdr.len; 235 #if 1 /* XXX */ 236 switch (dst->sa_family) { 237 case AF_INET: 238 case AF_INET6: 239 case AF_IPX: 240 case AF_APPLETALK: 241 break; 242 default: 243 printf("looutput: af=%d unexpected\n", dst->sa_family); 244 m_freem(m); 245 return (EAFNOSUPPORT); 246 } 247 #endif 248 return(if_simloop(ifp, m, dst->sa_family, 0)); 249 } 250 251 /* 252 * if_simloop() 253 * 254 * This function is to support software emulation of hardware loopback, 255 * i.e., for interfaces with the IFF_SIMPLEX attribute. Since they can't 256 * hear their own broadcasts, we create a copy of the packet that we 257 * would normally receive via a hardware loopback. 258 * 259 * This function expects the packet to include the media header of length hlen. 260 */ 261 262 int 263 if_simloop(ifp, m, af, hlen) 264 struct ifnet *ifp; 265 struct mbuf *m; 266 int af; 267 int hlen; 268 { 269 int isr; 270 271 M_ASSERTPKTHDR(m); 272 m->m_pkthdr.rcvif = ifp; 273 274 /* BPF write needs to be handled specially */ 275 if (af == AF_UNSPEC) { 276 KASSERT(m->m_len >= sizeof(int), ("if_simloop: m_len")); 277 af = *(mtod(m, int *)); 278 m->m_len -= sizeof(int); 279 m->m_pkthdr.len -= sizeof(int); 280 m->m_data += sizeof(int); 281 } 282 283 /* Let BPF see incoming packet */ 284 if (ifp->if_bpf) { 285 struct mbuf m0, *n = m; 286 287 if (ifp->if_bpf->bif_dlt == DLT_NULL) { 288 /* 289 * We need to prepend the address family as 290 * a four byte field. Cons up a dummy header 291 * to pacify bpf. This is safe because bpf 292 * will only read from the mbuf (i.e., it won't 293 * try to free it or keep a pointer a to it). 294 */ 295 m0.m_next = m; 296 m0.m_len = 4; 297 m0.m_data = (char *)⁡ 298 n = &m0; 299 } 300 BPF_MTAP(ifp, n); 301 } 302 303 /* Strip away media header */ 304 if (hlen > 0) { 305 m_adj(m, hlen); 306 #if defined(__alpha__) || defined(__ia64__) || defined(__sparc64__) 307 /* The alpha doesn't like unaligned data. 308 * We move data down in the first mbuf */ 309 if (mtod(m, vm_offset_t) & 3) { 310 KASSERT(hlen >= 3, ("if_simloop: hlen too small")); 311 bcopy(m->m_data, 312 (char *)(mtod(m, vm_offset_t) 313 - (mtod(m, vm_offset_t) & 3)), 314 m->m_len); 315 mtod(m,vm_offset_t) -= (mtod(m, vm_offset_t) & 3); 316 } 317 #endif 318 } 319 320 /* Deliver to upper layer protocol */ 321 switch (af) { 322 #ifdef INET 323 case AF_INET: 324 isr = NETISR_IP; 325 break; 326 #endif 327 #ifdef INET6 328 case AF_INET6: 329 m->m_flags |= M_LOOP; 330 isr = NETISR_IPV6; 331 break; 332 #endif 333 #ifdef IPX 334 case AF_IPX: 335 isr = NETISR_IPX; 336 break; 337 #endif 338 #ifdef NETATALK 339 case AF_APPLETALK: 340 isr = NETISR_ATALK2; 341 break; 342 #endif 343 default: 344 printf("if_simloop: can't handle af=%d\n", af); 345 m_freem(m); 346 return (EAFNOSUPPORT); 347 } 348 ifp->if_ipackets++; 349 ifp->if_ibytes += m->m_pkthdr.len; 350 netisr_dispatch(isr, m); 351 return (0); 352 } 353 354 /* ARGSUSED */ 355 static void 356 lortrequest(cmd, rt, info) 357 int cmd; 358 struct rtentry *rt; 359 struct rt_addrinfo *info; 360 { 361 if (rt) { 362 rt->rt_rmx.rmx_mtu = rt->rt_ifp->if_mtu; /* for ISO */ 363 /* 364 * For optimal performance, the send and receive buffers 365 * should be at least twice the MTU plus a little more for 366 * overhead. 367 */ 368 rt->rt_rmx.rmx_recvpipe = 369 rt->rt_rmx.rmx_sendpipe = 3 * LOMTU; 370 } 371 } 372 373 /* 374 * Process an ioctl request. 375 */ 376 /* ARGSUSED */ 377 int 378 loioctl(ifp, cmd, data) 379 register struct ifnet *ifp; 380 u_long cmd; 381 caddr_t data; 382 { 383 register struct ifaddr *ifa; 384 register struct ifreq *ifr = (struct ifreq *)data; 385 register int error = 0; 386 387 switch (cmd) { 388 389 case SIOCSIFADDR: 390 ifp->if_flags |= IFF_UP | IFF_RUNNING; 391 ifa = (struct ifaddr *)data; 392 ifa->ifa_rtrequest = lortrequest; 393 /* 394 * Everything else is done at a higher level. 395 */ 396 break; 397 398 case SIOCADDMULTI: 399 case SIOCDELMULTI: 400 if (ifr == 0) { 401 error = EAFNOSUPPORT; /* XXX */ 402 break; 403 } 404 switch (ifr->ifr_addr.sa_family) { 405 406 #ifdef INET 407 case AF_INET: 408 break; 409 #endif 410 #ifdef INET6 411 case AF_INET6: 412 break; 413 #endif 414 415 default: 416 error = EAFNOSUPPORT; 417 break; 418 } 419 break; 420 421 case SIOCSIFMTU: 422 ifp->if_mtu = ifr->ifr_mtu; 423 break; 424 425 case SIOCSIFFLAGS: 426 break; 427 428 default: 429 error = EINVAL; 430 } 431 return (error); 432 } 433