34
35#include "opt_bootp.h"
36#include "opt_ipfw.h"
37#include "opt_ipstealth.h"
38#include "opt_ipsec.h"
39#include "opt_route.h"
40
41#include <sys/param.h>
42#include <sys/systm.h>
43#include <sys/mbuf.h>
44#include <sys/malloc.h>
45#include <sys/domain.h>
46#include <sys/protosw.h>
47#include <sys/socket.h>
48#include <sys/time.h>
49#include <sys/kernel.h>
50#include <sys/lock.h>
51#include <sys/rwlock.h>
52#include <sys/syslog.h>
53#include <sys/sysctl.h>
54
55#include <net/pfil.h>
56#include <net/if.h>
57#include <net/if_types.h>
58#include <net/if_var.h>
59#include <net/if_dl.h>
60#include <net/route.h>
61#include <net/netisr.h>
62#include <net/vnet.h>
63#include <net/flowtable.h>
64
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_fw.h>
72#include <netinet/ip_icmp.h>
73#include <netinet/ip_options.h>
74#include <machine/in_cksum.h>
75#include <netinet/ip_carp.h>
76#ifdef IPSEC
77#include <netinet/ip_ipsec.h>
78#endif /* IPSEC */
79
80#include <sys/socketvar.h>
81
82#include <security/mac/mac_framework.h>
83
84#ifdef CTASSERT
85CTASSERT(sizeof(struct ip) == 20);
86#endif
87
88struct rwlock in_ifaddr_lock;
89RW_SYSINIT(in_ifaddr_lock, &in_ifaddr_lock, "in_ifaddr_lock");
90
91VNET_DEFINE(int, rsvp_on);
92
93VNET_DEFINE(int, ipforwarding);
94SYSCTL_VNET_INT(_net_inet_ip, IPCTL_FORWARDING, forwarding, CTLFLAG_RW,
95 &VNET_NAME(ipforwarding), 0,
96 "Enable IP forwarding between interfaces");
97
98static VNET_DEFINE(int, ipsendredirects) = 1; /* XXX */
99#define V_ipsendredirects VNET(ipsendredirects)
100SYSCTL_VNET_INT(_net_inet_ip, IPCTL_SENDREDIRECTS, redirect, CTLFLAG_RW,
101 &VNET_NAME(ipsendredirects), 0,
102 "Enable sending IP redirects");
103
104static VNET_DEFINE(int, ip_keepfaith);
105#define V_ip_keepfaith VNET(ip_keepfaith)
106SYSCTL_VNET_INT(_net_inet_ip, IPCTL_KEEPFAITH, keepfaith, CTLFLAG_RW,
107 &VNET_NAME(ip_keepfaith), 0,
108 "Enable packet capture for FAITH IPv4->IPv6 translater daemon");
109
110static VNET_DEFINE(int, ip_sendsourcequench);
111#define V_ip_sendsourcequench VNET(ip_sendsourcequench)
112SYSCTL_VNET_INT(_net_inet_ip, OID_AUTO, sendsourcequench, CTLFLAG_RW,
113 &VNET_NAME(ip_sendsourcequench), 0,
114 "Enable the transmission of source quench packets");
115
116VNET_DEFINE(int, ip_do_randomid);
117SYSCTL_VNET_INT(_net_inet_ip, OID_AUTO, random_id, CTLFLAG_RW,
118 &VNET_NAME(ip_do_randomid), 0,
119 "Assign random ip_id values");
120
121/*
122 * XXX - Setting ip_checkinterface mostly implements the receive side of
123 * the Strong ES model described in RFC 1122, but since the routing table
124 * and transmit implementation do not implement the Strong ES model,
125 * setting this to 1 results in an odd hybrid.
126 *
127 * XXX - ip_checkinterface currently must be disabled if you use ipnat
128 * to translate the destination address to another local interface.
129 *
130 * XXX - ip_checkinterface must be disabled if you add IP aliases
131 * to the loopback interface instead of the interface where the
132 * packets for those addresses are received.
133 */
134static VNET_DEFINE(int, ip_checkinterface);
135#define V_ip_checkinterface VNET(ip_checkinterface)
136SYSCTL_VNET_INT(_net_inet_ip, OID_AUTO, check_interface, CTLFLAG_RW,
137 &VNET_NAME(ip_checkinterface), 0,
138 "Verify packet arrives on correct interface");
139
140VNET_DEFINE(struct pfil_head, inet_pfil_hook); /* Packet filter hooks */
141
142static struct netisr_handler ip_nh = {
143 .nh_name = "ip",
144 .nh_handler = ip_input,
145 .nh_proto = NETISR_IP,
146 .nh_policy = NETISR_POLICY_FLOW,
147};
148
149extern struct domain inetdomain;
150extern struct protosw inetsw[];
151u_char ip_protox[IPPROTO_MAX];
152VNET_DEFINE(struct in_ifaddrhead, in_ifaddrhead); /* first inet address */
153VNET_DEFINE(struct in_ifaddrhashhead *, in_ifaddrhashtbl); /* inet addr hash table */
154VNET_DEFINE(u_long, in_ifaddrhmask); /* mask for hash table */
155
156static VNET_DEFINE(uma_zone_t, ipq_zone);
157static VNET_DEFINE(TAILQ_HEAD(ipqhead, ipq), ipq[IPREASS_NHASH]);
158static struct mtx ipqlock;
159
160#define V_ipq_zone VNET(ipq_zone)
161#define V_ipq VNET(ipq)
162
163#define IPQ_LOCK() mtx_lock(&ipqlock)
164#define IPQ_UNLOCK() mtx_unlock(&ipqlock)
165#define IPQ_LOCK_INIT() mtx_init(&ipqlock, "ipqlock", NULL, MTX_DEF)
166#define IPQ_LOCK_ASSERT() mtx_assert(&ipqlock, MA_OWNED)
167
168static void maxnipq_update(void);
169static void ipq_zone_change(void *);
170static void ip_drain_locked(void);
171
172static VNET_DEFINE(int, maxnipq); /* Administrative limit on # reass queues. */
173static VNET_DEFINE(int, nipq); /* Total # of reass queues */
174#define V_maxnipq VNET(maxnipq)
175#define V_nipq VNET(nipq)
176SYSCTL_VNET_INT(_net_inet_ip, OID_AUTO, fragpackets, CTLFLAG_RD,
177 &VNET_NAME(nipq), 0,
178 "Current number of IPv4 fragment reassembly queue entries");
179
180static VNET_DEFINE(int, maxfragsperpacket);
181#define V_maxfragsperpacket VNET(maxfragsperpacket)
182SYSCTL_VNET_INT(_net_inet_ip, OID_AUTO, maxfragsperpacket, CTLFLAG_RW,
183 &VNET_NAME(maxfragsperpacket), 0,
184 "Maximum number of IPv4 fragments allowed per packet");
185
186#ifdef IPCTL_DEFMTU
187SYSCTL_INT(_net_inet_ip, IPCTL_DEFMTU, mtu, CTLFLAG_RW,
188 &ip_mtu, 0, "Default MTU");
189#endif
190
191#ifdef IPSTEALTH
192VNET_DEFINE(int, ipstealth);
193SYSCTL_VNET_INT(_net_inet_ip, OID_AUTO, stealth, CTLFLAG_RW,
194 &VNET_NAME(ipstealth), 0,
195 "IP stealth mode, no TTL decrementation on forwarding");
196#endif
197
198#ifdef FLOWTABLE
199static VNET_DEFINE(int, ip_output_flowtable_size) = 2048;
200VNET_DEFINE(struct flowtable *, ip_ft);
201#define V_ip_output_flowtable_size VNET(ip_output_flowtable_size)
202
203SYSCTL_VNET_INT(_net_inet_ip, OID_AUTO, output_flowtable_size, CTLFLAG_RDTUN,
204 &VNET_NAME(ip_output_flowtable_size), 2048,
205 "number of entries in the per-cpu output flow caches");
206#endif
207
208static void ip_freef(struct ipqhead *, struct ipq *);
209
210/*
211 * IP statistics are stored in the "array" of counter(9)s.
212 */
213VNET_PCPUSTAT_DEFINE(struct ipstat, ipstat);
214VNET_PCPUSTAT_SYSINIT(ipstat);
215SYSCTL_VNET_PCPUSTAT(_net_inet_ip, IPCTL_STATS, stats, struct ipstat, ipstat,
216 "IP statistics (struct ipstat, netinet/ip_var.h)");
217
218#ifdef VIMAGE
219VNET_PCPUSTAT_SYSUNINIT(ipstat);
220#endif /* VIMAGE */
221
222/*
223 * Kernel module interface for updating ipstat. The argument is an index
224 * into ipstat treated as an array.
225 */
226void
227kmod_ipstat_inc(int statnum)
228{
229
230 counter_u64_add(VNET(ipstat)[statnum], 1);
231}
232
233void
234kmod_ipstat_dec(int statnum)
235{
236
237 counter_u64_add(VNET(ipstat)[statnum], -1);
238}
239
240static int
241sysctl_netinet_intr_queue_maxlen(SYSCTL_HANDLER_ARGS)
242{
243 int error, qlimit;
244
245 netisr_getqlimit(&ip_nh, &qlimit);
246 error = sysctl_handle_int(oidp, &qlimit, 0, req);
247 if (error || !req->newptr)
248 return (error);
249 if (qlimit < 1)
250 return (EINVAL);
251 return (netisr_setqlimit(&ip_nh, qlimit));
252}
253SYSCTL_PROC(_net_inet_ip, IPCTL_INTRQMAXLEN, intr_queue_maxlen,
254 CTLTYPE_INT|CTLFLAG_RW, 0, 0, sysctl_netinet_intr_queue_maxlen, "I",
255 "Maximum size of the IP input queue");
256
257static int
258sysctl_netinet_intr_queue_drops(SYSCTL_HANDLER_ARGS)
259{
260 u_int64_t qdrops_long;
261 int error, qdrops;
262
263 netisr_getqdrops(&ip_nh, &qdrops_long);
264 qdrops = qdrops_long;
265 error = sysctl_handle_int(oidp, &qdrops, 0, req);
266 if (error || !req->newptr)
267 return (error);
268 if (qdrops != 0)
269 return (EINVAL);
270 netisr_clearqdrops(&ip_nh);
271 return (0);
272}
273
274SYSCTL_PROC(_net_inet_ip, IPCTL_INTRQDROPS, intr_queue_drops,
275 CTLTYPE_INT|CTLFLAG_RD, 0, 0, sysctl_netinet_intr_queue_drops, "I",
276 "Number of packets dropped from the IP input queue");
277
278/*
279 * IP initialization: fill in IP protocol switch table.
280 * All protocols not implemented in kernel go to raw IP protocol handler.
281 */
282void
283ip_init(void)
284{
285 struct protosw *pr;
286 int i;
287
288 V_ip_id = time_second & 0xffff;
289
290 TAILQ_INIT(&V_in_ifaddrhead);
291 V_in_ifaddrhashtbl = hashinit(INADDR_NHASH, M_IFADDR, &V_in_ifaddrhmask);
292
293 /* Initialize IP reassembly queue. */
294 for (i = 0; i < IPREASS_NHASH; i++)
295 TAILQ_INIT(&V_ipq[i]);
296 V_maxnipq = nmbclusters / 32;
297 V_maxfragsperpacket = 16;
298 V_ipq_zone = uma_zcreate("ipq", sizeof(struct ipq), NULL, NULL, NULL,
299 NULL, UMA_ALIGN_PTR, 0);
300 maxnipq_update();
301
302 /* Initialize packet filter hooks. */
303 V_inet_pfil_hook.ph_type = PFIL_TYPE_AF;
304 V_inet_pfil_hook.ph_af = AF_INET;
305 if ((i = pfil_head_register(&V_inet_pfil_hook)) != 0)
306 printf("%s: WARNING: unable to register pfil hook, "
307 "error %d\n", __func__, i);
308
309#ifdef FLOWTABLE
310 if (TUNABLE_INT_FETCH("net.inet.ip.output_flowtable_size",
311 &V_ip_output_flowtable_size)) {
312 if (V_ip_output_flowtable_size < 256)
313 V_ip_output_flowtable_size = 256;
314 if (!powerof2(V_ip_output_flowtable_size)) {
315 printf("flowtable must be power of 2 size\n");
316 V_ip_output_flowtable_size = 2048;
317 }
318 } else {
319 /*
320 * round up to the next power of 2
321 */
322 V_ip_output_flowtable_size = 1 << fls((1024 + maxusers * 64)-1);
323 }
324 V_ip_ft = flowtable_alloc("ipv4", V_ip_output_flowtable_size, FL_PCPU);
325#endif
326
327 /* Skip initialization of globals for non-default instances. */
328 if (!IS_DEFAULT_VNET(curvnet))
329 return;
330
331 pr = pffindproto(PF_INET, IPPROTO_RAW, SOCK_RAW);
332 if (pr == NULL)
333 panic("ip_init: PF_INET not found");
334
335 /* Initialize the entire ip_protox[] array to IPPROTO_RAW. */
336 for (i = 0; i < IPPROTO_MAX; i++)
337 ip_protox[i] = pr - inetsw;
338 /*
339 * Cycle through IP protocols and put them into the appropriate place
340 * in ip_protox[].
341 */
342 for (pr = inetdomain.dom_protosw;
343 pr < inetdomain.dom_protoswNPROTOSW; pr++)
344 if (pr->pr_domain->dom_family == PF_INET &&
345 pr->pr_protocol && pr->pr_protocol != IPPROTO_RAW) {
346 /* Be careful to only index valid IP protocols. */
347 if (pr->pr_protocol < IPPROTO_MAX)
348 ip_protox[pr->pr_protocol] = pr - inetsw;
349 }
350
351 EVENTHANDLER_REGISTER(nmbclusters_change, ipq_zone_change,
352 NULL, EVENTHANDLER_PRI_ANY);
353
354 /* Initialize various other remaining things. */
355 IPQ_LOCK_INIT();
356 netisr_register(&ip_nh);
357}
358
359#ifdef VIMAGE
360void
361ip_destroy(void)
362{
363
364 /* Cleanup in_ifaddr hash table; should be empty. */
365 hashdestroy(V_in_ifaddrhashtbl, M_IFADDR, V_in_ifaddrhmask);
366
367 IPQ_LOCK();
368 ip_drain_locked();
369 IPQ_UNLOCK();
370
371 uma_zdestroy(V_ipq_zone);
372}
373#endif
374
375/*
376 * Ip input routine. Checksum and byte swap header. If fragmented
377 * try to reassemble. Process options. Pass to next level.
