1 /*- 2 * SPDX-License-Identifier: BSD-3-Clause 3 * 4 * Copyright (c) 1982, 1986, 1993 5 * The Regents of the University of California. All rights reserved. 6 * 7 * Redistribution and use in source and binary forms, with or without 8 * modification, are permitted provided that the following conditions 9 * are met: 10 * 1. Redistributions of source code must retain the above copyright 11 * notice, this list of conditions and the following disclaimer. 12 * 2. Redistributions in binary form must reproduce the above copyright 13 * notice, this list of conditions and the following disclaimer in the 14 * documentation and/or other materials provided with the distribution. 15 * 3. Neither the name of the University nor the names of its contributors 16 * may be used to endorse or promote products derived from this software 17 * without specific prior written permission. 18 * 19 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 20 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 21 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 22 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 23 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 24 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 25 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 26 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 27 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 28 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 29 * SUCH DAMAGE. 30 * 31 * @(#)if_loop.c 8.2 (Berkeley) 1/9/95 32 * $FreeBSD$ 33 */ 34 35 /* 36 * Loopback interface driver for protocol testing and timing. 37 */ 38 39 #include "opt_inet.h" 40 #include "opt_inet6.h" 41 #include "opt_rss.h" 42 43 #include <sys/param.h> 44 #include <sys/systm.h> 45 #include <sys/kernel.h> 46 #include <sys/mbuf.h> 47 #include <sys/module.h> 48 #include <machine/bus.h> 49 #include <sys/rman.h> 50 #include <sys/socket.h> 51 #include <sys/sockio.h> 52 #include <sys/sysctl.h> 53 54 #include <net/if.h> 55 #include <net/if_var.h> 56 #include <net/if_clone.h> 57 #include <net/if_types.h> 58 #include <net/netisr.h> 59 #include <net/route.h> 60 #include <net/bpf.h> 61 #include <net/vnet.h> 62 63 #ifdef INET 64 #include <netinet/in.h> 65 #include <netinet/in_var.h> 66 #endif 67 68 #ifdef INET6 69 #ifndef INET 70 #include <netinet/in.h> 71 #endif 72 #include <netinet6/in6_var.h> 73 #include <netinet/ip6.h> 74 #endif 75 76 #include <security/mac/mac_framework.h> 77 78 #ifdef TINY_LOMTU 79 #define LOMTU (1024+512) 80 #elif defined(LARGE_LOMTU) 81 #define LOMTU 131072 82 #else 83 #define LOMTU 16384 84 #endif 85 86 #define LO_CSUM_FEATURES (CSUM_IP | CSUM_TCP | CSUM_UDP | CSUM_SCTP) 87 #define LO_CSUM_FEATURES6 (CSUM_TCP_IPV6 | CSUM_UDP_IPV6 | CSUM_SCTP_IPV6) 88 #define LO_CSUM_SET (CSUM_DATA_VALID | CSUM_DATA_VALID_IPV6 | \ 89 CSUM_PSEUDO_HDR | \ 90 CSUM_IP_CHECKED | CSUM_IP_VALID | \ 91 CSUM_SCTP_VALID) 92 93 int loioctl(struct ifnet *, u_long, caddr_t); 