diff options
Diffstat (limited to 'sys/netinet6/ip6_input.c')
| -rw-r--r-- | sys/netinet6/ip6_input.c | 1643 |
1 files changed, 1643 insertions, 0 deletions
diff --git a/sys/netinet6/ip6_input.c b/sys/netinet6/ip6_input.c new file mode 100644 index 0000000..dcb74fb --- /dev/null +++ b/sys/netinet6/ip6_input.c @@ -0,0 +1,1643 @@ +/* $FreeBSD$ */ +/* $KAME: ip6_input.c,v 1.259 2002/01/21 04:58:09 jinmei Exp $ */ + +/* + * 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. + */ + +/* + * Copyright (c) 1982, 1986, 1988, 1993 + * The Regents of the University of California. 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. All advertising materials mentioning features or use of this software + * must display the following acknowledgement: + * This product includes software developed by the University of + * California, Berkeley and its contributors. + * 4. Neither the name of the University 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 REGENTS 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 REGENTS 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. + * + * @(#)ip_input.c 8.2 (Berkeley) 1/4/94 + */ + +#include "opt_ip6fw.h" +#include "opt_inet.h" +#include "opt_inet6.h" +#include "opt_ipsec.h" +#include "opt_pfil_hooks.h" + +#include <sys/param.h> +#include <sys/systm.h> +#include <sys/malloc.h> +#include <sys/mbuf.h> +#include <sys/proc.h> +#include <sys/domain.h> +#include <sys/protosw.h> +#include <sys/socket.h> +#include <sys/socketvar.h> +#include <sys/errno.h> +#include <sys/time.h> +#include <sys/kernel.h> +#include <sys/syslog.h> + +#include <net/if.h> +#include <net/if_types.h> +#include <net/if_dl.h> +#include <net/route.h> +#include <net/netisr.h> +#ifdef PFIL_HOOKS +#include <net/pfil.h> +#endif + +#include <netinet/in.h> +#include <netinet/in_systm.h> +#ifdef INET +#include <netinet/ip.h> +#include <netinet/ip_icmp.h> +#endif /* INET */ +#include <netinet/ip6.h> +#include <netinet6/in6_var.h> +#include <netinet6/ip6_var.h> +#include <netinet/in_pcb.h> +#include <netinet/icmp6.h> +#include <netinet6/in6_ifattach.h> +#include <netinet6/nd6.h> +#include <netinet6/in6_prefix.h> + +#ifdef IPSEC +#include <netinet6/ipsec.h> +#ifdef INET6 +#include <netinet6/ipsec6.h> +#endif +#endif + +#ifdef FAST_IPSEC +#include <netipsec/ipsec.h> +#include <netipsec/ipsec6.h> +#define IPSEC +#endif /* FAST_IPSEC */ + +#include <netinet6/ip6_fw.h> + +#include <netinet6/ip6protosw.h> + +#include <net/net_osdep.h> + +extern struct domain inet6domain; + +u_char ip6_protox[IPPROTO_MAX]; +static struct ifqueue ip6intrq; +static int ip6qmaxlen = IFQ_MAXLEN; +struct in6_ifaddr *in6_ifaddr; + +extern struct callout in6_tmpaddrtimer_ch; + +int ip6_forward_srcrt; /* XXX */ +int ip6_sourcecheck; /* XXX */ +int ip6_sourcecheck_interval; /* XXX */ + +int ip6_ours_check_algorithm; + + +/* firewall hooks */ +ip6_fw_chk_t *ip6_fw_chk_ptr; +ip6_fw_ctl_t *ip6_fw_ctl_ptr; +int ip6_fw_enable = 1; + +struct ip6stat ip6stat; + +static void ip6_init2 __P((void *)); +static struct ip6aux *ip6_setdstifaddr __P((struct mbuf *, struct in6_ifaddr *)); +static int ip6_hopopts_input __P((u_int32_t *, u_int32_t *, struct mbuf **, int *)); +#ifdef PULLDOWN_TEST +static struct mbuf *ip6_pullexthdr __P((struct mbuf *, size_t, int)); +#endif + + +/* + * IP6 initialization: fill in IP6 protocol switch table. + * All protocols not implemented in kernel go to raw IP6 protocol handler. + */ +void +ip6_init() +{ + struct ip6protosw *pr; + int i; + struct timeval tv; + +#ifdef DIAGNOSTIC + if (sizeof(struct protosw) != sizeof(struct ip6protosw)) + panic("sizeof(protosw) != sizeof(ip6protosw)"); +#endif + pr = (struct ip6protosw *)pffindproto(PF_INET6, IPPROTO_RAW, SOCK_RAW); + if (pr == 0) + panic("ip6_init"); + for (i = 0; i < IPPROTO_MAX; i++) + ip6_protox[i] = pr - inet6sw; + for (pr = (struct ip6protosw *)inet6domain.dom_protosw; + pr < (struct ip6protosw *)inet6domain.dom_protoswNPROTOSW; pr++) + if (pr->pr_domain->dom_family == PF_INET6 && + pr->pr_protocol && pr->pr_protocol != IPPROTO_RAW) + ip6_protox[pr->pr_protocol] = pr - inet6sw; + ip6intrq.ifq_maxlen = ip6qmaxlen; + mtx_init(&ip6intrq.ifq_mtx, "ip6_inq", NULL, MTX_DEF); + netisr_register(NETISR_IPV6, ip6_input, &ip6intrq); + nd6_init(); + frag6_init(); + /* + * in many cases, random() here does NOT return random number + * as initialization during bootstrap time occur in fixed order. + */ + microtime(&tv); + ip6_flow_seq = random() ^ tv.tv_usec; + microtime(&tv); + ip6_desync_factor = (random() ^ tv.tv_usec) % MAX_TEMP_DESYNC_FACTOR; +} + +static void +ip6_init2(dummy) + void *dummy; +{ + + /* + * to route local address of p2p link to loopback, + * assign loopback address first. + */ + in6_ifattach(&loif[0], NULL); + + /* nd6_timer_init */ + callout_init(&nd6_timer_ch, 0); + callout_reset(&nd6_timer_ch, hz, nd6_timer, NULL); + + /* router renumbering prefix list maintenance */ + callout_init(&in6_rr_timer_ch, 0); + callout_reset(&in6_rr_timer_ch, hz, in6_rr_timer, NULL); + + /* timer for regeneranation of temporary addresses randomize ID */ + callout_reset(&in6_tmpaddrtimer_ch, + (ip6_temp_preferred_lifetime - ip6_desync_factor - + ip6_temp_regen_advance) * hz, + in6_tmpaddrtimer, NULL); +} + +/* cheat */ +/* This must be after route_init(), which is now SI_ORDER_THIRD */ +SYSINIT(netinet6init2, SI_SUB_PROTO_DOMAIN, SI_ORDER_MIDDLE, ip6_init2, NULL); + +extern struct route_in6 ip6_forward_rt; + +void +ip6_input(m) + struct mbuf *m; +{ + struct ip6_hdr *ip6; + int off = sizeof(struct ip6_hdr), nest; + u_int32_t plen; + u_int32_t rtalert = ~0; + int nxt, ours = 0; + struct ifnet *deliverifp = NULL; +#ifdef PFIL_HOOKS + struct packet_filter_hook *pfh; + struct mbuf *m0; + int rv; +#endif /* PFIL_HOOKS */ + +#ifdef IPSEC + /* + * should the inner packet be considered authentic? + * see comment in ah4_input(). + */ + if (m) { + m->m_flags &= ~M_AUTHIPHDR; + m->m_flags &= ~M_AUTHIPDGM; + } +#endif + + /* + * make sure we don't have onion peering information into m_aux. + */ + ip6_delaux(m); + + /* + * mbuf statistics + */ + if (m->m_flags & M_EXT) { + if (m->m_next) + ip6stat.ip6s_mext2m++; + else + ip6stat.ip6s_mext1++; + } else { +#define M2MMAX (sizeof(ip6stat.ip6s_m2m)/sizeof(ip6stat.ip6s_m2m[0])) + if (m->m_next) { + if (m->m_flags & M_LOOP) { + ip6stat.ip6s_m2m[loif[0].if_index]++; /* XXX */ + } else if (m->m_pkthdr.rcvif->if_index < M2MMAX) + ip6stat.ip6s_m2m[m->m_pkthdr.rcvif->if_index]++; + else + ip6stat.ip6s_m2m[0]++; + } else + ip6stat.ip6s_m1++; +#undef M2MMAX + } + + in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_receive); + ip6stat.ip6s_total++; + +#ifndef PULLDOWN_TEST + /* + * L2 bridge code and some other code can return mbuf chain + * that does not conform to KAME requirement. too bad. + * XXX: fails to join if interface MTU > MCLBYTES. jumbogram? + */ + if (m && m->m_next != NULL && m->m_pkthdr.len < MCLBYTES) { + struct mbuf *n; + + MGETHDR(n, M_DONTWAIT, MT_HEADER); + if (n) + M_MOVE_PKTHDR(n, m); + if (n && n->m_pkthdr.len > MHLEN) { + MCLGET(n, M_DONTWAIT); + if ((n->m_flags & M_EXT) == 0) { + m_freem(n); + n = NULL; + } + } + if (n == NULL) { + m_freem(m); + return; /*ENOBUFS*/ + } + + m_copydata(m, 0, n->m_pkthdr.len, mtod(n, caddr_t)); + n->m_len = n->m_pkthdr.len; + m_freem(m); + m = n; + } + IP6_EXTHDR_CHECK(m, 0, sizeof(struct ip6_hdr), /*nothing*/); +#endif + + if (m->m_len < sizeof(struct ip6_hdr)) { + struct ifnet *inifp; + inifp = m->m_pkthdr.rcvif; + if ((m = m_pullup(m, sizeof(struct ip6_hdr))) == 0) { + ip6stat.ip6s_toosmall++; + in6_ifstat_inc(inifp, ifs6_in_hdrerr); + return; + } + } + + ip6 = mtod(m, struct ip6_hdr *); + + if ((ip6->ip6_vfc & IPV6_VERSION_MASK) != IPV6_VERSION) { + ip6stat.ip6s_badvers++; + in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_hdrerr); + goto bad; + } + +#ifdef PFIL_HOOKS + /* + * Run through list of hooks for input packets. If there are any + * filters which require that additional packets in the flow are + * not fast-forwarded, they must clear the M_CANFASTFWD flag. + * Note that filters must _never_ set this flag, as another filter + * in the list may have previously cleared it. + */ + m0 = m; + pfh = pfil_hook_get(PFIL_IN, &inet6sw[ip6_protox[IPPROTO_IPV6]].pr_pfh); + for (; pfh; pfh = pfh->pfil_link.tqe_next) + if (pfh->pfil_func) { + rv = pfh->pfil_func(ip6, sizeof(*ip6), + m->m_pkthdr.rcvif, 0, &m0); + if (rv) + return; + m = m0; + if (m == NULL) + return; + ip6 = mtod(m, struct ip6_hdr *); + } +#endif /* PFIL_HOOKS */ + + ip6stat.ip6s_nxthist[ip6->ip6_nxt]++; + + /* + * Check with the firewall... + */ + if (ip6_fw_enable && ip6_fw_chk_ptr) { + u_short port = 0; + /* If ipfw says divert, we have to just drop packet */ + /* use port as a dummy argument */ + if ((*ip6_fw_chk_ptr)(&ip6, NULL, &port, &m)) { + m_freem(m); + m = NULL; + } + if (!m) + return; + } + + /* + * Check against address spoofing/corruption. + */ + if (IN6_IS_ADDR_MULTICAST(&ip6->ip6_src) || + IN6_IS_ADDR_UNSPECIFIED(&ip6->ip6_dst)) { + /* + * XXX: "badscope" is not very suitable for a multicast source. + */ + ip6stat.ip6s_badscope++; + in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_addrerr); + goto bad; + } + if ((IN6_IS_ADDR_LOOPBACK(&ip6->ip6_src) || + IN6_IS_ADDR_LOOPBACK(&ip6->ip6_dst)) && + (m->m_pkthdr.rcvif->if_flags & IFF_LOOPBACK) == 0) { + ip6stat.ip6s_badscope++; + in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_addrerr); + goto bad; + } + + /* + * The following check is not documented in specs. A malicious + * party may be able to use IPv4 mapped addr to confuse tcp/udp stack + * and bypass security checks (act as if it was from 127.0.0.1 by using + * IPv6 src ::ffff:127.0.0.1). Be cautious. + * + * This check chokes if we are in an SIIT cloud. As none of BSDs + * support IPv4-less kernel compilation, we cannot support SIIT + * environment at all. So, it makes more sense for us to reject any + * malicious packets for non-SIIT environment, than try to do a + * partical support for SIIT environment. + */ + if (IN6_IS_ADDR_V4MAPPED(&ip6->ip6_src) || + IN6_IS_ADDR_V4MAPPED(&ip6->ip6_dst)) { + ip6stat.ip6s_badscope++; + in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_addrerr); + goto