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 */ 36 37 /* 38 * Loopback interface driver for protocol testing and timing. 39 */ 40 #include "use_loop.h" 41 42 #include "opt_inet.h" 43 #include "opt_inet6.h" 44 #include "opt_ipx.h" 45 46 #include <sys/param.h> 47 #include <sys/systm.h> 48 #include <sys/kernel.h> 49 #include <sys/lock.h> 50 #include <sys/mbuf.h> 51 #include <sys/socket.h> 52 #include <sys/sockio.h> 53 54 #include <sys/mplock2.h> 55 56 #include <net/if.h> 57 #include <net/if_types.h> 58 #include <net/ifq_var.h> 59 #include <net/netisr.h> 60 #include <net/route.h> 61 #include <net/bpf.h> 62 #include <net/bpfdesc.h> 63 64 #ifdef INET 65 #include <netinet/in.h> 66 #include <netinet/in_var.h> 67 #endif 68 69 #ifdef IPX 70 #include <netproto/ipx/ipx.h> 71 #include <netproto/ipx/ipx_if.h> 72 #endif 73 74 #ifdef INET6 75 #ifndef INET 76 #include <netinet/in.h> 77 #endif 78 #include <netinet6/in6_var.h> 79 #include <netinet/ip6.h> 80 #endif 81 82 static void loopattach(void *); 83 static int looutput(struct ifnet *, struct mbuf *, struct sockaddr *, 84 struct rtentry *); 85 static int loioctl(struct ifnet *, u_long, caddr_t, struct ucred *); 86 static void lortrequest(int, struct rtentry *, struct rt_addrinfo *); 87 #ifdef ALTQ 88 static void lo_altqstart(struct ifnet *, struct ifaltq_subque *); 89 #endif 90 PSEUDO_SET(loopattach, if_loop); 91 92 #ifdef TINY_LOMTU 93 #define LOMTU (1024+512) 94 #elif defined(LARGE_LOMTU) 95 #define LOMTU 131072 96 #else 97 #define LOMTU 16384 98 #endif 99 100 #define LO_CSUM_FEATURES (CSUM_IP | CSUM_UDP | CSUM_TCP) 101 102 struct ifnet loif[NLOOP]; 103 104 /* ARGSUSED */ 105 static void 106 loopattach(void *dummy) 107 { 108 struct ifnet *ifp; 109 int i; 110 111 for (i = 0, ifp = loif; i < NLOOP; i++, ifp++) { 112 if_initname(ifp, "lo", i); 113 ifp->if_mtu = LOMTU; 114 ifp->if_flags = IFF_LOOPBACK | IFF_MULTICAST; 115 ifp->if_capabilities = IFCAP_HWCSUM; 116 ifp->if_hwassist = LO_CSUM_FEATURES; 117 ifp->if_capenable = ifp->if_capabilities; 118 ifp->if_ioctl = loioctl; 119 ifp->if_output = looutput; 120 ifp->if_type = IFT_LOOP; 121 ifq_set_maxlen(&ifp->if_snd, ifqmaxlen); 122 ifq_set_ready(&ifp->if_snd); 123 #ifdef ALTQ 124 ifp->if_start = lo_altqstart; 125 #endif 126 if_attach(ifp, NULL); 127 bpfattach(ifp, DLT_NULL, sizeof(u_int)); 128 } 129 } 130 131 static int 132 looutput(struct ifnet *ifp, struct mbuf *m, struct sockaddr *dst, 133 struct rtentry *rt) 134 { 135 M_ASSERTPKTHDR(m); 136 137 if (rt && rt->rt_flags & (RTF_REJECT|RTF_BLACKHOLE)) { 138 m_freem(m); 139 return (rt->rt_flags & RTF_BLACKHOLE ? 