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 * 4. Neither the name of the University nor the names of its contributors 14 * may be used to endorse or promote products derived from this software 15 * without specific prior written permission. 16 * 17 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 18 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 19 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 20 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 21 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 22 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 23 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 24 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 25 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 26 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 27 * SUCH DAMAGE. 28 * 29 * @(#)if_loop.c 8.2 (Berkeley) 1/9/95 30 * $FreeBSD$ 31 */ 32 33 /* 34 * Loopback interface driver for protocol testing and timing. 35 */ 36 37 #include "opt_atalk.h" 38 #include "opt_inet.h" 39 #include "opt_inet6.h" 40 #include "opt_ipx.h" 41 42 #include <sys/param.h> 43 #include <sys/systm.h> 44 #include <sys/kernel.h> 45 #include <sys/malloc.h> 46 #include <sys/mbuf.h> 47 #include <sys/module.h> 48 #include <machine/bus.h> 49 #include <sys/rman.h> 50 #include <sys/socket.h> 51 #include <sys/sockio.h> 52 #include <sys/sysctl.h> 53 54 #include <net/if.h> 55 #include <net/if_clone.h> 56 #include <net/if_types.h> 57 #include <net/netisr.h> 58 #include <net/route.h> 59 #include <net/bpf.h> 60 #include <net/bpfdesc.h> 61 62 #ifdef INET 63 #include <netinet/in.h> 64 #include <netinet/in_var.h> 65 #endif 66 67 #ifdef IPX 68 #include <netipx/ipx.h> 69 #include <netipx/ipx_if.h> 70 #endif 71 72 #ifdef INET6 73 #ifndef INET 74 #include <netinet/in.h> 75 #endif 76 #include <netinet6/in6_var.h> 77 #include <netinet/ip6.h> 78 #endif 79 80 #ifdef NETATALK 81 #include <netatalk/at.h> 82 #include <netatalk/at_var.h> 83 #endif 84 85 #ifdef TINY_LOMTU 86 #define LOMTU (1024+512) 87 #elif defined(LARGE_LOMTU) 88 #define LOMTU 131072 89 #else 90 #define LOMTU 16384 91 #endif 92 93 #define LONAME "lo" 94 95 struct lo_softc { 96 struct ifnet sc_if; /* network-visible interface */ 97 LIST_ENTRY(lo_softc) sc_next; 98 }; 99 100 int loioctl(struct ifnet *, u_long, caddr_t); 101 static void lortrequest(int, struct rtentry *, struct rt_addrinfo *); 102 int looutput(struct ifnet *ifp, struct mbuf *m, 103 struct sockaddr *dst, struct rtentry *rt); 104 static int lo_clone_create(struct if_clone *, int); 105 static void lo_clone_destroy(struct ifnet *); 106 107 struct ifnet *loif = NULL; /* Used externally */ 108 109 static MALLOC_DEFINE(M_LO, LONAME, "Loopback Interface"); 110 111 static struct mtx lo_mtx; 112 static LIST_HEAD(lo_list, lo_softc) lo_list; 113 114 IFC_SIMPLE_DECLARE(lo, 1); 115 116 static void 117 lo_clone_destroy(ifp) 118 struct ifnet *ifp; 119 { 120 struct lo_softc *sc; 121 122 sc = ifp->if_softc; 123 124 /* XXX: destroying lo0 