1 /*-
2 * Copyright (c) 1982, 1986, 1988, 1993
3 * The Regents of the University of California. All rights reserved.
4 *
5 * Redistribution and use in source and binary forms, with or without
6 * modification, are permitted provided that the following conditions
7 * are met:
8 * 1. Redistributions of source code must retain the above copyright
9 * notice, this list of conditions and the following disclaimer.
10 * 2. Redistributions in binary form must reproduce the above copyright
11 * notice, this list of conditions and the following disclaimer in the
12 * documentation and/or other materials provided with the distribution.
13 * 4. Neither the name of the University nor the names of its contributors
14 * may be used to endorse or promote products derived from this software
15 * without specific prior written permission.
16 *
17 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
18 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
19 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
20 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
21 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
22 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
23 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
24 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
25 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
26 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
27 * SUCH DAMAGE.
28 */
29
30 #include <sys/cdefs.h>
31 __FBSDID("$FreeBSD: src/sys/netinet/ip_divert.c,v 1.141 2008/12/02 21:37:28 bz Exp $");
32
33 #if !defined(KLD_MODULE)
34 #include "opt_inet.h"
35 #include "opt_ipfw.h"
36 #include "opt_mac.h"
37 #ifndef INET
38 #error "IPDIVERT requires INET."
39 #endif
40 #ifndef IPFIREWALL
41 #error "IPDIVERT requires IPFIREWALL"
42 #endif
43 #endif
44
45 #include <sys/param.h>
46 #include <sys/kernel.h>
47 #include <sys/lock.h>
48 #include <sys/malloc.h>
49 #include <sys/mbuf.h>
50 #include <sys/module.h>
51 #include <sys/kernel.h>
52 #include <sys/priv.h>
53 #include <sys/proc.h>
54 #include <sys/protosw.h>
55 #include <sys/signalvar.h>
56 #include <sys/socket.h>
57 #include <sys/socketvar.h>
58 #include <sys/sx.h>
59 #include <sys/sysctl.h>
60 #include <sys/systm.h>
61 #include <sys/vimage.h>
62
63 #include <vm/uma.h>
64
65 #include <net/if.h>
66 #include <net/netisr.h>
67 #include <net/route.h>
68
69 #include <netinet/in.h>
70 #include <netinet/in_pcb.h>
71 #include <netinet/in_systm.h>
72 #include <netinet/in_var.h>
73 #include <netinet/ip.h>
74 #include <netinet/ip_divert.h>
75 #include <netinet/ip_var.h>
76 #include <netinet/ip_fw.h>
77 #include <netinet/vinet.h>
78
79 #include <security/mac/mac_framework.h>
80
81 /*
82 * Divert sockets
83 */
84
85 /*
86 * Allocate enough space to hold a full IP packet
87 */
88 #define DIVSNDQ (65536 + 100)
89 #define DIVRCVQ (65536 + 100)
90
91 /*
92 * Divert sockets work in conjunction with ipfw, see the divert(4)
93 * manpage for features.
94 * Internally, packets selected by ipfw in ip_input() or ip_output(),
95 * and never diverted before, are passed to the input queue of the
96 * divert socket with a given 'divert_port' number (as specified in
97 * the matching ipfw rule), and they are tagged with a 16 bit cookie
98 * (representing the rule number of the matching ipfw rule), which
99 * is passed to process reading from the socket.
100 *
101 * Packets written to the divert socket are again tagged with a cookie
102 * (usually the same as above) and a destination address.
103 * If the destination address is INADDR_ANY then the packet is
104 * treated as outgoing and sent to ip_output(), otherwise it is
105 * treated as incoming and sent to ip_input().
106 * In both cases, the packet is tagged with the cookie.
107 *
108 * On reinjection, processing in ip_input() and ip_output()
109 * will be exactly the same as for the original packet, except that
110 * ipfw processing will start at the rule number after the one
111 * written in the cookie (so, tagging a packet with a cookie of 0
112 * will cause it to be effectively considered as a standard packet).
