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_FEATURES6 (CSUM_TCP_IPV6 | CSUM_UDP_IPV6 | CSUM_SCTP_IPV6) 96 #define LO_CSUM_SET (CSUM_DATA_VALID | CSUM_DATA_VALID_IPV6 | \ 97 CSUM_PSEUDO_HDR | \ 98 CSUM_IP_CHECKED | CSUM_IP_VALID | \ 99 CSUM_SCTP_VALID) 100 101 int loioctl(struct ifnet *, u_long, caddr_t); 102 static void lortrequest(int, struct rtentry *, struct rt_addrinfo *); 103 int looutput(struct ifnet *ifp, struct mbuf *m, 104 struct sockaddr *dst, struct route *ro); 105 static int lo_clone_create(struct if_clone *, int, caddr_t); 106 static void lo_clone_destroy(struct ifnet *); 107 108 VNET_DEFINE(struct ifnet *, loif); /* Used externally */ 109 110 #ifdef VIMAGE 111 static VNET_DEFINE(struct ifc_simple_data, lo_cloner_data); 112 static VNET_DEFINE(struct if_clone, lo_cloner); 113 #define V_lo_cloner_data VNET(lo_cloner_data) 114 #define V_lo_cloner VNET(lo_cloner) 115 #endif 116 117 IFC_SIMPLE_DECLARE(lo, 1); 118 119 static void 120 lo_clone_destroy(struct ifnet *ifp) 121 { 122 123 #ifndef VIMAGE 124 /* XXX: destroying lo0 will lead to panics. */ 125 KASSERT(V_loif != ifp, ("%s: destroying lo0", __func__)); 126 #endif 127 128 bpfdetach(ifp); 129 if_detach(ifp); 130 if_free(ifp); 131 } 132 133 static int 134 lo_clone_create(struct if_clone *ifc, int unit, caddr_t params) 135 { 136 struct ifnet *ifp; 137 138 ifp = if_alloc(IFT_LOOP); 139 if (ifp == NULL) 140 return (ENOSPC); 141 142 if_initname(ifp, ifc->ifc_name, unit); 143 ifp->if_mtu = LOMTU; 144 ifp->if_flags = IFF_LOOPBACK | IFF_MULTICAST; 145 ifp->if_ioctl = loioctl; 146 ifp->if_output = looutput; 147 ifp->if_snd.ifq_maxlen = ifqmaxlen; 148 ifp->if_capabilities = ifp->if_capenable = 149 IFCAP_HWCSUM | IFCAP_HWCSUM_IPV6; 150 ifp->if_hwassist = LO_CSUM_FEATURES | LO_CSUM_FEATURES6; 151 if_attach(ifp); 152 bpfattach(ifp, DLT_NULL, sizeof(u_int32_t)); 153 if (V_loif == NULL) 154 V_loif = ifp; 155 156 return (0); 157 } 158 159 static void 160 vnet_loif_init(const void *unused __unused) 161 { 162 163 #ifdef VIMAGE 164 V_lo_cloner = lo_cloner; 165 V_lo_cloner_data = lo_cloner_data; 166 V_lo_cloner.ifc_data = &V_lo_cloner_data; 167 if_clone_attach(&V_lo_cloner); 168 #else 169 if_clone_attach(&lo_cloner); 170 #endif 171 } 172 VNET_SYSINIT(vnet_loif_init, SI_SUB_PROTO_IFATTACHDOMAIN, SI_ORDER_ANY, 173 vnet_loif_init, NULL); 174 175 #ifdef VIMAGE 176 static void 177 vnet_loif_uninit(const void *unused __unused) 178 { 179 180 if_clone_detach(&V_lo_cloner); 181 V_loif = NULL; 182 } 183 VNET_SYSUNINIT(vnet_loif_uninit, SI_SUB_PROTO_IFATTACHDOMAIN, SI_ORDER_ANY, 184 vnet_loif_uninit, NULL); 185 #endif 186 187 static int 188 loop_modevent(module_t mod, int type, void *data) 189 { 190 191 switch (type) { 192 case MOD_LOAD: 193 break; 194 195 case MOD_UNLOAD: 196 printf("loop module unload - not possible for this module type\n"); 197 return (EINVAL); 198 199 default: 200 return (EOPNOTSUPP); 201 } 202 return (0); 203 } 204 205 static moduledata_t loop_mod = { 206 "if_lo", 207 loop_modevent, 208 0 209 }; 210 211 