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); 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) 138 struct if_clone *ifc; 139 int unit; 140 { 141 struct ifnet *ifp; 142 struct lo_softc *sc; 143 144 MALLOC(sc, struct lo_softc *, sizeof(*sc), M_LO, M_WAITOK | M_ZERO); 145 ifp = sc->sc_ifp = if_alloc(IFT_LOOP); 146 if (ifp == NULL) { 147 free(sc, M_LO); 148 return (ENOSPC); 149 } 150 151 if_initname(ifp, ifc->ifc_name, unit); 152 ifp->if_mtu = LOMTU; 153 ifp->if_flags = IFF_LOOPBACK | IFF_MULTICAST; 154 ifp->if_ioctl = loioctl; 155 ifp->if_output = looutput; 156 ifp->if_snd.ifq_maxlen = ifqmaxlen; 157 ifp->if_softc = sc; 158 if_attach(ifp); 159 bpfattach(ifp, DLT_NULL, sizeof(u_int32_t)); 160 mtx_lock(&lo_mtx); 161 LIST_INSERT_HEAD(&lo_list, sc, sc_next); 162 mtx_unlock(&lo_mtx); 163 if (loif == NULL) 164 loif = ifp; 165 166 return (0); 167 } 168 169 static int 170 loop_modevent(module_t mod, int type, void *data) 171 { 172 switch (type) { 173 case MOD_LOAD: 174 mtx_init(&lo_mtx, "lo_mtx", NULL, MTX_DEF); 175 LIST_INIT(&lo_list); 176 if_clone_attach(&lo_cloner); 177 break; 178 case MOD_UNLOAD: 179 printf("loop module unload - not possible for this module type\n"); 180 return EINVAL; 181 default: 182 return EOPNOTSUPP; 183 } 184 return 0; 185 } 186 187 static moduledata_t loop_mod = { 188 "loop", 189 loop_modevent, 190 0 191 }; 192 193 DECLARE_MODULE(loop, loop_mod, SI_SUB_PROTO_IFATTACHDOMAIN, SI_ORDER_ANY); 194 195 int 196 looutput(ifp, m, dst, rt) 197 struct ifnet *ifp; 198 register struct mbuf *m; 199 struct sockaddr *dst; 200 register struct rtentry *rt; 201 { 202 u_int32_t af; 203 204 M_ASSERTPKTHDR(m); /* check if we have the packet header */ 205 206 if (rt && rt->rt_flags & (RTF_REJECT|RTF_BLACKHOLE)) { 207 m_freem(m); 208 return (rt->rt_flags & RTF_BLACKHOLE ? 0 : 209 rt->rt_flags & RTF_HOST ? EHOSTUNREACH : ENETUNREACH); 210 } 211 212 ifp->if_opackets++; 213 ifp->if_obytes += m->m_pkthdr.len; 214 215 /* BPF writes need to be handled specially. */ 216 if (dst->sa_family == AF_UNSPEC) { 217 bcopy(dst->sa_data, &af, sizeof(af)); 218 dst->sa_family = af; 219 } 220 221 #if 1 /* XXX */ 222 switch (dst->sa_family) { 223 case AF_INET: 224 case AF_INET6: 225 case AF_IPX: 226 case AF_APPLETALK: 227 break; 228 default: 229 printf("looutput: af=%d unexpected\n", dst->sa_family); 230 m_freem(m); 231 return (EAFNOSUPPORT); 232 } 233 #endif 234 return(if_simloop(ifp, m, dst->sa_family, 0)); 235 } 236 237 /* 238 * if_simloop() 239 * 240 * This function is to support software emulation of hardware loopback, 241 * i.e., for interfaces with the IFF_SIMPLEX attribute. Since they can't 242 * hear their own broadcasts, we create a copy of the packet that we 243 * would normally receive via a hardware loopback. 