113 */
114
115 /* Internal variables. */
116 #ifdef VIMAGE_GLOBALS
117 static struct inpcbhead divcb;
118 static struct inpcbinfo divcbinfo;
119 #endif
120
121 static u_long div_sendspace = DIVSNDQ; /* XXX sysctl ? */
122 static u_long div_recvspace = DIVRCVQ; /* XXX sysctl ? */
123
124 /*
125 * Initialize divert connection block queue.
126 */
127 static void
128 div_zone_change(void *tag)
129 {
130
131 uma_zone_set_max(V_divcbinfo.ipi_zone, maxsockets);
132 }
133
134 static int
135 div_inpcb_init(void *mem, int size, int flags)
136 {
137 struct inpcb *inp = mem;
138
139 INP_LOCK_INIT(inp, "inp", "divinp");
140 return (0);
141 }
142
143 static void
144 div_inpcb_fini(void *mem, int size)
145 {
146 struct inpcb *inp = mem;
147
148 INP_LOCK_DESTROY(inp);
149 }
150
151 void
152 div_init(void)
153 {
154 INIT_VNET_INET(curvnet);
155
156 INP_INFO_LOCK_INIT(&V_divcbinfo, "div");
157 LIST_INIT(&V_divcb);
158 V_divcbinfo.ipi_listhead = &V_divcb;
159 /*
160 * XXX We don't use the hash list for divert IP, but it's easier
161 * to allocate a one entry hash list than it is to check all
162 * over the place for hashbase == NULL.
163 */
164 V_divcbinfo.ipi_hashbase = hashinit(1, M_PCB, &V_divcbinfo.ipi_hashmask);
165 V_divcbinfo.ipi_porthashbase = hashinit(1, M_PCB,
166 &V_divcbinfo.ipi_porthashmask);
167 V_divcbinfo.ipi_zone = uma_zcreate("divcb", sizeof(struct inpcb),
168 NULL, NULL, div_inpcb_init, div_inpcb_fini, UMA_ALIGN_PTR,
169 UMA_ZONE_NOFREE);
170 uma_zone_set_max(divcbinfo.ipi_zone, maxsockets);
171 EVENTHANDLER_REGISTER(maxsockets_change, div_zone_change,
172 NULL, EVENTHANDLER_PRI_ANY);
173 }
174
175 /*
176 * IPPROTO_DIVERT is not in the real IP protocol number space; this
177 * function should never be called. Just in case, drop any packets.
178 */
179 void
180 div_input(struct mbuf *m, int off)
181 {
182 INIT_VNET_INET(curvnet);
183
184 V_ipstat.ips_noproto++;
185 m_freem(m);
186 }
187
188 /*
189 * Divert a packet by passing it up to the divert socket at port 'port'.
190 *
191 * Setup generic address and protocol structures for div_input routine,
192 * then pass them along with mbuf chain.
193 */
194 static void
195 divert_packet(struct mbuf *m, int incoming)
196 {
197 INIT_VNET_INET(curvnet);
198 struct ip *ip;
199 struct inpcb *inp;
200 struct socket *sa;
201 u_int16_t nport;
202 struct sockaddr_in divsrc;
203 struct m_tag *mtag;
204
205 mtag = m_tag_find(m, PACKET_TAG_DIVERT, NULL);
206 if (mtag == NULL) {
207 printf("%s: no divert tag\n", __func__);
208 m_freem(m);
209 return;
210 }
211 /* Assure header */
212 if (m->m_len < sizeof(struct ip) &&
213 (m = m_pullup(m, sizeof(struct ip))) == 0)
214 return;
215 ip = mtod(m, struct ip *);
216
217 /* Delayed checksums are currently not compatible with divert. */
218 if (m->m_pkthdr.csum_flags & CSUM_DELAY_DATA) {
219 ip->ip_len = ntohs(ip->ip_len);
220 in_delayed_cksum(m);
221 m->m_pkthdr.csum_flags &= ~CSUM_DELAY_DATA;
222 ip->ip_len = htons(ip->ip_len);
223 }
224
225 /*
226 * Record receive interface address, if any.
227 * But only for incoming packets.
