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/callout.h>
44#include <sys/mbuf.h>
45#include <sys/malloc.h>
46#include <sys/domain.h>
47#include <sys/protosw.h>
48#include <sys/socket.h>
49#include <sys/time.h>
50#include <sys/kernel.h>
51#include <sys/lock.h>
52#include <sys/rwlock.h>
53#include <sys/syslog.h>
54#include <sys/sysctl.h>
55
56#include <net/pfil.h>
57#include <net/if.h>
58#include <net/if_types.h>
59#include <net/if_var.h>
60#include <net/if_dl.h>
61#include <net/route.h>
62#include <net/netisr.h>
63#include <net/vnet.h>
64#include <net/flowtable.h>
65
66#include <netinet/in.h>
67#include <netinet/in_systm.h>
68#include <netinet/in_var.h>
69#include <netinet/ip.h>
70#include <netinet/in_pcb.h>
71#include <netinet/ip_var.h>
72#include <netinet/ip_fw.h>
73#include <netinet/ip_icmp.h>
74#include <netinet/ip_options.h>
75#include <machine/in_cksum.h>
76#include <netinet/ip_carp.h>
77#ifdef IPSEC
78#include <netinet/ip_ipsec.h>
79#endif /* IPSEC */
80
81#include <sys/socketvar.h>
82
83#include <security/mac/mac_framework.h>
84
85#ifdef CTASSERT
86CTASSERT(sizeof(struct ip) == 20);
87#endif
88
89struct rwlock in_ifaddr_lock;
90RW_SYSINIT(in_ifaddr_lock, &in_ifaddr_lock, "in_ifaddr_lock");
91
92VNET_DEFINE(int, rsvp_on);
93
94VNET_DEFINE(int, ipforwarding);
95SYSCTL_VNET_INT(_net_inet_ip, IPCTL_FORWARDING, forwarding, CTLFLAG_RW,
96 &VNET_NAME(ipforwarding), 0,
97 "Enable IP forwarding between interfaces");
98
99static VNET_DEFINE(int, ipsendredirects) = 1; /* XXX */
100#define V_ipsendredirects VNET(ipsendredirects)
101SYSCTL_VNET_INT(_net_inet_ip, IPCTL_SENDREDIRECTS, redirect, CTLFLAG_RW,
102 &VNET_NAME(ipsendredirects), 0,
103 "Enable sending IP redirects");
104
105VNET_DEFINE(int, ip_defttl) = IPDEFTTL;
106SYSCTL_VNET_INT(_net_inet_ip, IPCTL_DEFTTL, ttl, CTLFLAG_RW,
107 &VNET_NAME(ip_defttl), 0,
108 "Maximum TTL on IP packets");
109
110static VNET_DEFINE(int, ip_keepfaith);
111#define V_ip_keepfaith VNET(ip_keepfaith)
112SYSCTL_VNET_INT(_net_inet_ip, IPCTL_KEEPFAITH, keepfaith, CTLFLAG_RW,
113 &VNET_NAME(ip_keepfaith), 0,
114 "Enable packet capture for FAITH IPv4->IPv6 translater daemon");
115
116static VNET_DEFINE(int, ip_sendsourcequench);
117#define V_ip_sendsourcequench VNET(ip_sendsourcequench)
118SYSCTL_VNET_INT(_net_inet_ip, OID_AUTO, sendsourcequench, CTLFLAG_RW,
119 &VNET_NAME(ip_sendsourcequench), 0,
120 "Enable the transmission of source quench packets");
121
122VNET_DEFINE(int, ip_do_randomid);
123SYSCTL_VNET_INT(_net_inet_ip, OID_AUTO, random_id, CTLFLAG_RW,
124 &VNET_NAME(ip_do_randomid), 0,
125 "Assign random ip_id values");
126
127/*
128 * XXX - Setting ip_checkinterface mostly implements the receive side of
129 * the Strong ES model described in RFC 1122, but since the routing table
130 * and transmit implementation do not implement the Strong ES model,
131 * setting this to 1 results in an odd hybrid.
132 *
133 * XXX - ip_checkinterface currently must be disabled if you use ipnat
134 * to translate the destination address to another local interface.
135 *
136 * XXX - ip_checkinterface must be disabled if you add IP aliases
137 * to the loopback interface instead of the interface where the
138 * packets for those addresses are received.
139 */
140static VNET_DEFINE(int, ip_checkinterface);
141#define V_ip_checkinterface VNET(ip_checkinterface)
142SYSCTL_VNET_INT(_net_inet_ip, OID_AUTO, check_interface, CTLFLAG_RW,
143 &VNET_NAME(ip_checkinterface), 0,
144 "Verify packet arrives on correct interface");
145
146VNET_DEFINE(struct pfil_head, inet_pfil_hook); /* Packet filter hooks */
147
148static struct netisr_handler ip_nh = {
149 .nh_name = "ip",
150 .nh_handler = ip_input,
151 .nh_proto = NETISR_IP,
152 .nh_policy = NETISR_POLICY_FLOW,
153};
154
155extern struct domain inetdomain;
156extern struct protosw inetsw[];
157u_char ip_protox[IPPROTO_MAX];
158VNET_DEFINE(struct in_ifaddrhead, in_ifaddrhead); /* first inet address */
159VNET_DEFINE(struct in_ifaddrhashhead *, in_ifaddrhashtbl); /* inet addr hash table */
160VNET_DEFINE(u_long, in_ifaddrhmask); /* mask for hash table */
161
162VNET_DEFINE(struct ipstat, ipstat);
163SYSCTL_VNET_STRUCT(_net_inet_ip, IPCTL_STATS, stats, CTLFLAG_RW,
164 &VNET_NAME(ipstat), ipstat,
165 "IP statistics (struct ipstat, netinet/ip_var.h)");
166
167static VNET_DEFINE(uma_zone_t, ipq_zone);
168static VNET_DEFINE(TAILQ_HEAD(ipqhead, ipq), ipq[IPREASS_NHASH]);
169static struct mtx ipqlock;
170
171#define V_ipq_zone VNET(ipq_zone)
172#define V_ipq VNET(ipq)
173
174#define IPQ_LOCK() mtx_lock(&ipqlock)
175#define IPQ_UNLOCK() mtx_unlock(&ipqlock)
176#define IPQ_LOCK_INIT() mtx_init(&ipqlock, "ipqlock", NULL, MTX_DEF)
177#define IPQ_LOCK_ASSERT() mtx_assert(&ipqlock, MA_OWNED)
178
179static void maxnipq_update(void);
180static void ipq_zone_change(void *);
181static void ip_drain_locked(void);
182
183static VNET_DEFINE(int, maxnipq); /* Administrative limit on # reass queues. */
184static VNET_DEFINE(int, nipq); /* Total # of reass queues */
185#define V_maxnipq VNET(maxnipq)
186#define V_nipq VNET(nipq)
187SYSCTL_VNET_INT(_net_inet_ip, OID_AUTO, fragpackets, CTLFLAG_RD,
188 &VNET_NAME(nipq), 0,
189 "Current number of IPv4 fragment reassembly queue entries");
190
191static VNET_DEFINE(int, maxfragsperpacket);
192#define V_maxfragsperpacket VNET(maxfragsperpacket)
193SYSCTL_VNET_INT(_net_inet_ip, OID_AUTO, maxfragsperpacket, CTLFLAG_RW,
194 &VNET_NAME(maxfragsperpacket), 0,
195 "Maximum number of IPv4 fragments allowed per packet");
196
197struct callout ipport_tick_callout;
198
199#ifdef IPCTL_DEFMTU
200SYSCTL_INT(_net_inet_ip, IPCTL_DEFMTU, mtu, CTLFLAG_RW,
201 &ip_mtu, 0, "Default MTU");
202#endif
203
204#ifdef IPSTEALTH
205VNET_DEFINE(int, ipstealth);
206SYSCTL_VNET_INT(_net_inet_ip, OID_AUTO, stealth, CTLFLAG_RW,
207 &VNET_NAME(ipstealth), 0,
208 "IP stealth mode, no TTL decrementation on forwarding");
209#endif
210
211#ifdef FLOWTABLE
212static VNET_DEFINE(int, ip_output_flowtable_size) = 2048;
213VNET_DEFINE(struct flowtable *, ip_ft);
214#define V_ip_output_flowtable_size VNET(ip_output_flowtable_size)
215
216SYSCTL_VNET_INT(_net_inet_ip, OID_AUTO, output_flowtable_size, CTLFLAG_RDTUN,
217 &VNET_NAME(ip_output_flowtable_size), 2048,
218 "number of entries in the per-cpu output flow caches");
219#endif
220
221VNET_DEFINE(int, fw_one_pass) = 1;
222
223static void ip_freef(struct ipqhead *, struct ipq *);
224
225/*
226 * Kernel module interface for updating ipstat. The argument is an index
227 * into ipstat treated as an array of u_long. While this encodes the general
228 * layout of ipstat into the caller, it doesn't encode its location, so that
229 * future changes to add, for example, per-CPU stats support won't cause
230 * binary compatibility problems for kernel modules.
231 */
232void
233kmod_ipstat_inc(int statnum)
234{
235
236 (*((u_long *)&V_ipstat + statnum))++;
237}
238
239void
240kmod_ipstat_dec(int statnum)
241{
242
243 (*((u_long *)&V_ipstat + statnum))--;
244}
245
246static int
247sysctl_netinet_intr_queue_maxlen(SYSCTL_HANDLER_ARGS)
248{
249 int error, qlimit;
250
251 netisr_getqlimit(&ip_nh, &qlimit);
252 error = sysctl_handle_int(oidp, &qlimit, 0, req);
253 if (error || !req->newptr)
254 return (error);
255 if (qlimit < 1)
256 return (EINVAL);
257 return (netisr_setqlimit(&ip_nh, qlimit));
258}
259SYSCTL_PROC(_net_inet_ip, IPCTL_INTRQMAXLEN, intr_queue_maxlen,
260 CTLTYPE_INT|CTLFLAG_RW, 0, 0, sysctl_netinet_intr_queue_maxlen, "I",
261 "Maximum size of the IP input queue");
262
263static int
264sysctl_netinet_intr_queue_drops(SYSCTL_HANDLER_ARGS)
265{
266 u_int64_t qdrops_long;
267 int error, qdrops;
268
269 netisr_getqdrops(&ip_nh, &qdrops_long);
270 qdrops = qdrops_long;
271 error = sysctl_handle_int(oidp, &qdrops, 0, req);
272 if (error || !req->newptr)
273 return (error);
274 if (qdrops != 0)
275 return (EINVAL);
276 netisr_clearqdrops(&ip_nh);
277 return (0);
278}
279
280SYSCTL_PROC(_net_inet_ip, IPCTL_INTRQDROPS, intr_queue_drops,
281 CTLTYPE_INT|CTLFLAG_RD, 0, 0, sysctl_netinet_intr_queue_drops, "I",
282 "Number of packets dropped from the IP input queue");
283
284/*
285 * IP initialization: fill in IP protocol switch table.
286 * All protocols not implemented in kernel go to raw IP protocol handler.
287 */
288void
289ip_init(void)
290{
291 struct protosw *pr;
292 int i;
293
294 V_ip_id = time_second & 0xffff;
295
296 TAILQ_INIT(&V_in_ifaddrhead);
297 V_in_ifaddrhashtbl = hashinit(INADDR_NHASH, M_IFADDR, &V_in_ifaddrhmask);
298
299 /* Initialize IP reassembly queue. */
300 for (i = 0; i < IPREASS_NHASH; i++)
301 TAILQ_INIT(&V_ipq[i]);
302 V_maxnipq = nmbclusters / 32;
303 V_maxfragsperpacket = 16;
304 V_ipq_zone = uma_zcreate("ipq", sizeof(struct ipq), NULL, NULL, NULL,
305 NULL, UMA_ALIGN_PTR, 0);
306 maxnipq_update();
307
308 /* Initialize packet filter hooks. */
309 V_inet_pfil_hook.ph_type = PFIL_TYPE_AF;
310 V_inet_pfil_hook.ph_af = AF_INET;
311 if ((i = pfil_head_register(&V_inet_pfil_hook)) != 0)
312 printf("%s: WARNING: unable to register pfil hook, "
313 "error %d\n", __func__, i);
314
315#ifdef FLOWTABLE
316 if (TUNABLE_INT_FETCH("net.inet.ip.output_flowtable_size",
317 &V_ip_output_flowtable_size)) {
318 if (V_ip_output_flowtable_size < 256)
319 V_ip_output_flowtable_size = 256;
320 if (!powerof2(V_ip_output_flowtable_size)) {
321 printf("flowtable must be power of 2 size\n");
322 V_ip_output_flowtable_size = 2048;
323 }
324 } else {
325 /*
326 * round up to the next power of 2
327 */
328 V_ip_output_flowtable_size = 1 << fls((1024 + maxusers * 64)-1);
329 }
330 V_ip_ft = flowtable_alloc("ipv4", V_ip_output_flowtable_size, FL_PCPU);
331#endif
332
333 /* Skip initialization of globals for non-default instances. */
334 if (!IS_DEFAULT_VNET(curvnet))
335 return;
336
337 pr = pffindproto(PF_INET, IPPROTO_RAW, SOCK_RAW);
338 if (pr == NULL)
339 panic("ip_init: PF_INET not found");
340
341 /* Initialize the entire ip_protox[] array to IPPROTO_RAW. */
342 for (i = 0; i < IPPROTO_MAX; i++)
343 ip_protox[i] = pr - inetsw;
344 /*
345 * Cycle through IP protocols and put them into the appropriate place
346 * in ip_protox[].
347 */
348 for (pr = inetdomain.dom_protosw;
349 pr < inetdomain.dom_protoswNPROTOSW; pr++)
350 if (pr->pr_domain->dom_family == PF_INET &&
351 pr->pr_protocol && pr->pr_protocol != IPPROTO_RAW) {
352 /* Be careful to only index valid IP protocols. */
353 if (pr->pr_protocol < IPPROTO_MAX)
354 ip_protox[pr->pr_protocol] = pr - inetsw;
355 }
356
357 /* Start ipport_tick. */
358 callout_init(&ipport_tick_callout, CALLOUT_MPSAFE);
359 callout_reset(&ipport_tick_callout, 1, ipport_tick, NULL);
360 EVENTHANDLER_REGISTER(shutdown_pre_sync, ip_fini, NULL,
361 SHUTDOWN_PRI_DEFAULT);
362 EVENTHANDLER_REGISTER(nmbclusters_change, ipq_zone_change,
363 NULL, EVENTHANDLER_PRI_ANY);
364
365 /* Initialize various other remaining things. */
366 IPQ_LOCK_INIT();
367 netisr_register(&ip_nh);
368}
369
370#ifdef VIMAGE
371void
372ip_destroy(void)
373{
374
375 /* Cleanup in_ifaddr hash table; should be empty. */
376 hashdestroy(V_in_ifaddrhashtbl, M_IFADDR, V_in_ifaddrhmask);
377
378 IPQ_LOCK();
379 ip_drain_locked();
380 IPQ_UNLOCK();
381
382 uma_zdestroy(V_ipq_zone);
383}
384#endif
385
386void
387ip_fini(void *xtp)
388{
389
390 callout_stop(&ipport_tick_callout);
391}
392
393/*
394 * Ip input routine. Checksum and byte swap header. If fragmented
395 * try to reassemble. Process options. Pass to next level.
396 */
397void
398ip_input(struct mbuf *m)
399{
400 struct ip *ip = NULL;
401 struct in_ifaddr *ia = NULL;
402 struct ifaddr *ifa;
403 struct ifnet *ifp;
404 int checkif, hlen = 0;
405 u_short sum;
406 int dchg = 0; /* dest changed after fw */
407 struct in_addr odst; /* original dst address */
408
409 M_ASSERTPKTHDR(m);
410
411 if (m->m_flags & M_FASTFWD_OURS) {
412 /*
413 * Firewall or NAT changed destination to local.
414 * We expect ip_len and ip_off to be in host byte order.
