1 /*-
2 * SPDX-License-Identifier: BSD-3-Clause
3 *
4 * Copyright (c) 1982, 1986, 1988, 1993
5 * The Regents of the University of California. All rights reserved.
6 *
7 * Redistribution and use in source and binary forms, with or without
8 * modification, are permitted provided that the following conditions
9 * are met:
10 * 1. Redistributions of source code must retain the above copyright
11 * notice, this list of conditions and the following disclaimer.
12 * 2. Redistributions in binary form must reproduce the above copyright
13 * notice, this list of conditions and the following disclaimer in the
14 * documentation and/or other materials provided with the distribution.
15 * 3. Neither the name of the University nor the names of its contributors
16 * may be used to endorse or promote products derived from this software
17 * without specific prior written permission.
18 *
19 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
20 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
21 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
22 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
23 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
24 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
25 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
26 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
27 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
28 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
29 * SUCH DAMAGE.
30 */
31
32 #include <sys/cdefs.h>
33 #include "opt_inet.h"
34 #include "opt_inet6.h"
35 #include "opt_sctp.h"
36
37 #include <sys/param.h>
38 #include <sys/eventhandler.h>
39 #include <sys/kernel.h>
40 #include <sys/lock.h>
41 #include <sys/malloc.h>
42 #include <sys/mbuf.h>
43 #include <sys/module.h>
44 #include <sys/kernel.h>
45 #include <sys/priv.h>
46 #include <sys/proc.h>
47 #include <sys/domain.h>
48 #include <sys/protosw.h>
49 #include <sys/socket.h>
50 #include <sys/socketvar.h>
51 #include <sys/sysctl.h>
52 #include <net/vnet.h>
53
54 #include <net/if.h>
55 #include <net/if_var.h>
56 #include <net/if_private.h>
57 #include <net/netisr.h>
58
59 #include <netinet/in.h>
60 #include <netinet/in_pcb.h>
61 #include <netinet/in_systm.h>
62 #include <netinet/in_var.h>
63 #include <netinet/ip.h>
64 #include <netinet/ip_var.h>
65 #include <netinet/ip_divert.h>
66 #ifdef INET6
67 #include <netinet/ip6.h>
68 #include <netinet6/ip6_var.h>
69 #endif
70 #if defined(SCTP) || defined(SCTP_SUPPORT)
71 #include <netinet/sctp_crc32.h>
72 #endif
73
74 #include <security/mac/mac_framework.h>
75 /*
76 * Divert sockets
77 */
78
79 /*
80 * Allocate enough space to hold a full IP packet
81 */
82 #define DIVSNDQ (65536 + 100)
83 #define DIVRCVQ (65536 + 100)
84
85 /*
86 * Usually a system has very few divert ports. Previous implementation
87 * used a linked list.
88 */
89 #define DIVHASHSIZE (1 << 3) /* 8 entries, one cache line. */
90 #define DIVHASH(port) (port % DIVHASHSIZE)
91 #define DCBHASH(dcb) ((dcb)->dcb_port % DIVHASHSIZE)
92
93 /*
94 * Divert sockets work in conjunction with ipfw or other packet filters,
95 * see the divert(4) manpage for features.
96 * Packets are selected by the packet filter and tagged with an
97 * MTAG_IPFW_RULE tag carrying the 'divert port' number (as set by
98 * the packet filter) and information on the matching filter rule for
99 * subsequent reinjection. The divert_port is used to put the packet
100 * on the corresponding divert socket, while the rule number is passed
101 * up (at least partially) as the sin_port in the struct sockaddr.
102 *
103 * Packets written to the divert socket carry in sin_addr a
104 * destination address, and in sin_port the number of the filter rule
105 * after which to continue processing.
106 * If the destination address is INADDR_ANY, the packet is treated as
107 * as outgoing and sent to ip_output(); otherwise it is treated as
108 * incoming and sent to ip_input().
109 * Further, sin_zero carries some information on the interface,
110 * which can be used in the reinject -- see comments in the code.
111 *
112 * On reinjection, processing in ip_input() and ip_output()
113 * will be exactly the same as for the original packet, except that
114 * packet filter processing will start at the rule number after the one
115 * written in the sin_port (ipfw does not allow a rule #0, so sin_port=0
116 * will apply the entire ruleset to the packet).
