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/bpf.h> 58 #include <net/vnet.h> 59 60 #ifdef INET 61 #include <netinet/in.h> 62 #include <netinet/in_var.h> 63 #endif 64 65 #ifdef INET6 66 #ifndef INET 67 #include <netinet/in.h> 68 #endif 69 #include <netinet6/in6_var.h> 70 #include <netinet/ip6.h> 71 #endif 72 73 #include <security/mac/mac_framework.h> 74 75 #ifdef TINY_LOMTU 76 #define LOMTU (1024+512) 77 #elif defined(LARGE_LOMTU) 78 #define LOMTU 131072 79 #else 80 #define LOMTU 16384 81 #endif 82 83 #define LO_CSUM_FEATURES (CSUM_IP | CSUM_TCP | CSUM_UDP | CSUM_SCTP) 84 #define LO_CSUM_FEATURES6 (CSUM_TCP_IPV6 | CSUM_UDP_IPV6 | CSUM_SCTP_IPV6) 85 #define LO_CSUM_SET (CSUM_DATA_VALID | CSUM_DATA_VALID_IPV6 | \ 86 CSUM_PSEUDO_HDR | \ 87 CSUM_IP_CHECKED | CSUM_IP_VALID | \ 88 CSUM_SCTP_VALID) 89 90 int loioctl(struct ifnet *, u_long, caddr_t); 91 static void lortrequest(int, struct rtentry *, struct rt_addrinfo *); 92 int looutput(struct ifnet *ifp, struct mbuf *m, 93 const struct sockaddr *dst, struct route *ro); 94 static int lo_clone_create(struct if_clone *, int, caddr_t); 95 static void lo_clone_destroy(struct ifnet *); 96 97 VNET_DEFINE(struct ifnet *, loif); /* Used externally */ 98 99 #ifdef VIMAGE 100 static VNET_DEFINE(struct if_clone *, lo_cloner); 101 #define V_lo_cloner VNET(lo_cloner) 102 #endif 103 104 static struct if_clone *lo_cloner; 105 static const char loname[] = "lo"; 106 107 static void 108 lo_clone_destroy(struct ifnet *ifp) 109 { 110 111 #ifndef VIMAGE 112 /* XXX: destroying lo0 will lead to panics. */ 113 KASSERT(V_loif != ifp, ("%s: destroying lo0", __func__)); 114 #endif 115 116 bpfdetach(ifp); 117 if_detach(ifp); 118 if_free(ifp); 119 } 120 121 static int 122 lo_clone_create(struct if_clone *ifc, int unit, caddr_t params) 123 { 124 struct ifnet *ifp; 125 126 ifp = if_alloc(IFT_LOOP); 127 if (ifp == NULL) 128 return (ENOSPC); 129 130 if_initname(ifp, loname, unit); 131 ifp->if_mtu = LOMTU; 132 ifp->if_flags = IFF_LOOPBACK | IFF_MULTICAST; 133 ifp->if_ioctl = loioctl; 134 ifp->if_output = looutput; 135 ifp->if_snd.ifq_maxlen = ifqmaxlen; 136 ifp->if_capabilities = ifp->if_capenable = 137 IFCAP_HWCSUM | IFCAP_HWCSUM_IPV6; 138 ifp->if_hwassist = LO_CSUM_FEATURES | LO_CSUM_FEATURES6; 139 if_attach(ifp); 140 bpfattach(ifp, DLT_NULL, sizeof(u_int32_t)); 141 if (V_loif == NULL) 142 V_loif = ifp; 143 144 return (0); 145 } 146 147 static void 148 vnet_loif_init(const void *unused __unused) 149 { 150 151 #ifdef VIMAGE 152 lo_cloner = if_clone_simple(loname, lo_clone_create, lo_clone_destroy, 153 1); 154 V_lo_cloner = lo_cloner; 155 #else 156 lo_cloner = if_clone_simple(loname, lo_clone_create, lo_clone_destroy, 157 1); 158 #endif 159 } 160 VNET_SYSINIT(vnet_loif_init, SI_SUB_PROTO_IFATTACHDOMAIN, SI_ORDER_ANY, 161 vnet_loif_init, NULL); 162 163 #ifdef VIMAGE 164 static void 165 vnet_loif_uninit(const void *unused __unused) 166 { 167 168 if_clone_detach(V_lo_cloner); 169 V_loif = NULL; 170 } 171 VNET_SYSUNINIT(vnet_loif_uninit, SI_SUB_PROTO_IFATTACHDOMAIN, SI_ORDER_ANY, 172 vnet_loif_uninit, NULL); 173 #endif 174 175 static int 176 loop_modevent(module_t mod, int type, void *data) 177 { 178 179 switch (type) { 180 case MOD_LOAD: 181 break; 182 183 case MOD_UNLOAD: 184 printf("loop module unload - not possible for this module type\n"); 