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 NETATALK 85 #include <netproto/atalk/at.h> 86 #include <netproto/atalk/at_var.h> 87 #endif 88 89 static void loopattach(void *); 90 static int looutput(struct ifnet *, struct mbuf *, struct sockaddr *, 91 struct rtentry *); 92 static int loioctl(struct ifnet *, u_long, caddr_t, struct ucred *); 93 static void lortrequest(int, struct rtentry *, struct rt_addrinfo *); 94 #ifdef ALTQ 95 static void lo_altqstart(struct ifnet *); 96 #endif 97 PSEUDO_SET(loopattach, if_loop); 98 99 #ifdef TINY_LOMTU 100 #define LOMTU (1024+512) 101 #elif defined(LARGE_LOMTU) 102 #define LOMTU 131072 103 #else 104 #define LOMTU 16384 105 #endif 106 107 #define LO_CSUM_FEATURES (CSUM_IP | CSUM_UDP | CSUM_TCP) 108 109 struct ifnet loif[NLOOP]; 110 111 /* ARGSUSED */ 112 static void 113 loopattach(void *dummy) 114 { 115 struct ifnet *ifp; 116 int i; 117 118 for (i = 0, ifp = loif; i < NLOOP; i++, ifp++) { 119 if_initname(ifp, "lo", i); 120 ifp->if_mtu = LOMTU; 121 ifp->if_flags = IFF_LOOPBACK | IFF_MULTICAST; 122 ifp->if_capabilities = IFCAP_HWCSUM; 123 ifp->if_hwassist = LO_CSUM_FEATURES; 124 ifp->if_capenable = ifp->if_capabilities; 125 ifp->if_ioctl = loioctl; 126 ifp->if_output = looutput; 127 ifp->if_type = IFT_LOOP; 128 ifq_set_maxlen(&ifp->if_snd, ifqmaxlen); 129 ifq_set_ready(&ifp->if_snd); 130 #ifdef ALTQ 131 ifp->if_start = lo_altqstart; 132 #endif 133 if_attach(ifp, NULL); 134 bpfattach(ifp, DLT_NULL, sizeof(u_int)); 135 } 136 } 137 138 static int 139 looutput(struct ifnet *ifp, struct mbuf *m, struct sockaddr *dst, 140 struct rtentry *rt) 141 { 142 M_ASSERTPKTHDR(m); 143 144 if (rt && rt->rt_flags & (RTF_REJECT|RTF_BLACKHOLE)) { 145 m_freem(m); 146 return (rt->rt_flags & RTF_BLACKHOLE ? 0 : 147 rt->rt_flags & RTF_HOST ? EHOSTUNREACH : ENETUNREACH); 148 } 149 150 ifp->if_opackets++; 151 ifp->if_obytes += m->m_pkthdr.len; 152 #if 1 /* XXX */ 153 switch (dst->sa_family) { 154 case AF_INET: 155 case AF_INET6: 156 case AF_IPX: 157 case AF_NS: 158 case AF_APPLETALK: 159 break; 160 default: 161 kprintf("looutput: af=%d unexpected\n", dst->sa_family); 162 m_freem(m); 163 return (EAFNOSUPPORT); 164 } 165 #endif 166 167 if (ifp->if_capenable & IFCAP_RXCSUM) { 168 int csum_flags = 0; 169 170 if (m->m_pkthdr.csum_flags & CSUM_IP) 171 csum_flags |= (CSUM_IP_CHECKED | CSUM_IP_VALID); 172 if (m->m_pkthdr.csum_flags & CSUM_DELAY_DATA) 173 csum_flags |= (CSUM_DATA_VALID | CSUM_PSEUDO_HDR); 174 175 m->m_pkthdr.csum_flags |= csum_flags; 176 if (csum_flags & CSUM_DATA_VALID) 177 m->m_pkthdr.csum_data = 0xffff; 178 } 179 return (if_simloop(ifp, m, dst->sa_family, 0)); 180 } 181 182 /* 183 * if_simloop() 184 * 185 * This function is to support software emulation of hardware loopback, 186 * i.e., for interfaces with the IFF_SIMPLEX attribute. Since they can't 187 * hear their own broadcasts, we create a copy of the packet that we 188 * would normally receive via a hardware loopback. 189 * 190 * This function expects the packet to include the media header of length hlen. 191 */ 192 int 193 if_simloop(struct ifnet *ifp, struct mbuf *m, int af, int hlen) 194 { 195 int isr; 196 197 KASSERT((m->m_flags & M_PKTHDR) != 0, ("if_simloop: no HDR")); 198 m->m_pkthdr.rcvif = ifp; 199 200 /* BPF write needs to be handled specially */ 201 if (af == AF_UNSPEC) { 202 KASSERT(m->m_len >= sizeof(int), ("if_simloop: m_len")); 203 af = *(mtod(m, int *)); 204 m->m_len -= sizeof(int); 205 m->m_pkthdr.len -= sizeof(int); 206 m->m_data += sizeof(int); 207 } 208 209 if (ifp->if_bpf) { 210 get_mplock(); 211 212 /* Re-check */ 213 if (ifp->if_bpf == NULL) 214 goto rel; 215 216 if (ifp->if_bpf->bif_dlt == DLT_NULL) { 217 uint32_t bpf_af = (uint32_t)af; 218 bpf_ptap(ifp->if_bpf, m, &bpf_af, 4); 219 } else { 220 bpf_mtap(ifp->if_bpf, m); 221 } 222 rel: 223 rel_mplock(); 224 } 225 226 /* Strip away media header */ 227 if (hlen > 0) 228 m_adj(m, hlen); 229 230 #ifdef ALTQ 231 /* 232 * altq for loop is just for debugging. 