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9cb8d207af
MFC after: 1 week
793 lines
20 KiB
C
793 lines
20 KiB
C
/*-
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* Copyright (C) 1995, 1996, 1997, and 1998 WIDE Project.
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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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* $KAME: frag6.c,v 1.33 2002/01/07 11:34:48 kjc Exp $
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*/
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#include <sys/cdefs.h>
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__FBSDID("$FreeBSD$");
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#include <sys/param.h>
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#include <sys/systm.h>
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#include <sys/malloc.h>
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#include <sys/mbuf.h>
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#include <sys/domain.h>
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#include <sys/protosw.h>
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#include <sys/socket.h>
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#include <sys/errno.h>
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#include <sys/time.h>
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#include <sys/kernel.h>
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#include <sys/syslog.h>
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#include <net/if.h>
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#include <net/route.h>
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#include <net/vnet.h>
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#include <netinet/in.h>
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#include <netinet/in_var.h>
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#include <netinet/ip6.h>
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#include <netinet6/ip6_var.h>
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#include <netinet/icmp6.h>
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#include <netinet/in_systm.h> /* for ECN definitions */
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#include <netinet/ip.h> /* for ECN definitions */
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#include <security/mac/mac_framework.h>
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/*
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* Define it to get a correct behavior on per-interface statistics.
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* You will need to perform an extra routing table lookup, per fragment,
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* to do it. This may, or may not be, a performance hit.
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*/
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#define IN6_IFSTAT_STRICT
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static void frag6_enq(struct ip6asfrag *, struct ip6asfrag *);
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static void frag6_deq(struct ip6asfrag *);
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static void frag6_insque(struct ip6q *, struct ip6q *);
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static void frag6_remque(struct ip6q *);
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static void frag6_freef(struct ip6q *);
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static struct mtx ip6qlock;
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/*
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* These fields all protected by ip6qlock.
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*/
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static VNET_DEFINE(u_int, frag6_nfragpackets);
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static VNET_DEFINE(u_int, frag6_nfrags);
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static VNET_DEFINE(struct ip6q, ip6q); /* ip6 reassemble queue */
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#define V_frag6_nfragpackets VNET(frag6_nfragpackets)
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#define V_frag6_nfrags VNET(frag6_nfrags)
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#define V_ip6q VNET(ip6q)
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#define IP6Q_LOCK_INIT() mtx_init(&ip6qlock, "ip6qlock", NULL, MTX_DEF);
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#define IP6Q_LOCK() mtx_lock(&ip6qlock)
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#define IP6Q_TRYLOCK() mtx_trylock(&ip6qlock)
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#define IP6Q_LOCK_ASSERT() mtx_assert(&ip6qlock, MA_OWNED)
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#define IP6Q_UNLOCK() mtx_unlock(&ip6qlock)
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static MALLOC_DEFINE(M_FTABLE, "fragment", "fragment reassembly header");
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/*
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* Initialise reassembly queue and fragment identifier.
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*/
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static void
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frag6_change(void *tag)
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{
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V_ip6_maxfragpackets = nmbclusters / 4;
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V_ip6_maxfrags = nmbclusters / 4;
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}
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void
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frag6_init(void)
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{
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V_ip6_maxfragpackets = nmbclusters / 4;
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V_ip6_maxfrags = nmbclusters / 4;
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V_ip6q.ip6q_next = V_ip6q.ip6q_prev = &V_ip6q;
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if (!IS_DEFAULT_VNET(curvnet))
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return;
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EVENTHANDLER_REGISTER(nmbclusters_change,
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frag6_change, NULL, EVENTHANDLER_PRI_ANY);
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IP6Q_LOCK_INIT();
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}
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/*
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* In RFC2460, fragment and reassembly rule do not agree with each other,
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* in terms of next header field handling in fragment header.
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* While the sender will use the same value for all of the fragmented packets,
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* receiver is suggested not to check the consistency.
