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_inet.h" 38 #include "opt_inet6.h" 39 40 #include <sys/param.h> 41 #include <sys/systm.h> 42 #include <sys/kernel.h> 43 #include <sys/mbuf.h> 44 #include <sys/module.h> 45 #include <machine/bus.h> 46 #include <sys/rman.h> 47 #include <sys/socket.h> 48 #include <sys/sockio.h> 49 #include <sys/sysctl.h> 50 51 #include <net/if.h> 52 #include <net/if_var.h> 53 #include <net/if_clone.h> 54 #include <net/if_types.h> 55 #include <net/netisr.h> 56 #include <net/route.h> 57 #include <net/route_internal.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 INET6 67 #ifndef INET 68 #include <netinet/in.h> 69 #endif 70 #include <netinet6/in6_var.h> 71 #include <netinet/ip6.h> 72 #endif 73 74 #include <security/mac/mac_framework.h> 75 76 #ifdef TINY_LOMTU 77 #define LOMTU (1024+512) 78 #elif defined(LARGE_LOMTU) 79 #define LOMTU 131072 80 #else 81 #define LOMTU 16384 82 #endif 83 84 #define LO_CSUM_FEATURES (CSUM_IP | CSUM_TCP | CSUM_UDP | CSUM_SCTP) 85 #define LO_CSUM_FEATURES6 (CSUM_TCP_IPV6 | CSUM_UDP_IPV6 | CSUM_SCTP_IPV6) 86 #define LO_CSUM_SET (CSUM_DATA_VALID | CSUM_DATA_VALID_IPV6 | \ 87 CSUM_PSEUDO_HDR | \ 88 CSUM_IP_CHECKED | CSUM_IP_VALID | \ 89 CSUM_SCTP_VALID) 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 const struct sockaddr *dst, struct route *ro); 95 static int lo_clone_create(struct if_clone *, int, caddr_t); 96 static void lo_clone_destroy(struct ifnet *); 97 98 VNET_DEFINE(struct ifnet *, loif); /* Used externally */ 99 100 #ifdef VIMAGE 101 static VNET_DEFINE(struct if_clone *, lo_cloner); 102 #define V_lo_cloner VNET(lo_cloner) 103 #endif 104 105 static struct if_clone *lo_cloner; 106 static const char loname[] = "lo"; 107 108 static void 109 lo_clone_destroy(struct ifnet *ifp) 110 { 111 112 #ifndef VIMAGE 113 /* XXX: destroying lo0 will lead to panics. */ 114 KASSERT(V_loif != ifp, ("%s: destroying lo0", __func__)); 115 #endif 116 117 bpfdetach(ifp); 118 if_detach(ifp); 119 if_free(ifp); 120 } 121 122 static int 123 lo_clone_create(struct if_clone *ifc, int unit, caddr_t params) 124 { 125 struct ifnet *ifp; 126 127 ifp = if_alloc(IFT_LOOP); 128 if (ifp == NULL) 129 return (ENOSPC); 130 131 if_initname(ifp, loname, unit); 132 ifp->if_mtu = LOMTU; 133 ifp->if_flags = IFF_LOOPBACK | IFF_MULTICAST; 134 ifp->if_ioctl = loioctl; 135 ifp->if_output = looutput; 136 ifp->if_snd.ifq_maxlen = ifqmaxlen; 137 ifp->if_capabilities = ifp->if_capenable = 138 IFCAP_HWCSUM | IFCAP_HWCSUM_IPV6; 139 ifp->if_hwassist = LO_CSUM_FEATURES | LO_CSUM_FEATURES6; 140 if_attach(ifp); 141 bpfattach(ifp, DLT_NULL, sizeof(u_int32_t)); 142 if (V_loif == NULL) 143 V_loif = ifp; 144 145 return (0); 146 } 147 148 static void 149 vnet_loif_init(const void *unused __unused) 150 { 151 152 #ifdef VIMAGE 153 lo_cloner = if_clone_simple(loname, lo_clone_create, lo_clone_destroy, 154 1); 155 V_lo_cloner = lo_cloner; 156 #else 157 lo_cloner = if_clone_simple(loname, lo_clone_create, lo_clone_destroy, 158 1); 159 #endif 160 } 161 VNET_SYSINIT(vnet_loif_init, SI_SUB_PROTO_IFATTACHDOMAIN, SI_ORDER_ANY, 162 vnet_loif_init, NULL); 163 164 #ifdef VIMAGE 165 static void 166 vnet_loif_uninit(const void *unused __unused) 167 { 168 169 if_clone_detach(V_lo_cloner); 170 V_loif = NULL; 171 } 172 VNET_SYSUNINIT(vnet_loif_uninit, SI_SUB_PROTO_IFATTACHDOMAIN, SI_ORDER_ANY, 173 vnet_loif_uninit, NULL); 174 #endif 175 176 static int 177 