30 */
31
32#if !defined(KLD_MODULE)
33#include "opt_inet.h"
34#include "opt_ipfw.h"
35#include "opt_mac.h"
36#ifndef INET
37#error "IPDIVERT requires INET."
38#endif
39#ifndef IPFIREWALL
40#error "IPDIVERT requires IPFIREWALL"
41#endif
42#endif
43
44#include <sys/param.h>
45#include <sys/kernel.h>
46#include <sys/lock.h>
47#include <sys/malloc.h>
48#include <sys/mac.h>
49#include <sys/mbuf.h>
50#include <sys/module.h>
51#include <sys/kernel.h>
52#include <sys/proc.h>
53#include <sys/protosw.h>
54#include <sys/signalvar.h>
55#include <sys/socket.h>
56#include <sys/socketvar.h>
57#include <sys/sx.h>
58#include <sys/sysctl.h>
59#include <sys/systm.h>
60
61#include <vm/uma.h>
62
63#include <net/if.h>
64#include <net/route.h>
65
66#include <netinet/in.h>
67#include <netinet/in_pcb.h>
68#include <netinet/in_systm.h>
69#include <netinet/in_var.h>
70#include <netinet/ip.h>
71#include <netinet/ip_divert.h>
72#include <netinet/ip_var.h>
73#include <netinet/ip_fw.h>
74
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 * Divert sockets work in conjunction with ipfw, see the divert(4)
87 * manpage for features.
88 * Internally, packets selected by ipfw in ip_input() or ip_output(),
89 * and never diverted before, are passed to the input queue of the
90 * divert socket with a given 'divert_port' number (as specified in
91 * the matching ipfw rule), and they are tagged with a 16 bit cookie
92 * (representing the rule number of the matching ipfw rule), which
93 * is passed to process reading from the socket.
94 *
95 * Packets written to the divert socket are again tagged with a cookie
96 * (usually the same as above) and a destination address.
97 * If the destination address is INADDR_ANY then the packet is
98 * treated as outgoing and sent to ip_output(), otherwise it is
99 * treated as incoming and sent to ip_input().
100 * In both cases, the packet is tagged with the cookie.
101 *
102 * On reinjection, processing in ip_input() and ip_output()
103 * will be exactly the same as for the original packet, except that
104 * ipfw processing will start at the rule number after the one
105 * written in the cookie (so, tagging a packet with a cookie of 0
106 * will cause it to be effectively considered as a standard packet).
107 */
108
109/* Internal variables. */
110static struct inpcbhead divcb;
111static struct inpcbinfo divcbinfo;
112
113static u_long div_sendspace = DIVSNDQ; /* XXX sysctl ? */
114static u_long div_recvspace = DIVRCVQ; /* XXX sysctl ? */
115
116/*
117 * Initialize divert connection block queue.
118 */
119void
120div_init(void)
121{
122 INP_INFO_LOCK_INIT(&divcbinfo, "div");
123 LIST_INIT(&divcb);
124 divcbinfo.listhead = &divcb;
125 /*
126 * XXX We don't use the hash list for divert IP, but it's easier
127 * to allocate a one entry hash list than it is to check all
128 * over the place for hashbase == NULL.
129 */
130 divcbinfo.hashbase = hashinit(1, M_PCB, &divcbinfo.hashmask);
131 divcbinfo.porthashbase = hashinit(1, M_PCB, &divcbinfo.porthashmask);
132 divcbinfo.ipi_zone = uma_zcreate("divcb", sizeof(struct inpcb),
133 NULL, NULL, NULL, NULL, UMA_ALIGN_PTR, UMA_ZONE_NOFREE);
134 uma_zone_set_max(divcbinfo.ipi_zone, maxsockets);
135}
136
137/*
138 * IPPROTO_DIVERT is not in the real IP protocol number space; this
139 * function should never be called. Just in case, drop any packets.
140 */
141void
142div_input(struct mbuf *m, int off)
143{
144 ipstat.ips_noproto++;
145 m_freem(m);
146}
147
148/*
149 * Divert a packet by passing it up to the divert socket at port 'port'.
150 *
151 * Setup generic address and protocol structures for div_input routine,
152 * then pass them along with mbuf chain.
153 */
154static void
155divert_packet(struct mbuf *m, int incoming)
156{
157 struct ip *ip;
158 struct inpcb *inp;
159 struct socket *sa;
160 u_int16_t nport;
161 struct sockaddr_in divsrc;
162 struct m_tag *mtag;
163
164 mtag = m_tag_find(m, PACKET_TAG_DIVERT, NULL);
165 if (mtag == NULL) {
166 printf("%s: no divert tag\n", __func__);
167 m_freem(m);
168 return;
169 }
170 /* Assure header */
171 if (m->m_len < sizeof(struct ip) &&
172 (m = m_pullup(m, sizeof(struct ip))) == 0)
173 return;
174 ip = mtod(m, struct ip *);
175
176 /* Delayed checksums are currently not compatible with divert. */
177 if (m->m_pkthdr.csum_flags & CSUM_DELAY_DATA) {
178 ip->ip_len = ntohs(ip->ip_len);
179 in_delayed_cksum(m);
180 m->m_pkthdr.csum_flags &= ~CSUM_DELAY_DATA;
181 ip->ip_len = htons(ip->ip_len);
182 }
183
184 /*
185 * Record receive interface address, if any.
186 * But only for incoming packets.