0 : 140 rt->rt_flags & RTF_HOST ? EHOSTUNREACH : ENETUNREACH); 141 } 142 143 ifp->if_opackets++; 144 ifp->if_obytes += m->m_pkthdr.len; 145 #if 1 /* XXX */ 146 switch (dst->sa_family) { 147 case AF_INET: 148 case AF_INET6: 149 case AF_IPX: 150 case AF_NS: 151 break; 152 default: 153 kprintf("looutput: af=%d unexpected\n", dst->sa_family); 154 m_freem(m); 155 return (EAFNOSUPPORT); 156 } 157 #endif 158 159 if (ifp->if_capenable & IFCAP_RXCSUM) { 160 int csum_flags = 0; 161 162 if (m->m_pkthdr.csum_flags & CSUM_IP) 163 csum_flags |= (CSUM_IP_CHECKED | CSUM_IP_VALID); 164 if (m->m_pkthdr.csum_flags & CSUM_DELAY_DATA) 165 csum_flags |= (CSUM_DATA_VALID | CSUM_PSEUDO_HDR); 166 167 m->m_pkthdr.csum_flags |= csum_flags; 168 if (csum_flags & CSUM_DATA_VALID) 169 m->m_pkthdr.csum_data = 0xffff; 170 } 171 return (if_simloop(ifp, m, dst->sa_family, 0)); 172 } 173 174 /* 175 * if_simloop() 176 * 177 * This function is to support software emulation of hardware loopback, 178 * i.e., for interfaces with the IFF_SIMPLEX attribute. Since they can't 179 * hear their own broadcasts, we create a copy of the packet that we 180 * would normally receive via a hardware loopback. 181 * 182 * This function expects the packet to include the media header of length hlen. 183 */ 184 int 185 if_simloop(struct ifnet *ifp, struct mbuf *m, int af, int hlen) 186 { 187 int isr; 188 189 KASSERT((m->m_flags & M_PKTHDR) != 0, ("if_simloop: no HDR")); 190 m->m_pkthdr.rcvif = ifp; 191 192 /* BPF write needs to be handled specially */ 193 if (af == AF_UNSPEC) { 194 KASSERT(m->m_len >= sizeof(int), ("if_simloop: m_len")); 195 af = *(mtod(m, int *)); 196 m->m_len -= sizeof(int); 197 m->m_pkthdr.len -= sizeof(int); 198 m->m_data += sizeof(int); 199 } 200 201 if (ifp->if_bpf) { 202 bpf_gettoken(); 203 204 /* Re-check */ 205 if (ifp->if_bpf == NULL) 206 goto rel; 207 208 if (ifp->if_bpf->bif_dlt == DLT_NULL) { 209 uint32_t bpf_af = (uint32_t)af; 210 bpf_ptap(ifp->if_bpf, m, &bpf_af, 4); 211 } else { 212 bpf_mtap(ifp->if_bpf, m); 213 } 214 rel: 215 bpf_reltoken(); 216 } 217 218 /* Strip away media header */ 219 if (hlen > 0) 220 m_adj(m, hlen); 221 222 #ifdef ALTQ 223 /* 224 * altq for loop is just for debugging. 225 * only used when called for loop interface (not for 226 * a simplex interface). 227 */ 228 if (ifq_is_enabled(&ifp->if_snd) && ifp->if_start == lo_altqstart) { 229 struct ifaltq_subque *ifsq = ifq_get_subq_default(&ifp->if_snd); 230 struct altq_pktattr pktattr; 231 int32_t *afp; 232 int error; 233 234 /* 235 * if the queueing discipline needs packet classification, 236 * do it before prepending link headers. 237 */ 238 ifq_classify(&ifp->if_snd, m, af, &pktattr); 239 240 M_PREPEND(m, sizeof(int32_t), MB_DONTWAIT); 241 if (m == NULL) 242 return(ENOBUFS); 243 afp = mtod(m, int32_t *); 244 *afp = (int32_t)af; 245 246 /* 247 * A critical section is needed for subsystems protected by 248 * the MP lock, and the serializer is assumed to already 249 * be held for MPSAFE subsystems. 