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 * 3. All advertising materials mentioning features or use of this software 14 * must display the following acknowledgement: 15 * This product includes software developed by the University of 16 * California, Berkeley and its contributors. 17 * 4. Neither the name of the University nor the names of its contributors 18 * may be used to endorse or promote products derived from this software 19 * without specific prior written permission. 20 * 21 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 22 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 23 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 24 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 25 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 26 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 27 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 28 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 29 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 30 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 31 * SUCH DAMAGE. 32 * 33 * @(#)if_loop.c 8.1 (Berkeley) 6/10/93 34 * $FreeBSD: src/sys/net/if_loop.c,v 1.47.2.9 2004/02/08 08:40:24 silby Exp $ 35 * $DragonFly: src/sys/net/if_loop.c,v 1.26 2008/10/04 11:21:10 sephe Exp $ 36 */ 37 38 /* 39 * Loopback interface driver for protocol testing and timing. 40 */ 41 #include "use_loop.h" 42 43 #include "opt_atalk.h" 44 #include "opt_inet.h" 45 #include "opt_inet6.h" 46 #include "opt_ipx.h" 47 48 #include <sys/param.h> 49 #include <sys/systm.h> 50 #include <sys/kernel.h> 51 #include <sys/lock.h> 52 #include <sys/mbuf.h> 53 #include <sys/socket.h> 54 #include <sys/sockio.h> 55 56 #include <sys/mplock2.h> 57 58 #include <net/if.h> 59 #include <net/if_types.h> 60 #include <net/ifq_var.h> 61 #include <net/netisr.h> 62 #include <net/route.h> 63 #include <net/bpf.h> 64 #include <net/bpfdesc.h> 65 66 #ifdef INET 67 #include <netinet/in.h> 68 #include <netinet/in_var.h> 69 #endif 70 71 #ifdef IPX 72 #include <netproto/ipx/ipx.h> 73 #include <netproto/ipx/ipx_if.h> 74 #endif 75 76 #ifdef INET6 77 #ifndef INET 78 #include <netinet/in.h> 79 #endif 80 #include <netinet6/in6_var.h> 81 #include <netinet/ip6.h> 82 #endif 83 84 #ifdef NS 85 #include <netns/ns.h> 86 #include <netns/ns_if.h> 87 #endif 88 89 #ifdef NETATALK 90 #include <netproto/atalk/at.h> 91 #include <netproto/atalk/at_var.h> 92 #endif 93 94 static void loopattach(void *); 95 static int looutput(struct ifnet *, struct mbuf *, struct sockaddr *, 96 struct rtentry *); 97 static int loioctl(struct ifnet *, u_long, caddr_t, struct ucred *); 98 static void lortrequest(int, struct rtentry *, struct rt_addrinfo *); 99 #ifdef ALTQ 100 static void lo_altqstart(struct ifnet *); 101 #endif 102 PSEUDO_SET(loopattach, if_loop); 103 104 #ifdef TINY_LOMTU 105 #define LOMTU (1024+512) 106 #elif defined(LARGE_LOMTU) 107 #define LOMTU 131072 108 #else 109 #define LOMTU 16384 110 #endif 111 112 #define LO_CSUM_FEATURES (CSUM_IP | CSUM_UDP | CSUM_TCP) 113 114 struct ifnet loif[NLOOP]; 115 116 /* ARGSUSED */ 117 static void 118 loopattach(void *dummy) 119 { 120 struct ifnet *ifp; 121 int i; 122 123 for (i = 0, ifp = loif; i < NLOOP; i++, ifp++) { 124 if_initname(ifp, "lo", i); 125 ifp->if_mtu = LOMTU; 126 ifp->if_flags = IFF_LOOPBACK | IFF_MULTICAST; 127 ifp->if_capabilities = IFCAP_HWCSUM; 128 