/*- * SPDX-License-Identifier: BSD-2-Clause-NetBSD * * Copyright (c) 1998 The NetBSD Foundation, Inc. * Copyright (c) 2014, 2018 Andrey V. Elsukov * All rights reserved. * * This code is derived from software contributed to The NetBSD Foundation * by Heiko W.Rupp * * IPv6-over-GRE contributed by Gert Doering * * 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. * * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. 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 FOUNDATION 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. * * $NetBSD: ip_gre.c,v 1.29 2003/09/05 23:02:43 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 #include #include #include #include #ifdef INET6 #include #endif #include #include #define GRE_TTL 30 VNET_DEFINE(int, ip_gre_ttl) = GRE_TTL; #define V_ip_gre_ttl VNET(ip_gre_ttl) SYSCTL_INT(_net_inet_ip, OID_AUTO, grettl, CTLFLAG_VNET | CTLFLAG_RW, &VNET_NAME(ip_gre_ttl), 0, "Default TTL value for encapsulated packets"); struct in_gre_socket { struct gre_socket base; in_addr_t addr; }; VNET_DEFINE_STATIC(struct gre_sockets *, ipv4_sockets) = NULL; VNET_DEFINE_STATIC(struct gre_list *, ipv4_hashtbl) = NULL; VNET_DEFINE_STATIC(struct gre_list *, ipv4_srchashtbl) = NULL; #define V_ipv4_sockets VNET(ipv4_sockets) #define V_ipv4_hashtbl VNET(ipv4_hashtbl) #define V_ipv4_srchashtbl VNET(ipv4_srchashtbl) #define GRE_HASH(src, dst) (V_ipv4_hashtbl[\ in_gre_hashval((src), (dst)) & (GRE_HASH_SIZE - 1)]) #define GRE_SRCHASH(src) (V_ipv4_srchashtbl[\ fnv_32_buf(&(src), sizeof(src), FNV1_32_INIT) & (GRE_HASH_SIZE - 1)]) #define GRE_SOCKHASH(src) (V_ipv4_sockets[\ fnv_32_buf(&(src), sizeof(src), FNV1_32_INIT) & (GRE_HASH_SIZE - 1)]) #define GRE_HASH_SC(sc) GRE_HASH((sc)->gre_oip.ip_src.s_addr,\ (sc)->gre_oip.ip_dst.s_addr) static uint32_t in_gre_hashval(in_addr_t src, in_addr_t dst) { uint32_t ret; ret = fnv_32_buf(&src, sizeof(src), FNV1_32_INIT); return (fnv_32_buf(&dst, sizeof(dst), ret)); } static struct gre_socket* in_gre_lookup_socket(in_addr_t addr) { struct gre_socket *gs; struct in_gre_socket *s; CK_LIST_FOREACH(gs, &GRE_SOCKHASH(addr), chain) { s = __containerof(gs, struct in_gre_socket, base); if (s->addr == addr) break; } return (gs); } static int in_gre_checkdup(const struct gre_softc *sc, in_addr_t src, in_addr_t dst, uint32_t opts) { struct gre_list *head; struct gre_softc *tmp; struct gre_socket *gs; if (sc->gre_family == AF_INET && sc->gre_oip.ip_src.s_addr == src && sc->gre_oip.ip_dst.s_addr == dst && (sc->gre_options & GRE_UDPENCAP) == (opts & GRE_UDPENCAP)) return (EEXIST); if (opts & GRE_UDPENCAP) { gs = in_gre_lookup_socket(src); if (gs == NULL) return (0); head = &gs->list; } else head = &GRE_HASH(src, dst); CK_LIST_FOREACH(tmp, head, chain) { if (tmp == sc) continue; if (tmp->gre_oip.ip_src.s_addr == src && tmp->gre_oip.ip_dst.s_addr == dst) return (EADDRNOTAVAIL); } return (0); } static int in_gre_lookup(const struct mbuf *m, int off, int proto, void **arg) { const struct ip *ip; struct gre_softc *sc; if (V_ipv4_hashtbl == NULL) return (0); NET_EPOCH_ASSERT(); ip = mtod(m, const struct ip *); CK_LIST_FOREACH(sc, &GRE_HASH(ip->ip_dst.s_addr, ip->ip_src.s_addr), chain) { /* * This is an inbound