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_ifp; 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, caddr_t); 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 if_free(ifp); 133 free(sc, M_LO); 134 } 135 136 static int 137 lo_clone_create(ifc, unit, params) 138 struct if_clone *ifc; 139 int unit; 140 caddr_t params; 141 { 142 struct ifnet *ifp; 143 struct lo_softc *sc; 144 145 MALLOC(sc, struct lo_softc *, sizeof(*sc), M_LO, M_WAITOK | M_ZERO); 146 ifp = sc->sc_ifp = if_alloc(IFT_LOOP); 147 if (ifp == NULL) { 148 free(sc, M_LO); 149 return (ENOSPC); 150 } 151 152 if_initname(ifp, ifc->ifc_name, unit); 153 ifp->if_mtu = LOMTU; 154 ifp->if_flags = IFF_LOOPBACK | IFF_MULTICAST; 155 ifp->if_ioctl = loioctl; 156 ifp->if_output = looutput; 157 ifp->if_snd.ifq_maxlen = ifqmaxlen; 158 ifp->if_softc = sc; 159 if_attach(ifp); 160 bpfattach(ifp, DLT_NULL, sizeof(u_int32_t)); 161 mtx_lock(&lo_mtx); 162 LIST_INSERT_HEAD(&lo_list, sc, sc_next); 163 mtx_unlock(&lo_mtx); 164 if (loif == NULL) 165 loif = ifp; 166 167 return (0); 168 } 169 170 static int 171 loop_modevent(module_t mod, int type, void *data) 172 { 173 switch (type) { 174 case MOD_LOAD: 175 mtx_init(&lo_mtx, "lo_mtx", NULL, MTX_DEF); 176 LIST_INIT(&lo_list); 177 if_clone_attach(&lo_cloner); 178 break; 179 case MOD_UNLOAD: 180 printf("loop module unload - not possible for this module type\n"); 181 return EINVAL; 182 default: 183 return EOPNOTSUPP; 184 } 185 return 0; 186 } 187 188 static moduledata_t loop_mod = { 189 "loop", 190 loop_modevent, 191 0 192 }; 193 194 DECLARE_MODULE(loop, loop_mod, SI_SUB_PROTO_IFATTACHDOMAIN, SI_ORDER_ANY); 195 196 int 197 looutput(ifp, m, dst, rt) 198 struct ifnet *ifp; 199 register struct mbuf *m; 200 struct sockaddr *dst; 201 register struct rtentry *rt; 202 { 203 u_int32_t af; 204 205 M_ASSERTPKTHDR(m); /* check if we have the packet header */ 206 207 if (rt && rt->rt_flags & (RTF_REJECT|RTF_BLACKHOLE)) { 208 m_freem(m); 209 return (rt->rt_flags & RTF_BLACKHOLE ? 0 : 210 rt->rt_flags & RTF_HOST ? EHOSTUNREACH : ENETUNREACH); 211 } 212 213 ifp->if_opackets++; 214 ifp->if_obytes += m->m_pkthdr.len; 215 216 /* BPF writes need to be handled specially. */ 217 if (dst->sa_family == AF_UNSPEC) { 218 bcopy(dst->sa_data, &af, sizeof(af)); 219 dst->sa_family = af; 220 } 221 222 #if 1 /* XXX */ 223 switch (dst->sa_family) { 224 case AF_INET: 225 case AF_INET6: 226 case AF_IPX: 227 case AF_APPLETALK: 228 break; 229 default: 230 printf("looutput: af=%d unexpected\n", dst->sa_family); 231 m_freem(m); 232 return (EAFNOSUPPORT); 233 } 234 #endif 235 return(if_simloop(ifp, m, dst->sa_family, 0)); 236 } 237 238 /* 239 * if_simloop() 240 * 241 * This function is to support software emulation of hardware loopback, 242 * i.e., for interfaces with the IFF_SIMPLEX attribute. Since they can't 243 * hear their own broadcasts, we create a copy of the packet that we 244 * would normally receive via a hardware loopback. 