/* $FreeBSD$ */ /* $KAME: if_gif.c,v 1.87 2001/10/19 08:50:27 itojun 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. */ #include "opt_inet.h" #include "opt_inet6.h" #include "opt_mac.h" #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #ifdef INET #include #include #include #endif /* INET */ #ifdef INET6 #ifndef INET #include #endif #include #include #include #include #include #endif /* INET6 */ #include #include #include #define GIFNAME "gif" /* * gif_mtx protects the global gif_softc_list, and access to gif_called. * XXX: See comment blow on gif_called. * XXX: Per-softc locking is still required. */ static struct mtx gif_mtx; static MALLOC_DEFINE(M_GIF, "gif", "Generic Tunnel Interface"); static LIST_HEAD(, gif_softc) gif_softc_list; /* * XXX: gif_called is a recursion counter to prevent misconfiguration to * cause unbounded looping in the network stack. However, this is a flawed * approach as it assumes non-reentrance in the stack. This should be * changed to use packet tags to track recusion.. */ static int gif_called = 0; void (*ng_gif_input_p)(struct ifnet *ifp, struct mbuf **mp, int af); void (*ng_gif_input_orphan_p)(struct ifnet *ifp, struct mbuf *m, int af); void (*ng_gif_attach_p)(struct ifnet *ifp); void (*ng_gif_detach_p)(struct ifnet *ifp); int gif_clone_create(struct if_clone *, int); void gif_clone_destroy(struct ifnet *); struct if_clone gif_cloner = IF_CLONE_INITIALIZER("gif", gif_clone_create, gif_clone_destroy, 0, IF_MAXUNIT); static int gifmodevent(module_t, int, void *); SYSCTL_DECL(_net_link); SYSCTL_NODE(_net_link, IFT_GIF, gif, CTLFLAG_RW, 0, "Generic Tunnel Interface"); #ifndef MAX_GIF_NEST /* * This macro controls the default upper limitation on nesting of gif tunnels. * Since, setting a large value to this macro with a careless configuration * may introduce system crash, we don't allow any nestings by default. * If you need to configure nested gif tunnels, you can define this macro * in your kernel configuration file. However, if you do so, please be * careful to configure the tunnels so that it won't make a loop. */ #define MAX_GIF_NEST 1 #endif static int max_gif_nesting = MAX_GIF_NEST; SYSCTL_INT(_net_link_gif, OID_AUTO, max_nesting, CTLFLAG_RW, &max_gif_nesting, 0, "Max nested tunnels"); /* * By default, we disallow creation of multiple tunnels between the same * pair of addresses. Some applications require this functionality so * we allow control over this check here. */ #ifdef XBONEHACK static int parallel_tunnels = 1; #else static int parallel_tunnels = 0; #endif SYSCTL_INT(_net_link_gif, OID_AUTO, parallel_tunnels, CTLFLAG_RW, ¶llel_tunnels, 0, "Allow parallel tunnels?"); int gif_clone_create(ifc, unit) struct if_clone *ifc; int unit; { struct gif_softc *sc; sc = malloc (sizeof(struct gif_softc), M_GIF, M_WAITOK); bzero(sc, sizeof(struct gif_softc)); sc->gif_if.if_softc = sc; if_initname(&sc->gif_if, ifc->ifc_name, unit); gifattach0(sc); mtx_lock(&gif_mtx); LIST_INSERT_HEAD(&gif_softc_list, sc, gif_list); mtx_unlock(&gif_mtx); return (0); } void gifattach0(sc) struct gif_softc *sc; { sc->encap_cookie4 = sc->encap_cookie6 = NULL; sc->gif_if.if_addrlen = 0; sc->gif_if.if_mtu = GIF_MTU; sc->gif_if.if_flags = IFF_POINTOPOINT | IFF_MULTICAST; #if 0 /* turn off ingress filter */ sc->gif_if.if_flags |= IFF_LINK2; #endif sc->gif_if.if_ioctl = gif_ioctl; sc->gif_if.if_output = gif_output; sc->gif_if.if_type = IFT_GIF; sc->gif_if.if_snd.ifq_maxlen = IFQ_MAXLEN; if_attach(&sc->gif_if); bpfattach(&sc->gif_if, DLT_NULL, sizeof(u_int)); if (ng_gif_attach_p != NULL) (*ng_gif_attach_p)(&sc->gif_if); } static void gif_destroy(struct gif_softc *sc) { struct ifnet *ifp = &sc->gif_if; int err; gif_delete_tunnel(ifp); #ifdef INET6 if (sc->encap_cookie6 != NULL) { err = encap_detach(sc->encap_cookie6); KASSERT(err == 0, ("Unexpected error detaching encap_cookie6")); } #endif #ifdef INET if (sc->encap_cookie4 != NULL) { err = encap_detach(sc->encap_cookie4); KASSERT(err == 0, ("Unexpected error detaching encap_cookie4")); } #endif if (ng_gif_detach_p != NULL) (*ng_gif_detach_p)(ifp); bpfdetach(ifp); if_detach(ifp); free(sc, M_GIF); } void gif_clone_destroy(ifp) struct ifnet *ifp; { struct gif_softc *sc = ifp->if_softc; mtx_lock(&gif_mtx); LIST_REMOVE(sc, gif_list); mtx_unlock(&gif_mtx); gif_destroy(sc); } static int gifmodevent(mod, type, data) module_t mod; int type; void *data; { struct gif_softc *sc; switch (type) { case MOD_LOAD: mtx_init(&gif_mtx, "gif_mtx", NULL, MTX_DEF); LIST_INIT(&gif_softc_list); if_clone_attach(&gif_cloner); #ifdef INET6 ip6_gif_hlim = GIF_HLIM; #endif break; case MOD_UNLOAD: if_clone_detach(&gif_cloner); mtx_lock(&gif_mtx); while ((sc = LIST_FIRST(&gif_softc_list)) != NULL) { LIST_REMOVE(sc, gif_list); mtx_unlock(&gif_mtx); gif_destroy(sc); mtx_lock(&gif_mtx); } mtx_unlock(&gif_mtx); mtx_destroy(&gif_mtx); #ifdef INET6 ip6_gif_hlim = 0; #endif break; } return 0; } static moduledata_t gif_mod = { "if_gif", gifmodevent, 0 }; DECLARE_MODULE(if_gif, gif_mod, SI_SUB_PSEUDO, SI_ORDER_ANY); MODULE_VERSION(if_gif, 1); int gif_encapcheck(m, off, proto, arg) const struct mbuf *m; int off; int proto; void *arg; { struct ip ip; struct gif_softc *sc; sc = (struct gif_softc *)arg; if (sc == NULL) return 0; if ((sc->gif_if.if_flags & IFF_UP) == 0) return 0; /* no physical address */ if (!sc->gif_psrc || !sc->gif_pdst) return 0; switch (proto) { #ifdef INET case IPPROTO_IPV4: break; #endif #ifdef INET6 case IPPROTO_IPV6: break; #endif default: return 0; } /* Bail on short packets */ if (m->m_pkthdr.len < sizeof(ip)) return 0; m_copydata(m, 0, sizeof(ip), (caddr_t)&ip); switch (ip.ip_v) { #ifdef INET case 4: if (sc->gif_psrc->sa_family != AF_INET || sc->gif_pdst->sa_family != AF_INET) return 0; return gif_encapcheck4(m, off, proto, arg); #endif #ifdef INET6 case 6: if (m->m_pkthdr.len < sizeof(struct ip6_hdr)) return 0; if (sc->gif_psrc->sa_family != AF_INET6 || sc->gif_pdst->sa_family != AF_INET6) return 0; return gif_encapcheck6(m, off, proto, arg); #endif default: return 0; } } int gif_output(ifp, m, dst, rt) struct ifnet *ifp; struct mbuf *m; struct sockaddr *dst; struct rtentry *rt; /* added in net2 */ { struct gif_softc *sc = (struct gif_softc*)ifp; int error = 0; #ifdef MAC error = mac_check_ifnet_transmit(ifp, m); if (error) { m_freem(m); goto end; } #endif /* * gif may cause infinite recursion calls when misconfigured. * We'll prevent this by introducing upper limit. * XXX: this mechanism may introduce another problem about * mutual exclusion of the variable CALLED, especially if we * use kernel thread. */ mtx_lock(&gif_mtx); if (++gif_called > max_gif_nesting) { mtx_unlock(&gif_mtx); log(LOG_NOTICE, "gif_output: recursively called too many times(%d)\n", gif_called); m_freem(m); error = EIO; /* is there better errno? */ goto end; } mtx_unlock(&gif_mtx); m->m_flags &= ~(M_BCAST|M_MCAST); if (!