94 int looutput(struct ifnet *ifp, struct mbuf *m, 95 const struct sockaddr *dst, struct route *ro); 96 static int lo_clone_create(struct if_clone *, int, caddr_t); 97 static void lo_clone_destroy(struct ifnet *); 98 99 VNET_DEFINE(struct ifnet *, loif); /* Used externally */ 100 101 #ifdef VIMAGE 102 VNET_DEFINE_STATIC(struct if_clone *, lo_cloner); 103 #define V_lo_cloner VNET(lo_cloner) 104 #endif 105 106 static struct if_clone *lo_cloner; 107 static const char loname[] = "lo"; 108 109 static void 110 lo_clone_destroy(struct ifnet *ifp) 111 { 112 113 #ifndef VIMAGE 114 /* XXX: destroying lo0 will lead to panics. */ 115 KASSERT(V_loif != ifp, ("%s: destroying lo0", __func__)); 116 #endif 117 118 bpfdetach(ifp); 119 if_detach(ifp); 120 if_free(ifp); 121 } 122 123 static int 124 lo_clone_create(struct if_clone *ifc, int unit, caddr_t params) 125 { 126 struct ifnet *ifp; 127 128 ifp = if_alloc(IFT_LOOP); 129 if (ifp == NULL) 130 return (ENOSPC); 131 132 if_initname(ifp, loname, unit); 133 ifp->if_mtu = LOMTU; 134 ifp->if_flags = IFF_LOOPBACK | IFF_MULTICAST; 135 ifp->if_ioctl = loioctl; 136 ifp->if_output = looutput; 137 ifp->if_snd.ifq_maxlen = ifqmaxlen; 138 ifp->if_capabilities = ifp->if_capenable = 139 IFCAP_HWCSUM | IFCAP_HWCSUM_IPV6 | IFCAP_LINKSTATE; 140 ifp->if_hwassist = LO_CSUM_FEATURES | LO_CSUM_FEATURES6; 141 if_attach(ifp); 142 bpfattach(ifp, DLT_NULL, sizeof(u_int32_t)); 143 if (V_loif == NULL) 144 V_loif = ifp; 145 146 return (0); 147 } 148 149 static void 150 vnet_loif_init(const void *unused __unused) 151 { 152 153 #ifdef VIMAGE 154 lo_cloner = if_clone_simple(loname, lo_clone_create, lo_clone_destroy, 155 1); 156 V_lo_cloner = lo_cloner; 157 #else 158 lo_cloner = if_clone_simple(loname, lo_clone_create, lo_clone_destroy, 159 1); 160 #endif 161 } 162 VNET_SYSINIT(vnet_loif_init, SI_SUB_PSEUDO, SI_ORDER_ANY, 163 vnet_loif_init, NULL); 164 165 #ifdef VIMAGE 166 static void 167 vnet_loif_uninit(const void *unused __unused) 168 { 169 170 if_clone_detach(V_lo_cloner); 171 V_loif = NULL; 172 } 173 VNET_SYSUNINIT(vnet_loif_uninit, SI_SUB_INIT_IF, SI_ORDER_SECOND, 174 vnet_loif_uninit, NULL); 175 #endif 176 177 static int 178 loop_modevent(module_t mod, int type, void *data) 179 { 180 181 switch (type) { 182 case MOD_LOAD: 183 break; 184 185 case MOD_UNLOAD: 186 printf("loop module unload - not possible for this module type\n"); 187 return (EINVAL); 188 189 default: 190 return (EOPNOTSUPP); 191 } 192 return (0); 193 } 194 195 static moduledata_t loop_mod = { 196 "if_lo", 197 loop_modevent, 198 0 199 }; 200 201 DECLARE_MODULE(if_lo, loop_mod, SI_SUB_PROTO_IFATTACHDOMAIN, SI_ORDER_ANY); 202 203 int 204 looutput(struct ifnet *ifp, struct mbuf *m, const struct sockaddr *dst, 205 struct route *ro) 206 { 207 u_int32_t af; 208 #ifdef MAC 209 int error; 210 #endif 211 212 M_ASSERTPKTHDR(m); /* check if we have the packet header */ 213 214 #ifdef MAC 215 error = mac_ifnet_check_transmit(ifp, m); 216 if (error) { 217 m_freem(m); 218 return (error); 219 } 220 #endif 221 222 if (ro != NULL && ro->ro_flags & (RT_REJECT|RT_BLACKHOLE)) { 223 m_freem(m); 224 return (ro->ro_flags & RT_BLACKHOLE ? 