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/mbuf.h> 46 #include <sys/module.h> 47 #include <machine/bus.h> 48 #include <sys/rman.h> 49 #include <sys/socket.h> 50 #include <sys/sockio.h> 51 #include <sys/sysctl.h> 52 #include <sys/vimage.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/vnet.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 int loioctl(struct ifnet *, u_long, caddr_t); 94 static void lortrequest(int, struct rtentry *, struct rt_addrinfo *); 95 int looutput(struct ifnet *ifp, struct mbuf *m, 96 struct sockaddr *dst, struct rtentry *rt); 97 static int lo_clone_create(struct if_clone *, int, caddr_t); 98 static void lo_clone_destroy(struct ifnet *); 99 100 #ifdef VIMAGE_GLOBALS 101 struct ifnet *loif; /* Used externally */ 102 #endif 103 104 IFC_SIMPLE_DECLARE(lo, 1); 105 106 static void 107 lo_clone_destroy(struct ifnet *ifp) 108 { 109 #ifdef INVARIANTS 110 INIT_VNET_NET(ifp->if_vnet); 111 #endif 112 113 /* XXX: destroying lo0 will lead to panics. */ 114 KASSERT(V_loif != ifp, ("%s: destroying lo0", __func__)); 115 116 bpfdetach(ifp); 117 if_detach(ifp); 118 if_free(ifp); 119 } 120 121 static int 122 lo_clone_create(struct if_clone *ifc, int unit, caddr_t params) 123 { 124 INIT_VNET_NET(curvnet); 125 struct ifnet *ifp; 126 127 ifp = if_alloc(IFT_LOOP); 128 if (ifp == NULL) 129 return (ENOSPC); 130 131 if_initname(ifp, ifc->ifc_name, unit); 132 ifp->if_mtu = LOMTU; 133 ifp->if_flags = IFF_LOOPBACK | IFF_MULTICAST; 134 ifp->if_ioctl = loioctl; 135 ifp->if_output = looutput; 136 ifp->if_snd.ifq_maxlen = ifqmaxlen; 137 if_attach(ifp); 138 bpfattach(ifp, DLT_NULL, sizeof(u_int32_t)); 139 if (V_loif == NULL) 140 V_loif = ifp; 141 142 return (0); 143 } 144 145 static int 146 loop_modevent(module_t mod, int type, void *data) 147 { 148 INIT_VNET_NET(curvnet); 149 150 switch (type) { 151 case MOD_LOAD: 152 V_loif = NULL; 153 if_clone_attach(&lo_cloner); 154 break; 155 156 case MOD_UNLOAD: 157 printf("loop module unload - not possible for this module type\n"); 158 return (EINVAL); 159 160 default: 161 return (EOPNOTSUPP); 162 } 163 return (0); 164 } 165 166 static moduledata_t loop_mod = { 167 "loop", 168 loop_modevent, 169 0 170 }; 171 172 DECLARE_MODULE(loop, loop_mod, SI_SUB_PROTO_IFATTACHDOMAIN, SI_ORDER_ANY); 173 174 int 175 looutput(struct ifnet *ifp, struct mbuf *m, struct sockaddr *dst, 176 struct rtentry *rt) 177 { 178 u_int32_t af; 179 180 M_ASSERTPKTHDR(m); /* check if we have the packet header */ 181 182 if (rt && rt->rt_flags & (RTF_REJECT|RTF_BLACKHOLE)) { 183 m_freem(m); 184 return (rt->rt_flags & RTF_BLACKHOLE ? 0 : 185 rt->rt_flags & RTF_HOST ? EHOSTUNREACH : ENETUNREACH); 186 } 187 188 ifp->if_opackets++; 189 ifp->if_obytes += m->m_pkthdr.len; 190 191 /* BPF writes need to be handled specially. */ 192 if (dst->sa_family == AF_UNSPEC) { 193 bcopy(dst->sa_data, &af, sizeof(af)); 194 dst->sa_family = af; 195 } 196 197 #if 1 /* XXX */ 198 switch (dst->sa_family) { 199 case AF_INET: 200 case AF_INET6: 201 case AF_IPX: 202 case AF_APPLETALK: 203 break; 204 default: 205 printf("looutput: af=%d unexpected\n", dst->sa_family); 206 m_freem(m); 207 return (EAFNOSUPPORT); 208 } 209 #endif 210 return (if_simloop(ifp, m, dst->sa_family, 0)); 211 } 212 213 /* 214 * if_simloop() 215 * 216 * This function is to support software emulation of hardware loopback, 217 * i.e., for interfaces with the IFF_SIMPLEX attribute. Since they can't 218 * hear their own broadcasts, we create a copy of the packet that we 219 * would normally receive via a hardware loopback. 