2 * Copyright (c) 1982, 1986, 1988, 1993
3 * The Regents of the University of California. All rights reserved.
5 * Redistribution and use in source and binary forms, with or without
6 * modification, are permitted provided that the following conditions
8 * 1. Redistributions of source code must retain the above copyright
9 * notice, this list of conditions and the following disclaimer.
10 * 2. Redistributions in binary form must reproduce the above copyright
11 * notice, this list of conditions and the following disclaimer in the
12 * documentation and/or other materials provided with the distribution.
13 * 4. Neither the name of the University nor the names of its contributors
14 * may be used to endorse or promote products derived from this software
15 * without specific prior written permission.
17 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
18 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
19 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
20 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
21 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
22 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
23 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
24 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
25 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
26 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
29 * @(#)ip_input.c 8.2 (Berkeley) 1/4/94
32 #include <sys/cdefs.h>
33 __FBSDID("$FreeBSD$");
35 #include "opt_bootp.h"
37 #include "opt_ipstealth.h"
38 #include "opt_ipsec.h"
42 #include <sys/param.h>
43 #include <sys/systm.h>
44 #include <sys/callout.h>
46 #include <sys/malloc.h>
47 #include <sys/domain.h>
48 #include <sys/protosw.h>
49 #include <sys/socket.h>
51 #include <sys/kernel.h>
52 #include <sys/syslog.h>
53 #include <sys/sysctl.h>
54 #include <sys/vimage.h>
58 #include <net/if_types.h>
59 #include <net/if_var.h>
60 #include <net/if_dl.h>
61 #include <net/route.h>
62 #include <net/netisr.h>
65 #include <netinet/in.h>
66 #include <netinet/in_systm.h>
67 #include <netinet/in_var.h>
68 #include <netinet/ip.h>
69 #include <netinet/in_pcb.h>
70 #include <netinet/ip_var.h>
71 #include <netinet/ip_icmp.h>
72 #include <netinet/ip_options.h>
73 #include <machine/in_cksum.h>
74 #include <netinet/vinet.h>
76 #include <netinet/ip_carp.h>
79 #include <netinet/ip_ipsec.h>
82 #include <sys/socketvar.h>
84 /* XXX: Temporary until ipfw_ether and ipfw_bridge are converted. */
85 #include <netinet/ip_fw.h>
86 #include <netinet/ip_dummynet.h>
88 #include <security/mac/mac_framework.h>
91 CTASSERT(sizeof(struct ip) == 20);
95 static int ipsendredirects;
96 static int ip_checkinterface;
97 static int ip_keepfaith;
98 static int ip_sendsourcequench;
102 struct in_ifaddrhead in_ifaddrhead; /* first inet address */
103 struct in_ifaddrhashhead *in_ifaddrhashtbl; /* inet addr hash table */
104 u_long in_ifaddrhmask; /* mask for hash table */
105 struct ipstat ipstat;
106 static int ip_rsvp_on;
107 struct socket *ip_rsvpd;
109 static struct ipqhead ipq[IPREASS_NHASH];
110 static int maxnipq; /* Administrative limit on # reass queues. */
111 static int maxfragsperpacket;
113 static int nipq; /* Total # of reass queues */
116 SYSCTL_V_INT(V_NET, vnet_inet, _net_inet_ip, IPCTL_FORWARDING,
117 forwarding, CTLFLAG_RW, ipforwarding, 0,
118 "Enable IP forwarding between interfaces");
120 SYSCTL_V_INT(V_NET, vnet_inet, _net_inet_ip, IPCTL_SENDREDIRECTS,
121 redirect, CTLFLAG_RW, ipsendredirects, 0,
122 "Enable sending IP redirects");
124 SYSCTL_V_INT(V_NET, vnet_inet, _net_inet_ip, IPCTL_DEFTTL,
125 ttl, CTLFLAG_RW, ip_defttl, 0, "Maximum TTL on IP packets");
127 SYSCTL_V_INT(V_NET, vnet_inet, _net_inet_ip, IPCTL_KEEPFAITH,
128 keepfaith, CTLFLAG_RW, ip_keepfaith, 0,
129 "Enable packet capture for FAITH IPv4->IPv6 translater daemon");
131 SYSCTL_V_INT(V_NET, vnet_inet, _net_inet_ip, OID_AUTO,
132 sendsourcequench, CTLFLAG_RW, ip_sendsourcequench, 0,
133 "Enable the transmission of source quench packets");
135 SYSCTL_V_INT(V_NET, vnet_inet, _net_inet_ip, OID_AUTO, random_id,
136 CTLFLAG_RW, ip_do_randomid, 0, "Assign random ip_id values");
139 * XXX - Setting ip_checkinterface mostly implements the receive side of
140 * the Strong ES model described in RFC 1122, but since the routing table
141 * and transmit implementation do not implement the Strong ES model,
142 * setting this to 1 results in an odd hybrid.
144 * XXX - ip_checkinterface currently must be disabled if you use ipnat
145 * to translate the destination address to another local interface.
147 * XXX - ip_checkinterface must be disabled if you add IP aliases
148 * to the loopback interface instead of the interface where the
149 * packets for those addresses are received.