117 */
118 static SYSCTL_NODE(_net_inet, OID_AUTO, divert, CTLFLAG_RW | CTLFLAG_MPSAFE, 0,
119 "divert(4)");
120
121 VNET_PCPUSTAT_DEFINE_STATIC(struct divstat, divstat);
122 VNET_PCPUSTAT_SYSINIT(divstat);
123 #ifdef VIMAGE
124 VNET_PCPUSTAT_SYSUNINIT(divstat);
125 #endif
126 SYSCTL_VNET_PCPUSTAT(_net_inet_divert, OID_AUTO, stats, struct divstat,
127 divstat, "divert(4) socket statistics");
128 #define DIVSTAT_INC(name) \
129 VNET_PCPUSTAT_ADD(struct divstat, divstat, div_ ## name, 1)
130
131 static u_long div_sendspace = DIVSNDQ; /* XXX sysctl ? */
132 static u_long div_recvspace = DIVRCVQ; /* XXX sysctl ? */
133
134 static int div_output_inbound(int fmaily, struct socket *so, struct mbuf *m,
135 struct sockaddr_in *sin);
136 static int div_output_outbound(int family, struct socket *so, struct mbuf *m);
137
138 struct divcb {
139 union {
140 SLIST_ENTRY(divcb) dcb_next;
141 intptr_t dcb_bound;
142 #define DCB_UNBOUND ((intptr_t)-1)
143 };
144 struct socket *dcb_socket;
145 uint16_t dcb_port;
146 uint64_t dcb_gencnt;
147 struct epoch_context dcb_epochctx;
148 };
149
150 SLIST_HEAD(divhashhead, divcb);
151
152 VNET_DEFINE_STATIC(struct divhashhead, divhash[DIVHASHSIZE]) = {};
153 #define V_divhash VNET(divhash)
154 VNET_DEFINE_STATIC(uint64_t, dcb_count) = 0;
155 #define V_dcb_count VNET(dcb_count)
156 VNET_DEFINE_STATIC(uint64_t, dcb_gencnt) = 0;
157 #define V_dcb_gencnt VNET(dcb_gencnt)
158
159 static struct mtx divert_mtx;
160 MTX_SYSINIT(divert, &divert_mtx, "divert(4) socket pcb lists", MTX_DEF);
161 #define DIVERT_LOCK() mtx_lock(&divert_mtx)
162 #define DIVERT_UNLOCK() mtx_unlock(&divert_mtx)
163
164 /*
165 * Divert a packet by passing it up to the divert socket at port 'port'.
166 */
167 static void
divert_packet(struct mbuf * m,bool incoming)168 divert_packet(struct mbuf *m, bool incoming)
169 {
170 struct divcb *dcb;
171 u_int16_t nport;
172 struct sockaddr_in divsrc;
173 struct m_tag *mtag;
174 uint16_t cookie;
175
176 NET_EPOCH_ASSERT();
177
178 mtag = m_tag_locate(m, MTAG_IPFW_RULE, 0, NULL);
179 if (mtag != NULL) {
180 cookie = ((struct ipfw_rule_ref *)(mtag+1))->rulenum;
181 nport = htons((uint16_t)
182 (((struct ipfw_rule_ref *)(mtag+1))->info));
183 } else if ((mtag = m_tag_locate(m, MTAG_PF_DIVERT, 0, NULL)) != NULL) {
184 cookie = ((struct pf_divert_mtag *)(mtag+1))->idir;
185 nport = htons(((struct pf_divert_mtag *)(mtag+1))->port);
186 } else {
187 m_freem(m);
188 return;
189 }
190 /* Assure header */
191 if (m->m_len < sizeof(struct ip) &&
192 (m = m_pullup(m, sizeof(struct ip))) == NULL)
193 return;
194 #ifdef INET
195 /* Delayed checksums are currently not compatible with divert. */
196 if (m->m_pkthdr.csum_flags & CSUM_DELAY_DATA) {
197 in_delayed_cksum(m);
198 m->m_pkthdr.csum_flags &= ~CSUM_DELAY_DATA;
199 }
200 #if defined(SCTP) || defined(SCTP_SUPPORT)
201 if (m->m_pkthdr.csum_flags & CSUM_SCTP) {
202 struct ip *ip;
203
204 ip = mtod(m, struct ip *);
205 sctp_delayed_cksum(m, (uint32_t)(ip->ip_hl << 2));
206 m->m_pkthdr.csum_flags &= ~CSUM_SCTP;
207 }
208 #endif