378 */
379void
380ip_input(struct mbuf *m)
381{
382 struct ip *ip = NULL;
383 struct in_ifaddr *ia = NULL;
384 struct ifaddr *ifa;
385 struct ifnet *ifp;
386 int checkif, hlen = 0;
387 uint16_t sum, ip_len;
388 int dchg = 0; /* dest changed after fw */
389 struct in_addr odst; /* original dst address */
390
391 M_ASSERTPKTHDR(m);
392
393 if (m->m_flags & M_FASTFWD_OURS) {
394 m->m_flags &= ~M_FASTFWD_OURS;
395 /* Set up some basics that will be used later. */
396 ip = mtod(m, struct ip *);
397 hlen = ip->ip_hl << 2;
398 ip_len = ntohs(ip->ip_len);
399 goto ours;
400 }
401
402 IPSTAT_INC(ips_total);
403
404 if (m->m_pkthdr.len < sizeof(struct ip))
405 goto tooshort;
406
407 if (m->m_len < sizeof (struct ip) &&
408 (m = m_pullup(m, sizeof (struct ip))) == NULL) {
409 IPSTAT_INC(ips_toosmall);
410 return;
411 }
412 ip = mtod(m, struct ip *);
413
414 if (ip->ip_v != IPVERSION) {
415 IPSTAT_INC(ips_badvers);
416 goto bad;
417 }
418
419 hlen = ip->ip_hl << 2;
420 if (hlen < sizeof(struct ip)) { /* minimum header length */
421 IPSTAT_INC(ips_badhlen);
422 goto bad;
423 }
424 if (hlen > m->m_len) {
425 if ((m = m_pullup(m, hlen)) == NULL) {
426 IPSTAT_INC(ips_badhlen);
427 return;
428 }
429 ip = mtod(m, struct ip *);
430 }
431
432 /* 127/8 must not appear on wire - RFC1122 */
433 ifp = m->m_pkthdr.rcvif;
434 if ((ntohl(ip->ip_dst.s_addr) >> IN_CLASSA_NSHIFT) == IN_LOOPBACKNET ||
435 (ntohl(ip->ip_src.s_addr) >> IN_CLASSA_NSHIFT) == IN_LOOPBACKNET) {
436 if ((ifp->if_flags & IFF_LOOPBACK) == 0) {
437 IPSTAT_INC(ips_badaddr);
438 goto bad;
439 }
440 }
441
442 if (m->m_pkthdr.csum_flags & CSUM_IP_CHECKED) {
443 sum = !(m->m_pkthdr.csum_flags & CSUM_IP_VALID);
444 } else {
445 if (hlen == sizeof(struct ip)) {
446 sum = in_cksum_hdr(ip);
447 } else {
448 sum = in_cksum(m, hlen);
449 }
450 }
451 if (sum) {
452 IPSTAT_INC(ips_badsum);
453 goto bad;
454 }
455
456#ifdef ALTQ
457 if (altq_input != NULL && (*altq_input)(m, AF_INET) == 0)
458 /* packet is dropped by traffic conditioner */
459 return;
460#endif
461
462 ip_len = ntohs(ip->ip_len);
463 if (ip_len < hlen) {
464 IPSTAT_INC(ips_badlen);
465 goto bad;
466 }
467
468 /*
469 * Check that the amount of data in the buffers
470 * is as at least much as the IP header would have us expect.
471 * Trim mbufs if longer than we expect.
472 * Drop packet if shorter than we expect.
473 */
474 if (m->m_pkthdr.len < ip_len) {
475tooshort:
476 IPSTAT_INC(ips_tooshort);
477 goto bad;
478 }
479 if (m->m_pkthdr.len > ip_len) {
480 if (m->m_len == m->m_pkthdr.len) {
481 m->m_len = ip_len;
482 m->m_pkthdr.len = ip_len;
483 } else
484 m_adj(m, ip_len - m->m_pkthdr.len);
485 }
486#ifdef IPSEC
487 /*
488 * Bypass packet filtering for packets previously handled by IPsec.
489 */
490 if (ip_ipsec_filtertunnel(m))
491 goto passin;
492#endif /* IPSEC */
493
494 /*
495 * Run through list of hooks for input packets.
496 *
497 * NB: Beware of the destination address changing (e.g.
498 * by NAT rewriting). When this happens, tell
499 * ip_forward to do the right thing.
500 */
501
502 /* Jump over all PFIL processing if hooks are not active. */
503 if (!PFIL_HOOKED(&V_inet_pfil_hook))
504 goto passin;
505
506 odst = ip->ip_dst;
507 if (pfil_run_hooks(&V_inet_pfil_hook, &m, ifp, PFIL_IN, NULL) != 0)
508 return;
509 if (m == NULL) /* consumed by filter */
510 return;
511
512 ip = mtod(m, struct ip *);
513 dchg = (odst.s_addr != ip->ip_dst.s_addr);
514 ifp = m->m_pkthdr.rcvif;
515
516 if (m->m_flags & M_FASTFWD_OURS) {
517 m->m_flags &= ~M_FASTFWD_OURS;
518 goto ours;
519 }
520 if (m->m_flags & M_IP_NEXTHOP) {
521 dchg = (m_tag_find(m, PACKET_TAG_IPFORWARD, NULL) != NULL);
522 if (dchg != 0) {
523 /*
524 * Directly ship the packet on. This allows
525 * forwarding packets originally destined to us
526 * to some other directly connected host.
527 */
528 ip_forward(m, 1);
529 return;
530 }
531 }
532passin:
533
534 /*
535 * Process options and, if not destined for us,
536 * ship it on. ip_dooptions returns 1 when an
537 * error was detected (causing an icmp message
538 * to be sent and the original packet to be freed).
539 */
540 if (hlen > sizeof (struct ip) && ip_dooptions(m, 0))
541 return;
542
543 /* greedy RSVP, snatches any PATH packet of the RSVP protocol and no
544 * matter if it is destined to another node, or whether it is
545 * a multicast one, RSVP wants it! and prevents it from being forwarded
546 * anywhere else. Also checks if the rsvp daemon is running before
547 * grabbing the packet.
548 */
549 if (V_rsvp_on && ip->ip_p==IPPROTO_RSVP)
550 goto ours;
551
552 /*
553 * Check our list of addresses, to see if the packet is for us.
554 * If we don't have any addresses, assume any unicast packet
555 * we receive might be for us (and let the upper layers deal
556 * with it).
557 */
558 if (TAILQ_EMPTY(&V_in_ifaddrhead) &&
559 (m->m_flags & (M_MCAST|M_BCAST)) == 0)
560 goto ours;
561
562 /*
563 * Enable a consistency check between the destination address
564 * and the arrival interface for a unicast packet (the RFC 1122
565 * strong ES model) if IP forwarding is disabled and the packet
566 * is not locally generated and the packet is not subject to
567 * 'ipfw fwd'.
568 *
569 * XXX - Checking also should be disabled if the destination
570 * address is ipnat'ed to a different interface.
571 *
572 * XXX - Checking is incompatible with IP aliases added
573 * to the loopback interface instead of the interface where
574 * the packets are received.
575 *
576 * XXX - This is the case for carp vhost IPs as well so we
577 * insert a workaround. If the packet got here, we already
578 * checked with carp_iamatch() and carp_forus().
579 */
580 checkif = V_ip_checkinterface && (V_ipforwarding == 0) &&
581 ifp != NULL && ((ifp->if_flags & IFF_LOOPBACK) == 0) &&
582 ifp->if_carp == NULL && (dchg == 0);
583
584 /*
585 * Check for exact addresses in the hash bucket.
586 */
587 /* IN_IFADDR_RLOCK(); */
588 LIST_FOREACH(ia, INADDR_HASH(ip->ip_dst.s_addr), ia_hash) {
589 /*
590 * If the address matches, verify that the packet
591 * arrived via the correct interface if checking is
592 * enabled.
593 */
594 if (IA_SIN(ia)->sin_addr.s_addr == ip->ip_dst.s_addr &&
595 (!checkif || ia->ia_ifp == ifp)) {
596 ifa_ref(&ia->ia_ifa);
597 /* IN_IFADDR_RUNLOCK(); */
598 goto ours;
599 }
600 }
601 /* IN_IFADDR_RUNLOCK(); */
602
603 /*
604 * Check for broadcast addresses.
605 *
606 * Only accept broadcast packets that arrive via the matching
607 * interface. Reception of forwarded directed broadcasts would
608 * be handled via ip_forward() and ether_output() with the loopback
609 * into the stack for SIMPLEX interfaces handled by ether_output().
610 */
611 if (ifp != NULL && ifp->if_flags & IFF_BROADCAST) {
612 IF_ADDR_RLOCK(ifp);
613 TAILQ_FOREACH(ifa, &ifp->if_addrhead, ifa_link) {
614 if (ifa->ifa_addr->sa_family != AF_INET)
615 continue;
616 ia = ifatoia(ifa);
617 if (satosin(&ia->ia_broadaddr)->sin_addr.s_addr ==
618 ip->ip_dst.s_addr) {
619 ifa_ref(ifa);
620 IF_ADDR_RUNLOCK(ifp);
621 goto ours;
622 }
623#ifdef BOOTP_COMPAT
624 if (IA_SIN(ia)->sin_addr.s_addr == INADDR_ANY) {
625 ifa_ref(ifa);
626 IF_ADDR_RUNLOCK(ifp);
627 goto ours;
628 }
629#endif
630 }
631 IF_ADDR_RUNLOCK(ifp);
632 ia = NULL;
633 }
634 /* RFC 3927 2.7: Do not forward datagrams for 169.254.0.0/16. */
635 if (IN_LINKLOCAL(ntohl(ip->ip_dst.s_addr))) {
636 IPSTAT_INC(ips_cantforward);
637 m_freem(m);
638 return;
639 }
640 if (IN_MULTICAST(ntohl(ip->ip_dst.s_addr))) {
641 if (V_ip_mrouter) {
642 /*
643 * If we are acting as a multicast router, all
644 * incoming multicast packets are passed to the
645 * kernel-level multicast forwarding function.
646 * The packet is returned (relatively) intact; if
647 * ip_mforward() returns a non-zero value, the packet
648 * must be discarded, else it may be accepted below.
649 */
650 if (ip_mforward && ip_mforward(ip, ifp, m, 0) != 0) {
651 IPSTAT_INC(ips_cantforward);
652 m_freem(m);
653 return;
654 }
655
656 /*
657 * The process-level routing daemon needs to receive
658 * all multicast IGMP packets, whether or not this
659 * host belongs to their destination groups.
660 */
661 if (ip->ip_p == IPPROTO_IGMP)
662 goto ours;
663 IPSTAT_INC(ips_forward);
664 }
665 /*
666 * Assume the packet is for us, to avoid prematurely taking
667 * a lock on the in_multi hash. Protocols must perform
668 * their own filtering and update statistics accordingly.
669 */
670 goto ours;
671 }
672 if (ip->ip_dst.s_addr == (u_long)INADDR_BROADCAST)
673 goto ours;
674 if (ip->ip_dst.s_addr == INADDR_ANY)
675 goto ours;
676
677 /*
678 * FAITH(Firewall Aided Internet Translator)
679 */
680 if (ifp && ifp->if_type == IFT_FAITH) {
681 if (V_ip_keepfaith) {
682 if (ip->ip_p == IPPROTO_TCP || ip->ip_p == IPPROTO_ICMP)
683 goto ours;
684 }
685 m_freem(m);
686 return;
687 }
688
689 /*
690 * Not for us; forward if possible and desirable.
691 */
692 if (V_ipforwarding == 0) {
693 IPSTAT_INC(ips_cantforward);
694 m_freem(m);
695 } else {
696#ifdef IPSEC
697 if (ip_ipsec_fwd(m))
698 goto bad;
699#endif /* IPSEC */
700 ip_forward(m, dchg);
701 }
702 return;
703
704ours:
705#ifdef IPSTEALTH
706 /*
707 * IPSTEALTH: Process non-routing options only
708 * if the packet is destined for us.
709 */
710 if (V_ipstealth && hlen > sizeof (struct ip) && ip_dooptions(m, 1)) {
711 if (ia != NULL)
712 ifa_free(&ia->ia_ifa);
713 return;
714 }
715#endif /* IPSTEALTH */
716
717 /* Count the packet in the ip address stats */
718 if (ia != NULL) {
719 ia->ia_ifa.if_ipackets++;
720 ia->ia_ifa.if_ibytes += m->m_pkthdr.len;
721 ifa_free(&ia->ia_ifa);
722 }
723
724 /*
725 * Attempt reassembly; if it succeeds, proceed.
726 * ip_reass() will return a different mbuf.
727 */
728 if (ip->ip_off & htons(IP_MF | IP_OFFMASK)) {
729 m = ip_reass(m);
730 if (m == NULL)
731 return;
732 ip = mtod(m, struct ip *);
733 /* Get the header length of the reassembled packet */
734 hlen = ip->ip_hl << 2;
735 }
736
737#ifdef IPSEC
738 /*
739 * enforce IPsec policy checking if we are seeing last header.
740 * note that we do not visit this with protocols with pcb layer
741 * code - like udp/tcp/raw ip.
742 */
743 if (ip_ipsec_input(m))
744 goto bad;
745#endif /* IPSEC */
746
747 /*
748 * Switch out to protocol's input routine.
749 */
750 IPSTAT_INC(ips_delivered);
751
752 (*inetsw[ip_protox[ip->ip_p]].pr_input)(m, hlen);
753 return;
754bad:
755 m_freem(m);
756}
757
758/*
759 * After maxnipq has been updated, propagate the change to UMA. The UMA zone
760 * max has slightly different semantics than the sysctl, for historical
761 * reasons.
762 */
763static void
764maxnipq_update(void)
765{
766
767 /*
768 * -1 for unlimited allocation.
769 */
770 if (V_maxnipq < 0)
771 uma_zone_set_max(V_ipq_zone, 0);
772 /*
773 * Positive number for specific bound.
774 */
775 if (V_maxnipq > 0)
776 uma_zone_set_max(V_ipq_zone, V_maxnipq);
777 /*
778 * Zero specifies no further fragment queue allocation -- set the
779 * bound very low, but rely on implementation elsewhere to actually
780 * prevent allocation and reclaim current queues.
781 */
782 if (V_maxnipq == 0)
783 uma_zone_set_max(V_ipq_zone, 1);
784}
785
786static void
787ipq_zone_change(void *tag)
788{
789
790 if (V_maxnipq > 0 && V_maxnipq < (nmbclusters / 32)) {
791 V_maxnipq = nmbclusters / 32;
792 maxnipq_update();
793 }
794}
795
796static int
797sysctl_maxnipq(SYSCTL_HANDLER_ARGS)
798{
799 int error, i;
800
801 i = V_maxnipq;
802 error = sysctl_handle_int(oidp, &i, 0, req);
803 if (error || !req->newptr)
804 return (error);
805
806 /*
807 * XXXRW: Might be a good idea to sanity check the argument and place
808 * an extreme upper bound.
809 */
810 if (i < -1)
811 return (EINVAL);
812 V_maxnipq = i;
813 maxnipq_update();
814 return (0);
815}
816
817SYSCTL_PROC(_net_inet_ip, OID_AUTO, maxfragpackets, CTLTYPE_INT|CTLFLAG_RW,
818 NULL, 0, sysctl_maxnipq, "I",
819 "Maximum number of IPv4 fragment reassembly queue entries");
820
821/*
822 * Take incoming datagram fragment and try to reassemble it into
823 * whole datagram. If the argument is the first fragment or one
824 * in between the function will return NULL and store the mbuf
825 * in the fragment chain. If the argument is the last fragment
826 * the packet will be reassembled and the pointer to the new
827 * mbuf returned for further processing. Only m_tags attached
828 * to the first packet/fragment are preserved.
829 * The IP header is *NOT* adjusted out of iplen.
830 */
831struct mbuf *
832ip_reass(struct mbuf *m)
833{
834 struct ip *ip;
835 struct mbuf *p, *q, *nq, *t;
836 struct ipq *fp = NULL;
837 struct ipqhead *head;
838 int i, hlen, next;
839 u_int8_t ecn, ecn0;
840 u_short hash;
841
842 /* If maxnipq or maxfragsperpacket are 0, never accept fragments. */
843 if (V_maxnipq == 0 || V_maxfragsperpacket == 0) {
844 IPSTAT_INC(ips_fragments);
845 IPSTAT_INC(ips_fragdropped);
846 m_freem(m);
847 return (NULL);
848 }
849
850 ip = mtod(m, struct ip *);
851 hlen = ip->ip_hl << 2;
852
853 hash = IPREASS_HASH(ip->ip_src.s_addr, ip->ip_id);
854 head = &V_ipq[hash];
855 IPQ_LOCK();
856
857 /*
858 * Look for queue of fragments
859 * of this datagram.
860 */
861 TAILQ_FOREACH(fp, head, ipq_list)
862 if (ip->ip_id == fp->ipq_id &&
863 ip->ip_src.s_addr == fp->ipq_src.s_addr &&
864 ip->ip_dst.s_addr == fp->ipq_dst.s_addr &&
865#ifdef MAC
866 mac_ipq_match(m, fp) &&
867#endif
868 ip->ip_p == fp->ipq_p)
869 goto found;
870
871 fp = NULL;
872
873 /*
874 * Attempt to trim the number of allocated fragment queues if it
875 * exceeds the administrative limit.
