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 }; 98 99 int loioctl(struct ifnet *, u_long, caddr_t); 100 static void lortrequest(int, struct rtentry *, struct rt_addrinfo *); 101 int looutput(struct ifnet *ifp, struct mbuf *m, 102 struct sockaddr *dst, struct rtentry *rt); 103 static int lo_clone_create(struct if_clone *, int, caddr_t); 104 static void lo_clone_destroy(struct ifnet *); 105 106 struct ifnet *loif = NULL; /* Used externally */ 107 108 static MALLOC_DEFINE(M_LO, LONAME, "Loopback Interface"); 109 110 IFC_SIMPLE_DECLARE(lo, 1); 111 112 static void 113 lo_clone_destroy(ifp) 114 struct ifnet *ifp; 115 { 116 struct lo_softc *sc; 117 118 sc = ifp->if_softc; 119 120 /* XXX: destroying lo0 will lead to panics. */ 121 KASSERT(loif != ifp, ("%s: destroying lo0", __func__)); 122 123 bpfdetach(ifp); 124 if_detach(ifp); 125 if_free(ifp); 126 free(sc, M_LO); 127 } 128 129 static int 130 lo_clone_create(ifc, unit, params) 131 struct if_clone *ifc; 132 int unit; 133 caddr_t params; 134 { 135 struct ifnet *ifp; 136 struct lo_softc *sc; 137 138 MALLOC(sc, struct lo_softc *, sizeof(*sc), M_LO, M_WAITOK | M_ZERO); 139 ifp = sc->sc_ifp = if_alloc(IFT_LOOP); 140 if (ifp == NULL) { 141 free(sc, M_LO); 142 return (ENOSPC); 143 } 144 145 if_initname(ifp, ifc->ifc_name, unit); 146 ifp->if_mtu = LOMTU; 147 ifp->if_flags = IFF_LOOPBACK | IFF_MULTICAST; 148 ifp->if_ioctl = loioctl; 149 ifp->if_output = looutput; 150 ifp->if_snd.ifq_maxlen = ifqmaxlen; 151 ifp->if_softc = sc; 152 if_attach(ifp); 153 bpfattach(ifp, DLT_NULL, sizeof(u_int32_t)); 154 if (loif == NULL) 155 loif = ifp; 156 157 return (0); 158 } 159 160 static int 161 loop_modevent(module_t mod, int type, void *data) 162 { 163 switch (type) { 164 case MOD_LOAD: 165 if_clone_attach(&lo_cloner); 166 break; 167 case MOD_UNLOAD: 168 printf("loop module unload - not possible for this module type\n"); 169 return EINVAL; 170 default: 171 return EOPNOTSUPP; 172 } 173 return 0; 174 } 175 176 static moduledata_t loop_mod = { 177 "loop", 178 loop_modevent, 179 0 180 }; 181 182 DECLARE_MODULE(loop, loop_mod, SI_SUB_PROTO_IFATTACHDOMAIN, SI_ORDER_ANY); 183 184 int 185 looutput(ifp, m, dst, rt) 186 struct ifnet *ifp; 187 register struct mbuf *m; 188 struct sockaddr *dst; 189 register struct rtentry *rt; 190 { 191 u_int32_t af; 192 193 M_ASSERTPKTHDR(m); /* check if we have the packet header */ 194 195 if (rt && rt->rt_flags & (RTF_REJECT|RTF_BLACKHOLE)) { 196 m_freem(m); 197 return (rt->rt_flags & RTF_BLACKHOLE ? 0 : 198 rt->rt_flags & RTF_HOST ? EHOSTUNREACH : ENETUNREACH); 199 } 200 201 ifp->if_opackets++; 202 ifp->if_obytes += m->m_pkthdr.len; 203 204 /* BPF writes need to be handled specially. */ 205 if (dst->sa_family == AF_UNSPEC) { 206 bcopy(dst->sa_data, &af, sizeof(af)); 207 dst->sa_family = af; 208 } 209 210 #if 1 /* XXX */ 211 switch (dst->sa_family) { 212 case AF_INET: 213 case AF_INET6: 214 case AF_IPX: 215 case AF_APPLETALK: 216 break; 217 default: 218 printf("looutput: af=%d unexpected\n", dst->sa_family); 219 m_freem(m); 220 return (EAFNOSUPPORT); 221 } 222 #endif 223 return(if_simloop(ifp, m, dst->sa_family, 0)); 224 } 225 226 /* 227 * if_simloop() 228 * 229 * This function is to support software emulation of hardware loopback, 230 * i.e., for interfaces with the IFF_SIMPLEX attribute. Since they can't 231 * hear their own broadcasts, we create a copy of the packet that we 232 * would normally receive via a hardware loopback. 