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 #include <net/vnet.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 #include <security/mac/mac_framework.h> 85 86 #ifdef TINY_LOMTU 87 #define LOMTU (1024+512) 88 #elif defined(LARGE_LOMTU) 89 #define LOMTU 131072 90 #else 91 #define LOMTU 16384 92 #endif 93 94 #define LO_CSUM_FEATURES (CSUM_IP | CSUM_TCP | CSUM_UDP | CSUM_SCTP) 95 #define LO_CSUM_SET (CSUM_DATA_VALID | CSUM_PSEUDO_HDR | \ 96 CSUM_IP_CHECKED | CSUM_IP_VALID | \ 97 CSUM_SCTP_VALID) 98 99 int loioctl(struct ifnet *, u_long, caddr_t); 100 static void lortrequest(int, struct rtentry *, struct rt_addrinfo *); 101 int looutput(struct ifnet *ifp, struct mbuf *m, 102 struct sockaddr *dst, struct route *ro); 103 static int lo_clone_create(struct if_clone *, int, caddr_t); 104 static void lo_clone_destroy(struct ifnet *); 105 106 VNET_DEFINE(struct ifnet *, loif); /* Used externally */ 107 108 #ifdef VIMAGE 109 static VNET_DEFINE(struct ifc_simple_data, lo_cloner_data); 110 static VNET_DEFINE(struct if_clone, lo_cloner); 111 #define V_lo_cloner_data VNET(lo_cloner_data) 112 #define V_lo_cloner VNET(lo_cloner) 113 #endif 114 115 IFC_SIMPLE_DECLARE(lo, 1); 116 117 static void 118 lo_clone_destroy(struct ifnet *ifp) 119 { 120 121 #ifndef VIMAGE 122 /* XXX: destroying lo0 will lead to panics. */ 123 KASSERT(V_loif != ifp, ("%s: destroying lo0", __func__)); 124 #endif 125 126 bpfdetach(ifp); 127 if_detach(ifp); 128 if_free(ifp); 129 } 130 131 static int 132 lo_clone_create(struct if_clone *ifc, int unit, caddr_t params) 133 { 134 struct ifnet *ifp; 135 136 ifp = if_alloc(IFT_LOOP); 137 if (ifp == NULL) 138 return (ENOSPC); 139 140 if_initname(ifp, ifc->ifc_name, unit); 141 ifp->if_mtu = LOMTU; 142 ifp->if_flags = IFF_LOOPBACK | IFF_MULTICAST; 143 ifp->if_ioctl = loioctl; 144 ifp->if_output = looutput; 145 ifp->if_snd.ifq_maxlen = ifqmaxlen; 146 ifp->if_capabilities = ifp->if_capenable = IFCAP_HWCSUM; 147 ifp->if_hwassist = LO_CSUM_FEATURES; 148 if_attach(ifp); 149 bpfattach(ifp, DLT_NULL, sizeof(u_int32_t)); 150 if (V_loif == NULL) 151 V_loif = ifp; 152 153 return (0); 154 } 155 156 static void 157 vnet_loif_init(const void *unused __unused) 158 { 159 160 #ifdef VIMAGE 161 V_lo_cloner = lo_cloner; 162 V_lo_cloner_data = lo_cloner_data; 163 V_lo_cloner.ifc_data = &V_lo_cloner_data; 164 if_clone_attach(&V_lo_cloner); 165 #else 166 if_clone_attach(&lo_cloner); 167 #endif 168 } 169 VNET_SYSINIT(vnet_loif_init, SI_SUB_PROTO_IFATTACHDOMAIN, SI_ORDER_ANY, 170 vnet_loif_init, NULL); 171 172 #ifdef VIMAGE 173 static void 174 vnet_loif_uninit(const void *unused __unused) 175 { 176 177 if_clone_detach(&V_lo_cloner); 178 V_loif = NULL; 179 } 180 VNET_SYSUNINIT(vnet_loif_uninit, SI_SUB_PROTO_IFATTACHDOMAIN, SI_ORDER_ANY, 181 vnet_loif_uninit, NULL); 182 #endif 183 184 static int 185 loop_modevent(module_t mod, int type, void *data) 186 { 187 188 switch (type) { 189 case MOD_LOAD: 190 break; 191 192 case MOD_UNLOAD: 