151 SYSCTL_V_INT(V_NET, vnet_inet, _net_inet_ip, OID_AUTO,
152 check_interface, CTLFLAG_RW, ip_checkinterface, 0,
153 "Verify packet arrives on correct interface");
155 struct pfil_head inet_pfil_hook; /* Packet filter hooks */
157 static struct ifqueue ipintrq;
158 static int ipqmaxlen = IFQ_MAXLEN;
160 extern struct domain inetdomain;
161 extern struct protosw inetsw[];
162 u_char ip_protox[IPPROTO_MAX];
164 SYSCTL_INT(_net_inet_ip, IPCTL_INTRQMAXLEN, intr_queue_maxlen, CTLFLAG_RW,
165 &ipintrq.ifq_maxlen, 0, "Maximum size of the IP input queue");
166 SYSCTL_INT(_net_inet_ip, IPCTL_INTRQDROPS, intr_queue_drops, CTLFLAG_RD,
167 &ipintrq.ifq_drops, 0,
168 "Number of packets dropped from the IP input queue");
170 SYSCTL_V_STRUCT(V_NET, vnet_inet, _net_inet_ip, IPCTL_STATS, stats, CTLFLAG_RW,
171 ipstat, ipstat, "IP statistics (struct ipstat, netinet/ip_var.h)");
173 static uma_zone_t ipq_zone;
174 static struct mtx ipqlock;
176 #define IPQ_LOCK() mtx_lock(&ipqlock)
177 #define IPQ_UNLOCK() mtx_unlock(&ipqlock)
178 #define IPQ_LOCK_INIT() mtx_init(&ipqlock, "ipqlock", NULL, MTX_DEF)
179 #define IPQ_LOCK_ASSERT() mtx_assert(&ipqlock, MA_OWNED)
181 static void maxnipq_update(void);
182 static void ipq_zone_change(void *);
184 SYSCTL_V_INT(V_NET, vnet_inet, _net_inet_ip, OID_AUTO, fragpackets,
186 "Current number of IPv4 fragment reassembly queue entries");
188 SYSCTL_V_INT(V_NET, vnet_inet, _net_inet_ip, OID_AUTO, maxfragsperpacket,
189 CTLFLAG_RW, maxfragsperpacket, 0,
190 "Maximum number of IPv4 fragments allowed per packet");
192 struct callout ipport_tick_callout;
195 SYSCTL_INT(_net_inet_ip, IPCTL_DEFMTU, mtu, CTLFLAG_RW,
196 &ip_mtu, 0, "Default MTU");
200 SYSCTL_V_INT(V_NET, vnet_inet, _net_inet_ip, OID_AUTO, stealth, CTLFLAG_RW,
201 ipstealth, 0, "IP stealth mode, no TTL decrementation on forwarding");
205 * ipfw_ether and ipfw_bridge hooks.
206 * XXX: Temporary until those are converted to pfil_hooks as well.
208 ip_fw_chk_t *ip_fw_chk_ptr = NULL;
209 ip_dn_io_t *ip_dn_io_ptr = NULL;
212 static void ip_freef(struct ipqhead *, struct ipq *);
215 * IP initialization: fill in IP protocol switch table.
216 * All protocols not implemented in kernel go to raw IP protocol handler.
221 INIT_VNET_INET(curvnet);
225 V_ipsendredirects = 1; /* XXX */
226 V_ip_checkinterface = 0;
228 V_ip_sendsourcequench = 0;
230 V_ip_defttl = IPDEFTTL;
231 V_ip_do_randomid = 0;
234 V_nipq = 0; /* Total # of reass queues */
236 V_ipport_lowfirstauto = IPPORT_RESERVED - 1; /* 1023 */
237 V_ipport_lowlastauto = IPPORT_RESERVEDSTART; /* 600 */
238 V_ipport_firstauto = IPPORT_EPHEMERALFIRST; /* 10000 */
239 V_ipport_lastauto = IPPORT_EPHEMERALLAST; /* 65535 */
240 V_ipport_hifirstauto = IPPORT_HIFIRSTAUTO; /* 49152 */
241 V_ipport_hilastauto = IPPORT_HILASTAUTO; /* 65535 */
242 V_ipport_reservedhigh = IPPORT_RESERVED - 1; /* 1023 */
243 V_ipport_reservedlow = 0;
244 V_ipport_randomized = 1; /* user controlled via sysctl */
245 V_ipport_randomcps = 10; /* user controlled via sysctl */
246 V_ipport_randomtime = 45; /* user controlled via sysctl */
247 V_ipport_stoprandom = 0; /* toggled by ipport_tick */
250 /* XXX global static but not instantiated in this file */
251 V_ipfastforward_active = 0;
252 V_subnetsarelocal = 0;
253 V_sameprefixcarponly = 0;
256 TAILQ_INIT(&V_in_ifaddrhead);
257 V_in_ifaddrhashtbl = hashinit(INADDR_NHASH, M_IFADDR, &V_in_ifaddrhmask);
258 pr = pffindproto(PF_INET, IPPROTO_RAW, SOCK_RAW);
260 panic("ip_init: PF_INET not found");
262 /* Initialize the entire ip_protox[] array to IPPROTO_RAW. */
263 for (i = 0; i < IPPROTO_MAX; i++)
264 ip_protox[i] = pr - inetsw;
266 * Cycle through IP protocols and put them into the appropriate place
269 for (pr = inetdomain.dom_protosw;
270 pr < inetdomain.dom_protoswNPROTOSW; pr++)
271 if (pr->pr_domain->dom_family == PF_INET &&
272 pr->pr_protocol && pr->pr_protocol != IPPROTO_RAW) {
273 /* Be careful to only index valid IP protocols. */
274 if (pr->pr_protocol < IPPROTO_MAX)
275 ip_protox[pr->pr_protocol] = pr - inetsw;
278 /* Initialize packet filter hooks. */
279 inet_pfil_hook.ph_type = PFIL_TYPE_AF;
280 inet_pfil_hook.ph_af = AF_INET;
281 if ((i = pfil_head_register(&inet_pfil_hook)) != 0)
282 printf("%s: WARNING: unable to register pfil hook, "
283 "error %d\n", __func__, i);
285 /* Initialize IP reassembly queue. */
287 for (i = 0; i < IPREASS_NHASH; i++)
288 TAILQ_INIT(&V_ipq[i]);
289 V_maxnipq = nmbclusters / 32;
290 V_maxfragsperpacket = 16;
291 V_ipq_zone = uma_zcreate("ipq", sizeof(struct ipq), NULL, NULL, NULL,
292 NULL, UMA_ALIGN_PTR, 0);
295 /* Start ipport_tick. */
296 callout_init(&ipport_tick_callout, CALLOUT_MPSAFE);
298 EVENTHANDLER_REGISTER(shutdown_pre_sync, ip_fini, NULL,
299 SHUTDOWN_PRI_DEFAULT);
300 EVENTHANDLER_REGISTER(nmbclusters_change, ipq_zone_change,
301 NULL, EVENTHANDLER_PRI_ANY);
303 /* Initialize various other remaining things. */
304 V_ip_id = time_second & 0xffff;
305 ipintrq.ifq_maxlen = ipqmaxlen;
306 mtx_init(&ipintrq.ifq_mtx, "ip_inq", NULL, MTX_DEF);
307 netisr_register(NETISR_IP, ip_input, &ipintrq, 0);
314 callout_stop(&ipport_tick_callout);
318 * Ip input routine. Checksum and byte swap header. If fragmented
319 * try to reassemble. Process options. Pass to next level.
