1057 lines
28 KiB
C
1057 lines
28 KiB
C
/* $KAME: if_stf.c,v 1.73 2001/12/03 11:08:30 keiichi Exp $ */
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/*-
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* SPDX-License-Identifier: BSD-3-Clause
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*
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* Copyright (C) 2000 WIDE Project.
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* Copyright (c) 2010 Hiroki Sato <hrs@FreeBSD.org>
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* Copyright (c) 2013 Ermal Luci <eri@FreeBSD.org>
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* Copyright (c) 2017-2021 Rubicon Communications, LLC (Netgate)
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* All rights reserved.
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*
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* Redistribution and use in source and binary forms, with or without
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* modification, are permitted provided that the following conditions
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* are met:
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* 1. Redistributions of source code must retain the above copyright
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* notice, this list of conditions and the following disclaimer.
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* 2. Redistributions in binary form must reproduce the above copyright
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* notice, this list of conditions and the following disclaimer in the
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* documentation and/or other materials provided with the distribution.
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* 3. Neither the name of the project nor the names of its contributors
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* may be used to endorse or promote products derived from this software
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* without specific prior written permission.
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*
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* THIS SOFTWARE IS PROVIDED BY THE PROJECT AND CONTRIBUTORS ``AS IS'' AND
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* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
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* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
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* ARE DISCLAIMED. IN NO EVENT SHALL THE PROJECT OR CONTRIBUTORS BE LIABLE
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* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
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* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
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* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
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* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
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* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
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* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
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* SUCH DAMAGE.
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*/
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/*
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* 6to4 interface, based on RFC3056.
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*
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* 6to4 interface is NOT capable of link-layer (I mean, IPv4) multicasting.
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* There is no address mapping defined from IPv6 multicast address to IPv4
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* address. Therefore, we do not have IFF_MULTICAST on the interface.
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*
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* Due to the lack of address mapping for link-local addresses, we cannot
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* throw packets toward link-local addresses (fe80::x). Also, we cannot throw
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* packets to link-local multicast addresses (ff02::x).
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*
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* Here are interesting symptoms due to the lack of link-local address:
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*
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* Unicast routing exchange:
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* - RIPng: Impossible. Uses link-local multicast packet toward ff02::9,
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* and link-local addresses as nexthop.
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* - OSPFv6: Impossible. OSPFv6 assumes that there's link-local address
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* assigned to the link, and makes use of them. Also, HELLO packets use
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* link-local multicast addresses (ff02::5 and ff02::6).
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* - BGP4+: Maybe. You can only use global address as nexthop, and global
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* address as TCP endpoint address.
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*
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* Multicast routing protocols:
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* - PIM: Hello packet cannot be used to discover adjacent PIM routers.
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* Adjacent PIM routers must be configured manually (is it really spec-wise
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* correct thing to do?).
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*
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* ICMPv6:
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* - Redirects cannot be used due to the lack of link-local address.
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*
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* stf interface does not have, and will not need, a link-local address.
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* It seems to have no real benefit and does not help the above symptoms much.
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* Even if we assign link-locals to interface, we cannot really
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* use link-local unicast/multicast on top of 6to4 cloud (since there's no
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* encapsulation defined for link-local address), and the above analysis does
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* not change. RFC3056 does not mandate the assignment of link-local address
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* either.
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*
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* 6to4 interface has security issues. Refer to
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* http://playground.iijlab.net/i-d/draft-itojun-ipv6-transition-abuse-00.txt
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* for details. The code tries to filter out some of malicious packets.
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* Note that there is no way to be 100% secure.
