/*- * SPDX-License-Identifier: BSD-3-Clause * * Copyright (C) 1995, 1996, 1997, and 1998 WIDE Project. * Copyright (c) 2018 Andrey V. Elsukov * 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. * * $KAME: in6_gif.c,v 1.49 2001/05/14 14:02:17 itojun Exp $ */ #include __FBSDID("$FreeBSD$"); #include "opt_inet.h" #include "opt_inet6.h" #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #ifdef INET #include #include #endif #include #include #include #include #include #include #include #include #define GIF_HLIM 30 VNET_DEFINE_STATIC(int, ip6_gif_hlim) = GIF_HLIM; #define V_ip6_gif_hlim VNET(ip6_gif_hlim) SYSCTL_DECL(_net_inet6_ip6); SYSCTL_INT(_net_inet6_ip6, IPV6CTL_GIF_HLIM, gifhlim, CTLFLAG_VNET | CTLFLAG_RW, &VNET_NAME(ip6_gif_hlim), 0, "Default hop limit for encapsulated packets"); /* * We keep interfaces in a hash table using src+dst as key. * Interfaces with GIF_IGNORE_SOURCE flag are linked into plain list. */ VNET_DEFINE_STATIC(struct gif_list *, ipv6_hashtbl) = NULL; VNET_DEFINE_STATIC(struct gif_list *, ipv6_srchashtbl) = NULL; VNET_DEFINE_STATIC(struct gif_list, ipv6_list) = CK_LIST_HEAD_INITIALIZER(); #define V_ipv6_hashtbl VNET(ipv6_hashtbl) #define V_ipv6_srchashtbl VNET(ipv6_srchashtbl) #define V_ipv6_list VNET(ipv6_list) #define GIF_HASH(src, dst) (V_ipv6_hashtbl[\ in6_gif_hashval((src), (dst)) & (GIF_HASH_SIZE - 1)]) #define GIF_SRCHASH(src) (V_ipv6_srchashtbl[\ fnv_32_buf((src), sizeof(*src), FNV1_32_INIT) & (GIF_HASH_SIZE - 1)]) #define GIF_HASH_SC(sc) GIF_HASH(&(sc)->gif_ip6hdr->ip6_src,\ &(sc)->gif_ip6hdr->ip6_dst) static uint32_t in6_gif_hashval(const struct in6_addr *src, const struct in6_addr *dst) { uint32_t ret; ret = fnv_32_buf(src, sizeof(*src), FNV1_32_INIT); return (fnv_32_buf(dst, sizeof(*dst), ret)); } static int in6_gif_checkdup(const struct gif_softc *sc, const struct in6_addr *src, const struct in6_addr *dst) { struct gif_softc *tmp; if (sc->gif_family == AF_INET6 && IN6_ARE_ADDR_EQUAL(&sc->gif_ip6hdr->ip6_src, src) && IN6_ARE_ADDR_EQUAL(&sc->gif_ip6hdr->ip6_dst, dst)) return (EEXIST); CK_LIST_FOREACH(tmp, &GIF_HASH(src, dst), chain) { if (tmp == sc) continue; if (IN6_ARE_ADDR_EQUAL(&tmp->gif_ip6hdr->ip6_src, src) && IN6_ARE_ADDR_EQUAL(&tmp->gif_ip6hdr->ip6_dst, dst)) return (EADDRNOTAVAIL); } return (0); } /* * Check that ingress address belongs to local host. */ static void in6_gif_set_running(struct gif_softc *sc) { if (in6_localip(&sc->gif_ip6hdr->ip6_src)) GIF2IFP(sc)->if_drv_flags |= IFF_DRV_RUNNING; else GIF2IFP(sc)->if_drv_flags &= ~IFF_DRV_RUNNING; } /* * ifaddr_event handler. * Clear IFF_DRV_RUNNING flag when ingress address disappears to prevent * source address spoofing. */ static void in6_gif_srcaddr(void *arg __unused, const struct sockaddr *sa, int event) { const struct sockaddr_in6 *sin; struct gif_softc *sc; /* Check that VNET is ready */ if (V_ipv6_hashtbl == NULL) return; NET_EPOCH_ASSERT(); sin = (const struct sockaddr_in6 *)sa; CK_LIST_FOREACH(sc, &GIF_SRCHASH(&sin->sin6_addr), srchash) { if (IN6_ARE_ADDR_EQUAL(&sc->gif_ip6hdr->ip6_src, &sin->sin6_addr) == 0) continue; in6_gif_set_running(sc); } } static void in6_gif_attach(struct gif_softc *sc) { if (sc->gif_options & GIF_IGNORE_SOURCE) CK_LIST_INSERT_HEAD(&V_ipv6_list, sc, chain); else CK_LIST_INSERT_HEAD(&GIF_HASH_SC(sc), sc, chain); CK_LIST_INSERT_HEAD(&GIF_SRCHASH(&sc->gif_ip6hdr->ip6_src), sc, srchash); } int in6_gif_setopts(struct