frag6.c revision 121355
162587Sitojun/* $FreeBSD: head/sys/netinet6/frag6.c 121355 2003-10-22 19:03:49Z ume $ */ 295023Ssuz/* $KAME: frag6.c,v 1.33 2002/01/07 11:34:48 kjc Exp $ */ 362587Sitojun 453541Sshin/* 553541Sshin * Copyright (C) 1995, 1996, 1997, and 1998 WIDE Project. 653541Sshin * All rights reserved. 753541Sshin * 853541Sshin * Redistribution and use in source and binary forms, with or without 953541Sshin * modification, are permitted provided that the following conditions 1053541Sshin * are met: 1153541Sshin * 1. Redistributions of source code must retain the above copyright 1253541Sshin * notice, this list of conditions and the following disclaimer. 1353541Sshin * 2. Redistributions in binary form must reproduce the above copyright 1453541Sshin * notice, this list of conditions and the following disclaimer in the 1553541Sshin * documentation and/or other materials provided with the distribution. 1653541Sshin * 3. Neither the name of the project nor the names of its contributors 1753541Sshin * may be used to endorse or promote products derived from this software 1853541Sshin * without specific prior written permission. 1953541Sshin * 2053541Sshin * THIS SOFTWARE IS PROVIDED BY THE PROJECT AND CONTRIBUTORS ``AS IS'' AND 2153541Sshin * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 2253541Sshin * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 2353541Sshin * ARE DISCLAIMED. IN NO EVENT SHALL THE PROJECT OR CONTRIBUTORS BE LIABLE 2453541Sshin * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 2553541Sshin * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 2653541Sshin * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 2753541Sshin * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 2853541Sshin * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 2953541Sshin * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 3053541Sshin * SUCH DAMAGE. 3153541Sshin */ 3253541Sshin 33120645Sume#include "opt_random_ip_id.h" 34120645Sume 3553541Sshin#include <sys/param.h> 3653541Sshin#include <sys/systm.h> 3753541Sshin#include <sys/malloc.h> 3853541Sshin#include <sys/mbuf.h> 3953541Sshin#include <sys/domain.h> 4053541Sshin#include <sys/protosw.h> 4153541Sshin#include <sys/socket.h> 4253541Sshin#include <sys/errno.h> 4353541Sshin#include <sys/time.h> 4453541Sshin#include <sys/kernel.h> 4553541Sshin#include <sys/syslog.h> 4653541Sshin 4753541Sshin#include <net/if.h> 4853541Sshin#include <net/route.h> 4953541Sshin 5053541Sshin#include <netinet/in.h> 5153541Sshin#include <netinet/in_var.h> 5262587Sitojun#include <netinet/ip6.h> 5353541Sshin#include <netinet6/ip6_var.h> 5462587Sitojun#include <netinet/icmp6.h> 5553541Sshin 5653541Sshin#include <net/net_osdep.h> 5753541Sshin 5853541Sshin/* 5953541Sshin * Define it to get a correct behavior on per-interface statistics. 6053541Sshin * You will need to perform an extra routing table lookup, per fragment, 6153541Sshin * to do it. This may, or may not be, a performance hit. 6253541Sshin */ 6362587Sitojun#define IN6_IFSTAT_STRICT 6453541Sshin 6562587Sitojunstatic void frag6_enq __P((struct ip6asfrag *, struct ip6asfrag *)); 6662587Sitojunstatic void frag6_deq __P((struct ip6asfrag *)); 6762587Sitojunstatic void frag6_insque __P((struct ip6q *, struct ip6q *)); 6862587Sitojunstatic void frag6_remque __P((struct ip6q *)); 6962587Sitojunstatic void frag6_freef __P((struct ip6q *)); 7053541Sshin 71121346Sumestatic struct mtx ip6qlock; 72121346Sume/* 73121346Sume * These fields all protected by ip6qlock. 