233 * only used when called for loop interface (not for 234 * a simplex interface). 235 */ 236 if (ifq_is_enabled(&ifp->if_snd) && ifp->if_start == lo_altqstart) { 237 struct altq_pktattr pktattr; 238 int32_t *afp; 239 int error; 240 241 /* 242 * if the queueing discipline needs packet classification, 243 * do it before prepending link headers. 244 */ 245 ifq_classify(&ifp->if_snd, m, af, &pktattr); 246 247 M_PREPEND(m, sizeof(int32_t), MB_DONTWAIT); 248 if (m == 0) 249 return(ENOBUFS); 250 afp = mtod(m, int32_t *); 251 *afp = (int32_t)af; 252 253 /* 254 * A critical section is needed for subsystems protected by 255 * the MP lock, and the serializer is assumed to already 256 * be held for MPSAFE subsystems. 257 */ 258 crit_enter(); 259 error = ifq_enqueue(&ifp->if_snd, m, &pktattr); 260 ifnet_serialize_tx(ifp); 261 ifp->if_start(ifp); 262 ifnet_deserialize_tx(ifp); 263 crit_exit(); 264 return (error); 265 } 266 #endif /* ALTQ */ 267 268 /* Deliver to upper layer protocol */ 269 switch (af) { 270 #ifdef INET 271 case AF_INET: 272 isr = NETISR_IP; 273 break; 274 #endif 275 #ifdef INET6 276 case AF_INET6: 277 m->m_flags |= M_LOOP; 278 isr = NETISR_IPV6; 279 break; 280 #endif 281 #ifdef IPX 282 case AF_IPX: 283 isr = NETISR_IPX; 284 break; 285 #endif 286 #ifdef NETATALK 287 case AF_APPLETALK: 288 isr = NETISR_ATALK2; 289 break; 290 #endif 291 default: 292 kprintf("if_simloop: can't handle af=%d\n", af); 293 m_freem(m); 294 return (EAFNOSUPPORT); 295 } 296 297 ifp->if_ipackets++; 298 ifp->if_ibytes += m->m_pkthdr.len; 299 netisr_queue(isr, m); 300 return (0); 301 } 302 303 #ifdef ALTQ 304 static void 305 lo_altqstart(struct ifnet *ifp) 306 { 307 struct mbuf *m; 308 int32_t af, *afp; 309 int isr; 310 311 while (1) { 312 crit_enter(); 313 m = ifq_dequeue(&ifp->if_snd, NULL); 314 crit_exit(); 315 if (m == NULL) 316 return; 317 318 afp = mtod(m, int32_t *); 319 af = *afp; 320 m_adj(m, sizeof(int32_t)); 321 322 switch (af) { 323 #ifdef INET 324 case AF_INET: 325 isr = NETISR_IP; 326 break; 327 #endif 328 #ifdef INET6 329 case AF_INET6: 330 m->m_flags |= M_LOOP; 331 isr = NETISR_IPV6; 332 break; 333 #endif 334 #ifdef IPX 335 case AF_IPX: 336 isr = NETISR_IPX; 337 break; 338 #endif 339 #ifdef ISO 340 case AF_ISO: 341 isr = NETISR_ISO; 342 break; 343 #endif 344 #ifdef NETATALK 345 case AF_APPLETALK: 346 isr = NETISR_ATALK2; 347 break; 348 #endif 349 default: 350 kprintf("lo_altqstart: can't handle af%d\n", af); 351 m_freem(m); 352 return; 353 } 354 355 ifp->if_ipackets++; 356 ifp->if_ibytes += m->m_pkthdr.len; 357 netisr_queue(isr, m); 358 } 359 } 360 #endif /* ALTQ */ 361 362 /* ARGSUSED */ 363 static void 364 lortrequest(int cmd, struct rtentry *rt, struct rt_addrinfo *info) 365 { 366 if (rt) { 367 rt->rt_rmx.rmx_mtu = rt->rt_ifp->if_mtu; /* for ISO */ 368 /* 369 * For optimal performance, the send and receive buffers 370 * should be at least twice the MTU plus a little more for 371 * overhead. 372 */ 373 rt->rt_rmx.rmx_recvpipe = rt->rt_rmx.rmx_sendpipe = 3 * LOMTU; 374 } 375 } 376 377 /* 378 * Process an ioctl request. 379 */ 380 /* ARGSUSED */ 381 static int 382 loioctl(struct ifnet *ifp, u_long cmd, caddr_t data, struct ucred *cr) 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 | IFF_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 = (ifr->ifr_reqcap ^ ifp->if_capenable) & IFCAP_HWCSUM; 430 if (mask) { 431 ifp->if_capenable ^= mask; 432 if (IFCAP_TXCSUM & ifp->if_capenable) 433 ifp->if_hwassist = LO_CSUM_FEATURES; 434 else 435 ifp->if_hwassist = 0; 436 } 437 break; 438 439 default: 440 error = EINVAL; 441 } 442 return (error); 443 } 444