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 IFNET_STAT_INC(ifp, opackets, 1); 144 IFNET_STAT_INC(ifp, 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 altq_pktattr pktattr; 230 int32_t *afp; 231 232 /* 233 * if the queueing discipline needs packet classification, 234 * do it before prepending link headers. 235 */ 236 ifq_classify(&ifp->if_snd, m, af, &pktattr); 237 238 M_PREPEND(m, sizeof(int32_t), MB_DONTWAIT); 239 if (m == NULL) 240 return(ENOBUFS); 241 afp = mtod(m, int32_t *); 242 *afp = (int32_t)af; 243 244 return ifq_dispatch(ifp, m, &pktattr); 245 } 246 #endif /* ALTQ */ 247 248 /* Deliver to upper layer protocol */ 249 switch (af) { 250 #ifdef INET 251 case AF_INET: 252 isr = NETISR_IP; 253 break; 254 #endif 255 #ifdef INET6 256 case AF_INET6: 257 m->m_flags |= M_LOOP; 258 isr = NETISR_IPV6; 259 break; 260 #endif 261 #ifdef IPX 262 case AF_IPX: 263 isr = NETISR_IPX; 264 break; 265 #endif 266 default: 267 kprintf("if_simloop: can't handle af=%d\n", af); 268 m_freem(m); 269 return (EAFNOSUPPORT); 270 } 271 272 IFNET_STAT_INC(ifp, ipackets, 1); 273 IFNET_STAT_INC(ifp, ibytes, m->m_pkthdr.len); 274 netisr_queue(isr, m); 275 return (0); 276 } 277 278 #ifdef ALTQ 279 static void 280 lo_altqstart(struct ifnet *ifp, struct ifaltq_subque *ifsq) 281 { 282 struct mbuf *m; 283 int32_t af, *afp; 284 int isr; 285 286 while (1) { 287 crit_enter(); 288 m = ifsq_dequeue(ifsq, NULL); 289 crit_exit(); 290 if (m == NULL) 291 return; 292 293 afp = mtod(m, int32_t *); 294 af = *afp; 295 m_adj(m, sizeof(int32_t)); 296 297 switch (af) { 298 #ifdef INET 299 case AF_INET: 300 isr = NETISR_IP; 301 break; 302 #endif 303 #ifdef INET6 304 case AF_INET6: 305 m->m_flags |= M_LOOP; 306 isr = NETISR_IPV6; 307 break; 308 #endif 309 #ifdef IPX 310 case AF_IPX: 311 isr = NETISR_IPX; 312 break; 313 #endif 314 #ifdef ISO 315 case AF_ISO: 316 isr = NETISR_ISO; 317 break; 318 #endif 319 default: 320 kprintf("lo_altqstart: can't handle af%d\n", af); 321 m_freem(m); 322 return; 323 } 324 325 IFNET_STAT_INC(ifp, ipackets, 1); 326 IFNET_STAT_INC(ifp, ibytes, m->m_pkthdr.len); 327 netisr_queue(isr, m); 328 } 329 } 330 #endif /* ALTQ */ 331 332 /* ARGSUSED */ 333 static void 334 lortrequest(int cmd, struct rtentry *rt, struct rt_addrinfo *info) 335 { 336 if (rt) { 337 rt->rt_rmx.rmx_mtu = rt->rt_ifp->if_mtu; /* for ISO */ 338 /* 339 * For optimal performance, the send and receive buffers 340 * should be at least twice the MTU plus a little more for 341 * overhead. 342 */ 343 rt->rt_rmx.rmx_recvpipe = rt->rt_rmx.rmx_sendpipe = 3 * LOMTU; 344 } 345 } 346 347 /* 348 * Process an ioctl request. 349 */ 350 /* ARGSUSED */ 351 static int 352 loioctl(struct ifnet *ifp, u_long cmd, caddr_t data, struct ucred *cr) 353 { 354 struct ifaddr *ifa; 355 struct ifreq *ifr = (struct ifreq *)data; 356 int error = 0, mask; 357 358 switch (cmd) { 359 case SIOCSIFADDR: 360 ifp->if_flags |= IFF_UP | IFF_RUNNING; 361 ifa = (struct ifaddr *)data; 362 ifa->ifa_rtrequest = lortrequest; 363 /* 364 * Everything else is done at a higher level. 365 */ 366 break; 367 368 case SIOCADDMULTI: 369 case SIOCDELMULTI: 370 if (ifr == NULL) { 371 error = EAFNOSUPPORT; /* XXX */ 372 break; 373 } 374 switch (ifr->ifr_addr.sa_family) { 375 376 #ifdef INET 377 case AF_INET: 378 break; 379 #endif 380 #ifdef INET6 381 case AF_INET6: 382 break; 383 #endif 384 385 default: 386 error = EAFNOSUPPORT; 387 break; 388 } 389 break; 390 391 case SIOCSIFMTU: 392 ifp->if_mtu = ifr->ifr_mtu; 393 break; 394 395 case SIOCSIFFLAGS: 396 break; 397 398 case SIOCSIFCAP: 399 mask = (ifr->ifr_reqcap ^ ifp->if_capenable) & IFCAP_HWCSUM; 400 if (mask) { 401 ifp->if_capenable ^= mask; 402 if (IFCAP_TXCSUM & ifp->if_capenable) 403 ifp->if_hwassist = LO_CSUM_FEATURES; 404 else 405 ifp->if_hwassist = 0; 406 } 407 break; 408 409 default: 410 error = EINVAL; 411 } 412 return (error); 413 } 414