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- /* $KAME: if_stf.c,v 1.73 2001/12/03 11:08:30 keiichi Exp $ */
- /*-
- * SPDX-License-Identifier: BSD-3-Clause
- *
- * Copyright (C) 2000 WIDE Project.
- * Copyright (c) 2010 Hiroki Sato <hrs@FreeBSD.org>
- * Copyright (c) 2013 Ermal Luci <eri@FreeBSD.org>
- * Copyright (c) 2017-2021 Rubicon Communications, LLC (Netgate)
- * 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.
- */
- /*
- * 6to4 interface, based on RFC3056.
- *
- * 6to4 interface is NOT capable of link-layer (I mean, IPv4) multicasting.
- * There is no address mapping defined from IPv6 multicast address to IPv4
- * address. Therefore, we do not have IFF_MULTICAST on the interface.
- *
- * Due to the lack of address mapping for link-local addresses, we cannot
- * throw packets toward link-local addresses (fe80::x). Also, we cannot throw
- * packets to link-local multicast addresses (ff02::x).
- *
- * Here are interesting symptoms due to the lack of link-local address:
- *
- * Unicast routing exchange:
- * - RIPng: Impossible. Uses link-local multicast packet toward ff02::9,
- * and link-local addresses as nexthop.
- * - OSPFv6: Impossible. OSPFv6 assumes that there's link-local address
- * assigned to the link, and makes use of them. Also, HELLO packets use
- * link-local multicast addresses (ff02::5 and ff02::6).
- * - BGP4+: Maybe. You can only use global address as nexthop, and global
- * address as TCP endpoint address.
- *
- * Multicast routing protocols:
- * - PIM: Hello packet cannot be used to discover adjacent PIM routers.
- * Adjacent PIM routers must be configured manually (is it really spec-wise
- * correct thing to do?).
- *
- * ICMPv6:
- * - Redirects cannot be used due to the lack of link-local address.
- *
- * stf interface does not have, and will not need, a link-local address.
- * It seems to have no real benefit and does not help the above symptoms much.
- * Even if we assign link-locals to interface, we cannot really
- * use link-local unicast/multicast on top of 6to4 cloud (since there's no
- * encapsulation defined for link-local address), and the above analysis does
- * not change. RFC3056 does not mandate the assignment of link-local address
- * either.
- *
- * 6to4 interface has security issues. Refer to
- * http://playground.iijlab.net/i-d/draft-itojun-ipv6-transition-abuse-00.txt
- * for details. The code tries to filter out some of malicious packets.
- * Note that there is no way to be 100% secure.
- */
- #include <sys/param.h>
- #include <sys/systm.h>
- #include <sys/socket.h>
- #include <sys/sockio.h>
- #include <sys/mbuf.h>
- #include <sys/endian.h>
- #include <sys/errno.h>
- #include <sys/kernel.h>
- #include <sys/lock.h>
- #include <sys/module.h>
- #include <sys/priv.h>
- #include <sys/proc.h>
- #include <sys/queue.h>
- #include <sys/sdt.h>
- #include <sys/sysctl.h>
- #include <machine/cpu.h>
- #include <sys/malloc.h>
- #include <net/if.h>
- #include <net/if_var.h>
- #include <net/if_private.h>
- #include <net/if_clone.h>
- #include <net/route.h>
- #include <net/route/nhop.h>
- #include <net/netisr.h>
- #include <net/if_stf.h>
- #include <net/if_types.h>
- #include <net/vnet.h>
- #include <netinet/in.h>
- #include <netinet/in_fib.h>
- #include <netinet/in_systm.h>
- #include <netinet/ip.h>
- #include <netinet/ip_var.h>
- #include <netinet/in_var.h>
- #include <netinet/ip6.h>
- #include <netinet6/in6_fib.h>
- #include <netinet6/ip6_var.h>
- #include <netinet6/in6_var.h>
- #include <netinet/ip_ecn.h>
- #include <netinet/ip_encap.h>
- #include <machine/stdarg.h>
- #include <net/bpf.h>
- #include <security/mac/mac_framework.h>
- SDT_PROVIDER_DEFINE(if_stf);
- SDT_PROBE_DEFINE3(if_stf, , encapcheck, in, "struct mbuf *", "int", "int");
- SDT_PROBE_DEFINE0(if_stf, , encapcheck, accept);
- SDT_PROBE_DEFINE3(if_stf, , getsrcifa6, in, "struct ifnet *",
- "struct in6_addr *", "struct in6_addr *");
- SDT_PROBE_DEFINE2(if_stf, , getsrcifa6, found, "struct in6_addr *",
- "struct in6_addr *");
- SDT_PROBE_DEFINE0(if_stf, , getsrcifa6, notfound);
