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 32 /* 33 * Loopback interface driver for protocol testing and timing. 34 */ 35 36 #include "opt_inet.h" 37 #include "opt_inet6.h" 38 #include "opt_rss.h" 39 40 #include <sys/param.h> 41 #include <sys/systm.h> 42 #include <sys/kernel.h> 43 #include <sys/mbuf.h> 44 #include <sys/module.h> 45 #include <machine/bus.h> 46 #include <sys/rman.h> 47 #include <sys/socket.h> 48 #include <sys/sockio.h> 49 #include <sys/sysctl.h> 50 51 #include <net/if.h> 52 #include <net/if_var.h> 53 #include <net/if_private.h> 54 #include <net/if_clone.h> 55 #include <net/if_types.h> 56 #include <net/netisr.h> 57 #include <net/route.h> 58 #include <net/bpf.h> 59 #include <net/vnet.h> 60 61 #ifdef INET 62 #include <netinet/in.h> 63 #include <netinet/in_var.h> 64 #endif 65 66 #ifdef INET6 67 #ifndef INET 68 #include <netinet/in.h> 69 #endif 70 #include <netinet6/in6_var.h> 71 #include <netinet/ip6.h> 72 #endif 73 74 #include <security/mac/mac_framework.h> 75 76 #ifdef TINY_LOMTU 77 #define LOMTU (1024+512) 78 #elif defined(LARGE_LOMTU) 79 #define LOMTU 131072 80 #else 81 #define LOMTU 16384 82 #endif 83 84 #define LO_CSUM_FEATURES (CSUM_IP | CSUM_TCP | CSUM_UDP | CSUM_SCTP) 85 #define LO_CSUM_FEATURES6 (CSUM_TCP_IPV6 | CSUM_UDP_IPV6 | CSUM_SCTP_IPV6) 86 #define LO_CSUM_SET (CSUM_DATA_VALID | CSUM_DATA_VALID_IPV6 | \ 87 CSUM_PSEUDO_HDR | \ 88 CSUM_IP_CHECKED | CSUM_IP_VALID | \ 89 CSUM_SCTP_VALID) 90 91 static int loioctl(struct ifnet *, u_long, caddr_t); 92 static int looutput(struct ifnet *ifp, struct mbuf *m, 93 const struct sockaddr *dst, struct route *ro); 94 95 VNET_DEFINE(struct ifnet *, loif); /* Used externally */ 96 VNET_DEFINE_STATIC(struct if_clone *, lo_cloner); 97 #define V_lo_cloner VNET(lo_cloner) 98 99 static const char loname[] = "lo"; 100 101 static int 102 lo_clone_destroy(struct if_clone *ifc, struct ifnet *ifp, uint32_t flags) 103 { 104 if (ifp->if_dunit == 0 && (flags & IFC_F_FORCE) == 0) 105 return (EINVAL); 106 107 #ifndef VIMAGE 108 /* XXX: destroying lo0 will lead to panics. */ 109 KASSERT(V_loif != ifp, ("%s: destroying lo0", __func__)); 110 #endif 111 112 bpfdetach(ifp); 113 if_detach(ifp); 114 if_free(ifp); 115 116 return (0); 117 } 118 119 static int 120 lo_clone_create(struct if_clone *ifc, char *name, size_t len, 121 struct ifc_data *ifd, struct ifnet **ifpp) 122 { 123 struct ifnet *ifp; 124 125 ifp = if_alloc(IFT_LOOP); 126 if_initname(ifp, loname, ifd->unit); 127 ifp->if_mtu = LOMTU; 128 ifp->if_flags = IFF_LOOPBACK | IFF_MULTICAST; 129 ifp->if_ioctl = loioctl; 130 ifp->if_output = looutput; 131 ifp->if_snd.ifq_maxlen = ifqmaxlen; 132 ifp->if_capabilities = ifp->if_capenable = 133 IFCAP_HWCSUM | IFCAP_HWCSUM_IPV6 | IFCAP_LINKSTATE; 134 ifp->if_hwassist = LO_CSUM_FEATURES | LO_CSUM_FEATURES6; 135 if_attach(ifp); 136 bpfattach(ifp, DLT_NULL, sizeof(u_int32_t)); 137 *ifpp = ifp; 138 139 return (0); 140 } 141 142 static void 143 vnet_loif_init(const void *unused __unused) 144 { 145 struct if_clone_addreq req = { 146 .create_f = lo_clone_create, 147 .destroy_f = lo_clone_destroy, 148 .flags = IFC_F_AUTOUNIT, 149 }; 150 V_lo_cloner = ifc_attach_cloner(loname, &req); 151 struct ifc_data ifd = { .unit = 0 }; 152 ifc_create_ifp(loname, &ifd, &V_loif); 153 } 154 VNET_SYSINIT(vnet_loif_init, SI_SUB_PROTO_IF, SI_ORDER_ANY, 155 vnet_loif_init, NULL); 156 157 #ifdef VIMAGE 158 static void 159 vnet_loif_uninit(const void *unused __unused) 160 { 161 162 ifc_detach_cloner(V_lo_cloner); 