250 */ 251 crit_enter(); 252 error = ifsq_enqueue(ifsq, m, &pktattr); 253 ifnet_serialize_tx(ifp); 254 ifp->if_start(ifp, ifsq); 255 ifnet_deserialize_tx(ifp); 256 crit_exit(); 257 return (error); 258 } 259 #endif /* ALTQ */ 260 261 /* Deliver to upper layer protocol */ 262 switch (af) { 263 #ifdef INET 264 case AF_INET: 265 isr = NETISR_IP; 266 break; 267 #endif 268 #ifdef INET6 269 case AF_INET6: 270 m->m_flags |= M_LOOP; 271 isr = NETISR_IPV6; 272 break; 273 #endif 274 #ifdef IPX 275 case AF_IPX: 276 isr = NETISR_IPX; 277 break; 278 #endif 279 default: 280 kprintf("if_simloop: can't handle af=%d\n", af); 281 m_freem(m); 282 return (EAFNOSUPPORT); 283 } 284 285 ifp->if_ipackets++; 286 ifp->if_ibytes += m->m_pkthdr.len; 287 netisr_queue(isr, m); 288 return (0); 289 } 290 291 #ifdef ALTQ 292 static void 293 lo_altqstart(struct ifnet *ifp, struct ifaltq_subque *ifsq) 294 { 295 struct mbuf *m; 296 int32_t af, *afp; 297 int isr; 298 299 while (1) { 300 crit_enter(); 301 m = ifsq_dequeue(ifsq, NULL); 302 crit_exit(); 303 if (m == NULL) 304 return; 305 306 afp = mtod(m, int32_t *); 307 af = *afp; 308 m_adj(m, sizeof(int32_t)); 309 310 switch (af) { 311 #ifdef INET 312 case AF_INET: 313 isr = NETISR_IP; 314 break; 315 #endif 316 #ifdef INET6 317 case AF_INET6: 318 m->m_flags |= M_LOOP; 319 isr = NETISR_IPV6; 320 break; 321 #endif 322 #ifdef IPX 323 case AF_IPX: 324 isr = NETISR_IPX; 325 break; 326 #endif 327 #ifdef ISO 328 case AF_ISO: 329 isr = NETISR_ISO; 330 break; 331 #endif 332 default: 333 kprintf("lo_altqstart: can't handle af%d\n", af); 334 m_freem(m); 335 return; 336 } 337 338 ifp->if_ipackets++; 339 ifp->if_ibytes += m->m_pkthdr.len; 340 netisr_queue(isr, m); 341 } 342 } 343 #endif /* ALTQ */ 344 345 /* ARGSUSED */ 346 static void 347 lortrequest(int cmd, struct rtentry *rt, struct rt_addrinfo *info) 348 { 349 if (rt) { 350 rt->rt_rmx.rmx_mtu = rt->rt_ifp->if_mtu; /* for ISO */ 351 /* 352 * For optimal performance, the send and receive buffers 353 * should be at least twice the MTU plus a little more for 354 * overhead. 355 */ 356 rt->rt_rmx.rmx_recvpipe = rt->rt_rmx.rmx_sendpipe = 3 * LOMTU; 357 } 358 } 359 360 /* 361 * Process an ioctl request. 362 */ 363 /* ARGSUSED */ 364 static int 365 loioctl(struct ifnet *ifp, u_long cmd, caddr_t data, struct ucred *cr) 366 { 367 struct ifaddr *ifa; 368 struct ifreq *ifr = (struct ifreq *)data; 369 int error = 0, mask; 370 371 switch (cmd) { 372 case SIOCSIFADDR: 373 ifp->if_flags |= IFF_UP | IFF_RUNNING; 374 ifa = (struct ifaddr *)data; 375 ifa->ifa_rtrequest = lortrequest; 376 /* 377 * Everything else is done at a higher level. 378 */ 379 break; 380 381 case SIOCADDMULTI: 382 case SIOCDELMULTI: 383 if (ifr == NULL) { 384 error = EAFNOSUPPORT; /* XXX */ 385 break; 386 } 387 switch (ifr->ifr_addr.sa_family) { 388 389 #ifdef INET 390 case AF_INET: 391 break; 392 #endif 393 #ifdef INET6 394 case AF_INET6: 395 break; 396 #endif 397 398 default: 399 error = EAFNOSUPPORT; 400 break; 401 } 402 break; 403 404 case SIOCSIFMTU: 405 ifp->if_mtu = ifr->ifr_mtu; 406 break; 407 408 case SIOCSIFFLAGS: 409 break; 410 411 case SIOCSIFCAP: 412 mask = (ifr->ifr_reqcap ^ ifp->if_capenable) & IFCAP_HWCSUM; 413 if (mask) { 414 ifp->if_capenable ^= mask; 415 if (IFCAP_TXCSUM & ifp->if_capenable) 416 ifp->if_hwassist = LO_CSUM_FEATURES; 417 else 418 ifp->if_hwassist = 0; 419 } 420 break; 421 422 default: 423 error = EINVAL; 424 } 425 return (error); 426 } 427