- SDT_PROBE_DEFINE4(if_stf, , stf_output, in, "struct ifnet *", "struct mbuf *",
- "struct sockaddr *", "struct route *");
- SDT_PROBE_DEFINE2(if_stf, , stf_output, error, "int", "int");
- SDT_PROBE_DEFINE1(if_stf, , stf_output, out, "int");
- SDT_PROBE_DEFINE3(if_stf, , checkaddr6, in, "struct stf_softc *",
- "struct in6_addr *", "struct ifnet *");
- SDT_PROBE_DEFINE2(if_stf, , checkaddr6, out, "int", "int");
- SDT_PROBE_DEFINE3(if_stf, , stf_input, in, "struct mbuf *", "int", "int");
- SDT_PROBE_DEFINE2(if_stf, , stf_input, out, "int", "int");
- SDT_PROBE_DEFINE3(if_stf, , ioctl, sv4net, "struct in_addr *",
- "struct in_addr *", "int");
- SDT_PROBE_DEFINE1(if_stf, , ioctl, sdstv4, "struct in_addr *");
- SDT_PROBE_DEFINE1(if_stf, , ioctl, ifaddr, "struct ifaddr *");
- SDT_PROBE_DEFINE4(if_stf, , getin4addr_in6, out, "struct in6_addr *",
- "struct in6_addr *", "struct in6_addr *", "struct sockaddr_in *");
- SDT_PROBE_DEFINE2(if_stf, , getin4addr, in, "struct in6_addr *", "struct in6_addr *");
- SDT_PROBE_DEFINE1(if_stf, , getin4addr, out, "struct sockaddr_in *");
- SYSCTL_DECL(_net_link);
- static SYSCTL_NODE(_net_link, IFT_STF, stf, CTLFLAG_RW | CTLFLAG_MPSAFE, 0,
- "6to4 Interface");
- static int stf_permit_rfc1918 = 0;
- SYSCTL_INT(_net_link_stf, OID_AUTO, permit_rfc1918, CTLFLAG_RWTUN,
- &stf_permit_rfc1918, 0, "Permit the use of private IPv4 addresses");
- #define STFUNIT 0
- #define IN6_IS_ADDR_6TO4(x) (ntohs((x)->s6_addr16[0]) == 0x2002)
- /*
- * XXX: Return a pointer with 16-bit aligned. Don't cast it to
- * struct in_addr *; use bcopy() instead.
- */
- #define GET_V4(x) (&(x)->s6_addr16[1])
- struct stf_softc {
- struct ifnet *sc_ifp;
- in_addr_t braddr; /* Border relay IPv4 address */
- in_addr_t srcv4_addr; /* Our IPv4 WAN address */
- u_int v4prefixlen; /* How much of the v4 address to include in our address. */
- u_int sc_fibnum;
- const struct encaptab *encap_cookie;
- };
- #define STF2IFP(sc) ((sc)->sc_ifp)
- static const char stfname[] = "stf";
- static MALLOC_DEFINE(M_STF, stfname, "6to4 Tunnel Interface");
- static const int ip_stf_ttl = 40;
- static int in_stf_input(struct mbuf *, int, int, void *);
- static char *stfnames[] = {"stf0", "stf", "6to4", NULL};
- static int stfmodevent(module_t, int, void *);
- static int stf_encapcheck(const struct mbuf *, int, int, void *);
- static int stf_getsrcifa6(struct ifnet *, struct in6_addr *, struct in6_addr *);
- static int stf_output(struct ifnet *, struct mbuf *, const struct sockaddr *,
- struct route *);
- static int isrfc1918addr(struct in_addr *);
- static int stf_checkaddr4(struct stf_softc *, struct in_addr *,
- struct ifnet *);
- static int stf_checkaddr6(struct stf_softc *, struct in6_addr *,
- struct ifnet *);
- static struct sockaddr_in *stf_getin4addr_in6(struct stf_softc *,
- struct sockaddr_in *, struct in6_addr, struct in6_addr,
- struct in6_addr);
- static struct sockaddr_in *stf_getin4addr(struct stf_softc *,
- struct sockaddr_in *, struct in6_addr, struct in6_addr);
- static int stf_ioctl(struct ifnet *, u_long, caddr_t);
- VNET_DEFINE_STATIC(struct if_clone *, stf_cloner);
- #define V_stf_cloner VNET(stf_cloner)
- static const struct encap_config ipv4_encap_cfg = {
- .proto = IPPROTO_IPV6,
- .min_length = sizeof(struct ip),
- .exact_match = (sizeof(in_addr_t) << 3) + 8,
- .check = stf_encapcheck,
- .input = in_stf_input
- };
- static int
- stf_clone_match(struct if_clone *ifc, const char *name)
- {
- int i;
- for(i = 0; stfnames[i] != NULL; i++) {
- if (strcmp(stfnames[i], name) == 0)
- return (1);
- }
- return (0);
- }
- static int
- stf_clone_create(struct if_clone *ifc, char *name, size_t len,
- struct ifc_data *ifd, struct ifnet **ifpp)
- {
- char *dp;
- int err, unit, wildcard;
- struct stf_softc *sc;
- struct ifnet *ifp;
- err = ifc_name2unit(name, &unit);
- if (err != 0)
- return (err);
- wildcard = (unit < 0);
- /*
- * We can only have one unit, but since unit allocation is
- * already locked, we use it to keep from allocating extra
- * interfaces.