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*
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* fragment rule (p20):
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* (2) A Fragment header containing:
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* The Next Header value that identifies the first header of
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* the Fragmentable Part of the original packet.
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* -> next header field is same for all fragments
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*
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* reassembly rule (p21):
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* The Next Header field of the last header of the Unfragmentable
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* Part is obtained from the Next Header field of the first
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* fragment's Fragment header.
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* -> should grab it from the first fragment only
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*
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* The following note also contradicts with fragment rule - noone is going to
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* send different fragment with different next header field.
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*
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* additional note (p22):
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* The Next Header values in the Fragment headers of different
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* fragments of the same original packet may differ. Only the value
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* from the Offset zero fragment packet is used for reassembly.
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* -> should grab it from the first fragment only
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*
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* There is no explicit reason given in the RFC. Historical reason maybe?
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*/
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/*
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* Fragment input
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*/
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int
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frag6_input(struct mbuf **mp, int *offp, int proto)
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{
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struct mbuf *m = *mp, *t;
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struct ip6_hdr *ip6;
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struct ip6_frag *ip6f;
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struct ip6q *q6;
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struct ip6asfrag *af6, *ip6af, *af6dwn;
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#ifdef IN6_IFSTAT_STRICT
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struct in6_ifaddr *ia;
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#endif
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int offset = *offp, nxt, i, next;
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int first_frag = 0;
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int fragoff, frgpartlen; /* must be larger than u_int16_t */
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struct ifnet *dstifp;
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u_int8_t ecn, ecn0;
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#if 0
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char ip6buf[INET6_ADDRSTRLEN];
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#endif
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ip6 = mtod(m, struct ip6_hdr *);
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#ifndef PULLDOWN_TEST
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IP6_EXTHDR_CHECK(m, offset, sizeof(struct ip6_frag), IPPROTO_DONE);
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ip6f = (struct ip6_frag *)((caddr_t)ip6 + offset);
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#else
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IP6_EXTHDR_GET(ip6f, struct ip6_frag *, m, offset, sizeof(*ip6f));
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if (ip6f == NULL)
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return (IPPROTO_DONE);
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#endif
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dstifp = NULL;
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#ifdef IN6_IFSTAT_STRICT
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/* find the destination interface of the packet. */
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if ((ia = ip6_getdstifaddr(m)) != NULL) {
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dstifp = ia->ia_ifp;
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ifa_free(&ia->ia_ifa);
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}
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#else
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/* we are violating the spec, this is not the destination interface */
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if ((m->m_flags & M_PKTHDR) != 0)
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dstifp = m->m_pkthdr.rcvif;
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#endif
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/* jumbo payload can't contain a fragment header */
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if (ip6->ip6_plen == 0) {
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icmp6_error(m, ICMP6_PARAM_PROB, ICMP6_PARAMPROB_HEADER, offset);
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in6_ifstat_inc(dstifp, ifs6_reass_fail);
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return IPPROTO_DONE;
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}
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/*
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* check whether fragment packet's fragment length is
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* multiple of 8 octets.
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* sizeof(struct ip6_frag) == 8
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* sizeof(struct ip6_hdr) = 40
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*/
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if ((ip6f->ip6f_offlg & IP6F_MORE_FRAG) &&
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(((ntohs(ip6->ip6_plen) - offset) & 0x7) != 0)) {
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icmp6_error(m, ICMP6_PARAM_PROB, ICMP6_PARAMPROB_HEADER,
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offsetof(struct ip6_hdr, ip6_plen));
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in6_ifstat_inc(dstifp, ifs6_reass_fail);
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return IPPROTO_DONE;
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}
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IP6STAT_INC(ip6s_fragments);
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in6_ifstat_inc(dstifp, ifs6_reass_reqd);
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/* offset now points to data portion */
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offset += sizeof(struct ip6_frag);
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/*
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* XXX-BZ RFC XXXX (draft-gont-6man-ipv6-atomic-fragments)
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* Handle "atomic" fragments (offset and m bit set to 0) upfront,
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* unrelated to any reassembly. Just skip the fragment header.