193 printf("loop module unload - not possible for this module type\n"); 194 return (EINVAL); 195 196 default: 197 return (EOPNOTSUPP); 198 } 199 return (0); 200 } 201 202 static moduledata_t loop_mod = { 203 "if_lo", 204 loop_modevent, 205 0 206 }; 207 208 DECLARE_MODULE(if_lo, loop_mod, SI_SUB_PROTO_IFATTACHDOMAIN, SI_ORDER_ANY); 209 210 int 211 looutput(struct ifnet *ifp, struct mbuf *m, struct sockaddr *dst, 212 struct route *ro) 213 { 214 u_int32_t af; 215 struct rtentry *rt = NULL; 216 #ifdef MAC 217 int error; 218 #endif 219 220 M_ASSERTPKTHDR(m); /* check if we have the packet header */ 221 222 if (ro != NULL) 223 rt = ro->ro_rt; 224 #ifdef MAC 225 error = mac_ifnet_check_transmit(ifp, m); 226 if (error) { 227 m_freem(m); 228 return (error); 229 } 230 #endif 231 232 if (rt && rt->rt_flags & (RTF_REJECT|RTF_BLACKHOLE)) { 233 m_freem(m); 234 return (rt->rt_flags & RTF_BLACKHOLE ? 0 : 235 rt->rt_flags & RTF_HOST ? EHOSTUNREACH : ENETUNREACH); 236 } 237 238 ifp->if_opackets++; 239 ifp->if_obytes += m->m_pkthdr.len; 240 241 /* BPF writes need to be handled specially. */ 242 if (dst->sa_family == AF_UNSPEC) { 243 bcopy(dst->sa_data, &af, sizeof(af)); 244 dst->sa_family = af; 245 } 246 247 #if 1 /* XXX */ 248 switch (dst->sa_family) { 249 case AF_INET: 250 if (ifp->if_capenable & IFCAP_RXCSUM) { 251 m->m_pkthdr.csum_data = 0xffff; 252 m->m_pkthdr.csum_flags = LO_CSUM_SET; 253 } 254 m->m_pkthdr.csum_flags &= ~LO_CSUM_FEATURES; 255 case AF_INET6: 256 case AF_IPX: 257 case AF_APPLETALK: 258 break; 259 default: 260 printf("looutput: af=%d unexpected\n", dst->sa_family); 261 m_freem(m); 262 return (EAFNOSUPPORT); 263 } 264 #endif 265 return (if_simloop(ifp, m, dst->sa_family, 0)); 266 } 267 268 /* 269 * if_simloop() 270 * 271 * This function is to support software emulation of hardware loopback, 272 * i.e., for interfaces with the IFF_SIMPLEX attribute. Since they can't 273 * hear their own broadcasts, we create a copy of the packet that we 274 * would normally receive via a hardware loopback. 275 * 276 * This function expects the packet to include the media header of length hlen. 277 */ 278 int 279 if_simloop(struct ifnet *ifp, struct mbuf *m, int af, int hlen) 280 { 281 int isr; 282 283 M_ASSERTPKTHDR(m); 284 m_tag_delete_nonpersistent(m); 285 m->m_pkthdr.rcvif = ifp; 286 287 #ifdef MAC 288 mac_ifnet_create_mbuf(ifp, m); 289 #endif 290 291 /* 292 * Let BPF see incoming packet in the following manner: 293 * - Emulated packet loopback for a simplex interface 294 * (net/if_ethersubr.c) 295 * -> passes it to ifp's BPF 296 * - IPv4/v6 multicast packet loopback (netinet(6)/ip(6)_output.c) 297 * -> not passes it to any BPF 298 * - Normal packet loopback from myself to myself (net/if_loop.c) 299 * -> passes to lo0's BPF (even in case of IPv6, where ifp!=lo0) 300 */ 301 if (hlen > 0) { 302 if (bpf_peers_present(ifp->if_bpf)) { 303 bpf_mtap(ifp->if_bpf, m); 304 } 305 } else { 306 if (bpf_peers_present(V_loif->if_bpf)) { 307 if ((m->m_flags & M_MCAST) == 0 || V_loif == ifp) { 308 /* XXX beware sizeof(af) != 4 */ 309 u_int32_t af1 = af; 310 311 /* 312 * We need to prepend the address family. 