74121346Sume */ 75121346Sumestatic u_int frag6_nfragpackets; 76121346Sumestatic u_int frag6_nfrags; 77121346Sumestatic struct ip6q ip6q; /* ip6 reassemble queue */ 7853541Sshin 79121346Sume#define IP6Q_LOCK_INIT() mtx_init(&ip6qlock, "ip6qlock", NULL, MTX_DEF); 80121346Sume#define IP6Q_LOCK() mtx_lock(&ip6qlock) 81121346Sume#define IP6Q_TRYLOCK() mtx_trylock(&ip6qlock) 82121355Sume#define IP6Q_LOCK_ASSERT() mtx_assert(&ip6qlock, MA_OWNED) 83121346Sume#define IP6Q_UNLOCK() mtx_unlock(&ip6qlock) 84121345Sume 8569774Sphkstatic MALLOC_DEFINE(M_FTABLE, "fragment", "fragment reassembly header"); 8662587Sitojun 8753541Sshin/* 8853541Sshin * Initialise reassembly queue and fragment identifier. 8953541Sshin */ 9053541Sshinvoid 9153541Sshinfrag6_init() 9253541Sshin{ 9353541Sshin 9477969Sjesper ip6_maxfragpackets = nmbclusters / 4; 95121345Sume ip6_maxfrags = nmbclusters / 4; 9677969Sjesper 97121346Sume IP6Q_LOCK_INIT(); 98121346Sume 99120645Sume#ifndef RANDOM_IP_ID 100120648Sume ip6_id = arc4random(); 101120643Sume#endif 10253541Sshin ip6q.ip6q_next = ip6q.ip6q_prev = &ip6q; 10353541Sshin} 10453541Sshin 10553541Sshin/* 10662587Sitojun * In RFC2460, fragment and reassembly rule do not agree with each other, 10762587Sitojun * in terms of next header field handling in fragment header. 10862587Sitojun * While the sender will use the same value for all of the fragmented packets, 10962587Sitojun * receiver is suggested not to check the consistency. 11062587Sitojun * 11162587Sitojun * fragment rule (p20): 11262587Sitojun * (2) A Fragment header containing: 11362587Sitojun * The Next Header value that identifies the first header of 11462587Sitojun * the Fragmentable Part of the original packet. 11562587Sitojun * -> next header field is same for all fragments 11662587Sitojun * 11762587Sitojun * reassembly rule (p21): 11862587Sitojun * The Next Header field of the last header of the Unfragmentable 11962587Sitojun * Part is obtained from the Next Header field of the first 12062587Sitojun * fragment's Fragment header. 12162587Sitojun * -> should grab it from the first fragment only 12262587Sitojun * 12362587Sitojun * The following note also contradicts with fragment rule - noone is going to 12462587Sitojun * send different fragment with different next header field. 12562587Sitojun * 12662587Sitojun * additional note (p22): 12762587Sitojun * The Next Header values in the Fragment headers of different 12862587Sitojun * fragments of the same original packet may differ. Only the value 12962587Sitojun * from the Offset zero fragment packet is used for reassembly. 13062587Sitojun * -> should grab it from the first fragment only 13162587Sitojun * 13262587Sitojun * There is no explicit reason given in the RFC. Historical reason maybe? 13362587Sitojun */ 13462587Sitojun/* 13553541Sshin * Fragment input 13653541Sshin */ 13753541Sshinint 13853541Sshinfrag6_input(mp, offp, proto) 13953541Sshin struct mbuf **mp; 14053541Sshin int *offp, proto; 14153541Sshin{ 14253541Sshin struct mbuf *m = *mp, *t; 14353541Sshin struct ip6_hdr *ip6; 14453541Sshin struct ip6_frag *ip6f; 14553541Sshin struct ip6q *q6; 14662587Sitojun struct ip6asfrag *af6, *ip6af, *af6dwn; 14753541Sshin int offset = *offp, nxt, i, next; 14853541Sshin int first_frag = 0; 14962587Sitojun int fragoff, frgpartlen; /* must be larger than u_int16_t */ 15053541Sshin struct ifnet *dstifp; 15153541Sshin#ifdef IN6_IFSTAT_STRICT 15253541Sshin static struct route_in6 ro; 15353541Sshin struct sockaddr_in6 *dst; 15453541Sshin#endif 15553541Sshin 15662587Sitojun ip6 = mtod(m, struct ip6_hdr *); 15762587Sitojun#ifndef PULLDOWN_TEST 15853541Sshin