163 V_loif = NULL; 164 } 165 VNET_SYSUNINIT(vnet_loif_uninit, SI_SUB_INIT_IF, SI_ORDER_SECOND, 166 vnet_loif_uninit, NULL); 167 #endif 168 169 static int 170 loop_modevent(module_t mod, int type, void *data) 171 { 172 173 switch (type) { 174 case MOD_LOAD: 175 break; 176 177 case MOD_UNLOAD: 178 printf("loop module unload - not possible for this module type\n"); 179 return (EINVAL); 180 181 default: 182 return (EOPNOTSUPP); 183 } 184 return (0); 185 } 186 187 static moduledata_t loop_mod = { 188 "if_lo", 189 loop_modevent, 190 0 191 }; 192 193 DECLARE_MODULE(if_lo, loop_mod, SI_SUB_PROTO_IFATTACHDOMAIN, SI_ORDER_ANY); 194 195 static int 196 looutput(struct ifnet *ifp, struct mbuf *m, const struct sockaddr *dst, 197 struct route *ro) 198 { 199 u_int32_t af; 200 #ifdef MAC 201 int error; 202 #endif 203 204 M_ASSERTPKTHDR(m); /* check if we have the packet header */ 205 206 #ifdef MAC 207 error = mac_ifnet_check_transmit(ifp, m); 208 if (error) { 209 m_freem(m); 210 return (error); 211 } 212 #endif 213 214 if (ro != NULL && ro->ro_flags & (RT_REJECT|RT_BLACKHOLE)) { 215 m_freem(m); 216 return (ro->ro_flags & RT_BLACKHOLE ? 0 : EHOSTUNREACH); 217 } 218 219 if_inc_counter(ifp, IFCOUNTER_OPACKETS, 1); 220 if_inc_counter(ifp, IFCOUNTER_OBYTES, m->m_pkthdr.len); 221 222 #ifdef RSS 223 M_HASHTYPE_CLEAR(m); 224 #endif 225 226 /* BPF writes need to be handled specially. */ 227 if (dst->sa_family == AF_UNSPEC || dst->sa_family == pseudo_AF_HDRCMPLT) 228 bcopy(dst->sa_data, &af, sizeof(af)); 229 else 230 af = RO_GET_FAMILY(ro, dst); 231 232 #if 1 /* XXX */ 233 switch (af) { 234 case AF_INET: 235 if (ifp->if_capenable & IFCAP_RXCSUM) { 236 m->m_pkthdr.csum_data = 0xffff; 237 m->m_pkthdr.csum_flags = LO_CSUM_SET; 238 } 239 m->m_pkthdr.csum_flags &= ~LO_CSUM_FEATURES; 240 break; 241 case AF_INET6: 242 #if 0 243 /* 244 * XXX-BZ for now always claim the checksum is good despite 245 * any interface flags. This is a workaround for 9.1-R and 246 * a proper solution ought to be sought later. 247 */ 248 if (ifp->if_capenable & IFCAP_RXCSUM_IPV6) { 249 m->m_pkthdr.csum_data = 0xffff; 250 m->m_pkthdr.csum_flags = LO_CSUM_SET; 251 } 252 #else 253 m->m_pkthdr.csum_data = 0xffff; 254 m->m_pkthdr.csum_flags = LO_CSUM_SET; 255 #endif 256 m->m_pkthdr.csum_flags &= ~LO_CSUM_FEATURES6; 257 break; 258 default: 259 printf("looutput: af=%d unexpected\n", af); 260 m_freem(m); 261 return (EAFNOSUPPORT); 262 } 263 #endif 264 return (if_simloop(ifp, m, af, 0)); 265 } 266 267 /* 268 * if_simloop() 269 * 270 * This function is to support software emulation of hardware loopback, 271 * i.e., for interfaces with the IFF_SIMPLEX attribute. Since they can't 272 * hear their own broadcasts, we create a copy of the packet that we 273 * would normally receive via a hardware loopback. 274 * 275 * This function expects the packet to include the media header of length hlen. 276 */ 277 int 278 if_simloop(struct ifnet *ifp, struct mbuf *m, int af, int hlen) 279 { 280 int isr; 281 int32_t len; 282 283 M_ASSERTPKTHDR(m); 284 m_tag_delete_nonpersistent(m); 285 m->m_pkthdr.rcvif = ifp; 286 287 #ifdef MAC 288 mac_ifnet_create_mbuf(ifp, m); 289 #endif 290 291 /* 292 * Let BPF see incoming packet in the following manner: 293 * - Emulated packet loopback for a simplex interface 294 * (net/if_ethersubr.c) 295 * -> passes it to ifp's BPF 296 * - IPv4/v6 multicast packet loopback (netinet(6)/ip(6)_output.c) 297 * -> not passes it to any BPF 298 * - Normal packet loopback from myself to myself (net/if_loop.c) 299 * -> passes to lo0's BPF (even in case of IPv6, where ifp!