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_IP_TCP | CSUM_IP_UDP | \ 85 CSUM_IP_SCTP) 86 #define LO_CSUM_FEATURES6 (CSUM_IP6_TCP | CSUM_IP6_UDP | CSUM_IP6_SCTP) 87 #define LO_CSUM_SET (CSUM_L3_CALC | CSUM_L3_VALID | \ 88 CSUM_L4_CALC | CSUM_L4_VALID) 89 90 static int loioctl(struct ifnet *, u_long, caddr_t); 91 static int looutput(struct ifnet *ifp, struct mbuf *m, 92 const struct sockaddr *dst, struct route *ro); 93 94 VNET_DEFINE(struct ifnet *, loif); /* Used externally */ 95 VNET_DEFINE_STATIC(struct if_clone *, lo_cloner); 96 #define V_lo_cloner VNET(lo_cloner) 97 98 static const char loname[] = "lo"; 99 100 static int 101 lo_clone_destroy(struct if_clone *ifc, struct ifnet *ifp, uint32_t flags) 102 { 103 if (ifp->if_dunit == 0 && (flags & IFC_F_FORCE) == 0) 104 return (EINVAL); 105 106 #ifndef VIMAGE 107 /* XXX: destroying lo0 will lead to panics. */ 108 KASSERT(V_loif != ifp, ("%s: destroying lo0", __func__)); 109 #endif 110 111 bpfdetach(ifp); 112 if_detach(ifp); 113 if_free(ifp); 114 115 return (0); 116 } 117 118 static int 119 lo_clone_create(struct if_clone *ifc, char *name, size_t len, 120 struct ifc_data *ifd, struct ifnet **ifpp) 121 { 122 struct ifnet *ifp; 123 124 ifp = if_alloc(IFT_LOOP); 125 if_initname(ifp, loname, ifd->unit); 126 ifp->if_mtu = LOMTU; 127 ifp->if_flags = IFF_LOOPBACK | IFF_MULTICAST; 128 ifp->if_ioctl = loioctl; 129 ifp->if_output = looutput; 130 ifp->if_snd.ifq_maxlen = ifqmaxlen; 131 ifp->if_capabilities = ifp->if_capenable = 132 IFCAP_HWCSUM | IFCAP_HWCSUM_IPV6 | IFCAP_LINKSTATE; 133 ifp->if_hwassist = LO_CSUM_FEATURES | LO_CSUM_FEATURES6; 134 if_attach(ifp); 135 bpfattach(ifp, DLT_NULL, sizeof(u_int32_t)); 136 *ifpp = ifp; 137 138 return (0); 139 } 140 141 static void 142 vnet_loif_init(const void *unused __unused) 143 { 144 struct if_clone_addreq req = { 145 .create_f = lo_clone_create, 146 .destroy_f = lo_clone_destroy, 147 .flags = IFC_F_AUTOUNIT, 148 }; 149 V_lo_cloner = ifc_attach_cloner(loname, &req); 150 struct ifc_data ifd = { .unit = 0 }; 151 ifc_create_ifp(loname, &ifd, &V_loif); 152 } 153 VNET_SYSINIT(vnet_loif_init, SI_SUB_PROTO_IF, SI_ORDER_ANY, 154 vnet_loif_init, NULL); 155 156 #ifdef VIMAGE 157 static void 158 vnet_loif_uninit(const void *unused __unused) 159 { 160 161 ifc_detach_cloner(V_lo_cloner); 162 V_loif = NULL; 163 } 164 VNET_SYSUNINIT(vnet_loif_uninit, SI_SUB_INIT_IF, SI_ORDER_SECOND, 165 vnet_loif_uninit, NULL); 166 #endif 167 168 static int 169 loop_modevent(module_t mod, int type, void *data) 170 { 171 172 switch (type) { 173 case MOD_LOAD: 174 break; 175 176 case MOD_UNLOAD: 177 printf("loop module unload - not possible for this module type\n"); 178 return (EINVAL); 179 180 default: 181 return (EOPNOTSUPP); 182 } 183 return (0); 184 } 185 186 static moduledata_t loop_mod = { 187 "if_lo", 188 loop_modevent, 189 0 190 }; 191 192 