228 */
229 bzero(&divsrc, sizeof(divsrc));
230 divsrc.sin_len = sizeof(divsrc);
231 divsrc.sin_family = AF_INET;
232 divsrc.sin_port = divert_cookie(mtag); /* record matching rule */
233 if (incoming) {
234 struct ifaddr *ifa;
235
236 /* Sanity check */
237 M_ASSERTPKTHDR(m);
238
239 /* Find IP address for receive interface */
240 TAILQ_FOREACH(ifa, &m->m_pkthdr.rcvif->if_addrhead, ifa_link) {
241 if (ifa->ifa_addr->sa_family != AF_INET)
242 continue;
243 divsrc.sin_addr =
244 ((struct sockaddr_in *) ifa->ifa_addr)->sin_addr;
245 break;
246 }
247 }
248 /*
249 * Record the incoming interface name whenever we have one.
250 */
251 if (m->m_pkthdr.rcvif) {
252 /*
253 * Hide the actual interface name in there in the
254 * sin_zero array. XXX This needs to be moved to a
255 * different sockaddr type for divert, e.g.
256 * sockaddr_div with multiple fields like
257 * sockaddr_dl. Presently we have only 7 bytes
258 * but that will do for now as most interfaces
259 * are 4 or less + 2 or less bytes for unit.
260 * There is probably a faster way of doing this,
261 * possibly taking it from the sockaddr_dl on the iface.
262 * This solves the problem of a P2P link and a LAN interface
263 * having the same address, which can result in the wrong
264 * interface being assigned to the packet when fed back
265 * into the divert socket. Theoretically if the daemon saves
266 * and re-uses the sockaddr_in as suggested in the man pages,
267 * this iface name will come along for the ride.
268 * (see div_output for the other half of this.)
269 */
270 strlcpy(divsrc.sin_zero, m->m_pkthdr.rcvif->if_xname,
271 sizeof(divsrc.sin_zero));
272 }
273
274 /* Put packet on socket queue, if any */
275 sa = NULL;
276 nport = htons((u_int16_t)divert_info(mtag));
277 INP_INFO_RLOCK(&V_divcbinfo);
278 LIST_FOREACH(inp, &V_divcb, inp_list) {
279 /* XXX why does only one socket match? */
280 if (inp->inp_lport == nport) {
281 INP_RLOCK(inp);
282 sa = inp->inp_socket;
283 SOCKBUF_LOCK(&sa->so_rcv);
284 if (sbappendaddr_locked(&sa->so_rcv,
285 (struct sockaddr *)&divsrc, m,
286 (struct mbuf *)0) == 0) {
287 SOCKBUF_UNLOCK(&sa->so_rcv);
288 sa = NULL; /* force mbuf reclaim below */
289 } else
290 sorwakeup_locked(sa);
291 INP_RUNLOCK(inp);
292 break;
293 }
294 }
295 INP_INFO_RUNLOCK(&V_divcbinfo);
296 if (sa == NULL) {
297 m_freem(m);
298 V_ipstat.ips_noproto++;
299 V_ipstat.ips_delivered--;
300 }
301 }
302
303 /*
304 * Deliver packet back into the IP processing machinery.
305 *
306 * If no address specified, or address is 0.0.0.0, send to ip_output();
307 * otherwise, send to ip_input() and mark as having been received on
308 * the interface with that address.
309 */
310 static int
311 div_output(struct socket *so, struct mbuf *m, struct sockaddr_in *sin,
312 struct mbuf *control)
313 {
314 INIT_VNET_INET(curvnet);
315 struct m_tag *mtag;
316 struct divert_tag *dt;
317 int error = 0;
318 struct mbuf *options;
319
320 /*
321 * An mbuf may hasn't come from userland, but we pretend
322 * that it has.