loop_modevent(module_t mod, int type, void *data) 178 { 179 180 switch (type) { 181 case MOD_LOAD: 182 break; 183 184 case MOD_UNLOAD: 185 printf("loop module unload - not possible for this module type\n"); 186 return (EINVAL); 187 188 default: 189 return (EOPNOTSUPP); 190 } 191 return (0); 192 } 193 194 static moduledata_t loop_mod = { 195 "if_lo", 196 loop_modevent, 197 0 198 }; 199 200 DECLARE_MODULE(if_lo, loop_mod, SI_SUB_PROTO_IFATTACHDOMAIN, SI_ORDER_ANY); 201 202 int 203 looutput(struct ifnet *ifp, struct mbuf *m, const struct sockaddr *dst, 204 struct route *ro) 205 { 206 u_int32_t af; 207 struct rtentry *rt = NULL; 208 #ifdef MAC 209 int error; 210 #endif 211 212 M_ASSERTPKTHDR(m); /* check if we have the packet header */ 213 214 if (ro != NULL) 215 rt = ro->ro_rt; 216 #ifdef MAC 217 error = mac_ifnet_check_transmit(ifp, m); 218 if (error) { 219 m_freem(m); 220 return (error); 221 } 222 #endif 223 224 if (rt && rt->rt_flags & (RTF_REJECT|RTF_BLACKHOLE)) { 225 m_freem(m); 226 return (rt->rt_flags & RTF_BLACKHOLE ? 0 : 227 rt->rt_flags & RTF_HOST ? EHOSTUNREACH : ENETUNREACH); 228 } 229 230 if_inc_counter(ifp, IFCOUNTER_OPACKETS, 1); 231 if_inc_counter(ifp, IFCOUNTER_OBYTES, m->m_pkthdr.len); 232 233 /* BPF writes need to be handled specially. */ 234 if (dst->sa_family == AF_UNSPEC) 235 bcopy(dst->sa_data, &af, sizeof(af)); 236 else 237 af = dst->sa_family; 238 239 #if 1 /* XXX */ 240 switch (af) { 241 case AF_INET: 242 if (ifp->if_capenable & IFCAP_RXCSUM) { 243 m->m_pkthdr.csum_data = 0xffff; 244 m->m_pkthdr.csum_flags = LO_CSUM_SET; 245 } 246 m->m_pkthdr.csum_flags &= ~LO_CSUM_FEATURES; 247 break; 248 case AF_INET6: 249 #if 0 250 /* 251 * XXX-BZ for now always claim the checksum is good despite 252 * any interface flags. This is a workaround for 9.1-R and 253 * a proper solution ought to be sought later. 254 */ 255 if (ifp->if_capenable & IFCAP_RXCSUM_IPV6) { 256 m->m_pkthdr.csum_data = 0xffff; 257 m->m_pkthdr.csum_flags = LO_CSUM_SET; 258 } 259 #else 260 m->m_pkthdr.csum_data = 0xffff; 261 m->m_pkthdr.csum_flags = LO_CSUM_SET; 262 #endif 263 m->m_pkthdr.csum_flags &= ~LO_CSUM_FEATURES6; 264 break; 265 default: 266 printf("looutput: af=%d unexpected\n", af); 267 m_freem(m); 268 return (EAFNOSUPPORT); 269 } 270 #endif 271 return (if_simloop(ifp, m, af, 0)); 272 } 273 274 /* 275 * if_simloop() 276 * 277 * This function is to support software emulation of hardware loopback, 278 * i.e., for interfaces with the IFF_SIMPLEX attribute. Since they can't 279 * hear their own broadcasts, we create a copy of the packet that we 280 * would normally receive via a hardware loopback. 281 * 282 * This function expects the packet to include the media header of length hlen. 283 */ 284 int 285 if_simloop(struct ifnet *ifp, struct mbuf *m, int af, int hlen) 286 { 287 int isr; 288 289 M_ASSERTPKTHDR(m); 290 m_tag_delete_nonpersistent(m); 291 m->m_pkthdr.rcvif = ifp; 292 293 #ifdef MAC 294 mac_ifnet_create_mbuf(ifp, m); 295 #endif 296 297 /* 298 * Let BPF see incoming packet in the following manner: 299 * - Emulated packet loopback for a simplex interface 300 * (net/if_ethersubr.c) 301 * -> passes it to ifp's BPF 302 * - IPv4/v6 multicast packet loopback (netinet(6)/ip(6)_output.c) 303 * -> not passes it to any BPF 304 * - Normal packet loopback from myself to myself (net/if_loop.c) 305 * -> passes to lo0's BPF (even in case of IPv6, where ifp!