1 /* $OpenBSD: if_loop.c,v 1.99 2025/01/03 21:27:40 bluhm Exp $ */ 2 /* $NetBSD: if_loop.c,v 1.15 1996/05/07 02:40:33 thorpej Exp $ */ 3 4 /* 5 * Copyright (C) 1995, 1996, 1997, and 1998 WIDE Project. 6 * All rights reserved. 7 * 8 * Redistribution and use in source and binary forms, with or without 9 * modification, are permitted provided that the following conditions 10 * are met: 11 * 1. Redistributions of source code must retain the above copyright 12 * notice, this list of conditions and the following disclaimer. 13 * 2. Redistributions in binary form must reproduce the above copyright 14 * notice, this list of conditions and the following disclaimer in the 15 * documentation and/or other materials provided with the distribution. 16 * 3. Neither the name of the project nor the names of its contributors 17 * may be used to endorse or promote products derived from this software 18 * without specific prior written permission. 19 * 20 * THIS SOFTWARE IS PROVIDED BY THE PROJECT AND CONTRIBUTORS ``AS IS'' AND 21 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 22 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 23 * ARE DISCLAIMED. IN NO EVENT SHALL THE PROJECT OR CONTRIBUTORS BE LIABLE 24 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 25 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 26 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 27 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 28 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 29 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 30 * SUCH DAMAGE. 31 */ 32 33 /* 34 * Copyright (c) 1982, 1986, 1993 35 * The Regents of the University of California. All rights reserved. 36 * 37 * Redistribution and use in source and binary forms, with or without 38 * modification, are permitted provided that the following conditions 39 * are met: 40 * 1. Redistributions of source code must retain the above copyright 41 * notice, this list of conditions and the following disclaimer. 42 * 2. Redistributions in binary form must reproduce the above copyright 43 * notice, this list of conditions and the following disclaimer in the 44 * documentation and/or other materials provided with the distribution. 45 * 3. Neither the name of the University nor the names of its contributors 46 * may be used to endorse or promote products derived from this software 47 * without specific prior written permission. 48 * 49 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 50 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 51 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 52 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 53 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 54 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 55 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 56 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 57 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 58 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 59 * SUCH DAMAGE. 60 * 61 * @(#)if_loop.c 8.1 (Berkeley) 6/10/93 62 */ 63 64 /* 65 * @(#)COPYRIGHT 1.1 (NRL) 17 January 1995 66 * 67 * NRL grants permission for redistribution and use in source and binary 68 * forms, with or without modification, of the software and documentation 69 * created at NRL provided that the following conditions are met: 70 * 71 * 1. Redistributions of source code must retain the above copyright 72 * notice, this list of conditions and the following disclaimer. 73 * 2. Redistributions in binary form must reproduce the above copyright 74 * notice, this list of conditions and the following disclaimer in the 75 * documentation and/or other materials provided with the distribution. 76 * 3. All advertising materials mentioning features or use of this software 77 * must display the following acknowledgements: 78 * This product includes software developed by the University of 79 * California, Berkeley and its contributors. 80 * This product includes software developed at the Information 81 * Technology Division, US Naval Research Laboratory. 82 * 4. Neither the name of the NRL nor the names of its contributors 83 * may be used to endorse or promote products derived from this software 84 * without specific prior written permission. 85 * 86 * THE SOFTWARE PROVIDED BY NRL IS PROVIDED BY NRL AND CONTRIBUTORS ``AS 87 * IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED 88 * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A 89 * PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL NRL OR 90 * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, 91 * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, 92 * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR 93 * PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF 94 * LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING 95 * NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS 96 * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 97 * 98 * The views and conclusions contained in the software and documentation 99 * are those of the authors and should not be interpreted as representing 100 * official policies, either expressed or implied, of the US Naval 101 * Research Laboratory (NRL). 102 */ 103 104 /* 105 * Loopback interface driver for protocol testing and timing. 