415 */
416 m->m_flags &= ~M_FASTFWD_OURS;
417 /* Set up some basics that will be used later. */
418 ip = mtod(m, struct ip *);
419 hlen = ip->ip_hl << 2;
420 goto ours;
421 }
422
423 IPSTAT_INC(ips_total);
424
425 if (m->m_pkthdr.len < sizeof(struct ip))
426 goto tooshort;
427
428 if (m->m_len < sizeof (struct ip) &&
429 (m = m_pullup(m, sizeof (struct ip))) == NULL) {
430 IPSTAT_INC(ips_toosmall);
431 return;
432 }
433 ip = mtod(m, struct ip *);
434
435 if (ip->ip_v != IPVERSION) {
436 IPSTAT_INC(ips_badvers);
437 goto bad;
438 }
439
440 hlen = ip->ip_hl << 2;
441 if (hlen < sizeof(struct ip)) { /* minimum header length */
442 IPSTAT_INC(ips_badhlen);
443 goto bad;
444 }
445 if (hlen > m->m_len) {
446 if ((m = m_pullup(m, hlen)) == NULL) {
447 IPSTAT_INC(ips_badhlen);
448 return;
449 }
450 ip = mtod(m, struct ip *);
451 }
452
453 /* 127/8 must not appear on wire - RFC1122 */
454 ifp = m->m_pkthdr.rcvif;
455 if ((ntohl(ip->ip_dst.s_addr) >> IN_CLASSA_NSHIFT) == IN_LOOPBACKNET ||
456 (ntohl(ip->ip_src.s_addr) >> IN_CLASSA_NSHIFT) == IN_LOOPBACKNET) {
457 if ((ifp->if_flags & IFF_LOOPBACK) == 0) {
458 IPSTAT_INC(ips_badaddr);
459 goto bad;
460 }
461 }
462
463 if (m->m_pkthdr.csum_flags & CSUM_IP_CHECKED) {
464 sum = !(m->m_pkthdr.csum_flags & CSUM_IP_VALID);
465 } else {
466 if (hlen == sizeof(struct ip)) {
467 sum = in_cksum_hdr(ip);
468 } else {
469 sum = in_cksum(m, hlen);
470 }
471 }
472 if (sum) {
473 IPSTAT_INC(ips_badsum);
474 goto bad;
475 }
476
477#ifdef ALTQ
478 if (altq_input != NULL && (*altq_input)(m, AF_INET) == 0)
479 /* packet is dropped by traffic conditioner */
480 return;
481#endif
482
483 /*
484 * Convert fields to host representation.
485 */
486 ip->ip_len = ntohs(ip->ip_len);
487 if (ip->ip_len < hlen) {
488 IPSTAT_INC(ips_badlen);
489 goto bad;
490 }
491 ip->ip_off = ntohs(ip->ip_off);
492
493 /*
494 * Check that the amount of data in the buffers
495 * is as at least much as the IP header would have us expect.
496 * Trim mbufs if longer than we expect.
497 * Drop packet if shorter than we expect.
498 */
499 if (m->m_pkthdr.len < ip->ip_len) {
500tooshort:
501 IPSTAT_INC(ips_tooshort);
502 goto bad;
503 }
504 if (m->m_pkthdr.len > ip->ip_len) {
505 if (m->m_len == m->m_pkthdr.len) {
506 m->m_len = ip->ip_len;
507 m->m_pkthdr.len = ip->ip_len;
508 } else
509 m_adj(m, ip->ip_len - m->m_pkthdr.len);
510 }
511#ifdef IPSEC
512 /*
513 * Bypass packet filtering for packets from a tunnel (gif).
514 */
515 if (ip_ipsec_filtertunnel(m))
516 goto passin;
517#endif /* IPSEC */
518
519 /*
520 * Run through list of hooks for input packets.
521 *
522 * NB: Beware of the destination address changing (e.g.
523 * by NAT rewriting). When this happens, tell
524 * ip_forward to do the right thing.
525 */
526
527 /* Jump over all PFIL processing if hooks are not active. */
528 if (!PFIL_HOOKED(&V_inet_pfil_hook))
529 goto passin;
530
531 odst = ip->ip_dst;
532 if (pfil_run_hooks(&V_inet_pfil_hook, &m, ifp, PFIL_IN, NULL) != 0)
533 return;
534 if (m == NULL) /* consumed by filter */
535 return;
536
537 ip = mtod(m, struct ip *);
538 dchg = (odst.s_addr != ip->ip_dst.s_addr);
539 ifp = m->m_pkthdr.rcvif;
540
541#ifdef IPFIREWALL_FORWARD
542 if (m->m_flags & M_FASTFWD_OURS) {
543 m->m_flags &= ~M_FASTFWD_OURS;
544 goto ours;
545 }
546 if ((dchg = (m_tag_find(m, PACKET_TAG_IPFORWARD, NULL) != NULL)) != 0) {
547 /*
548 * Directly ship the packet on. This allows forwarding
549 * packets originally destined to us to some other directly
550 * connected host.
551 */
552 ip_forward(m, dchg);
553 return;
554 }
555#endif /* IPFIREWALL_FORWARD */
556
557passin:
558 /*
559 * Process options and, if not destined for us,
560 * ship it on. ip_dooptions returns 1 when an
561 * error was detected (causing an icmp message
562 * to be sent and the original packet to be freed).
563 */
564 if (hlen > sizeof (struct ip) && ip_dooptions(m, 0))
565 return;
566
567 /* greedy RSVP, snatches any PATH packet of the RSVP protocol and no
568 * matter if it is destined to another node, or whether it is
569 * a multicast one, RSVP wants it! and prevents it from being forwarded
570 * anywhere else. Also checks if the rsvp daemon is running before
571 * grabbing the packet.
572 */
573 if (V_rsvp_on && ip->ip_p==IPPROTO_RSVP)
574 goto ours;
575
576 /*
577 * Check our list of addresses, to see if the packet is for us.
578 * If we don't have any addresses, assume any unicast packet
579 * we receive might be for us (and let the upper layers deal
580 * with it).
581 */
582 if (TAILQ_EMPTY(&V_in_ifaddrhead) &&
583 (m->m_flags & (M_MCAST|M_BCAST)) == 0)
584 goto ours;
585
586 /*
587 * Enable a consistency check between the destination address
588 * and the arrival interface for a unicast packet (the RFC 1122
589 * strong ES model) if IP forwarding is disabled and the packet
590 * is not locally generated and the packet is not subject to
591 * 'ipfw fwd'.
592 *
593 * XXX - Checking also should be disabled if the destination
594 * address is ipnat'ed to a different interface.
595 *
596 * XXX - Checking is incompatible with IP aliases added
597 * to the loopback interface instead of the interface where
598 * the packets are received.
599 *
600 * XXX - This is the case for carp vhost IPs as well so we
601 * insert a workaround. If the packet got here, we already
602 * checked with carp_iamatch() and carp_forus().
603 */
604 checkif = V_ip_checkinterface && (V_ipforwarding == 0) &&
605 ifp != NULL && ((ifp->if_flags & IFF_LOOPBACK) == 0) &&
606 ifp->if_carp == NULL && (dchg == 0);
607
608 /*
609 * Check for exact addresses in the hash bucket.
610 */
611 /* IN_IFADDR_RLOCK(); */
612 LIST_FOREACH(ia, INADDR_HASH(ip->ip_dst.s_addr), ia_hash) {
613 /*
614 * If the address matches, verify that the packet
615 * arrived via the correct interface if checking is
616 * enabled.
617 */
618 if (IA_SIN(ia)->sin_addr.s_addr == ip->ip_dst.s_addr &&
619 (!checkif || ia->ia_ifp == ifp)) {
620 ifa_ref(&ia->ia_ifa);
621 /* IN_IFADDR_RUNLOCK(); */
622 goto ours;
623 }
624 }
625 /* IN_IFADDR_RUNLOCK(); */
626
627 /*
628 * Check for broadcast addresses.
629 *
630 * Only accept broadcast packets that arrive via the matching
631 * interface. Reception of forwarded directed broadcasts would
632 * be handled via ip_forward() and ether_output() with the loopback
633 * into the stack for SIMPLEX interfaces handled by ether_output().
634 */
635 if (ifp != NULL && ifp->if_flags & IFF_BROADCAST) {
636 IF_ADDR_LOCK(ifp);
637 TAILQ_FOREACH(ifa, &ifp->if_addrhead, ifa_link) {
638 if (ifa->ifa_addr->sa_family != AF_INET)
639 continue;
640 ia = ifatoia(ifa);
641 if (satosin(&ia->ia_broadaddr)->sin_addr.s_addr ==
642 ip->ip_dst.s_addr) {
643 ifa_ref(ifa);
644 IF_ADDR_UNLOCK(ifp);
645 goto ours;
646 }
647 if (ia->ia_netbroadcast.s_addr == ip->ip_dst.s_addr) {
648 ifa_ref(ifa);
649 IF_ADDR_UNLOCK(ifp);
650 goto ours;
651 }
652#ifdef BOOTP_COMPAT
653 if (IA_SIN(ia)->sin_addr.s_addr == INADDR_ANY) {
654 ifa_ref(ifa);
655 IF_ADDR_UNLOCK(ifp);
656 goto ours;
657 }
658#endif
659 }
660 IF_ADDR_UNLOCK(ifp);
661 ia = NULL;
662 }
663 /* RFC 3927 2.7: Do not forward datagrams for 169.254.0.0/16. */
664 if (IN_LINKLOCAL(ntohl(ip->ip_dst.s_addr))) {
665 IPSTAT_INC(ips_cantforward);
666 m_freem(m);
667 return;
668 }
669 if (IN_MULTICAST(ntohl(ip->ip_dst.s_addr))) {
670 if (V_ip_mrouter) {
671 /*
672 * If we are acting as a multicast router, all
673 * incoming multicast packets are passed to the
674 * kernel-level multicast forwarding function.
675 * The packet is returned (relatively) intact; if
676 * ip_mforward() returns a non-zero value, the packet
677 * must be discarded, else it may be accepted below.
678 */
679 if (ip_mforward && ip_mforward(ip, ifp, m, 0) != 0) {
680 IPSTAT_INC(ips_cantforward);
681 m_freem(m);
682 return;
683 }
684
685 /*
686 * The process-level routing daemon needs to receive
687 * all multicast IGMP packets, whether or not this
688 * host belongs to their destination groups.
689 */
690 if (ip->ip_p == IPPROTO_IGMP)
691 goto ours;
692 IPSTAT_INC(ips_forward);
693 }
694 /*
695 * Assume the packet is for us, to avoid prematurely taking
696 * a lock on the in_multi hash. Protocols must perform
697 * their own filtering and update statistics accordingly.
698 */
699 goto ours;
700 }
701 if (ip->ip_dst.s_addr == (u_long)INADDR_BROADCAST)
702 goto ours;
703 if (ip->ip_dst.s_addr == INADDR_ANY)
704 goto ours;
705
706 /*
707 * FAITH(Firewall Aided Internet Translator)
708 */
709 if (ifp && ifp->if_type == IFT_FAITH) {
710 if (V_ip_keepfaith) {
711 if (ip->ip_p == IPPROTO_TCP || ip->ip_p == IPPROTO_ICMP)
712 goto ours;
713 }
714 m_freem(m);
715 return;
716 }
717
718 /*
719 * Not for us; forward if possible and desirable.
720 */
721 if (V_ipforwarding == 0) {
722 IPSTAT_INC(ips_cantforward);
723 m_freem(m);
724 } else {
725#ifdef IPSEC
726 if (ip_ipsec_fwd(m))
727 goto bad;
728#endif /* IPSEC */
729 ip_forward(m, dchg);
730 }
731 return;
732
733ours:
734#ifdef IPSTEALTH
735 /*
736 * IPSTEALTH: Process non-routing options only
737 * if the packet is destined for us.
738 */
739 if (V_ipstealth && hlen > sizeof (struct ip) && ip_dooptions(m, 1)) {
740 if (ia != NULL)
741 ifa_free(&ia->ia_ifa);
742 return;
743 }
744#endif /* IPSTEALTH */
745
746 /* Count the packet in the ip address stats */
747 if (ia != NULL) {
748 ia->ia_ifa.if_ipackets++;
749 ia->ia_ifa.if_ibytes += m->m_pkthdr.len;
750 ifa_free(&ia->ia_ifa);
751 }
752
753 /*
754 * Attempt reassembly; if it succeeds, proceed.
755 * ip_reass() will return a different mbuf.
756 */
757 if (ip->ip_off & (IP_MF | IP_OFFMASK)) {
758 m = ip_reass(m);
759 if (m == NULL)
760 return;
761 ip = mtod(m, struct ip *);
762 /* Get the header length of the reassembled packet */
763 hlen = ip->ip_hl << 2;
764 }
765
766 /*
767 * Further protocols expect the packet length to be w/o the
768 * IP header.
769 */
770 ip->ip_len -= hlen;
771
772#ifdef IPSEC
773 /*
774 * enforce IPsec policy checking if we are seeing last header.
775 * note that we do not visit this with protocols with pcb layer
776 * code - like udp/tcp/raw ip.
777 */
778 if (ip_ipsec_input(m))
779 goto bad;
780#endif /* IPSEC */
781
782 /*
783 * Switch out to protocol's input routine.
784 */
785 IPSTAT_INC(ips_delivered);
786
787 (*inetsw[ip_protox[ip->ip_p]].pr_input)(m, hlen);
788 return;
789bad:
790 m_freem(m);
791}
792
793/*
794 * After maxnipq has been updated, propagate the change to UMA. The UMA zone
795 * max has slightly different semantics than the sysctl, for historical
796 * reasons.
797 */
798static void
799maxnipq_update(void)
800{
801
802 /*
803 * -1 for unlimited allocation.
804 */
805 if (V_maxnipq < 0)
806 uma_zone_set_max(V_ipq_zone, 0);
807 /*
808 * Positive number for specific bound.
809 */
810 if (V_maxnipq > 0)
811 uma_zone_set_max(V_ipq_zone, V_maxnipq);
812 /*
813 * Zero specifies no further fragment queue allocation -- set the
814 * bound very low, but rely on implementation elsewhere to actually
815 * prevent allocation and reclaim current queues.
816 */
817 if (V_maxnipq == 0)
818 uma_zone_set_max(V_ipq_zone, 1);
819}
820
821static void
822ipq_zone_change(void *tag)
823{
824
825 if (V_maxnipq > 0 && V_maxnipq < (nmbclusters / 32)) {
826 V_maxnipq = nmbclusters / 32;
827 maxnipq_update();
828 }
829}
830
831static int
832sysctl_maxnipq(SYSCTL_HANDLER_ARGS)
833{
834 int error, i;
835
836 i = V_maxnipq;
837 error = sysctl_handle_int(oidp, &i, 0, req);
838 if (error || !req->newptr)
839 return (error);
840
841 /*
842 * XXXRW: Might be a good idea to sanity check the argument and place
843 * an extreme upper bound.
844 */
845 if (i < -1)
846 return (EINVAL);
847 V_maxnipq = i;
848 maxnipq_update();
849 return (0);
850}
851
852SYSCTL_PROC(_net_inet_ip, OID_AUTO, maxfragpackets, CTLTYPE_INT|CTLFLAG_RW,
853 NULL, 0, sysctl_maxnipq, "I",
854 "Maximum number of IPv4 fragment reassembly queue entries");
855
856/*
857 * Take incoming datagram fragment and try to reassemble it into
858 * whole datagram. If the argument is the first fragment or one
859 * in between the function will return NULL and store the mbuf
860 * in the fragment chain. If the argument is the last fragment
861 * the packet will be reassembled and the pointer to the new
862 * mbuf returned for further processing. Only m_tags attached
863 * to the first packet/fragment are preserved.
864 * The IP header is *NOT* adjusted out of iplen.
865 */
866struct mbuf *
867ip_reass(struct mbuf *m)
868{
869 struct ip *ip;
870 struct mbuf *p, *q, *nq, *t;
871 struct ipq *fp = NULL;
872 struct ipqhead *head;
873 int i, hlen, next;
874 u_int8_t ecn, ecn0;
875 u_short hash;
876
877 /* If maxnipq or maxfragsperpacket are 0, never accept fragments. */
878 if (V_maxnipq == 0 || V_maxfragsperpacket == 0) {
879 IPSTAT_INC(ips_fragments);
880 IPSTAT_INC(ips_fragdropped);
881 m_freem(m);
882 return (NULL);
883 }
884
885 ip = mtod(m, struct ip *);
886 hlen = ip->ip_hl << 2;
887
888 hash = IPREASS_HASH(ip->ip_src.s_addr, ip->ip_id);
889 head = &V_ipq[hash];
890 IPQ_LOCK();
891
892 /*
893 * Look for queue of fragments
894 * of this datagram.
895 */
896 TAILQ_FOREACH(fp, head, ipq_list)
897 if (ip->ip_id == fp->ipq_id &&
898 ip->ip_src.s_addr == fp->ipq_src.s_addr &&
899 ip->ip_dst.s_addr == fp->ipq_dst.s_addr &&
900#ifdef MAC
901 mac_ipq_match(m, fp) &&
902#endif
903 ip->ip_p == fp->ipq_p)
904 goto found;
905
906 fp = NULL;
907
908 /*
909 * Attempt to trim the number of allocated fragment queues if it
910 * exceeds the administrative limit.