will lead to panics. */ 125 KASSERT(loif != ifp, ("%s: destroying lo0", __func__)); 126 127 mtx_lock(&lo_mtx); 128 LIST_REMOVE(sc, sc_next); 129 mtx_unlock(&lo_mtx); 130 bpfdetach(ifp); 131 if_detach(ifp); 132 free(sc, M_LO); 133 } 134 135 static int 136 lo_clone_create(ifc, unit) 137 struct if_clone *ifc; 138 int unit; 139 { 140 struct lo_softc *sc; 141 142 MALLOC(sc, struct lo_softc *, sizeof(*sc), M_LO, M_WAITOK | M_ZERO); 143 144 if_initname(&sc->sc_if, ifc->ifc_name, unit); 145 sc->sc_if.if_mtu = LOMTU; 146 sc->sc_if.if_flags = IFF_LOOPBACK | IFF_MULTICAST; 147 sc->sc_if.if_ioctl = loioctl; 148 sc->sc_if.if_output = looutput; 149 sc->sc_if.if_type = IFT_LOOP; 150 sc->sc_if.if_snd.ifq_maxlen = ifqmaxlen; 151 sc->sc_if.if_softc = sc; 152 if_attach(&sc->sc_if); 153 bpfattach(&sc->sc_if, DLT_NULL, sizeof(u_int)); 154 mtx_lock(&lo_mtx); 155 LIST_INSERT_HEAD(&lo_list, sc, sc_next); 156 mtx_unlock(&lo_mtx); 157 if (loif == NULL) 158 loif = &sc->sc_if; 159 160 return (0); 161 } 162 163 static int 164 loop_modevent(module_t mod, int type, void *data) 165 { 166 switch (type) { 167 case MOD_LOAD: 168 mtx_init(&lo_mtx, "lo_mtx", NULL, MTX_DEF); 169 LIST_INIT(&lo_list); 170 if_clone_attach(&lo_cloner); 171 break; 172 case MOD_UNLOAD: 173 printf("loop module unload - not possible for this module type\n"); 174 return EINVAL; 175 } 176 return 0; 177 } 178 179 static moduledata_t loop_mod = { 180 "loop", 181 loop_modevent, 182 0 183 }; 184 185 DECLARE_MODULE(loop, loop_mod, SI_SUB_PROTO_IFATTACHDOMAIN, SI_ORDER_ANY); 186 187 int 188 looutput(ifp, m, dst, rt) 189 struct ifnet *ifp; 190 register struct mbuf *m; 191 struct sockaddr *dst; 192 register struct rtentry *rt; 193 { 194 M_ASSERTPKTHDR(m); /* check if we have the packet header */ 195 196 if (rt && rt->rt_flags & (RTF_REJECT|RTF_BLACKHOLE)) { 197 m_freem(m); 198 return (rt->rt_flags & RTF_BLACKHOLE ? 0 : 199 rt->rt_flags & RTF_HOST ? EHOSTUNREACH : ENETUNREACH); 200 } 201 202 ifp->if_opackets++; 203 ifp->if_obytes += m->m_pkthdr.len; 204 #if 1 /* XXX */ 205 switch (dst->sa_family) { 206 case AF_INET: 207 case AF_INET6: 208 case AF_IPX: 209 case AF_APPLETALK: 210 break; 211 default: 212 printf("looutput: af=%d unexpected\n", dst->sa_family); 213 m_freem(m); 214 return (EAFNOSUPPORT); 215 } 216 #endif 217 return(if_simloop(ifp, m, dst->sa_family, 0)); 218 } 219 220 /* 221 * if_simloop() 222 * 223 * This function is to support software emulation of hardware loopback, 224 * i.e., for interfaces with the IFF_SIMPLEX attribute. Since they can't 225 * hear their own broadcasts, we create a copy of the packet that we 226 * would normally receive via a hardware loopback. 