322 ip_input(struct mbuf *m)
324 INIT_VNET_INET(curvnet);
325 struct ip *ip = NULL;
326 struct in_ifaddr *ia = NULL;
328 int checkif, hlen = 0;
330 int dchg = 0; /* dest changed after fw */
331 struct in_addr odst; /* original dst address */
335 if (m->m_flags & M_FASTFWD_OURS) {
337 * Firewall or NAT changed destination to local.
338 * We expect ip_len and ip_off to be in host byte order.
340 m->m_flags &= ~M_FASTFWD_OURS;
341 /* Set up some basics that will be used later. */
342 ip = mtod(m, struct ip *);
343 hlen = ip->ip_hl << 2;
347 V_ipstat.ips_total++;
349 if (m->m_pkthdr.len < sizeof(struct ip))
352 if (m->m_len < sizeof (struct ip) &&
353 (m = m_pullup(m, sizeof (struct ip))) == NULL) {
354 V_ipstat.ips_toosmall++;
357 ip = mtod(m, struct ip *);
359 if (ip->ip_v != IPVERSION) {
360 V_ipstat.ips_badvers++;
364 hlen = ip->ip_hl << 2;
365 if (hlen < sizeof(struct ip)) { /* minimum header length */
366 V_ipstat.ips_badhlen++;
369 if (hlen > m->m_len) {
370 if ((m = m_pullup(m, hlen)) == NULL) {
371 V_ipstat.ips_badhlen++;
374 ip = mtod(m, struct ip *);
377 /* 127/8 must not appear on wire - RFC1122 */
378 if ((ntohl(ip->ip_dst.s_addr) >> IN_CLASSA_NSHIFT) == IN_LOOPBACKNET ||
379 (ntohl(ip->ip_src.s_addr) >> IN_CLASSA_NSHIFT) == IN_LOOPBACKNET) {
380 if ((m->m_pkthdr.rcvif->if_flags & IFF_LOOPBACK) == 0) {
381 V_ipstat.ips_badaddr++;
386 if (m->m_pkthdr.csum_flags & CSUM_IP_CHECKED) {
387 sum = !(m->m_pkthdr.csum_flags & CSUM_IP_VALID);
389 if (hlen == sizeof(struct ip)) {
390 sum = in_cksum_hdr(ip);
392 sum = in_cksum(m, hlen);
396 V_ipstat.ips_badsum++;
401 if (altq_input != NULL && (*altq_input)(m, AF_INET) == 0)
402 /* packet is dropped by traffic conditioner */
407 * Convert fields to host representation.
409 ip->ip_len = ntohs(ip->ip_len);
410 if (ip->ip_len < hlen) {
411 V_ipstat.ips_badlen++;
414 ip->ip_off = ntohs(ip->ip_off);
417 * Check that the amount of data in the buffers
418 * is as at least much as the IP header would have us expect.
419 * Trim mbufs if longer than we expect.
420 * Drop packet if shorter than we expect.
422 if (m->m_pkthdr.len < ip->ip_len) {
424 V_ipstat.ips_tooshort++;
427 if (m->m_pkthdr.len > ip->ip_len) {
428 if (m->m_len == m->m_pkthdr.len) {
429 m->m_len = ip->ip_len;
430 m->m_pkthdr.len = ip->ip_len;
432 m_adj(m, ip->ip_len - m->m_pkthdr.len);
436 * Bypass packet filtering for packets from a tunnel (gif).
438 if (ip_ipsec_filtertunnel(m))
443 * Run through list of hooks for input packets.
445 * NB: Beware of the destination address changing (e.g.
446 * by NAT rewriting). When this happens, tell
447 * ip_forward to do the right thing.
450 /* Jump over all PFIL processing if hooks are not active. */
451 if (!PFIL_HOOKED(&inet_pfil_hook))
455 if (pfil_run_hooks(&inet_pfil_hook, &m, m->m_pkthdr.rcvif,
458 if (m == NULL) /* consumed by filter */
461 ip = mtod(m, struct ip *);
462 dchg = (odst.s_addr != ip->ip_dst.s_addr);
464 #ifdef IPFIREWALL_FORWARD
465 if (m->m_flags & M_FASTFWD_OURS) {
466 m->m_flags &= ~M_FASTFWD_OURS;
469 if ((dchg = (m_tag_find(m, PACKET_TAG_IPFORWARD, NULL) != NULL)) != 0) {
471 * Directly ship on the packet. This allows to forward packets
472 * that were destined for us to some other directly connected
478 #endif /* IPFIREWALL_FORWARD */
482 * Process options and, if not destined for us,
483 * ship it on. ip_dooptions returns 1 when an
484 * error was detected (causing an icmp message
485 * to be sent and the original packet to be freed).
487 if (hlen > sizeof (struct ip) && ip_dooptions(m, 0))
490 /* greedy RSVP, snatches any PATH packet of the RSVP protocol and no
491 * matter if it is destined to another node, or whether it is
492 * a multicast one, RSVP wants it! and prevents it from being forwarded
493 * anywhere else. Also checks if the rsvp daemon is running before
494 * grabbing the packet.
496 if (V_rsvp_on && ip->ip_p==IPPROTO_RSVP)
500 * Check our list of addresses, to see if the packet is for us.
501 * If we don't have any addresses, assume any unicast packet
502 * we receive might be for us (and let the upper layers deal
505 if (TAILQ_EMPTY(&V_in_ifaddrhead) &&
506 (m->m_flags & (M_MCAST|M_BCAST)) == 0)
510 * Enable a consistency check between the destination address
511 * and the arrival interface for a unicast packet (the RFC 1122
512 * strong ES model) if IP forwarding is disabled and the packet
513 * is not locally generated and the packet is not subject to
516 * XXX - Checking also should be disabled if the destination
517 * address is ipnat'ed to a different interface.
519 * XXX - Checking is incompatible with IP aliases added
520 * to the loopback interface instead of the interface where
521 * the packets are received.
523 * XXX - This is the case for carp vhost IPs as well so we
524 * insert a workaround. If the packet got here, we already
525 * checked with carp_iamatch() and carp_forus().
