From cad2014b2749528351ec5180e88a5929efebbfc4 Mon Sep 17 00:00:00 2001 From: shin Date: Mon, 22 Nov 1999 02:45:11 +0000 Subject: KAME netinet6 basic part(no IPsec,no V6 Multicast Forwarding, no UDP/TCP for IPv6 yet) With this patch, you can assigne IPv6 addr automatically, and can reply to IPv6 ping. Reviewed by: freebsd-arch, cvs-committers Obtained from: KAME project --- sys/netinet6/ip6_forward.c | 391 +++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 391 insertions(+) create mode 100644 sys/netinet6/ip6_forward.c (limited to 'sys/netinet6/ip6_forward.c') diff --git a/sys/netinet6/ip6_forward.c b/sys/netinet6/ip6_forward.c new file mode 100644 index 0000000..0a4745b --- /dev/null +++ b/sys/netinet6/ip6_forward.c @@ -0,0 +1,391 @@ +/* + * Copyright (C) 1995, 1996, 1997, and 1998 WIDE Project. + * All rights reserved. + * + * Redistribution and use in source and binary forms, with or without + * modification, are permitted provided that the following conditions + * are met: + * 1. Redistributions of source code must retain the above copyright + * notice, this list of conditions and the following disclaimer. + * 2. Redistributions in binary form must reproduce the above copyright + * notice, this list of conditions and the following disclaimer in the + * documentation and/or other materials provided with the distribution. + * 3. Neither the name of the project nor the names of its contributors + * may be used to endorse or promote products derived from this software + * without specific prior written permission. + * + * THIS SOFTWARE IS PROVIDED BY THE PROJECT AND CONTRIBUTORS ``AS IS'' AND + * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE + * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE + * ARE DISCLAIMED. IN NO EVENT SHALL THE PROJECT OR CONTRIBUTORS BE LIABLE + * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL + * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS + * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) + * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT + * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY + * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF + * SUCH DAMAGE. + * + * $FreeBSD$ + */ + +#include "opt_ip6fw.h" +#include "opt_inet.h" +#include "opt_ipsec.h" +#include "opt_key.h" + +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include + +#include +#include + +#include +#include +#include +#include +#include +#include + +#ifdef IPSEC_IPV6FWD +#include +#ifdef INET6 +#include +#endif /* INET6 */ +#include +#ifdef KEY_DEBUG +#include +#ifdef INET6 +#include +#endif /* INET6 */ +#else +#define DPRINTF(lev,arg) +#define DDO(lev, stmt) +#define DP(x, y, z) +#endif /* KEY_DEBUG */ +#endif /* IPSEC_IPV6FWD */ + +#ifdef IPV6FIREWALL +#include +#endif + +#include + +struct route_in6 ip6_forward_rt; + +/* + * Forward a packet. If some error occurs return the sender + * an icmp packet. Note we can't always generate a meaningful + * icmp message because icmp doesn't have a large enough repertoire + * of codes and types. + * + * If not forwarding, just drop the packet. This could be confusing + * if ipforwarding was zero but some routing protocol was advancing + * us as a gateway to somewhere. However, we must let the routing + * protocol deal with that. + * + */ + +void +ip6_forward(m, srcrt) + struct mbuf *m; + int srcrt; +{ + struct ip6_hdr *ip6 = mtod(m, struct ip6_hdr *); + register struct sockaddr_in6 *dst; + register