323 */
324 m->m_pkthdr.rcvif = NULL;
325 m->m_nextpkt = NULL;
326 M_SETFIB(m, so->so_fibnum);
327
328 if (control)
329 m_freem(control); /* XXX */
330
331 if ((mtag = m_tag_find(m, PACKET_TAG_DIVERT, NULL)) == NULL) {
332 mtag = m_tag_get(PACKET_TAG_DIVERT, sizeof(struct divert_tag),
333 M_NOWAIT | M_ZERO);
334 if (mtag == NULL) {
335 error = ENOBUFS;
336 goto cantsend;
337 }
338 dt = (struct divert_tag *)(mtag+1);
339 m_tag_prepend(m, mtag);
340 } else
341 dt = (struct divert_tag *)(mtag+1);
342
343 /* Loopback avoidance and state recovery */
344 if (sin) {
345 int i;
346
347 dt->cookie = sin->sin_port;
348 /*
349 * Find receive interface with the given name, stuffed
350 * (if it exists) in the sin_zero[] field.
351 * The name is user supplied data so don't trust its size
352 * or that it is zero terminated.
353 */
354 for (i = 0; i < sizeof(sin->sin_zero) && sin->sin_zero[i]; i++)
355 ;
356 if ( i > 0 && i < sizeof(sin->sin_zero))
357 m->m_pkthdr.rcvif = ifunit(sin->sin_zero);
358 }
359
360 /* Reinject packet into the system as incoming or outgoing */
361 if (!sin || sin->sin_addr.s_addr == 0) {
362 struct ip *const ip = mtod(m, struct ip *);
363 struct inpcb *inp;
364
365 dt->info |= IP_FW_DIVERT_OUTPUT_FLAG;
366 INP_INFO_WLOCK(&V_divcbinfo);
367 inp = sotoinpcb(so);
368 INP_RLOCK(inp);
369 /*
370 * Don't allow both user specified and setsockopt options,
371 * and don't allow packet length sizes that will crash
372 */
373 if (((ip->ip_hl != (sizeof (*ip) >> 2)) && inp->inp_options) ||
374 ((u_short)ntohs(ip->ip_len) > m->m_pkthdr.len)) {
375 error = EINVAL;
376 INP_RUNLOCK(inp);
377 INP_INFO_WUNLOCK(&V_divcbinfo);
378 m_freem(m);
379 } else {
380 /* Convert fields to host order for ip_output() */
381 ip->ip_len = ntohs(ip->ip_len);
382 ip->ip_off = ntohs(ip->ip_off);
383
384 /* Send packet to output processing */
385 V_ipstat.ips_rawout++; /* XXX */
386
387 #ifdef MAC
388 mac_inpcb_create_mbuf(inp, m);
389 #endif
390 /*
391 * Get ready to inject the packet into ip_output().
392 * Just in case socket options were specified on the
393 * divert socket, we duplicate them. This is done
394 * to avoid having to hold the PCB locks over the call
395 * to ip_output(), as doing this results in a number of
396 * lock ordering complexities.
397 *
398 * Note that we set the multicast options argument for
399 * ip_output() to NULL since it should be invariant that
400 * they are not present.
401 */
402 KASSERT(inp->inp_moptions == NULL,
403 ("multicast options set on a divert socket"));
404 options = NULL;
405 /*
406 * XXXCSJP: It is unclear to me whether or not it makes
407 * sense for divert sockets to have options. However,
408 * for now we will duplicate them with the INP locks
409 * held so we can use them in ip_output() without
410 * requring a reference to the pcb.
411 */
412 if (inp->inp_options != NULL) {
413 options = m_dup(inp->inp_options, M_DONTWAIT);
414 if (options == NULL)
415 error = ENOBUFS;
416 }
417 INP_RUNLOCK(inp);
418 INP_INFO_WUNLOCK(&V_divcbinfo);
419 if (error == ENOBUFS) {
420 m_freem(m);
421 return (error);
422 }
423 error = ip_output(m, options, NULL,
424 ((so->so_options & SO_DONTROUTE) ?
425 IP_ROUTETOIF : 0) | IP_ALLOWBROADCAST |
426 IP_RAWOUTPUT, NULL, NULL);
427 if (options != NULL)
428 m_freem(options);
429 }
430 } else {
431 dt->info |= IP_FW_DIVERT_LOOPBACK_FLAG;
432 if (m->m_pkthdr.rcvif == NULL) {
433 /*
434 * No luck with the name, check by IP address.
435 * Clear the port and the ifname to make sure
436 * there are no distractions for ifa_ifwithaddr.