911 */
912 if ((V_nipq > V_maxnipq) && (V_maxnipq > 0)) {
913 /*
914 * drop something from the tail of the current queue
915 * before proceeding further
916 */
917 struct ipq *q = TAILQ_LAST(head, ipqhead);
918 if (q == NULL) { /* gak */
919 for (i = 0; i < IPREASS_NHASH; i++) {
920 struct ipq *r = TAILQ_LAST(&V_ipq[i], ipqhead);
921 if (r) {
922 IPSTAT_ADD(ips_fragtimeout,
923 r->ipq_nfrags);
924 ip_freef(&V_ipq[i], r);
925 break;
926 }
927 }
928 } else {
929 IPSTAT_ADD(ips_fragtimeout, q->ipq_nfrags);
930 ip_freef(head, q);
931 }
932 }
933
934found:
935 /*
936 * Adjust ip_len to not reflect header,
937 * convert offset of this to bytes.
938 */
939 ip->ip_len -= hlen;
940 if (ip->ip_off & IP_MF) {
941 /*
942 * Make sure that fragments have a data length
943 * that's a non-zero multiple of 8 bytes.
944 */
945 if (ip->ip_len == 0 || (ip->ip_len & 0x7) != 0) {
946 IPSTAT_INC(ips_toosmall); /* XXX */
947 goto dropfrag;
948 }
949 m->m_flags |= M_FRAG;
950 } else
951 m->m_flags &= ~M_FRAG;
952 ip->ip_off <<= 3;
953
954
955 /*
956 * Attempt reassembly; if it succeeds, proceed.
957 * ip_reass() will return a different mbuf.
958 */
959 IPSTAT_INC(ips_fragments);
960 m->m_pkthdr.header = ip;
961
962 /* Previous ip_reass() started here. */
963 /*
964 * Presence of header sizes in mbufs
965 * would confuse code below.
966 */
967 m->m_data += hlen;
968 m->m_len -= hlen;
969
970 /*
971 * If first fragment to arrive, create a reassembly queue.
972 */
973 if (fp == NULL) {
974 fp = uma_zalloc(V_ipq_zone, M_NOWAIT);
975 if (fp == NULL)
976 goto dropfrag;
977#ifdef MAC
978 if (mac_ipq_init(fp, M_NOWAIT) != 0) {
979 uma_zfree(V_ipq_zone, fp);
980 fp = NULL;
981 goto dropfrag;
982 }
983 mac_ipq_create(m, fp);
984#endif
985 TAILQ_INSERT_HEAD(head, fp, ipq_list);
986 V_nipq++;
987 fp->ipq_nfrags = 1;
988 fp->ipq_ttl = IPFRAGTTL;
989 fp->ipq_p = ip->ip_p;
990 fp->ipq_id = ip->ip_id;
991 fp->ipq_src = ip->ip_src;
992 fp->ipq_dst = ip->ip_dst;
993 fp->ipq_frags = m;
994 m->m_nextpkt = NULL;
995 goto done;
996 } else {
997 fp->ipq_nfrags++;
998#ifdef MAC
999 mac_ipq_update(m, fp);
1000#endif
1001 }
1002
1003#define GETIP(m) ((struct ip*)((m)->m_pkthdr.header))
1004
1005 /*
1006 * Handle ECN by comparing this segment with the first one;
1007 * if CE is set, do not lose CE.
1008 * drop if CE and not-ECT are mixed for the same packet.
1009 */
1010 ecn = ip->ip_tos & IPTOS_ECN_MASK;
1011 ecn0 = GETIP(fp->ipq_frags)->ip_tos & IPTOS_ECN_MASK;
1012 if (ecn == IPTOS_ECN_CE) {
1013 if (ecn0 == IPTOS_ECN_NOTECT)
1014 goto dropfrag;
1015 if (ecn0 != IPTOS_ECN_CE)
1016 GETIP(fp->ipq_frags)->ip_tos |= IPTOS_ECN_CE;
1017 }
1018 if (ecn == IPTOS_ECN_NOTECT && ecn0 != IPTOS_ECN_NOTECT)
1019 goto dropfrag;
1020
1021 /*
1022 * Find a segment which begins after this one does.
1023 */
1024 for (p = NULL, q = fp->ipq_frags; q; p = q, q = q->m_nextpkt)
1025 if (GETIP(q)->ip_off > ip->ip_off)
1026 break;
1027
1028 /*
1029 * If there is a preceding segment, it may provide some of
1030 * our data already. If so, drop the data from the incoming
1031 * segment. If it provides all of our data, drop us, otherwise
1032 * stick new segment in the proper place.
1033 *
| 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/callout.h>
44#include <sys/mbuf.h>
45#include <sys/malloc.h>
46#include <sys/domain.h>
47#include <sys/protosw.h>
48#include <sys/socket.h>
49#include <sys/time.h>
50#include <sys/kernel.h>
51#include <sys/lock.h>
52#include <sys/rwlock.h>
53#include <sys/syslog.h>
54#include <sys/sysctl.h>
55
56#include <net/pfil.h>
57#include <net/if.h>
58#include <net/if_types.h>
59#include <net/if_var.h>
60#include <net/if_dl.h>
61#include <net/route.h>
62#include <net/netisr.h>
63#include <net/vnet.h>
64#include <net/flowtable.h>
65
66#include <netinet/in.h>
67#include <netinet/in_systm.h>
68#include <netinet/in_var.h>
69#include <netinet/ip.h>
70#include <netinet/in_pcb.h>
71#include <netinet/ip_var.h>
72#include <netinet/ip_fw.h>
73#include <netinet/ip_icmp.h>
74#include <netinet/ip_options.h>
75#include <machine/in_cksum.h>
76#include <netinet/ip_carp.h>
77#ifdef IPSEC
78#include <netinet/ip_ipsec.h>
79#endif /* IPSEC */
80
81#include <sys/socketvar.h>
82
83#include <security/mac/mac_framework.h>
84
85#ifdef CTASSERT
86CTASSERT(sizeof(struct ip) == 20);
87#endif
88
89struct rwlock in_ifaddr_lock;
90RW_SYSINIT(in_ifaddr_lock, &in_ifaddr_lock, "in_ifaddr_lock");
91
92VNET_DEFINE(int, rsvp_on);
93
94VNET_DEFINE(int, ipforwarding);
95SYSCTL_VNET_INT(_net_inet_ip, IPCTL_FORWARDING, forwarding, CTLFLAG_RW,
96 &VNET_NAME(ipforwarding), 0,
97 "Enable IP forwarding between interfaces");
98
99static VNET_DEFINE(int, ipsendredirects) = 1; /* XXX */
100#define V_ipsendredirects VNET(ipsendredirects)
101SYSCTL_VNET_INT(_net_inet_ip, IPCTL_SENDREDIRECTS, redirect, CTLFLAG_RW,
102 &VNET_NAME(ipsendredirects), 0,
103 "Enable sending IP redirects");
104
105VNET_DEFINE(int, ip_defttl) = IPDEFTTL;
106SYSCTL_VNET_INT(_net_inet_ip, IPCTL_DEFTTL, ttl, CTLFLAG_RW,
107 &VNET_NAME(ip_defttl), 0,
108 "Maximum TTL on IP packets");
109
110static VNET_DEFINE(int, ip_keepfaith);
111#define V_ip_keepfaith VNET(ip_keepfaith)
112SYSCTL_VNET_INT(_net_inet_ip, IPCTL_KEEPFAITH, keepfaith, CTLFLAG_RW,
113 &VNET_NAME(ip_keepfaith), 0,
114 "Enable packet capture for FAITH IPv4->IPv6 translater daemon");
115
116static VNET_DEFINE(int, ip_sendsourcequench);
117#define V_ip_sendsourcequench VNET(ip_sendsourcequench)
118SYSCTL_VNET_INT(_net_inet_ip, OID_AUTO, sendsourcequench, CTLFLAG_RW,
119 &VNET_NAME(ip_sendsourcequench), 0,
120 "Enable the transmission of source quench packets");
121
122VNET_DEFINE(int, ip_do_randomid);
123SYSCTL_VNET_INT(_net_inet_ip, OID_AUTO, random_id, CTLFLAG_RW,
124 &VNET_NAME(ip_do_randomid), 0,
125 "Assign random ip_id values");
126
127/*
128 * XXX - Setting ip_checkinterface mostly implements the receive side of
129 * the Strong ES model described in RFC 1122, but since the routing table
130 * and transmit implementation do not implement the Strong ES model,
131 * setting this to 1 results in an odd hybrid.
132 *
133 * XXX - ip_checkinterface currently must be disabled if you use ipnat
134 * to translate the destination address to another local interface.
135 *
136 * XXX - ip_checkinterface must be disabled if you add IP aliases
137 * to the loopback interface instead of the interface where the
138 * packets for those addresses are received.
139 */
140static VNET_DEFINE(int, ip_checkinterface);
141#define V_ip_checkinterface VNET(ip_checkinterface)
142SYSCTL_VNET_INT(_net_inet_ip, OID_AUTO, check_interface, CTLFLAG_RW,
143 &VNET_NAME(ip_checkinterface), 0,
144 "Verify packet arrives on correct interface");
145
146VNET_DEFINE(struct pfil_head, inet_pfil_hook); /* Packet filter hooks */
147
148static struct netisr_handler ip_nh = {
149 .nh_name = "ip",
150 .nh_handler = ip_input,
151 .nh_proto = NETISR_IP,
152 .nh_policy = NETISR_POLICY_FLOW,
153};
154
155extern struct domain inetdomain;
156extern struct protosw inetsw[];
157u_char ip_protox[IPPROTO_MAX];
158VNET_DEFINE(struct in_ifaddrhead, in_ifaddrhead); /* first inet address */
159VNET_DEFINE(struct in_ifaddrhashhead *, in_ifaddrhashtbl); /* inet addr hash table */
160VNET_DEFINE(u_long, in_ifaddrhmask); /* mask for hash table */
161
162VNET_DEFINE(struct ipstat, ipstat);
163SYSCTL_VNET_STRUCT(_net_inet_ip, IPCTL_STATS, stats, CTLFLAG_RW,
164 &VNET_NAME(ipstat), ipstat,
165 "IP statistics (struct ipstat, netinet/ip_var.h)");
166
167static VNET_DEFINE(uma_zone_t, ipq_zone);
168static VNET_DEFINE(TAILQ_HEAD(ipqhead, ipq), ipq[IPREASS_NHASH]);
169static struct mtx ipqlock;
170
171#define V_ipq_zone VNET(ipq_zone)
172#define V_ipq VNET(ipq)
173
174#define IPQ_LOCK() mtx_lock(&ipqlock)
175#define IPQ_UNLOCK() mtx_unlock(&ipqlock)
176#define IPQ_LOCK_INIT() mtx_init(&ipqlock, "ipqlock", NULL, MTX_DEF)
177#define IPQ_LOCK_ASSERT() mtx_assert(&ipqlock, MA_OWNED)
178
179static void maxnipq_update(void);
180static void ipq_zone_change(void *);
181static void ip_drain_locked(void);
182
183static VNET_DEFINE(int, maxnipq); /* Administrative limit on # reass queues. */
184static VNET_DEFINE(int, nipq); /* Total # of reass queues */
185#define V_maxnipq VNET(maxnipq)
186#define V_nipq VNET(nipq)
187SYSCTL_VNET_INT(_net_inet_ip, OID_AUTO, fragpackets, CTLFLAG_RD,
188 &VNET_NAME(nipq), 0,
189 "Current number of IPv4 fragment reassembly queue entries");
190
191static VNET_DEFINE(int, maxfragsperpacket);
192#define V_maxfragsperpacket VNET(maxfragsperpacket)
193SYSCTL_VNET_INT(_net_inet_ip, OID_AUTO, maxfragsperpacket, CTLFLAG_RW,
194 &VNET_NAME(maxfragsperpacket), 0,
195 "Maximum number of IPv4 fragments allowed per packet");
196
197struct callout ipport_tick_callout;
198
199#ifdef IPCTL_DEFMTU
200SYSCTL_INT(_net_inet_ip, IPCTL_DEFMTU, mtu, CTLFLAG_RW,
201 &ip_mtu, 0, "Default MTU");
202#endif
203
204#ifdef IPSTEALTH
205VNET_DEFINE(int, ipstealth);
206SYSCTL_VNET_INT(_net_inet_ip, OID_AUTO, stealth, CTLFLAG_RW,
207 &VNET_NAME(ipstealth), 0,
208 "IP stealth mode, no TTL decrementation on forwarding");
209#endif
210
211#ifdef FLOWTABLE
212static VNET_DEFINE(int, ip_output_flowtable_size) = 2048;
213VNET_DEFINE(struct flowtable *, ip_ft);
214#define V_ip_output_flowtable_size VNET(ip_output_flowtable_size)
215
216SYSCTL_VNET_INT(_net_inet_ip, OID_AUTO, output_flowtable_size, CTLFLAG_RDTUN,
217 &VNET_NAME(ip_output_flowtable_size), 2048,
218 "number of entries in the per-cpu output flow caches");
219#endif
220
221VNET_DEFINE(int, fw_one_pass) = 1;
222
223static void ip_freef(struct ipqhead *, struct ipq *);
224
225/*
226 * Kernel module interface for updating ipstat. The argument is an index
227 * into ipstat treated as an array of u_long. While this encodes the general
228 * layout of ipstat into the caller, it doesn't encode its location, so that
229 * future changes to add, for example, per-CPU stats support won't cause
230 * binary compatibility problems for kernel modules.
231 */
232void
233kmod_ipstat_inc(int statnum)
234{
235
236 (*((u_long *)&V_ipstat + statnum))++;
237}
238
239void
240kmod_ipstat_dec(int statnum)
241{
242
243 (*((u_long *)&V_ipstat + statnum))--;
244}
245
246static int
247sysctl_netinet_intr_queue_maxlen(SYSCTL_HANDLER_ARGS)
248{
249 int error, qlimit;
250
251 netisr_getqlimit(&ip_nh, &qlimit);
252 error = sysctl_handle_int(oidp, &qlimit, 0, req);
253 if (error || !req->newptr)
254 return (error);
255 if (qlimit < 1)
256 return (EINVAL);
257 return (netisr_setqlimit(&ip_nh, qlimit));
258}
259SYSCTL_PROC(_net_inet_ip, IPCTL_INTRQMAXLEN, intr_queue_maxlen,
260 CTLTYPE_INT|CTLFLAG_RW, 0, 0, sysctl_netinet_intr_queue_maxlen, "I",
261 "Maximum size of the IP input queue");
262
263static int
264sysctl_netinet_intr_queue_drops(SYSCTL_HANDLER_ARGS)
265{
266 u_int64_t qdrops_long;
267 int error, qdrops;
268
269 netisr_getqdrops(&ip_nh, &qdrops_long);
270 qdrops = qdrops_long;
271 error = sysctl_handle_int(oidp, &qdrops, 0, req);
272 if (error || !req->newptr)
273 return (error);
274 if (qdrops != 0)
275 return (EINVAL);
276 netisr_clearqdrops(&ip_nh);
277 return (0);
278}
279
280SYSCTL_PROC(_net_inet_ip, IPCTL_INTRQDROPS, intr_queue_drops,
281 CTLTYPE_INT|CTLFLAG_RD, 0, 0, sysctl_netinet_intr_queue_drops, "I",
282 "Number of packets dropped from the IP input queue");
283
284/*
285 * IP initialization: fill in IP protocol switch table.
286 * All protocols not implemented in kernel go to raw IP protocol handler.