187 */
188 bzero(&divsrc, sizeof(divsrc));
189 divsrc.sin_len = sizeof(divsrc);
190 divsrc.sin_family = AF_INET;
191 divsrc.sin_port = divert_cookie(mtag); /* record matching rule */
192 if (incoming) {
193 struct ifaddr *ifa;
194
195 /* Sanity check */
196 M_ASSERTPKTHDR(m);
197
198 /* Find IP address for receive interface */
199 TAILQ_FOREACH(ifa, &m->m_pkthdr.rcvif->if_addrhead, ifa_link) {
200 if (ifa->ifa_addr == NULL)
201 continue;
202 if (ifa->ifa_addr->sa_family != AF_INET)
203 continue;
204 divsrc.sin_addr =
205 ((struct sockaddr_in *) ifa->ifa_addr)->sin_addr;
206 break;
207 }
208 }
209 /*
210 * Record the incoming interface name whenever we have one.
211 */
212 if (m->m_pkthdr.rcvif) {
213 /*
214 * Hide the actual interface name in there in the
215 * sin_zero array. XXX This needs to be moved to a
216 * different sockaddr type for divert, e.g.
217 * sockaddr_div with multiple fields like
218 * sockaddr_dl. Presently we have only 7 bytes
219 * but that will do for now as most interfaces
220 * are 4 or less + 2 or less bytes for unit.
221 * There is probably a faster way of doing this,
222 * possibly taking it from the sockaddr_dl on the iface.
223 * This solves the problem of a P2P link and a LAN interface
224 * having the same address, which can result in the wrong
225 * interface being assigned to the packet when fed back
226 * into the divert socket. Theoretically if the daemon saves
227 * and re-uses the sockaddr_in as suggested in the man pages,
228 * this iface name will come along for the ride.
229 * (see div_output for the other half of this.)
230 */
231 strlcpy(divsrc.sin_zero, m->m_pkthdr.rcvif->if_xname,
232 sizeof(divsrc.sin_zero));
233 }
234
235 /* Put packet on socket queue, if any */
236 sa = NULL;
237 nport = htons((u_int16_t)divert_info(mtag));
238 INP_INFO_RLOCK(&divcbinfo);
239 LIST_FOREACH(inp, &divcb, inp_list) {
240 INP_LOCK(inp);
241 /* XXX why does only one socket match? */
242 if (inp->inp_lport == nport) {
243 sa = inp->inp_socket;
244 SOCKBUF_LOCK(&sa->so_rcv);
245 if (sbappendaddr_locked(&sa->so_rcv,
246 (struct sockaddr *)&divsrc, m,
247 (struct mbuf *)0) == 0) {
248 SOCKBUF_UNLOCK(&sa->so_rcv);
249 sa = NULL; /* force mbuf reclaim below */
250 } else
251 sorwakeup_locked(sa);
252 INP_UNLOCK(inp);
253 break;
254 }
255 INP_UNLOCK(inp);
256 }
257 INP_INFO_RUNLOCK(&divcbinfo);
258 if (sa == NULL) {
259 m_freem(m);
260 ipstat.ips_noproto++;
261 ipstat.ips_delivered--;
262 }
263}
264
265/*
266 * Deliver packet back into the IP processing machinery.
267 *
268 * If no address specified, or address is 0.0.0.0, send to ip_output();
269 * otherwise, send to ip_input() and mark as having been received on
270 * the interface with that address.
271 */
272static int
273div_output(struct socket *so, struct mbuf *m,
274 struct sockaddr_in *sin, struct mbuf *control)
275{
276 struct m_tag *mtag;
277 struct divert_tag *dt;
278 int error = 0;
279
280 /*
281 * An mbuf may hasn't come from userland, but we pretend
282 * that it has.
283 */
284 m->m_pkthdr.rcvif = NULL;
285 m->m_nextpkt = NULL;
286
287 if (control)
288 m_freem(control); /* XXX */
289
290 if ((mtag = m_tag_find(m, PACKET_TAG_DIVERT, NULL)) == NULL) {
291 mtag = m_tag_get(PACKET_TAG_DIVERT, sizeof(struct divert_tag),
292 M_NOWAIT | M_ZERO);
293 if (mtag == NULL) {
294 error = ENOBUFS;
295 goto cantsend;
296 }
297 dt = (struct divert_tag *)(mtag+1);
298 m_tag_prepend(m, mtag);
299 } else
300 dt = (struct divert_tag *)(mtag+1);
301
302 /* Loopback avoidance and state recovery */
303 if (sin) {
304 int i;
305
306 dt->cookie = sin->sin_port;
307 /*
308 * Find receive interface with the given name, stuffed
309 * (if it exists) in the sin_zero[] field.
310 * The name is user supplied data so don't trust its size
311 * or that it is zero terminated.
312 */
313 for (i = 0; i < sizeof(sin->sin_zero) && sin->sin_zero[i]; i++)
314 ;
315 if ( i > 0 && i < sizeof(sin->sin_zero))
316 m->m_pkthdr.rcvif = ifunit(sin->sin_zero);
317 }
318
319 /* Reinject packet into the system as incoming or outgoing */
320 if (!sin || sin->sin_addr.s_addr == 0) {
321 struct ip *const ip = mtod(m, struct ip *);
322 struct inpcb *inp;
323
324 dt->info |= IP_FW_DIVERT_OUTPUT_FLAG;
325 INP_INFO_WLOCK(&divcbinfo);
326 inp = sotoinpcb(so);
327 INP_LOCK(inp);
328 /*
329 * Don't allow both user specified and setsockopt options,
330 * and don't allow packet length sizes that will crash
331 */
332 if (((ip->ip_hl != (sizeof (*ip) >> 2)) && inp->inp_options) ||
333 ((u_short)ntohs(ip->ip_len) > m->m_pkthdr.len)) {
334 error = EINVAL;
335 m_freem(m);
336 } else {
337 /* Convert fields to host order for ip_output() */
338 ip->ip_len = ntohs(ip->ip_len);
339 ip->ip_off = ntohs(ip->ip_off);
340
341 /* Send packet to output processing */
342 ipstat.ips_rawout++; /* XXX */
343
344#ifdef MAC
345 mac_create_mbuf_from_inpcb(inp, m);
346#endif
347 error = ip_output(m,
348 inp->inp_options, NULL,
349 ((so->so_options & SO_DONTROUTE) ?