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*/
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if ((ip6f->ip6f_offlg & ~IP6F_RESERVED_MASK) == 0) {
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/* XXX-BZ we want dedicated counters for this. */
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IP6STAT_INC(ip6s_reassembled);
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in6_ifstat_inc(dstifp, ifs6_reass_ok);
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*offp = offset;
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return (ip6f->ip6f_nxt);
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}
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IP6Q_LOCK();
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/*
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* Enforce upper bound on number of fragments.
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* If maxfrag is 0, never accept fragments.
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* If maxfrag is -1, accept all fragments without limitation.
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*/
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if (V_ip6_maxfrags < 0)
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;
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else if (V_frag6_nfrags >= (u_int)V_ip6_maxfrags)
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goto dropfrag;
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for (q6 = V_ip6q.ip6q_next; q6 != &V_ip6q; q6 = q6->ip6q_next)
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if (ip6f->ip6f_ident == q6->ip6q_ident &&
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IN6_ARE_ADDR_EQUAL(&ip6->ip6_src, &q6->ip6q_src) &&
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IN6_ARE_ADDR_EQUAL(&ip6->ip6_dst, &q6->ip6q_dst)
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#ifdef MAC
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&& mac_ip6q_match(m, q6)
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#endif
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)
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break;
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if (q6 == &V_ip6q) {
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/*
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* the first fragment to arrive, create a reassembly queue.
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*/
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first_frag = 1;
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/*
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* Enforce upper bound on number of fragmented packets
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* for which we attempt reassembly;
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* If maxfragpackets is 0, never accept fragments.
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* If maxfragpackets is -1, accept all fragments without
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* limitation.
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*/
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if (V_ip6_maxfragpackets < 0)
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;
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else if (V_frag6_nfragpackets >= (u_int)V_ip6_maxfragpackets)
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goto dropfrag;
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V_frag6_nfragpackets++;
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q6 = (struct ip6q *)malloc(sizeof(struct ip6q), M_FTABLE,
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M_NOWAIT);
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if (q6 == NULL)
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goto dropfrag;
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bzero(q6, sizeof(*q6));
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#ifdef MAC
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if (mac_ip6q_init(q6, M_NOWAIT) != 0) {
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free(q6, M_FTABLE);
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goto dropfrag;
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}
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mac_ip6q_create(m, q6);
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#endif
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frag6_insque(q6, &V_ip6q);
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/* ip6q_nxt will be filled afterwards, from 1st fragment */
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q6->ip6q_down = q6->ip6q_up = (struct ip6asfrag *)q6;
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#ifdef notyet
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q6->ip6q_nxtp = (u_char *)nxtp;
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#endif
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q6->ip6q_ident = ip6f->ip6f_ident;
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q6->ip6q_ttl = IPV6_FRAGTTL;
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q6->ip6q_src = ip6->ip6_src;
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q6->ip6q_dst = ip6->ip6_dst;
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q6->ip6q_ecn =
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(ntohl(ip6->ip6_flow) >> 20) & IPTOS_ECN_MASK;
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q6->ip6q_unfrglen = -1; /* The 1st fragment has not arrived. */
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q6->ip6q_nfrag = 0;
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}
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/*
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* If it's the 1st fragment, record the length of the
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* unfragmentable part and the next header of the fragment header.
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*/
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fragoff = ntohs(ip6f->ip6f_offlg & IP6F_OFF_MASK);
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if (fragoff == 0) {
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q6->ip6q_unfrglen = offset - sizeof(struct ip6_hdr) -
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sizeof(struct ip6_frag);
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q6->ip6q_nxt = ip6f->ip6f_nxt;
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}
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/*
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* Check that the reassembled packet would not exceed 65535 bytes
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* in size.
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* If it would exceed, discard the fragment and return an ICMP error.
