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