350 IP_ROUTETOIF : 0) |
351 IP_ALLOWBROADCAST | IP_RAWOUTPUT,
352 inp->inp_moptions, NULL);
353 }
354 INP_UNLOCK(inp);
355 INP_INFO_WUNLOCK(&divcbinfo);
356 } else {
357 dt->info |= IP_FW_DIVERT_LOOPBACK_FLAG;
358 if (m->m_pkthdr.rcvif == NULL) {
359 /*
360 * No luck with the name, check by IP address.
361 * Clear the port and the ifname to make sure
362 * there are no distractions for ifa_ifwithaddr.
363 */
364 struct ifaddr *ifa;
365
366 bzero(sin->sin_zero, sizeof(sin->sin_zero));
367 sin->sin_port = 0;
368 ifa = ifa_ifwithaddr((struct sockaddr *) sin);
369 if (ifa == NULL) {
370 error = EADDRNOTAVAIL;
371 goto cantsend;
372 }
373 m->m_pkthdr.rcvif = ifa->ifa_ifp;
374 }
375#ifdef MAC
376 SOCK_LOCK(so);
377 mac_create_mbuf_from_socket(so, m);
378 SOCK_UNLOCK(so);
379#endif
380 /* Send packet to input processing */
381 ip_input(m);
382 }
383
384 return error;
385
386cantsend:
387 m_freem(m);
388 return error;
389}
390
391static int
392div_attach(struct socket *so, int proto, struct thread *td)
393{
394 struct inpcb *inp;
395 int error;
396
397 INP_INFO_WLOCK(&divcbinfo);
398 inp = sotoinpcb(so);
399 if (inp != 0) {
400 INP_INFO_WUNLOCK(&divcbinfo);
401 return EINVAL;
402 }
403 if (td && (error = suser(td)) != 0) {
404 INP_INFO_WUNLOCK(&divcbinfo);
405 return error;
406 }
407 error = soreserve(so, div_sendspace, div_recvspace);
408 if (error) {
409 INP_INFO_WUNLOCK(&divcbinfo);
410 return error;
411 }
412 error = in_pcballoc(so, &divcbinfo, "divinp");
413 if (error) {
414 INP_INFO_WUNLOCK(&divcbinfo);
415 return error;
416 }
417 inp = (struct inpcb *)so->so_pcb;
418 INP_LOCK(inp);
419 INP_INFO_WUNLOCK(&divcbinfo);
420 inp->inp_ip_p = proto;
421 inp->inp_vflag |= INP_IPV4;
422 inp->inp_flags |= INP_HDRINCL;
423 INP_UNLOCK(inp);
424 return 0;
425}
426
427static int
428div_detach(struct socket *so)
429{
430 struct inpcb *inp;
431
432 INP_INFO_WLOCK(&divcbinfo);
433 inp = sotoinpcb(so);
434 if (inp == 0) {
435 INP_INFO_WUNLOCK(&divcbinfo);
436 return EINVAL;
437 }
438 INP_LOCK(inp);
439 in_pcbdetach(inp);
440 INP_INFO_WUNLOCK(&divcbinfo);
441 return 0;
442}
443
444static int
445div_bind(struct socket *so, struct sockaddr *nam, struct thread *td)
446{
447 struct inpcb *inp;
448 int error;
449
450 INP_INFO_WLOCK(&divcbinfo);
451 inp = sotoinpcb(so);
452 if (inp == 0) {
453 INP_INFO_WUNLOCK(&divcbinfo);
454 return EINVAL;
455 }
456 /* in_pcbbind assumes that nam is a sockaddr_in
457 * and in_pcbbind requires a valid address. Since divert
458 * sockets don't we need to make sure the address is
459 * filled in properly.
460 * XXX -- divert should not be abusing in_pcbind
461 * and should probably have its own family.
462 */
463 if (nam->sa_family != AF_INET)
464 error = EAFNOSUPPORT;
465 else {
466 ((struct sockaddr_in *)nam)->sin_addr.s_addr = INADDR_ANY;
467 INP_LOCK(inp);
468 error = in_pcbbind(inp, nam, td->td_ucred);
469 INP_UNLOCK(inp);
470 }
471 INP_INFO_WUNLOCK(&divcbinfo);
472 return error;
473}
474
475static int
476div_shutdown(struct socket *so)
477{
478 struct inpcb *inp;
479
480 INP_INFO_RLOCK(&divcbinfo);
481 inp = sotoinpcb(so);
482 if (inp == 0) {
483 INP_INFO_RUNLOCK(&divcbinfo);
484 return EINVAL;
485 }
486 INP_LOCK(inp);
487 INP_INFO_RUNLOCK(&divcbinfo);
488 socantsendmore(so);
489 INP_UNLOCK(inp);
490 return 0;
491}
492
493static int
494div_send(struct socket *so, int flags, struct mbuf *m, struct sockaddr *nam,
495 struct mbuf *control, struct thread *td)
496{
497 /* Packet must have a header (but that's about it) */
498 if (m->m_len < sizeof (struct ip) &&
499 (m = m_pullup(m, sizeof (struct ip))) == 0) {
500 ipstat.ips_toosmall++;
501 m_freem(m);
502 return EINVAL;
503 }
504
505 /* Send packet */
506 return div_output(so, m, (struct sockaddr_in *)nam, control);
507}
508
509void
510div_ctlinput(int cmd, struct sockaddr *sa, void *vip)
511{
512 struct in_addr faddr;
513
514 faddr = ((struct sockaddr_in *)sa)->sin_addr;
515 if (sa->sa_family != AF_INET || faddr.s_addr == INADDR_ANY)
516 return;
517 if (PRC_IS_REDIRECT(cmd))
518 return;
519}
520
521static int
522div_pcblist(SYSCTL_HANDLER_ARGS)
523{
524 int error, i, n;
525 struct inpcb *inp, **inp_list;
526 inp_gen_t gencnt;
527 struct xinpgen xig;
528
529 /*
530 * The process of preparing the TCB list is too time-consuming and
531 * resource-intensive to repeat twice on every request.