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*/
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frgpartlen = sizeof(struct ip6_hdr) + ntohs(ip6->ip6_plen) - offset;
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if (q6->ip6q_unfrglen >= 0) {
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/* The 1st fragment has already arrived. */
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if (q6->ip6q_unfrglen + fragoff + frgpartlen > IPV6_MAXPACKET) {
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icmp6_error(m, ICMP6_PARAM_PROB, ICMP6_PARAMPROB_HEADER,
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offset - sizeof(struct ip6_frag) +
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offsetof(struct ip6_frag, ip6f_offlg));
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IP6Q_UNLOCK();
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return (IPPROTO_DONE);
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}
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} else if (fragoff + frgpartlen > IPV6_MAXPACKET) {
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icmp6_error(m, ICMP6_PARAM_PROB, ICMP6_PARAMPROB_HEADER,
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offset - sizeof(struct ip6_frag) +
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offsetof(struct ip6_frag, ip6f_offlg));
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IP6Q_UNLOCK();
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return (IPPROTO_DONE);
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}
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/*
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* If it's the first fragment, do the above check for each
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* fragment already stored in the reassembly queue.
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*/
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if (fragoff == 0) {
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for (af6 = q6->ip6q_down; af6 != (struct ip6asfrag *)q6;
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af6 = af6dwn) {
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af6dwn = af6->ip6af_down;
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if (q6->ip6q_unfrglen + af6->ip6af_off + af6->ip6af_frglen >
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IPV6_MAXPACKET) {
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struct mbuf *merr = IP6_REASS_MBUF(af6);
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struct ip6_hdr *ip6err;
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int erroff = af6->ip6af_offset;
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/* dequeue the fragment. */
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frag6_deq(af6);
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free(af6, M_FTABLE);
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/* adjust pointer. */
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ip6err = mtod(merr, struct ip6_hdr *);
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/*
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* Restore source and destination addresses
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* in the erroneous IPv6 header.
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*/
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ip6err->ip6_src = q6->ip6q_src;
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ip6err->ip6_dst = q6->ip6q_dst;
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icmp6_error(merr, ICMP6_PARAM_PROB,
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ICMP6_PARAMPROB_HEADER,
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erroff - sizeof(struct ip6_frag) +
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offsetof(struct ip6_frag, ip6f_offlg));
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}
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}
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}
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ip6af = (struct ip6asfrag *)malloc(sizeof(struct ip6asfrag), M_FTABLE,
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M_NOWAIT);
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if (ip6af == NULL)
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goto dropfrag;
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bzero(ip6af, sizeof(*ip6af));
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ip6af->ip6af_mff = ip6f->ip6f_offlg & IP6F_MORE_FRAG;
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ip6af->ip6af_off = fragoff;
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ip6af->ip6af_frglen = frgpartlen;
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ip6af->ip6af_offset = offset;
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IP6_REASS_MBUF(ip6af) = m;
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if (first_frag) {
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af6 = (struct ip6asfrag *)q6;
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goto insert;
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}
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/*
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* Handle ECN by comparing this segment with the first one;
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* if CE is set, do not lose CE.
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* drop if CE and not-ECT are mixed for the same packet.
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*/
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ecn = (ntohl(ip6->ip6_flow) >> 20) & IPTOS_ECN_MASK;
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ecn0 = q6->ip6q_ecn;
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if (ecn == IPTOS_ECN_CE) {
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if (ecn0 == IPTOS_ECN_NOTECT) {
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free(ip6af, M_FTABLE);
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goto dropfrag;
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}
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if (ecn0 != IPTOS_ECN_CE)
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q6->ip6q_ecn = IPTOS_ECN_CE;
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}
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if (ecn == IPTOS_ECN_NOTECT && ecn0 != IPTOS_ECN_NOTECT) {
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free(ip6af, M_FTABLE);
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goto dropfrag;
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}
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/*
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* Find a segment which begins after this one does.