(ifp->if_flags & IFF_UP) || sc->gif_psrc == NULL || sc->gif_pdst == NULL) { m_freem(m); error = ENETDOWN; goto end; } if (ifp->if_bpf) { u_int32_t af = dst->sa_family; bpf_mtap2(ifp->if_bpf, &af, sizeof(af), m); } ifp->if_opackets++; ifp->if_obytes += m->m_pkthdr.len; /* inner AF-specific encapsulation */ /* XXX should we check if our outer source is legal? */ /* dispatch to output logic based on outer AF */ switch (sc->gif_psrc->sa_family) { #ifdef INET case AF_INET: error = in_gif_output(ifp, dst->sa_family, m); break; #endif #ifdef INET6 case AF_INET6: error = in6_gif_output(ifp, dst->sa_family, m); break; #endif default: m_freem(m); error = ENETDOWN; goto end; } end: mtx_lock(&gif_mtx); gif_called = 0; /* reset recursion counter */ mtx_unlock(&gif_mtx); if (error) ifp->if_oerrors++; return error; } void gif_input(m, af, ifp) struct mbuf *m; int af; struct ifnet *ifp; { int isr; if (ifp == NULL) { /* just in case */ m_freem(m); return; } m->m_pkthdr.rcvif = ifp; #ifdef MAC mac_create_mbuf_from_ifnet(ifp, m); #endif if (ifp->if_bpf) { u_int32_t af1 = af; bpf_mtap2(ifp->if_bpf, &af1, sizeof(af1), m); } if (ng_gif_input_p != NULL) { (*ng_gif_input_p)(ifp, &m, af); if (m == NULL) return; } /* * Put the packet to the network layer input queue according to the * specified address family. * Note: older versions of gif_input directly called network layer * input functions, e.g. ip6_input, here. We changed the policy to * prevent too many recursive calls of such input functions, which * might cause kernel panic. But the change may introduce another * problem; if the input queue is full, packets are discarded. * The kernel stack overflow really happened, and we believed * queue-full rarely occurs, so we changed the policy. */ switch (af) { #ifdef INET case AF_INET: isr = NETISR_IP; break; #endif #ifdef INET6 case AF_INET6: isr = NETISR_IPV6; break; #endif default: if (ng_gif_input_orphan_p != NULL) (*ng_gif_input_orphan_p)(ifp, m, af); else m_freem(m); return; } ifp->if_ipackets++; ifp->if_ibytes += m->m_pkthdr.len; netisr_dispatch(isr, m); } /* XXX how should we handle IPv6 scope on SIOC[GS]IFPHYADDR? */ int gif_ioctl(ifp, cmd, data) struct ifnet *ifp; u_long cmd; caddr_t data; { struct gif_softc *sc = (struct gif_softc*)ifp; struct ifreq *ifr = (struct ifreq*)data; int error = 0, size; struct sockaddr *dst, *src; #ifdef SIOCSIFMTU /* xxx */ u_long mtu; #endif switch (cmd) { case SIOCSIFADDR: ifp->if_flags |= IFF_UP; break; case SIOCSIFDSTADDR: break; case SIOCADDMULTI: case SIOCDELMULTI: break; #ifdef SIOCSIFMTU /* xxx */ case SIOCGIFMTU: break; case SIOCSIFMTU: mtu = ifr->ifr_mtu; if (mtu < GIF_MTU_MIN || mtu > GIF_MTU_MAX) return (EINVAL); ifp->if_mtu = mtu; break; #endif /* SIOCSIFMTU */ #ifdef INET case SIOCSIFPHYADDR: #endif #ifdef INET6 case SIOCSIFPHYADDR_IN6: #endif /* INET6 */ case SIOCSLIFPHYADDR: switch (cmd) { #ifdef INET case