IP6_EXTHDR_CHECK(m, offset, sizeof(struct ip6_frag), IPPROTO_DONE); 15953541Sshin ip6f = (struct ip6_frag *)((caddr_t)ip6 + offset); 16062587Sitojun#else 16162587Sitojun IP6_EXTHDR_GET(ip6f, struct ip6_frag *, m, offset, sizeof(*ip6f)); 16262587Sitojun if (ip6f == NULL) 163120856Sume return (IPPROTO_DONE); 16462587Sitojun#endif 16553541Sshin 16653541Sshin dstifp = NULL; 16753541Sshin#ifdef IN6_IFSTAT_STRICT 16853541Sshin /* find the destination interface of the packet. */ 16953541Sshin dst = (struct sockaddr_in6 *)&ro.ro_dst; 17053541Sshin if (ro.ro_rt 17153541Sshin && ((ro.ro_rt->rt_flags & RTF_UP) == 0 17253541Sshin || !IN6_ARE_ADDR_EQUAL(&dst->sin6_addr, &ip6->ip6_dst))) { 17353541Sshin RTFREE(ro.ro_rt); 17453541Sshin ro.ro_rt = (struct rtentry *)0; 17553541Sshin } 17653541Sshin if (ro.ro_rt == NULL) { 17753541Sshin bzero(dst, sizeof(*dst)); 17853541Sshin dst->sin6_family = AF_INET6; 17953541Sshin dst->sin6_len = sizeof(struct sockaddr_in6); 18053541Sshin dst->sin6_addr = ip6->ip6_dst; 18153541Sshin } 18254350Sshin rtalloc((struct route *)&ro); 18353541Sshin if (ro.ro_rt != NULL && ro.ro_rt->rt_ifa != NULL) 18453541Sshin dstifp = ((struct in6_ifaddr *)ro.ro_rt->rt_ifa)->ia_ifp; 18553541Sshin#else 18653541Sshin /* we are violating the spec, this is not the destination interface */ 18753541Sshin if ((m->m_flags & M_PKTHDR) != 0) 18853541Sshin dstifp = m->m_pkthdr.rcvif; 18953541Sshin#endif 19053541Sshin 19153541Sshin /* jumbo payload can't contain a fragment header */ 19253541Sshin if (ip6->ip6_plen == 0) { 19353541Sshin icmp6_error(m, ICMP6_PARAM_PROB, ICMP6_PARAMPROB_HEADER, offset); 19453541Sshin in6_ifstat_inc(dstifp, ifs6_reass_fail); 19553541Sshin return IPPROTO_DONE; 19653541Sshin } 19753541Sshin 19853541Sshin /* 19953541Sshin * check whether fragment packet's fragment length is 20053541Sshin * multiple of 8 octets. 20153541Sshin * sizeof(struct ip6_frag) == 8 20253541Sshin * sizeof(struct ip6_hdr) = 40 20353541Sshin */ 20453541Sshin if ((ip6f->ip6f_offlg & IP6F_MORE_FRAG) && 20553541Sshin (((ntohs(ip6->ip6_plen) - offset) & 0x7) != 0)) { 206120891Sume icmp6_error(m, ICMP6_PARAM_PROB, ICMP6_PARAMPROB_HEADER, 207120891Sume offsetof(struct ip6_hdr, ip6_plen)); 20853541Sshin in6_ifstat_inc(dstifp, ifs6_reass_fail); 20953541Sshin return IPPROTO_DONE; 21053541Sshin } 21153541Sshin 21253541Sshin ip6stat.ip6s_fragments++; 21353541Sshin in6_ifstat_inc(dstifp, ifs6_reass_reqd); 214120891Sume 21562587Sitojun /* offset now points to data portion */ 21653541Sshin offset += sizeof(struct ip6_frag); 21753541Sshin 218121345Sume IP6Q_LOCK(); 21978064Sume 220121345Sume /* 221121345Sume * Enforce upper bound on number of fragments. 222121345Sume * If maxfrag is 0, never accept fragments. 223121345Sume * If maxfrag is -1, accept all fragments without limitation. 224121345Sume */ 225121345Sume if (ip6_maxfrags < 0) 226121345Sume ; 227121345Sume else if (frag6_nfrags >= (u_int)ip6_maxfrags) 228121345Sume goto dropfrag; 229121345Sume 23053541Sshin for (q6 = ip6q.ip6q_next; q6 != &ip6q; q6 = q6->ip6q_next) 23153541Sshin if (ip6f->ip6f_ident == q6->ip6q_ident && 23253541Sshin IN6_ARE_ADDR_EQUAL(&ip6->ip6_src, &q6->ip6q_src) && 23353541Sshin IN6_ARE_ADDR_EQUAL(&ip6->ip6_dst, &q6->ip6q_dst)) 23453541Sshin break; 23553541Sshin 23653541Sshin if (q6 == &ip6q) { 23753541Sshin /* 23853541Sshin * the first fragment to arrive, create a reassembly queue. 23953541Sshin */ 24053541Sshin first_frag = 1; 24153541Sshin 24253541Sshin /* 24353541Sshin * Enforce upper bound on number of fragmented packets 24453541Sshin * for which we attempt reassembly; 245121345Sume * If maxfragpackets is 0, never accept fragments. 