527 checkif = V_ip_checkinterface && (V_ipforwarding == 0) &&
528 m->m_pkthdr.rcvif != NULL &&
529 ((m->m_pkthdr.rcvif->if_flags & IFF_LOOPBACK) == 0) &&
531 !m->m_pkthdr.rcvif->if_carp &&
536 * Check for exact addresses in the hash bucket.
538 LIST_FOREACH(ia, INADDR_HASH(ip->ip_dst.s_addr), ia_hash) {
540 * If the address matches, verify that the packet
541 * arrived via the correct interface if checking is
544 if (IA_SIN(ia)->sin_addr.s_addr == ip->ip_dst.s_addr &&
545 (!checkif || ia->ia_ifp == m->m_pkthdr.rcvif))
549 * Check for broadcast addresses.
551 * Only accept broadcast packets that arrive via the matching
552 * interface. Reception of forwarded directed broadcasts would
553 * be handled via ip_forward() and ether_output() with the loopback
554 * into the stack for SIMPLEX interfaces handled by ether_output().
556 if (m->m_pkthdr.rcvif != NULL &&
557 m->m_pkthdr.rcvif->if_flags & IFF_BROADCAST) {
558 TAILQ_FOREACH(ifa, &m->m_pkthdr.rcvif->if_addrhead, ifa_link) {
559 if (ifa->ifa_addr->sa_family != AF_INET)
562 if (satosin(&ia->ia_broadaddr)->sin_addr.s_addr ==
565 if (ia->ia_netbroadcast.s_addr == ip->ip_dst.s_addr)
568 if (IA_SIN(ia)->sin_addr.s_addr == INADDR_ANY)
573 /* RFC 3927 2.7: Do not forward datagrams for 169.254.0.0/16. */
574 if (IN_LINKLOCAL(ntohl(ip->ip_dst.s_addr))) {
575 V_ipstat.ips_cantforward++;
579 if (IN_MULTICAST(ntohl(ip->ip_dst.s_addr))) {
580 struct in_multi *inm;
583 * If we are acting as a multicast router, all
584 * incoming multicast packets are passed to the
585 * kernel-level multicast forwarding function.
586 * The packet is returned (relatively) intact; if
587 * ip_mforward() returns a non-zero value, the packet
588 * must be discarded, else it may be accepted below.
591 ip_mforward(ip, m->m_pkthdr.rcvif, m, 0) != 0) {
592 V_ipstat.ips_cantforward++;
598 * The process-level routing daemon needs to receive
599 * all multicast IGMP packets, whether or not this
600 * host belongs to their destination groups.
602 if (ip->ip_p == IPPROTO_IGMP)
604 V_ipstat.ips_forward++;
607 * See if we belong to the destination multicast group on the
611 IN_LOOKUP_MULTI(ip->ip_dst, m->m_pkthdr.rcvif, inm);
614 V_ipstat.ips_notmember++;
620 if (ip->ip_dst.s_addr == (u_long)INADDR_BROADCAST)
622 if (ip->ip_dst.s_addr == INADDR_ANY)
626 * FAITH(Firewall Aided Internet Translator)
628 if (m->m_pkthdr.rcvif && m->m_pkthdr.rcvif->if_type == IFT_FAITH) {
629 if (V_ip_keepfaith) {
630 if (ip->ip_p == IPPROTO_TCP || ip->ip_p == IPPROTO_ICMP)
638 * Not for us; forward if possible and desirable.
640 if (V_ipforwarding == 0) {
641 V_ipstat.ips_cantforward++;
655 * IPSTEALTH: Process non-routing options only
656 * if the packet is destined for us.
658 if (V_ipstealth && hlen > sizeof (struct ip) &&
661 #endif /* IPSTEALTH */
663 /* Count the packet in the ip address stats */
665 ia->ia_ifa.if_ipackets++;
666 ia->ia_ifa.if_ibytes += m->m_pkthdr.len;
670 * Attempt reassembly; if it succeeds, proceed.
671 * ip_reass() will return a different mbuf.
673 if (ip->ip_off & (IP_MF | IP_OFFMASK)) {
677 ip = mtod(m, struct ip *);
678 /* Get the header length of the reassembled packet */
679 hlen = ip->ip_hl << 2;
683 * Further protocols expect the packet length to be w/o the
690 * enforce IPsec policy checking if we are seeing last header.
691 * note that we do not visit this with protocols with pcb layer
692 * code - like udp/tcp/raw ip.
694 if (ip_ipsec_input(m))
699 * Switch out to protocol's input routine.
701 V_ipstat.ips_delivered++;
703 (*inetsw[ip_protox[ip->ip_p]].pr_input)(m, hlen);
710 * After maxnipq has been updated, propagate the change to UMA. The UMA zone
711 * max has slightly different semantics than the sysctl, for historical
717 INIT_VNET_INET(curvnet);
720 * -1 for unlimited allocation.
723 uma_zone_set_max(V_ipq_zone, 0);
725 * Positive number for specific bound.
728 uma_zone_set_max(V_ipq_zone, V_maxnipq);
730 * Zero specifies no further fragment queue allocation -- set the
731 * bound very low, but rely on implementation elsewhere to actually
732 * prevent allocation and reclaim current queues.
735 uma_zone_set_max(V_ipq_zone, 1);
739 ipq_zone_change(void *tag)
741 INIT_VNET_INET(curvnet);
743 if (V_maxnipq > 0 && V_maxnipq < (nmbclusters / 32)) {
744 V_maxnipq = nmbclusters / 32;
750 sysctl_maxnipq(SYSCTL_HANDLER_ARGS)
752 INIT_VNET_INET(curvnet);
756 error = sysctl_handle_int(oidp, &i, 0, req);
757 if (error || !req->newptr)
761 * XXXRW: Might be a good idea to sanity check the argument and place
762 * an extreme upper bound.
771 SYSCTL_PROC(_net_inet_ip, OID_AUTO, maxfragpackets, CTLTYPE_INT|CTLFLAG_RW,
772 NULL, 0, sysctl_maxnipq, "I",
773 "Maximum number of IPv4 fragment reassembly queue entries");
776 * Take incoming datagram fragment and try to reassemble it into
777 * whole datagram. If the argument is the first fragment or one
778 * in between the function will return NULL and store the mbuf
779 * in the fragment chain. If the argument is the last fragment
780 * the packet will be reassembled and the pointer to the new
781 * mbuf returned for further processing. Only m_tags attached
782 * to the first packet/fragment are preserved.
