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 */ 33 34 /* 35 * Loopback interface driver for protocol testing and timing. 36 */ 37 38 #include "opt_inet.h" 39 #include "opt_inet6.h" 40 #include "opt_rss.h" 41 42 #include <sys/param.h> 43 #include <sys/systm.h> 44 #include <sys/kernel.h> 45 #include <sys/mbuf.h> 46 #include <sys/module.h> 47 #include <machine/bus.h> 48 #include <sys/rman.h> 49 #include <sys/socket.h> 50 #include <sys/sockio.h> 51 #include <sys/sysctl.h> 52 53 #include <net/if.h> 54 #include <net/if_var.h> 55 #include <net/if_private.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 static int loioctl(struct ifnet *, u_long, caddr_t); 94 static int looutput(struct ifnet *ifp, struct mbuf *m, 95 const struct sockaddr *dst, struct route *ro); 96 97 VNET_DEFINE(struct ifnet *, loif); /* Used externally */ 98 VNET_DEFINE_STATIC(struct if_clone *, lo_cloner); 99 #define V_lo_cloner VNET(lo_cloner) 100 101 static const char loname[] = "lo"; 102 103 static int 104 lo_clone_destroy(struct if_clone *ifc, struct ifnet *ifp, uint32_t flags) 105 { 106 if (ifp->if_dunit == 0 && (flags & IFC_F_FORCE) == 0) 107 return (EINVAL); 108 109 #ifndef VIMAGE 110 /* XXX: destroying lo0 will lead to panics. */ 111 KASSERT(V_loif != ifp, ("%s: destroying lo0", __func__)); 112 #endif 113 114 bpfdetach(ifp); 115 if_detach(ifp); 116 if_free(ifp); 117 118 return (0); 119 } 120 121 static int 122 lo_clone_create(struct if_clone *ifc, char *name, size_t len, 123 struct ifc_data *ifd, struct ifnet **ifpp) 124 { 125 struct ifnet *ifp; 126 127 ifp = if_alloc(IFT_LOOP); 128 if_initname(ifp, loname, ifd->unit); 129 ifp->if_mtu = LOMTU; 130 ifp->if_flags = IFF_LOOPBACK | IFF_MULTICAST; 131 ifp->if_ioctl = loioctl; 132 ifp->if_output = looutput; 133 ifp->if_snd.ifq_maxlen = ifqmaxlen; 134 ifp->if_capabilities = ifp->if_capenable = 135 IFCAP_HWCSUM | IFCAP_HWCSUM_IPV6 | IFCAP_LINKSTATE; 136 ifp->if_hwassist = LO_CSUM_FEATURES | LO_CSUM_FEATURES6; 137 if_attach(ifp); 138 bpfattach(ifp, DLT_NULL, sizeof(u_int32_t)); 139 *ifpp = ifp; 140 141 return (0); 142 } 143 144 static void 145 vnet_loif_init(const void *unused __unused) 146 { 147 struct if_clone_addreq req = { 148 .create_f = lo_clone_create, 149 .destroy_f = lo_clone_destroy, 150 .flags = IFC_F_AUTOUNIT, 151 }; 152 V_lo_cloner = ifc_attach_cloner(loname, &req); 153 struct ifc_data ifd = { .unit = 0 }; 154 ifc_create_ifp(loname, &ifd, &V_loif); 155 } 156 VNET_SYSINIT(vnet_loif_init, SI_SUB_PSEUDO, SI_ORDER_ANY, 157 vnet_loif_init, NULL); 158 159 #ifdef VIMAGE 160 static void 161 vnet_loif_uninit(const void *unused __unused) 162 { 163 164 ifc_detach_cloner(V_lo_cloner); 165 V_loif = NULL; 166 } 167 VNET_SYSUNINIT(vnet_loif_uninit, SI_SUB_INIT_IF, SI_ORDER_SECOND, 168 vnet_loif_uninit, NULL); 169 #endif 170 171 static int 172 loop_modevent(module_t mod, int type, void *data) 173 { 174 175 switch (type) { 176 case MOD_LOAD: 177 break; 178 179 case MOD_UNLOAD: 180 printf("loop module unload - not possible for this module type\n"); 181 return (EINVAL); 182 183 default: 184 return (EOPNOTSUPP); 185 } 186 return (0); 187 } 188 189 static moduledata_t loop_mod = { 190 "if_lo", 