struct rtentry *rt; + int error, type = 0, code = 0; + struct mbuf *mcopy; +#ifdef IPSEC_IPV6FWD + struct secpolicy *sp = NULL; +#endif + +#ifdef IPSEC_IPV6FWD + /* + * Check AH/ESP integrity. + */ + /* + * Don't increment ip6s_cantforward because this is the check + * before forwarding packet actually. + */ + if (ipsec6_in_reject(m, NULL)) { + ipsec6stat.in_polvio++; + m_freem(m); + return; + } +#endif /*IPSEC_IPV6FWD*/ + + if (m->m_flags & (M_BCAST|M_MCAST) || + in6_canforward(&ip6->ip6_src, &ip6->ip6_dst) == 0) { + ip6stat.ip6s_cantforward++; + ip6stat.ip6s_badscope++; + /* XXX in6_ifstat_inc(rt->rt_ifp, ifs6_in_discard) */ + if (ip6_log_time + ip6_log_interval < time_second) { + char addr[INET6_ADDRSTRLEN]; + ip6_log_time = time_second; + strncpy(addr, ip6_sprintf(&ip6->ip6_src), sizeof(addr)); + log(LOG_DEBUG, + "cannot forward " + "from %s to %s nxt %d received on %s\n", + addr, ip6_sprintf(&ip6->ip6_dst), + ip6->ip6_nxt, + if_name(m->m_pkthdr.rcvif)); + } + m_freem(m); + return; + } + + if (ip6->ip6_hlim <= IPV6_HLIMDEC) { + /* XXX in6_ifstat_inc(rt->rt_ifp, ifs6_in_discard) */ + icmp6_error(m, ICMP6_TIME_EXCEEDED, + ICMP6_TIME_EXCEED_TRANSIT, 0); + return; + } + ip6->ip6_hlim -= IPV6_HLIMDEC; + +#ifdef IPSEC_IPV6FWD + /* get a security policy for this packet */ + sp = ipsec6_getpolicybyaddr(m, IPSEC_DIR_OUTBOUND, 0, &error); + if (sp == NULL) { + ipsec6stat.out_inval++; + ip6stat.ip6s_cantforward++; + /* XXX: any icmp ? */ + m_freem(m); + return; + } + + error = 0; + + /* check policy */ + switch (sp->policy) { + case IPSEC_POLICY_DISCARD: + /* + * This packet is just discarded. + */ + ipsec6stat.out_polvio++; + ip6stat.ip6s_cantforward++; + key_freesp(sp); + /* XXX: any icmp ? */ + m_freem(m); + return; + + case IPSEC_POLICY_BYPASS: + case IPSEC_POLICY_NONE: + /* no need to do IPsec. */ + key_freesp(sp); + goto skip_ipsec; + + case IPSEC_POLICY_IPSEC: + if (sp->req == NULL) { + /* XXX should be panic ? */ + printf("ip6_forward: No IPsec request specified.\n"); + ip6stat.ip6s_cantforward++; + key_freesp(sp); + /* XXX: any icmp ? */ + m_freem(m); + return; + } + /* do IPsec */ + break; + + case IPSEC_POLICY_ENTRUST: + default: + /* should be panic ?? */ + printf("ip6_forward: Invalid policy found. %d\n", sp->policy); + key_freesp(sp); + goto skip_ipsec; + } + + { + struct ipsec_output_state state; + + /* + * All the extension headers will become inaccessible + * (since they can be encrypted). + * Don't panic, we need no more updates to extension headers + * on inner IPv6 packet (since they are now encapsulated). + * + * IPv6 [ESP|AH] IPv6 [extension headers] payload + */ + bzero(&state, sizeof(state)); + state.m = m; + state.ro = NULL; /* update at ipsec6_output_tunnel() */ + state.dst = NULL; /* update at ipsec6_output_tunnel() */ + + error = ipsec6_output_tunnel(&state, sp, 0); + + m = state.m; + /* XXX allocate a route (ro, dst) again later */ + key_freesp(sp); + + if (error) { + /* mbuf is already reclaimed in ipsec6_output_tunnel. */ + switch (error) { + case EHOSTUNREACH: + case ENETUNREACH: + case EMSGSIZE: + case ENOBUFS: + case ENOMEM: + break; + default: + printf("ip6_output (ipsec): error code %d\n", error); + /*fall through*/ + case ENOENT: + /* don't show these error codes to the user */ + break; + } + ip6stat.ip6s_cantforward++; + /* XXX: any icmp ? */ + m_freem(m); + return; + } + } + skip_ipsec: +#endif /* IPSEC_IPV6FWD */ + + dst = &ip6_forward_rt.ro_dst; + if (!srcrt) { + /* + * ip6_forward_rt.ro_dst.sin6_addr is equal to ip6->ip6_dst + */ + if (ip6_forward_rt.ro_rt == 0 || + (ip6_forward_rt.ro_rt->rt_flags & RTF_UP) == 0) { + if (ip6_forward_rt.ro_rt) { + RTFREE(ip6_forward_rt.ro_rt); + ip6_forward_rt.ro_rt = 0; + } + /* this probably fails but give it a try again */ + rtalloc_ign((struct route *)&ip6_forward_rt, + RTF_PRCLONING); + } + + if (ip6_forward_rt.ro_rt == 0) { + ip6stat.ip6s_noroute++; + /* XXX in6_ifstat_inc(rt->rt_ifp, ifs6_in_noroute) */ + icmp6_error(m, ICMP6_DST_UNREACH, + ICMP6_DST_UNREACH_NOROUTE, 0); + return; + } + } else if ((rt = ip6_forward_rt.ro_rt) == 0 || + !IN6_ARE_ADDR_EQUAL(&ip6->ip6_dst, &dst->sin6_addr)) { + if (ip6_forward_rt.ro_rt) { + RTFREE(ip6_forward_rt.ro_rt); + ip6_forward_rt.ro_rt = 0; + } + bzero(dst, sizeof(*dst)); + dst->sin6_len = sizeof(struct sockaddr_in6); + dst->sin6_family = AF_INET6; + dst->sin6_addr = ip6->ip6_dst; + + rtalloc_ign((struct route *)&ip6_forward_rt, RTF_PRCLONING); + if (ip6_forward_rt.ro_rt == 0) { + ip6stat.ip6s_noroute++; + /* XXX in6_ifstat_inc(rt->rt_ifp, ifs6_in_noroute) */ + icmp6_error(m, ICMP6_DST_UNREACH, + ICMP6_DST_UNREACH_NOROUTE, 0); + return; + } + } + rt = ip6_forward_rt.ro_rt; + if (m->m_pkthdr.len > rt->rt_ifp->if_mtu){ + in6_ifstat_inc(rt->rt_ifp, ifs6_in_toobig); + icmp6_error(m, ICMP6_PACKET_TOO_BIG, 0, rt->rt_ifp->if_mtu); + return; + } + + if (rt->rt_flags & RTF_GATEWAY) + dst = (struct sockaddr_in6 *)rt->rt_gateway; + /* + * Save at most 528 bytes of the packet in case + * we need to generate an ICMP6 message to the src. + * Thanks to M_EXT, in most cases copy will not occur. + */ + mcopy = m_copy(m, 0, imin(m->m_pkthdr.len, ICMPV6_PLD_MAXLEN)); + + /* + * If we are to forward the packet using the same interface + * as one we got the packet from, perhaps we should send a redirect + * to sender to shortcut a hop. + * Only send redirect if source is sending directly to us, + * and if packet was not source routed (or has any options). + * Also, don't send redirect if forwarding using a route + * modified by a redirect. + */ + if (rt->rt_ifp == m->m_pkthdr.rcvif && !srcrt && + (rt->rt_flags & (RTF_DYNAMIC|RTF_MODIFIED)) == 0) + type = ND_REDIRECT; + +#ifdef IPV6FIREWALL + /* + * Check with the firewall... + */ + if (ip6_fw_chk_ptr) { + u_short port = 0; + /* If ipfw says divert, we have to just drop packet */ + if ((*ip6_fw_chk_ptr)(&ip6, rt->rt_ifp, &port, &m)) { + m_freem(m); + goto freecopy; + } + if (!m) + goto freecopy; + } +#endif + + error = nd6_output(rt->rt_ifp, m, dst, rt); + if (error) { + in6_ifstat_inc(rt->rt_ifp, ifs6_out_discard); + ip6stat.ip6s_cantforward++; + } else { + ip6stat.ip6s_forward++; + in6_ifstat_inc(rt->rt_ifp, ifs6_out_forward); + if (type) + ip6stat.ip6s_redirectsent++; + else { + if (mcopy) + goto freecopy; + } + } + if (mcopy == NULL) + return; + + switch (error) { + case 0: + if (type == ND_REDIRECT) { + icmp6_redirect_output(mcopy, rt); + return; + } + goto freecopy; + + case EMSGSIZE: + /* xxx MTU is constant in PPP? */ + goto freecopy; + + case ENOBUFS: + /* Tell source to slow down like source quench in IP? */ + goto freecopy; + + case ENETUNREACH: /* shouldn't happen, checked above */ + case EHOSTUNREACH: + case ENETDOWN: + case EHOSTDOWN: + default: + type = ICMP6_DST_UNREACH; + code = ICMP6_DST_UNREACH_ADDR; + break; + } + icmp6_error(mcopy, type, code, 0); + return; + + freecopy: + m_freem(mcopy); + return; +} -- cgit v1.1