287 */
288void
289ip_init(void)
290{
291 struct protosw *pr;
292 int i;
293
294 V_ip_id = time_second & 0xffff;
295
296 TAILQ_INIT(&V_in_ifaddrhead);
297 V_in_ifaddrhashtbl = hashinit(INADDR_NHASH, M_IFADDR, &V_in_ifaddrhmask);
298
299 /* Initialize IP reassembly queue. */
300 for (i = 0; i < IPREASS_NHASH; i++)
301 TAILQ_INIT(&V_ipq[i]);
302 V_maxnipq = nmbclusters / 32;
303 V_maxfragsperpacket = 16;
304 V_ipq_zone = uma_zcreate("ipq", sizeof(struct ipq), NULL, NULL, NULL,
305 NULL, UMA_ALIGN_PTR, 0);
306 maxnipq_update();
307
308 /* Initialize packet filter hooks. */
309 V_inet_pfil_hook.ph_type = PFIL_TYPE_AF;
310 V_inet_pfil_hook.ph_af = AF_INET;
311 if ((i = pfil_head_register(&V_inet_pfil_hook)) != 0)
312 printf("%s: WARNING: unable to register pfil hook, "
313 "error %d\n", __func__, i);
314
315#ifdef FLOWTABLE
316 if (TUNABLE_INT_FETCH("net.inet.ip.output_flowtable_size",
317 &V_ip_output_flowtable_size)) {
318 if (V_ip_output_flowtable_size < 256)
319 V_ip_output_flowtable_size = 256;
320 if (!powerof2(V_ip_output_flowtable_size)) {
321 printf("flowtable must be power of 2 size\n");
322 V_ip_output_flowtable_size = 2048;
323 }
324 } else {
325 /*
326 * round up to the next power of 2
327 */
328 V_ip_output_flowtable_size = 1 << fls((1024 + maxusers * 64)-1);
329 }
330 V_ip_ft = flowtable_alloc("ipv4", V_ip_output_flowtable_size, FL_PCPU);
331#endif
332
333 /* Skip initialization of globals for non-default instances. */
334 if (!IS_DEFAULT_VNET(curvnet))
335 return;
336
337 pr = pffindproto(PF_INET, IPPROTO_RAW, SOCK_RAW);
338 if (pr == NULL)
339 panic("ip_init: PF_INET not found");
340
341 /* Initialize the entire ip_protox[] array to IPPROTO_RAW. */
342 for (i = 0; i < IPPROTO_MAX; i++)
343 ip_protox[i] = pr - inetsw;
344 /*
345 * Cycle through IP protocols and put them into the appropriate place
346 * in ip_protox[].
347 */
348 for (pr = inetdomain.dom_protosw;
349 pr < inetdomain.dom_protoswNPROTOSW; pr++)
350 if (pr->pr_domain->dom_family == PF_INET &&
351 pr->pr_protocol && pr->pr_protocol != IPPROTO_RAW) {
352 /* Be careful to only index valid IP protocols. */
353 if (pr->pr_protocol < IPPROTO_MAX)
354 ip_protox[pr->pr_protocol] = pr - inetsw;
355 }
356
357 /* Start ipport_tick. */
358 callout_init(&ipport_tick_callout, CALLOUT_MPSAFE);
359 callout_reset(&ipport_tick_callout, 1, ipport_tick, NULL);
360 EVENTHANDLER_REGISTER(shutdown_pre_sync, ip_fini, NULL,
361 SHUTDOWN_PRI_DEFAULT);
362 EVENTHANDLER_REGISTER(nmbclusters_change, ipq_zone_change,
363 NULL, EVENTHANDLER_PRI_ANY);
364
365 /* Initialize various other remaining things. */
366 IPQ_LOCK_INIT();
367 netisr_register(&ip_nh);
368}
369
370#ifdef VIMAGE
371void
372ip_destroy(void)
373{
374
375 /* Cleanup in_ifaddr hash table; should be empty. */
376 hashdestroy(V_in_ifaddrhashtbl, M_IFADDR, V_in_ifaddrhmask);
377
378 IPQ_LOCK();
379 ip_drain_locked();
380 IPQ_UNLOCK();
381
382 uma_zdestroy(V_ipq_zone);
383}
384#endif
385
386void
387ip_fini(void *xtp)
388{
389
390 callout_stop(&ipport_tick_callout);
391}
392
393/*
394 * Ip input routine. Checksum and byte swap header. If fragmented
395 * try to reassemble. Process options. Pass to next level.
396 */
397void
398ip_input(struct mbuf *m)
399{
400 struct ip *ip = NULL;
401 struct in_ifaddr *ia = NULL;
402 struct ifaddr *ifa;
403 struct ifnet *ifp;
404 int checkif, hlen = 0;
405 u_short sum;
406 int dchg = 0; /* dest changed after fw */
407 struct in_addr odst; /* original dst address */
408
409 M_ASSERTPKTHDR(m);
410
411 if (m->m_flags & M_FASTFWD_OURS) {
412 /*
413 * Firewall or NAT changed destination to local.
414 * We expect ip_len and ip_off to be in host byte order.
415 */
416 m->m_flags &= ~M_FASTFWD_OURS;
417 /* Set up some basics that will be used later. */
418 ip = mtod(m, struct ip *);
419 hlen = ip->ip_hl << 2;
420 goto ours;
421 }
422
423 IPSTAT_INC(ips_total);
424
425 if (m->m_pkthdr.len < sizeof(struct ip))
426 goto tooshort;
427
428 if (m->m_len < sizeof (struct ip) &&
429 (m = m_pullup(m, sizeof (struct ip))) == NULL) {
430 IPSTAT_INC(ips_toosmall);
431 return;
432 }
433 ip = mtod(m, struct ip *);
434
435 if (ip->ip_v != IPVERSION) {
436 IPSTAT_INC(ips_badvers);
437 goto bad;
438 }
439
440 hlen = ip->ip_hl << 2;
441 if (hlen < sizeof(struct ip)) { /* minimum header length */
442 IPSTAT_INC(ips_badhlen);
443 goto bad;
444 }
445 if (hlen > m->m_len) {
446 if ((m = m_pullup(m, hlen)) == NULL) {
447 IPSTAT_INC(ips_badhlen);
448 return;
449 }
450 ip = mtod(m, struct ip *);
451 }
452
453 /* 127/8 must not appear on wire - RFC1122 */
454 ifp = m->m_pkthdr.rcvif;
455 if ((ntohl(ip->ip_dst.s_addr) >> IN_CLASSA_NSHIFT) == IN_LOOPBACKNET ||
456 (ntohl(ip->ip_src.s_addr) >> IN_CLASSA_NSHIFT) == IN_LOOPBACKNET) {
457 if ((ifp->if_flags & IFF_LOOPBACK) == 0) {
458 IPSTAT_INC(ips_badaddr);
459 goto bad;
460 }
461 }
462
463 if (m->m_pkthdr.csum_flags & CSUM_IP_CHECKED) {
464 sum = !(m->m_pkthdr.csum_flags & CSUM_IP_VALID);
465 } else {
466 if (hlen == sizeof(struct ip)) {
467 sum = in_cksum_hdr(ip);
468 } else {
469 sum = in_cksum(m, hlen);
470 }
471 }
472 if (sum) {
473 IPSTAT_INC(ips_badsum);
474 goto bad;
475 }
476
477#ifdef ALTQ
478 if (altq_input != NULL && (*altq_input)(m, AF_INET) == 0)
479 /* packet is dropped by traffic conditioner */
480 return;
481#endif
482
483 /*
484 * Convert fields to host representation.
485 */
486 ip->ip_len = ntohs(ip->ip_len);
487 if (ip->ip_len < hlen) {
488 IPSTAT_INC(ips_badlen);
489 goto bad;
490 }
491 ip->ip_off = ntohs(ip->ip_off);
492
493 /*
494 * Check that the amount of data in the buffers
495 * is as at least much as the IP header would have us expect.
496 * Trim mbufs if longer than we expect.
497 * Drop packet if shorter than we expect.
498 */
499 if (m->m_pkthdr.len < ip->ip_len) {
500tooshort:
501 IPSTAT_INC(ips_tooshort);
502 goto bad;
503 }
504 if (m->m_pkthdr.len > ip->ip_len) {
505 if (m->m_len == m->m_pkthdr.len) {
506 m->m_len = ip->ip_len;
507 m->m_pkthdr.len = ip->ip_len;
508 } else
509 m_adj(m, ip->ip_len - m->m_pkthdr.len);
510 }
511#ifdef IPSEC
512 /*
513 * Bypass packet filtering for packets from a tunnel (gif).
514 */
515 if (ip_ipsec_filtertunnel(m))
516 goto passin;
517#endif /* IPSEC */
518
519 /*
520 * Run through list of hooks for input packets.
521 *
522 * NB: Beware of the destination address changing (e.g.
523 * by NAT rewriting). When this happens, tell
524 * ip_forward to do the right thing.
525 */
526
527 /* Jump over all PFIL processing if hooks are not active. */
528 if (!PFIL_HOOKED(&V_inet_pfil_hook))
529 goto passin;
530
531 odst = ip->ip_dst;
532 if (pfil_run_hooks(&V_inet_pfil_hook, &m, ifp, PFIL_IN, NULL) != 0)
533 return;
534 if (m == NULL) /* consumed by filter */
535 return;
536
537 ip = mtod(m, struct ip *);
538 dchg = (odst.s_addr != ip->ip_dst.s_addr);
539 ifp = m->m_pkthdr.rcvif;
540
541#ifdef IPFIREWALL_FORWARD
542 if (m->m_flags & M_FASTFWD_OURS) {
543 m->m_flags &= ~M_FASTFWD_OURS;
544 goto ours;
545 }
546 if ((dchg = (m_tag_find(m, PACKET_TAG_IPFORWARD, NULL) != NULL)) != 0) {
547 /*
548 * Directly ship the packet on. This allows forwarding
549 * packets originally destined to us to some other directly
550 * connected host.
551 */
552 ip_forward(m, dchg);
553 return;
554 }
555#endif /* IPFIREWALL_FORWARD */
556
557passin:
558 /*
559 * Process options and, if not destined for us,
560 * ship it on. ip_dooptions returns 1 when an
561 * error was detected (causing an icmp message
562 * to be sent and the original packet to be freed).
563 */
564 if (hlen > sizeof (struct ip) && ip_dooptions(m, 0))
565 return;
566
567 /* greedy RSVP, snatches any PATH packet of the RSVP protocol and no
568 * matter if it is destined to another node, or whether it is
569 * a multicast one, RSVP wants it! and prevents it from being forwarded
570 * anywhere else. Also checks if the rsvp daemon is running before
571 * grabbing the packet.
572 */
573 if (V_rsvp_on && ip->ip_p==IPPROTO_RSVP)
574 goto ours;
575
576 /*
577 * Check our list of addresses, to see if the packet is for us.
578 * If we don't have any addresses, assume any unicast packet
579 * we receive might be for us (and let the upper layers deal
580 * with it).
581 */
582 if (TAILQ_EMPTY(&V_in_ifaddrhead) &&
583 (m->m_flags & (M_MCAST|M_BCAST)) == 0)
584 goto ours;
585
586 /*
587 * Enable a consistency check between the destination address
588 * and the arrival interface for a unicast packet (the RFC 1122
589 * strong ES model) if IP forwarding is disabled and the packet
590 * is not locally generated and the packet is not subject to
591 * 'ipfw fwd'.
592 *
593 * XXX - Checking also should be disabled if the destination
594 * address is ipnat'ed to a different interface.
595 *
596 * XXX - Checking is incompatible with IP aliases added
597 * to the loopback interface instead of the interface where
598 * the packets are received.
599 *
600 * XXX - This is the case for carp vhost IPs as well so we
601 * insert a workaround. If the packet got here, we already
602 * checked with carp_iamatch() and carp_forus().
603 */
604 checkif = V_ip_checkinterface && (V_ipforwarding == 0) &&
605 ifp != NULL && ((ifp->if_flags & IFF_LOOPBACK) == 0) &&
606 ifp->if_carp == NULL && (dchg == 0);
607
608 /*
609 * Check for exact addresses in the hash bucket.
610 */
611 /* IN_IFADDR_RLOCK(); */
612 LIST_FOREACH(ia, INADDR_HASH(ip->ip_dst.s_addr), ia_hash) {
613 /*
614 * If the address matches, verify that the packet
615 * arrived via the correct interface if checking is
616 * enabled.
617 */
618 if (IA_SIN(ia)->sin_addr.s_addr == ip->ip_dst.s_addr &&
619 (!checkif || ia->ia_ifp == ifp)) {
620 ifa_ref(&ia->ia_ifa);
621 /* IN_IFADDR_RUNLOCK(); */
622 goto ours;
623 }
624 }
625 /* IN_IFADDR_RUNLOCK(); */
626
627 /*
628 * Check for broadcast addresses.
629 *
630 * Only accept broadcast packets that arrive via the matching
631 * interface. Reception of forwarded directed broadcasts would
632 * be handled via ip_forward() and ether_output() with the loopback
633 * into the stack for SIMPLEX interfaces handled by ether_output().
634 */
635 if (ifp != NULL && ifp->if_flags & IFF_BROADCAST) {
636 IF_ADDR_LOCK(ifp);
637 TAILQ_FOREACH(ifa, &ifp->if_addrhead, ifa_link) {
638 if (ifa->ifa_addr->sa_family != AF_INET)
639 continue;
640 ia = ifatoia(ifa);
641 if (satosin(&ia->ia_broadaddr)->sin_addr.s_addr ==
642 ip->ip_dst.s_addr) {
643 ifa_ref(ifa);
644 IF_ADDR_UNLOCK(ifp);
645 goto ours;
646 }
647 if (ia->ia_netbroadcast.s_addr == ip->ip_dst.s_addr) {
648 ifa_ref(ifa);
649 IF_ADDR_UNLOCK(ifp);
650 goto ours;
651 }
652#ifdef BOOTP_COMPAT
653 if (IA_SIN(ia)->sin_addr.s_addr == INADDR_ANY) {
654 ifa_ref(ifa);
655 IF_ADDR_UNLOCK(ifp);
656 goto ours;
657 }
658#endif
659 }
660 IF_ADDR_UNLOCK(ifp);
661 ia = NULL;
662 }
663 /* RFC 3927 2.7: Do not forward datagrams for 169.254.0.0/16. */
664 if (IN_LINKLOCAL(ntohl(ip->ip_dst.s_addr))) {
665 IPSTAT_INC(ips_cantforward);
666 m_freem(m);
667 return;
668 }
669 if (IN_MULTICAST(ntohl(ip->ip_dst.s_addr))) {
670 if (V_ip_mrouter) {
671 /*
672 * If we are acting as a multicast router, all
673 * incoming multicast packets are passed to the
674 * kernel-level multicast forwarding function.
675 * The packet is returned (relatively) intact; if
676 * ip_mforward() returns a non-zero value, the packet
677 * must be discarded, else it may be accepted below.
678 */
679 if (ip_mforward && ip_mforward(ip, ifp, m, 0) != 0) {
680 IPSTAT_INC(ips_cantforward);
681 m_freem(m);
682 return;
683 }
684
685 /*
686 * The process-level routing daemon needs to receive
687 * all multicast IGMP packets, whether or not this
688 * host belongs to their destination groups.
689 */
690 if (ip->ip_p == IPPROTO_IGMP)
691 goto ours;
692 IPSTAT_INC(ips_forward);
693 }
694 /*
695 * Assume the packet is for us, to avoid prematurely taking
696 * a lock on the in_multi hash. Protocols must perform
697 * their own filtering and update statistics accordingly.
698 */
699 goto ours;
700 }
701 if (ip->ip_dst.s_addr == (u_long)INADDR_BROADCAST)
702 goto ours;
703 if (ip->ip_dst.s_addr == INADDR_ANY)
704 goto ours;
705
706 /*
707 * FAITH(Firewall Aided Internet Translator)
708 */
709 if (ifp && ifp->if_type == IFT_FAITH) {
710 if (V_ip_keepfaith) {
711 if (ip->ip_p == IPPROTO_TCP || ip->ip_p == IPPROTO_ICMP)
712 goto ours;
713 }
714 m_freem(m);
715 return;
716 }
717
718 /*
719 * Not for us; forward if possible and desirable.
720 */
721 if (V_ipforwarding == 0) {
722 IPSTAT_INC(ips_cantforward);
723 m_freem(m);
724 } else {
725#ifdef IPSEC
726 if (ip_ipsec_fwd(m))
727 goto bad;
728#endif /* IPSEC */
729 ip_forward(m, dchg);
730 }
731 return;
732
733ours:
734#ifdef IPSTEALTH
735 /*
736 * IPSTEALTH: Process non-routing options only
737 * if the packet is destined for us.
738 */
739 if (V_ipstealth && hlen > sizeof (struct ip) && ip_dooptions(m, 1)) {
740 if (ia != NULL)
741 ifa_free(&ia->ia_ifa);
742 return;
743 }
744#endif /* IPSTEALTH */
745
746 /* Count the packet in the ip address stats */
747 if (ia != NULL) {
748 ia->ia_ifa.if_ipackets++;
749 ia->ia_ifa.if_ibytes += m->m_pkthdr.len;
750 ifa_free(&ia->ia_ifa);
751 }
752
753 /*
754 * Attempt reassembly; if it succeeds, proceed.
755 * ip_reass() will return a different mbuf.
756 */
757 if (ip->ip_off & (IP_MF | IP_OFFMASK)) {
758 m = ip_reass(m);
759 if (m == NULL)
760 return;
761 ip = mtod(m, struct ip *);
762 /* Get the header length of the reassembled packet */
763 hlen = ip->ip_hl << 2;
764 }
765
766 /*
767 * Further protocols expect the packet length to be w/o the
768 * IP header.
769 */
770 ip->ip_len -= hlen;
771
772#ifdef IPSEC
773 /*
774 * enforce IPsec policy checking if we are seeing last header.
