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. Neither the name of the University nor the names of its contributors 14 * may be used to endorse or promote products derived from this software 15 * without specific prior written permission. 16 * 17 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 18 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 19 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 20 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 21 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 22 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 23 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 24 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 25 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 26 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 27 * SUCH DAMAGE. 28 * 29 * @(#)if_loop.c 8.1 (Berkeley) 6/10/93 30 * $FreeBSD: src/sys/net/if_loop.c,v 1.47.2.9 2004/02/08 08:40:24 silby Exp $ 31 */ 32 33 /* 34 * Loopback interface driver for protocol testing and timing. 35 */ 36 #include "use_loop.h" 37 38 #include "opt_inet.h" 39 #include "opt_inet6.h" 40 41 #include <sys/param.h> 42 #include <sys/systm.h> 43 #include <sys/kernel.h> 44 #include <sys/lock.h> 45 #include <sys/malloc.h> 46 #include <sys/mbuf.h> 47 #include <sys/socket.h> 48 #include <sys/sockio.h> 49 50 #include <net/if.h> 51 #include <net/if_types.h> 52 #include <net/if_clone.h> 53 #include <net/ifq_var.h> 54 #include <net/netisr.h> 55 #include <net/route.h> 56 #include <net/bpf.h> 57 #include <net/bpfdesc.h> 58 59 #ifdef INET 60 #include <netinet/in.h> 61 #include <netinet/in_var.h> 62 #endif 63 64 #ifdef INET6 65 #ifndef INET 66 #include <netinet/in.h> 67 #endif 68 #include <netinet6/in6_var.h> 69 #include <netinet/ip6.h> 70 #endif 71 72 static int lo_clone_create(struct if_clone *, int, caddr_t, caddr_t); 73 static int lo_clone_destroy(struct ifnet *); 74 75 static int lo_output(struct ifnet *, struct mbuf *, struct sockaddr *, 76 struct rtentry *); 77 static int lo_ioctl(struct ifnet *, u_long, caddr_t, struct ucred *); 78 static void lo_rtrequest(int, struct rtentry *); 79 #ifdef ALTQ 80 static void lo_altqstart(struct ifnet *, struct ifaltq_subque *); 81 #endif 82 83 #if defined(TINY_LOMTU) 84 #define LOMTU (1024+512) 85 #elif defined(LARGE_LOMTU) 86 #define LOMTU 131072 87 #else 88 #define LOMTU 16384 89 #endif 90 91 #define LO_CSUM_FEATURES (CSUM_IP | CSUM_UDP | CSUM_TCP) 92 93 struct ifnet *loif; 94 95 static struct if_clone lo_cloner = IF_CLONE_INITIALIZER("lo", 96 lo_clone_create, lo_clone_destroy, NLOOP, IF_MAXUNIT); 97 98 static void 99 lo_sysinit(void *dummy __unused) 100 { 101 if_clone_attach(&lo_cloner); 102 } 103 SYSINIT(lo_sysinit, SI_SUB_PSEUDO, SI_ORDER_ANY, lo_sysinit, NULL); 104 105 static int 106 lo_clone_create(struct if_clone *ifc, int unit, 107 caddr_t params __unused, caddr_t data __unused) 108 { 109 struct ifnet *ifp; 110 111 ifp = kmalloc(sizeof(*ifp), M_IFNET, M_WAITOK | M_ZERO); 112 if_initname(ifp, ifc->ifc_name, unit); 113 ifp->if_mtu = LOMTU; 114 ifp->if_flags = IFF_LOOPBACK | IFF_MULTICAST; 115 ifp->if_capabilities = IFCAP_HWCSUM | IFCAP_RSS; 