gif_softc *sc, u_int options) { /* NOTE: we are protected with gif_ioctl_sx lock */ MPASS(sc->gif_family == AF_INET6); MPASS(sc->gif_options != options); if ((options & GIF_IGNORE_SOURCE) != (sc->gif_options & GIF_IGNORE_SOURCE)) { CK_LIST_REMOVE(sc, srchash); CK_LIST_REMOVE(sc, chain); sc->gif_options = options; in6_gif_attach(sc); } return (0); } int in6_gif_ioctl(struct gif_softc *sc, u_long cmd, caddr_t data) { struct in6_ifreq *ifr = (struct in6_ifreq *)data; struct sockaddr_in6 *dst, *src; struct ip6_hdr *ip6; int error; /* NOTE: we are protected with gif_ioctl_sx lock */ error = EINVAL; switch (cmd) { case SIOCSIFPHYADDR_IN6: src = &((struct in6_aliasreq *)data)->ifra_addr; dst = &((struct in6_aliasreq *)data)->ifra_dstaddr; /* sanity checks */ if (src->sin6_family != dst->sin6_family || src->sin6_family != AF_INET6 || src->sin6_len != dst->sin6_len || src->sin6_len != sizeof(*src)) break; if (IN6_IS_ADDR_UNSPECIFIED(&src->sin6_addr) || IN6_IS_ADDR_UNSPECIFIED(&dst->sin6_addr)) { error = EADDRNOTAVAIL; break; } /* * Check validity of the scope zone ID of the * addresses, and convert it into the kernel * internal form if necessary. */ if ((error = sa6_embedscope(src, 0)) != 0 || (error = sa6_embedscope(dst, 0)) != 0) break; if (V_ipv6_hashtbl == NULL) { V_ipv6_hashtbl = gif_hashinit(); V_ipv6_srchashtbl = gif_hashinit(); } error = in6_gif_checkdup(sc, &src->sin6_addr, &dst->sin6_addr); if (error == EADDRNOTAVAIL) break; if (error == EEXIST) { /* Addresses are the same. Just return. */ error = 0; break; } ip6 = malloc(sizeof(*ip6), M_GIF, M_WAITOK | M_ZERO); ip6->ip6_src = src->sin6_addr; ip6->ip6_dst = dst->sin6_addr; ip6->ip6_vfc = IPV6_VERSION; if (sc->gif_family != 0) { /* Detach existing tunnel first */ CK_LIST_REMOVE(sc, srchash); CK_LIST_REMOVE(sc, chain); GIF_WAIT(); free(sc->gif_hdr, M_GIF); /* XXX: should we notify about link state change? */ } sc->gif_family = AF_INET6; sc->gif_ip6hdr = ip6; in6_gif_attach(sc); in6_gif_set_running(sc); break; case SIOCGIFPSRCADDR_IN6: case SIOCGIFPDSTADDR_IN6: if (sc->gif_family != AF_INET6) { error = EADDRNOTAVAIL; break; } src = (struct sockaddr_in6 *)&ifr->ifr_addr; memset(src, 0, sizeof(*src)); src->sin6_family = AF_INET6; src->sin6_len = sizeof(*src); src->sin6_addr = (cmd == SIOCGIFPSRCADDR_IN6) ? sc->gif_ip6hdr->ip6_src: sc->gif_ip6hdr->ip6_dst; error = prison_if(curthread->td_ucred, (struct sockaddr *)src); if (error == 0) error = sa6_recoverscope(src); if (error != 0) memset(src, 0, sizeof(*src)); break; } return (error); } int in6_gif_output(struct ifnet *ifp, struct mbuf *m, int proto, uint8_t ecn) { struct gif_softc *sc = ifp->if_softc; struct ip6_hdr *ip6; int len; /* prepend new IP header */ NET_EPOCH_ASSERT(); len = sizeof(struct ip6_hdr); #ifndef __NO_STRICT_ALIGNMENT if (proto == IPPROTO_ETHERIP) len += ETHERIP_ALIGN; #endif M_PREPEND(m, len, M_NOWAIT); if (m == NULL) return (ENOBUFS); #ifndef __NO_STRICT_ALIGNMENT if (proto == IPPROTO_ETHERIP) { len = mtod(m, vm_offset_t) & 3; KASSERT(len == 0 || len == ETHERIP_ALIGN, ("in6_gif_output: unexpected misalignment")); m->m_data += len; m->m_len -= ETHERIP_ALIGN; } #endif ip6 = mtod(m, struct ip6_hdr *); MPASS(sc->gif_family == AF_INET6); bcopy(sc->gif_ip6hdr, ip6, sizeof(struct ip6_hdr)); ip6->ip6_flow |= htonl((uint32_t)ecn << 20); ip6->ip6_nxt = proto; ip6->ip6_hlim = V_ip6_gif_hlim; /* * force fragmentation to minimum MTU, to avoid path MTU