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 M_HASHTYPE_CLEAR(m); 223 224 /* BPF writes need to be handled specially. */ 225 if (dst->sa_family == AF_UNSPEC || dst->sa_family == pseudo_AF_HDRCMPLT) 226 bcopy(dst->sa_data, &af, sizeof(af)); 227 else 228 af = RO_GET_FAMILY(ro, dst); 229 230 #if 1 /* XXX */ 231 switch (af) { 232 case AF_INET: 233 if (ifp->if_capenable & IFCAP_RXCSUM) { 234 m->m_pkthdr.csum_data = 0xffff; 235 m->m_pkthdr.csum_flags = LO_CSUM_SET; 236 } 237 m->m_pkthdr.csum_flags &= ~LO_CSUM_FEATURES; 238 break; 239 case AF_INET6: 240 #if 0 241 /* 242 * XXX-BZ for now always claim the checksum is good despite 243 * any interface flags. This is a workaround for 9.1-R and 244 * a proper solution ought to be sought later. 245 */ 246 if (ifp->if_capenable & IFCAP_RXCSUM_IPV6) { 247 m->m_pkthdr.csum_data = 0xffff; 248 m->m_pkthdr.csum_flags = LO_CSUM_SET; 249 } 250 #else 251 m->m_pkthdr.csum_data = 0xffff; 252 m->m_pkthdr.csum_flags = LO_CSUM_SET; 253 #endif 254 m->m_pkthdr.csum_flags &= ~LO_CSUM_FEATURES6; 255 break; 256 default: 257 printf("looutput: af=%d unexpected\n", af); 258 m_freem(m); 259 return (EAFNOSUPPORT); 260 } 261 #endif 262 return (if_simloop(ifp, m, af, 0)); 263 } 264 265 /* 266 * if_simloop() 267 * 268 * This function is to support software emulation of hardware loopback, 269 * i.e., for interfaces with the IFF_SIMPLEX attribute. Since they can't 270 * hear their own broadcasts, we create a copy of the packet that we 271 * would normally receive via a hardware loopback. 272 * 273 * This function expects the packet to include the media header of length hlen. 274 */ 275 int 276 if_simloop(struct ifnet *ifp, struct mbuf *m, int af, int hlen) 277 { 278 int isr; 279 int32_t len; 280 281 M_ASSERTPKTHDR(m); 282 m_tag_delete_nonpersistent(m); 283 m->m_pkthdr.rcvif = ifp; 284 285 #ifdef MAC 286 mac_ifnet_create_mbuf(ifp, m); 287 #endif 288 289 /* 290 * Let BPF see incoming packet in the following manner: 291 * - Emulated packet loopback for a simplex interface 292 * (net/if_ethersubr.c) 293 * -> passes it to ifp's BPF 294 * - IPv4/v6 multicast packet loopback (netinet(6)/ip(6)_output.c) 295 * -> not passes it to any BPF 296 * - Normal packet loopback from myself to myself (net/if_loop.c) 297 * -> passes to lo0's BPF (even in case of IPv6, where ifp!=lo0) 298 */ 299 if (hlen > 0) { 300 if (bpf_peers_present(ifp->if_bpf)) { 301 bpf_mtap(ifp->if_bpf, m); 302 } 303 } else { 304 if (bpf_peers_present(V_loif->if_bpf)) { 305 if ((m->m_flags & M_MCAST) == 0 || V_loif == ifp) { 306 /* XXX beware sizeof(af) != 4 */ 307 u_int32_t af1 = af; 308 309 /* 310 * We need to prepend the address family. 