783 * The IP header is *NOT* adjusted out of iplen.
786 ip_reass(struct mbuf *m)
788 INIT_VNET_INET(curvnet);
790 struct mbuf *p, *q, *nq, *t;
791 struct ipq *fp = NULL;
792 struct ipqhead *head;
797 /* If maxnipq or maxfragsperpacket are 0, never accept fragments. */
798 if (V_maxnipq == 0 || V_maxfragsperpacket == 0) {
799 V_ipstat.ips_fragments++;
800 V_ipstat.ips_fragdropped++;
805 ip = mtod(m, struct ip *);
806 hlen = ip->ip_hl << 2;
808 hash = IPREASS_HASH(ip->ip_src.s_addr, ip->ip_id);
813 * Look for queue of fragments
816 TAILQ_FOREACH(fp, head, ipq_list)
817 if (ip->ip_id == fp->ipq_id &&
818 ip->ip_src.s_addr == fp->ipq_src.s_addr &&
819 ip->ip_dst.s_addr == fp->ipq_dst.s_addr &&
821 mac_ipq_match(m, fp) &&
823 ip->ip_p == fp->ipq_p)
829 * Attempt to trim the number of allocated fragment queues if it
830 * exceeds the administrative limit.
832 if ((V_nipq > V_maxnipq) && (V_maxnipq > 0)) {
834 * drop something from the tail of the current queue
835 * before proceeding further
837 struct ipq *q = TAILQ_LAST(head, ipqhead);
838 if (q == NULL) { /* gak */
839 for (i = 0; i < IPREASS_NHASH; i++) {
840 struct ipq *r = TAILQ_LAST(&V_ipq[i], ipqhead);
842 V_ipstat.ips_fragtimeout +=
844 ip_freef(&V_ipq[i], r);
849 V_ipstat.ips_fragtimeout += q->ipq_nfrags;
856 * Adjust ip_len to not reflect header,
857 * convert offset of this to bytes.
860 if (ip->ip_off & IP_MF) {
862 * Make sure that fragments have a data length
863 * that's a non-zero multiple of 8 bytes.
865 if (ip->ip_len == 0 || (ip->ip_len & 0x7) != 0) {
866 V_ipstat.ips_toosmall++; /* XXX */
869 m->m_flags |= M_FRAG;
871 m->m_flags &= ~M_FRAG;
876 * Attempt reassembly; if it succeeds, proceed.
877 * ip_reass() will return a different mbuf.
879 V_ipstat.ips_fragments++;
880 m->m_pkthdr.header = ip;
882 /* Previous ip_reass() started here. */
884 * Presence of header sizes in mbufs
885 * would confuse code below.
891 * If first fragment to arrive, create a reassembly queue.
894 fp = uma_zalloc(V_ipq_zone, M_NOWAIT);
898 if (mac_ipq_init(fp, M_NOWAIT) != 0) {
899 uma_zfree(V_ipq_zone, fp);
903 mac_ipq_create(m, fp);
905 TAILQ_INSERT_HEAD(head, fp, ipq_list);
908 fp->ipq_ttl = IPFRAGTTL;
909 fp->ipq_p = ip->ip_p;
910 fp->ipq_id = ip->ip_id;
911 fp->ipq_src = ip->ip_src;
912 fp->ipq_dst = ip->ip_dst;
919 mac_ipq_update(m, fp);
923 #define GETIP(m) ((struct ip*)((m)->m_pkthdr.header))
926 * Handle ECN by comparing this segment with the first one;
927 * if CE is set, do not lose CE.
928 * drop if CE and not-ECT are mixed for the same packet.
930 ecn = ip->ip_tos & IPTOS_ECN_MASK;
931 ecn0 = GETIP(fp->ipq_frags)->ip_tos & IPTOS_ECN_MASK;
932 if (ecn == IPTOS_ECN_CE) {
933 if (ecn0 == IPTOS_ECN_NOTECT)
935 if (ecn0 != IPTOS_ECN_CE)
936 GETIP(fp->ipq_frags)->ip_tos |= IPTOS_ECN_CE;
938 if (ecn == IPTOS_ECN_NOTECT && ecn0 != IPTOS_ECN_NOTECT)
942 * Find a segment which begins after this one does.
944 for (p = NULL, q = fp->ipq_frags; q; p = q, q = q->m_nextpkt)
945 if (GETIP(q)->ip_off > ip->ip_off)
949 * If there is a preceding segment, it may provide some of
950 * our data already. If so, drop the data from the incoming
951 * segment. If it provides all of our data, drop us, otherwise
952 * stick new segment in the proper place.
954 * If some of the data is dropped from the the preceding
955 * segment, then it's checksum is invalidated.
958 i = GETIP(p)->ip_off + GETIP(p)->ip_len - ip->ip_off;
963 m->m_pkthdr.csum_flags = 0;
967 m->m_nextpkt = p->m_nextpkt;
970 m->m_nextpkt = fp->ipq_frags;
975 * While we overlap succeeding segments trim them or,
976 * if they are completely covered, dequeue them.
978 for (; q != NULL && ip->ip_off + ip->ip_len > GETIP(q)->ip_off;
980 i = (ip->ip_off + ip->ip_len) - GETIP(q)->ip_off;
981 if (i < GETIP(q)->ip_len) {
982 GETIP(q)->ip_len -= i;
983 GETIP(q)->ip_off += i;
985 q->m_pkthdr.csum_flags = 0;
990 V_ipstat.ips_fragdropped++;
996 * Check for complete reassembly and perform frag per packet
999 * Frag limiting is performed here so that the nth frag has
1000 * a chance to complete the packet before we drop the packet.
1001 * As a result, n+1 frags are actually allowed per packet, but
1002 * only n will ever be stored. (n = maxfragsperpacket.)
1006 for (p = NULL, q = fp->ipq_frags; q; p = q, q = q->m_nextpkt) {
1007 if (GETIP(q)->ip_off != next) {
1008 if (fp->ipq_nfrags > V_maxfragsperpacket) {
1009 V_ipstat.ips_fragdropped += fp->ipq_nfrags;
1014 next += GETIP(q)->ip_len;
1016 /* Make sure the last packet didn't have the IP_MF flag */
1017 if (p->m_flags & M_FRAG) {
1018 if (fp->ipq_nfrags > V_maxfragsperpacket) {
1019 V_ipstat.ips_fragdropped += fp->ipq_nfrags;
1026 * Reassembly is complete. Make sure the packet is a sane size.