775 * note that we do not visit this with protocols with pcb layer
776 * code - like udp/tcp/raw ip.
777 */
778 if (ip_ipsec_input(m))
779 goto bad;
780#endif /* IPSEC */
781
782 /*
783 * Switch out to protocol's input routine.
784 */
785 IPSTAT_INC(ips_delivered);
786
787 (*inetsw[ip_protox[ip->ip_p]].pr_input)(m, hlen);
788 return;
789bad:
790 m_freem(m);
791}
792
793/*
794 * After maxnipq has been updated, propagate the change to UMA. The UMA zone
795 * max has slightly different semantics than the sysctl, for historical
796 * reasons.
797 */
798static void
799maxnipq_update(void)
800{
801
802 /*
803 * -1 for unlimited allocation.
804 */
805 if (V_maxnipq < 0)
806 uma_zone_set_max(V_ipq_zone, 0);
807 /*
808 * Positive number for specific bound.
809 */
810 if (V_maxnipq > 0)
811 uma_zone_set_max(V_ipq_zone, V_maxnipq);
812 /*
813 * Zero specifies no further fragment queue allocation -- set the
814 * bound very low, but rely on implementation elsewhere to actually
815 * prevent allocation and reclaim current queues.
816 */
817 if (V_maxnipq == 0)
818 uma_zone_set_max(V_ipq_zone, 1);
819}
820
821static void
822ipq_zone_change(void *tag)
823{
824
825 if (V_maxnipq > 0 && V_maxnipq < (nmbclusters / 32)) {
826 V_maxnipq = nmbclusters / 32;
827 maxnipq_update();
828 }
829}
830
831static int
832sysctl_maxnipq(SYSCTL_HANDLER_ARGS)
833{
834 int error, i;
835
836 i = V_maxnipq;
837 error = sysctl_handle_int(oidp, &i, 0, req);
838 if (error || !req->newptr)
839 return (error);
840
841 /*
842 * XXXRW: Might be a good idea to sanity check the argument and place
843 * an extreme upper bound.
844 */
845 if (i < -1)
846 return (EINVAL);
847 V_maxnipq = i;
848 maxnipq_update();
849 return (0);
850}
851
852SYSCTL_PROC(_net_inet_ip, OID_AUTO, maxfragpackets, CTLTYPE_INT|CTLFLAG_RW,
853 NULL, 0, sysctl_maxnipq, "I",
854 "Maximum number of IPv4 fragment reassembly queue entries");
855
856/*
857 * Take incoming datagram fragment and try to reassemble it into
858 * whole datagram. If the argument is the first fragment or one
859 * in between the function will return NULL and store the mbuf
860 * in the fragment chain. If the argument is the last fragment
861 * the packet will be reassembled and the pointer to the new
862 * mbuf returned for further processing. Only m_tags attached
863 * to the first packet/fragment are preserved.
864 * The IP header is *NOT* adjusted out of iplen.
865 */
866struct mbuf *
867ip_reass(struct mbuf *m)
868{
869 struct ip *ip;
870 struct mbuf *p, *q, *nq, *t;
871 struct ipq *fp = NULL;
872 struct ipqhead *head;
873 int i, hlen, next;
874 u_int8_t ecn, ecn0;
875 u_short hash;
876
877 /* If maxnipq or maxfragsperpacket are 0, never accept fragments. */
878 if (V_maxnipq == 0 || V_maxfragsperpacket == 0) {
879 IPSTAT_INC(ips_fragments);
880 IPSTAT_INC(ips_fragdropped);
881 m_freem(m);
882 return (NULL);
883 }
884
885 ip = mtod(m, struct ip *);
886 hlen = ip->ip_hl << 2;
887
888 hash = IPREASS_HASH(ip->ip_src.s_addr, ip->ip_id);
889 head = &V_ipq[hash];
890 IPQ_LOCK();
891
892 /*
893 * Look for queue of fragments
894 * of this datagram.
895 */
896 TAILQ_FOREACH(fp, head, ipq_list)
897 if (ip->ip_id == fp->ipq_id &&
898 ip->ip_src.s_addr == fp->ipq_src.s_addr &&
899 ip->ip_dst.s_addr == fp->ipq_dst.s_addr &&
900#ifdef MAC
901 mac_ipq_match(m, fp) &&
902#endif
903 ip->ip_p == fp->ipq_p)
904 goto found;
905
906 fp = NULL;
907
908 /*
909 * Attempt to trim the number of allocated fragment queues if it
910 * exceeds the administrative limit.
911 */
912 if ((V_nipq > V_maxnipq) && (V_maxnipq > 0)) {
913 /*
914 * drop something from the tail of the current queue
915 * before proceeding further
916 */
917 struct ipq *q = TAILQ_LAST(head, ipqhead);
918 if (q == NULL) { /* gak */
919 for (i = 0; i < IPREASS_NHASH; i++) {
920 struct ipq *r = TAILQ_LAST(&V_ipq[i], ipqhead);
921 if (r) {
922 IPSTAT_ADD(ips_fragtimeout,
923 r->ipq_nfrags);
924 ip_freef(&V_ipq[i], r);
925 break;
926 }
927 }
928 } else {
929 IPSTAT_ADD(ips_fragtimeout, q->ipq_nfrags);
930 ip_freef(head, q);
931 }
932 }
933
934found:
935 /*
936 * Adjust ip_len to not reflect header,
937 * convert offset of this to bytes.
938 */
939 ip->ip_len -= hlen;
940 if (ip->ip_off & IP_MF) {
941 /*
942 * Make sure that fragments have a data length
943 * that's a non-zero multiple of 8 bytes.
944 */
945 if (ip->ip_len == 0 || (ip->ip_len & 0x7) != 0) {
946 IPSTAT_INC(ips_toosmall); /* XXX */
947 goto dropfrag;
948 }
949 m->m_flags |= M_FRAG;
950 } else
951 m->m_flags &= ~M_FRAG;
952 ip->ip_off <<= 3;
953
954
955 /*
956 * Attempt reassembly; if it succeeds, proceed.
957 * ip_reass() will return a different mbuf.
958 */
959 IPSTAT_INC(ips_fragments);
960 m->m_pkthdr.header = ip;
961
962 /* Previous ip_reass() started here. */
963 /*
964 * Presence of header sizes in mbufs
965 * would confuse code below.
966 */
967 m->m_data += hlen;
968 m->m_len -= hlen;
969
970 /*
971 * If first fragment to arrive, create a reassembly queue.
972 */
973 if (fp == NULL) {
974 fp = uma_zalloc(V_ipq_zone, M_NOWAIT);
975 if (fp == NULL)
976 goto dropfrag;
977#ifdef MAC
978 if (mac_ipq_init(fp, M_NOWAIT) != 0) {
979 uma_zfree(V_ipq_zone, fp);
980 fp = NULL;
981 goto dropfrag;
982 }
983 mac_ipq_create(m, fp);
984#endif
985 TAILQ_INSERT_HEAD(head, fp, ipq_list);
986 V_nipq++;
987 fp->ipq_nfrags = 1;
988 fp->ipq_ttl = IPFRAGTTL;
989 fp->ipq_p = ip->ip_p;
990 fp->ipq_id = ip->ip_id;
991 fp->ipq_src = ip->ip_src;
992 fp->ipq_dst = ip->ip_dst;
993 fp->ipq_frags = m;
994 m->m_nextpkt = NULL;
995 goto done;
996 } else {
997 fp->ipq_nfrags++;
998#ifdef MAC
999 mac_ipq_update(m, fp);
1000#endif
1001 }
1002
1003#define GETIP(m) ((struct ip*)((m)->m_pkthdr.header))
1004
1005 /*
1006 * Handle ECN by comparing this segment with the first one;
1007 * if CE is set, do not lose CE.
1008 * drop if CE and not-ECT are mixed for the same packet.
1009 */
1010 ecn = ip->ip_tos & IPTOS_ECN_MASK;
1011 ecn0 = GETIP(fp->ipq_frags)->ip_tos & IPTOS_ECN_MASK;
1012 if (ecn == IPTOS_ECN_CE) {
1013 if (ecn0 == IPTOS_ECN_NOTECT)
1014 goto dropfrag;
1015 if (ecn0 != IPTOS_ECN_CE)
1016 GETIP(fp->ipq_frags)->ip_tos |= IPTOS_ECN_CE;
1017 }
1018 if (ecn == IPTOS_ECN_NOTECT && ecn0 != IPTOS_ECN_NOTECT)
1019 goto dropfrag;
1020
1021 /*
1022 * Find a segment which begins after this one does.
1023 */
1024 for (p = NULL, q = fp->ipq_frags; q; p = q, q = q->m_nextpkt)
1025 if (GETIP(q)->ip_off > ip->ip_off)
1026 break;
1027
1028 /*
1029 * If there is a preceding segment, it may provide some of
1030 * our data already. If so, drop the data from the incoming
1031 * segment. If it provides all of our data, drop us, otherwise
1032 * stick new segment in the proper place.
1033 *
|
1035 * segment, then it's checksum is invalidated.
1036 */
1037 if (p) {
1038 i = GETIP(p)->ip_off + GETIP(p)->ip_len - ip->ip_off;
1039 if (i > 0) {
1040 if (i >= ip->ip_len)
1041 goto dropfrag;
1042 m_adj(m, i);
1043 m->m_pkthdr.csum_flags = 0;
1044 ip->ip_off += i;
1045 ip->ip_len -= i;
1046 }
1047 m->m_nextpkt = p->m_nextpkt;
1048 p->m_nextpkt = m;
1049 } else {
1050 m->m_nextpkt = fp->ipq_frags;
1051 fp->ipq_frags = m;
1052 }
1053
1054 /*
1055 * While we overlap succeeding segments trim them or,
1056 * if they are completely covered, dequeue them.
1057 */
1058 for (; q != NULL && ip->ip_off + ip->ip_len > GETIP(q)->ip_off;
1059 q = nq) {
1060 i = (ip->ip_off + ip->ip_len) - GETIP(q)->ip_off;
1061 if (i < GETIP(q)->ip_len) {
1062 GETIP(q)->ip_len -= i;
1063 GETIP(q)->ip_off += i;
1064 m_adj(q, i);
1065 q->m_pkthdr.csum_flags = 0;
1066 break;
1067 }
1068 nq = q->m_nextpkt;
1069 m->m_nextpkt = nq;
1070 IPSTAT_INC(ips_fragdropped);
1071 fp->ipq_nfrags--;
1072 m_freem(q);
1073 }
1074
1075 /*
1076 * Check for complete reassembly and perform frag per packet
1077 * limiting.
1078 *
1079 * Frag limiting is performed here so that the nth frag has
1080 * a chance to complete the packet before we drop the packet.
1081 * As a result, n+1 frags are actually allowed per packet, but
1082 * only n will ever be stored. (n = maxfragsperpacket.)
1083 *
1084 */
1085 next = 0;
1086 for (p = NULL, q = fp->ipq_frags; q; p = q, q = q->m_nextpkt) {
1087 if (GETIP(q)->ip_off != next) {
1088 if (fp->ipq_nfrags > V_maxfragsperpacket) {
1089 IPSTAT_ADD(ips_fragdropped, fp->ipq_nfrags);
1090 ip_freef(head, fp);
1091 }
1092 goto done;
1093 }
1094 next += GETIP(q)->ip_len;
1095 }
1096 /* Make sure the last packet didn't have the IP_MF flag */
1097 if (p->m_flags & M_FRAG) {
1098 if (fp->ipq_nfrags > V_maxfragsperpacket) {
1099 IPSTAT_ADD(ips_fragdropped, fp->ipq_nfrags);
1100 ip_freef(head, fp);
1101 }
1102 goto done;
1103 }
1104
1105 /*
1106 * Reassembly is complete. Make sure the packet is a sane size.
1107 */
1108 q = fp->ipq_frags;
1109 ip = GETIP(q);
1110 if (next + (ip->ip_hl << 2) > IP_MAXPACKET) {
1111 IPSTAT_INC(ips_toolong);
1112 IPSTAT_ADD(ips_fragdropped, fp->ipq_nfrags);
1113 ip_freef(head, fp);
1114 goto done;
1115 }
1116
1117 /*
1118 * Concatenate fragments.
1119 */
1120 m = q;
1121 t = m->m_next;
1122 m->m_next = NULL;
1123 m_cat(m, t);
1124 nq = q->m_nextpkt;
1125 q->m_nextpkt = NULL;
1126 for (q = nq; q != NULL; q = nq) {
1127 nq = q->m_nextpkt;
1128 q->m_nextpkt = NULL;
1129 m->m_pkthdr.csum_flags &= q->m_pkthdr.csum_flags;
1130 m->m_pkthdr.csum_data += q->m_pkthdr.csum_data;
1131 m_cat(m, q);
1132 }
1133 /*
1134 * In order to do checksumming faster we do 'end-around carry' here
1135 * (and not in for{} loop), though it implies we are not going to
1136 * reassemble more than 64k fragments.
1137 */
1138 m->m_pkthdr.csum_data =
1139 (m->m_pkthdr.csum_data & 0xffff) + (m->m_pkthdr.csum_data >> 16);
1140#ifdef MAC
1141 mac_ipq_reassemble(fp, m);
1142 mac_ipq_destroy(fp);
1143#endif
1144
1145 /*
1146 * Create header for new ip packet by modifying header of first
1147 * packet; dequeue and discard fragment reassembly header.
1148 * Make header visible.
1149 */
1150 ip->ip_len = (ip->ip_hl << 2) + next;
1151 ip->ip_src = fp->ipq_src;
1152 ip->ip_dst = fp->ipq_dst;
1153 TAILQ_REMOVE(head, fp, ipq_list);
1154 V_nipq--;
1155 uma_zfree(V_ipq_zone, fp);
1156 m->m_len += (ip->ip_hl << 2);
1157 m->m_data -= (ip->ip_hl << 2);
1158 /* some debugging cruft by sklower, below, will go away soon */
1159 if (m->m_flags & M_PKTHDR) /* XXX this should be done elsewhere */
1160 m_fixhdr(m);
1161 IPSTAT_INC(ips_reassembled);
1162 IPQ_UNLOCK();
1163 return (m);
1164
1165dropfrag:
1166 IPSTAT_INC(ips_fragdropped);
1167 if (fp != NULL)
1168 fp->ipq_nfrags--;
1169 m_freem(m);
1170done:
1171 IPQ_UNLOCK();
1172 return (NULL);
1173
1174#undef GETIP
1175}
1176
1177/*
1178 * Free a fragment reassembly header and all
1179 * associated datagrams.
1180 */
1181static void
1182ip_freef(struct ipqhead *fhp, struct ipq *fp)
1183{
1184 struct mbuf *q;
1185
1186 IPQ_LOCK_ASSERT();
1187
1188 while (fp->ipq_frags) {
1189 q = fp->ipq_frags;
1190 fp->ipq_frags = q->m_nextpkt;
1191 m_freem(q);
1192 }
1193 TAILQ_REMOVE(fhp, fp, ipq_list);
1194 uma_zfree(V_ipq_zone, fp);
1195 V_nipq--;
1196}
1197
1198/*
1199 * IP timer processing;
1200 * if a timer expires on a reassembly
1201 * queue, discard it.
1202 */
1203void
1204ip_slowtimo(void)
1205{
1206 VNET_ITERATOR_DECL(vnet_iter);
1207 struct ipq *fp;
1208 int i;
1209
1210 VNET_LIST_RLOCK_NOSLEEP();
1211 IPQ_LOCK();
1212 VNET_FOREACH(vnet_iter) {
1213 CURVNET_SET(vnet_iter);
1214 for (i = 0; i < IPREASS_NHASH; i++) {
1215 for(fp = TAILQ_FIRST(&V_ipq[i]); fp;) {
1216 struct ipq *fpp;
1217
1218 fpp = fp;
1219 fp = TAILQ_NEXT(fp, ipq_list);
1220 if(--fpp->ipq_ttl == 0) {
1221 IPSTAT_ADD(ips_fragtimeout,
1222 fpp->ipq_nfrags);
1223 ip_freef(&V_ipq[i], fpp);
1224 }
1225 }
1226 }
1227 /*
1228 * If we are over the maximum number of fragments
1229 * (due to the limit being lowered), drain off
1230 * enough to get down to the new limit.
1231 */
1232 if (V_maxnipq >= 0 && V_nipq > V_maxnipq) {
1233 for (i = 0; i < IPREASS_NHASH; i++) {
1234 while (V_nipq > V_maxnipq &&
1235 !TAILQ_EMPTY(&V_ipq[i])) {
1236 IPSTAT_ADD(ips_fragdropped,
1237 TAILQ_FIRST(&V_ipq[i])->ipq_nfrags);
1238 ip_freef(&V_ipq[i],
1239 TAILQ_FIRST(&V_ipq[i]));
1240 }
1241 }
1242 }
1243 CURVNET_RESTORE();
1244 }
1245 IPQ_UNLOCK();
1246 VNET_LIST_RUNLOCK_NOSLEEP();
1247}
1248
1249/*
1250 * Drain off all datagram fragments.
