/* $OpenBSD: if_loop.c,v 1.103 2025/09/09 09:16:18 bluhm Exp $ */ /* $NetBSD: if_loop.c,v 1.15 1996/05/07 02:40:33 thorpej Exp $ */ /* * Copyright (C) 1995, 1996, 1997, and 1998 WIDE Project. * All rights reserved. * * Redistribution and use in source and binary forms, with or without * modification, are permitted provided that the following conditions * are met: * 1. Redistributions of source code must retain the above copyright * notice, this list of conditions and the following disclaimer. * 2. Redistributions in binary form must reproduce the above copyright * notice, this list of conditions and the following disclaimer in the * documentation and/or other materials provided with the distribution. * 3. Neither the name of the project nor the names of its contributors * may be used to endorse or promote products derived from this software * without specific prior written permission. * * THIS SOFTWARE IS PROVIDED BY THE PROJECT AND CONTRIBUTORS ``AS IS'' AND * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE * ARE DISCLAIMED. IN NO EVENT SHALL THE PROJECT OR CONTRIBUTORS BE LIABLE * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF * SUCH DAMAGE. */ /* * Copyright (c) 1982, 1986, 1993 * The Regents of the University of California. All rights reserved. * * Redistribution and use in source and binary forms, with or without * modification, are permitted provided that the following conditions * are met: * 1. Redistributions of source code must retain the above copyright * notice, this list of conditions and the following disclaimer. * 2. Redistributions in binary form must reproduce the above copyright * notice, this list of conditions and the following disclaimer in the * documentation and/or other materials provided with the distribution. * 3. Neither the name of the University nor the names of its contributors * may be used to endorse or promote products derived from this software * without specific prior written permission. * * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF * SUCH DAMAGE. * * @(#)if_loop.c 8.1 (Berkeley) 6/10/93 */ /* * @(#)COPYRIGHT 1.1 (NRL) 17 January 1995 * * NRL grants permission for redistribution and use in source and binary * forms, with or without modification, of the software and documentation * created at NRL provided that the following conditions are met: * * 1. Redistributions of source code must retain the above copyright * notice, this list of conditions and the following disclaimer. * 2. Redistributions in binary form must reproduce the above copyright * notice, this list of conditions and the following disclaimer in the * documentation and/or other materials provided with the distribution. * 3. All advertising materials mentioning features or use of this software * must display the following acknowledgements: * This product includes software developed by the University of * California, Berkeley and its contributors. * This product includes software developed at the Information * Technology Division, US Naval Research Laboratory. * 4. Neither the name of the NRL nor the names of its contributors * may be used to endorse or promote products derived from this software * without specific prior written permission. * * THE SOFTWARE PROVIDED BY NRL IS PROVIDED BY NRL AND CONTRIBUTORS ``AS * IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A * PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL NRL OR * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR * PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF * LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING * NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. * * The views and conclusions contained in the software and documentation * are those of the authors and should not be interpreted as representing * official policies, either expressed or implied, of the US Naval * Research Laboratory (NRL). */ /* * Loopback interface driver for protocol testing and timing. */ #include "bpfilter.h" #include <sys/param.h> #include <sys/systm.h> #include <sys/mbuf.h> #include <sys/socket.h> #include <sys/errno.h> #include <sys/ioctl.h> #include <net/if.h> #include <net/if_var.h> #include <net/if_types.h> #include <net/rtable.h> #include <net/route.h> #if NBPFILTER > 0 #include <net/bpf.h> #endif #define LOMTU 32768 int loioctl(struct ifnet *, u_long, caddr_t); void loopattach(int); void lortrequest(struct ifnet *, int, struct rtentry *); void loinput(struct ifnet *, struct mbuf *, struct netstack *); int looutput(struct ifnet *, struct mbuf *, struct sockaddr *, struct rtentry *); int lo_bpf_mtap(caddr_t, const struct mbuf *, u_int); int loop_clone_create(struct if_clone *, int); int loop_clone_destroy(struct ifnet *); struct if_clone loop_cloner = IF_CLONE_INITIALIZER("lo", loop_clone_create, loop_clone_destroy); void loopattach(int n) { if (loop_clone_create(&loop_cloner, 0)) panic("unable to create lo0"); if_clone_attach(&loop_cloner); } int loop_clone_create(struct if_clone *ifc, int unit) { struct ifnet *ifp; ifp = malloc(sizeof(*ifp), M_DEVBUF, M_WAITOK|M_ZERO); snprintf(ifp->if_xname, sizeof ifp->if_xname, "lo%d", unit); ifp->if_softc = NULL; ifp->if_mtu = LOMTU; ifp->if_flags = IFF_LOOPBACK | IFF_MULTICAST; ifp->if_xflags = IFXF_CLONED | IFXF_LRO; ifp->if_capabilities = IFCAP_CSUM_IPv4 | IFCAP_CSUM_TCPv4 | IFCAP_CSUM_UDPv4 | IFCAP_CSUM_TCPv6 | IFCAP_CSUM_UDPv6 | IFCAP_LRO | IFCAP_TSOv4 | IFCAP_TSOv6; ifp->if_bpf_mtap = lo_bpf_mtap; ifp->if_rtrequest = lortrequest; ifp->if_ioctl = loioctl; ifp->if_input = loinput; ifp->if_output = looutput; ifp->if_type = IFT_LOOP; ifp->if_hdrlen = sizeof(u_int32_t); if_counters_alloc(ifp); if (unit == 0) { if_attachhead(ifp); if_addgroup(ifp, ifc->ifc_name); rtable_l2set(0, 0, ifp->if_index); } else if_attach(ifp); if_attach_queues(ifp, softnet_count()); if_attach_iqueues(ifp, softnet_count()); if_alloc_sadl(ifp); #if NBPFILTER > 0 bpfattach(&ifp->if_bpf, ifp, DLT_LOOP, sizeof(u_int32_t)); #endif return (0); } int loop_clone_destroy(struct ifnet *ifp) { struct ifnet *p; unsigned int rdomain = 0; if (ifp->if_index == rtable_loindex(ifp->if_rdomain)) { /* rdomain 0 always needs a loopback */ if (ifp->if_rdomain == 0) return (EPERM); /* if there is any other interface in this rdomain, deny */ NET_LOCK_SHARED(); TAILQ_FOREACH(p, &ifnetlist, if_list) { if (p->if_rdomain != ifp->if_rdomain) continue; if (p->if_index == ifp->if_index) continue; NET_UNLOCK_SHARED(); return (EBUSY); } NET_UNLOCK_SHARED(); rdomain = ifp->if_rdomain; } if_detach(ifp); free(ifp, M_DEVBUF, sizeof(*ifp)); if (rdomain) rtable_l2set(rdomain, 0, 0); return (0); } int lo_bpf_mtap(caddr_t if_bpf, const struct mbuf *m, u_int dir) { /* loopback dumps on output, disable input bpf */ return (0); } void loinput(struct ifnet *ifp, struct mbuf *m, struct netstack *ns) { int error; if ((m->m_flags & M_PKTHDR) == 0) panic("%s: no header mbuf", __func__); error = if_input_local(ifp, m, m->m_pkthdr.ph_family, ns); if (error) counters_inc(ifp->if_counters, ifc_ierrors); } int looutput(struct ifnet *ifp, struct mbuf *m, struct sockaddr *dst, struct rtentry *rt) { if ((m->m_flags & M_PKTHDR) == 0) panic("%s: no header mbuf", __func__); if (rt && rt->rt_flags & (RTF_REJECT|RTF_BLACKHOLE)) { m_freem(m); return (rt->rt_flags & RTF_BLACKHOLE ? 0 : rt->rt_flags & RTF_HOST ? EHOSTUNREACH : ENETUNREACH); } /* * Do not call if_input_local() directly. Queue the packet to avoid * stack overflow and make TCP handshake over loopback work. */ return (if_output_local(ifp, m, dst->sa_family)); } void lortrequest(struct ifnet *ifp, int cmd, struct rtentry *rt) { if (rt != NULL) atomic_cas_uint(&rt->rt_mtu, 0, LOMTU); } /* * Process an ioctl request. */ int loioctl(struct ifnet *ifp, u_long cmd, caddr_t data) { struct ifreq *ifr; int error = 0; switch (cmd) { case SIOCSIFFLAGS: if (ISSET(ifp->if_xflags, IFXF_LRO)) SET(ifp->if_capabilities, IFCAP_TSOv4 | IFCAP_TSOv6); else CLR(ifp->if_capabilities, IFCAP_TSOv4 | IFCAP_TSOv6); break; case SIOCSIFADDR: ifp->if_flags |= IFF_RUNNING; if_up(ifp); /* send up RTM_IFINFO */ /* * Everything else is done at a higher level. */ break; case SIOCADDMULTI: case SIOCDELMULTI: break; case SIOCSIFMTU: ifr = (struct ifreq *)data; ifp->if_mtu = ifr->ifr_mtu; break; default: error = ENOTTY; } return (error); }