227 * 228 * This function expects the packet to include the media header of length hlen. 229 */ 230 231 int 232 if_simloop(ifp, m, af, hlen) 233 struct ifnet *ifp; 234 struct mbuf *m; 235 int af; 236 int hlen; 237 { 238 int isr; 239 240 M_ASSERTPKTHDR(m); 241 m_tag_delete_nonpersistent(m); 242 m->m_pkthdr.rcvif = ifp; 243 244 /* BPF write needs to be handled specially */ 245 if (af == AF_UNSPEC) { 246 KASSERT(m->m_len >= sizeof(int), ("if_simloop: m_len")); 247 af = *(mtod(m, int *)); 248 m->m_len -= sizeof(int); 249 m->m_pkthdr.len -= sizeof(int); 250 m->m_data += sizeof(int); 251 } 252 253 /* Let BPF see incoming packet */ 254 if (ifp->if_bpf) { 255 if (ifp->if_bpf->bif_dlt == DLT_NULL) { 256 u_int32_t af1 = af; /* XXX beware sizeof(af) != 4 */ 257 /* 258 * We need to prepend the address family. 259 */ 260 bpf_mtap2(ifp->if_bpf, &af1, sizeof(af1), m); 261 } else 262 bpf_mtap(ifp->if_bpf, m); 263 } 264 265 /* Strip away media header */ 266 if (hlen > 0) { 267 m_adj(m, hlen); 268 #if defined(__alpha__) || defined(__ia64__) || defined(__sparc64__) 269 /* The alpha doesn't like unaligned data. 270 * We move data down in the first mbuf */ 271 if (mtod(m, vm_offset_t) & 3) { 272 KASSERT(hlen >= 3, ("if_simloop: hlen too small")); 273 bcopy(m->m_data, 274 (char *)(mtod(m, vm_offset_t) 275 - (mtod(m, vm_offset_t) & 3)), 276 m->m_len); 277 mtod(m,vm_offset_t) -= (mtod(m, vm_offset_t) & 3); 278 } 279 #endif 280 } 281 282 /* Deliver to upper layer protocol */ 283 switch (af) { 284 #ifdef INET 285 case AF_INET: 286 isr = NETISR_IP; 287 break; 288 #endif 289 #ifdef INET6 290 case AF_INET6: 291 m->m_flags |= M_LOOP; 292 isr = NETISR_IPV6; 293 break; 294 #endif 295 #ifdef IPX 296 case AF_IPX: 297 isr = NETISR_IPX; 298 break; 299 #endif 300 #ifdef NETATALK 301 case AF_APPLETALK: 302 isr = NETISR_ATALK2; 303 break; 304 #endif 305 default: 306 printf("if_simloop: can't handle af=%d\n", af); 307 m_freem(m); 308 return (EAFNOSUPPORT); 309 } 310 ifp->if_ipackets++; 311 ifp->if_ibytes += m->m_pkthdr.len; 312 netisr_queue(isr, m); 313 return (0); 314 } 315 316 /* ARGSUSED */ 317 static void 318 lortrequest(cmd, rt, info) 319 int cmd; 320 struct rtentry *rt; 321 struct rt_addrinfo *info; 322 { 323 RT_LOCK_ASSERT(rt); 324 if (rt) 325 rt->rt_rmx.rmx_mtu = rt->rt_ifp->if_mtu; 326 } 327 328 /* 329 * Process an ioctl request. 330 */ 331 /* ARGSUSED */ 332 int 333 loioctl(ifp, cmd, data) 334 register struct ifnet *ifp; 335 u_long cmd; 336 caddr_t data; 337 { 338 register struct ifaddr *ifa; 339 register struct ifreq *ifr = (struct ifreq *)data; 340 register int error = 0; 341 342 switch (cmd) { 343 344 case SIOCSIFADDR: 345 ifp->if_flags |= IFF_UP | IFF_RUNNING; 346 ifa = (struct ifaddr *)data; 347 ifa->ifa_rtrequest = lortrequest; 348 /* 349 * Everything else is done at a higher level. 350 */ 351 break; 352 353 case SIOCADDMULTI: 354 case SIOCDELMULTI: 355 if (ifr == 0) { 356 error = EAFNOSUPPORT; /* XXX */ 357 break; 358 } 359 switch (ifr->ifr_addr.sa_family) { 360 361 #ifdef INET 362 case AF_INET: 363 break; 364 #endif 365 #ifdef INET6 366 case AF_INET6: 367 break; 368 #endif 369 370 default: 371 error = EAFNOSUPPORT; 372 break; 373 } 374 break; 375 376 case SIOCSIFMTU: 377 ifp->if_mtu = ifr->ifr_mtu; 378 break; 379 380 case SIOCSIFFLAGS: 381 break; 382 383 default: 384 error = EINVAL; 385 } 386 return (error); 387 } 388