- */
- unit = STFUNIT;
- err = ifc_alloc_unit(ifc, &unit);
- if (err != 0)
- return (err);
- sc = malloc(sizeof(struct stf_softc), M_STF, M_WAITOK | M_ZERO);
- ifp = STF2IFP(sc) = if_alloc(IFT_STF);
- ifp->if_softc = sc;
- sc->sc_fibnum = curthread->td_proc->p_fibnum;
- /*
- * Set the name manually rather then using if_initname because
- * we don't conform to the default naming convention for interfaces.
- * In the wildcard case, we need to update the name.
- */
- if (wildcard) {
- for (dp = name; *dp != '\0'; dp++);
- if (snprintf(dp, len - (dp-name), "%d", unit) >
- len - (dp-name) - 1) {
- /*
- * This can only be a programmer error and
- * there's no straightforward way to recover if
- * it happens.
- */
- panic("if_clone_create(): interface name too long");
- }
- }
- strlcpy(ifp->if_xname, name, IFNAMSIZ);
- ifp->if_dname = stfname;
- ifp->if_dunit = IF_DUNIT_NONE;
- sc->encap_cookie = ip_encap_attach(&ipv4_encap_cfg, sc, M_WAITOK);
- ifp->if_mtu = IPV6_MMTU;
- ifp->if_ioctl = stf_ioctl;
- ifp->if_output = stf_output;
- ifp->if_snd.ifq_maxlen = ifqmaxlen;
- if_attach(ifp);
- bpfattach(ifp, DLT_NULL, sizeof(u_int32_t));
- *ifpp = ifp;
- return (0);
- }
- static int
- stf_clone_destroy(struct if_clone *ifc, struct ifnet *ifp, uint32_t flags)
- {
- struct stf_softc *sc = ifp->if_softc;
- int err __unused;
- err = ip_encap_detach(sc->encap_cookie);
- KASSERT(err == 0, ("Unexpected error detaching encap_cookie"));
- bpfdetach(ifp);
- if_detach(ifp);
- if_free(ifp);
- free(sc, M_STF);
- ifc_free_unit(ifc, STFUNIT);
- return (0);
- }
- static void
- vnet_stf_init(const void *unused __unused)
- {
- struct if_clone_addreq req = {
- .match_f = stf_clone_match,
- .create_f = stf_clone_create,
- .destroy_f = stf_clone_destroy,
- };
- V_stf_cloner = ifc_attach_cloner(stfname, &req);
- }
- VNET_SYSINIT(vnet_stf_init, SI_SUB_PSEUDO, SI_ORDER_ANY, vnet_stf_init, NULL);
- static void
- vnet_stf_uninit(const void *unused __unused)
- {
- if_clone_detach(V_stf_cloner);
- V_stf_cloner = NULL;
- }
- VNET_SYSUNINIT(vnet_stf_uninit, SI_SUB_PSEUDO, SI_ORDER_ANY, vnet_stf_uninit,
- NULL);
- static int
- stfmodevent(module_t mod, int type, void *data)
- {
- switch (type) {
- case MOD_LOAD:
- /* Done in vnet_stf_init() */
- break;
- case MOD_UNLOAD:
- /* Done in vnet_stf_uninit() */
- break;
- default:
- return (EOPNOTSUPP);
- }
- return (0);
- }
- static moduledata_t stf_mod = {
- "if_stf",
- stfmodevent,
- 0
- };
- DECLARE_MODULE(if_stf, stf_mod, SI_SUB_PSEUDO, SI_ORDER_ANY);
- MODULE_VERSION(if_stf, 2);
- static int
- stf_encapcheck(const struct mbuf *m, int off, int proto, void *arg)
- {
- struct ip ip;
- struct stf_softc *sc;
- struct in6_addr addr6, mask6;
- struct sockaddr_in sin4addr, sin4mask;
- SDT_PROBE3(if_stf, , encapcheck, in, m, off, proto);
- sc = (struct stf_softc *)arg;
- if (sc == NULL)
- return (0);
- if ((STF2IFP(sc)->if_flags & IFF_UP) == 0)
- return (0);
- /* IFF_LINK0 means "no decapsulation" */
- if ((STF2IFP(sc)->if_flags & IFF_LINK0) != 0)
- return (0);
- if (proto != IPPROTO_IPV6)
- return (0);
- m_copydata(m, 0, sizeof(ip), (caddr_t)&ip);
- if (ip.ip_v != 4)
- return (0);
- if (stf_getsrcifa6(STF2IFP(sc), &addr6, &mask6) != 0)
- return (0);
- if (sc->srcv4_addr != INADDR_ANY) {
- sin4addr.sin_addr.s_addr = sc->srcv4_addr;
- sin4addr.sin_family = AF_INET;
- } else
- if (stf_getin4addr(sc, &sin4addr, addr6, mask6) == NULL)
- return (0);
- if (sin4addr.sin_addr.s_addr != ip.ip_dst.s_addr)
- return (0);
- if (IN6_IS_ADDR_6TO4(&addr6)) {
- /*
- * 6to4 (RFC 3056).