bad; + } +#if 0 + /* + * Reject packets with IPv4 compatible addresses (auto tunnel). + * + * The code forbids auto tunnel relay case in RFC1933 (the check is + * stronger than RFC1933). We may want to re-enable it if mech-xx + * is revised to forbid relaying case. + */ + if (IN6_IS_ADDR_V4COMPAT(&ip6->ip6_src) || + IN6_IS_ADDR_V4COMPAT(&ip6->ip6_dst)) { + ip6stat.ip6s_badscope++; + in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_addrerr); + goto bad; + } +#endif + + /* drop packets if interface ID portion is already filled */ + if ((m->m_pkthdr.rcvif->if_flags & IFF_LOOPBACK) == 0) { + if (IN6_IS_SCOPE_LINKLOCAL(&ip6->ip6_src) && + ip6->ip6_src.s6_addr16[1]) { + ip6stat.ip6s_badscope++; + goto bad; + } + if (IN6_IS_SCOPE_LINKLOCAL(&ip6->ip6_dst) && + ip6->ip6_dst.s6_addr16[1]) { + ip6stat.ip6s_badscope++; + goto bad; + } + } + + if (IN6_IS_SCOPE_LINKLOCAL(&ip6->ip6_src)) + ip6->ip6_src.s6_addr16[1] + = htons(m->m_pkthdr.rcvif->if_index); + if (IN6_IS_SCOPE_LINKLOCAL(&ip6->ip6_dst)) + ip6->ip6_dst.s6_addr16[1] + = htons(m->m_pkthdr.rcvif->if_index); + +#if 0 /* this case seems to be unnecessary. (jinmei, 20010401) */ + /* + * We use rt->rt_ifp to determine if the address is ours or not. + * If rt_ifp is lo0, the address is ours. + * The problem here is, rt->rt_ifp for fe80::%lo0/64 is set to lo0, + * so any address under fe80::%lo0/64 will be mistakenly considered + * local. The special case is supplied to handle the case properly + * by actually looking at interface addresses + * (using in6ifa_ifpwithaddr). + */ + if ((m->m_pkthdr.rcvif->if_flags & IFF_LOOPBACK) != 0 && + IN6_IS_ADDR_LINKLOCAL(&ip6->ip6_dst)) { + if (!in6ifa_ifpwithaddr(m->m_pkthdr.rcvif, &ip6->ip6_dst)) { + icmp6_error(m, ICMP6_DST_UNREACH, + ICMP6_DST_UNREACH_ADDR, 0); + /* m is already freed */ + return; + } + + ours = 1; + deliverifp = m->m_pkthdr.rcvif; + goto hbhcheck; + } +#endif + + /* + * Multicast check + */ + if (IN6_IS_ADDR_MULTICAST(&ip6->ip6_dst)) { + struct in6_multi *in6m = 0; + + in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_mcast); + /* + * See if we belong to the destination multicast group on the + * arrival interface. + */ + IN6_LOOKUP_MULTI(ip6->ip6_dst, m->m_pkthdr.rcvif, in6m); + if (in6m) + ours = 1; + else if (!ip6_mrouter) { + ip6stat.ip6s_notmember++; + ip6stat.ip6s_cantforward++; + in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_discard); + goto bad; + } + deliverifp = m->m_pkthdr.rcvif; + goto hbhcheck; + } + + /* + * Unicast check + */ + switch (ip6_ours_check_algorithm) { + default: + /* + * XXX: I intentionally broke our indentation rule here, + * since this switch-case is just for measurement and + * therefore should soon be removed. + */ + if (ip6_forward_rt.ro_rt != NULL && + (ip6_forward_rt.ro_rt->rt_flags & RTF_UP) != 0 && + IN6_ARE_ADDR_EQUAL(&ip6->ip6_dst, + &((struct sockaddr_in6 *)(&ip6_forward_rt.ro_dst))->sin6_addr)) + ip6stat.ip6s_forward_cachehit++; + else { + struct sockaddr_in6 *dst6; + + if (ip6_forward_rt.ro_rt) { + /* route is down or destination is different */ + ip6stat.ip6s_forward_cachemiss++; + RTFREE(ip6_forward_rt.ro_rt); + ip6_forward_rt.ro_rt = 0; + } + + bzero(&ip6_forward_rt.ro_dst, sizeof(struct sockaddr_in6)); + dst6 = (struct sockaddr_in6 *)&ip6_forward_rt.ro_dst; + dst6->sin6_len = sizeof(struct sockaddr_in6); + dst6->sin6_family = AF_INET6; + dst6->sin6_addr = ip6->ip6_dst; +#ifdef SCOPEDROUTING + ip6_forward_rt.ro_dst.sin6_scope_id = + in6_addr2scopeid(m->m_pkthdr.rcvif, &ip6->ip6_dst); +#endif + + rtalloc_ign((struct route *)&ip6_forward_rt, RTF_PRCLONING); + } + +#define rt6_key(r) ((struct sockaddr_in6 *)((r)->rt_nodes->rn_key)) + + /* + * Accept the packet if the forwarding interface to the destination + * according to the routing table is the loopback interface, + * unless the associated route has a gateway. + * Note that this approach causes to accept a packet if there is a + * route to the loopback interface for the destination of the packet. + * But we think it's even useful in some situations, e.g. when using + * a special daemon which wants to intercept the packet. + * + * XXX: some OSes automatically make a cloned route for the destination + * of an outgoing packet. If the outgoing interface of the packet + * is a loopback one, the kernel would consider the packet to be + * accepted, even if we have no such address assinged on the interface. + * We check the cloned flag of the route entry to reject such cases, + * assuming that route entries for our own addresses are not made by + * cloning (it should be true because in6_addloop explicitly installs + * the host route). However, we might have to do an explicit check + * while it would be less efficient. Or, should we rather install a + * reject route for such a case? + */ + if (ip6_forward_rt.ro_rt && + (ip6_forward_rt.ro_rt->rt_flags & + (RTF_HOST|RTF_GATEWAY)) == RTF_HOST && +#ifdef RTF_WASCLONED + !(ip6_forward_rt.ro_rt->rt_flags & RTF_WASCLONED) && +#endif +#ifdef RTF_CLONED + !