packet, its ip_dst is source address * in softc. */ if (sc->gre_oip.ip_src.s_addr == ip->ip_dst.s_addr && sc->gre_oip.ip_dst.s_addr == ip->ip_src.s_addr) { if ((GRE2IFP(sc)->if_flags & IFF_UP) == 0) return (0); *arg = sc; return (ENCAP_DRV_LOOKUP); } } return (0); } /* * Check that ingress address belongs to local host. */ static void in_gre_set_running(struct gre_softc *sc) { if (in_localip(sc->gre_oip.ip_src)) GRE2IFP(sc)->if_drv_flags |= IFF_DRV_RUNNING; else GRE2IFP(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 in_gre_srcaddr(void *arg __unused, const struct sockaddr *sa, int event __unused) { const struct sockaddr_in *sin; struct gre_softc *sc; /* Check that VNET is ready */ if (V_ipv4_hashtbl == NULL) return; NET_EPOCH_ASSERT(); sin = (const struct sockaddr_in *)sa; CK_LIST_FOREACH(sc, &GRE_SRCHASH(sin->sin_addr.s_addr), srchash) { if (sc->gre_oip.ip_src.s_addr != sin->sin_addr.s_addr) continue; in_gre_set_running(sc); } } static void in_gre_udp_input(struct mbuf *m, int off, struct inpcb *inp, const struct sockaddr *sa, void *ctx) { struct epoch_tracker et; struct gre_socket *gs; struct gre_softc *sc; in_addr_t dst; NET_EPOCH_ENTER(et); /* * udp_append() holds reference to inp, it is safe to check * inp_flags2 without INP_RLOCK(). * If socket was closed before we have entered NET_EPOCH section, * INP_FREED flag should be set. Otherwise it should be safe to * make access to ctx data, because gre_so will be freed by * gre_sofree() via NET_EPOCH_CALL(). */ if (__predict_false(inp->inp_flags2 & INP_FREED)) { NET_EPOCH_EXIT(et); m_freem(m); return; } gs = (struct gre_socket *)ctx; dst = ((const struct sockaddr_in *)sa)->sin_addr.s_addr; CK_LIST_FOREACH(sc, &gs->list, chain) { if (sc->gre_oip.ip_dst.s_addr == dst) break; } if (sc != NULL && (GRE2IFP(sc)->if_flags & IFF_UP) != 0){ gre_input(m, off + sizeof(struct udphdr), IPPROTO_UDP, sc); NET_EPOCH_EXIT(et); return; } m_freem(m); NET_EPOCH_EXIT(et); } static int in_gre_setup_socket(struct gre_softc *sc) { struct sockopt sopt; struct sockaddr_in sin; struct in_gre_socket *s; struct gre_socket *gs; in_addr_t addr; int error, value; /* * NOTE: we are protected with gre_ioctl_sx lock. * * First check that socket is already configured. * If so, check that source addres was not changed. * If address is different, check that there are no other tunnels * and close socket. */ addr = sc->gre_oip.ip_src.s_addr; gs = sc->gre_so; if (gs != NULL) { s = __containerof(gs, struct in_gre_socket, base); if (s->addr != addr) { if (CK_LIST_EMPTY(&gs->list)) { CK_LIST_REMOVE(gs, chain); soclose(gs->so); NET_EPOCH_CALL(gre_sofree, &gs->epoch_ctx); } gs = sc->gre_so = NULL; } } if (gs == NULL) { /* * Check that socket for given address is already * configured. */ gs = in_gre_lookup_socket(addr); if (gs == NULL) { s = malloc(sizeof(*s), M_GRE, M_WAITOK | M_ZERO); s->addr = addr; gs = &s->base; error = socreate(sc->gre_family, &gs->so, SOCK_DGRAM, IPPROTO_UDP, curthread->td_ucred, curthread); if (error != 0) { if_printf(GRE2IFP(sc), "cannot create socket: %d\n", error); free(s, M_GRE); return (error); } error = udp_set_kernel_tunneling(gs->so, in_gre_udp_input, NULL, gs); if (error != 0) { if_printf(GRE2IFP(sc), "cannot