- * Check if IPv4 src matches the IPv4 address derived
- * from the local 6to4 address masked by prefixmask.
- * success on: src = 10.1.1.1, ia6->ia_addr = 2002:0a00:.../24
- * fail on: src = 10.1.1.1, ia6->ia_addr = 2002:0b00:.../24
- */
- memcpy(&sin4mask.sin_addr, GET_V4(&mask6),
- sizeof(sin4mask.sin_addr));
- if ((sin4addr.sin_addr.s_addr & sin4mask.sin_addr.s_addr) !=
- (ip.ip_src.s_addr & sin4mask.sin_addr.s_addr))
- return (0);
- } else {
- /* 6rd (RFC 5569) */
- /*
- * No restriction on the src address in the case of
- * 6rd because the stf(4) interface always has a
- * prefix which covers whole of IPv4 src address
- * range. So, stf_output() will catch all of
- * 6rd-capsuled IPv4 traffic with suspicious inner dst
- * IPv4 address (i.e. the IPv6 destination address is
- * one the admin does not like to route to outside),
- * and then it discard them silently.
- */
- }
- SDT_PROBE0(if_stf, , encapcheck, accept);
- /* stf interface makes single side match only */
- return (32);
- }
- static int
- stf_getsrcifa6(struct ifnet *ifp, struct in6_addr *addr, struct in6_addr *mask)
- {
- struct ifaddr *ia;
- struct in_ifaddr *ia4;
- struct in6_addr addr6, mask6;
- struct sockaddr_in sin4;
- struct stf_softc *sc;
- struct in_addr in;
- NET_EPOCH_ASSERT();
- sc = ifp->if_softc;
- SDT_PROBE3(if_stf, , getsrcifa6, in, ifp, addr, mask);
- CK_STAILQ_FOREACH(ia, &ifp->if_addrhead, ifa_link) {
- if (ia->ifa_addr->sa_family != AF_INET6)
- continue;
- addr6 = *IFA_IN6(ia);
- mask6 = *IFA_MASKIN6(ia);
- if (sc->srcv4_addr != INADDR_ANY)
- bcopy(&sc->srcv4_addr, &in, sizeof(in));
- else {
- if (stf_getin4addr(sc, &sin4, addr6, mask6) == NULL)
- continue;
- bcopy(&sin4.sin_addr, &in, sizeof(in));
- }
- CK_LIST_FOREACH(ia4, INADDR_HASH(in.s_addr), ia_hash)
- if (ia4->ia_addr.sin_addr.s_addr == in.s_addr)
- break;
- if (ia4 == NULL)
- continue;
- *addr = addr6;
- *mask = mask6;
- SDT_PROBE2(if_stf, , getsrcifa6, found, addr, mask);
- return (0);
- }
- SDT_PROBE0(if_stf, , getsrcifa6, notfound);
- return (ENOENT);
- }
- static int
- stf_output(struct ifnet *ifp, struct mbuf *m, const struct sockaddr *dst,
- struct route *ro)
- {
- struct stf_softc *sc;
- const struct sockaddr_in6 *dst6;
- struct sockaddr_in dst4, src4;
- u_int8_t tos;
- struct ip *ip;
- struct ip6_hdr *ip6;
- struct in6_addr addr6, mask6;
- int error;
- SDT_PROBE4(if_stf, , stf_output, in, ifp, m, dst, ro);
- #ifdef MAC
- error = mac_ifnet_check_transmit(ifp, m);
- if (error) {
- m_freem(m);
- SDT_PROBE2(if_stf, , stf_output, error, error, __LINE__);
- return (error);
- }
- #endif
- sc = ifp->if_softc;
- dst6 = (const struct sockaddr_in6 *)dst;
- /* just in case */
- if ((ifp->if_flags & IFF_UP) == 0) {
- m_freem(m);
- if_inc_counter(ifp, IFCOUNTER_OERRORS, 1);
- SDT_PROBE2(if_stf, , stf_output, error, ENETDOWN, __LINE__);
- return (ENETDOWN);
- }
- /*
- * If we don't have an ip4 address that match my inner ip6 address,
- * we shouldn't generate output. Without this check, we'll end up
- * using wrong IPv4 source.