532 */
533 if (req->oldptr == 0) {
534 n = divcbinfo.ipi_count;
535 req->oldidx = 2 * (sizeof xig)
536 + (n + n/8) * sizeof(struct xinpcb);
537 return 0;
538 }
539
540 if (req->newptr != 0)
541 return EPERM;
542
543 /*
544 * OK, now we're committed to doing something.
545 */
546 INP_INFO_RLOCK(&divcbinfo);
547 gencnt = divcbinfo.ipi_gencnt;
548 n = divcbinfo.ipi_count;
549 INP_INFO_RUNLOCK(&divcbinfo);
550
551 error = sysctl_wire_old_buffer(req,
552 2 * sizeof(xig) + n*sizeof(struct xinpcb));
553 if (error != 0)
554 return (error);
555
556 xig.xig_len = sizeof xig;
557 xig.xig_count = n;
558 xig.xig_gen = gencnt;
559 xig.xig_sogen = so_gencnt;
560 error = SYSCTL_OUT(req, &xig, sizeof xig);
561 if (error)
562 return error;
563
564 inp_list = malloc(n * sizeof *inp_list, M_TEMP, M_WAITOK);
565 if (inp_list == 0)
566 return ENOMEM;
567
568 INP_INFO_RLOCK(&divcbinfo);
569 for (inp = LIST_FIRST(divcbinfo.listhead), i = 0; inp && i < n;
570 inp = LIST_NEXT(inp, inp_list)) {
571 INP_LOCK(inp);
572 if (inp->inp_gencnt <= gencnt &&
573 cr_canseesocket(req->td->td_ucred, inp->inp_socket) == 0)
574 inp_list[i++] = inp;
575 INP_UNLOCK(inp);
576 }
577 INP_INFO_RUNLOCK(&divcbinfo);
578 n = i;
579
580 error = 0;
581 for (i = 0; i < n; i++) {
582 inp = inp_list[i];
583 if (inp->inp_gencnt <= gencnt) {
584 struct xinpcb xi;
585 bzero(&xi, sizeof(xi));
586 xi.xi_len = sizeof xi;
587 /* XXX should avoid extra copy */
588 bcopy(inp, &xi.xi_inp, sizeof *inp);
589 if (inp->inp_socket)
590 sotoxsocket(inp->inp_socket, &xi.xi_socket);
591 error = SYSCTL_OUT(req, &xi, sizeof xi);
592 }
593 }
594 if (!error) {
595 /*
596 * Give the user an updated idea of our state.
597 * If the generation differs from what we told
598 * her before, she knows that something happened
599 * while we were processing this request, and it
600 * might be necessary to retry.
601 */
602 INP_INFO_RLOCK(&divcbinfo);
603 xig.xig_gen = divcbinfo.ipi_gencnt;
604 xig.xig_sogen = so_gencnt;
605 xig.xig_count = divcbinfo.ipi_count;
606 INP_INFO_RUNLOCK(&divcbinfo);
607 error = SYSCTL_OUT(req, &xig, sizeof xig);
608 }
609 free(inp_list, M_TEMP);
610 return error;
611}
612
613/*
614 * This is the wrapper function for in_setsockaddr. We just pass down
615 * the pcbinfo for in_setpeeraddr to lock.
616 */
617static int
618div_sockaddr(struct socket *so, struct sockaddr **nam)
619{
620 return (in_setsockaddr(so, nam, &divcbinfo));
621}
622
623/*
624 * This is the wrapper function for in_setpeeraddr. We just pass down
625 * the pcbinfo for in_setpeeraddr to lock.
626 */
627static int
628div_peeraddr(struct socket *so, struct sockaddr **nam)
629{
630 return (in_setpeeraddr(so, nam, &divcbinfo));
631}
632
633#ifdef SYSCTL_NODE
634SYSCTL_NODE(_net_inet, IPPROTO_DIVERT, divert, CTLFLAG_RW, 0, "IPDIVERT");
635SYSCTL_PROC(_net_inet_divert, OID_AUTO, pcblist, CTLFLAG_RD, 0, 0,
636 div_pcblist, "S,xinpcb", "List of active divert sockets");
637#endif
638
639struct pr_usrreqs div_usrreqs = {
640 .pru_attach = div_attach,
641 .pru_bind = div_bind,
642 .pru_control = in_control,
643 .pru_detach = div_detach,
644 .pru_peeraddr = div_peeraddr,
645 .pru_send = div_send,
646 .pru_shutdown = div_shutdown,
647 .pru_sockaddr = div_sockaddr,
648 .pru_sosetlabel = in_pcbsosetlabel
649};
650
651struct protosw div_protosw = {
| 30 */
31
32#if !defined(KLD_MODULE)
33#include "opt_inet.h"
34#include "opt_ipfw.h"
35#include "opt_mac.h"
36#ifndef INET
37#error "IPDIVERT requires INET."
