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