1251 */
1252static void
1253ip_drain_locked(void)
1254{
1255 int i;
1256
1257 IPQ_LOCK_ASSERT();
1258
1259 for (i = 0; i < IPREASS_NHASH; i++) {
1260 while(!TAILQ_EMPTY(&V_ipq[i])) {
1261 IPSTAT_ADD(ips_fragdropped,
1262 TAILQ_FIRST(&V_ipq[i])->ipq_nfrags);
1263 ip_freef(&V_ipq[i], TAILQ_FIRST(&V_ipq[i]));
1264 }
1265 }
1266}
1267
1268void
1269ip_drain(void)
1270{
1271 VNET_ITERATOR_DECL(vnet_iter);
1272
1273 VNET_LIST_RLOCK_NOSLEEP();
1274 IPQ_LOCK();
1275 VNET_FOREACH(vnet_iter) {
1276 CURVNET_SET(vnet_iter);
1277 ip_drain_locked();
1278 CURVNET_RESTORE();
1279 }
1280 IPQ_UNLOCK();
1281 VNET_LIST_RUNLOCK_NOSLEEP();
1282 in_rtqdrain();
1283}
1284
1285/*
1286 * The protocol to be inserted into ip_protox[] must be already registered
1287 * in inetsw[], either statically or through pf_proto_register().
1288 */
1289int
1290ipproto_register(short ipproto)
1291{
1292 struct protosw *pr;
1293
1294 /* Sanity checks. */
1295 if (ipproto <= 0 || ipproto >= IPPROTO_MAX)
1296 return (EPROTONOSUPPORT);
1297
1298 /*
1299 * The protocol slot must not be occupied by another protocol
1300 * already. An index pointing to IPPROTO_RAW is unused.
1301 */
1302 pr = pffindproto(PF_INET, IPPROTO_RAW, SOCK_RAW);
1303 if (pr == NULL)
1304 return (EPFNOSUPPORT);
1305 if (ip_protox[ipproto] != pr - inetsw) /* IPPROTO_RAW */
1306 return (EEXIST);
1307
1308 /* Find the protocol position in inetsw[] and set the index. */
1309 for (pr = inetdomain.dom_protosw;
1310 pr < inetdomain.dom_protoswNPROTOSW; pr++) {
1311 if (pr->pr_domain->dom_family == PF_INET &&
1312 pr->pr_protocol && pr->pr_protocol == ipproto) {
1313 ip_protox[pr->pr_protocol] = pr - inetsw;
1314 return (0);
1315 }
1316 }
1317 return (EPROTONOSUPPORT);
1318}
1319
1320int
1321ipproto_unregister(short ipproto)
1322{
1323 struct protosw *pr;
1324
1325 /* Sanity checks. */
1326 if (ipproto <= 0 || ipproto >= IPPROTO_MAX)
1327 return (EPROTONOSUPPORT);
1328
1329 /* Check if the protocol was indeed registered. */
1330 pr = pffindproto(PF_INET, IPPROTO_RAW, SOCK_RAW);
1331 if (pr == NULL)
1332 return (EPFNOSUPPORT);
1333 if (ip_protox[ipproto] == pr - inetsw) /* IPPROTO_RAW */
1334 return (ENOENT);
1335
1336 /* Reset the protocol slot to IPPROTO_RAW. */
1337 ip_protox[ipproto] = pr - inetsw;
1338 return (0);
1339}
1340
1341/*
1342 * Given address of next destination (final or next hop), return (referenced)
1343 * internet address info of interface to be used to get there.
1344 */
1345struct in_ifaddr *
1346ip_rtaddr(struct in_addr dst, u_int fibnum)
1347{
1348 struct route sro;
1349 struct sockaddr_in *sin;
1350 struct in_ifaddr *ia;
1351
1352 bzero(&sro, sizeof(sro));
1353 sin = (struct sockaddr_in *)&sro.ro_dst;
1354 sin->sin_family = AF_INET;
1355 sin->sin_len = sizeof(*sin);
1356 sin->sin_addr = dst;
1357 in_rtalloc_ign(&sro, 0, fibnum);
1358
1359 if (sro.ro_rt == NULL)
1360 return (NULL);
1361
1362 ia = ifatoia(sro.ro_rt->rt_ifa);
1363 ifa_ref(&ia->ia_ifa);
1364 RTFREE(sro.ro_rt);
1365 return (ia);
1366}
1367
1368u_char inetctlerrmap[PRC_NCMDS] = {
1369 0, 0, 0, 0,
1370 0, EMSGSIZE, EHOSTDOWN, EHOSTUNREACH,
1371 EHOSTUNREACH, EHOSTUNREACH, ECONNREFUSED, ECONNREFUSED,
1372 EMSGSIZE, EHOSTUNREACH, 0, 0,
1373 0, 0, EHOSTUNREACH, 0,
1374 ENOPROTOOPT, ECONNREFUSED
1375};
1376
1377/*
1378 * Forward a packet. If some error occurs return the sender
1379 * an icmp packet. Note we can't always generate a meaningful
1380 * icmp message because icmp doesn't have a large enough repertoire
1381 * of codes and types.
1382 *
1383 * If not forwarding, just drop the packet. This could be confusing
1384 * if ipforwarding was zero but some routing protocol was advancing
1385 * us as a gateway to somewhere. However, we must let the routing
1386 * protocol deal with that.
1387 *
1388 * The srcrt parameter indicates whether the packet is being forwarded
1389 * via a source route.
1390 */
1391void
1392ip_forward(struct mbuf *m, int srcrt)
1393{
1394 struct ip *ip = mtod(m, struct ip *);
1395 struct in_ifaddr *ia;
1396 struct mbuf *mcopy;
1397 struct in_addr dest;
1398 struct route ro;
1399 int error, type = 0, code = 0, mtu = 0;
1400
1401 if (m->m_flags & (M_BCAST|M_MCAST) || in_canforward(ip->ip_dst) == 0) {
1402 IPSTAT_INC(ips_cantforward);
1403 m_freem(m);
1404 return;
1405 }
1406#ifdef IPSTEALTH
1407 if (!V_ipstealth) {
1408#endif
1409 if (ip->ip_ttl <= IPTTLDEC) {
1410 icmp_error(m, ICMP_TIMXCEED, ICMP_TIMXCEED_INTRANS,
1411 0, 0);
1412 return;
1413 }
1414#ifdef IPSTEALTH
1415 }
1416#endif
1417
1418 ia = ip_rtaddr(ip->ip_dst, M_GETFIB(m));
1419#ifndef IPSEC
1420 /*
1421 * 'ia' may be NULL if there is no route for this destination.
1422 * In case of IPsec, Don't discard it just yet, but pass it to
1423 * ip_output in case of outgoing IPsec policy.
1424 */
1425 if (!srcrt && ia == NULL) {
1426 icmp_error(m, ICMP_UNREACH, ICMP_UNREACH_HOST, 0, 0);
1427 return;
1428 }
1429#endif
1430
1431 /*
1432 * Save the IP header and at most 8 bytes of the payload,
1433 * in case we need to generate an ICMP message to the src.
1434 *
1435 * XXX this can be optimized a lot by saving the data in a local
1436 * buffer on the stack (72 bytes at most), and only allocating the
1437 * mbuf if really necessary. The vast majority of the packets
1438 * are forwarded without having to send an ICMP back (either
1439 * because unnecessary, or because rate limited), so we are
1440 * really we are wasting a lot of work here.
1441 *
1442 * We don't use m_copy() because it might return a reference
1443 * to a shared cluster. Both this function and ip_output()
1444 * assume exclusive access to the IP header in `m', so any
1445 * data in a cluster may change before we reach icmp_error().
1446 */
1447 MGETHDR(mcopy, M_DONTWAIT, m->m_type);
1448 if (mcopy != NULL && !m_dup_pkthdr(mcopy, m, M_DONTWAIT)) {
1449 /*
1450 * It's probably ok if the pkthdr dup fails (because
1451 * the deep copy of the tag chain failed), but for now
1452 * be conservative and just discard the copy since
1453 * code below may some day want the tags.
1454 */
1455 m_free(mcopy);
1456 mcopy = NULL;
1457 }
1458 if (mcopy != NULL) {
1459 mcopy->m_len = min(ip->ip_len, M_TRAILINGSPACE(mcopy));
1460 mcopy->m_pkthdr.len = mcopy->m_len;
1461 m_copydata(m, 0, mcopy->m_len, mtod(mcopy, caddr_t));
1462 }
1463
1464#ifdef IPSTEALTH
1465 if (!V_ipstealth) {
1466#endif
1467 ip->ip_ttl -= IPTTLDEC;
1468#ifdef IPSTEALTH
1469 }
1470#endif
1471
1472 /*
1473 * If forwarding packet using same interface that it came in on,
1474 * perhaps should send a redirect to sender to shortcut a hop.
1475 * Only send redirect if source is sending directly to us,
1476 * and if packet was not source routed (or has any options).
1477 * Also, don't send redirect if forwarding using a default route
1478 * or a route modified by a redirect.
1479 */
1480 dest.s_addr = 0;
1481 if (!srcrt && V_ipsendredirects &&
1482 ia != NULL && ia->ia_ifp == m->m_pkthdr.rcvif) {
1483 struct sockaddr_in *sin;
1484 struct rtentry *rt;
1485
1486 bzero(&ro, sizeof(ro));
1487 sin = (struct sockaddr_in *)&ro.ro_dst;
1488 sin->sin_family = AF_INET;
1489 sin->sin_len = sizeof(*sin);
1490 sin->sin_addr = ip->ip_dst;
1491 in_rtalloc_ign(&ro, 0, M_GETFIB(m));
1492
1493 rt = ro.ro_rt;
1494
1495 if (rt && (rt->rt_flags & (RTF_DYNAMIC|RTF_MODIFIED)) == 0 &&
1496 satosin(rt_key(rt))->sin_addr.s_addr != 0) {
1497#define RTA(rt) ((struct in_ifaddr *)(rt->rt_ifa))
1498 u_long src = ntohl(ip->ip_src.s_addr);
1499
1500 if (RTA(rt) &&
1501 (src & RTA(rt)->ia_subnetmask) == RTA(rt)->ia_subnet) {
1502 if (rt->rt_flags & RTF_GATEWAY)
1503 dest.s_addr = satosin(rt->rt_gateway)->sin_addr.s_addr;
1504 else
1505 dest.s_addr = ip->ip_dst.s_addr;
1506 /* Router requirements says to only send host redirects */
1507 type = ICMP_REDIRECT;
1508 code = ICMP_REDIRECT_HOST;
1509 }
1510 }
1511 if (rt)
1512 RTFREE(rt);
1513 }
1514
1515 /*
1516 * Try to cache the route MTU from ip_output so we can consider it for
1517 * the ICMP_UNREACH_NEEDFRAG "Next-Hop MTU" field described in RFC1191.
1518 */
1519 bzero(&ro, sizeof(ro));
1520
1521 error = ip_output(m, NULL, &ro, IP_FORWARDING, NULL, NULL);
1522
1523 if (error == EMSGSIZE && ro.ro_rt)
1524 mtu = ro.ro_rt->rt_rmx.rmx_mtu;
1525 if (ro.ro_rt)
1526 RTFREE(ro.ro_rt);
1527
1528 if (error)
1529 IPSTAT_INC(ips_cantforward);
1530 else {
1531 IPSTAT_INC(ips_forward);
1532 if (type)
1533 IPSTAT_INC(ips_redirectsent);
1534 else {
1535 if (mcopy)
1536 m_freem(mcopy);
1537 if (ia != NULL)
1538 ifa_free(&ia->ia_ifa);
1539 return;
1540 }
1541 }
1542 if (mcopy == NULL) {
1543 if (ia != NULL)
1544 ifa_free(&ia->ia_ifa);
1545 return;
1546 }
1547
1548 switch (error) {
1549
1550 case 0: /* forwarded, but need redirect */
1551 /* type, code set above */
1552 break;
1553
1554 case ENETUNREACH:
1555 case EHOSTUNREACH:
1556 case ENETDOWN:
1557 case EHOSTDOWN:
1558 default:
1559 type = ICMP_UNREACH;
1560 code = ICMP_UNREACH_HOST;
1561 break;
1562
1563 case EMSGSIZE:
1564 type = ICMP_UNREACH;
1565 code = ICMP_UNREACH_NEEDFRAG;
1566
1567#ifdef IPSEC
1568 /*
1569 * If IPsec is configured for this path,
1570 * override any possibly mtu value set by ip_output.
1571 */
1572 mtu = ip_ipsec_mtu(mcopy, mtu);
1573#endif /* IPSEC */
1574 /*
1575 * If the MTU was set before make sure we are below the
1576 * interface MTU.
1577 * If the MTU wasn't set before use the interface mtu or
1578 * fall back to the next smaller mtu step compared to the
1579 * current packet size.
1580 */
1581 if (mtu != 0) {
1582 if (ia != NULL)
1583 mtu = min(mtu, ia->ia_ifp->if_mtu);
1584 } else {
1585 if (ia != NULL)
1586 mtu = ia->ia_ifp->if_mtu;
1587 else
1588 mtu = ip_next_mtu(ip->ip_len, 0);
1589 }
1590 IPSTAT_INC(ips_cantfrag);
1591 break;
1592
1593 case ENOBUFS:
1594 /*
1595 * A router should not generate ICMP_SOURCEQUENCH as
1596 * required in RFC1812 Requirements for IP Version 4 Routers.
1597 * Source quench could be a big problem under DoS attacks,
1598 * or if the underlying interface is rate-limited.
1599 * Those who need source quench packets may re-enable them
1600 * via the net.inet.ip.sendsourcequench sysctl.
1601 */
1602 if (V_ip_sendsourcequench == 0) {
1603 m_freem(mcopy);
1604 if (ia != NULL)
1605 ifa_free(&ia->ia_ifa);
1606 return;
1607 } else {
1608 type = ICMP_SOURCEQUENCH;
1609 code = 0;
1610 }
1611 break;
1612
1613 case EACCES: /* ipfw denied packet */
1614 m_freem(mcopy);
1615 if (ia != NULL)
1616 ifa_free(&ia->ia_ifa);
1617 return;
1618 }
1619 if (ia != NULL)
1620 ifa_free(&ia->ia_ifa);
1621 icmp_error(mcopy, type, code, dest.s_addr, mtu);
1622}
1623
1624void
1625ip_savecontrol(struct inpcb *inp, struct mbuf **mp, struct ip *ip,
1626 struct mbuf *m)
1627{
1628
1629 if (inp->inp_socket->so_options & (SO_BINTIME | SO_TIMESTAMP)) {
1630 struct bintime bt;
1631
1632 bintime(&bt);
1633 if (inp->inp_socket->so_options & SO_BINTIME) {
1634 *mp = sbcreatecontrol((caddr_t) &bt, sizeof(bt),
1635 SCM_BINTIME, SOL_SOCKET);
1636 if (*mp)
1637 mp = &(*mp)->m_next;
1638 }
1639 if (inp->inp_socket->so_options & SO_TIMESTAMP) {
1640 struct timeval tv;
1641
1642 bintime2timeval(&bt, &tv);
1643 *mp = sbcreatecontrol((caddr_t) &tv, sizeof(tv),
1644 SCM_TIMESTAMP, SOL_SOCKET);
1645 if (*mp)
1646 mp = &(*mp)->m_next;
1647 }
1648 }
1649 if (inp->inp_flags & INP_RECVDSTADDR) {
1650 *mp = sbcreatecontrol((caddr_t) &ip->ip_dst,
1651 sizeof(struct in_addr), IP_RECVDSTADDR, IPPROTO_IP);
1652 if (*mp)
1653 mp = &(*mp)->m_next;
1654 }
1655 if (inp->inp_flags & INP_RECVTTL) {
1656 *mp = sbcreatecontrol((caddr_t) &ip->ip_ttl,
1657 sizeof(u_char), IP_RECVTTL, IPPROTO_IP);
1658 if (*mp)
1659 mp = &(*mp)->m_next;
1660 }
1661#ifdef notyet
1662 /* XXX
1663 * Moving these out of udp_input() made them even more broken
1664 * than they already were.