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*/
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for (af6 = q6->ip6q_down; af6 != (struct ip6asfrag *)q6;
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af6 = af6->ip6af_down)
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if (af6->ip6af_off > ip6af->ip6af_off)
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break;
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#if 0
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/*
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* If there is a preceding segment, it may provide some of
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* our data already. If so, drop the data from the incoming
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* segment. If it provides all of our data, drop us.
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*/
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if (af6->ip6af_up != (struct ip6asfrag *)q6) {
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i = af6->ip6af_up->ip6af_off + af6->ip6af_up->ip6af_frglen
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- ip6af->ip6af_off;
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if (i > 0) {
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if (i >= ip6af->ip6af_frglen)
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goto dropfrag;
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m_adj(IP6_REASS_MBUF(ip6af), i);
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ip6af->ip6af_off += i;
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ip6af->ip6af_frglen -= i;
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}
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}
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/*
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* While we overlap succeeding segments trim them or,
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* if they are completely covered, dequeue them.
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*/
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while (af6 != (struct ip6asfrag *)q6 &&
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ip6af->ip6af_off + ip6af->ip6af_frglen > af6->ip6af_off) {
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i = (ip6af->ip6af_off + ip6af->ip6af_frglen) - af6->ip6af_off;
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if (i < af6->ip6af_frglen) {
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af6->ip6af_frglen -= i;
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af6->ip6af_off += i;
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m_adj(IP6_REASS_MBUF(af6), i);
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break;
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}
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af6 = af6->ip6af_down;
|
|
m_freem(IP6_REASS_MBUF(af6->ip6af_up));
|
|
frag6_deq(af6->ip6af_up);
|
|
}
|
|
#else
|
|
/*
|
|
* If the incoming framgent overlaps some existing fragments in
|
|
* the reassembly queue, drop it, since it is dangerous to override
|
|
* existing fragments from a security point of view.
|
|
* We don't know which fragment is the bad guy - here we trust
|
|
* fragment that came in earlier, with no real reason.
|
|
*
|
|
* Note: due to changes after disabling this part, mbuf passed to
|
|
* m_adj() below now does not meet the requirement.
|
|
*/
|
|
if (af6->ip6af_up != (struct ip6asfrag *)q6) {
|
|
i = af6->ip6af_up->ip6af_off + af6->ip6af_up->ip6af_frglen
|
|
- ip6af->ip6af_off;
|
|
if (i > 0) {
|
|
#if 0 /* suppress the noisy log */
|
|
log(LOG_ERR, "%d bytes of a fragment from %s "
|
|
"overlaps the previous fragment\n",
|
|
i, ip6_sprintf(ip6buf, &q6->ip6q_src));
|
|
#endif
|
|
free(ip6af, M_FTABLE);
|
|
goto dropfrag;
|
|
}
|
|
}
|
|
if (af6 != (struct ip6asfrag *)q6) {
|
|
i = (ip6af->ip6af_off + ip6af->ip6af_frglen) - af6->ip6af_off;
|
|
if (i > 0) {
|
|
#if 0 /* suppress the noisy log */
|
|
log(LOG_ERR, "%d bytes of a fragment from %s "
|
|
"overlaps the succeeding fragment",
|
|
i, ip6_sprintf(ip6buf, &q6->ip6q_src));
|
|
#endif
|
|
free(ip6af, M_FTABLE);
|
|
goto dropfrag;
|
|
}
|
|
}
|
|
#endif
|
|
|
|
insert:
|
|
#ifdef MAC
|
|
if (!first_frag)
|
|
mac_ip6q_update(m, q6);
|
|
#endif
|
|
|
|
/*
|
|
* Stick new segment in its place;
|
|
* check for complete reassembly.
|
|
* Move to front of packet queue, as we are
|
|
* the most recently active fragmented packet.