220 * 221 * This function expects the packet to include the media header of length hlen. 222 */ 223 int 224 if_simloop(struct ifnet *ifp, struct mbuf *m, int af, int hlen) 225 { 226 INIT_VNET_NET(ifp->if_vnet); 227 int isr; 228 229 M_ASSERTPKTHDR(m); 230 m_tag_delete_nonpersistent(m); 231 m->m_pkthdr.rcvif = ifp; 232 233 /* 234 * Let BPF see incoming packet in the following manner: 235 * - Emulated packet loopback for a simplex interface 236 * (net/if_ethersubr.c) 237 * -> passes it to ifp's BPF 238 * - IPv4/v6 multicast packet loopback (netinet(6)/ip(6)_output.c) 239 * -> not passes it to any BPF 240 * - Normal packet loopback from myself to myself (net/if_loop.c) 241 * -> passes to lo0's BPF (even in case of IPv6, where ifp!=lo0) 242 */ 243 if (hlen > 0) { 244 if (bpf_peers_present(ifp->if_bpf)) { 245 bpf_mtap(ifp->if_bpf, m); 246 } 247 } else { 248 if (bpf_peers_present(V_loif->if_bpf)) { 249 if ((m->m_flags & M_MCAST) == 0 || V_loif == ifp) { 250 /* XXX beware sizeof(af) != 4 */ 251 u_int32_t af1 = af; 252 253 /* 254 * We need to prepend the address family. 255 */ 256 bpf_mtap2(V_loif->if_bpf, &af1, sizeof(af1), m); 257 } 258 } 259 } 260 261 /* Strip away media header */ 262 if (hlen > 0) { 263 m_adj(m, hlen); 264 #ifndef __NO_STRICT_ALIGNMENT 265 /* 266 * Some archs do not like unaligned data, so 267 * we move data down in the first mbuf. 268 */ 269 if (mtod(m, vm_offset_t) & 3) { 270 KASSERT(hlen >= 3, ("if_simloop: hlen too small")); 271 bcopy(m->m_data, 272 (char *)(mtod(m, vm_offset_t) 273 - (mtod(m, vm_offset_t) & 3)), 274 m->m_len); 275 m->m_data -= (mtod(m,vm_offset_t) & 3); 276 } 277 #endif 278 } 279 280 /* Deliver to upper layer protocol */ 281 switch (af) { 282 #ifdef INET 283 case AF_INET: 284 isr = NETISR_IP; 285 break; 286 #endif 287 #ifdef INET6 288 case AF_INET6: 289 m->m_flags |= M_LOOP; 290 isr = NETISR_IPV6; 291 break; 292 #endif 293 #ifdef IPX 294 case AF_IPX: 295 isr = NETISR_IPX; 296 break; 297 #endif 298 #ifdef NETATALK 299 case AF_APPLETALK: 300 isr = NETISR_ATALK2; 301 break; 302 #endif 303 default: 304 printf("if_simloop: can't handle af=%d\n", af); 305 m_freem(m); 306 return (EAFNOSUPPORT); 307 } 308 ifp->if_ipackets++; 309 ifp->if_ibytes += m->m_pkthdr.len; 310 netisr_queue(isr, m); /* mbuf is free'd on failure. */ 311 return (0); 312 } 313 314 /* ARGSUSED */ 315 static void 316 lortrequest(int cmd, struct rtentry *rt, struct rt_addrinfo *info) 317 { 318 319 RT_LOCK_ASSERT(rt); 320 rt->rt_rmx.rmx_mtu = rt->rt_ifp->if_mtu; 321 } 322 323 /* 324 * Process an ioctl request. 325 */ 326 /* ARGSUSED */ 327 int 328 loioctl(struct ifnet *ifp, u_long cmd, caddr_t data) 329 { 330 struct ifaddr *ifa; 331 struct ifreq *ifr = (struct ifreq *)data; 332 int error = 0; 333 334 switch (cmd) { 335 case SIOCSIFADDR: 336 ifp->if_flags |= IFF_UP; 337 ifp->if_drv_flags |= IFF_DRV_RUNNING; 338 ifa = (struct ifaddr *)data; 339 ifa->ifa_rtrequest = lortrequest; 340 /* 341 * Everything else is done at a higher level. 342 */ 343 break; 344 345 case SIOCADDMULTI: 346 case SIOCDELMULTI: 347 if (ifr == 0) { 348 error = EAFNOSUPPORT; /* XXX */ 349 break; 350 } 351 switch (ifr->ifr_addr.sa_family) { 352 353 #ifdef INET 354 case AF_INET: 355 break; 356 #endif 357 #ifdef INET6 358 case AF_INET6: 359 break; 360 #endif 361 362 default: 363 error = EAFNOSUPPORT; 364 break; 365 } 366 break; 367 368 case SIOCSIFMTU: 369 ifp->if_mtu = ifr->ifr_mtu; 370 break; 371 372 case SIOCSIFFLAGS: 373 break; 374 375 default: 376 error = EINVAL; 377 } 378 return (error); 379 } 380