876 */
877 if ((V_nipq > V_maxnipq) && (V_maxnipq > 0)) {
878 /*
879 * drop something from the tail of the current queue
880 * before proceeding further
881 */
882 struct ipq *q = TAILQ_LAST(head, ipqhead);
883 if (q == NULL) { /* gak */
884 for (i = 0; i < IPREASS_NHASH; i++) {
885 struct ipq *r = TAILQ_LAST(&V_ipq[i], ipqhead);
886 if (r) {
887 IPSTAT_ADD(ips_fragtimeout,
888 r->ipq_nfrags);
889 ip_freef(&V_ipq[i], r);
890 break;
891 }
892 }
893 } else {
894 IPSTAT_ADD(ips_fragtimeout, q->ipq_nfrags);
895 ip_freef(head, q);
896 }
897 }
898
899found:
900 /*
901 * Adjust ip_len to not reflect header,
902 * convert offset of this to bytes.
903 */
904 ip->ip_len = htons(ntohs(ip->ip_len) - hlen);
905 if (ip->ip_off & htons(IP_MF)) {
906 /*
907 * Make sure that fragments have a data length
908 * that's a non-zero multiple of 8 bytes.
909 */
910 if (ip->ip_len == htons(0) || (ntohs(ip->ip_len) & 0x7) != 0) {
911 IPSTAT_INC(ips_toosmall); /* XXX */
912 goto dropfrag;
913 }
914 m->m_flags |= M_IP_FRAG;
915 } else
916 m->m_flags &= ~M_IP_FRAG;
917 ip->ip_off = htons(ntohs(ip->ip_off) << 3);
918
919 /*
920 * Attempt reassembly; if it succeeds, proceed.
921 * ip_reass() will return a different mbuf.
922 */
923 IPSTAT_INC(ips_fragments);
| 34
35#include "opt_bootp.h"
36#include "opt_ipfw.h"
37#include "opt_ipstealth.h"
38#include "opt_ipsec.h"
39#include "opt_route.h"
40
41#include <sys/param.h>
42#include <sys/systm.h>
43#include <sys/mbuf.h>
44#include <sys/malloc.h>
45#include <sys/domain.h>
46#include <sys/protosw.h>
47#include <sys/socket.h>
48#include <sys/time.h>
49#include <sys/kernel.h>
50#include <sys/lock.h>
51#include <sys/rwlock.h>
52#include <sys/syslog.h>
53#include <sys/sysctl.h>
54
55#include <net/pfil.h>
56#include <net/if.h>
57#include <net/if_types.h>
58#include <net/if_var.h>
59#include <net/if_dl.h>
60#include <net/route.h>
61#include <net/netisr.h>
62#include <net/vnet.h>
63#include <net/flowtable.h>
64
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_fw.h>
72#include <netinet/ip_icmp.h>
73#include <netinet/ip_options.h>
74#include <machine/in_cksum.h>
75#include <netinet/ip_carp.h>
76#ifdef IPSEC
77#include <netinet/ip_ipsec.h>
78#endif /* IPSEC */
79
80#include <sys/socketvar.h>
81
82#include <security/mac/mac_framework.h>
83
84#ifdef CTASSERT
85CTASSERT(sizeof(struct ip) == 20);
86#endif
87
88struct rwlock in_ifaddr_lock;
89RW_SYSINIT(in_ifaddr_lock, &in_ifaddr_lock, "in_ifaddr_lock");
90
91VNET_DEFINE(int, rsvp_on);
92
93VNET_DEFINE(int, ipforwarding);
94SYSCTL_VNET_INT(_net_inet_ip, IPCTL_FORWARDING, forwarding, CTLFLAG_RW,
95 &VNET_NAME(ipforwarding), 0,
96 "Enable IP forwarding between interfaces");
97
98static VNET_DEFINE(int, ipsendredirects) = 1; /* XXX */
99#define V_ipsendredirects VNET(ipsendredirects)
100SYSCTL_VNET_INT(_net_inet_ip, IPCTL_SENDREDIRECTS, redirect, CTLFLAG_RW,
101 &VNET_NAME(ipsendredirects), 0,
102 "Enable sending IP redirects");
103
104static VNET_DEFINE(int, ip_keepfaith);
105#define V_ip_keepfaith VNET(ip_keepfaith)
106SYSCTL_VNET_INT(_net_inet_ip, IPCTL_KEEPFAITH, keepfaith, CTLFLAG_RW,
107 &VNET_NAME(ip_keepfaith), 0,
108 "Enable packet capture for FAITH IPv4->IPv6 translater daemon");
109
110static VNET_DEFINE(int, ip_sendsourcequench);
111#define V_ip_sendsourcequench VNET(ip_sendsourcequench)
112SYSCTL_VNET_INT(_net_inet_ip, OID_AUTO, sendsourcequench, CTLFLAG_RW,
113 &VNET_NAME(ip_sendsourcequench), 0,
114 "Enable the transmission of source quench packets");
115
116VNET_DEFINE(int, ip_do_randomid);
117SYSCTL_VNET_INT(_net_inet_ip, OID_AUTO, random_id, CTLFLAG_RW,
118 &VNET_NAME(ip_do_randomid), 0,
119 "Assign random ip_id values");
120
121/*
122 * XXX - Setting ip_checkinterface mostly implements the receive side of
123 * the Strong ES model described in RFC 1122, but since the routing table
124 * and transmit implementation do not implement the Strong ES model,
125 * setting this to 1 results in an odd hybrid.
126 *
127 * XXX - ip_checkinterface currently must be disabled if you use ipnat
128 * to translate the destination address to another local interface.
129 *
130 * XXX - ip_checkinterface must be disabled if you add IP aliases
131 * to the loopback interface instead of the interface where the
132 * packets for those addresses are received.
133 */
134static VNET_DEFINE(int, ip_checkinterface);
135#define V_ip_checkinterface VNET(ip_checkinterface)
136SYSCTL_VNET_INT(_net_inet_ip, OID_AUTO, check_interface, CTLFLAG_RW,
137 &VNET_NAME(ip_checkinterface), 0,
138 "Verify packet arrives on correct interface");
139
140VNET_DEFINE(struct pfil_head, inet_pfil_hook); /* Packet filter hooks */
141
142static struct netisr_handler ip_nh = {
143 .nh_name = "ip",
144 .nh_handler = ip_input,
145 .nh_proto = NETISR_IP,
146 .nh_policy = NETISR_POLICY_FLOW,
147};
148
149extern struct domain inetdomain;
150extern struct protosw inetsw[];
151u_char ip_protox[IPPROTO_MAX];
152VNET_DEFINE(struct in_ifaddrhead, in_ifaddrhead); /* first inet address */
153VNET_DEFINE(struct in_ifaddrhashhead *, in_ifaddrhashtbl); /* inet addr hash table */
154VNET_DEFINE(u_long, in_ifaddrhmask); /* mask for hash table */
155
156static VNET_DEFINE(uma_zone_t, ipq_zone);
157static VNET_DEFINE(TAILQ_HEAD(ipqhead, ipq), ipq[IPREASS_NHASH]);
158static struct mtx ipqlock;
159
160#define V_ipq_zone VNET(ipq_zone)
161#define V_ipq VNET(ipq)
162
163#define IPQ_LOCK() mtx_lock(&ipqlock)
164#define IPQ_UNLOCK() mtx_unlock(&ipqlock)
165#define IPQ_LOCK_INIT() mtx_init(&ipqlock, "ipqlock", NULL, MTX_DEF)
166#define IPQ_LOCK_ASSERT() mtx_assert(&ipqlock, MA_OWNED)
167
168static void maxnipq_update(void);
169static void ipq_zone_change(void *);
170static void ip_drain_locked(void);
171
172static VNET_DEFINE(int, maxnipq); /* Administrative limit on # reass queues. */
173static VNET_DEFINE(int, nipq); /* Total # of reass queues */
174#define V_maxnipq VNET(maxnipq)
175#define V_nipq VNET(nipq)
176SYSCTL_VNET_INT(_net_inet_ip, OID_AUTO, fragpackets, CTLFLAG_RD,
177 &VNET_NAME(nipq), 0,
178 "Current number of IPv4 fragment reassembly queue entries");
179
180static VNET_DEFINE(int, maxfragsperpacket);
181#define V_maxfragsperpacket VNET(maxfragsperpacket)
182SYSCTL_VNET_INT(_net_inet_ip, OID_AUTO, maxfragsperpacket, CTLFLAG_RW,
183 &VNET_NAME(maxfragsperpacket), 0,
184 "Maximum number of IPv4 fragments allowed per packet");
185
186#ifdef IPCTL_DEFMTU
187SYSCTL_INT(_net_inet_ip, IPCTL_DEFMTU, mtu, CTLFLAG_RW,
188 &ip_mtu, 0, "Default MTU");
189#endif
190
191#ifdef IPSTEALTH
192VNET_DEFINE(int, ipstealth);
193SYSCTL_VNET_INT(_net_inet_ip, OID_AUTO, stealth, CTLFLAG_RW,
194 &VNET_NAME(ipstealth), 0,
195 "IP stealth mode, no TTL decrementation on forwarding");
196#endif
197
198#ifdef FLOWTABLE
199static VNET_DEFINE(int, ip_output_flowtable_size) = 2048;
200VNET_DEFINE(struct flowtable *, ip_ft);
201#define V_ip_output_flowtable_size VNET(ip_output_flowtable_size)
202
203SYSCTL_VNET_INT(_net_inet_ip, OID_AUTO, output_flowtable_size, CTLFLAG_RDTUN,
204 &VNET_NAME(ip_output_flowtable_size), 2048,
205 "number of entries in the per-cpu output flow caches");
206#endif
207
208static void ip_freef(struct ipqhead *, struct ipq *);
209
210/*
211 * IP statistics are stored in the "array" of counter(9)s.
212 */
213VNET_PCPUSTAT_DEFINE(struct ipstat, ipstat);
214VNET_PCPUSTAT_SYSINIT(ipstat);
215SYSCTL_VNET_PCPUSTAT(_net_inet_ip, IPCTL_STATS, stats, struct ipstat, ipstat,
216 "IP statistics (struct ipstat, netinet/ip_var.h)");
217
218#ifdef VIMAGE
219VNET_PCPUSTAT_SYSUNINIT(ipstat);
220#endif /* VIMAGE */
221
222/*
223 * Kernel module interface for updating ipstat. The argument is an index
224 * into ipstat treated as an array.
225 */
226void
227kmod_ipstat_inc(int statnum)
228{
229
230 counter_u64_add(VNET(ipstat)[statnum], 1);
231}
232
233void
234kmod_ipstat_dec(int statnum)
235{
236
237 counter_u64_add(VNET(ipstat)[statnum], -1);
238}
239
240static int
241sysctl_netinet_intr_queue_maxlen(SYSCTL_HANDLER_ARGS)
242{
243 int error, qlimit;
244
245 netisr_getqlimit(&ip_nh, &qlimit);
246 error = sysctl_handle_int(oidp, &qlimit, 0, req);
247 if (error || !req->newptr)
248 return (error);
249 if (qlimit < 1)
250 return (EINVAL);
251 return (netisr_setqlimit(&ip_nh, qlimit));
252}
253SYSCTL_PROC(_net_inet_ip, IPCTL_INTRQMAXLEN, intr_queue_maxlen,
254 CTLTYPE_INT|CTLFLAG_RW, 0, 0, sysctl_netinet_intr_queue_maxlen, "I",
255 "Maximum size of the IP input queue");
256
257static int
258sysctl_netinet_intr_queue_drops(SYSCTL_HANDLER_ARGS)
259{
260 u_int64_t qdrops_long;
261 int error, qdrops;
262
263 netisr_getqdrops(&ip_nh, &qdrops_long);
264 qdrops = qdrops_long;
265 error = sysctl_handle_int(oidp, &qdrops, 0, req);
266 if (error || !req->newptr)
267 return (error);
268 if (qdrops != 0)
269 return (EINVAL);
270 netisr_clearqdrops(&ip_nh);
271 return (0);
272}
273
274SYSCTL_PROC(_net_inet_ip, IPCTL_INTRQDROPS, intr_queue_drops,
275 CTLTYPE_INT|CTLFLAG_RD, 0, 0, sysctl_netinet_intr_queue_drops, "I",
276 "Number of packets dropped from the IP input queue");
277
278/*
279 * IP initialization: fill in IP protocol switch table.
280 * All protocols not implemented in kernel go to raw IP protocol handler.
281 */
282void
283ip_init(void)
284{
285 struct protosw *pr;
286 int i;
287
288 V_ip_id = time_second & 0xffff;
289
290 TAILQ_INIT(&V_in_ifaddrhead);
291 V_in_ifaddrhashtbl = hashinit(INADDR_NHASH, M_IFADDR, &V_in_ifaddrhmask);
292
293 /* Initialize IP reassembly queue. */
294 for (i = 0; i < IPREASS_NHASH; i++)
295 TAILQ_INIT(&V_ipq[i]);
296 V_maxnipq = nmbclusters / 32;
297 V_maxfragsperpacket = 16;
298 V_ipq_zone = uma_zcreate("ipq", sizeof(struct ipq), NULL, NULL, NULL,
299 NULL, UMA_ALIGN_PTR, 0);
300 maxnipq_update();
301
302 /* Initialize packet filter hooks. */
303 V_inet_pfil_hook.ph_type = PFIL_TYPE_AF;
304 V_inet_pfil_hook.ph_af = AF_INET;
305 if ((i = pfil_head_register(&V_inet_pfil_hook)) != 0)
306 printf("%s: WARNING: unable to register pfil hook, "
307 "error %d\n", __func__, i);
308
309#ifdef FLOWTABLE
310 if (TUNABLE_INT_FETCH("net.inet.ip.output_flowtable_size",
311 &V_ip_output_flowtable_size)) {
312 if (V_ip_output_flowtable_size < 256)
313 V_ip_output_flowtable_size = 256;
314 if (!powerof2(V_ip_output_flowtable_size)) {
315 printf("flowtable must be power of 2 size\n");
316 V_ip_output_flowtable_size = 2048;
317 }
318 } else {
319 /*
320 * round up to the next power of 2
321 */
322 V_ip_output_flowtable_size = 1 << fls((1024 + maxusers * 64)-1);
323 }
324 V_ip_ft = flowtable_alloc("ipv4", V_ip_output_flowtable_size, FL_PCPU);
325#endif
326
327 /* Skip initialization of globals for non-default instances. */
328 if (!IS_DEFAULT_VNET(curvnet))
329 return;
330
331 pr = pffindproto(PF_INET, IPPROTO_RAW, SOCK_RAW);
332 if (pr == NULL)
333 panic("ip_init: PF_INET not found");
334
335 /* Initialize the entire ip_protox[] array to IPPROTO_RAW. */
336 for (i = 0; i < IPPROTO_MAX; i++)
337 ip_protox[i] = pr - inetsw;
338 /*
339 * Cycle through IP protocols and put them into the appropriate place
340 * in ip_protox[].
341 */
342 for (pr = inetdomain.dom_protosw;
343 pr < inetdomain.dom_protoswNPROTOSW; pr++)
344 if (pr->pr_domain->dom_family == PF_INET &&
345 pr->pr_protocol && pr->pr_protocol != IPPROTO_RAW) {
346 /* Be careful to only index valid IP protocols. */
347 if (pr->pr_protocol < IPPROTO_MAX)
348 ip_protox[pr->pr_protocol] = pr - inetsw;
349 }
350
351 EVENTHANDLER_REGISTER(nmbclusters_change, ipq_zone_change,
352 NULL, EVENTHANDLER_PRI_ANY);
353
354 /* Initialize various other remaining things. */
355 IPQ_LOCK_INIT();
356 netisr_register(&ip_nh);
357}
358
359#ifdef VIMAGE
360void
361ip_destroy(void)
362{
363
364 /* Cleanup in_ifaddr hash table; should be empty. */
365 hashdestroy(V_in_ifaddrhashtbl, M_IFADDR, V_in_ifaddrhmask);
366
367 IPQ_LOCK();
368 ip_drain_locked();
369 IPQ_UNLOCK();
370
371 uma_zdestroy(V_ipq_zone);
372}
373#endif
374
375/*
376 * Ip input routine. Checksum and byte swap header. If fragmented
377 * try to reassemble. Process options. Pass to next level.