|
|
*/
|
|
frag6_enq(ip6af, af6->ip6af_up);
|
|
V_frag6_nfrags++;
|
|
q6->ip6q_nfrag++;
|
|
#if 0 /* xxx */
|
|
if (q6 != V_ip6q.ip6q_next) {
|
|
frag6_remque(q6);
|
|
frag6_insque(q6, &V_ip6q);
|
|
}
|
|
#endif
|
|
next = 0;
|
|
for (af6 = q6->ip6q_down; af6 != (struct ip6asfrag *)q6;
|
|
af6 = af6->ip6af_down) {
|
|
if (af6->ip6af_off != next) {
|
|
IP6Q_UNLOCK();
|
|
return IPPROTO_DONE;
|
|
}
|
|
next += af6->ip6af_frglen;
|
|
}
|
|
if (af6->ip6af_up->ip6af_mff) {
|
|
IP6Q_UNLOCK();
|
|
return IPPROTO_DONE;
|
|
}
|
|
|
|
/*
|
|
* Reassembly is complete; concatenate fragments.
|
|
*/
|
|
ip6af = q6->ip6q_down;
|
|
t = m = IP6_REASS_MBUF(ip6af);
|
|
af6 = ip6af->ip6af_down;
|
|
frag6_deq(ip6af);
|
|
while (af6 != (struct ip6asfrag *)q6) {
|
|
af6dwn = af6->ip6af_down;
|
|
frag6_deq(af6);
|
|
while (t->m_next)
|
|
t = t->m_next;
|
|
t->m_next = IP6_REASS_MBUF(af6);
|
|
m_adj(t->m_next, af6->ip6af_offset);
|
|
free(af6, M_FTABLE);
|
|
af6 = af6dwn;
|
|
}
|
|
|
|
/* adjust offset to point where the original next header starts */
|
|
offset = ip6af->ip6af_offset - sizeof(struct ip6_frag);
|
|
free(ip6af, M_FTABLE);
|
|
ip6 = mtod(m, struct ip6_hdr *);
|
|
ip6->ip6_plen = htons((u_short)next + offset - sizeof(struct ip6_hdr));
|
|
if (q6->ip6q_ecn == IPTOS_ECN_CE)
|
|
ip6->ip6_flow |= htonl(IPTOS_ECN_CE << 20);
|
|
nxt = q6->ip6q_nxt;
|
|
#ifdef notyet
|
|
*q6->ip6q_nxtp = (u_char)(nxt & 0xff);
|
|
#endif
|
|
|
|
/* Delete frag6 header */
|
|
if (m->m_len >= offset + sizeof(struct ip6_frag)) {
|
|
/* This is the only possible case with !PULLDOWN_TEST */
|
|
ovbcopy((caddr_t)ip6, (caddr_t)ip6 + sizeof(struct ip6_frag),
|
|
offset);
|
|
m->m_data += sizeof(struct ip6_frag);
|
|
m->m_len -= sizeof(struct ip6_frag);
|
|
} else {
|
|
/* this comes with no copy if the boundary is on cluster */
|
|
if ((t = m_split(m, offset, M_NOWAIT)) == NULL) {
|
|
frag6_remque(q6);
|
|
V_frag6_nfrags -= q6->ip6q_nfrag;
|
|
#ifdef MAC
|
|
mac_ip6q_destroy(q6);
|
|
#endif
|
|
free(q6, M_FTABLE);
|
|
V_frag6_nfragpackets--;
|
|
goto dropfrag;
|
|
}
|
|
m_adj(t, sizeof(struct ip6_frag));
|
|
m_cat(m, t);
|
|
}
|
|
|
|
/*
|
|
* Store NXT to the original.
