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); 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, caddr_t param __unused) 107 { 108 struct ifnet *ifp; 109 110 ifp = kmalloc(sizeof(*ifp), M_IFNET, M_WAITOK | M_ZERO); 111 if_initname(ifp, ifc->ifc_name, unit); 112 ifp->if_mtu = LOMTU; 113 ifp->if_flags = IFF_LOOPBACK | IFF_MULTICAST; 114 ifp->if_capabilities = IFCAP_HWCSUM | IFCAP_RSS; 115 ifp->if_hwassist = LO_CSUM_FEATURES; 116 ifp->if_capenable = ifp->if_capabilities; 117 ifp->if_ioctl = lo_ioctl; 118 ifp->if_output = lo_output; 119 ifp->if_type = IFT_LOOP; 120 ifq_set_maxlen(&ifp->if_snd, ifqmaxlen); 121 ifq_set_ready(&ifp->if_snd); 122 #ifdef ALTQ 123 ifp->if_start = lo_altqstart; 124 #endif 125 if_attach(ifp, NULL); 126 bpfattach(ifp, DLT_NULL, sizeof(u_int)); 127 128 if (loif == NULL) { 129 KASSERT(unit == 0, ("loif is %s", ifp->if_xname)); 130 loif = ifp; 131 } 132 return (0); 133 } 134 135 static int 136 lo_clone_destroy(struct ifnet *ifp) 137 { 138 if (loif == ifp) 139 return (EPERM); 140 141 bpfdetach(ifp); 142 if_detach(ifp); 143 kfree(ifp, M_IFNET); 144 return (0); 145 } 146 147 static int 148 lo_output(struct ifnet *ifp, struct mbuf *m, struct sockaddr *dst, 149 struct rtentry *rt) 150 { 151 M_ASSERTPKTHDR(m); 152 153 if (rt && rt->rt_flags & (RTF_REJECT|RTF_BLACKHOLE)) { 154 m_freem(m); 155 return (rt->rt_flags & RTF_BLACKHOLE ? 0 : 156 rt->rt_flags & RTF_HOST ? EHOSTUNREACH : ENETUNREACH); 157 } 158 159 IFNET_STAT_INC(ifp, opackets, 1); 160 IFNET_STAT_INC(ifp, obytes, m->m_pkthdr.len); 161 #if 1 /* XXX */ 162 switch (dst->sa_family) { 163 case AF_INET: 164 case AF_INET6: 165 break; 166 default: 167 kprintf("lo_output: af=%d unexpected\n", dst->sa_family); 168 m_freem(m); 169 return (EAFNOSUPPORT); 170 } 171 #endif 172 173 if (ifp->if_capenable & IFCAP_RXCSUM) { 174 int csum_flags = 0; 175 176 if (m->m_pkthdr.csum_flags & CSUM_IP) 177 csum_flags |= (CSUM_IP_CHECKED | CSUM_IP_VALID); 178 if (m->m_pkthdr.csum_flags & CSUM_DELAY_DATA) 179 csum_flags |= (CSUM_DATA_VALID | CSUM_PSEUDO_HDR); 180 181 m->m_pkthdr.csum_flags |= csum_flags; 182 if (csum_flags & CSUM_DATA_VALID) 183 m->m_pkthdr.csum_data = 0xffff; 184 } 185 if ((ifp->if_capenable & IFCAP_RSS) == 0) 186 m->m_flags &= ~M_HASH; 187 return (if_simloop(ifp, m, dst->sa_family, 0)); 188 } 189 190 /* 191 * if_simloop() 192 * 193 * This function is to support software emulation of hardware loopback, 194 * i.e., for interfaces with the IFF_SIMPLEX attribute. Since they can't 195 * hear their own broadcasts, we create a copy of the packet that we 196 * would normally receive via a hardware loopback. 197 * 198 * This function expects the packet to include the media header of length hlen. 199 */ 200 int 201 if_simloop(struct ifnet *ifp, struct mbuf *m, int af, int hlen) 202 { 203 int isr; 204 205 KASSERT((m->m_flags & M_PKTHDR) != 0, ("if_simloop: no HDR")); 206 m->m_pkthdr.rcvif = ifp; 207 208 /* BPF write needs to be handled specially */ 209 if (af == AF_UNSPEC) { 210 KASSERT(m->m_len >= sizeof(int), ("if_simloop: m_len")); 211 af = *(mtod(m, int *)); 212 m->m_len -= sizeof(int); 213 m->m_pkthdr.len -= sizeof(int); 214 m->m_data += sizeof(int); 215 } 216 217 if (ifp->if_bpf) { 218 bpf_gettoken(); 219 220 /* Re-check */ 221 if (ifp->if_bpf == NULL) 222 goto rel; 223 224 if (ifp->if_bpf->bif_dlt == DLT_NULL) { 225 uint32_t bpf_af = (uint32_t)af; 226 bpf_ptap(ifp->if_bpf, m, &bpf_af, 4); 227 } else { 228 bpf_mtap(ifp->if_bpf, m); 229 } 230 rel: 231 bpf_reltoken(); 232 } 233 234 /* Strip away media header */ 235 if (hlen > 0) 236 m_adj(m, hlen); 237 238 #ifdef ALTQ 239 /* 240 * altq for loop is just for debugging. 