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 #include "opt_route.h" 42 #include "opt_mac.h" 43 44 #include <sys/param.h> 45 #include <sys/systm.h> 46 #include <sys/kernel.h> 47 #include <sys/mbuf.h> 48 #include <sys/module.h> 49 #include <machine/bus.h> 50 #include <sys/rman.h> 51 #include <sys/socket.h> 52 #include <sys/sockio.h> 53 #include <sys/sysctl.h> 54 #include <sys/vimage.h> 55 56 #include <net/if.h> 57 #include <net/if_clone.h> 58 #include <net/if_types.h> 59 #include <net/netisr.h> 60 #include <net/route.h> 61 #include <net/bpf.h> 62 #include <net/vnet.h> 63 64 #ifdef INET 65 #include <netinet/in.h> 66 #include <netinet/in_var.h> 67 #endif 68 69 #ifdef IPX 70 #include <netipx/ipx.h> 71 #include <netipx/ipx_if.h> 72 #endif 73 74 #ifdef INET6 75 #ifndef INET 76 #include <netinet/in.h> 77 #endif 78 #include <netinet6/in6_var.h> 79 #include <netinet/ip6.h> 80 #endif 81 82 #ifdef NETATALK 83 #include <netatalk/at.h> 84 #include <netatalk/at_var.h> 85 #endif 86 87 #include <security/mac/mac_framework.h> 88 89 #ifdef TINY_LOMTU 90 #define LOMTU (1024+512) 91 #elif defined(LARGE_LOMTU) 92 #define LOMTU 131072 93 #else 94 #define LOMTU 16384 95 #endif 96 97 int loioctl(struct ifnet *, u_long, caddr_t); 98 static void lortrequest(int, struct rtentry *, struct rt_addrinfo *); 99 int looutput(struct ifnet *ifp, struct mbuf *m, 100 struct sockaddr *dst, struct rtentry *rt); 101 static int lo_clone_create(struct if_clone *, int, caddr_t); 102 static void lo_clone_destroy(struct ifnet *); 103 104 #ifdef VIMAGE_GLOBALS 105 struct ifnet *loif; /* Used externally */ 106 #endif 107 108 IFC_SIMPLE_DECLARE(lo, 1); 109 110 static void 111 lo_clone_destroy(struct ifnet *ifp) 112 { 113 #ifdef INVARIANTS 114 INIT_VNET_NET(ifp->if_vnet); 115 #endif 116 117 /* XXX: destroying lo0 will lead to panics. */ 118 KASSERT(V_loif != ifp, ("%s: destroying lo0", __func__)); 119 120 bpfdetach(ifp); 121 if_detach(ifp); 122 if_free(ifp); 123 } 124 125 static int 126 lo_clone_create(struct if_clone *ifc, int unit, caddr_t params) 127 { 128 INIT_VNET_NET(curvnet); 129 struct ifnet *ifp; 130 131 ifp = if_alloc(IFT_LOOP); 132 if (ifp == NULL) 133 return (ENOSPC); 134 135 if_initname(ifp, ifc->ifc_name, unit); 136 ifp->if_mtu = LOMTU; 137 ifp->if_flags = IFF_LOOPBACK | IFF_MULTICAST; 138 ifp->if_ioctl = loioctl; 139 ifp->if_output = looutput; 140 ifp->if_snd.ifq_maxlen = ifqmaxlen; 141 if_attach(ifp); 142 bpfattach(ifp, DLT_NULL, sizeof(u_int32_t)); 143 if (V_loif == NULL) 144 V_loif = ifp; 145 146 return (0); 147 } 148 149 static int 150 loop_modevent(module_t mod, int type, void *data) 151 { 152 INIT_VNET_NET(curvnet); 153 154 switch (type) { 155 case MOD_LOAD: 156 V_loif = NULL; 157 if_clone_attach(&lo_cloner); 158 break; 159 160 case MOD_UNLOAD: 161 printf("loop module unload - not possible for this module type\n"); 162 return (EINVAL); 163 164 default: 165 return (EOPNOTSUPP); 166 } 167 return (0); 168 } 169 170 static moduledata_t loop_mod = { 171 "loop", 172 loop_modevent, 173 0 174 }; 175 176 DECLARE_MODULE(loop, loop_mod, SI_SUB_PROTO_IFATTACHDOMAIN, SI_ORDER_ANY); 177 178 int 179 looutput(struct ifnet *ifp, struct mbuf *m, struct sockaddr *dst, 180 struct rtentry *rt) 181 { 182 u_int32_t af; 183 #ifdef MAC 184 int error; 185 #endif 186 187 M_ASSERTPKTHDR(m); /* check if we have the packet header */ 188 189 #ifdef MAC 190 error = mac_ifnet_check_transmit(ifp, m); 191 if (error) { 192 m_freem(m); 193 return (error); 194 } 195 #endif 196 197 if (rt && rt->rt_flags & (RTF_REJECT|RTF_BLACKHOLE)) { 198 m_freem(m); 199 return (rt->rt_flags & RTF_BLACKHOLE ? 