|
|
*/
|
|
{
|
|
char *prvnxtp = ip6_get_prevhdr(m, offset); /* XXX */
|
|
*prvnxtp = nxt;
|
|
}
|
|
|
|
frag6_remque(q6);
|
|
V_frag6_nfrags -= q6->ip6q_nfrag;
|
|
#ifdef MAC
|
|
mac_ip6q_reassemble(q6, m);
|
|
mac_ip6q_destroy(q6);
|
|
#endif
|
|
free(q6, M_FTABLE);
|
|
V_frag6_nfragpackets--;
|
|
|
|
if (m->m_flags & M_PKTHDR) { /* Isn't it always true? */
|
|
int plen = 0;
|
|
for (t = m; t; t = t->m_next)
|
|
plen += t->m_len;
|
|
m->m_pkthdr.len = plen;
|
|
}
|
|
|
|
IP6STAT_INC(ip6s_reassembled);
|
|
in6_ifstat_inc(dstifp, ifs6_reass_ok);
|
|
|
|
/*
|
|
* Tell launch routine the next header
|
|
*/
|
|
|
|
*mp = m;
|
|
*offp = offset;
|
|
|
|
IP6Q_UNLOCK();
|
|
return nxt;
|
|
|
|
dropfrag:
|
|
IP6Q_UNLOCK();
|
|
in6_ifstat_inc(dstifp, ifs6_reass_fail);
|
|
IP6STAT_INC(ip6s_fragdropped);
|
|
m_freem(m);
|
|
return IPPROTO_DONE;
|
|
}
|
|
|
|
/*
|
|
* Free a fragment reassembly header and all
|
|
* associated datagrams.
|
|
*/
|
|
void
|
|
frag6_freef(struct ip6q *q6)
|
|
{
|
|
struct ip6asfrag *af6, *down6;
|
|
|
|
IP6Q_LOCK_ASSERT();
|
|
|
|
for (af6 = q6->ip6q_down; af6 != (struct ip6asfrag *)q6;
|
|
af6 = down6) {
|
|
struct mbuf *m = IP6_REASS_MBUF(af6);
|
|
|
|
down6 = af6->ip6af_down;
|
|
frag6_deq(af6);
|
|
|
|
/*
|
|
* Return ICMP time exceeded error for the 1st fragment.
|
|
* Just free other fragments.
|
|
*/
|
|
if (af6->ip6af_off == 0) {
|
|
struct ip6_hdr *ip6;
|
|
|
|
/* adjust pointer */
|
|
ip6 = mtod(m, struct ip6_hdr *);
|
|
|
|
/* restore source and destination addresses */
|
|
ip6->ip6_src = q6->ip6q_src;
|
|
ip6->ip6_dst = q6->ip6q_dst;
|
|
|
|
icmp6_error(m, ICMP6_TIME_EXCEEDED,
|
|
ICMP6_TIME_EXCEED_REASSEMBLY, 0);
|
|
} else
|
|
m_freem(m);
|
|
free(af6, M_FTABLE);
|
|
}
|
|
frag6_remque(q6);
|
|
V_frag6_nfrags -= q6->ip6q_nfrag;
|
|
#ifdef MAC
|
|
mac_ip6q_destroy(q6);
|
|
#endif
|
|
free(q6, M_FTABLE);
|
|
V_frag6_nfragpackets--;
|
|
}
|
|
|
|
/*
|
|
* Put an ip fragment on a reassembly chain.
|
|
* Like insque, but pointers in middle of structure.
|
|
*/
|
|
void
|
|
frag6_enq(struct ip6asfrag *af6, struct ip6asfrag *up6)
|
|
{
|
|
|
|
IP6Q_LOCK_ASSERT();
|
|
|
|
af6->ip6af_up = up6;
|
|
af6->ip6af_down = up6->ip6af_down;
|
|
up6->ip6af_down->ip6af_up = af6;
|
|
up6->ip6af_down = af6;
|
|
}
|
|
|
|
/*
|
|
* To frag6_enq as remque is to insque.