378 */
379void
380ip_input(struct mbuf *m)
381{
382 struct ip *ip = NULL;
383 struct in_ifaddr *ia = NULL;
384 struct ifaddr *ifa;
385 struct ifnet *ifp;
386 int checkif, hlen = 0;
387 uint16_t sum, ip_len;
388 int dchg = 0; /* dest changed after fw */
389 struct in_addr odst; /* original dst address */
390
391 M_ASSERTPKTHDR(m);
392
393 if (m->m_flags & M_FASTFWD_OURS) {
394 m->m_flags &= ~M_FASTFWD_OURS;
395 /* Set up some basics that will be used later. */
396 ip = mtod(m, struct ip *);
397 hlen = ip->ip_hl << 2;
398 ip_len = ntohs(ip->ip_len);
399 goto ours;
400 }
401
402 IPSTAT_INC(ips_total);
403
404 if (m->m_pkthdr.len < sizeof(struct ip))
405 goto tooshort;
406
407 if (m->m_len < sizeof (struct ip) &&
408 (m = m_pullup(m, sizeof (struct ip))) == NULL) {
409 IPSTAT_INC(ips_toosmall);
410 return;
411 }
412 ip = mtod(m, struct ip *);
413
414 if (ip->ip_v != IPVERSION) {
415 IPSTAT_INC(ips_badvers);
416 goto bad;
417 }
418
419 hlen = ip->ip_hl << 2;
420 if (hlen < sizeof(struct ip)) { /* minimum header length */
421 IPSTAT_INC(ips_badhlen);
422 goto bad;
423 }
424 if (hlen > m->m_len) {
425 if ((m = m_pullup(m, hlen)) == NULL) {
426 IPSTAT_INC(ips_badhlen);
427 return;
428 }
429 ip = mtod(m, struct ip *);
430 }
431
432 /* 127/8 must not appear on wire - RFC1122 */
433 ifp = m->m_pkthdr.rcvif;
434 if ((ntohl(ip->ip_dst.s_addr) >> IN_CLASSA_NSHIFT) == IN_LOOPBACKNET ||
435 (ntohl(ip->ip_src.s_addr) >> IN_CLASSA_NSHIFT) == IN_LOOPBACKNET) {
436 if ((ifp->if_flags & IFF_LOOPBACK) == 0) {
437 IPSTAT_INC(ips_badaddr);
438 goto bad;
439 }
440 }
441
442 if (m->m_pkthdr.csum_flags & CSUM_IP_CHECKED) {
443 sum = !(m->m_pkthdr.csum_flags & CSUM_IP_VALID);
444 } else {
445 if (hlen == sizeof(struct ip)) {
446 sum = in_cksum_hdr(ip);
447 } else {
448 sum = in_cksum(m, hlen);
449 }
450 }
451 if (sum) {
452 IPSTAT_INC(ips_badsum);
453 goto bad;
454 }
455
456#ifdef ALTQ
457 if (altq_input != NULL && (*altq_input)(m, AF_INET) == 0)
458 /* packet is dropped by traffic conditioner */
459 return;
460#endif
461
462 ip_len = ntohs(ip->ip_len);
463 if (ip_len < hlen) {
464 IPSTAT_INC(ips_badlen);
465 goto bad;
466 }
467
468 /*
469 * Check that the amount of data in the buffers
470 * is as at least much as the IP header would have us expect.
471 * Trim mbufs if longer than we expect.
472 * Drop packet if shorter than we expect.
473 */
474 if (m->m_pkthdr.len < ip_len) {
475tooshort:
476 IPSTAT_INC(ips_tooshort);
477 goto bad;
478 }
479 if (m->m_pkthdr.len > ip_len) {
480 if (m->m_len == m->m_pkthdr.len) {
481 m->m_len = ip_len;
482 m->m_pkthdr.len = ip_len;
483 } else
484 m_adj(m, ip_len - m->m_pkthdr.len);
485 }
486#ifdef IPSEC
487 /*
488 * Bypass packet filtering for packets previously handled by IPsec.
489 */
490 if (ip_ipsec_filtertunnel(m))
491 goto passin;
492#endif /* IPSEC */
493
494 /*
495 * Run through list of hooks for input packets.
496 *
497 * NB: Beware of the destination address changing (e.g.
498 * by NAT rewriting). When this happens, tell
499 * ip_forward to do the right thing.
500 */
501
502 /* Jump over all PFIL processing if hooks are not active. */
503 if (!PFIL_HOOKED(&V_inet_pfil_hook))
504 goto passin;
505
506 odst = ip->ip_dst;
507 if (pfil_run_hooks(&V_inet_pfil_hook, &m, ifp, PFIL_IN, NULL) != 0)
508 return;
509 if (m == NULL) /* consumed by filter */
510 return;
511
512 ip = mtod(m, struct ip *);
513 dchg = (odst.s_addr != ip->ip_dst.s_addr);
514 ifp = m->m_pkthdr.rcvif;
515
516 if (m->m_flags & M_FASTFWD_OURS) {
517 m->m_flags &= ~M_FASTFWD_OURS;
518 goto ours;
519 }
520 if (m->m_flags & M_IP_NEXTHOP) {
521 dchg = (m_tag_find(m, PACKET_TAG_IPFORWARD, NULL) != NULL);
522 if (dchg != 0) {
523 /*
524 * Directly ship the packet on. This allows
525 * forwarding packets originally destined to us
526 * to some other directly connected host.
527 */
528 ip_forward(m, 1);
529 return;
530 }
531 }
532passin:
533
534 /*
535 * Process options and, if not destined for us,
536 * ship it on. ip_dooptions returns 1 when an
537 * error was detected (causing an icmp message
538 * to be sent and the original packet to be freed).
539 */
540 if (hlen > sizeof (struct ip) && ip_dooptions(m, 0))
541 return;
542
543 /* greedy RSVP, snatches any PATH packet of the RSVP protocol and no
544 * matter if it is destined to another node, or whether it is
545 * a multicast one, RSVP wants it! and prevents it from being forwarded
546 * anywhere else. Also checks if the rsvp daemon is running before
547 * grabbing the packet.
548 */
549 if (V_rsvp_on && ip->ip_p==IPPROTO_RSVP)
550 goto ours;
551
552 /*
553 * Check our list of addresses, to see if the packet is for us.
554 * If we don't have any addresses, assume any unicast packet
555 * we receive might be for us (and let the upper layers deal
556 * with it).
557 */
558 if (TAILQ_EMPTY(&V_in_ifaddrhead) &&
559 (m->m_flags & (M_MCAST|M_BCAST)) == 0)
560 goto ours;
561
562 /*
563 * Enable a consistency check between the destination address
564 * and the arrival interface for a unicast packet (the RFC 1122
565 * strong ES model) if IP forwarding is disabled and the packet
566 * is not locally generated and the packet is not subject to
567 * 'ipfw fwd'.
568 *
569 * XXX - Checking also should be disabled if the destination
570 * address is ipnat'ed to a different interface.
571 *
572 * XXX - Checking is incompatible with IP aliases added
573 * to the loopback interface instead of the interface where
574 * the packets are received.
575 *
576 * XXX - This is the case for carp vhost IPs as well so we
577 * insert a workaround. If the packet got here, we already
578 * checked with carp_iamatch() and carp_forus().
579 */
580 checkif = V_ip_checkinterface && (V_ipforwarding == 0) &&
581 ifp != NULL && ((ifp->if_flags & IFF_LOOPBACK) == 0) &&
582 ifp->if_carp == NULL && (dchg == 0);
583
584 /*
585 * Check for exact addresses in the hash bucket.
586 */
587 /* IN_IFADDR_RLOCK(); */
588 LIST_FOREACH(ia, INADDR_HASH(ip->ip_dst.s_addr), ia_hash) {
589 /*
590 * If the address matches, verify that the packet
591 * arrived via the correct interface if checking is
592 * enabled.
593 */
594 if (IA_SIN(ia)->sin_addr.s_addr == ip->ip_dst.s_addr &&
595 (!checkif || ia->ia_ifp == ifp)) {
596 ifa_ref(&ia->ia_ifa);
597 /* IN_IFADDR_RUNLOCK(); */
598 goto ours;
599 }
600 }
601 /* IN_IFADDR_RUNLOCK(); */
602
603 /*
604 * Check for broadcast addresses.
605 *
606 * Only accept broadcast packets that arrive via the matching
607 * interface. Reception of forwarded directed broadcasts would
608 * be handled via ip_forward() and ether_output() with the loopback
609 * into the stack for SIMPLEX interfaces handled by ether_output().
610 */
611 if (ifp != NULL && ifp->if_flags & IFF_BROADCAST) {
612 IF_ADDR_RLOCK(ifp);
613 TAILQ_FOREACH(ifa, &ifp->if_addrhead, ifa_link) {
614 if (ifa->ifa_addr->sa_family != AF_INET)
615 continue;
616 ia = ifatoia(ifa);
617 if (satosin(&ia->ia_broadaddr)->sin_addr.s_addr ==
618 ip->ip_dst.s_addr) {
619 ifa_ref(ifa);
620 IF_ADDR_RUNLOCK(ifp);
621 goto ours;
622 }
623#ifdef BOOTP_COMPAT
624 if (IA_SIN(ia)->sin_addr.s_addr == INADDR_ANY) {
625 ifa_ref(ifa);
626 IF_ADDR_RUNLOCK(ifp);
627 goto ours;
628 }
629#endif
630 }
631 IF_ADDR_RUNLOCK(ifp);
632 ia = NULL;
633 }
634 /* RFC 3927 2.7: Do not forward datagrams for 169.254.0.0/16. */
635 if (IN_LINKLOCAL(ntohl(ip->ip_dst.s_addr))) {
636 IPSTAT_INC(ips_cantforward);
637 m_freem(m);
638 return;
639 }
640 if (IN_MULTICAST(ntohl(ip->ip_dst.s_addr))) {
641 if (V_ip_mrouter) {
642 /*
643 * If we are acting as a multicast router, all
644 * incoming multicast packets are passed to the
645 * kernel-level multicast forwarding function.
646 * The packet is returned (relatively) intact; if
647 * ip_mforward() returns a non-zero value, the packet
648 * must be discarded, else it may be accepted below.
649 */
650 if (ip_mforward && ip_mforward(ip, ifp, m, 0) != 0) {
651 IPSTAT_INC(ips_cantforward);
652 m_freem(m);
653 return;
654 }
655
656 /*
657 * The process-level routing daemon needs to receive
658 * all multicast IGMP packets, whether or not this
659 * host belongs to their destination groups.
660 */
661 if (ip->ip_p == IPPROTO_IGMP)
662 goto ours;
663 IPSTAT_INC(ips_forward);
664 }
665 /*
666 * Assume the packet is for us, to avoid prematurely taking
667 * a lock on the in_multi hash. Protocols must perform
668 * their own filtering and update statistics accordingly.
669 */
670 goto ours;
671 }
672 if (ip->ip_dst.s_addr == (u_long)INADDR_BROADCAST)
673 goto ours;
674 if (ip->ip_dst.s_addr == INADDR_ANY)
675 goto ours;
676
677 /*
678 * FAITH(Firewall Aided Internet Translator)
679 */
680 if (ifp && ifp->if_type == IFT_FAITH) {
681 if (V_ip_keepfaith) {
682 if (ip->ip_p == IPPROTO_TCP || ip->ip_p == IPPROTO_ICMP)
683 goto ours;
684 }
685 m_freem(m);
686 return;
687 }
688
689 /*
690 * Not for us; forward if possible and desirable.
691 */
692 if (V_ipforwarding == 0) {
693 IPSTAT_INC(ips_cantforward);
694 m_freem(m);
695 } else {
696#ifdef IPSEC
697 if (ip_ipsec_fwd(m))
698 goto bad;
699#endif /* IPSEC */
700 ip_forward(m, dchg);
701 }
702 return;
703
704ours:
705#ifdef IPSTEALTH
706 /*
707 * IPSTEALTH: Process non-routing options only
708 * if the packet is destined for us.
709 */
710 if (V_ipstealth && hlen > sizeof (struct ip) && ip_dooptions(m, 1)) {
711 if (ia != NULL)
712 ifa_free(&ia->ia_ifa);
713 return;
714 }
715#endif /* IPSTEALTH */
716
717 /* Count the packet in the ip address stats */
718 if (ia != NULL) {
719 ia->ia_ifa.if_ipackets++;
720 ia->ia_ifa.if_ibytes += m->m_pkthdr.len;
721 ifa_free(&ia->ia_ifa);
722 }
723
724 /*
725 * Attempt reassembly; if it succeeds, proceed.
726 * ip_reass() will return a different mbuf.
727 */
728 if (ip->ip_off & htons(IP_MF | IP_OFFMASK)) {
729 m = ip_reass(m);
730 if (m == NULL)
731 return;
732 ip = mtod(m, struct ip *);
733 /* Get the header length of the reassembled packet */
734 hlen = ip->ip_hl << 2;
735 }
736
737#ifdef IPSEC
738 /*
739 * enforce IPsec policy checking if we are seeing last header.
740 * note that we do not visit this with protocols with pcb layer
741 * code - like udp/tcp/raw ip.
742 */
743 if (ip_ipsec_input(m))
744 goto bad;
745#endif /* IPSEC */
746
747 /*
748 * Switch out to protocol's input routine.
749 */
750 IPSTAT_INC(ips_delivered);
751
752 (*inetsw[ip_protox[ip->ip_p]].pr_input)(m, hlen);
753 return;
754bad:
755 m_freem(m);
756}
757
758/*
759 * After maxnipq has been updated, propagate the change to UMA. The UMA zone
760 * max has slightly different semantics than the sysctl, for historical
761 * reasons.
762 */
763static void
764maxnipq_update(void)
765{
766
767 /*
768 * -1 for unlimited allocation.
769 */
770 if (V_maxnipq < 0)
771 uma_zone_set_max(V_ipq_zone, 0);
772 /*
773 * Positive number for specific bound.
774 */
775 if (V_maxnipq > 0)
776 uma_zone_set_max(V_ipq_zone, V_maxnipq);
777 /*
778 * Zero specifies no further fragment queue allocation -- set the
779 * bound very low, but rely on implementation elsewhere to actually
780 * prevent allocation and reclaim current queues.
781 */
782 if (V_maxnipq == 0)
783 uma_zone_set_max(V_ipq_zone, 1);
784}
785
786static void
787ipq_zone_change(void *tag)
788{
789
790 if (V_maxnipq > 0 && V_maxnipq < (nmbclusters / 32)) {
791 V_maxnipq = nmbclusters / 32;
792 maxnipq_update();
793 }
794}
795
796static int
797sysctl_maxnipq(SYSCTL_HANDLER_ARGS)
798{
799 int error, i;
800
801 i = V_maxnipq;
802 error = sysctl_handle_int(oidp, &i, 0, req);
803 if (error || !req->newptr)
804 return (error);
805
806 /*
807 * XXXRW: Might be a good idea to sanity check the argument and place
808 * an extreme upper bound.
809 */
810 if (i < -1)
811 return (EINVAL);
812 V_maxnipq = i;
813 maxnipq_update();
814 return (0);
815}
816
817SYSCTL_PROC(_net_inet_ip, OID_AUTO, maxfragpackets, CTLTYPE_INT|CTLFLAG_RW,
818 NULL, 0, sysctl_maxnipq, "I",
819 "Maximum number of IPv4 fragment reassembly queue entries");
820
821/*
822 * Take incoming datagram fragment and try to reassemble it into
823 * whole datagram. If the argument is the first fragment or one
824 * in between the function will return NULL and store the mbuf
825 * in the fragment chain. If the argument is the last fragment
826 * the packet will be reassembled and the pointer to the new
827 * mbuf returned for further processing. Only m_tags attached
828 * to the first packet/fragment are preserved.
829 * The IP header is *NOT* adjusted out of iplen.
830 */
831struct mbuf *
832ip_reass(struct mbuf *m)
833{
834 struct ip *ip;
835 struct mbuf *p, *q, *nq, *t;
836 struct ipq *fp = NULL;
837 struct ipqhead *head;
838 int i, hlen, next;
839 u_int8_t ecn, ecn0;
840 u_short hash;
841
842 /* If maxnipq or maxfragsperpacket are 0, never accept fragments. */
843 if (V_maxnipq == 0 || V_maxfragsperpacket == 0) {
844 IPSTAT_INC(ips_fragments);
845 IPSTAT_INC(ips_fragdropped);
846 m_freem(m);
847 return (NULL);
848 }
849
850 ip = mtod(m, struct ip *);
851 hlen = ip->ip_hl << 2;
852
853 hash = IPREASS_HASH(ip->ip_src.s_addr, ip->ip_id);
854 head = &V_ipq[hash];
855 IPQ_LOCK();
856
857 /*
858 * Look for queue of fragments
859 * of this datagram.