ifp->if_hwassist = LO_CSUM_FEATURES; 129 ifp->if_capenable = ifp->if_capabilities; 130 ifp->if_ioctl = loioctl; 131 ifp->if_output = looutput; 132 ifp->if_type = IFT_LOOP; 133 ifq_set_maxlen(&ifp->if_snd, ifqmaxlen); 134 ifq_set_ready(&ifp->if_snd); 135 #ifdef ALTQ 136 ifp->if_start = lo_altqstart; 137 #endif 138 if_attach(ifp, NULL); 139 bpfattach(ifp, DLT_NULL, sizeof(u_int)); 140 } 141 } 142 143 static int 144 looutput(struct ifnet *ifp, struct mbuf *m, struct sockaddr *dst, 145 struct rtentry *rt) 146 { 147 M_ASSERTPKTHDR(m); 148 149 if (rt && rt->rt_flags & (RTF_REJECT|RTF_BLACKHOLE)) { 150 m_freem(m); 151 return (rt->rt_flags & RTF_BLACKHOLE ? 0 : 152 rt->rt_flags & RTF_HOST ? EHOSTUNREACH : ENETUNREACH); 153 } 154 155 ifp->if_opackets++; 156 ifp->if_obytes += m->m_pkthdr.len; 157 #if 1 /* XXX */ 158 switch (dst->sa_family) { 159 case AF_INET: 160 case AF_INET6: 161 case AF_IPX: 162 case AF_NS: 163 case AF_APPLETALK: 164 break; 165 default: 166 kprintf("looutput: af=%d unexpected\n", dst->sa_family); 167 m_freem(m); 168 return (EAFNOSUPPORT); 169 } 170 #endif 171 172 if (ifp->if_capenable & IFCAP_RXCSUM) { 173 int csum_flags = 0; 174 175 if (m->m_pkthdr.csum_flags & CSUM_IP) 176 csum_flags |= (CSUM_IP_CHECKED | CSUM_IP_VALID); 177 if (m->m_pkthdr.csum_flags & CSUM_DELAY_DATA) 178 csum_flags |= (CSUM_DATA_VALID | CSUM_PSEUDO_HDR); 179 180 m->m_pkthdr.csum_flags |= csum_flags; 181 if (csum_flags & CSUM_DATA_VALID) 182 m->m_pkthdr.csum_data = 0xffff; 183 } 184 return (if_simloop(ifp, m, dst->sa_family, 0)); 185 } 186 187 /* 188 * if_simloop() 189 * 190 * This function is to support software emulation of hardware loopback, 191 * i.e., for interfaces with the IFF_SIMPLEX attribute. Since they can't 192 * hear their own broadcasts, we create a copy of the packet that we 193 * would normally receive via a hardware loopback. 194 * 195 * This function expects the packet to include the media header of length hlen. 196 */ 197 int 198 if_simloop(struct ifnet *ifp, struct mbuf *m, int af, int hlen) 199 { 200 int isr; 201 202 KASSERT((m->m_flags & M_PKTHDR) != 0, ("if_simloop: no HDR")); 203 m->m_pkthdr.rcvif = ifp; 204 205 /* BPF write needs to be handled specially */ 206 if (af == AF_UNSPEC) { 207 KASSERT(m->m_len >= sizeof(int), ("if_simloop: m_len")); 208 af = *(mtod(m, int *)); 209 m->m_len -= sizeof(int); 210 m->m_pkthdr.len -= sizeof(int); 211 m->m_data += sizeof(int); 212 } 213 214 if (ifp->if_bpf) { 215 get_mplock(); 216 217 /* Re-check */ 218 if (ifp->if_bpf == NULL) 219 goto rel; 220 221 if (ifp->if_bpf->bif_dlt == DLT_NULL) { 222 uint32_t bpf_af = (uint32_t)af; 223 bpf_ptap(ifp->if_bpf, m, &bpf_af, 4); 224 } else { 225 bpf_mtap(ifp->if_bpf, m); 226 } 227 rel: 228 rel_mplock(); 229 } 230 231 /* Strip away media header */ 232 if (hlen > 0) 233 m_adj(m, hlen); 234 235 #ifdef ALTQ 236 /* 237 * altq for loop is just for debugging. 238 * only used when called for loop interface (not for 239 * a simplex interface). 240 */ 241 if (ifq_is_enabled(&ifp->if_snd) && ifp->if_start == lo_altqstart) { 242 struct altq_pktattr pktattr; 243 int32_t *afp; 244 int error; 245 246 /* 247 * if the queueing discipline needs packet classification, 248 * do it before prepending link headers. 