437 */
438 struct ifaddr *ifa;
439
440 bzero(sin->sin_zero, sizeof(sin->sin_zero));
441 sin->sin_port = 0;
442 ifa = ifa_ifwithaddr((struct sockaddr *) sin);
443 if (ifa == NULL) {
444 error = EADDRNOTAVAIL;
445 goto cantsend;
446 }
447 m->m_pkthdr.rcvif = ifa->ifa_ifp;
448 }
449 #ifdef MAC
450 SOCK_LOCK(so);
451 mac_socket_create_mbuf(so, m);
452 SOCK_UNLOCK(so);
453 #endif
454 /* Send packet to input processing via netisr */
455 netisr_queue(NETISR_IP, m);
456 }
457
458 return error;
459
460 cantsend:
461 m_freem(m);
462 return error;
463 }
464
465 static int
466 div_attach(struct socket *so, int proto, struct thread *td)
467 {
468 INIT_VNET_INET(so->so_vnet);
469 struct inpcb *inp;
470 int error;
471
472 inp = sotoinpcb(so);
473 KASSERT(inp == NULL, ("div_attach: inp != NULL"));
474 if (td != NULL) {
475 error = priv_check(td, PRIV_NETINET_DIVERT);
476 if (error)
477 return (error);
478 }
479 error = soreserve(so, div_sendspace, div_recvspace);
480 if (error)
481 return error;
482 INP_INFO_WLOCK(&V_divcbinfo);
483 error = in_pcballoc(so, &V_divcbinfo);
484 if (error) {
485 INP_INFO_WUNLOCK(&V_divcbinfo);
486 return error;
487 }
488 inp = (struct inpcb *)so->so_pcb;
489 INP_INFO_WUNLOCK(&V_divcbinfo);
490 inp->inp_ip_p = proto;
491 inp->inp_vflag |= INP_IPV4;
492 inp->inp_flags |= INP_HDRINCL;
493 INP_WUNLOCK(inp);
494 return 0;
495 }
496
497 static void
498 div_detach(struct socket *so)
499 {
500 INIT_VNET_INET(so->so_vnet);
501 struct inpcb *inp;
502
503 inp = sotoinpcb(so);
504 KASSERT(inp != NULL, ("div_detach: inp == NULL"));
505 INP_INFO_WLOCK(&V_divcbinfo);
506 INP_WLOCK(inp);
507 in_pcbdetach(inp);
508 in_pcbfree(inp);
509 INP_INFO_WUNLOCK(&V_divcbinfo);
510 }
511
512 static int
513 div_bind(struct socket *so, struct sockaddr *nam, struct thread *td)
514 {
515 INIT_VNET_INET(so->so_vnet);
516 struct inpcb *inp;
517 int error;
518
519 inp = sotoinpcb(so);
520 KASSERT(inp != NULL, ("div_bind: inp == NULL"));
521 /* in_pcbbind assumes that nam is a sockaddr_in
522 * and in_pcbbind requires a valid address. Since divert
523 * sockets don't we need to make sure the address is
524 * filled in properly.
525 * XXX -- divert should not be abusing in_pcbind
526 * and should probably have its own family.
