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 53 #include <net/if.h> 54 #include <net/if_clone.h> 55 #include <net/if_types.h> 56 #include <net/netisr.h> 57 #include <net/route.h> 58 #include <net/bpf.h> 59 60 #ifdef INET 61 #include <netinet/in.h> 62 #include <netinet/in_var.h> 63 #endif 64 65 #ifdef IPX 66 #include <netipx/ipx.h> 67 #include <netipx/ipx_if.h> 68 #endif 69 70 #ifdef INET6 71 #ifndef INET 72 #include <netinet/in.h> 73 #endif 74 #include <netinet6/in6_var.h> 75 #include <netinet/ip6.h> 76 #endif 77 78 #ifdef NETATALK 79 #include <netatalk/at.h> 80 #include <netatalk/at_var.h> 81 #endif 82 83 #ifdef TINY_LOMTU 84 #define LOMTU (1024+512) 85 #elif defined(LARGE_LOMTU) 86 #define LOMTU 131072 87 #else 88 #define LOMTU 16384 89 #endif 90 91 int loioctl(struct ifnet *, u_long, caddr_t); 92 static void lortrequest(int, struct rtentry *, struct rt_addrinfo *); 93 int looutput(struct ifnet *ifp, struct mbuf *m, 94 struct sockaddr *dst, struct rtentry *rt); 95 static int lo_clone_create(struct if_clone *, int, caddr_t); 96 static void lo_clone_destroy(struct ifnet *); 97 98 struct ifnet *loif = NULL; /* Used externally */ 99 100 IFC_SIMPLE_DECLARE(lo, 1); 101 102 static void 103 lo_clone_destroy(struct ifnet *ifp) 104 { 105 106 /* XXX: destroying lo0 will lead to panics. */ 107 KASSERT(loif != ifp, ("%s: destroying lo0", __func__)); 108 109 bpfdetach(ifp); 110 if_detach(ifp); 111 if_free(ifp); 112 } 113 114 static int 115 lo_clone_create(struct if_clone *ifc, int unit, caddr_t params) 116 { 117 struct ifnet *ifp; 118 119 ifp = if_alloc(IFT_LOOP); 120 if (ifp == NULL) 121 return (ENOSPC); 122 123 if_initname(ifp, ifc->ifc_name, unit); 124 ifp->if_mtu = LOMTU; 125 ifp->if_flags = IFF_LOOPBACK | IFF_MULTICAST; 126 ifp->if_ioctl = loioctl; 127 ifp->if_output = looutput; 128 ifp->if_snd.ifq_maxlen = ifqmaxlen; 129 if_attach(ifp); 130 bpfattach(ifp, DLT_NULL, sizeof(u_int32_t)); 131 if (loif == NULL) 132 loif = ifp; 133 134 return (0); 135 } 136 137 static int 138 loop_modevent(module_t mod, int type, void *data) 139 { 140 141 switch (type) { 142 case MOD_LOAD: 143 if_clone_attach(&lo_cloner); 144 break; 145 146 case MOD_UNLOAD: 147 printf("loop module unload - not possible for this module type\n"); 148 return (EINVAL); 149 150 default: 151 return (EOPNOTSUPP); 152 } 153 return (0); 154 } 155 156 static moduledata_t loop_mod = { 157 "loop", 158 loop_modevent, 159 0 160 }; 161 162 DECLARE_MODULE(loop, loop_mod, SI_SUB_PROTO_IFATTACHDOMAIN, SI_ORDER_ANY); 163 164 int 165 looutput(struct ifnet *ifp, struct mbuf *m, struct sockaddr *dst, 166 struct rtentry *rt) 167 { 168 u_int32_t af; 169 170 M_ASSERTPKTHDR(m); /* check if we have the packet header */ 171 172 if (rt && rt->rt_flags & (RTF_REJECT|RTF_BLACKHOLE)) { 173 m_freem(m); 174 return (rt->rt_flags & RTF_BLACKHOLE ? 0 : 175 rt->rt_flags & RTF_HOST ? EHOSTUNREACH : ENETUNREACH); 176 } 177 178 ifp->if_opackets++; 179 ifp->if_obytes += m->m_pkthdr.len; 180 181 /* BPF writes need to be handled specially. */ 182 if (dst->sa_family == AF_UNSPEC) { 183 bcopy(dst->sa_data, &af, sizeof(af)); 184 dst->sa_family = af; 185 } 186 187 #if 1 /* XXX */ 188 switch (dst->sa_family) { 189 case AF_INET: 190 case AF_INET6: 191 case AF_IPX: 192 case AF_APPLETALK: 193 break; 194 default: 195 printf("looutput: af=%d unexpected\n", dst->sa_family); 196 m_freem(m); 197 return (EAFNOSUPPORT); 198 } 199 #endif 200 return (if_simloop(ifp, m, dst->sa_family, 0)); 201 } 202 203 /* 204 * if_simloop() 205 * 206 * This function is to support software emulation of hardware loopback, 207 * i.e., for interfaces with the IFF_SIMPLEX attribute. Since they can't 208 * hear their own broadcasts, we create a copy of the packet that we 209 * would normally receive via a hardware loopback. 