249 */ 250 ifq_classify(&ifp->if_snd, m, af, &pktattr); 251 252 M_PREPEND(m, sizeof(int32_t), MB_DONTWAIT); 253 if (m == 0) 254 return(ENOBUFS); 255 afp = mtod(m, int32_t *); 256 *afp = (int32_t)af; 257 258 /* 259 * A critical section is needed for subsystems protected by 260 * the MP lock, and the serializer is assumed to already 261 * be held for MPSAFE subsystems. 262 */ 263 crit_enter(); 264 error = ifq_enqueue(&ifp->if_snd, m, &pktattr); 265 ifnet_serialize_tx(ifp); 266 ifp->if_start(ifp); 267 ifnet_deserialize_tx(ifp); 268 crit_exit(); 269 return (error); 270 } 271 #endif /* ALTQ */ 272 273 /* Deliver to upper layer protocol */ 274 switch (af) { 275 #ifdef INET 276 case AF_INET: 277 isr = NETISR_IP; 278 break; 279 #endif 280 #ifdef INET6 281 case AF_INET6: 282 m->m_flags |= M_LOOP; 283 isr = NETISR_IPV6; 284 break; 285 #endif 286 #ifdef IPX 287 case AF_IPX: 288 isr = NETISR_IPX; 289 break; 290 #endif 291 #ifdef NS 292 case AF_NS: 293 isr = NETISR_NS; 294 break; 295 #endif 296 #ifdef NETATALK 297 case AF_APPLETALK: 298 isr = NETISR_ATALK2; 299 break; 300 #endif 301 default: 302 kprintf("if_simloop: can't handle af=%d\n", af); 303 m_freem(m); 304 return (EAFNOSUPPORT); 305 } 306 307 ifp->if_ipackets++; 308 ifp->if_ibytes += m->m_pkthdr.len; 309 netisr_queue(isr, m); 310 return (0); 311 } 312 313 #ifdef ALTQ 314 static void 315 lo_altqstart(struct ifnet *ifp) 316 { 317 struct mbuf *m; 318 int32_t af, *afp; 319 int isr; 320 321 while (1) { 322 crit_enter(); 323 m = ifq_dequeue(&ifp->if_snd, NULL); 324 crit_exit(); 325 if (m == NULL) 326 return; 327 328 afp = mtod(m, int32_t *); 329 af = *afp; 330 m_adj(m, sizeof(int32_t)); 331 332 switch (af) { 333 #ifdef INET 334 case AF_INET: 335 isr = NETISR_IP; 336 break; 337 #endif 338 #ifdef INET6 339 case AF_INET6: 340 m->m_flags |= M_LOOP; 341 isr = NETISR_IPV6; 342 break; 343 #endif 344 #ifdef IPX 345 case AF_IPX: 346 isr = NETISR_IPX; 347 break; 348 #endif 349 #ifdef NS 350 case AF_NS: 351 isr = NETISR_NS; 352 break; 353 #endif 354 #ifdef ISO 355 case AF_ISO: 356 isr = NETISR_ISO; 357 break; 358 #endif 359 #ifdef NETATALK 360 case AF_APPLETALK: 361 isr = NETISR_ATALK2; 362 break; 363 #endif 364 default: 365 kprintf("lo_altqstart: can't handle af%d\n", af); 366 m_freem(m); 367 return; 368 } 369 370 ifp->if_ipackets++; 371 ifp->if_ibytes += m->m_pkthdr.len; 372 netisr_queue(isr, m); 373 } 374 } 375 #endif /* ALTQ */ 376 377 /* ARGSUSED */ 378 static void 379 lortrequest(int cmd, struct rtentry *rt, struct rt_addrinfo *info) 380 { 381 if (rt) { 382 rt->rt_rmx.rmx_mtu = rt->rt_ifp->if_mtu; /* for ISO */ 383 /* 384 * For optimal performance, the send and receive buffers 385 * should be at least twice the MTU plus a little more for 386 * overhead. 387 */ 388 rt->rt_rmx.rmx_recvpipe = rt->rt_rmx.rmx_sendpipe = 3 * LOMTU; 389 } 390 } 391 392 /* 393 * Process an ioctl request. 394 */ 395 /* ARGSUSED */ 396 static int 397 loioctl(struct ifnet *ifp, u_long cmd, caddr_t data, struct ucred *cr) 398 { 399 struct ifaddr *ifa; 400 struct ifreq *ifr = (struct ifreq *)data; 401 int error = 0, mask; 402 403 switch (cmd) { 404 case SIOCSIFADDR: 405 ifp->if_flags |= IFF_UP | IFF_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 = (ifr->ifr_reqcap ^ ifp->if_capenable) & IFCAP_HWCSUM; 445 if (mask) { 446 ifp->if_capenable ^= mask; 447 if (IFCAP_TXCSUM & ifp->if_capenable) 448 ifp->if_hwassist = LO_CSUM_FEATURES; 449 else 450 ifp->if_hwassist = 0; 451 } 452 break; 453 454 default: 455 error = EINVAL; 456 } 457 return (error); 458 } 459