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