DECLARE_MODULE(if_lo, loop_mod, SI_SUB_PROTO_IFATTACHDOMAIN, SI_ORDER_ANY); 193 194 static int 195 looutput(struct ifnet *ifp, struct mbuf *m, const struct sockaddr *dst, 196 struct route *ro) 197 { 198 u_int32_t af; 199 #ifdef MAC 200 int error; 201 #endif 202 203 M_ASSERTPKTHDR(m); /* check if we have the packet header */ 204 205 #ifdef MAC 206 error = mac_ifnet_check_transmit(ifp, m); 207 if (error) { 208 m_freem(m); 209 return (error); 210 } 211 #endif 212 213 if (ro != NULL && ro->ro_flags & (RT_REJECT|RT_BLACKHOLE)) { 214 m_freem(m); 215 return (ro->ro_flags & RT_BLACKHOLE ? 0 : EHOSTUNREACH); 216 } 217 218 if_inc_counter(ifp, IFCOUNTER_OPACKETS, 1); 219 if_inc_counter(ifp, IFCOUNTER_OBYTES, m->m_pkthdr.len); 220 221 #ifdef RSS 222 M_HASHTYPE_CLEAR(m); 223 #endif 224 225 /* BPF writes need to be handled specially. */ 226 if (dst->sa_family == AF_UNSPEC || dst->sa_family == pseudo_AF_HDRCMPLT) 227 bcopy(dst->sa_data, &af, sizeof(af)); 228 else 229 af = RO_GET_FAMILY(ro, dst); 230 231 switch (af) { 232 case AF_INET: 233 if ((ifp->if_capenable & IFCAP_RXCSUM) == 0) { 234 m->m_pkthdr.csum_flags &= ~LO_CSUM_SET; 235 } 236 break; 237 case AF_INET6: 238 if ((ifp->if_capenable & IFCAP_RXCSUM_IPV6) == 0) { 239 m->m_pkthdr.csum_flags &= ~LO_CSUM_SET; 240 } 241 break; 242 default: 243 printf("looutput: af=%d unexpected\n", af); 244 m_freem(m); 245 return (EAFNOSUPPORT); 246 } 247 return (if_simloop(ifp, m, af, 0)); 248 } 249 250 /* 251 * if_simloop() 252 * 253 * This function is to support software emulation of hardware loopback, 254 * i.e., for interfaces with the IFF_SIMPLEX attribute. Since they can't 255 * hear their own broadcasts, we create a copy of the packet that we 256 * would normally receive via a hardware loopback. 257 * 258 * This function expects the packet to include the media header of length hlen. 259 */ 260 int 261 if_simloop(struct ifnet *ifp, struct mbuf *m, int af, int hlen) 262 { 263 int isr; 264 int32_t len; 265 266 M_ASSERTPKTHDR(m); 267 m_tag_delete_nonpersistent(m); 268 m->m_pkthdr.rcvif = ifp; 269 270 #ifdef MAC 271 mac_ifnet_create_mbuf(ifp, m); 272 #endif 273 274 /* 275 * Let BPF see incoming packet in the following manner: 276 * - Emulated packet loopback for a simplex interface 277 * (net/if_ethersubr.c) 278 * -> passes it to ifp's BPF 279 * - IPv4/v6 multicast packet loopback (netinet(6)/ip(6)_output.c) 280 * -> not passes it to any BPF 281 * - Normal packet loopback from myself to myself (net/if_loop.c) 282 * -> passes to lo0's BPF (even in case of IPv6, where ifp!=lo0) 283 */ 284 if (hlen > 0) { 285 if (bpf_peers_present(ifp->if_bpf)) { 286 bpf_mtap(ifp->if_bpf, m); 287 } 288 } else { 289 if (bpf_peers_present(V_loif->if_bpf)) { 290 if ((m->m_flags & M_MCAST) == 0 || V_loif == ifp) { 291 /* XXX beware sizeof(af) != 4 */ 292 u_int32_t af1 = af; 293 294 /* 295 * We need to prepend the address family. 