241 * only used when called for loop interface (not for 242 * a simplex interface). 243 */ 244 if (ifq_is_enabled(&ifp->if_snd) && ifp->if_start == lo_altqstart) { 245 struct altq_pktattr pktattr; 246 int32_t *afp; 247 248 /* 249 * if the queueing discipline needs packet classification, 250 * do it before prepending link headers. 251 */ 252 ifq_classify(&ifp->if_snd, m, af, &pktattr); 253 254 M_PREPEND(m, sizeof(int32_t), M_NOWAIT); 255 if (m == NULL) 256 return(ENOBUFS); 257 afp = mtod(m, int32_t *); 258 *afp = (int32_t)af; 259 260 return ifq_dispatch(ifp, m, &pktattr); 261 } 262 #endif /* ALTQ */ 263 264 /* Deliver to upper layer protocol */ 265 switch (af) { 266 #ifdef INET 267 case AF_INET: 268 isr = NETISR_IP; 269 break; 270 #endif 271 #ifdef INET6 272 case AF_INET6: 273 m->m_flags |= M_LOOP; 274 isr = NETISR_IPV6; 275 break; 276 #endif 277 default: 278 kprintf("if_simloop: can't handle af=%d\n", af); 279 m_freem(m); 280 return (EAFNOSUPPORT); 281 } 282 283 IFNET_STAT_INC(ifp, ipackets, 1); 284 IFNET_STAT_INC(ifp, ibytes, m->m_pkthdr.len); 285 netisr_queue(isr, m); 286 return (0); 287 } 288 289 #ifdef ALTQ 290 static void 291 lo_altqstart(struct ifnet *ifp, struct ifaltq_subque *ifsq) 292 { 293 struct mbuf *m; 294 int32_t af, *afp; 295 int isr; 296 297 while (1) { 298 crit_enter(); 299 m = ifsq_dequeue(ifsq); 300 crit_exit(); 301 if (m == NULL) 302 return; 303 304 afp = mtod(m, int32_t *); 305 af = *afp; 306 m_adj(m, sizeof(int32_t)); 307 308 switch (af) { 309 #ifdef INET 310 case AF_INET: 311 isr = NETISR_IP; 312 break; 313 #endif 314 #ifdef INET6 315 case AF_INET6: 316 m->m_flags |= M_LOOP; 317 isr = NETISR_IPV6; 318 break; 319 #endif 320 default: 321 kprintf("lo_altqstart: can't handle af%d\n", af); 322 m_freem(m); 323 return; 324 } 325 326 IFNET_STAT_INC(ifp, ipackets, 1); 327 IFNET_STAT_INC(ifp, ibytes, m->m_pkthdr.len); 328 netisr_queue(isr, m); 329 } 330 } 331 #endif /* ALTQ */ 332 333 /* ARGSUSED */ 334 static void 335 lo_rtrequest(int cmd, struct rtentry *rt) 336 { 337 if (rt) { 338 rt->rt_rmx.rmx_mtu = rt->rt_ifp->if_mtu; /* for ISO */ 339 /* 340 * For optimal performance, the send and receive buffers 341 * should be at least twice the MTU plus a little more for 342 * overhead. 343 */ 344 rt->rt_rmx.rmx_recvpipe = rt->rt_rmx.rmx_sendpipe = 3 * LOMTU; 345 } 346 } 347 348 /* 349 * Process an ioctl request. 350 */ 351 /* ARGSUSED */ 352 static int 353 lo_ioctl(struct ifnet *ifp, u_long cmd, caddr_t data, struct ucred *cr) 354 { 355 struct ifaddr *ifa; 356 struct ifreq *ifr = (struct ifreq *)data; 357 int error = 0, mask; 358 359 switch (cmd) { 360 case SIOCSIFADDR: 361 ifp->if_flags |= IFF_UP | IFF_RUNNING; 362 ifa = (struct ifaddr *)data; 363 ifa->ifa_rtrequest = lo_rtrequest; 364 /* 365 * Everything else is done at a higher level. 366 */ 367 break; 368 369 case SIOCADDMULTI: 370 case SIOCDELMULTI: 371 if (ifr == NULL) { 372 error = EAFNOSUPPORT; /* XXX */ 373 break; 374 } 375 switch (ifr->ifr_addr.sa_family) { 376 377 #ifdef INET 378 case AF_INET: 379 break; 380 #endif 381 #ifdef INET6 382 case AF_INET6: 383 break; 384 #endif 385 386 default: 387 error = EAFNOSUPPORT; 388 break; 389 } 390 break; 391 392 case SIOCSIFMTU: 393 ifp->if_mtu = ifr->ifr_mtu; 394 break; 395 396 case SIOCSIFFLAGS: 397 break; 398 399 case SIOCSIFCAP: 400 mask = ifr->ifr_reqcap ^ ifp->if_capenable; 401 if (mask & IFCAP_HWCSUM) { 402 ifp->if_capenable ^= (mask & IFCAP_HWCSUM); 403 if (IFCAP_TXCSUM & ifp->if_capenable) 404 ifp->if_hwassist = LO_CSUM_FEATURES; 405 else 406 ifp->if_hwassist = 0; 407 } 408 if (mask & IFCAP_RSS) 409 ifp->if_capenable ^= IFCAP_RSS; 410 break; 411 412 default: 413 error = EINVAL; 414 } 415 return (error); 416 } 417