38#endif
39#ifndef IPFIREWALL
40#error "IPDIVERT requires IPFIREWALL"
41#endif
42#endif
43
44#include <sys/param.h>
45#include <sys/kernel.h>
46#include <sys/lock.h>
47#include <sys/malloc.h>
48#include <sys/mac.h>
49#include <sys/mbuf.h>
50#include <sys/module.h>
51#include <sys/kernel.h>
52#include <sys/proc.h>
53#include <sys/protosw.h>
54#include <sys/signalvar.h>
55#include <sys/socket.h>
56#include <sys/socketvar.h>
57#include <sys/sx.h>
58#include <sys/sysctl.h>
59#include <sys/systm.h>
60
61#include <vm/uma.h>
62
63#include <net/if.h>
64#include <net/route.h>
65
66#include <netinet/in.h>
67#include <netinet/in_pcb.h>
68#include <netinet/in_systm.h>
69#include <netinet/in_var.h>
70#include <netinet/ip.h>
71#include <netinet/ip_divert.h>
72#include <netinet/ip_var.h>
73#include <netinet/ip_fw.h>
74
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 * Divert sockets work in conjunction with ipfw, see the divert(4)
87 * manpage for features.
88 * Internally, packets selected by ipfw in ip_input() or ip_output(),
89 * and never diverted before, are passed to the input queue of the
90 * divert socket with a given 'divert_port' number (as specified in
91 * the matching ipfw rule), and they are tagged with a 16 bit cookie
92 * (representing the rule number of the matching ipfw rule), which
93 * is passed to process reading from the socket.
94 *
95 * Packets written to the divert socket are again tagged with a cookie
96 * (usually the same as above) and a destination address.
97 * If the destination address is INADDR_ANY then the packet is
98 * treated as outgoing and sent to ip_output(), otherwise it is
99 * treated as incoming and sent to ip_input().
100 * In both cases, the packet is tagged with the cookie.
101 *
102 * On reinjection, processing in ip_input() and ip_output()
103 * will be exactly the same as for the original packet, except that
104 * ipfw processing will start at the rule number after the one
105 * written in the cookie (so, tagging a packet with a cookie of 0
106 * will cause it to be effectively considered as a standard packet).
107 */
108
109/* Internal variables. */
110static struct inpcbhead divcb;
111static struct inpcbinfo divcbinfo;
112
113static u_long div_sendspace = DIVSNDQ; /* XXX sysctl ? */
114static u_long div_recvspace = DIVRCVQ; /* XXX sysctl ? */
115
116/*
117 * Initialize divert connection block queue.
118 */
119void
120div_init(void)
121{
122 INP_INFO_LOCK_INIT(&divcbinfo, "div");
123 LIST_INIT(&divcb);
124 divcbinfo.listhead = &divcb;
125 /*
126 * XXX We don't use the hash list for divert IP, but it's easier
127 * to allocate a one entry hash list than it is to check all
128 * over the place for hashbase == NULL.
129 */
130 divcbinfo.hashbase = hashinit(1, M_PCB, &divcbinfo.hashmask);
131 divcbinfo.porthashbase = hashinit(1, M_PCB, &divcbinfo.porthashmask);
132 divcbinfo.ipi_zone = uma_zcreate("divcb", sizeof(struct inpcb),
133 NULL, NULL, NULL, NULL, UMA_ALIGN_PTR, UMA_ZONE_NOFREE);
134 uma_zone_set_max(divcbinfo.ipi_zone, maxsockets);
135}
136
137/*
138 * IPPROTO_DIVERT is not in the real IP protocol number space; this
139 * function should never be called. Just in case, drop any packets.
140 */
141void
142div_input(struct mbuf *m, int off)
143{
144 ipstat.ips_noproto++;
145 m_freem(m);
146}
147
148/*
149 * Divert a packet by passing it up to the divert socket at port 'port'.
150 *
151 * Setup generic address and protocol structures for div_input routine,
152 * then pass them along with mbuf chain.
153 */
154static void
155divert_packet(struct mbuf *m, int incoming)
156{
157 struct ip *ip;
158 struct inpcb *inp;
159 struct socket *sa;
160 u_int16_t nport;
161 struct sockaddr_in divsrc;
162 struct m_tag *mtag;
163
164 mtag = m_tag_find(m, PACKET_TAG_DIVERT, NULL);
165 if (mtag == NULL) {
166 printf("%s: no divert tag\n", __func__);
167 m_freem(m);
168 return;
169 }
170 /* Assure header */
171 if (m->m_len < sizeof(struct ip) &&
172 (m = m_pullup(m, sizeof(struct ip))) == 0)
173 return;
174 ip = mtod(m, struct ip *);
175
176 /* Delayed checksums are currently not compatible with divert. */
177 if (m->m_pkthdr.csum_flags & CSUM_DELAY_DATA) {
178 ip->ip_len = ntohs(ip->ip_len);
179 in_delayed_cksum(m);
180 m->m_pkthdr.csum_flags &= ~CSUM_DELAY_DATA;
181 ip->ip_len = htons(ip->ip_len);
182 }
183
184 /*
185 * Record receive interface address, if any.
186 * But only for incoming packets.