0 : 200 rt->rt_flags & RTF_HOST ? EHOSTUNREACH : ENETUNREACH); 201 } 202 203 ifp->if_opackets++; 204 ifp->if_obytes += m->m_pkthdr.len; 205 206 /* BPF writes need to be handled specially. */ 207 if (dst->sa_family == AF_UNSPEC) { 208 bcopy(dst->sa_data, &af, sizeof(af)); 209 dst->sa_family = af; 210 } 211 212 #if 1 /* XXX */ 213 switch (dst->sa_family) { 214 case AF_INET: 215 case AF_INET6: 216 case AF_IPX: 217 case AF_APPLETALK: 218 break; 219 default: 220 printf("looutput: af=%d unexpected\n", dst->sa_family); 221 m_freem(m); 222 return (EAFNOSUPPORT); 223 } 224 #endif 225 return (if_simloop(ifp, m, dst->sa_family, 0)); 226 } 227 228 /* 229 * if_simloop() 230 * 231 * This function is to support software emulation of hardware loopback, 232 * i.e., for interfaces with the IFF_SIMPLEX attribute. Since they can't 233 * hear their own broadcasts, we create a copy of the packet that we 234 * would normally receive via a hardware loopback. 235 * 236 * This function expects the packet to include the media header of length hlen. 237 */ 238 int 239 if_simloop(struct ifnet *ifp, struct mbuf *m, int af, int hlen) 240 { 241 INIT_VNET_NET(ifp->if_vnet); 242 int isr; 243 244 M_ASSERTPKTHDR(m); 245 m_tag_delete_nonpersistent(m); 246 m->m_pkthdr.rcvif = ifp; 247 248 #ifdef MAC 249 mac_ifnet_create_mbuf(ifp, m); 250 #endif 251 252 /* 253 * Let BPF see incoming packet in the following manner: 254 * - Emulated packet loopback for a simplex interface 255 * (net/if_ethersubr.c) 256 * -> passes it to ifp's BPF 257 * - IPv4/v6 multicast packet loopback (netinet(6)/ip(6)_output.c) 258 * -> not passes it to any BPF 259 * - Normal packet loopback from myself to myself (net/if_loop.c) 260 * -> passes to lo0's BPF (even in case of IPv6, where ifp!=lo0) 261 */ 262 if (hlen > 0) { 263 if (bpf_peers_present(ifp->if_bpf)) { 264 bpf_mtap(ifp->if_bpf, m); 265 } 266 } else { 267 if (bpf_peers_present(V_loif->if_bpf)) { 268 if ((m->m_flags & M_MCAST) == 0 || V_loif == ifp) { 269 /* XXX beware sizeof(af) != 4 */ 270 u_int32_t af1 = af; 271 272 /* 273 * We need to prepend the address family. 274 */ 275 bpf_mtap2(V_loif->if_bpf, &af1, sizeof(af1), m); 276 } 277 } 278 } 279 280 /* Strip away media header */ 281 if (hlen > 0) { 282 m_adj(m, hlen); 283 #ifndef __NO_STRICT_ALIGNMENT 284 /* 285 * Some archs do not like unaligned data, so 286 * we move data down in the first mbuf. 287 */ 288 if (mtod(m, vm_offset_t) & 3) { 289 KASSERT(hlen >= 3, ("if_simloop: hlen too small")); 290 bcopy(m->m_data, 291 (char *)(mtod(m, vm_offset_t) 292 - (mtod(m, vm_offset_t) & 3)), 293 m->m_len); 294 m->m_data -= (mtod(m,vm_offset_t) & 3); 295 } 296 #endif 297 } 298 299 /* Deliver to upper layer protocol */ 300 switch (af) { 301 #ifdef INET 302 case AF_INET: 303 isr = NETISR_IP; 304 break; 305 #endif 306 #ifdef INET6 307 case AF_INET6: 308 m->m_flags |= M_LOOP; 309 isr = NETISR_IPV6; 310 break; 311 #endif 312 #ifdef IPX 313 case AF_IPX: 314 isr = NETISR_IPX; 315 break; 316 #endif 317 #ifdef NETATALK 318 case AF_APPLETALK: 319 isr = NETISR_ATALK2; 320 break; 321 #endif 322 default: 323 printf("if_simloop: can't handle af=%d\n", af); 324 m_freem(m); 325 return (EAFNOSUPPORT); 326 } 327 ifp->if_ipackets++; 328 ifp->if_ibytes += m->m_pkthdr.len; 329 netisr_queue(isr, m); /* mbuf is free'd on failure. */ 330 return (0); 331 } 332 333 /* ARGSUSED */ 334 static void 335 lortrequest(int cmd, struct rtentry *rt, struct rt_addrinfo *info) 336 { 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(struct ifnet *ifp, u_long cmd, caddr_t data) 348 { 349 struct ifaddr *ifa; 350 struct ifreq *ifr = (struct ifreq *)data; 351 int error = 0; 352 353 switch (cmd) { 354 case SIOCSIFADDR: 355 ifp->if_flags |= IFF_UP; 356 ifp->if_drv_flags |= IFF_DRV_RUNNING; 357 ifa = (struct ifaddr *)data; 358 ifa->ifa_rtrequest = lortrequest; 359 /* 360 * Everything else is done at a higher level. 361 */ 362 break; 363 364 case SIOCADDMULTI: 365 case SIOCDELMULTI: 366 if (ifr == 0) { 367 error = EAFNOSUPPORT; /* XXX */ 368 break; 369 } 370 switch (ifr->ifr_addr.sa_family) { 371 372 #ifdef INET 373 case AF_INET: 374 break; 375 #endif 376 #ifdef INET6 377 case AF_INET6: 378 break; 379 #endif 380 381 default: 382 error = EAFNOSUPPORT; 383 break; 384 } 385 break; 386 387 case SIOCSIFMTU: 388 ifp->if_mtu = ifr->ifr_mtu; 389 break; 390 391 case SIOCSIFFLAGS: 392 break; 393 394 default: 395 error = EINVAL; 396 } 397 return (error); 398 } 399