DECLARE_MODULE(if_lo, loop_mod, SI_SUB_PROTO_IFATTACHDOMAIN, SI_ORDER_ANY); 212 213 int 214 looutput(struct ifnet *ifp, struct mbuf *m, struct sockaddr *dst, 215 struct route *ro) 216 { 217 u_int32_t af; 218 struct rtentry *rt = NULL; 219 #ifdef MAC 220 int error; 221 #endif 222 223 M_ASSERTPKTHDR(m); /* check if we have the packet header */ 224 225 if (ro != NULL) 226 rt = ro->ro_rt; 227 #ifdef MAC 228 error = mac_ifnet_check_transmit(ifp, m); 229 if (error) { 230 m_freem(m); 231 return (error); 232 } 233 #endif 234 235 if (rt && rt->rt_flags & (RTF_REJECT|RTF_BLACKHOLE)) { 236 m_freem(m); 237 return (rt->rt_flags & RTF_BLACKHOLE ? 0 : 238 rt->rt_flags & RTF_HOST ? EHOSTUNREACH : ENETUNREACH); 239 } 240 241 ifp->if_opackets++; 242 ifp->if_obytes += m->m_pkthdr.len; 243 244 /* BPF writes need to be handled specially. */ 245 if (dst->sa_family == AF_UNSPEC) { 246 bcopy(dst->sa_data, &af, sizeof(af)); 247 dst->sa_family = af; 248 } 249 250 #if 1 /* XXX */ 251 switch (dst->sa_family) { 252 case AF_INET: 253 if (ifp->if_capenable & IFCAP_RXCSUM) { 254 m->m_pkthdr.csum_data = 0xffff; 255 m->m_pkthdr.csum_flags = LO_CSUM_SET; 256 } 257 m->m_pkthdr.csum_flags &= ~LO_CSUM_FEATURES; 258 break; 259 case AF_INET6: 260 if (ifp->if_capenable & IFCAP_RXCSUM_IPV6) { 261 m->m_pkthdr.csum_data = 0xffff; 262 m->m_pkthdr.csum_flags = LO_CSUM_SET; 263 } 264 m->m_pkthdr.csum_flags &= ~LO_CSUM_FEATURES6; 265 break; 266 case AF_IPX: 267 case AF_APPLETALK: 268 break; 269 default: 270 printf("looutput: af=%d unexpected\n", dst->sa_family); 271 m_freem(m); 272 return (EAFNOSUPPORT); 273 } 274 #endif 275 return (if_simloop(ifp, m, dst->sa_family, 0)); 276 } 277 278 /* 279 * if_simloop() 280 * 281 * This function is to support software emulation of hardware loopback, 282 * i.e., for interfaces with the IFF_SIMPLEX attribute. Since they can't 283 * hear their own broadcasts, we create a copy of the packet that we 284 * would normally receive via a hardware loopback. 285 * 286 * This function expects the packet to include the media header of length hlen. 287 */ 288 int 289 if_simloop(struct ifnet *ifp, struct mbuf *m, int af, int hlen) 290 { 291 int isr; 292 293 M_ASSERTPKTHDR(m); 294 m_tag_delete_nonpersistent(m); 295 m->m_pkthdr.rcvif = ifp; 296 297 #ifdef MAC 298 mac_ifnet_create_mbuf(ifp, m); 299 #endif 300 301 /* 302 * Let BPF see incoming packet in the following manner: 303 * - Emulated packet loopback for a simplex interface 304 * (net/if_ethersubr.c) 305 * -> passes it to ifp's BPF 306 * - IPv4/v6 multicast packet loopback (netinet(6)/ip(6)_output.c) 307 * -> not passes it to any BPF 308 * - Normal packet loopback from myself to myself (net/if_loop.c) 309 * -> passes to lo0's BPF (even in case of IPv6, where ifp!=lo0) 310 */ 311 if (hlen > 0) { 312 if (bpf_peers_present(ifp->if_bpf)) { 313 bpf_mtap(ifp->if_bpf, m); 314 } 315 } else { 316 if (bpf_peers_present(V_loif->if_bpf)) { 317 if ((m->m_flags & M_MCAST) == 0 || V_loif == ifp) { 318 /* XXX beware sizeof(af) != 4 */ 319 u_int32_t af1 = af; 320 321 /* 322 * We need to prepend the address family. 