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*/
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#include <sys/param.h>
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#include <sys/systm.h>
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#include <sys/socket.h>
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#include <sys/sockio.h>
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#include <sys/mbuf.h>
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#include <sys/endian.h>
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#include <sys/errno.h>
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#include <sys/kernel.h>
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#include <sys/lock.h>
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#include <sys/module.h>
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#include <sys/priv.h>
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#include <sys/proc.h>
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#include <sys/queue.h>
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#include <sys/sdt.h>
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#include <sys/sysctl.h>
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#include <machine/cpu.h>
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#include <sys/malloc.h>
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#include <net/if.h>
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#include <net/if_var.h>
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#include <net/if_private.h>
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#include <net/if_clone.h>
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#include <net/route.h>
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#include <net/route/nhop.h>
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#include <net/netisr.h>
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#include <net/if_stf.h>
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#include <net/if_types.h>
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#include <net/vnet.h>
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#include <netinet/in.h>
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#include <netinet/in_fib.h>
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#include <netinet/in_systm.h>
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#include <netinet/ip.h>
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#include <netinet/ip_var.h>
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#include <netinet/in_var.h>
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#include <netinet/ip6.h>
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#include <netinet6/in6_fib.h>
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#include <netinet6/ip6_var.h>
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#include <netinet6/in6_var.h>
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#include <netinet/ip_ecn.h>
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#include <netinet/ip_encap.h>
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#include <machine/stdarg.h>
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#include <net/bpf.h>
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#include <security/mac/mac_framework.h>
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SDT_PROVIDER_DEFINE(if_stf);
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SDT_PROBE_DEFINE3(if_stf, , encapcheck, in, "struct mbuf *", "int", "int");
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SDT_PROBE_DEFINE0(if_stf, , encapcheck, accept);
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SDT_PROBE_DEFINE3(if_stf, , getsrcifa6, in, "struct ifnet *",
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"struct in6_addr *", "struct in6_addr *");
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SDT_PROBE_DEFINE2(if_stf, , getsrcifa6, found, "struct in6_addr *",
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"struct in6_addr *");
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SDT_PROBE_DEFINE0(if_stf, , getsrcifa6, notfound);
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SDT_PROBE_DEFINE4(if_stf, , stf_output, in, "struct ifnet *", "struct mbuf *",
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"struct sockaddr *", "struct route *");
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SDT_PROBE_DEFINE2(if_stf, , stf_output, error, "int", "int");
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SDT_PROBE_DEFINE1(if_stf, , stf_output, out, "int");
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SDT_PROBE_DEFINE3(if_stf, , checkaddr6, in, "struct stf_softc *",
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"struct in6_addr *", "struct ifnet *");
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SDT_PROBE_DEFINE2(if_stf, , checkaddr6, out, "int", "int");
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SDT_PROBE_DEFINE3(if_stf, , stf_input, in, "struct mbuf *", "int", "int");
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SDT_PROBE_DEFINE2(if_stf, , stf_input, out, "int", "int");
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SDT_PROBE_DEFINE3(if_stf, , ioctl, sv4net, "struct in_addr *",
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"struct in_addr *", "int");
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SDT_PROBE_DEFINE1(if_stf, , ioctl, sdstv4, "struct in_addr *");
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SDT_PROBE_DEFINE1(if_stf, , ioctl, ifaddr, "struct ifaddr *");
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SDT_PROBE_DEFINE4(if_stf, , getin4addr_in6, out, "struct in6_addr *",
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"struct in6_addr *", "struct in6_addr *", "struct sockaddr_in *");
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SDT_PROBE_DEFINE2(if_stf, , getin4addr, in, "struct in6_addr *", "struct in6_addr *");
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SDT_PROBE_DEFINE1(if_stf, , getin4addr, out, "struct sockaddr_in *");
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SYSCTL_DECL(_net_link);
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static SYSCTL_NODE(_net_link, IFT_STF, stf, CTLFLAG_RW | CTLFLAG_MPSAFE, 0,
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"6to4 Interface");
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static int stf_permit_rfc1918 = 0;
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SYSCTL_INT(_net_link_stf, OID_AUTO, permit_rfc1918, CTLFLAG_RWTUN,
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&stf_permit_rfc1918, 0, "Permit the use of private IPv4 addresses");
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#define STFUNIT 0
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#define IN6_IS_ADDR_6TO4(x) (ntohs((x)->s6_addr16[0]) == 0x2002)
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/*
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* XXX: Return a pointer with 16-bit aligned. Don't cast it to
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* struct in_addr *; use bcopy() instead.