0 : EHOSTUNREACH); 225 } 226 227 if_inc_counter(ifp, IFCOUNTER_OPACKETS, 1); 228 if_inc_counter(ifp, IFCOUNTER_OBYTES, m->m_pkthdr.len); 229 230 #ifdef RSS 231 M_HASHTYPE_CLEAR(m); 232 #endif 233 234 /* BPF writes need to be handled specially. */ 235 if (dst->sa_family == AF_UNSPEC || dst->sa_family == pseudo_AF_HDRCMPLT) 236 bcopy(dst->sa_data, &af, sizeof(af)); 237 else 238 af = dst->sa_family; 239 240 #if 1 /* XXX */ 241 switch (af) { 242 case AF_INET: 243 if (ifp->if_capenable & IFCAP_RXCSUM) { 244 m->m_pkthdr.csum_data = 0xffff; 245 m->m_pkthdr.csum_flags = LO_CSUM_SET; 246 } 247 m->m_pkthdr.csum_flags &= ~LO_CSUM_FEATURES; 248 break; 249 case AF_INET6: 250 #if 0 251 /* 252 * XXX-BZ for now always claim the checksum is good despite 253 * any interface flags. This is a workaround for 9.1-R and 254 * a proper solution ought to be sought later. 255 */ 256 if (ifp->if_capenable & IFCAP_RXCSUM_IPV6) { 257 m->m_pkthdr.csum_data = 0xffff; 258 m->m_pkthdr.csum_flags = LO_CSUM_SET; 259 } 260 #else 261 m->m_pkthdr.csum_data = 0xffff; 262 m->m_pkthdr.csum_flags = LO_CSUM_SET; 263 #endif 264 m->m_pkthdr.csum_flags &= ~LO_CSUM_FEATURES6; 265 break; 266 default: 267 printf("looutput: af=%d unexpected\n", af); 268 m_freem(m); 269 return (EAFNOSUPPORT); 270 } 271 #endif 272 return (if_simloop(ifp, m, af, 0)); 273 } 274 275 /* 276 * if_simloop() 277 * 278 * This function is to support software emulation of hardware loopback, 279 * i.e., for interfaces with the IFF_SIMPLEX attribute. Since they can't 280 * hear their own broadcasts, we create a copy of the packet that we 281 * would normally receive via a hardware loopback. 282 * 283 * This function expects the packet to include the media header of length hlen. 284 */ 285 int 286 if_simloop(struct ifnet *ifp, struct mbuf *m, int af, int hlen) 287 { 288 int isr; 289 290 M_ASSERTPKTHDR(m); 291 m_tag_delete_nonpersistent(m); 292 m->m_pkthdr.rcvif = ifp; 293 294 #ifdef MAC 295 mac_ifnet_create_mbuf(ifp, m); 296 #endif 297 298 /* 299 * Let BPF see incoming packet in the following manner: 300 * - Emulated packet loopback for a simplex interface 301 * (net/if_ethersubr.c) 302 * -> passes it to ifp's BPF 303 * - IPv4/v6 multicast packet loopback (netinet(6)/ip(6)_output.c) 304 * -> not passes it to any BPF 305 * - Normal packet loopback from myself to myself (net/if_loop.c) 306 * -> passes to lo0's BPF (even in case of IPv6, where ifp!=lo0) 307 */ 308 if (hlen > 0) { 309 if (bpf_peers_present(ifp->if_bpf)) { 310 bpf_mtap(ifp->if_bpf, m); 311 } 312 } else { 313 if (bpf_peers_present(V_loif->if_bpf)) { 314 if ((m->m_flags & M_MCAST) == 0 || V_loif == ifp) { 315 /* XXX beware sizeof(af) != 4 */ 316 u_int32_t af1 = af; 317 318 /* 319 * We need to prepend the address family. 