323 */ 324 bpf_mtap2(V_loif->if_bpf, &af1, sizeof(af1), m); 325 } 326 } 327 } 328 329 /* Strip away media header */ 330 if (hlen > 0) { 331 m_adj(m, hlen); 332 #ifndef __NO_STRICT_ALIGNMENT 333 /* 334 * Some archs do not like unaligned data, so 335 * we move data down in the first mbuf. 336 */ 337 if (mtod(m, vm_offset_t) & 3) { 338 KASSERT(hlen >= 3, ("if_simloop: hlen too small")); 339 bcopy(m->m_data, 340 (char *)(mtod(m, vm_offset_t) 341 - (mtod(m, vm_offset_t) & 3)), 342 m->m_len); 343 m->m_data -= (mtod(m,vm_offset_t) & 3); 344 } 345 #endif 346 } 347 348 /* Deliver to upper layer protocol */ 349 switch (af) { 350 #ifdef INET 351 case AF_INET: 352 isr = NETISR_IP; 353 break; 354 #endif 355 #ifdef INET6 356 case AF_INET6: 357 m->m_flags |= M_LOOP; 358 isr = NETISR_IPV6; 359 break; 360 #endif 361 #ifdef IPX 362 case AF_IPX: 363 isr = NETISR_IPX; 364 break; 365 #endif 366 #ifdef NETATALK 367 case AF_APPLETALK: 368 isr = NETISR_ATALK2; 369 break; 370 #endif 371 default: 372 printf("if_simloop: can't handle af=%d\n", af); 373 m_freem(m); 374 return (EAFNOSUPPORT); 375 } 376 ifp->if_ipackets++; 377 ifp->if_ibytes += m->m_pkthdr.len; 378 netisr_queue(isr, m); /* mbuf is free'd on failure. */ 379 return (0); 380 } 381 382 /* ARGSUSED */ 383 static void 384 lortrequest(int cmd, struct rtentry *rt, struct rt_addrinfo *info) 385 { 386 387 RT_LOCK_ASSERT(rt); 388 rt->rt_rmx.rmx_mtu = rt->rt_ifp->if_mtu; 389 } 390 391 /* 392 * Process an ioctl request. 393 */ 394 /* ARGSUSED */ 395 int 396 loioctl(struct ifnet *ifp, u_long cmd, caddr_t data) 397 { 398 struct ifaddr *ifa; 399 struct ifreq *ifr = (struct ifreq *)data; 400 int error = 0, mask; 401 402 switch (cmd) { 403 case SIOCSIFADDR: 404 ifp->if_flags |= IFF_UP; 405 ifp->if_drv_flags |= IFF_DRV_RUNNING; 406 ifa = (struct ifaddr *)data; 407 ifa->ifa_rtrequest = lortrequest; 408 /* 409 * Everything else is done at a higher level. 410 */ 411 break; 412 413 case SIOCADDMULTI: 414 case SIOCDELMULTI: 415 if (ifr == 0) { 416 error = EAFNOSUPPORT; /* XXX */ 417 break; 418 } 419 switch (ifr->ifr_addr.sa_family) { 420 421 #ifdef INET 422 case AF_INET: 423 break; 424 #endif 425 #ifdef INET6 426 case AF_INET6: 427 break; 428 #endif 429 430 default: 431 error = EAFNOSUPPORT; 432 break; 433 } 434 break; 435 436 case SIOCSIFMTU: 437 ifp->if_mtu = ifr->ifr_mtu; 438 break; 439 440 case SIOCSIFFLAGS: 441 break; 442 443 case SIOCSIFCAP: 444 mask = ifp->if_capenable ^ ifr->ifr_reqcap; 445 if ((mask & IFCAP_RXCSUM) != 0) 446 ifp->if_capenable ^= IFCAP_RXCSUM; 447 if ((mask & IFCAP_TXCSUM) != 0) 448 ifp->if_capenable ^= IFCAP_TXCSUM; 449 if ((mask & IFCAP_RXCSUM_IPV6) != 0) 450 ifp->if_capenable ^= IFCAP_RXCSUM_IPV6; 451 if ((mask & IFCAP_TXCSUM_IPV6) != 0) 452 ifp->if_capenable ^= IFCAP_TXCSUM_IPV6; 453 ifp->if_hwassist = 0; 454 if (ifp->if_capenable & IFCAP_TXCSUM) 455 ifp->if_hwassist = LO_CSUM_FEATURES; 456 if (ifp->if_capenable & IFCAP_TXCSUM_IPV6) 457 ifp->if_hwassist |= LO_CSUM_FEATURES6; 458 break; 459 460 default: 461 error = EINVAL; 462 } 463 return (error); 464 } 465