/* $NetBSD: if_loop.c,v 1.107.2.1 2019/11/14 15:34:35 martin 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 8.2 (Berkeley) 1/9/95 */ /* * Loopback interface driver for protocol testing and timing. */ #include __KERNEL_RCSID(0, "$NetBSD: if_loop.c,v 1.107.2.1 2019/11/14 15:34:35 martin Exp $"); #ifdef _KERNEL_OPT #include "opt_inet.h" #include "opt_atalk.h" #include "opt_mbuftrace.h" #include "opt_mpls.h" #include "opt_net_mpsafe.h" #endif #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #ifdef INET #include #include #include #include #include #endif #ifdef INET6 #ifndef INET #include #endif #include #include #include #endif #ifdef MPLS #include #include #endif #ifdef NETATALK #include #include #endif #include #if defined(LARGE_LOMTU) #define LOMTU (131072 + MHLEN + MLEN) #define LOMTU_MAX LOMTU #else #define LOMTU (32768 + MHLEN + MLEN) #define LOMTU_MAX (65536 + MHLEN + MLEN) #endif #ifdef ALTQ static void lostart(struct ifnet *); #endif static int loop_clone_create(struct if_clone *, int); static int loop_clone_destroy(struct ifnet *); static void loop_rtrequest(int, struct rtentry *, const struct rt_addrinfo *); static struct if_clone loop_cloner = IF_CLONE_INITIALIZER("lo", loop_clone_create, loop_clone_destroy); void loopattach(int n) { #ifndef _MODULE loop_clone_create(&loop_cloner, 0); /* lo0 always exists */ #endif } void loopinit(void) { if (lo0ifp != NULL) /* can happen in rump kernel */ return; #ifdef _MODULE loop_clone_create(&loop_cloner, 0); /* lo0 always exists */ #endif if_clone_attach(&loop_cloner); } static int loopdetach(void) { /* no detach for now; we don't allow lo0 to be deleted */ return EBUSY; } static int loop_clone_create(struct if_clone *ifc, int unit) { struct ifnet *ifp; int rv; ifp = if_alloc(IFT_LOOP); if_initname(ifp, ifc->ifc_name, unit); ifp->if_mtu = LOMTU; ifp->if_flags = IFF_LOOPBACK | IFF_MULTICAST; ifp->if_extflags = IFEF_NO_LINK_STATE_CHANGE; #ifdef NET_MPSAFE ifp->if_extflags |= IFEF_MPSAFE; #endif ifp->if_ioctl = loioctl; ifp->if_output = looutput; #ifdef ALTQ ifp->if_start = lostart; #endif ifp->if_type = IFT_LOOP; ifp->if_hdrlen = 0; ifp->if_addrlen = 0; ifp->if_dlt = DLT_NULL; IFQ_SET_READY(&ifp->if_snd); if (unit == 0) lo0ifp = ifp; rv = if_attach(ifp); if (rv != 0) { if_free(ifp); return rv; } if_alloc_sadl(ifp); bpf_attach(ifp, DLT_NULL, sizeof(u_int)); #ifdef MBUFTRACE ifp->if_mowner = malloc(sizeof(struct mowner), M_DEVBUF, M_WAITOK | M_ZERO); strlcpy(ifp->if_mowner->mo_name, ifp->if_xname, sizeof(ifp->if_mowner->mo_name)); MOWNER_ATTACH(ifp->if_mowner); #endif ifp->if_flags |= IFF_RUNNING; return (0); } static int loop_clone_destroy(struct ifnet *ifp) { if (ifp == lo0ifp) return (EPERM); ifp->if_flags &= ~IFF_RUNNING; #ifdef MBUFTRACE MOWNER_DETACH(ifp->if_mowner); free(ifp->if_mowner, M_DEVBUF); #endif bpf_detach(ifp); if_detach(ifp); if_free(ifp); return (0); } int looutput(struct ifnet *ifp, struct mbuf *m, const struct sockaddr *dst, const struct rtentry *rt) { pktqueue_t *pktq = NULL; struct ifqueue *ifq = NULL; int s, isr = -1; int csum_flags; int error = 0; size_t pktlen; MCLAIM(m, ifp->if_mowner); KERNEL_LOCK_UNLESS_NET_MPSAFE(); if ((m->m_flags & M_PKTHDR) == 0) panic("looutput: no header mbuf"); if (ifp->if_flags & IFF_LOOPBACK) bpf_mtap_af(ifp, dst->sa_family, m, BPF_D_OUT); m_set_rcvif(m, ifp); if (rt && rt->rt_flags & (RTF_REJECT|RTF_BLACKHOLE)) { m_freem(m); error = (rt->rt_flags & RTF_BLACKHOLE ? 0 : rt->rt_flags & RTF_HOST ? EHOSTUNREACH : ENETUNREACH); goto out; } pktlen = m->m_pkthdr.len; ifp->if_opackets++; ifp->if_obytes += pktlen; #ifdef ALTQ /* * ALTQ on the loopback interface is just for debugging. It's * used only for loopback interfaces, not for a simplex interface. */ if ((ALTQ_IS_ENABLED(&ifp->if_snd) || TBR_IS_ENABLED(&ifp->if_snd)) && ifp->if_start == lostart) { /* * If the queueing discipline needs packet classification, * do it before prepending the link headers. */ IFQ_CLASSIFY(&ifp->if_snd, m, dst->sa_family); M_PREPEND(m, sizeof(uint32_t), M_DONTWAIT); if (m == NULL) { error = ENOBUFS; goto out; } *(mtod(m, uint32_t *)) = dst->sa_family; error = if_transmit_lock(ifp, m); goto out; } #endif /* ALTQ */ m_tag_delete_chain(m); #ifdef MPLS if (rt != NULL && rt_gettag(rt) != NULL && rt_gettag(rt)->sa_family == AF_MPLS && (m->m_flags & (M_MCAST | M_BCAST)) == 0) { union mpls_shim msh; msh.s_addr = MPLS_GETSADDR(rt); if (msh.shim.label != MPLS_LABEL_IMPLNULL) { ifq = &mplsintrq; isr = NETISR_MPLS; } } if (isr != NETISR_MPLS) #endif switch (dst->sa_family) { #ifdef INET case AF_INET: csum_flags = m->m_pkthdr.csum_flags; KASSERT((csum_flags & ~(M_CSUM_IPv4|M_CSUM_UDPv4)) == 0); if (csum_flags != 0 && IN_LOOPBACK_NEED_CHECKSUM(csum_flags)) { in_undefer_cksum(m, 0, csum_flags); m->m_pkthdr.csum_flags = 0; } else { /* * Do nothing. Pass M_CSUM_IPv4 and M_CSUM_UDPv4 as * they are to tell those are calculated and good. */ } pktq = ip_pktq; break; #endif #ifdef INET6 case AF_INET6: csum_flags = m->m_pkthdr.csum_flags; KASSERT((csum_flags & ~M_CSUM_UDPv6) == 0); if (csum_flags != 0 && IN6_LOOPBACK_NEED_CHECKSUM(csum_flags)) { in6_undefer_cksum(m, 0, csum_flags); m->m_pkthdr.csum_flags = 0; } else { /* * Do nothing. Pass M_CSUM_UDPv6 as * they are to tell those are calculated and good. */ } m->m_flags |= M_LOOP; pktq = ip6_pktq; break; #endif #ifdef NETATALK case AF_APPLETALK: ifq = &atintrq2; isr = NETISR_ATALK; break; #endif default: printf("%s: can't handle af%d\n", ifp->if_xname, dst->sa_family); m_freem(m); error = EAFNOSUPPORT; goto out; } s = splnet(); if (__predict_true(pktq)) { error = 0; if (__predict_true(pktq_enqueue(pktq, m, 0))) { ifp->if_ipackets++; ifp->if_ibytes += pktlen; } else { m_freem(m); error = ENOBUFS; } splx(s); goto out; } if (IF_QFULL(ifq)) { IF_DROP(ifq); m_freem(m); splx(s); error = ENOBUFS; goto out; } ifp->if_ipackets++; ifp->if_ibytes += m->m_pkthdr.len; IF_ENQUEUE(ifq, m); schednetisr(isr); splx(s); out: KERNEL_UNLOCK_UNLESS_NET_MPSAFE(); return error; } #ifdef ALTQ static void lostart(struct ifnet *ifp) { for (;;) { pktqueue_t *pktq = NULL; struct ifqueue *ifq = NULL; struct mbuf *m; size_t pktlen; uint32_t af; int s, isr = 0; IFQ_DEQUEUE(&ifp->if_snd, m); if (m == NULL) return; af = *(mtod(m, uint32_t *)); m_adj(m, sizeof(uint32_t)); switch (af) { #ifdef INET case AF_INET: pktq = ip_pktq; break; #endif #ifdef INET6 case AF_INET6: m->m_flags |= M_LOOP; pktq = ip6_pktq; break; #endif #ifdef NETATALK case AF_APPLETALK: ifq = &atintrq2; isr = NETISR_ATALK; break; #endif default: printf("%s: can't handle af%d\n", ifp->if_xname, af); m_freem(m); return; } pktlen = m->m_pkthdr.len; s = splnet(); if (__predict_true(pktq)) { if (__predict_false(pktq_enqueue(pktq, m, 0))) { m_freem(m); splx(s); return; } ifp->if_ipackets++; ifp->if_ibytes += pktlen; splx(s); continue; } if (IF_QFULL(ifq)) { IF_DROP(ifq); splx(s); m_freem(m); return; } IF_ENQUEUE(ifq, m); schednetisr(isr); ifp->if_ipackets++; ifp->if_ibytes += pktlen; splx(s); } } #endif /* ALTQ */ /* ARGSUSED */ static void loop_rtrequest(int cmd, struct rtentry *rt, const struct rt_addrinfo *info) { if (rt) rt->rt_rmx.rmx_mtu = lo0ifp->if_mtu; } /* * Process an ioctl request. */ /* ARGSUSED */ int loioctl(struct ifnet *ifp, u_long cmd, void *data) { struct ifaddr *ifa; struct ifreq *ifr = data; int error = 0; switch (cmd) { case SIOCINITIFADDR: ifp->if_flags |= IFF_UP; ifa = (struct ifaddr *)data; if (ifa != NULL) ifa->ifa_rtrequest = loop_rtrequest; /* * Everything else is done at a higher level. */ break; case SIOCSIFMTU: if ((unsigned)ifr->ifr_mtu > LOMTU_MAX) error = EINVAL; else if ((error = ifioctl_common(ifp, cmd, data)) == ENETRESET){ error = 0; } break; case SIOCADDMULTI: case SIOCDELMULTI: if (ifr == NULL) { error = EAFNOSUPPORT; /* XXX */ break; } switch (ifreq_getaddr(cmd, ifr)->sa_family) { #ifdef INET case AF_INET: break; #endif #ifdef INET6 case AF_INET6: break; #endif default: error = EAFNOSUPPORT; break; } break; default: error = ifioctl_common(ifp, cmd, data); } return (error); } /* * Module infrastructure */ #include "if_module.h" IF_MODULE(MODULE_CLASS_DRIVER, loop, NULL)