209 #endif
210 #ifdef INET6
211 if (m->m_pkthdr.csum_flags & CSUM_DELAY_DATA_IPV6) {
212 in6_delayed_cksum(m, m->m_pkthdr.len -
213 sizeof(struct ip6_hdr), sizeof(struct ip6_hdr));
214 m->m_pkthdr.csum_flags &= ~CSUM_DELAY_DATA_IPV6;
215 }
216 #if defined(SCTP) || defined(SCTP_SUPPORT)
217 if (m->m_pkthdr.csum_flags & CSUM_SCTP_IPV6) {
218 sctp_delayed_cksum(m, sizeof(struct ip6_hdr));
219 m->m_pkthdr.csum_flags &= ~CSUM_SCTP_IPV6;
220 }
221 #endif
222 #endif /* INET6 */
223 bzero(&divsrc, sizeof(divsrc));
224 divsrc.sin_len = sizeof(divsrc);
225 divsrc.sin_family = AF_INET;
226 /* record matching rule, in host format */
227 divsrc.sin_port = cookie;
228 /*
229 * Record receive interface address, if any.
230 * But only for incoming packets.
231 */
232 if (incoming) {
233 struct ifaddr *ifa;
234 struct ifnet *ifp;
235
236 /* Sanity check */
237 M_ASSERTPKTHDR(m);
238
239 /* Find IP address for receive interface */
240 ifp = m->m_pkthdr.rcvif;
241 CK_STAILQ_FOREACH(ifa, &ifp->if_addrhead, ifa_link) {
242 if (ifa->ifa_addr->sa_family != AF_INET)
243 continue;
244 divsrc.sin_addr =
245 ((struct sockaddr_in *) ifa->ifa_addr)->sin_addr;
246 break;
247 }
248 }
249 /*
250 * Record the incoming interface name whenever we have one.
251 */
252 if (m->m_pkthdr.rcvif) {
253 /*
254 * Hide the actual interface name in there in the
255 * sin_zero array. XXX This needs to be moved to a
256 * different sockaddr type for divert, e.g.
257 * sockaddr_div with multiple fields like
258 * sockaddr_dl. Presently we have only 7 bytes
259 * but that will do for now as most interfaces
260 * are 4 or less + 2 or less bytes for unit.
261 * There is probably a faster way of doing this,
262 * possibly taking it from the sockaddr_dl on the iface.
263 * This solves the problem of a P2P link and a LAN interface
264 * having the same address, which can result in the wrong
265 * interface being assigned to the packet when fed back
266 * into the divert socket. Theoretically if the daemon saves
267 * and re-uses the sockaddr_in as suggested in the man pages,
268 * this iface name will come along for the ride.
269 * (see div_output for the other half of this.)
270 */
271 strlcpy(divsrc.sin_zero, m->m_pkthdr.rcvif->if_xname,
272 sizeof(divsrc.sin_zero));
273 }
274
275 /* Put packet on socket queue, if any */
276 SLIST_FOREACH(dcb, &V_divhash[DIVHASH(nport)], dcb_next)
277 if (dcb->dcb_port == nport)
278 break;
279
280 if (dcb != NULL) {
281 struct socket *sa = dcb->dcb_socket;
282
283 SOCKBUF_LOCK(&sa->so_rcv);
284 if (sbappendaddr_locked(&sa->so_rcv,
285 (struct sockaddr *)&divsrc, m, NULL) == 0) {
286 soroverflow_locked(sa);
287 m_freem(m);
288 } else {
289 sorwakeup_locked(sa);
290 DIVSTAT_INC(diverted);
291 }
292 } else {
293 DIVSTAT_INC(noport);
294 m_freem(m);
295 }
296 }
297
298 /*
299 * Deliver packet back into the IP processing machinery.
300 *
301 * If no address specified, or address is 0.0.0.0, send to ip_output();
302 * otherwise, send to ip_input() and mark as having been received on
303 * the interface with that address.
