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