185 return (EINVAL); 186 187 default: 188 return (EOPNOTSUPP); 189 } 190 return (0); 191 } 192 193 static moduledata_t loop_mod = { 194 "if_lo", 195 loop_modevent, 196 0 197 }; 198 199 DECLARE_MODULE(if_lo, loop_mod, SI_SUB_PROTO_IFATTACHDOMAIN, SI_ORDER_ANY); 200 201 int 202 looutput(struct ifnet *ifp, struct mbuf *m, const struct sockaddr *dst, 203 struct route *ro) 204 { 205 u_int32_t af; 206 struct rtentry *rt = NULL; 207 #ifdef MAC 208 int error; 209 #endif 210 211 M_ASSERTPKTHDR(m); /* check if we have the packet header */ 212 213 if (ro != NULL) 214 rt = ro->ro_rt; 215 #ifdef MAC 216 error = mac_ifnet_check_transmit(ifp, m); 217 if (error) { 218 m_freem(m); 219 return (error); 220 } 221 #endif 222 223 if (rt && rt->rt_flags & (RTF_REJECT|RTF_BLACKHOLE)) { 224 m_freem(m); 225 return (rt->rt_flags & RTF_BLACKHOLE ? 0 : 226 rt->rt_flags & RTF_HOST ? EHOSTUNREACH : ENETUNREACH); 227 } 228 229 if_inc_counter(ifp, IFCOUNTER_OPACKETS, 1); 230 if_inc_counter(ifp, IFCOUNTER_OBYTES, m->m_pkthdr.len); 231 232 /* BPF writes need to be handled specially. */ 233 if (dst->sa_family == AF_UNSPEC) 234 bcopy(dst->sa_data, &af, sizeof(af)); 235 else 236 af = dst->sa_family; 237 238 #if 1 /* XXX */ 239 switch (af) { 240 case AF_INET: 241 if (ifp->if_capenable & IFCAP_RXCSUM) { 242 m->m_pkthdr.csum_data = 0xffff; 243 m->m_pkthdr.csum_flags = LO_CSUM_SET; 244 } 245 m->m_pkthdr.csum_flags &= ~LO_CSUM_FEATURES; 246 break; 247 case AF_INET6: 248 #if 0 249 /* 250 * XXX-BZ for now always claim the checksum is good despite 251 * any interface flags. This is a workaround for 9.1-R and 252 * a proper solution ought to be sought later. 253 */ 254 if (ifp->if_capenable & IFCAP_RXCSUM_IPV6) { 255 m->m_pkthdr.csum_data = 0xffff; 256 m->m_pkthdr.csum_flags = LO_CSUM_SET; 257 } 258 #else 259 m->m_pkthdr.csum_data = 0xffff; 260 m->m_pkthdr.csum_flags = LO_CSUM_SET; 261 #endif 262 m->m_pkthdr.csum_flags &= ~LO_CSUM_FEATURES6; 263 break; 264 default: 265 printf("looutput: af=%d unexpected\n", af); 266 m_freem(m); 267 return (EAFNOSUPPORT); 268 } 269 #endif 270 return (if_simloop(ifp, m, af, 0)); 271 } 272 273 /* 274 * if_simloop() 275 * 276 * This function is to support software emulation of hardware loopback, 277 * i.e., for interfaces with the IFF_SIMPLEX attribute. Since they can't 278 * hear their own broadcasts, we create a copy of the packet that we 279 * would normally receive via a hardware loopback. 280 * 281 * This function expects the packet to include the media header of length hlen. 282 */ 283 int 284 if_simloop(struct ifnet *ifp, struct mbuf *m, int af, int hlen) 285 { 286 int isr; 287 288 M_ASSERTPKTHDR(m); 289 m_tag_delete_nonpersistent(m); 290 m->m_pkthdr.rcvif = ifp; 291 292 #ifdef MAC 293 mac_ifnet_create_mbuf(ifp, m); 294 #endif 295 296 /* 297 * Let BPF see incoming packet in the following manner: 298 * - Emulated packet loopback for a simplex interface 299 * (net/if_ethersubr.c) 300 * -> passes it to ifp's BPF 301 * - IPv4/v6 multicast packet loopback (netinet(6)/ip(6)_output.c) 302 * -> not passes it to any BPF 303 * - Normal packet loopback from myself to myself (net/if_loop.c) 304 * -> passes to lo0's BPF (even in case of IPv6, where ifp!