304 */
305 static int
div_send(struct socket * so,int flags,struct mbuf * m,struct sockaddr * nam,struct mbuf * control,struct thread * td)306 div_send(struct socket *so, int flags, struct mbuf *m, struct sockaddr *nam,
307 struct mbuf *control, struct thread *td)
308 {
309 struct epoch_tracker et;
310 struct sockaddr_in *sin = (struct sockaddr_in *)nam;
311 const struct ip *ip;
312 struct m_tag *mtag;
313 struct ipfw_rule_ref *dt;
314 struct pf_divert_mtag *pfdt;
315 int error, family;
316
317 if (control)
318 m_freem(control);
319
320 /* Packet must have a header (but that's about it) */
321 if (m->m_len < sizeof (struct ip) &&
322 (m = m_pullup(m, sizeof (struct ip))) == NULL) {
323 m_freem(m);
324 return (EINVAL);
325 }
326
327 if (sin != NULL) {
328 if (sin->sin_family != AF_INET) {
329 m_freem(m);
330 return (EAFNOSUPPORT);
331 }
332 if (sin->sin_len != sizeof(*sin)) {
333 m_freem(m);
334 return (EINVAL);
335 }
336 }
337
338 /*
339 * An mbuf may hasn't come from userland, but we pretend
340 * that it has.
341 */
342 m->m_pkthdr.rcvif = NULL;
343 m->m_nextpkt = NULL;
344 M_SETFIB(m, so->so_fibnum);
345
346 mtag = m_tag_locate(m, MTAG_IPFW_RULE, 0, NULL);
347 if (mtag == NULL) {
348 /* this should be normal */
349 mtag = m_tag_alloc(MTAG_IPFW_RULE, 0,
350 sizeof(struct ipfw_rule_ref), M_NOWAIT | M_ZERO);
351 if (mtag == NULL) {
352 m_freem(m);
353 return (ENOBUFS);
354 }
355 m_tag_prepend(m, mtag);
356 }
357 dt = (struct ipfw_rule_ref *)(mtag+1);
358
359 /* Loopback avoidance and state recovery */
360 if (sin) {
361 int i;
362
363 /* set the starting point. We provide a non-zero slot,
364 * but a non_matching chain_id to skip that info and use
365 * the rulenum/rule_id.
366 */
367 dt->slot = 1; /* dummy, chain_id is invalid */
368 dt->chain_id = 0;
369 dt->rulenum = sin->sin_port+1; /* host format ? */
370 dt->rule_id = 0;
371 /* XXX: broken for IPv6 */
372 /*
373 * Find receive interface with the given name, stuffed
374 * (if it exists) in the sin_zero[] field.
375 * The name is user supplied data so don't trust its size
376 * or that it is zero terminated.
377 */
378 for (i = 0; i < sizeof(sin->sin_zero) && sin->sin_zero[i]; i++)
379 ;
380 if ( i > 0 && i < sizeof(sin->sin_zero))
381 m->m_pkthdr.rcvif = ifunit(sin->sin_zero);
382 }
383
384 ip = mtod(m, struct ip *);
385 switch (ip->ip_v) {
386 #ifdef INET
387 case IPVERSION:
388 family = AF_INET;
389 break;
390 #endif
391 #ifdef INET6
392 case IPV6_VERSION >> 4:
393 family = AF_INET6;
394 break;
395 #endif
396 default:
397 m_freem(m);
398 return (EAFNOSUPPORT);
399 }
400
401 mtag = m_tag_locate(m, MTAG_PF_DIVERT, 0, NULL);
402 if (mtag == NULL) {
403 /* this should be normal */
404 mtag = m_tag_alloc(MTAG_PF_DIVERT, 0,
405 sizeof(struct pf_divert_mtag), M_NOWAIT | M_ZERO);
406 if (mtag == NULL) {
407 m_freem(m);
408 return (ENOBUFS);
409 }
410 m_tag_prepend(m, mtag);
411 }
412 pfdt = (struct pf_divert_mtag *)(mtag+1);
413 if (sin)
414 pfdt->idir = sin->sin_port;
415
416 /* Reinject packet into the system as incoming or outgoing */
417 NET_EPOCH_ENTER(et);
418 if (!sin || sin->sin_addr.s_addr == 0) {
419 dt->info |= IPFW_IS_DIVERT | IPFW_INFO_OUT;
420 pfdt->ndir = PF_DIVERT_MTAG_DIR_OUT;
421 error = div_output_outbound(family, so, m);
422 } else {
423 dt->info |= IPFW_IS_DIVERT | IPFW_INFO_IN;
424 pfdt->ndir = PF_DIVERT_MTAG_DIR_IN;
425 error = div_output_inbound(family, so, m, sin);
426 }
427 NET_EPOCH_EXIT(et);
428
429 return (error);
430 }
431
432 /*
433 * Sends mbuf @m to the wire via ip[6]_output().