1030 if (next + (ip->ip_hl << 2) > IP_MAXPACKET) {
1031 V_ipstat.ips_toolong++;
1032 V_ipstat.ips_fragdropped += fp->ipq_nfrags;
1038 * Concatenate fragments.
1045 q->m_nextpkt = NULL;
1046 for (q = nq; q != NULL; q = nq) {
1048 q->m_nextpkt = NULL;
1049 m->m_pkthdr.csum_flags &= q->m_pkthdr.csum_flags;
1050 m->m_pkthdr.csum_data += q->m_pkthdr.csum_data;
1054 * In order to do checksumming faster we do 'end-around carry' here
1055 * (and not in for{} loop), though it implies we are not going to
1056 * reassemble more than 64k fragments.
1058 m->m_pkthdr.csum_data =
1059 (m->m_pkthdr.csum_data & 0xffff) + (m->m_pkthdr.csum_data >> 16);
1061 mac_ipq_reassemble(fp, m);
1062 mac_ipq_destroy(fp);
1066 * Create header for new ip packet by modifying header of first
1067 * packet; dequeue and discard fragment reassembly header.
1068 * Make header visible.
1070 ip->ip_len = (ip->ip_hl << 2) + next;
1071 ip->ip_src = fp->ipq_src;
1072 ip->ip_dst = fp->ipq_dst;
1073 TAILQ_REMOVE(head, fp, ipq_list);
1075 uma_zfree(V_ipq_zone, fp);
1076 m->m_len += (ip->ip_hl << 2);
1077 m->m_data -= (ip->ip_hl << 2);
1078 /* some debugging cruft by sklower, below, will go away soon */
1079 if (m->m_flags & M_PKTHDR) /* XXX this should be done elsewhere */
1081 V_ipstat.ips_reassembled++;
1086 V_ipstat.ips_fragdropped++;
1098 * Free a fragment reassembly header and all
1099 * associated datagrams.
1102 ip_freef(struct ipqhead *fhp, struct ipq *fp)
1104 INIT_VNET_INET(curvnet);
1109 while (fp->ipq_frags) {
1111 fp->ipq_frags = q->m_nextpkt;
1114 TAILQ_REMOVE(fhp, fp, ipq_list);
1115 uma_zfree(V_ipq_zone, fp);
1120 * IP timer processing;
1121 * if a timer expires on a reassembly
1122 * queue, discard it.
1127 VNET_ITERATOR_DECL(vnet_iter);
1133 VNET_FOREACH(vnet_iter) {
1134 CURVNET_SET(vnet_iter);
1135 INIT_VNET_INET(vnet_iter);
1136 for (i = 0; i < IPREASS_NHASH; i++) {
1137 for(fp = TAILQ_FIRST(&V_ipq[i]); fp;) {
1141 fp = TAILQ_NEXT(fp, ipq_list);
1142 if(--fpp->ipq_ttl == 0) {
1143 V_ipstat.ips_fragtimeout +=
1145 ip_freef(&V_ipq[i], fpp);
1150 * If we are over the maximum number of fragments
1151 * (due to the limit being lowered), drain off
1152 * enough to get down to the new limit.
1154 if (V_maxnipq >= 0 && V_nipq > V_maxnipq) {
1155 for (i = 0; i < IPREASS_NHASH; i++) {
1156 while (V_nipq > V_maxnipq &&
1157 !TAILQ_EMPTY(&V_ipq[i])) {
1158 V_ipstat.ips_fragdropped +=
1159 TAILQ_FIRST(&V_ipq[i])->ipq_nfrags;
1161 TAILQ_FIRST(&V_ipq[i]));
1167 VNET_LIST_RUNLOCK();
1172 * Drain off all datagram fragments.
1177 VNET_ITERATOR_DECL(vnet_iter);
1182 VNET_FOREACH(vnet_iter) {
1183 CURVNET_SET(vnet_iter);
1184 INIT_VNET_INET(vnet_iter);
1185 for (i = 0; i < IPREASS_NHASH; i++) {
1186 while(!TAILQ_EMPTY(&V_ipq[i])) {
1187 V_ipstat.ips_fragdropped +=
1188 TAILQ_FIRST(&V_ipq[i])->ipq_nfrags;
1189 ip_freef(&V_ipq[i], TAILQ_FIRST(&V_ipq[i]));
1194 VNET_LIST_RUNLOCK();
1200 * The protocol to be inserted into ip_protox[] must be already registered
1201 * in inetsw[], either statically or through pf_proto_register().
1204 ipproto_register(u_char ipproto)
1208 /* Sanity checks. */
1210 return (EPROTONOSUPPORT);
1213 * The protocol slot must not be occupied by another protocol
1214 * already. An index pointing to IPPROTO_RAW is unused.
1216 pr = pffindproto(PF_INET, IPPROTO_RAW, SOCK_RAW);
1218 return (EPFNOSUPPORT);
1219 if (ip_protox[ipproto] != pr - inetsw) /* IPPROTO_RAW */
1222 /* Find the protocol position in inetsw[] and set the index. */
1223 for (pr = inetdomain.dom_protosw;
1224 pr < inetdomain.dom_protoswNPROTOSW; pr++) {
1225 if (pr->pr_domain->dom_family == PF_INET &&
1226 pr->pr_protocol && pr->pr_protocol == ipproto) {
1227 /* Be careful to only index valid IP protocols. */
1228 if (pr->pr_protocol < IPPROTO_MAX) {
1229 ip_protox[pr->pr_protocol] = pr - inetsw;
1235 return (EPROTONOSUPPORT);
1239 ipproto_unregister(u_char ipproto)
1243 /* Sanity checks. */
1245 return (EPROTONOSUPPORT);
1247 /* Check if the protocol was indeed registered. */
1248 pr = pffindproto(PF_INET, IPPROTO_RAW, SOCK_RAW);
1250 return (EPFNOSUPPORT);
1251 if (ip_protox[ipproto] == pr - inetsw) /* IPPROTO_RAW */
1254 /* Reset the protocol slot to IPPROTO_RAW. */
1255 ip_protox[ipproto] = pr - inetsw;
1260 * Given address of next destination (final or next hop),
1261 * return internet address info of interface to be used to get there.