296 */ 297 bpf_mtap2(V_loif->if_bpf, &af1, sizeof(af1), m); 298 } 299 } 300 } 301 302 /* Strip away media header */ 303 if (hlen > 0) { 304 m_adj(m, hlen); 305 #ifndef __NO_STRICT_ALIGNMENT 306 /* 307 * Some archs do not like unaligned data, so 308 * we move data down in the first mbuf. 309 */ 310 if (mtod(m, vm_offset_t) & 3) { 311 KASSERT(hlen >= 3, ("if_simloop: hlen too small")); 312 bcopy(m->m_data, 313 (char *)(mtod(m, vm_offset_t) 314 - (mtod(m, vm_offset_t) & 3)), 315 m->m_len); 316 m->m_data -= (mtod(m,vm_offset_t) & 3); 317 } 318 #endif 319 } 320 321 /* Deliver to upper layer protocol */ 322 switch (af) { 323 #ifdef INET 324 case AF_INET: 325 isr = NETISR_IP; 326 break; 327 #endif 328 #ifdef INET6 329 case AF_INET6: 330 m->m_flags |= M_LOOP; 331 isr = NETISR_IPV6; 332 break; 333 #endif 334 default: 335 printf("if_simloop: can't handle af=%d\n", af); 336 m_freem(m); 337 return (EAFNOSUPPORT); 338 } 339 len = m->m_pkthdr.len; 340 if (netisr_queue(isr, m) == 0) { 341 if_inc_counter(ifp, IFCOUNTER_IPACKETS, 1); 342 if_inc_counter(ifp, IFCOUNTER_IBYTES, len); 343 } else { 344 /* mbuf is free'd on failure. */ 345 if_inc_counter(ifp, IFCOUNTER_IQDROPS, 1); 346 } 347 return (0); 348 } 349 350 /* 351 * Process an ioctl request. 352 */ 353 static int 354 loioctl(struct ifnet *ifp, u_long cmd, caddr_t data) 355 { 356 struct ifreq *ifr = (struct ifreq *)data; 357 int error = 0, mask; 358 359 switch (cmd) { 360 case SIOCSIFADDR: 361 ifp->if_flags |= IFF_UP; 362 ifp->if_drv_flags |= IFF_DRV_RUNNING; 363 if_link_state_change(ifp, LINK_STATE_UP); 364 /* 365 * Everything else is done at a higher level. 366 */ 367 break; 368 369 case SIOCADDMULTI: 370 case SIOCDELMULTI: 371 if (ifr == NULL) { 372 error = EAFNOSUPPORT; /* XXX */ 373 break; 374 } 375 switch (ifr->ifr_addr.sa_family) { 376 #ifdef INET 377 case AF_INET: 378 break; 379 #endif 380 #ifdef INET6 381 case AF_INET6: 382 break; 383 #endif 384 385 default: 386 error = EAFNOSUPPORT; 387 break; 388 } 389 break; 390 391 case SIOCSIFMTU: 392 ifp->if_mtu = ifr->ifr_mtu; 393 break; 394 395 case SIOCSIFFLAGS: 396 if_link_state_change(ifp, (ifp->if_flags & IFF_UP) ? 397 LINK_STATE_UP: LINK_STATE_DOWN); 398 break; 399 400 case SIOCSIFCAP: 401 mask = ifp->if_capenable ^ ifr->ifr_reqcap; 402 if ((mask & IFCAP_RXCSUM) != 0) 403 ifp->if_capenable ^= IFCAP_RXCSUM; 404 if ((mask & IFCAP_TXCSUM) != 0) 405 ifp->if_capenable ^= IFCAP_TXCSUM; 406 if ((mask & IFCAP_RXCSUM_IPV6) != 0) 407 ifp->if_capenable ^= IFCAP_RXCSUM_IPV6; 408 if ((mask & IFCAP_TXCSUM_IPV6) != 0) 409 ifp->if_capenable ^= IFCAP_TXCSUM_IPV6; 410 ifp->if_hwassist = 0; 411 if (ifp->if_capenable & IFCAP_TXCSUM) 412 ifp->if_hwassist = LO_CSUM_FEATURES; 413 if (ifp->if_capenable & IFCAP_TXCSUM_IPV6) 414 ifp->if_hwassist |= LO_CSUM_FEATURES6; 415 break; 416 417 default: 418 error = EINVAL; 419 } 420 return (error); 421 } 422