187 */
188 bzero(&divsrc, sizeof(divsrc));
189 divsrc.sin_len = sizeof(divsrc);
190 divsrc.sin_family = AF_INET;
191 divsrc.sin_port = divert_cookie(mtag); /* record matching rule */
192 if (incoming) {
193 struct ifaddr *ifa;
194
195 /* Sanity check */
196 M_ASSERTPKTHDR(m);
197
198 /* Find IP address for receive interface */
199 TAILQ_FOREACH(ifa, &m->m_pkthdr.rcvif->if_addrhead, ifa_link) {
200 if (ifa->ifa_addr == NULL)
201 continue;
202 if (ifa->ifa_addr->sa_family != AF_INET)
203 continue;
204 divsrc.sin_addr =
205 ((struct sockaddr_in *) ifa->ifa_addr)->sin_addr;
206 break;
207 }
208 }
209 /*
210 * Record the incoming interface name whenever we have one.
211 */
212 if (m->m_pkthdr.rcvif) {
213 /*
214 * Hide the actual interface name in there in the
215 * sin_zero array. XXX This needs to be moved to a
216 * different sockaddr type for divert, e.g.
217 * sockaddr_div with multiple fields like
218 * sockaddr_dl. Presently we have only 7 bytes
219 * but that will do for now as most interfaces
220 * are 4 or less + 2 or less bytes for unit.
221 * There is probably a faster way of doing this,
222 * possibly taking it from the sockaddr_dl on the iface.
223 * This solves the problem of a P2P link and a LAN interface
224 * having the same address, which can result in the wrong
225 * interface being assigned to the packet when fed back
226 * into the divert socket. Theoretically if the daemon saves
227 * and re-uses the sockaddr_in as suggested in the man pages,
228 * this iface name will come along for the ride.
229 * (see div_output for the other half of this.)
230 */
231 strlcpy(divsrc.sin_zero, m->m_pkthdr.rcvif->if_xname,
232 sizeof(divsrc.sin_zero));
233 }
234
235 /* Put packet on socket queue, if any */
236 sa = NULL;
237 nport = htons((u_int16_t)divert_info(mtag));
238 INP_INFO_RLOCK(&divcbinfo);
239 LIST_FOREACH(inp, &divcb, inp_list) {
240 INP_LOCK(inp);
241 /* XXX why does only one socket match? */
242 if (inp->inp_lport == nport) {
243 sa = inp->inp_socket;
244 SOCKBUF_LOCK(&sa->so_rcv);
245 if (sbappendaddr_locked(&sa->so_rcv,
246 (struct sockaddr *)&divsrc, m,
247 (struct mbuf *)0) == 0) {
248 SOCKBUF_UNLOCK(&sa->so_rcv);
249 sa = NULL; /* force mbuf reclaim below */
250 } else
251 sorwakeup_locked(sa);
252 INP_UNLOCK(inp);
253 break;
254 }
255 INP_UNLOCK(inp);
256 }
257 INP_INFO_RUNLOCK(&divcbinfo);
258 if (sa == NULL) {
259 m_freem(m);
260 ipstat.ips_noproto++;
261 ipstat.ips_delivered--;
262 }
263}
264
265/*
266 * Deliver packet back into the IP processing machinery.
267 *
268 * If no address specified, or address is 0.0.0.0, send to ip_output();
269 * otherwise, send to ip_input() and mark as having been received on
270 * the interface with that address.
271 */
272static int
273div_output(struct socket *so, struct mbuf *m,
274 struct sockaddr_in *sin, struct mbuf *control)
275{
276 struct m_tag *mtag;
277 struct divert_tag *dt;
278 int error = 0;
279
280 /*
281 * An mbuf may hasn't come from userland, but we pretend
282 * that it has.
283 */
284 m->m_pkthdr.rcvif = NULL;
285 m->m_nextpkt = NULL;
286
287 if (control)
288 m_freem(control); /* XXX */
289
290 if ((mtag = m_tag_find(m, PACKET_TAG_DIVERT, NULL)) == NULL) {
291 mtag = m_tag_get(PACKET_TAG_DIVERT, sizeof(struct divert_tag),
292 M_NOWAIT | M_ZERO);
293 if (mtag == NULL) {
294 error = ENOBUFS;
295 goto cantsend;
296 }
297 dt = (struct divert_tag *)(mtag+1);
298 m_tag_prepend(m, mtag);
299 } else
300 dt = (struct divert_tag *)(mtag+1);
301
302 /* Loopback avoidance and state recovery */
303 if (sin) {
304 int i;
305
306 dt->cookie = sin->sin_port;
307 /*
308 * Find receive interface with the given name, stuffed
309 * (if it exists) in the sin_zero[] field.
310 * The name is user supplied data so don't trust its size
311 * or that it is zero terminated.
312 */
313 for (i = 0; i < sizeof(sin->sin_zero) && sin->sin_zero[i]; i++)
314 ;
315 if ( i > 0 && i < sizeof(sin->sin_zero))
316 m->m_pkthdr.rcvif = ifunit(sin->sin_zero);
317 }
318
319 /* Reinject packet into the system as incoming or outgoing */
320 if (!sin || sin->sin_addr.s_addr == 0) {
321 struct ip *const ip = mtod(m, struct ip *);
322 struct inpcb *inp;
323
324 dt->info |= IP_FW_DIVERT_OUTPUT_FLAG;
325 INP_INFO_WLOCK(&divcbinfo);
326 inp = sotoinpcb(so);
327 INP_LOCK(inp);
328 /*
329 * Don't allow both user specified and setsockopt options,
330 * and don't allow packet length sizes that will crash
331 */
332 if (((ip->ip_hl != (sizeof (*ip) >> 2)) && inp->inp_options) ||
333 ((u_short)ntohs(ip->ip_len) > m->m_pkthdr.len)) {
334 error = EINVAL;
335 m_freem(m);
336 } else {
337 /* Convert fields to host order for ip_output() */
338 ip->ip_len = ntohs(ip->ip_len);
339 ip->ip_off = ntohs(ip->ip_off);
340
341 /* Send packet to output processing */
342 ipstat.ips_rawout++; /* XXX */
343
344#ifdef MAC
345 mac_create_mbuf_from_inpcb(inp, m);
346#endif
347 error = ip_output(m,
348 inp->inp_options, NULL,
349 ((so->so_options & SO_DONTROUTE) ?