860 */
861 TAILQ_FOREACH(fp, head, ipq_list)
862 if (ip->ip_id == fp->ipq_id &&
863 ip->ip_src.s_addr == fp->ipq_src.s_addr &&
864 ip->ip_dst.s_addr == fp->ipq_dst.s_addr &&
865#ifdef MAC
866 mac_ipq_match(m, fp) &&
867#endif
868 ip->ip_p == fp->ipq_p)
869 goto found;
870
871 fp = NULL;
872
873 /*
874 * Attempt to trim the number of allocated fragment queues if it
875 * exceeds the administrative limit.
876 */
877 if ((V_nipq > V_maxnipq) && (V_maxnipq > 0)) {
878 /*
879 * drop something from the tail of the current queue
880 * before proceeding further
881 */
882 struct ipq *q = TAILQ_LAST(head, ipqhead);
883 if (q == NULL) { /* gak */
884 for (i = 0; i < IPREASS_NHASH; i++) {
885 struct ipq *r = TAILQ_LAST(&V_ipq[i], ipqhead);
886 if (r) {
887 IPSTAT_ADD(ips_fragtimeout,
888 r->ipq_nfrags);
889 ip_freef(&V_ipq[i], r);
890 break;
891 }
892 }
893 } else {
894 IPSTAT_ADD(ips_fragtimeout, q->ipq_nfrags);
895 ip_freef(head, q);
896 }
897 }
898
899found:
900 /*
901 * Adjust ip_len to not reflect header,
902 * convert offset of this to bytes.
903 */
904 ip->ip_len = htons(ntohs(ip->ip_len) - hlen);
905 if (ip->ip_off & htons(IP_MF)) {
906 /*
907 * Make sure that fragments have a data length
908 * that's a non-zero multiple of 8 bytes.
909 */
910 if (ip->ip_len == htons(0) || (ntohs(ip->ip_len) & 0x7) != 0) {
911 IPSTAT_INC(ips_toosmall); /* XXX */
912 goto dropfrag;
913 }
914 m->m_flags |= M_IP_FRAG;
915 } else
916 m->m_flags &= ~M_IP_FRAG;
917 ip->ip_off = htons(ntohs(ip->ip_off) << 3);
918
919 /*
920 * Attempt reassembly; if it succeeds, proceed.
921 * ip_reass() will return a different mbuf.
922 */
923 IPSTAT_INC(ips_fragments);
|
968
969 /*
970 * Handle ECN by comparing this segment with the first one;
971 * if CE is set, do not lose CE.
972 * drop if CE and not-ECT are mixed for the same packet.
973 */
974 ecn = ip->ip_tos & IPTOS_ECN_MASK;
975 ecn0 = GETIP(fp->ipq_frags)->ip_tos & IPTOS_ECN_MASK;
976 if (ecn == IPTOS_ECN_CE) {
977 if (ecn0 == IPTOS_ECN_NOTECT)
978 goto dropfrag;
979 if (ecn0 != IPTOS_ECN_CE)
980 GETIP(fp->ipq_frags)->ip_tos |= IPTOS_ECN_CE;
981 }
982 if (ecn == IPTOS_ECN_NOTECT && ecn0 != IPTOS_ECN_NOTECT)
983 goto dropfrag;
984
985 /*
986 * Find a segment which begins after this one does.
987 */
988 for (p = NULL, q = fp->ipq_frags; q; p = q, q = q->m_nextpkt)
989 if (ntohs(GETIP(q)->ip_off) > ntohs(ip->ip_off))
990 break;
991
992 /*
993 * If there is a preceding segment, it may provide some of
994 * our data already. If so, drop the data from the incoming
995 * segment. If it provides all of our data, drop us, otherwise
996 * stick new segment in the proper place.
997 *
998 * If some of the data is dropped from the preceding
999 * segment, then it's checksum is invalidated.
1000 */
1001 if (p) {
1002 i = ntohs(GETIP(p)->ip_off) + ntohs(GETIP(p)->ip_len) -
1003 ntohs(ip->ip_off);
1004 if (i > 0) {
1005 if (i >= ntohs(ip->ip_len))
1006 goto dropfrag;
1007 m_adj(m, i);
1008 m->m_pkthdr.csum_flags = 0;
1009 ip->ip_off = htons(ntohs(ip->ip_off) + i);
1010 ip->ip_len = htons(ntohs(ip->ip_len) - i);
1011 }
1012 m->m_nextpkt = p->m_nextpkt;
1013 p->m_nextpkt = m;
1014 } else {
1015 m->m_nextpkt = fp->ipq_frags;
1016 fp->ipq_frags = m;
1017 }
1018
1019 /*
1020 * While we overlap succeeding segments trim them or,
1021 * if they are completely covered, dequeue them.
1022 */
1023 for (; q != NULL && ntohs(ip->ip_off) + ntohs(ip->ip_len) >
1024 ntohs(GETIP(q)->ip_off); q = nq) {
1025 i = (ntohs(ip->ip_off) + ntohs(ip->ip_len)) -
1026 ntohs(GETIP(q)->ip_off);
1027 if (i < ntohs(GETIP(q)->ip_len)) {
1028 GETIP(q)->ip_len = htons(ntohs(GETIP(q)->ip_len) - i);
1029 GETIP(q)->ip_off = htons(ntohs(GETIP(q)->ip_off) + i);
1030 m_adj(q, i);
1031 q->m_pkthdr.csum_flags = 0;
1032 break;
1033 }
1034 nq = q->m_nextpkt;
1035 m->m_nextpkt = nq;
1036 IPSTAT_INC(ips_fragdropped);
1037 fp->ipq_nfrags--;
1038 m_freem(q);
1039 }
1040
1041 /*
1042 * Check for complete reassembly and perform frag per packet
1043 * limiting.
1044 *
1045 * Frag limiting is performed here so that the nth frag has
1046 * a chance to complete the packet before we drop the packet.
1047 * As a result, n+1 frags are actually allowed per packet, but
1048 * only n will ever be stored. (n = maxfragsperpacket.)
1049 *
1050 */
1051 next = 0;
1052 for (p = NULL, q = fp->ipq_frags; q; p = q, q = q->m_nextpkt) {
1053 if (ntohs(GETIP(q)->ip_off) != next) {
1054 if (fp->ipq_nfrags > V_maxfragsperpacket) {
1055 IPSTAT_ADD(ips_fragdropped, fp->ipq_nfrags);
1056 ip_freef(head, fp);
1057 }
1058 goto done;
1059 }
1060 next += ntohs(GETIP(q)->ip_len);
1061 }
1062 /* Make sure the last packet didn't have the IP_MF flag */
1063 if (p->m_flags & M_IP_FRAG) {
1064 if (fp->ipq_nfrags > V_maxfragsperpacket) {
1065 IPSTAT_ADD(ips_fragdropped, fp->ipq_nfrags);
1066 ip_freef(head, fp);
1067 }
1068 goto done;
1069 }
1070
1071 /*
1072 * Reassembly is complete. Make sure the packet is a sane size.
1073 */
1074 q = fp->ipq_frags;
1075 ip = GETIP(q);
1076 if (next + (ip->ip_hl << 2) > IP_MAXPACKET) {
1077 IPSTAT_INC(ips_toolong);
1078 IPSTAT_ADD(ips_fragdropped, fp->ipq_nfrags);
1079 ip_freef(head, fp);
1080 goto done;
1081 }
1082
1083 /*
1084 * Concatenate fragments.
1085 */
1086 m = q;
1087 t = m->m_next;
1088 m->m_next = NULL;
1089 m_cat(m, t);
1090 nq = q->m_nextpkt;
1091 q->m_nextpkt = NULL;
1092 for (q = nq; q != NULL; q = nq) {
1093 nq = q->m_nextpkt;
1094 q->m_nextpkt = NULL;
1095 m->m_pkthdr.csum_flags &= q->m_pkthdr.csum_flags;
1096 m->m_pkthdr.csum_data += q->m_pkthdr.csum_data;
1097 m_cat(m, q);
1098 }
1099 /*
1100 * In order to do checksumming faster we do 'end-around carry' here
1101 * (and not in for{} loop), though it implies we are not going to
1102 * reassemble more than 64k fragments.
1103 */
1104 m->m_pkthdr.csum_data =
1105 (m->m_pkthdr.csum_data & 0xffff) + (m->m_pkthdr.csum_data >> 16);
1106#ifdef MAC
1107 mac_ipq_reassemble(fp, m);
1108 mac_ipq_destroy(fp);
1109#endif
1110
1111 /*
1112 * Create header for new ip packet by modifying header of first
1113 * packet; dequeue and discard fragment reassembly header.
1114 * Make header visible.
1115 */
1116 ip->ip_len = htons((ip->ip_hl << 2) + next);
1117 ip->ip_src = fp->ipq_src;
1118 ip->ip_dst = fp->ipq_dst;
1119 TAILQ_REMOVE(head, fp, ipq_list);
1120 V_nipq--;
1121 uma_zfree(V_ipq_zone, fp);
1122 m->m_len += (ip->ip_hl << 2);
1123 m->m_data -= (ip->ip_hl << 2);
1124 /* some debugging cruft by sklower, below, will go away soon */
1125 if (m->m_flags & M_PKTHDR) /* XXX this should be done elsewhere */
1126 m_fixhdr(m);
1127 IPSTAT_INC(ips_reassembled);
1128 IPQ_UNLOCK();
1129 return (m);
1130
1131dropfrag:
1132 IPSTAT_INC(ips_fragdropped);
1133 if (fp != NULL)
1134 fp->ipq_nfrags--;
1135 m_freem(m);
1136done:
1137 IPQ_UNLOCK();
1138 return (NULL);
1139
1140#undef GETIP
1141}
1142
1143/*
1144 * Free a fragment reassembly header and all
1145 * associated datagrams.
1146 */
1147static void
1148ip_freef(struct ipqhead *fhp, struct ipq *fp)
1149{
1150 struct mbuf *q;
1151
1152 IPQ_LOCK_ASSERT();
1153
1154 while (fp->ipq_frags) {
1155 q = fp->ipq_frags;
1156 fp->ipq_frags = q->m_nextpkt;
1157 m_freem(q);
1158 }
1159 TAILQ_REMOVE(fhp, fp, ipq_list);
1160 uma_zfree(V_ipq_zone, fp);
1161 V_nipq--;
1162}
1163
1164/*
1165 * IP timer processing;
1166 * if a timer expires on a reassembly
1167 * queue, discard it.
1168 */
1169void
1170ip_slowtimo(void)
1171{
1172 VNET_ITERATOR_DECL(vnet_iter);
1173 struct ipq *fp;
1174 int i;
1175
1176 VNET_LIST_RLOCK_NOSLEEP();
1177 IPQ_LOCK();
1178 VNET_FOREACH(vnet_iter) {
1179 CURVNET_SET(vnet_iter);
1180 for (i = 0; i < IPREASS_NHASH; i++) {
1181 for(fp = TAILQ_FIRST(&V_ipq[i]); fp;) {
1182 struct ipq *fpp;
1183
1184 fpp = fp;
1185 fp = TAILQ_NEXT(fp, ipq_list);
1186 if(--fpp->ipq_ttl == 0) {
1187 IPSTAT_ADD(ips_fragtimeout,
1188 fpp->ipq_nfrags);
1189 ip_freef(&V_ipq[i], fpp);
1190 }
1191 }
1192 }
1193 /*
1194 * If we are over the maximum number of fragments
1195 * (due to the limit being lowered), drain off
1196 * enough to get down to the new limit.
1197 */
1198 if (V_maxnipq >= 0 && V_nipq > V_maxnipq) {
1199 for (i = 0; i < IPREASS_NHASH; i++) {
1200 while (V_nipq > V_maxnipq &&
1201 !TAILQ_EMPTY(&V_ipq[i])) {
1202 IPSTAT_ADD(ips_fragdropped,
1203 TAILQ_FIRST(&V_ipq[i])->ipq_nfrags);
1204 ip_freef(&V_ipq[i],
1205 TAILQ_FIRST(&V_ipq[i]));
1206 }
1207 }
1208 }
1209 CURVNET_RESTORE();
1210 }
1211 IPQ_UNLOCK();
1212 VNET_LIST_RUNLOCK_NOSLEEP();
1213}
1214
1215/*
1216 * Drain off all datagram fragments.
1217 */
1218static void
1219ip_drain_locked(void)
1220{
1221 int i;
1222
1223 IPQ_LOCK_ASSERT();
1224
1225 for (i = 0; i < IPREASS_NHASH; i++) {
1226 while(!TAILQ_EMPTY(&V_ipq[i])) {
1227 IPSTAT_ADD(ips_fragdropped,
1228 TAILQ_FIRST(&V_ipq[i])->ipq_nfrags);
1229 ip_freef(&V_ipq[i], TAILQ_FIRST(&V_ipq[i]));
1230 }
1231 }
1232}
1233
1234void
1235ip_drain(void)
1236{
1237 VNET_ITERATOR_DECL(vnet_iter);
1238
1239 VNET_LIST_RLOCK_NOSLEEP();
1240 IPQ_LOCK();
1241 VNET_FOREACH(vnet_iter) {
1242 CURVNET_SET(vnet_iter);
1243 ip_drain_locked();
1244 CURVNET_RESTORE();
1245 }
1246 IPQ_UNLOCK();
1247 VNET_LIST_RUNLOCK_NOSLEEP();
1248 in_rtqdrain();
1249}
1250
1251/*
1252 * The protocol to be inserted into ip_protox[] must be already registered
1253 * in inetsw[], either statically or through pf_proto_register().
1254 */
1255int
1256ipproto_register(short ipproto)
1257{
1258 struct protosw *pr;
1259
1260 /* Sanity checks. */
1261 if (ipproto <= 0 || ipproto >= IPPROTO_MAX)
1262 return (EPROTONOSUPPORT);
1263
1264 /*
1265 * The protocol slot must not be occupied by another protocol
1266 * already. An index pointing to IPPROTO_RAW is unused.
1267 */
1268 pr = pffindproto(PF_INET, IPPROTO_RAW, SOCK_RAW);
1269 if (pr == NULL)
1270 return (EPFNOSUPPORT);
1271 if (ip_protox[ipproto] != pr - inetsw) /* IPPROTO_RAW */
1272 return (EEXIST);
1273
1274 /* Find the protocol position in inetsw[] and set the index. */
1275 for (pr = inetdomain.dom_protosw;
1276 pr < inetdomain.dom_protoswNPROTOSW; pr++) {
1277 if (pr->pr_domain->dom_family == PF_INET &&
1278 pr->pr_protocol && pr->pr_protocol == ipproto) {
1279 ip_protox[pr->pr_protocol] = pr - inetsw;
1280 return (0);
1281 }
1282 }
1283 return (EPROTONOSUPPORT);
1284}
1285
1286int
1287ipproto_unregister(short ipproto)
1288{
1289 struct protosw *pr;
1290
1291 /* Sanity checks. */
1292 if (ipproto <= 0 || ipproto >= IPPROTO_MAX)
1293 return (EPROTONOSUPPORT);
1294
1295 /* Check if the protocol was indeed registered. */
1296 pr = pffindproto(PF_INET, IPPROTO_RAW, SOCK_RAW);
1297 if (pr == NULL)
1298 return (EPFNOSUPPORT);
1299 if (ip_protox[ipproto] == pr - inetsw) /* IPPROTO_RAW */
1300 return (ENOENT);
1301
1302 /* Reset the protocol slot to IPPROTO_RAW. */
1303 ip_protox[ipproto] = pr - inetsw;
1304 return (0);
1305}
1306
1307/*
1308 * Given address of next destination (final or next hop), return (referenced)
1309 * internet address info of interface to be used to get there.