246121345Sume * If maxfragpackets is -1, accept all fragments without 247121345Sume * limitation. 24853541Sshin */ 24978064Sume if (ip6_maxfragpackets < 0) 25078064Sume ; 25178064Sume else if (frag6_nfragpackets >= (u_int)ip6_maxfragpackets) 25278064Sume goto dropfrag; 25378064Sume frag6_nfragpackets++; 25453541Sshin q6 = (struct ip6q *)malloc(sizeof(struct ip6q), M_FTABLE, 255120891Sume M_DONTWAIT); 25653541Sshin if (q6 == NULL) 25753541Sshin goto dropfrag; 25862587Sitojun bzero(q6, sizeof(*q6)); 25953541Sshin 26053541Sshin frag6_insque(q6, &ip6q); 26153541Sshin 26262587Sitojun /* ip6q_nxt will be filled afterwards, from 1st fragment */ 26353541Sshin q6->ip6q_down = q6->ip6q_up = (struct ip6asfrag *)q6; 26462587Sitojun#ifdef notyet 26562587Sitojun q6->ip6q_nxtp = (u_char *)nxtp; 26662587Sitojun#endif 26753541Sshin q6->ip6q_ident = ip6f->ip6f_ident; 26853541Sshin q6->ip6q_arrive = 0; /* Is it used anywhere? */ 26953541Sshin q6->ip6q_ttl = IPV6_FRAGTTL; 27053541Sshin q6->ip6q_src = ip6->ip6_src; 27153541Sshin q6->ip6q_dst = ip6->ip6_dst; 27253541Sshin q6->ip6q_unfrglen = -1; /* The 1st fragment has not arrived. */ 273121345Sume 274121345Sume q6->ip6q_nfrag = 0; 27553541Sshin } 27653541Sshin 27753541Sshin /* 27853541Sshin * If it's the 1st fragment, record the length of the 27953541Sshin * unfragmentable part and the next header of the fragment header. 28053541Sshin */ 28153541Sshin fragoff = ntohs(ip6f->ip6f_offlg & IP6F_OFF_MASK); 28253541Sshin if (fragoff == 0) { 283120891Sume q6->ip6q_unfrglen = offset - sizeof(struct ip6_hdr) - 284120891Sume sizeof(struct ip6_frag); 28553541Sshin q6->ip6q_nxt = ip6f->ip6f_nxt; 28653541Sshin } 28753541Sshin 28853541Sshin /* 28953541Sshin * Check that the reassembled packet would not exceed 65535 bytes 29053541Sshin * in size. 29153541Sshin * If it would exceed, discard the fragment and return an ICMP error. 29253541Sshin */ 29362587Sitojun frgpartlen = sizeof(struct ip6_hdr) + ntohs(ip6->ip6_plen) - offset; 29453541Sshin if (q6->ip6q_unfrglen >= 0) { 29553541Sshin /* The 1st fragment has already arrived. */ 29653541Sshin if (q6->ip6q_unfrglen + fragoff + frgpartlen > IPV6_MAXPACKET) { 29753541Sshin icmp6_error(m, ICMP6_PARAM_PROB, ICMP6_PARAMPROB_HEADER, 298120891Sume offset - sizeof(struct ip6_frag) + 299120891Sume offsetof(struct ip6_frag, ip6f_offlg)); 300121345Sume IP6Q_UNLOCK(); 301120856Sume return (IPPROTO_DONE); 30253541Sshin } 303120891Sume } else if (fragoff + frgpartlen > IPV6_MAXPACKET) { 30453541Sshin icmp6_error(m, ICMP6_PARAM_PROB, ICMP6_PARAMPROB_HEADER, 305120891Sume offset - sizeof(struct ip6_frag) + 306120891Sume offsetof(struct ip6_frag, ip6f_offlg)); 307121345Sume IP6Q_UNLOCK(); 308120856Sume return (IPPROTO_DONE); 30953541Sshin } 31053541Sshin /* 31153541Sshin * If it's the first fragment, do the above check for each 31253541Sshin * fragment already stored in the reassembly queue. 31353541Sshin */ 31453541Sshin if (fragoff == 0) { 31553541Sshin for (af6 = q6->ip6q_down; af6 != (struct ip6asfrag *)q6; 31653541Sshin af6 = af6dwn) { 31753541Sshin af6dwn = af6->ip6af_down; 31853541Sshin 31953541Sshin if (q6->ip6q_unfrglen + af6->ip6af_off + af6->ip6af_frglen > 32053541Sshin IPV6_MAXPACKET) { 32153541Sshin struct mbuf *merr = IP6_REASS_MBUF(af6); 32253541Sshin struct ip6_hdr *ip6err; 32353541Sshin int erroff = af6->ip6af_offset; 32453541Sshin 32553541Sshin /* dequeue the fragment. */ 32653541Sshin frag6_deq(af6); 32762587Sitojun free(af6, M_FTABLE); 32853541Sshin 32953541Sshin /* adjust pointer. */ 33053541Sshin ip6err = mtod(merr, struct ip6_hdr *); 33153541Sshin 33253541Sshin /* 33353541Sshin * Restore source and destination addresses 33453541Sshin * in the erroneous IPv6 header. 