1665 */
1666 /* options were tossed already */
1667 if (inp->inp_flags & INP_RECVOPTS) {
1668 *mp = sbcreatecontrol((caddr_t) opts_deleted_above,
1669 sizeof(struct in_addr), IP_RECVOPTS, IPPROTO_IP);
1670 if (*mp)
1671 mp = &(*mp)->m_next;
1672 }
1673 /* ip_srcroute doesn't do what we want here, need to fix */
1674 if (inp->inp_flags & INP_RECVRETOPTS) {
1675 *mp = sbcreatecontrol((caddr_t) ip_srcroute(m),
1676 sizeof(struct in_addr), IP_RECVRETOPTS, IPPROTO_IP);
1677 if (*mp)
1678 mp = &(*mp)->m_next;
1679 }
1680#endif
1681 if (inp->inp_flags & INP_RECVIF) {
1682 struct ifnet *ifp;
1683 struct sdlbuf {
1684 struct sockaddr_dl sdl;
1685 u_char pad[32];
1686 } sdlbuf;
1687 struct sockaddr_dl *sdp;
1688 struct sockaddr_dl *sdl2 = &sdlbuf.sdl;
1689
1690 if (((ifp = m->m_pkthdr.rcvif))
1691 && ( ifp->if_index && (ifp->if_index <= V_if_index))) {
1692 sdp = (struct sockaddr_dl *)ifp->if_addr->ifa_addr;
1693 /*
1694 * Change our mind and don't try copy.
1695 */
1696 if ((sdp->sdl_family != AF_LINK)
1697 || (sdp->sdl_len > sizeof(sdlbuf))) {
1698 goto makedummy;
1699 }
1700 bcopy(sdp, sdl2, sdp->sdl_len);
1701 } else {
1702makedummy:
1703 sdl2->sdl_len
1704 = offsetof(struct sockaddr_dl, sdl_data[0]);
1705 sdl2->sdl_family = AF_LINK;
1706 sdl2->sdl_index = 0;
1707 sdl2->sdl_nlen = sdl2->sdl_alen = sdl2->sdl_slen = 0;
1708 }
1709 *mp = sbcreatecontrol((caddr_t) sdl2, sdl2->sdl_len,
1710 IP_RECVIF, IPPROTO_IP);
1711 if (*mp)
1712 mp = &(*mp)->m_next;
1713 }
1714}
1715
1716/*
1717 * XXXRW: Multicast routing code in ip_mroute.c is generally MPSAFE, but the
1718 * ip_rsvp and ip_rsvp_on variables need to be interlocked with rsvp_on
1719 * locking. This code remains in ip_input.c as ip_mroute.c is optionally
1720 * compiled.
1721 */
1722static VNET_DEFINE(int, ip_rsvp_on);
1723VNET_DEFINE(struct socket *, ip_rsvpd);
1724
1725#define V_ip_rsvp_on VNET(ip_rsvp_on)
1726
1727int
1728ip_rsvp_init(struct socket *so)
1729{
1730
1731 if (so->so_type != SOCK_RAW ||
1732 so->so_proto->pr_protocol != IPPROTO_RSVP)
1733 return EOPNOTSUPP;
1734
1735 if (V_ip_rsvpd != NULL)
1736 return EADDRINUSE;
1737
1738 V_ip_rsvpd = so;
1739 /*
1740 * This may seem silly, but we need to be sure we don't over-increment
1741 * the RSVP counter, in case something slips up.
1742 */
1743 if (!V_ip_rsvp_on) {
1744 V_ip_rsvp_on = 1;
1745 V_rsvp_on++;
1746 }
1747
1748 return 0;
1749}
1750
1751int
1752ip_rsvp_done(void)
1753{
1754
1755 V_ip_rsvpd = NULL;
1756 /*
1757 * This may seem silly, but we need to be sure we don't over-decrement
1758 * the RSVP counter, in case something slips up.
1759 */
1760 if (V_ip_rsvp_on) {
1761 V_ip_rsvp_on = 0;
1762 V_rsvp_on--;
1763 }
1764 return 0;
1765}
1766
1767void
1768rsvp_input(struct mbuf *m, int off) /* XXX must fixup manually */
1769{
1770
1771 if (rsvp_input_p) { /* call the real one if loaded */
1772 rsvp_input_p(m, off);
1773 return;
1774 }
1775
1776 /* Can still get packets with rsvp_on = 0 if there is a local member
1777 * of the group to which the RSVP packet is addressed. But in this
1778 * case we want to throw the packet away.
1779 */
1780
1781 if (!V_rsvp_on) {
1782 m_freem(m);
1783 return;
1784 }
1785
1786 if (V_ip_rsvpd != NULL) {
1787 rip_input(m, off);
1788 return;
1789 }
1790 /* Drop the packet */
1791 m_freem(m);
1792}
| 1035 * segment, then it's checksum is invalidated.
1036 */
1037 if (p) {
1038 i = GETIP(p)->ip_off + GETIP(p)->ip_len - ip->ip_off;
1039 if (i > 0) {
1040 if (i >= ip->ip_len)
1041 goto dropfrag;
1042 m_adj(m, i);
1043 m->m_pkthdr.csum_flags = 0;
1044 ip->ip_off += i;
1045 ip->ip_len -= i;
1046 }
1047 m->m_nextpkt = p->m_nextpkt;
1048 p->m_nextpkt = m;
1049 } else {
1050 m->m_nextpkt = fp->ipq_frags;
1051 fp->ipq_frags = m;
1052 }
1053
1054 /*
1055 * While we overlap succeeding segments trim them or,
1056 * if they are completely covered, dequeue them.
1057 */
1058 for (; q != NULL && ip->ip_off + ip->ip_len > GETIP(q)->ip_off;
1059 q = nq) {
1060 i = (ip->ip_off + ip->ip_len) - GETIP(q)->ip_off;
1061 if (i < GETIP(q)->ip_len) {
1062 GETIP(q)->ip_len -= i;
1063 GETIP(q)->ip_off += i;
1064 m_adj(q, i);
1065 q->m_pkthdr.csum_flags = 0;
1066 break;
1067 }
1068 nq = q->m_nextpkt;
1069 m->m_nextpkt = nq;
1070 IPSTAT_INC(ips_fragdropped);
1071 fp->ipq_nfrags--;
1072 m_freem(q);
1073 }
1074
1075 /*
1076 * Check for complete reassembly and perform frag per packet
1077 * limiting.
1078 *
1079 * Frag limiting is performed here so that the nth frag has
1080 * a chance to complete the packet before we drop the packet.
1081 * As a result, n+1 frags are actually allowed per packet, but
1082 * only n will ever be stored. (n = maxfragsperpacket.)
1083 *
1084 */
1085 next = 0;
1086 for (p = NULL, q = fp->ipq_frags; q; p = q, q = q->m_nextpkt) {
1087 if (GETIP(q)->ip_off != next) {
1088 if (fp->ipq_nfrags > V_maxfragsperpacket) {
1089 IPSTAT_ADD(ips_fragdropped, fp->ipq_nfrags);
1090 ip_freef(head, fp);
1091 }
1092 goto done;
1093 }
1094 next += GETIP(q)->ip_len;
1095 }
1096 /* Make sure the last packet didn't have the IP_MF flag */
1097 if (p->m_flags & M_FRAG) {
1098 if (fp->ipq_nfrags > V_maxfragsperpacket) {
1099 IPSTAT_ADD(ips_fragdropped, fp->ipq_nfrags);
1100 ip_freef(head, fp);
1101 }
1102 goto done;
1103 }
1104
1105 /*
1106 * Reassembly is complete. Make sure the packet is a sane size.
1107 */
1108 q = fp->ipq_frags;
1109 ip = GETIP(q);
1110 if (next + (ip->ip_hl << 2) > IP_MAXPACKET) {
1111 IPSTAT_INC(ips_toolong);
1112 IPSTAT_ADD(ips_fragdropped, fp->ipq_nfrags);
1113 ip_freef(head, fp);
1114 goto done;
1115 }
1116
1117 /*
1118 * Concatenate fragments.
1119 */
1120 m = q;
1121 t = m->m_next;
1122 m->m_next = NULL;
1123 m_cat(m, t);
1124 nq = q->m_nextpkt;
1125 q->m_nextpkt = NULL;
1126 for (q = nq; q != NULL; q = nq) {
1127 nq = q->m_nextpkt;
1128 q->m_nextpkt = NULL;
1129 m->m_pkthdr.csum_flags &= q->m_pkthdr.csum_flags;
1130 m->m_pkthdr.csum_data += q->m_pkthdr.csum_data;
1131 m_cat(m, q);
1132 }
1133 /*
1134 * In order to do checksumming faster we do 'end-around carry' here
1135 * (and not in for{} loop), though it implies we are not going to
1136 * reassemble more than 64k fragments.
1137 */
1138 m->m_pkthdr.csum_data =
1139 (m->m_pkthdr.csum_data & 0xffff) + (m->m_pkthdr.csum_data >> 16);
1140#ifdef MAC
1141 mac_ipq_reassemble(fp, m);
1142 mac_ipq_destroy(fp);
1143#endif
1144
1145 /*
1146 * Create header for new ip packet by modifying header of first
1147 * packet; dequeue and discard fragment reassembly header.
1148 * Make header visible.
1149 */
1150 ip->ip_len = (ip->ip_hl << 2) + next;
1151 ip->ip_src = fp->ipq_src;
1152 ip->ip_dst = fp->ipq_dst;
1153 TAILQ_REMOVE(head, fp, ipq_list);
1154 V_nipq--;
1155 uma_zfree(V_ipq_zone, fp);
1156 m->m_len += (ip->ip_hl << 2);
1157 m->m_data -= (ip->ip_hl << 2);
1158 /* some debugging cruft by sklower, below, will go away soon */
1159 if (m->m_flags & M_PKTHDR) /* XXX this should be done elsewhere */
1160 m_fixhdr(m);
1161 IPSTAT_INC(ips_reassembled);
1162 IPQ_UNLOCK();
1163 return (m);
1164
1165dropfrag:
1166 IPSTAT_INC(ips_fragdropped);
1167 if (fp != NULL)
1168 fp->ipq_nfrags--;
1169 m_freem(m);
1170done:
1171 IPQ_UNLOCK();
1172 return (NULL);
1173
1174#undef GETIP
1175}
1176
1177/*
1178 * Free a fragment reassembly header and all
1179 * associated datagrams.
1180 */
1181static void
1182ip_freef(struct ipqhead *fhp, struct ipq *fp)
1183{
1184 struct mbuf *q;
1185
1186 IPQ_LOCK_ASSERT();
1187
1188 while (fp->ipq_frags) {
1189 q = fp->ipq_frags;
1190 fp->ipq_frags = q->m_nextpkt;
1191 m_freem(q);
1192 }
1193 TAILQ_REMOVE(fhp, fp, ipq_list);
1194 uma_zfree(V_ipq_zone, fp);
1195 V_nipq--;
1196}
1197
1198/*
1199 * IP timer processing;
1200 * if a timer expires on a reassembly
1201 * queue, discard it.
1202 */
1203void
1204ip_slowtimo(void)
1205{
1206 VNET_ITERATOR_DECL(vnet_iter);
1207 struct ipq *fp;
1208 int i;
1209
1210 VNET_LIST_RLOCK_NOSLEEP();
1211 IPQ_LOCK();
1212 VNET_FOREACH(vnet_iter) {
1213 CURVNET_SET(vnet_iter);
1214 for (i = 0; i < IPREASS_NHASH; i++) {
1215 for(fp = TAILQ_FIRST(&V_ipq[i]); fp;) {
1216 struct ipq *fpp;
1217
1218 fpp = fp;
1219 fp = TAILQ_NEXT(fp, ipq_list);
1220 if(--fpp->ipq_ttl == 0) {
1221 IPSTAT_ADD(ips_fragtimeout,
1222 fpp->ipq_nfrags);
1223 ip_freef(&V_ipq[i], fpp);
1224 }
1225 }
1226 }
1227 /*
1228 * If we are over the maximum number of fragments
1229 * (due to the limit being lowered), drain off
1230 * enough to get down to the new limit.
1231 */
1232 if (V_maxnipq >= 0 && V_nipq > V_maxnipq) {
1233 for (i = 0; i < IPREASS_NHASH; i++) {
1234 while (V_nipq > V_maxnipq &&
1235 !TAILQ_EMPTY(&V_ipq[i])) {
1236 IPSTAT_ADD(ips_fragdropped,
1237 TAILQ_FIRST(&V_ipq[i])->ipq_nfrags);
1238 ip_freef(&V_ipq[i],
1239 TAILQ_FIRST(&V_ipq[i]));
1240 }
1241 }
1242 }
1243 CURVNET_RESTORE();
1244 }
1245 IPQ_UNLOCK();
1246 VNET_LIST_RUNLOCK_NOSLEEP();
1247}
1248
1249/*
1250 * Drain off all datagram fragments.
1251 */
1252static void
1253ip_drain_locked(void)
1254{
1255 int i;
1256
1257 IPQ_LOCK_ASSERT();
1258
1259 for (i = 0; i < IPREASS_NHASH; i++) {
1260 while(!TAILQ_EMPTY(&V_ipq[i])) {
1261 IPSTAT_ADD(ips_fragdropped,
1262 TAILQ_FIRST(&V_ipq[i])->ipq_nfrags);
1263 ip_freef(&V_ipq[i], TAILQ_FIRST(&V_ipq[i]));
1264 }
1265 }
1266}
1267
1268void
1269ip_drain(void)
1270{
1271 VNET_ITERATOR_DECL(vnet_iter);
1272
1273 VNET_LIST_RLOCK_NOSLEEP();
1274 IPQ_LOCK();
1275 VNET_FOREACH(vnet_iter) {
1276 CURVNET_SET(vnet_iter);
1277 ip_drain_locked();
1278 CURVNET_RESTORE();
1279 }
1280 IPQ_UNLOCK();
1281 VNET_LIST_RUNLOCK_NOSLEEP();
1282 in_rtqdrain();
1283}
1284
1285/*
1286 * The protocol to be inserted into ip_protox[] must be already registered
1287 * in inetsw[], either statically or through pf_proto_register().
1288 */
1289int
1290ipproto_register(short ipproto)
1291{
1292 struct protosw *pr;
1293
1294 /* Sanity checks. */
1295 if (ipproto <= 0 || ipproto >= IPPROTO_MAX)
1296 return (EPROTONOSUPPORT);
1297
1298 /*
1299 * The protocol slot must not be occupied by another protocol
1300 * already. An index pointing to IPPROTO_RAW is unused.
1301 */
1302 pr = pffindproto(PF_INET, IPPROTO_RAW, SOCK_RAW);
1303 if (pr == NULL)
1304 return (EPFNOSUPPORT);
1305 if (ip_protox[ipproto] != pr - inetsw) /* IPPROTO_RAW */
1306 return (EEXIST);
1307
1308 /* Find the protocol position in inetsw[] and set the index. */
1309 for (pr = inetdomain.dom_protosw;
1310 pr < inetdomain.dom_protoswNPROTOSW; pr++) {
1311 if (pr->pr_domain->dom_family == PF_INET &&
1312 pr->pr_protocol && pr->pr_protocol == ipproto) {
1313 ip_protox[pr->pr_protocol] = pr - inetsw;
1314 return (0);
1315 }
1316 }
1317 return (EPROTONOSUPPORT);
1318}
1319
1320int
1321ipproto_unregister(short ipproto)
1322{
1323 struct protosw *pr;
1324
1325 /* Sanity checks. */
1326 if (ipproto <= 0 || ipproto >= IPPROTO_MAX)
1327 return (EPROTONOSUPPORT);
1328
1329 /* Check if the protocol was indeed registered. */
1330 pr = pffindproto(PF_INET, IPPROTO_RAW, SOCK_RAW);
1331 if (pr == NULL)
1332 return (EPFNOSUPPORT);
1333 if (ip_protox[ipproto] == pr - inetsw) /* IPPROTO_RAW */
1334 return (ENOENT);
1335
1336 /* Reset the protocol slot to IPPROTO_RAW. */
1337 ip_protox[ipproto] = pr - inetsw;
1338 return (0);
1339}
1340
1341/*
1342 * Given address of next destination (final or next hop), return (referenced)
1343 * internet address info of interface to be used to get there.