191 loop_modevent, 192 0 193 }; 194 195 DECLARE_MODULE(if_lo, loop_mod, SI_SUB_PROTO_IFATTACHDOMAIN, SI_ORDER_ANY); 196 197 static int 198 looutput(struct ifnet *ifp, struct mbuf *m, const struct sockaddr *dst, 199 struct route *ro) 200 { 201 u_int32_t af; 202 #ifdef MAC 203 int error; 204 #endif 205 206 M_ASSERTPKTHDR(m); /* check if we have the packet header */ 207 208 #ifdef MAC 209 error = mac_ifnet_check_transmit(ifp, m); 210 if (error) { 211 m_freem(m); 212 return (error); 213 } 214 #endif 215 216 if (ro != NULL && ro->ro_flags & (RT_REJECT|RT_BLACKHOLE)) { 217 m_freem(m); 218 return (ro->ro_flags & RT_BLACKHOLE ? 0 : EHOSTUNREACH); 219 } 220 221 if_inc_counter(ifp, IFCOUNTER_OPACKETS, 1); 222 if_inc_counter(ifp, IFCOUNTER_OBYTES, m->m_pkthdr.len); 223 224 #ifdef RSS 225 M_HASHTYPE_CLEAR(m); 226 #endif 227 228 /* BPF writes need to be handled specially. */ 229 if (dst->sa_family == AF_UNSPEC || dst->sa_family == pseudo_AF_HDRCMPLT) 230 bcopy(dst->sa_data, &af, sizeof(af)); 231 else 232 af = RO_GET_FAMILY(ro, dst); 233 234 #if 1 /* XXX */ 235 switch (af) { 236 case AF_INET: 237 if (ifp->if_capenable & IFCAP_RXCSUM) { 238 m->m_pkthdr.csum_data = 0xffff; 239 m->m_pkthdr.csum_flags = LO_CSUM_SET; 240 } 241 m->m_pkthdr.csum_flags &= ~LO_CSUM_FEATURES; 242 break; 243 case AF_INET6: 244 #if 0 245 /* 246 * XXX-BZ for now always claim the checksum is good despite 247 * any interface flags. This is a workaround for 9.1-R and 248 * a proper solution ought to be sought later. 249 */ 250 if (ifp->if_capenable & IFCAP_RXCSUM_IPV6) { 251 m->m_pkthdr.csum_data = 0xffff; 252 m->m_pkthdr.csum_flags = LO_CSUM_SET; 253 } 254 #else 255 m->m_pkthdr.csum_data = 0xffff; 256 m->m_pkthdr.csum_flags = LO_CSUM_SET; 257 #endif 258 m->m_pkthdr.csum_flags &= ~LO_CSUM_FEATURES6; 259 break; 260 default: 261 printf("looutput: af=%d unexpected\n", af); 262 m_freem(m); 263 return (EAFNOSUPPORT); 264 } 265 #endif 266 return (if_simloop(ifp, m, af, 0)); 267 } 268 269 /* 270 * if_simloop() 271 * 272 * This function is to support software emulation of hardware loopback, 273 * i.e., for interfaces with the IFF_SIMPLEX attribute. Since they can't 274 * hear their own broadcasts, we create a copy of the packet that we 275 * would normally receive via a hardware loopback. 276 * 277 * This function expects the packet to include the media header of length hlen. 278 */ 279 int 280 if_simloop(struct ifnet *ifp, struct mbuf *m, int af, int hlen) 281 { 282 int isr; 283 284 M_ASSERTPKTHDR(m); 285 m_tag_delete_nonpersistent(m); 286 m->m_pkthdr.rcvif = ifp; 287 288 #ifdef MAC 289 mac_ifnet_create_mbuf(ifp, m); 290 #endif 291 292 /* 293 * Let BPF see incoming packet in the following manner: 294 * - Emulated packet loopback for a simplex interface 295 * (net/if_ethersubr.c) 296 * -> passes it to ifp's BPF 297 * - IPv4/v6 multicast packet loopback (netinet(6)/ip(6)_output.c) 298 * -> not passes it to any BPF 299 * - Normal packet loopback from myself to myself (net/if_loop.c) 300 * -> passes to lo0's BPF (even in case of IPv6, where ifp!