116 ifp->if_hwassist = LO_CSUM_FEATURES; 117 ifp->if_capenable = ifp->if_capabilities; 118 ifp->if_ioctl = lo_ioctl; 119 ifp->if_output = lo_output; 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(uint32_t)); 128 129 if (loif == NULL) { 130 KASSERT(unit == 0, ("loif is %s", ifp->if_xname)); 131 loif = ifp; 132 } 133 return (0); 134 } 135 136 static int 137 lo_clone_destroy(struct ifnet *ifp) 138 { 139 if (loif == ifp) 140 return (EPERM); 141 142 bpfdetach(ifp); 143 if_detach(ifp); 144 kfree(ifp, M_IFNET); 145 return (0); 146 } 147 148 static int 149 lo_output(struct ifnet *ifp, struct mbuf *m, struct sockaddr *dst, 150 struct rtentry *rt) 151 { 152 M_ASSERTPKTHDR(m); 153 154 if (rt && rt->rt_flags & (RTF_REJECT|RTF_BLACKHOLE)) { 155 m_freem(m); 156 return (rt->rt_flags & RTF_BLACKHOLE ? 0 : 157 rt->rt_flags & RTF_HOST ? EHOSTUNREACH : ENETUNREACH); 158 } 159 160 IFNET_STAT_INC(ifp, opackets, 1); 161 IFNET_STAT_INC(ifp, obytes, m->m_pkthdr.len); 162 #if 1 /* XXX */ 163 switch (dst->sa_family) { 164 case AF_INET: 165 case AF_INET6: 166 break; 167 default: 168 kprintf("lo_output: af=%d unexpected\n", dst->sa_family); 169 m_freem(m); 170 return (EAFNOSUPPORT); 171 } 172 #endif 173 174 if (ifp->if_capenable & IFCAP_RXCSUM) { 175 int csum_flags = 0; 176 177 if (m->m_pkthdr.csum_flags & CSUM_IP) 178 csum_flags |= (CSUM_IP_CHECKED | CSUM_IP_VALID); 179 if (m->m_pkthdr.csum_flags & CSUM_DELAY_DATA) 180 csum_flags |= (CSUM_DATA_VALID | CSUM_PSEUDO_HDR); 181 182 m->m_pkthdr.csum_flags |= csum_flags; 183 if (csum_flags & CSUM_DATA_VALID) 184 m->m_pkthdr.csum_data = 0xffff; 185 } 186 if ((ifp->if_capenable & IFCAP_RSS) == 0) 187 m->m_flags &= ~M_HASH; 188 return (if_simloop(ifp, m, dst->sa_family, 0)); 189 } 190 191 /* 192 * if_simloop() 193 * 194 * This function is to support software emulation of hardware loopback, 195 * i.e., for interfaces with the IFF_SIMPLEX attribute. Since they can't 196 * hear their own broadcasts, we create a copy of the packet that we 197 * would normally receive via a hardware loopback. 198 * 199 * This function expects the packet to include the media header of length hlen. 200 */ 201 int 202 if_simloop(struct ifnet *ifp, struct mbuf *m, int af, int hlen) 203 { 204 int isr; 205 206 KASSERT((m->m_flags & M_PKTHDR) != 0, ("if_simloop: no HDR")); 207 m->m_pkthdr.rcvif = ifp; 208 209 /* BPF write needs to be handled specially */ 210 if (af == AF_UNSPEC) { 211 KASSERT(m->m_len >= sizeof(int), ("if_simloop: m_len")); 212 af = *(mtod(m, int *)); 213 m->m_len -= sizeof(int); 214 m->m_pkthdr.len -= sizeof(int); 215 m->m_data += sizeof(int); 216 } 217 218 if (ifp->if_bpf) { 219 bpf_gettoken(); 220 221 /* Re-check */ 222 if (ifp->if_bpf == NULL) 223 goto rel; 224 225 if (ifp->if_bpf->bif_dlt == DLT_NULL) { 226 uint32_t bpf_af = (uint32_t)af; 227 bpf_ptap(ifp->if_bpf, m, &bpf_af, 4); 228 } else { 229 bpf_mtap(ifp->if_bpf, m); 230 } 231 rel: 232 bpf_reltoken(); 233 } 234 235 /* Strip away media header */ 236 if (hlen > 0) 237 m_adj(m, hlen); 238 239 #ifdef ALTQ 240 /* 241 * altq for loop is just for debugging. 242 * only used when called for loop interface (not for 243 * a simplex interface). 