1310 */
1311struct in_ifaddr *
1312ip_rtaddr(struct in_addr dst, u_int fibnum)
1313{
1314 struct route sro;
1315 struct sockaddr_in *sin;
1316 struct in_ifaddr *ia;
1317
1318 bzero(&sro, sizeof(sro));
1319 sin = (struct sockaddr_in *)&sro.ro_dst;
1320 sin->sin_family = AF_INET;
1321 sin->sin_len = sizeof(*sin);
1322 sin->sin_addr = dst;
1323 in_rtalloc_ign(&sro, 0, fibnum);
1324
1325 if (sro.ro_rt == NULL)
1326 return (NULL);
1327
1328 ia = ifatoia(sro.ro_rt->rt_ifa);
1329 ifa_ref(&ia->ia_ifa);
1330 RTFREE(sro.ro_rt);
1331 return (ia);
1332}
1333
1334u_char inetctlerrmap[PRC_NCMDS] = {
1335 0, 0, 0, 0,
1336 0, EMSGSIZE, EHOSTDOWN, EHOSTUNREACH,
1337 EHOSTUNREACH, EHOSTUNREACH, ECONNREFUSED, ECONNREFUSED,
1338 EMSGSIZE, EHOSTUNREACH, 0, 0,
1339 0, 0, EHOSTUNREACH, 0,
1340 ENOPROTOOPT, ECONNREFUSED
1341};
1342
1343/*
1344 * Forward a packet. If some error occurs return the sender
1345 * an icmp packet. Note we can't always generate a meaningful
1346 * icmp message because icmp doesn't have a large enough repertoire
1347 * of codes and types.
1348 *
1349 * If not forwarding, just drop the packet. This could be confusing
1350 * if ipforwarding was zero but some routing protocol was advancing
1351 * us as a gateway to somewhere. However, we must let the routing
1352 * protocol deal with that.
1353 *
1354 * The srcrt parameter indicates whether the packet is being forwarded
1355 * via a source route.
1356 */
1357void
1358ip_forward(struct mbuf *m, int srcrt)
1359{
1360 struct ip *ip = mtod(m, struct ip *);
1361 struct in_ifaddr *ia;
1362 struct mbuf *mcopy;
1363 struct in_addr dest;
1364 struct route ro;
1365 int error, type = 0, code = 0, mtu = 0;
1366
1367 if (m->m_flags & (M_BCAST|M_MCAST) || in_canforward(ip->ip_dst) == 0) {
1368 IPSTAT_INC(ips_cantforward);
1369 m_freem(m);
1370 return;
1371 }
1372#ifdef IPSTEALTH
1373 if (!V_ipstealth) {
1374#endif
1375 if (ip->ip_ttl <= IPTTLDEC) {
1376 icmp_error(m, ICMP_TIMXCEED, ICMP_TIMXCEED_INTRANS,
1377 0, 0);
1378 return;
1379 }
1380#ifdef IPSTEALTH
1381 }
1382#endif
1383
1384 ia = ip_rtaddr(ip->ip_dst, M_GETFIB(m));
1385#ifndef IPSEC
1386 /*
1387 * 'ia' may be NULL if there is no route for this destination.
1388 * In case of IPsec, Don't discard it just yet, but pass it to
1389 * ip_output in case of outgoing IPsec policy.
1390 */
1391 if (!srcrt && ia == NULL) {
1392 icmp_error(m, ICMP_UNREACH, ICMP_UNREACH_HOST, 0, 0);
1393 return;
1394 }
1395#endif
1396
1397 /*
1398 * Save the IP header and at most 8 bytes of the payload,
1399 * in case we need to generate an ICMP message to the src.
1400 *
1401 * XXX this can be optimized a lot by saving the data in a local
1402 * buffer on the stack (72 bytes at most), and only allocating the
1403 * mbuf if really necessary. The vast majority of the packets
1404 * are forwarded without having to send an ICMP back (either
1405 * because unnecessary, or because rate limited), so we are
1406 * really we are wasting a lot of work here.
1407 *
1408 * We don't use m_copy() because it might return a reference
1409 * to a shared cluster. Both this function and ip_output()
1410 * assume exclusive access to the IP header in `m', so any
1411 * data in a cluster may change before we reach icmp_error().
1412 */
1413 mcopy = m_gethdr(M_NOWAIT, m->m_type);
1414 if (mcopy != NULL && !m_dup_pkthdr(mcopy, m, M_NOWAIT)) {
1415 /*
1416 * It's probably ok if the pkthdr dup fails (because
1417 * the deep copy of the tag chain failed), but for now
1418 * be conservative and just discard the copy since
1419 * code below may some day want the tags.
1420 */
1421 m_free(mcopy);
1422 mcopy = NULL;
1423 }
1424 if (mcopy != NULL) {
1425 mcopy->m_len = min(ntohs(ip->ip_len), M_TRAILINGSPACE(mcopy));
1426 mcopy->m_pkthdr.len = mcopy->m_len;
1427 m_copydata(m, 0, mcopy->m_len, mtod(mcopy, caddr_t));
1428 }
1429
1430#ifdef IPSTEALTH
1431 if (!V_ipstealth) {
1432#endif
1433 ip->ip_ttl -= IPTTLDEC;
1434#ifdef IPSTEALTH
1435 }
1436#endif
1437
1438 /*
1439 * If forwarding packet using same interface that it came in on,
1440 * perhaps should send a redirect to sender to shortcut a hop.
1441 * Only send redirect if source is sending directly to us,
1442 * and if packet was not source routed (or has any options).
1443 * Also, don't send redirect if forwarding using a default route
1444 * or a route modified by a redirect.
1445 */
1446 dest.s_addr = 0;
1447 if (!srcrt && V_ipsendredirects &&
1448 ia != NULL && ia->ia_ifp == m->m_pkthdr.rcvif) {
1449 struct sockaddr_in *sin;
1450 struct rtentry *rt;
1451
1452 bzero(&ro, sizeof(ro));
1453 sin = (struct sockaddr_in *)&ro.ro_dst;
1454 sin->sin_family = AF_INET;
1455 sin->sin_len = sizeof(*sin);
1456 sin->sin_addr = ip->ip_dst;
1457 in_rtalloc_ign(&ro, 0, M_GETFIB(m));
1458
1459 rt = ro.ro_rt;
1460
1461 if (rt && (rt->rt_flags & (RTF_DYNAMIC|RTF_MODIFIED)) == 0 &&
1462 satosin(rt_key(rt))->sin_addr.s_addr != 0) {
1463#define RTA(rt) ((struct in_ifaddr *)(rt->rt_ifa))
1464 u_long src = ntohl(ip->ip_src.s_addr);
1465
1466 if (RTA(rt) &&
1467 (src & RTA(rt)->ia_subnetmask) == RTA(rt)->ia_subnet) {
1468 if (rt->rt_flags & RTF_GATEWAY)
1469 dest.s_addr = satosin(rt->rt_gateway)->sin_addr.s_addr;
1470 else
1471 dest.s_addr = ip->ip_dst.s_addr;
1472 /* Router requirements says to only send host redirects */
1473 type = ICMP_REDIRECT;
1474 code = ICMP_REDIRECT_HOST;
1475 }
1476 }
1477 if (rt)
1478 RTFREE(rt);
1479 }
1480
1481 /*
1482 * Try to cache the route MTU from ip_output so we can consider it for
1483 * the ICMP_UNREACH_NEEDFRAG "Next-Hop MTU" field described in RFC1191.
1484 */
1485 bzero(&ro, sizeof(ro));
1486
1487 error = ip_output(m, NULL, &ro, IP_FORWARDING, NULL, NULL);
1488
1489 if (error == EMSGSIZE && ro.ro_rt)
1490 mtu = ro.ro_rt->rt_rmx.rmx_mtu;
1491 RO_RTFREE(&ro);
1492
1493 if (error)
1494 IPSTAT_INC(ips_cantforward);
1495 else {
1496 IPSTAT_INC(ips_forward);
1497 if (type)
1498 IPSTAT_INC(ips_redirectsent);
1499 else {
1500 if (mcopy)
1501 m_freem(mcopy);
1502 if (ia != NULL)
1503 ifa_free(&ia->ia_ifa);
1504 return;
1505 }
1506 }
1507 if (mcopy == NULL) {
1508 if (ia != NULL)
1509 ifa_free(&ia->ia_ifa);
1510 return;
1511 }
1512
1513 switch (error) {
1514
1515 case 0: /* forwarded, but need redirect */
1516 /* type, code set above */
1517 break;
1518
1519 case ENETUNREACH:
1520 case EHOSTUNREACH:
1521 case ENETDOWN:
1522 case EHOSTDOWN:
1523 default:
1524 type = ICMP_UNREACH;
1525 code = ICMP_UNREACH_HOST;
1526 break;
1527
1528 case EMSGSIZE:
1529 type = ICMP_UNREACH;
1530 code = ICMP_UNREACH_NEEDFRAG;
1531
1532#ifdef IPSEC
1533 /*
1534 * If IPsec is configured for this path,
1535 * override any possibly mtu value set by ip_output.
1536 */
1537 mtu = ip_ipsec_mtu(mcopy, mtu);
1538#endif /* IPSEC */
1539 /*
1540 * If the MTU was set before make sure we are below the
1541 * interface MTU.
1542 * If the MTU wasn't set before use the interface mtu or
1543 * fall back to the next smaller mtu step compared to the
1544 * current packet size.
1545 */
1546 if (mtu != 0) {
1547 if (ia != NULL)
1548 mtu = min(mtu, ia->ia_ifp->if_mtu);
1549 } else {
1550 if (ia != NULL)
1551 mtu = ia->ia_ifp->if_mtu;
1552 else
1553 mtu = ip_next_mtu(ntohs(ip->ip_len), 0);
1554 }
1555 IPSTAT_INC(ips_cantfrag);
1556 break;
1557
1558 case ENOBUFS:
1559 /*
1560 * A router should not generate ICMP_SOURCEQUENCH as
1561 * required in RFC1812 Requirements for IP Version 4 Routers.
1562 * Source quench could be a big problem under DoS attacks,
1563 * or if the underlying interface is rate-limited.
1564 * Those who need source quench packets may re-enable them
1565 * via the net.inet.ip.sendsourcequench sysctl.
1566 */
1567 if (V_ip_sendsourcequench == 0) {
1568 m_freem(mcopy);
1569 if (ia != NULL)
1570 ifa_free(&ia->ia_ifa);
1571 return;
1572 } else {
1573 type = ICMP_SOURCEQUENCH;
1574 code = 0;
1575 }
1576 break;
1577
1578 case EACCES: /* ipfw denied packet */
1579 m_freem(mcopy);
1580 if (ia != NULL)
1581 ifa_free(&ia->ia_ifa);
1582 return;
1583 }
1584 if (ia != NULL)
1585 ifa_free(&ia->ia_ifa);
1586 icmp_error(mcopy, type, code, dest.s_addr, mtu);
1587}
1588
1589void
1590ip_savecontrol(struct inpcb *inp, struct mbuf **mp, struct ip *ip,
1591 struct mbuf *m)
1592{
1593
1594 if (inp->inp_socket->so_options & (SO_BINTIME | SO_TIMESTAMP)) {
1595 struct bintime bt;
1596
1597 bintime(&bt);
1598 if (inp->inp_socket->so_options & SO_BINTIME) {
1599 *mp = sbcreatecontrol((caddr_t)&bt, sizeof(bt),
1600 SCM_BINTIME, SOL_SOCKET);
1601 if (*mp)
1602 mp = &(*mp)->m_next;
1603 }
1604 if (inp->inp_socket->so_options & SO_TIMESTAMP) {
1605 struct timeval tv;
1606
1607 bintime2timeval(&bt, &tv);
1608 *mp = sbcreatecontrol((caddr_t)&tv, sizeof(tv),
1609 SCM_TIMESTAMP, SOL_SOCKET);
1610 if (*mp)
1611 mp = &(*mp)->m_next;
1612 }
1613 }
1614 if (inp->inp_flags & INP_RECVDSTADDR) {
1615 *mp = sbcreatecontrol((caddr_t)&ip->ip_dst,
1616 sizeof(struct in_addr), IP_RECVDSTADDR, IPPROTO_IP);
1617 if (*mp)
1618 mp = &(*mp)->m_next;
1619 }
1620 if (inp->inp_flags & INP_RECVTTL) {
1621 *mp = sbcreatecontrol((caddr_t)&ip->ip_ttl,
1622 sizeof(u_char), IP_RECVTTL, IPPROTO_IP);
1623 if (*mp)
1624 mp = &(*mp)->m_next;
1625 }
1626#ifdef notyet
1627 /* XXX
1628 * Moving these out of udp_input() made them even more broken
1629 * than they already were.
1630 */
1631 /* options were tossed already */
1632 if (inp->inp_flags & INP_RECVOPTS) {
1633 *mp = sbcreatecontrol((caddr_t)opts_deleted_above,
1634 sizeof(struct in_addr), IP_RECVOPTS, IPPROTO_IP);
1635 if (*mp)
1636 mp = &(*mp)->m_next;
1637 }
1638 /* ip_srcroute doesn't do what we want here, need to fix */
1639 if (inp->inp_flags & INP_RECVRETOPTS) {
1640 *mp = sbcreatecontrol((caddr_t)ip_srcroute(m),
1641 sizeof(struct in_addr), IP_RECVRETOPTS, IPPROTO_IP);
1642 if (*mp)
1643 mp = &(*mp)->m_next;
1644 }
1645#endif
1646 if (inp->inp_flags & INP_RECVIF) {
1647 struct ifnet *ifp;
1648 struct sdlbuf {
1649 struct sockaddr_dl sdl;
1650 u_char pad[32];
1651 } sdlbuf;
1652 struct sockaddr_dl *sdp;
1653 struct sockaddr_dl *sdl2 = &sdlbuf.sdl;
1654
1655 if ((ifp = m->m_pkthdr.rcvif) &&
1656 ifp->if_index && ifp->if_index <= V_if_index) {
1657 sdp = (struct sockaddr_dl *)ifp->if_addr->ifa_addr;
1658 /*
1659 * Change our mind and don't try copy.
1660 */
1661 if (sdp->sdl_family != AF_LINK ||
1662 sdp->sdl_len > sizeof(sdlbuf)) {
1663 goto makedummy;
1664 }
1665 bcopy(sdp, sdl2, sdp->sdl_len);
1666 } else {
1667makedummy:
1668 sdl2->sdl_len =
1669 offsetof(struct sockaddr_dl, sdl_data[0]);
1670 sdl2->sdl_family = AF_LINK;
1671 sdl2->sdl_index = 0;
1672 sdl2->sdl_nlen = sdl2->sdl_alen = sdl2->sdl_slen = 0;
1673 }
1674 *mp = sbcreatecontrol((caddr_t)sdl2, sdl2->sdl_len,
1675 IP_RECVIF, IPPROTO_IP);
1676 if (*mp)
1677 mp = &(*mp)->m_next;
1678 }
1679 if (inp->inp_flags & INP_RECVTOS) {
1680 *mp = sbcreatecontrol((caddr_t)&ip->ip_tos,
1681 sizeof(u_char), IP_RECVTOS, IPPROTO_IP);
1682 if (*mp)
1683 mp = &(*mp)->m_next;
1684 }
1685}
1686
1687/*
1688 * XXXRW: Multicast routing code in ip_mroute.c is generally MPSAFE, but the
1689 * ip_rsvp and ip_rsvp_on variables need to be interlocked with rsvp_on
1690 * locking. This code remains in ip_input.c as ip_mroute.c is optionally
1691 * compiled.
1692 */
1693static VNET_DEFINE(int, ip_rsvp_on);
1694VNET_DEFINE(struct socket *, ip_rsvpd);
1695
1696#define V_ip_rsvp_on VNET(ip_rsvp_on)
1697
1698int
1699ip_rsvp_init(struct socket *so)
1700{
1701
1702 if (so->so_type != SOCK_RAW ||
1703 so->so_proto->pr_protocol != IPPROTO_RSVP)
1704 return EOPNOTSUPP;
1705
1706 if (V_ip_rsvpd != NULL)
1707 return EADDRINUSE;
1708
1709 V_ip_rsvpd = so;
1710 /*
1711 * This may seem silly, but we need to be sure we don't over-increment
1712 * the RSVP counter, in case something slips up.
