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 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 99 #ifdef VIMAGE 100 VNET_DEFINE_STATIC(struct if_clone *, lo_cloner); 101 #define V_lo_cloner VNET(lo_cloner) 102 #endif 103 104 static struct if_clone *lo_cloner; 105 static const char loname[] = "lo"; 106 107 static int 108 lo_clone_destroy(struct if_clone *ifc, struct ifnet *ifp, uint32_t flags) 109 { 110 if (ifp->if_dunit == 0 && (flags & IFC_F_FORCE) == 0) 111 return (EINVAL); 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 return (0); 123 } 124 125 static int 126 lo_clone_create(struct if_clone *ifc, char *name, size_t len, 127 struct ifc_data *ifd, struct ifnet **ifpp) 128 { 129 struct ifnet *ifp; 130 131 ifp = if_alloc(IFT_LOOP); 132 if (ifp == NULL) 133 return (ENOSPC); 134 135 if_initname(ifp, loname, ifd->unit); 136 ifp->if_mtu = LOMTU; 137 ifp->if_flags = IFF_LOOPBACK | IFF_MULTICAST; 138 ifp->if_ioctl = loioctl; 139 ifp->if_output = looutput; 140 ifp->if_snd.ifq_maxlen = ifqmaxlen; 141 ifp->if_capabilities = ifp->if_capenable = 142 IFCAP_HWCSUM | IFCAP_HWCSUM_IPV6 | IFCAP_LINKSTATE; 143 ifp->if_hwassist = LO_CSUM_FEATURES | LO_CSUM_FEATURES6; 144 if_attach(ifp); 145 bpfattach(ifp, DLT_NULL, sizeof(u_int32_t)); 146 if (V_loif == NULL) 147 V_loif = ifp; 148 *ifpp = ifp; 149 150 return (0); 151 } 152 153 static void 154 vnet_loif_init(const void *unused __unused) 155 { 156 struct if_clone_addreq req = { 157 .create_f = lo_clone_create, 158 .destroy_f = lo_clone_destroy, 159 .flags = IFC_F_AUTOUNIT, 160 }; 161 lo_cloner = ifc_attach_cloner(loname, &req); 162 #ifdef VIMAGE 163 V_lo_cloner = lo_cloner; 164 #endif 165 struct ifc_data ifd = { .unit = 0 }; 166 ifc_create_ifp(loname, &ifd, NULL); 167 } 168 VNET_SYSINIT(vnet_loif_init, SI_SUB_PSEUDO, SI_ORDER_ANY, 169 vnet_loif_init, NULL); 170 171 #ifdef VIMAGE 172 static void 173 vnet_loif_uninit(const void *unused __unused) 174 { 175 176 ifc_detach_cloner(V_lo_cloner); 177 V_loif = NULL; 178 } 179 VNET_SYSUNINIT(vnet_loif_uninit, SI_SUB_INIT_IF, SI_ORDER_SECOND, 180 vnet_loif_uninit, NULL); 181 #endif 182 183 static int 184 loop_modevent(module_t mod, int type, void *data) 185 { 186 187 switch (type) { 188 case MOD_LOAD: 189 break; 190 191 case MOD_UNLOAD: 192 printf("loop module unload - not possible for this module type\n"); 193 return (EINVAL); 194 195 default: 196 return (EOPNOTSUPP); 197 } 198 return (0); 199 } 200 201 static moduledata_t loop_mod = { 202 "if_lo", 203 loop_modevent, 204 0 205 }; 206 207 DECLARE_MODULE(if_lo, loop_mod, SI_SUB_PROTO_IFATTACHDOMAIN, SI_ORDER_ANY); 208 209 static int 210 looutput(struct ifnet *ifp, struct mbuf *m, const struct sockaddr *dst, 211 struct route *ro) 212 { 213 u_int32_t af; 214 #ifdef MAC 215 int error; 216 #endif 217 218 M_ASSERTPKTHDR(m); /* check if we have the packet header */ 219 220 #ifdef MAC 221 error = mac_ifnet_check_transmit(ifp, m); 222 if (error) { 223 m_freem(m); 224 return (error); 225 } 226 #endif 227 228 if (ro != NULL && ro->ro_flags & (RT_REJECT|RT_BLACKHOLE)) { 229 m_freem(m); 230 return (ro->ro_flags & RT_BLACKHOLE ? 