- */
- if (stf_getsrcifa6(ifp, &addr6, &mask6) != 0) {
- m_freem(m);
- if_inc_counter(ifp, IFCOUNTER_OERRORS, 1);
- SDT_PROBE2(if_stf, , stf_output, error, ENETDOWN, __LINE__);
- return (ENETDOWN);
- }
- if (m->m_len < sizeof(*ip6)) {
- m = m_pullup(m, sizeof(*ip6));
- if (!m) {
- if_inc_counter(ifp, IFCOUNTER_OERRORS, 1);
- SDT_PROBE2(if_stf, , stf_output, error, ENOBUFS,
- __LINE__);
- return (ENOBUFS);
- }
- }
- ip6 = mtod(m, struct ip6_hdr *);
- tos = IPV6_TRAFFIC_CLASS(ip6);
- /*
- * Pickup the right outer dst addr from the list of candidates.
- * ip6_dst has priority as it may be able to give us shorter IPv4 hops.
- */
- if (stf_getin4addr_in6(sc, &dst4, addr6, mask6,
- ip6->ip6_dst) == NULL) {
- if (sc->braddr != INADDR_ANY)
- dst4.sin_addr.s_addr = sc->braddr;
- else if (stf_getin4addr_in6(sc, &dst4, addr6, mask6,
- dst6->sin6_addr) == NULL) {
- m_freem(m);
- if_inc_counter(ifp, IFCOUNTER_OERRORS, 1);
- SDT_PROBE2(if_stf, , stf_output, error, ENETUNREACH,
- __LINE__);
- return (ENETUNREACH);
- }
- }
- if (bpf_peers_present(ifp->if_bpf)) {
- /*
- * We need to prepend the address family as
- * a four byte field. Cons up a dummy header
- * to pacify bpf. This is safe because bpf
- * will only read from the mbuf (i.e., it won't
- * try to free it or keep a pointer a to it).
- */
- u_int af = AF_INET6;
- bpf_mtap2(ifp->if_bpf, &af, sizeof(af), m);
- }
- M_PREPEND(m, sizeof(struct ip), M_NOWAIT);
- if (m == NULL) {
- if_inc_counter(ifp, IFCOUNTER_OERRORS, 1);
- SDT_PROBE2(if_stf, , stf_output, error, ENOBUFS, __LINE__);
- return (ENOBUFS);
- }
- ip = mtod(m, struct ip *);
- bzero(ip, sizeof(*ip));
- if (sc->srcv4_addr != INADDR_ANY)
- src4.sin_addr.s_addr = sc->srcv4_addr;
- else if (stf_getin4addr(sc, &src4, addr6, mask6) == NULL) {
- m_freem(m);
- if_inc_counter(ifp, IFCOUNTER_OERRORS, 1);
- SDT_PROBE2(if_stf, , stf_output, error, ENETUNREACH, __LINE__);
- return (ENETUNREACH);
- }
- bcopy(&src4.sin_addr, &ip->ip_src, sizeof(ip->ip_src));
- bcopy(&dst4.sin_addr, &ip->ip_dst, sizeof(ip->ip_dst));
- ip->ip_p = IPPROTO_IPV6;
- ip->ip_ttl = ip_stf_ttl;
- ip->ip_len = htons(m->m_pkthdr.len);
- if (ifp->if_flags & IFF_LINK1)
- ip_ecn_ingress(ECN_ALLOWED, &ip->ip_tos, &tos);
- else
- ip_ecn_ingress(ECN_NOCARE, &ip->ip_tos, &tos);
- M_SETFIB(m, sc->sc_fibnum);
- if_inc_counter(ifp, IFCOUNTER_OPACKETS, 1);
- error = ip_output(m, NULL, NULL, 0, NULL, NULL);
- SDT_PROBE1(if_stf, , stf_output, out, error);
- return (error);
- }
- static int
- isrfc1918addr(struct in_addr *in)
- {
- /*
- * returns 1 if private address range:
- * 10.0.0.0/8 172.16.0.0/12 192.168.0.0/16
- */
- if (stf_permit_rfc1918 == 0 && (
- (ntohl(in->s_addr) & 0xff000000) >> 24 == 10 ||
- (ntohl(in->s_addr) & 0xfff00000) >> 16 == 172 * 256 + 16 ||
- (ntohl(in->s_addr) & 0xffff0000) >> 16 == 192 * 256 + 168))
- return (1);
- return (0);
- }
- static int
- stf_checkaddr4(struct stf_softc *sc, struct in_addr *in, struct ifnet *inifp)
- {
- struct in_ifaddr *ia4;
- /*
- * reject packets with the following address:
- * 224.0.0.0/4 0.0.0.0/8 127.0.0.0/8 255.0.0.0/8
- */
- if (IN_MULTICAST(ntohl(in->s_addr)))
- return (-1);
- switch ((ntohl(in->s_addr) & 0xff000000) >> 24) {