1264 ip_rtaddr(struct in_addr dst, u_int fibnum)
1267 struct sockaddr_in *sin;
1268 struct in_ifaddr *ifa;
1270 bzero(&sro, sizeof(sro));
1271 sin = (struct sockaddr_in *)&sro.ro_dst;
1272 sin->sin_family = AF_INET;
1273 sin->sin_len = sizeof(*sin);
1274 sin->sin_addr = dst;
1275 in_rtalloc_ign(&sro, RTF_CLONING, fibnum);
1277 if (sro.ro_rt == NULL)
1280 ifa = ifatoia(sro.ro_rt->rt_ifa);
1285 u_char inetctlerrmap[PRC_NCMDS] = {
1287 0, EMSGSIZE, EHOSTDOWN, EHOSTUNREACH,
1288 EHOSTUNREACH, EHOSTUNREACH, ECONNREFUSED, ECONNREFUSED,
1289 EMSGSIZE, EHOSTUNREACH, 0, 0,
1290 0, 0, EHOSTUNREACH, 0,
1291 ENOPROTOOPT, ECONNREFUSED
1295 * Forward a packet. If some error occurs return the sender
1296 * an icmp packet. Note we can't always generate a meaningful
1297 * icmp message because icmp doesn't have a large enough repertoire
1298 * of codes and types.
1300 * If not forwarding, just drop the packet. This could be confusing
1301 * if ipforwarding was zero but some routing protocol was advancing
1302 * us as a gateway to somewhere. However, we must let the routing
1303 * protocol deal with that.
1305 * The srcrt parameter indicates whether the packet is being forwarded
1306 * via a source route.
1309 ip_forward(struct mbuf *m, int srcrt)
1311 INIT_VNET_INET(curvnet);
1312 struct ip *ip = mtod(m, struct ip *);
1313 struct in_ifaddr *ia = NULL;
1315 struct in_addr dest;
1317 int error, type = 0, code = 0, mtu = 0;
1319 if (m->m_flags & (M_BCAST|M_MCAST) || in_canforward(ip->ip_dst) == 0) {
1320 V_ipstat.ips_cantforward++;
1327 if (ip->ip_ttl <= IPTTLDEC) {
1328 icmp_error(m, ICMP_TIMXCEED, ICMP_TIMXCEED_INTRANS,
1336 ia = ip_rtaddr(ip->ip_dst, M_GETFIB(m));
1337 if (!srcrt && ia == NULL) {
1338 icmp_error(m, ICMP_UNREACH, ICMP_UNREACH_HOST, 0, 0);
1343 * Save the IP header and at most 8 bytes of the payload,
1344 * in case we need to generate an ICMP message to the src.
1346 * XXX this can be optimized a lot by saving the data in a local
1347 * buffer on the stack (72 bytes at most), and only allocating the
1348 * mbuf if really necessary. The vast majority of the packets
1349 * are forwarded without having to send an ICMP back (either
1350 * because unnecessary, or because rate limited), so we are
1351 * really we are wasting a lot of work here.
1353 * We don't use m_copy() because it might return a reference
1354 * to a shared cluster. Both this function and ip_output()
1355 * assume exclusive access to the IP header in `m', so any
1356 * data in a cluster may change before we reach icmp_error().
1358 MGETHDR(mcopy, M_DONTWAIT, m->m_type);
1359 if (mcopy != NULL && !m_dup_pkthdr(mcopy, m, M_DONTWAIT)) {
1361 * It's probably ok if the pkthdr dup fails (because
1362 * the deep copy of the tag chain failed), but for now
1363 * be conservative and just discard the copy since
1364 * code below may some day want the tags.
1369 if (mcopy != NULL) {
1370 mcopy->m_len = min(ip->ip_len, M_TRAILINGSPACE(mcopy));
1371 mcopy->m_pkthdr.len = mcopy->m_len;
1372 m_copydata(m, 0, mcopy->m_len, mtod(mcopy, caddr_t));
1378 ip->ip_ttl -= IPTTLDEC;
1384 * If forwarding packet using same interface that it came in on,
1385 * perhaps should send a redirect to sender to shortcut a hop.
1386 * Only send redirect if source is sending directly to us,
1387 * and if packet was not source routed (or has any options).
1388 * Also, don't send redirect if forwarding using a default route
1389 * or a route modified by a redirect.
1392 if (!srcrt && V_ipsendredirects && ia->ia_ifp == m->m_pkthdr.rcvif) {
1393 struct sockaddr_in *sin;
1396 bzero(&ro, sizeof(ro));
1397 sin = (struct sockaddr_in *)&ro.ro_dst;
1398 sin->sin_family = AF_INET;
1399 sin->sin_len = sizeof(*sin);
1400 sin->sin_addr = ip->ip_dst;
1401 in_rtalloc_ign(&ro, RTF_CLONING, M_GETFIB(m));
1405 if (rt && (rt->rt_flags & (RTF_DYNAMIC|RTF_MODIFIED)) == 0 &&
1406 satosin(rt_key(rt))->sin_addr.s_addr != 0) {
1407 #define RTA(rt) ((struct in_ifaddr *)(rt->rt_ifa))
1408 u_long src = ntohl(ip->ip_src.s_addr);
1411 (src & RTA(rt)->ia_subnetmask) == RTA(rt)->ia_subnet) {
1412 if (rt->rt_flags & RTF_GATEWAY)
1413 dest.s_addr = satosin(rt->rt_gateway)->sin_addr.s_addr;
1415 dest.s_addr = ip->ip_dst.s_addr;
1416 /* Router requirements says to only send host redirects */
1417 type = ICMP_REDIRECT;
1418 code = ICMP_REDIRECT_HOST;
1426 * Try to cache the route MTU from ip_output so we can consider it for
1427 * the ICMP_UNREACH_NEEDFRAG "Next-Hop MTU" field described in RFC1191.
1429 bzero(&ro, sizeof(ro));
1431 error = ip_output(m, NULL, &ro, IP_FORWARDING, NULL, NULL);
1433 if (error == EMSGSIZE && ro.ro_rt)
1434 mtu = ro.ro_rt->rt_rmx.rmx_mtu;
1439 V_ipstat.ips_cantforward++;
1441 V_ipstat.ips_forward++;
1443 V_ipstat.ips_redirectsent++;
1455 case 0: /* forwarded, but need redirect */
1456 /* type, code set above */
1459 case ENETUNREACH: /* shouldn't happen, checked above */
1464 type = ICMP_UNREACH;
1465 code = ICMP_UNREACH_HOST;
1469 type = ICMP_UNREACH;
1470 code = ICMP_UNREACH_NEEDFRAG;
1474 * If IPsec is configured for this path,
1475 * override any possibly mtu value set by ip_output.