set UDP tunneling: %d\n", error); goto fail; } memset(&sopt, 0, sizeof(sopt)); sopt.sopt_dir = SOPT_SET; sopt.sopt_level = IPPROTO_IP; sopt.sopt_name = IP_BINDANY; sopt.sopt_val = &value; sopt.sopt_valsize = sizeof(value); value = 1; error = sosetopt(gs->so, &sopt); if (error != 0) { if_printf(GRE2IFP(sc), "cannot set IP_BINDANY opt: %d\n", error); goto fail; } memset(&sin, 0, sizeof(sin)); sin.sin_family = AF_INET; sin.sin_len = sizeof(sin); sin.sin_addr.s_addr = addr; sin.sin_port = htons(GRE_UDPPORT); error = sobind(gs->so, (struct sockaddr *)&sin, curthread); if (error != 0) { if_printf(GRE2IFP(sc), "cannot bind socket: %d\n", error); goto fail; } /* Add socket to the chain */ CK_LIST_INSERT_HEAD(&GRE_SOCKHASH(addr), gs, chain); } } /* Add softc to the socket's list */ CK_LIST_INSERT_HEAD(&gs->list, sc, chain); sc->gre_so = gs; return (0); fail: soclose(gs->so); free(s, M_GRE); return (error); } static int in_gre_attach(struct gre_softc *sc) { struct grehdr *gh; int error; if (sc->gre_options & GRE_UDPENCAP) { sc->gre_csumflags = CSUM_UDP; sc->gre_hlen = sizeof(struct greudp); sc->gre_oip.ip_p = IPPROTO_UDP; gh = &sc->gre_udphdr->gi_gre; gre_update_udphdr(sc, &sc->gre_udp, in_pseudo(sc->gre_oip.ip_src.s_addr, sc->gre_oip.ip_dst.s_addr, 0)); } else { sc->gre_hlen = sizeof(struct greip); sc->gre_oip.ip_p = IPPROTO_GRE; gh = &sc->gre_iphdr->gi_gre; } sc->gre_oip.ip_v = IPVERSION; sc->gre_oip.ip_hl = sizeof(struct ip) >> 2; gre_update_hdr(sc, gh); /* * If we return error, this means that sc is not linked, * and caller should reset gre_family and free(sc->gre_hdr). */ if (sc->gre_options & GRE_UDPENCAP) { error = in_gre_setup_socket(sc); if (error != 0) return (error); } else CK_LIST_INSERT_HEAD(&GRE_HASH_SC(sc), sc, chain); CK_LIST_INSERT_HEAD(&GRE_SRCHASH(sc->gre_oip.ip_src.s_addr), sc, srchash); /* Set IFF_DRV_RUNNING if interface is ready */ in_gre_set_running(sc); return (0); } int in_gre_setopts(struct gre_softc *sc, u_long cmd, uint32_t value) { int error; /* NOTE: we are protected with gre_ioctl_sx lock */ MPASS(cmd == GRESKEY || cmd == GRESOPTS || cmd == GRESPORT); MPASS(sc->gre_family == AF_INET); /* * If we are going to change encapsulation protocol, do check * for duplicate tunnels. Return EEXIST here to do not confuse * user. */ if (cmd == GRESOPTS && (sc->gre_options & GRE_UDPENCAP) != (value & GRE_UDPENCAP) && in_gre_checkdup(sc, sc->gre_oip.ip_src.s_addr, sc->gre_oip.ip_dst.s_addr, value) == EADDRNOTAVAIL) return (EEXIST); CK_LIST_REMOVE(sc, chain); CK_LIST_REMOVE(sc, srchash); GRE_WAIT(); switch (cmd) { case GRESKEY: sc->gre_key = value; break; case GRESOPTS: sc->gre_options = value; break; case GRESPORT: sc->gre_port = value; break; } error = in_gre_attach(sc); if (error != 0) { sc->gre_family = 0; free(sc->gre_hdr, M_GRE); } return (error); } int in_gre_ioctl(struct gre_softc *sc, u_long cmd, caddr_t data) { struct ifreq *ifr = (struct ifreq *)data; struct sockaddr_in *dst, *src; struct ip *ip; int error; /* NOTE: we are protected with gre_ioctl_sx lock */ error = EINVAL; switch (cmd) { case SIOCSIFPHYADDR: src = &((struct in_aliasreq *)data)->ifra_addr; dst = &((struct in_aliasreq *)data)->ifra_dstaddr; /* sanity checks */ if (src->sin_family != dst->sin_family || src->sin_family != AF_INET || src->sin_len != dst->sin_len || src->sin_len != sizeof(*src)) break; if (src->sin_addr.s_addr == INADDR_ANY || dst->sin_addr.s_addr == INADDR_ANY) { error = EADDRNOTAVAIL; break; } if (V_ipv4_hashtbl == NULL) { V_ipv4_hashtbl = gre_hashinit(); V_ipv4_srchashtbl = gre_hashinit(); V_ipv4_sockets = (struct gre_sockets *)gre_hashinit(); } error = in_gre_checkdup(sc, src->sin_addr.s_addr, dst->sin_addr.s_addr, sc->gre_options); if (error == EADDRNOTAVAIL) break; if (error == EEXIST) { /* Addresses are the same. Just return. */ error = 0; break; } ip = malloc(sizeof(struct greudp) + 3 * sizeof(uint32_t), M_GRE, M_WAITOK | M_ZERO); ip->ip_src.s_addr = src->sin_addr.s_addr; ip->ip_dst.s_addr = dst->sin_addr.s_addr; if (sc->gre_family != 0) { /* Detach existing tunnel first */ CK_LIST_REMOVE(sc, chain); CK_LIST_REMOVE(sc, srchash); GRE_WAIT(); free(sc->gre_hdr, M_GRE); /* XXX: should we notify about link state change? */ } sc->gre_family = AF_INET; sc->gre_hdr = ip; sc->gre_oseq = 0; sc->gre_iseq = UINT32_MAX; error = in_gre_attach(sc); if (error != 0) { sc->gre_family = 0; free(sc->gre_hdr, M_GRE); } break; case SIOCGIFPSRCADDR: case SIOCGIFPDSTADDR: if (sc->gre_family != AF_INET) { error = EADDRNOTAVAIL; break; } src = (struct sockaddr_in *)&ifr->ifr_addr; memset(src, 0, sizeof(*src)); src->sin_family = AF_INET; src->sin_len = sizeof(*src); src->sin_addr = (cmd == SIOCGIFPSRCADDR) ? sc->gre_oip.ip_src: sc->gre_oip.ip_dst; error = prison_if(curthread->td_ucred, (struct sockaddr *)src); if (error != 0) memset(src, 0, sizeof(*src)); break; } return (error); } int in_gre_output(struct mbuf *m, int af, int hlen) { struct greip *gi; gi = mtod(m, struct greip *); switch (af) { case AF_INET: /* * gre_transmit() has used M_PREPEND() that doesn't guarantee * m_data is contiguous more than hlen bytes. Use m_copydata() * here to avoid m_pullup(). */ m_copydata(m, hlen + offsetof(struct ip, ip_tos), sizeof(u_char), &gi->gi_ip.ip_tos); m_copydata(m, hlen + offsetof(struct ip, ip_id), sizeof(u_short), (caddr_t)&gi->gi_ip.ip_id); break; #ifdef INET6 case AF_INET6: gi->gi_ip.ip_tos = 0; /* XXX */ ip_fillid(&gi->gi_ip); break; #endif } gi->gi_ip.ip_ttl = V_ip_gre_ttl; gi->gi_ip.ip_len = htons(m->m_pkthdr.len); return (ip_output(m, NULL, NULL, IP_FORWARDING, NULL, NULL)); } static const struct srcaddrtab *ipv4_srcaddrtab = NULL; static const struct encaptab *ecookie = NULL; static const struct encap_config ipv4_encap_cfg = { .proto = IPPROTO_GRE, .min_length = sizeof(struct greip) + sizeof(struct ip), .exact_match = ENCAP_DRV_LOOKUP, .lookup = in_gre_lookup, .input = gre_input }; void in_gre_init(void) { if (!IS_DEFAULT_VNET(curvnet)) return; ipv4_srcaddrtab = ip_encap_register_srcaddr(in_gre_srcaddr, NULL, M_WAITOK); ecookie = ip_encap_attach(&ipv4_encap_cfg, NULL, M_WAITOK); } void in_gre_uninit(void) { if (IS_DEFAULT_VNET(curvnet)) { ip_encap_detach(ecookie); ip_encap_unregister_srcaddr(ipv4_srcaddrtab); } if (V_ipv4_hashtbl != NULL) { gre_hashdestroy(V_ipv4_hashtbl); V_ipv4_hashtbl = NULL; GRE_WAIT(); gre_hashdestroy(V_ipv4_srchashtbl); gre_hashdestroy((struct gre_list *)V_ipv4_sockets); } }