33553541Sshin */ 33653541Sshin ip6err->ip6_src = q6->ip6q_src; 33753541Sshin ip6err->ip6_dst = q6->ip6q_dst; 33853541Sshin 33953541Sshin icmp6_error(merr, ICMP6_PARAM_PROB, 340120891Sume ICMP6_PARAMPROB_HEADER, 341120891Sume erroff - sizeof(struct ip6_frag) + 342120891Sume offsetof(struct ip6_frag, ip6f_offlg)); 34353541Sshin } 34453541Sshin } 34553541Sshin } 34653541Sshin 34762587Sitojun ip6af = (struct ip6asfrag *)malloc(sizeof(struct ip6asfrag), M_FTABLE, 348111119Simp M_DONTWAIT); 34962587Sitojun if (ip6af == NULL) 35062587Sitojun goto dropfrag; 35162587Sitojun bzero(ip6af, sizeof(*ip6af)); 35262587Sitojun ip6af->ip6af_head = ip6->ip6_flow; 35362587Sitojun ip6af->ip6af_len = ip6->ip6_plen; 35462587Sitojun ip6af->ip6af_nxt = ip6->ip6_nxt; 35562587Sitojun ip6af->ip6af_hlim = ip6->ip6_hlim; 35653541Sshin ip6af->ip6af_mff = ip6f->ip6f_offlg & IP6F_MORE_FRAG; 35753541Sshin ip6af->ip6af_off = fragoff; 35853541Sshin ip6af->ip6af_frglen = frgpartlen; 35953541Sshin ip6af->ip6af_offset = offset; 36053541Sshin IP6_REASS_MBUF(ip6af) = m; 36153541Sshin 36253541Sshin if (first_frag) { 36353541Sshin af6 = (struct ip6asfrag *)q6; 36453541Sshin goto insert; 36553541Sshin } 36653541Sshin 36753541Sshin /* 36853541Sshin * Find a segment which begins after this one does. 36953541Sshin */ 37053541Sshin for (af6 = q6->ip6q_down; af6 != (struct ip6asfrag *)q6; 37153541Sshin af6 = af6->ip6af_down) 37253541Sshin if (af6->ip6af_off > ip6af->ip6af_off) 37353541Sshin break; 37453541Sshin 37562587Sitojun#if 0 37653541Sshin /* 37762587Sitojun * If there is a preceding segment, it may provide some of 37862587Sitojun * our data already. If so, drop the data from the incoming 37962587Sitojun * segment. If it provides all of our data, drop us. 38062587Sitojun */ 38162587Sitojun if (af6->ip6af_up != (struct ip6asfrag *)q6) { 38262587Sitojun i = af6->ip6af_up->ip6af_off + af6->ip6af_up->ip6af_frglen 38362587Sitojun - ip6af->ip6af_off; 38462587Sitojun if (i > 0) { 38562587Sitojun if (i >= ip6af->ip6af_frglen) 38662587Sitojun goto dropfrag; 38762587Sitojun m_adj(IP6_REASS_MBUF(ip6af), i); 38862587Sitojun ip6af->ip6af_off += i; 38962587Sitojun ip6af->ip6af_frglen -= i; 39062587Sitojun } 39162587Sitojun } 39262587Sitojun 39362587Sitojun /* 39462587Sitojun * While we overlap succeeding segments trim them or, 39562587Sitojun * if they are completely covered, dequeue them. 39662587Sitojun */ 39762587Sitojun while (af6 != (struct ip6asfrag *)q6 && 39862587Sitojun ip6af->ip6af_off + ip6af->ip6af_frglen > af6->ip6af_off) { 39962587Sitojun i = (ip6af->ip6af_off + ip6af->ip6af_frglen) - af6->ip6af_off; 40062587Sitojun if (i < af6->ip6af_frglen) { 40162587Sitojun af6->ip6af_frglen -= i; 40262587Sitojun af6->ip6af_off += i; 40362587Sitojun m_adj(IP6_REASS_MBUF(af6), i); 40462587Sitojun break; 40562587Sitojun } 40662587Sitojun af6 = af6->ip6af_down; 40762587Sitojun m_freem(IP6_REASS_MBUF(af6->ip6af_up)); 40862587Sitojun frag6_deq(af6->ip6af_up); 40962587Sitojun } 41062587Sitojun#else 41162587Sitojun /* 41253541Sshin * If the incoming framgent overlaps some existing fragments in 41353541Sshin * the reassembly queue, drop it, since it is dangerous to override 41453541Sshin * existing fragments from a security point of view. 415121345Sume * We don't know which fragment is the bad guy - here we trust 416121345Sume * fragment that came in earlier, with no real reason. 