|
|
*/
|
|
void
|
|
frag6_deq(struct ip6asfrag *af6)
|
|
{
|
|
|
|
IP6Q_LOCK_ASSERT();
|
|
|
|
af6->ip6af_up->ip6af_down = af6->ip6af_down;
|
|
af6->ip6af_down->ip6af_up = af6->ip6af_up;
|
|
}
|
|
|
|
void
|
|
frag6_insque(struct ip6q *new, struct ip6q *old)
|
|
{
|
|
|
|
IP6Q_LOCK_ASSERT();
|
|
|
|
new->ip6q_prev = old;
|
|
new->ip6q_next = old->ip6q_next;
|
|
old->ip6q_next->ip6q_prev= new;
|
|
old->ip6q_next = new;
|
|
}
|
|
|
|
void
|
|
frag6_remque(struct ip6q *p6)
|
|
{
|
|
|
|
IP6Q_LOCK_ASSERT();
|
|
|
|
p6->ip6q_prev->ip6q_next = p6->ip6q_next;
|
|
p6->ip6q_next->ip6q_prev = p6->ip6q_prev;
|
|
}
|
|
|
|
/*
|
|
* IPv6 reassembling timer processing;
|
|
* if a timer expires on a reassembly
|
|
* queue, discard it.
|
|
*/
|
|
void
|
|
frag6_slowtimo(void)
|
|
{
|
|
VNET_ITERATOR_DECL(vnet_iter);
|
|
struct ip6q *q6;
|
|
|
|
VNET_LIST_RLOCK_NOSLEEP();
|
|
IP6Q_LOCK();
|
|
VNET_FOREACH(vnet_iter) {
|
|
CURVNET_SET(vnet_iter);
|
|
q6 = V_ip6q.ip6q_next;
|
|
if (q6)
|
|
while (q6 != &V_ip6q) {
|
|
--q6->ip6q_ttl;
|
|
q6 = q6->ip6q_next;
|
|
if (q6->ip6q_prev->ip6q_ttl == 0) {
|
|
IP6STAT_INC(ip6s_fragtimeout);
|
|
/* XXX in6_ifstat_inc(ifp, ifs6_reass_fail) */
|
|
frag6_freef(q6->ip6q_prev);
|
|
}
|
|
}
|
|
/*
|
|
* If we are over the maximum number of fragments
|
|
* (due to the limit being lowered), drain off
|
|
* enough to get down to the new limit.
|
|
*/
|
|
while (V_frag6_nfragpackets > (u_int)V_ip6_maxfragpackets &&
|
|
V_ip6q.ip6q_prev) {
|
|
IP6STAT_INC(ip6s_fragoverflow);
|
|
/* XXX in6_ifstat_inc(ifp, ifs6_reass_fail) */
|
|
frag6_freef(V_ip6q.ip6q_prev);
|
|
}
|
|
CURVNET_RESTORE();
|
|
}
|
|
IP6Q_UNLOCK();
|
|
VNET_LIST_RUNLOCK_NOSLEEP();
|
|
}
|
|
|
|
/*
|
|
* Drain off all datagram fragments.
|
|
*/
|
|
void
|
|
frag6_drain(void)
|
|
{
|
|
VNET_ITERATOR_DECL(vnet_iter);
|
|
|
|
VNET_LIST_RLOCK_NOSLEEP();
|
|
if (IP6Q_TRYLOCK() == 0) {
|
|
VNET_LIST_RUNLOCK_NOSLEEP();
|
|
return;
|
|
}
|
|
VNET_FOREACH(vnet_iter) {
|
|
CURVNET_SET(vnet_iter);
|
|
while (V_ip6q.ip6q_next != &V_ip6q) {
|
|
IP6STAT_INC(ip6s_fragdropped);
|
|
/* XXX in6_ifstat_inc(ifp, ifs6_reass_fail) */
|
|
frag6_freef(V_ip6q.ip6q_next);
|
|
}
|
|
CURVNET_RESTORE();
|
|
}
|
|
IP6Q_UNLOCK();
|
|
VNET_LIST_RUNLOCK_NOSLEEP();
|
|
}
|