1713 */
1714 if (!V_ip_rsvp_on) {
1715 V_ip_rsvp_on = 1;
1716 V_rsvp_on++;
1717 }
1718
1719 return 0;
1720}
1721
1722int
1723ip_rsvp_done(void)
1724{
1725
1726 V_ip_rsvpd = NULL;
1727 /*
1728 * This may seem silly, but we need to be sure we don't over-decrement
1729 * the RSVP counter, in case something slips up.
1730 */
1731 if (V_ip_rsvp_on) {
1732 V_ip_rsvp_on = 0;
1733 V_rsvp_on--;
1734 }
1735 return 0;
1736}
1737
1738void
1739rsvp_input(struct mbuf *m, int off) /* XXX must fixup manually */
1740{
1741
1742 if (rsvp_input_p) { /* call the real one if loaded */
1743 rsvp_input_p(m, off);
1744 return;
1745 }
1746
1747 /* Can still get packets with rsvp_on = 0 if there is a local member
1748 * of the group to which the RSVP packet is addressed. But in this
1749 * case we want to throw the packet away.
1750 */
1751
1752 if (!V_rsvp_on) {
1753 m_freem(m);
1754 return;
1755 }
1756
1757 if (V_ip_rsvpd != NULL) {
1758 rip_input(m, off);
1759 return;
1760 }
1761 /* Drop the packet */
1762 m_freem(m);
1763}
| 968
969 /*
970 * Handle ECN by comparing this segment with the first one;
971 * if CE is set, do not lose CE.
972 * drop if CE and not-ECT are mixed for the same packet.
973 */
974 ecn = ip->ip_tos & IPTOS_ECN_MASK;
975 ecn0 = GETIP(fp->ipq_frags)->ip_tos & IPTOS_ECN_MASK;
976 if (ecn == IPTOS_ECN_CE) {
977 if (ecn0 == IPTOS_ECN_NOTECT)
978 goto dropfrag;
979 if (ecn0 != IPTOS_ECN_CE)
980 GETIP(fp->ipq_frags)->ip_tos |= IPTOS_ECN_CE;
981 }
982 if (ecn == IPTOS_ECN_NOTECT && ecn0 != IPTOS_ECN_NOTECT)
983 goto dropfrag;
984
985 /*
986 * Find a segment which begins after this one does.
987 */
988 for (p = NULL, q = fp->ipq_frags; q; p = q, q = q->m_nextpkt)
989 if (ntohs(GETIP(q)->ip_off) > ntohs(ip->ip_off))
990 break;
991
992 /*
993 * If there is a preceding segment, it may provide some of
994 * our data already. If so, drop the data from the incoming
995 * segment. If it provides all of our data, drop us, otherwise
996 * stick new segment in the proper place.
997 *
998 * If some of the data is dropped from the preceding
999 * segment, then it's checksum is invalidated.
1000 */
1001 if (p) {
1002 i = ntohs(GETIP(p)->ip_off) + ntohs(GETIP(p)->ip_len) -
1003 ntohs(ip->ip_off);
1004 if (i > 0) {
1005 if (i >= ntohs(ip->ip_len))
1006 goto dropfrag;
1007 m_adj(m, i);
1008 m->m_pkthdr.csum_flags = 0;
1009 ip->ip_off = htons(ntohs(ip->ip_off) + i);
1010 ip->ip_len = htons(ntohs(ip->ip_len) - i);
1011 }
1012 m->m_nextpkt = p->m_nextpkt;
1013 p->m_nextpkt = m;
1014 } else {
1015 m->m_nextpkt = fp->ipq_frags;
1016 fp->ipq_frags = m;
1017 }
1018
1019 /*
1020 * While we overlap succeeding segments trim them or,
1021 * if they are completely covered, dequeue them.
1022 */
1023 for (; q != NULL && ntohs(ip->ip_off) + ntohs(ip->ip_len) >
1024 ntohs(GETIP(q)->ip_off); q = nq) {
1025 i = (ntohs(ip->ip_off) + ntohs(ip->ip_len)) -
1026 ntohs(GETIP(q)->ip_off);
1027 if (i < ntohs(GETIP(q)->ip_len)) {
1028 GETIP(q)->ip_len = htons(ntohs(GETIP(q)->ip_len) - i);
1029 GETIP(q)->ip_off = htons(ntohs(GETIP(q)->ip_off) + i);
1030 m_adj(q, i);
1031 q->m_pkthdr.csum_flags = 0;
1032 break;
1033 }
1034 nq = q->m_nextpkt;
1035 m->m_nextpkt = nq;
1036 IPSTAT_INC(ips_fragdropped);
1037 fp->ipq_nfrags--;
1038 m_freem(q);
1039 }
1040
1041 /*
1042 * Check for complete reassembly and perform frag per packet
1043 * limiting.
1044 *
1045 * Frag limiting is performed here so that the nth frag has
1046 * a chance to complete the packet before we drop the packet.
1047 * As a result, n+1 frags are actually allowed per packet, but
1048 * only n will ever be stored. (n = maxfragsperpacket.)
1049 *
1050 */
1051 next = 0;
1052 for (p = NULL, q = fp->ipq_frags; q; p = q, q = q->m_nextpkt) {
1053 if (ntohs(GETIP(q)->ip_off) != next) {
1054 if (fp->ipq_nfrags > V_maxfragsperpacket) {
1055 IPSTAT_ADD(ips_fragdropped, fp->ipq_nfrags);
1056 ip_freef(head, fp);
1057 }
1058 goto done;
1059 }
1060 next += ntohs(GETIP(q)->ip_len);
1061 }
1062 /* Make sure the last packet didn't have the IP_MF flag */
1063 if (p->m_flags & M_IP_FRAG) {
1064 if (fp->ipq_nfrags > V_maxfragsperpacket) {
1065 IPSTAT_ADD(ips_fragdropped, fp->ipq_nfrags);
1066 ip_freef(head, fp);
1067 }
1068 goto done;
1069 }
1070
1071 /*
1072 * Reassembly is complete. Make sure the packet is a sane size.
1073 */
1074 q = fp->ipq_frags;
1075 ip = GETIP(q);
1076 if (next + (ip->ip_hl << 2) > IP_MAXPACKET) {
1077 IPSTAT_INC(ips_toolong);
1078 IPSTAT_ADD(ips_fragdropped, fp->ipq_nfrags);
1079 ip_freef(head, fp);
1080 goto done;
1081 }
1082
1083 /*
1084 * Concatenate fragments.
1085 */
1086 m = q;
1087 t = m->m_next;
1088 m->m_next = NULL;
1089 m_cat(m, t);
1090 nq = q->m_nextpkt;
1091 q->m_nextpkt = NULL;
1092 for (q = nq; q != NULL; q = nq) {
1093 nq = q->m_nextpkt;
1094 q->m_nextpkt = NULL;
1095 m->m_pkthdr.csum_flags &= q->m_pkthdr.csum_flags;
1096 m->m_pkthdr.csum_data += q->m_pkthdr.csum_data;
1097 m_cat(m, q);
1098 }
1099 /*
1100 * In order to do checksumming faster we do 'end-around carry' here
1101 * (and not in for{} loop), though it implies we are not going to
1102 * reassemble more than 64k fragments.
1103 */
1104 m->m_pkthdr.csum_data =
1105 (m->m_pkthdr.csum_data & 0xffff) + (m->m_pkthdr.csum_data >> 16);
1106#ifdef MAC
1107 mac_ipq_reassemble(fp, m);
1108 mac_ipq_destroy(fp);
1109#endif
1110
1111 /*
1112 * Create header for new ip packet by modifying header of first
1113 * packet; dequeue and discard fragment reassembly header.
1114 * Make header visible.
1115 */
1116 ip->ip_len = htons((ip->ip_hl << 2) + next);
1117 ip->ip_src = fp->ipq_src;
1118 ip->ip_dst = fp->ipq_dst;
1119 TAILQ_REMOVE(head, fp, ipq_list);
1120 V_nipq--;
1121 uma_zfree(V_ipq_zone, fp);
1122 m->m_len += (ip->ip_hl << 2);
1123 m->m_data -= (ip->ip_hl << 2);
1124 /* some debugging cruft by sklower, below, will go away soon */
1125 if (m->m_flags & M_PKTHDR) /* XXX this should be done elsewhere */
1126 m_fixhdr(m);
1127 IPSTAT_INC(ips_reassembled);
1128 IPQ_UNLOCK();
1129 return (m);
1130
1131dropfrag:
1132 IPSTAT_INC(ips_fragdropped);
1133 if (fp != NULL)
1134 fp->ipq_nfrags--;
1135 m_freem(m);
1136done:
1137 IPQ_UNLOCK();
1138 return (NULL);
1139
1140#undef GETIP
1141}
1142
1143/*
1144 * Free a fragment reassembly header and all
1145 * associated datagrams.
1146 */
1147static void
1148ip_freef(struct ipqhead *fhp, struct ipq *fp)
1149{
1150 struct mbuf *q;
1151
1152 IPQ_LOCK_ASSERT();
1153
1154 while (fp->ipq_frags) {
1155 q = fp->ipq_frags;
1156 fp->ipq_frags = q->m_nextpkt;
1157 m_freem(q);
1158 }
1159 TAILQ_REMOVE(fhp, fp, ipq_list);
1160 uma_zfree(V_ipq_zone, fp);
1161 V_nipq--;
1162}
1163
1164/*
1165 * IP timer processing;
1166 * if a timer expires on a reassembly
1167 * queue, discard it.
1168 */
1169void
1170ip_slowtimo(void)
1171{
1172 VNET_ITERATOR_DECL(vnet_iter);
1173 struct ipq *fp;
1174 int i;
1175
1176 VNET_LIST_RLOCK_NOSLEEP();
1177 IPQ_LOCK();
1178 VNET_FOREACH(vnet_iter) {
1179 CURVNET_SET(vnet_iter);
1180 for (i = 0; i < IPREASS_NHASH; i++) {
1181 for(fp = TAILQ_FIRST(&V_ipq[i]); fp;) {
1182 struct ipq *fpp;
1183
1184 fpp = fp;
1185 fp = TAILQ_NEXT(fp, ipq_list);
1186 if(--fpp->ipq_ttl == 0) {
1187 IPSTAT_ADD(ips_fragtimeout,
1188 fpp->ipq_nfrags);
1189 ip_freef(&V_ipq[i], fpp);
1190 }
1191 }
1192 }
1193 /*
1194 * If we are over the maximum number of fragments
1195 * (due to the limit being lowered), drain off
1196 * enough to get down to the new limit.
1197 */
1198 if (V_maxnipq >= 0 && V_nipq > V_maxnipq) {
1199 for (i = 0; i < IPREASS_NHASH; i++) {
1200 while (V_nipq > V_maxnipq &&
1201 !TAILQ_EMPTY(&V_ipq[i])) {
1202 IPSTAT_ADD(ips_fragdropped,
1203 TAILQ_FIRST(&V_ipq[i])->ipq_nfrags);
1204 ip_freef(&V_ipq[i],
1205 TAILQ_FIRST(&V_ipq[i]));
1206 }
1207 }
1208 }
1209 CURVNET_RESTORE();
1210 }
1211 IPQ_UNLOCK();
1212 VNET_LIST_RUNLOCK_NOSLEEP();
1213}
1214
1215/*
1216 * Drain off all datagram fragments.
1217 */
1218static void
1219ip_drain_locked(void)
1220{
1221 int i;
1222
1223 IPQ_LOCK_ASSERT();
1224
1225 for (i = 0; i < IPREASS_NHASH; i++) {
1226 while(!TAILQ_EMPTY(&V_ipq[i])) {
1227 IPSTAT_ADD(ips_fragdropped,
1228 TAILQ_FIRST(&V_ipq[i])->ipq_nfrags);
1229 ip_freef(&V_ipq[i], TAILQ_FIRST(&V_ipq[i]));
1230 }
1231 }
1232}
1233
1234void
1235ip_drain(void)
1236{
1237 VNET_ITERATOR_DECL(vnet_iter);
1238
1239 VNET_LIST_RLOCK_NOSLEEP();
1240 IPQ_LOCK();
1241 VNET_FOREACH(vnet_iter) {
1242 CURVNET_SET(vnet_iter);
1243 ip_drain_locked();
1244 CURVNET_RESTORE();
1245 }
1246 IPQ_UNLOCK();
1247 VNET_LIST_RUNLOCK_NOSLEEP();
1248 in_rtqdrain();
1249}
1250
1251/*
1252 * The protocol to be inserted into ip_protox[] must be already registered
1253 * in inetsw[], either statically or through pf_proto_register().
1254 */
1255int
1256ipproto_register(short ipproto)
1257{
1258 struct protosw *pr;
1259
1260 /* Sanity checks. */
1261 if (ipproto <= 0 || ipproto >= IPPROTO_MAX)
1262 return (EPROTONOSUPPORT);
1263
1264 /*
1265 * The protocol slot must not be occupied by another protocol
1266 * already. An index pointing to IPPROTO_RAW is unused.
1267 */
1268 pr = pffindproto(PF_INET, IPPROTO_RAW, SOCK_RAW);
1269 if (pr == NULL)
1270 return (EPFNOSUPPORT);
1271 if (ip_protox[ipproto] != pr - inetsw) /* IPPROTO_RAW */
1272 return (EEXIST);
1273
1274 /* Find the protocol position in inetsw[] and set the index. */
1275 for (pr = inetdomain.dom_protosw;
1276 pr < inetdomain.dom_protoswNPROTOSW; pr++) {
1277 if (pr->pr_domain->dom_family == PF_INET &&
1278 pr->pr_protocol && pr->pr_protocol == ipproto) {
1279 ip_protox[pr->pr_protocol] = pr - inetsw;
1280 return (0);
1281 }
1282 }
1283 return (EPROTONOSUPPORT);
1284}
1285
1286int
1287ipproto_unregister(short ipproto)
1288{
1289 struct protosw *pr;
1290
1291 /* Sanity checks. */
1292 if (ipproto <= 0 || ipproto >= IPPROTO_MAX)
1293 return (EPROTONOSUPPORT);
1294
1295 /* Check if the protocol was indeed registered. */
1296 pr = pffindproto(PF_INET, IPPROTO_RAW, SOCK_RAW);
1297 if (pr == NULL)
1298 return (EPFNOSUPPORT);
1299 if (ip_protox[ipproto] == pr - inetsw) /* IPPROTO_RAW */
1300 return (ENOENT);
1301
1302 /* Reset the protocol slot to IPPROTO_RAW. */
1303 ip_protox[ipproto] = pr - inetsw;
1304 return (0);
1305}
1306
1307/*
1308 * Given address of next destination (final or next hop), return (referenced)
1309 * internet address info of interface to be used to get there.
1310 */
1311struct in_ifaddr *
1312ip_rtaddr(struct in_addr dst, u_int fibnum)
1313{
1314 struct route sro;
1315 struct sockaddr_in *sin;
1316 struct in_ifaddr *ia;
1317
1318 bzero(&sro, sizeof(sro));
1319 sin = (struct sockaddr_in *)&sro.ro_dst;
1320 sin->sin_family = AF_INET;
1321 sin->sin_len = sizeof(*sin);
1322 sin->sin_addr = dst;
1323 in_rtalloc_ign(&sro, 0, fibnum);
1324
1325 if (sro.ro_rt == NULL)
1326 return (NULL);
1327
1328 ia = ifatoia(sro.ro_rt->rt_ifa);
1329 ifa_ref(&ia->ia_ifa);
1330 RTFREE(sro.ro_rt);
1331 return (ia);
1332}
1333
1334u_char inetctlerrmap[PRC_NCMDS] = {
1335 0, 0, 0, 0,
1336 0, EMSGSIZE, EHOSTDOWN, EHOSTUNREACH,
1337 EHOSTUNREACH, EHOSTUNREACH, ECONNREFUSED, ECONNREFUSED,
1338 EMSGSIZE, EHOSTUNREACH, 0, 0,
1339 0, 0, EHOSTUNREACH, 0,
1340 ENOPROTOOPT, ECONNREFUSED
1341};
1342
1343/*
1344 * Forward a packet. If some error occurs return the sender
1345 * an icmp packet. Note we can't always generate a meaningful
1346 * icmp message because icmp doesn't have a large enough repertoire
1347 * of codes and types.