41753541Sshin */ 41853541Sshin if (af6->ip6af_up != (struct ip6asfrag *)q6) { 41953541Sshin i = af6->ip6af_up->ip6af_off + af6->ip6af_up->ip6af_frglen 42053541Sshin - ip6af->ip6af_off; 42153541Sshin if (i > 0) { 42276899Ssumikawa#if 0 /* suppress the noisy log */ 42353541Sshin log(LOG_ERR, "%d bytes of a fragment from %s " 42453541Sshin "overlaps the previous fragment\n", 42553541Sshin i, ip6_sprintf(&q6->ip6q_src)); 42676899Ssumikawa#endif 42776899Ssumikawa free(ip6af, M_FTABLE); 42853541Sshin goto dropfrag; 42953541Sshin } 43053541Sshin } 43153541Sshin if (af6 != (struct ip6asfrag *)q6) { 43253541Sshin i = (ip6af->ip6af_off + ip6af->ip6af_frglen) - af6->ip6af_off; 43353541Sshin if (i > 0) { 43476899Ssumikawa#if 0 /* suppress the noisy log */ 43553541Sshin log(LOG_ERR, "%d bytes of a fragment from %s " 43653541Sshin "overlaps the succeeding fragment", 43753541Sshin i, ip6_sprintf(&q6->ip6q_src)); 43876899Ssumikawa#endif 43976899Ssumikawa free(ip6af, M_FTABLE); 44053541Sshin goto dropfrag; 44153541Sshin } 44253541Sshin } 44362587Sitojun#endif 44453541Sshin 44553541Sshininsert: 44653541Sshin 44753541Sshin /* 44853541Sshin * Stick new segment in its place; 44953541Sshin * check for complete reassembly. 45053541Sshin * Move to front of packet queue, as we are 45153541Sshin * the most recently active fragmented packet. 45253541Sshin */ 45353541Sshin frag6_enq(ip6af, af6->ip6af_up); 454121345Sume frag6_nfrags++; 455121345Sume q6->ip6q_nfrag++; 45662587Sitojun#if 0 /* xxx */ 45762587Sitojun if (q6 != ip6q.ip6q_next) { 45862587Sitojun frag6_remque(q6); 45962587Sitojun frag6_insque(q6, &ip6q); 46062587Sitojun } 46162587Sitojun#endif 46253541Sshin next = 0; 46353541Sshin for (af6 = q6->ip6q_down; af6 != (struct ip6asfrag *)q6; 46453541Sshin af6 = af6->ip6af_down) { 46553541Sshin if (af6->ip6af_off != next) { 466121345Sume IP6Q_UNLOCK(); 46753541Sshin return IPPROTO_DONE; 46853541Sshin } 46953541Sshin next += af6->ip6af_frglen; 47053541Sshin } 47153541Sshin if (af6->ip6af_up->ip6af_mff) { 472121345Sume IP6Q_UNLOCK(); 47353541Sshin return IPPROTO_DONE; 47453541Sshin } 47553541Sshin 47653541Sshin /* 47753541Sshin * Reassembly is complete; concatenate fragments. 47853541Sshin */ 47953541Sshin ip6af = q6->ip6q_down; 48053541Sshin t = m = IP6_REASS_MBUF(ip6af); 48153541Sshin af6 = ip6af->ip6af_down; 48262587Sitojun frag6_deq(ip6af); 48353541Sshin while (af6 != (struct ip6asfrag *)q6) { 48462587Sitojun af6dwn = af6->ip6af_down; 48562587Sitojun frag6_deq(af6); 48653541Sshin while (t->m_next) 48753541Sshin t = t->m_next; 48853541Sshin t->m_next = IP6_REASS_MBUF(af6); 48962587Sitojun m_adj(t->m_next, af6->ip6af_offset); 49062587Sitojun free(af6, M_FTABLE); 49162587Sitojun af6 = af6dwn; 49253541Sshin } 49353541Sshin 49453541Sshin /* adjust offset to point where the original next header starts */ 49553541Sshin offset = ip6af->ip6af_offset - sizeof(struct ip6_frag); 49662587Sitojun free(ip6af, M_FTABLE); 49762587Sitojun ip6 = mtod(m, struct ip6_hdr *); 49853541Sshin ip6->ip6_plen = htons((u_short)next + offset - sizeof(struct ip6_hdr)); 49953541Sshin ip6->ip6_src = q6->ip6q_src; 50053541Sshin ip6->ip6_dst = q6->ip6q_dst; 50153541Sshin nxt = q6->ip6q_nxt; 50262587Sitojun#ifdef notyet 50362587Sitojun *q6->ip6q_nxtp = (u_char)(nxt & 0xff); 50462587Sitojun#endif 50553541Sshin 50653541Sshin /* 50753541Sshin * Delete frag6 header with as a few cost as possible. 