1 /* $OpenBSD: if_loop.c,v 1.95 2023/07/02 19:59:15 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 *); 149 150 int loop_clone_create(struct if_clone *, int); 151 int loop_clone_destroy(struct ifnet *); 152 153 struct if_clone loop_cloner = 154 IF_CLONE_INITIALIZER("lo", loop_clone_create, loop_clone_destroy); 155 156 void 157 loopattach(int n) 158 { 159 if (loop_clone_create(&loop_cloner, 0)) 160 panic("unable to create lo0"); 161 162 if_clone_attach(&loop_cloner); 163 } 164 165 int 166 loop_clone_create(struct if_clone *ifc, int unit) 167 { 168 struct ifnet *ifp; 169 170 ifp = malloc(sizeof(*ifp), M_DEVBUF, M_WAITOK|M_ZERO); 171 snprintf(ifp->if_xname, sizeof ifp->if_xname, "lo%d", unit); 172 ifp->if_softc = NULL; 173 ifp->if_mtu = LOMTU; 174 ifp->if_flags = IFF_LOOPBACK | IFF_MULTICAST; 175 ifp->if_xflags = IFXF_CLONED; 176 ifp->if_capabilities = IFCAP_CSUM_IPv4 | 177 IFCAP_CSUM_TCPv4 | IFCAP_CSUM_UDPv4 | 178 IFCAP_CSUM_TCPv6 | IFCAP_CSUM_UDPv6 | 179 IFCAP_LRO; 180 ifp->if_rtrequest = lortrequest; 181 ifp->if_ioctl = loioctl; 182 ifp->if_input = loinput; 183 ifp->if_output = looutput; 184 ifp->if_type = IFT_LOOP; 185 ifp->if_hdrlen = sizeof(u_int32_t); 186 if (unit == 0) { 187 if_attachhead(ifp); 188 if_addgroup(ifp, ifc->ifc_name); 189 rtable_l2set(0, 0, ifp->if_index); 190 } else 191 if_attach(ifp); 192 if_alloc_sadl(ifp); 193 #if NBPFILTER > 0 194 bpfattach(&ifp->if_bpf, ifp, DLT_LOOP, sizeof(u_int32_t)); 195 #endif 196 return (0); 197 } 198 199 int 200 loop_clone_destroy(struct ifnet *ifp) 201 { 202 struct ifnet *p; 203 unsigned int rdomain = 0; 204 205 if (ifp->if_index == rtable_loindex(ifp->if_rdomain)) { 206 /* rdomain 0 always needs a loopback */ 207 if (ifp->if_rdomain == 0) 208 return (EPERM); 209 210 /* if there is any other interface in this rdomain, deny */ 211 NET_LOCK_SHARED(); 212 TAILQ_FOREACH(p, &ifnetlist, if_list) { 213 if (p->if_rdomain != ifp->if_rdomain) 214 continue; 215 if (p->if_index == ifp->if_index) 216 continue; 217 NET_UNLOCK_SHARED(); 218 return (EBUSY); 219 } 220 NET_UNLOCK_SHARED(); 221 222 rdomain = ifp->if_rdomain; 223 } 224 225 if_detach(ifp); 226 227 free(ifp, M_DEVBUF, sizeof(*ifp)); 228 229 if (rdomain) 230 rtable_l2set(rdomain, 0, 0); 231 return (0); 232 } 233 234 void 235 loinput(struct ifnet *ifp, struct mbuf *m) 236 { 237 int error; 238 239 if ((m->m_flags & M_PKTHDR) == 0) 240 panic("%s: no header mbuf", __func__); 241 242 error = if_input_local(ifp, m, m->m_pkthdr.ph_family); 243 if (error) 244 ifp->if_ierrors++; 245 } 246 247 int 248 looutput(struct ifnet *ifp, struct mbuf *m, struct sockaddr *dst, 249 struct rtentry *rt) 250 { 251 if ((m->m_flags & M_PKTHDR) == 0) 252 panic("%s: no header mbuf", __func__); 253 254 if (rt && rt->rt_flags & (RTF_REJECT|RTF_BLACKHOLE)) { 255 m_freem(m); 256 return (rt->rt_flags & RTF_BLACKHOLE ? 0 : 257 rt->rt_flags & RTF_HOST ? EHOSTUNREACH : ENETUNREACH); 258 } 259 260 /* 261 * Do not call if_input_local() directly. Queue the packet to avoid 262 * stack overflow and make TCP handshake over loopback work. 263 */ 264 return (if_output_local(ifp, m, dst->sa_family)); 265 } 266 267 void 268 lortrequest(struct ifnet *ifp, int cmd, struct rtentry *rt) 269 { 270 if (rt && rt->rt_mtu == 0) 271 rt->rt_mtu = LOMTU; 272 } 273 274 /* 275 * Process an ioctl request. 276 */ 277 int 278 loioctl(struct ifnet *ifp, u_long cmd, caddr_t data) 279 { 280 struct ifreq *ifr; 281 int error = 0; 282 283 switch (cmd) { 284 case SIOCSIFFLAGS: 285 if (ISSET(ifp->if_xflags, IFXF_LRO)) 286 SET(ifp->if_capabilities, IFCAP_TSOv4 | IFCAP_TSOv6); 287 else 288 CLR(ifp->if_capabilities, IFCAP_TSOv4 | IFCAP_TSOv6); 289 break; 290 291 case SIOCSIFADDR: 292 ifp->if_flags |= IFF_RUNNING; 293 if_up(ifp); /* send up RTM_IFINFO */ 294 /* 295 * Everything else is done at a higher level. 296 */ 297 break; 298 299 case SIOCADDMULTI: 300 case SIOCDELMULTI: 301 break; 302 303 case SIOCSIFMTU: 304 ifr = (struct ifreq *)data; 305 ifp->if_mtu = ifr->ifr_mtu; 306 break; 307 308 default: 309 error = ENOTTY; 310 } 311 return (error); 312 } 313