320 */ 321 bpf_mtap2(V_loif->if_bpf, &af1, sizeof(af1), m); 322 } 323 } 324 } 325 326 /* Strip away media header */ 327 if (hlen > 0) { 328 m_adj(m, hlen); 329 #ifndef __NO_STRICT_ALIGNMENT 330 /* 331 * Some archs do not like unaligned data, so 332 * we move data down in the first mbuf. 333 */ 334 if (mtod(m, vm_offset_t) & 3) { 335 KASSERT(hlen >= 3, ("if_simloop: hlen too small")); 336 bcopy(m->m_data, 337 (char *)(mtod(m, vm_offset_t) 338 - (mtod(m, vm_offset_t) & 3)), 339 m->m_len); 340 m->m_data -= (mtod(m,vm_offset_t) & 3); 341 } 342 #endif 343 } 344 345 /* Deliver to upper layer protocol */ 346 switch (af) { 347 #ifdef INET 348 case AF_INET: 349 isr = NETISR_IP; 350 break; 351 #endif 352 #ifdef INET6 353 case AF_INET6: 354 m->m_flags |= M_LOOP; 355 isr = NETISR_IPV6; 356 break; 357 #endif 358 default: 359 printf("if_simloop: can't handle af=%d\n", af); 360 m_freem(m); 361 return (EAFNOSUPPORT); 362 } 363 if_inc_counter(ifp, IFCOUNTER_IPACKETS, 1); 364 if_inc_counter(ifp, IFCOUNTER_IBYTES, m->m_pkthdr.len); 365 netisr_queue(isr, m); /* mbuf is free'd on failure. */ 366 return (0); 367 } 368 369 /* 370 * Process an ioctl request. 371 */ 372 /* ARGSUSED */ 373 int 374 loioctl(struct ifnet *ifp, u_long cmd, caddr_t data) 375 { 376 struct ifreq *ifr = (struct ifreq *)data; 377 int error = 0, mask; 378 379 switch (cmd) { 380 case SIOCSIFADDR: 381 ifp->if_flags |= IFF_UP; 382 ifp->if_drv_flags |= IFF_DRV_RUNNING; 383 if_link_state_change(ifp, LINK_STATE_UP); 384 /* 385 * Everything else is done at a higher level. 386 */ 387 break; 388 389 case SIOCADDMULTI: 390 case SIOCDELMULTI: 391 if (ifr == NULL) { 392 error = EAFNOSUPPORT; /* XXX */ 393 break; 394 } 395 switch (ifr->ifr_addr.sa_family) { 396 #ifdef INET 397 case AF_INET: 398 break; 399 #endif 400 #ifdef INET6 401 case AF_INET6: 402 break; 403 #endif 404 405 default: 406 error = EAFNOSUPPORT; 407 break; 408 } 409 break; 410 411 case SIOCSIFMTU: 412 ifp->if_mtu = ifr->ifr_mtu; 413 break; 414 415 case SIOCSIFFLAGS: 416 if_link_state_change(ifp, (ifp->if_flags & IFF_UP) ? 417 LINK_STATE_UP: LINK_STATE_DOWN); 418 break; 419 420 case SIOCSIFCAP: 421 mask = ifp->if_capenable ^ ifr->ifr_reqcap; 422 if ((mask & IFCAP_RXCSUM) != 0) 423 ifp->if_capenable ^= IFCAP_RXCSUM; 424 if ((mask & IFCAP_TXCSUM) != 0) 425 ifp->if_capenable ^= IFCAP_TXCSUM; 426 if ((mask & IFCAP_RXCSUM_IPV6) != 0) { 427 #if 0 428 ifp->if_capenable ^= IFCAP_RXCSUM_IPV6; 429 #else 430 error = EOPNOTSUPP; 431 break; 432 #endif 433 } 434 if ((mask & IFCAP_TXCSUM_IPV6) != 0) { 435 #if 0 436 ifp->if_capenable ^= IFCAP_TXCSUM_IPV6; 437 #else 438 error = EOPNOTSUPP; 439 break; 440 #endif 441 } 442 ifp->if_hwassist = 0; 443 if (ifp->if_capenable & IFCAP_TXCSUM) 444 ifp->if_hwassist = LO_CSUM_FEATURES; 445 #if 0 446 if (ifp->if_capenable & IFCAP_TXCSUM_IPV6) 447 ifp->if_hwassist |= LO_CSUM_FEATURES6; 448 #endif 449 break; 450 451 default: 452 error = EINVAL; 453 } 454 return (error); 455 } 456