=lo0) 300 */ 301 if (hlen > 0) { 302 if (bpf_peers_present(ifp->if_bpf)) { 303 bpf_mtap(ifp->if_bpf, m); 304 } 305 } else { 306 if (bpf_peers_present(V_loif->if_bpf)) { 307 if ((m->m_flags & M_MCAST) == 0 || V_loif == ifp) { 308 /* XXX beware sizeof(af) != 4 */ 309 u_int32_t af1 = af; 310 311 /* 312 * We need to prepend the address family. 313 */ 314 bpf_mtap2(V_loif->if_bpf, &af1, sizeof(af1), m); 315 } 316 } 317 } 318 319 /* Strip away media header */ 320 if (hlen > 0) { 321 m_adj(m, hlen); 322 #ifndef __NO_STRICT_ALIGNMENT 323 /* 324 * Some archs do not like unaligned data, so 325 * we move data down in the first mbuf. 326 */ 327 if (mtod(m, vm_offset_t) & 3) { 328 KASSERT(hlen >= 3, ("if_simloop: hlen too small")); 329 bcopy(m->m_data, 330 (char *)(mtod(m, vm_offset_t) 331 - (mtod(m, vm_offset_t) & 3)), 332 m->m_len); 333 m->m_data -= (mtod(m,vm_offset_t) & 3); 334 } 335 #endif 336 } 337 338 /* Deliver to upper layer protocol */ 339 switch (af) { 340 #ifdef INET 341 case AF_INET: 342 isr = NETISR_IP; 343 break; 344 #endif 345 #ifdef INET6 346 case AF_INET6: 347 m->m_flags |= M_LOOP; 348 isr = NETISR_IPV6; 349 break; 350 #endif 351 default: 352 printf("if_simloop: can't handle af=%d\n", af); 353 m_freem(m); 354 return (EAFNOSUPPORT); 355 } 356 len = m->m_pkthdr.len; 357 if (netisr_queue(isr, m) == 0) { 358 if_inc_counter(ifp, IFCOUNTER_IPACKETS, 1); 359 if_inc_counter(ifp, IFCOUNTER_IBYTES, len); 360 } else { 361 /* mbuf is free'd on failure. */ 362 if_inc_counter(ifp, IFCOUNTER_IQDROPS, 1); 363 } 364 return (0); 365 } 366 367 /* 368 * Process an ioctl request. 369 */ 370 static int 371 loioctl(struct ifnet *ifp, u_long cmd, caddr_t data) 372 { 373 struct ifreq *ifr = (struct ifreq *)data; 374 int error = 0, mask; 375 376 switch (cmd) { 377 case SIOCSIFADDR: 378 ifp->if_flags |= IFF_UP; 379 ifp->if_drv_flags |= IFF_DRV_RUNNING; 380 if_link_state_change(ifp, LINK_STATE_UP); 381 /* 382 * Everything else is done at a higher level. 383 */ 384 break; 385 386 case SIOCADDMULTI: 387 case SIOCDELMULTI: 388 if (ifr == NULL) { 389 error = EAFNOSUPPORT; /* XXX */ 390 break; 391 } 392 switch (ifr->ifr_addr.sa_family) { 393 #ifdef INET 394 case AF_INET: 395 break; 396 #endif 397 #ifdef INET6 398 case AF_INET6: 399 break; 400 #endif 401 402 default: 403 error = EAFNOSUPPORT; 404 break; 405 } 406 break; 407 408 case SIOCSIFMTU: 409 ifp->if_mtu = ifr->ifr_mtu; 410 break; 411 412 case SIOCSIFFLAGS: 413 if_link_state_change(ifp, (ifp->if_flags & IFF_UP) ? 414 LINK_STATE_UP: LINK_STATE_DOWN); 415 break; 416 417 case SIOCSIFCAP: 418 mask = ifp->if_capenable ^ ifr->ifr_reqcap; 419 if ((mask & IFCAP_RXCSUM) != 0) 420 ifp->if_capenable ^= IFCAP_RXCSUM; 421 if ((mask & IFCAP_TXCSUM) != 0) 422 ifp->if_capenable ^= IFCAP_TXCSUM; 423 if ((mask & IFCAP_RXCSUM_IPV6) != 0) { 424 #if 0 425 ifp->if_capenable ^= IFCAP_RXCSUM_IPV6; 426 #else 427 error = EOPNOTSUPP; 428 break; 429 #endif 430 } 431 if ((mask & IFCAP_TXCSUM_IPV6) != 0) { 432 #if 0 433 ifp->if_capenable ^= IFCAP_TXCSUM_IPV6; 434 #else 435 error = EOPNOTSUPP; 436 break; 437 #endif 438 } 439 ifp->if_hwassist = 0; 440 if (ifp->if_capenable & IFCAP_TXCSUM) 441 ifp->if_hwassist = LO_CSUM_FEATURES; 442 #if 0 443 if (ifp->if_capenable & IFCAP_TXCSUM_IPV6) 444 ifp->if_hwassist |= LO_CSUM_FEATURES6; 445 #endif 446 break; 447 448 default: 449 error = EINVAL; 450 } 451 return (error); 452 } 453