50853541Sshin */ 50962587Sitojun if (offset < m->m_len) { 51053541Sshin ovbcopy((caddr_t)ip6, (caddr_t)ip6 + sizeof(struct ip6_frag), 51153541Sshin offset); 51262587Sitojun m->m_data += sizeof(struct ip6_frag); 51362587Sitojun m->m_len -= sizeof(struct ip6_frag); 51462587Sitojun } else { 51562587Sitojun /* this comes with no copy if the boundary is on cluster */ 516111119Simp if ((t = m_split(m, offset, M_DONTWAIT)) == NULL) { 51762587Sitojun frag6_remque(q6); 518121345Sume frag6_nfrags -= q6->ip6q_nfrag; 51962587Sitojun free(q6, M_FTABLE); 52062587Sitojun frag6_nfragpackets--; 52162587Sitojun goto dropfrag; 52262587Sitojun } 52362587Sitojun m_adj(t, sizeof(struct ip6_frag)); 52462587Sitojun m_cat(m, t); 52553541Sshin } 52653541Sshin 52753541Sshin /* 52853541Sshin * Store NXT to the original. 52953541Sshin */ 53053541Sshin { 53153541Sshin char *prvnxtp = ip6_get_prevhdr(m, offset); /* XXX */ 53253541Sshin *prvnxtp = nxt; 53353541Sshin } 53453541Sshin 53553541Sshin frag6_remque(q6); 536121345Sume frag6_nfrags -= q6->ip6q_nfrag; 53753541Sshin free(q6, M_FTABLE); 53853541Sshin frag6_nfragpackets--; 53953541Sshin 54053541Sshin if (m->m_flags & M_PKTHDR) { /* Isn't it always true? */ 54153541Sshin int plen = 0; 54253541Sshin for (t = m; t; t = t->m_next) 54353541Sshin plen += t->m_len; 54453541Sshin m->m_pkthdr.len = plen; 54553541Sshin } 546120891Sume 54753541Sshin ip6stat.ip6s_reassembled++; 54853541Sshin in6_ifstat_inc(dstifp, ifs6_reass_ok); 54953541Sshin 55053541Sshin /* 55153541Sshin * Tell launch routine the next header 55253541Sshin */ 55353541Sshin 55453541Sshin *mp = m; 55553541Sshin *offp = offset; 55653541Sshin 557121345Sume IP6Q_UNLOCK(); 55853541Sshin return nxt; 55953541Sshin 56053541Sshin dropfrag: 561121346Sume IP6Q_UNLOCK(); 56253541Sshin in6_ifstat_inc(dstifp, ifs6_reass_fail); 56353541Sshin ip6stat.ip6s_fragdropped++; 56453541Sshin m_freem(m); 56553541Sshin return IPPROTO_DONE; 56653541Sshin} 56753541Sshin 56853541Sshin/* 56953541Sshin * Free a fragment reassembly header and all 57053541Sshin * associated datagrams. 57153541Sshin */ 57253541Sshinvoid 57353541Sshinfrag6_freef(q6) 57453541Sshin struct ip6q *q6; 57553541Sshin{ 57653541Sshin struct ip6asfrag *af6, *down6; 57753541Sshin 578121355Sume IP6Q_LOCK_ASSERT(); 579121345Sume 58053541Sshin for (af6 = q6->ip6q_down; af6 != (struct ip6asfrag *)q6; 58153541Sshin af6 = down6) { 58253541Sshin struct mbuf *m = IP6_REASS_MBUF(af6); 58353541Sshin 58453541Sshin down6 = af6->ip6af_down; 58553541Sshin frag6_deq(af6); 58653541Sshin 58753541Sshin /* 58853541Sshin * Return ICMP time exceeded error for the 1st fragment. 58953541Sshin * Just free other fragments. 59053541Sshin */ 59153541Sshin if (af6->ip6af_off == 0) { 59253541Sshin struct ip6_hdr *ip6; 59353541Sshin 59453541Sshin /* adjust pointer */ 59553541Sshin ip6 = mtod(m, struct ip6_hdr *); 59653541Sshin 597120891Sume /* restore source and destination addresses */ 59853541Sshin ip6->ip6_src = q6->ip6q_src; 59953541Sshin ip6->ip6_dst = q6->ip6q_dst; 60053541Sshin 60153541Sshin icmp6_error(m, ICMP6_TIME_EXCEEDED, 60253541Sshin ICMP6_TIME_EXCEED_REASSEMBLY, 0); 60362587Sitojun } else 60453541Sshin m_freem(m); 60562587Sitojun free(af6, M_FTABLE); 60653541Sshin } 60753541Sshin frag6_remque(q6); 608121345Sume frag6_nfrags -= q6->ip6q_nfrag; 60953541Sshin free(q6, M_FTABLE); 61053541Sshin frag6_nfragpackets--; 61153541Sshin} 61253541Sshin 61353541Sshin/* 61453541Sshin * Put an ip fragment on a reassembly chain. 61553541Sshin * Like insque, but pointers in middle of structure. 61653541Sshin */ 61753541Sshinvoid 61853541Sshinfrag6_enq(af6, up6) 61953541Sshin struct ip6asfrag *af6, *up6; 62053541Sshin{ 621121345Sume 622121355Sume IP6Q_LOCK_ASSERT(); 623121345Sume 62453541Sshin af6->ip6af_up = up6; 62553541Sshin af6->ip6af_down = up6->ip6af_down; 62653541Sshin up6->ip6af_down->ip6af_up = af6; 62753541Sshin up6->ip6af_down = af6; 62853541Sshin} 62953541Sshin 63053541Sshin/* 63153541Sshin * To frag6_enq as remque is to insque. 