- case 0: case 127: case 255:
- return (-1);
- }
- /*
- * reject packets with broadcast
- */
- CK_STAILQ_FOREACH(ia4, &V_in_ifaddrhead, ia_link) {
- if ((ia4->ia_ifa.ifa_ifp->if_flags & IFF_BROADCAST) == 0)
- continue;
- if (in->s_addr == ia4->ia_broadaddr.sin_addr.s_addr) {
- return (-1);
- }
- }
- /*
- * perform ingress filter
- */
- if (sc && (STF2IFP(sc)->if_flags & IFF_LINK2) == 0 && inifp) {
- struct nhop_object *nh;
- NET_EPOCH_ASSERT();
- nh = fib4_lookup(sc->sc_fibnum, *in, 0, 0, 0);
- if (nh == NULL)
- return (-1);
- if (nh->nh_ifp != inifp)
- return (-1);
- }
- return (0);
- }
- static int
- stf_checkaddr6(struct stf_softc *sc, struct in6_addr *in6, struct ifnet *inifp)
- {
- SDT_PROBE3(if_stf, , checkaddr6, in, sc, in6, inifp);
- /*
- * check 6to4 addresses
- */
- if (IN6_IS_ADDR_6TO4(in6)) {
- struct in_addr in4;
- int ret;
- bcopy(GET_V4(in6), &in4, sizeof(in4));
- ret = stf_checkaddr4(sc, &in4, inifp);
- SDT_PROBE2(if_stf, , checkaddr6, out, ret, __LINE__);
- return (ret);
- }
- /*
- * reject anything that look suspicious. the test is implemented
- * in ip6_input too, but we check here as well to
- * (1) reject bad packets earlier, and
- * (2) to be safe against future ip6_input change.
- */
- if (IN6_IS_ADDR_V4COMPAT(in6)) {
- SDT_PROBE2(if_stf, , checkaddr6, out, -1, __LINE__);
- return (-1);
- }
- if (IN6_IS_ADDR_V4MAPPED(in6)) {
- SDT_PROBE2(if_stf, , checkaddr6, out, -1, __LINE__);
- return (-1);
- }
- SDT_PROBE2(if_stf, , checkaddr6, out, 0, __LINE__);
- return (0);
- }
- static int
- in_stf_input(struct mbuf *m, int off, int proto, void *arg)
- {
- struct stf_softc *sc = arg;
- struct ip ip;
- struct ip6_hdr *ip6;
- u_int8_t otos, itos;
- struct ifnet *ifp;
- struct nhop_object *nh;
- NET_EPOCH_ASSERT();
- SDT_PROBE3(if_stf, , stf_input, in, m, off, proto);
- if (proto != IPPROTO_IPV6) {
- m_freem(m);
- SDT_PROBE2(if_stf, , stf_input, out, IPPROTO_DONE, __LINE__);
- return (IPPROTO_DONE);
- }
- m_copydata(m, 0, sizeof(struct ip), (caddr_t)&ip);
- if (sc == NULL || (STF2IFP(sc)->if_flags & IFF_UP) == 0) {
- m_freem(m);
- SDT_PROBE2(if_stf, , stf_input, out, IPPROTO_DONE, __LINE__);
- return (IPPROTO_DONE);
- }
- ifp = STF2IFP(sc);
- #ifdef MAC
- mac_ifnet_create_mbuf(ifp, m);
- #endif
- /*
- * perform sanity check against outer src/dst.
- * for source, perform ingress filter as well.
- */
- if (stf_checkaddr4(sc, &ip.ip_dst, NULL) < 0 ||
- stf_checkaddr4(sc, &ip.ip_src, m->m_pkthdr.rcvif) < 0) {
- m_freem(m);
- SDT_PROBE2(if_stf, , stf_input, out, IPPROTO_DONE, __LINE__);
- return (IPPROTO_DONE);
- }
- otos = ip.ip_tos;
- m_adj(m, off);
- if (m->m_len < sizeof(*ip6)) {
- m = m_pullup(m, sizeof(*ip6));
- if (!m) {
- SDT_PROBE2(if_stf, , stf_input, out, IPPROTO_DONE,
- __LINE__);
- return (IPPROTO_DONE);
- }
- }
- ip6 = mtod(m, struct ip6_hdr *);
- /*
- * perform sanity check against inner src/dst.
- * for source, perform ingress filter as well.
- */
- if (stf_checkaddr6(sc, &ip6->ip6_dst, NULL) < 0 ||
- stf_checkaddr6(sc, &ip6->ip6_src, m->m_pkthdr.rcvif) < 0) {
- m_freem(m);
- SDT_PROBE2(if_stf, , stf_input, out, IPPROTO_DONE, __LINE__);
- return (IPPROTO_DONE);
- }
- /*
- * reject packets with private address range.