(ip6_forward_rt.ro_rt->rt_flags & RTF_CLONED) && +#endif +#if 0 + /* + * The check below is redundant since the comparison of + * the destination and the key of the rtentry has + * already done through looking up the routing table. + */ + IN6_ARE_ADDR_EQUAL(&ip6->ip6_dst, + &rt6_key(ip6_forward_rt.ro_rt)->sin6_addr) +#endif + ip6_forward_rt.ro_rt->rt_ifp->if_type == IFT_LOOP) { + struct in6_ifaddr *ia6 = + (struct in6_ifaddr *)ip6_forward_rt.ro_rt->rt_ifa; + + /* + * record address information into m_aux. + */ + (void)ip6_setdstifaddr(m, ia6); + + /* + * packets to a tentative, duplicated, or somehow invalid + * address must not be accepted. + */ + if (!(ia6->ia6_flags & IN6_IFF_NOTREADY)) { + /* this address is ready */ + ours = 1; + deliverifp = ia6->ia_ifp; /* correct? */ + /* Count the packet in the ip address stats */ + ia6->ia_ifa.if_ipackets++; + ia6->ia_ifa.if_ibytes += m->m_pkthdr.len; + goto hbhcheck; + } else { + /* address is not ready, so discard the packet. */ + nd6log((LOG_INFO, + "ip6_input: packet to an unready address %s->%s\n", + ip6_sprintf(&ip6->ip6_src), + ip6_sprintf(&ip6->ip6_dst))); + + goto bad; + } + } + } /* XXX indentation (see above) */ + + /* + * FAITH(Firewall Aided Internet Translator) + */ + if (ip6_keepfaith) { + if (ip6_forward_rt.ro_rt && ip6_forward_rt.ro_rt->rt_ifp + && ip6_forward_rt.ro_rt->rt_ifp->if_type == IFT_FAITH) { + /* XXX do we need more sanity checks? */ + ours = 1; + deliverifp = ip6_forward_rt.ro_rt->rt_ifp; /* faith */ + goto hbhcheck; + } + } + + /* + * Now there is no reason to process the packet if it's not our own + * and we're not a router. + */ + if (!ip6_forwarding) { + ip6stat.ip6s_cantforward++; + in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_discard); + goto bad; + } + + hbhcheck: + /* + * record address information into m_aux, if we don't have one yet. + * note that we are unable to record it, if the address is not listed + * as our interface address (e.g. multicast addresses, addresses + * within FAITH prefixes and such). + */ + if (deliverifp && !ip6_getdstifaddr(m)) { + struct in6_ifaddr *ia6; + + ia6 = in6_ifawithifp(deliverifp, &ip6->ip6_dst); + if (ia6) { + if (!ip6_setdstifaddr(m, ia6)) { + /* + * XXX maybe we should drop the packet here, + * as we could not provide enough information + * to the upper layers. + */ + } + } + } + + /* + * Process Hop-by-Hop options header if it's contained. + * m may be modified in ip6_hopopts_input(). + * If a JumboPayload option is included, plen will also be modified. + */ + plen = (u_int32_t)ntohs(ip6->ip6_plen); + if (ip6->ip6_nxt == IPPROTO_HOPOPTS) { + struct ip6_hbh *hbh; + + if (ip6_hopopts_input(&plen, &rtalert, &m, &off)) { +#if 0 /*touches NULL pointer*/ + in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_discard); +#endif + return; /* m have already been freed */ + } + + /* adjust pointer */ + ip6 = mtod(m, struct ip6_hdr *); + + /* + * if the payload length field is 0 and the next header field + * indicates Hop-by-Hop Options header, then a Jumbo Payload + * option MUST be included. + */ + if (ip6->ip6_plen == 0 && plen == 0) { + /* + * Note that if a valid jumbo payload option is + * contained, ip6_hoptops_input() must set a valid + * (non-zero) payload length to the variable plen. + */ + ip6stat.ip6s_badoptions++; + in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_discard); + in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_hdrerr); + icmp6_error(m, ICMP6_PARAM_PROB, + ICMP6_PARAMPROB_HEADER, + (caddr_t)&ip6->ip6_plen - (caddr_t)ip6); + return; + } +#ifndef PULLDOWN_TEST + /* ip6_hopopts_input() ensures that mbuf is contiguous */ + hbh = (struct ip6_hbh *)(ip6 + 1); +#else + IP6_EXTHDR_GET(hbh, struct ip6_hbh *, m, sizeof(struct ip6_hdr), + sizeof(struct ip6_hbh)); + if (hbh == NULL) { + ip6stat.ip6s_tooshort++; + return; + } +#endif + nxt = hbh->ip6h_nxt; + + /* + * accept the packet if a router alert option is included + * and we act as an IPv6 router. + */ + if (rtalert != ~0 && ip6_forwarding) + ours = 1; + } else + nxt = ip6->ip6_nxt; + + /* + * Check that the amount of data in the buffers + * is as at least much as the IPv6 header would have us expect. + * Trim mbufs if longer than we expect. + * Drop packet if shorter than we expect. + */ + if (m->m_pkthdr.len - sizeof(struct ip6_hdr) < plen) { + ip6stat.ip6s_tooshort++; + in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_truncated); + goto bad; + } + if (m->m_pkthdr.len > sizeof(struct ip6_hdr) + plen) { + if (m->m_len == m->m_pkthdr.len) { + m->m_len = sizeof(struct ip6_hdr) + plen; + m->m_pkthdr.len = sizeof(struct ip6_hdr) + plen; + } else + m_adj(m, sizeof(struct ip6_hdr) + plen - m->m_pkthdr.len); + } + + /* + * Forward if desirable. + */ + if (IN6_IS_ADDR_MULTICAST(&ip6->ip6_dst)) { + /* + * If we are acting as a multicast router, all + * incoming multicast packets are passed to the + * kernel-level multicast forwarding function. + * The packet is returned (relatively) intact; if + * ip6_mforward() returns a non-zero value, the packet + * must be discarded, else it may be accepted below. + */ + if (ip6_mrouter && ip6_mforward(ip6, m->m_pkthdr.rcvif, m)) { + ip6stat.ip6s_cantforward++; + m_freem(m); + return; + } + if (!ours) { + m_freem(m); + return; + } + } else if (!ours) { + ip6_forward(m, 0); + return; + } + + ip6 = mtod(m, struct ip6_hdr *); + + /* + * Malicious party may be able to use IPv4 mapped addr to confuse + * tcp/udp stack and bypass security checks (act as if it was from + * 127.0.0.1 by using IPv6 src ::ffff:127.0.0.1). Be cautious. + * + * For SIIT end node behavior, you may want to disable the check. + * However, you will become vulnerable to attacks using IPv4 mapped + * source. + */ + if (IN6_IS_ADDR_V4MAPPED(&ip6->ip6_src) || + IN6_IS_ADDR_V4MAPPED(&ip6->ip6_dst)) { + ip6stat.ip6s_badscope++; + in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_addrerr); + goto bad; + } + + /* + * Tell launch routine the next header + */ + ip6stat.ip6s_delivered++; + in6_ifstat_inc(deliverifp, ifs6_in_deliver); + nest = 0; + + while (nxt != IPPROTO_DONE) { + if (ip6_hdrnestlimit && (++nest > ip6_hdrnestlimit)) { + ip6stat.ip6s_toomanyhdr++; + goto bad; + } + + /* + * protection against faulty packet - there should be + * more sanity checks in header chain processing. + */ + if (m->m_pkthdr.len < off) { + ip6stat.ip6s_tooshort++; + in6_ifstat_inc(m->m_pkthdr.rcvif, ifs6_in_truncated); + goto bad; + } + +#if 0 + /* + * do we need to do it for every header? yeah, other + * functions can play with it (like re-allocate and copy). + */ + mhist = ip6_addaux(m); + if (mhist && M_TRAILINGSPACE(mhist) >= sizeof(nxt)) { + hist = mtod(mhist, caddr_t) + mhist->m_len; + bcopy(&nxt, hist, sizeof(nxt)); + mhist->m_len += sizeof(nxt); + } else { + ip6stat.ip6s_toomanyhdr++; + goto bad; + } +#endif + +#ifdef IPSEC + /* + * enforce IPsec policy checking if we are seeing last header. + * note that we do not visit this with protocols with pcb layer + * code - like udp/tcp/raw ip. + */ + if ((inet6sw[ip6_protox[nxt]].pr_flags & PR_LASTHDR) != 0 && + ipsec6_in_reject(m, NULL)) { + ipsec6stat.in_polvio++; + goto bad; + } +#endif + + nxt = (*inet6sw[ip6_protox[nxt]].pr_input)(&m, &off, nxt); + } + return; + bad: + m_freem(m); +} + +/* + * set/grab in6_ifaddr correspond to IPv6 destination address. + * XXX backward compatibility wrapper + */ +static struct ip6aux * +ip6_setdstifaddr(m, ia6) + struct mbuf *m; + struct in6_ifaddr *ia6; +{ + struct ip6aux *n; + + n = ip6_addaux(m); + if (n) + n->ip6a_dstia6 = ia6; + return n; /* NULL if failed to set */ +} + +struct in6_ifaddr * +ip6_getdstifaddr(m) + struct mbuf *m; +{ + struct ip6aux *n; + + n = ip6_findaux(m); + if (n) + return n->ip6a_dstia6; + else + return NULL; +} + +/* + * Hop-by-Hop options header processing. If a valid jumbo payload option is + * included, the real payload length will be stored in plenp. + */ +static int +ip6_hopopts_input(plenp, rtalertp, mp, offp) + u_int32_t *plenp; + u_int32_t *rtalertp; /* XXX: should be stored more smart way */ + struct mbuf **mp; + int *offp; +{ + struct mbuf *m = *mp; + int off = *offp, hbhlen; + struct ip6_hbh *hbh; + u_int8_t *opt; + + /* validation of the length of the header */ +#ifndef PULLDOWN_TEST + IP6_EXTHDR_CHECK(m, off, sizeof(*hbh), -1); + hbh = (struct ip6_hbh *)(mtod(m, caddr_t) + off); + hbhlen = (hbh->ip6h_len + 1) << 3; + + IP6_EXTHDR_CHECK(m, off, hbhlen, -1); + hbh = (struct ip6_hbh *)(mtod(m, caddr_t) + off); +#else + IP6_EXTHDR_GET(hbh, struct ip6_hbh *, m, + sizeof(struct ip6_hdr), sizeof(struct ip6_hbh)); + if (hbh == NULL) { + ip6stat.ip6s_tooshort++; + return -1; + } + hbhlen = (hbh->ip6h_len + 1) << 3; + IP6_EXTHDR_GET(hbh, struct ip6_hbh *, m, sizeof(struct ip6_hdr), + hbhlen); + if (hbh == NULL) { + ip6stat.ip6s_tooshort++; + return -1; + } +#endif + off += hbhlen; + hbhlen -= sizeof(struct ip6_hbh); + opt = (u_int8_t *)hbh + sizeof(struct ip6_hbh); + + if (ip6_process_hopopts(m, (u_int8_t *)hbh + sizeof(struct ip6_hbh), + hbhlen, rtalertp, plenp) < 0) + return(-1); + + *offp = off; + *mp = m; + return(0); +} + +/* + * Search header for all Hop-by-hop options and process each option. + * This function is separate from ip6_hopopts_input() in order to + * handle a case where the sending node itself process its hop-by-hop + * options header. In such a case, the function is called from ip6_output(). + * + * The function assumes that hbh header is located right after the IPv6 header + * (RFC2460 p7), opthead is pointer into data content in m, and opthead to + * opthead + hbhlen is located in continuous memory region. + */ +int +ip6_process_hopopts(m, opthead, hbhlen, rtalertp, plenp) + struct mbuf *m; + u_int8_t *opthead; + int hbhlen; + u_int32_t *rtalertp; + u_int32_t *plenp; +{ + struct ip6_hdr *ip6; + int optlen = 0; + u_int8_t *opt = opthead; + u_int16_t rtalert_val; + u_int32_t jumboplen; + const int erroff = sizeof(struct ip6_hdr) + sizeof(struct ip6_hbh); + + for (; hbhlen > 0; hbhlen -= optlen, opt += optlen) { + switch (*opt) { + case IP6OPT_PAD1: + optlen = 1; + break; + case IP6OPT_PADN: + if (hbhlen < IP6OPT_MINLEN) { + ip6stat.ip6s_toosmall++; + goto