1477 mtu = ip_ipsec_mtu(m, mtu);
1480 * If the MTU was set before make sure we are below the
1482 * If the MTU wasn't set before use the interface mtu or
1483 * fall back to the next smaller mtu step compared to the
1484 * current packet size.
1488 mtu = min(mtu, ia->ia_ifp->if_mtu);
1491 mtu = ia->ia_ifp->if_mtu;
1493 mtu = ip_next_mtu(ip->ip_len, 0);
1495 V_ipstat.ips_cantfrag++;
1500 * A router should not generate ICMP_SOURCEQUENCH as
1501 * required in RFC1812 Requirements for IP Version 4 Routers.
1502 * Source quench could be a big problem under DoS attacks,
1503 * or if the underlying interface is rate-limited.
1504 * Those who need source quench packets may re-enable them
1505 * via the net.inet.ip.sendsourcequench sysctl.
1507 if (V_ip_sendsourcequench == 0) {
1511 type = ICMP_SOURCEQUENCH;
1516 case EACCES: /* ipfw denied packet */
1520 icmp_error(mcopy, type, code, dest.s_addr, mtu);
1524 ip_savecontrol(struct inpcb *inp, struct mbuf **mp, struct ip *ip,
1527 INIT_VNET_NET(inp->inp_vnet);
1529 if (inp->inp_socket->so_options & (SO_BINTIME | SO_TIMESTAMP)) {
1533 if (inp->inp_socket->so_options & SO_BINTIME) {
1534 *mp = sbcreatecontrol((caddr_t) &bt, sizeof(bt),
1535 SCM_BINTIME, SOL_SOCKET);
1537 mp = &(*mp)->m_next;
1539 if (inp->inp_socket->so_options & SO_TIMESTAMP) {
1542 bintime2timeval(&bt, &tv);
1543 *mp = sbcreatecontrol((caddr_t) &tv, sizeof(tv),
1544 SCM_TIMESTAMP, SOL_SOCKET);
1546 mp = &(*mp)->m_next;
1549 if (inp->inp_flags & INP_RECVDSTADDR) {
1550 *mp = sbcreatecontrol((caddr_t) &ip->ip_dst,
1551 sizeof(struct in_addr), IP_RECVDSTADDR, IPPROTO_IP);
1553 mp = &(*mp)->m_next;
1555 if (inp->inp_flags & INP_RECVTTL) {
1556 *mp = sbcreatecontrol((caddr_t) &ip->ip_ttl,
1557 sizeof(u_char), IP_RECVTTL, IPPROTO_IP);
1559 mp = &(*mp)->m_next;
1563 * Moving these out of udp_input() made them even more broken
1564 * than they already were.
1566 /* options were tossed already */
1567 if (inp->inp_flags & INP_RECVOPTS) {
1568 *mp = sbcreatecontrol((caddr_t) opts_deleted_above,
1569 sizeof(struct in_addr), IP_RECVOPTS, IPPROTO_IP);
1571 mp = &(*mp)->m_next;
1573 /* ip_srcroute doesn't do what we want here, need to fix */
1574 if (inp->inp_flags & INP_RECVRETOPTS) {
1575 *mp = sbcreatecontrol((caddr_t) ip_srcroute(m),
1576 sizeof(struct in_addr), IP_RECVRETOPTS, IPPROTO_IP);
1578 mp = &(*mp)->m_next;
1581 if (inp->inp_flags & INP_RECVIF) {
1584 struct sockaddr_dl sdl;
1587 struct sockaddr_dl *sdp;
1588 struct sockaddr_dl *sdl2 = &sdlbuf.sdl;
1590 if (((ifp = m->m_pkthdr.rcvif))
1591 && ( ifp->if_index && (ifp->if_index <= V_if_index))) {
1592 sdp = (struct sockaddr_dl *)ifp->if_addr->ifa_addr;
1594 * Change our mind and don't try copy.
1596 if ((sdp->sdl_family != AF_LINK)
1597 || (sdp->sdl_len > sizeof(sdlbuf))) {
1600 bcopy(sdp, sdl2, sdp->sdl_len);
1604 = offsetof(struct sockaddr_dl, sdl_data[0]);
1605 sdl2->sdl_family = AF_LINK;
1606 sdl2->sdl_index = 0;
1607 sdl2->sdl_nlen = sdl2->sdl_alen = sdl2->sdl_slen = 0;
1609 *mp = sbcreatecontrol((caddr_t) sdl2, sdl2->sdl_len,
1610 IP_RECVIF, IPPROTO_IP);
1612 mp = &(*mp)->m_next;
1617 * XXXRW: Multicast routing code in ip_mroute.c is generally MPSAFE, but the
1618 * ip_rsvp and ip_rsvp_on variables need to be interlocked with rsvp_on
1619 * locking. This code remains in ip_input.c as ip_mroute.c is optionally
1623 ip_rsvp_init(struct socket *so)
1625 INIT_VNET_INET(so->so_vnet);
1627 if (so->so_type != SOCK_RAW ||
1628 so->so_proto->pr_protocol != IPPROTO_RSVP)
1631 if (V_ip_rsvpd != NULL)
1636 * This may seem silly, but we need to be sure we don't over-increment
1637 * the RSVP counter, in case something slips up.
1639 if (!V_ip_rsvp_on) {
1650 INIT_VNET_INET(curvnet);
1654 * This may seem silly, but we need to be sure we don't over-decrement
1655 * the RSVP counter, in case something slips up.
1665 rsvp_input(struct mbuf *m, int off) /* XXX must fixup manually */
1667 INIT_VNET_INET(curvnet);
1669 if (rsvp_input_p) { /* call the real one if loaded */
1670 rsvp_input_p(m, off);
1674 /* Can still get packets with rsvp_on = 0 if there is a local member
1675 * of the group to which the RSVP packet is addressed. But in this
1676 * case we want to throw the packet away.
1684 if (V_ip_rsvpd != NULL) {
1688 /* Drop the packet */