0 : EHOSTUNREACH); 231 } 232 233 if_inc_counter(ifp, IFCOUNTER_OPACKETS, 1); 234 if_inc_counter(ifp, IFCOUNTER_OBYTES, m->m_pkthdr.len); 235 236 #ifdef RSS 237 M_HASHTYPE_CLEAR(m); 238 #endif 239 240 /* BPF writes need to be handled specially. */ 241 if (dst->sa_family == AF_UNSPEC || dst->sa_family == pseudo_AF_HDRCMPLT) 242 bcopy(dst->sa_data, &af, sizeof(af)); 243 else 244 af = RO_GET_FAMILY(ro, dst); 245 246 #if 1 /* XXX */ 247 switch (af) { 248 case AF_INET: 249 if (ifp->if_capenable & IFCAP_RXCSUM) { 250 m->m_pkthdr.csum_data = 0xffff; 251 m->m_pkthdr.csum_flags = LO_CSUM_SET; 252 } 253 m->m_pkthdr.csum_flags &= ~LO_CSUM_FEATURES; 254 break; 255 case AF_INET6: 256 #if 0 257 /* 258 * XXX-BZ for now always claim the checksum is good despite 259 * any interface flags. This is a workaround for 9.1-R and 260 * a proper solution ought to be sought later. 261 */ 262 if (ifp->if_capenable & IFCAP_RXCSUM_IPV6) { 263 m->m_pkthdr.csum_data = 0xffff; 264 m->m_pkthdr.csum_flags = LO_CSUM_SET; 265 } 266 #else 267 m->m_pkthdr.csum_data = 0xffff; 268 m->m_pkthdr.csum_flags = LO_CSUM_SET; 269 #endif 270 m->m_pkthdr.csum_flags &= ~LO_CSUM_FEATURES6; 271 break; 272 default: 273 printf("looutput: af=%d unexpected\n", af); 274 m_freem(m); 275 return (EAFNOSUPPORT); 276 } 277 #endif 278 return (if_simloop(ifp, m, af, 0)); 279 } 280 281 /* 282 * if_simloop() 283 * 284 * This function is to support software emulation of hardware loopback, 285 * i.e., for interfaces with the IFF_SIMPLEX attribute. Since they can't 286 * hear their own broadcasts, we create a copy of the packet that we 287 * would normally receive via a hardware loopback. 288 * 289 * This function expects the packet to include the media header of length hlen. 290 */ 291 int 292 if_simloop(struct ifnet *ifp, struct mbuf *m, int af, int hlen) 293 { 294 int isr; 295 296 M_ASSERTPKTHDR(m); 297 m_tag_delete_nonpersistent(m); 298 m->m_pkthdr.rcvif = ifp; 299 300 #ifdef MAC 301 mac_ifnet_create_mbuf(ifp, m); 302 #endif 303 304 /* 305 * Let BPF see incoming packet in the following manner: 306 * - Emulated packet loopback for a simplex interface 307 * (net/if_ethersubr.c) 308 * -> passes it to ifp's BPF 309 * - IPv4/v6 multicast packet loopback (netinet(6)/ip(6)_output.c) 310 * -> not passes it to any BPF 311 * - Normal packet loopback from myself to myself (net/if_loop.c) 312 * -> passes to lo0's BPF (even in case of IPv6, where ifp!=lo0) 313 */ 314 if (hlen > 0) { 315 if (bpf_peers_present(ifp->if_bpf)) { 316 bpf_mtap(ifp->if_bpf, m); 317 } 318 } else { 319 if (bpf_peers_present(V_loif->if_bpf)) { 320 if ((m->m_flags & M_MCAST) == 0 || V_loif == ifp) { 321 /* XXX beware sizeof(af) != 4 */ 322 u_int32_t af1 = af; 323 324 /* 325 * We need to prepend the address family. 