244 * 245 * This function expects the packet to include the media header of length hlen. 246 */ 247 248 int 249 if_simloop(ifp, m, af, hlen) 250 struct ifnet *ifp; 251 struct mbuf *m; 252 int af; 253 int hlen; 254 { 255 int isr; 256 257 M_ASSERTPKTHDR(m); 258 m_tag_delete_nonpersistent(m); 259 m->m_pkthdr.rcvif = ifp; 260 261 /* Let BPF see incoming packet */ 262 if (bpf_peers_present(ifp->if_bpf)) { 263 if (ifp->if_bpf->bif_dlt == DLT_NULL) { 264 u_int32_t af1 = af; /* XXX beware sizeof(af) != 4 */ 265 /* 266 * We need to prepend the address family. 267 */ 268 bpf_mtap2(ifp->if_bpf, &af1, sizeof(af1), m); 269 } else 270 bpf_mtap(ifp->if_bpf, m); 271 } 272 273 /* Strip away media header */ 274 if (hlen > 0) { 275 m_adj(m, hlen); 276 #if defined(__ia64__) || defined(__sparc64__) 277 /* 278 * Some archs do not like unaligned data, so 279 * we move data down in the first mbuf. 280 */ 281 if (mtod(m, vm_offset_t) & 3) { 282 KASSERT(hlen >= 3, ("if_simloop: hlen too small")); 283 bcopy(m->m_data, 284 (char *)(mtod(m, vm_offset_t) 285 - (mtod(m, vm_offset_t) & 3)), 286 m->m_len); 287 m->m_data -= (mtod(m,vm_offset_t) & 3); 288 } 289 #endif 290 } 291 292 /* Deliver to upper layer protocol */ 293 switch (af) { 294 #ifdef INET 295 case AF_INET: 296 isr = NETISR_IP; 297 break; 298 #endif 299 #ifdef INET6 300 case AF_INET6: 301 m->m_flags |= M_LOOP; 302 isr = NETISR_IPV6; 303 break; 304 #endif 305 #ifdef IPX 306 case AF_IPX: 307 isr = NETISR_IPX; 308 break; 309 #endif 310 #ifdef NETATALK 311 case AF_APPLETALK: 312 isr = NETISR_ATALK2; 313 break; 314 #endif 315 default: 316 printf("if_simloop: can't handle af=%d\n", af); 317 m_freem(m); 318 return (EAFNOSUPPORT); 319 } 320 ifp->if_ipackets++; 321 ifp->if_ibytes += m->m_pkthdr.len; 322 netisr_queue(isr, m); /* mbuf is free'd on failure. */ 323 return (0); 324 } 325 326 /* ARGSUSED */ 327 static void 328 lortrequest(cmd, rt, info) 329 int cmd; 330 struct rtentry *rt; 331 struct rt_addrinfo *info; 332 { 333 RT_LOCK_ASSERT(rt); 334 rt->rt_rmx.rmx_mtu = rt->rt_ifp->if_mtu; 335 } 336 337 /* 338 * Process an ioctl request. 339 */ 340 /* ARGSUSED */ 341 int 342 loioctl(ifp, cmd, data) 343 register struct ifnet *ifp; 344 u_long cmd; 345 caddr_t data; 346 { 347 register struct ifaddr *ifa; 348 register struct ifreq *ifr = (struct ifreq *)data; 349 register int error = 0; 350 351 switch (cmd) { 352 353 case SIOCSIFADDR: 354 ifp->if_flags |= IFF_UP; 355 ifp->if_drv_flags |= IFF_DRV_RUNNING; 356 ifa = (struct ifaddr *)data; 357 ifa->ifa_rtrequest = lortrequest; 358 /* 359 * Everything else is done at a higher level. 360 */ 361 break; 362 363 case SIOCADDMULTI: 364 case SIOCDELMULTI: 365 if (ifr == 0) { 366 error = EAFNOSUPPORT; /* XXX */ 367 break; 368 } 369 switch (ifr->ifr_addr.sa_family) { 370 371 #ifdef INET 372 case AF_INET: 373 break; 374 #endif 375 #ifdef INET6 376 case AF_INET6: 377 break; 378 #endif 379 380 default: 381 error = EAFNOSUPPORT; 382 break; 383 } 384 break; 385 386 case SIOCSIFMTU: 387 ifp->if_mtu = ifr->ifr_mtu; 388 break; 389 390 case SIOCSIFFLAGS: 391 break; 392 393 default: 394 error = EINVAL; 395 } 396 return (error); 397 } 398