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*/
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#define GET_V4(x) (&(x)->s6_addr16[1])
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struct stf_softc {
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struct ifnet *sc_ifp;
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in_addr_t braddr; /* Border relay IPv4 address */
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in_addr_t srcv4_addr; /* Our IPv4 WAN address */
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u_int v4prefixlen; /* How much of the v4 address to include in our address. */
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u_int sc_fibnum;
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const struct encaptab *encap_cookie;
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};
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#define STF2IFP(sc) ((sc)->sc_ifp)
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static const char stfname[] = "stf";
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static MALLOC_DEFINE(M_STF, stfname, "6to4 Tunnel Interface");
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static const int ip_stf_ttl = 40;
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static int in_stf_input(struct mbuf *, int, int, void *);
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static char *stfnames[] = {"stf0", "stf", "6to4", NULL};
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static int stfmodevent(module_t, int, void *);
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static int stf_encapcheck(const struct mbuf *, int, int, void *);
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static int stf_getsrcifa6(struct ifnet *, struct in6_addr *, struct in6_addr *);
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static int stf_output(struct ifnet *, struct mbuf *, const struct sockaddr *,
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struct route *);
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static int isrfc1918addr(struct in_addr *);
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static int stf_checkaddr4(struct stf_softc *, struct in_addr *,
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struct ifnet *);
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static int stf_checkaddr6(struct stf_softc *, struct in6_addr *,
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struct ifnet *);
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static struct sockaddr_in *stf_getin4addr_in6(struct stf_softc *,
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struct sockaddr_in *, struct in6_addr, struct in6_addr,
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struct in6_addr);
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static struct sockaddr_in *stf_getin4addr(struct stf_softc *,
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struct sockaddr_in *, struct in6_addr, struct in6_addr);
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static int stf_ioctl(struct ifnet *, u_long, caddr_t);
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VNET_DEFINE_STATIC(struct if_clone *, stf_cloner);
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#define V_stf_cloner VNET(stf_cloner)
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static const struct encap_config ipv4_encap_cfg = {
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.proto = IPPROTO_IPV6,
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.min_length = sizeof(struct ip),
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.exact_match = (sizeof(in_addr_t) << 3) + 8,
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.check = stf_encapcheck,
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.input = in_stf_input
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};
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static int
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stf_clone_match(struct if_clone *ifc, const char *name)
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{
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int i;
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for(i = 0; stfnames[i] != NULL; i++) {
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if (strcmp(stfnames[i], name) == 0)
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return (1);
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}
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return (0);
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}
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static int
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stf_clone_create(struct if_clone *ifc, char *name, size_t len,
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struct ifc_data *ifd, struct ifnet **ifpp)
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{
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char *dp;
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int err, unit, wildcard;
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struct stf_softc *sc;
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struct ifnet *ifp;
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err = ifc_name2unit(name, &unit);
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if (err != 0)
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return (err);
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wildcard = (unit < 0);
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/*
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* We can only have one unit, but since unit allocation is
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* already locked, we use it to keep from allocating extra
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* interfaces.
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*/
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unit = STFUNIT;
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err = ifc_alloc_unit(ifc, &unit);
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if (err != 0)
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return (err);
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sc = malloc(sizeof(struct stf_softc), M_STF, M_WAITOK | M_ZERO);
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ifp = STF2IFP(sc) = if_alloc(IFT_STF);
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if (ifp == NULL) {
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free(sc, M_STF);
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ifc_free_unit(ifc, unit);
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return (ENOSPC);
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}
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ifp->if_softc = sc;
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sc->sc_fibnum = curthread->td_proc->p_fibnum;
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/*
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* Set the name manually rather then using if_initname because
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* we don't conform to the default naming convention for interfaces.
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* In the wildcard case, we need to update the name.
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*/
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if (wildcard) {
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for (dp = name; *dp != '\0'; dp++);
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if (snprintf(dp, len - (dp-name), "%d", unit) >
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len - (dp-name) - 1) {
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/*
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* This can only be a programmer error and
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* there's no straightforward way to recover if
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* it happens.