326 */ 327 bpf_mtap2(V_loif->if_bpf, &af1, sizeof(af1), m); 328 } 329 } 330 } 331 332 /* Strip away media header */ 333 if (hlen > 0) { 334 m_adj(m, hlen); 335 #ifndef __NO_STRICT_ALIGNMENT 336 /* 337 * Some archs do not like unaligned data, so 338 * we move data down in the first mbuf. 339 */ 340 if (mtod(m, vm_offset_t) & 3) { 341 KASSERT(hlen >= 3, ("if_simloop: hlen too small")); 342 bcopy(m->m_data, 343 (char *)(mtod(m, vm_offset_t) 344 - (mtod(m, vm_offset_t) & 3)), 345 m->m_len); 346 m->m_data -= (mtod(m,vm_offset_t) & 3); 347 } 348 #endif 349 } 350 351 /* Deliver to upper layer protocol */ 352 switch (af) { 353 #ifdef INET 354 case AF_INET: 355 isr = NETISR_IP; 356 break; 357 #endif 358 #ifdef INET6 359 case AF_INET6: 360 m->m_flags |= M_LOOP; 361 isr = NETISR_IPV6; 362 break; 363 #endif 364 default: 365 printf("if_simloop: can't handle af=%d\n", af); 366 m_freem(m); 367 return (EAFNOSUPPORT); 368 } 369 if_inc_counter(ifp, IFCOUNTER_IPACKETS, 1); 370 if_inc_counter(ifp, IFCOUNTER_IBYTES, m->m_pkthdr.len); 371 netisr_queue(isr, m); /* mbuf is free'd on failure. */ 372 return (0); 373 } 374 375 /* 376 * Process an ioctl request. 377 */ 378 static int 379 loioctl(struct ifnet *ifp, u_long cmd, caddr_t data) 380 { 381 struct ifreq *ifr = (struct ifreq *)data; 382 int error = 0, mask; 383 384 switch (cmd) { 385 case SIOCSIFADDR: 386 ifp->if_flags |= IFF_UP; 387 ifp->if_drv_flags |= IFF_DRV_RUNNING; 388 if_link_state_change(ifp, LINK_STATE_UP); 389 /* 390 * Everything else is done at a higher level. 391 */ 392 break; 393 394 case SIOCADDMULTI: 395 case SIOCDELMULTI: 396 if (ifr == NULL) { 397 error = EAFNOSUPPORT; /* XXX */ 398 break; 399 } 400 switch (ifr->ifr_addr.sa_family) { 401 #ifdef INET 402 case AF_INET: 403 break; 404 #endif 405 #ifdef INET6 406 case AF_INET6: 407 break; 408 #endif 409 410 default: 411 error = EAFNOSUPPORT; 412 break; 413 } 414 break; 415 416 case SIOCSIFMTU: 417 ifp->if_mtu = ifr->ifr_mtu; 418 break; 419 420 case SIOCSIFFLAGS: 421 if_link_state_change(ifp, (ifp->if_flags & IFF_UP) ? 422 LINK_STATE_UP: LINK_STATE_DOWN); 423 break; 424 425 case SIOCSIFCAP: 426 mask = ifp->if_capenable ^ ifr->ifr_reqcap; 427 if ((mask & IFCAP_RXCSUM) != 0) 428 ifp->if_capenable ^= IFCAP_RXCSUM; 429 if ((mask & IFCAP_TXCSUM) != 0) 430 ifp->if_capenable ^= IFCAP_TXCSUM; 431 if ((mask & IFCAP_RXCSUM_IPV6) != 0) { 432 #if 0 433 ifp->if_capenable ^= IFCAP_RXCSUM_IPV6; 434 #else 435 error = EOPNOTSUPP; 436 break; 437 #endif 438 } 439 if ((mask & IFCAP_TXCSUM_IPV6) != 0) { 440 #if 0 441 ifp->if_capenable ^= IFCAP_TXCSUM_IPV6; 442 #else 443 error = EOPNOTSUPP; 444 break; 445 #endif 446 } 447 ifp->if_hwassist = 0; 448 if (ifp->if_capenable & IFCAP_TXCSUM) 449 ifp->if_hwassist = LO_CSUM_FEATURES; 450 #if 0 451 if (ifp->if_capenable & IFCAP_TXCSUM_IPV6) 452 ifp->if_hwassist |= LO_CSUM_FEATURES6; 453 #endif 454 break; 455 456 default: 457 error = EINVAL; 458 } 459 return (error); 460 } 461