350 IP_ROUTETOIF : 0) |
351 IP_ALLOWBROADCAST | IP_RAWOUTPUT,
352 inp->inp_moptions, NULL);
353 }
354 INP_UNLOCK(inp);
355 INP_INFO_WUNLOCK(&divcbinfo);
356 } else {
357 dt->info |= IP_FW_DIVERT_LOOPBACK_FLAG;
358 if (m->m_pkthdr.rcvif == NULL) {
359 /*
360 * No luck with the name, check by IP address.
361 * Clear the port and the ifname to make sure
362 * there are no distractions for ifa_ifwithaddr.
363 */
364 struct ifaddr *ifa;
365
366 bzero(sin->sin_zero, sizeof(sin->sin_zero));
367 sin->sin_port = 0;
368 ifa = ifa_ifwithaddr((struct sockaddr *) sin);
369 if (ifa == NULL) {
370 error = EADDRNOTAVAIL;
371 goto cantsend;
372 }
373 m->m_pkthdr.rcvif = ifa->ifa_ifp;
374 }
375#ifdef MAC
376 SOCK_LOCK(so);
377 mac_create_mbuf_from_socket(so, m);
378 SOCK_UNLOCK(so);
379#endif
380 /* Send packet to input processing */
381 ip_input(m);
382 }
383
384 return error;
385
386cantsend:
387 m_freem(m);
388 return error;
389}
390
391static int
392div_attach(struct socket *so, int proto, struct thread *td)
393{
394 struct inpcb *inp;
395 int error;
396
397 INP_INFO_WLOCK(&divcbinfo);
398 inp = sotoinpcb(so);
399 if (inp != 0) {
400 INP_INFO_WUNLOCK(&divcbinfo);
401 return EINVAL;
402 }
403 if (td && (error = suser(td)) != 0) {
404 INP_INFO_WUNLOCK(&divcbinfo);
405 return error;
406 }
407 error = soreserve(so, div_sendspace, div_recvspace);
408 if (error) {
409 INP_INFO_WUNLOCK(&divcbinfo);
410 return error;
411 }
412 error = in_pcballoc(so, &divcbinfo, "divinp");
413 if (error) {
414 INP_INFO_WUNLOCK(&divcbinfo);
415 return error;
416 }
417 inp = (struct inpcb *)so->so_pcb;
418 INP_LOCK(inp);
419 INP_INFO_WUNLOCK(&divcbinfo);
420 inp->inp_ip_p = proto;
421 inp->inp_vflag |= INP_IPV4;
422 inp->inp_flags |= INP_HDRINCL;
423 INP_UNLOCK(inp);
424 return 0;
425}
426
427static int
428div_detach(struct socket *so)
429{
430 struct inpcb *inp;
431
432 INP_INFO_WLOCK(&divcbinfo);
433 inp = sotoinpcb(so);
434 if (inp == 0) {
435 INP_INFO_WUNLOCK(&divcbinfo);
436 return EINVAL;
437 }
438 INP_LOCK(inp);
439 in_pcbdetach(inp);
440 INP_INFO_WUNLOCK(&divcbinfo);
441 return 0;
442}
443
444static int
445div_bind(struct socket *so, struct sockaddr *nam, struct thread *td)
446{
447 struct inpcb *inp;
448 int error;
449
450 INP_INFO_WLOCK(&divcbinfo);
451 inp = sotoinpcb(so);
452 if (inp == 0) {
453 INP_INFO_WUNLOCK(&divcbinfo);
454 return EINVAL;
455 }
456 /* in_pcbbind assumes that nam is a sockaddr_in
457 * and in_pcbbind requires a valid address. Since divert
458 * sockets don't we need to make sure the address is
459 * filled in properly.
460 * XXX -- divert should not be abusing in_pcbind
461 * and should probably have its own family.
462 */
463 if (nam->sa_family != AF_INET)
464 error = EAFNOSUPPORT;
465 else {
466 ((struct sockaddr_in *)nam)->sin_addr.s_addr = INADDR_ANY;
467 INP_LOCK(inp);
468 error = in_pcbbind(inp, nam, td->td_ucred);
469 INP_UNLOCK(inp);
470 }
471 INP_INFO_WUNLOCK(&divcbinfo);
472 return error;
473}
474
475static int
476div_shutdown(struct socket *so)
477{
478 struct inpcb *inp;
479
480 INP_INFO_RLOCK(&divcbinfo);
481 inp = sotoinpcb(so);
482 if (inp == 0) {
483 INP_INFO_RUNLOCK(&divcbinfo);
484 return EINVAL;
485 }
486 INP_LOCK(inp);
487 INP_INFO_RUNLOCK(&divcbinfo);
488 socantsendmore(so);
489 INP_UNLOCK(inp);
490 return 0;
491}
492
493static int
494div_send(struct socket *so, int flags, struct mbuf *m, struct sockaddr *nam,
495 struct mbuf *control, struct thread *td)
496{
497 /* Packet must have a header (but that's about it) */
498 if (m->m_len < sizeof (struct ip) &&
499 (m = m_pullup(m, sizeof (struct ip))) == 0) {
500 ipstat.ips_toosmall++;
501 m_freem(m);
502 return EINVAL;
503 }
504
505 /* Send packet */
506 return div_output(so, m, (struct sockaddr_in *)nam, control);
507}
508
509void
510div_ctlinput(int cmd, struct sockaddr *sa, void *vip)
511{
512 struct in_addr faddr;
513
514 faddr = ((struct sockaddr_in *)sa)->sin_addr;
515 if (sa->sa_family != AF_INET || faddr.s_addr == INADDR_ANY)
516 return;
517 if (PRC_IS_REDIRECT(cmd))
518 return;
519}
520
521static int
522div_pcblist(SYSCTL_HANDLER_ARGS)
523{
524 int error, i, n;
525 struct inpcb *inp, **inp_list;
526 inp_gen_t gencnt;
527 struct xinpgen xig;
528
529 /*
530 * The process of preparing the TCB list is too time-consuming and
531 * resource-intensive to repeat twice on every request.
