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 *); 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 get_mplock(); 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 rel_mplock(); 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 altq_pktattr pktattr; 230 int32_t *afp; 231 int error; 232 233 /* 234 * if the queueing discipline needs packet classification, 235 * do it before prepending link headers. 236 */ 237 ifq_classify(&ifp->if_snd, m, af, &pktattr); 238 239 M_PREPEND(m, sizeof(int32_t), MB_DONTWAIT); 240 if (m == NULL) 241 return(ENOBUFS); 242 afp = mtod(m, int32_t *); 243 *afp = (int32_t)af; 244 245 /* 246 * A critical section is needed for subsystems protected by 247 * the MP lock, and the serializer is assumed to already 248 * be held for MPSAFE subsystems. 249 */ 250 crit_enter(); 251 error = ifq_enqueue(&ifp->if_snd, m, &pktattr); 252 ifnet_serialize_tx(ifp); 253 ifp->if_start(ifp); 254 ifnet_deserialize_tx(ifp); 255 crit_exit(); 256 return (error); 257 } 258 #endif /* ALTQ */ 259 260 /* Deliver to upper layer protocol */ 261 switch (af) { 262 #ifdef INET 263 case AF_INET: 264 isr = NETISR_IP; 265 break; 266 #endif 267 #ifdef INET6 268 case AF_INET6: 269 m->m_flags |= M_LOOP; 270 isr = NETISR_IPV6; 271 break; 272 #endif 273 #ifdef IPX 274 case AF_IPX: 275 isr = NETISR_IPX; 276 break; 277 #endif 278 default: 279 kprintf("if_simloop: can't handle af=%d\n", af); 280 m_freem(m); 281 return (EAFNOSUPPORT); 282 } 283 284 ifp->if_ipackets++; 285 ifp->if_ibytes += m->m_pkthdr.len; 286 netisr_queue(isr, m); 287 return (0); 288 } 289 290 #ifdef ALTQ 291 static void 292 lo_altqstart(struct ifnet *ifp) 293 { 294 struct mbuf *m; 295 int32_t af, *afp; 296 int isr; 297 298 while (1) { 299 crit_enter(); 300 m = ifq_dequeue(&ifp->if_snd, NULL); 301 crit_exit(); 302 if (m == NULL) 303 return; 304 305 afp = mtod(m, int32_t *); 306 af = *afp; 307 m_adj(m, sizeof(int32_t)); 308 309 switch (af) { 310 #ifdef INET 311 case AF_INET: 312 isr = NETISR_IP; 313 break; 314 #endif 315 #ifdef INET6 316 case AF_INET6: 317 m->m_flags |= M_LOOP; 318 isr = NETISR_IPV6; 319 break; 320 #endif 321 #ifdef IPX 322 case AF_IPX: 323 isr = NETISR_IPX; 324 break; 325 #endif 326 #ifdef ISO 327 case AF_ISO: 328 isr = NETISR_ISO; 329 break; 330 #endif 331 default: 332 kprintf("lo_altqstart: can't handle af%d\n", af); 333 m_freem(m); 334 return; 335 } 336 337 ifp->if_ipackets++; 338 ifp->if_ibytes += m->m_pkthdr.len; 339 netisr_queue(isr, m); 340 } 341 } 342 #endif /* ALTQ */ 343 344 /* ARGSUSED */ 345 static void 346 lortrequest(int cmd, struct rtentry *rt, struct rt_addrinfo *info) 347 { 348 if (rt) { 349 rt->rt_rmx.rmx_mtu = rt->rt_ifp->if_mtu; /* for ISO */ 350 /* 351 * For optimal performance, the send and receive buffers 352 * should be at least twice the MTU plus a little more for 353 * overhead. 354 */ 355 rt->rt_rmx.rmx_recvpipe = rt->rt_rmx.rmx_sendpipe = 3 * LOMTU; 356 } 357 } 358 359 /* 360 * Process an ioctl request. 361 */ 362 /* ARGSUSED */ 363 static int 364 loioctl(struct ifnet *ifp, u_long cmd, caddr_t data, struct ucred *cr) 365 { 366 struct ifaddr *ifa; 367 struct ifreq *ifr = (struct ifreq *)data; 368 int error = 0, mask; 369 370 switch (cmd) { 371 case SIOCSIFADDR: 372 ifp->if_flags |= IFF_UP | IFF_RUNNING; 373 ifa = (struct ifaddr *)data; 374 ifa->ifa_rtrequest = lortrequest; 375 /* 376 * Everything else is done at a higher level. 377 */ 378 break; 379 380 case SIOCADDMULTI: 381 case SIOCDELMULTI: 382 if (ifr == NULL) { 383 error = EAFNOSUPPORT; /* XXX */ 384 break; 385 } 386 switch (ifr->ifr_addr.sa_family) { 387 388 #ifdef INET 389 case AF_INET: 390 break; 391 #endif 392 #ifdef INET6 393 case AF_INET6: 394 break; 395 #endif 396 397 default: 398 error = EAFNOSUPPORT; 399 break; 400 } 401 break; 402 403 case SIOCSIFMTU: 404 ifp->if_mtu = ifr->ifr_mtu; 405 break; 406 407 case SIOCSIFFLAGS: 408 break; 409 410 case SIOCSIFCAP: 411 mask = (ifr->ifr_reqcap ^ ifp->if_capenable) & IFCAP_HWCSUM; 412 if (mask) { 413 ifp->if_capenable ^= mask; 414 if (IFCAP_TXCSUM & ifp->if_capenable) 415 ifp->if_hwassist = LO_CSUM_FEATURES; 416 else 417 ifp->if_hwassist = 0; 418 } 419 break; 420 421 default: 422 error = EINVAL; 423 } 424 return (error); 425 } 426