527 */
528 if (nam->sa_family != AF_INET)
529 return EAFNOSUPPORT;
530 ((struct sockaddr_in *)nam)->sin_addr.s_addr = INADDR_ANY;
531 INP_INFO_WLOCK(&V_divcbinfo);
532 INP_WLOCK(inp);
533 error = in_pcbbind(inp, nam, td->td_ucred);
534 INP_WUNLOCK(inp);
535 INP_INFO_WUNLOCK(&V_divcbinfo);
536 return error;
537 }
538
539 static int
540 div_shutdown(struct socket *so)
541 {
542 struct inpcb *inp;
543
544 inp = sotoinpcb(so);
545 KASSERT(inp != NULL, ("div_shutdown: inp == NULL"));
546 INP_WLOCK(inp);
547 socantsendmore(so);
548 INP_WUNLOCK(inp);
549 return 0;
550 }
551
552 static int
553 div_send(struct socket *so, int flags, struct mbuf *m, struct sockaddr *nam,
554 struct mbuf *control, struct thread *td)
555 {
556 INIT_VNET_INET(so->so_vnet);
557
558 /* Packet must have a header (but that's about it) */
559 if (m->m_len < sizeof (struct ip) &&
560 (m = m_pullup(m, sizeof (struct ip))) == 0) {
561 V_ipstat.ips_toosmall++;
562 m_freem(m);
563 return EINVAL;
564 }
565
566 /* Send packet */
567 return div_output(so, m, (struct sockaddr_in *)nam, control);
568 }
569
570 void
571 div_ctlinput(int cmd, struct sockaddr *sa, void *vip)
572 {
573 struct in_addr faddr;
574
575 faddr = ((struct sockaddr_in *)sa)->sin_addr;
576 if (sa->sa_family != AF_INET || faddr.s_addr == INADDR_ANY)
577 return;
578 if (PRC_IS_REDIRECT(cmd))
579 return;
580 }
581
582 static int
583 div_pcblist(SYSCTL_HANDLER_ARGS)
584 {
585 INIT_VNET_INET(curvnet);
586 int error, i, n;
587 struct inpcb *inp, **inp_list;
588 inp_gen_t gencnt;
589 struct xinpgen xig;
590
591 /*
592 * The process of preparing the TCB list is too time-consuming and
593 * resource-intensive to repeat twice on every request.
594 */
595 if (req->oldptr == 0) {
596 n = V_divcbinfo.ipi_count;
597 req->oldidx = 2 * (sizeof xig)
598 + (n + n/8) * sizeof(struct xinpcb);
599 return 0;
600 }
601
602 if (req->newptr != 0)
603 return EPERM;
604
605 /*
606 * OK, now we're committed to doing something.
607 */
608 INP_INFO_RLOCK(&V_divcbinfo);
609 gencnt = V_divcbinfo.ipi_gencnt;
610 n = V_divcbinfo.ipi_count;
611 INP_INFO_RUNLOCK(&V_divcbinfo);
612
613 error = sysctl_wire_old_buffer(req,
614 2 * sizeof(xig) + n*sizeof(struct xinpcb));
615 if (error != 0)
616 return (error);
617
618 xig.xig_len = sizeof xig;
619 xig.xig_count = n;
620 xig.xig_gen = gencnt;
621 xig.xig_sogen = so_gencnt;
622 error = SYSCTL_OUT(req, &xig, sizeof xig);
623 if (error)
624 return error;
625
626 inp_list = malloc(n * sizeof *inp_list, M_TEMP, M_WAITOK);
627 if (inp_list == 0)
628 return ENOMEM;
629
630 INP_INFO_RLOCK(&V_divcbinfo);
631 for (inp = LIST_FIRST(V_divcbinfo.ipi_listhead), i = 0; inp && i < n;
632 inp = LIST_NEXT(inp, inp_list)) {
633 INP_RLOCK(inp);
634 if (inp->inp_gencnt <= gencnt &&
635 cr_canseeinpcb(req->td->td_ucred, inp) == 0)
636 inp_list[i++] = inp;
637 INP_RUNLOCK(inp);
638 }
639 INP_INFO_RUNLOCK(&V_divcbinfo);
640 n = i;
641
642 error = 0;
643 for (i = 0; i < n; i++) {
644 inp = inp_list[i];
645 INP_RLOCK(inp);
646 if (inp->inp_gencnt <= gencnt) {
647 struct xinpcb xi;
648 bzero(&xi, sizeof(xi));
649 xi.xi_len = sizeof xi;
650 /* XXX should avoid extra copy */
651 bcopy(inp, &xi.xi_inp, sizeof *inp);
652 if (inp->inp_socket)
653 sotoxsocket(inp->inp_socket, &xi.xi_socket);
654 INP_RUNLOCK(inp);
655 error = SYSCTL_OUT(req, &xi, sizeof xi);
656 } else
657 INP_RUNLOCK(inp);
658 }
659 if (!error) {
660 /*
661 * Give the user an updated idea of our state.
662 * If the generation differs from what we told
663 * her before, she knows that something happened
664 * while we were processing this request, and it
665 * might be necessary to retry.