=lo0) 306 */ 307 if (hlen > 0) { 308 if (bpf_peers_present(ifp->if_bpf)) { 309 bpf_mtap(ifp->if_bpf, m); 310 } 311 } else { 312 if (bpf_peers_present(V_loif->if_bpf)) { 313 if ((m->m_flags & M_MCAST) == 0 || V_loif == ifp) { 314 /* XXX beware sizeof(af) != 4 */ 315 u_int32_t af1 = af; 316 317 /* 318 * We need to prepend the address family. 319 */ 320 bpf_mtap2(V_loif->if_bpf, &af1, sizeof(af1), m); 321 } 322 } 323 } 324 325 /* Strip away media header */ 326 if (hlen > 0) { 327 m_adj(m, hlen); 328 #ifndef __NO_STRICT_ALIGNMENT 329 /* 330 * Some archs do not like unaligned data, so 331 * we move data down in the first mbuf. 332 */ 333 if (mtod(m, vm_offset_t) & 3) { 334 KASSERT(hlen >= 3, ("if_simloop: hlen too small")); 335 bcopy(m->m_data, 336 (char *)(mtod(m, vm_offset_t) 337 - (mtod(m, vm_offset_t) & 3)), 338 m->m_len); 339 m->m_data -= (mtod(m,vm_offset_t) & 3); 340 } 341 #endif 342 } 343 344 /* Deliver to upper layer protocol */ 345 switch (af) { 346 #ifdef INET 347 case AF_INET: 348 isr = NETISR_IP; 349 break; 350 #endif 351 #ifdef INET6 352 case AF_INET6: 353 m->m_flags |= M_LOOP; 354 isr = NETISR_IPV6; 355 break; 356 #endif 357 default: 358 printf("if_simloop: can't handle af=%d\n", af); 359 m_freem(m); 360 return (EAFNOSUPPORT); 361 } 362 if_inc_counter(ifp, IFCOUNTER_IPACKETS, 1); 363 if_inc_counter(ifp, IFCOUNTER_IBYTES, m->m_pkthdr.len); 364 netisr_queue(isr, m); /* mbuf is free'd on failure. */ 365 return (0); 366 } 367 368 /* ARGSUSED */ 369 static void 370 lortrequest(int cmd, struct rtentry *rt, struct rt_addrinfo *info) 371 { 372 373 RT_LOCK_ASSERT(rt); 374 rt->rt_mtu = rt->rt_ifp->if_mtu; 375 } 376 377 /* 378 * Process an ioctl request. 379 */ 380 /* ARGSUSED */ 381 int 382 loioctl(struct ifnet *ifp, u_long cmd, caddr_t data) 383 { 384 struct ifaddr *ifa; 385 struct ifreq *ifr = (struct ifreq *)data; 386 int error = 0, mask; 387 388 switch (cmd) { 389 case SIOCSIFADDR: 390 ifp->if_flags |= IFF_UP; 391 ifp->if_drv_flags |= IFF_DRV_RUNNING; 392 ifa = (struct ifaddr *)data; 393 ifa->ifa_rtrequest = lortrequest; 394 /* 395 * Everything else is done at a higher level. 396 */ 397 break; 398 399 case SIOCADDMULTI: 400 case SIOCDELMULTI: 401 if (ifr == 0) { 402 error = EAFNOSUPPORT; /* XXX */ 403 break; 404 } 405 switch (ifr->ifr_addr.sa_family) { 406 407 #ifdef INET 408 case AF_INET: 409 break; 410 #endif 411 #ifdef INET6 412 case AF_INET6: 413 break; 414 #endif 415 416 default: 417 error = EAFNOSUPPORT; 418 break; 419 } 420 break; 421 422 case SIOCSIFMTU: 423 ifp->if_mtu = ifr->ifr_mtu; 424 break; 425 426 case SIOCSIFFLAGS: 427 break; 428 429 case SIOCSIFCAP: 430 mask = ifp->if_capenable ^ ifr->ifr_reqcap; 431 if ((mask & IFCAP_RXCSUM) != 0) 432 ifp->if_capenable ^= IFCAP_RXCSUM; 433 if ((mask & IFCAP_TXCSUM) != 0) 434 ifp->if_capenable ^= IFCAP_TXCSUM; 435 if ((mask & IFCAP_RXCSUM_IPV6) != 0) { 436 #if 0 437 ifp->if_capenable ^= IFCAP_RXCSUM_IPV6; 438 #else 439 error = EOPNOTSUPP; 440 break; 441 #endif 442 } 443 if ((mask & IFCAP_TXCSUM_IPV6) != 0) { 444 #if 0 445 ifp->if_capenable ^= IFCAP_TXCSUM_IPV6; 446 #else 447 error = EOPNOTSUPP; 448 break; 449 #endif 450 } 451 ifp->if_hwassist = 0; 452 if (ifp->if_capenable & IFCAP_TXCSUM) 453 ifp->if_hwassist = LO_CSUM_FEATURES; 454 #if 0 455 if (ifp->if_capenable & IFCAP_TXCSUM_IPV6) 456 ifp->if_hwassist |= LO_CSUM_FEATURES6; 457 #endif 458 break; 459 460 default: 461 error = EINVAL; 462 } 463 return (error); 464 } 465