=lo0) 301 */ 302 if (hlen > 0) { 303 if (bpf_peers_present(ifp->if_bpf)) { 304 bpf_mtap(ifp->if_bpf, m); 305 } 306 } else { 307 if (bpf_peers_present(V_loif->if_bpf)) { 308 if ((m->m_flags & M_MCAST) == 0 || V_loif == ifp) { 309 /* XXX beware sizeof(af) != 4 */ 310 u_int32_t af1 = af; 311 312 /* 313 * We need to prepend the address family. 314 */ 315 bpf_mtap2(V_loif->if_bpf, &af1, sizeof(af1), m); 316 } 317 } 318 } 319 320 /* Strip away media header */ 321 if (hlen > 0) { 322 m_adj(m, hlen); 323 #ifndef __NO_STRICT_ALIGNMENT 324 /* 325 * Some archs do not like unaligned data, so 326 * we move data down in the first mbuf. 327 */ 328 if (mtod(m, vm_offset_t) & 3) { 329 KASSERT(hlen >= 3, ("if_simloop: hlen too small")); 330 bcopy(m->m_data, 331 (char *)(mtod(m, vm_offset_t) 332 - (mtod(m, vm_offset_t) & 3)), 333 m->m_len); 334 m->m_data -= (mtod(m,vm_offset_t) & 3); 335 } 336 #endif 337 } 338 339 /* Deliver to upper layer protocol */ 340 switch (af) { 341 #ifdef INET 342 case AF_INET: 343 isr = NETISR_IP; 344 break; 345 #endif 346 #ifdef INET6 347 case AF_INET6: 348 m->m_flags |= M_LOOP; 349 isr = NETISR_IPV6; 350 break; 351 #endif 352 default: 353 printf("if_simloop: can't handle af=%d\n", af); 354 m_freem(m); 355 return (EAFNOSUPPORT); 356 } 357 if_inc_counter(ifp, IFCOUNTER_IPACKETS, 1); 358 if_inc_counter(ifp, IFCOUNTER_IBYTES, m->m_pkthdr.len); 359 netisr_queue(isr, m); /* mbuf is free'd on failure. */ 360 return (0); 361 } 362 363 /* 364 * Process an ioctl request. 365 */ 366 static int 367 loioctl(struct ifnet *ifp, u_long cmd, caddr_t data) 368 { 369 struct ifreq *ifr = (struct ifreq *)data; 370 int error = 0, mask; 371 372 switch (cmd) { 373 case SIOCSIFADDR: 374 ifp->if_flags |= IFF_UP; 375 ifp->if_drv_flags |= IFF_DRV_RUNNING; 376 if_link_state_change(ifp, LINK_STATE_UP); 377 /* 378 * Everything else is done at a higher level. 379 */ 380 break; 381 382 case SIOCADDMULTI: 383 case SIOCDELMULTI: 384 if (ifr == NULL) { 385 error = EAFNOSUPPORT; /* XXX */ 386 break; 387 } 388 switch (ifr->ifr_addr.sa_family) { 389 #ifdef INET 390 case AF_INET: 391 break; 392 #endif 393 #ifdef INET6 394 case AF_INET6: 395 break; 396 #endif 397 398 default: 399 error = EAFNOSUPPORT; 400 break; 401 } 402 break; 403 404 case SIOCSIFMTU: 405 ifp->if_mtu = ifr->ifr_mtu; 406 break; 407 408 case SIOCSIFFLAGS: 409 if_link_state_change(ifp, (ifp->if_flags & IFF_UP) ? 410 LINK_STATE_UP: LINK_STATE_DOWN); 411 break; 412 413 case SIOCSIFCAP: 414 mask = ifp->if_capenable ^ ifr->ifr_reqcap; 415 if ((mask & IFCAP_RXCSUM) != 0) 416 ifp->if_capenable ^= IFCAP_RXCSUM; 417 if ((mask & IFCAP_TXCSUM) != 0) 418 ifp->if_capenable ^= IFCAP_TXCSUM; 419 if ((mask & IFCAP_RXCSUM_IPV6) != 0) { 420 #if 0 421 ifp->if_capenable ^= IFCAP_RXCSUM_IPV6; 422 #else 423 error = EOPNOTSUPP; 424 break; 425 #endif 426 } 427 if ((mask & IFCAP_TXCSUM_IPV6) != 0) { 428 #if 0 429 ifp->if_capenable ^= IFCAP_TXCSUM_IPV6; 430 #else 431 error = EOPNOTSUPP; 432 break; 433 #endif 434 } 435 ifp->if_hwassist = 0; 436 if (ifp->if_capenable & IFCAP_TXCSUM) 437 ifp->if_hwassist = LO_CSUM_FEATURES; 438 #if 0 439 if (ifp->if_capenable & IFCAP_TXCSUM_IPV6) 440 ifp->if_hwassist |= LO_CSUM_FEATURES6; 441 #endif 442 break; 443 444 default: 445 error = EINVAL; 446 } 447 return (error); 448 } 449