=lo0) 305 */ 306 if (hlen > 0) { 307 if (bpf_peers_present(ifp->if_bpf)) { 308 bpf_mtap(ifp->if_bpf, m); 309 } 310 } else { 311 if (bpf_peers_present(V_loif->if_bpf)) { 312 if ((m->m_flags & M_MCAST) == 0 || V_loif == ifp) { 313 /* XXX beware sizeof(af) != 4 */ 314 u_int32_t af1 = af; 315 316 /* 317 * We need to prepend the address family. 318 */ 319 bpf_mtap2(V_loif->if_bpf, &af1, sizeof(af1), m); 320 } 321 } 322 } 323 324 /* Strip away media header */ 325 if (hlen > 0) { 326 m_adj(m, hlen); 327 #ifndef __NO_STRICT_ALIGNMENT 328 /* 329 * Some archs do not like unaligned data, so 330 * we move data down in the first mbuf. 331 */ 332 if (mtod(m, vm_offset_t) & 3) { 333 KASSERT(hlen >= 3, ("if_simloop: hlen too small")); 334 bcopy(m->m_data, 335 (char *)(mtod(m, vm_offset_t) 336 - (mtod(m, vm_offset_t) & 3)), 337 m->m_len); 338 m->m_data -= (mtod(m,vm_offset_t) & 3); 339 } 340 #endif 341 } 342 343 /* Deliver to upper layer protocol */ 344 switch (af) { 345 #ifdef INET 346 case AF_INET: 347 isr = NETISR_IP; 348 break; 349 #endif 350 #ifdef INET6 351 case AF_INET6: 352 m->m_flags |= M_LOOP; 353 isr = NETISR_IPV6; 354 break; 355 #endif 356 default: 357 printf("if_simloop: can't handle af=%d\n", af); 358 m_freem(m); 359 return (EAFNOSUPPORT); 360 } 361 if_inc_counter(ifp, IFCOUNTER_IPACKETS, 1); 362 if_inc_counter(ifp, IFCOUNTER_IBYTES, m->m_pkthdr.len); 363 netisr_queue(isr, m); /* mbuf is free'd on failure. */ 364 return (0); 365 } 366 367 /* ARGSUSED */ 368 static void 369 lortrequest(int cmd, struct rtentry *rt, struct rt_addrinfo *info) 370 { 371 372 RT_LOCK_ASSERT(rt); 373 rt->rt_mtu = rt->rt_ifp->if_mtu; 374 } 375 376 /* 377 * Process an ioctl request. 378 */ 379 /* ARGSUSED */ 380 int 381 loioctl(struct ifnet *ifp, u_long cmd, caddr_t data) 382 { 383 struct ifaddr *ifa; 384 struct ifreq *ifr = (struct ifreq *)data; 385 int error = 0, mask; 386 387 switch (cmd) { 388 case SIOCSIFADDR: 389 ifp->if_flags |= IFF_UP; 390 ifp->if_drv_flags |= IFF_DRV_RUNNING; 391 ifa = (struct ifaddr *)data; 392 ifa->ifa_rtrequest = lortrequest; 393 /* 394 * Everything else is done at a higher level. 395 */ 396 break; 397 398 case SIOCADDMULTI: 399 case SIOCDELMULTI: 400 if (ifr == 0) { 401 error = EAFNOSUPPORT; /* XXX */ 402 break; 403 } 404 switch (ifr->ifr_addr.sa_family) { 405 406 #ifdef INET 407 case AF_INET: 408 break; 409 #endif 410 #ifdef INET6 411 case AF_INET6: 412 break; 413 #endif 414 415 default: 416 error = EAFNOSUPPORT; 417 break; 418 } 419 break; 420 421 case SIOCSIFMTU: 422 ifp->if_mtu = ifr->ifr_mtu; 423 break; 424 425 case SIOCSIFFLAGS: 426 break; 427 428 case SIOCSIFCAP: 429 mask = ifp->if_capenable ^ ifr->ifr_reqcap; 430 if ((mask & IFCAP_RXCSUM) != 0) 431 ifp->if_capenable ^= IFCAP_RXCSUM; 432 if ((mask & IFCAP_TXCSUM) != 0) 433 ifp->if_capenable ^= IFCAP_TXCSUM; 434 if ((mask & IFCAP_RXCSUM_IPV6) != 0) { 435 #if 0 436 ifp->if_capenable ^= IFCAP_RXCSUM_IPV6; 437 #else 438 error = EOPNOTSUPP; 439 break; 440 #endif 441 } 442 if ((mask & IFCAP_TXCSUM_IPV6) != 0) { 443 #if 0 444 ifp->if_capenable ^= IFCAP_TXCSUM_IPV6; 445 #else 446 error = EOPNOTSUPP; 447 break; 448 #endif 449 } 450 ifp->if_hwassist = 0; 451 if (ifp->if_capenable & IFCAP_TXCSUM) 452 ifp->if_hwassist = LO_CSUM_FEATURES; 453 #if 0 454 if (ifp->if_capenable & IFCAP_TXCSUM_IPV6) 455 ifp->if_hwassist |= LO_CSUM_FEATURES6; 456 #endif 457 break; 458 459 default: 460 error = EINVAL; 461 } 462 return (error); 463 } 464