666 */
667 INP_INFO_RLOCK(&V_divcbinfo);
668 xig.xig_gen = V_divcbinfo.ipi_gencnt;
669 xig.xig_sogen = so_gencnt;
670 xig.xig_count = V_divcbinfo.ipi_count;
671 INP_INFO_RUNLOCK(&V_divcbinfo);
672 error = SYSCTL_OUT(req, &xig, sizeof xig);
673 }
674 free(inp_list, M_TEMP);
675 return error;
676 }
677
678 #ifdef SYSCTL_NODE
679 SYSCTL_NODE(_net_inet, IPPROTO_DIVERT, divert, CTLFLAG_RW, 0, "IPDIVERT");
680 SYSCTL_PROC(_net_inet_divert, OID_AUTO, pcblist, CTLFLAG_RD, 0, 0,
681 div_pcblist, "S,xinpcb", "List of active divert sockets");
682 #endif
683
684 struct pr_usrreqs div_usrreqs = {
685 .pru_attach = div_attach,
686 .pru_bind = div_bind,
687 .pru_control = in_control,
688 .pru_detach = div_detach,
689 .pru_peeraddr = in_getpeeraddr,
690 .pru_send = div_send,
691 .pru_shutdown = div_shutdown,
692 .pru_sockaddr = in_getsockaddr,
693 .pru_sosetlabel = in_pcbsosetlabel
694 };
695
696 struct protosw div_protosw = {
697 .pr_type = SOCK_RAW,
698 .pr_protocol = IPPROTO_DIVERT,
699 .pr_flags = PR_ATOMIC|PR_ADDR,
700 .pr_input = div_input,
701 .pr_ctlinput = div_ctlinput,
702 .pr_ctloutput = ip_ctloutput,
703 .pr_init = div_init,
704 .pr_usrreqs = &div_usrreqs
705 };
706
707 static int
708 div_modevent(module_t mod, int type, void *unused)
709 {
710 int err = 0;
711 int n;
712
713 switch (type) {
714 case MOD_LOAD:
715 /*
716 * Protocol will be initialized by pf_proto_register().
717 * We don't have to register ip_protox because we are not
718 * a true IP protocol that goes over the wire.
719 */
720 err = pf_proto_register(PF_INET, &div_protosw);
721 ip_divert_ptr = divert_packet;
722 break;
723 case MOD_QUIESCE:
724 /*
725 * IPDIVERT may normally not be unloaded because of the
726 * potential race conditions. Tell kldunload we can't be
727 * unloaded unless the unload is forced.
728 */
729 err = EPERM;
730 break;
731 case MOD_UNLOAD:
732 /*
733 * Forced unload.
734 *
735 * Module ipdivert can only be unloaded if no sockets are
736 * connected. Maybe this can be changed later to forcefully
737 * disconnect any open sockets.
738 *
739 * XXXRW: Note that there is a slight race here, as a new
740 * socket open request could be spinning on the lock and then
741 * we destroy the lock.
742 */
743 INP_INFO_WLOCK(&V_divcbinfo);
744 n = V_divcbinfo.ipi_count;
745 if (n != 0) {
746 err = EBUSY;
747 INP_INFO_WUNLOCK(&V_divcbinfo);
748 break;
749 }
750 ip_divert_ptr = NULL;
751 err = pf_proto_unregister(PF_INET, IPPROTO_DIVERT, SOCK_RAW);
752 INP_INFO_WUNLOCK(&V_divcbinfo);
753 INP_INFO_LOCK_DESTROY(&V_divcbinfo);
754 uma_zdestroy(V_divcbinfo.ipi_zone);
755 break;
756 default:
757 err = EOPNOTSUPP;
758 break;
759 }
760 return err;
761 }
762
763 static moduledata_t ipdivertmod = {
764 "ipdivert",
765 div_modevent,
766 0
767 };
768
769 DECLARE_MODULE(ipdivert, ipdivertmod, SI_SUB_PROTO_IFATTACHDOMAIN, SI_ORDER_ANY);
770 MODULE_DEPEND(dummynet, ipfw, 2, 2, 2);
771 MODULE_VERSION(ipdivert, 1);
772
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