210 * 211 * This function expects the packet to include the media header of length hlen. 212 */ 213 int 214 if_simloop(struct ifnet *ifp, struct mbuf *m, int af, int hlen) 215 { 216 int isr; 217 218 M_ASSERTPKTHDR(m); 219 m_tag_delete_nonpersistent(m); 220 m->m_pkthdr.rcvif = ifp; 221 222 /* 223 * Let BPF see incoming packet in the following manner: 224 * - Emulated packet loopback for a simplex interface 225 * (net/if_ethersubr.c) 226 * -> passes it to ifp's BPF 227 * - IPv4/v6 multicast packet loopback (netinet(6)/ip(6)_output.c) 228 * -> not passes it to any BPF 229 * - Normal packet loopback from myself to myself (net/if_loop.c) 230 * -> passes to lo0's BPF (even in case of IPv6, where ifp!=lo0) 231 */ 232 if (hlen > 0) { 233 if (bpf_peers_present(ifp->if_bpf)) { 234 bpf_mtap(ifp->if_bpf, m); 235 } 236 } else { 237 if (bpf_peers_present(loif->if_bpf)) { 238 if ((m->m_flags & M_MCAST) == 0 || loif == ifp) { 239 /* XXX beware sizeof(af) != 4 */ 240 u_int32_t af1 = af; 241 242 /* 243 * We need to prepend the address family. 244 */ 245 bpf_mtap2(loif->if_bpf, &af1, sizeof(af1), m); 246 } 247 } 248 } 249 250 /* Strip away media header */ 251 if (hlen > 0) { 252 m_adj(m, hlen); 253 #ifndef __NO_STRICT_ALIGNMENT 254 /* 255 * Some archs do not like unaligned data, so 256 * we move data down in the first mbuf. 257 */ 258 if (mtod(m, vm_offset_t) & 3) { 259 KASSERT(hlen >= 3, ("if_simloop: hlen too small")); 260 bcopy(m->m_data, 261 (char *)(mtod(m, vm_offset_t) 262 - (mtod(m, vm_offset_t) & 3)), 263 m->m_len); 264 m->m_data -= (mtod(m,vm_offset_t) & 3); 265 } 266 #endif 267 } 268 269 /* Deliver to upper layer protocol */ 270 switch (af) { 271 #ifdef INET 272 case AF_INET: 273 isr = NETISR_IP; 274 break; 275 #endif 276 #ifdef INET6 277 case AF_INET6: 278 m->m_flags |= M_LOOP; 279 isr = NETISR_IPV6; 280 break; 281 #endif 282 #ifdef IPX 283 case AF_IPX: 284 isr = NETISR_IPX; 285 break; 286 #endif 287 #ifdef NETATALK 288 case AF_APPLETALK: 289 isr = NETISR_ATALK2; 290 break; 291 #endif 292 default: 293 printf("if_simloop: can't handle af=%d\n", af); 294 m_freem(m); 295 return (EAFNOSUPPORT); 296 } 297 ifp->if_ipackets++; 298 ifp->if_ibytes += m->m_pkthdr.len; 299 netisr_queue(isr, m); /* mbuf is free'd on failure. */ 300 return (0); 301 } 302 303 /* ARGSUSED */ 304 static void 305 lortrequest(int cmd, struct rtentry *rt, struct rt_addrinfo *info) 306 { 307 308 RT_LOCK_ASSERT(rt); 309 rt->rt_rmx.rmx_mtu = rt->rt_ifp->if_mtu; 310 } 311 312 /* 313 * Process an ioctl request. 314 */ 315 /* ARGSUSED */ 316 int 317 loioctl(struct ifnet *ifp, u_long cmd, caddr_t data) 318 { 319 struct ifaddr *ifa; 320 struct ifreq *ifr = (struct ifreq *)data; 321 int error = 0; 322 323 switch (cmd) { 324 case SIOCSIFADDR: 325 ifp->if_flags |= IFF_UP; 326 ifp->if_drv_flags |= IFF_DRV_RUNNING; 327 ifa = (struct ifaddr *)data; 328 ifa->ifa_rtrequest = lortrequest; 329 /* 330 * Everything else is done at a higher level. 331 */ 332 break; 333 334 case SIOCADDMULTI: 335 case SIOCDELMULTI: 336 if (ifr == 0) { 337 error = EAFNOSUPPORT; /* XXX */ 338 break; 339 } 340 switch (ifr->ifr_addr.sa_family) { 341 342 #ifdef INET 343 case AF_INET: 344 break; 345 #endif 346 #ifdef INET6 347 case AF_INET6: 348 break; 349 #endif 350 351 default: 352 error = EAFNOSUPPORT; 353 break; 354 } 355 break; 356 357 case SIOCSIFMTU: 358 ifp->if_mtu = ifr->ifr_mtu; 359 break; 360 361 case SIOCSIFFLAGS: 362 break; 363 364 default: 365 error = EINVAL; 366 } 367 return (error); 368 } 369