311 */ 312 bpf_mtap2(V_loif->if_bpf, &af1, sizeof(af1), m); 313 } 314 } 315 } 316 317 /* Strip away media header */ 318 if (hlen > 0) { 319 m_adj(m, hlen); 320 #ifndef __NO_STRICT_ALIGNMENT 321 /* 322 * Some archs do not like unaligned data, so 323 * we move data down in the first mbuf. 324 */ 325 if (mtod(m, vm_offset_t) & 3) { 326 KASSERT(hlen >= 3, ("if_simloop: hlen too small")); 327 bcopy(m->m_data, 328 (char *)(mtod(m, vm_offset_t) 329 - (mtod(m, vm_offset_t) & 3)), 330 m->m_len); 331 m->m_data -= (mtod(m,vm_offset_t) & 3); 332 } 333 #endif 334 } 335 336 /* Deliver to upper layer protocol */ 337 switch (af) { 338 #ifdef INET 339 case AF_INET: 340 isr = NETISR_IP; 341 break; 342 #endif 343 #ifdef INET6 344 case AF_INET6: 345 m->m_flags |= M_LOOP; 346 isr = NETISR_IPV6; 347 break; 348 #endif 349 default: 350 printf("if_simloop: can't handle af=%d\n", af); 351 m_freem(m); 352 return (EAFNOSUPPORT); 353 } 354 len = m->m_pkthdr.len; 355 if (netisr_queue(isr, m) == 0) { 356 if_inc_counter(ifp, IFCOUNTER_IPACKETS, 1); 357 if_inc_counter(ifp, IFCOUNTER_IBYTES, len); 358 } else { 359 /* mbuf is free'd on failure. */ 360 if_inc_counter(ifp, IFCOUNTER_IQDROPS, 1); 361 } 362 return (0); 363 } 364 365 /* 366 * Process an ioctl request. 367 */ 368 static int 369 loioctl(struct ifnet *ifp, u_long cmd, caddr_t data) 370 { 371 struct ifreq *ifr = (struct ifreq *)data; 372 int error = 0, mask; 373 374 switch (cmd) { 375 case SIOCSIFADDR: 376 ifp->if_flags |= IFF_UP; 377 ifp->if_drv_flags |= IFF_DRV_RUNNING; 378 if_link_state_change(ifp, LINK_STATE_UP); 379 /* 380 * Everything else is done at a higher level. 381 */ 382 break; 383 384 case SIOCADDMULTI: 385 case SIOCDELMULTI: 386 if (ifr == NULL) { 387 error = EAFNOSUPPORT; /* XXX */ 388 break; 389 } 390 switch (ifr->ifr_addr.sa_family) { 391 #ifdef INET 392 case AF_INET: 393 break; 394 #endif 395 #ifdef INET6 396 case AF_INET6: 397 break; 398 #endif 399 400 default: 401 error = EAFNOSUPPORT; 402 break; 403 } 404 break; 405 406 case SIOCSIFMTU: 407 ifp->if_mtu = ifr->ifr_mtu; 408 break; 409 410 case SIOCSIFFLAGS: 411 if_link_state_change(ifp, (ifp->if_flags & IFF_UP) ? 412 LINK_STATE_UP: LINK_STATE_DOWN); 413 break; 414 415 case SIOCSIFCAP: 416 mask = ifp->if_capenable ^ ifr->ifr_reqcap; 417 if ((mask & IFCAP_RXCSUM) != 0) 418 ifp->if_capenable ^= IFCAP_RXCSUM; 419 if ((mask & IFCAP_TXCSUM) != 0) 420 ifp->if_capenable ^= IFCAP_TXCSUM; 421 if ((mask & IFCAP_RXCSUM_IPV6) != 0) { 422 #if 0 423 ifp->if_capenable ^= IFCAP_RXCSUM_IPV6; 424 #else 425 error = EOPNOTSUPP; 426 break; 427 #endif 428 } 429 if ((mask & IFCAP_TXCSUM_IPV6) != 0) { 430 #if 0 431 ifp->if_capenable ^= IFCAP_TXCSUM_IPV6; 432 #else 433 error = EOPNOTSUPP; 434 break; 435 #endif 436 } 437 ifp->if_hwassist = 0; 438 if (ifp->if_capenable & IFCAP_TXCSUM) 439 ifp->if_hwassist = LO_CSUM_FEATURES; 440 #if 0 441 if (ifp->if_capenable & IFCAP_TXCSUM_IPV6) 442 ifp->if_hwassist |= LO_CSUM_FEATURES6; 443 #endif 444 break; 445 446 default: 447 error = EINVAL; 448 } 449 return (error); 450 } 451