313 */ 314 bpf_mtap2(V_loif->if_bpf, &af1, sizeof(af1), m); 315 } 316 } 317 } 318 319 /* Strip away media header */ 320 if (hlen > 0) { 321 m_adj(m, hlen); 322 #ifndef __NO_STRICT_ALIGNMENT 323 /* 324 * Some archs do not like unaligned data, so 325 * we move data down in the first mbuf. 326 */ 327 if (mtod(m, vm_offset_t) & 3) { 328 KASSERT(hlen >= 3, ("if_simloop: hlen too small")); 329 bcopy(m->m_data, 330 (char *)(mtod(m, vm_offset_t) 331 - (mtod(m, vm_offset_t) & 3)), 332 m->m_len); 333 m->m_data -= (mtod(m,vm_offset_t) & 3); 334 } 335 #endif 336 } 337 338 /* Deliver to upper layer protocol */ 339 switch (af) { 340 #ifdef INET 341 case AF_INET: 342 isr = NETISR_IP; 343 break; 344 #endif 345 #ifdef INET6 346 case AF_INET6: 347 m->m_flags |= M_LOOP; 348 isr = NETISR_IPV6; 349 break; 350 #endif 351 #ifdef IPX 352 case AF_IPX: 353 isr = NETISR_IPX; 354 break; 355 #endif 356 #ifdef NETATALK 357 case AF_APPLETALK: 358 isr = NETISR_ATALK2; 359 break; 360 #endif 361 default: 362 printf("if_simloop: can't handle af=%d\n", af); 363 m_freem(m); 364 return (EAFNOSUPPORT); 365 } 366 ifp->if_ipackets++; 367 ifp->if_ibytes += m->m_pkthdr.len; 368 netisr_queue(isr, m); /* mbuf is free'd on failure. */ 369 return (0); 370 } 371 372 /* ARGSUSED */ 373 static void 374 lortrequest(int cmd, struct rtentry *rt, struct rt_addrinfo *info) 375 { 376 377 RT_LOCK_ASSERT(rt); 378 rt->rt_rmx.rmx_mtu = rt->rt_ifp->if_mtu; 379 } 380 381 /* 382 * Process an ioctl request. 383 */ 384 /* ARGSUSED */ 385 int 386 loioctl(struct ifnet *ifp, u_long cmd, caddr_t data) 387 { 388 struct ifaddr *ifa; 389 struct ifreq *ifr = (struct ifreq *)data; 390 int error = 0, mask; 391 392 switch (cmd) { 393 case SIOCSIFADDR: 394 ifp->if_flags |= IFF_UP; 395 ifp->if_drv_flags |= IFF_DRV_RUNNING; 396 ifa = (struct ifaddr *)data; 397 ifa->ifa_rtrequest = lortrequest; 398 /* 399 * Everything else is done at a higher level. 400 */ 401 break; 402 403 case SIOCADDMULTI: 404 case SIOCDELMULTI: 405 if (ifr == 0) { 406 error = EAFNOSUPPORT; /* XXX */ 407 break; 408 } 409 switch (ifr->ifr_addr.sa_family) { 410 411 #ifdef INET 412 case AF_INET: 413 break; 414 #endif 415 #ifdef INET6 416 case AF_INET6: 417 break; 418 #endif 419 420 default: 421 error = EAFNOSUPPORT; 422 break; 423 } 424 break; 425 426 case SIOCSIFMTU: 427 ifp->if_mtu = ifr->ifr_mtu; 428 break; 429 430 case SIOCSIFFLAGS: 431 break; 432 433 case SIOCSIFCAP: 434 mask = ifp->if_capenable ^ ifr->ifr_reqcap; 435 if ((mask & IFCAP_RXCSUM) != 0) 436 ifp->if_capenable ^= IFCAP_RXCSUM; 437 if ((mask & IFCAP_TXCSUM) != 0) 438 ifp->if_capenable ^= IFCAP_TXCSUM; 439 if (ifp->if_capenable & IFCAP_TXCSUM) 440 ifp->if_hwassist = LO_CSUM_FEATURES; 441 else 442 ifp->if_hwassist = 0; 443 break; 444 445 default: 446 error = EINVAL; 447 } 448 return (error); 449 } 450