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 61 #ifdef INET 62 #include <netinet/in.h> 63 #include <netinet/in_var.h> 64 #endif 65 66 #ifdef IPX 67 #include <netipx/ipx.h> 68 #include <netipx/ipx_if.h> 69 #endif 70 71 #ifdef INET6 72 #ifndef INET 73 #include <netinet/in.h> 74 #endif 75 #include <netinet6/in6_var.h> 76 #include <netinet/ip6.h> 77 #endif 78 79 #ifdef NETATALK 80 #include <netatalk/at.h> 81 #include <netatalk/at_var.h> 82 #endif 83 84 #ifdef TINY_LOMTU 85 #define LOMTU (1024+512) 86 #elif defined(LARGE_LOMTU) 87 #define LOMTU 131072 88 #else 89 #define LOMTU 16384 90 #endif 91 92 #define LONAME "lo" 93 94 struct lo_softc { 95 struct ifnet *sc_ifp; 96 }; 97 98 int loioctl(struct ifnet *, u_long, caddr_t); 99 static void lortrequest(int, struct rtentry *, struct rt_addrinfo *); 100 int looutput(struct ifnet *ifp, struct mbuf *m, 101 struct sockaddr *dst, struct rtentry *rt); 102 static int lo_clone_create(struct if_clone *, int, caddr_t); 103 static void lo_clone_destroy(struct ifnet *); 104 105 struct ifnet *loif = NULL; /* Used externally */ 106 107 static MALLOC_DEFINE(M_LO, LONAME, "Loopback Interface"); 108 109 IFC_SIMPLE_DECLARE(lo, 1); 110 111 static void 112 lo_clone_destroy(ifp) 113 struct ifnet *ifp; 114 { 115 struct lo_softc *sc; 116 117 sc = ifp->if_softc; 118 119 /* XXX: destroying lo0 will lead to panics. */ 120 KASSERT(loif != ifp, ("%s: destroying lo0", __func__)); 121 122 bpfdetach(ifp); 123 if_detach(ifp); 124 if_free(ifp); 125 free(sc, M_LO); 126 } 127 128 static int 129 lo_clone_create(ifc, unit, params) 130 struct if_clone *ifc; 131 int unit; 132 caddr_t params; 133 { 134 struct ifnet *ifp; 135 struct lo_softc *sc; 136 137 MALLOC(sc, struct lo_softc *, sizeof(*sc), M_LO, M_WAITOK | M_ZERO); 138 ifp = sc->sc_ifp = if_alloc(IFT_LOOP); 139 if (ifp == NULL) { 140 free(sc, M_LO); 141 return (ENOSPC); 142 } 143 144 if_initname(ifp, ifc->ifc_name, unit); 145 ifp->if_mtu = LOMTU; 146 ifp->if_flags = IFF_LOOPBACK | IFF_MULTICAST; 147 ifp->if_ioctl = loioctl; 148 ifp->if_output = looutput; 149 ifp->if_snd.ifq_maxlen = ifqmaxlen; 150 ifp->if_softc = sc; 151 if_attach(ifp); 152 bpfattach(ifp, DLT_NULL, sizeof(u_int32_t)); 153 if (loif == NULL) 154 loif = ifp; 155 156 return (0); 157 } 158 159 static int 160 loop_modevent(module_t mod, int type, void *data) 161 { 162 switch (type) { 163 case MOD_LOAD: 164 if_clone_attach(&lo_cloner); 165 break; 166 case MOD_UNLOAD: 167 printf("loop module unload - not possible for this module type\n"); 168 return EINVAL; 169 default: 170 return EOPNOTSUPP; 171 } 172 return 0; 173 } 174 175 static moduledata_t loop_mod = { 176 "loop", 177 loop_modevent, 178 0 179 }; 180 181 DECLARE_MODULE(loop, loop_mod, SI_SUB_PROTO_IFATTACHDOMAIN, SI_ORDER_ANY); 182 183 int 184 looutput(ifp, m, dst, rt) 185 struct ifnet *ifp; 186 register struct mbuf *m; 187 struct sockaddr *dst; 188 register struct rtentry *rt; 189 { 190 u_int32_t af; 191 192 M_ASSERTPKTHDR(m); /* check if we have the packet header */ 193 194 if (rt && rt->rt_flags & (RTF_REJECT|RTF_BLACKHOLE)) { 195 m_freem(m); 196 return (rt->rt_flags & RTF_BLACKHOLE ? 0 : 197 rt->rt_flags & RTF_HOST ? EHOSTUNREACH : ENETUNREACH); 198 } 199 200 ifp->if_opackets++; 201 ifp->if_obytes += m->m_pkthdr.len; 202 203 /* BPF writes need to be handled specially. */ 204 if (dst->sa_family == AF_UNSPEC) { 205 bcopy(dst->sa_data, &af, sizeof(af)); 206 dst->sa_family = af; 207 } 208 209 #if 1 /* XXX */ 210 switch (dst->sa_family) { 211 case AF_INET: 212 case AF_INET6: 213 case AF_IPX: 214 case AF_APPLETALK: 215 break; 216 default: 217 printf("looutput: af=%d unexpected\n", dst->sa_family); 218 m_freem(m); 219 return (EAFNOSUPPORT); 220 } 221 #endif 222 return(if_simloop(ifp, m, dst->sa_family, 0)); 223 } 224 225 /* 226 * if_simloop() 227 * 228 * This function is to support software emulation of hardware loopback, 229 * i.e., for interfaces with the IFF_SIMPLEX attribute. Since they can't 230 * hear their own broadcasts, we create a copy of the packet that we 231 * would normally receive via a hardware loopback. 