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*/
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panic("if_clone_create(): interface name too long");
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}
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}
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strlcpy(ifp->if_xname, name, IFNAMSIZ);
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ifp->if_dname = stfname;
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ifp->if_dunit = IF_DUNIT_NONE;
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sc->encap_cookie = ip_encap_attach(&ipv4_encap_cfg, sc, M_WAITOK);
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ifp->if_mtu = IPV6_MMTU;
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ifp->if_ioctl = stf_ioctl;
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ifp->if_output = stf_output;
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ifp->if_snd.ifq_maxlen = ifqmaxlen;
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if_attach(ifp);
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bpfattach(ifp, DLT_NULL, sizeof(u_int32_t));
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*ifpp = ifp;
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return (0);
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}
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static int
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stf_clone_destroy(struct if_clone *ifc, struct ifnet *ifp, uint32_t flags)
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{
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struct stf_softc *sc = ifp->if_softc;
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int err __unused;
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err = ip_encap_detach(sc->encap_cookie);
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KASSERT(err == 0, ("Unexpected error detaching encap_cookie"));
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bpfdetach(ifp);
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if_detach(ifp);
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if_free(ifp);
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free(sc, M_STF);
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ifc_free_unit(ifc, STFUNIT);
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return (0);
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}
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static void
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vnet_stf_init(const void *unused __unused)
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{
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struct if_clone_addreq req = {
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.match_f = stf_clone_match,
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.create_f = stf_clone_create,
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.destroy_f = stf_clone_destroy,
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};
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V_stf_cloner = ifc_attach_cloner(stfname, &req);
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}
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VNET_SYSINIT(vnet_stf_init, SI_SUB_PSEUDO, SI_ORDER_ANY, vnet_stf_init, NULL);
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static void
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vnet_stf_uninit(const void *unused __unused)
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{
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if_clone_detach(V_stf_cloner);
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V_stf_cloner = NULL;
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}
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VNET_SYSUNINIT(vnet_stf_uninit, SI_SUB_PSEUDO, SI_ORDER_ANY, vnet_stf_uninit,
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NULL);
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static int
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stfmodevent(module_t mod, int type, void *data)
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{
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switch (type) {
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case MOD_LOAD:
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/* Done in vnet_stf_init() */
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break;
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case MOD_UNLOAD:
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/* Done in vnet_stf_uninit() */
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break;
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default:
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return (EOPNOTSUPP);
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}
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return (0);
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}
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static moduledata_t stf_mod = {
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"if_stf",
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stfmodevent,
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0
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};
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DECLARE_MODULE(if_stf, stf_mod, SI_SUB_PSEUDO, SI_ORDER_ANY);
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MODULE_VERSION(if_stf, 2);
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static int
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stf_encapcheck(const struct mbuf *m, int off, int proto, void *arg)
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{
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struct ip ip;
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struct stf_softc *sc;
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struct in6_addr addr6, mask6;
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struct sockaddr_in sin4addr, sin4mask;
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SDT_PROBE3(if_stf, , encapcheck, in, m, off, proto);
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sc = (struct stf_softc *)arg;
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if (sc == NULL)
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return (0);
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if ((STF2IFP(sc)->if_flags & IFF_UP) == 0)
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return (0);
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/* IFF_LINK0 means "no decapsulation" */
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if ((STF2IFP(sc)->if_flags & IFF_LINK0) != 0)
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return (0);
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if (proto != IPPROTO_IPV6)
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return (0);
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m_copydata(m, 0, sizeof(ip), (caddr_t)&ip);
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if (ip.ip_v != 4)
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return (0);
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if (stf_getsrcifa6(STF2IFP(sc), &addr6, &mask6) != 0)
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return (0);
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if (sc->srcv4_addr != INADDR_ANY) {
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sin4addr.sin_addr.s_addr = sc->srcv4_addr;
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sin4addr.sin_family = AF_INET;
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} else
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if (stf_getin4addr(sc, &sin4addr, addr6, mask6) == NULL)
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return (0);
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if (sin4addr.sin_addr.s_addr != ip.ip_dst.s_addr)
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return (0);
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if (IN6_IS_ADDR_6TO4(&addr6)) {
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/*
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* 6to4 (RFC 3056).
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* Check if IPv4 src matches the IPv4 address derived
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* from the local 6to4 address masked by prefixmask.
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* success on: src = 10.1.1.1, ia6->ia_addr = 2002:0a00:.../24
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* fail on: src = 10.1.1.1, ia6->ia_addr = 2002:0b00:.../24
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*/
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memcpy(&sin4mask.sin_addr, GET_V4(&mask6),
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sizeof(sin4mask.sin_addr));
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if ((sin4addr.sin_addr.s_addr & sin4mask.sin_addr.s_addr) !=
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(ip.ip_src.s_addr & sin4mask.sin_addr.s_addr))
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return (0);
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} else {
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/* 6rd (RFC 5569) */
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/*
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* No restriction on the src address in the case of
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* 6rd because the stf(4) interface always has a
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* prefix which covers whole of IPv4 src address
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* range. So, stf_output() will catch all of
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* 6rd-capsuled IPv4 traffic with suspicious inner dst
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* IPv4 address (i.e. the IPv6 destination address is
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* one the admin does not like to route to outside),
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* and then it discard them silently.
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*/
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}
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SDT_PROBE0(if_stf, , encapcheck, accept);
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/* stf interface makes single side match only */
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return (32);
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}
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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);
|
|
}
|