245 * 246 * This function expects the packet to include the media header of length hlen. 247 */ 248 249 int 250 if_simloop(ifp, m, af, hlen) 251 struct ifnet *ifp; 252 struct mbuf *m; 253 int af; 254 int hlen; 255 { 256 int isr; 257 258 M_ASSERTPKTHDR(m); 259 m_tag_delete_nonpersistent(m); 260 m->m_pkthdr.rcvif = ifp; 261 262 /* 263 * Let BPF see incoming packet in the following manner: 264 * - Emulated packet loopback for a simplex interface 265 * (net/if_ethersubr.c) 266 * -> passes it to ifp's BPF 267 * - IPv4/v6 multicast packet loopback (netinet(6)/ip(6)_output.c) 268 * -> not passes it to any BPF 269 * - Normal packet loopback from myself to myself (net/if_loop.c) 270 * -> passes to lo0's BPF (even in case of IPv6, where ifp!=lo0) 271 */ 272 if (hlen > 0) { 273 if (bpf_peers_present(ifp->if_bpf)) { 274 bpf_mtap(ifp->if_bpf, m); 275 } 276 } else { 277 if (bpf_peers_present(loif->if_bpf)) { 278 if ((m->m_flags & M_MCAST) == 0 || loif == ifp) { 279 /* XXX beware sizeof(af) != 4 */ 280 u_int32_t af1 = af; 281 282 /* 283 * We need to prepend the address family. 284 */ 285 bpf_mtap2(loif->if_bpf, &af1, sizeof(af1), m); 286 } 287 } 288 } 289 290 /* Strip away media header */ 291 if (hlen > 0) { 292 m_adj(m, hlen); 293 #ifndef __NO_STRICT_ALIGNMENT 294 /* 295 * Some archs do not like unaligned data, so 296 * we move data down in the first mbuf. 297 */ 298 if (mtod(m, vm_offset_t) & 3) { 299 KASSERT(hlen >= 3, ("if_simloop: hlen too small")); 300 bcopy(m->m_data, 301 (char *)(mtod(m, vm_offset_t) 302 - (mtod(m, vm_offset_t) & 3)), 303 m->m_len); 304 m->m_data -= (mtod(m,vm_offset_t) & 3); 305 } 306 #endif 307 } 308 309 /* Deliver to upper layer protocol */ 310 switch (af) { 311 #ifdef INET 312 case AF_INET: 313 isr = NETISR_IP; 314 break; 315 #endif 316 #ifdef INET6 317 case AF_INET6: 318 m->m_flags |= M_LOOP; 319 isr = NETISR_IPV6; 320 break; 321 #endif 322 #ifdef IPX 323 case AF_IPX: 324 isr = NETISR_IPX; 325 break; 326 #endif 327 #ifdef NETATALK 328 case AF_APPLETALK: 329 isr = NETISR_ATALK2; 330 break; 331 #endif 332 default: 333 printf("if_simloop: can't handle af=%d\n", af); 334 m_freem(m); 335 return (EAFNOSUPPORT); 336 } 337 ifp->if_ipackets++; 338 ifp->if_ibytes += m->m_pkthdr.len; 339 netisr_queue(isr, m); /* mbuf is free'd on failure. */ 340 return (0); 341 } 342 343 /* ARGSUSED */ 344 static void 345 lortrequest(cmd, rt, info) 346 int cmd; 347 struct rtentry *rt; 348 struct rt_addrinfo *info; 349 { 350 RT_LOCK_ASSERT(rt); 351 rt->rt_rmx.rmx_mtu = rt->rt_ifp->if_mtu; 352 } 353 354 /* 355 * Process an ioctl request. 356 */ 357 /* ARGSUSED */ 358 int 359 loioctl(ifp, cmd, data) 360 register struct ifnet *ifp; 361 u_long cmd; 362 caddr_t data; 363 { 364 register struct ifaddr *ifa; 365 register struct ifreq *ifr = (struct ifreq *)data; 366 register int error = 0; 367 368 switch (cmd) { 369 370 case SIOCSIFADDR: 371 ifp->if_flags |= IFF_UP; 372 ifp->if_drv_flags |= IFF_DRV_RUNNING; 373 ifa = (struct ifaddr *)data; 374 ifa->ifa_rtrequest = lortrequest; 375 /* 376 * Everything else is done at a higher level. 377 */ 378 break; 379 380 case SIOCADDMULTI: 381 case SIOCDELMULTI: 382 if (ifr == 0) { 383 error = EAFNOSUPPORT; /* XXX */ 384 break; 385 } 386 switch (ifr->ifr_addr.sa_family) { 387 388 #ifdef INET 389 case AF_INET: 390 break; 391 #endif 392 #ifdef INET6 393 case AF_INET6: 394 break; 395 #endif 396 397 default: 398 error = EAFNOSUPPORT; 399 break; 400 } 401 break; 402 403 case SIOCSIFMTU: 404 ifp->if_mtu = ifr->ifr_mtu; 405 break; 406 407 case SIOCSIFFLAGS: 408 break; 409 410 default: 411 error = EINVAL; 412 } 413 return (error); 414 } 415