232 * 233 * This function expects the packet to include the media header of length hlen. 234 */ 235 236 int 237 if_simloop(ifp, m, af, hlen) 238 struct ifnet *ifp; 239 struct mbuf *m; 240 int af; 241 int hlen; 242 { 243 int isr; 244 245 M_ASSERTPKTHDR(m); 246 m_tag_delete_nonpersistent(m); 247 m->m_pkthdr.rcvif = ifp; 248 249 /* 250 * Let BPF see incoming packet in the following manner: 251 * - Emulated packet loopback for a simplex interface 252 * (net/if_ethersubr.c) 253 * -> passes it to ifp's BPF 254 * - IPv4/v6 multicast packet loopback (netinet(6)/ip(6)_output.c) 255 * -> not passes it to any BPF 256 * - Normal packet loopback from myself to myself (net/if_loop.c) 257 * -> passes to lo0's BPF (even in case of IPv6, where ifp!=lo0) 258 */ 259 if (hlen > 0) { 260 if (bpf_peers_present(ifp->if_bpf)) { 261 bpf_mtap(ifp->if_bpf, m); 262 } 263 } else { 264 if (bpf_peers_present(loif->if_bpf)) { 265 if ((m->m_flags & M_MCAST) == 0 || loif == ifp) { 266 /* XXX beware sizeof(af) != 4 */ 267 u_int32_t af1 = af; 268 269 /* 270 * We need to prepend the address family. 271 */ 272 bpf_mtap2(loif->if_bpf, &af1, sizeof(af1), m); 273 } 274 } 275 } 276 277 /* Strip away media header */ 278 if (hlen > 0) { 279 m_adj(m, hlen); 280 #ifndef __NO_STRICT_ALIGNMENT 281 /* 282 * Some archs do not like unaligned data, so 283 * we move data down in the first mbuf. 284 */ 285 if (mtod(m, vm_offset_t) & 3) { 286 KASSERT(hlen >= 3, ("if_simloop: hlen too small")); 287 bcopy(m->m_data, 288 (char *)(mtod(m, vm_offset_t) 289 - (mtod(m, vm_offset_t) & 3)), 290 m->m_len); 291 m->m_data -= (mtod(m,vm_offset_t) & 3); 292 } 293 #endif 294 } 295 296 /* Deliver to upper layer protocol */ 297 switch (af) { 298 #ifdef INET 299 case AF_INET: 300 isr = NETISR_IP; 301 break; 302 #endif 303 #ifdef INET6 304 case AF_INET6: 305 m->m_flags |= M_LOOP; 306 isr = NETISR_IPV6; 307 break; 308 #endif 309 #ifdef IPX 310 case AF_IPX: 311 isr = NETISR_IPX; 312 break; 313 #endif 314 #ifdef NETATALK 315 case AF_APPLETALK: 316 isr = NETISR_ATALK2; 317 break; 318 #endif 319 default: 320 printf("if_simloop: can't handle af=%d\n", af); 321 m_freem(m); 322 return (EAFNOSUPPORT); 323 } 324 ifp->if_ipackets++; 325 ifp->if_ibytes += m->m_pkthdr.len; 326 netisr_queue(isr, m); /* mbuf is free'd on failure. */ 327 return (0); 328 } 329 330 /* ARGSUSED */ 331 static void 332 lortrequest(cmd, rt, info) 333 int cmd; 334 struct rtentry *rt; 335 struct rt_addrinfo *info; 336 { 337 RT_LOCK_ASSERT(rt); 338 rt->rt_rmx.rmx_mtu = rt->rt_ifp->if_mtu; 339 } 340 341 /* 342 * Process an ioctl request. 343 */ 344 /* ARGSUSED */ 345 int 346 loioctl(ifp, cmd, data) 347 register struct ifnet *ifp; 348 u_long cmd; 349 caddr_t data; 350 { 351 register struct ifaddr *ifa; 352 register struct ifreq *ifr = (struct ifreq *)data; 353 register int error = 0; 354 355 switch (cmd) { 356 357 case SIOCSIFADDR: 358 ifp->if_flags |= IFF_UP; 359 ifp->if_drv_flags |= IFF_DRV_RUNNING; 360 ifa = (struct ifaddr *)data; 361 ifa->ifa_rtrequest = lortrequest; 362 /* 363 * Everything else is done at a higher level. 364 */ 365 break; 366 367 case SIOCADDMULTI: 368 case SIOCDELMULTI: 369 if (ifr == 0) { 370 error = EAFNOSUPPORT; /* XXX */ 371 break; 372 } 373 switch (ifr->ifr_addr.sa_family) { 374 375 #ifdef INET 376 case AF_INET: 377 break; 378 #endif 379 #ifdef INET6 380 case AF_INET6: 381 break; 382 #endif 383 384 default: 385 error = EAFNOSUPPORT; 386 break; 387 } 388 break; 389 390 case SIOCSIFMTU: 391 ifp->if_mtu = ifr->ifr_mtu; 392 break; 393 394 case SIOCSIFFLAGS: 395 break; 396 397 default: 398 error = EINVAL; 399 } 400 return (error); 401 } 402