532 */
533 if (req->oldptr == 0) {
534 n = divcbinfo.ipi_count;
535 req->oldidx = 2 * (sizeof xig)
536 + (n + n/8) * sizeof(struct xinpcb);
537 return 0;
538 }
539
540 if (req->newptr != 0)
541 return EPERM;
542
543 /*
544 * OK, now we're committed to doing something.
545 */
546 INP_INFO_RLOCK(&divcbinfo);
547 gencnt = divcbinfo.ipi_gencnt;
548 n = divcbinfo.ipi_count;
549 INP_INFO_RUNLOCK(&divcbinfo);
550
551 error = sysctl_wire_old_buffer(req,
552 2 * sizeof(xig) + n*sizeof(struct xinpcb));
553 if (error != 0)
554 return (error);
555
556 xig.xig_len = sizeof xig;
557 xig.xig_count = n;
558 xig.xig_gen = gencnt;
559 xig.xig_sogen = so_gencnt;
560 error = SYSCTL_OUT(req, &xig, sizeof xig);
561 if (error)
562 return error;
563
564 inp_list = malloc(n * sizeof *inp_list, M_TEMP, M_WAITOK);
565 if (inp_list == 0)
566 return ENOMEM;
567
568 INP_INFO_RLOCK(&divcbinfo);
569 for (inp = LIST_FIRST(divcbinfo.listhead), i = 0; inp && i < n;
570 inp = LIST_NEXT(inp, inp_list)) {
571 INP_LOCK(inp);
572 if (inp->inp_gencnt <= gencnt &&
573 cr_canseesocket(req->td->td_ucred, inp->inp_socket) == 0)
574 inp_list[i++] = inp;
575 INP_UNLOCK(inp);
576 }
577 INP_INFO_RUNLOCK(&divcbinfo);
578 n = i;
579
580 error = 0;
581 for (i = 0; i < n; i++) {
582 inp = inp_list[i];
583 if (inp->inp_gencnt <= gencnt) {
584 struct xinpcb xi;
585 bzero(&xi, sizeof(xi));
586 xi.xi_len = sizeof xi;
587 /* XXX should avoid extra copy */
588 bcopy(inp, &xi.xi_inp, sizeof *inp);
589 if (inp->inp_socket)
590 sotoxsocket(inp->inp_socket, &xi.xi_socket);
591 error = SYSCTL_OUT(req, &xi, sizeof xi);
592 }
593 }
594 if (!error) {
595 /*
596 * Give the user an updated idea of our state.
597 * If the generation differs from what we told
598 * her before, she knows that something happened
599 * while we were processing this request, and it
600 * might be necessary to retry.
601 */
602 INP_INFO_RLOCK(&divcbinfo);
603 xig.xig_gen = divcbinfo.ipi_gencnt;
604 xig.xig_sogen = so_gencnt;
605 xig.xig_count = divcbinfo.ipi_count;
606 INP_INFO_RUNLOCK(&divcbinfo);
607 error = SYSCTL_OUT(req, &xig, sizeof xig);
608 }
609 free(inp_list, M_TEMP);
610 return error;
611}
612
613/*
614 * This is the wrapper function for in_setsockaddr. We just pass down
615 * the pcbinfo for in_setpeeraddr to lock.
616 */
617static int
618div_sockaddr(struct socket *so, struct sockaddr **nam)
619{
620 return (in_setsockaddr(so, nam, &divcbinfo));
621}
622
623/*
624 * This is the wrapper function for in_setpeeraddr. We just pass down
625 * the pcbinfo for in_setpeeraddr to lock.
626 */
627static int
628div_peeraddr(struct socket *so, struct sockaddr **nam)
629{
630 return (in_setpeeraddr(so, nam, &divcbinfo));
631}
632
633#ifdef SYSCTL_NODE
634SYSCTL_NODE(_net_inet, IPPROTO_DIVERT, divert, CTLFLAG_RW, 0, "IPDIVERT");
635SYSCTL_PROC(_net_inet_divert, OID_AUTO, pcblist, CTLFLAG_RD, 0, 0,
636 div_pcblist, "S,xinpcb", "List of active divert sockets");
637#endif
638
639struct pr_usrreqs div_usrreqs = {
640 .pru_attach = div_attach,
641 .pru_bind = div_bind,
642 .pru_control = in_control,
643 .pru_detach = div_detach,
644 .pru_peeraddr = div_peeraddr,
645 .pru_send = div_send,
646 .pru_shutdown = div_shutdown,
647 .pru_sockaddr = div_sockaddr,
648 .pru_sosetlabel = in_pcbsosetlabel
649};
650
651struct protosw div_protosw = {
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