434 *
435 * Returns 0 on success or an errno value on failure. @m is always consumed.
436 */
437 static int
div_output_outbound(int family,struct socket * so,struct mbuf * m)438 div_output_outbound(int family, struct socket *so, struct mbuf *m)
439 {
440 int error;
441
442 switch (family) {
443 #ifdef INET
444 case AF_INET:
445 {
446 struct ip *const ip = mtod(m, struct ip *);
447
448 /* Don't allow packet length sizes that will crash. */
449 if (((u_short)ntohs(ip->ip_len) > m->m_pkthdr.len)) {
450 m_freem(m);
451 return (EINVAL);
452 }
453 break;
454 }
455 #endif
456 #ifdef INET6
457 case AF_INET6:
458 {
459 struct ip6_hdr *const ip6 = mtod(m, struct ip6_hdr *);
460
461 /* Don't allow packet length sizes that will crash */
462 if (((u_short)ntohs(ip6->ip6_plen) > m->m_pkthdr.len)) {
463 m_freem(m);
464 return (EINVAL);
465 }
466 break;
467 }
468 #endif
469 }
470
471 #ifdef MAC
472 mac_socket_create_mbuf(so, m);
473 #endif
474
475 error = 0;
476 switch (family) {
477 #ifdef INET
478 case AF_INET:
479 error = ip_output(m, NULL, NULL,
480 ((so->so_options & SO_DONTROUTE) ? IP_ROUTETOIF : 0)
481 | IP_ALLOWBROADCAST | IP_RAWOUTPUT, NULL, NULL);
482 break;
483 #endif
484 #ifdef INET6
485 case AF_INET6:
486 error = ip6_output(m, NULL, NULL, 0, NULL, NULL, NULL);
487 break;
488 #endif
489 }
490 if (error == 0)
491 DIVSTAT_INC(outbound);
492
493 return (error);
494 }
495
496 /*
497 * Schedules mbuf @m for local processing via IPv4/IPv6 netisr queue.
498 *
499 * Returns 0 on success or an errno value on failure. @m is always consumed.
500 */
501 static int
div_output_inbound(int family,struct socket * so,struct mbuf * m,struct sockaddr_in * sin)502 div_output_inbound(int family, struct socket *so, struct mbuf *m,
503 struct sockaddr_in *sin)
504 {
505 struct ifaddr *ifa;
506
507 if (m->m_pkthdr.rcvif == NULL) {
508 /*
509 * No luck with the name, check by IP address.
510 * Clear the port and the ifname to make sure
511 * there are no distractions for ifa_ifwithaddr.
512 */
513
514 /* XXX: broken for IPv6 */
515 bzero(sin->sin_zero, sizeof(sin->sin_zero));
516 sin->sin_port = 0;
517 ifa = ifa_ifwithaddr((struct sockaddr *) sin);
518 if (ifa == NULL) {
519 m_freem(m);
520 return (EADDRNOTAVAIL);
521 }
522 m->m_pkthdr.rcvif = ifa->ifa_ifp;
523 }
524 #ifdef MAC
525 mac_socket_create_mbuf(so, m);
526 #endif
527 /* Send packet to input processing via netisr */
528 switch (family) {
529 #ifdef INET
530 case AF_INET:
531 {
532 const struct ip *ip;
533
534 ip = mtod(m, struct ip *);
535 /*
536 * Restore M_BCAST flag when destination address is
537 * broadcast. It is expected by ip_tryforward().