1348 *
1349 * If not forwarding, just drop the packet. This could be confusing
1350 * if ipforwarding was zero but some routing protocol was advancing
1351 * us as a gateway to somewhere. However, we must let the routing
1352 * protocol deal with that.
1353 *
1354 * The srcrt parameter indicates whether the packet is being forwarded
1355 * via a source route.
1356 */
1357void
1358ip_forward(struct mbuf *m, int srcrt)
1359{
1360 struct ip *ip = mtod(m, struct ip *);
1361 struct in_ifaddr *ia;
1362 struct mbuf *mcopy;
1363 struct in_addr dest;
1364 struct route ro;
1365 int error, type = 0, code = 0, mtu = 0;
1366
1367 if (m->m_flags & (M_BCAST|M_MCAST) || in_canforward(ip->ip_dst) == 0) {
1368 IPSTAT_INC(ips_cantforward);
1369 m_freem(m);
1370 return;
1371 }
1372#ifdef IPSTEALTH
1373 if (!V_ipstealth) {
1374#endif
1375 if (ip->ip_ttl <= IPTTLDEC) {
1376 icmp_error(m, ICMP_TIMXCEED, ICMP_TIMXCEED_INTRANS,
1377 0, 0);
1378 return;
1379 }
1380#ifdef IPSTEALTH
1381 }
1382#endif
1383
1384 ia = ip_rtaddr(ip->ip_dst, M_GETFIB(m));
1385#ifndef IPSEC
1386 /*
1387 * 'ia' may be NULL if there is no route for this destination.
1388 * In case of IPsec, Don't discard it just yet, but pass it to
1389 * ip_output in case of outgoing IPsec policy.
1390 */
1391 if (!srcrt && ia == NULL) {
1392 icmp_error(m, ICMP_UNREACH, ICMP_UNREACH_HOST, 0, 0);
1393 return;
1394 }
1395#endif
1396
1397 /*
1398 * Save the IP header and at most 8 bytes of the payload,
1399 * in case we need to generate an ICMP message to the src.
1400 *
1401 * XXX this can be optimized a lot by saving the data in a local
1402 * buffer on the stack (72 bytes at most), and only allocating the
1403 * mbuf if really necessary. The vast majority of the packets
1404 * are forwarded without having to send an ICMP back (either
1405 * because unnecessary, or because rate limited), so we are
1406 * really we are wasting a lot of work here.
1407 *
1408 * We don't use m_copy() because it might return a reference
1409 * to a shared cluster. Both this function and ip_output()
1410 * assume exclusive access to the IP header in `m', so any
1411 * data in a cluster may change before we reach icmp_error().
1412 */
1413 mcopy = m_gethdr(M_NOWAIT, m->m_type);
1414 if (mcopy != NULL && !m_dup_pkthdr(mcopy, m, M_NOWAIT)) {
1415 /*
1416 * It's probably ok if the pkthdr dup fails (because
1417 * the deep copy of the tag chain failed), but for now
1418 * be conservative and just discard the copy since
1419 * code below may some day want the tags.
1420 */
1421 m_free(mcopy);
1422 mcopy = NULL;
1423 }
1424 if (mcopy != NULL) {
1425 mcopy->m_len = min(ntohs(ip->ip_len), M_TRAILINGSPACE(mcopy));
1426 mcopy->m_pkthdr.len = mcopy->m_len;
1427 m_copydata(m, 0, mcopy->m_len, mtod(mcopy, caddr_t));
1428 }
1429
1430#ifdef IPSTEALTH
1431 if (!V_ipstealth) {
1432#endif
1433 ip->ip_ttl -= IPTTLDEC;
1434#ifdef IPSTEALTH
1435 }
1436#endif
1437
1438 /*
1439 * If forwarding packet using same interface that it came in on,
1440 * perhaps should send a redirect to sender to shortcut a hop.
1441 * Only send redirect if source is sending directly to us,
1442 * and if packet was not source routed (or has any options).
1443 * Also, don't send redirect if forwarding using a default route
1444 * or a route modified by a redirect.
1445 */
1446 dest.s_addr = 0;
1447 if (!srcrt && V_ipsendredirects &&
1448 ia != NULL && ia->ia_ifp == m->m_pkthdr.rcvif) {
1449 struct sockaddr_in *sin;
1450 struct rtentry *rt;
1451
1452 bzero(&ro, sizeof(ro));
1453 sin = (struct sockaddr_in *)&ro.ro_dst;
1454 sin->sin_family = AF_INET;
1455 sin->sin_len = sizeof(*sin);
1456 sin->sin_addr = ip->ip_dst;
1457 in_rtalloc_ign(&ro, 0, M_GETFIB(m));
1458
1459 rt = ro.ro_rt;
1460
1461 if (rt && (rt->rt_flags & (RTF_DYNAMIC|RTF_MODIFIED)) == 0 &&
1462 satosin(rt_key(rt))->sin_addr.s_addr != 0) {
1463#define RTA(rt) ((struct in_ifaddr *)(rt->rt_ifa))
1464 u_long src = ntohl(ip->ip_src.s_addr);
1465
1466 if (RTA(rt) &&
1467 (src & RTA(rt)->ia_subnetmask) == RTA(rt)->ia_subnet) {
1468 if (rt->rt_flags & RTF_GATEWAY)
1469 dest.s_addr = satosin(rt->rt_gateway)->sin_addr.s_addr;
1470 else
1471 dest.s_addr = ip->ip_dst.s_addr;
1472 /* Router requirements says to only send host redirects */
1473 type = ICMP_REDIRECT;
1474 code = ICMP_REDIRECT_HOST;
1475 }
1476 }
1477 if (rt)
1478 RTFREE(rt);
1479 }
1480
1481 /*
1482 * Try to cache the route MTU from ip_output so we can consider it for
1483 * the ICMP_UNREACH_NEEDFRAG "Next-Hop MTU" field described in RFC1191.
1484 */
1485 bzero(&ro, sizeof(ro));
1486
1487 error = ip_output(m, NULL, &ro, IP_FORWARDING, NULL, NULL);
1488
1489 if (error == EMSGSIZE && ro.ro_rt)
1490 mtu = ro.ro_rt->rt_rmx.rmx_mtu;
1491 RO_RTFREE(&ro);
1492
1493 if (error)
1494 IPSTAT_INC(ips_cantforward);
1495 else {
1496 IPSTAT_INC(ips_forward);
1497 if (type)
1498 IPSTAT_INC(ips_redirectsent);
1499 else {
1500 if (mcopy)
1501 m_freem(mcopy);
1502 if (ia != NULL)
1503 ifa_free(&ia->ia_ifa);
1504 return;
1505 }
1506 }
1507 if (mcopy == NULL) {
1508 if (ia != NULL)
1509 ifa_free(&ia->ia_ifa);
1510 return;
1511 }
1512
1513 switch (error) {
1514
1515 case 0: /* forwarded, but need redirect */
1516 /* type, code set above */
1517 break;
1518
1519 case ENETUNREACH:
1520 case EHOSTUNREACH:
1521 case ENETDOWN:
1522 case EHOSTDOWN:
1523 default:
1524 type = ICMP_UNREACH;
1525 code = ICMP_UNREACH_HOST;
1526 break;
1527
1528 case EMSGSIZE:
1529 type = ICMP_UNREACH;
1530 code = ICMP_UNREACH_NEEDFRAG;
1531
1532#ifdef IPSEC
1533 /*
1534 * If IPsec is configured for this path,
1535 * override any possibly mtu value set by ip_output.
1536 */
1537 mtu = ip_ipsec_mtu(mcopy, mtu);
1538#endif /* IPSEC */
1539 /*
1540 * If the MTU was set before make sure we are below the
1541 * interface MTU.
1542 * If the MTU wasn't set before use the interface mtu or
1543 * fall back to the next smaller mtu step compared to the
1544 * current packet size.
1545 */
1546 if (mtu != 0) {
1547 if (ia != NULL)
1548 mtu = min(mtu, ia->ia_ifp->if_mtu);
1549 } else {
1550 if (ia != NULL)
1551 mtu = ia->ia_ifp->if_mtu;
1552 else
1553 mtu = ip_next_mtu(ntohs(ip->ip_len), 0);
1554 }
1555 IPSTAT_INC(ips_cantfrag);
1556 break;
1557
1558 case ENOBUFS:
1559 /*
1560 * A router should not generate ICMP_SOURCEQUENCH as
1561 * required in RFC1812 Requirements for IP Version 4 Routers.
1562 * Source quench could be a big problem under DoS attacks,
1563 * or if the underlying interface is rate-limited.
1564 * Those who need source quench packets may re-enable them
1565 * via the net.inet.ip.sendsourcequench sysctl.
1566 */
1567 if (V_ip_sendsourcequench == 0) {
1568 m_freem(mcopy);
1569 if (ia != NULL)
1570 ifa_free(&ia->ia_ifa);
1571 return;
1572 } else {
1573 type = ICMP_SOURCEQUENCH;
1574 code = 0;
1575 }
1576 break;
1577
1578 case EACCES: /* ipfw denied packet */
1579 m_freem(mcopy);
1580 if (ia != NULL)
1581 ifa_free(&ia->ia_ifa);
1582 return;
1583 }
1584 if (ia != NULL)
1585 ifa_free(&ia->ia_ifa);
1586 icmp_error(mcopy, type, code, dest.s_addr, mtu);
1587}
1588
1589void
1590ip_savecontrol(struct inpcb *inp, struct mbuf **mp, struct ip *ip,
1591 struct mbuf *m)
1592{
1593
1594 if (inp->inp_socket->so_options & (SO_BINTIME | SO_TIMESTAMP)) {
1595 struct bintime bt;
1596
1597 bintime(&bt);
1598 if (inp->inp_socket->so_options & SO_BINTIME) {
1599 *mp = sbcreatecontrol((caddr_t)&bt, sizeof(bt),
1600 SCM_BINTIME, SOL_SOCKET);
1601 if (*mp)
1602 mp = &(*mp)->m_next;
1603 }
1604 if (inp->inp_socket->so_options & SO_TIMESTAMP) {
1605 struct timeval tv;
1606
1607 bintime2timeval(&bt, &tv);
1608 *mp = sbcreatecontrol((caddr_t)&tv, sizeof(tv),
1609 SCM_TIMESTAMP, SOL_SOCKET);
1610 if (*mp)
1611 mp = &(*mp)->m_next;
1612 }
1613 }
1614 if (inp->inp_flags & INP_RECVDSTADDR) {
1615 *mp = sbcreatecontrol((caddr_t)&ip->ip_dst,
1616 sizeof(struct in_addr), IP_RECVDSTADDR, IPPROTO_IP);
1617 if (*mp)
1618 mp = &(*mp)->m_next;
1619 }
1620 if (inp->inp_flags & INP_RECVTTL) {
1621 *mp = sbcreatecontrol((caddr_t)&ip->ip_ttl,
1622 sizeof(u_char), IP_RECVTTL, IPPROTO_IP);
1623 if (*mp)
1624 mp = &(*mp)->m_next;
1625 }
1626#ifdef notyet
1627 /* XXX
1628 * Moving these out of udp_input() made them even more broken
1629 * than they already were.
1630 */
1631 /* options were tossed already */
1632 if (inp->inp_flags & INP_RECVOPTS) {
1633 *mp = sbcreatecontrol((caddr_t)opts_deleted_above,
1634 sizeof(struct in_addr), IP_RECVOPTS, IPPROTO_IP);
1635 if (*mp)
1636 mp = &(*mp)->m_next;
1637 }
1638 /* ip_srcroute doesn't do what we want here, need to fix */
1639 if (inp->inp_flags & INP_RECVRETOPTS) {
1640 *mp = sbcreatecontrol((caddr_t)ip_srcroute(m),
1641 sizeof(struct in_addr), IP_RECVRETOPTS, IPPROTO_IP);
1642 if (*mp)
1643 mp = &(*mp)->m_next;
1644 }
1645#endif
1646 if (inp->inp_flags & INP_RECVIF) {
1647 struct ifnet *ifp;
1648 struct sdlbuf {
1649 struct sockaddr_dl sdl;
1650 u_char pad[32];
1651 } sdlbuf;
1652 struct sockaddr_dl *sdp;
1653 struct sockaddr_dl *sdl2 = &sdlbuf.sdl;
1654
1655 if ((ifp = m->m_pkthdr.rcvif) &&
1656 ifp->if_index && ifp->if_index <= V_if_index) {
1657 sdp = (struct sockaddr_dl *)ifp->if_addr->ifa_addr;
1658 /*
1659 * Change our mind and don't try copy.
1660 */
1661 if (sdp->sdl_family != AF_LINK ||
1662 sdp->sdl_len > sizeof(sdlbuf)) {
1663 goto makedummy;
1664 }
1665 bcopy(sdp, sdl2, sdp->sdl_len);
1666 } else {
1667makedummy:
1668 sdl2->sdl_len =
1669 offsetof(struct sockaddr_dl, sdl_data[0]);
1670 sdl2->sdl_family = AF_LINK;
1671 sdl2->sdl_index = 0;
1672 sdl2->sdl_nlen = sdl2->sdl_alen = sdl2->sdl_slen = 0;
1673 }
1674 *mp = sbcreatecontrol((caddr_t)sdl2, sdl2->sdl_len,
1675 IP_RECVIF, IPPROTO_IP);
1676 if (*mp)
1677 mp = &(*mp)->m_next;
1678 }
1679 if (inp->inp_flags & INP_RECVTOS) {
1680 *mp = sbcreatecontrol((caddr_t)&ip->ip_tos,
1681 sizeof(u_char), IP_RECVTOS, IPPROTO_IP);
1682 if (*mp)
1683 mp = &(*mp)->m_next;
1684 }
1685}
1686
1687/*
1688 * XXXRW: Multicast routing code in ip_mroute.c is generally MPSAFE, but the
1689 * ip_rsvp and ip_rsvp_on variables need to be interlocked with rsvp_on
1690 * locking. This code remains in ip_input.c as ip_mroute.c is optionally
1691 * compiled.
1692 */
1693static VNET_DEFINE(int, ip_rsvp_on);
1694VNET_DEFINE(struct socket *, ip_rsvpd);
1695
1696#define V_ip_rsvp_on VNET(ip_rsvp_on)
1697
1698int
1699ip_rsvp_init(struct socket *so)
1700{
1701
1702 if (so->so_type != SOCK_RAW ||
1703 so->so_proto->pr_protocol != IPPROTO_RSVP)
1704 return EOPNOTSUPP;
1705
1706 if (V_ip_rsvpd != NULL)
1707 return EADDRINUSE;
1708
1709 V_ip_rsvpd = so;
1710 /*
1711 * This may seem silly, but we need to be sure we don't over-increment
1712 * the RSVP counter, in case something slips up.
1713 */
1714 if (!V_ip_rsvp_on) {
1715 V_ip_rsvp_on = 1;
1716 V_rsvp_on++;
1717 }
1718
1719 return 0;
1720}
1721
1722int
1723ip_rsvp_done(void)
1724{
1725
1726 V_ip_rsvpd = NULL;
1727 /*
1728 * This may seem silly, but we need to be sure we don't over-decrement
1729 * the RSVP counter, in case something slips up.
1730 */
1731 if (V_ip_rsvp_on) {
1732 V_ip_rsvp_on = 0;
1733 V_rsvp_on--;
1734 }
1735 return 0;
1736}
1737
1738void
1739rsvp_input(struct mbuf *m, int off) /* XXX must fixup manually */
1740{
1741
1742 if (rsvp_input_p) { /* call the real one if loaded */
1743 rsvp_input_p(m, off);
1744 return;
1745 }
1746
1747 /* Can still get packets with rsvp_on = 0 if there is a local member
1748 * of the group to which the RSVP packet is addressed. But in this
1749 * case we want to throw the packet away.
1750 */
1751
1752 if (!V_rsvp_on) {
1753 m_freem(m);
1754 return;
1755 }
1756
1757 if (V_ip_rsvpd != NULL) {
1758 rip_input(m, off);
1759 return;
1760 }
1761 /* Drop the packet */
1762 m_freem(m);
1763}
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