233 * 234 * This function expects the packet to include the media header of length hlen. 235 */ 236 237 int 238 if_simloop(ifp, m, af, hlen) 239 struct ifnet *ifp; 240 struct mbuf *m; 241 int af; 242 int hlen; 243 { 244 int isr; 245 246 M_ASSERTPKTHDR(m); 247 m_tag_delete_nonpersistent(m); 248 m->m_pkthdr.rcvif = ifp; 249 250 /* 251 * Let BPF see incoming packet in the following manner: 252 * - Emulated packet loopback for a simplex interface 253 * (net/if_ethersubr.c) 254 * -> passes it to ifp's BPF 255 * - IPv4/v6 multicast packet loopback (netinet(6)/ip(6)_output.c) 256 * -> not passes it to any BPF 257 * - Normal packet loopback from myself to myself (net/if_loop.c) 258 * -> passes to lo0's BPF (even in case of IPv6, where ifp!=lo0) 259 */ 260 if (hlen > 0) { 261 if (bpf_peers_present(ifp->if_bpf)) { 262 bpf_mtap(ifp->if_bpf, m); 263 } 264 } else { 265 if (bpf_peers_present(loif->if_bpf)) { 266 if ((m->m_flags & M_MCAST) == 0 || loif == ifp) { 267 /* XXX beware sizeof(af) != 4 */ 268 u_int32_t af1 = af; 269 270 /* 271 * We need to prepend the address family. 272 */ 273 bpf_mtap2(loif->if_bpf, &af1, sizeof(af1), m); 274 } 275 } 276 } 277 278 /* Strip away media header */ 279 if (hlen > 0) { 280 m_adj(m, hlen); 281 #ifndef __NO_STRICT_ALIGNMENT 282 /* 283 * Some archs do not like unaligned data, so 284 * we move data down in the first mbuf. 285 */ 286 if (mtod(m, vm_offset_t) & 3) { 287 KASSERT(hlen >= 3, ("if_simloop: hlen too small")); 288 bcopy(m->m_data, 289 (char *)(mtod(m, vm_offset_t) 290 - (mtod(m, vm_offset_t) & 3)), 291 m->m_len); 292 m->m_data -= (mtod(m,vm_offset_t) & 3); 293 } 294 #endif 295 } 296 297 /* Deliver to upper layer protocol */ 298 switch (af) { 299 #ifdef INET 300 case AF_INET: 301 isr = NETISR_IP; 302 break; 303 #endif 304 #ifdef INET6 305 case AF_INET6: 306 m->m_flags |= M_LOOP; 307 isr = NETISR_IPV6; 308 break; 309 #endif 310 #ifdef IPX 311 case AF_IPX: 312 isr = NETISR_IPX; 313 break; 314 #endif 315 #ifdef NETATALK 316 case AF_APPLETALK: 317 isr = NETISR_ATALK2; 318 break; 319 #endif 320 default: 321 printf("if_simloop: can't handle af=%d\n", af); 322 m_freem(m); 323 return (EAFNOSUPPORT); 324 } 325 ifp->if_ipackets++; 326 ifp->if_ibytes += m->m_pkthdr.len; 327 netisr_queue(isr, m); /* mbuf is free'd on failure. */ 328 return (0); 329 } 330 331 /* ARGSUSED */ 332 static void 333 lortrequest(cmd, rt, info) 334 int cmd; 335 struct rtentry *rt; 336 struct rt_addrinfo *info; 337 { 338 RT_LOCK_ASSERT(rt); 339 rt->rt_rmx.rmx_mtu = rt->rt_ifp->if_mtu; 340 } 341 342 /* 343 * Process an ioctl request. 344 */ 345 /* ARGSUSED */ 346 int 347 loioctl(ifp, cmd, data) 348 register struct ifnet *ifp; 349 u_long cmd; 350 caddr_t data; 351 { 352 register struct ifaddr *ifa; 353 register struct ifreq *ifr = (struct ifreq *)data; 354 register int error = 0; 355 356 switch (cmd) { 357 358 case SIOCSIFADDR: 359 ifp->if_flags |= IFF_UP; 360 ifp->if_drv_flags |= IFF_DRV_RUNNING; 361 ifa = (struct ifaddr *)data; 362 ifa->ifa_rtrequest = lortrequest; 363 /* 364 * Everything else is done at a higher level. 365 */ 366 break; 367 368 case SIOCADDMULTI: 369 case SIOCDELMULTI: 370 if (ifr == 0) { 371 error = EAFNOSUPPORT; /* XXX */ 372 break; 373 } 374 switch (ifr->ifr_addr.sa_family) { 375 376 #ifdef INET 377 case AF_INET: 378 break; 379 #endif 380 #ifdef INET6 381 case AF_INET6: 382 break; 383 #endif 384 385 default: 386 error = EAFNOSUPPORT; 387 break; 388 } 389 break; 390 391 case SIOCSIFMTU: 392 ifp->if_mtu = ifr->ifr_mtu; 393 break; 394 395 case SIOCSIFFLAGS: 396 break; 397 398 default: 399 error = EINVAL; 400 } 401 return (error); 402 } 403