538 */
539 if (IN_MULTICAST(ntohl(ip->ip_dst.s_addr)))
540 m->m_flags |= M_MCAST;
541 else if (in_broadcast(ip->ip_dst, m->m_pkthdr.rcvif))
542 m->m_flags |= M_BCAST;
543 netisr_queue_src(NETISR_IP, (uintptr_t)so, m);
544 DIVSTAT_INC(inbound);
545 break;
546 }
547 #endif
548 #ifdef INET6
549 case AF_INET6:
550 netisr_queue_src(NETISR_IPV6, (uintptr_t)so, m);
551 DIVSTAT_INC(inbound);
552 break;
553 #endif
554 default:
555 m_freem(m);
556 return (EINVAL);
557 }
558
559 return (0);
560 }
561
562 static int
div_attach(struct socket * so,int proto,struct thread * td)563 div_attach(struct socket *so, int proto, struct thread *td)
564 {
565 struct divcb *dcb;
566 int error;
567
568 if (td != NULL) {
569 error = priv_check(td, PRIV_NETINET_DIVERT);
570 if (error)
571 return (error);
572 }
573 error = soreserve(so, div_sendspace, div_recvspace);
574 if (error)
575 return error;
576 dcb = malloc(sizeof(*dcb), M_PCB, M_WAITOK);
577 dcb->dcb_bound = DCB_UNBOUND;
578 dcb->dcb_socket = so;
579 DIVERT_LOCK();
580 V_dcb_count++;
581 dcb->dcb_gencnt = ++V_dcb_gencnt;
582 DIVERT_UNLOCK();
583 so->so_pcb = dcb;
584
585 return (0);
586 }
587
588 static void
div_free(epoch_context_t ctx)589 div_free(epoch_context_t ctx)
590 {
591 struct divcb *dcb = __containerof(ctx, struct divcb, dcb_epochctx);
592
593 free(dcb, M_PCB);
594 }
595
596 static void
div_detach(struct socket * so)597 div_detach(struct socket *so)
598 {
599 struct divcb *dcb = so->so_pcb;
600
601 so->so_pcb = NULL;
602 DIVERT_LOCK();
603 if (dcb->dcb_bound != DCB_UNBOUND)
604 SLIST_REMOVE(&V_divhash[DCBHASH(dcb)], dcb, divcb, dcb_next);
605 V_dcb_count--;
606 V_dcb_gencnt++;
607 DIVERT_UNLOCK();
608 NET_EPOCH_CALL(div_free, &dcb->dcb_epochctx);
609 }
610
611 static int
div_bind(struct socket * so,struct sockaddr * nam,struct thread * td)612 div_bind(struct socket *so, struct sockaddr *nam, struct thread *td)
613 {
614 struct divcb *dcb;
615 uint16_t port;
616
617 if (nam->sa_family != AF_INET)
618 return EAFNOSUPPORT;
619 if (nam->sa_len != sizeof(struct sockaddr_in))
620 return EINVAL;
621 port = ((struct sockaddr_in *)nam)->sin_port;
622 DIVERT_LOCK();
623 SLIST_FOREACH(dcb, &V_divhash[DIVHASH(port)], dcb_next)
624 if (dcb->dcb_port == port) {
625 DIVERT_UNLOCK();
626 return (EADDRINUSE);
627 }
628 dcb = so->so_pcb;
629 if (dcb->dcb_bound != DCB_UNBOUND)
630 SLIST_REMOVE(&V_divhash[DCBHASH(dcb)], dcb, divcb, dcb_next);
631 dcb->dcb_port = port;
632 SLIST_INSERT_HEAD(&V_divhash[DIVHASH(port)], dcb, dcb_next);
633 DIVERT_UNLOCK();
634
635 return (0);
636 }
637
638 static int
div_pcblist(SYSCTL_HANDLER_ARGS)639 div_pcblist(SYSCTL_HANDLER_ARGS)
640 {
641 struct xinpgen xig;
642 struct divcb *dcb;
643 int error;
644
645 if (req->newptr != 0)
646 return EPERM;
647
648 if (req->oldptr == 0) {
649 u_int n;
650
651 n = V_dcb_count;
652 n += imax(n / 8, 10);
653 req->oldidx = 2 * (sizeof xig) + n * sizeof(struct xinpcb);
654 return 0;
655 }
656
657 if ((error = sysctl_wire_old_buffer(req, 0)) != 0)
658 return (error);
659
660 bzero(&xig, sizeof(xig));
661 xig.xig_len = sizeof xig;
662 xig.xig_count = V_dcb_count;
663 xig.xig_gen = V_dcb_gencnt;
664 xig.xig_sogen = so_gencnt;
665 error = SYSCTL_OUT(req, &xig, sizeof xig);
666 if (error)
667 return error;
668
669 DIVERT_LOCK();
670 for (int i = 0; i < DIVHASHSIZE; i++)
671 SLIST_FOREACH(dcb, &V_divhash[i], dcb_next) {
672 if (dcb->dcb_gencnt <= xig.xig_gen) {
673 struct xinpcb xi;
674
675 bzero(&xi, sizeof(xi));
676 xi.xi_len = sizeof(struct xinpcb);
677 sotoxsocket(dcb->dcb_socket, &xi.xi_socket);
678 xi.inp_gencnt = dcb->dcb_gencnt;
679 xi.inp_vflag = INP_IPV4; /* XXX: netstat(1) */
680 xi.inp_inc.inc_ie.ie_lport = dcb->dcb_port;
681 error = SYSCTL_OUT(req, &xi, sizeof xi);
682 if (error)
683 goto errout;
684 }
685 }
686
687 /*
688 * Give the user an updated idea of our state.