244 */ 245 if (ifq_is_enabled(&ifp->if_snd) && ifp->if_start == lo_altqstart) { 246 struct altq_pktattr pktattr; 247 int32_t *afp; 248 249 /* 250 * if the queueing discipline needs packet classification, 251 * do it before prepending link headers. 252 */ 253 ifq_classify(&ifp->if_snd, m, af, &pktattr); 254 255 M_PREPEND(m, sizeof(int32_t), M_NOWAIT); 256 if (m == NULL) 257 return(ENOBUFS); 258 afp = mtod(m, int32_t *); 259 *afp = (int32_t)af; 260 261 return ifq_dispatch(ifp, m, &pktattr); 262 } 263 #endif /* ALTQ */ 264 265 /* Deliver to upper layer protocol */ 266 switch (af) { 267 #ifdef INET 268 case AF_INET: 269 isr = NETISR_IP; 270 break; 271 #endif 272 #ifdef INET6 273 case AF_INET6: 274 m->m_flags |= M_LOOP; 275 isr = NETISR_IPV6; 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 IFNET_STAT_INC(ifp, ipackets, 1); 285 IFNET_STAT_INC(ifp, 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, struct ifaltq_subque *ifsq) 293 { 294 struct mbuf *m; 295 int32_t af, *afp; 296 int isr; 297 298 while (1) { 299 crit_enter(); 300 m = ifsq_dequeue(ifsq); 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 default: 322 kprintf("lo_altqstart: can't handle af%d\n", af); 323 m_freem(m); 324 return; 325 } 326 327 IFNET_STAT_INC(ifp, ipackets, 1); 328 IFNET_STAT_INC(ifp, ibytes, m->m_pkthdr.len); 329 netisr_queue(isr, m); 330 } 331 } 332 #endif /* ALTQ */ 333 334 /* ARGSUSED */ 335 static void 336 lo_rtrequest(int cmd, struct rtentry *rt) 337 { 338 if (rt) { 339 rt->rt_rmx.rmx_mtu = rt->rt_ifp->if_mtu; /* for ISO */ 340 /* 341 * For optimal performance, the send and receive buffers 342 * should be at least twice the MTU plus a little more for 343 * overhead. 344 */ 345 rt->rt_rmx.rmx_recvpipe = rt->rt_rmx.rmx_sendpipe = 3 * LOMTU; 346 } 347 } 348 349 /* 350 * Process an ioctl request. 351 */ 352 /* ARGSUSED */ 353 static int 354 lo_ioctl(struct ifnet *ifp, u_long cmd, caddr_t data, struct ucred *cr) 355 { 356 struct ifaddr *ifa; 357 struct ifreq *ifr = (struct ifreq *)data; 358 int error = 0, mask; 359 360 switch (cmd) { 361 case SIOCSIFADDR: 362 ifp->if_flags |= IFF_UP | IFF_RUNNING; 363 ifa = (struct ifaddr *)data; 364 ifa->ifa_rtrequest = lo_rtrequest; 365 /* 366 * Everything else is done at a higher level. 367 */ 368 break; 369 370 case SIOCADDMULTI: 371 case SIOCDELMULTI: 372 if (ifr == NULL) { 373 error = EAFNOSUPPORT; /* XXX */ 374 break; 375 } 376 switch (ifr->ifr_addr.sa_family) { 377 378 #ifdef INET 379 case AF_INET: 380 break; 381 #endif 382 #ifdef INET6 383 case AF_INET6: 384 break; 385 #endif 386 387 default: 388 error = EAFNOSUPPORT; 389 break; 390 } 391 break; 392 393 case SIOCSIFMTU: 394 ifp->if_mtu = ifr->ifr_mtu; 395 break; 396 397 case SIOCSIFFLAGS: 398 break; 399 400 case SIOCSIFCAP: 401 mask = ifr->ifr_reqcap ^ ifp->if_capenable; 402 if (mask & IFCAP_HWCSUM) { 403 ifp->if_capenable ^= (mask & IFCAP_HWCSUM); 404 if (IFCAP_TXCSUM & ifp->if_capenable) 405 ifp->if_hwassist = LO_CSUM_FEATURES; 406 else 407 ifp->if_hwassist = 0; 408 } 409 if (mask & IFCAP_RSS) 410 ifp->if_capenable ^= IFCAP_RSS; 411 break; 412 413 default: 414 error = EINVAL; 415 } 416 return (error); 417 } 418