1344 */
1345struct in_ifaddr *
1346ip_rtaddr(struct in_addr dst, u_int fibnum)
1347{
1348 struct route sro;
1349 struct sockaddr_in *sin;
1350 struct in_ifaddr *ia;
1351
1352 bzero(&sro, sizeof(sro));
1353 sin = (struct sockaddr_in *)&sro.ro_dst;
1354 sin->sin_family = AF_INET;
1355 sin->sin_len = sizeof(*sin);
1356 sin->sin_addr = dst;
1357 in_rtalloc_ign(&sro, 0, fibnum);
1358
1359 if (sro.ro_rt == NULL)
1360 return (NULL);
1361
1362 ia = ifatoia(sro.ro_rt->rt_ifa);
1363 ifa_ref(&ia->ia_ifa);
1364 RTFREE(sro.ro_rt);
1365 return (ia);
1366}
1367
1368u_char inetctlerrmap[PRC_NCMDS] = {
1369 0, 0, 0, 0,
1370 0, EMSGSIZE, EHOSTDOWN, EHOSTUNREACH,
1371 EHOSTUNREACH, EHOSTUNREACH, ECONNREFUSED, ECONNREFUSED,
1372 EMSGSIZE, EHOSTUNREACH, 0, 0,
1373 0, 0, EHOSTUNREACH, 0,
1374 ENOPROTOOPT, ECONNREFUSED
1375};
1376
1377/*
1378 * Forward a packet. If some error occurs return the sender
1379 * an icmp packet. Note we can't always generate a meaningful
1380 * icmp message because icmp doesn't have a large enough repertoire
1381 * of codes and types.
1382 *
1383 * If not forwarding, just drop the packet. This could be confusing
1384 * if ipforwarding was zero but some routing protocol was advancing
1385 * us as a gateway to somewhere. However, we must let the routing
1386 * protocol deal with that.
1387 *
1388 * The srcrt parameter indicates whether the packet is being forwarded
1389 * via a source route.
1390 */
1391void
1392ip_forward(struct mbuf *m, int srcrt)
1393{
1394 struct ip *ip = mtod(m, struct ip *);
1395 struct in_ifaddr *ia;
1396 struct mbuf *mcopy;
1397 struct in_addr dest;
1398 struct route ro;
1399 int error, type = 0, code = 0, mtu = 0;
1400
1401 if (m->m_flags & (M_BCAST|M_MCAST) || in_canforward(ip->ip_dst) == 0) {
1402 IPSTAT_INC(ips_cantforward);
1403 m_freem(m);
1404 return;
1405 }
1406#ifdef IPSTEALTH
1407 if (!V_ipstealth) {
1408#endif
1409 if (ip->ip_ttl <= IPTTLDEC) {
1410 icmp_error(m, ICMP_TIMXCEED, ICMP_TIMXCEED_INTRANS,
1411 0, 0);
1412 return;
1413 }
1414#ifdef IPSTEALTH
1415 }
1416#endif
1417
1418 ia = ip_rtaddr(ip->ip_dst, M_GETFIB(m));
1419#ifndef IPSEC
1420 /*
1421 * 'ia' may be NULL if there is no route for this destination.
1422 * In case of IPsec, Don't discard it just yet, but pass it to
1423 * ip_output in case of outgoing IPsec policy.
1424 */
1425 if (!srcrt && ia == NULL) {
1426 icmp_error(m, ICMP_UNREACH, ICMP_UNREACH_HOST, 0, 0);
1427 return;
1428 }
1429#endif
1430
1431 /*
1432 * Save the IP header and at most 8 bytes of the payload,
1433 * in case we need to generate an ICMP message to the src.
1434 *
1435 * XXX this can be optimized a lot by saving the data in a local
1436 * buffer on the stack (72 bytes at most), and only allocating the
1437 * mbuf if really necessary. The vast majority of the packets
1438 * are forwarded without having to send an ICMP back (either
1439 * because unnecessary, or because rate limited), so we are
1440 * really we are wasting a lot of work here.
1441 *
1442 * We don't use m_copy() because it might return a reference
1443 * to a shared cluster. Both this function and ip_output()
1444 * assume exclusive access to the IP header in `m', so any
1445 * data in a cluster may change before we reach icmp_error().
1446 */
1447 MGETHDR(mcopy, M_DONTWAIT, m->m_type);
1448 if (mcopy != NULL && !m_dup_pkthdr(mcopy, m, M_DONTWAIT)) {
1449 /*
1450 * It's probably ok if the pkthdr dup fails (because
1451 * the deep copy of the tag chain failed), but for now
1452 * be conservative and just discard the copy since
1453 * code below may some day want the tags.
1454 */
1455 m_free(mcopy);
1456 mcopy = NULL;
1457 }
1458 if (mcopy != NULL) {
1459 mcopy->m_len = min(ip->ip_len, M_TRAILINGSPACE(mcopy));
1460 mcopy->m_pkthdr.len = mcopy->m_len;
1461 m_copydata(m, 0, mcopy->m_len, mtod(mcopy, caddr_t));
1462 }
1463
1464#ifdef IPSTEALTH
1465 if (!V_ipstealth) {
1466#endif
1467 ip->ip_ttl -= IPTTLDEC;
1468#ifdef IPSTEALTH
1469 }
1470#endif
1471
1472 /*
1473 * If forwarding packet using same interface that it came in on,
1474 * perhaps should send a redirect to sender to shortcut a hop.
1475 * Only send redirect if source is sending directly to us,
1476 * and if packet was not source routed (or has any options).
1477 * Also, don't send redirect if forwarding using a default route
1478 * or a route modified by a redirect.
1479 */
1480 dest.s_addr = 0;
1481 if (!srcrt && V_ipsendredirects &&
1482 ia != NULL && ia->ia_ifp == m->m_pkthdr.rcvif) {
1483 struct sockaddr_in *sin;
1484 struct rtentry *rt;
1485
1486 bzero(&ro, sizeof(ro));
1487 sin = (struct sockaddr_in *)&ro.ro_dst;
1488 sin->sin_family = AF_INET;
1489 sin->sin_len = sizeof(*sin);
1490 sin->sin_addr = ip->ip_dst;
1491 in_rtalloc_ign(&ro, 0, M_GETFIB(m));
1492
1493 rt = ro.ro_rt;
1494
1495 if (rt && (rt->rt_flags & (RTF_DYNAMIC|RTF_MODIFIED)) == 0 &&
1496 satosin(rt_key(rt))->sin_addr.s_addr != 0) {
1497#define RTA(rt) ((struct in_ifaddr *)(rt->rt_ifa))
1498 u_long src = ntohl(ip->ip_src.s_addr);
1499
1500 if (RTA(rt) &&
1501 (src & RTA(rt)->ia_subnetmask) == RTA(rt)->ia_subnet) {
1502 if (rt->rt_flags & RTF_GATEWAY)
1503 dest.s_addr = satosin(rt->rt_gateway)->sin_addr.s_addr;
1504 else
1505 dest.s_addr = ip->ip_dst.s_addr;
1506 /* Router requirements says to only send host redirects */
1507 type = ICMP_REDIRECT;
1508 code = ICMP_REDIRECT_HOST;
1509 }
1510 }
1511 if (rt)
1512 RTFREE(rt);
1513 }
1514
1515 /*
1516 * Try to cache the route MTU from ip_output so we can consider it for
1517 * the ICMP_UNREACH_NEEDFRAG "Next-Hop MTU" field described in RFC1191.
1518 */
1519 bzero(&ro, sizeof(ro));
1520
1521 error = ip_output(m, NULL, &ro, IP_FORWARDING, NULL, NULL);
1522
1523 if (error == EMSGSIZE && ro.ro_rt)
1524 mtu = ro.ro_rt->rt_rmx.rmx_mtu;
1525 if (ro.ro_rt)
1526 RTFREE(ro.ro_rt);
1527
1528 if (error)
1529 IPSTAT_INC(ips_cantforward);
1530 else {
1531 IPSTAT_INC(ips_forward);
1532 if (type)
1533 IPSTAT_INC(ips_redirectsent);
1534 else {
1535 if (mcopy)
1536 m_freem(mcopy);
1537 if (ia != NULL)
1538 ifa_free(&ia->ia_ifa);
1539 return;
1540 }
1541 }
1542 if (mcopy == NULL) {
1543 if (ia != NULL)
1544 ifa_free(&ia->ia_ifa);
1545 return;
1546 }
1547
1548 switch (error) {
1549
1550 case 0: /* forwarded, but need redirect */
1551 /* type, code set above */
1552 break;
1553
1554 case ENETUNREACH:
1555 case EHOSTUNREACH:
1556 case ENETDOWN:
1557 case EHOSTDOWN:
1558 default:
1559 type = ICMP_UNREACH;
1560 code = ICMP_UNREACH_HOST;
1561 break;
1562
1563 case EMSGSIZE:
1564 type = ICMP_UNREACH;
1565 code = ICMP_UNREACH_NEEDFRAG;
1566
1567#ifdef IPSEC
1568 /*
1569 * If IPsec is configured for this path,
1570 * override any possibly mtu value set by ip_output.
1571 */
1572 mtu = ip_ipsec_mtu(mcopy, mtu);
1573#endif /* IPSEC */
1574 /*
1575 * If the MTU was set before make sure we are below the
1576 * interface MTU.
1577 * If the MTU wasn't set before use the interface mtu or
1578 * fall back to the next smaller mtu step compared to the
1579 * current packet size.
1580 */
1581 if (mtu != 0) {
1582 if (ia != NULL)
1583 mtu = min(mtu, ia->ia_ifp->if_mtu);
1584 } else {
1585 if (ia != NULL)
1586 mtu = ia->ia_ifp->if_mtu;
1587 else
1588 mtu = ip_next_mtu(ip->ip_len, 0);
1589 }
1590 IPSTAT_INC(ips_cantfrag);
1591 break;
1592
1593 case ENOBUFS:
1594 /*
1595 * A router should not generate ICMP_SOURCEQUENCH as
1596 * required in RFC1812 Requirements for IP Version 4 Routers.
1597 * Source quench could be a big problem under DoS attacks,
1598 * or if the underlying interface is rate-limited.
1599 * Those who need source quench packets may re-enable them
1600 * via the net.inet.ip.sendsourcequench sysctl.
1601 */
1602 if (V_ip_sendsourcequench == 0) {
1603 m_freem(mcopy);
1604 if (ia != NULL)
1605 ifa_free(&ia->ia_ifa);
1606 return;
1607 } else {
1608 type = ICMP_SOURCEQUENCH;
1609 code = 0;
1610 }
1611 break;
1612
1613 case EACCES: /* ipfw denied packet */
1614 m_freem(mcopy);
1615 if (ia != NULL)
1616 ifa_free(&ia->ia_ifa);
1617 return;
1618 }
1619 if (ia != NULL)
1620 ifa_free(&ia->ia_ifa);
1621 icmp_error(mcopy, type, code, dest.s_addr, mtu);
1622}
1623
1624void
1625ip_savecontrol(struct inpcb *inp, struct mbuf **mp, struct ip *ip,
1626 struct mbuf *m)
1627{
1628
1629 if (inp->inp_socket->so_options & (SO_BINTIME | SO_TIMESTAMP)) {
1630 struct bintime bt;
1631
1632 bintime(&bt);
1633 if (inp->inp_socket->so_options & SO_BINTIME) {
1634 *mp = sbcreatecontrol((caddr_t) &bt, sizeof(bt),
1635 SCM_BINTIME, SOL_SOCKET);
1636 if (*mp)
1637 mp = &(*mp)->m_next;
1638 }
1639 if (inp->inp_socket->so_options & SO_TIMESTAMP) {
1640 struct timeval tv;
1641
1642 bintime2timeval(&bt, &tv);
1643 *mp = sbcreatecontrol((caddr_t) &tv, sizeof(tv),
1644 SCM_TIMESTAMP, SOL_SOCKET);
1645 if (*mp)
1646 mp = &(*mp)->m_next;
1647 }
1648 }
1649 if (inp->inp_flags & INP_RECVDSTADDR) {
1650 *mp = sbcreatecontrol((caddr_t) &ip->ip_dst,
1651 sizeof(struct in_addr), IP_RECVDSTADDR, IPPROTO_IP);
1652 if (*mp)
1653 mp = &(*mp)->m_next;
1654 }
1655 if (inp->inp_flags & INP_RECVTTL) {
1656 *mp = sbcreatecontrol((caddr_t) &ip->ip_ttl,
1657 sizeof(u_char), IP_RECVTTL, IPPROTO_IP);
1658 if (*mp)
1659 mp = &(*mp)->m_next;
1660 }
1661#ifdef notyet
1662 /* XXX
1663 * Moving these out of udp_input() made them even more broken
1664 * than they already were.
1665 */
1666 /* options were tossed already */
1667 if (inp->inp_flags & INP_RECVOPTS) {
1668 *mp = sbcreatecontrol((caddr_t) opts_deleted_above,
1669 sizeof(struct in_addr), IP_RECVOPTS, IPPROTO_IP);
1670 if (*mp)
1671 mp = &(*mp)->m_next;
1672 }
1673 /* ip_srcroute doesn't do what we want here, need to fix */
1674 if (inp->inp_flags & INP_RECVRETOPTS) {
1675 *mp = sbcreatecontrol((caddr_t) ip_srcroute(m),
1676 sizeof(struct in_addr), IP_RECVRETOPTS, IPPROTO_IP);
1677 if (*mp)
1678 mp = &(*mp)->m_next;
1679 }
1680#endif
1681 if (inp->inp_flags & INP_RECVIF) {
1682 struct ifnet *ifp;
1683 struct sdlbuf {
1684 struct sockaddr_dl sdl;
1685 u_char pad[32];
1686 } sdlbuf;
1687 struct sockaddr_dl *sdp;
1688 struct sockaddr_dl *sdl2 = &sdlbuf.sdl;
1689
1690 if (((ifp = m->m_pkthdr.rcvif))
1691 && ( ifp->if_index && (ifp->if_index <= V_if_index))) {
1692 sdp = (struct sockaddr_dl *)ifp->if_addr->ifa_addr;
1693 /*
1694 * Change our mind and don't try copy.
1695 */
1696 if ((sdp->sdl_family != AF_LINK)
1697 || (sdp->sdl_len > sizeof(sdlbuf))) {
1698 goto makedummy;
1699 }
1700 bcopy(sdp, sdl2, sdp->sdl_len);
1701 } else {
1702makedummy:
1703 sdl2->sdl_len
1704 = offsetof(struct sockaddr_dl, sdl_data[0]);
1705 sdl2->sdl_family = AF_LINK;
1706 sdl2->sdl_index = 0;
1707 sdl2->sdl_nlen = sdl2->sdl_alen = sdl2->sdl_slen = 0;
1708 }
1709 *mp = sbcreatecontrol((caddr_t) sdl2, sdl2->sdl_len,
1710 IP_RECVIF, IPPROTO_IP);
1711 if (*mp)
1712 mp = &(*mp)->m_next;
1713 }
1714}
1715
1716/*
1717 * XXXRW: Multicast routing code in ip_mroute.c is generally MPSAFE, but the
1718 * ip_rsvp and ip_rsvp_on variables need to be interlocked with rsvp_on
1719 * locking. This code remains in ip_input.c as ip_mroute.c is optionally
1720 * compiled.
1721 */
1722static VNET_DEFINE(int, ip_rsvp_on);
1723VNET_DEFINE(struct socket *, ip_rsvpd);
1724
1725#define V_ip_rsvp_on VNET(ip_rsvp_on)
1726
1727int
1728ip_rsvp_init(struct socket *so)
1729{
1730
1731 if (so->so_type != SOCK_RAW ||
1732 so->so_proto->pr_protocol != IPPROTO_RSVP)
1733 return EOPNOTSUPP;
1734
1735 if (V_ip_rsvpd != NULL)
1736 return EADDRINUSE;
1737
1738 V_ip_rsvpd = so;
1739 /*
1740 * This may seem silly, but we need to be sure we don't over-increment
1741 * the RSVP counter, in case something slips up.
1742 */
1743 if (!V_ip_rsvp_on) {
1744 V_ip_rsvp_on = 1;
1745 V_rsvp_on++;
1746 }
1747
1748 return 0;
1749}
1750
1751int
1752ip_rsvp_done(void)
1753{
1754
1755 V_ip_rsvpd = NULL;
1756 /*
1757 * This may seem silly, but we need to be sure we don't over-decrement
1758 * the RSVP counter, in case something slips up.
1759 */
1760 if (V_ip_rsvp_on) {
1761 V_ip_rsvp_on = 0;
1762 V_rsvp_on--;
1763 }
1764 return 0;
1765}
1766
1767void
1768rsvp_input(struct mbuf *m, int off) /* XXX must fixup manually */
1769{
1770
1771 if (rsvp_input_p) { /* call the real one if loaded */
1772 rsvp_input_p(m, off);
1773 return;
1774 }
1775
1776 /* Can still get packets with rsvp_on = 0 if there is a local member
1777 * of the group to which the RSVP packet is addressed. But in this
1778 * case we want to throw the packet away.
1779 */
1780
1781 if (!V_rsvp_on) {
1782 m_freem(m);
1783 return;
1784 }
1785
1786 if (V_ip_rsvpd != NULL) {
1787 rip_input(m, off);
1788 return;
1789 }
1790 /* Drop the packet */
1791 m_freem(m);
1792}
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