discovery. * it is too painful to ask for resend of inner packet, to achieve * path MTU discovery for encapsulated packets. */ return (ip6_output(m, 0, NULL, IPV6_MINMTU, 0, NULL, NULL)); } static int in6_gif_input(struct mbuf *m, int off, int proto, void *arg) { struct gif_softc *sc = arg; struct ifnet *gifp; struct ip6_hdr *ip6; uint8_t ecn; NET_EPOCH_ASSERT(); if (sc == NULL) { m_freem(m); IP6STAT_INC(ip6s_nogif); return (IPPROTO_DONE); } gifp = GIF2IFP(sc); if ((gifp->if_flags & IFF_UP) != 0) { ip6 = mtod(m, struct ip6_hdr *); ecn = (ntohl(ip6->ip6_flow) >> 20) & 0xff; m_adj(m, off); gif_input(m, gifp, proto, ecn); } else { m_freem(m); IP6STAT_INC(ip6s_nogif); } return (IPPROTO_DONE); } static int in6_gif_lookup(const struct mbuf *m, int off, int proto, void **arg) { const struct ip6_hdr *ip6; struct gif_softc *sc; int ret; if (V_ipv6_hashtbl == NULL) return (0); NET_EPOCH_ASSERT(); /* * NOTE: it is safe to iterate without any locking here, because softc * can be reclaimed only when we are not within net_epoch_preempt * section, but ip_encap lookup+input are executed in epoch section. */ ip6 = mtod(m, const struct ip6_hdr *); ret = 0; CK_LIST_FOREACH(sc, &GIF_HASH(&ip6->ip6_dst, &ip6->ip6_src), chain) { /* * This is an inbound packet, its ip6_dst is source address * in softc. */ if (IN6_ARE_ADDR_EQUAL(&sc->gif_ip6hdr->ip6_src, &ip6->ip6_dst) && IN6_ARE_ADDR_EQUAL(&sc->gif_ip6hdr->ip6_dst, &ip6->ip6_src)) { ret = ENCAP_DRV_LOOKUP; goto done; } } /* * No exact match. * Check the list of interfaces with GIF_IGNORE_SOURCE flag. */ CK_LIST_FOREACH(sc, &V_ipv6_list, chain) { if (IN6_ARE_ADDR_EQUAL(&sc->gif_ip6hdr->ip6_src, &ip6->ip6_dst)) { ret = 128 + 8; /* src + proto */ goto done; } } return (0); done: if ((GIF2IFP(sc)->if_flags & IFF_UP) == 0) return (0); /* ingress filters on outer source */ if ((GIF2IFP(sc)->if_flags & IFF_LINK2) == 0) { if (fib6_check_urpf(sc->gif_fibnum, &ip6->ip6_src, ntohs(in6_getscope(&ip6->ip6_src)), NHR_NONE, m->m_pkthdr.rcvif) == 0) return (0); } *arg = sc; return (ret); } static const struct srcaddrtab *ipv6_srcaddrtab; static struct { const struct encap_config encap; const struct encaptab *cookie; } ipv6_encap_cfg[] = { #ifdef INET { .encap = { .proto = IPPROTO_IPV4, .min_length = sizeof(struct ip6_hdr) + sizeof(struct ip), .exact_match = ENCAP_DRV_LOOKUP, .lookup = in6_gif_lookup, .input = in6_gif_input }, }, #endif { .encap = { .proto = IPPROTO_IPV6, .min_length = 2 * sizeof(struct ip6_hdr), .exact_match = ENCAP_DRV_LOOKUP, .lookup = in6_gif_lookup, .input = in6_gif_input }, }, { .encap = { .proto = IPPROTO_ETHERIP, .min_length = sizeof(struct ip6_hdr) + sizeof(struct etherip_header) + sizeof(struct ether_header), .exact_match = ENCAP_DRV_LOOKUP, .lookup = in6_gif_lookup, .input = in6_gif_input }, } }; void in6_gif_init(void) { int i; if (!IS_DEFAULT_VNET(curvnet)) return; ipv6_srcaddrtab = ip6_encap_register_srcaddr(in6_gif_srcaddr, NULL, M_WAITOK); for (i = 0; i < nitems(ipv6_encap_cfg); i++) ipv6_encap_cfg[i].cookie = ip6_encap_attach( &ipv6_encap_cfg[i].encap, NULL, M_WAITOK); } void in6_gif_uninit(void) { int i; if (IS_DEFAULT_VNET(curvnet)) { for (i = 0; i < nitems(ipv6_encap_cfg); i++) ip6_encap_detach(ipv6_encap_cfg[i].cookie); ip6_encap_unregister_srcaddr(ipv6_srcaddrtab); } if (V_ipv6_hashtbl != NULL) { gif_hashdestroy(V_ipv6_hashtbl); V_ipv6_hashtbl = NULL; GIF_WAIT(); gif_hashdestroy(V_ipv6_srchashtbl); } }