- * (requirement from RFC3056 section 2 1st paragraph)
- */
- if ((IN6_IS_ADDR_6TO4(&ip6->ip6_src) && isrfc1918addr(&ip.ip_src)) ||
- (IN6_IS_ADDR_6TO4(&ip6->ip6_dst) && isrfc1918addr(&ip.ip_dst))) {
- m_freem(m);
- SDT_PROBE2(if_stf, , stf_input, out, IPPROTO_DONE, __LINE__);
- return (IPPROTO_DONE);
- }
- /*
- * Ignore if the destination is the same stf interface because
- * all of valid IPv6 outgoing traffic should go interfaces
- * except for it.
- */
- nh = fib6_lookup(sc->sc_fibnum, &ip6->ip6_dst, 0, 0, 0);
- if (nh == NULL) {
- m_free(m);
- SDT_PROBE2(if_stf, , stf_input, out, IPPROTO_DONE, __LINE__);
- return (IPPROTO_DONE);
- }
- if ((nh->nh_ifp == ifp) &&
- (!IN6_ARE_ADDR_EQUAL(&ip6->ip6_src, &nh->gw6_sa.sin6_addr))) {
- m_free(m);
- SDT_PROBE2(if_stf, , stf_input, out, IPPROTO_DONE, __LINE__);
- return (IPPROTO_DONE);
- }
- itos = IPV6_TRAFFIC_CLASS(ip6);
- if ((ifp->if_flags & IFF_LINK1) != 0)
- ip_ecn_egress(ECN_ALLOWED, &otos, &itos);
- else
- ip_ecn_egress(ECN_NOCARE, &otos, &itos);
- ip6->ip6_flow &= ~htonl(0xff << 20);
- ip6->ip6_flow |= htonl((u_int32_t)itos << 20);
- m->m_pkthdr.rcvif = ifp;
- if (bpf_peers_present(ifp->if_bpf)) {
- /*
- * We need to prepend the address family as
- * a four byte field. Cons up a dummy header
- * to pacify bpf. This is safe because bpf
- * will only read from the mbuf (i.e., it won't
- * try to free it or keep a pointer a to it).
- */
- u_int32_t af = AF_INET6;
- bpf_mtap2(ifp->if_bpf, &af, sizeof(af), m);
- }
- /*
- * Put the packet to the network layer input queue according to the
- * specified address family.
- * See net/if_gif.c for possible issues with packet processing
- * reorder due to extra queueing.
- */
- if_inc_counter(ifp, IFCOUNTER_IPACKETS, 1);
- if_inc_counter(ifp, IFCOUNTER_IBYTES, m->m_pkthdr.len);
- M_SETFIB(m, ifp->if_fib);
- netisr_dispatch(NETISR_IPV6, m);
- SDT_PROBE2(if_stf, , stf_input, out, IPPROTO_DONE, __LINE__);
- return (IPPROTO_DONE);
- }
- static struct sockaddr_in *
- stf_getin4addr_in6(struct stf_softc *sc, struct sockaddr_in *sin,
- struct in6_addr addr6, struct in6_addr mask6, struct in6_addr in6)
- {
- int i;
- struct sockaddr_in *out;
- /*
- * When (src addr & src mask) != (in6 & src mask),
- * the dst is not in the 6rd domain. The IPv4 address must
- * not be used.
- */
- for (i = 0; i < sizeof(addr6); i++) {
- if ((((u_char *)&addr6)[i] & ((u_char *)&mask6)[i]) !=
- (((u_char *)&in6)[i] & ((u_char *)&mask6)[i])) {
- SDT_PROBE4(if_stf, , getin4addr_in6, out, &addr6,
- &mask6, &in6, NULL);
- return (NULL);
- }
- }
- /* After the mask check, use in6 instead of addr6. */
- out = stf_getin4addr(sc, sin, in6, mask6);
- SDT_PROBE4(if_stf, , getin4addr_in6, out, &addr6, &mask6, &in6, out);
- return (out);
- }
- static struct sockaddr_in *
- stf_getin4addr(struct stf_softc *sc, struct sockaddr_in *sin,
- struct in6_addr addr6, struct in6_addr mask6)
- {
- struct in_addr *in;
- SDT_PROBE2(if_stf, , getin4addr, in, &addr6, &mask6);
- memset(sin, 0, sizeof(*sin));
- in = &sin->sin_addr;
- if (IN6_IS_ADDR_6TO4(&addr6)) {
- /* 6to4 (RFC 3056) */
- bcopy(GET_V4(&addr6), in, sizeof(*in));
- if (isrfc1918addr(in))
- return (NULL);
- } else {
- /* 6rd (RFC 5569) */
- in_addr_t v4prefix;
- uint8_t *v6 = (uint8_t*)&addr6;
- uint64_t v6prefix;
- u_int plen;
- u_int v4suffixlen;
- v4prefix = 0;
- if (sc->v4prefixlen < 32) {
- v4suffixlen = 32 - sc->v4prefixlen;