689 * If the generation differs from what we told
690 * her before, she knows that something happened
691 * while we were processing this request, and it
692 * might be necessary to retry.
693 */
694 xig.xig_gen = V_dcb_gencnt;
695 xig.xig_sogen = so_gencnt;
696 xig.xig_count = V_dcb_count;
697 error = SYSCTL_OUT(req, &xig, sizeof xig);
698
699 errout:
700 DIVERT_UNLOCK();
701
702 return (error);
703 }
704 SYSCTL_PROC(_net_inet_divert, OID_AUTO, pcblist,
705 CTLTYPE_OPAQUE | CTLFLAG_RD | CTLFLAG_MPSAFE, NULL, 0, div_pcblist,
706 "S,xinpcb", "List of active divert sockets");
707
708 static struct protosw div_protosw = {
709 .pr_type = SOCK_RAW,
710 .pr_flags = PR_ATOMIC|PR_ADDR,
711 .pr_attach = div_attach,
712 .pr_bind = div_bind,
713 .pr_detach = div_detach,
714 .pr_send = div_send,
715 };
716
717 static struct domain divertdomain = {
718 .dom_family = PF_DIVERT,
719 .dom_name = "divert",
720 .dom_nprotosw = 1,
721 .dom_protosw = { &div_protosw },
722 };
723
724 static int
div_modevent(module_t mod,int type,void * unused)725 div_modevent(module_t mod, int type, void *unused)
726 {
727 int err = 0;
728
729 switch (type) {
730 case MOD_LOAD:
731 domain_add(&divertdomain);
732 ip_divert_ptr = divert_packet;
733 break;
734 case MOD_QUIESCE:
735 /*
736 * IPDIVERT may normally not be unloaded because of the
737 * potential race conditions. Tell kldunload we can't be
738 * unloaded unless the unload is forced.
739 */
740 err = EPERM;
741 break;
742 case MOD_UNLOAD:
743 /*
744 * Forced unload.
745 *
746 * Module ipdivert can only be unloaded if no sockets are
747 * connected. Maybe this can be changed later to forcefully
748 * disconnect any open sockets.
749 *
750 * XXXRW: Note that there is a slight race here, as a new
751 * socket open request could be spinning on the lock and then
752 * we destroy the lock.
753 *
754 * XXXGL: One more reason this code is incorrect is that it
755 * checks only the current vnet.
756 */
757 DIVERT_LOCK();
758 if (V_dcb_count != 0) {
759 DIVERT_UNLOCK();
760 err = EBUSY;
761 break;
762 }
763 DIVERT_UNLOCK();
764 ip_divert_ptr = NULL;
765 domain_remove(&divertdomain);
766 break;
767 default:
768 err = EOPNOTSUPP;
769 break;
770 }
771 return err;
772 }
773
774 static moduledata_t ipdivertmod = {
775 "ipdivert",
776 div_modevent,
777 0
778 };
779
780 DECLARE_MODULE(ipdivert, ipdivertmod, SI_SUB_PROTO_FIREWALL, SI_ORDER_ANY);
781 MODULE_VERSION(ipdivert, 1);
782