106 */ 107 108 #include "bpfilter.h" 109 110 #include <sys/param.h> 111 #include <sys/systm.h> 112 #include <sys/kernel.h> 113 #include <sys/mbuf.h> 114 #include <sys/socket.h> 115 #include <sys/errno.h> 116 #include <sys/ioctl.h> 117 #include <sys/time.h> 118 119 120 #include <net/if.h> 121 #include <net/if_var.h> 122 #include <net/if_types.h> 123 #include <net/netisr.h> 124 #include <net/rtable.h> 125 #include <net/route.h> 126 127 #include <netinet/in.h> 128 129 #ifdef INET6 130 #include <netinet/ip6.h> 131 #endif 132 133 #ifdef MPLS 134 #include <netmpls/mpls.h> 135 #endif 136 137 #if NBPFILTER > 0 138 #include <net/bpf.h> 139 #endif 140 141 #define LOMTU 32768 142 143 int loioctl(struct ifnet *, u_long, caddr_t); 144 void loopattach(int); 145 void lortrequest(struct ifnet *, int, struct rtentry *); 146 void loinput(struct ifnet *, struct mbuf *); 147 int looutput(struct ifnet *, 148 struct mbuf *, struct sockaddr *, struct rtentry *); 149 int lo_bpf_mtap(caddr_t, const struct mbuf *, u_int); 150 151 int loop_clone_create(struct if_clone *, int); 152 int loop_clone_destroy(struct ifnet *); 153 154 struct if_clone loop_cloner = 155 IF_CLONE_INITIALIZER("lo", loop_clone_create, loop_clone_destroy); 156 157 void 158 loopattach(int n) 159 { 160 if (loop_clone_create(&loop_cloner, 0)) 161 panic("unable to create lo0"); 162 163 if_clone_attach(&loop_cloner); 164 } 165 166 int 167 loop_clone_create(struct if_clone *ifc, int unit) 168 { 169 struct ifnet *ifp; 170 171 ifp = malloc(sizeof(*ifp), M_DEVBUF, M_WAITOK|M_ZERO); 172 snprintf(ifp->if_xname, sizeof ifp->if_xname, "lo%d", unit); 173 ifp->if_softc = NULL; 174 ifp->if_mtu = LOMTU; 175 ifp->if_flags = IFF_LOOPBACK | IFF_MULTICAST; 176 ifp->if_xflags = IFXF_CLONED | IFXF_LRO; 177 ifp->if_capabilities = IFCAP_CSUM_IPv4 | 178 IFCAP_CSUM_TCPv4 | IFCAP_CSUM_UDPv4 | 179 IFCAP_CSUM_TCPv6 | IFCAP_CSUM_UDPv6 | 180 IFCAP_LRO | IFCAP_TSOv4 | IFCAP_TSOv6; 181 ifp->if_bpf_mtap = lo_bpf_mtap; 182 ifp->if_rtrequest = lortrequest; 183 ifp->if_ioctl = loioctl; 184 ifp->if_input = loinput; 185 ifp->if_output = looutput; 186 ifp->if_type = IFT_LOOP; 187 ifp->if_hdrlen = sizeof(u_int32_t); 188 if_counters_alloc(ifp); 189 if (unit == 0) { 190 if_attachhead(ifp); 191 if_addgroup(ifp, ifc->ifc_name); 192 rtable_l2set(0, 0, ifp->if_index); 193 } else 194 if_attach(ifp); 195 if_alloc_sadl(ifp); 196 #if NBPFILTER > 0 197 bpfattach(&ifp->if_bpf, ifp, DLT_LOOP, sizeof(u_int32_t)); 198 #endif 199 return (0); 200 } 201 202 int 203 loop_clone_destroy(struct ifnet *ifp) 204 { 205 struct ifnet *p; 206 unsigned int rdomain = 0; 207 208 if (ifp->if_index == rtable_loindex(ifp->if_rdomain)) { 209 /* rdomain 0 always needs a loopback */ 210 if (ifp->if_rdomain == 0) 211 return (EPERM); 212 213 /* if there is any other interface in this rdomain, deny */ 214 NET_LOCK_SHARED(); 215 TAILQ_FOREACH(p, &ifnetlist, if_list) { 216 if (p->if_rdomain != ifp->if_rdomain) 217 continue; 218 if (p->if_index == ifp->if_index) 219 continue; 220 NET_UNLOCK_SHARED(); 221 return (EBUSY); 222 } 223 NET_UNLOCK_SHARED(); 224 225 rdomain = ifp->if_rdomain; 226 } 227 228 if_detach(ifp); 229 230 free(ifp, M_DEVBUF, sizeof(*ifp)); 231 232 if (rdomain) 233 rtable_l2set(rdomain, 0, 0); 234 return (0); 235 } 236 237 int 238 lo_bpf_mtap(caddr_t if_bpf, const struct mbuf *m, u_int dir) 239 { 240 /* loopback dumps on output, disable input bpf */ 241 return (0); 242 } 243 244 void 245 loinput(struct ifnet *ifp, struct mbuf *m) 246 { 247 int error; 248 249 if ((m->m_flags & M_PKTHDR) == 0) 250 panic("%s: no header mbuf", __func__); 251 252 error = if_input_local(ifp, m, m->m_pkthdr.ph_family); 253 if (error) 254 counters_inc(ifp->if_counters, ifc_ierrors); 255 } 256 257 int 258 looutput(struct ifnet *ifp, struct mbuf *m, struct sockaddr *dst, 259 struct rtentry *rt) 260 { 261 if ((m->m_flags & M_PKTHDR) == 0) 262 panic("%s: no header mbuf", __func__); 263 264 if (rt && rt->rt_flags & (RTF_REJECT|RTF_BLACKHOLE)) { 265 m_freem(m); 266 return (rt->rt_flags & RTF_BLACKHOLE ? 0 : 267 rt->rt_flags & RTF_HOST ? EHOSTUNREACH : ENETUNREACH); 268 } 269 270 /* 271 * Do not call if_input_local() directly. Queue the packet to avoid 272 * stack overflow and make TCP handshake over loopback work. 273 */ 274 return (if_output_local(ifp, m, dst->sa_family)); 275 } 276 277 void 278 lortrequest(struct ifnet *ifp, int cmd, struct rtentry *rt) 279 { 280 if (rt != NULL) 281 atomic_cas_uint(&rt->rt_mtu, 0, LOMTU); 282 } 283 284 /* 285 * Process an ioctl request. 286 */ 287 int 288 loioctl(struct ifnet *ifp, u_long cmd, caddr_t data) 289 { 290 struct ifreq *ifr; 291 int error = 0; 292 293 switch (cmd) { 294 case SIOCSIFFLAGS: 295 if (ISSET(ifp->if_xflags, IFXF_LRO)) 296 SET(ifp->if_capabilities, IFCAP_TSOv4 | IFCAP_TSOv6); 297 else 298 CLR(ifp->if_capabilities, IFCAP_TSOv4 | IFCAP_TSOv6); 299 break; 300 301 case SIOCSIFADDR: 302 ifp->if_flags |= IFF_RUNNING; 303 if_up(ifp); /* send up RTM_IFINFO */ 304 /* 305 * Everything else is done at a higher level. 306 */ 307 break; 308 309 case SIOCADDMULTI: 310 case SIOCDELMULTI: 311 break; 312 313 case SIOCSIFMTU: 314 ifr = (struct ifreq *)data; 315 ifp->if_mtu = ifr->ifr_mtu; 316 break; 317 318 default: 319 error = ENOTTY; 320 } 321 return (error); 322 } 323