63253541Sshin */ 63353541Sshinvoid 63453541Sshinfrag6_deq(af6) 63553541Sshin struct ip6asfrag *af6; 63653541Sshin{ 637121345Sume 638121355Sume IP6Q_LOCK_ASSERT(); 639121345Sume 64053541Sshin af6->ip6af_up->ip6af_down = af6->ip6af_down; 64153541Sshin af6->ip6af_down->ip6af_up = af6->ip6af_up; 64253541Sshin} 64353541Sshin 64453541Sshinvoid 64553541Sshinfrag6_insque(new, old) 64653541Sshin struct ip6q *new, *old; 64753541Sshin{ 648121345Sume 649121355Sume IP6Q_LOCK_ASSERT(); 650121345Sume 65153541Sshin new->ip6q_prev = old; 65253541Sshin new->ip6q_next = old->ip6q_next; 65353541Sshin old->ip6q_next->ip6q_prev= new; 65453541Sshin old->ip6q_next = new; 65553541Sshin} 65653541Sshin 65753541Sshinvoid 65853541Sshinfrag6_remque(p6) 65953541Sshin struct ip6q *p6; 66053541Sshin{ 661121345Sume 662121355Sume IP6Q_LOCK_ASSERT(); 663121345Sume 66453541Sshin p6->ip6q_prev->ip6q_next = p6->ip6q_next; 66553541Sshin p6->ip6q_next->ip6q_prev = p6->ip6q_prev; 66653541Sshin} 66753541Sshin 66853541Sshin/* 66978064Sume * IPv6 reassembling timer processing; 67053541Sshin * if a timer expires on a reassembly 67153541Sshin * queue, discard it. 67253541Sshin */ 67353541Sshinvoid 67453541Sshinfrag6_slowtimo() 67553541Sshin{ 67653541Sshin struct ip6q *q6; 67753541Sshin int s = splnet(); 67853541Sshin 679121345Sume IP6Q_LOCK(); 68053541Sshin q6 = ip6q.ip6q_next; 68153541Sshin if (q6) 68253541Sshin while (q6 != &ip6q) { 68353541Sshin --q6->ip6q_ttl; 68453541Sshin q6 = q6->ip6q_next; 68553541Sshin if (q6->ip6q_prev->ip6q_ttl == 0) { 68653541Sshin ip6stat.ip6s_fragtimeout++; 68753541Sshin /* XXX in6_ifstat_inc(ifp, ifs6_reass_fail) */ 68853541Sshin frag6_freef(q6->ip6q_prev); 68953541Sshin } 69053541Sshin } 69153541Sshin /* 69253541Sshin * If we are over the maximum number of fragments 69353541Sshin * (due to the limit being lowered), drain off 69453541Sshin * enough to get down to the new limit. 69553541Sshin */ 69678064Sume while (frag6_nfragpackets > (u_int)ip6_maxfragpackets && 69778064Sume ip6q.ip6q_prev) { 69853541Sshin ip6stat.ip6s_fragoverflow++; 69953541Sshin /* XXX in6_ifstat_inc(ifp, ifs6_reass_fail) */ 70053541Sshin frag6_freef(ip6q.ip6q_prev); 70153541Sshin } 702121345Sume IP6Q_UNLOCK(); 70362587Sitojun 70462587Sitojun#if 0 70562587Sitojun /* 70662587Sitojun * Routing changes might produce a better route than we last used; 70762587Sitojun * make sure we notice eventually, even if forwarding only for one 70862587Sitojun * destination and the cache is never replaced. 70962587Sitojun */ 71062587Sitojun if (ip6_forward_rt.ro_rt) { 71162587Sitojun RTFREE(ip6_forward_rt.ro_rt); 71262587Sitojun ip6_forward_rt.ro_rt = 0; 71362587Sitojun } 71462587Sitojun if (ipsrcchk_rt.ro_rt) { 71562587Sitojun RTFREE(ipsrcchk_rt.ro_rt); 71662587Sitojun ipsrcchk_rt.ro_rt = 0; 71762587Sitojun } 71862587Sitojun#endif 71962587Sitojun 72053541Sshin splx(s); 72153541Sshin} 72253541Sshin 72353541Sshin/* 72453541Sshin * Drain off all datagram fragments. 72553541Sshin */ 72653541Sshinvoid 72753541Sshinfrag6_drain() 72853541Sshin{ 729121345Sume 730121346Sume if (IP6Q_TRYLOCK() == 0) 73153541Sshin return; 73253541Sshin while (ip6q.ip6q_next != &ip6q) { 73353541Sshin ip6stat.ip6s_fragdropped++; 73453541Sshin /* XXX in6_ifstat_inc(ifp, ifs6_reass_fail) */ 73553541Sshin frag6_freef(ip6q.ip6q_next); 73653541Sshin } 737121345Sume IP6Q_UNLOCK(); 73853541Sshin} 739