- v4prefix = ntohl(sc->srcv4_addr) &
- (0xffffffffU << v4suffixlen);
- } else {
- MPASS(sc->v4prefixlen == 32);
- v4suffixlen = 32;
- }
- plen = in6_mask2len(&mask6, NULL);
- if (plen > 64)
- return (NULL);
- /* To make this simple we do not support prefixes longer than
- * 64 bits. RFC5969 says "a 6rd delegated prefix SHOULD be /64
- * or shorter." so this is a moderately safe assumption. */
- v6prefix = be64toh(*(uint64_t *)v6);
- /* Shift away the v6 prefix itself. */
- v6prefix <<= plen;
- v6prefix >>= plen;
- /* Now shift away everything after the v4 address. */
- v6prefix >>= 64 - plen - v4suffixlen;
- sin->sin_addr.s_addr = htonl(v4prefix | (uint32_t)v6prefix);
- }
- SDT_PROBE1(if_stf, , getin4addr, out, sin);
- return (sin);
- }
- static int
- stf_ioctl(struct ifnet *ifp, u_long cmd, caddr_t data)
- {
- struct ifaddr *ifa;
- struct ifdrv *ifd;
- struct ifreq *ifr;
- struct sockaddr_in sin4;
- struct stf_softc *sc_cur;
- struct stfv4args args;
- int error, mtu;
- error = 0;
- sc_cur = ifp->if_softc;
- switch (cmd) {
- case SIOCSDRVSPEC:
- ifd = (struct ifdrv *)data;
- error = priv_check(curthread, PRIV_NET_ADDIFADDR);
- if (error)
- break;
- if (ifd->ifd_cmd == STF6RD_SV4NET) {
- if (ifd->ifd_len != sizeof(args)) {
- error = EINVAL;
- break;
- }
- bzero(&args, sizeof(args));
- error = copyin(ifd->ifd_data, &args, ifd->ifd_len);
- if (error)
- break;
- if (args.v4_prefixlen < 1 || args.v4_prefixlen > 32) {
- error = EINVAL;
- break;
- }
- bcopy(&args.srcv4_addr, &sc_cur->srcv4_addr,
- sizeof(sc_cur->srcv4_addr));
- sc_cur->v4prefixlen = args.v4_prefixlen;
- SDT_PROBE3(if_stf, , ioctl, sv4net, sc_cur->srcv4_addr,
- sc_cur->srcv4_addr, sc_cur->v4prefixlen);
- } else if (ifd->ifd_cmd == STF6RD_SBR) {
- if (ifd->ifd_len != sizeof(args)) {
- error = EINVAL;
- break;
- }
- bzero(&args, sizeof(args));
- error = copyin(ifd->ifd_data, &args, ifd->ifd_len);
- if (error)
- break;
- sc_cur->braddr = args.braddr.s_addr;
- SDT_PROBE1(if_stf, , ioctl, sdstv4,
- sc_cur->braddr);
- } else
- error = EINVAL;
- break;
- case SIOCGDRVSPEC:
- ifd = (struct ifdrv *)data;
- if (ifd->ifd_cmd != STF6RD_GV4NET) {
- error = EINVAL;
- break;
- }
- if (ifd->ifd_len != sizeof(args)) {
- error = EINVAL;
- break;
- }
- bzero(&args, sizeof(args));
- args.srcv4_addr.s_addr = sc_cur->srcv4_addr;
- args.braddr.s_addr = sc_cur->braddr;
- args.v4_prefixlen = sc_cur->v4prefixlen;
- error = copyout(&args, ifd->ifd_data, ifd->ifd_len);
- break;
- case SIOCSIFADDR:
- ifa = (struct ifaddr *)data;
- SDT_PROBE1(if_stf, , ioctl, ifaddr, ifa);
- if (ifa == NULL || ifa->ifa_addr->sa_family != AF_INET6) {
- error = EAFNOSUPPORT;
- break;
- }
- if (stf_getin4addr(sc_cur, &sin4,
- satosin6(ifa->ifa_addr)->sin6_addr,
- satosin6(ifa->ifa_netmask)->sin6_addr) == NULL) {
- error = EINVAL;
- break;
- }
- ifp->if_flags |= IFF_UP;
- ifp->if_drv_flags |= IFF_DRV_RUNNING;
- break;
- case SIOCADDMULTI:
- case SIOCDELMULTI:
- ifr = (struct ifreq *)data;
- if (ifr && ifr->ifr_addr.sa_family == AF_INET6)
- ;
- else
- error = EAFNOSUPPORT;
- break;
- case SIOCGIFMTU:
- break;
- case SIOCSIFMTU:
- ifr = (struct ifreq *)data;
- mtu = ifr->ifr_mtu;
- /* RFC 4213 3.2 ideal world MTU */
- if (mtu < IPV6_MINMTU || mtu > IF_MAXMTU - 20)
- return (EINVAL);
- ifp->if_mtu = mtu;
- break;
- default:
- error = EINVAL;
- break;
- }
- return (error);
- }
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