bad; + } + optlen = *(opt + 1) + 2; + break; + case IP6OPT_RTALERT: + /* XXX may need check for alignment */ + if (hbhlen < IP6OPT_RTALERT_LEN) { + ip6stat.ip6s_toosmall++; + goto bad; + } + if (*(opt + 1) != IP6OPT_RTALERT_LEN - 2) { + /* XXX stat */ + icmp6_error(m, ICMP6_PARAM_PROB, + ICMP6_PARAMPROB_HEADER, + erroff + opt + 1 - opthead); + return(-1); + } + optlen = IP6OPT_RTALERT_LEN; + bcopy((caddr_t)(opt + 2), (caddr_t)&rtalert_val, 2); + *rtalertp = ntohs(rtalert_val); + break; + case IP6OPT_JUMBO: + /* XXX may need check for alignment */ + if (hbhlen < IP6OPT_JUMBO_LEN) { + ip6stat.ip6s_toosmall++; + goto bad; + } + if (*(opt + 1) != IP6OPT_JUMBO_LEN - 2) { + /* XXX stat */ + icmp6_error(m, ICMP6_PARAM_PROB, + ICMP6_PARAMPROB_HEADER, + erroff + opt + 1 - opthead); + return(-1); + } + optlen = IP6OPT_JUMBO_LEN; + + /* + * IPv6 packets that have non 0 payload length + * must not contain a jumbo payload option. + */ + ip6 = mtod(m, struct ip6_hdr *); + if (ip6->ip6_plen) { + ip6stat.ip6s_badoptions++; + icmp6_error(m, ICMP6_PARAM_PROB, + ICMP6_PARAMPROB_HEADER, + erroff + opt - opthead); + return(-1); + } + + /* + * We may see jumbolen in unaligned location, so + * we'd need to perform bcopy(). + */ + bcopy(opt + 2, &jumboplen, sizeof(jumboplen)); + jumboplen = (u_int32_t)htonl(jumboplen); + +#if 1 + /* + * if there are multiple jumbo payload options, + * *plenp will be non-zero and the packet will be + * rejected. + * the behavior may need some debate in ipngwg - + * multiple options does not make sense, however, + * there's no explicit mention in specification. + */ + if (*plenp != 0) { + ip6stat.ip6s_badoptions++; + icmp6_error(m, ICMP6_PARAM_PROB, + ICMP6_PARAMPROB_HEADER, + erroff + opt + 2 - opthead); + return(-1); + } +#endif + + /* + * jumbo payload length must be larger than 65535. + */ + if (jumboplen <= IPV6_MAXPACKET) { + ip6stat.ip6s_badoptions++; + icmp6_error(m, ICMP6_PARAM_PROB, + ICMP6_PARAMPROB_HEADER, + erroff + opt + 2 - opthead); + return(-1); + } + *plenp = jumboplen; + + break; + default: /* unknown option */ + if (hbhlen < IP6OPT_MINLEN) { + ip6stat.ip6s_toosmall++; + goto bad; + } + optlen = ip6_unknown_opt(opt, m, + erroff + opt - opthead); + if (optlen == -1) + return(-1); + optlen += 2; + break; + } + } + + return(0); + + bad: + m_freem(m); + return(-1); +} + +/* + * Unknown option processing. + * The third argument `off' is the offset from the IPv6 header to the option, + * which is necessary if the IPv6 header the and option header and IPv6 header + * is not continuous in order to return an ICMPv6 error. + */ +int +ip6_unknown_opt(optp, m, off) + u_int8_t *optp; + struct mbuf *m; + int off; +{ + struct ip6_hdr *ip6; + + switch (IP6OPT_TYPE(*optp)) { + case IP6OPT_TYPE_SKIP: /* ignore the option */ + return((int)*(optp + 1)); + case IP6OPT_TYPE_DISCARD: /* silently discard */ + m_freem(m); + return(-1); + case IP6OPT_TYPE_FORCEICMP: /* send ICMP even if multicasted */ + ip6stat.ip6s_badoptions++; + icmp6_error(m, ICMP6_PARAM_PROB, ICMP6_PARAMPROB_OPTION, off); + return(-1); + case IP6OPT_TYPE_ICMP: /* send ICMP if not multicasted */ + ip6stat.ip6s_badoptions++; + ip6 = mtod(m, struct ip6_hdr *); + if (IN6_IS_ADDR_MULTICAST(&ip6->ip6_dst) || + (m->m_flags & (M_BCAST|M_MCAST))) + m_freem(m); + else + icmp6_error(m, ICMP6_PARAM_PROB, + ICMP6_PARAMPROB_OPTION, off); + return(-1); + } + + m_freem(m); /* XXX: NOTREACHED */ + return(-1); +} + +/* + * Create the "control" list for this pcb. + * The function will not modify mbuf chain at all. + * + * with KAME mbuf chain restriction: + * The routine will be called from upper layer handlers like tcp6_input(). + * Thus the routine assumes that the caller (tcp6_input) have already + * called IP6_EXTHDR_CHECK() and all the extension headers are located in the + * very first mbuf on the mbuf chain. + */ +void +ip6_savecontrol(in6p, mp, ip6, m) + struct inpcb *in6p; + struct mbuf **mp; + struct ip6_hdr *ip6; + struct mbuf *m; +{ +#if __FreeBSD_version >= 500000 + struct thread *td = curthread; /* XXX */ +#else + struct proc *td = curproc; /* XXX */ +#endif + int privileged = 0; + int rthdr_exist = 0; + + + if (td && !suser(td)) + privileged++; + +#ifdef SO_TIMESTAMP + if ((in6p->in6p_socket->so_options & SO_TIMESTAMP) != 0) { + struct timeval tv; + + microtime(&tv); + *mp = sbcreatecontrol((caddr_t) &tv, sizeof(tv), + SCM_TIMESTAMP, SOL_SOCKET); + if (*mp) { + mp = &(*mp)->m_next; + } + } +#endif + + /* RFC 2292 sec. 5 */ + if ((in6p->in6p_flags & IN6P_PKTINFO) != 0) { + struct in6_pktinfo pi6; + bcopy(&ip6->ip6_dst, &pi6.ipi6_addr, sizeof(struct in6_addr)); + if (IN6_IS_SCOPE_LINKLOCAL(&pi6.ipi6_addr)) + pi6.ipi6_addr.s6_addr16[1] = 0; + pi6.ipi6_ifindex = (m && m->m_pkthdr.rcvif) + ? m->m_pkthdr.rcvif->if_index + : 0; + *mp = sbcreatecontrol((caddr_t) &pi6, + sizeof(struct in6_pktinfo), IPV6_PKTINFO, + IPPROTO_IPV6); + if (*mp) + mp = &(*mp)->m_next; + } + + if ((in6p->in6p_flags & IN6P_HOPLIMIT) != 0) { + int hlim = ip6->ip6_hlim & 0xff; + *mp = sbcreatecontrol((caddr_t) &hlim, + sizeof(int), IPV6_HOPLIMIT, IPPROTO_IPV6); + if (*mp) + mp = &(*mp)->m_next; + } + + /* + * IPV6_HOPOPTS socket option. We require super-user privilege + * for the option, but it might be too strict, since there might + * be some hop-by-hop options which can be returned to normal user. + * See RFC 2292 section 6. + */ + if ((in6p->in6p_flags & IN6P_HOPOPTS) != 0 && privileged) { + /* + * Check if a hop-by-hop options header is contatined in the + * received packet, and if so, store the options as ancillary + * data. Note that a hop-by-hop options header must be + * just after the IPv6 header, which fact is assured through + * the IPv6 input processing. + */ + struct ip6_hdr *ip6 = mtod(m, struct ip6_hdr *); + if (ip6->ip6_nxt == IPPROTO_HOPOPTS) { + struct ip6_hbh *hbh; + int hbhlen = 0; +#ifdef PULLDOWN_TEST + struct mbuf *ext; +#endif + +#ifndef PULLDOWN_TEST + hbh = (struct ip6_hbh *)(ip6 + 1); + hbhlen = (hbh->ip6h_len + 1) << 3; +#else + ext = ip6_pullexthdr(m, sizeof(struct ip6_hdr), + ip6->ip6_nxt); + if (ext == NULL) { + ip6stat.ip6s_tooshort++; + return; + } + hbh = mtod(ext, struct ip6_hbh *); + hbhlen = (hbh->ip6h_len + 1) << 3; + if (hbhlen != ext->m_len) { + m_freem(ext); + ip6stat.ip6s_tooshort++; + return; + } +#endif + + /* + * XXX: We copy whole the header even if a jumbo + * payload option is included, which option is to + * be removed before returning in the RFC 2292. + * Note: this constraint is removed in 2292bis. + */ + *mp = sbcreatecontrol((caddr_t)hbh, hbhlen, + IPV6_HOPOPTS, IPPROTO_IPV6); + if (*mp) + mp = &(*mp)->m_next; +#ifdef PULLDOWN_TEST + m_freem(ext); +#endif + } + } + + /* IPV6_DSTOPTS and IPV6_RTHDR socket options */ + if ((in6p->in6p_flags & (IN6P_DSTOPTS | IN6P_RTHDRDSTOPTS)) != 0) { + int proto, off, nxt; + + /* + * go through the header chain to see if a routing header is + * contained in the packet. We need this information to store + * destination options headers (if any) properly. + * XXX: performance issue. We should record this info when + * processing extension headers in incoming routine. + * (todo) use m_aux? + */ + proto = IPPROTO_IPV6; + off = 0; + nxt = -1; + while (1) { + int newoff; + + newoff = ip6_nexthdr(m, off, proto, &nxt); + if (newoff < 0) + break; + if (newoff < off) /* invalid, check for safety */ + break; + if ((proto = nxt) == IPPROTO_ROUTING) { + rthdr_exist = 1; + break; + } + off = newoff; + } + } + + if ((in6p->in6p_flags & + (IN6P_RTHDR | IN6P_DSTOPTS | IN6P_RTHDRDSTOPTS)) != 0) { + struct ip6_hdr *ip6 = mtod(m, struct ip6_hdr *); + int nxt = ip6->ip6_nxt, off = sizeof(struct ip6_hdr); + + /* + * Search for destination options headers or routing + * header(s) through the header chain, and stores each + * header as ancillary data. + * Note that the order of the headers remains in + * the chain of ancillary data. + */ + while (1) { /* is explicit loop prevention necessary? */ + struct ip6_ext *ip6e = NULL; + int elen; +#ifdef PULLDOWN_TEST + struct mbuf *ext = NULL; +#endif + + /* + * if it is not an extension header, don't try to + * pull it from the chain. + */ + switch (nxt) { + case IPPROTO_DSTOPTS: + case IPPROTO_ROUTING: + case IPPROTO_HOPOPTS: + case IPPROTO_AH: /* is it possible? */ + break; + default: + goto loopend; + } + +#ifndef PULLDOWN_TEST + if (off + sizeof(*ip6e) > m->m_len) + goto loopend; + ip6e = (struct ip6_ext *)(mtod(m, caddr_t) + off); + if (nxt == IPPROTO_AH) + elen = (ip6e->ip6e_len + 2) << 2; + else + elen = (ip6e->ip6e_len + 1) << 3; + if (off + elen > m->m_len) + goto loopend; +#else + ext = ip6_pullexthdr(m, off, nxt); + if (ext == NULL) { + ip6stat.ip6s_tooshort++; + return; + } + ip6e = mtod(ext, struct ip6_ext *); + if (nxt == IPPROTO_AH) + elen = (ip6e->ip6e_len + 2) << 2; + else + elen = (ip6e->ip6e_len + 1) << 3; + if (elen != ext->m_len) { + m_freem(ext); + ip6stat.ip6s_tooshort++; + return; + } +#endif + + switch (nxt) { + case IPPROTO_DSTOPTS: + if ((in6p->in6p_flags & IN6P_DSTOPTS) == 0) + break; + + /* + * We also require super-user privilege for + * the option. + * See the comments on IN6_HOPOPTS. + */ + if (!privileged) + break; + + *mp = sbcreatecontrol((caddr_t)ip6e, elen, + IPV6_DSTOPTS, + IPPROTO_IPV6); + if (*mp) + mp = &(*mp)->m_next; + break; + case IPPROTO_ROUTING: + if (!in6p->in6p_flags & IN6P_RTHDR) + break; + + *mp = sbcreatecontrol((caddr_t)ip6e, elen, + IPV6_RTHDR, + IPPROTO_IPV6); + if (*mp) + mp = &(*mp)->m_next; + break; + case IPPROTO_HOPOPTS: + case IPPROTO_AH: /* is it possible? */ + break; + + default: + /* + * other cases have been filtered in the above. + * none will visit this case. here we supply + * the code just in case (nxt overwritten or + * other cases). + */ +#ifdef PULLDOWN_TEST + m_freem(ext); +#endif + goto loopend; + + } + + /* proceed with the next header. */ + off += elen; + nxt = ip6e->ip6e_nxt; + ip6e = NULL; +#ifdef PULLDOWN_TEST + m_freem(ext); + ext = NULL; +#endif + } + loopend: + ; + } + +} + +#ifdef PULLDOWN_TEST +/* + * pull single extension header from mbuf chain. returns single mbuf that + * contains the result, or NULL on error. + */ +static struct mbuf * +ip6_pullexthdr(m, off, nxt) + struct mbuf *m; + size_t off; + int nxt; +{ + struct ip6_ext ip6e; + size_t elen; + struct mbuf *n; + +#ifdef DIAGNOSTIC + switch (nxt) { + case IPPROTO_DSTOPTS: + case IPPROTO_ROUTING: + case IPPROTO_HOPOPTS: + case IPPROTO_AH: /* is it possible? */ + break; + default: + printf("ip6_pullexthdr: invalid nxt=%d\n", nxt); + } +#endif + + m_copydata(m, off, sizeof(ip6e), (caddr_t)&ip6e); + if (nxt == IPPROTO_AH) + elen = (ip6e.ip6e_len + 2) << 2; + else + elen = (ip6e.ip6e_len + 1) << 3; + + MGET(n, M_DONTWAIT, MT_DATA); + if (n && elen >= MLEN) { + MCLGET(n, M_DONTWAIT); + if ((n->m_flags & M_EXT) == 0) { + m_free(n); + n = NULL; + } + } + if (!n) + return NULL; + + n->m_len = 0; + if (elen >= M_TRAILINGSPACE(n)) { + m_free(n); + return NULL; + } + + m_copydata(m, off, elen, mtod(n, caddr_t)); + n->m_len = elen; + return n; +} +#endif + +/* + * Get pointer to the previous header followed by the header + * currently processed. + * XXX: This function supposes that + * M includes all headers, + * the next header field and the header length field of each header + * are valid, and + * the sum of each header length equals to OFF. + * Because of these assumptions, this function must be called very + * carefully. Moreover, it will not be used in the near future when + * we develop `neater' mechanism to process extension headers. + */ +char * +ip6_get_prevhdr(m, off) + struct mbuf *m; + int off; +{ + struct ip6_hdr *ip6 = mtod(m, struct ip6_hdr *); + + if (off == sizeof(struct ip6_hdr)) + return(&ip6->ip6_nxt); + else { + int len, nxt; + struct ip6_ext *ip6e = NULL; + + nxt = ip6->ip6_nxt; + len = sizeof(struct ip6_hdr); + while (len < off) { + ip6e = (struct ip6_ext *)(mtod(m, caddr_t) + len); + + switch (nxt) { + case IPPROTO_FRAGMENT: + len += sizeof(struct ip6_frag); + break; + case IPPROTO_AH: + len += (ip6e->ip6e_len + 2) << 2; + break; + default: + len += (ip6e->ip6e_len + 1) << 3; + break; + } + nxt = ip6e->ip6e_nxt; + } + if (ip6e) + return(&ip6e->ip6e_nxt); + else + return NULL; + } +} + +/* + * get next header offset. m will be retained. + */ +int +ip6_nexthdr(m, off, proto, nxtp) + struct mbuf *m; + int off; + int proto; + int *nxtp; +{ + struct ip6_hdr ip6; + struct ip6_ext ip6e; + struct ip6_frag fh; + + /* just in case */ + if (m == NULL) + panic("ip6_nexthdr: m == NULL"); + if ((m->m_flags & M_PKTHDR) == 0 || m->m_pkthdr.len < off) + return -1; + + switch (proto) { + case IPPROTO_IPV6: + if (m->m_pkthdr.len < off + sizeof(ip6)) + return -1; + m_copydata(m, off, sizeof(ip6), (caddr_t)&ip6); + if (nxtp) + *nxtp = ip6.ip6_nxt; + off += sizeof(ip6); + return off; + + case IPPROTO_FRAGMENT: + /* + * terminate parsing if it is not the first fragment, + * it does not make sense to parse through it. + */ + if (m->m_pkthdr.len < off + sizeof(fh)) + return -1; + m_copydata(m, off, sizeof(fh), (caddr_t)&fh); + if ((ntohs(fh.ip6f_offlg) & IP6F_OFF_MASK) != 0) + return -1; + if (nxtp) + *nxtp = fh.ip6f_nxt; + off += sizeof(struct ip6_frag); + return off; + + case IPPROTO_AH: + if (m->m_pkthdr.len < off + sizeof(ip6e)) + return -1; + m_copydata(m, off, sizeof(ip6e), (caddr_t)&ip6e); + if (nxtp) + *nxtp = ip6e.ip6e_nxt; + off += (ip6e.ip6e_len + 2) << 2; + return off; + + case IPPROTO_HOPOPTS: + case IPPROTO_ROUTING: + case IPPROTO_DSTOPTS: + if (m->m_pkthdr.len < off + sizeof(ip6e)) + return -1; + m_copydata(m, off, sizeof(ip6e), (caddr_t)&ip6e); + if (nxtp) + *nxtp = ip6e.ip6e_nxt; + off += (ip6e.ip6e_len + 1) << 3; + return off; + + case IPPROTO_NONE: + case IPPROTO_ESP: + case IPPROTO_IPCOMP: + /* give up */ + return -1; + + default: + return -1; + } + + return -1; +} + +/* + * get offset for the last header in the chain. m will be kept untainted. + */ +int +ip6_lasthdr(m, off, proto, nxtp) + struct mbuf *m; + int off; + int proto; + int *nxtp; +{ + int newoff; + int nxt; + + if (!nxtp) { + nxt = -1; + nxtp = &nxt; + } + while (1) { + newoff = ip6_nexthdr(m, off, proto, nxtp); + if (newoff < 0) + return off; + else if (newoff < off) + return -1; /* invalid */ + else if (newoff == off) + return newoff; + + off = newoff; + proto = *nxtp; + } +} + +struct ip6aux * +ip6_addaux(m) + struct mbuf *m; +{ + struct m_tag *tag = m_tag_find(m, PACKET_TAG_IPV6_INPUT, NULL); + if (!tag) { + tag = m_tag_get(PACKET_TAG_IPV6_INPUT, + sizeof (struct ip6aux), + M_NOWAIT); + if (tag) + m_tag_prepend(m, tag); + } + if (tag) + bzero(tag+1, sizeof (struct ip6aux)); + return tag ? (struct ip6aux*)(tag+1) : NULL; +} + +struct ip6aux * +ip6_findaux(m) + struct mbuf *m; +{ + struct m_tag *tag = m_tag_find(m, PACKET_TAG_IPV6_INPUT, NULL); + return tag ? (struct ip6aux*)(tag+1) : NULL; +} + +void +ip6_delaux(m) + struct mbuf *m; +{ + struct m_tag *tag = m_tag_find(m, PACKET_TAG_IPV6_INPUT, NULL); + if (tag) + m_tag_delete(m, tag); +} + +/* + * System control for IP6 + */ + +u_char inet6ctlerrmap[PRC_NCMDS] = { + 0, 0, 0, 0, + 0, EMSGSIZE, EHOSTDOWN, EHOSTUNREACH, + EHOSTUNREACH, EHOSTUNREACH, ECONNREFUSED, ECONNREFUSED, + EMSGSIZE, EHOSTUNREACH, 0, 0, + 0, 0, 0, 0, + ENOPROTOOPT +}; |