SIOCSIFPHYADDR: src = (struct sockaddr *) &(((struct in_aliasreq *)data)->ifra_addr); dst = (struct sockaddr *) &(((struct in_aliasreq *)data)->ifra_dstaddr); break; #endif #ifdef INET6 case SIOCSIFPHYADDR_IN6: src = (struct sockaddr *) &(((struct in6_aliasreq *)data)->ifra_addr); dst = (struct sockaddr *) &(((struct in6_aliasreq *)data)->ifra_dstaddr); break; #endif case SIOCSLIFPHYADDR: src = (struct sockaddr *) &(((struct if_laddrreq *)data)->addr); dst = (struct sockaddr *) &(((struct if_laddrreq *)data)->dstaddr); break; default: return EINVAL; } /* sa_family must be equal */ if (src->sa_family != dst->sa_family) return EINVAL; /* validate sa_len */ switch (src->sa_family) { #ifdef INET case AF_INET: if (src->sa_len != sizeof(struct sockaddr_in)) return EINVAL; break; #endif #ifdef INET6 case AF_INET6: if (src->sa_len != sizeof(struct sockaddr_in6)) return EINVAL; break; #endif default: return EAFNOSUPPORT; } switch (dst->sa_family) { #ifdef INET case AF_INET: if (dst->sa_len != sizeof(struct sockaddr_in)) return EINVAL; break; #endif #ifdef INET6 case AF_INET6: if (dst->sa_len != sizeof(struct sockaddr_in6)) return EINVAL; break; #endif default: return EAFNOSUPPORT; } /* check sa_family looks sane for the cmd */ switch (cmd) { case SIOCSIFPHYADDR: if (src->sa_family == AF_INET) break; return EAFNOSUPPORT; #ifdef INET6 case SIOCSIFPHYADDR_IN6: if (src->sa_family == AF_INET6) break; return EAFNOSUPPORT; #endif /* INET6 */ case SIOCSLIFPHYADDR: /* checks done in the above */ break; } error = gif_set_tunnel(&sc->gif_if, src, dst); break; #ifdef SIOCDIFPHYADDR case SIOCDIFPHYADDR: gif_delete_tunnel(&sc->gif_if); break; #endif case SIOCGIFPSRCADDR: #ifdef INET6 case SIOCGIFPSRCADDR_IN6: #endif /* INET6 */ if (sc->gif_psrc == NULL) { error = EADDRNOTAVAIL; goto bad; } src = sc->gif_psrc; switch (cmd) { #ifdef INET case SIOCGIFPSRCADDR: dst = &ifr->ifr_addr; size = sizeof(ifr->ifr_addr); break; #endif /* INET */ #ifdef INET6 case SIOCGIFPSRCADDR_IN6: dst = (struct sockaddr *) &(((struct in6_ifreq *)data)->ifr_addr); size = sizeof(((struct in6_ifreq *)data)->ifr_addr); break; #endif /* INET6 */ default: error = EADDRNOTAVAIL; goto bad; } if (src->sa_len > size) return EINVAL; bcopy((caddr_t)src, (caddr_t)dst, src->sa_len); break; case SIOCGIFPDSTADDR: #ifdef INET6 case SIOCGIFPDSTADDR_IN6: #endif /* INET6 */ if (sc->gif_pdst == NULL) { error = EADDRNOTAVAIL; goto bad; } src = sc->gif_pdst; switch (cmd) { #ifdef INET case SIOCGIFPDSTADDR: dst = &ifr->ifr_addr; size = sizeof(ifr->ifr_addr); break; #endif /* INET */ #ifdef INET6 case SIOCGIFPDSTADDR_IN6: dst = (struct sockaddr *) &(((struct in6_ifreq *)data)->ifr_addr); size = sizeof(((struct in6_ifreq *)data)->ifr_addr); break; #endif /* INET6 */ default: error = EADDRNOTAVAIL; goto bad; } if (src->sa_len > size) return EINVAL; bcopy((caddr_t)src, (caddr_t)dst, src->sa_len); break; case SIOCGLIFPHYADDR: if (sc->gif_psrc == NULL || sc->gif_pdst == NULL) { error = EADDRNOTAVAIL; goto bad; } /* copy src */ src = sc->gif_psrc; dst = (struct sockaddr *) &(((struct if_laddrreq *)data)->addr); size = sizeof(((struct if_laddrreq *)data)->addr); if (src->sa_len > size) return EINVAL; bcopy((caddr_t)src, (caddr_t)dst, src->sa_len); /* copy dst */ src = sc->gif_pdst; dst = (struct sockaddr *) &(((struct if_laddrreq *)data)->dstaddr); size = sizeof(((struct if_laddrreq *)data)->dstaddr); if (src->sa_len > size) return EINVAL; bcopy((caddr_t)src, (caddr_t)dst, src->sa_len); break; case SIOCSIFFLAGS: /* if_ioctl() takes care of it */ break; default: error = EINVAL; break; } bad: return error; } /* * XXXRW: There's a general event-ordering issue here: the code to check * if a given tunnel is already present happens before we perform a * potentially blocking setup of the tunnel. This code needs to be * re-ordered so that the check and replacement can be atomic using * a mutex. */ int gif_set_tunnel(ifp, src, dst) struct ifnet *ifp; struct sockaddr *src; struct sockaddr *dst; { struct gif_softc *sc = (struct gif_softc *)ifp; struct gif_softc *sc2; struct sockaddr *osrc, *odst, *sa; int s; int error = 0; s = splnet(); mtx_lock(&gif_mtx); LIST_FOREACH(sc2, &gif_softc_list, gif_list) { if (sc2 == sc) continue; if (!sc2->gif_pdst || !sc2->gif_psrc) continue; if (sc2->gif_pdst->sa_family != dst->sa_family || sc2->gif_pdst->sa_len != dst->sa_len || sc2->gif_psrc->sa_family != src->sa_family || sc2->gif_psrc->sa_len != src->sa_len) continue; /* * Disallow parallel tunnels unless instructed * otherwise. */ if (!parallel_tunnels && bcmp(sc2->gif_pdst, dst, dst->sa_len) == 0 && bcmp(sc2->gif_psrc, src, src->sa_len) == 0) { error = EADDRNOTAVAIL; mtx_unlock(&gif_mtx); goto bad; } /* XXX both end must be valid? (I mean, not 0.0.0.0) */ } mtx_unlock(&gif_mtx); /* XXX we can detach from both, but be polite just in case */ if (sc->gif_psrc) switch (sc->gif_psrc->sa_family) { #ifdef INET case AF_INET: (void)in_gif_detach(sc); break; #endif #ifdef INET6 case AF_INET6: (void)in6_gif_detach(sc); break; #endif } osrc = sc->gif_psrc; sa = (struct sockaddr *)malloc(src->sa_len, M_IFADDR, M_WAITOK); bcopy((caddr_t)src, (caddr_t)sa, src->sa_len); sc->gif_psrc = sa; odst = sc->gif_pdst; sa = (struct sockaddr *)malloc(dst->sa_len, M_IFADDR, M_WAITOK); bcopy((caddr_t)dst, (caddr_t)sa, dst->sa_len); sc->gif_pdst = sa; switch (sc->gif_psrc->sa_family) { #ifdef INET case AF_INET: error = in_gif_attach(sc); break; #endif #ifdef INET6 case AF_INET6: error = in6_gif_attach(sc); break; #endif } if (error) { /* rollback */ free((caddr_t)sc->gif_psrc, M_IFADDR); free((caddr_t)sc->gif_pdst, M_IFADDR); sc->gif_psrc = osrc; sc->gif_pdst = odst; goto bad; } if (osrc) free((caddr_t)osrc, M_IFADDR); if (odst) free((caddr_t)odst, M_IFADDR); if (sc->gif_psrc && sc->gif_pdst) ifp->if_flags |= IFF_RUNNING; else ifp->if_flags &= ~IFF_RUNNING; splx(s); return 0; bad: if (sc->gif_psrc && sc->gif_pdst) ifp->if_flags |= IFF_RUNNING; else ifp->if_flags &= ~IFF_RUNNING; splx(s); return error; } void gif_delete_tunnel(ifp) struct ifnet *ifp; { struct gif_softc *sc = (struct gif_softc *)ifp; int s; s = splnet(); if (sc->gif_psrc) { free((caddr_t)sc->gif_psrc, M_IFADDR); sc->gif_psrc = NULL; } if (sc->gif_pdst) { free((caddr_t)sc->gif_pdst, M_IFADDR); sc->gif_pdst = NULL; } /* it is safe to detach from both */ #ifdef INET (void)in_gif_detach(sc); #endif #ifdef INET6 (void)in6_gif_detach(sc); #endif if (sc->gif_psrc && sc->gif_pdst) ifp->if_flags |= IFF_RUNNING; else ifp->if_flags &= ~IFF_RUNNING; splx(s); }